scholarly journals Molecular Characterization of β-Lactamase Genes and Their Genetic Structures in Acinetobacter Genospecies 3 Isolates in Taiwan

2010 ◽  
Vol 54 (6) ◽  
pp. 2699-2703 ◽  
Author(s):  
Li-Yueh Huang ◽  
Po-Liang Lu ◽  
Te-Li Chen ◽  
Fang-Yee Chang ◽  
Chang-Phone Fung ◽  
...  

ABSTRACT The genetic structure of β-lactamases in Acinetobacter genospecies 3 (AG3) isolates in Taiwan was studied to analyze their high rates of resistance to β-lactams, including carbapenems (57.9%). bla IMP-1 and bla IMP-8 were located in a class 1 integron. bla OXA-58 was bracketed by ISAba3. A novel TnpF-like integrase gene was identified upstream of bla VEB-3. Adjacent to the 5′ sequence of the bla ADC gene, folE was identified. Four new Acinetobacter-derived cephalosporinase (ADC) enzymes were found, which clustered phylogenetically with published AG3 ADC proteins.

2014 ◽  
Vol 8 (05) ◽  
pp. 666-669 ◽  
Author(s):  
German M Traglia ◽  
Marisa Almuzara ◽  
Elisabet Vilacoba ◽  
Alicia Tuduri ◽  
Gabriela Neumann ◽  
...  

Introduction: Infections caused by Acinetobacter junii are rarely reported. However, some outbreaks of septicemia in neonates and pediatric oncology patients, as well as meningitis, peritonitis, and ocular infection have been described. Since it is highly infrequent to find the molecular characterization of A. junii strains in literature, in this study we described the molecular characterization of A. junii isolates recovered from blood samples of a renal transplant patient. Methodology: The case was defined as a catheter-related bacteremia caused by A. junii. The patient responded favorably after catheter removal and treatment with ciprofloxacin. Results and Conclusion: The complete molecular characterization of the isolate showed that it harbored a class 1 integron and diverse DNA mobile elements. This explains its genomic plasticity for acquiring antimicrobial resistance determinants and for adapting to a nosocomial niche.


2001 ◽  
Vol 183 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Thierry Naas ◽  
Yuzuru Mikami ◽  
Tamae Imai ◽  
Laurent Poirel ◽  
Patrice Nordmann

ABSTRACT Further characterization of the genetic environment of the gene encoding the Escherichia coli extended-spectrum β-lactamase, bla VEB-1, revealed the presence of a plasmid-located class 1 integron, In53, which carried eight functional resistance gene cassettes in addition tobla VEB-1. While the aadB and the arr-2 gene cassettes were identical to those previously described, the remaining cassettes were novel: (i) a novel nonenzymatic chloramphenicol resistance gene of the cmlAfamily, (ii) a qac allele encoding a member of the small multidrug resistance family of proteins, (iii) a cassette,aacA1b/orfG, which encodes a novel 6′-N-acetyltransferase, and (iv) a fused gene cassette,oxa10/aadA1, which is made of two cassettes previously described as single cassettes. In addition, oxa10 andaadA1 genes were expressed from their own promoter sequence present upstream of the oxa10 cassette.arr-2 coded for a protein that shared 54% amino acid identity with the rifampin ADP-ribosylating transferase encoded by thearr-1 gene from Mycobacterium smegmatisDSM43756. While in M. smegmatis, the main inactivated compound was 23-ribosyl-rifampin, the inactivated antibiotic recovered from E. coli culture was 23-O-ADP-ribosyl-rifampin. The integrase gene of In53 was interrupted by an IS26 insertion sequence, which was also present in the 3′ conserved segment. Thus, In53 is a truncated integron located on a composite transposon, named Tn2000, bounded by two IS26 elements in opposite orientations. Target site duplication at both ends of the transposon indicated that the integron likely was inserted into the plasmid through a transpositional process. This is the first description of an integron located on a composite transposon.


2015 ◽  
Vol 59 (7) ◽  
pp. 4293-4295 ◽  
Author(s):  
Jun Wu ◽  
Lianyan Xie ◽  
Fangfang Zhang ◽  
Yuxing Ni ◽  
Jingyong Sun

ABSTRACTWe report the detection of PER-1 extended-spectrum β-lactamase (ESBL) in a clinical non-O1, non-O139Vibrio choleraestrain from China. ISCR1-mediatedblaPER-1was embedded in a complex In4family class 1 integron belonging to the lineage of Tn1696on a conjugative IncA/C plasmid. A free 8.98-kb circular molecule present with the ISCR1-blaPER-1–truncated 3′-conserved sequence (CS) structure was detected in this isolate. These findings may provide insight into the mobilization ofblaPER-1.


2000 ◽  
Vol 44 (10) ◽  
pp. 2684-2688 ◽  
Author(s):  
Marie-Cécile Ploy ◽  
François Denis ◽  
Patrice Courvalin ◽  
Thierry Lambert

ABSTRACT Twenty Acinetobacter baumannii strains resistant to various antibiotics were analyzed for integron content and sequences of the amplification products. Sixteen clinical isolates had a class 1 integron, 2 contained an additional class 1 or class 2 integron, but no class 3 integron was detected. Thirteen strains had integrons with a single cassette: aac(3)-Ia (9 strains), ant(2")-Ia (2 strains), or aac(6′)-Ib (2 strains); 1 hadaac(6′)-Ib and oxa20cassettes and an unknown gene; and 1 had an integron containingant(2")-Ia and an oxa3cassette truncated by IS6100. The remaining strains harbored class 1 integrons with gene cassettes previously found inEnterobacteriaceae. One integron had a hybrid structure composed of intI2 and the 3′ conserved segment of class 1 integrons. These data indicate that integrons play a major role in multidrug resistance in Acinetobacter.


2012 ◽  
Vol 58 (10) ◽  
pp. 1167-1173 ◽  
Author(s):  
Yang Liu ◽  
Xiang-Yang Li ◽  
La-Gen Wan ◽  
Wei-Yan Jiang ◽  
Fang-Qu Li ◽  
...  

The present study was conducted to confirm the presence of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae associated with a nosocomial outbreak in a Chinese pediatric hospital. From July 2009 to January 2011, 124 nonduplicated K. pneumoniae isolates were collected from specimens from patients of pediatric units in the hospital. Twelve of the 124 isolates possessed the blaKPC-2gene and showed 7 different pulsed-field gel electrophoresis (PFGE) patterns. Meanwhile, 16S rRNA methylase, acc(6′)-Ib-cr, and several types of β-lactamases were also produced by the majority of the KPC-producing isolates. Class 1 integron-encoded intI1 integrase gene was subsequently found in all strains, and amplification, sequencing, and comparison of DNA between 5′ conserved segment and 3′ conserved segment region showed the presence of several known antibiotic resistance gene cassettes of various sizes. The conjugation and plasmid-curing experiments indicated some KPC-2-encoding genes were transmissible. In addition, conjugal cotransfer of multidrug-resistant phenotypes with KPC-positive phenotypes was observed in KPC-producing strains. Restriction endonuclease analysis and DNA hybridization with a KPC-specific probe showed that the blaKPC-2gene was carried by plasmid DNA from K. pneumoniae of PFGE pattern B. The overall results indicate that the emergence and outbreak of KPC-producing K. pneumoniae in our pediatric wards occurred in conjunction with plasmids coharboring 16S rRNA methylase and extended-spectrum β-lactamases.


10.3823/821 ◽  
2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Husam F. Qouzah ◽  
Feras Hawari ◽  
Luay F. Abu-Qatouseh ◽  
Asem A. Shehabi

Background: During the last decade, the prevalence of carbapenem-resistant infection associated with multidrug resistant (MDR) Acinetobacter baumanniiin patients has been continuously increasing.  This prospective study aimed to determine the occurrence and molecular characterization of metallo-β-lactamases (MBLs) and carbapenem hydrolyzing oxacillinases among A. baumannii isolates from cancer patients over a period of 6-month. Methods:Antimicrobial susceptibility profile of 70 randomly collected A. baumannii isolates was first determined using disc diffusion test, and second, the MICs of 45 representative multidrug resistant (MDR) isolates were tested to useful drugs in treatment of their infections using E-test.  PCR assays were used to detect the common four types of class D carbapenem hydrolyzing oxacillinases, two types of class A carbapenemases, four types of class B metallo-β –lactamases, and prevalence of Class 1 Integron among MDR isolates. Results: All 70 isolates were MDR, including 100% resistance to meropenom, aztreonem, piperacillin/tazobactum and 99% to carbapenem.  All isolates carried blaOXA-23 and blaOXA-51, but none carried a blaOXA-24 like or blaOXA-58. The isolates also were positive for NDM-1, NDM, VIM, GES, KPC and SPM at the rates of 29%, 20%, 29%,19%,7% and 2%, respectively.  Class 1 Integron was positive in 82% of A. baumanniiisolates. The clonal relationship of 42 MDR A. baumanniiisolates using ERIC-PCR and constructed dendrogram showed 3 major genotype clusters of genetically related isolates. These include 4 genotype groups, each composed of 2 isolates with 100 % similarity of DNA bands.  Conclusion:This study demonstrates that A. baumannii colonize frequently cancer patients in association with antibiotic treatment. The organism is mostly carrying wide spectrum of antibiotic resistance genetic factors, especially many types of ESBLs and MBLs and Class 1 Integron. This fact should be considered when therapy is selected for treatment of patients infected with MDR A. baumannii. Key words. Acinetobacter baumannii, ESBLs, MBLs, Class 1 Integron, Jordanian cancer patients.  


2005 ◽  
Vol 54 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Ashraf M Ahmed ◽  
Shin-ichi Miyoshi ◽  
Sumio Shinoda ◽  
Tadashi Shimamoto

Enteroinvasive Escherichia coli (EIEC) O164 strain RIMD05091045 was isolated from a travelling patient suffering from diarrhoea at the Osaka airport quarantine facility in Japan. The strain showed multidrug resistance against streptomycin, spectinomycin, co-trimoxazole (trimethoprim/sulfamethoxazole) and ampicillin, and reduced susceptibility to ciprofloxacin. Molecular characterization of the multidrug-resistance phenotype revealed the presence of a class 1 integron containing three genes, a dihydrofolate reductase type XII gene, dfrXII, which confers resistance to trimethoprim, an aminoglycoside adenyltransferase gene, aadA2, which confers resistance to streptomycin and spectinomycin, and an ORF of unknown function. Southern blot hybridization and conjugation experiments showed that the class 1 integron was located on a transferable plasmid that was less than 90 kb in size. The resistance of EIEC O164 to ampicillin was found to be due to the presence of TEM-1 β-lactamase. On the other hand, a single mutation that has not previously been described, P158-to-S, was detected downstream of the quinolone-resistance-determining region of parC of topoisomerase IV and may be responsible for the reduced susceptibility to ciprofloxacin in this strain.


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