Bacteriology Gram Negative Flashcards
What bacteria are gram negative enterobacterales rods?
E. coli
Salmonella
Yersinia
Klebsiella pneumonia
Proteus
What bacteria are gram negative pasteurella rods?
Pasteurella
Mannheimia
Actinobacillus
Histophilus/Glaess/Avi
What are the shared features of enterobacterales?
Gram negative rods
Facultative anaerobic
Oxidase negative
Flagella
grows on blood agar and MacConkey’s agar+/- fermentation
Should you see gram negative cocci?
No, because there aren’t any gram negative cocci that are important in veterinary medicine
What do entereobacterales look like on a blood agar plate?
Grey colonies
Proteus swarms the plate
What are the lactose fermenting bacteria within enterobacterales?
Escherichia
Klebsiella
What are the non lactose fermenting bacteria within enterobacterales?
Proteus
Salmonella
Yersinia
What are the most pathogenic enterobacterales?
E.coli
Salmonella
Yersinia spp.
What are the mildly pathogenic enterobacterales?
Klebsiella pneumoniae
Proteus spp
What are the least pathogenic enterobacterales?
Enterobacter, serratia
Where does E.coli come from?
Normal flora of most animals
Lower ileum & large intestine
One of the first bacteria that colonize neonatal GIT within hours of birth
Dose E. coli survive well in the environment?
Yes
How does E.coli get transmitted
Fecal-oral
Inhalation
Direct inoculation
Ascending infections
What are common ascending infections associated with E. Coli?
Cystitis
Pyometra
Transient in urogenital tract
Is E. Coli a virulent bacteria?
Some of the strains are relatively virulent and some are pretty harmless
What influences the virulence factors of E. coli?
The different sites have different virulence factors
What are some virulence factors that some E. coli have?
Attachment
Avoidance of phagocytosis
Cellular effects (physiological or toxicity)
Systemic effects
What virulence factors do non-enteric E. coli infections have?
Fimbriae (pili) or dhesion
Capsules
Hemolysis & cytotoxic necrotizing factors
Endotoxins
What specific diseases does E. coli cause?
Sepsis in neonates
Pyometra
Cystitis
Endocarditis
Just about anything really
How do we diagnose E. Coli infections?
Collected from sterile site using the 4 point rule
How do you treat Enterobacterales non-enteric infections?
Need to do susceptibility testing because they are not predictably susceptible
Surgery/drainage/debridement
Fluid therapy
Anti-endotoxin therapies
Find the source of how patient got infected in the first place
Where does salmonella come from?
Not part of normal flora
Carrier animals with it in GIT
Survive for a long time in the environment
What are the two main strains of salmonella?how is salmonella transmitted?
Salmonella enterica
Salmonella bongeri
how is salmonella transmitted?
Fecal oral transmission from Carrier animal (reptiles, cattle, horses)
Recrudescence of infection in carrier animals
How does salmonella cause disease?
Facultative intracellular parasites & live in macrophages
What are the 3 main clinical syndromes salmonella cause?
Enteritis in horses and cattle
Septicemia with localization (lungs, joints, kidneys, hearts, & spleen)
Carrier state (she’s in feces intermittently)
How do we diagnose salmonella
Isolate from sterile site
Use 4 point rule
Where does Yersinia pestis come from?
Yersinia lives in fleas which can be infested by mice and then eaten by cats and then get near us
Why is Yersinia pestis so important?
ZOONOTIC
How does Yersinia cause disease
Facultative intracellular parasites & live in macrophages
What specific disease does Yersinia cause
Y. pestis
Y. pseudotuberculosis
What are the characteristics of Y. pestis?
Non-enteric
Most virulent of the Yersinia
Plague (Black Death) in humans & cats
What are the different forms of Y. Pestis and what do they normally infect
Bubonic—lymph nodes
Pneumonic—lungs
Septicemia—
How do you diagnose Y. Pestis infections?
Use extreme caution
Send aspirates of pus, blood, and lymph nodes to specialized lab
Notify pUblic health
PCR & culture
How do you treat Y. pestis?
Euthanasia
Isolate from cat & treat for flea immediately
Antibiotics
Lance and flush infected lymph nodes
What is the most commonly isolated from Klebsiella infections in animals?
K. pneumoniae
Where does Klebsiella come from?
Normal fecal flora
sprophyte
They love sawdust
What diseases does Klebsiella cause
Pneumonia
Cycstitis
Mastitis
Endometritis
Navel ill
Nosocomial infections
What their bacteria is Klebsiella similar to as far as what diseases it causes?
E. coli
Where does proteus come from?
Normal fecal flora
Likes moist environments= saprophytes
What diseases does proteus cause?
Cystitis
Otitis externa
Prostatis
Wound infections
What characteristics does proteus have on a blood agar plate?
It swarms the whole plate
What bacteria are part of the pasteurella?
Pasteurella
Mannheimia
Actinobacillus
Histophilus/glaess/Avi
What are the gram stain characteristics of pasteurellaceae?
Long rods
Pink to red in color
No branching
What are the shared characteristics of pasteurellaceae?
Gram negative rods
Facultatively anaerobic
Oxidase positive
Non-motile
Grow on blood agar
Do not survive long in environment
What pasteurellaceae do not grow on blood agar?
Histophilus, glaeserella, avibacterium
& grow on chocolate agar
What pasteurellaceae do not grow on MacConkey’s agar?
P. Multi idea, histophilus somni, glaeserella parasitis
What is the main species of pasteurellaceae that we will be discussing?
P. multocida
Where does pasteurellaceae come from
Normal flora of mucus membranes or mucus membranes of carrier animals & birds
Upper respiratory tract
Digestive tract
Lower genital tract
How are pasteurellaceae transmitted?
Inhalation
Direct inoculation locally or systemically
How do pasteurellaceae cause disease?
Attachment fimbriae or adhesion
Capsules
Exotoxins
Endotoxins
How many types of capsules does P. multocida?
5
What is the most important virulence factor for pasteurellaceae?
Exotoxins
What are the risk factors of pasteurellaceae?
Young animals
Co-mingling
Overcrowding
Viral infections
Poor weather
What 4 categories do pasteurella multocida?
Pneumonia
Rhinitis
Bite wounds
Septicemia
What is the most important disease caused by pasterella and what animals does it affect
Pneumonia
Associated with bovine respiratory disease complex or sniping fever
Horses, pigs, cattle, small ruminants
What is the number 2 disease caused by pasteurella and what species does it affect?
Rhinitis
Rabbits and pigs
What disease is called snuffles and what species does it affect?
Rhinitis & rabbits
What bacteria causes atrophic rhinitis and what species does it affect and what does sit cause?
Pasturella
Pigs
Destruction of turbinates & conceal bones of the snout
What clinical signs will you see with atrophic rhinitis?
Sneezing
Epistaxis
Facial distortion
What bacteria causes cat bite abscesses?
Pasteurella multocida
What bacteria causes bovine hemorrhagic septicemia?
P. Multocida associated with B & E capsule strains that are exotic to the US
Can pasturella multocida cause septicemia & if so what species?
Yes , birds and cattle
What specific diseases do Mannheimia haemolytica?
Pneumonia/bronchopneumonia
Necrotizing mastitis
Septicemia
What diseases does Actinobacillus equuli?
Sleepy foal disease= septicemia
Peritonitis in adult horses
Pneumonia & pleuropneuminia
What diseases does Actinobacillus lignieresii?
Wooden tongue in ruminants which results in pyogranulomatous abcesses
What diseases does A. Pleuropneumonia cause and in what species?
Fibrinous pneumonia & pleuritis in pigs
Economic importance
What diseases does Actinobacillus suits cause and in what species?
Septicemia in young piglets
What diseases does Glaeserella parasuis & what species does it effect?
Bronchopneumonia
Glasser’s disease septicemia & polyserositis in young pigs
What diseases does Histophilus somni & in what species?
Causes thrombotic lesions in cattle & produces disease where it localizes
What diseases does Avibacterium paragallinarum and what species does it affects?
Inflammation of turbinates, sinus epithelium and causes sneezing in chickens
