enterobacteriaceae report
TRANSCRIPT
Tribe Klebsielleae1. Klebsiella2. Enterobacter3. Serratia4. Pantoea5. Cronobacter6. Hafnia
Habitat:
1. Intestinal tract of humans2. Free-living in soil, water and on plants
Common characteristics:• Simmons citrate, potassium cyanide broth• None produce hydrogen sulfide• A few hydrolyze urea slowly• (-) methyl red test• (+) Voges Proskauer test• With few exceptions, indole is not produced from
tryptophan• Motility is variable
Klebsiella
diseases: pneumoniabacteremiathrombophlebitisUTIcholecystitisdiarrheaupper respiratory tract infectionwound infectionosteomyelitismeningitisrhinoscleromaozena
Antibiogram:Aminoglycozidesamykacine, TobramycineImipenemaztreoname
K. pneumoniae
• Most commonly isolated species• Polysaccharide capsule • Lower respiratory tract infections• Wound infections, UTIs, bacteremia• Nosocomial outbreaks: plasmid transfer of
antimicrobial resistance
K. ozaenae
• Nasal secretions and cerebral abscesses• Plasmid-mediated ESBLs
K. rhinoscleromatis• Patients with rhinoscleroma
Both were true species but reclassified based on nucleic acid studies
K. onrithinolyticaK. planticola
• Urine• Respiratory tracts• Human blood
Klebsiella oxytoca
• Identical to Klebsiella pneumoniae except:– Production of indole– Ornithine positive
Enterobacterinfections:Bacteremialower respiratory tract infectionsskin and soft tissue infectionsurinary tract infections (UTIs)endocarditisIntra-abdominal infectionsseptic arthritisosteomyelitisophthalmic infections
• 12 species (1 with 2 biotypes)– E. cloacae– E. aerogenes– E. gergoviae– E. hormaechei
• Motile• Simmons citrate medium, potassium cyanide broth• (-) methyl red test• (+) Voges-Proskauer test• Produce ornithine decarboxylase• Produce lysine decarboxylase
(except E. gergoviae & E. cloacae)
E. gergoviae & E. cloacae
• 2 most common isolates• Wounds, urine, blood, csf
Pantoea (Enterobacter) agglomerans
• Nationwide outbreak of septicemia• E. Agglomerans complex• Triple decarboxylases negative :
(-) lysine, ornithine, arginine• >13 hybridization groups:
P. Agglomerans HG XIII
E. gergoviae
• Respiratory samples• Rarely isolated from blood cultures
Cronobacter (Enterobacter) sakazaki
• Produces yellow pigment• Pathogen in neonates• Meningitis and bacteremia• Powdered infant formula• Brain abscesses, respiratory & wound infections
E. hormaechei -Blood, wounds, sputum
-biochemically similar to E.cloacae- blood, urine, feces, sputum,
wounds
- Traumatic wounds, osteomyelitis- Formerly E. taylorae
- Newly recognized
E. Asburiae
E. Dissolvents,E. nimipressuralis
E. cancerogenus
Serratia• Opportunistic pathogens• Nosocomial outbreaks• Ferment lactose slowly (except S. fonticola)• (+) ortho-nitrophenyl galactoside• Produces extracellular DNase• Resistance to a wide range of antimicrobials
Prodigiosin- pink to red pigment (esp. If incubated at room temp)
• s. marcescens– most clinically significant– Nosocomial infections of urinary/respratory tract– Bactermic outbreaks in nurseries, cardiac surgery & burn units– Septic arthritis
• s. plymuthica- osteomyelitis (motorcycle accident)
• s. rubidaea- human sources (s. liquefaciens, s. fonticola)
S. odorifera
• Dirty, musty odor (potato-like)• 2 biogroups:– Biogroup 1
respiratory tract (+) sucrose, raffinose, ornithine, (60%) indole
– Biogroup 2 blood, CSF(-) sucrose, raffinose, ornithine (50%) indole (+)
• S. ficaria• S. entomophila
Hafnia
• Human anatomic sites and environment• Stool cultures (occasionally)• Delayed (+) citrate reaction• 1 species with 2 biotypes H. alvei
H. alvei biotype 1– Beer wort of breweries– Has not been isolated clinically
Tribe Proteeae
1. Proteus2. Morganella3. Providencia
Proteus• Normal intestinal microbiota• Opportunistic pathogens• Deaminate phenylalanine• Non lactose fermenting• 3% of all nosocomial infection in US (esp UTIs)• Infects upper & lower urinary tract and proximal
tubules• Glomerulonephritis
(urinary tract defects and catheterization
P. mirabilis, P. vulgaris• Widely recognized human pathogens• Produce H2S and hydrolize urea• Urine, wounds, ear, bacteremic infections• Swarming colonies– on nonselective media– Produce “burnt chocolate” odor– Ascending nature of Proteus-associated UTIs– Tightly regulated cycle of differentiation swimmers (standard vegetative cells)
Swarmers (hyperflaggellated, elongated, polyploid cells)
indole and ornithine decarboxylase testP. mirabilis• Does not produce indole from tryptophan• (+) ornithine
P. vulgaris• produces indole from tryptophan• (-) ornithine• Acid/acid reaction in TSI agar
P. penneri
• Swarm colonies• Patients with diarrhea
• Gypsy moths• Large amount of slime
P. myxofaciens
Morganella
• Documented cause of UTI• Has been isolated from other body sites• 1 species: P. morganii
2subspieces: morganii sibonii
Providencia
• 5 species• Documented pathogen of urinary tract• Occasional nosomial outbreaks• Diarrheal disease among travelers
• Burn units• Urine cultures• P. stuartii, P. rettgeri infections:
difficult to treat
P. stuartii
P. alcalifaciens
• Feces of children with diarrhea
• Formerly strain of P. Alcalifaciens• Rarely isolated• Unproven pathogenecity
• Yet to be isolated from clinical specimens
P. rustigianii
P. heimobachae
Edwardsiella
• (-) urea• (+) lysine carboxylase, hydrogen sulfide, indole• Do not grow on Simmons citrate
E. tarda• the only recognized human pathogen• Opportunist• Causes bacteremia & wound infections
E. hoshinae• Snakes, birds, water
E. ictaluri• Fish: enteric septicemia
Plant pathogens
Erwinia• Poor growth at 37o• Fail to grow on selective media & other media
typically used for enteric isolations
Pectobacterium
Citrobacter
• 11 species• Hydrolyze urea slowly• MAC: resembles those of E. coli• Grow on Simmons citrate medium• (+) methyl red test
C. freundii
• Diarrheal stool cultures• Nosocomial diseases• UTI, pneumonia, intra-abdominal abscesses• Intravenous drug abusers: endocarditis• (80%) (+) hydrogen sulfide• (50%) (-) lactose
• C. freundii• C. koseri
(C. diversus)• C. amalonaticus• C.farmeri• C. braaki
• C. gillenii• C. murliniae• C. rodentium• C. sedlakii• C. werkmanii• C. youngae
BiochemicalTests
C. freundii Salmonella
Hydrolize urea +(70%)
-
Decarboxylate lysine
- +
C. koseri
• Nursery outbreaks of neonatal mening• Brain abscesses
C. almalonaticus• Feces• Sites of extraintestinal infections
(blood, wounds)
Sites of infection
Proteus mirabilis with peritrichous flagella
Swarming colony of Proteus mirabilis