RESUMO
Mycobacterium avium-intracellulare complex (MAC) infections have been described in many mammalian species, including humans and pets. We isolated and molecularly typed the causative agent of a rare case of disseminated mycobacteriosis in a dog. We identified the pathogen as M. avium subspecies avium by sequencing the partial genes gyrB and rpsA. Considering the zoonotic potential of this infection, and in an attempt to ensure the most effective treatment for the animal, we also determined the drug susceptibility profile of the isolate to the most common drugs used to treat MAC disease in humans. The pathogen was tested in vitro against the macrolide clarithromycin, as well as against amikacin, ciprofloxacin, rifampicin, ethambutol and linezolid, by the resazurin microdilution assay. It was found to be sensitive to all tested drugs apart from ethambutol. Despite the fact that the pathogen was sensitive to the therapies administered, the dog's overall clinical status worsened and the animal died shortly after antimicrobial susceptibility results became available. Nucleotide sequencing of the embB gene, the target gene most commonly associated with ethambutol resistance, showed new missense mutations when compared to sequences available in public databases. In conclusion, we molecularly identified the MAC pathogen and determined its drug susceptibility profile in a relatively short period of time (7 days). We also characterized new genetic mutations likely to have been involved in the observed ethambutol resistance. Our results confirmed the usefulness of both the gyrB and the rpsA genes as biomarkers for an accurate identification and differentiation of MAC pathogens.
RESUMO
OBJECTIVE: To evaluate performance of a human portable blood glucose meter (PBGM), a veterinary PBGM, and a veterinary benchtop analyzer for measuring blood glucose concentration in rabbits and to evaluate the effect of sample characteristics on their performance. DESIGN: Observational prospective cross-sectional study. SAMPLE: Blood samples from 89 pet rabbits. PROCEDURES: Blood glucose concentration was measured with a human PBGM (n = 89 rabbits), a veterinary PBGM (89), and a benchtop analyzer (32) and compared with results obtained with plasma in a laboratory analyzer (hexokinase method). RESULTS: The human PBGM underestimated blood glucose concentration, had decreased accuracy at high Hcts, and had the lowest total error observed (11.4%). The veterinary PBGM overestimated blood glucose concentration, had decreased accuracy at low Hcts and at high blood glucose concentrations, and had the highest total error (15.5% and 29.8% for canine and feline settings, respectively). The benchtop analyzer had good accuracy and was not influenced by Hct or glucose concentrations. Clinical errors would have occurred in 0% of cases with the human PBGM and with the benchtop analyzer and in 9% (canine setting) to 6.7% (feline setting) of cases with the veterinary PBGM. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that use of the human PBGM evaluated in this study would be acceptable for point-of-care testing of blood glucose concentration in rabbits when benchtop analyzers are not available. The use of the veterinary PBGM evaluated in this study may alter both treatment and diagnostic decisions because of the overestimation of glucose concentrations in some rabbits.