2622

INVASIVE INFECTIONS CAUSED BY STREPTOCOCCUS PNEUMONIAEY HAEMOPHILUS INFLUENZAE TYPE B: SENSITIVITY AND RESISTANCE PATTERNS TO COMMONLY USED DIFFERENT ANTIMICROBIAL AGENTS

Gonzalez SN, Yee AA, Chacon SJ.

National Institute of Pediarics, Mexico City, Mexico

Objective: To know the resistance rate and sensitivity found in strains of S. pneumoniae (Spn) and Haemophilus influenzae type b (Hib) to different antimicrobial agents.

Material and Methods: A prospective, cross sectional, descriptive and observational study was conducted to know the sensitivity and resistance of Spn and Hib in children of any gender or sex that were admitted to the National Institute of Pediatrics from January 1994 to July 2000. Strains of Spn and Hib isolated from different body fluids were included. Antibiotic sensitivity was established through the minimal inhibitory concentration method determined by NCCLS. Reference strains were used for strains according to ATCC.

Results: 149 strains of Spn were isolated from different body fluids (57 in invasive diseases), performing sensitivity tests for penicillin and to other commonly used antimicrobial agents. We found 32.9% total penicillin resistance, only 13.4% was highly resistance. The most common serotypes were 23F, 19^a, 19F, 14, 7. 40 strains of Haemophilus Influenzae type b were identified, mainly from CSF, which were amplicillin resistant in 20% and chloramphenicol resistant in 17.5%, finding a resistance rate of this organism similar to that previously reported in the literature.

Conclusions: Even though total penicillin resistance for Spn is 32.9%,only 13.4% of the invasive strains were highly resistant. Regarding Hib, we found a resistance rate to ampicillin and chloramphenicol similar to the one previously reported in other studies, however, our sample is small and the study needs to be continued.