RESUMO
Objective To investigate the prevalence of mcr-1 gene,a plasmid-mediated polymyxin resistance gene,in Escherichia coli(E.coli) strains isolated in Dongyang of Zhejiang Province and to under-stand the epidemiological characteristics of E.coli strains carrying mcr-1 gene in order to provide local clini-cians with a theoretical basis for prevention and control of the spread of mcr-1-bearing E.coli strains. Meth-ods A total of 315 E.coli strains were collected in the People′s Hospital of Dongyang, Zhejiang Province from January to December 2016. All strains were isolated from specimens of blood,urine,respiratory tract, etc. PCR was performed to detect the genes confering resistance to polymyxin (mcr-1 gene), β-lactamase and carbapenem. Minimal inhibitory concentrations (MIC) of antibiotics against mcr-1-positive strains were determined by micro-broth dilution method. Conjugation test was performed to confirm whether the mcr-1 gene was located on the transferable plasmid. Multilocus sequence typing (MLST) was used for molecular typing of mcr-1-positive strains. Results Five mcr-1-positive strains were identified from 315 E.coli strains with a positive rate of 1.6%. Two out of the five mcr-1-positive E.coli strains contained β-lactamase resist-ance genes,blaTEM-1and blaCTX-M-14. Both of them were resistant to the first, second and third generation of cephalosporins and one was also resistant to cefepime. All of the five mcr-1-positive E.coli strains were sen-sitive to ciprofloxacin and levofloxacin,but resistant to ticarcillin/clavulanic acid. No carbapenem resistance genes were detected. One transconjugant was successfully obtained by transconjugation assay. MLST analysis showed that a total of four sequence types were identified, including ST131 (two strains), ST43 (one strain),ST69 (one strain) and ST349(one strain). Conclusion Only 1.6% of all E.coli strains isolated in Dongyang area of Zhejiang Province carry mcr-1 gene,indicating that there is no epidemic of mcr-1 gene-positive E.coli infection. The coexistence of mcr-1 gene and β-lactamase resistance genes in E.coli strains isolated in Dongyang suggests that local clinicians should avoid antibiotic abuse to prevent the spread of drug-resistant E.coli.
RESUMO
Objective To detect carbapenemase production in enterobacteriaceae by using modified Hedge test (MHT) and investigate the distribution of carbapenemase genes.Methods A total of 3 718 isolates from enterobacteriaceae were collected from 4 hospitals,including Second Affiliated Hospital of Zhejiang University,People's Hospital of Dongyang,Beijing Hospital,and Huaxi Hospital of Sichuan University.Susceptibility of enterobacteriaceae to ertapenem was tested by K-B method.MHT was used to detect carbapenemase in enterobacteriaceae and the common carbapenemase genes were amplified by using PCR.Results The total resistance rate ( resistance and intermediate resistance) of enterobacteriaceae to ertapenem was 3.04％ (113/3718) and there were differences in resistance rate of enterobacteriaceae to ertapenem among 4 hospitals (5.09％,2.15％,2.59％,and 1.72％,respectively).Of the 3718 isolates,2.29％ (85) were positive to MHT,and there were differences in positive rate to MHT among 4 hospitals (4.73％,1.21％,1.06％,and 1.58％,respectivdy).Of 113 non-susceptible isolates to ertapenem,82 were positive to MHT and 31 were negative.Of 85 MHT-positive isolates,82 were resistant or intermediate resistant to ertapenem and only 3 were susceptible.Of 82 MHT-pesitive and non-susceptible isolates to ertapenem,65 were positive to KPC gene,15 were positive to IMP gene (two of them were positive to both KPC and IMP),and 4 were negative to all tested carbapenemase genes.Thirty-one MHT-negative and nonsusceptible to ertapenem and 3 MHT-positive and susceptible isolates to ertapenem were negative to all tested carbapenemase genes.Conclusions MHT is used to detect carbapenemase in enterobacteriaceae with high sensitivity and low false positive rate.KPC gene is the most occurred gene to be dominant in the production of carbapenemase in enterobacteriaceae, and the IMP gene is also responsible to the genesis ofcarbapenemase in enterobacteriaceae..
RESUMO
OBJECTIVE To analyze the susceptible factors and resistance of Acinetobacter baumannii in ICU,in order to create a novel thought of effective prevention and control of A. baumannii cross-infection. METHODS Specimens were collected from ICU patients with infections from Sep 2006 to Sep 2008. The infection characteristic was analyzed and the drug sensitivity was tested to know the risk factors of infection retrospectively. RESULTS The factors of low immunity,severe wound,invasive operation and using ventilator led to the serious cross-infection of A. baumannii in ICU .In vitro drug susceptibility test,the sensitive rates only to cefoperazone/sulbactam and amikacin were higher. They were 65.09% and 72.64%,respectively. CONCLUSIONS It has great significance in the prevention and control of A. baumannii cross-infection in ICU to strengthen the environment disinfection,were education of nosocomial infection knowledge among medical staff,executeing the hand-washing system strictly,useing the antibiotics rationally,keeping the susceptible crowd and adopting de-escalation strategy of prevention and control.
RESUMO
OBJECTIVE To investigate the change in antibiotic resistance of Pseudomonas aeruginosa(PAE) in our hospital,for the guidance of rational use of antibacterials. METHODS We reviewed the isolation rates of antimicrobial agents from 2004 to 2007,and its construction ratio among the commonly encountered Gram-negative bacilli,and the resistance rates of P.aeruginosa to 14 kinds. RESULTS We totally isolated 823 strains of PAE and the isolation rates of PAE was 13.3% in 2004 but 18.5% in 2007.In the four years,there was the highest isolation rate of 72.54% in sputum and throat mucus specimens.The lowest resistance rate was to amikacin(from 12.2% to 6.21%,the average was 8.75%),and the next was to cefoperazone/sulbactam(from 6.10% to 12.26%,the average was 8.99%);the total resistance rates to ticarcillin and piperacillin was more than 36.00% and there was a lower resistance rate to ticarcillin/clavulanic acid(32.93%)after adding the enzyme inhibitor,while to piperacillin/tazobactam was 20.16%.Drug-resistance rate to ceftazidime was from 19.51% to 43.17%(the average was 33.05%);to cefepime from 22.34% to 34.16%(the average was 29.40%);to imipenem from 19.51% to 23.29%(the average was 22.60%);to meropenem from 11.17% to 18.18%(the average was 15.43%);to the fluoroquinolones antibiotics ciprofloxacin from 32.61% to 44.59%(the average was 38.52%);and to levofloxacin was 26.40% in average. CONCLUSIONS There is commonly increasing resistance of PAE.Reviewing the resistance situation dynamically and selecting the antibiotics reasonably can produce great significance for clinical therapy and postpon its multidrug-resistance.
RESUMO
OBJECTIVE To survey the distribution of the pathogenic microorganisms in biles collected from cholelithiasis patients and their susceptibility to antibiotics,to guide the selection of reasonable antibiotics.METHODS Totally 546 bile samples were cultured and tested for antibiotics susceptibility.RESULTS Bacteria were cultured from 332 samples with a positive rate of 60.81%,the first three were Escherichia coli(32.96%),Enterococcus faecalis(12.74%),and Klebsiella pneumoniae(9.97%).The pathogenic microorganisms were more sensitive to the third and fourth generation cephalosporins,antibiotic/?lactamase inhibitor combination,carbopenems and aminoglycosides antibiotics,while less sensitive to the first and second generation cephalosporins,penicillins,macrolide antibiotics and fluoroquinolones.CONCLUSIONS The pathogenic microorganisms in bile are very various,E.coli,E.faecalis and K.pneumoniae are usually cultured,fungous and anaerobic infections cannot be ignored.Doctors should pay more attention to analyze the bacterial resistance profile and use the antibiotics properly.