Enterobacteria

1. Enterobacteriaceae

2. Erwiniaceae

3. Hafniaceae

4. Morganellaceae

5. Pectobacteriaceae

6. Thorselliaceae

7. Yersiniaceae

7 Families of enterobacteriales

1. Escherichia coli

2. Salmonella

3. Yersinia

Major pathogens of enterobacteria

1. Proteus species (mirabilis, vulgaris)

2. Klebsiella species (pneumoniae)

3. Enterobacter species (aerogenes)

4. Edwardsiella tarda; Morganella morganii; Serratia marcescens

Opportunistic pathogens

1. Hafnia

2. Erwinia

Non pathogen species

1. Genus Escherichia

2. Genus Klebsiella

3. Genus Citrobacter

4. Genus Enterobacter

5. Genus Serratia

6. Salmonella Arizonae

Lactose fermenters

1. Genus Salmonella

2. Genus Shigella

3. Genus Proteus

4. Genus Edwardsiella

5. Genus Morganella

6. Genus Providencia

7. Genus Yersinia

Non Lactose Fermenters

Red colonies (alkaline reaction)

Salmonella reaction to brilliant green agar

Red colonies w/ black centers (H2s production)

Salmonella reaction to Xylose-lysine-Deoxycholate agar (XLD)

Green metallic sheen

E coli in Eosin-Methylene blue agar (EMB)

Blue green colonies (based on B glucuronidase)

E coli in Harlequin TBGA / TBX agar

1. Klebsiella spp.

2. Enterobacter spp.

Mucoid colonies

Proteus spp.

Swarming / spreading growth organism in BAP

Serratia marcescens

Colony with reg pigment production

Prodigiosin

Serratia marcescens produce ______ resulting in red colonies at room temp

Red slant/yellow butt/ black

Salmonella reaction to TSI

Slide agglutination tests with antisera

test to detect OHK antigens

+++-+

Cat, Indo, Methyl red, Voges-proskauer, Lysine decarboxylase tests result of Ecoli

pink colonies

E coli produces what color on MCA

Fish and cold blooded animals

E coli is usually absent in what organisms

O antigen

somatic antigen, part of LPS on the cell wall

H antigen

flagellar antigen, protein in nature

K antigen

capsular polysaccharide antigen

F antigen

fimbrial antigen, acts as an adhesin

Heat-labile enterotoxin (LT)

Activates adenylate cyclase

Heat-stable enterotoxin (ST)

Activates guanylate cyclase

Fimbrial antigens

present on many ETEC; for attachment to mucosal surfaces of the SI and in the lower urinary tract

pigs

Fimbrial antigens K88 (F4)

calves

Fimbrial antigens K99 (F5),F41

lambs

Fimbrial antigens K99 (F5)

•Intimin

asso.with attaching and effacing E.coli ; an adhesin for binding of EPEC to enterocytes

Edema disease toxin

thermolabile proteins causes paralysis and death in mice; inhibit protein synthesis in endothelial cells of blood vessels causing hypertension with panarteritis; antigenic; damage results to thrombosis etc

Shigalike toxin (SLT) /verotoxin

inhibits protein synthesis in intestinal epithelial cells, thus destroys gut cell microvilli (results to malabsorption syndrome); lethal to mice; cause of enteritis in human infants

Verotoxin VT2e

implicated in edema dss in pigs

Cytotoxic necrotizing factors CNF1 and CNF2

Induce pathological changes in lab.animals and tissue culture

Alpha hemolysin

increase the availability of iron for invading organisms

Siderophores

aerobactin & enterobactin; contribute to bacterial survival

Enterotoxigenic E. coli (ETEC)

Produces LT and/or ST enterotoxins, Causes watery diarrhea, Common in neonatal calves, piglets, lambs

Attaching & Effacing E. coli (AEEC)

Causes attaching and effacing (A/E) lesions

enteropathogenic E. coli

EPEC

Shiga toxin– producing E. coli

STEC

Avian pathogenic E.coli

(APEC)

Septicemic E.coli

SEPEC

Uropathogenic E.coli

UPEC

Enterotoxigenic E. coli (ETEC)

produce enterotoxins (LT & ST) which cause fluid and electrolyte loss into the intestinal lumen resulting to diarrhea

Enteropathogenic E. coli (EPEC)

penetrate and multiply within subepithelial tissues (intimin required for colonization); destruction of microvilli, atrophy & shedding of enterocytes, stunting of villi

Attaching and Effacing E. coli (AEEC)

dense adhesion on mucosal surface with colonization of SI, while producing Shigalike toxins (exotoxin) which inhibit protein synthesis and destroying microvillus layer

Enteroinvasive E. coli (EIEC)

invade electrolytes and the deep layers of the mucosa of the intestine; the ones that cause damages in the intestinal cells

Verotoxins: VT1, VT2, VT2 e

damage to vasculature in intestine and other locations

Enteric Colibacillosis

Primarily affects neonatal calves, lambs, piglets , Oral infection → intestinal colonization, watery diarrhea

Colisepticemia

Common in calves, lambs, poultry

Bacteria enter bloodstream from intestine, lungs, or navel (navel ill)

Poultry: airsacculitis, pericarditis

Coligranuloma (Hjarre’s disease)

Chronic inflammatory lesions

Resemble tuberculous granulomas

Mainly in poultry

white scour

neonates; diarrhea, normal temp, very common

Coligranuloma (Hjarre’s disease)

Disease of e coli in poultry characterized by chronic respiratory infection

Colisepticemia

Disease of E coli in young birds

Neonatal enteritis

Disease of E coli in 1-4 days old pig

Post-weaning diarrhea

Disease of E coli in 1-2 weeks old pig

Edema disease

Disease of E coli in 8-12 weeks old pig

Mastitis

Disease of E coli in sows

Foal septicemia

Disease of E coli in horses characterized by high mortality

E. coli O157:H7

E coli strain that targets humans

Uropathogenic E. coli (UPEC)

cystitis in bitches

Fluid & electrolyte replacement

Main treatment for e coli

1. Gentamicin

2. trimethoprim-sulfas

3. enrofloxacin

4. apramycin

5. ceftiofur

6. Tetracyclines

7. ampicillin

8. amoxicillin

9. neomycin

Antimicrobials used for ecoli

1. Klebsiella

2. Shigella

3. Yersinia pestis

Non motile species

negative

Indole test for klebsiella

Cephalexin

TX for Klebsiella pneumoniae

Catalase, VP, Citrate

Biochemical test where Enterobacter is positive

some are capsulated

is enterobacter capsulated or not

Enterobacter aerogenes

Enterobacter that is opportunistic pathogen: considered a saprophyte of vegetable matter; occasionally produces bovine masti

Enterobacter cloacae

Enterobacter that is an important pathogen responsible for a wide range of healthcare-associated illnesses; a nosocomial pathogen

Enterobacter sakazakii

known occasionally to cause meningitis and sepsis in human neonates

Cronobacter sakazakii

new name for Enterobacter sakazakii

Lactose and surcrose

What does Citrobacter ferments

1. Citrobacter freundii

2. C. intermedius

opportunistic pathogen in extra-intestinal infections; should be differentiated from Salmonella (similar biochemically and even produce the same colony)

Klebsiella pneumoniae

cause of coliform mastitis in cattle

yes

is klebsiella pneumoniae a nosocomial concern

Serratia marcescens

responsible for the infrequent cases of bovine mastitis and other uncommon sporadic infections in domestic animals, Septicemia in chicken but also infects geckos and tortoises

1. S. Typhi

2. S. Paratyphi A

Salmonella is usually citrate positive except

O H Vi

Antigens of Salmonella

Kaufmann and White schema

Serotyping is based on ________________ in which O (Somatic) and H (flagellar) antigens are identified

S. enterica subsp. enterica

Majority of veterinary salmonellae belong to which organism

Enterotoxin

heat labile protein: responsible for diarrhea

9

Salmonella survive in damp, shaded soil up to ____ months

Enteric Fever

Septicemic form of salmonellosis

Enteritis

Diarrhea: foul-smelling, watery feces ± mucus, fibrin, sometimes blood may lead to dehydration and acid–base imbalance → shock

Enteric fever (septicemic form)

Dissemination via lymphatics while inside phagocytes

Endotoxin release → fever, vascular permeability changes

May progress to shock and death

Enterocolitis Acute

Fever, depression, anorexia

Profuse foul-smelling diarrhea (may contain blood, mucus, epithelial casts)

Chronic Enterocolitis

Targets Pigs , cattle, horses

Intermittent fever, soft feces, and gradual weight loss leading to emaciation

4

Septicemic Salmonellosis most common in calves, neonatal foals, and pigs < ____months

Septicemic Salmonellosis

High fever, depression, recumbency

Death may occur within 48 hours

Survivors may develop persistent diarrhea, arthritis, meningitis, or pneumonia

S. Choleraesuis

bluish discoloration of ears and snout

1. Salmonella Gallinarum

2. Salmonella Pullorum

3. Salmonella Enteritidis

CA of Salmonellosis in poultry

Pullorum Disease (Bacillary White Diarrhea)

Affects young chicks and turkey poults (≤ 2–3 weeks old) High mortality rate

Birds are anorexic and depressed

Whitish diarrhea with fecal pasting around vents

Salmonella Gallinarum

CA Fowl Typhoid

Fowl Typhoid

Infects young chicks and poults

Enlarged, friable, bile-stained liver Enlarged spleen Sudden death in adults due to septicemia

tetrathionate or selenite F broth;

Rappaport-Vassiliadis broth

Selective enrichment for Salmonella

IV antibiotics

type of antibiotic for septicemic case of salmonella

S. Dublin

live attenuated vax for cattle of Salmonella

S. Typhimurium and S. Choleraesuis

live attenuated vax for pig of Salmonella