Microbiology Exam 2 Notes (Gerina Chen) PDF

Microbe Condition Caused Route of Infection Ecology Acanthamoeba When Acanthamoeba infects the eye, it causes Forms cysts & trophozoites Found in natural environments of...

Microbe Condition Caused Route of Infection Ecology Acanthamoeba When Acanthamoeba infects the eye, it causes Forms cysts & trophozoites Found in natural environments of inflammation of the cornea known as that can enter in many ways. unchlorinated fresh waters (lakes, Acanthamoeba keratitis. Can lead to corneal rivers, hot springs), in the soil, Amoebozoa (moves damage, vision impairment, or blindness if left Eye- Acanthamoeba keratitis using pseudopodia) dust, and air. untreated. Poses a greater risk for contact Protozoan (single cell wearers because it thrives in the space btwn the Skin/Wounds- ulcers, abscess, contact lens and the cornea. Form resistant cysts that allow eukaryote, animal-like nodules, lesions survival in harsh conditions, movement/predation) Acanthamoeba enters through wounds or Nasal / Respiratory Tract including chlorine treatment. respiratory tract but does not usually cause diseases except in immunocompromised, Travel to N.S / Brain- GAE Free-living Acanthamoeba feed on affecting the skin, lungs, or other organs, In rare bacteria (opportunistic pathogen cases however, the infection can spread to the Diagnosed with symptoms, in the human body). Controls nervous system and cause GAE, granulomatous samples, or skin biopsies. microbe population and nutrient amoebic encephalitis, a severe brain infection. Difficult to treat, needs prompt cycling. treatment to prevent regression. Topical antiseptics, painkillers. Aspergillus Cutaneous aspergillosis is a fungal infection Aspergillus is a common affecting outer layers of the skin, hair, nails. Skin- cutaneous aspergillosis, Primary (rare) begins in the skin at the site of filamentous fungus present in the Fungi results in eschars injury, usually in agricultural or outdoor soil, dust, and in damp or environments. Secondary (more common) begins (diagnosed with Pt Hx, culture, decaying organic debris. Mold (made up of in the respiratory system and spreads different species) skin biopsy. treated with anti- systemically. Both result in distinctive eschars They are important decomposers (mass of dead skin tissues). fungal medication or surgery) in our ecosystem, and break down dead organic matter. Opportunistic Aspergillus infections occur in healthcare settings at IV catheter sites, burn, and Respiratory Tract- Nearly everyone has been exposed surgical wounds. It is the 2nd most common respiratory aspergillosis, to the mold in our everyday lives, fungal HAI after candidiasis, and affects the allergy-like reactions, can lead immunocompromised. but it primarily affects to pulmonary/brain hemorrhage immunocompromised. Respiratory aspergillosis (inhalation of spores) (diagnosed w. chest radiographs, leads to SOB, coughing, wheezing, runny nose, fluid samples, and skin tests. and headaches. Fungal balls (aspergilloma) form when hyphal colonies collect in the lungs, which treated with antifungal agents can invade host tissues, causing fatal pulmonary and immunosuppressants) or brain hemorrhages and a bloody cough. Bacillus anthracis Anthrax is a zoonotic disease that primarily Contact with infected animals Found in soil, particularly in areas or animal products (wool/hide). where livestock graze. affects animals (sheep, cattle, deer) but can be Bacteria (gram + rod, found in humans. Endospores are widespread in Form resilient endospores that endospore-forming, Cutaneous Anthrax occurs when anthrax soil and survive long periods. survive for long periods. facultative anaerobe.) endospores enter through skin abrasions. It is “Wool Sorter’s Disease” characterized by a skin nodule which turns into Skin- enter through abrasions, Commonly affects herbivores an eschar when the cells die. Localized infections cutaneous anthrax (95-99%) such as cattle or sheep. lead to bacteremia or septicemia (in blood) and if left untreated causes death in 20% of patients. (more difficult to treat:) B. anthracis colonies cultured on Endospores germinate, producing capsules that blood agar have a rough texture prevent phagocytization, and binary exotoxins Digestive Tract- and serrated edges, which form an that cause edema and tissue damage. gastrointestinal anthrax undulating band. Digestive (GI Anthrax) has a 40% mortality rate Respiratory Tract- even with treatment. Pulmonary/Inhalation Anthrax Respiratory (Pulmonary/Inhalation Anthrax) Intravenous Drug Injection- occurs when spores are inhaled and causes Injection Anthrax Flu-like symptoms with mortality rates of 45% (treated) and 85% (untreated). Treated with broad spectrum antibiotics. Vaccines for those Injection Anthrax (IV) occurs when drugs in high risk environments. contaminated with anthracis are injected and Used as a bioweapon in 2011 cause symptoms of severe soft tissue infection (contaminated letters sent to and high mortality rates. U.S. United Nations diplomats) Bordetella Bordetella pertussis causes pertussis, or the Droplet: spreads through pertussis whooping cough. It is characterized by mucus respiratory droplets from Bordetella pertussis is typically accumulation in the lungs, severe coughing, and coughing or sneezing of an found in the nasopharyngeal inflamed restricted airways. Can infect adults, region of humans. Bacteria (gram - infected person. but symptoms are most pronounced in infants coccobacillus) and children (cough can fracture ribs, prolonged It can survive in the environment Diagnosed in the first 2 weeks causes death). Highly communicable droplet for a short period of time but is “Whooping Cough” transmission. Attaches to epithelial cells with of infection by culturing generally a human pathogen. adhesin, grows, and produces exotoxins which directly from the nasopharynx. disrupt cellular signaling, enhances inflammatory First month through PCR, and response, and cytotoxins that damage cells, later stages through assay. causing mucus. The mucus supports growth of other microbes, can lead to secondary infections. Pertussis is a self-limiting disease with antibiotics only Pertussis can be divided into 3 stages: catarrhal effective in the early stages and stage (1st, most infectious) with congestion, fever, and runny nose, paroxysmal (2nd) with reduces transmission later on. uncontrollable coughing lasting several weeks, and a long convalescence stage (3rd) with a Vaccination for prevention is chronic cough that can last up to several months. important (DTap/Tdap). Candida albicans C. albicans is part of the Habitat: Found in the human Candida albicans is a part of the normal human microbiota in the skin, respiratory, GI, and UG normal microbiota, but can microbiome, particularly in the GI Fungi tract. However, when it overgrows, it can cause overgrow. Transmitted through tract, mouth, and vagina. yeast infections in the skin, vagina, and mouth. contaminated surfaces, medical Yeast (can form devices, or sexual contact. Survival: can survive in various pseudohyphae, Cutaneous candidiasis causes skin infections environments, including soil and multicellular fungus such as intertrigo (rash that occurs in skin folds). Skin- diagnosed through decaying organic matter. under certain It can also affect the nails, causing them to clinical observation, culture, conditions w. mold become yellow and hardened. gram stain, and KOH wet Interaction w. Microbes: can characteristics) mounts. Treated topically or outcompete microorganisms, esp Lactobacilli in the vagina inhibits the growth of with antifungal medications. when the microbiota is disrupted. C. albicans, however the use of antibiotics or immunosuppressants can cause overgrowth. This Urogenital- diagnosed through - Adheres to and invades host cells causes genital or vaginal candidiasis (yeast microscopic evaluation and - Forms biofilms* infection), with pruritus (itching), white/yellow samples. Treatments include - secretes hydrolases discharge, and odor. It can also be transmitted topical or oral medications. (help spread through tissues) through sexual contact but is not an STI. - change phenotype Oral- diagnosed through (hides from the immune system) Candida infection in the oral cavity is known as clinical observation. treatments oral thrush. It is most common in infants because include topical/systemic meds. Uses quorum sensing in biofilms they have underdeveloped immune systems and which helps to detect cell density Because candida is invasive, through autoinducers. Once microbiota, as well as immunodeficient patients. preventive treatments for reaching a critical density, cells It is characterized by pseudomembranous, white immunocompromised pts can can produce virulence factors and patches in the mouth, and potential bleeding. be helpful. Avoiding excessive overwhelm the host defence. moisture and good hygiene. Coccidioides Inhalation: breathing in Lives in the soil of arid immitis Coccidioides immitis is a dimorphic fungus that airborne arthrospores or environments. Thrives in dry and causes coccidioidomycosis, a lung disease that is arthroconidia from disturbed dusty conditions. also known as “Valley Fever”. It is acquired by Fungi soil, in the S.W. U.S., Mexico, inhaling the fungal spores (arthrospores) which Central, or South America. Coccidioides immitis exists as a are formed by hyphal fragmentation. In the Dimorphic mold in the soil and produces body, the fungal spores differentiate into Diagnosed w. culture samples (mold in environment, arthroconidia spores which are spherules which are filled with endospores. but can be dangerous as it spherule in host body) infectious. When the soil is causes lab-acquired infections. disturbed (farming, construction, C. immitis infections affect the lungs, are Serological antibody tests are “Valley Fever” (San wind) the spores become airborne. asymptomatic, and self-limiting but can be more commonly used. Joaquin Valley, CA) serious for immunocompromised patients, since It plays a role in soil endospores can spread in the blood leading to Mild cases = no intervention decomposition but can cause lesions in the face, nose, or brain (meningitis). Disseminated infection = serious disease in humans and antifungal drugs animals when inhaled. Common cold The common cold is a generic term for the viral Spreads through droplet Humans are the primary host for infection of the nasal cavity. It can be caused by transmission. common cold viruses. It affects caused by a variety of 200+ known viruses including rhinovirus, the upper respiratory tract and viruses (200+) coronavirus, and adenovirus. These infections Indirect contact: Sneezing and replicates best in the nasal are widespread within humans and transmitted coughing can cause droplets to passages which have cooler rhinovirus, through direct contact or droplets. Coughing and land on fomites such tables, temperatures. coronavirus, RSV, sneezing produces infectious aerosols which can doors, or syringes and catheters adenovirus, etc persist on surfaces for up to a week. in the healthcare setting. When Survives in low humidity, drying a susceptible host later touches out the mucous membranes, Rhinovirus replicates best between 33°C - 35°C the fomite and transports making it easier for the virus to (91.4°F-95°F) which is below normal body temp droplets to a portal of entry, penetrate natural defenses. and tends to infect the cooler tissues in the nasal infection transmission occurs. cavity. This irritates the nasal mucosa and leads Highly transmissible in crowded to an inflammation in the upper respiratory tract. Direct Contact: environments, especially during Symptoms include runny nose, congestion, sore Direct contact of an infected cold seasons (low temperature and throat, coughing, and sneezing. Common colds individual such as through a humidity) where people stay tend to have low temp fevers, which helps to handshake or breathing in the indoors in close contact, differentiate them from Influenza infections with droplets of a cough or sneeze. increasing droplet transmission. high fevers. Aches and pains are severe in the flu, but congestion and sneezing is rare. No effective antiviral treatment. Non-enveloped viruses like Anti- bacterial drugs should not rhinoviruses and adenoviruses can Some colds may progress to cause otitis media be prescribed. Common cold persist on inanimate surfaces for (fluid buildup in the middle ear), pharyngitis, viruses are related so immunity hours and days. laryngitis, headaches, and body aches. It is will develop throughout life but self-limiting and resolves in 1-2 weeks. not for all species (200+). Corynebacterium Corynebacterium diptheriae causes diphtheria. Part of the normal Humans are the only known diptheriae Diphtheroids are common members of the nasopharyngeal microbiota and reservoir for Corynebacterium normal nasopharyngeal microbiota but some can become pathogenic. diphtheriae. It colonizes the strains become pathogenic due to diphtheria mucous membranes of the upper toxin. Diphtheria is a respiratory infection of the Spreads through respiratory respiratory tract or skin. Bacteria (gram + rod, oropharynx and can cause impetigo-like lesions droplet transmission. characteristic club on the skin. Affects mainly those under 5 or 40+. Often found in areas with poor shape when stained.) Indirect Contact: touching sanitation practices or low It is transmitted through droplets and aerosols contaminated objects/surfaces vaccination rates. produced when coughing. After colonizing the containing the bacterium. throat, the bacterium releases diphtheria toxin It produces a potent exotoxin Direct Contact: direct contact which leads to the death of host cells and an (diphtheria toxin) that inhibits with infected individuals. inflammatory response. A gray mass of dead host protein synthesis, leading to tissue cells, pus, RBC, etc can form a pseudomembrane damage. Diagnosed through clinical which covers the mucous membranes of the symptoms, vaccination history nasal cavity, tonsils, pharynx, larynx, etc. As the (DTaP, Tdap, DT, Td), and disease progresses, the mass can enlarge and throat swab cultures. obstruct the airway and lead to suffocation/death. Trachea tubes can be used in advanced infections. Treatment includes antibiotics If the toxin spreads, it can damage other tissues like penicillin, and antitoxins if like the nerves and heart (myocarditis). toxins have been produced. Cryptococcus Cryptococcus neoformans is an encapsulated Inhalation: Infective spores are neoformans yeast fungus that causes cryptococcosis. It is inhaled from the soil or Found in soil, particularly in areas found in the soil and can be isolated from bird, decaying matter with the fungus enriched with bird droppings, such particularly pigeon feces. Immunocompromised as pigeon feces. Fungi patients inhale the basidiospores from aerosols. Contact: Less common but can These spores have a polysaccharide capsule that infect through skin contact, Contributes to nutrient recycling Encapsulated Yeast enables them to avoid detection by the alveolar particularly the by breaking down organic matter. macrophages. immunocompromised. Can exist in symbiotic Symptoms of the infection include fever, fatigue, Diagnosed based on relationships w. other organisms. and dry cough that usually spontaneously resolve examination of lung tissue or with no long-term consequences. For the CSF and serological tests. It is Able to survive in diverse immunocompromised, the pulmonary infection easily cultured in the lab and environmental conditions and can spread to the brain and cause meningitis, identified based on the capsule. avoid detection using the capsule, headaches, confusion, and light sensitivity, which increasing pathogenic potential. is fatal if left untreated. Treatment involves antifungal drugs such as Amphotericin B and flucytosine. Fifth Disease Fifth’s Disease (erythema infectiosum) is a Spread through respiratory highly contagious illness that results in a distinct Parvovirus B19 is specific to droplet transmission. rash. It is caused by Parvovirus B19 and is humans and circulates primarily in Virus transmitted by contact with respiratory secretions communities, especially in school (non-enveloped) Indirect Contact: touching from individuals. It is more common in children settings. contaminated objects/surfaces than adults. 20% of people are asymptomatic, Parvovirus B19 containing virus droplets. while others exhibit cold-like symptoms Epidemics often occur in late (headache, fever, and upset stomach) during the winter and early spring. Direct Contact: direct contact early stages where it is most infectious. with infected individuals The virus replicates in red blood through sneezing or coughing. Several days later, a distinct red facial rash cell precursors (erythroblast) in appears (“slapped cheek”). A second rash may the bone marrow. Fifth’s Disease can also spread appear on the arms, legs, chest, back, buttocks in through blood products from the coming days. The rash comes and goes for an infected mother to its fetus. several weeks, but usually disappears within 7-21 days when it becomes lacy in appearance. The disease resolves w/o treatment in children. But in adults it causes joint pain and swelling that can last weeks/months. Immunocompromised patients can develop severe anemia and may need blood transfusions. While the rash is important in diagnosis, symptoms are not always consistent. Haemophilus Haemophilus influenzae is fastidious (requires Spread through respiratory Part of the normal flora of the influenzae specific growth factors not on normal mediums) droplet transmission. human respiratory tract and in and must be grown on heated blood “chocolate” mucosal surfaces such as the agar. It is a facultative anaerobe and can be Indirect Contact: touching nasopharynx. Bacteria grown in a candle jar (low O₂, high CO₂). contaminated objects/surfaces containing virus droplets. Can be opportunistic, invade, and (gram - Bacterial conjunctivitis (pinkeye) with sticky cause disease when the immune coccobacillus) discharge fluid is most commonly caused by H. Direct Contact: direct contact defenses are compromised or in influenzae. It is highly contagious, transmitted with infected individuals children who are not vaccinated. through infected secretions. Symptoms include through sneezing or coughing. eye pain, blurred vision, and light sensitivity, but H. influenzae produces 16 usually resolves in a few days. It is resistant to a lot of different virulence factors antibiotics. A vaccine, if including LOS, penetration, Can cause acute otitis media (AOM), buildup of developed, can help protect adhesion, and capsule. pus in the middle ear, leading to pain, swelling, humans against conjunctivitis fever, nausea in older infants & children under 14. and AOM. Encapsulated strains of H. influenzae cause meningitis spread through respiratory secretions. It Meningitis from H. influenzae colonizes mucous membranes and spreads into the serotype B has an effective Hib blood, with 70% fatal, 20% survival (tissue vaccine. damage, neuro trauma). Non-encapsulated strains cause pneumonia and spread by cough droplets. It is found in the throats of healthy children, but H. pneumonia is found in the elderly. It infects the alveoli and results in accumulation of fluid. HSV I Causes latent infections of the oral and gential Both can be transmitted during HSV has several virulence factors HSV II* areas. HSV I typically transmitted through orally outbreaks, and even when like ICP that help in replication, and HSV II sexually, but cross infection is symptoms are not visible. and inhibits dendritic cell (herpes simplex virus) possible and becoming more common. maturation to avoid immune system elimination. Surface Virus HSV I (oral) manifests as cold sores or fever HSV-1: Spread through direct glycoproteins on the virus allow it (enveloped, blisters on or around the lips. It can also cause contact with infected saliva or to appear as “self” cells. double-stranded DNA) keratitis in the eyes. Lesions can also spread to skin, typically through kissing the neck, shoulders, and trunk. It is highly or sharing items like utensils. HSV is highly adapted to humans, contagious ~65% of the population having it but evolving to persist in hosts asymptomatic. The virus is latent for long No cure, but topical/antiviral (latency), in neuron pathways. periods, but reoccurs with stress. It spreads with meds can reduce symptoms During latency, the virus remains direct contact even when asymptomatic. HSV I and risk of transmission. dormant in nerve cells and can can also cause acute herpetic gingivostomatitis, reactivate and infect in response to causing ulcers of the mucous membranes in the triggers such as stress/illness. *2nd most common STI in the US mouth. Usually self limiting, unless immunocom.  HSV II (sexual) is associated with genital herpes. HSV-2: Spread through sexual Many infected do not present with symptoms, contact w. an infected person. but symptoms include fever, chills, malaise (discomfort), swollen lymph nodes, and pain. No cure or vaccine, but Fluid filled vesicles may develop which can antiviral meds can keep the burst and release infectious fluids. For males, virus latent, reduce symptoms. lesions on penis and water discharge. In females, But if medication is vesicles on the vulva, vagina, or cervix, along discontinued, the condition with urinary discomfort. Condoms may not fully returns to the original severity. prevent spread as lesions appear in other areas. Latent ( transmissible), but reoccurs (more than Diagnosed with clinical exams, HSV I) where new lesions appear under stress. cultures, or biopsies. Can also use virologic or serologic Herpes can transit to newborns (neonatal herpes) techniques and PCR. during childbirth through pathogens in the birth canal. Limited to skin, mucous membrane, and eye infections, but can spread and impact CNS, impacting motor functions. Some occur before birth when the virus crosses the placenta and cause developmental complications/disabilities. Histoplasma Histoplasma capsulatum is a dimorphic fungi Inhalation: inhaling airborne Histoplasma capsulatum thrives in capsulatum that grows as mold in soil that has been exposed spores (conidia) found in moist, nitrogen-rich soils, with to bird or bat feces. It can grow as a yeast when contaminated soil, in areas organic bird or bat fecal matter. the spores are inhaled, living in the human body. with bird or bat feces. Fungus In the lungs, the spores get phagocytized by Commonly found in the river (dimorphic) alveolar macrophages, survive, quickly multiply, (construction sites, caves, etc) valleys of Mississippi and Ohio. causing the chronic lung disease, histoplasmosis. mold in environment Diagnosis is based on chest Exists as a mold in the yeast when pathogenic Histoplasmosis commonly occurs in the radiographs and cultures environment and converts to yeast Mississippi Valley, S. America, Africa, Asia, and grown. Staining and form in the human body. Australia. It is not transmitted from human to serological tests can also be (a thermally dimorphic fungus). human, but can have high exposures within a used to identify the fungus. community. Symptoms include fever, headache, weakness, and chest discomfort. Focal infections Infection is self-limiting and cause granulomatous lesions (immune response) does not require any antifungal and lead to calcification. Histoplasmosis can treatment unless disease spreads. become chronic with reactivations, and spread to the lymph, blood, liver, or spleen. Few individuals experience symptoms but it can affect the young, elderly, and immunocompromised. Human HPV causes skin infections and is transmitted Direct Skin-to-Skin Contact: HPV infects only humans, papillomavirus through direct contact. There are over 200 most often during sexual typically targeting the epithelial different strands, with 40 of them causing STIs. activity (vaginal, anal, or oral). cells of the skin and mucous (HPV) It is the most common STI in the country and membranes. presents as skin warts as well as genital warts. Non-sexual: contact with Virus contaminated surfaces (rare) It can persist long-term, often Common Warts (fingers, back of hand, nails) asymptomatic in the host and later Non-enveloped, Plantar Warts (sole of foot, grow inward, painful) Vertical Transmission: passed progress to diseases like cancer. double-stranded Flat Wart (anywhere on body, numerous, smooth) from mother to child during circular DNA Filiform Warts (long, threadlike, grow quickly) childbirth, potentially causing HPV can survive outside the body respiratory papillomatosis. (rare) for short periods, but it is not HPV infection is often asymptomatic and highly resilient outside the host. self-limiting. Condylomata acuminata (genitial Vaccination is available for warts) is an extremely prevalent symptom of HPV. some strains of HPV. It presents as soft, pink, irregular growths on the genitals or anus. HPV can also cause cervical or Immune system may prevent genital cancers (has virulence factors that some warts, but established inactivate proteins that suppress tumors). warts removed through topical meds, freeze, cut, burning, etc. HPV cannot be cultured. Detected primarily through molecular tests. Routine screening/pap smears (detects abnormal cells that may turn into cancer) is recommended. Influenza Influenza is a common viral disease that is caused Droplets: Respiratory droplets Host: Primarily infects humans, by orthomyxovirus. It is enveloped, with 7 to 8 or aerosols inhaled from but can also infect birds, pigs, and RNA genome sections, and spike proteins. One coughing, sneezing, or talking. other mammals. Virus spike protein, hemagglutinin, elicits a strong (enveloped) immune response. However, the virus changes Surface contact: Touching Natural Reservoir: Wild birds are rapidly so the new variants are able to evade the contaminated surfaces a significant reservoir, which can Orthomyxovirus immune system (antigenic shift). There are 3 followed by contact with the harbor various strains of the virus. Influenza classes, A, B, C, from severe to mild. mouth, nose, or eyes. It affects the upper respiratory tract but can also Influenza often shows seasonal Most lethal pandemic of patterns, peaking in colder months extend into the lower tract. It is worldwide, with Influenza was in 1918-1919, in in temperate regions. 3k-50k deaths in the U.S. per year, depending on which it underwent an the virulence factor and type of variant. antigenic shift. Often referred Symptoms include high fever, chills, and body to as the Spanish Flu. aches. It presents similar to the common cold, but with severe aches and fatigue (rarely nasal Diagnosed through RDIT congestion or sneezing). The illness is generally (rapid diagnostic influenza self-limiting, but severe cases can lead to testing). There are drugs that pneumonia or fatal infections. It is most common inhibit influenza, and yearly in the very young or in elders. Some specific vaccines that limit outbreaks. strains affect young adults (cytokine inflammatory response loop). Reye's Syndrome is a complication that can occur with the flu, which can affect the liver, brain, and potentially fatal. Legionella L. pneumophila is an aerobic, Gram-, bacillus Aerosol Inhalation: inhalation Commonly found in freshwater pneumophila bacterium that causes atypical pneumonia known of aerosolized water droplets environments (rivers, lakes) and as Legionnaires. It infects free-living amoeba in containing the bacteria man-made water systems. moist environments. Infection typically occurs in (showers, hot tubs, AC). Bacteria man-made structures (AC towers, humidifiers, It proliferates in warm, stagnant misting systems, fountains). Aerosols from these Legionella pneumophila is a water, with organic materials. (gram - reservoirs lead to infection, especially those who fastidious bacteria. It is bacillus, aerobic) are immunocompromised. difficult to culture or gram It can form biofilms on water stain for diagnosis. Scientists systems, persist, and multiply. When L. pneumophila enters the alveoli, they are have developed a rapid antigen phagocytized by macrophages. It then secretes test for 1 serotype. Have protozoan hosts (amoebae) protein that inhibits lysosome fusion and allows in water systems where they can the bacteria to proliferate inside. The pneumonia 10% of patients die from survive and replicate. can range from mild to severe, depending on complications. Treated with immune defenses. It can also cause fever, nausea, antibiotics. No vaccine. vomiting, confusion, and neurological damage. Loa loa Loa loa is a parasitic helminth nematode worm Vector: Transmitted by the bite Found primarily in tropical that causes loiasis. It is endemic to West/Central of infected Chrysops flies ( aka regions of West/Central Africa, Africa and does not occur outside the region mango flies or deer flies). especially in forested areas where Parasitic Helminth unless by travelers. Genetics can affect how deer flies are present. Nematode susceptible an individual is to the disease, and After the bite, larvae enter the presentation of symptoms vary. bloodstream and mature into Life Cycle: “African Eyeworm” adult worms. Larvae are taken up by deer flies Loa loa is spread by deerflies, which ingest the when they feed on blood meals. larvae from an infected human through a blood Deer fly deposits larvae in another You are able to test for Loa loa meal. The deerfly bites another human, deposits human. It matures into adult antibodies, but the tests are not larvae in the bloodstream, and some larvae worms. Adults shed larvae on accurate. They just represent develop into adult worms in 5 months. These fluids, blood, and urine. an exposure in the past. worms grow several cm long, and can survive in the subcutaneous tissue for years. The worms may be surgically It is given the common name “eyeworm” bc the removed, which only alleviates worms live in the subcutaneous tissues, and the discomfort, but not the migrate slowly. You can see them migrate across infection, since there are many the conjunctivitis of the eye or under the skin. worms. The preferred med is diethylcarbamazine, an anti- Some people are asymptomatic, but in others the parasitic, but it can produce migrating worm can cause fever and areas of risky side effects. allergic inflammation called Calabar swellings. Other symptoms include hives, joint, and muscle If left untreated, loiasis can pain. In the eye, they can cause temporary eye damage the kidneys, lungs, and pain, itching, but no permanent damage. heart. Mycobacterium M. Tuberculosis is a bacterium that can develop Airborne: spreads through Primarily associated with human tuberculosis antibiotic resistance, causes tuberculosis and inhalation of respiratory hosts as it does not survive long chronic granulomatous. It is a gram +, bacillus, droplets or aerosols when an outside hosts in the environment. and acid fast, meaning it resists decolorization of infected person coughs, stains by acids (retains color) hard to see grain sneezes, or talks. Resides in alveolar macrophages, Bacteria stain. This is due to the waxy mycolic acid layer forms granulomas (clusters of which also causes it to grow slowly. The Bacteria enter the lungs where WBC, immune cells) in order to (gram +, bacillus, bacterium has high amounts of G/C nucleotides, they can be engulfed by evade the immune response. acid-fast, high G + C, and does not form endospores. However the alveolar macrophages, and may no endospores formed) infectious dose is only 10 cells. survive and multiply. After inhalation, the bacteria enters the alveoli, are phagocytized by macrophages, survive due to the mycolic acid, and multiply. If they don’t get phagocytized, it results in inflammation and influx of WBCs, which form small lesions in the alveoli, called tubercles, where bacteria proliferates and causes tissue damage. If the tubercle erupts, bacteria can spread in the bloodstream to other organs or aerosol droplets, which is why masks and negative ventilation are important in preventing airborne transmission. These lesions in the alveoli can heal and form calcified Ghon complexes, which can be used for diagnosis on radiographs. However, bacteria can still remain and produce secondary tuberculosis. TB is a chronic disease with treatments lasting months or years. However, since it is antibiotic resistant, misuse can create deadly strains. Norwalk Virus Norwalk Virus, or norovirus, are caliciviruses Fecal-oral: contaminated food, Norovirus is a human specific that cause gastroenteritis (inflammation of the water, or surfaces. pathogen that is highly contagious stomach or intestines) in humans, with symptoms and stable in the environment, (non-enveloped, Person-to-person: Contact with of abdominal pain, watery diarrhea, vomiting, persisting on surfaces like single-stranded RNA) infected individuals. nausea, dehydration, and fever. countertops and doorknobs. “Norovirus” Aerosolized particles: vomiting The illness is relatively mild, developing 12-48 Outbreaks are common in closed, or flushing of infected stool hours after exposure, and clears in a few days crowded spaces such as cruise can create virus aerosols. w/o treatment. There are ~1 mil cases per year in ships, schools, and hospitals. infants, children, and the elderly, and is highly PCR or EIA detection. No contagious. Norwalk virus is transmitted through medication but is self-limiting. direct contact, contaminated surfaces, or food. It Rehydration and electrolytes is not killed by standard bacterial disinfectants so are advised. Good hygiene and transmission can remain after cleaning. food prep for prevention. Pseudomonas Pseudomonas aeruginosa is known for its role as HAI: Spread via contaminated Found commonly in soil, water, aeruginosa an opportunistic pathogen. It can form biofilms surfaces, medical equipment, plants, and healthcare settings on medical devices and tissues, leading to or hands of healthcare workers. (especially in patients with chronic infections and antibiotic resistance. compromised immune systems or Bacteria indwelling medical devices. Because of its ability to adhere to contact lenses, (gram -, bacillus, P. aeruginosa can cause keratitis. It is commonly aerobic, can be found in the soil and on human skin, where it can facultative anaerobe) cause opportunistic infections on wounds/burns. Known as “hot tub rash” it causes folliculitis in pool/hot tub users. It can also cause otitis externa, infection of the ear canal (itching, redness, pain), osteomyelitis, inflammation of bone tissues, and bladder infections. It also causes serious cases of bacterial pneumonia in patients with CF (50%+) and artificial ventilators, where contaminated equipment causes the pathogen to be aspirated, dried mucus buildup, and prevents clear airways. P. aeruginosa wounds have a distinctive odor of grape soda or corn tortillas, and a blue-green pus. It has several virulence factors which include  producing exotoxins and enzymes that contribute to tissue damage and evading phagocytosis. It is resistant to many antibiotics due to its ability to form biofilms, prevent uptake of and expel drugs. Roseola Roseola is a mild viral infection caused by Droplets: saliva, respiratory Common worldwide. It can persist human herpesvirus-6 (HHV-6) and occasionally droplets, secretions, or aerosols. in the host by establishing latent Virus by HHV-7. It is commonly seen in children, and infections, remaining dormant in spread via direct contact with salivary or Contact: person to person, the body and can reactivate later enveloped respiratory secretions of infected individuals particularly through caregivers in life. double-stranded DNA through droplets or aerosols. in close contact with infants. (roseola infantum “sixth Primarily infects T-cells. Symptoms include runny nose, sore throat, Diagnosed through observation disease”, or , exanthem of symptoms. Serological tests subitum “sudden rash”) cough, and a high fever. 3-5 days after the fever, a rash may appear on the chest and abdomen, can be used to confirm. which causes no discomfort. The rash forms flat Usually resolves without macules or firm, slightly raised papules, some treatment, within a week of the with a white ring. The rash may spread to the fever. Immunocompromised neck and arms, sometimes to the face and legs. may be more at risk. (starts at trunk, spreads outward) Rotavirus Rotavirus is a non-enveloped, double-stranded Fecal-Oral Route: Ingestion of Common worldwide. Persists on RNA virus, belonging to the Reoviridae family. contaminated particles (hands, surfaces or environments for a It is transmitted through the fecal-oral route or hands, water or food) common long time, especially in water Virus through contaminated surfaces but is becoming in areas with poor sanitation. sources. Non-enveloped preventable through vaccination. double-stranded RNA Prevention through vaccination. Infects the epithelial cells of the Rotavirus is a common cause of gastroenteritis, small intestine, leading to Reoviridae Family causing watery diarrhea, vomiting, fever, and Detected using enzyme disruption of normal absorption severe dehydration. The virus can survive in the immunoassay of stool samples, and secretion processes. stomach after a meal, but is normally found on latex agglutination assays, and the epithelial cells of villi in the small intestines. RT-PCR tests. Infection causes food intolerance, esp to lactose, fluid loss, and dehydration. Repeat infections can Treatment: oral rehydration, lead to malnutrition and the risk of death. typically self-limiting. Rotavirus is widespread in children. Because of immune memory, adults who come in contact with rotavirus will not contract it or be asymptomatic. Elders are more at risk due to a weaker immune system and can spread in nursing homes. The illness appears after a 2 day incubation period and lasts for about a week (3-8 days). Rubeola Rubeola is caused by Paramyxovirus, which Droplets: inhaling infectious Humans are the only natural hosts causes highly contagious measles. It is an respiratory droplets from for Rubeola. enveloped, single-stranded RNA virus, with coughing or sneezing. Virus embedded hemagglutinin spikes, and is a major The virus is found in the nasal and Paramyxovirus cause of childhood mortality worldwide. Airborne: can remain throat secretions of infected infectious in the air for up to 2 individuals. Enveloped, Rubeola is spread by direct contact with hours after the infected person spikes of embedded infectious secretions or through the inhalation of has left the area. hemagglutinin proteins airborne droplets from breathing, coughing, or sneezing. It is initially characterized by high Diagnosed through appearance single-stranded RNA fever (105+ °F), runny nose, cough, sore throat, of rash or Koplik spots. Can be and conjunctivitis. As it moves systemically detected by serological tests, or through the bloodstream, it causes a red, raised, direct hemagglutination assays. macular rash, forming initially on the face, spreads to the extremities, eventually becoming There are no effective confluent, and lasts for several days. White spots treatments for measles. may also form on the inner lining of the inflamed However, it is preventable cheeks, known as Koplik spots. through the MMR vaccine (measles, mumps, rubella). Although Rubeola is generally self-limiting, it can lead to pneumonia, encephalitis, and death particularly in young children and the immuno- compromised. Additionally, the inhibition of the cells in the immune system by Rubeola can predispose patients to secondary infections. Staphylococcus Staphylococcus aureus is a gram+, coccus bacteria Direct Contact: contaminated Naturally and commonly found on aureus that often grows in bunches. It is a part of the surfaces or skin, through human skin, in the nose and microbiota and commonly found in the nasal wounds, cuts, or surgical sites. mucous membranes. passages, sinuses, and on healthy skin. It can be Bacteria transferred from a healthy individual onto an Inhalation: cases like As an opportunistic pathogen, it immunocompromised one through surgical sites pneumonia usually exists harmlessly but can (gram +, coccus, or wounds and become pathogenic. These strains cause disease when it enters the grows in bunches, are the causes of chronic granulomatous disease, Ingestion: contaminated food body through breaches in the skin catalase positive) infections of the skin, and other body systems. It or immune system vulnerabilities. is a highly contagious microbe and can spread You can use samples to culture from skin-to-skin contact. Some strains are S. aureus. It is catalase +. antibiotic resistant (ex: MRSA) and are common within healthcare and community settings. Although it is resistant against (HA-MRSA, CA-MRSA). methicillin, there are MRSA effective drugs for treatments. S. aureus has several virulence factors including one that releases chemicals that are cytotoxic to For SSSS, blood tests can be can cause impetigo the skin and WB cells. It also produces coagulase, used to check for elevated as well causing platelet clotting and abscess formation. WBC count and culturing. IV antibiotics and fluid therapy Staphylococcal scalded skin syndrome (SSSS) is are used as treatment. another superficial infection that is commonly seen in young children and infants. The bacterial Staph. Food Poisoning exotoxins first produce erythema (redness of skin) diagnosis requires observing followed by severe peeling. rapid onset of the illness, S. aureus can also cause healthcare-associated gathering enterotoxin samples, pneumonia, with the elderly and immuno- and serological tests. compromised being at risk. Diagnosis of endocarditis is Staphylococcal Food Poisoning is a form of food determined using blood intoxication that is commonly associated with raw cultures, echocardiograms, and or uncooked meat and dairy, along with poor clinical symptoms. Treatment sanitation practices. When the bacteria grows on includes high doses of IV food, it may produce enterotoxins that are resistant antibiotics. to low acidic pH and boiling. When ingested, the enterotoxins produce a large immune response, Diagnosis of pericarditis is with symptoms of dehydration, nausea, diarrhea, made with chest radiographS, cramping, and vomiting within 1-6 hours. Severe EKC, echocardiogram, cases can cause headaches and changes in blood pericardial fluid, or biopsy. pressure and heart rate. However, symptoms Antibiotics may be prescribed. resolve quickly within 24-48 hours w/o treatment. S. aureus can cause Staphylococcal Toxic Shock Syndrome. Some strains produce a superantigen called (TSST-1). TSS occurs as a result of this and other complications or localized infections. Those highest at risk for TSS are people with S. aureus colonization of the vagina and leave tampons or other devices in, past the recommended time. S. aureus can infect the endocardium of the heart and cause (acute or subacute) endocarditis. It can breach the body’s defenses and enter the bloodstream. Individuals with preexisting heart damage have a higher risk. It can rapidly destroy the heart valves and if untreated, can lead to death within a few days (acute). In subacute bacterial endocarditis, the damage to the heart valves occurs slowly over months. Over time, blood clots can form in the heart, which can protect the bacteria from phagocytosis. Immune responses cause fibrosis of the heart valves and may require replacement. Symptoms of subacute include fever. S. aureus can infect and inflame the tissues surrounding the heart, causing acute pericarditis. This condition is marked by chest pain, difficulty breathing, and a dry cough. It is self-limiting, and clinical intervention is not necessary. Streptococcus S. pneumoniae is a gram+ bacteria that appears as Inhalation: inhalation of Part of the normal flora of the pneumoniae diplococci, a pair of cells, rather than in long respiratory droplets that are upper respiratory tract and mouth chains like most streptococci. It is found as part of expelled when an infected but opportunistic, causing disease the normal microbiota in the upper respiratory person coughs, sneezes, or talks. in other body systems or when the Bacteria tract and mouth of healthy people. Scientists have host defenses are compromised. known since the 19th century that S. pneumoniae Colonization: S. pneumoniae (gram +, diplococci) causes pneumonia and other respiratory infections. typically colonizes the upper It can also cause meningitis, septicemia, respiratory tract of healthy osteomyelitis, and endocarditis (esp in newborns, individuals w/o causing disease. elderly, and the immunocompromised). However, under certain conditions, like a weakened S. pneumoniae is able to grow a capsule, which immune system, it can spread to helps it to evade phagocytosis, aiding in its other parts of the body and pathogenicity. Encapsulated strains of the bacteria cause infections. are more virulent than the non-encapsulated ones and are more likely to invade the bloodstream and S. pneumoniae is identified cause septicemia and meningitis. In 1928, through cultures or serotyped. It Frederick Griffith showed that a live, non- is treated with antibiotics and pathogenic S. pneumoniae could be transformed prevented with vaccines. into a pathogenic bacteria through exposure to a heat-killed pathogenic strain. This concluded that a “transforming principle” was passed from the dead pathogenic bacteria to the live non- pathogenic bacteria. Later, the transforming principle was identified to be DNA, giving part to its virulence factor. S. pneumoniae can also alter their own PBP, penicillin-binding-proteins, providing resistance to multiple antibiotic drugs. Among neonates, older infants, and children under 14, encapsulated strains of S. pneumoniae are the most common causes of AOM (acute otitis media), which causes fluid and pus in the middle ear, leading to inflammation and pain. S. pneumoniae is one of the main causes of community acquired pneumonia. (Pneumonia is a general term for infections of the lung that lead to inflammation and accumulation of fluid and WBC in the alveoli. Air exchange becomes impaired and patients experience respiratory distress.) S. pneumoniae initially colonizes the bronchioles of the lungs and spreads to the alveoli, where the polysaccharide capsule prevents it from being phagocytized or cleared. There, other virulence factors include damaging host cells, adherence, and inflammatory response, leading to WBC and RBC filling up the alveoli (bloody sputum). S. pneumoniae can also spread from the upper respiratory tract, into the bloodstream, and access the CNS. It is commonly found in healthy people, spread by respiratory secretions, and can cause bacterial meningitis (inflammation) in the brain. Without a proper systematic antibacterial treatment, fatality can be as high as 70%, with 20% of survivors having permanent neuro damage. Streptococcus S. pyogen is a gram+, coccus bacteria, belonging Direct Contact: Transmitted Commonly found in the human pyogenes to Group A Streptococcus (GAS) and grows in person-to-person through throat and skin as part of the chains. It is a part of the healthy human flora of respiratory droplets from normal flora. the mouth. However, it can bind to the host cell’s coughs or sneezes. Bacteria Can survive in the environment extracellular matrix in order to establish infections Skin Contact: Direct skin contact but usually thrives in (gram +, coccus, (ex: binds to oropharynx cells to cause strep or contaminated surfaces can warm-blooded hosts. grows in chains, throat). It produces a variety of extracellular lead to infections like impetigo. Group A Strep) enzymes that aid in transmission, inflammatory Can act as an opportunistic response, and a capsule that avoids phagocytosis. Wound Contamination: pathogen, especially when the S. pyogen is considered pyogenic because of the Infections can occur through immune system is compromised pus production observed with its infections. breaks in the skin. or during bacterial imbalance.  S. pyogens is the most common cause of bacterial Impetigo is diagnosed through pharyngitis (strep throat) and of skin infections appearance, cultures, and such as impetigo (relatively mild) and necrotizing susceptibility tests. Oral or fasciitis (life threatening, flesh-eating disease). topical antibiotic treatments are Impetigo causes the formation of vesicles, typically used. pustules, and bullae (large fluid-filled blisters) often around the nose and mouth. Impetigo can Treatment of necrotizing be either non-bullous or bullous. Nonbullous, the fasciitis requires surgical vesicles and pustules rupture and become removal of the dead or infected encrusted sores with yellow crust or draining tissues and IV antibiotics. exudate. Bullous, the bullae fill up and rupture, resulting in larger draining and crusted lesions. Respiratory strep and Scarlet Impetigo is common in children and highly Fever are diagnosed quickly contagious. S. pyogens can also spread to and using a rapid enzyme infect the fascia, a thin layer of connective tissue immunoassay, but high false between the skin and muscle, which causes negatives occur, so culture Necrotising Fasciitis, otherwise known as flesh identification is the gold eating bacteria. Virulence Factors of the bacteria standard. Treatment includes adhere to, invade, and overcome host defenses. using penicillin. Bacterial proteases that are unique to S. pyogenes aggressively filtrate and destroy host tissues, Diagnosis of puerperal sepsis is preventing the migration of WBC to the site of based on the timing of fever, infection. Tissue death spreads rapidly, as large identification of agent in blood, areas of skin become infected, detached, and die. wound, or urine. Prevention of disease is through antiseptic S. pyogenes infection can develop in the dermis use and handwashing by or the hypodermis, through a cut or abrasion and workers during delivery. cause cellulitis, erysipelas, or erythema nodosum. Cellulitis causes the infected area to become Osteomyelitis diagnosed with reddened, painful, and warm to the touch. radiography, imaging, blood Erysipelas causes a large, intensely inflamed cultures, or bone cultures. patch of skin that can have bullus or be pus-filled. Antibiotic therapy is typically Erythema nodosum causes inflammation of the used to treat osteomyelitis. In subcutaneous fat cells in the hypodermis and red serious cases, surgery is used nodules on the skin (mostly in the shins). to remove the site of infection. Streptococcus pyogenes (cont.) S. pyogenes causes pharyngitis and scarlet fever. Pharyngitis is a common upper respiratory infection, often known as strep throat. It is caused by the damage of mucosal membranes in the pharynx, by the exoenzymes and exotoxins released by S. pyogenes. It degrades connective tissues (using hyaluronidase, collagenase and streptokinase), prevents blood clots, and can destroy red and white blood cells. Symptoms of strep throat can include a fever higher than 100.4℉, intense pharyngeal pain, erythema, swelling, dark-red tonsils often dotted with pus, and petechiae on the palette of the mouth. The submandibular lymph nodes (under the angle of the jaw) are also often swollen. Some strains of S. pyogenes produce erythrogenic toxins that attach the plasma membranes of capillary endothelial cells, leading to scarlet fever. Scarlet fever is characterized by fine rashes on the skin and tongue and severe cases may lead to STSS. S. pyogenes can cause streptococcal toxic shock-like syndrome (STSS). Symptoms include fevers, chills, nausea, abdominal pain, diarrhea, and can cause acute respiratory distress syndrome. 50% of patients also develop bacteremia and necrotizing fasciitis. Strep Throats are treated aggressively with antibiotics because 1-3% untreated can lead to sequelae illnesses such as rheumatic fever and acute glomerulonephritis. Acute rheumatic fever occurs primarily in children 2-3 weeks after untreated pharyngitis, and is caused by specific rheumatogenic strains of S. pyogenes. It results from the cross reaction of the patient’s antibodies, the bacteria’s surface proteins, and proteins on the cardiac, neuronal, and synovial tissues. Damage to the nerves and joints leads to swelling and is reversible. However, the autoimmune attack that damages and causes inflammation of the heart (cardidits), is not. It can lead to stiffening of the heart valves, scarring, and permanent murmurs. Acute glomerulonephritis can develop from phagitis infections (6-10 days after) or from cutaneous infections (up to 21 days after). An immune complex forms between the bacterial antigens and the body’s antibodies, and lodge themselves into the endothelial, causing damage and inflammation to the kidney and glomeruli. S. Pyogenes causes puerperal sepsis, which occurs in the weeks after giving birth. The bacteria attaches to the host tissues using M protein, produces a capsule to avoid phagocytosis, and releases exotoxins. It originates in the genitial tract, breasts, urinary tract, or surgical wounds and can spread quickly, resulting in peritonitis (inflammation of the abdomen), septicemia, and death. Puerperal sepsis was a major cause of death for mothers after childbirth before developments occurred in the 19th century. Osteomyelitis, inflammation of the bone tissues, can occur by entry of the S. pyogenes through trauma, surgery, or the bloodstream. Symptoms include fever, localized pain, edema, and ulcers in soft tissues near the site of infection. The infection can also spread to the joints, resulting in infectious arthritis, or to the blood, leading to sepsis and thrombosis. Streptococcus pyogenes is easily spread by direct contact or droplet transmissions, through coughing or sneezing. Sporothrix Sporotrichosis schenkii is a dimorphic fungus Cutaneous Transmission: Commonly found in soil, decaying schenkii (occurs as mold in the environment, yeast in the Direct inoculation of the plant matter, and on plants. host) that dwells in the soil and can cause an fungus into the skin via cuts, (especially in the tropical and infection known as rose gardener’s disease. It scratches, or puncture wounds, subtropical regions). often infects landscapers and gardeners. Under often when handling Fungi most conditions, the fungi cannot produce skin contaminated plant material. Thrives in warm and humid infections in healthy individuals since the skin conditions; can persist in the Dimorphic and mucous membranes keep it at bay. However, Respiratory Route: (rare) environment as a mold. (mold in environment, small wounds in the skin, such as those caused inhalation of spores can lead to yeast in host) by rose thorns or splinters can provide an pulmonary sporotrichosis, esp. Acts as an opportunistic pathogen opening to the opportunistic pathogen. in immunocompromised when introduced into the body. “rose garden disease” individuals. “rose thorn disease” Once it breaches the skin barrier, S. schenkii can infect the skin and underlying tissues. It causes a Diagnosed based on histologic subcutaneous mycosis (spread from skin to examination of the affected deeper tissue) known as sporotrichosis. The tissue and culturing microbe. infection presents as small ulcers or lesions on Treated with itraconazole, an the skin. However, the fungus can spread to the antifungal drug. lymphatic system and beyond. As it spreads to the lymph nodes, nodules appear, become necrotic, and may ulcerate or turn into abscesses. Avoided getting infected by The infection may even spread throughout the wearing gloves and protective body, although it is relatively uncommon. clothing while gardening and promptly cleaning and wounds Other pathogens may also enter through the from outdoor activities. infected opening, caused by the thorn or splinter, causing secondary bacterial infections. tinea Tinea are a group of cutaneous mycoses, caused Direct contact: Skin-to-skin Dermatophytes thrive in warm, by dermatophytes, a fungal mold that requires contact with an infected person. moist environments, such as keratin (keratin protein is found in the skin, hair, locker rooms, swimming pools, and nails). There are 3 genres of dermatophytes, Indirect contact: Contact with and communal showers. all of which can cause cutaneous mycoses: contaminated surfaces or Trichophyton, Epidermophyton, Microsporum. objects (towels, shoes, They are typically found in soil, on equipment, or animals). animals, and human skin, where Tinea can occur in many areas of the body and they can persist in dead skin cells. specific locations can have distinct names and symptoms: A Wood’s UV lamp can be used tinea corporis, capitis, pedis (of body, to diagnose tineas, which glow scalp, and feet ringworm) fluorescent under the light. tinea barbae (beard, barber’s itch) Direct specimen samples from tinea cruris (groin, jock itch) skin scraping, hairs, or nails can tinea unguium (toenail, fingernails) also be used to identify. Dermatophytes are commonly found in the Various antifungal treatments environment or soil and are transferred to the are effective against tineas. skin through humans and animals. They grow in Most mycoses of the skin can moist, dark environments. Tinea pedis spreads in be avoided through good public showers, and grows in sweaty shoes and hygiene and proper wound care. socks. Tinea cruris spreads in communal living areas, and grows in dark, sweaty undergarments. Tinea corporis produces lesions that grow outwards and heal from the center, forming a red ring (thus the name ringworm). Amoeba/Protozoa Acanthamoeba Helminth Loa loa (Nematode) Bacillus anthracis (Gram+, Bacillus, Forms Endospores) Bacteria Corynebacterium diptheriae (Gram+, Bacillus, Club-Shaped when stained) Mycobacterium tuberculosis (Gram +, Bacillus) Staphylococcus aureus (Gram+, Coccus, grows in bunches) Streptococcus pneumoniae (Gram+, Diplococci) Streptococcus pyogenes (Gram +, Coccus, grows in chains) Bordetella pertussis (Gram-, Coccobacillus) Haemophilus influenzae (Gram -, Coccobacillus) Legionella pneumophila (Gram -, Bacillus) Pseudomonas aeruginosa (Gram -, Bacillus) Fungi Aspergillus (mold of different species) Candida albicans (yeast, can form pseudohyphae) Coccidioides immitis (mold in environment, spherule in host) Cryptococcus neoformans (encapsulated yeast) Histoplasma capsulatum (mold in environment, yeast when pathogenic) Sporothrix schenkii (mold in environment, yeast in host) Tinea Virus Common Cold (200+ viruses) Fifth disease (Parvovirus B19, Non-enveloped, single-stranded DNA) Human papillomavirus (HPV, Non-enveloped, double-stranded circular DNA) Norwalk Virus (Non-enveloped, single-stranded RNA) Rotavirus (Non-enveloped, double-stranded RNA) Herpes Simplex Virus I & II (Enveloped, double-stranded DNA) Influenza (Orthomyxovirus, Enveloped, single-stranded RNA, HG spike proteins) Roseola (Enveloped, double-stranded DNA) Rubeola (Enveloped, single-stranded RNA, HG spike proteins) You need to know what these are and what they do. How are they used in metabolism and growth? ATP (Adenosine triphosphate): ADP (Adenosine Diphosphate): The primary intracellular carrier of energy in living organisms. It plays ADP (Adenosine Diphosphate) is a crucial molecule in microbial a central role in metabolism and is the most important energy supplier metabolism and growth. It is a nucleotide consisting of adenine, ribose, in many enzymatic reactions. ATP stores and provides energy for and two phosphate groups. various cellular processes. It releases energy when the bond between its phosphate groups is broken, converting ATP to ADP. Energy Conversion: ADP is converted to ATP during cellular respiration (e.g., in glycolysis, ATP is used during: the Krebs cycle, and oxidative phosphorylation). Catabolism- breakdown of nutrients (glucose in glycolysis), ATP is ATP Synthesis: generated through substrate-level phosphorylation and oxidative When microbes metabolize nutrients, energy is stored by adding a phosphorylation. phosphate group to ADP to form ATP. This process happens in substrate-level phosphorylation or oxidative phosphorylation. Anabolism- buildup of molecules. the energy required for biosynthetic processes, including the synthesis of proteins, nucleic acids, and cell Energy Release: When a cell needs energy for processes like growth, wall components. division, or movement, ATP is broken down to ADP, releasing energy for these activities. Growth: ATP fuels cellular activities essential for microbial growth, e.g. DNA replication, protein synthesis, and cell division. Phosphorylation through solar or mechanical energy creates ATP. When it loses a phosphate group and turns into ADP, it is known as dephosphorylation, which creates energy available to do cellular work such as anabolism. Substrate-level Phosphorylation and Oxidative Phosphorylation are two distinct mechanisms by which cells produce ATP. Substrate-Level Phosphorylation: Occurs through the direct transfer of a phosphate group from a substrate, to ADP (making ATP). This happens without the involvement of an electron transport system and without oxygen. Typically seen in the cytoplasm during glycolysis, and the mitochondrial matrix (cytoplasm still, in prokaryotes) during the Krebs Cycle. Since it occurs independently of the ETS, substrate-level phosphorylation produces only a small amount of ATP. (ex: during glycolysis, only 2 ATP per glucose). Oxidative Phosphorylation: A more complex and efficient method of producing ATP. It generates most of the ATP during aerobic respiration. This process takes place in the inner mitochondrial membrane (eukaryotes) or the cell membrane (prokaryotes). It involves the electron transport system, where electrons from the electron carriers (ex: NADH, FADH2) are passed through a series of protein complexes. As they move along the chain, the electrons release energy, which pumps protons across the membrane, creating a proton gradient. This proton gradient is known as the “proton motive force” and drives ATP production via the enzyme ATP synthase. Oxidative phosphorylation is efficient, producing up to 34 ATP molecules per glucose during cellular respiration. While substrate-level phosphorylation provides a direct and immediate source of ATP, oxidative phosphorylation is essential for yielding the large amounts of ATP required for most cellular activities, especially in aerobic conditions. DNA (Deoxyribonucleic Acid): RNA (Ribonucleic Acid): Deoxyribonucleic acid (DNA) is the hereditary material in all living Ribonucleic acid (RNA) is a nucleic acid present in all living cells, organisms, encoding the genetic instructions necessary for playing a crucial role in coding, decoding, regulation, and expression of development, function, growth, and reproduction. It carries the genes genes. that determine the traits and metabolic capabilities of microorganisms, influencing their survival and adaptability. mRNA carries genetic information from DNA to ribosomes for protein synthesis. It facilitates the production of enzymes and proteins, essential DNA replication during cell division: genetic information passed onto for metabolic pathways and cellular functions. daughter cells, allows for population growth. tRNA transfers specific amino acids to ribosomes during protein DNA transcription to mRNA: produces proteins essential for metabolic synthesis, to match the codons on mRNA. It ensures accurate translation processes, enzyme activity, and cellular structure. of mRNA into proteins, for cell growth and division. DNA genes encode enzymes: drives biochemical reactions, allows the rRNA forms the structural and functional components of ribosomes, microbe to metabolize nutrients (carbs, proteins, fats) for energy/growth where protein synthesis occurs. It is important for ribosome function, t