Freitag Thurid, Squires Richard A, Schmid Jan, Elliott Jonathan, Rycroft Andrew N
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
J Vet Intern Med. 2006 Mar-Apr;20(2):245-9. doi: 10.1892/0891-6640(2006)20[245:aspdnr]2.0.co;2.
Older cats with chronic renal failure (CRF) commonly develop urinary tract infections (UTI). Uropathogenic Escherichia coli (UPEC) is identified as the causal agent of UTI in most affected cats. Infections are often complicated, and UPEC infections may persist or recur in these cats. Antibiotic sensitivity profiles have been used to distinguish relapsing or persisting UTI from reinfection by different clones of the same species. However, the accuracy with which antibiograms discriminate different urinary E coli clones in cats is uncertain. We studied 17 cystocentesis-derived UPEC isolates collected from 5 cats with stable CRF and multiple diagnoses of UTI. UTIs were classified as relapses versus persistent infections or reinfections using antibiograms determined by Kirby-Bauer discs and Etests. Subsequently, clonality of UPEC isolates was determined by pulsed-field gel electrophoresis (PFGE). A comparison of PFGE results with antibiograms indicated that antibiotic resistance patterns varied considerably within several individual E coli clones. Both antibiotic susceptibility tests differentiated between relapsing or persistent infections and reinfections with only 58% overall efficiency. Thus, antibiotic sensitivity profiles cannot be relied upon to distinguish between persisting or relapsing infections as compared to reinfections in cats with CRF and multiple diagnoses of E coli UTI.
患有慢性肾衰竭（CRF）的老年猫通常会发生尿路感染（UTI）。尿路致病性大肠杆菌（UPEC）被确定为大多数受影响猫尿路感染的病原体。感染往往较为复杂，UPEC感染在这些猫中可能会持续或复发。抗生素敏感性谱已被用于区分复发性或持续性尿路感染与同一物种不同克隆的再感染。然而，抗菌谱区分猫尿液中不同大肠杆菌克隆的准确性尚不确定。我们研究了从5只患有稳定CRF且多次诊断为UTI的猫中收集的17株经膀胱穿刺获得的UPEC分离株。使用Kirby-Bauer纸片法和Etest测定的抗菌谱将UTI分类为复发与持续性感染或再感染。随后，通过脉冲场凝胶电泳（PFGE）确定UPEC分离株的克隆性。PFGE结果与抗菌谱的比较表明，在几个单独的大肠杆菌克隆中，抗生素耐药模式差异很大。两种抗生素敏感性试验区分复发性或持续性感染与再感染的总体效率仅为58%。因此，与患有CRF且多次诊断为大肠杆菌UTI的猫的再感染相比，不能依靠抗生素敏感性谱来区分持续性或复发性感染。
