ABSTRACT
Objective Class 1 integrase(intI 1),qacE△1-sul1 and sul2 genes were detected in trimethoprim-sulfamethoxazole resistant Stenotrophomonas maltophilia by PCR to assess the relationship between the antibiotic resistance mechanism for trimethoprim-sulfamethoxazole (TMP-SMZ)and these genes distribution.Methods S.maltophilia isolates were collected from patients treated in Affilitated hospital of Nanjing University of TCM during January to May in 2013,DNA was ab-stracted by boiling method and genes were detected by polymerase chain reaction.Results intI 1 genes were observed posi-tive in 25 of 28 strains resistant for TMP-SMZ,qacE△1-sul1 genes were positive in 21 while sul2 genes positive in 15,the positive rates of intI 1,qacE△1-sul1 and sul2 genes were 89.29%,75% and 53.57%;in 18 trimethoprim-sulfamethoxazole sensitive strains,5 were intI 1 positive,4 were qacE△1-sul1 positive while sul2 were none,the positive rates of intI1 and qacE△1-sul1 were 27.78% and 22.22%.Conclusion Most of stenotrophomonas maltophilia resisted trimethoprim-sulfa-methoxazole had intI 1,qacEΔ1-sul 1 and sul2 genes.
ABSTRACT
BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacillus and a nosocomial pathogen in immunocompromised patients. Trimethoprim/sulfamethoxazole (TMP/SMX) is the drug of choice for treating S. maltophilia infection; however, resistance to TMP/SMX is increasing. In this study, we investigated the relationship between the incidence of TMP/SMX resistance and the presence of sul genes and mobile elements. METHODS: A total of 120 S. maltophilia isolates were collected from 3 university hospitals between April 2007 and April 2009. Antimicrobial susceptibilities were determined using the disk diffusion method. PCR and DNA sequencing were conducted for the detection of sul1, sul2, class 1 integron, and ISCR2 element. Repetitive extragenic palindromic sequence-based PCR (REP-PCR) was carried out to evaluate the genetic relatedness. RESULTS: The TMP/SMX-resistant (R) isolates harbored a significantly higher proportion of sul1 gene and class 1 integron than TMP/SMX-susceptible (S) isolates (P<0.001). Seventeen of 28 isolates with sul1 also had a class 1 integron, but none of the isolates without sul1 had a class 1 integron. The identified gene cassettes within class 1 integrons include aacA4, aadA1, aac6'-II, and qac. None of the 120 isolates carried sul2, glmM, or ISCR2 element. REP-PCR did not show any genetic relatedness among the isolates. CONCLUSIONS: In Korea, the resistance of S. maltophilia isolates to TMP/SMX is due to sul1 within a class 1 integron rather than to sul2. The class 1 integron also harbors multiple antibiotic resistance genes in addition to sul1, and therefore it could mediate multidrug resistance in S. maltophilia.
Subject(s)
Humans , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Carrier Proteins/genetics , DNA, Bacterial/genetics , Disk Diffusion Antimicrobial Tests , Drug Resistance, Multiple, Bacterial/genetics , Integrons/genetics , Polymerase Chain Reaction , Stenotrophomonas maltophilia/drug effects , Trimethoprim, Sulfamethoxazole Drug Combination/pharmacologyABSTRACT
OBJECTIVE To detect the disinfectants-resistant gene of qacE-sul1 in nosocomial infected patients.METHODS The disinfectants-resistant gene of qacE-sul1 was detected by polymerase chain reaction(PCR).RESULTS The positive rate of gene of qacE-sul1 in 222 strains was 54.5%.The positive rate of gene qacE-sul1 in Klebsiella pneumoniae,Escherichia coli,Staphylococcus aureus,Proteus,Pseudomonas aeruginosa,Enterococcus,and Acinetobacter baumannii were 47.6%,58.3%,57.6%,54.2%,53.6%,53.3%,and 55.0%,respectively.CONCLUSIONS There are higher positive percentages of gene qacE-sul1 in nosocomial infected patients which possibly causes nosocomial infection and should be attention to.
ABSTRACT
OBJECTIVE To investigate the disinfectant-sulfanilamide resistance gene(qacE△1-sul1)and integrase gene(IntⅠ1)of Acinetobacter baumannii(ABA)isolated in pediatric clinic and analyze the relationship between these genes and multidrug resistance.METHODS Twenty eight strains of A.baumannii were collected and isolated from the sputum culture in the deep trachea of children with pneumonia during 2006.Identification of bacteria and susceptibility test by VITEK-32 automicroscan using GNI and GNS cards,were undertaken,qacE△1-sul1 gene and IntⅠ1 gene were analyzed by polymerase chain reaction(PCR).RESULTS Three of 28 strains of A.baumannii showed multidrug resistance,the positive rate was 10.71%.A.baumannii 4 strains were resistant to sulfamethoxazole/trimethoprim(SXT)with the positive rate 14.29%.Eleven strains that carrying qacE△1-sul1 genes and 4 strains carrying IntⅠ1 genes were detected,the positive rate was 39.29% and 14.29%,and qacE△1-sul1 and IntⅠ1 genes positive strains of A.baumannii were resistant to SXT,the other 7 qacE△1-sul1 positive strains were sensitive to SXT.CONCLUSIONS The main drug resistance in ABA resistant to SXT is to obtain qacE△1-sul1 gene.It should be paid attention to qacE△1-suⅠ1 positive but sensitive to SXT strains.It indicates that the strain carrying integron Ⅰ may show multidrug resistance.
ABSTRACT
OBJECTIVE To detect genes sul1 and sul2 in Stenotrophomonas maltophilia,and their relationship to drug resistance to trimethoprim-sulfamethoxazole(SXT).METHODS K-B was carried out to detect the drug resistance to SXT of S.maltophilia;minimal inhibitory concentration(MIC) was measured with micro broth dilution method.Genes sul1 and sul2 were amplified by PCR.RESULTS Eight isolates(7.8%) showed resistance to trimethoprim-sulfamethoxazole,sul1 Was positive in four isolates in which one contained sul2 also.Four isolates showed high MIC to SXT.CONCLUSIONS Genes sul1 and sul2 of S.maltophilia are associated with the high drug resistance to SXT.
ABSTRACT
OBJECTIVE To study the antibiotic resistance gene of qacE△1-sul1 in Acinetobacter baumannii isolated from inpatients in Urumqi and the distribution and difference of qacE△1-sul1 genotype in Xinjiang. METHODS Bacterial strains were identified by system of API and antibiotic susceptibility test was detected by K-B and microdilution methods according CLSI.PCR was used to determine the gene of qacE△1-sul1 and compared with the sequences in GenBank. RESULTS Antibiotic resistance phenotypes showed the resistance rate to cefataxime and tetracycline was the highest(100.0%),but that to cefoperazone/sulbactam was the lowest.The positive rate of qacE△1-sul1 gene in A.baumannii was 52.2%. CONCLUSIONS High resistance in A.baumannii is found in Xinjiang.The positive rate of qacE△1-sul1 is high.Strengthening epidemiology surveillance of resistance carried by integron-carrying gene is important.
ABSTRACT
OBJECTIVE To study the existence status of class Ⅰ integron and transposable element of multi-resistant Acinetobactor baumannii isolated form ICU of Yinzhou People′s Hospital in Ningbo. METHODS The samples of 20 A.baumannii isolates were collected from Oct 2007 to Jul 2008.The susceptibility to 32 antibiotics of the isolates was measured.The genetic markers of integron qacE△1-sul1 and transposable element tnpU were analyzed by polymerase chain reaction(PCR).The PCR products of tnpU or qacE△1-sul1 were sequenced for determination. RESULTS In the 20 ABA isolates,the positive rate of class Ⅰ integron qacE△1-sull was 75%,and the positive rate of transposable element tnpU was 55.0%. CONCLUSIONS The positive rate of the integron qacE△1-sul1 and transposable element tnpU for multi-resistant A.baumannii is high in Yinzhou People′s Hospital in Ningbo.It should be reevaluated the preventative role of chlorhexidine for operation.
ABSTRACT
OBJECTIVE To investigate the disinfectant-resistant gene qacE△1-sul1 in Pseudomonas aeruginosa isolated from burned patients. METHODS GNS-448 and K-B tests were performed to detect the susceptibility of 19 kinds of antimicrobial agents against these strains. Genotype was analyzed by polymerase chain reaction(PCR) and verified by DNA sequencing. RESULTS The 32 strains isolated were all resistant to ampicillin,cefuroxime,cefoxitin,SMZ/TPM. The sensitive rates to amikacin and gentamicin were 68.0%,and 46.9%,respectively,the resistant rates to imipenem and meropenem were 68.8% and 59.4%,respectively. The positive rate of gene qacE△1-sul1 was 50.0%. CONCLUSIONS The resistance of P. aeruginosa isolated from burned patients is a serious issue.There is high positive percentage of qacE△1-sul1 gene in P. aeruginosa isolated from burned patients.