First detection of TEM-116 extended-spectrum β-lactamase in a Providencia stuartii isolate from a Tunisian hospital.

Purpose: To study the resistance to third-generation cephalosporins in Providencia stuartii strain isolated from hospitalized patient in Tunisia and to identify the responsible genes Materials and Methods: This strain was analysed by PCR and sequencing to identify the genes responsible for the β-lactamase resistance phenotypes. The transferability of the phenotypes was tested by conjugation to Escherichia coli J53. The isoelectric point was determinate by isoelectrofocalisation. Results: This resistance was carried by a 60 kb plasmid that encoded a β-lactamase with a pI of 5.4. This β-lactamase revealed identity with the blaTEM-1 gene encoding the TEM-1 β-lactamase, except for a replacement of the Val residue at position 84 by Ile, and the Ala residue at position 184 by Val. These two mutations were encountered in TEM-116 β-lactamase. Conclusion: This study demonstrates the first description of TEM-116 in the P. stuartii species in the world and the first one in a Tunisian hospital.

Drug-resistant Genes Associated with Beta-lactamases in Acinetobactor baumannii Isolated from ICU / 中华医院感染学杂志

OBJECTIVE To investigate the antibiotics resistance of multi-resistant Acinetobactor baumannii(ABA) and genotypes of beta-lactamases in ICU.METHODS The samples of 20 A.baumannii isolates were collected from Oct 2007 to Jul 2008 from patients in ICU.To determine the sensitivity to the 32 kinds of antibacterials,K-B method was used and the detection of ESBLs and AmpC beta-lactamases was performed by three dimensional test and 21 types of beta-lactamases genes were analyzed by polymerase chain reaction(PCR).RESULTS Among the 20 ABA isolates,all carried TEM beta-lactamases gens(100%),10 carried OXA-23 beta-lactamases gens(50%) and 15 strains carried ADC beta-lactamases gene(75%),50% strains produced TEM,OXA-23 and ADC beta-lactamases simultaneously.Through determining sequence of one PCR product from TEM,OX23 and ADC respectively,we found TEM-116,OXA-73 and ADC-25 type beta-lactamases genes.CONCLUSIONS The antibiotics resistance of ABA is very serious.TEM,OXA-23 and ADC exist in multi-resistant A.baumannii widely.It should be the main causes as high rate of drug-resistantce to beta-lactamantibiotics.

Resistance to Antibiotics of Clinical Isolates of Klebsiella pneumoniae Producing TEM-116 ?-Lactamases / 中华医院感染学杂志

OBJECTIVE To understand characteristics of TEM-116 ?-lactamases through comparative study on resistance to antibiotics of clinical isolates of Klebsiella pneumoniae producing TEM-116 ?-lactamases.METHODS K.pneumoniae susceptibility to ?-lactamases was determined by disk diffusion tests,and their isoelectric points(PI) were detected using analytic isoelectric focusing(IEF),and resistance to antibiotics of clinical isolates of K.pneumoniae producing TEM-116 and TEM-1?-lactamases was studied.RESULTS Both of K.pneumoniae producing TEM-116 ?-lactamases and producing TEM-1 ?-lactamases were 100% resistant to AMP,and highly resistant to the first and second generation cephalosporin,but greatly susceptible to FEP and IPM.There was greatly difference between resistance to AMC,TZP,AMK,and GEN of clinical isolates of K.pneumoniae producing TEM-116 ?-lactamases and that of K.pneumoniae producing TEM-116 ?-lactamases,the TEM-116 isolates were higher resistant than TEM-1 isolates.Analytic IEF results showed that PI of TEM-116 ?-lactamases was 5.4,and most strains of K.pneumoniae TEM-116 ?-lactamases displayed two electrophoresis bands or more,only one strain of them just displayed one band,resistant to majority of antibiotics.CONCLUSIONS The results show that K.pneumoniae producing TEM-116 ?-lactamases are more resistant to antibiotics than K.pneumoniae producing TEM-1 ?-lactamases,and indicate TEM-116 ?-lactamases work as ESBLs.