Pneumococcal nasopharyngeal carriage in infants of mothers immunized with 23V non-conjugate pneumococcal polysaccharide vaccine.

To assess the effects of maternal immunization on pneumococcal colonization in infants, pregnant women were assigned into three groups. The group Pregn Vac received the Pn23V during pregnancy, the group Puerp Vac received vaccine during immediate puerperium and the group No Vac received no vaccine. Nasopharyngeal samples were collected at 3 and 6 months. A total of 150 pregnant women were selected during the prenatal period. The proportion of pneumococcal carriage in at least one evaluation was in group Pregn Vac 22.2% (10/45), group Puerp Vac 23.4% (11/47) and group No Vac 21.2% (10/47), respectively. The most frequently isolated serotype in group Puerp Va and group No Vac was 6B and 6A. In the Pregn Vac, the most important serotype was 19F. Although this study was unable to demonstrate any effect of maternal vaccination in reducing pneumococcal colonization, reduction of colonization for serotype 6B in infants may be an important effect.

Analysis of invasive pneumonia-causing strains of Streptococcus pneumoniae: serotypes and antimicrobial susceptibility.

OBJECTIVES: To identify the most common pneumococcal serotypes in children hospitalized with invasive pneumonia, correlate isolated serotypes with those included in conjugate vaccines, and ascertain the sensitivity of the isolated pneumococcal strains to penicillin and other antibiotics. METHODS: From January 2003 to October 2008, a retrospective study of hospitalized children with a diagnosis of Streptococcus pneumoniae pneumonia was conducted at the university hospital of Universidade de São Paulo. Criteria for inclusion were: age greater than 29 days and less than 15 years, radiological and clinical diagnosis of pneumonia, and isolation of Streptococcus pneumoniae in blood cultures and/or pleural effusion. RESULTS: The study included 107 children. The most common serotypes were 14 (36.5%), 1 (16%), 5 (14.6%), 6B (6.3%) and 3 (4.2%). The proportion of identified serotypes contained in the heptavalent, 10-valent and 13-valent conjugate vaccines was 53.1, 86.5, and 96.9%, respectively. Pneumococcal strains were sensitive to penicillin (minimum inhibitory concentration, MIC ≤ 2 µg/mL) in 100 cases (93.5%) and displayed intermediate resistance (MIC = 4 µg/mL) in 7 cases (6.5%). No strains were penicillin-resistant (MIC ≥ 8 µg/mL) according to the Clinical and Laboratory Standards Institute 2008 standards. Tested isolates were highly sensitive to vancomycin, rifampicin, ceftriaxone, clindamycin, erythromycin, and chloramphenicol. CONCLUSIONS: Our results confirm a significant potential impact of conjugate vaccines, mainly 10-valent and 13-valent, on invasive pneumonia. Furthermore, susceptibility testing results show that penicillin is still the treatment of choice for invasive pneumonia in our setting.

Análise das cepas de Streptococcus pneumoniae causadores de pneumonia invasiva: sorotipos e sensibilidade aos antimicrobianos / Analysis of invasive pneumonia-causing strains of Streptococcus pneumoniae: serotypes and antimicrobial susceptibility

OBJETIVOS: Identificar os sorotipos de pneumococo mais frequentemente isolados de crianças internadas com pneumonia invasiva, comparar os sorotipos com os incluídos em vacinas conjugadas e analisar sua sensibilidade aos antimicrobianos mais utilizados na faixa etária pediátrica. MÉTODOS: Estudo descritivo, retrospectivo das pneumonias pneumocócicas identificadas em crianças internadas no hospital universitário da Universidade de São Paulo, no período de janeiro de 2003 a outubro de 2008. Os critérios de inclusão foram: faixa etária de 29 dias até 15 anos incompletos com diagnóstico clínico e radiológico de pneumonia e com cultura de sangue e/ou líquido pleural com crescimento de Streptococcus pneumoniae. RESULTADOS: Foram incluídas no estudo 107 crianças. Os sorotipos mais frequentes foram: 14 (36,5 por cento), 1 (16,7 por cento), 5 (14,6 por cento), 6B (6,3 por cento) e 3 (4,2 por cento). A proporção de sorotipos contidos na vacina conjugada heptavalente seria de 53,1 por cento, na vacina 10-valente de 86,5 por cento e na 13-valente seria de 96,9 por cento. De acordo com os padrões do Clinical and Laboratory Standards Institute 2008, 100 cepas (93,5 por cento) de pneumococos foram sensíveis à penicilina (concentração inibitória mínima, CIM < 2 µg/mL), 7 cepas (6,5 por cento) com resistência intermediária (CIM = 4 µg/mL) e nenhuma com resistência (CIM > 8 µg/mL). Verificamos alta taxa de sensibilidade para as cepas testadas para vancomicina, rifampicina, ceftriaxone, clindamicina, cloranfenicol e eritromicina. CONCLUSÕES: Nossos resultados confirmam um expressivo impacto potencial das vacinas conjugadas, principalmente pela 10-valente e 13-valente, sobre os casos de pneumonias invasivas. Os resultados de sensibilidade à penicilina evidenciam que a opção terapêutica de escolha para o tratamento das pneumonias invasivas continua sendo a penicilina.

OBJECTIVES: To identify the most common pneumococcal serotypes in children hospitalized with invasive pneumonia, correlate isolated serotypes with those included in conjugate vaccines, and ascertain the sensitivity of the isolated pneumococcal strains to penicillin and other antibiotics. METHODS: From January 2003 to October 2008, a retrospective study of hospitalized children with a diagnosis of Streptococcus pneumoniae pneumonia was conducted at the university hospital of Universidade de São Paulo. Criteria for inclusion were: age greater than 29 days and less than 15 years, radiological and clinical diagnosis of pneumonia, and isolation of Streptococcus pneumoniae in blood cultures and/or pleural effusion. RESULTS: The study included 107 children. The most common serotypes were 14 (36.5 percent), 1 (16 percent), 5 (14.6 percent), 6B (6.3 percent) and 3 (4.2 percent). The proportion of identified serotypes contained in the heptavalent, 10-valent and 13-valent conjugate vaccines was 53.1, 86.5, and 96.9 percent, respectively. Pneumococcal strains were sensitive to penicillin (minimum inhibitory concentration, MIC < 2 µg/mL) in 100 cases (93.5 percent) and displayed intermediate resistance (MIC = 4 µg/mL) in 7 cases (6.5 percent). No strains were penicillin-resistant (MIC > 8 µg/mL) according to the Clinical and Laboratory Standards Institute 2008 standards. Tested isolates were highly sensitive to vancomycin, rifampicin, ceftriaxone, clindamycin, erythromycin, and chloramphenicol. CONCLUSIONS: Our results confirm a significant potential impact of conjugate vaccines, mainly 10-valent and 13-valent, on invasive pneumonia. Furthermore, susceptibility testing results show that penicillin is still the treatment of choice for invasive pneumonia in our setting.

Distribution of Streptococcus pneumoniae serotypes in nasopharyngeal carriage and in invasive pneumococcal disease in Sao Paulo, Brazil.

To determine whether serotypes of S. pneumoniae isolated from the nasopharynx (NP) are representative of data from patients with invasive disease, we collected NP swab specimens from children, between 3 months and 5 years and obtained data from 105 children hospitalized with invasive disease. The prevalence of penicillin nonsusceptible strains in the NP carriage and invasive disease group was 16.4% and 17%, respectively, in the first period and 42% and 45% in the second period. The serotypes 23F, 6A, 14 and 19F were the most common in the NP study and 14, 1, 5 and 6B were the most common in invasive infections.

[Prevalence of serotypes and antimicrobial resistance of invasive strains of Streptococcus pneumoniae]. / Prevalência de sorotipos e resistência antimicrobiana de cepas invasivas do Streptococcus pneumoniae.

OBJECTIVE: To determine the prevalence of serotypes and antimicrobial susceptibility of invasive strains of Streptococcus pneumoniae and to discuss the implications of these findings for vaccine formulation. METHODS: Strains of Streptococcus pneumoniae obtained from normally sterile fluids from patients admitted with invasive diseases were isolated and identified at the Hospital de Clínicas, Universidade Federal de Uberlândia, state of Minas Gerais, and forwarded to Instituto Adolfo Lutz, state of São Paulo, for further identification, serotyping and determination of antimicrobial susceptibility. RESULTS: From April 1999 to March 2003, 148 invasive strains of Streptococcus pneumoniae were obtained. The age of patients ranged from 1 day to 88.83 years (mean: 21.33+/-25.82 years; median: 4.42 years). Eighty-four (56.7%) patients were male. The most common diagnoses were pneumonia (91 cases; 61.4%), meningitis (32 cases; 21.6%) and occult bacteremia (15 cases; 10.1%). Strains were isolated mostly from blood (76 occasions; 51.3%), pleural fluid (39 occasions; 26.3%) and cerebrospinal fluid (30 occasions; 20.2%). There were 23 different serotypes, and the most common were 14, 3, 1, 5, 6A, 6B and 18C. Among 30 (20.2%) oxacillin-resistant strains, 23 (15.5%) were confirmed as resistant to penicillin (12.8% intermediate resistance and 2.7% full resistance). Oxacillin-resistant strains were restricted to serotypes 14, 23F, 19A and 6B. Resistance to penicillin varied with age, being more common in children under two years of age (p = 0.0008). We observed decreased sensibility to sulfamethoxazole-trimethoprim (92 isolates; 63.4%), to erythromycin (12 isolates; 8.3%), to clindamycin (12 isolates; 8.7%), to ofloxacin (one strain; 0.8%) and to cefotaxime (three strains; 2%; also resistant to penicillin). All isolates were susceptible to chloramphenicol, rifampin and vancomycin. CONCLUSIONS: The decreased susceptibility to penicillin, detected in 15.5% of the strains was predominant in children under two years of age. There were 23 different Streptococcus pneumoniae serotypes. The 23-valent polysaccharide vaccine covers 82.6% of the serotypes and 90.2% of the invasive strains isolated in this population. In addition, 46.7% of the serotypes and 63.6% of the strains isolated from children until five years of age are covered in the currently available 7-valent conjugated vaccine (PN CRM7).

[Invasive pneumococcal strains isolated from children and adolescents in Salvador]. / Cepas invasivas de pneumococo isoladas de crianças e adolescentes em Salvador.

OBJECTIVES: To describe the antimicrobial resistance and serotype distribution of pneumococcal strains. METHODS: In a 57-month period, a laboratory-based surveillance of invasive pneumococcal strains from patients aged < 20 years was conducted. Pneumococcus was identified by means of tests for solubility in bile and optochin. Pneumococcal resistance to penicillin was screened by 1 micro g oxacillin disc and minimal inhibitory concentration was determined for the strains not susceptible to penicillin. Disc diffusion and broth microdilution methods were used for surveillance of resistance to other antimicrobials. Pneumococci were serotyped by means of the Neufeld-Quellung reactions. RESULTS: Of 70 patients, 57.1% were males. The mean age was 1.92 yrs (mean 3.19 +/- 3.66 yrs, range 1 month to 19.5 yrs); 52.9% and 81.4% were < 2 yrs and < 5 yrs, respectively. The strains were isolated from blood (91.4%), CSF (2.9%), pleural (2.9%), peritoneal (1.4%) and abscess (1.4%) fluids from patients with pneumonia (77.1%), fever without localizing signs (10.0%), meningitis (4.3%), others (8.6%). Resistance was detected to penicillin (20.0%), trimethoprim-sulfamethoxazole (65.7%), tetracycline (21.4%), ofloxacin (6.3%), erythromycin (5.7%), clindamycin (2.9%). All tested strains were susceptible to chloramphenicol and vancomycin. Among penicillin-resistant strains, high resistance was detected in one, the same that showed intermediate resistance to cefotaxime. The most frequent serotypes were: 14 (22.9%), 5 and 6A (10.0% each), 6B and 19F (8.6% each), 9V, 18C and 23F (5.7% each). Resistance to penicillin was detected in serotypes 14 (71.4%), 6B and 19F (14.3% each). CONCLUSIONS: Of 70 strains, 67.2% were classified as serotypes included in the heptavalent conjugate pneumococcal vaccine, as were all penicillin-resistant strains.

Cepas invasivas de pneumococo isoladas de crianças e adolescentes en Salvador / Invasive pneumococcal strains isolated from children and adolescents in Salvador

Objetivos: descrever resistencia antimicrobiana e sorotipos de cepas de pneumococo. Metodos: durante 57 meses, foi conduzida uma vigilancia de cepas invasivas de pneumococo de pacientes com idade maior de 20 anos. O pneumococo foi identificado pelos testes de solubilidade da bile e optoquina. A resistência a penicilina foi avaliada com o disco de oxacilina (I╡g) e, para as cepas não suscetiveis, foi determinada a concentração inibitariamonima. Provas de difusão de disco e de microdiluiτπo em placa foram utilizadas para avaliação da resistência a outros antimicrobianos...