Melissa Brewer

Prevalence of Bartonella species, haemoplasma species, Ehrlichia species, Anaplasma phagocytophilum, and Neorickettsia risticii DNA in the blood of cats and their fleas in the United States

Ctenocephalides felis were killed and collected from 92 cats in Alabama, Maryland, and Texas. The fleas and blood from the corresponding cat were digested and assessed in polymerase chain reaction assays that amplify DNA of Ehrlichia species, Anaplasma phagocytophilum, Neorickettsia risticii, Mycoplasma haemofelis, ‘Candidatus M haemominutum’ and Bartonella species. DNA consistent with B henselae, B clarridgeiae, M haemofelis, or ‘Candidatus M haemominutum’ was commonly amplified from cats (60.9%) and their fleas (65.2%). Results of this study support the recommendation to maintain flea control on cats in endemic areas.

Evaluation of the association of Bartonella species, feline herpesvirus 1, feline calicivirus, feline leukemia virus and feline immunodeficiency virus with chronic feline gingivostomatitis

Gingivostomatitis (GS) is a significant condition in cats because of oral discomfort and associated periodontal disease. Several infectious agents have been associated with the presence of GS, but a causal relationship is unclear. The cats in this study were housed together, had a history of flea exposure, and were vaccinated with a modified live FVRCP product. There were nine cats with active GS and 36 unaffected cats at the time of sample collection. Serum was tested for feline leukemia virus (FeLV) antigen and antibodies against feline immunodeficiency virus, feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), and Bartonella species (enzyme-linked immunosorbent assay and Western blot immunoassay). PCR assays for Bartonella species and FHV-1 and a reverse transcriptase PCR assay for FCV were performed on blood and throat swabs. All cats were negative for FeLV. Assay results failed to correlate to the presence of GS in the group of cats studied.

Association of Bartonella species, feline calicivirus, and feline herpesvirus 1 infection with gingivostomatitis in cats.

Feline gingivostomatitis (FGS) is a common syndrome in cats; feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), and Bartonella species are common differential diagnoses. In this study, blood from 70 cats with FGS and 61 healthy control cats was tested for Bartonella species antibodies in serum by enzyme-linked immunosorbent assay and Western blot immunoassay and DNA in blood using a conventional polymerase chain reaction assay. Additionally, fresh oral biopsies from cats with FGS (n=42) and 19 healthy controls were tested for FCV RNA, FHV-1 DNA and Bartonella species DNA. The prevalence rates for Bartonella species antibodies and DNA in the blood and the tissues did not differ between the two groups. FHV-1 DNA was also not significantly different between groups. Only FCV RNA was present in significantly more cats with FGS (40.5%) than control cats (0%). The results suggest that FCV was associated with FGS in some of the cats.

Detection of Toxoplasma gondii in the milk of experimentally infected lactating cats

Tachyzoites of Toxoplasma gondii have been found in the milk of sheep, goats, cows and mice and infection by ingestion of raw goat milk has been documented in humans. Lactational transmission from infected cats to their kittens is suspected but the organism has not been detected in the milk. The purpose of this study was to demonstrate the presence of T. gondii in the milk of experimentally infected cats. Pregnant specific pathogen free cats were inoculated orally with T. gondii at various times prior to parturition. Feces were examined for oocyst shedding after sugar solution centrifugation. Milk was collected for polymerase chain reaction (PCR) and bioassay in mice. T. gondii was detected in the milk of five of six cats by either bioassay or PCR.

Prevalence of Bartonella species antibodies and Bartonella species DNA in the blood of cats with and without fever

The purpose of this study was to determine whether there are associations between Bartonella species antibody (enzyme-linked immunosorbent assay (ELISA) and Western blot (WB)) and polymerase chain reaction assay results in cats with and without fever. Afebrile control cats (39/93; 42.0%) were more likely to have Bartonella species antibodies than cats with fever (29/93; 31.2%). The difference in prevalence of Bartonella species deoxyribonucleic acid (DNA) in blood of cats with fever (14/81; 17.3%) as compared to afebrile control cats (6/81; 7.4%) approached statistical significance (P=0.0571). Bartonella species ELISA or WB results frequently did not correlate to the presence or absence of Bartonella species DNA in blood. The results of this study indicate that in cats, Bartonella species antibody tests cannot predict whether fever is due to Bartonella species infection and should not be used to determine the Bartonella species infection status.

Prevalence of Rickettsia species antibodies and Rickettsia species DNA in the blood of cats with and without fever

Rickettsia species antibodies have been detected in some cats but it is unknown whether infected cats develop clinical signs. The prevalence of Rickettsia species deoxyribonucleic acid (DNA) in blood from clinically ill cats has not been determined. The objective of this study was to determine if cats with fever (body temperature ≥102.5°F [39.2°C]) were more likely to have evidence of rickettsial infection than healthy, age-matched, control cats with a body temperature<102.5°F. Rickettsia species polymerase chain reaction (PCR) assays were performed to detect rickettsial DNA extracted from blood (71 paired samples), indirect immunofluorescence assays (IFA) were performed to detect serum antibodies against Rickettsia felis (90 paired samples) and Rickettsia rickettsii (91 paired samples), and the results between pairs were compared. All samples were negative for Rickettsia species DNA. More cats with fever were seropositive for R felis or R rickettsii than control cats, but results were not statistically significant. Results of this pilot study failed to show an association between Rickettsia species DNA or Rickettsia species antibodies and fever.

A flea and tick collar containing 10% imidacloprid and 4.5% flumethrin prevents flea transmission of Bartonella henselae in cats

BackgroundBartonella henselae is transmitted amongst cats by Ctenocephalides felis and is associated with multiple clinical syndromes in cats and people. In a previous study, monthly spot-on administration of 10% imidacloprid/1% moxidectin was shown to block transmission of B. henselae amongst cats experimentally exposed to infected C. felis. The purpose of this study was to determine whether application of a flea and tick collar containing 10% imidacloprid and 4.5% flumethrin would lessen C. felis transmission of B. henselae amongst cats for 8 months.MethodsSpecific pathogen free cats (n = 19) were housed in three adjoining enclosures that were separated by mesh to allow C. felis to pass among groups but prevent cats in different enclosures from contacting one another. One group of 4 cats was inoculated intravenously with B. henselae and after infection was confirmed in all cats based on positive PCR assay results, the cats were housed in the middle enclosure. The B. henselae infected cat group was flanked by a group of 8 cats that had the collar placed and maintained for the duration of the study and a group of 7 cats that were not treated. Ctenocephalides felis (50 males and 50 females) raised in an insectary were placed on each of the 4 cats in the B. henselae infected group monthly for 7 applications and then every 2 weeks for 4 applications starting the day the collar was applied. Blood was collected from all cats weekly for Bartonella spp. PCR, serology and culture.ResultsWhile side-effects associated with the collars were not noted, persistent fever necessitating enrofloxacin therapy occurred in two of the untreated cats. While B. henselae infection was ultimately confirmed in 4 of 7 of the untreated cats, none of the cats with collars became infected (P = 0.026).ConclusionsIn this study design, use of a collar containing 10% imidacloprid and 4.5% flumethrin was well tolerated and prevented C. felis transmission of B. henselae amongst cats for 8 months.

Prevalence of Coxiella burnetii DNA in vaginal and uterine samples from healthy cats of north-central Colorado.

Q fever is a worldwide zoonotic disease caused by Coxiella burnetii. Although traditionally associated with livestock exposure, human infection has also been documented from contact with parturient cats. The goal of this study was to determine the prevalence of C burnetii DNA in uterine and vaginal tissues from healthy client-owned and shelter cats of north-central Colorado using polymerase chain reaction assay. Coxiella burnetii was not amplified from vaginal samples of any cat or uterine biopsies of shelter cats. However, a nucleotide sequence with 99% homology to C burnetii DNA was amplified from four of 47 (8.5%) uterine biopsies of client-owned cats. This study demonstrates that clinically normal cats in north-central Colorado can harbor C burnetii. Care should be taken when attending to parturient cats and contact with parturient secretions should be avoided. Additional studies are indicated to further characterize the role of cats in zoonotic Q fever.

Flea species infesting dogs in Florida and Bartonella spp. prevalence rates.

Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S-23S intergenic spacer region. A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I. Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols.

Prevalence of Bartonella henselae antibodies in serum of cats with and without clinical signs of central nervous system disease

Bartonella henselae is occasionally associated with neurological dysfunction in people and some experimentally infected cats. The purpose of this study was to determine whether B henselae seroprevalence or titer magnitude varies among cats with neurological disease, cats with non-neurological diseases, and healthy cats while controlling for age and flea exposure. There was no difference in B henselae seroprevalence rates between cats with seizures and cats with other neurological diseases. Cats with non-neurological disease and healthy cats were more likely than cats with neurological disease to be seropositive. While the median B henselae antibody titer was greater in cats with seizures than in cats with other neurological disease, the median B henselae antibody titer was also greater in healthy cats than cats with seizures. The results suggest that titer magnitude cannot be used alone to document clinical disease associated with B henselae infection and that presence of B henselae antibodies in serum of cats with neurological disease does not prove the clinical signs are related to B henselae.