Makarova M A, Matveeva Z N, Smirnova E V, Semchenkova L I, Derevianchenko I A, Sokol'nik S E, Zchirnova L Y, Kotova N K, Pelenko T V, Dudnikov D S, Vasilyeva N V, Kaftyreva L A
Saint-Petersburg Pasteur Institute, 197101, Saint-Petersburg, Russia.
North-Western State Medical University named after I.I. Mechnikov, the medical microbiology department, 191015, Saint-Petersburg, Russia.
Klin Lab Diagn. 2020;65(6):368-374. doi: 10.18821/0869-2084-2020-65-6-368-374.
Were studied the genes encoding the virulence factors of 221 strains: E. coli O:H (194) and E. coli O:H (27), isolated in 2014-2018 from stool samples of children and adults examined according to epidemic indications. Molecular methods included PCR with hybridization-fluorescence and electrophoresis detection of amplified products. The strains did not have virulence genes for diarrheagenic E. coli (DEC) pathogroups EPEC, ETEC, EIEC, EHEC, EAggEC, and belonged to the phylogenetic group B2. They contained from four to eight genes encoding virulence factors of ExPEC: E. coli O:H - pap (68,6%), sfa (87,6%), fimH (96,4%), hly (62,4%), cnf (74,7%), iutA (97,9%), fyuA (95,9%), chu (100%); E. coli O:H - pap (66,7%), afa (22,2%), fimH (100%), hly (44,4%), cnf (44,4%), iutA (100%) , fyuA (100%), chu (100%). The antimicrobial susceptibility testing to 6 classes of antimicrobials (beta-lactams, fluoroquinolones, aminoglycosides, nitrofurantoin, sulfanilamide, trimethoprim / sulfamethoxazole) according the EUCAST. 60,3% of E. coli O:H were sensitive to antibiotics, E. coli O25:H4 remained sensitive to carbapenems and nitrofurans. Extended-spectrum cephalosporins resistance was due to the production ESBL (CTX-M). The 57,1% resistant strains of E. coli O:H and 100% of E. coli O:H strains belonged to the MDR phenotype. The XDR phenotype had one in five MDR strains of E. coli O6:H1 and E. coli O:H. All strains of E. coli O:H belonged to ST131. Given the important role of E. coli in human pathology, detection of virulence genes should be performed to confirm the etiological significance of the isolated strain.
对221株菌株的毒力因子编码基因进行了研究：2014 - 2018年从根据流行指征检查的儿童和成人粪便样本中分离出的大肠杆菌O:H（194株）和大肠杆菌O:H（27株）。分子方法包括采用杂交 - 荧光PCR以及扩增产物的电泳检测。这些菌株没有致泻性大肠杆菌（DEC）致病群EPEC、ETEC、EIEC、EHEC、EAggEC的毒力基因，属于系统发育群B2。它们含有4至8个编码肠外致病性大肠杆菌（ExPEC）毒力因子的基因：大肠杆菌O:H - pap（68.6%）、sfa（87.6%）、fimH（96.4%）、hly（62.4%）、cnf（74.7%）、iutA（97.9%）、fyuA（95.9%）、chu（100%）；大肠杆菌O:H - pap（66.7%）、afa（22.2%）、fimH（100%）、hly（44.4%）、cnf（44.4%）、iutA（100%）、fyuA（100%）、chu（100%）。根据欧盟CAST标准对6类抗菌药物（β - 内酰胺类、氟喹诺酮类、氨基糖苷类、呋喃妥因、磺胺类、甲氧苄啶/磺胺甲恶唑）进行药敏试验。60.3%的大肠杆菌O:H对抗生素敏感，大肠杆菌O25:H4对碳青霉烯类和呋喃类仍敏感。超广谱头孢菌素耐药是由于产生ESBL（CTX - M）。57.1%的大肠杆菌O:H耐药菌株和100%的大肠杆菌O:H菌株属于多重耐药（MDR）表型。广泛耐药（XDR）表型在大肠杆菌O6:H1和大肠杆菌O:H的五分之一MDR菌株中出现。所有大肠杆菌O:H菌株都属于ST131。鉴于大肠杆菌在人类病理学中的重要作用，应进行毒力基因检测以确认分离菌株的病因学意义。
