Hemotropic mycoplasma prevalence in shelter and client-owned cats in Saskatchewan and a comparison of polymerase chain reaction (PCR) - Results from two independent laboratories.

The primary objective of this study was to determine the prevalence of subclinical hemotropic mycoplasma (HM) infections in 2 distinct feline populations: cats from a local shelter and client-owned cats presented for elective procedures (vaccination, ovariohysterectomy, orchiectomy) at the Western College of Veterinary Medicine - Veterinary Teaching Hospital (WCVM-VTH). The second objective of this study was to evaluate the inter-test agreement of 2 independent conventional polymerase chain reaction (PCR) assays used for the diagnosis of feline HM-infections.Fifty-eight clinically healthy shelter cats and 57 clinically healthy client-owned cats were screened for subclinical HM-infection using a conventional PCR assay to detect the 16S rRNA of Mycoplasma haemofelis and "Candidatus M. haemominutum." All cats in both groups had normal physical examinations. Sex, age (estimated for shelter cats), breed, reproductive status and the presence or absence of ectoparasites were determined. Packed cell volume (PCV), total protein, retroviral status, and blood smear evidence of HM-infection were evaluated. Subclinical HM-infection was identified by PCR assay in 12% (7/58) of the shelter cats and 4% (2/57) of the client-owned cats. M. haemofelis was found in 3/7 HM-infected shelter cats and 2/2 of the HM-infected client-owned cats; "Candidatus M. haemominutum" was found in 4/7 of the HM-infected shelter cats. There was no significant difference in prevalence of HM-infection between the populations (OR 3.8, 95% CI 0.75 to 19, P = 0.16), and no risk factors for infection were identified in either population.Blood samples from 44 cats with known PCR results (26 cats sampled in the prevalence study and 18 clinical cases) were submitted to a second independent laboratory for HM PCR assay to assess inter-laboratory agreement. There was substantial, but not complete agreement between the 2 independent laboratories for PCR detection of M. haemofelis (kappa = 0.66) and "Candidatus M. haemominutum" (kappa = 0.70).

Anemia in cats with hemotropic mycoplasma infection: retrospective evaluation of 23 cases (1996-2005).

This study summarizes the diagnostic findings from all anemic cats diagnosed with hemotropic mycoplasma (HM) infections at the Western College of Veterinary Medicine-Veterinary Teaching Hospital between 1996 and 2005. The objectives were to determine the frequency of HM-induced anemia among all cats presented with anemia during this period, the clinical findings and risk factors associated with clinical HM infection, and factors affecting or predicting survival. Medical records were examined from 23 cats with HM-induced anemia from the total of 170 cats diagnosed with anemia during this period. The frequency of HM-induced anemia was 14% (23/170) among all anemic cats. Cats with HM-induced anemia were less likely to be purebred (P = 0.04) than other cats with anemia. Of the cats with HM-induced anemia, those with positive retroviral status (P = 0.01), concurrent illness (P < 0.01), or lack of erythroid regeneration (P = 0.01) were most likely to die. The 1-year survival of HM-infected cats was 65% (13/20).

Evaluation of real-time PCR for diagnosis of Bordetella pertussis infection.

BACKGROUND: Nucleic acid amplification of the IS481 region by PCR is more sensitive than culture for detection and diagnosis of Bordetella pertussis but the assay has known cross-reactivity for Bordetella holmesii and its use as a routine diagnostic assay has not been widely evaluated. METHODS: The objectives of this study were: 1) to assess the diagnostic utility of real-time IS481 PCR by comparison of results with culture and direct fluorescent antigen (DFA) testing for B. pertussis, 2) to employ a PCR assay designed against a different insertion sequence (IS1001) to assess the incidence of B. holmesii in symptomatic individuals and 3) to design and evaluate a new PCR-based assay which could be used for B. pertussis confirmation. A total of 808 nasopharyngeal specimens were included in the study the majority of which were submitted in charcoal transport medium (88%) with the rest submitted in Regan-Lowe medium. RESULTS: Concordant results for PCR, DFA and culture were obtained for 21 B. pertussis positive and 729 B. pertussis negative specimens. DFA was prone to false positive and negative reactions when compared with both PCR and culture. The IS481 PCR identified 28 positive results for specimens that were DFA and culture negative. A novel real-time PCR targeting the B. pertussis toxin promoter was found to be specific and useful for confirming the majority of IS481 positive specimens as B. pertussis. B. holmesii was not detected in any of the submitted samples. CONCLUSION: The potential pick up of B. holmesii by the IS481 PCR had minimal diagnostic relevance in the Alberta population during the time period of our study. The IS481 PCR assay is now used in our laboratory routinely for front-line screening of samples for B. pertussis with associated enhancement in diagnostic sensitivity compared with DFA and culture. Retrospectively, patients' samples are batched and tested by the IS1001 MB and TPR assays for research purposes and to ensure there is no change in B. holmesii incidence in the population.