Prevalência de sorotipos e resistência antimicrobiana de cepas invasivas do pneumococo em crianças: análise de 9 anos / Prevalence of serotypes and antimicrobial resistance of invasive strains of pneumococcus in children: analysis of 9 years

OBJETIVO: Avaliar o perfil de sorotipos e a sensibilidade aos antimicrobianos de cepas de pneumococo obtidas de crianças e as implicações na formulação de vacinas pneumocócicas. MÉTODOS: Cepas de pneumococo isoladas no Hospital de Clínicas da Universidade Federal de Uberlândia, Uberlândia (MG), a partir de pacientes com doença invasiva, foram enviadas ao Instituto Adolfo Lutz, São Paulo (SP), para confirmação da identificação, sorotipagem e determinação da sensibilidade aos antimicrobianos. RESULTADOS: De abril de 1999 a dezembro de 2008, foram avaliadas 142 cepas de pneumococo obtidas de crianças de até 5 anos de idade. Setenta e cinco (52,8 por cento) eram de pacientes do sexo masculino, e a idade variou de 1 a 60 meses (média de 19±15,4 meses e mediana de 15 meses). Os diagnósticos clínicos mais comuns foram pneumonia [92 casos (64,8 por cento)] e meningite [33 casos (23,2 por cento)], e as principais fontes de recuperação foram sangue [61 amostras (43 por cento)], líquido pleural [52 (36,6 por cento)] e liquor [28 (19,7 por cento)]. Os sorotipos mais comuns foram o 14, 5, 6B, 1, 6A, 18C, 19A, 3, 9V, 19F, 23F, 9N e 10A. Foram detectadas 14 (9,9 por cento) cepas penicilina-resistentes, restritas aos sorotipos 14, 6B, 19F, 19A e 23F e predominantes no período de 2004 a 2008 (p = 0,000). Foi detectada sensibilidade diminuída ao cotrimoxazol (79,5 por cento), à eritromicina e à clindamicina (11,3 por cento cada) e à ceftriaxona (5,6 por cento). CONCLUSÕES: A resistência à penicilina foi detectada em 9,9 por cento das cepas e predominou no período de 2004 a 2008. Foram identificados 20 diferentes sorotipos de pneumococo, e a cifra de cobertura pela vacina 7-valente atualmente disponível (PN CRM7) é de 71,9 por cento.

OBJECTIVE: To determine the prevalence of serotypes and antimicrobial susceptibility of strains of pneumococcus in children and to evaluate the implications for vaccine formulation. METHODS: Strains of pneumococcus obtained from children admitted with invasive diseases were isolated at Hospital de Clínicas of Universidade Federal de Uberlândia, Uberlândia, Brazil, and sent to Instituto Adolfo Lutz, São Paulo, Brazil, for further identification, serotyping, and determination of antimicrobial susceptibility. RESULTS: From April 1999 to December 2008, 142 strains of pneumococcus, obtained from children under 5 years of age, were analyzed. Seventy-five (52.8 percent) patients were male, and the age ranged from 1 to 60 months (mean age = 19±15.4 months; median = 15 months). The most common diagnoses were pneumonia [92 cases (64.8 percent)] and meningitis [33 cases (23.2 percent)]. The strains were mostly isolated from blood [61 samples (43 percent)], pleural fluid [52 samples (36.6 percent)], and cerebrospinal fluid [28 samples (19.7 percent)]. The most common serotypes were 14, 5, 6B, 1, 6A, 18C, 19A, 3, 9V, 19F, 23F, 9N, and 10A. There were 14 [9.9 percent] penicillin-resistant strains, which was detected only in the following serotypes: 14, 6B, 19F, 19A, and 23F, being predominant from 2004 to 2008 (p = 0.000). There was reduced susceptibility to co-trimoxazole (79.5 percent), erythromycin and clindamycin (11.3 percent each), and ceftriaxone (5.6 percent). CONCLUSIONS: Penicillin resistance was detected in 9.9 percent of the strains, being predominant from 2004 to 2008. Twenty different pneumococcal serotypes were identified, and 71.9 percent of the serotypes were represented in the 7-valent conjugate vaccine (PN CRM7) currently available.

New susceptibility breakpoints in antimicrobial resistance rates of invasive pneumococcal strains.

OBJECTIVE: To evaluate the impact of new penicillin susceptibility breakpoints on resistance rates of pneumococcal strains collected from children with pneumonia. METHODS: Pneumococcal strains collected from patients admitted with pneumonia were isolated at the clinical analysis lab of Hospital de Clínicas de Uberlândia, Uberlândia, Brazil, and sent to Instituto Adolfo Lutz, São Paulo, Brazil, for further identification, serotyping and determination of antimicrobial susceptibility. RESULTS: From April 1999 to December 2008, 330 strains of pneumococcus were sent to Instituto Adolfo Lutz; of these, 195 (59%) were collected from patients with pneumonia. One hundred strains collected from patients < or = 12 years old were analyzed. The patients' age ranged from 1 to 12.6 years old (with mean age of 2.4 and median of 1.7 years). Forty-seven patients were male. The strains were isolated from blood (42%) and pleural fluid (58%). There were 35 oxacillin-resistant strains: according to the criteria defined by the Clinical and Laboratory Standards Institute (CLSI) in 2007 [minimum inhibitory concentration (MIC) < or = 0.06 microg/mL for susceptibility (S), 0.12 to 1 microg/mL for intermediate resistance (IR), and > or = 2 microg/mL for full resistance (FR)], 22 strains had IR and 11 strains had FR. According to the current breakpoints defined by the CLSI in 2008 (< or = 2 microg/mL for S, 4 microg/mL for IR and > or = 8 microg/mL for FR), only one strain had IR to penicillin. There was resistance to co-trimoxazole (80%), tetracycline (21%), erythromycin (13%), clindamycin (13%), and ceftriaxone (one strain simultaneously resistant to penicillin). CONCLUSIONS: When the new breakpoints for in vitro susceptibility were applied, penicillin resistance rates dropped 97%, from 33 to 1%.

Prevalence of serotypes and antimicrobial resistance of invasive strains of pneumococcus in children: analysis of 9 years.

OBJECTIVE: To determine the prevalence of serotypes and antimicrobial susceptibility of strains of pneumococcus in children and to evaluate the implications for vaccine formulation. METHODS: Strains of pneumococcus obtained from children admitted with invasive diseases were isolated at Hospital de Clínicas of Universidade Federal de Uberlândia, Uberlândia, Brazil, and sent to Instituto Adolfo Lutz, São Paulo, Brazil, for further identification, serotyping, and determination of antimicrobial susceptibility. RESULTS: From April 1999 to December 2008, 142 strains of pneumococcus, obtained from children under 5 years of age, were analyzed. Seventy-five (52.8%) patients were male, and the age ranged from 1 to 60 months (mean age = 19+/-15.4 months; median = 15 months). The most common diagnoses were pneumonia [92 cases (64.8%)] and meningitis [33 cases (23.2%)]. The strains were mostly isolated from blood [61 samples (43%)], pleural fluid [52 samples (36.6%)], and cerebrospinal fluid [28 samples (19.7%)]. The most common serotypes were 14, 5, 6B, 1, 6A, 18C, 19A, 3, 9V, 19F, 23F, 9N, and 10A. There were 14 [9.9%] penicillin-resistant strains, which was detected only in the following serotypes: 14, 6B, 19F, 19A, and 23F, being predominant from 2004 to 2008 (p = 0.000). There was reduced susceptibility to co-trimoxazole (79.5%), erythromycin and clindamycin (11.3% each), and ceftriaxone (5.6%). CONCLUSIONS: Penicillin resistance was detected in 9.9% of the strains, being predominant from 2004 to 2008. Twenty different pneumococcal serotypes were identified, and 71.9% of the serotypes were represented in the 7-valent conjugate vaccine (PN CRM7) currently available.