Abstract

Seventy six non-typhoid Salmonella were isolated from both human and poultry in Egypt and Algeria and tested for their antibiotics resistance. The incidence of multiple antibiotics resistance was high. To study β-lactams resistance mechanisms, double disk synergy test (DDST) with and without cloxacilline was used, results revealed the production of extended spectrum β-lactamases (ESBLs) and cephalosporinase in seven and one human Egyptian isolates, respectively. The seven ESBL isolates were identified asSalmonella enterica serotype Poona and their molecular typing by ERIC-PCR revealed unrelated genetic patterns, indicating that these isolates are not clonal. The Cephalosporinase-ESBL- producing isolate was identified as S. enterica serotype Hadar. Polymerase chain reaction (PCR) with specific primers showed the presence of bla_TEMand bla_SHV genes, respectively, in all and four ESBL producers, and bla_AmpC gene was detected in cephalosporinase-producing isolate. Genetic transfer by conjugation and plasmid profiles analysis showed that these genes and their resistance markers were transferable in association with plasmids of 60 kb for ESBLs and 64 and 3.2 kb for AmpC cephalosporinase.

Key words: non-typhoid Salmonella, extended spectrum β-lactamases, cephalosporinase, Egypt, Algeria