Final Study Guide 2023 PDF
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This document is a study guide for a final exam on pathogens, covering microbiology and infectious diseases. It includes questions about pathogens, their characteristics, transmission, and treatments.
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Information Sheet on Pathogen 1. What is its name? 2. What is it? Bacteria? Gram+/- or other? Shape? Arrangement? Motile? Anaerobe/Aerobe? Endospores? Additional structures and characteristics? - Protozoan, sporozoan, fungus, helminth, virus, etc. would have similar quest...
Information Sheet on Pathogen 1. What is its name? 2. What is it? Bacteria? Gram+/- or other? Shape? Arrangement? Motile? Anaerobe/Aerobe? Endospores? Additional structures and characteristics? - Protozoan, sporozoan, fungus, helminth, virus, etc. would have similar questions 3. Where normally found? Zoonosis? Vector? Humans? Transmission? 4. Portal of Entry? Portal of Exit? Target infection sites and pattern of infection? 5. Name of disease(s)? Signs and symptoms? What happens if untreated? How do you determine if you have a pathogen? 6. How to prevent the spread of disease? In the hospital? How to treat infection/ target of treatment? Relevant terminology (not an all inclusive list of questions) inal Exam is only on: F 1. Staphylococcal aureus Morphology-spherical bacteria in clusters, gram positive. Transmission-direct contact with an infected person,by using a contaminated object, or by inhaling infected droplets dispersed by sneezing or coughing. Portals-invade skin through wounds, follicles orglands Name of disease- MRSA Localized cutaneous infections-Folliculitis, furuncle, carbuncle, impetigo Systemic infections- bacteremia, osteomyelitis Toxigenic disease- food intoxication, enterotoxins( GI distress), staphylococcal scalded skin syndrome, toxic shock syndrome. S/S: Skin infections- area of red, irritated or painful skin, pus-filled blisters, fever, Food poisoning- nausea and vomiting, diarrhea, dehydration, low blood pressure Toxic shock syndrome- high fever, nausea and vomiting, rash on palms and soles, confusion, muscle aches, diarrhea, stomach pain If untreated:can cause serious infections such asbloodstream infections, pneumonia or bone and joint infections. Diagnosis:obtaining culture from the area of suspectedinfection. Tests for clumping factor, coagulase, hemolysins and thermostable deoxyribonuclease are used to identify S aureus. Treatment-cefazolin, nafcillin, oxacillin, daptomycin,and linezolid. For staph resistant strains give vancomycin Prevention-contact precaution (gloves, hand wash,proper sneezing and c oughing techniques) -keep wounds covered, reduce tampon risks, keep personal items personal, wash clothing and bedding, take food safety precautions. 2. Streptococcus pyogenes Morphology-spherical bacteria in chains, gram positiveand facultative anaerobic. Transmission-contact, droplets, food, fomites Portals-portal of entry generally skin or pharynx. Name of disease-strep throat, scarlet fever, impetigo(pyoderma), erysipelas, type 2 necrotizing fasciitis (flesh-eating disease), cellulitis, toxic shock syndrome, rheumatic fever, glomerulonephritis, sequelae, pneumonia, pancarditis S/S:sore, red throat or tonsils. Pus on throat ortonsils, pain on swallowing. Fever and chills. Swollen and tender lymph nodes in the neck. Vomiting, nausea and abdominal pain. Headache and muscle aches. Malaise. If untreated:infections can result in postinfectioussequela, acute rheumatic fever and post-streptococcal glomerulonephritis. Invasive infections cause necrotizing fasciitis and toxic shock syndrome. Diagnosis:Rapid antigen test on swab sample fromyour throat, throat culture or PCR test. Treatment-penicillin or one its derivatives. Erythromycinor cephalosporin if allergic to penicillin. No specific treatments for rheumatic fever or acute glomerulonephritis Prevention-Droplet precaution 3. Streptococcus pneumonia Morphology-Spherical bacteria in chains, alpha-hemolytic.Found in pairs and do not form spores and are non motile. Gram positive T ransmission-direct contact with respiratory droplets(saliva or mucus). Inhaling or direct exposure to the bacteria droplet through coughing or sneezing from an infected person. Portals-upper respiratory tract. Name of disease-pneumococcal disease. S/S:fever, chills, cough, rapid breathing or difficultybreathing and chest pain. If untreated:it can cause empyema, lung abscess,necrotizing pneumonia, parapneumonic effusion, pericarditis, septic shock, endobronchial obstruction or atelectasis. Diagnosis:blood test (CBC), urine test (urinalysis),phlegm test, chest x-ray, spin tap. Treatment-Penicillins , cephalosporins, and carbapenems Prevention-droplet precaution. Vaccines help preventpneumococcal disease. 4. Neisseria meningitidis Morphology-Kidney bean shape. Non spore forming,non-motile, encapsulated, and non acid-fast diplococci. Gram negative. Obligate parasites. T ransmission-bacteria attach to mucosa and enterthe bloodstream causing pharyngitis. Cross the blood-brain barrier, permeate the meninges. Grow in the cerebrospinal fluid. Portals-human reservoir- nasopharynx Name of disease- Meningitis-very rapid onset S/S:fever, sore throat, headache, stiff neck, convulsions,vomiting. Potentially get brain infection, meningococcal infection. Endotoxin causes hemmorrhage and shock. If untreated:.Permanent effects are cognitive impairment,learning disabilities, deafness, amputations, death. Diagnosis:Gram stain, CSF, blood, or nasopharyngealsample. Culture for differentiation. Rapid tests for capsular polysaccharide Treatment-cephalosporin (3rd generation that crossesblood-brain barrier) Prevention-vaccines 5. Clostridium perfringens M orphology- Pleomorphic with straight or curved rods. It is capsulated, non-motile, and non-flagellated. Gram positive. Strict anaerobic. Transmission-spores found in soil, human skin, intestineand vagina P ortals-involved in soft tissue and wound infections-Myonecrosis (gas gangrene). Surgical incisions, compound fractures, diabetic ulcers, septic abortions, puncture wounds, gunshot wounds (war injuries) -needs a way to get in. Can cause minor food poisoning. Name of disease- Myonecrosis(gas gangrene), tetanus,botulism, pseudomembranous colitis and food poisoning. S/S:gas under the skin (subcutaneous emphysema),blisters filled with brown-red fluid, drainage from the tissues, foul smelling brown-red or bloody fluid, moderate to high fever, pain. Pale skin color, later becoming dusky and changing to dark red or purple. Swelling that worsens around a skin injury. If untreated:bloodstream infection can result intoxin-mediated intravascular hemolysis and septic shock. Can lead to amputation; death if untreated Diagnosis:stool culture Treatment- large doses of cephalosporin or penicillin.Hyperbaric oxygen therapy (strict anaerobe) Prevention-Immediate cleansing of dirty wounds, deepwounds, compound fractures, and infections incisions. Debridement of disease tissue. 6. Listeria monocytogenes Morphology-gram positive rod, non spore forming,facultative anaerobic, catalase-positive, and oxidase-negative organisms. Transmission-oral, through ingestion ofcontaminatedfood. Associated with consumptions of meats and cheeses. Infects cells from moving from one cell to another by burrowing. Portals-intestine tract is the portal of entry Name of disease-Listeriosis S/S:fever, muscle aches, nausea, vomiting, and diarrhea.Severe symptoms include: gas gangrene, tetanus, botulism, pseudomembranouscolitis and food poisoning. If untreated: life-threatening complications, including:Generalized blood infection. Inflammation of the membranes and fluid surrounding the brain (meningitis) Diagnosis:culture of the bacteria from the blood,cerebral spinal fluid or placental fluid Treatment-treat with antibiotics such as sulfamethoxazoleand ampicillin. Prevention- cook thoroughly raw food, wash vegetables, avoid unpasteurized milk or foods, avoid cross contamination of uncooked meats from vegetables. 7. Mycobacterium tuberculosis Morphology-rod shaped, strictly aerobic, acid-fast. Transmission-airborne respiratory droplets Portals-inhaled into lungs Name of disease-tuberculosis S/S:cough, coughing up blood or mucus, chest pain,pain with breathing or coughing, fever, chills, night sweats and weight loss. If untreated:kidney failure, sterility, neurologicaldamage, collapsing vertebrae, meningitis, death Diagnosis:In vivo or tuberculin test. Mantoux test.X-rays, direct identification of acid-fast bacilli in specimen Treatment-6-24 months of at least 2 drugs from alist of 11. One pill called rifater (isoniazid, rifampin, pyrazinamide) Prevention-good ventilation, natural light, goodhygiene. Airborne precaution 8. Bortedella pertussis Morphology-rod-shaped, coccoid gram negative bacteriathat is encapsulated and does not produce spores. Transmission-droplets produced during coughing orsneezing Portals-through your nose, mouth or eyes. Name of disease-whooping cough S/S:ru nny or stuffed up nose. Low grade fever. If untreated:complications include pneumonia, middle ear infection, loss of ppetite, dehydration, seizures, brain disorders, hernia, rib fractures, rectal a prolapse, episodes of cessation breathing. Severe cases can lead to death. Diagnosis:nose and throat swab culture or PCR Treatment-macrolides erythromycin, clarithromycinand azithromycin, trimethoprim-sulfamethoxazole. Prevention-droplet precaution 9. Treponema pallidum Morphology- helically coiled, corkscrew shaped (spirochete)gram negative Transmission-sexually transmitted Portals-close skin to skin contact Name of disease-syphilis S/S: skin rashes, usually on palms of hands and soleof feet. Sores are called mucous patches in or around the mouth, vagina or penis. Moist, warty patches (called condylomata lata) in the genitals or skin folds. fever, swollen lymph nodes, sore throat, hair loss, weight loss, muscle pain If untreated:It can damage your heart, brain, eyes,and other organs. It can lead to irreversible neurological and cardiovascular complications. Diagnosis:Serological testing for detection of antibodies,PCR. Cannot be grown in culture. Treatment-a single injection of long acting benzathinepenicillin G. If allergic to then doxycycline. Prevention-get tested regularly and use condoms and/ordental dams during sex. 10. Borrelia burgdorferi Morphology- gram negative spirochetes (spiral orwave like) bacteria with flagella. Transmission-transmission by ticks Portals-tick bites humans, creating an opening inthe skin. Must gina access to the bloodstream Name of disease- lyme disease S/S:50-70% get bulls eye rash. Initial fever, headache,stiff neck and dizziness. Mimics neuromuscular and rheumatoid conditions If untreated:can progress to serious cardiac andneurological symptoms, poly arthritis. Diagnosis:lyme antibody tests Treatment- treated with tetracycline or amoxicillin Prevention-wear protective clothing, use insect repellent,remove ticks promptly, apply pesticides and reducing tick habitat. 11. Vibrio cholera Morphology-curved rod (comma-shaped) gram-negativeaerobic. Transmission-bacteria is ingested in food or water(needs high infectious dose) Portals-infects mucous barrier of small intestine,noninvasive Name of disease-Cholerais an acutediarrhealdisease S/S:releases enterotoxin cholera toxin that causeselectrolyte and water loss through secretory diarrhea (RICE WATER STOOL) Muscle cramps, severe thirst, flaccid skin and sunken eyes, hypotension, cyanosis, shock If untreated:can lose 50% of body weight during courseof disease Diagnosis:stool cultures on specific media or rapidtests such as stool dipsticks Treatment-can be treated with tetracycline. Rehydratewith a simple sugar-salt solution. Prevention-prevent with proper sewage disposal andwater purification 12. Helicobacter pylori Morphology:Helical-shape with flagella, gram-negative,microaerophilic Transmission:Person-to-person via saliva or fecalcontamination Portals:direct contact with saliva, stool, or vomit Name of disease:peptic ulcers and gastritis S/S:abdominal pain, blood in stool/black feces, bloodyvomit/looks like coffee grounds If untreated:stomach cancer Diagnosis:PCR test from stool, stool antigen test, Treatment:proton pump inhibitors (PPIs): omeprazole,esomeprazole, lanosoprazole, pantoprazole Bismuth subsalicylate (pepto bismol) Histamine (H-2) blockers: cimetidine Prevention:Handwashing, eat food that is properlyprepared, drinking safe/clean water 13. Chlamydia trachomatis Morphology:small, gram-negative, obligate intracellularparasite ○ Elementary body: infectious form ○ Reticulate body: grows within host cell vacuoles Transmission:sexual contact or mother to baby Portals:urethra, placenta, in to eye by contaminatedfingers or fomites Name of disease:ocular trachoma, inclusion conjunctivitis,STD S/S:deforms eyelids and cornea, sores in mouth orgentialia If untreated:blindness, lymphogranuloma venereum Diagnosis:nucleic acid amplification tests (NAATss),cell culture Treatment:doxycycline, azithromycin, or levofloxacin Prevention:condoms, abstinence 14. Coccidioides immitis Morphology:diphasic/pleomorphic fungus with saprobicgrowth phase Transmission:inhalation of airborne arthroconidiafrom contaminated soil Portals:nasal canals to lungs Name of disease:valley fever S/S:fatigue, cough, fever, shortness of breath, headache,night sweats, muscle ache/joint pain, rash on upper body or legs If untreated:develops into meningitis Diagnosis:blood sample to look for coccidioides antibodies/antigens,chest x-rays or CT of lungs Treatment:3-6 months of fluconazole Prevention:avoid outside if windy, air filtration,clean cuts/scrapes with soap and water, wear N95 mask if outdoors 15. Entamoeba histolytica Morphology:protozoan w/trophozoite and cyst forms Transmission:ingestion of cyst form via fecal contaminatedfood/water Portals:entry-oral; exit-fecal Name of disease:Amebiasis S/S:nausea, diarrhea, weight loss, stomach tenderness,occasional fever If untreated:toxic megacolon, amoebic liver abscessformation Diagnosis:stool examination, blood tests, pcr, imaging,colonoscopy/biopsy Treatment:metronidazole, tinidazole, ornidazole,nitazoxanide Prevention:proper hygiene, proper sewage disposal 16. Giardia intestinalis Morphology:protozoan w/cysts and trophozoites Transmission:through contaminated water, food, orobjects or via person to person Portals:entry-oral, exit-fecal Name of disease:giardiasis/beaver fever S/S:diarrhea, gas, foul-smelling/greasy poop, stomachcramps or pain, upset stomach or nausea, dehydration If untreated:IBS, malnutrition in children Diagnosis:microscopy of stool sample Treatment:Tinidazole Prevention:hand hygiene, avoid drinking untreatedwater 17. Necator americanus M orphology:nematode, curved ends and hooked mouths Transmission:burrow into bare feet and travel fromblood into lungs, proceed up bronchi and throat then swallowed Portals:feet, blood, lungs, and feces Name of disease:hookworm disease S/S:pneumonia, nausea, vomiting, cramps, bloody diarrhea If untreated:anemia Diagnosis:finding characteristic ova in feces Treatment:antihelminthic like albendazole or mebendazole Prevention:wear shoes 18. Trichinella spiralis Morphology:smallest known nematode parasite of humans Transmission:eating undercooked pork or bear meat(animal reservoir) Portals:entry-oral Name of disease:trichinellosis S/S:first symptoms-flu-like, diarrhea; 2nd symptoms-muscleand joint pain, SOB, conjunctivitis, swelling of eyelids or face, rash If untreated:persistent/chronic muscle pain and impairedmuscle strength Diagnosis:blood test or muscle biopsy Treatment:mebendazole thiabendazole in initial stage,no sure after larva have encysted Prevention:thoroughly cooked meat 19. herpes simplex virus 2 Morphology:dsDNA virus with envelope, capsid andglycoprotein spikes Transmission:sexual/intimate contact Portals:oral, rectal Name of disease:genital herpes, herpetic whitlow S/S:lesions on genitalia or oral/rectal, malaise,fever, bilateral swelling and tenderness in groin If untreated:urethritis, painful urination, cervicitis,itching; vesicles ulcerate Diagnosis:vesicles and exudate, scrapings from baseof lesions showing giant cells, direct fluorescent antibody testes Treatment:acyclovir, famciclovir, valacyclovir, topicalmedications Prevention:condoms, abstinence 20. Epstein-Barr virus Morphology:dsDNA virus w/ envelope, capsid, and glycoproteinspikes Transmission:bodily fluids, esp saliva Portals:saliva, blood, semen Name of disease:mononucleosis (mono) S/S:fatigue, ffever, inflamed throat, swollen lymphnodes in neck, enlarged s pleen, swollen liver, rash If untreated:progressive immunodeficiency and cansuccumb to opportunistic infections Diagnosis:blood test that detects antibodies Treatment:no specific treatment except to relievesymptoms Prevention:no kissing, sharing drinks or foods orpersonal items 21. Hepatitis B virus Morphology:contains both double-stranded and single-strandedDNA, enveloped Transmission:blood products, sexually transmitted,birth, shared toothbrush/razor, mosquitoes Portals:entry-through break in skin or mucous membraneor by injection Name of disease:Hepatitis B S/S:initially-malaise, fever, abdominal discomfort,rash, diarrhea Severe-jaundice, arthritis If untreated:increased risk of liver cancer, chronicliver disease- necrosis, cirrhosis, cancer Diagnosis:blood test, liver ultrasound Treatment:interferon treatments for chronic infections,passive immunization Prevention:vaccination 22. Morbillivirus Morphology:enveloped, nonsegmented, ssRNA virus Transmission:respiratory aerosols, humans only reservoir Portals:nasal, oral (sneezing, coughing) Name of disease:Measles S/S:sore throat, dry cough, headache, conjunctivitis,lymphadenitis, fever, koplik spots (oral lesions), exanthem (skin rash) If untreated:pneumonia, subacute sclerosing panencephalitis (SSPE)-progressive neurological degeneration of cerebral cortex, white matter, and brain stem, frequent cause of death worldwide Diagnosis:lab blood and tissue tests, symptoms Treatment:no specific treatment, provide comfortmeasures to relieve symptoms Prevention:attenuated viral vaccine MMR 23. HIV Morphology:retrovirus, enveloped, ssRNA Transmission:blood exposure through needles or sexualcontact, semen or vaginal fluid exposure during sexual intercourse Portals:blood, semen, vaginal fluids Name of disease:human immunodeficiency virus, leadsto acquired immunodeficiency syndrome (AIDS) S/S:extreme leukopenia, formation of giant T cellsallowing the virus to spread irectly from cell to cell, infected macrophages release the virus which can target d helper t cells, cough, body aches, nasal congestion, and sore throat If untreated:turns into AIDS, opportunistic infectionsand cancers Diagnosis:ELISA, latex agglutination, and rapid antibodytests followed by western blot analysis Treatment:no cure but therapies available to slowdown or diminish disease such as inhibit viral enzymes, inhibit fusion to cells, and inhibit viral integration to genome, highly active antiretroviral therapy (HAART) most common Prevention:practice safe sex (condoms), never sharingneedles, abstinence Name Bacteria Gram + Gram - other Additional structures? Staphylococcus aureus yes ound bacteria in clusters. R Facultative Anaerobe Streptococcus pyogenes yes ound bacteria in chains. R Beta-hemolytic Extracellular toxins: Streptolysins: hemolysins that also injure many cells/tissues Erythrogenic toxin- induces fever and typical red rash (not all strains) Superantigens- over stimulation of immune response; damages many body structures. Ex: toxic shock syndrome. Produces surface antigens Streptococcus pneumonia yes pherical bacteria, alpha-hemolytic. S Found in pairs and do not form spores and are non motile. Neisseria meningitidis yes idney bean shape. Non spore forming, K non-motile, encapsulated, and non acid-fast diplococci Clostridium perfringens yes leomorphic with straight or curved P rods. It is capsulated, non-motile, and non-flagellated. Obligate parasites. Strict anaerobic Listeria monocytogenes yes od shaped, non-spore-forming, R catalase-positive and oxidase-negative organisms. Facultative anaerobic Mycobacterium tuberculosis Acid-fast od shaped, acid fast. Produces no R infection exotoxins or enzymes. Strictly aerobic Bortedella pertussis yes r od-shaped, coccoid gram negative bacteria that is encapsulated and does not produce spores. Treponema pallidum yes elically coiled, corkscrew-shaped H (spirochete) Borrelia burgdorferi yes pirochetes (spiral or wave like) with s flagella Vibrio cholera yes urved rod (comma-shaped) aerobic. C It’s antigenic structure consist of flagellar H antigen and a somatic O antigen. Heicobacter pylori yes Aerophilic Helical-shape with flagella Name Fungus Protozoan Helminth Virus DNA/RNA ingle/double s naked/encapsulated? stranded? Coccidioides immitis yes Entamoeba histolytica yes Giardia intestinalis yes Necator americanus yes Trichinella spiralis yes Herpes simplex 2 DNA ds Encapsulated Epstein-Barr DNA ds Encapsulated Hepatitis B DNA Ss and ds Encapsulated Morbillivirus RNA ss Encapsulated HIV RNA ss Encapsulated
