OBJECTIVE To investigate in vitro antibacterial activity of meropenem in Gram-negative bacilli isolated from clinical specimens.METHODS Gram-negative bacilli were isolated from various clinical specimens in our hosptial from Jan 2008 to Dec 2008.The identification test was determined by VITEK-32 Full Automated Microbiology Analyzer,the antimicrobiol susceptibility was detected by K-B method.RESULTS The resistance rate of Enterobacteriaceae to meropenem was extremly low.The resistance rates of Escherichia coli,Klebsiella pneumoniae and Enterobacter cloacae to meropenem were 0,27.6% and 4.2%.The resistance rates of Stenotrophomonas maltophilia,Burkholderia cepacia,Chryseobacterium meningosepticum,Pseudomonas aeruginosa and Acinetobacter baumannii to meropenem were 100.00%,48.81%,94.12%,21.85% and 31.72% respectively.CONCLUSIONS Meropenem has high in vitro antimicrobial activity to Enterobacteriaceae.but generally low to non-fermentative Gram-negative bacilli.

OBJECTIVE To investigate the prevalence of PER-1 type ESBLs-producing Enterobacteriaceae and their antimicrobial-resistance profile. METHODS Totally 167 strains of Escherichia coli, 154 strains of Klebsiella pneumoniae and 67 strains of Enterobacter cloacae were tested. All of them were isolated from all kinds of clinical specimens in four hospitals of Nanchang city from Aug 2003 to Jun 2004. Antimicrobial susceptibility test(AST) was determined by K-B disk diffusion test. double-disk test(CTX, CTX/CA and CAZ, CAZ/CA)and three- dimension extract test were used to determine ESBLs. PER-1 genes were amplified by PCR. The products of PCR were sequenced to identify its ?-lactamase encoding gene. RESULTS Sixteen isolates were PER-1 gene positive. The PER-1 gene positive rates of E. coli, K. pneumoniae and E. cloacae were 3.6%, 3.2% and 9.0% , respectively . The antimicrobial-resistant rates of isolates harboring blaPER-1 to cefotaxime, ceftaxidime, amikacin , cefoxitin , cefepime and imipenem were 100%,100%, 56%, 94%, 31% and 0%, respectively. CONCLUSIONS blaPER-1 is detected in E. coli, K. pneumoniae and E. cloacace, and has diffused in Enterobacteriaceae . Imipenem and amikacin may be used to treat the infection caused by bacteria harboring blaPER -1.

OBJECTIVE To investigate the vicissitudes of antimicrobial resistance to imipenem in Gram-negative bacilli isolated from clinical specimens.METHODS Gram-negative bacilli were isolated from various clinical specimens in our hosptial from Oct 2003 to Jun 2006.The identification and antimicrobiol susceptiblity test were determined by VITEK-AMS Full Automated Microbiology Analyzer.RESULTS A total of 2045 strains of Gram-negative bacilli were isolated,including 35 species.From them 912 isolates of Enterobacteriaceae and 1120 isolates of non-fermenters accounted for 44.6% and 54.8%,respectively.The most predominant pathogens were Pseudomonas aeruginosa(21.1%),Escherichia coli(20.4%),Acinetobacter baumannii(14.2%),Klebsiella pneumoniae(9.4%),and Burkholderia cepacia(7.9%).The resistance rate of Enterobacteriaceae to imipenem was very low.The rates of Stenotrophomonas maltophilia,B.cepacia,Chryseobacterium meningosepticum,P.aeruginosa and A.baumannii to imipenem were 100.0%,98.6%,98.3%,22.3% and 20.6%.CONCLUSIONS Non-fermenters are predominant pathogens.Imipenem has high antimicrobial activity to Enterobacteriaceae in vitro,but not to non-fermenters.The resistance rates of P.aeruginosa and A.baumannii to imipenem increase gradually.

OBJECTIVE To investigate the drug resistance of clinical isolates of Streptococcus pneumoniae and molecular epidemiology with BOX-PCR in Nanchang. METHODS Antibiotic susceptibility was determined by the Etest methods or K-B disk diffusion test. Twenty-nine Penicillin-resistant S. pneumoniae(PRSP) clinical isolates were molecularly typed by BOX-PCR to detect the clonal relationship of them. RESULTS 85.7% were resistant to erythromycin,57.1% were PRSP. The resistant rates to tetracycline,clindamycin,trimethoprim-sulfamethoxazole and chloramphenicol were 88.1%,79.8%,60.7%,and 28.6%. Amoxicillin/clavulanic acid,levofloxacin and ceftriaxone retained activity against most of the isolates. All of strains were susceptible to vancomycin. Twenty-nine S. pneumoniae strains were divided into 14 distinct types,and 19 subtypes with subtype A (n=4) as the predominant type. CONCLUSIONS The resistance rate of S. pneumoniae to penicillin is very high,BOX-PCR typing demonstrats a high discriminatory potential and easy to be accurately analyzed.