Burden, Antibiotic Resistance, and Clonality of spp. Implicated in Community-Acquired Acute Diarrhoea in Lilongwe, Malawi.

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.