| Object: 1. To investigate the epidemiology trends of clinical isolated methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCoNS) in a general hospital in Tianjin. 2. To investigated the relationship between the S. aureus carriage statement and the infection caused by S. aureus.Method: 1. Data of the patients in Hospital A from which 191 Staphylococcus species strains isolated during 2002.7-2004.6 was analyzed. The MIC to penicillin, oxacillin ,ampicillin , ciprofloxacin, tetracycline , cefazolin , chloramphenicol, lincomycin, Gentamycin, ceftriaxone, vancomycin and erythromycin of 191 clinical isolated strains determined Staphylococcus species included 150 Staphylococcus aureus and 41 coagulase-negative Staphylococcus were tested by micro-diluted broth method. 2. In Hospital B, in order to collect the Staphylococcus aureus of carriage and infection statement, the nasal swab was performed when the patients were pathogenetic diagnosised as Staphylococcus infection. The MIC test of these strains were performed by micro-diluted broth method.Result: 1. In Hospital A, totally 191 Staphylococcus strains were isolated from inpatients during a two years continued period. The two year were divided by time point 6/30/2003. 191 Staphylococcus isolates were mainly come from internal medicine ward and Intensive Care Unit. Nearly 77.33% S. aureus and 70.73% CoNS was come from sputum culture respectively. The ratio of MRSA in 2002 and 2003 were 72.84% and 67.33%, respectively. There has no statistical differences between the isolation rate of MRSA in two years. 2. The "paired S.aureus" P242 and P248 are both MSSA, and the phenotype of two strains is same.Conclusions: 1. the epidemiology analysis show the risk factors profile of infection caused by Staphyiococcus species among inpatients. Ratio of isolated MRSA from Hospital A in have no statistical differences between two years. No vancomycin resistant strains founded. 2. The antibiotic spectrum of " the pairedS. aureus " from Hospital B have no differences.. These two strains was come from urine culture and nasal swab of a inpatient enduring hospital acquired urinary infection respectively. This hint that the carriage strain has a potential relative to infection strains.Objective: 1. To analyze the genetic background of clinical isolated Staphylococcus in Tianjin. 2. To identify the genetic relationship between P242 and P248: "the paired strains" collected from a single patients. Methed: Three genetic typing method were used. 1. The SCCmec typing by multiplex PCR: 8 pair of rimers synthesized according to the sequence report in genebank. These 8 locus were selected from the region specific to SCCmec type I~IV and their subtype respectively. 2. MLST analyze to Staphylococcus aureus. 7 housekeeping gene were selected and the primer were synthesized according to the sequence reported in genebank. The sequence of every PCR product was determined and submitted to the database web site: http://saureus.mtet.net to obtain the ST type. 3. In order to typing Staphylococcus genetic background, PFGE were performed according to standards protocol described before. The PFGE pattern was determined by visualize and Gelcompar software.Result: 1. In 8 MRSA, TH10 and TH13 carried type Ilia SCCmec, TH56 and TH82 carried type III SCCmec. Four MRSA can't be typed by multiplex PCR. There is no DNA fragment founded after PCR reaction of 4 MSSA strains. In 24 MRCoNS, 9 carried the type I, la, II, III, Ilia, and IV SCCmec that have been founded in hospital-acquired MRSA. The mecA internal control is positive in 15 MRCoNS strains, but the SCCmec can not be typed. 2. 6 of 12 the Staphylococcus aureus in this study were typed by MLST. The ST profile of 6 in the 8 MRSA strains is 2-1-1-4-4-3, the genetic background is Brazilian/Hungarian clone accrding to the study reported before. 3. PFGE typing shows the genetic background similarity of TH10, TH13 and TH18 is 100%, and the similarity between SE76 and SE137 is 90%. 4. The "paired S. aureus" P242 and P248 belong to ST1, and the PFGE typing shows the genetic background is 100% in similarity.Conclusions: The prodophytium of MRSA isolated in Tianjin maybe the Brazilian/Hungarian clone. This result is consistent to recent report about the MRSA in China and Estern Asia. 2. mecA is widely distributed in CoNS. Some of... |
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