Takahashi Eizo, Sultan Zafar, Shimada Sumika, Aung Wah Wah, Nyein Mar Mar, Oo Khin Nwe, Nair Gopinath Balakrish, Takeda Yoshifumi, Okamoto Keinosuke
Department of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
Microbiol Immunol. 2008 Jan;52(1):2-8. doi: 10.1111/j.1348-0421.2008.00001.x.
Escherichia coli isolates from 217 children in Myanmar with diarrhea were investigated for the presence of virulence genes related to diarrhea by colony hybridization and PCR. The genes examined were lt, stI, stII, stx1, stx2, eae, bfp, pCVD (which is the representative gene of plasmid of pCVD of EAEC), and ial (which is invasion-associated locus of the invasion plasmid found in EIEC). Isolates from 47 of 217 children (21.7%) possessed virulence genes characteristic of diarrheagenic E. coli. No instance was found of co-existence of different E. coli strains with different virulence genes in the same patient. Diarrheagenic E. coli are currently classified into five categories based on their virulence markers: ETEC, EHEC, EPEC, EAEC, and EIEC. Of the 47 isolates examined, 30 were EAEC, 12 were EPEC and 5 were ETEC. Susceptibility tests for antimicrobial agents showed that almost all diarrheagenic isolates were resistant to penicillin, tetracycline and streptomycin. However, the majority of strains were sensitive to cephalexin, nalidixic acid and norfloxacin. In particular, 42 of the 47 isolates were sensitive to norfloxacin, which is a fluoroquinolone. This study shows EAEC and EPEC are responsible for sporadic diarrhea in Myanmar and fluoroquinolones appear to be effective in the treatment of these patients.
通过菌落杂交和聚合酶链反应（PCR），对从缅甸217名腹泻儿童中分离出的大肠杆菌进行了与腹泻相关毒力基因的检测。检测的基因包括lt、stI、stII、stx1、stx2、eae、bfp、pCVD（肠集聚性大肠杆菌pCVD质粒的代表性基因）和ial（侵袭性大肠杆菌侵袭质粒的侵袭相关位点）。217名儿童中有47名（21.7%）的分离株携带致泻性大肠杆菌的毒力基因。未发现同一患者体内存在不同毒力基因的不同大肠杆菌菌株共存的情况。目前，致泻性大肠杆菌根据其毒力标记分为五类：肠毒素型大肠杆菌（ETEC）、肠出血性大肠杆菌（EHEC）、肠致病性大肠杆菌（EPEC）、肠集聚性大肠杆菌（EAEC）和侵袭性大肠杆菌（EIEC）。在所检测的47株分离株中，30株为EAEC，12株为EPEC，5株为ETEC。抗菌药物敏感性试验表明，几乎所有致泻性分离株对青霉素、四环素和链霉素耐药。然而，大多数菌株对头孢氨苄、萘啶酸和诺氟沙星敏感。特别是，47株分离株中有42株对氟喹诺酮类药物诺氟沙星敏感。本研究表明，EAEC和EPEC是缅甸散发性腹泻的病因，氟喹诺酮类药物似乎对这些患者的治疗有效。
