ANTIBIOTIC-RESISTANCE MECHANISMS IN SALMONELLA SPECIES CAUSING BACTEREMIA IN MALAWI AND KENYA

In two studies on the causative agents of bacteraemia in Malawi and Ke nya, 33 Salmonella strains were isolated. Fourteen strains of Salmonel la typhimurium and Salmonella enteritidis were found to exhibit resist ance to amoxicillin, amoxicillin/clavulanic acid and cotrimoxazole as well as decreased susceptibility to a range of aminoglycosides. The re sistant strains were studied to establish their resistance mechanisms. Beta-lactamase co-focusing with TEM-1 was present in 12 strains. In t wo strains, both S. typhimurium from Kenya, an OXA-1 beta-lactamase wa s detected. The aminoglycoside-modifying enzyme ANT(2 '') was found in 10 strains. The presence of the encoding genes was confirmed by PCR. For comparison, susceptibility records of 73 Salmonella strains isolat ed during the past 14 years in our hospital were studied retrospective ly. Only one of these strains was resistant to amoxicillin. This resis tance was acquired during therapy.