Analysis of antibiotic resistance regions in Gram-negative bacteria

Partridge, Sally R.

doi:10.1111/j.1574-6976.2011.00277.x

Cited by 295 publications

(268 citation statements)

References 213 publications

(313 reference statements)

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“…The role of class 1 integrons is well documented in the spread of antibiotic resistance genes in gram-negative bacteria [5]. Class 1 integron positive gram-negative bacteria includes Acinetobacter, Aeromonas, Alacaligenes, Burkholderia, Campylobacter, Citrobacter, Enterobacter, Escherichia, Unsellable, Pseudomonas, Salmonella, Serratia, Shigella, Stenotrophomonas and Vibrio [21].…”

Section: Discussionmentioning

confidence: 99%

“…While the role of class 1 integrons is well documented in the spread of antibiotic resistance genes in gramnegative bacteria, there is less information about the prevalence of class 1 integrons in gram-positive bacteria [5,10]. The presence of class 1 integrons in clinical staphylococcal isolates has been only shown in the studies from China [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 98%

“…DNA transfer occurs via transduction, transmission, and conjugation or addition of DNA by mobile genetic elements such as plasmids, transposons, gene cassettes and integrons [5]. Integrons are genetic units that contain integrase (intI) gene, attI site and strong promoters related to integrase gene and integrated gene cassettes.…”

Section: Introductionmentioning

confidence: 99%

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A Study on Class I Integrons and Antimicrobial Resistance among Clinical Staphylococci Isolates from a Turkish Hospital

Güney¹

2014

Clin Microbiol

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Purpose: Methicillin-resistant staphylococci (MRS) are increasingly significant in the hospital setting due to multidrug resistance. Integrons are genetic elements that can play a role in the dissemination of antimicrobial resistance. While their role is well established in gram-negative bacteria, less is known about the presence of integrons in gram-positive bacteria. Our aim was to investigate the presence of class 1 integrons in clinical MRS isolates. Methods:One hundred clinical MRS isolates were included in the study. Identification of MRS isolates was confirmed by multiplex PCR in which staphylococcal 16S rRNA, nuc and mecA genes-specific primers were used. The presence of class 1 integron was investigated by PCR with intI 1-specific primers.Results: All methicillin-resistant Staphylococcus aureus (MRSA) isolates were positive for 16S rRNA, nuc and mecA genes. All methicillin-resistant coagulase negative staphylococci (MRCoNS) were positive for 16S rRNA and mecA, and negative for nuc gene. The existence of class 1 integron was not detected in all the isolates tested. Conclusions: Class 1 integron positive clinicial MRS strains have only been shown in a few studies from East Asia. Further studies are needed in order to determine the significance of integrons in staphylococci and their role in DNA transfer between gram-positive and gram-negative bacteria.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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A Study on Class I Integrons and Antimicrobial Resistance among Clinical Staphylococci Isolates from a Turkish Hospital

Güney¹

2014

Clin Microbiol

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“…Members of this family were among the first transposable elements to be identified in bacteria. They are notorious for the number and variety of accessory genes they transport and their prominent contribution to antibiotic resistance dissemination (6)(7)(8). Notably, Tn3-family members are involved in the rising prevalence of resistance to carbapenems, often considered as the "last chance" antibiotics, causing a serious public health threat worldwide (9)(10)(11).…”

mentioning

confidence: 99%

Unlocking Tn3-family transposase activity in vitro unveils an asymetric pathway for transposome assembly

Nicolas

Oger

Nguyen

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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The Tn3 family is a widespread group of replicative transposons that are notorious for their contribution to the dissemination of antibiotic resistance and the emergence of multiresistant pathogens worldwide. The TnpA transposase of these elements catalyzes DNA breakage and rejoining reactions required for transposition. It also is responsible for target immunity, a phenomenon that prevents multiple insertions of the transposon into the same genomic region. However, the molecular mechanisms whereby TnpA acts in both processes remain unknown. Here, we have developed sensitive biochemical assays for the TnpA transposase of the Tn3-family transposon Tn4430 and used these assays to characterize previously isolated TnpA mutants that are selectively affected in immunity. Compared with wild-type TnpA, these mutants exhibit deregulated activities. They spontaneously assemble a unique asymmetric synaptic complex in which one TnpA molecule simultaneously binds two transposon ends. In this complex, TnpA is in an activated state competent for DNA cleavage and strand transfer. Wild-type TnpA can form this complex only on precleaved ends mimicking the initial step of transposition. The data suggest that transposition is controlled at an early stage of transpososome assembly, before DNA cleavage, and that mutations affecting immunity have unlocked TnpA by stabilizing the protein in a monomeric activated synaptic configuration. We propose an asymmetric pathway for coupling active transpososome assembly with proper target recruitment and discuss this model with respect to possible immunity mechanisms.

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“…Avian pathogenic Escherichia coli is considered a potentially zoonotic pathogen (Ewers et al, 2007). It has a similar phylogenetic background and virulence gene (VG) suite as human ExPEC and, beyond direct pathogenic potential, can act as a reservoir for VGs and antimicrobial resistance genes (ARGs), which via plasmids or other mobile integrative elements may transfer to other ExPECs (da Costa et al, 2010;Diarra et al, 2007;Manges and Johnson, 2012;Partridge, 2011) and other pathogenic or commensal bacteria (Carattoli, 2013).…”

Section: Introductionmentioning

confidence: 99%

Studies on avian pathogenic Escherichia coli in commercial broiler chicken in South East Queensland

Awawdeh¹,

Turni²,

Henning³

et al.

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Avian pathogenic Escherichia coli (APEC) is the causative agent of avian colibacillosis, a localised or systemic infection resulting in clinical diseases such as colisepticemia, chronic respiratory disease and swollen-head syndrome. Globally, avian colibacillosis is the leading cause of morbidity and mortality in poultry, and it has been associated with massive economic losses and welfare problems.This organism is of public health significance as APEC is communicable to humans. The diagnosis of avian colibacillosis relies on clinical signs, typical pathological lesions and culture of E. coli from affected tissue(s). Antimicrobial therapy is often used both for treatment and control. Previous overseas studies have characterised APEC and identified virulence genes (VGs) that can be used as molecular markers for the identification of APEC. Little is known about APEC in broiler chickens in Australia.The aim of this thesis was to gain a better understanding of the epidemiology of APEC in Australian broiler flocks and how factors including presence of VGs and phylogenetic group can improve the identification of this pathotype in Australia. Firstly, three faecal DNA extraction methods were evaluated. Faeces were collected from healthy chickens and chickens with colibacillosis from commercial broiler farms in South East Queensland (SEQ). The extracted DNA was screened by a pentaplex-PCR for five APEC-associated VGs (iroN, iutA, iss, hlyF and ompT). DNA extracted from E. coli isolates cultured from the cloaca and organs of the birds were screened using the same PCR.Repeated bead beating plus column elution was the preferred DNA extraction method, as it yielded good PCR quality and adequate quantity DNA. However, identifying APEC by direct detection of the five VGs from the faecal material was not feasible as all of these genes were also detected in all of the birds. However, the VGs were more commonly detected in E. coli isolates cultured from birds with colibacillosis.A cross-sectional study was performed to estimate APEC farm-level prevalence in healthy broiler chickens in SEQ and to identify potential risk factors associated with the carriage of APEC. At the farm-level, all of the 40 farms sampled were positive for APEC, that is at least one bird per farm carried APEC, while the within-farm prevalence was 63% (95% Confidence Interval: 55.8, 70.2).Higher APEC within-farm bird-level prevalence was significantly associated with the usage of well water as a source of drinking water, failure to disinfect the water line after each flock, farm visitors not showering before entering the shed, distances greater than 20 metres between the car park and the poultry shed and the presence of wild birds within 50 metres of the shed. Chlorinating the drinking water combined with automatic water filtration reduced within-farm bird-level APEC prevalence. Page | 3Therefore, based on the results concluded from the multivariable model, improving biosecurity and water treatments might reduce APEC prevalence, decrease the risk of co...

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Analysis of antibiotic resistance regions in Gram-negative bacteria

Cited by 295 publications

References 213 publications

A Study on Class I Integrons and Antimicrobial Resistance among Clinical Staphylococci Isolates from a Turkish Hospital

A Study on Class I Integrons and Antimicrobial Resistance among Clinical Staphylococci Isolates from a Turkish Hospital

Unlocking Tn3-family transposase activity in vitro unveils an asymetric pathway for transposome assembly

Studies on avian pathogenic Escherichia coli in commercial broiler chicken in South East Queensland

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