- 學位論文
多重抗藥性大腸桿菌 O25b-ST131 的危機：社區型泌尿道感染
Emergence of Drug-resistant Escherichia coli O25b-ST131：A Major Community-acquired Uropathogen in Infants
摘要
ESBL E. coli O25b-ST131菌株已經成為全世界抗藥性感染的重要問題。在台灣， ESBL 大腸桿菌引起菌血症而造成泌尿道感染的文獻相當多，但關於 ESBL 大腸桿菌引起嬰幼兒泌尿道感染的文獻並不多，尤其是基因分型與臨床表現的關係。 我們蒐集 2008 年到 2012 年嬰幼兒泌尿道感染所分離出來之菌株共 113 株進行分析，且 ESBLs 的菌株比例逐年有明顯增加的趨勢。亞洲地區的 ESBL E. coli的 CTX-M 基因分型多為 CTX-M-3、CTX-M-14。在113 株 E. coli 菌株中基因分型為 CTX-M-14之菌株佔88.4%；以chuA、yjaA與TspE4C2基因做親緣性分析( Phylogenetic Group )，結果顯示大多為 B2 group。 在O25b 血清型分型結果當中發現，共有 79 株為 O25b type，剩下 33 株為非 O25b type。佔總菌株百分比為 70 %；以MLST分析，結果顯示為O25b-ST131的菌株比例逐年增加。本研究中探討嬰幼兒泌尿道感染ESBL E.coli O25b-ST131和非 O25b-ST131 與臨床表現、實驗室數據與醫學影像檢查(如：血液中白血球細胞量、血紅素、血小板、葡萄糖、血液中尿素、在ESBL E.coli中菌血症等等)與以往疾病歷史統計分析後發現，與病情的嚴重程度(如：菌血症、腎盂腎炎等) 沒有顯著的差異，而且大多數嬰幼兒泌尿道感染之前，都很健康幾乎沒有任何明顯的致病危險因子存在。我們發現 ESBL E.coli 所引起的嬰幼兒泌尿道感染致病率幾乎為成人兩倍。從研究結果推論，大多數的ESBL E.coli 感染為社區型感染。此外，ESBL E.coli O25b-ST131與 non- O25b-ST131 相比，O25b-ST131對於 gentamicin 和 ciprofloxacin 抗藥性逐漸增加，但對 minocycline、cefoxitin與TMP/SMX敏感性卻增加。
並列摘要
Extended-spectrum β-lactamase (ESBL)-producing E. coli O25b-ST131 has become an important issue of worldwide drug-resistant infections. In Taiwan, there are many literatures concern about ESBL E. coli of bacteremia caused by urinary tract infections (UTIs) caused considerable literature, but less one focus on ESBL E. coli causes pediatric urinary tract infections in infants. Especially lack the reports about the relation between bacterial genotyping and clinical outcome. Clinical and laboratory data from 2009 to 2012. were collected from 113 infants under one year of age who were hospitalized for UTIs caused by ESBL-producing E. coli. ESBL strains revealed the increase trends year by year. The common genotyping of CTX-M in Asia were CTX-M-3 and CTX-M-14 and also there was 88.4% distribution of CTX-M-14 to these 113 strains. Phylogenetic Group with chuA, yjaA and TspE4C2 genes revealed that most strains were belong to B2 group. In these 113 E. coli strains, there 70% (79 strains) were the O25b serotype, By Multi Locus Sequence Typing (MLST) analysis showed that O25b-ST131 strains increased every year. Analysis of the clinical outcome of UTIs with O25b-ST131 or non-O25b-ST131 strains were not significant different such as white blood cells, hemoglobin, platelets, glucose, blood urea, bacteremia, pyelonephritis, etc. In addition, surgical procedures, previous hospitalization, and underlying diseases (such as neonatal infections, hydronephrosis, and congenital heart disease) also didn't affect the outcome of UTIs with O25b-ST131 or non-O25b-ST131 strains. We found that the morbidity of infant UTIs caused by ESBL E.coli was almost twice higher than adults, From the results suggested that the ESBL E. coli results form community infection. Antimicrobial susceptibility between the ESBL E. coli O25b-ST131 and non-O25b-ST131 isolates were significant different. O25b-ST131 strains increased higher resistance to ciprofloxacin, gentamicin and a greater susceptibility to cefoxitin, minocycline, and TMP/SMX than non-O25b-ST131 isolates.