Enterobacteriacae characteristics, Virulence factors
Gram Neg bacilli, motile except some
Catalase (+), FERMENTS GLUCOSE
Enterobacterial common antigen= core ploysac antigen in nearly all.
Virulence: have some pilli for adhesion and sex
LPS endotoxins.
Coliforms are a subgroup of Enterobacteriacae, what is special about them?
Which are they?
FERMENT LACTOSE
Pink to purple on MacConkey agar.
Escherichia, Klebsiellia, enterobacter, citrobacter,
Escherichia characteristics and virulence
Gram (-) bacilli, most are motile
Glucose and Lactose fermenters
virulence: adhesion by common pilli, ST heat stable and LT heat labile
K capsular antigens, K1 antigen- neonatal meningitis
Escherichia Colli disease, dx and rx
UTI by fecal contamination
Sepsis
Neonatal meningitis
Pathogenic diarrhea
dx: culture in blood media or Mcconkey, shiga toxin assay
Rx: antibiotics
Escherichia coli antigens
enterotoxigenic, enteropathogenic, enteroinvasive, enterohemmoragic
enterotoxigenic: travlers diarrhea
Enteropathogenic: infantilie diarrhea, salmonella-like
Enteroinvasive ( shigella-like): shigella like diarrhea, bloody
Enterohemmoragic: hemmorhagic colitis, bloody stool
Klebsiella
Coliform, gram - bacilli
GLUCOSE and LACTOSE fermenters
Dx: blood smears pcr
Rx: antibiotics
Which are lactose fermenters?
Klebsiella, escherichia, coliform subgroups
K. pneumoniae
hemorrhagic pneumonia with red currant jelly. most common cause of nosocomial respiratory infections
wound and soft tissue infections
K oxytoca
colitis, sepsis, wound and soft tissue infection
K granulomatis
Donovan bodies in mos in smears
Granuloma inguinal with painless genital ulcers
ENTERobacter
Common pathogens
Rx:
Coliform, ferment lactose, gram neg bacilii
Virulence: B lactamases
Lactose fermenter
pathogens: enterobacter cloacae & e. Gerogens
Rx: antibiotics, CANNOT use B lactamases, even if sensitivity shows it’s sensitive.
Citrobacter
Pathogen:
Rx:
Cloriform, Lactose fermenter
B lactamase production, LPS endotoxin,
Pathogens: citrobacteria koeseri
Rx: antibiotics
Salmonella enterica group characteristics
Dx:
Rx:
H2S (rotten egg smell), Vi capsular antigen, Faculative intracellular parasite
Dx: culture in Hektoen enteric agar (demonstrates no lactose fermentation but + h2S fermentation
Rx: antibiotics
Salmonella enterica enterica, serovar Enteritidis
serovar Typhi
Entertidis: eating contaminated food. activate adenylate cyclase= diarrhea. Produce toxins in mucosa
serovar Typhi: Enteric (typhoid) fever, can mimic apendicitis
Shigella
Dysentaria
Non cloriform gram -
acid tolerance, invasion proteins
DX: Hectoen (negative lactose and H2S)
Rx:oral rehydration
Dysentaria: enteroinvasive dysentery, cramps and watery bloody diarrhea. Shiga toxins inhibits ribosomes
Yersinia
bipolar staining coccobacilli, Noncoliform