ABSTRACT
Campylobacter is a leading cause of foodborne gastroenteritis. Recent studies have indicated a rise in fluoroquinolone-resistant (FQ-R) Campylobacter in cattle, where FQ is used to control bovine respiratory disease (BRD). To assess the effect of danofloxacin treatment on the development of FQ-resistance in C. jejuni, 30 commercial calves were divided into Group 1, Group 2, and Group 3 (n = 10), and were all inoculated orally with FQ-susceptible (FQ-S) C. jejuni; seven days later, Group 3 was challenged with transtracheal Mannheimia haemolytica, and one week later, Group 2 and Group 3 were injected subcutaneously with danofloxacin. Rectal feces were collected to determine relative percentages of FQ-R Campylobacter via culture. Before oral inoculation with C. jejuni, 87% of calves were naturally colonized by FQ-R C. jejuni. Two days after the inoculation, FQ-R C. jejuni decreased substantially in the majority of calves. Within 24 h of danofloxacin injection, almost all C. jejuni populations shifted to an FQ-R phenotype in both FQ-treated groups, which was only transitory, as FQ-S strains became predominant during later periods. Genotyping indicated that the spike seen in FQ-R C. jejuni populations following the injection was due mainly to enrichment of preexisting FQ-R C. jejuni, rather than development of de novo FQ resistance in susceptible strains. These results provide important insights into the dynamic changes of FQ-resistant Campylobacter in cattle in response to FQ treatment.
ABSTRACT
BACKGROUND: Antibiotic stewardship programs have been a major focus in recent years to curtail antibiotic resistance. The purpose of this study was to evaluate antibiotic utilization for acute respiratory tract infections (ARTI) in the Emergency Department (ED) setting. MATERIAL AND METHODS: A retrospective analysis of adult ARTI visits to EDs utilizing 2011-2017 National Hospital Ambulatory Medical Care Survey- Emergency Department (NHAMCS-ED) datasets was conducted. Included were all visits of adults (≥18 years) diagnosed with ARTI. Antibiotics were determined based upon NHAMCS-ED use of the Multum Lexicon Drug Database coding system. All significance tests were two-sided, P-value <0.05 for significance. RESULTS: A total of 4632 unweighted ED visits, which represented more than 28 million US ED visits from 2011 to 2017, with 57.2% receiving a prescription for antibiotics. Antibiotic prescriptions for ARTI significantly declined from 65.8% in 2011 to 54.3% in 2017 (P = 0.046). Among all visits, patients were more likely to receive an antibiotic if they were over age 45 (33.0% vs 27.6%, P = 0.005), male (36.7% vs. 32.3%, P = 0.039), and presenting in a non-MSA ED (21.4% vs. 14.5%, P = 0.002). No association was found between antibiotic prescription and race (P = 0.076) insurance (P = 0.488), CBC (P = 0.148), x-ray (P = 0.278), and blood cultures (P = 0.182). CONCLUSION: We found a significant reduction in the utilization of antibiotics among adult ARTI visits to U.S. EDs from 2011 to 2017. This is an improvement from previous studies which showed no change, suggesting that antimicrobial stewardship efforts may be impacting overall antibiotic use and should continue to be practiced.
