SEROTYPE DISTRIBUTION AND SENSITIVITY TO PENICILLIN OF Streptococcus pneumoniae ISOLATES FROM 1998 TO 2007 IN THE REGION OF RIB

AC32

 Medeiros, MIC (1)  micmedeiros@ial.sp.gov.br, Silva, P (1), Silva, JO (1), Carneiro,AMM (1), Guerra, ML (2), Neme, SN (1)

(1) Instituto Adolfo Lutz - Laboratório de Ribeirão Preto(2) Instituto Adolfo Lutz - Laboratório de São Paulo

Introduction: Streptococcus pneumoniae (pneumococci) is usually found in the nasopharyngeal passages of healthy individuals, 20-40% children and 5-10% adults but it could be disseminated through   the blood stream causing bacteremia , meningitis, pneumonia or other infections. Pneumococci are the most common agents of bacterial meningitis and the main causes of pneumonia in the elderly and children.  In the 1960s, most pneumoccocci strains were sensitive to penicillin and the treatment of choice was the use of  β-actam antibiotics. However, resistance to this class of drugs has been increasing through the years.  Objective: To evaluate serotype distribution and the susceptibility pattern of pneumococci in the region of Ribeirao Preto. Material and Methods: Five hundred and three pneumococcal isolates were processed at the Adolfo Lutz Institute during the period of 1998 to 2007.  The samples, isolated from Cerebrospinal Fluid, blood, pleural effusion and other clinical samples were from municipal and regional patients. Isolate identification was by conventional methods.  Oxacillin discs, 1mg, were used to detect resistance to penicillin. Antibiotic Minimal Inhibitory Concentrations (MIC)s , determined as indicated by the Clinical and Laboratory  Standards Institute(CLSI) and typing utilizing the Quellung reaction were conducted at the Regional Laboratory Sao Paulo, Adolfo Lutz Institute.  Results: During the last 10 years, the origins of the 503 pneumococcal isolates were as follows: 221 (43.94%) from meningitis patients; 217 (43.14%) from pneumonia; 15 (2.985) from bacteremia and 50 (9.94%) from other clinical sources.  Serotype 14 prevailed in 17.49% of the cases, followed by types 3,1, 9V, 19F, 23F, 6A, 6B, 19A and 4. Most isolates were from patients of 16 to 60 years of age.  After the general survey with the oxacillin discs, MICs were determined in 132 samples (26.24%) of which  108 (21.47%) showed intermediate resistance, 42 (8.35%) were resistant and 72 (14.31%) were sensitive. Conclusion: Decisions on vaccine formulations depend on regional and temporal information about which serotypes may cause disease, as epidemiological aspects of this condition vary from country to country and in the course of time.  Thus, establishing control strategies needs local periodic evaluations. In addition, rational choice of the initial empirical treatment of pneumococcal diseases  is based on the clinically important monitoring of resistance to antimicrobials .