Data from: Antimicrobial resistance trends in fecal Salmonella isolates from northern California dairy cattle admitted to a veterinary teaching hospital, 2002-2016

Nontyphoidal Salmonella infections contribute to approximately 1.2 million
annual illnesses in the United States. Historical and recent outbreaks
have been associated with dairy products, ground beef, and direct contact
with cattle. Salmonella antimicrobial resistance (AMR) is a serious
concern that can reduce successful treatment of infections, increasing
recovery time, medical costs, and mortality rates in humans and animals.
This highlights the need to track AMR in Salmonella isolated from cattle
to improve treatment plans, manage trends in AMR, and prevent future AMR
development. A total of 242 Salmonella isolates were retrieved from 9,162
cattle fecal samples submitted to the University of California, Davis
Veterinary Medical Teaching Hospital from 2002 to 2016. These isolates
were tested for antimicrobial susceptibility using a standardized broth
dilution panel. Multidrug resistance (MDR) to three or more classes of
antimicrobials was observed in 50.8% of isolates, and the most common MDR
pattern was
amoxicillin-ampicillin-cefoxitin-ceftiofur-ceftriaxone-chloramphenicol-streptomycin-tetracycline (23.2%). There were significantly greater odds for antimicrobial resistance to aminoglycosides (OR: 2.03, 95% CI: 1.1 - 3.7), penicillins (OR: 1.87, 95% CI: 1.007 - 3.5), and tetracyclines (OR: 1.87, 95% CI: 1.017 - 3.4) for the 2002-2009 period when compared to the 2010-2016 period. The most prevalent MDR serotypes were Newport (100% MDR, n= 52), Typhimurium (100%, n= 20), and Dublin (71% MDR, n= 46). Risk factors associated with higher odds for isolating MDR Salmonella included isolates from calves when compared to adult cattle (OR: 22.0; 95% C.I.: 3.9 - 125.7), and isolates obtained from cattle suspect of having salmonellosis versus from the infectious disease control surveillance program (OR:13.7; 95%C.I.: 2.8 - 66.8). Despite a temporal trend for reduced AMR to most antimicrobial drug classes, a lack of this observed in the 2002-2009 period when compared to the 2010-2016 period for important drug classes such as cephalosporins (OR: 1.6, 95% CI: 0.87 - 3.1), and a trend for temporal increase in resistant to quinolones drugs (P value 0.004) highlight the relevance of AMR surveillance in cattle with Salmonella infections with the aim of targeting future prophylactic interventions.

非伤寒沙门氏菌感染每年在美国导致约120万例疾病。历史及近期暴发与乳制品、绞碎牛肉及直接接触牛只相关。沙门氏菌的抗微生物耐药性（Antimicrobial Resistance, AMR）是一个严重问题，其会降低感染治疗的成功率，增加人类与动物的恢复时间、医疗成本及死亡率。这凸显了追踪从牛分离的沙门氏菌中AMR的必要性，以改进治疗方案、管理AMR趋势并预防未来AMR的发展。2002年至2016年间，从加州大学戴维斯分校兽医学院教学医院提交的9162份牛粪便样本中检索到242株沙门氏菌分离株。这些分离株采用标准化肉汤稀释板进行抗微生物药敏测试。50.8%的分离株对三类或以上抗微生物药物表现出多重耐药性（Multidrug Resistance, MDR），最常见的MDR模式为阿莫西林-氨苄西林-头孢西丁-头孢噻呋-头孢曲松-氯霉素-链霉素-四环素（23.2%）。与2010-2016年期间相比，2002-2009年期间分离株对氨基糖苷类（OR：2.03，95% CI：1.1–3.7）、青霉素类（OR：1.87，95% CI：1.007–3.5）及四环素类（OR：1.87，95% CI：1.017–3.4）的耐药性比值比显著更高。最常见的MDR血清型为Newport（100% MDR，n=52）、Typhimurium（100%，n=20）及Dublin（71% MDR，n=46）。与成年牛相比，来自犊牛的分离株（OR：22.0；95% CI：3.9–125.7），以及从疑似沙门氏菌病的牛只中获得的分离株与从传染病控制监测项目中获得的分离株相比（OR：13.7；95% CI：2.8–66.8），分离出MDR沙门氏菌的比值比更高。尽管大多数抗微生物药物类别存在AMR降低的时间趋势，但2002-2009年与2010-2016年相比，在头孢菌素类等重要药物类别中未观察到此趋势（OR：1.6，95% CI：0.87–3.1），且对喹诺酮类药物的耐药性呈时间性增加趋势（P值0.004），这凸显了针对沙门氏菌感染牛只开展AMR监测的重要性，旨在为未来预防性干预措施提供靶向依据。