Matthew F. Poore

Prevalence of and Risk Factors for Feline Tritrichomonas foetus and Giardia Infection

ABSTRACT Data were gathered for 117 cats from 89 catteries at an international cat show to examine prevalence and risk factors for feline Tritrichomonas foetus and Giardia infection. Prevalence of T. foetus was 31% among cats (36 out of 117) and catteries (28 out of 89) based on results of fecal smear examination (5 out of 36), fecal culture in modified Diamonds medium (9 out of 36), fecal culture in In Pouch TF medium (20 out of 36), or PCR amplification of the ribosomal RNA gene from feces with T. foetus-specific primers (34 out of 36). Catteries in which T. foetus was identified were more likely to have had a recent history of diarrhea, historical diagnosis of coccidia infection in adult cats, and a decreased number of square feet of facility per cat. Evidence did not exist for the ongoing transmission of T. foetus by water, food, or contact with other species.

TRITRICHOMONAS FOETUS AND NOT PENTATRICHOMONAS HOMINIS IS THE ETIOLOGIC AGENT OF FELINE TRICHOMONAL DIARRHEA

Recently, several investigators have reported large-bowel diarrhea in cats associated with intestinal trichomonad parasites. These reports have presumptively identified the flagellates as Pentatrichomonas hominis, an organism putatively capable of infecting the intestinal tracts of a number of mammalian hosts, including cats, dogs, and man. The purpose of the present study was to determine the identity of this recently recognized flagellate by means of rRNA gene sequence analysis; restriction enzyme digest mapping; and light, transmission, and scanning electron microscopy (SEM).

Efficacy of Ronidazole for Treatment of Feline Tritrichomonas foetus Infection

OBJECTIVES To determine the efficacy of ronidazole (RDZ), tinidazole (TDZ), and metronidazole (MDZ) against Tritrichomonas foetus in vitro and of RDZ for treatment of feline naturally occurring or experimentally induced T. foetus infection. ANIMALS A cat naturally infected with T. foetus infection and diarrhea. Ten specific-pathogen-free (SPF) kittens. PROCEDURE RDZ, TDZ, and MDZ were tested for activity against 3 different feline isolates of T. foetus in vitro. RDZ then was administered to a naturally infected cat at 10 mg/kg PO q24h for 10 days. SPF kittens were infected orogastrically with feline T. foetus and treated with either placebo or RDZ (10 mg/kg PO q12h for 14 days). Cats with relapsing infection or those receiving placebo were treated subsequently with RDZ (either 30 or 50 mg/kg PO q12h for 14 days). Feces were examined for T. foetus by direct microscopy, culture, and polymerase chain reaction (PCR) testing weekly. RESULTS Both RDZ and TDZ killed T. foetus at concentrations >0.1 microg/mL in vitro. In the naturally infected cat, RDZ abolished diarrhea and T. foetus infection for 85 days after treatment, at which time infection and diarrhea relapsed. Retreatment with RDZ eradicated diarrhea and T. foetus infection for over 407 days. In experimentally induced infection, RDZ at 10 mg/kg caused initial improvement, but infection relapsed in all 5 cats 2 to 20 weeks after treatment. At 30 or 50 mg/kg, 10/10 cats were negative for T. foetus infection for follow-up durations of 21 to 30 weeks after treatment. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of RDZ at 30 to 50 mg/kg q12h for 14 days resolved diarrhea and eradicated infection (on the basis of polymerase chain reaction [PCR] testing) in 1 naturally infected cat and 10 experimentally inoculated cats receiving a different isolate of T. foetus.

Serosurvey of antiBabesia antibodies in stray dogs and American pit bull terriers and American staffordshire terriers from North Carolina.

Stray dogs (n=359) and kennel dogs (n=149) from North Carolina were tested for evidence of antiBabesia antibodies. AntiBabesia antibodies were detected in 21/359 and 22/149 of the stray and kennel dogs, respectively. A total of 57 dogs from both groups were tested for babesiasis by light microscopy and polymerase chain reaction (PCR). Babesia deoxyribonucleic acid (DNA) was detected in 3/28 of the stray dogs and 14/29 of the kennel dogs. When Babesia DNA was detected by PCR, the species-specific PCR results differed from the Babesia species antibody titer results in 6/17 of the PCR-positive dogs. There was no association between antiBabesia antibodies and the presence of ticks. There are currently Babesia gibsoni epizootics affecting American pit bull terrier kennels.

Clinostomum complanatum and Clinostomum marginatum (Rudolphi, 1819) (Digenea: Clinostomidae) Are Separate Species Based on Differences in Ribosomal DNA

Infections by metacercariae of Clinostomum (Leidy, 1856) species adversely affect aquacultured fish and are potentially transmissible to humans. Molecular methodologies are efficient tools, which enable diagnosis of all life-history stages of trematodes in their diverse hosts. The small subunit of ribosomal DNA genes of adults of the Old World Clinostomum complanatum (Rudolphi, 1819) and the New World Clinostomum marginatum (Rudolphi, 1819), obtained from a little egret Egretta garzetta (Linnaeus, 1766) and the great blue heron Ardea herodias (Linnaeus, 1758), respectively, were amplified, sequenced, and aligned. The resulting alignment was used to develop a genetic assay to differentiate between these species.

Digeneans Collected from Piscivorous Birds in North Carolina, U.S.A

Abstract During investigations of digenetic fluke diseases of aquaculture fish, 11 digeneans (Apharyngostrigea simplex, Apharyngostrigea cornu, Diplostomum compactum, Diplostomum spathaceum, Posthodiplostomum minimum, Hysteromorpha triloba, Clinostomum marginatum, Drepanocephalus spathans, Mesorchis denticulatus, Microparyphium facetum, and Notocotylus pacifera) were collected from 5 species of piscivorous birds (Ardea herodias, Fulica americana, Larus delawarensis, Nycticorax nycticorax, and Phalacrocorax auritus) from North Carolina, U.S.A. Apharyngostrigea simplex from A. herodias represents a new host record. Diplostomum spathaceum, P. minimum, C. marginatum, and M. denticulatus have previously been reported from North Carolina; the remainder represent new locality records.

Experimental infection of native north Carolina salamanders with Batrachochytrium dendrobatidis.

Chytridiomycosis is an often fatal fungal disease of amphibians caused by Batrachochytrium dendrobatidis. This disease has been implicated in the worldwide decline of many anuran species, but studies of chytridiomycosis in wild salamanders are limited. Between August 2006 and December 2006, we tested wild amphibians in North Carolina, USA (n=212) by polymerase chain reaction (PCR). We identified three PCR-positive animals: one Rana clamitans and two Plethodontid salamanders. We experimentally infected two species of native North Carolina Plethodontid salamanders, the slimy salamander (Plethodon glutinosus) and the Blue Ridge Mountain dusky salamander (Desmognathus orestes) with 1,000,000 zoospores of B. dendrobatidis per animal. Susceptibility was species dependent; all slimy salamanders developed clinical signs of chytridiomycosis, and one died, whereas dusky salamanders remained unaffected. In a second experiment, we challenged naïve slimy salamanders with either 10,000 or 100,000 motile zoospores per animal. Clinical signs consistent with chytridiomycosis were not observed at either dose or in uninfected controls during the 45 days of this experiment. All animals inoculated with B. dendrobatidis in both experiments, regardless of dose, tested positive by PCR. Our study indicates that slimy salamanders are more susceptible to clinical chytridiomycosis than dusky salamanders, and in a laboratory setting, a dose greater than 100,000 zoospores per animal is required to induce clinical disease. This study also indicates that PCR is a very sensitive tool for detecting B. dendrobatidis infection, even in animals that are clinically unaffected, thus positive results should be interpreted with caution.

Cercariae of Bolbophorus damnificus and Bolbophorus sp. with Notes on North American Bolbophorids

Abstract Single-species and dual infections of Bolbophorus damnificus and a second cryptic species of Bolbophorus were distinguished in marsh rams-horn snails, Planorbella trivolvis, from aquaculture ponds in Mississippi, U.S.A. The cercariae of both B. damnificus and Bolbophorus sp. are described and distinguished using differences in body length, tail stem length, intestinal primordia, and integument spine patterns.