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Objective To indicate the restriction profiles of pbps in Streptococcus pneumoniae(S.pneumoniae), and relationship between pbps profiles and the penicillin MIC.Methods The E-test MIC method was used to determinate penicillin susceptibility of 132 S.pneumoniae strains consisting of 69 penicillin susceptible S.pneumoniae (PSSP) strains and 63 nonsusceptible S.pneumoniae (PNSP) strains. Furthermore, we compared these strains by detecting restriction fragment length polymorphism (RFLP) of the PBPs genes pbp1a, pbp2b and pbp2x.Results The RFLP results showed that 9 genotypes were founded for pbp1a, in which 2 were detected from PSSP and some PNSP strains. The other 7 ones were founded mainly in the PNSP with penicillin MIC≥0.25 ?g/ml. Ten genotypes were founded for pbp2b, in which 3 were detected from PSSP and some PNSP strains. The other 7 ones, similar with pbp1a, were founded mainly in the PNSP with penicillin MIC≥0.25 ?g/ml. Thirty-one restrictive patterns were founded for pbp2x. Seventeen patternss from them were detected in PSSP, and 13 ones were founded only in PSSP. The other 14 patterns all were covered PNSP strains. A total of 47 patterns were found according to the three pbps types. Twenty-three patterns from them were detected in PSSP, and 17 ones were founded only in PSSP. The other 24 patterns all were detected in PNSP.Conclusions Results of the study are consistent with the concept that mutations in PBP1a, PBP2b and PBP2x play an important role in the development of resistance to ?-lactam antibiotics by S.pneumoniae. In the meantime, the profiles of pbps can predict penicillin susceptibility.
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Objective To determine the incidence of bacterial infection in neonates due to group B streptococcus(GBS) in our hospital. Methods The specimens were collected from 141 neonatal infants with infectious symptoms and maternal risk factors. 93 blood and 6 CSF samples were performed bacterial culture.141 blood sera, 65 urine and 6 CSF samples were tested for GBS antigen by countercurrent immunoelectrophoresis(CIE). Results In 141 neonatal infants, 27 cases were found GBS polysaccharide antigen positive(19.1%). Blood and CSF culture were positive only in 1 case. In 27 cases , there were 2 cases with meningitis, 6 cases with sepsis, 12 cases with infectious pneumonia , 2 cases with omphalitis, and 5 cases were only premature babies .There were 20 cases of early onset disease and 7 cases of late onset disease. There was one case that the same serotype(III/R) and DNA genes of GBS were found in the blood and CSF cultures of baby and his mother's vaginal swab culture . The antibacterial activity was found in the urine specimens of 32/34 cases in the first day on admission by micrococcus inhibition test, only 2 cases were negative. All patients were treated with Penicillin and Ampicillin. Conclusions (1)GBS is one of the pathogens in neonatal infection.(2)CIE method for identification of GBS polysaccharide antigen is sensitive and specific.(3)Penicillin was the first choice for neonatal GBS infection.
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Objectives To determine the prevalence of Staphylococcus aureus (S. Aureus) colonization and S. aureus-derived exotoxins in lesions of childhood atopic dermatitis (AD) and evaluate the role of S.aureus-derived exotoxins in the pathogenesis of childhood AD. Methods Specimens were taken from the skin lesions of 148 patients, non-lesional skin of 30 patients, and the skin of 250 controls for bacterial cultures. S. aureus-derived exotoxins were detected by reverse passive latex agglutination. Total IgE levels were determined with immunoradiometric assay. Results The prevalence of S. aureus colonization was significantly increased in both the lesional and non-lesional skin of patients with AD in comparison with the controls (P 0.05). However, patients with increased total IgE levels showed significantly high SCORAD indices (P