摘要
目的为了解生鲜乳中大肠杆菌生物特性及流行特点,本研究采集新疆北疆3个地区6个规模化牛场生鲜乳。方法采用分离纯化、16S rRNA基因测序和构建系统进化树等方法对大肠杆菌进行分离鉴定;通过PCR方法对分离株进行多位点序列分型(MLST)和8种耐药基因分析,利用微量肉汤稀释法和结晶紫染色法检测分离株对13种抗生素的耐药性和生物被膜形成能力,小鼠感染试验分析其致病性。结果共分离鉴定了7株大肠杆菌,分离率38.9%,且具有不同程度致病性;7株大肠杆菌分3个ST型,分别为ST183(57.1%)、ST58(28.6%)、ST49(14.3%);分离株对头孢曲松钠、头孢吡肟耐药率为85.7%,对阿米卡星、庆大霉素、氧氟沙星耐药率分别为71.4%、42.9%、14.3%;100%分离株携带β-内酰胺类blaTEM,71.4%菌株携带喹诺酮类aac(6′)-Ib基因,42.8%的菌株携带gyrA,71.4%的菌株携带四环素类Tet(B)基因;KT株具有强生物被膜形成形成能力,SHZ1-1、SHZ2、SHZ3、SHZ4、YL为中等生物被膜形成菌株,SHZ1-2为弱成膜菌株。结论表明分离于生鲜乳大肠杆菌具有多重耐药特点,并携带多种耐药基因,能形成较强生物被膜,该结果为评估新疆部分地区生鲜乳中大肠杆菌特点和临床用药提供理论依据。
Objective In order to understand the characteristics and prevalence of E.coli in raw milk,E.coli in raw milk from 6 large scale cattle farms in 3 regions of northern Xinjiang were identified by conventional separation and purification combined with 16S rRNA sequence analysis.Methods The PCR method was used to analyzed MLST type and the resistance genes of isolates.The resistance phenotypes to 13 antibiotics of isolates were detected by microbroth dilution method.The micro broth dilution method and crystal violet staining method were used to detect the resistance and biofilm formation ability of isolated strains to 13 antibiotics,and the pathogenici-ty was analyzed through mouse infection test.Conclusion 7 strains of E.coli were isolated,with an isolation rate of 38.9%and with different degrees of pathogenicity.There were 3 ST types in 7 E.coli,namely ST183(57.1%),ST58(28.6%)and ST49(14.3%).The resistance rates of isolates to ceftriaxone sodium and cefepime were 85.7%and to amikacin,gentamicin,gentamicin and ofloxacin were 71.4%,42.9%and 14.3%.100%of the isolates carriedβ-lactam blaTEM gene,71.4%carried quinolone aac(6′)-Ib gene,42.8%carried gyrA,and 71.4%carried tetracycline Tet(B)gene.KT strain had strong biofilm formation ability.SHZ1-1,SHZ2,SHZ3,SHZ4,YL were medium biofilm forming strains and SHZ1-2 was weak film-forming strain.Results Indicated that E.coli isolated from row milk had multidrug resistance and carried multiple drug resistance genes,which could form strong bio-film.The results provide a theoretical basis for evaluating the characteristics and clinical medication use of E.coli in raw milk in some areas of Xinjiang.
作者
王巧梅
王子杰
操义恒
王晓兰
周霞
吴洁
孙志华
王震
张辉
WANG Qiaomei;WANG Zijie;CAO Yiheng;WANG Xiaolan;ZHOU Xia;WU Jie;SUN Zhihua;WANG Zhen;ZHANG Hui(College of Animal Science and Technology,Shihezi University,Shihezi,Xinjiang 832003,China;Animal Husbandry and Veterinary Workstation of the Eighth Division of Xinjiang Production and Construction Corps,Shihezi,Xinjiang 832003,China)
出处
《石河子大学学报（自然科学版）》
CAS
北大核心
2023年第5期555-561,共7页
Journal of Shihezi University(Natural Science)
基金
新疆生产建设兵团重点领域科技攻关计划项目(2021AB012,2019AB029)。
