1st Spanish epidemic of plasmid resistance to 3d generation cephalosporins: the implication of SHV-2
Fernández-Rodríguez, A.; Reguera, J.A.; Pérez-Díaz, J.C.; Picazo, J.J.; Baquero, F.
Enfermedades Infecciosas y Microbiologia Clinica 10(8): 456-461
1992
ISSN/ISBN: 0213-005X PMID: 1489773 Document Number: 398815
The first spanish outbreak of bacterial strains showing resistance to third generation cephalosporins and due to the presence of the extended spectrum beta-lactamase SHV-2 is reported. This outbreak was observed in Madrid during the years 1988-1990 and involved the San Carlos University Hospital with the same type of isolates at the Ramón y Cajal University Hospital. The screening for extended-spectrum beta-lactamases was performed by the double-disk synergy test. Analytical isoelectric focusing and susceptibility tests were performed in all the strains showing a presumptive extended-spectrum beta-lactamase. Fifty-nine strains belonging to four bacterial species (Klebsiella pneumoniae, 61%; Serratia marcescens, 31%; Klebsiella oxytoca, 5%, and Escherichia coli, 3%) showed a beta-lactamase of point isoelectric 7.6; the susceptibility tests demonstrated more resistance to cefotaxime and ceftriaxone than to ceftazidime and aztreonam. The biochemical, kinetic and isoelectrofocusing parameters demonstrated the presence of a SHV-2 enzyme. The blind application of NCCLS breakpoints would lead to false "susceptibility" results in over 40% of the cases.