Characterization of a novel class 1 integron InSW39 and a novel transposon Tn5393k identified in an imipenem-nonsusceptible Salmonella Typhimurium strain in Sichuan, China

2021 ◽  
Vol 99 (3) ◽  
pp. 115263
Author(s):  
Liu Yao ◽  
Yinhuan Ding ◽  
Manlin Ding ◽  
Xiangjin Yan ◽  
Feiyang Zhang ◽  
...  
2008 ◽  
Vol 52 (10) ◽  
pp. 3589-3596 ◽  
Author(s):  
Carlos Juan ◽  
Alejandro Beceiro ◽  
Olivia Gutiérrez ◽  
Sebastián Albertí ◽  
Margalida Garau ◽  
...  

ABSTRACT During a survey conducted to evaluate the incidence of class B carbapenemase (metallo-β-lactamase [MBL])-producing Pseudomonas aeruginosa strains from hospitals in Majorca, Spain, five clinical isolates showed a positive Etest MBL screening test result. In one of them, strain PA-SL2, the presence of a new bla VIM derivative (bla VIM-13) was detected by PCR amplification with bla VIM-1-specific primers followed by sequencing. The bla VIM-13-producing isolate showed resistance to all β-lactams (except aztreonam), gentamicin, tobramycin, and ciprofloxacin. VIM-13 exhibited 93% and 88% amino acid sequence identities with VIM-1 and VIM-2, respectively. bla VIM-13 was cloned in parallel with bla VIM-1, and the resistance profile conferred was analyzed both in Escherichia coli and in P. aeruginosa backgrounds. Compared to VIM-1, VIM-13 conferred slightly higher levels of resistance to piperacillin and lower levels of resistance to ceftazidime and cefepime. VIM-13 and VIM-1 were purified in parallel as well, and their kinetic parameters were compared. The k cat/K m ratios for the antibiotics mentioned above were in good agreement with the MIC data. Furthermore, EDTA inhibited the activity of VIM-13 approximately 25 times less than it inhibited the activity of VIM-1. VIM-13 was harbored in a class 1 integron, along with a new variant (Ala108Thr) of the aminoglycoside-modifying enzyme encoding gene aacA4, which confers resistance to gentamicin and tobramycin. Finally, the VIM-13 integron was apparently located in the chromosome, since transformation and conjugation experiments consistently yielded negative results and the bla VIM-13 probe hybridized only with the genomic DNA.


1999 ◽  
Vol 43 (12) ◽  
pp. 2925-2929 ◽  
Author(s):  
Lydia Bass ◽  
Cynthia A. Liebert ◽  
Margie D. Lee ◽  
Anne O. Summers ◽  
David G. White ◽  
...  

ABSTRACT Antibiotic resistance among avian bacterial isolates is common and is of great concern to the poultry industry. Approximately 36% (n = 100) of avian, pathogenic Escherichia coli isolates obtained from diseased poultry exhibited multiple-antibiotic resistance to tetracycline, oxytetracycline, streptomycin, sulfonamides, and gentamicin. Clinical avian E. coli isolates were further screened for the presence of markers for class 1 integrons, the integron recombinase intI1 and the quaternary ammonium resistance gene qacEΔ1, in order to determine the contribution of integrons to the observed multiple-antibiotic resistance phenotypes. Sixty-three percent of the clinical isolates were positive for the class 1 integron markersintI1 and qacEΔ1. PCR analysis with the conserved class 1 integron primers yielded amplicons of approximately 1 kb from E. coli isolates positive for intI1 andqacEΔ1. These PCR amplicons contained the spectinomycin-streptomycin resistance gene aadA1. Further characterization of the identified integrons revealed that many were part of the transposon Tn21, a genetic element that encodes both antibiotic resistance and heavy-metal resistance to mercuric compounds. Fifty percent of the clinical isolates positive for the integron marker gene intI1 as well as for theqacEΔ1 and aadA1 cassettes also contained the mercury reductase gene merA. The correlation between the presence of the merA gene with that of the integrase and antibiotic resistance genes suggests that these integrons are located in Tn21. The presence of these elements among avianE. coli isolates of diverse genetic makeup as well as inSalmonella suggests the mobility of Tn21 among pathogens in humans as well as poultry.


2003 ◽  
Vol 225 (1) ◽  
pp. 149-153 ◽  
Author(s):  
S. Vourli ◽  
L.S. Tzouvelekis ◽  
E. Tzelepi ◽  
E. Lebessi ◽  
N.J. Legakis ◽  
...  

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.


2020 ◽  
Vol 26 (12) ◽  
pp. 1437-1441
Author(s):  
Fatma Zohra Zaidi ◽  
Radia Dali-Yahia ◽  
Karima Zenati ◽  
Leila Yazi ◽  
Manon Lounes ◽  
...  

2016 ◽  
Vol 47 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Natália Canal ◽  
Karine Lena Meneghetti ◽  
Clara Ponzi de Almeida ◽  
Marina da Rosa Bastos ◽  
Letícia Muner Otton ◽  
...  

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.


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.


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