Pathogenic Organisms

What is the mode of transport of Staph. aureus?

Direct contact, respiratory methods, cuts, contaminated foods, fomites

Define Fomites

Surface transport

What illness can Staph aureus cause?

Food poisoning, pimples, impetigo, carditis, meningitis, osteomyelitis, blood infections, MRSA, and toxic shock syndrome

What are virulence factors of Staph. aureus?

Exotoxins (hemolysins) and coagulase

Where do infections by Strep. pyogenes occur?

Upper respiratory tract

What diseases does Strep. pyogenes cause?

Strep throat, Scarlet fever, Rheumatic fever, and Impetigo

What virulence factor causes Scarlet Fever?

phage-encoded erythrotoxin

What kind of virulence factor causes Strep throat?

B-hemolysin

What proteins does Strep. Pyogenes have?

Surface A, B, and Surface M proteins

What is indicative of impetigo?

Red, crusty skin rash

What is Rheumatic fever?

Autoimmune disease that causes immune system to attack heart tissue

What methods can be used to identify Strep. pyogenes?

ELISA test and fluorescent test, positive throat culture

Where does Strep. pneumoniae infections occur?

Lower respiratory system

What virulence factor does Strep. pneumoniae have?

Capsule

What can be used to identify Strep pneumoniae?

Gram Stain (Gram + diplococci culture)

What disease does Corynebacterium diphtheria cause?

Diptheria

What are symptoms of Diptheria?

Kidney and Heart damage and pseudomembrane formation

What factor is responsible for Diphtheria?

A phage that inhibits protein synthesis (Diptheria toxin)

What disease does Bordetella pertussis cause?

Whooping cough

What does Bordetella pertussis look like?

Gram - aerobic coccobacillus

Are adults or infants more affected by bordetella pertussis?

Infants

What are the virulence factors of Bordetella pertussis?

Beta-hemolysin and filamentous hemagglutinin

What is diagnostic of the first stage of Bordetella pertussis infection?

Upper respiratory infection, severe cough with increasing intensity

What is diagnostic of second stage of Bordetella pertussis infection?

THE Whooping cough

How can Bordetella pertussis be identified?

Fluorescent antibody test; chocolate or blood agar

What methods can be used to determine person-to-person diseases?

ELISA test, antibody tests (when specific disease is suspected), PCR analysis, Western blotting

What is the most common disease worldwide?

Tuberculosis

What organism causes tuberculosis?

Mycobacterium tuberculosis

What are the stages of TB?

Primary and postprimary

Why can Mycobacterium tuberculosis be hard to ID?

It is impermeable to most things

How can TB be identified?

Acid fast test from sputum, Tuberculin test, Chest X-Rays in postprimary TB

What is the cause for Leprosy?

Mycobacterium leprae

What are symptoms of leprosy?

Loss of sensation in extremities, deformities, swelling of nerves

Where can Mycobacterium leprae be located?

Inside nerves and in macrophages

Where is Leprosy most common?

Africa, Asia, Brazil, Hawaii, LA

What organism causes ulcers?

Helicobacter pylori

What virulence factor does Helicobacter pylori have?

urease

How can Neisseria meningitis be identifies?

Capsular polysacharride, modified Thyer-Martin Media

What are examples of person-to-person diseases?

Staph. aureus, Strep pyogenes and pneumoniae, Corynebacterium diptheria, Bordetella pertussis, Mycobacterium tuberculosis, Mycobacterium leprae, helicobacter pylori, and Neisseria meningitis

What are some person-to-person viral infections?

Measles (Rubeola and Rubella), Mumps, colds, SARS, MRS, COVID, Chickenpox/Shingles, Influenza

What type of virus causes Rubeola (Measles)?

Paramyxovirus (ssRNA)

What are symptoms of Measles?

rash, fever, hearing loss, rarely encaphalomyelitis

What type of virus is responsible for German Measles (Rubeola)?

ss+RNA virus

What is the major difference between German Measles and Measles?

German Measles is more infectious

What type of virus is responsible for Mumps?

paramyxovirus

What are some symptoms of Mumps?

Salivary gland inflammation, rarely encephalitis

How do most coronaviruses function?

Initial suppression of immune responses followed overstimulation of immune system

How do corona suppress the immune system?

Blocking cell expression of MHC I and pulling on binding sites

What are symptoms of coronaviruses?

pneumonia, sepsis, cytokine storm

How is Hepatitis A contracted?

fecal contaminated food and shellfish

How is Hepatitis B transported?

Infected blood

What are general symptoms of Hepatitis

Liver cancer, cirrhosis, or jaundice

How can Hepatitis be identified?

PCR, Enzyme linked immunoassays,

What are the general typed of venereal diseases?

Bacteria, protozoa, viruses, fungi, and arthropods

What organism causes syphilis?

Treponema pallidium ( not cultured)

What are symptoms of syphilis?

Rash and chancre lesions

What is the morphology of Treponema pallidium?

spirochete

How can Syphilis be identified

Gram stain in early lesions, darkfield microscopy, and Hemagglutinin analysis

What organism causes Gonorrhea?

Neisserium gonorrhoeae

What is the morphology of Neisserium gonorrhoeae

Gram - diplococci

What are the symptoms of gonorrhea?

Pain in urination, chronic inflammation, and meningitis, carditis, and blindness once it spreads through the body

What are the virulence factors of gonorrhea?

pili and antibiotic resistance

How can gonorrhea be identified?

Direct staining, chocolate agar, candle and anaerobic jar

What is the most common STD

chlamydia

What causes chlamydia?

Intracellular parasite

What diseases can chlamydia cause?

trachoma, conjuctivitis, and arthritis

How can chlamydia be identidied?

Immunofluorescence and Geiemsa’s stain

What are the kinds of Herpes?

Type I (saliva) and Type II (sexual contact)

What causes Herpes?

dsDNA virus

What is the danger of HPV?

Can cause cervical cancer

What kind of virus is HIV?

ssRNA retrovirus

What sites does HIV bind to?

CD4 and CCR5 receptors

What causes trichomoniasis?

Flagellated protozoa

What is indicative of trichomoniasis in females

green, frothy discharge

How is Hantavirus spread?

Deer mouse urine

What is Rickettsial disease?

Obligate intracellular parasites

What three large fevers do rickettsial diseases cause?

Typhus fever, Rocky Mountain Spotted Fever, Q fever

How can Rickettsial diseases be identified?

Immunofluorescence, agglutination, and ELISA testing

How can Lyme Disease be identified?

ELISA, Western Blotting, but undetectable if gone too long

What causes malaria?

Plasmodium parasite

How can malaria be identified?

Blood smears

What kind of virus causes Yellow fever, Zika, Chikungunya, and Dengue fever

Flaviviruses

What are symptoms of Yellow fever?

Organ failure, toxic shock, and bloody vomiting

What are common soilborne organisms?

Clostridium tetani, Clostridium perfringens, Bacillus anthracis,

What organism is responsible for tetanus?

Clostridium tetani

What virulence factor does tetanus have?

exotoxins

What organism causes gas gangrene?

Clostridium perfringens

What virulence factor does perfringens have

exotoxins

What is Bacillus anthracis’ virulence factor

plasmid encoded exotoxin

How long is anthrax’s spore viable?

Upwards of 3000 years

What are common waterborne diseases?

giardiasis, cholera, Pseudomonas aeruginosa, Legionellosis

What is the morphology of Legionella pneumophila?

Gram - rod