Characterization of extended-spectrum beta-lactamases in Salmonella spp. at a tertiary hospital in Durban, South Africa

Extended-spectrum beta-lactamases (ESBLs) were characterized in 41 Salmonella spp. isolates from patients admitted to a pediatric ward of a tertiary hospital in Durban, South Africa. The most common (17/ 41) serotype was Salmonella enterica serotype Typhimurium, followed by S. enterica serotype Isangi (16/41), S. enterica serotype Saint-paul (2/41), S. enterica serotype Kissi (2/41), S. enterica serotype Kivu (2/41), and S. enterica serotype Reading (1/41). All isolates were resistant to ampicillin, amoxicillin-clavulanate, piperacillin, ceftazidime, and aztreonam but susceptible to meropenem. SHV-12 found in 39% of the isolates was the most common ESBL. TEM-63 was produced in 29% and TEM-116 in 10% of the isolates, and TEM-131 was found in 1 isolate. Other ESBLs that were identified included SHV-2 (n = 2), CTX-M-3 (n = 1), CTX-M-15 (n = 2), and CTX-M-37 (n = 5). In addition, CMY-2 (n = 3) and the OXA-1(n = 1) beta-lactamase were also detected. The diversity of ESBLs suggests that its incidence in Salmonellae needs to be monitored.