Phiri Abel F N D, Abia Akebe Luther King, Amoako Daniel Gyamfi, Mkakosya Rajab, Sundsfjord Arnfinn, Essack Sabiha Y, Simonsen Gunnar Skov
Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
National Microbiology Reference Laboratory, Ministry of Health, Lilongwe 3, Malawi.
Trop Med Infect Dis. 2021 Apr 28;6(2):63. doi: 10.3390/tropicalmed6020063.
Although numerous studies have investigated diarrhoea aetiology in many sub-Saharan African countries, recent data on species' involvement in community-acquired acute diarrhoea (CA-AD) in Malawi are scarce. This study investigated the incidence, antibiotic susceptibility profile, genotypic characteristics, and clonal relationships of among 243 patients presenting with acute diarrhoea at a District Hospital in Lilongwe, Malawi. spp. were isolated and identified using standard microbiological and serological methods and confirmed by identifying the gene using real-time polymerase chain reaction. The isolates' antibiotic susceptibility to 20 antibiotics was determined using the VITEK 2 system according to EUCAST guidelines. Genes conferring resistance to sulfamethoxazole (, and ), trimethoprim (, and ) and ampicillin ( and ), and virulence genes (, , , , , and ) were detected by real-time PCR. Clonal relatedness was assessed using ERIC-PCR. Thirty-four isolates were isolated (an overall incidence of 14.0%). All the isolates were fully resistant to sulfamethoxazole/trimethoprim (100%) and ampicillin (100%) but susceptible to the other antibiotics tested. The (79%), (79%), (47%), (71%) and (56%) sulfonamide and trimethoprim resistance genes were identified; , and were not detected. The virulence genes (85%), (85%), (82%), (76%), (71%), (71%), (26%) and (18%) were detected. ERIC-PCR profiling revealed that the isolates were genetically distinct and clonally unrelated, indicating the potential involvement of genetically distinct in CA-AD in Malawi. The high percentage resistance to ampicillin and sulfamethoxazole/trimethoprim and the presence of several virulence determinants in these isolates emphasises a need for continuous molecular surveillance studies to inform preventive measures and management of -associated diarrhoeal infections in Malawi.
尽管众多研究已对撒哈拉以南非洲许多国家的腹泻病因进行了调查，但关于马拉维社区获得性急性腹泻（CA-AD）中相关物种参与情况的最新数据却很匮乏。本研究调查了马拉维利隆圭一家区级医院243例急性腹泻患者中的发病率、抗生素敏感性谱、基因型特征及克隆关系。使用标准微生物学和血清学方法分离并鉴定了志贺氏菌属，通过实时聚合酶链反应鉴定ipaH基因进行确认。根据欧盟CAST指南，使用VITEK 2系统测定分离株对20种抗生素的敏感性。通过实时PCR检测赋予对磺胺甲恶唑（sul1、sul2和sul3）、甲氧苄啶（dfrA1、dfrA5和dfrA12）和氨苄西林（blaTEM和blaSHV）耐药的基因以及毒力基因（ipaH、set1、set2、set3、set4、set5和set6）。使用ERIC-PCR评估克隆相关性。分离出34株志贺氏菌属（总发病率为14.0%）。所有分离株对磺胺甲恶唑/甲氧苄啶（100%）和氨苄西林（100%）均完全耐药，但对其他测试抗生素敏感。鉴定出sul1（79%）、sul2（79%）、sul3（47%）、dfrA1（71%）和dfrA5（56%）磺胺和甲氧苄啶耐药基因；未检测到dfrA12、blaTEM和blaSHV。检测到毒力基因ipaH（85%）、set1（85%）、set2（82%）、set3（76%）、set4（71%）、set5（71%）、set6（26%）和setX（18%）。ERIC-PCR分析表明，志贺氏菌属分离株在基因上不同且无克隆相关性，表明基因不同的志贺氏菌属可能参与了马拉维的CA-AD。这些分离株对氨苄西林和磺胺甲恶唑/甲氧苄啶的高耐药率以及几种毒力决定因素的存在强调了需要持续进行分子监测研究，以为马拉维志贺氏菌属相关腹泻感染的预防措施和管理提供依据。
