Antimicrobial resistance of gram-negative bacilli isolated from 14 teaching hospitals across China in 2016 / 中华检验医学杂志

Objective To investigate antimicrobial resistance among nosocomial gram-negative bacilli in 2016 across China.Methods About 1 394 consecutive and non-repetitive gram-negative bacilli were isolated from 14 teaching hospitals from March to August in 2016 across China.All of these isolates were sent to the central laboratory for reidentification and susceptibility testing.The minimal inhibitory concentration(MICs)of meropenem and other antibacterial agents were determined by agar dilution method.The data were analyzed by using WHONET-5.6 software.Results The activity of antimicrobial agents against Enterobacteriaceae was as follows in descending order of susceptible rate: meropenem (95.2%,891/936), amikacin (94.6%,885/936), ertapenem (92.1%,862/936), piperacillin/tazobactam (88.1%,825/936), imipenem (88.0%,823/936), cefoperazone-sulbactam (83.1%,778/936), cefepime (72.2%,676/936), cefiazidime (72.2%,676/936), levofloxacin(68.8%,644/936), ciprofloxacin (63.2%,592/936), minocyline (62.9%,589/936), cefiriaxone (54.9%,514/936), cefotaxime (54.0%,505/936), cefoxitin (44.3%,415/936).The sensitivities of E.coli to carbapenems, amikacin, piperacillin-tazobactam, polymyxin B and cefoperazone-sulbactam were over 80%.The more sensitive antibiotic to Klebsiella pneumoniae was polymyxin B (99.0%), followed by amikacin (84.9%), meropenem (84.4%) and imipenem (82.0%).The prevalence of extended-spectrum β-lactamase was 62.8%(137/218)in Escherichia coli and 28.3%(58/205)in Klebsiella pneumonia.The activity of antimicrobial agents against E.cloacae, E.aerogenes and Citrobacter freundii was as follows in descending order of susceptible rate: meropenem (97.0%-98.5%), amikacin (95.8%-98.3%), imipenem (94.5%-97.5%), polymyxin B (96.4%-100%), cefoperazone-sulbactam (76.5%-90.0%), ertapenem (73.3%-90.1%), piperacillin/tazobactam (82.4%-88.3%).The most active agents against Pseudomonas aeruginosa were polymyxinB (100%), followed by amikacin (89.3%) and ciprofloxacin (82.4%).The most active agents against Acinetobacter baumannii were polymyxinB (100%).The sensitivities of Acinetobacter baumannii to meropenem, imipenem, minocycline and cefoperazone-sulbactam were 20.3%(39/202), 19.3%(41/202), 66.3%(134/202) and 24.8%(50/202), respectively.Conclusions Carbapenems remain high sensitive against Enterobacteriaceae.Controlling carbapenem resistant Klebsiella pneumoniae is urgent.Drug antimicrobial resistance in A.baumanni is a still serious problem.

Analysis of distribution and drug resistance of pathogenic bacteria in burn wards / 上海交通大学学报（医学版）

Objective·To analyze changes in the type distribution and drug resistance of pathogenic bacteria isolated from burn wards and to provide evidence for rational use of antibiotics, reduction of drug-resistant isolates, and hospital infection control. Methods·Isolates from burn patients were collected from January 2011 to December 2014. Statistical analysis of infection sources, type distribution, and changes in resistance rates of main pathogens during the four year period was performed. Results·A total of 2399 isolates were collected, including 1286 (53.61%) gram-negative bacilli (G-b), 1088 (45.35%) gram-positive cocci (G+c), and 25 (1.04%) fungi. The most common G-b pathogens were Pseudomonas aeruginosa (447, 34.76%) and Acinetobacter baumannii (369, 28.69%). The most common G+c pathogen and fungus were Staphylococcus aureus (489, 44.94%) and Candida albicans (8, 33.33%), respectively. In the last two years, the detection rates of S.aureus and A.baumannii were significantly lower and the detection rate of P.aeruginosa was significantly higher than those in the first two years (P80%) to the third and fourth generation cephalosporins, carbapenems, aminoglycosides and quinolones, but the changes were not statistically significant (P>0.05). S.aureus was only highly resistant to penicillin (97.58%) and was 100% susceptible to vancomycin. Its resistance rates toward cefazolin, ampicillin/sulbactam, gentamicin, levofloxacin, and rifampin decreased significantly (P<0.05). The detection rate of methicillin-resistant S. aureus (MRSA) dropped from 72.28% to 63.00%. Conclusion·Many types of drug resistant bacteria were detected in burn wards. The drug resistance problem was serious. Improving management and rational use of antibiotics can reduce the occurrence of drug-resistant bacteria and increase the efficacy of clinical anti-infective treatment and nosocomial infection control.

Multicenter study on risk factors for multidrug-resistant organism health-care-associated pneumonia / 中国感染控制杂志

Objective To assess the risk factors of multidrug-resistant organism(MDRO)healthcare-associated pneumonia(HCAP).Methods The case-control study was conducted in patients admitted to 22 hospitals in 4 cities between April 1 ,2013 and December 31 ,2013,patients with HCAP caused by MDRO (MRSA,MDRPA,MDRAB, ESBL KP,ESBL E.coli)(drug-resistant group )and drug-sensitive organisms (MSSA,PA,AB,KP,E.coli)(drug-sensitive group )were surveyed .Univariate and multivariate statistical analysis methods were used to evaluate the risk factors for MDRO HCAP.The prognosis,cost and length of hospital stay between drug-resistant group and drug-sensitive group were compared .Results A total of 1 656 patients were included in the study ,including 43 pa-tients (2.60%)with mixed infection caused by both drug-resistant and drug-sensitive organisms ;there were 927 ca-ses (55.98%)in drug-resistant group and 772 cases(46.62%)in drug-sensitive group .Logistic regression model re-vealed that admission to ICUs (OR 95%CI :1 .55[1 .14-2.11]),mechanical ventilation (OR 95%CI :1 .45[1 .15-1 .84]),arteriovenous catheterization (OR 95%CI :1 .29 [1 .02 - 1 .63 ]),fiberbronchoscopy (OR 95%CI :1 .46 [1 .02-2.09]),antimicrobial use(OR 95%CI :1 .63[1 .20-2.22]),chronic lung diseases (OR 95%CI :1 .54[1 .13-2.10]),and chronic cardiovascular and cerebrovascular diseases (OR 95%CI :1 .42[1 .15-1 .74])were independ-ent risk factors for MDRO HCAP .Compared with drug-sensitive group ,drug-resistant group prolonged length of hospital stay by an average of 5.89 days,increased hospitalization and antimicrobial expense by ￥40 739.30 and￥2 805.80 respectively;prognoses was worse,risk factor was 1 .66-fold of drug-sensitive group(OR 95%CI :1 .16-2.35).Conclusion Admission to ICUs,invasive operations,antimicrobial use,chronic lung diseases and chronic cardiovascular and cerebrovascular diseases can increase the risk of MDRO HCAP .

Distribution and antimicrobial resistance of pathogens isolated from hospi-talized patients with bloodstream infections / 中国感染控制杂志

Objective To investigate the species and drug resistance of pathogens causing bloodstream infections in hospitalized patients,and provide scientific evidence for antimicrobial use and control of healthcare-associated blood-stream infection.Methods From January 1 to December 31,2012,16 428 blood specimens were performed blood culture,pathogens were isolated and performed antimicrobial susceptibility testing.Results Of 16 428 blood speci-mens from 5 546 patients,384 (6.92%)were positive for blood culture,398 pathogenic isolates were detected,of which gram-positive bacteria,gram-negative bacteria,and fungi accounted for 23.62% (n=94),68.34% (n=272),and 8.04% (n=32)respectively,positive rate of blood culture were highest in 61-80 age group(8.26%), the top five departments of positive rate of blood culture were departments of burn,traditional Chinese medicine, cardiac intensive care unit,transplantation and traumatology;gram-positive cocci were highly susceptible to vanco-mycin,teicoplanin and linezolid,one Enterococcus faecium strain was found to be resistant to vancomycin;Among gram-negative bacilli,Enterobacteriaceae were highly susceptible to amikacin and carbapenems;drug resistance rates of Acinetobacterbaumannii and Pseudomonasaeruginosa to carbapenems was 70.97% and 35.90% respective-ly.Conclusion Gram-negative bacteria are the major pathogens causing bloodstream infection,positive rate of blood culture of elderly people is high.It is necessary to conduct regular surveillance on distribution and drug resistance of pathogens.

Investigation of antibacterial activity of topical antimicrobials against methicillin-resistant Staphylococcus aureus / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the antibacterial activity of silver sulfadiazine (SD-Ag), mupirocin, and clotrimazole used alone or in combination against methicillin-resistant Staphylococcus aureus (MRSA) isolated from burn wounds.</p><p><b>METHODS</b>Eighteen MRSA isolates from wound excretion of 18 burn patients hospitalized in our unit from July to December 2011 were collected continuously and non-repetitively. (1) Minimum inhibitory concentration (MIC), 50% MIC (MIC50), and 90% MIC (MIC90) of SD-Ag, mupirocin, and clotrimazole used alone, those of SD-Ag and mupirocin used in combination, and those of SD-Ag, mupirocin, and clotrimazole used in combination to MRSA were determined by checkerboard agar dilution method. (2) Fractional inhibitory concentration (FIC) index was calculated to determine the combined effect of SD-Ag plus mupirocin, and SD-Ag plus mupirocin and clotrimazole. Synergy with FIC index less than or equal to 0.5 or additivity with FIC index more than 0.5 and less than or equal to 1.0 was regarded as effective, and indifference with FIC index more than 1.0 and less than or equal to 4.0 or antagonism with FIC index more than 4.0 was regarded as ineffective. The effective ratio was compared with overall ratio (assumed as 0) by unilateral binomial distribution test.</p><p><b>RESULTS</b>The MIC, MIC50, and MIC90 of SD-Ag, mupirocin, and clotrimazole used alone against 18 MRSA isolates were respectively 8, 8, 16 µg/mL; 2, 16, 64 µg/mL; 2, 2, 2 µg/mL. MIC of antimicrobial agents used in combination decreased from 3.1% to 50.0% as compared with that of individual agent used alone. Compared with those of single application of SD-Ag and mupirocin, MIC50 of SD-Ag and that of mupirocin both decreased 75.0%, and MIC90 of them decreased 87.5% when SD-Ag and mupirocin were used in combination. Compared with those of single application of SD-Ag, mupirocin, and clotrimazole, MIC50 of SD-Ag, mupirocin, and clotrimazole respectively decreased 75.0%, 87.5%, and 50.0%; MIC90 of them respectively decreased 87.5%, 96.9%, and 50.0% when SD-Ag, mupirocin, and clotrimazole were used in combination. Among the 18 MRSA isolates, the combined effect of SD-Ag and mupirocin was synergic in 9 isolates, additive in 7 isolates, indifferent in 2 isolates, and antagonistic in 0 isolate; the combined effect of SD-Ag, mupirocin, and clotrimazole was additive in 16 isolates, indifferent in 2 isolates, and antagonistic in 0 isolate. There were statistically significant differences between effective ratio and overall ratio of 18 MRSA isolates treated with combined antimicrobial agents (P values all above 0.01).</p><p><b>CONCLUSIONS</b>For burn wounds at middle and late stages infected with Staphylococcus aureus or Staphylococcus aureus and Fungus, low dose of SD-Ag or combination of above-mentioned antimicrobial agents can effectively control infection and decrease the adverse effect of antimicrobial agents on wound healing.</p>

Relationship between antibiotic use and antimicrobial resistance in Acinetobacter baumannii / 中国感染与化疗杂志

Objective To investigate the relationship between antibiotic use and antimicrobial resistance in Acinetobacter bau-mannii for rational use of antibiotics.Methods Antibiotic use density (AUD)of common antibiotics in hospitalized patients were collected in a tertiary hospital between 2006 and 2010.Clinical isolates of A.baumannii from those patients were collect-ed.The resistance to common antimicrobial agents were tested by disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI,2012)guidelines.Relationship between antibiotic use and antimicrobial resistance in A.baumannii was analysed by SPSS 16.0.Results The resistant rates of A.baumannii isolated from inpatients were high.Consumption of cephalosporins and quinolones were large.There was a positive correlation between the resistant rate of A.baumannii to imi-penem and AUD of carbapenems (r=0.975,P <0.05).The resistant rate of A.baumannii to meropenem showed significantly positive relation to AUD of carbapenems (r= 0.975,P <0.05).Resistant rates of aminoglycosides,quinolones,cephalospo-rins and beta-lactamase inhibitors was not correlated to AUD of those antibiotics.Conclusions We should pay more attention to the high prevalence of resistant A.baumannnii strains.Application of imipenem and meropenem should be strictly controlled.Amikacin and beta-lactamase inhibitors are better choice for empirical antibiotic therapy in the treatment of infections caused by A. baumannii.

Evaluation on the capability of CHROMagar orientation medium combined with simple biochemical tests for identificaction of common oxidase-negtive gram-negative bacilli / 中华微生物学和免疫学杂志

Objective To evaluate the practicability of CHROMagar orientation medium combined with simple biochemical tests for identification of common oxidase-negtive gram-negative bacilli.Methods The CHROMagar orientation medium was used together with biochemical tests including indole test , ornithine decarboxylase test and lysine decarboxylase test for identification of common oxidase -negtive gram-negative bacilli.The sensitivity, specificity, likelihood ratio, Youden index and Kappa value of the diagnostic assays were evaluated .McNemar test was performed to evaluate facticity, accuracy and cost of the method in com-parison with the Vitek-2 system as reference method .Results The identification of oxidase-negtive gram-negative bacilli from 318 bacterial strains showed that the sensitivities and specificities of CHROMagar orien-tation mediumm in combination with simple biochemical tests to Serratia marcescens, Stenotrophomonas mal-tophilia and Acinetobacter baumannii reached 100%, and for Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoiae were above 90%.The specificities for identification of Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Proteus mirabilis were all above 90%, but the sensitivities were around 75%-90%.Kappa values of the assays were above 0.85, howerer, which was only 0.5947 for Citrobacter freundii.McNemar test showed that all P values were above 0.05, and cost of the assays was reduced by 90%.Conclusion CHROMagar orientation medium in combination with simple biochemical tests is a cost-effective assay for identification of common oxidase-negtive gram-negative bacilli .

Evaluation of the capability of three phenotypic tests used alone or in combination for identification of Staphylococcus aureus / 中华微生物学和免疫学杂志

Objective To evaluate the capability of three tests used alone or in combination for identification of Staphylococcus aureus.Methods Identification of Staphylococcus aureus by the detection of spa gene with PCR and the Vitek-2 system were selected as the reference methods.Comparison of three phenotypic tests including DNase,mannitol fermentation and tube coagulase test was carried out to analyze the sensitivity,specificity,positive/negative predictive value,positive/negative likelihood ratio and Youden index.The consistency,cost and related indexes of the assays were analyzed between the combined phenotypic tests and the reference methods.Results In the present study,324 isolates of Staphylococci,including 293 Staphylococcus aureus and 31 non-Staphylococcus aureus,were collected.Single biochemical test could not identify Staphylococcus aureus efficiently.Comparison between the reference methods and the combined three biochemical tests by Kappa statistic analysis indicated that an overall Kappa value was 0.9441,and the algorithm of combined test was less costly.The sensitivity and specificity of this algorithm were 100％ and 90.3％,respectively.Conclusion The cost-effective algorithm of combined DNase,mannitol fermentation and tube coagulase test could efficiently distinguish Staphylococcus aureus from other Staphylococcus species.

Co-production of carbapenem-hydrolyzing enzyme KPC-2 and ArmA 16S rRNA methylase in pandrugs resistant Enterobacter cloacae / 中华微生物学和免疫学杂志

Objective To investigate the production of carbapenemase and 16S rRNA methylase in five isolates of pan-drugs resistant E.cloacae recovered in Ruijin hospital.Methods MICs of the five isolates to 10 antibiotics were determined by E test.Six kinds of 16S rRNA methylase genes and a series of β- lactamase genes were amplified by PCR.Shotgun cloning was performed to detect carbapenem resistance determinant.The conjugal transfer of carbapenemase gene and 16S rRNA methylase gene was performed in broth culture with E.coli J53 as the recipient.Pulsed-field gel electrophoresis (PFGE) was carried out to analyse the genotyping.IEF was performed to detect β-1actamases.Southern blot was performed to determine the location of carbapenem resistance determinant.Results The MICs of 10 antibiotics were ＞32 mg/L.Four β-1actamases with pIs of 5.4 ( TEM-1 ),6.7 ( KPC-2 ),8.2 ( SHV-12 ),8.4 (CTX-M-14) were determined.The insertion sequence in the recombinant plasmid was blaKPC-2 flanked by a transposon.blaKPC-2 was located on a large non-conjugative plasmid whereas armA was located on an other conjugative plasmid.PFGE patterns of 5 isolates were identical.Conclusion KPC-2 was responsible for carbapenem resistance in pandrugs resistant Enterobacter cloacae.There was no relationship between blaKPC-2 and armA.Although pandrug resistant Enterobacteriaceae remain rare,the emergence of this group of organism merits monitoring.

Leukocidin prevalence and molecular epidemiology of methicillin-resistant Staphy-lococcus aureus / 中国感染与化疗杂志

Objective Methicillin-resistant Staphylococcus aureus (MRSA) is a growing public health concern that has been associated with pediatric fatalities. This study investigated the genotypes of staphylococcal cassette chromosomal mec (SCCmec) and Panton-Valentine Leukocidin (PVL) in MRSA strains isolated from Shanghai Children's Hospital by PCR. Methods A total of 30 strains of MRSA were isolated from various clinical specimens from October 2005 to June 2006. The antimicrobial susceptibility was measured by agar diffusion method. SCCmec typing was conducted using a novel multiplex PCR assay allowing for concomitant detection of methicillin resistance (mecA gene) to facilitate detection and classification of all currently described SCCmec typesⅠ, Ⅱ, Ⅲ, Ⅳa, b, c, d andⅤ. PVL gene was also determined by PCR. Results mecA gene was positive in all the strains. SCCmecⅡ was identified in 6(20.0%) isolates, SCCmecⅢ in 15(50.0%) isolates, SCCmecⅤ in 2 and SCCmecⅣa in 1 isolate. Six MRSA strains were non-typeable. The isolates with SCCmecⅡ or SCCmecⅢ were resistant to multiple antibiotics. The strains harboring SCCmecⅣa or SCCmecⅤwere susceptible to all antibiotics except β-lactams. Eleven (36.7%) isolates were PVL positive. The genotypes and subgenotypes of staphylococcal chromosomal cassette mec of eleven PVL-positive MRSA were SCCmecⅡ(1 isolates), SCCmecⅢ (5 isolates), SCCmecⅣa (1 isolate), SCCmecⅤ (2 iso-Lates) non-typeable (2 isolates). Conclusions SCCmecⅡ and SCCmecⅢ are the major genotypes of MRSA in our hospital. These isolates are multi-resistant to antibiotics. The prevalence of PVL gene is higher in SCCmecⅡ- or SCCmeⅢ-positive MRSA. The isolates with SCCmecⅡ or SCCmecⅢ were resistant to multiple antibiotics.

Antimicrobial Resistance and Staphylococcal Cassette Chromosome mec Genotype of Meticillin-resistant Staphylococcus aureus from Lower Respiratory Tract / 中华医院感染学杂志

OBJECTIVE To investigate antimicrobial resistance and molecular epidemiology profiles of meticillin-resistant Staphylococcus aureus(MRSA)sampled from lower respiratory tract.METHODS Totally 107 MRSA strains were isolated from lower respiratory tract specimens at Shanghai Pulmonary Hospital between Dec 2005 and Dec 2006.PVL genes were detected by PCR.The genotypes of SCCmec were identified by multiplex PCR.The antimicrobial resistance of MRSA were tested by Kirby-Bauer agar dilution.We also performed the homology of 32 MRSA strains using pulsed-field gel electrophoresis(PFGE).RESULTS All of the 107 MRSA strains were negative in the PVL locus detection and the most frequent SCCmec types were type Ⅲ(81.3%),the others including type Ⅱ(15.9%),type Ⅳ(2.8%),type Ⅰ and type Ⅴ were not found in this group.Those 3 different types of SCCmec were all resistant to ?-lactam antibiotics,less resistant to rifampin,and susceptible to vancomycin,teicoplanin and daptomycin.The resistant rate of those 3 types were different to the non-?-lactam antimicrobial drugs such as trimethoprim/sulfamethoxazole,clindamycin,erythromycin,gentamicin,levofloxacin,and tetracycline,the resistant rate in the types Ⅱ and Ⅲ was significantly higher than the type Ⅳ.PFGE analyses assorted the 32 MRSA strains into 4 PFGE patterns:pulsotype A(25 strains),including subtypes A1(17strains),A2(1 strain)and A3(7 strains);pulsotype B(5 strains),pulsotype C(1 strain),and pulsotype D(1 strain).CONCLUSIONS This study does not found positive PVL locus in the MRSA strains in our hospital,the most frequent SCCmec types are type Ⅲ and some are type Ⅱ.PFGE presented that there are outbreaks of MRSA in ICU ward and TB ward No 5 at that time and the pandemic strains are subtypes A1 and A3,most of these MRSA strains are multiple resistant,which deserves attention from both the clinical staff and infection-control department of the hospital.

The epidemiological study of methicillin-resistant Staphylococcus aureus in Shanghai / 中华检验医学杂志

Objective To investigate antibiotic resistance and molecular epidemiology profile of methicillin-resistant Staphylococcus aureus (MRSA) in Shanghai. Methods The antibiograms of 140 MRSA isolates from 5 hospitals for 13 drugs were analyzed by agar dilution and broth dilution. The PVL gene and SCCmec were detected by PCR; The clonal relatedness of 140 isolates were determined by PFGE and 39 strains were chosen to be characterized further by spa typing. Results All 140 MRSA are PVL negative and most of them were identified as SCCmec Ⅲ [45.7% (64/140)], followed by SCCmec Ⅲ a [25.0% (35/140)], SCCmecⅢb [14.3% (20/140)], SCCmecⅡ [10.7% (15/140)] and SCCmecⅣ [4.3% (6/140)]. All isolates were susceptible to vancomycin, teicoplanin and daptomycin. The resistance to gentamicin, sulphamethoxazole and clindamycin was 98. 6% (138/140), 98. 6% (137/140) and 97. 9% (137/140), respectively. Resistance to erythromycin, ciprofloxacin and tetracycline was above 80%, and resistance to rifampicin was 10. 7% (15/140). Sixteen different PFGE patterns(A-P) were found and most of MRSA belonged to group C[30. 7% (43/140)] ,B[13.6% (19/140)]and Ⅰ [10. 7% (15/140)]. Among 39 strains with prevalent PFGE patterns, 4 spa genotypes were identified: t002133. 33% (13/39)] ,t030 [12. 82% (5/39)] ,t037[51.28% (20/39)]and t459[2. 57% (1/39)]. Conclusions Sixteen different PFGE patterns and 4 spa genotypos were found from 5 hospitals in Shanghai. The most popular MRSA clone is PVL negative, SCCmec Ⅲ, with resistant profile of erythromycin, ciprofloxacin,clindamycin,etracycline, gentamicin,and sulphamethoxazole [E-C-L-T-G-M-]. This result suggests that hospital infection control and reasonable antibiotic usage are critical.

The evolution and dissemination of macrolide-resistance Streptococcus pneumoniae in Shanghai / 中华检验医学杂志

Objective To determine the genetic background and evolutional route of macrolideresistance Streptococcus pneumoniae(MRSP)strains in Shanghai.Methods Forty-seven MRSP clinical isolates were genotyped by pulse field gel electrophoresis(PFGE)to detect the donal relationship of therm.Serotyping and muhilocus sequence typing(MIST)on 6 multi-resistant strains wag used to investigate the evolutional relationship between serum types and international epidemic strain among MRSP strains in Shanghai.Results There were 2 epidemical clones(type A 45%,type B 17%)in MRSP clinical isolates containing both the ermB and the mefE genes in Shanghai.MIST analysis showed that all 6 multi-resistant strains whose PFGE pattern was A type belonging to Asia clonal complex-CC236(Taiwan19F-14 clone).There was a novel ST-ST2116,which might derived from CC236 due to the recombination with alldic change.Conclusion,The high prevalence of erythromycin-resistant Streptococcus pneumoniae containing both the ermB and the mere genes in Shanghai is partly due to the clonal spread of a few mtdtidrng-resistant clones.

ESBLs′ Genotypes of Escherichia coli and Klebsiella pneumoniae / 中华医院感染学杂志

OBJECTIVE To investigate the ESBLs ′ genotypes and the resistance of Escherichia coli and Klebsiella pneumoniae in Taizhou Hospital of Zhejiang Province.METHODS We collected 30 strains of E.coli and K.pneumoniae expressing ESBLs,then analyzed their encoding genotypes of TEM,SHV,PER,VEB and CTX genes by PCR and DNA sequencing technology separately.RESULTS There were 26 strains expressing blaCTS-M gene among 30 strains,in which 16 strains belonged to blaCTS-M-9 subgroup genotype,8 strains to blaCTX-M-1,7 strains to blaCTX-M-2,4 strains to blaCTX-M-1 as well as blaCTX-M-2,1 strain to blaCTX-M-2 as well as blaCTX-M-9 and 1 strain belonged to blaCTX-M-1 as well as blaCTX-M-9.CONCLUSIONS The prevalent clinical genotype of E.coli and K.pneumoniae is blaCTX-M-9.

ESBLs Produced by Enterobacter cloacae / 中华医院感染学杂志

OBJECTIVE To investigate the ESBLs produced by clinical strains of Enterobacter cloacae.METHODS Production of ESBLs was identified with modification of the double-disk test(MDDT).Eight kinds of primers(CTXM,CTXM-1,CTX-M-2,CTX-M-9,SHV,TEM,VEB,and PER)were used for the PCR amplification.Gene clone and DNA sequencing were performed then.RESULTS The result of MDDT was positive,amplicons were gained by PCR amplification with CTXM-1.DNA sequencing of amplicons of this strain revealed ESBLs of CTX-M-3.CONCLUSIONS ESBLs are the important reason for E.cloacae resisting to the third-generation cephalosporins.

Distribution and Antibiotic Resistance Analysis of 1275 Pathogens Isolated from Urinary Tract Infection / 中华医院感染学杂志

OBJECTIVE To investigate the distribution and antibiotic susceptibility of pathogens causing urinary infection,for the guide of rational use of antimicrobial agents in clinic. METHODS The bacteria isolated from the middle segment urine sample were identified by ATB system,and K-B method was used to study the antimicrobial resistance.The data were analyzed by WHONET 5.3. RESULTS Escherichia coli was one of the most common bacteria in the urinary tract infection(57.6%),and then were Enterococcus(14.4%).The results of antibiotic susceptibility test in vitro showed the susceptibility rate of Enterobacteriaceae and Acinetobacter baumannii to imipenem,was 100.0%,but the resistance rate of Pseudomonas aeruginosa was 13.6%.Gram-positive cocci were sensitive to glycopeptide antibiotics and linezolid. CONCLUSIONS Clinician should pay attention to the kinds of pathogenic bacteria causing urinary tract infection and their susceptibility to clinically common used antibiotics for reasonable use of drugs.