Ch 20 STUDYGUIDE

Gram Neg bacilli

explain the morphology of Pseudomonas aeruginosa

• small gram negative cells with single polar flagellum

• aerobic & does not ferment lactose

• it is an OPPURTUNISTIC pathogen

what is the habitat of Pseudomonas aeruginosa

soil, water, intestinal resident of 10% of heaalthy people

what is disease/infection is Bordetella Pertussis responsible for

whooping cough (pertussis)

what is the habitat of Bordetella Pertussis

humans and reserviors

what are the 2 stages of Bordetella Pertussis

1. catarrhal stage: mucous builds

2. parroxsymal stage: persistent coughing “whooping” due to mucous

what is HKO

three major antigens (surface structures) found in certain Gram-negative bacteria, especially Enterobacteriaceae like Escherichia coli and Salmonella. These antigens are important for bacterial classification, immune evasion, and virulence

what is H

flagellar antigen; enables colonization of host tissues

what is K

capsule/ fimbral antigen; aids in biofilms and enhances survival in the blood stream

what is O

somatic/ cell wall antigen; provides resistance to host defenses & contributes to septic shock through its liposaccharide

do all species carry HKO

not all species carry HK but all gram negative carry O

what E. coli oathogenic strain is E.coli O157:H7 a part of

Enterohemorrhagic Escherichia coli (EHEC)

what diseases does E.coli O157:H7 cause

• Acute diarrhea

• Hemorrhagic colitis: Severe bloody diarrhea, abdominal cramps

• Hemolytic uremic syndrome (HUS): Serious complication, especially in children—leads to kidney failure, hemolytic anemia, and low platelets

enterohemorragic E. oli causes (EHEC) what

hemorrhagic colitis (shiga toxin)

what are the 2 extoxins in enterotoxigenic E. coli that cause dirrrareal illness

Heat Labile (HL) and Heat Stable (SL)

what is the function of HL and SL

it stimulates water secretion

what are the infections/diseases that E.coli causes

acute diarrhea and UTI

all strains of E.coli possess a what

LPS endotoxin and a capsule

what are the virluence factors of E.coli

Fimbriae/pili – for adhesion

toxins: shiga toxin(EHEC), LT/ST

O, H, and K antigens – used in serotyping

when are antibiotics used for E.coli

used for UTI’s caused by E.coli but NEVER for EHEC

what are the 2 species of Salmonella

S.bongori & S.enterica

what does S.enterica cause

S.enterica serotype Typhi (typhoid fever → diarrhea → septicemia→ peritnous)

S. enterica serotype Paratyphi (paratyphoid fever)

how is S.bongori contracted

through contact with cold blooded animals

what is the differenence between Sylvatic and Urban plague

Sylvatic is “wild” and poses a low human risk

Ubran is found on city rats and poses a high human risk, cause of the black death

which bacteria has a ‘saftey pin’ like appeareance

Yersinia pestis