Lecture 16: Infections of the Urogenital System 4

salient features of campylobacter spp.

• gram-negative, slender, curved, rods in gull-winged shapes and spiral forms

• non-fermentative, oxidase-positive

• pathogens in the repro and intestinal tracts

what are the campylobacter species

• C. fetus, sub. venerealis

• C. fetus, sub. fetus

• C. jejuni

C. fetus subsp. venerealis

• in bovine repro tract

• causes venereal disease in cattle, early embryonic death, temporary infertility

C. fetus subsp. fetus

• in the intestinal tract of sheep, goats, and cattle

• causes abortions, stillbirths in sheep and goats, weak lambs and kids, sporadic abortion in cattle

C. jejuni

• in the intestinal tract of birds and mammals

• causes abortion in sheep, enteritis in dogs, avian hepatitis, enterocolitis in humans

where does campylobacter species survive?

• under moist conditions

• some strains tolerate cold

campylobacter remains viable in

feces, milk, water, vaginal discharges, poultry litter

campylobacter fetus possess a

microcapsule or S layer that consists of high-molecular weight proteins in lattice formation

the S layer of campylobacter confers resistance to

serum-mediated destruction and phagocytosis

how many antigenic variants do campylobacter lattice proteins have?

eight

putative virulence factors of campylobacter

• adhesins, eg. CadF

• type 4 secretion system

diagnostic procedures of campylobacter

• require microaerophilic conditions for growth

• smears stained with dilute carbol fuchsin (DCF) for 4 mins

• C. jejuni grows at 42 degrees C

what is the principal causative agent of bovine genital campylobacteriosis?

campylobacter fetus subsp. venerealis

bovine genital campylobacteriosis transmission

occurs during coitus to susceptible cows from asymptomatic carrier bulls

bovine genital campylobacteriosis is characterized by

• temporary infertility associated with embryonic death

• return to estrus at irregular periods

• sporadic abortion

true or false: about one third of cows become carriers for bovine genital campylobacteriosis.

true

C. fetus subsp. venerealis persists in

the vagina of the carrier cows → feature attributed to antigenic shifts in the S layer proteins

natural immunity to bovine genital campylobacteriosis develops after

3-5 months with IgA in vagina and IgG in uterus

C. fetus subsp. fetus is acquired by

ingestion

diagnosis of bovine genital campylobacteriosis

• fluorescent antibody technique in sheath washing in bulls and cervicovaginal mucus in cows

• isolation and identification from vaginal or preputial mucus

treatment of bovine genital campylobacteriosis

• dihydrostreptomycin administered in the prepuce

• intrauterine administration of dihydrostreptomycin

• vaccination (bacterin) and AI for control

ovine genital campylobacteriosis is caused by

C. fetus subsp. fetus or C. jejuni

what is the most common cause of ovine abortion in some countries?

ovine genital campylobacteriosis

characteristics of ovine genital campylobacteriosis

• emergence of single tetracycline-resistant clone of C. jejuni

• transmission by fecal-oral route

• localization in the uterus of susceptible ewes can occur during pregnancy

• necrotic placentitis can lead to abortion late in pregnancy

what kind of lesions occur with ovine genital campylobacteriosis?

round necrotic lesions with pale raised rims and dark depressed centers on the liver surface

diagnosis of ovine genital campylobacteriosis

• typical hepatic lesions in aborted lambs are pathogenic

• presumptive diagnosis can be made by demonstrating the organism in fetal abomasal contents

treatment and control of ovine genital campylobacteriosis

• aborting ewes should be isolated

• routine vaccination of ewes with bacterin before and after mating, with a booster after the second month of gestation and then annually after that

• chlortetracycline daily in feed

coxiellosis is caused by

gram-negative coccobacillus C. burnetii

coxiellosis is

a zoonotic bacterial infection associated with parturient ruminants i

true or false: coxiellosis can cause rare, sporadic abortions in sheep, goats, and cattle.

true

coxiellosis is considered a

potential agent of bioterrorism

pathogenesis of coxiellosis

• C. burnetii forms small resistant forms during replication that remain viable in the environment for 150 days

• prefers to grow in the acid environment of phagolysosomes of macrophages

transmission of coxiellosis

• greatest risk occurs at parturition by inhalation, ingestion, or direct contact with birth fluids or placenta

• shed in milk, urine, and feces

what will effectively kill coxiellosis bacteria?

high-temperature pasteurization

clinical signs of coxiellosis

• ruminant infection is subclinical but can cause anorexia and late abortion

• infertility and sporadic abortion

what happens when coxiellosis infection is subclinical?

animals shed much lower bacterial loads of the organism than when abortion occurs

diagnosis of coxiellosis

• specimens must be collected and handled with care, and diagnostic procedures must be carried out in a biosafety cabinet

• smears from placental tissue reveal small clumps of red coccobacillary bodies

treatment and control of coxiellosis

• vaccines have been developed but are not commercially available in the USA

• parenteral tetracyclines during abortion storms

• standard abortion control measures should be taken

what is a notifiable disease in the USA?

Q-fever

bovine mycotic abortion is caused by

aspergillus spp.

aspergillosis in ruminants

• dead fetus is aborted at 6-9 month gestation and fetal membranes are retained

• lesions are found in the uterus, fetal membranes, and often the fetal skin

what happens to the intercaruncular areas in the uterus during aspregillosis infection?

they are grossly thickened, leathery, dark red to tan

what happens to maternal caruncles in the uterus due to aspergillosis infection?

they are dark red to brown and the fetal cotyledons are thickened

what do cutaneous lesions in aborted fetuses resemble if they have aspergillosis?

ringworm

what does the microscopy of aspergillus show?

hyaline, septate hyphae that branch dichotomously with a 45 degree angle