RESUMEN
BACKGROUND: Hospital-based surveillance for pneumococcal meningitis has been conducted since January 1996 in the city of Salvador, Brazil. The purpose of this study was to describe the temporal evolution of Penicillin Non-Susceptible Streptococcus pneumoniae (PNSSP) in regards to serotype distributions and clonal diversity recovered from meningitis cases over 17 years. METHODS: Broth microdilution was used to identify pneumococcal isolates that were PNSSP (Minimum Inhibitory Concentration > 0.12 µg/ml). The annual incidence rate of meningitis cases was calculated. Serotyping was defined using multiplex polymerase chain reaction assays and quellung reaction. Genetic diversity of PNSSP isolates was assessed using both pulsed-field gel electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) analyses. RESULTS: A total of 854 cerebrospinal fluid (CSF) culture pneumococcal isolates were tested by broth microdilution method and serotyped. A total of 173 (20.3%) were penicillin non-susceptible (PNSSP) (Minimum Inhibitory concentration ≥ 0.12 µg/ml). The annual incidence of meningitis cases declined from 1.65/100,000 population (1996) to 0.2/100,000 population in 2012 and the rate due to PNSSP declined 82% over the 17-years of surveillance. PNSSP isolates were restricted to 13 serotypes, being the most common ones serotypes 14 (45.1%; 78/173), 23 F (19.1%; 33/173), 6B (14.4%; 25/173), 19 F (9.2%; 16/173) and 19A (5.2%; 9/173). Among the PNSSP isolates, 94% had serotypes represented in the 10-valent conjugate vaccine (PCV10). The predominant serotype 14 clonal groups were identified as PFGE group A/multilocus sequence type 66 (ST66) [35.3% (61/173)] and PFGE group GK/ST156 [4.6% (8/173)], the latter one associated with high level resistance to penicillin and ceftriaxone. CONCLUSIONS: Our results show sustained reductions in pneumococcal meningitis cases in the Metropolitan region of Salvador from 1996 to 2012. This might reflect a beneficial impact of conjugate vaccines. Continued surveillance and further studies need to be conducted to better understanding on PCV10 vaccine impact.
Asunto(s)
Meningitis Neumocócica/epidemiología , Meningitis Neumocócica/microbiología , Resistencia a las Penicilinas , Streptococcus pneumoniae/clasificación , Variación Antigénica , Técnicas de Tipificación Bacteriana/métodos , Brasil/epidemiología , Ceftriaxona/uso terapéutico , Niño , Preescolar , Femenino , Variación Genética , Humanos , Incidencia , Lactante , Masculino , Meningitis Neumocócica/tratamiento farmacológico , Meningitis Neumocócica/prevención & control , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa Multiplex , Penicilina G/uso terapéutico , Resistencia a las Penicilinas/genética , Resistencia a las Penicilinas/inmunología , Vacunas Neumococicas/uso terapéutico , Serotipificación , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/inmunología , Factores de Tiempo , Vacunas Conjugadas/uso terapéuticoRESUMEN
OBJETIVO: Determinar a freqüência dos sorotipos capsulares e a susceptibilidade antimicrobiana de cepas de Streptococcus pneumoniae, assim como dar suporte à indicação de vacinas disponíveis e ao uso de antimicrobianos. MÉTODOS: Neste estudo retrospectivo, foram adotadas metodologias padronizadas para identificar, sorotipar e determinar a susceptibilidade à penicilina, cefotaxima e vancomicina. O estudo foi realizado com cepas de pneumococo isoladas de liquor em pacientes atendidos nos hospitais públicos e em três hospitais particulares do Distrito Federal no período de janeiro de 1995 a dezembro de 2004. A identificação e a determinação de susceptibilidade a antimicrobianos foi realizada no Laboratório Central de Saúde Pública no Distrito Federal. A sorotipagem foi realizada no Instituto Adolfo Lutz. RESULTADOS: Foram isoladas 232 cepas de pneumococo, compreendendo 126 cepas (54,31 por cento) de pacientes do sexo masculino. A idade dos pacientes variou de 0 a 62 anos, sendo agrupados em faixas etárias de 0 a 5, 6 a 17, 18 a 50 e acima de 50 anos. Identificaram-se 36 sorotipos distintos. Desses destacaram-se oito: 14, 6B, 18C, 5, 19F, 23F, 9V e 6A. O teste de oxacilina caracterizou 67 cepas resistentes à penicilina; dessas, 47 foram confirmadas pelo E teste com resistência de nível intermediário. Nenhuma cepa apresentou resistência de alto nível. CONCLUSÃO: A resistência do pneumococo à penicilina apresentou um aumento gradativo nos últimos 10 anos no Distrito Federal. Os sorotipos mais isolados na faixa etária de 0 a 5 anos foram também os mais envolvidos na resistência à penicilina, e estão incluídos na vacina 7-valente.
OBJECTIVE: To determine the frequency of capsular serotypes and the antimicrobial susceptibility of strains of Streptococcus pneumoniae, as well as to provide recommendations on the use of available vaccines and antimicrobial drugs. METHODS: In this retrospective study, standard procedures were followed to identify, serotype, and determine bacterial susceptibility to penicillin, cefotaxime, and vancomycin. Pneumococcal strains were isolated from the cerebrospinal fluid (CSF) of patients admitted to nine public and three private hospitals in Distrito Federal, Brazil, between January 1995 and December 2004. Identification and antimicrobial susceptibility tests were carried out at the Central Laboratory of Public Health (Laboratório Central de Saúde Pública). Serotyping was performed at Instituto Adolfo Lutz. RESULTS: A total of 232 pneumococcal strains were isolated, including 126 (54.31 percent) strains from male patients. Patients had an age range of 0 to 62 years and were distributed into four age groups: 0 to 5, 6 to 17, 18 to 50, and above 50. From the 36 distinct serotypes identified, eight were more prevalent: 14, 6B, 18C, 5, 19F, 23F, 9V, and 6A. The oxacillin test identified 67 penicillin-resistant strains, out of which 47 were confirmed by the E test as having intermediate level of resistance. None of the strains exhibited high-level resistance. CONCLUSIONS: Pneumococcal resistance to penicillin has gradually increased over the last 10 years in Distrito Federal. Serotypes more frequently isolated in the 0 to 5 years age group were the same involved in penicillin-resistance, all of which are covered by the 7-valent vaccine.
Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Farmacorresistencia Bacteriana/inmunología , Meningitis Neumocócica/líquido cefalorraquídeo , Meningitis Neumocócica/inmunología , Resistencia a las Penicilinas/inmunología , Vacunas Neumococicas/inmunología , Streptococcus pneumoniae/aislamiento & purificación , Distribución por Edad , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Meningitis Neumocócica/tratamiento farmacológico , Oxacilina/farmacología , Resistencia a las Penicilinas/efectos de los fármacos , Vacunas Neumococicas/uso terapéutico , Estudios Retrospectivos , SerotipificaciónRESUMEN
Avaliou-se a susceptibilidade a antibióticos em 146 cepas de Streptococcus pneumoniae isoladas de líquido cerebroespinhal. Sete cepas (3 com o fenótipo de resistência e 4 com o fenótipo de susceptibilidade moderada) apresentaram resultados semelhantes para a oxacilina segundo o método da difusäo em disco, e para a penicilina segundo o método da concentraçäo mínima inibitória. Duas cepas tiveram comportamentos discrepantes ao comparar-se os resultados de 2 métodos. Todas as outras cepas (137) apresentaram inibiçäo de crescimento para uma concentraçäo de oxacilina de 1 mg/ml, segundo o método da difusäo em disco