title: Comparison of three different PCR-based methods to predict the penicillin nonsusceptible Streptococcus pneumoniae isolates from China.
abstract: OBJECTIVE
  To find a quick and reliable diagnostic technique for penicillin nonsusceptible Streptococcus pneumoniae (PNSSP) from Nanjing, China.
  
  
  RESULTS
  A total of 130 S. pneumoniae clinical isolates and 50 healthy carriers' isolates were collected from seven teaching hospitals in Nanjing between March 2005 and June 2007. Three different methods, PCR, seminested-PCR, and PCR-RFLP, were applied in detecting PNSSP. The prevalence of PNSSP was 73.9%, the penicillin-resistance rate of children's group and adults' group were 87.8% and 31.2%, respectively. The PCR method had difficulty in identifying intermediate-resistant and resistant isolates, the PCR-RFLP method could only be used for susceptible isolates and had poor sensitivity. Seminested-PCR was fast, sensitive for detection, and successfully differentiated between moderately and highly resistant S. pneumoniae; 96.1% of the PCR results were in agreement with the minimum inhibitory concentration (MIC) data.
  
  
  CONCLUSIONS
  The penicillin resistance rate in isolates from children was much higher than of isolates from adults in China. Seminested-PCR for pbp1A was the best diagnostic method.
  
  
  CONCLUSIONS
  We compared three different strategies for the first time in identification of PNSSP in China. In conclusion, seminested-PCR can be applied in clinical microbiology laboratories for detection of serious infections caused by S. pneumoniae.
authors.affiliation: Department of Respiratory Medicine, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China.
authors.forename: J-J
authors.initials: JJ
authors.lastname: Ding
authors.forename: X
authors.initials: X
authors.lastname: Su
authors.forename: F-M
authors.initials: FM
authors.lastname: Guo
authors.forename: Y
authors.initials: Y
authors.lastname: Shi
authors.forename: H-F
authors.initials: HF
authors.lastname: Shao
authors.forename: X-Z
authors.initials: XZ
authors.lastname: Meng
mesh_terms: D000293:Adolescent; D000328:Adult; D001426:Bacterial Proteins / Q000235:genetics*; D002353:Carrier State / Q000382:microbiology; D002675:Child, Preschool; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D010403:Penicillin Resistance; D010458:Peptidyl Transferases / Q000235:genetics*; D011008:Pneumococcal Infections / Q000175:diagnosis* / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; C480727:PBP1a protein, Streptococcus pneumoniae; D010458:Peptidyl Transferases