Yandag Munkhdelger, Tsend-Ayush Altansukh, Gunregjav Nyamaa, Erdenebayar Otgontsetseg, Byambadorj Bayarlakh, Juniichiro Nishi, Jav Sarantuya
Department of Molecular Biology and Genetics, School of Biomedicine, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
J Infect Dev Ctries. 2023 Feb 28;17(2):202-209. doi: 10.3855/jidc.17256.
Diarrheal diseases are common with worldwide distribution, and diarrheagenic Escherichia coli (DEC) strains are the main causative agents. The present study aimed to define the association of various pathotypes of E. coli from diarrheal patients in Mongolia.
A total of 341 E. coli strains were isolated from the stool of diarrheal patients. Bacterial susceptibility to antimicrobial agents was determined by the Kirby Bauer disk diffusion method. DEC isolates were identified by HEp-2 cell adherence assay and multiplex polymerase chain reaction (PCR).
DEC pathogens were detected in 53.7% of 341 E. coli isolates. Enteroaggregative E. coli (EAEC) was the most common DEC pathotype identified by HEp-2 adherence assay and multiplex PCR methods in 97 samples (28.4%), followed by atypical enteropathogenic E. coli (EPEC) in 50 samples (14.7%), diffusely adherent E. coli (DAEC) in 25 samples (7.3%), enterohaemorrhagic E. coli (EHEC) in 6 samples (1.8%), enterotoxigenic E. coli (ETEC) in 4 samples (1.2%), and enteroinvasive E. coli (EIEC) in 1 sample (0.3%). DEC strains had > 50% antibiotic resistance against cephalothin, ampicillin, and trimethoprim/sulfamethoxazole. All tested DEC strains were susceptible to imipenem. Among the 183 DEC strains, 27 (14.8%) were extended spectrum beta-lactamase producing isolates, and 125 (68.3%) isolates were multiple drug resistant.
We have identified six pathotypes of DEC from the clinical isolates tested and concluded that a high prevalence of antimicrobial resistance was observed in these pathotypes. EAEC was the most common pathotype identified and this is the first report of EHEC identification in Mongolia.
腹泻病在全球范围内普遍存在，而致泻性大肠杆菌（DEC）菌株是主要致病原。本研究旨在确定蒙古腹泻患者中不同大肠杆菌致病型之间的关联。
从腹泻患者粪便中分离出341株大肠杆菌菌株。采用 Kirby Bauer 纸片扩散法测定细菌对抗菌药物的敏感性。通过 HEp-2 细胞黏附试验和多重聚合酶链反应（PCR）鉴定DEC分离株。
在341株大肠杆菌分离株中，53.7%检测到DEC病原体。通过HEp-2黏附试验和多重PCR方法鉴定，肠集聚性大肠杆菌（EAEC）是最常见的DEC致病型，共97株（28.4%），其次是非典型肠致病性大肠杆菌（EPEC）50株（14.7%），弥漫性黏附性大肠杆菌（DAEC）25株（7.3%），肠出血性大肠杆菌（EHEC）6株（1.8%），产肠毒素大肠杆菌（ETEC）4株（1.2%），肠侵袭性大肠杆菌（EIEC）1株（0.3%）。DEC菌株对头孢噻吩、氨苄西林和甲氧苄啶/磺胺甲恶唑的耐药率超过50%。所有检测的DEC菌株对亚胺培南敏感。在183株DEC菌株中，27株（14.8%）为产超广谱β-内酰胺酶分离株，125株（68.3%）分离株为多重耐药。
我们从检测的临床分离株中鉴定出六种DEC致病型，并得出结论，这些致病型中抗菌药物耐药性普遍存在。EAEC是鉴定出的最常见致病型，这是蒙古首次报告鉴定出EHEC。
