title: Antimicrobial susceptibility patterns of Streptococcus pneumoniae in Mexico.
abstract: The susceptibility to 14 beta-lactam and non-beta-lactam antimicrobial agents was evaluated for Streptococcus pneumoniae from patients with community-acquired respiratory infections in a Mexican medical center. Three hundred fifteen pneumococcal isolates obtained from patients between 1995 and 2001 were tested by the broth microdilution test. Fifty-two percent of the isolates were nonsusceptible to penicillin (minimal inhibitory concentration, >0.06 microg/mL). Penicillin-nonsusceptible isolates were more likely to exhibit resistance to cephalosporins, macrolides, ciprofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, and tetracycline when compared to penicillin-susceptible isolates. Ninety-three percent of the penicillin-nonsusceptible isolates were resistant to at least one other class of antimicrobials, in contrast to only 47% of the penicillin-susceptible strains (p < 0.0001). More than 90% of the tested isolates were susceptible to amoxicillin/clavulanate, ceftriaxone, levofloxacin, and gatifloxacin. Reduced susceptibility to penicillin was considered to be a reliable marker for the higher probability of multidrug resistance, thus requiring in vitro tests to guide chemotherapy or the choices of parenteral extended spectrum cephalosporins or newer respiratory quinolones.
authors.affiliation: Servicio de Microbiología Clínica, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Quiñones-Falconi
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Calva
authors.forename: Yolanda
authors.initials: Y
authors.lastname: López-Vidal
authors.forename: Miriam
authors.initials: M
authors.lastname: Galicia-Velazco
authors.forename: María Elena
authors.initials: ME
authors.lastname: Jiménez-Martinez
authors.forename: Lina
authors.initials: L
authors.lastname: Larios-Mondragón
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016001:Confidence Intervals; D024881:Drug Resistance, Bacterial; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D016017:Odds Ratio; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents