Microbial resistance to antibiotics used to treat urinary tract infections in Mexican children.

Urinary tract infections are one of the most common bacterial infections in female children. This infection has a prevalence of 4.1 to 7.1% during infancy. The bacterial agents causing the urinary tract infection are Escherichia coil (80-90%), followed by other gram negative germs such as Klebsiella pneumoniae and Enterococcus species and gram positive such as Staphylococcus species. Typical treatment for this infection is ampicillin or the mixture of trimethoprim and sulfamethoxazole (TMT/SMX) among others. However, a high incidence of microbial resistance to these antibiotics has been observed recently. The purpose of this study was to assess the microbial resistance of the most frequent infectious agents in urinary tract of Mexican children from January to December 2000. A total of 725 urinary cultures were collected during all year. Of these, 293 patients were positive of the most frequently reported bacteria including Escherichia coil (205 patients, 69.9%), Klebsiella pneumoniae (67 patients, 22.8%) and Proteus mirabilis (21 patients, 7.1%). Infections produced by Escherichia coil were highly resistant to ampicillin (83.5%) and TMT/SMX (76.7%). Results indicate a high incidence of microbial resistance to ampicillin and TMT/SMX in urinary tract infections in Mexican children and suggest caution before giving a treatment with antibiotic in this condition.