Lecture 16: Infections of the Urogenital System IV

What is the general morphology of campylobacter spp.?

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

• motile, microaerophilic

• non-fermentative, oxidase-positive with variable catalase reactions

Where are campylobacter spp. found?

• commensals of the intestinal tract and sometimes reproductive tract

• pathogens in the reproductive and intestinal tracts

What C. fetus subspecies affects bovine reproductive tract causing venereal disease in cattle, early embryonic death, temporary infertility?

venerealis

What C. fetus subspecies affects the intestinal tract of sheep, goats, and cattle causing abortions, stillbirths, weak lambs and kids, and sporadic abortion in cattle?

fetus

What campylobacter species affects intestinal tract of birds and mammals causing abortion in sheep, enteritis in dogs, avian hepatitis, and enterocolitis in humans?

C. jejuni

What does campylobacter species remain viable in?

feces, milk, water, vaginal discharges, poultry litter

What component does campylobacter fetus possess that ehances its survival in the genital tract?

a microcapsule or S layer consisting of high-molecular-weight proteins arranged in lattice formation conferring resistance to serum-mediated destruction and phagocytosis

How are campylobacter spp. infections diagnosed?

• requires microaerophilic conditions for growth

• smears stained with dilute carbon fuchsin (DCF)

• identification

What are the criteria for campylobacter spp. identification?

• growth under microaeophilic conditions

• colonial morphology

• cell morphology

• antibiotic susceptibility pattern

• PCR-based methods

What are the clinical signs of campylobacter spp. infections?

• infertility in cattle due to C. fetus subsp. veneralis

• abortion in ewes caused by C. fetus or C. jejuni

What is the causative agent of bovine genital campylobacteriosis?

campylobacter fetus subsp. venerealis

How is bovine campylobacteriosis transmitted?

during coitus to susceptible cows from asymptomatic carrier bulls

What is bovine campylobacteriosis characterized by?

• Temporary infertility (3-5 mo) associated with embryonic death

• Return to estrus at irregular periods

• Sporadic abortion

About one third of cows infected with bovine genital campylobacteriosis, how?

• C. fetus subsp. venerealis persists in the vagina of the carrier cows

• Feature attributed to antigenic shifts in the immune-dominant antigens of S-layer proteins

True or false: Natural immunity to bovine genital campylobacteriosis develops after 3-5 months with IgA (in vagina) and IgG (in uterus) antibodies that last up to 4 years.

true

How is C. fetus subsp. fetus infection acquired?

ingestion

How is bovine genital campylobacteriosis diagnosed?

• Fluorescent antibody technique (FAT) in sheath washing in bulls, cervicovaginal mucus in cows

• isolation and identification from vaginal or preputial mucus is confirmatory

How is bovine genital campylobacteriosis treated?

• dihydrostreptomycin administered either systemically or topically into the prepuce is used for treating bulls

• Intrauterine administration of dihydrostreptomycin

• Vaccination (bacterin) and AI for control

What pathogen causes ovine genital campylobacteriosois?

C. fetus subsp. fetus or C. jejuni

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

ovine genital campylobacteriosis

How is ovine genital campylobacteriosis transmitted?

fecal-oral route

What occurs during a pregnancy impactive by ovine genital campylobacteriosis?

localization in the uterus of susceptible ewes may occur following bacteremia; the subsequent necrotic placentitis leads to abortion late in pregnancy or in stillborn or weak lambs

What is found on the liver surface in some lambs aborted to ovine genital campylobacteriosis?

round necrotic lesions up to 2 cm in diameter with pale raised rims and dark depressed centers

How is ovine genital campylobacteriosis diagnosed?

• typical hepatic lesions in aborted lambs are pathognomonic

• demonstrating the organisms in fetal abomasa contents or birth fluids

• isolation and identification

• vaginal mucus agglutination test

• ELISA

How is ovine genital campylobacteriosis treated and controlled?

• isolate aborting ewes

• promptly remove placentae and aborted fetuses

• vaccination

• chlortetracycline

What is the pathogen causing coxiellosis?

gram-negative coccobacillus C. burnetii

What is coxiellosis?

a zoonotic bacterial infection associated primarily with parturient ruminants causing a subclinical infection, rare sporadic abortions in sheep, goats, and cattle, and Q-fever in humans

What type of pathogen is C. burnetii

obligate intracellular pathogen

How does C. burnetii remain viable in the environment for up to 150 days?

small endospore-like resistant forms are formed during replication

Where does C. burnetii grow preferentially?

in the acid environment of phagolysosomes of macrophages

How is coxiellosis transmitted?

• parturition by inhalation, ingestion, or direct contact with birth fluids or placenta

• shed in milk, urine, and feces

What effectively kills the organism causing coxiellosis?

high temperature pasteurization effectively killing the organism

What are the clinical signs of coxiellosis?

• usually subclinical, but can cause anorexia and late abortion

• infertility and sporadic abortion with a necrotizing placentitis in sheep, goats, and cattle

When coxiellosis infection is subclinical, animals shed ________ bacterial loads of the organisms than when abortion occurs.

much lower

How is coxiellosis diagnosed?

• small clumps of red coccobacillary bodies from placental tissue and uterine discharge smears

• PCR

• culture, serology, immunofluorescence

How is coxiellosis treated and controlled?

• Q-fever in people is notifiable disease in USA

• parenteral tetracyclines during abortion storms

• standard abortion control measures

What is the causative agent of bovine mycotic abortion?

aspergillus spp.

What are the clinical manifestations of bovine mycotic abortion?

• Lesions found in uterus, fetal membranes, and often fetal skin

• in uterus, the intercaruncular areas are grossly thickened, leathery, dark red to tan, and contain elevated or eroded foci covered by a yellow-gray adherent pseudomembrane

• Maternal caruncles are dark red to brown, and the adherent fetal cotyledons are markedly thickened

• Cutaneous lesions in aborted fetuses consist of soft, red to gray, elevated discrete foci that resemble ringworm

How is an aspergillum spp. infection diagnosed?

• clinical presentation

• microscopy of tissue samples: hyaline, septate hyphae that branch dichotomously with a 45 degree angle