5.10 Curved Gram Negative Rods and Spirochetes Flashcards
what is the characteristic appearance of campylobacter spp. on staining
seagulls (gram-negative curved rods)
what is the habitat(s) of campylobacter
intestinal; genital tract in some species
what are the two main Campylobacter spp of interest, what is their host(s) and what do they cause
- C. jejuni (all species) -> diarrhea
- C. coli (pigs, humans) -> diarrhea
T/F campylobacter jejuni is zoonotic and reportable
F; zoonotic but not reportable
what is the major difference between campylobacter and salmonella
campylobacter cannot replicate in food whereas salmonella can; lower infectious dose for campylobacter
what are the conditions in which C. jejuni infection is more common
poor hygiene and close contact between farm animals; more common in young vs adult animals
what is the route of infection of campylobacter jejuni
fecal contamination of food or water
what is the main reservoir for C. jejuni? C. coli?
C. jejuni: broiler chickens
C. coli: pigs
what type of diarrhea does C. jejuni cause (2 names for the diseases)
superficial erosive colitis and ileitis-colitis
what are the two “outcomes” of C. jejuni infection
- self-limiting infection that resolves within 1-2 weeks
- bacteremia and abortions if it becomes severe
what are the two C. jejuni toxins
1) Cytolethal distending toxin (cdt gene)
2) LT-like adenylate cyclase-activating enterotoxin
the ____________ toxin is responsible for erosions and _________ toxins is responsible for diarrhea caused by C. jejuni
cytolethal distending toxin; LT-like adenylate cyclase activating enterotoxin
what special media and conditions are used to culture C. jejuni
selective (feces); microaerophilic (6% O2)
how do we treat C. jejuni
antibiotics
certain serotypes of C. jejuni are responsible for what disease in humans? What is it characterized by
Guillain-Barre syndrome; PNS demyelination
what is the main source of C. jejuni infection in humans (be specific)
contaminated raw chicken
what are some ways to control C. jejuni
food production and kitchen hygeine; preventing cross-contamination; cooking meat fully; slaughterhouse processing
T/F there is a C. jejuni vaccine available for chicken
F
where does Lawsonia intracellularis live
in the apical cytoplasm of ileal epithelial cells
what does Lawsonia intracellularis cause in young animals? old animals?
young: proliferative intestinal adenomatosis (diarrhea, decreased weight gain)
old: proliferative hemorrhagic enteropathy (PHE)
Lawsonia intracellularis mainly infects what animals
weaner pigs and yearling foals
T/F Lawsonia intracellularis has a broad host range
T
T/F Lawsonia intracellularis is zoonotic and reportable
F; zoonotic but not reportable
how is Lawsonia intracellularis diagnosed
PCR on feces, ELISA
how do we control Lawsonia intracellularis
vaccination, antimicrobials, raising specific pathogen-free pigs
what is the structure of Spirochaetales spp.
coiled spiral organisms wrapped around an internalized flagellum
how do we stain Spirochaetales
using silver stain or dark field; do not stain well with gram
what are the Genera of Spirochaetales of interest to us
Leptospira and Borrelia
what lab test results are characteristic of leptospirosis and what diseases does this indicate
elevated creatinine and blood urea; elevate creatine phosphokinase and other muscle enzymes; elevated bilirubin and alkaline phosphatase
indicates renal failure and hepatitis
T/F leptospirosis is zoonotic and reportable
F; zoonotic but not reportable
T/F it takes a long time to grow leptospira and requires special medium and conditions
T
T/F all Leptospira spp. are pathogenic
F
what is the difference between the old and new antigenic classification for Leptospira
Old: 23 serogroups and 250 serovars
New: >60 species, then serovars
what conditions do Leptospira require for survival
wet, warm environments
T/F Leptospira are fastidious
T
what is the specific location in the body for leptospira
proximal convoluted tubule of kidney
what is the difference in infection between maintenance and accidental (incidental, non-maintenance) hosts of leptospira
maintenance: lifetime infection in kidney +/- genital tract
accidental: kidney infection for a few weeks
what is the classic “iceberg” infection
Leptospira (most infections subclinical or chronic)
do we see clinical signs of Leptospira in maintenance hosts, accidental hosts or both
in accidental (subclinical/chronic infections in maintenance)
T/F leptospira can cause bacteremic disease; if T, where does it localize
T: liver, kidney, CSF, eye
what are the maintenance vs incidental hosts of leptospira
maintenance: rodents
accidental: racoons, beavers, dogs, humans
describe the following manifestations of leptospira:
- peracute
- acute
- chronic
- subclinical
peracute: DIC, hemorrhage, death
acute: nephritis, hepatitis, abortion, fever
chronic: chronic nephritis, abortion (pigs, dogs)
subclinical: antibody rise only or mild flu-like illness
what type of leptospira is common in dogs and what are the clinical signs
Leptospira canicola: acute or chronic renal failure (interstitial nephritis)
What spp of Leptospira is common across large animal species and what are the signs/clinical dz
Leptospira pomona: abortion in all; nephritis in pigs; haemoglobinuria and mastitis in cows; uveitis in horses
How can we detect L. hardjo, in what species and why
in milk; causes mastitis (as well as abortion, stillbirth) in cows
what Leptospira is a major cause of acute renal failure in dogs? what else does it cause
L. grippotyphosa; hepatitis and fever
how do we detect Leptospira (be specific)
paired serum samples: want to see a 4x increase between the first and second ELISA; can also do direct demonstration (PCR; immunofluorescence; dark field)
why are the Leptospira vaccines not fool-proof
they do not protect across all serovars (5 or 6 covered)
how can we control/treat Leptospira
vaccination; vector control (rodents); antibiotics
where is Borrelia burgdorferi a problem
eastern, central, western US (due to resurgence in deer population)
describe the 3-host lifestyle of Borrelia burgdorferi
eggs hatch into Borrelia-free larvae -> feed on rodents/birds +/- pick up Borrelia -> become nymph -> feed on rodents/birds +/- pick up Borrelia -> become adult -> feed on deer or accidental host (dogs, humans)
what is the characteristic lesion created by Ixodes scapularis bite (tick carrying Borrelia burgdorferi)
target
which of the following stages of Borrelia burgdorferi are potentially infective:
- egg
- larvae
- nymph
- adult
- nymph
- adult
if you remove an adult tick within ____ you likely prevent transmission of Borrelia burgdorferi
24h
T/F Borrelia burgdorferi is reportable and zoonotic
F; zoonotic but not reportable
what are the two main Ixodes spp. that carry Borrelia burgdorferi and where are they located
western US/BC: Ixodes pacificus
eastern/central USA: Ixodes scapularis
where is lyme disease currently spreading
along the north shore of Lakes Erie and Ontario; Thousand Islands area
what are the acute and chronic signs of Borrelia burgdorferi infection in PEOPLE
acute: erythematous skin rash; fever; joint pain; muscle pain; meningeal irritation
chronic: peripheral neuropathy; arthritis; myocarditis
what does Borrelia burgdorferi cause in dogs (4)
fever, anorexia, arthritis, protein-losing glomerulopathy
what does Borrelia burgdorferi cause in horses
arthritis, abortion, panuveitis, encephalitis
how do we diagnose Lyme disease and why is it difficult in endemic areas
serology and response to antibiotics; hard to diagnose in endemic areas because many animals have seroconverted due to subclinical infection/exposure
how can we control Borrelia burgdorferi infection
vaccination
