[A nosocomial epidemic of Salmonella mbandaka which produces various broad spectrum beta-lactamases: preliminary results]

During a nosocomial epidemic of Salmonella mbandaka in Algeria, 99 strains were isolated from specimens. Study of 22 of them revealed minimum inhibiting concentrations ranged from 4 to 32 micrograms/ml for cefotaxime, 2 to 32 micrograms/ml for ceftazidime and 2 to 16 micrograms/ml for ceftriaxione. The mechanism underlying resistance was enzymatic with production of broad-spectrum beta-lactamase enzyme. Clavulinic acid at a dose of 2 micrograms/ml restored the activity of hydrolyzed beta-lactamases. Resistance to all antibiotics including cefotaxime was due to a single plasmid structure. The plasmid did not belong to any known compatibility group. All strains studied contained a plasmid of 26MDa and produced TEM-1 and TEM-2 beta-lactamases. Strains resistant to cefotaxime also synthetized a broad-spectrum beta-lactamase derived from TEM.