干旱区生态环境知识资源中心

The prevalence of ampicillin resistance and extended-spectrum beta-lactamases (ESBL) in the dominant Enterobacteriaceae from raw and spontaneously fermented camel milk (suusac) in Kenya and Somalia was characterized both phenotypically and genotypically. Globally important SHV and CTX-M-type extended-spectrum beta-lactamases (ESBLs) were tested. The Enterobacteriaceae belonged to 15 species from 10 genera. Dominant isolates were Escherichia coli (50), Klebsiella pneumonia subsp. pneumoniae (35) and Enterobacter sakazakii (20). Salmonella arizonae, Serratia odorifera and E. coli occurred at viable counts greater than 8 log cfu/ml. ESBL was studied for 96 E. coli, K. pneumonia subsp. pneumoniae and E. sakazakii. Total of 61 (63%) isolates consisting of 46 (48%) of E. coli, 45 (46%) K. pneumonia subsp. Pneumonia and 16 (7%) E. sakazakii were resistant to ampicillin. bla(SHV), bla(CTX-M-3)-like and bla(CTX-M-14)-like genes were detected in 37 (60%), 25 (40%) and 11 (18%) of the Enterobacteriaceae isolates respectively. K. pneumonia subsp. pneumoniae harbored majority of these bla genes (74%) with 1 strain possessing all 3 genes and 13 harbouring both bla(SHV) and bla(CTX-M-3)-like genes. The diversity of Enterobacteriaceae in camel milk calls for improved handling of camel milk. The ESBL genes in the isolates from the remote semi-arid regions emphasises the global antimicrobial resistance problem among Enterobacteriaceae.