scholarly journals Biocide use, integrons and novel genetic elements

2010 ◽  
Vol 31 (4) ◽  
pp. 192 ◽  
Author(s):  
Michael R Gillings
Keyword(s):  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Antibiotic Use ◽  
Consumer Products ◽  
Mobile Dna ◽  
Bacterial Strains ◽  
Class 1 Integron ◽  
Genetic Elements ◽  
Inappropriate Use ◽  
Selection Of

Resistance to antibiotics threatens our ability to control bacterial pathogens. It is clear that the persistence of cells containing resistance determinants is promoted by the strong selective pressure imposed by antibiotic use. This problem has been exacerbated by inappropriate and excessive use of antibiotics in both medicine and animal production. Concern has also been raised that inappropriate use of biocides contributes to the selection of resistant bacterial strains. This may occur because detoxification mechanisms for biocides and antibiotics are shared, or via selection for biocide resistance genes that are physically linked to antibiotic resistance genes and their mobile DNA vectors. In this brief review I will illustrate the latter phenomenon using the evolutionary history of the class 1 integron as an example, and then examine whether the increasing trend towards indiscriminate use of biocides in homes and consumer products might result in the selection of novel genetic elements that will have negative and unpredictable consequences for human health.

scholarly journals Prevalence and characterisation of class 1 and 2 integrons in multi-drug resistant Staphylococcus aureus isolates from pig farms in Chongqing, China

2020 ◽  
Vol 64 (3) ◽  
pp. 381-386
Author(s):  
Chao Ye ◽  
Fengqing Hou ◽  
Dongyi Xu ◽  
Qingyuan Huang ◽  
Xia Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Drug Resistant ◽  
Limited Information ◽  
Mobile Dna ◽  
Class 1 Integron ◽  
Pig Farms ◽  
Class 1 ◽  
Pig Farm

AbstractIntroductionIntegrons are mobile DNA elements that allow for acquisition and dissemination of antibiotic-resistance genes among pig farm-derived bacteria. Limited information is available on integrons of Staphylococcus aureus from pig farms. The aim of this study was to characterise and investigate the prevalence of class 1 and 2 integrons in multi-drug resistant (MDR) S. aureus isolates from pig farms.Material and MethodsA total of 724 swabs were collected from 12 pig farms in Chongqing, China, and examined by conventional microbial and molecular methods.ResultsIn total, 68 isolates were S. aureus, 57 of which were methicillin resistant (MRSA). All 68 isolates were MDR strains and carried integrons, of which 88.2% (60/68) harboured both class 1 and 2. In addition, 85.3% (58/68) of the class 2 integron-positive isolates carried the β-lactam resistance gene (blaTEM-1), and 66.7% (40/60) of the class 1 integron–positive isolates carried the aadA1c, aadA1 or dfrA1 gene for respective streptomycin and spectinomycin or trimethoprim resistance.ConclusionsClass 1 and 2 integrons are common among the pig farm-derived S. aureus isolates. On account of their significance for public health, the prevalence of the integrons and their associated resistance genes in pig farm-derived S. aureus isolates should be paid special attention.

scholarly journals Tetracycline-Resistant Bacteria Selected from Water and Zebrafish after Antibiotic Exposure

2021 ◽  
Vol 18 (6) ◽  
pp. 3218
Author(s):  
Ana Rita Almeida ◽  
Marta Tacão ◽  
Joana Soares ◽  
Inês Domingues ◽  
Isabel Henriques
Keyword(s):  
Statistical Significance ◽  
Recovery Period ◽  
Antibiotic Resistance Genes ◽  
Antibiotic Use ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Potential Impact ◽  
Susceptibility Profiles ◽  
Selection Of ◽  
Significant Mortality

The emergence of antibiotic-resistant pathogens due to worldwide antibiotic use is raising concern in several settings, including aquaculture. In this work, the selection of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) was evaluated after exposure of zebrafish to oxytetracycline (OTC) for two months, followed by a recovery period. The selection of ARB in water and fish was determined using selective media. The abundance of tetA genes was estimated through qPCR. Higher prevalence of ARB was measured in all samples exposed to the antibiotic when compared to control samples, although statistical significance was only achieved five days after exposure. Isolates recovered from samples exposed to the antibiotic were affiliated with Pseudomonas and Stenotrophomonas. Various antibiotic susceptibility profiles were detected and 37% of the isolates displayed multidrug resistance (MDR). The selection of the tetA gene was confirmed by qPCR at the highest OTC concentration tested. Two MDR isolates, tested using zebrafish embryos, caused significant mortality, indicating a potential impact on fish health and survival. Overall, our work highlights the potential impact of antibiotic contamination in the selection of potential pathogenic ARB and ARGS.

Mercury resistance (mer) operons in enterobacteria

2002 ◽  
Vol 30 (4) ◽  
pp. 719-722 ◽  
Author(s):  
J. L. Hobman ◽  
A. M. M. Essa ◽  
N. L. Brown
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mercury Resistance ◽  
Genetic Elements ◽  
Mercuric Ion

Mercury resistance is found in many genera of bacteria. Common amongst enterobacteria are transposons related to Tn21, which is both mercuric ion- and streptomycin-/spectinomycin-and sulphonamide-resistant. Other Tn21-related transposons often have different antibiotic resistances compared with Tn21, but share many non-antibiotic-resistance genes with it. In this article we discuss possible mechanisms for the evolution of Tn21 and related genetic elements.

scholarly journals Identification and antibiotic resistance profiling of bacterial isolates from septicaemic soft-shelled turtles (Pelodiscus sinensis)

2017 ◽  
Vol 62 (No. 3) ◽  
pp. 169-177 ◽  
Author(s):  
TH Chung ◽  
SW Yi ◽  
BS Kim ◽  
WI Kim ◽  
GW Shin
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Present Report ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Edwardsiella Tarda ◽  
Pelodiscus Sinensis ◽  
Class 1 Integron ◽  
Class 1 ◽  
M 14

The present study sought to identify pathogens associated with septicaemia in the Chinese soft-shelled turtle (Pelodiscus sinensis) and to characterise antibiotic resistance in these pathogens. Twenty-three isolates recovered from the livers of diseased soft-shelled turtles were genetically identified as Aeromonas hydrophila (n = 8), A. veronii (n = 3), Citrobacter freundii (n = 4), Morganella morganii (n = 3), Edwardsiella tarda (n = 2), Wohlfahrtiimonas chitiniclastica (n = 1), Chryseobacterium sp. (n = 1), and Comamonas sp. (n = 1). Most isolates (n = 21) were resistant to ampicillin whereas a low percentage of isolates was susceptible to aminoglycosides (amikacin, gentamicin, and tobramycin). PCR assays and sequence analysis revealed the presence of the qnrS2 and bla<sub>TEM</sub> antibiotic resistance genes in all isolates. The bla<sub>DHA-1</sub>, bla<sub>CTX-M-14</sub> and bla<sub>CMY-2</sub> genes were harboured by 17.4% (n = 4), 13.5% (n = 3) and 8.7% (n = 2) of the strains, respectively. One or more tetracycline resistance genes were detected in 60.9% (n = 14) of the isolates. Four isolates (17.4%) harboured single or multiple class 1 integron cassettes. Collectively, a variety of bacterial pathogens were involved in the occurrence of septicaemia in Chinese soft-shelled turtles and most of the isolates had multi-antibiotic resistant phenotypes. To our knowledge, the present report is the first to identify W. chitiniclastica and Comamonas sp. as causes of septicaemia in soft-shelled turtles and the first to identify Aeromonas spp. with bla<sub>CTX-M-14</sub> and bla<sub>DHA-1</sub> resistance genes.

scholarly journals Complete Nucleotide Sequence of the pCTX-M3 Plasmid and Its Involvement in Spread of the Extended-Spectrum β-Lactamase Gene blaCTX-M-3

2007 ◽  
Vol 51 (11) ◽  
pp. 3789-3795 ◽  
Author(s):  
M. Gołębiewski ◽  
I. Kern-Zdanowicz ◽  
M. Zienkiewicz ◽  
M. Adamczyk ◽  
J. Żyliǹska ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Conjugative Plasmid ◽  
Bacterial Strains ◽  
Extended Spectrum ◽  
Gene Coding ◽  
Kluyvera Ascorbata ◽  
Almost All ◽  
Lactamase Gene

ABSTRACT Here we report the nucleotide sequence of pCTX-M3, a highly conjugative plasmid that is responsible for the extensive spread of the gene coding for the CTX-M-3 extended-spectrum β-lactamase in clinical populations of the family Enterobacteriaceae in Poland. The plasmid belongs to the IncL/M incompatibility group, is 89,468 bp in size, and carries 103 putative genes. Besides bla CTX-M-3, it also bears the bla TEM-1, aacC2, and armA genes, as well as integronic aadA2, dfrA12, and sul1, which altogether confer resistance to the majority of β-lactams and aminoglycosides and to trimethoprim-sulfamethoxazole. The conjugal transfer genes are organized in two blocks, tra and trb, separated by a spacer sequence where almost all antibiotic resistance genes and multiple mobile genetic elements are located. Only bla CTX-M-3, accompanied by an ISEcp1 element, is placed separately, in a DNA fragment previously identified as a fragment of the Kluyvera ascorbata chromosome. On the basis of sequence analysis, we speculate that pCTX-M3 might have arisen from plasmid pEL60 from plant pathogen Erwinia amylovora by acquiring mobile elements with resistance genes. This suggests that plasmids of environmental bacterial strains could be the source of those plasmids now observed in bacteria pathogenic for humans.

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