Homologx analxsis on Staphylococcus isolated from infectious wound-re-lated environmental specimens / 中国感染控制杂志

Objective To monitor Staphylococcus infection in a hospital,and trace the source of Staphylococcus isolated from infectious wound-related hospital environment by molecular analysis. Methods By combination of fluorescence quanti-tative polymerase chain reaction (FQ-PCR)and culture method,environmental specimens related to 5 patients with wound infection were taken and performed multilocus sequence and MecA gene typing analysis. Results A total of 71 environmen-tal specimens were taken,Staphylococcus accounted for 36.62% (n= 26),88.46% (23/26 )of which were MecA+ methi-cillin-resistant strains. 77.78% (7/9)of Staphylococcus aureus (S. aureus)and 95.00% (19/20)of coagulase negative Staphylococcus (CNS)were methicillin-resistant strains. Multilocus sequence analysis revealed that ST239 (n= 6)was the most common sequence type in S. aureus;Staphylococcal cassette chromosome mec (SCCmec)analysis showed that the ma-jor type of S. aureus was typeⅢ,and CNS were typeⅢandⅣ. Conclusion Staphylococcus is common in healthcare-associated infection,and most Staphylococcus are multidrug-resistant,continuous monitor on drug-resistant Staph-ylococcus is necessary,and risk of Staphylococcus variant to medical institutes need to be paid attention.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococcus spp (CNS) are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN) remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT), VAN plus rifampin (RIF) and VAN plus imipenem (IPM) in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

Distribution and Drug Resistance in 251 Coagulase Negative Staphylococcus Strains / 中华医院感染学杂志

OBJECTIVE To investigate the antibiotic resistance status in coagulase negative staphylococcus (CNS) strains and provide the scientific evidence for the reasonable use of antibiotics. METHODS The drug resistance of 251 strains of CNS was ananlyzed. RESULTS The detection rate of methicillin-susceptible coagulase-negative Staphylococcus(MSCNS) was 12.75% (32/251), while that of methicillin-resistant coagulase-negative Staphylococcus (MRCNS) was 87.25%. The drug-resistance rate of MRCNS was higher than that of MSCNS. Vancomycin resistant and intermediate strains had not been detected. CONCLUSIONS Laboratory should monitor the drug resistance well and update in time to offer the evidence for the reasonable use age of the antibiotics.

Drug-resistant Gene of Meticillin-resistant Coagulase Negative Staphylococcus in Children Septicemia / 中华医院感染学杂志

OBJECTIVE To study the distribution of drug-resistant gene of meticillin-resistant coagulase negative Staphylococcus(MRCNS) in children septicemia.METHODS The total MRCNS isolates were 40,and whether in there harbored genes mec,erm and qac was studied.RESULTS Among 40 CNS strains,in there harbored genes mec,erm,and qac were 38(95.0%),30(75.0%) and 18(45.0%),respectively.CONCLUSIONS MRCNS in children septicemia where harbor drug resistance genes is very serious,so we should pay great heed to its effective control.

Microbial Features and Antibiotic Prophylaxis of Prosthetic Joint Infection / 감염

BACKGROUND: Success in orthopedic implant surgery relies on reducing infection by preventive methods including antibiotic prophylaxis. The lack of published data on orthopedic implant infections with methicillin-resistance Staphylococcus aureus (MRSA) and methicillin-resistance coagulase-negative staphylococcus (MRCNS) makes it difficult to choose correct prophylactic antibiotics. We therefore reviewed the etiology of prosthetic joint infection and the effectiveness of current antibiotic prophylaxis. METHODS: We reviewed retrospectively the clinical notes and microbial records of patients with prosthetic joint infection who had admitted in Asan Medical Center from June 1989 to July 1999. RESULTS: During a eleven-year period, prosthetic joint infections occurred in 18 (0.9%) of 2,028 patients who received a total hip or total knee arthroplasty at Asan Medical Center (AMC). The cephalosporins were administered to most of patients before surgery for prophylaxis. Twenty two patients were referred to our institution because of prosthetic joint infection. Thirty five patients had positive bacteriological cultures from tissue removed at the time of surgery or joint aspiration. Staphylococci were the most common pathogens and accounted for twenty four (68.8%) of the 35 isolates. Seven (50%) of the fourteen isolates of coagulase-negative staphylococci were MRCNS. Eight (80 %) of the ten ioslates of S. aureus were MRSA. Gram-negative bacilli accounted for five (14.3%) of the isolates and included Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa. CONCLUSION: First-or second-generation cephalosporins were effective prophylatic antibiotics in total hip or total knee arthroplasty because the rate of prosthetic joint infections was low (0.9%). But the prevalence of MRCNS or MRSA prosthetic joint infection was high, we must consider glycopeptides prophylaxis if there is, or has been, infection or carriage with MRCNS or MRSA.

Detection of MRCNS and analysis of their drug resistance / 重庆医科大学学报

0.5).The resistance rates of MRCNS to PEN,GEN,SXT,CIP,TET,ALL and ERY,are all above 50%.The resistant rates of MSCNS to other antibiotics are below about 50% except for PEN(80.4%)and ERY(57.1%).MRS are more than 70% and no VAN resistant in CNS.Conclusion:All the 5 methods are suitable for clinical detection of MRCNS ,and latex agglutination is the most convenient and rapid.MRCNS had a serious cross-resistance in aminoglycosides,guinolones,tetracycline,macrolides,sulfanilamide and,so the best choice for therapy is VAN.GEN,SXT,CIP,TET and CLI could be used for MSCNS,except VAN.