Resistance to methicillin and other antimicrobials among community-acquired and nosocomial Staphylococcus aureus strains in a pediatric teaching hospital in Salvador, Northeast Brazil.

To report the frequency of methicillin-resistant Staphylococcus aureus (MRSA) infection and to compare the antimicrobial resistance patterns between community-acquired (CA) and nosocomial (NI) strains stratified for resistance to methicillin, this retrospective study on patients under 20 years of age was conducted from April 1995 to December 2005 in a pediatric teaching hospital in Salvador, Brazil. Of 308 S. aureus strains isolated, 185 (60.1%) were reviewed, out of which 125 (67.6%) and 55 (29.7%) had CA or NI infection, respectively, and 5 were defined as colonization. Out of the nine patients with MRSA initially diagnosed as CA, three were excluded from the analysis because of report of hospitalization during the previous year. Resistance to methicillin was more frequent among NI (30.9% vs. 4.9%, p<0.001). Resistance to other antimicrobials was more common among NI-MRSA compared with CA-MRSA. Although at a low rate, CA-MRSA has occurred among children, in this region.

[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...

Community acquired Pneumonia among pediatric outpatients in Salvador, northeast Brazil, with emphasis on the role of pneumococcus

Pneumonia is one of the leading causes of hospitalization and death among children in developing counties,, and mortality due to pneumoniae has been associated with S. pneumoniae infection. This investigation was designed to describe the antimicrobial susceptibility and serotype patterns of pneumococcal strains recovered from the blood of children with community-acquired pneumonia (CAP) and to acess the clinical findings of pneumococcal bacteremic patients with pneumonia. In a 26 month prospective study, blood cultures were obtained as often as possible from children(<16 years of age) diagnosed with CAP in two emergency rooms. Antimicrobial drug susceptibility tests and serotyping were performed when pneumococcus was identified. We studied 3,431 cases and cultured blood samples from 65.5 percent of those. Pneumococcus was recovered from 0.8 percent of the blood samples. The differences in age, somnolence, wheezing and hospitalization among children with and without pneumococcal bacteremia were statistically significant. Pneumococcal bacteremia was age-related (mean 1.63 +1.55; median 0.92) and associated with somnolence and hospitalization among children with CAP. One strain was recovered from pleural fluid. Penicillin resistance was detected in 21.0 percent(4/19) of the strains at an intermediate level, whereas 63.0 percent of the strains were resistant to trimethoprim-sulfamethoxazole. The most common serotypes were 14 and 6B, and these serotypes included the resistant strains. Eight of our 18 isolates from blood were of types included in the heptavalent conjugate pneumococcal vaccine, recently licensed in the USA.