disease due to gram negative

what are the 3 major pathogens we learned about for enterobacteriaceae?

E.coli, salmonella and yersinia

Tell me some characteristics about enterobacteriaceae

• Bacilli (rod-shaped

• gram negative

• facultative anaerobe

• non-spore formine

• fermenting sugars (b-galactosidase)

• mostly motile except for shigella and klebsiella

where do we find enterobacteriaceae? how is it transmitted?

worlwide

inhabits gut

found in soil and sewage

fecal-oral transmission

What type of infections can E.bacterioceae cause?

GI illness

pneumonia

wound infection, mastitis

invasive infections of the blood or internal organs

Is escherichia coli commensal or pathogenic? what are some of the virulence factors? is it zoonotic? serotyped by what antigens?

Both

virulence factors:

• motility (petririchous flagelle)

• adhesions (fimbriae)

• Endotoxins: LPS

• Exotoxins: shigatoxins, verotohxin, enterotoxins

• Alpha-hemolysin

It is zoonotic

serotyped by O,H and K antigens

What is the disease caused by E.coli

Colibacillosis, all starts in the gut

EC e.coli pathotypes

Entero-toxigenic (ETEC)

Entero-pathogenic (EPEC)

eNTERO-HEMORRHAGIC (EHEC/STEC)

What does ETEC lead to and how

Hypersecretory diarrhea bc it attaches to surface with fibril adhesions and produces enterotoxins (exotoxins) which causes secretion of sodium and chloride this water draw out to lumen.

What is a disease of enteric colibacillosis that is caused by ETEC, what is the clinical presentation?

Calf scours, disease of newborn calves, lambs, piglets

Clinical presentation: Very profuse and watery brown diarrhea is typical

They are depressed and recumbent and won’t drink or suckle. Dehydrated

What are some factors favoring infection for calf scours?

Environment contamination

overcrowding

STRESS- transport

Naive immunity

No colostrum

How is calf scours contracted?

Ingestion from the environment

Tell me some characteristics of EPEC

Adhesion, no toxin

Watery diarrhea with mucus, no blood

EHEC tell me some information about it and what it causes

Adhesion, shigatoxin

Watery diarrhea with mucus and blood

What do both EPEC and EHEC lead to

Microvilli effacement

Malabsorption/maldigestion in small intestine

Reduced absorptive capacity of colonic mucosa

Osmotic diarrhea- draws water into colon

Inflammation ± hemorrhage

ETEC colisepticemia, what is it and who does it infect

invasion of blood stream by intestinal or extraintestinal coliform

Infects: calves, lambs, poultry or -immune compromised animals

What does ETEC colisepticemia cause and what are some clinical signs from it?

Inflammation and endotoxic shock from LPS

Clinical signs from endotoxin LPS:

• pyrexia, depression, tachycardia

• meningitis, pneumonia (common)

• profuse salivation, distended abdomen

• joint swelling, arthritis, lameness

  • With or without diarrhea

What is oedema disease of pigs? In who does it occur in?

Toxemia= toxin presence in blood

Hemolytic E.coli colonizing gut→ production of shigatoxin (STEC) → absorption into blood stream → damage to endothelial cells → perivascular oedema

Occurs in: young pigs, 1-2 weeks post-weaning, sudden onset of

What are symptoms of oedema disease:

No diarrhea

oedema of eyelid and frontal face, laryngeal oedema (dysphonia), paresis, tumor, flaccid paralysis before death

Fatal within 36-48 hours

morbidity about 30% and mortality around 90%

What is an example of systemic colibacillloses

Oedema disease in pigs

Local ascending collibacilloses, what are some disease?

Coliform mastitis, Urogenital tract infections in domestic carnivores

Coliform mastitis, what type of infection is it? how is it spread? how does the milk look?

Etiology: E.coli, Klebsiella, Enterobacter (coliforms)

Opportunic infection (environment + immunity)

Spread from: fecal contamination of udder skin

Milk appears watery with white specks. Is mostly self-limiting

Tell me about the etiology of UTI in domestic carnivores? what can it cause in female dogs, male dogs, cats?

Etiology: uropathogenic E.coli (UPEC)

An opportunistic ascending infection of urogenital tract

In female cats can cause: pyometrya and cystitis

In male dogs: prostatitis

In cats: nephritis

What is treatment and also control and elimination of colibacillosis

Tx: isolation, immediate rehydration and electrolytes, antimicrobials (if systemic symptoms), NSAID

Control and prevention: (eliminate opportunity)

• quarantine new arrivals

• Pasture for pregnant cows

• Isolation of newly-calved cows

• Immunization of dams against ETEC during pregnancy

• Colostrum in first hours of life

  • Improved hygiene (bedding + pasture)

Which of the following causes a hypersecretory diarrhea in calves, lambs, and piglets?

What type of mastitis is depicted by this type of bacteria?

E.coli recap, tell me the enteric, systemic, and local colibacillosis diseases

Enteric colibacillosis

• Calves, lambs, piglets

• Hypersecretory diarrhea: ETEC

• Osmotic diarrhea: EHEC and EPEC

Systemic:

• colisepticemia

• oedema disease in pigs

Local:

• UPEC, E.coli In carnivores

• Coliform mastitis

Tell me traits of salmonella spp. GRAM what? virulence factors? commensal?

gRAM (-) rods

Motile (flagella)

adhesion (fimbriae)

Do not ferment lactose or sucrose (not a coliform)

Not a commensal = never a friend, always a foe

Salmonella spp. is a common infection in what? how is it transmitted? serotyped by what?

Mammals, birds and reptiles

Common fecal contaminant of environmen, underlying is stress and poor hygiene

Serotyped by O (somatic) and H (flagellar) antigens

What are the two species for salmonella

S.bongori and S.enterica (veterinary species is mostly this one)

Salmonella pathogenesis

1. Adhesion (fimbriae)

2. Secretion and membrane ruffling

3. Internalization and membrane recovery

Enteric salmonellosis of pigs, explain acute and chronic and some symptoms

Acute:

• profuse, could-smelling diarrhea, often with blood, mucus, epithelial casts

• Dehydration, weight loss, fever

• Abortion in pregnant

• Mortality in young

Chroic

• Can follow acute disease

• Intermittent: fever, soft stool

• Slow emaciation

Septicemic salmonellosis of pig, tell me presentation

• Mostly in pig growers

• Fever, depression, recumbency

• Cyanosis

• Mortality within 48h

• Survivors: meningitis, arthritis, pneumonia, diarrhea

Enteric and septicemia salmonellosis of poultry how is it transmitted and what are some of the species

Transovarian transmission: S.pullorum, S.gallinarum, S.enteritidis, S.arizonae

Tell me about pullorum disease and what species of salmonella causes it, other name for it? what is seen post mortem?

AKA bacillary white diarrhea, pasty butt

S.pollorum

Seen in young chickd and poults (2-3 weeks)

High mortality

Postmortem-white nodes in lungs, necrotic liver

Tell me about town typhoid and what salmonella species causes it

S.gallinarum

Occurs in young and growing chicks and poults

Raw eggs, rusk of human food poisoning

What is one of the most common zoonoses and why

Salmonella due to contamination of water and soil in feces, meat, eggs, and offal.

Which of the following cause destruction of the microvilli in the gastrointestinal tract of young calves causing diarrhea?

Which serotype of S.enterica does not cause disease in birds

Tell me about yersinia spp. and the types that they want us to know

It is gram (-) rods

• bipolar on giemsa and wright stain

• Enteric or systemic infections

Types:

• Y.pestis (spread from flea)

• Y.enterocolica

• Y.pseudotuberculosis

What is the pathogenesis of yersinia spp.

Intracellular invasion of macrophages.

• Blood and/or lymph → lymph nodes

• Replication in lymph nodes

• Development of necrotic lesions

  • Infiltration of neutrophils

Y.pestis in humans (pneumonic, septicemic and bubonic)

P: bacteria enters respiratory. tract

S: bacteria enters blood

Bubonic: bacteria enters lymph nodes

Feline plague (Y.pestis) how are they infected, what do they develop and what are the clinical forms? how does it transmit to humans?

•Cats are highly susceptible to Y. pestis infection

•Infection through ingestion of infected rodents

•Develop sub-mandibular lymphadenitis (necrosis, rapture, oozing), dyspnea

•Clinical forms: bubonic, pneumonic and septicemic (often fatal)

•Transmissible to humans via aerosols, bites, scratches, fleas (indication for euthanasia)

•Dogs less likely to develop clinical illness than cats.

How can one try to prevent feline plague

Flea control and rodent control

What animal (s) is the natural reservoir (s) for yersinia pestis?

Enteric yersiniosis tell me about the different types and who they infect

•Y. enterocolica: pigs, wildlife, human

•Y. pseudotuberculosis: farmed deer, sheep, goats, cattle, pigs, human, laboratory rodents

•Stable in environment (pasture)

What are some signs of enteric yersiniosis

•< 1 year old animals

•Often subclinical

•Clinical enterocolitis develops with stress (winter, transport)

•Colitis à Diarrhea

What is the pathology and treatment and prevention of enteric yersiniosis

•Pathology: necrotic colitis and liver, adenopathy

•Treatment: fluid replacement, antibiotics

•Prevention: Y. ptuberculosis vaccine (killed), hygiene, stress reduction

Are E.coli, salmonella and yersinia all zoonotic?

Yes!!!