Antimicrobial treatment preferences among veterinarians for Golden Retrievers in the United States.

OBJECTIVE: To identify the preferred choices of antimicrobials by veterinarians for addressing infectious diseases in Golden Retrievers across the US. ANIMALS: 3,044 Golden Retrievers enrolled in the Golden Retriever Lifetime Study. METHODS: Demographic and veterinary visit data were retrieved from the Morris Animal Foundation Golden Retriever Lifetime Study, following 3,044 Golden Retrievers spanning from 2012 to 2020 collected through questionnaires. The R Studio program was used to clean and analyze the data in which the most common diagnoses were evaluated along with the most frequently used antimicrobials stratified by geographical region within the US. RESULTS: The most common diagnoses reported and treated with antimicrobials were otitis externa, diarrhea/gastritis, hot spots, and bladder infections. Otitis externa was the most frequently reported medical diagnosis as well as prescribed with antibiotics. The Southern region reported the most antimicrobial use, followed by the Midwest and Northeast. Of the total reported antibiotics prescribed for infectious disease, aminoglycosides were the most frequent (370/1,874 [19.74%]) followed by first-generation cephalosporins, nitroimidazoles, and penicillins. CLINICAL RELEVANCE: More effort in the prevention of otitis externa in Golden Retrievers may reduce overall antimicrobial usage and promote effective antimicrobial stewardship to combat further antimicrobial resistance.

Antimicrobial resistance and genetic diversity of Staphylococcus aureus collected from livestock, poultry and humans.

Staphylococcus aureus is one of the most prominent nosocomial, community and farm acquired bacterial infections among animals and human populations. The main purpose of our study was to identify and characterize antimicrobial resistance (AMR) among Staphylococcus aureus isolated from livestock, poultry and humans and to further identify the associated genes. Staphylococcus aureus isolates from human, bovine, swine and poultry were collected from different laboratories across the United States collected between 2003 and 2016. Antimicrobial susceptibility testing for 13 antimicrobials was performed and conventional PCR was used to detect the presence of the nuc gene, mec gene, and to detect int1 gene. Associations between the presence of mec and intl and specific AMR profiles were determined. Antimicrobial resistance was detected in all four host categories, with the highest overall rates found in swine, 100% resistant to tetracycline, 88% to penicillin and 64% clindamycin. The next highest was found among humans with 81.6% of isolates resistant to penicillin followed by 44% to clindamycin and 43% to erythromycin. Among beef cattle isolates, 63.2% were resistant to penicillin, 15.8% resistant to clindamycin and 15.8% to erythromycin. No isolates from any of the hosts were resistant to linezolid. Among poultry isolates, the highest AMR was found to clindamycin, followed by erythromycin and penicillin. Among dairy cattle, highest resistance was found to penicillin, followed by chloramphenicol and gentamicin. Dairy cattle were the only host category with isolates that are resistant to trimethoprim-sulfamethoxazole. Of the 220 isolates detected by latex agglutination, 217 were confirmed to be S. aureus via PCR of the nuc gene, 21.4% were positive for the mecA gene. Swine had the highest prevalence of the mecA gene, followed by humans, poultry and beef cattle. This study has demonstrated a high occurrence of penicillin resistance among all S. aureus isolates. There were differences observed between host species with tetracycline resistance being the highest among swine isolates and clindamycin being highest in poultry isolates. No detection of oxacillin resistance was found in isolates from dairy cattle but was found in isolates from all of the other host species, 94% of which contained the mecA gene.