Comparison of commercial next-generation sequencing assays to conventional culture methods for bacterial identification and antimicrobial susceptibility of samples obtained from clinical cases of canine superficial bacterial folliculitis.

BACKGROUND: Bacterial identification and antimicrobial susceptibility testing is an important step in timely therapeutic decisions for canine superficial bacterial folliculitis (SBF), commonly caused by Staphylococcus pseudintermedius. Next-generation sequencing (NGS) offers the appeal of potentially expedited results with complete detection of bacterial organisms and associated resistance genes compared to culture. Limited studies exist comparing the two methodologies for clinical samples. HYPOTHESIS/OBJECTIVES: To compare and contrast genotypic and phenotypic methods for bacterial identification and antimicrobial susceptibility from cases of canine SBF. ANIMALS: Twenty-four client-owned dogs with lesions consistent with SBF were enrolled. MATERIALS AND METHODS: A sterile culturette swab was used to sample dogs with SBF lesions. The swab was rinsed in 0.9 mL of sterile phosphate-buffered saline and vortexed to create a homogenous solution. Two swabs for NGS laboratories (Labs) and one swab for culture (Culture Lab) were randomly sampled from this solution and submitted for bacterial identification and antimicrobial susceptibility. RESULTS: No statistical difference regarding turnaround time for NGS Labs compared to Culture Lab was found. NGS Lab 1 identified more organisms than NGS Lab 2 and Culture Lab, which were both statistically significant. There was no statistical difference in detection frequency for Staphylococcus spp. among all laboratories. There was poor agreement for the presence of meticillin resistance and most antimicrobials among all laboratories. CONCLUSIONS AND CLINICAL RELEVANCE: Utilisation of NGS as a replacement for traditional culture when sampling canine SBF lesions is not supported at this time.

Comparison of Aerobic Bacterial Culture Among Four Veterinary Microbiology Laboratories from Dogs with Superficial Pyoderma.

Bacterial culture and susceptibility are widely used in veterinary medicine to determine the specific bacteria causing infection as well as aid in appropriate antimicrobial selection. Previous studies have shown variable results with culture and susceptibility depending on the laboratory and methodology used. Samples from dogs with superficial pyoderma were obtained to make a homogeneous solution of bacteria. Sample acquisition from this solution was randomized and submitted to four veterinary laboratories for microbial identification and sensitivity. There was fair agreement among the laboratories in identification of a Staphylococcus spp. as well as fair agreement among the laboratories on the same Staphylococcus sp. Very good agreement was noted on identification of methicillin-resistant Staphylococcus spp. Additionally, good to very good agreement was noted on all antimicrobials that were tested across all four laboratories. A difference in turnaround time for sample processing was observed between the laboratories in the present study. Overall, there was mild variability among the laboratory results in this study.

Successful management of cutaneous paralagenidiosis in a dog treated with mefenoxam, minocycline, prednisone, and hyperbaric oxygen therapy.

Cutaneous oomycotic infections are a rare dermatological disease primarily affecting horses and dogs. Response to medical management with antifungal therapies is poor because these organisms are not true fungi. Complete cure is unlikely if the infected tissue is unable to be completely surgically excised. This is a case report of successfully-managed cutaneous paralagenidiosis infection of the perianal tissue in an 11-month-old male intact Labrador retriever utilizing hyperbaric oxygen therapy, corticosteroids, minocycline, mefenoxam, and surgery.