多位点序列分型
脉冲场凝胶电泳
微生物学
生物
亚胺培南
基因型
氨苄西林
分子流行病学
美罗培南
病毒学
作者
John Y. Bolukaoto,Marleen M. Kock,Kathy-Anne Strydom,Nontombi Marylucy Mbelle,Marthie M. Ehlers
标识
DOI:10.1016/j.scitotenv.2019.07.119
摘要
Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is one of the major foodborne and waterborne pathogens causing severe diseases and outbreaks worldwide. There is scarcity of EHEC O157:H7 data in South Africa. This study was carried out to determine the molecular characteristics and genotypic diversity of EHEC O157:H7 isolates in the Gauteng region, South Africa. Samples were cultured on selective chromogenic media. Antibiotic susceptibility profile of isolates was determined using the VITEK®-2 automated system. Isolates were characterised using multiplex PCR assays and the genetic diversity was determined using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 520 samples of which 270 environmental water samples and 250 stool specimens were collected and analysed. Overall, EHEC O157:H7 was recovered from 2.3% (12/520) of samples collected. Environmental water samples and clinical stool specimens showed a prevalence of 4.07% (11/270) and 0.4% (1/250) respectively. Antibiotic susceptibility profile varied from isolates with full susceptibility to isolates with resistance to multiple antibiotics. Most resistance was detected to the penicillins, specifically ampicillin (7/12), amoxicillin (3/12) and piperacillin/Tazobactam (3/12) followed by one of the folate inhibitors, trimethoprim (3/12) and the carbapenems, imipenem and meropenem (2/12) each. Three isolates harboured a combination of Shiga-toxins ( Stx )-2, intimin ( eae ) and enterohaemolysin ( hly A) genes, while two isolates harboured the Stx -1, Stx- 2 and hly A genes. The PFGE performed showed that EHEC O157:H7 isolates were genetically diverse, with two minor pulsotypes and eight singletons. The MLST analysis identified three sequence types (STs) (ST10, ST11 and ST1204) that have been previously reported associated with outbreaks. The STs identified in this study pose a potential public health risk to consumers of untreated environmental water and closed human contacts. There is necessity to enhance surveillance in reducing the propagation of this bacterium which is a public health problem. • Environmental water samples and clinical stool specimens were analysed for the detection of EHEC O157:H7 • The EHEC O157:H7 isolates were more prevalent in environmental samples than in clinical specimens • The combination of virulence genes was detected among EHEC O157:H7 isolates • The EHEC O157:H7 isolates were genetically diverse. Three sequence types (ST10, ST11, ST1204) were identified in this study that have never been reported in South Africa • These STs pose potential public health risk to consumers of untreated water and closed human contacts
科研通智能强力驱动
Strongly Powered by AbleSci AI