(P) Lec 3.1: Bacterial Pathogenesis and Epidemiology, Antimicrobials and Mechanism of Bacterial Resistance, and Indigenous Microbial Flora Flashcards by Kchianna Lauren Coronel

T or F: There are more microorganisms than humans.

True the fire

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T or F: Microorganism-human encounters are inevitable.

True the fire ulit

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The mechanism of exposure depends on _____

Person’s activity/behavior

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Harmless microorganisms that inhabit the human body in large numbers

Pathogen

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Competes with potential pathogens for resources and attachment sites

Pathogen

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This aids in the digestion and nutrient absorption

Vitamin K

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What are the sterile body parts?

Blood
Lungs
Brain
Serous Fluids (pericardial, peritoneal, and pleural)

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What does sterile mean?

No microorganisms should be present.

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What happens if there are microorganisms present in supposedly sterile body parts?

Sepsis

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They are commonly found on or in body sites of healthy persons and are homegrown/native.

Indigenous Microbial Flora

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They colonize an area for months or years and are life-long members of the community.

Resident Microbial Flora

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They are present at a site temporarily (passing by daw sabi ni Sir Mabaggu) and are eliminated by host’s inherent immune defenses or by competition with resident biota.

Transient Microbial Flora

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What are the factors that determine the composition of the usual microbial flora?

Nutritional and Environmental Factors
Resistance to bile, lysozyme, or fatty acids
pH
Low Oxidation-Reduction Potential

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Factors that determine the composition of the usual microbial flora

More organisms inhabit moist areas than dry areas. (eg. diphtheroids & non-pathogenic corynebacterium)

Nutritional and Environmental Factors

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Factors that determine the composition of the usual microbial flora

Lipids and fatty acids are bactericidal to most bacteria.
Propionibacterium spp. (ex. P. acne – causative agent of pimples)

They are able to breakdown the skin lipids to fatty acids.

Resistance to bile, lysozyme, or fatty acids

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Factors that determine the composition of the usual microbial flora

Female genital tract microbiota depends on the pH of that environment (4.0-5.0)
Many bacteria do not survive at this extreme pH range (pero sabi ni Sir Mabaggu kaya daw ng Lactobacillus so maniwala na lang kayo hehe)

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Factors that determine the composition of the usual microbial flora

What is the usual pH of the female genital tract microbiota?

4.0 to 5.0

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Factors that determine the composition of the usual microbial flora

This environment supports only organisms capable of fermentation. (eg. gingival crevices - bacteroides and fusobacterium, obligate anaerobes)

Low Oxidation-Reduction Potential

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Composition of Microbial Biota

Has numerous mechanisms to prevent infection and protect underlying tissue.

Skin

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Composition of Microbial Biota

This includes:
* physical separation
* presence of fatty acids
* excretion of lysozyme (sweat glands)
* desquamation (skin)

Skin

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Composition of Microbial Biota (Skin)

Armpit, groin, axillae, and between toes

Aerobic Diphtheroids – Corynebacterium spp

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Composition of Microbial Biota (Skin)

Hair Follicles, sweat and sebaceous gland

Staphylococcus epidermidis and Propionibacterium spp.

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Composition of Microbial Biota

The oral cavity — contains a large number of bacteria, with Streptococcus being the predominant genus

Upper Respiratory Tract

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Composition of Microbial Biota (URT)

Mouth

Gram (-) anaerobes

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# Composition of Microbial Biota (URT) Nose

Diplococci and diphtheroids

# Composition of Microbial Biota (URT) Oropharynx

Mixture of streptococci *(mitis, mutans, milleri, sanguinis, salivarius, pneumoniae)*

# Composition of Microbial Biota * Comprises the esophagus, stomach, small intestine, and colon * Less microbial population in esophagus (mostly transient)

Gastrointestinal Tract

# Composition of Microbial Biota (GI Tract) Stomach

*Streptococcus Enterococcus Prevotella Opportunistic Helicobacter pylori*

# Composition of Microbial Biota (GI Tract) Colon ## Footnote (contains 70% of all the microbes in the body; these microbes (on the right) outnumber g(-) bacteria in the large intestine)

Obligate anaerobes *(Bacteroides, Clostridium, Prevotella, Porphyromonas)*

# Composition of Microbial Biota Kidney, bladder, cervix, and fallopian tube are?

Normally Sterile

# Composition of Microbial Biota (Genitourinary Tract) Vaginal biota (before puberty)

Yeasts Gram (-) bacilli Gram (+) cocci

# Composition of Microbial Biota (Genitourinary Tract) Vaginal biota (childbearing years)

Lactobacilli Anaerobic gram (-) bacilli Gram (+) cocci

# Composition of Microbial Biota Vagina epithelial cells maintain a ____ pH, which encourages the colonization of listed bacteria.

Low

Some organisms that make up the microbial biota live off the _____

Host's nutrients

in most cases, they provide some benefit to the host, creating a ____ relationship.

Symbiotic

Activation of Immune System

* Secretion of metabolic products * Prevention of pathogen adhesion

Recognized to cause disease in healthy immunocompetent individuals a high percentage of the time | *Yersinia pestis* and *Bacillus anthracis*

True Pathogens

Causes disease when their habitat is altered or when the host's immune system is compromised

Opportunists

Can be found in traumatized areas (accidental/surgical) and may reach sterile or other parts where these organisms are not part of the microbial biota

Opportunists

# Name the organisms *(sorry, I'm not a sadist)* Foreign bodies (catheters, shunts, prosthetic heart valves)

* Staphylococcus epidermidis * Propionibacterium acnes * Viridans streptococci * Serratia marcescens * Pseudomonas aeruginosa * Aspergillus spp * Candida albicans

# Name the organisms *(sorry, I'm not a sadist)* Alcoholism

* Streptococcus pneumoniae * Klebsiella pneumoniae

# Name the organisms *(sorry, I'm not a sadist)* Burns

* Pseudomonas aeruginosa * Acinetobacter baumannii-calcoaceticus complex (drug-resistant) * Staphylococcus aureus

# Name the organisms *(sorry, I'm not a sadist)* Hematoproliferative disorders

* Cryptococcus neoformans * Varicella-zoster virus

# Name the organisms *(sorry, I'm not a sadist)* Cystic Fibrosis

* Pseudomonas aeruginosa * Burkholderia cepacia

# Name the organisms *(sorry, I'm not a sadist)* Immunosuppresion (drugs, congenital disease)

* Candida albicans * Pneumocystis jirovecii * Herpes simplex virus * Aspergillus spp. * Diphtheroids (Corynebacterium spp.) * Cytomegalovirus * Staphylococcus spp. * Pseudomonas spp.

What do you call an infection that occurs as the result of treatment?

Iatrogenic Infection

Relative ability of a microorganism to cause disease or the degree of pathogenicity

Virulence

Ability to resist phagocytes (macrophages, neutrophils, badings)

Virulence

Ability to survive intracellularly and proliferate

Virulence

# Give the Virulence Factor E.Coli

**O antigen** (smooth strains) — somatic **K antigen** (acid polysacc) — capsular

# Give the Virulence Factor Neisseria gonorrhoeae (G(-) diplococci)

Fimbriae | *attaches to mucous membrane of GI tract*

# Give the Virulence Factor Pseudomonas aeruginosa

Polysaccharide slime (surface slime)

# Give the Virulence Factor Salmonella typhi

Vi antigen (enteric fever – foodborne)

# Give the Virulence Factor Bacillus anthracis

Toxic complex Capsular poly-D-glutamic acid

Check niyo yung transes for the table for microorganism, types of interference and mechanism.

Give yourself a break, ang hirap ng cards na 'to

Disease from infection is noticeable only if tissue damage occurs

Ability to produce extracellular toxins and enzymes

May be from toxins, either exotoxins or endotoxins, or from inflammatory substances that cause host-diven, immunologically mediated damage.

Ability to produce extracellular toxins and enzymes

* Poisonous substances produced by organisms that interact with host cells * Disrupts normal metabolism and causing harm

Toxins

Check niyo ulit yung table for the differences of exotoxins and endotoxins and the table for examples of exotoxins of pathogenic bacteria

Good luck, babes!

T or F: For diseases caused by **endotoxins**, adherence to host cells are not important.

F | Exotoxins, not endotoxins

What are the host resistance factors?

* Physical Barrier * Cleansing Mechanisms * Antimicrobial Substances * Indigenous Microbial Flora * Phagocytosis

# Host Reistance Factors Intact Skin and Microbial Flora and Sebaceous Glands

Physical Barrier

# Host Reistance Factors Stratified and cornified epithelium presents a physical barrier to penetration by most microorganisms

Intact Skin

# Host Reistance Factors Long-chain fatty acids secreted = low pH

Microbial Flora & Sebaceous glands

# Host Reistance Factors * Desquamation of the skin surface. * Tears bathing the cornea and sclera = lubrication + wash foreign matter and infectious agents *(also contain IgA and lysozyme)*

Cleansing Mechanism

# Host Reistance Factors (Antimicrobial Substances) A substance that plays a major role in resistance to infection

Lysozyme

# Host Resistance Factors (Antimicrobial Substances) Hydrolyzes the peptidoglycan layer of bacterial cell walls

Lysozyme

# Host Resistance Factors (Antimicrobial Substances) * Found in mucous secretions of the respiratory, genital, and digestive tracts * Serves as opsonins * Enhances phagocytosis * Fix complement and neutralize infecting organisms

Antibodies *(especially secretory IgA)*

# Host Resistance Factors (Antimicrobial Substances) Inhibits the proliferation of viruses

Interferons

# Host Resistance Factors (Indigeneous Microbial Flora) Lessens the chance that the pathogen will colonize the host

Competition

# Host Resistance Factors (Indigeneous Microbial Flora) Substances that inhibit the growth of closely related bacteria

Bacteriocins

# Host Resistance Factors Primary mechanism in the host defense against extracellular bacteria and numerous viruses and fungi

Phagocytosis

# Host Resistance Factors The PMNs, macrophages, and monocytes are the body's first line of defense

Phagocytosis

# Tissue Distribution of Monocytes/Macrophages Blood

Monocyte

# Tissue Distribution of Monocytes/Macrophages Liver

Kupffer Cell

# Tissue Distribution of Monocytes/Macrophages Lung

Alveolar Macrophage

# Tissue Distribution of Monocytes/Macrophages Connective Tissue

Histiocyte

# Tissue Distribution of Monocytes/Macrophages CNS

Microglial Cell

# Tissue Distribution of Monocytes/Macrophages Kidney

Mesangial Cells

# Tissue Distribution of Monocytes/Macrophages Spleen, Lymph Nodes

Macrophage

# Host Resistance Factors Four activities must occur for phagocytosis to take place and be effective in host defense

Chemotaxis

# Host Resistance Factors (Chemotaxis) What are the four activities that must occur for phagocytosis?

* **Migration** of phagocyte to the area of infection * **Attachment** of the particle to the phagocyte * **Ingestion** * **Killing**

# Host Resistance Factors Body’s non-specific response to injury or foreign body

Inflammation

# Host Resistance Factors (Inflammation) Accumulation of phagocytic cells

Hallmark

# Host Resistance Factors Consists of numerous cells and protein molecules that are responsible for recognizing and removing foreign substances

Immune Response

# Host Resistance Factors (Immune Responses) What are the two divisions of immune responses?

1. **Innate or Natural**: little to no specificity 2. **Adaptive or Specific**: highly specialized

# Types of Immunity * Non-specific, no memory * *Ex. skin, stomach acid, PMN, and NK cells*

Natural/Innate

# Types of immunity * Specific memory, with memory * *Ex. T cells (cytokines) and B cells (antibodies)*

Adaptive/Specific

* T cell that secretes lymphokines * Defense against Viral/Fungal (Intracellular)

Cellular Immunity

* B cells (plasma cells) * Defense against bacterial infections (Extracellular)

Humoral Immunity

# Antibodies/Immunoglobulins * Activates complement (component of innate immunity) * Greatest concentration in serum * Crosses the placenta (confers protection in both prenatal and postnatal period) * Secondary (in terms of response)

IgG

# Antibodies/Immunoglobulins * Prominent in early immune response * Fixes complement * Largest antibody; pentamer

IgM

# Antibodies/Immunoglobulins * Predominance in body secretions * Primary defense against local infections at mucosal surface * (Lysozyme, β-lysin) * A dimer

IgA

# Antibodies/Immunoglobulins * Allergy * Triggers the release of histamines from mast cells (tissue based basophil)

IgE

# Antibodies/Immunoglobulins * Present on B-cell surface (receptor for antigen) * Unknown functions

IgD

# Routes of Transmission The first step in initiating an infection is for the infectious agent to?

Gain access to the host

# Routes of Transmission The agent must be able to?

Evade host defenses and colonize the tissue at the point of entry

# Routes of Transmission T or F: Most agents have a preferred route.

True the fire

# Identify the route of transmission * Influenza * M. Tuberculosis

Respiratory droplets

# Route of Transmission * Capnocytophaga * Rabies *(sabi nung book)*

Animal bite

# Routes of Transmission * Salmonella * Shigella

Stool > water/food > mouth (Fecal-oral route)

# Routes of Transmission * Leptospira interrogans * R. ricketsii

Zoonotic

# Routes of Transmission * Hepatitis B * HIV * Malaria

Needle prick Blood transfusion

# Routes of Transmission * S. aureus *(sabi ni Sir Mabaggu)* * Human papillomavirus (warts) * Syphilis

Skin to Skin

# Routes of Transmission * N. gonorrhoeae * Chlamydia trachomatis

Genital secretions

# Routes of Transmission * P. aeruginosa * P. mirabilis

Urine > hand > catheter

Identify the organism responsible for the disease: Anthrax

Bacillus anthracis

Identify the organism responsible for the disease: Brucellosis

Brucella spp

Identify the organism responsible for the disease: Erysipeloid

Erysipeloithrix rhusiopathiae (acquired thru animal carcasses)

Identify the organism responsible for the disease: Leptospirosis

Leptospira interrogans

Identify the organism responsible for the disease: Tularemia

Franciscella tularensis (acquired thru animal carcasses)

Identify the organism responsible for the disease: Lyme dse

Borrelia burgdorferi

Identify the organism responsible for the disease: Plague

Yersinia Pestis (acquired thru anthropod vectors)

Identify the organism responsible for the disease: Rat bite fever

Streptobacillus monoliforms

(P) Lec 3.1: Bacterial Pathogenesis and Epidemiology, Antimicrobials and Mechanism of Bacterial Resistance, and Indigenous Microbial Flora Flashcards

Chapter 2 of Mahon's (114 cards)