Bacterial Infection Microbiology Notes PDF

HAZARDOUS WASTE handwashing. Handwashing is the corner stone These are substances, which singly or in of modern infection control program. combination, have a significant threat or hazard 4 COMM...

HAZARDOUS WASTE handwashing. Handwashing is the corner stone These are substances, which singly or in of modern infection control program. combination, have a significant threat or hazard 4 COMMON TYPES OF NOSOCOMIAL to human or to the environment and require INFECTION special handling, processing or disposal. Urinary tract infection Flammable, explosive, reactive, corrosive, Lung infection (Pneumonia) infectious, carcinogenic, bioconcentrative Surgical site infection persistent in nature, lethal, irritant, oxidizer, or Blood stream infection strong sensitizer. ❖ There are also predisposing factor for nosocomial DISPOSAL OF HAZARDOUS WASTE infections. All materials contaminated with potentially o First is there are varieties of infectious agents must be decontaminated before microorganisms that circulates in the disposal using an autoclave, incinerator or hospital environment. So, to be always alternative waste treatment methods. protected, you must wear masks. Pipettes, swab and other glass objects should be o Second factor is the patients are weak or placed inside a firm cardboard container before immunocompromised. Their immune disposal. system is somehow defective. Sharp objects (needles and scalpels) place in o Third factor is the chain transmission. It containers that are autoclaved and incinerated. can either be direct or indirect. LESSON 4: PATHOGENESIS o Fourth is fomites or the inanimate objects like catheter, needle, dressing, bed, or ❖ Pathogenesis is the development of infection and wheelchair. disease. There are certain virulence agents with o Fifth factor is the disease can be airborne mechanism of resistance against the host such as tuberculosis. It can also be protective factors are involved in the proliferation pertussis. of microorganisms and the progress of disease. o Lastly, vector borne transmission. INFECTION Anopheles can carry/give malaria. Aedes ❖ Infection involves growth and multiplication of can carry dengue. Cockroaches when microorganisms that causes damage to our host they perch on food and cause diarrhea. cell. TYPES OF INFECTION ACCORDING TO HOST ❖ This is also known as bodily invasion of DISTRIBUTION pathogenic microorganism to reproduce, multiply, and cause disease through local cellular injury, LOCAL INFECTION secrete toxins through antigen antibody reaction Confined in one area of our body. The signs and symptoms are confined in one TYPES OF INFECTION area. (localized) AUTOGENOUS INFECTION Ex. boils and abscesses, pimples, pigsa, pus. Infection from the host FOCAL INFECTION It is caused by microorganisms from the From local spreads to other part microbiota of the host. Starts from local infection then spread to other Auto = self parts of the body. IATROGENIC INFECTION Ex. Tonsillitis, tooth, wound infection by Clostridium tetani, etc. From medical treatment or procedure SYSTEMIC INFECTION It is a type of infection that occurs as the result of some medical treatment or procedure. Infection spreads through blood and lymph OPPORTUNISTIC INFECTION The microbes spread throughout the body through blood and lymph. Affects immunocompromised hosts but not the individual with a normal immune system. 4 TYPES OF SYSTEMIC INFECTION This happens when the immune system of the BACTEREMIA host is compromised or the host has a weak Presence of bacteria in the blood immune system. Bacteria = bacteria, emia = blood Ex: chemotherapeutic drugs, overusing This organism invades the blood stream without antibiotics, immune suppressive drugs, active multiplication. The highest concentration of undergoing chemo bacteria in the blood occurs before the fever NOSOCOMIAL INFECTION spikes. Hospital-acquired infection SEPTICEMIA It is a type of infection that is acquired at a health Active multiplication in the blood (sepsis) care facility. This can be avoided with proper PYEMIA Pus producing organisms invade blood TUAZON A. 21  Py = pus, emia = blood symptoms which are attributable to hereditary, This pus producing bacteria will localized in the infection, diet or environment. different parts of the body. ❖ Disease is a result when the infection produces TOXEMIA notable changes in human physiology specifically those that can cause damage to our body’s organ Presence of toxin in the blood. system. Bacteria are able to localized in one area but will produce a toxin that spreads and tit will be CLASSIFICATION OF INFECTIOUS DISEASE absorbed by the cells COMMUNICABLE OR CONTAGIOUS DISEASE EXTENT OF INFECTION Spread from one host to another (directly or PRIMARY INFECTION indirectly) Ex. tuberculosis, herpes, flu and chickenpox Initial infection that causes the illness. Ex: common colds, runny nose. NON-COMMUNICABLE DISEASE SECONDARY INFECTION Does not spread from one host to another It is usually caused by external microbes or Caused by opportunistic pathogen after the opportunistic pathogen living inside the body. primary infection has weakened the host’s immune system. Ex. tetanus and botulism Ex: pneumonia, bronchitis (developed from CLASSIFICATION OF DISEASE ACCORDING TO common colds) OCCURRENCE LATENT INFECTION (SILENT PHASE) SPORADIC DISEASE Clinically silent inside the body and cause no Infection occurs occasionally noticeable illness in the host. Then a severe and ENDEMIC DISEASE endemic - acute infection will manifest. Constantly present in a particular location and Ex: asymptomatic type of infection population. ↳ constantly present MIXED INFECTION EPIDEMIC DISEASE Two or more infection or organism. Ex: wound infection Affects large number of people in a short span of time demiort span of time ACUTE INFECTION PANDEMIC DISEASE Infection develops and progress slowly Affects population across large region around the Ex: cough world. CHRONIC INFECTION EFFECTS OF INFECTIOUS DISEASE Infection develops slowly(milder) but long lasting. Ex: tuberculosis SIGNS Objective changes that can be measured -> objective ROUTE OF INFECTION Ex. Fever, redness, swelling and paralysis DIRECT TRANSMISSION SYMPTOMS - symptoms I Congenital Subjective indications/complaints of the disease o From mother to fetus or baby. in a person Subjective o S. agalactiae (UTI), N. gonorrhoeae Ex. Pain and malaise (eyes, Ophthalmia Nneonatorum) and SYNDROME syphilis. Group of signs and symptoms that are associated Sexual contact - C. trachomatis, N. gonorrhoeae with the disease. and syphilis Ex. Acquired immune deficiency syndrome Infectious respiratory droplets - N. meningitidis (AIDS) (cough, sneezing) S. pyogenes PHASES OF INFECTIOUS DISEASE Hand to hand transmission – Rhinovirus INCUBATION PERIOD (causes common colds) Time between the exposure to pathogen and INDIRECT TRANSMISSION onset of symptoms Fomites interval o Inanimate objects. pro o... /bro... PRODROMAL PERIOD - Water here goes the signs and symptoms o Salmonella, Shigella and Vibrio (diarrhea Appearance of signs and symptoms or cholera) CLINICAL OR ILLNESS PERIOD Arthropod vectors Peak of characteristic sign and symptoms of an o Borrelia (tick), Francisella and Yersinia infection (rodents, mouse) DECLINE PERIOD DISEASE Period in which the signs and symptoms begin to ❖ Disease is a specific illness or disorder that is subside characterized by a recognizable set of signs and CONVALESCENCE OR PERIOD OF RECOVERY TUAZON A. 22  Period in which the surviving host is recuperating ENZYMATIC FACTORS towards full recovery. Produced by the bacteria that aid in the spread of ❖ Predisposing factor on having an illness or infection. disease. Ex. Hyaluronidase, coagulase, leukocidin, o Gender, genetic factors, nutritional, collagenase, streptokinase, hemolysin and stress or fatigue, environment, lifestyle, resitenase work place. CELLULAR STRUCTURE GENERAL CLASSES OF PATHOGENIC Capsule resist phagocytosis (engulfment of MICROORGANISMS microorganisms) TRUE PATHOGENS Encapsulated bacteria Organisms are able to invade the tissue of HOST RESISTANCE FACTORS healthy individual through some inherent ability PHYSICAL BARRIER causing various diseases. Normally found outside the host Skin serves as the physical and chemical barrier to microorganisms OPPORTUNISTIC PATHOGENS First line of defense. Normally do not cause disease in their natural Ex. Stricture of urethral opening, the flushing habitat to a healthy person. action of urination and thick mucus plug in the Cause disease if the host is cervical opening immunocompromised or if they enter a different CLEANSING MECHANISM part of the body. Ex. Neisseria meningitidis (usually harmless) and Nasal hair, cough-sneeze reflex and cell lining of trachea (contains cilia) Escherichia coli (urinary tract, colon, intestine infection) ANTIMICROBIAL SUBSTANCE HOST MICROBE RELATIONSHIP Lysozymes - destroy bacterial cell wall SYMBIOSIS Bile salts - disrupt bacterial membranes Association of two organisms living in close INDIGENOUS/NORMAL MICROBIAL FLORA OR proximity. MICROBIOTA MUTUALISM Microorganisms commonly found on or in the Symbiotic relationship in which both organisms body sites of healthy person. They serve as benefit from each another normal flora. Also known as microbiota. COMMENSALISM Ex: producing vitamin K through E. coli, Bacteroides, Lactobacillus acidophilus, vagina One organism benefit while there is no beneficial pH. or harmful effect to the other. One way relationship. TWO TYPES OF MICROBIOTA PARASITISM Resident microbiota One organism (parasite) benefits at the expense o temporarily inhabit, multiply in and of its host. colonize an area for months or years. VIRULENCE Transient microbiota o inhabit (do not multiply) and colonize an Ability of microorganisms to cause disease area until they are eliminated. It is the degree of pathogenicity Organisms that can establish infection with a DIFFERENT BODY SITES AND THIER relatively low infection dose. More virulent than RESPECTIVE MICROBIOTA those that requires high dose for infection. Skin Every pathogenic microorganism or rapidly o staphylococci, Propionibacterium and progressive condition is considered when there is Corynebacterium a high virulence factor. Mouth and oral cavity FACTORS INFLUENCING MICROBIAL o Viridans streptococci VIRULENCE Upper respiratory tract Toxic factors o Viridans streptococci, diphtheroids and Enzymatic factors epidermidis Cellular structure Nasopharynx TOXIC FACTORS o S.aureus, S.epidermidis and Toxins are substance produced by pathogenic N.meningitidis microorganisms causing tissue and cellular Colon damage o E. coli, bacteroides and lactobacilli Ex. Diphtheria toxin, tetanospasmin, botulism Urethra toxin, canned goods, enterotoxin, streptococcal o diphtheroids, S.epidermidis, alpha and erythrogenic toxin that causes scarlet fever. non hemolytic streptococci. TUAZON A. 23 PHAGOCYTOSIS In order to establish and cause disease a Process by which certain cells called phagocytes pathogen must multiply, following its attachment engulf and dispose of microorganisms and cell to host cells. debris. Inhibitors: antibody, lactoferrin and lysozymes Endocytosis - engulf microorganisms and digest that inhibits prefoliation. Cell eating bacteria such as neutrophils, Evasion of phagocytosis is essential for most eosinophils, basophil, macrophages EXCEPT pathogen to survive and reproduce. Bacillus klebsiella pneumoniae, S. pneumonia TISSUE DAMAGE that has a capsule. Results of either through preformed toxins or Phago = eat, cyto = cell disruption of the normal functioning of the INFLAMMATION intestinal cells Serves as a reinforcement mechanism against A disease is usually noticeable when it has a microbial survival and proliferation in tissue and tissue damage. organs. Ex: botulinum toxin, B. cereus, S. aureus that Signs: swelling, redness, burning sensation, pain produces toxin which can disrupt the normal in the affected areas. functioning of intestinal cell. Rubor, tumour, calor, dolor, function laesa PRODUCTION OF TOXINS During inflammation, phagocytes, neutrophils, Exotoxin macrophages, complement system, classical, Endotoxin alternative, lectin pathway, coagulation system, primary and secondary hemostasis, cytokines TWO CLASSIFICATIONS OF TOXINS that attracts different cells to help fight the Exotoxins infection. o One of the most lethal substances IMMUNO RESPONSE o Gram Positive bacteria o Do not require bacterial death to be Provides the human host with the ability to create release into circulation a specific protective response against o Example: cytotoxins, neurotoxins and microorganisms. enterotoxins It has the ability to memorize and recognize the o Bacteria: Clostridium botulinum, structure of microorganisms. Corynebacterium diphtheriae, This becomes defective if a person is Staphylococcus aureus and immunocompromised, during radiation and Streptococcus pyogenes chemotherapy. Endotoxins TWO TYPES OF IMMUNITY o Composed of the lipopolysaccharide Natural/Innate Immunity o Present only in Gram Negative bacteria o This includes the physical barriers e.g., o Release when bacteria die and their cell skin, cough reflex, flushing action of wall undergo lysis which consequently urine, pH of vagina, acidic pH of the liberates the endotoxin. stomach. o Toxicity is due to the LIPID A portion of LPS Adaptive/Acquired Immunity o LPS may elicit fever, chills, hypotension, o Antibodies, complement, memory B and granulocytosis, thrombocytopenia, and T cell. disseminated intravascular coagulation. TWO TYPES OF ADAPTIVE/ACQUIRED o NOTE: Endotoxic shock result of the IMMUNITY Gram-negative septicemia Humoral (Antibody-Mediated) Immunity INVASION o action of soluble proteins called Process of penetrating and growing in tissue antibodies occur on body fluid and In some organism the invasion only involves a surface of B-lymphocyte few layers of the cell while others have deep Cellular (Cell-Mediated) Immunity tissue penetration. o Action of specific kind of T-lymphocyte DISSEMINATION that directly attack the cells Spread of microorganisms to distant body sites. INFECTIOUS AGENT FACTORS Certain organisms that survive in phagocytosis ADHERENCE are disseminated rapidly to many body sites. Organisms must penetrate the mucus layer and ROUTE OF TRANSMISSION attach to the epithelium Airborne transmission Main adhesins in bacteria: common pili and Transmission by food and water surface polysaccharide. Close contact PROLIFERATION Cuts and bites TUAZON A. 24  Arthropods (tick, lice) APPLICATION OF HEAT Zoonoses (anthropology vectors that can cause Moist Heat plaque, secretion of animals that causes Dry heat brucellosis) EPIDEMIOLOGY MOIST HEAT Study of occurrence, distribution and causes of Destroys microorganisms through coagulation of disease and injury. enzymes and structural proteins and degradation of Nucleic acids. FACTORS CONTRIBUTING TO EPIDEMIOLOGY CARRIER BOILING Destroys vegetative bacteria (non-sporulating). Person or animal that harbor and spread organisms but does not become ill himself. Water bath TEMP: 100C. LIKLIHOOD OF BECOMING ENDEMIC TIME EXPOSURE: 10 to 15 minutes Organisms is constantly present in a population FOUR TYPES OF CARRIERS: Casual/Acute/Transient Carrier o harbors microorganisms temporarily for a few days or weeks Chronic Carrier o remain infected for a relatively long time, sometimes its entire life. Convalescent Carrier o individual recovered from infection but continues to harbor large number of AUTOCLAVING pathogens Active Carrier Fastest and simplest, all organisms (except for o individual who has an overt clinical case prions) including those that contains spores of a disease. Only the laboratory technician can use this. LIKELIHOOD OF BECOMING EPIDEMIC Before opening, make sure that the pressure or PSI is completely 0. epidemic if affects significant large number of PRINCIPLE: Steam under pressure. people in a short period of time. Ex. Influenza BIOLOGICAL INDICATOR: LIKELIHOOD OF BECOMING PANDEMIC o Bacillus stearothermophilus affects huge population across large regions like o New Name: Geobacillus countries and continent. Ex. COVID 19 stearothermophilus. INCIDENCE RATE o 121C, 15 psi for 15 mins (media, liquids, Number of times a new event occurs in a given pipettes, utensils, etc. period of time o 132C, 15 psi for 30-60 mins INCUBATION PERIOD decontaminating medical wastes o If the masking tape turns black, the time between exposure and onset of symptoms Geobacillus/Bacillus stearothermophilus MORBIDITY RATE is exposed to extreme convention. number of cases of a disease in a specified o Black stripes = sterilized population during defined time interval Measures th infectiousness of an organisms MORTALITY RATE number of death due to a disease in a population RESERVOIR source of an infection LESSON 4.1: STERILIZATION AND DISINFECTION TYNDALLIZATION STERILIZATION Destroys vegetative cells and Refers to the removal or destruction of all forms spores after 3 consecutive of life, including bacteria spores. days of sterilization PHYSICAL METHOD Fractional or Intermittent 1. Application of Heat Sterilization. 2. Filtration TEMP: 100C 3. Low/Cold Temperature TIME: 30 minutes for 3 consecutive days 4. Desiccation and Lyophilization Arnold’s sterilizer (free-flowing steam) 5. Osmotic Pressure INSPISSATION 6. Radiation TUAZON A. 25