Susceptibility to new beta-lactams of enterobacterial extended-spectrum beta-lactamase (ESBL) producers and penicillin-resistant Streptococcus pneumoniae in Mexico.
The activities of several beta-lactam antimicrobial agents, aminoglycosides and ciprofloxacin, were determined against 62 clinical isolates of enterobacteria resistant to oxyimino cephalosporins (extended-spectrum beta-lactamase producers), collected during 1991 to 1993, and 16 penicillin-resistant invasive isolates of Streptococcus pneumoniae collected during 1994-1996. The numbers and percentages of susceptible enterobacterial strains to tested antibiotics were: imipenem 60 (97%), ciprofloxacin 57 (92%), cefepime 56 (90%), cefpirome 34 (55%), aztreonam 13 (21%), cefotaxime 7 (11%), ceftazidime 0 (0%), amikacin 11 (18%) and gentamicin 16 (26%). Despite the fact that these strains had never been exposed previously to cefepime or cefpirome, the susceptibility was 90% and 55%, respectively. No penicillin-resistant strains of S. pneumoniae were susceptible to cefotaxime, imipenem or cefepime. Only one strain was susceptible to ceftazidime and 4 (25%) were susceptible to cefpirome. Erythromycin showed the greatest activity with 12 (75%) susceptible strains.
Silva
J
J
Instituto Nacional de Salud Pública, Centro de Investigaciones Sobre Enfermedades Infecciosas, Departamento de Genética Bacteriana, Cuernavaca, Mexico. jsilva@insp3.insp.mx
Aguilar
C
C
Estrada
M A
MA
Echániz
G
G
Carnalla
N
N
Soto
A
A
López-Antuñano
F J
FJ
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D018550:Cephalosporin Resistance; D002939:Ciprofloxacin / Q000494:pharmacology; D015169:Colony Count, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects*; D008800:Mexico; D010403:Penicillin Resistance; D013296:Streptococcus pneumoniae / Q000187:drug effects*; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D047090:beta-Lactams; D002939:Ciprofloxacin; D001618:beta-Lactamases