BACKGROUND Antimicrobial treatment protocols for foals with sepsis that do not improve clinically often are adjusted based on bacteriological and antimicrobial susceptibility testing results from samples collected at hospital admission. OBJECTIVES To evaluate whether hospitalization for ≥48 hours affects bacteriological and antimicrobial susceptibility testing results. ANIMALS Two-hundred sixty-seven foals <30 days of age admitted to a neonatal intensive care unit and diagnosed with sepsis. METHODS Medical records were reviewed retrospectively to identify foals with sepsis and positive bacteriological cultures. Results from samples collected at hospital admission were compared to those collected ≥48 hours after admission. Logistic regression for clustered data and exact logistic regression were used for statistical analysis. RESULTS Three-hundred fifty-three unique bacterial isolates were obtained from 231 foals at hospital admission and 92 unique bacterial isolates were obtained from 57 foals after ≥48 hours of hospitalization. Relative isolation frequency after ≥48 hours of hospitalization increased for Acinetobacter spp., 0.6% versus 3.3% (odds ratio [OR], 7.63; 95% confidence interval [CI], 1.28-45.45); Enterococcus spp., 4.8% versus 19.6% (OR, 5.37; 95% CI, 2.64-10.90); Klebsiella spp., 5.1% versus 10.9% (OR, 2.27; 95% CI, 1.05-4.89); Pseudomonas spp., 3.0% versus 7.6% (OR, 3.49; 95% CI, 3.49-240.50); and Serratia spp., 3.0% versus 5.4% (OR, 20.23; 95% CI, 2.20-186.14). Bacteria isolated after ≥48 hours of hospitalization were less susceptible to all tested antimicrobial drugs, except for imipenem. CONCLUSIONS AND CLINICAL IMPORTANCE Decreased antimicrobial susceptibility of bacteria isolated after ≥48 hours of hospitalization provides a rationale for repeated bacteriological culture and susceptibility testing in hospitalized foals with sepsis.

中文翻译：

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入院时和住院≥48小时后，从败血症小马驹分离出的细菌的分离率和抗菌药敏性差异。

背景技术基于在住院时收集的样品的细菌学和抗菌药物敏感性测试结果，对临床上通常不能改善的败血症小马驹的抗菌药物治疗方案进行调整。目的评估住院≥48小时是否会影响细菌学和抗菌药敏试验结果。动物年龄在30天以下的167只小马驹被送入新生儿重症监护病房并诊断为败血症。方法回顾性分析病历，以鉴定败血症和细菌培养阳性的小马驹。将入院时收集的样本结果与入院≥48小时后收集的样本进行比较。使用聚类数据的逻辑回归和精确逻辑回归进行统计分析。结果住院≥48小时后，从231只驹中获得了533个独特的细菌分离株，从57只驹中获得了92个独特的细菌分离株。不动杆菌属住院≥48小时后的相对隔离频率增加，分别为0.6％和3.3％（几率[OR]，7.63； 95％置信区间[CI]，1.28-45.45）；肠球菌，4.8％对19.6％（OR，5.37; 95％CI，2.64-10.90）; 克雷伯菌（Klebsiella spp。）5.1％和10.9％（OR，2.27; 95％CI，1.05-4.89）; 假单胞菌属，3.0％对7.6％（OR，3.49； 95％CI，3.49-240.50）；和Serratia spp。，分别为3.0％和5.4％（OR为20.23； 95％CI为2.20-186.14）。住院≥48小时后分离出的细菌对所有经测试的抗菌药物均较不敏感，除了亚胺培南。