2nd midterm

Question 1

Pyogenic

Answer 1

Involving or relating to the production of pus

Bacteria that cause pus are called pyogenic

Question 2

Lancfield grouping

Answer 2

Lancefield grouping is a method of grouping catalase-negative, coagulase-negative bacteria based on the carbohydrate composition of bacterial antigens found on their cell walls

Question 3

Major enteral medium for enteriobacteriae. Lactose test

Answer 3

Eosine-methylene blue (EM) medium:
the major enteral medium

Selective: Gram positives can not grow
Differentiating: based on lactose positivity

Lactose +: Dark purple colonies

1: E. coli
2: Klebsiella

Lactose –:Pink colonies

1: Proteus
2: Salmonella

Question 4

Urinary tract infections: Which bacteria?

Answer 4

E. coli (80%), Proteus, Klebsiella

Saphrophyticus in sexualy active females

Question 5

ESBL

Answer 5

“Extended spectrum beta-lactamases”

Often on plasmids (easy transfer to each other!), or chromosomal

„simple” ESBLs:
TEM, SHV, …
Resistance to penicillins and cephalosporins
Klebsiella, E. coli

MBLs:
Metallo-beta lactamases
Resistance to all β-lactams, including carbapenems !
Klebsiella, Pseudomonas, Acinetobacter

Question 6

Obligate enteral pathogens

Answer 6

Enterovirulent E. coli !!
Salmonella
Shigella
Yersinia

Question 7

Types of E.coli

Answer 7

EPEC - enteropathogenic E. coli
ETEC - enterotoxigenic E. coli
EHEC - enterohaemorrhagic E. coli
EIEC - enteroinvasive E. coli
EAEC - enteroaggregative E. coli

Question 8

Enteroinvasive E. coli - EIEC

Answer 8

Full invasion plasmid from Shigella
Classic dysentery !
Mucoid, bloody diarrhoea + fever
Acts in large intestine
Transmission:
     contact spread
     less easy than Shigella