A #MDR #Plasmid pIMP26, Carrying blaIMP-26, fosA5, blaDHA-1, and qnrB4 in #Enterobacter cloacae (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Article | OPEN | Published: 15 July 2019

A Multidrug Resistance Plasmid pIMP26, Carrying blaIMP-26, fosA5, blaDHA-1, and qnrB4 in Enterobacter cloacae

Su Wang,  Kaixin Zhou, Shuzhen Xiao, Lianyan Xie, Feifei Gu, Xinxin Li, Yuxing Ni, Jingyong Sun & Lizhong Han

Scientific Reports, volume 9, Article number: 10212 (2019)

 

Abstract

IMP-26 was a rare IMP variant with more carbapenem-hydrolyzing activities, which was increasingly reported now in China. This study characterized a transferable multidrug resistance plasmid harboring blaIMP-26 from one Enterobacter cloacae bloodstream isolate in Shanghai and investigated the genetic environment of resistance genes. The isolate was subjected to antimicrobial susceptibility testing and multilocus sequence typing using broth microdilution method, Etest and PCR. The plasmid was analyzed through conjugation experiments, S1-nuclease pulsed-field gel electrophoresis and hybridization. Whole genome sequencing and sequence analysis was conducted for further investigation of the plasmid. E. cloacae RJ702, belonging to ST528 and carrying blaIMP-26, blaDHA-1, qnrB4 and fosA5, was resistant to almost all β-lactams, but susceptible to quinolones and tigecycline. The transconjugant inherited the multidrug resistance. The resistance genes were located on a 329,420-bp IncHI2 conjugative plasmid pIMP26 (ST1 subtype), which contained trhK/trhV, tra, parA and stbA family operon. The blaIMP-26 was arranged following intI1. The blaDHA-1 and qnrB4cluster was the downstream of ISCR1, same as that in p505108-MDR. The fosA5 cassette was mediated by IS4. This was the first report on complete nucleotide of a blaIMP-26-carrying plasmid in E. cloacae in China. Plasmid pIMP26 hosted high phylogenetic mosaicism, transferability and plasticity.

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Enterobacter cloacae; Shanghai; China; Quinolones; Tigecycline.

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Optical #DNA #Mapping Combined with #Cas9-Targeted #Resistance #Gene #Identification for Rapid #Tracking of Resistance #Plasmids in a #NICU #Outbreak (mBio, abstract)

[Source: mBio, full page: (LINK). Abstract, edited.]

Optical DNA Mapping Combined with Cas9-Targeted Resistance Gene Identification for Rapid Tracking of Resistance Plasmids in a Neonatal Intensive Care Unit Outbreak

Santosh K. Bikkarolla, Viveka Nordberg, Fredrika Rajer, Vilhelm Müller, Muhammad Humaun Kabir, Sriram KK, Albertas Dvirnas, Tobias Ambjörnsson, Christian G. Giske, Lars Navér,Linus Sandegren, Fredrik Westerlund

Spyros Pournaras, Invited Editor, Karen Bush, Editor

DOI: 10.1128/mBio.00347-19

 

ABSTRACT

The global spread of antibiotic resistance among Enterobacteriaceae is largely due to multidrug resistance plasmids that can transfer between different bacterial strains and species. Horizontal gene transfer of resistance plasmids can complicate hospital outbreaks and cause problems in epidemiological tracing, since tracing is usually based on bacterial clonality. We have developed a method, based on optical DNA mapping combined with Cas9-assisted identification of resistance genes, which is used here to characterize plasmids during an extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae outbreak at a Swedish neonatal intensive care unit. The outbreak included 17 neonates initially colonized with ESBL-producing Klebsiella pneumoniae (ESBL-KP), some of which were found to carry additional ESBL-producing Escherichia coli (ESBL-EC) in follow-up samples. We demonstrate that all ESBL-KP isolates contained two plasmids with the blaCTX-M-15 gene located on the smaller one (~80 kbp). The same ESBL-KP clone was present in follow-up samples for up to 2 years in some patients, and the plasmid carrying the blaCTX-M-15 gene was stable throughout this time period. However, extensive genetic rearrangements within the second plasmid were observed in the optical DNA maps for several of the ESBL-KP isolates. Optical mapping also demonstrated that even though other bacterial clones and species carrying blaCTX-M group 1 genes were found in some neonates, no transfer of resistance plasmids had occurred. The data instead pointed toward unrelated acquisition of ESBL-producing Enterobacteriaceae (EPE). In addition to revealing important information about the specific outbreak, the method presented is a promising tool for surveillance and infection control in clinical settings.

IMPORTANCE

This study presents how a novel method, based on visualizing single plasmids using sequence-specific fluorescent labeling, could be used to analyze the genetic dynamics of an outbreak of resistant bacteria in a neonatal intensive care unit at a Swedish hospital. Plasmids are a central reason for the rapid global spread of bacterial resistance to antibiotics. In a single experimental procedure, this method replaces many traditional plasmid analysis techniques that together provide limited details and are slow to perform. The method is much faster than long-read whole-genome sequencing and offers direct genetic comparison of patient samples. We could conclude that no transfer of resistance plasmids had occurred between different bacteria during the outbreak and that secondary cases of ESBL-producing Enterobacteriaceae carriage were instead likely due to influx of new strains. We believe that the method offers potential in improving surveillance and infection control of resistant bacteria in hospitals.

Keywords: Antibiotics; Drugs Resistance; Enterobacteriaceae; Beta-lactams; Nosocomial Outbreaks; Diagnostic tests.

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Available #evidence of #antibiotic #resistance from #ESBL-producing #Enterobacteriaceae in #paediatric patients in 20 countries: a systematic review and meta-analysis (Bull World Health Organ., abstract)

[Source: Bulletin of the World Health Organization, full page: (LINK). Abstract, edited.]

Available evidence of antibiotic resistance from extended-spectrum β-lactamase-producing Enterobacteriaceae in paediatric patients in 20 countries: a systematic review and meta-analysis

Yanhong Jessika Hu,a, Anju Ogyu,a, Benjamin J Cowling,a, Keiji Fukuda a & Herbert H Pang a

{a} School of Public Health, Patrick Manson Building (North Wing), 7 Sassoon Road, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special
Administrative Region, China.

Correspondence to Yanhong Jessika Hu (email: huhubest@gmail.com).

Submitted: 20 October 2018 – Revised version received: 8 April 2019 – Accepted: 9 April 2019 – Published online: 14 May 2019

Bull World Health Organ 2019;97:486–501B | doi: http://dx.doi.org/10.2471/BLT.18.225698

 

Abstract

Objective

To make a systematic review of risk factors, outcomes and prevalence of extended-spectrum β-lactamase-associated infection in children and young adults in South-East Asia and the Western Pacific.

Methods

Up to June 2018 we searched online databases for published studies of infection with extended-spectrum β-lactamase-producing Enterobacteriaceae in individuals aged 0–21 years. We included case–control, cohort, cross-sectional and observational studies reporting patients positive and negative for these organisms. For the meta-analysis we used random-effects modelling of risk factors and outcomes for infection, and meta-regression for analysis of subgroups. We mapped the prevalence of these infections in 20 countries and areas using available surveillance data.

Findings

Of 6665 articles scanned, we included 40 studies from 11 countries and areas in the meta-analysis. The pooled studies included 2411 samples testing positive and 2874 negative. A higher risk of infectionwith extended-spectrum β-lactamase-producing bacteria was associated with previous hospital care, notably intensive care unit stays (pooled odds ratio, OR: 6.5; 95% confidence interval, CI: 3.04 to 13.73); antibiotic exposure (OR: 4.8; 95% CI: 2.25 to 10.27); and certain co-existing conditions. Empirical antibiotic therapy was protective against infection (OR: 0.29; 95% CI: 0.11 to 0.79). Infected patients had longer hospital stays (26 days; 95% CI: 12.81 to 38.89) and higher risk of death (OR: 3.2; 95% CI: 1.82 to 5.80). The population prevalence of infection was high in these regions and surveillance data for children were scarce.

Conclusion

Antibiotic stewardship policies to prevent infection and encourage appropriate treatment are needed in South-East Asia and the Western Pacific

Keywords: Antibiotics; Drugs Resistance; Pediatrics; Asia Region.

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Emergence of #carbapenem resistant #Pseudomonas asiatica producing #NDM-1 and #VIM-2 metallo-β-lactamases in #Myanmar (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Emergence of carbapenem-resistant Pseudomonas asiatica producing NDM-1 and VIM-2 metallo-β-lactamases in Myanmar

Mari Tohya, Tatsuya Tada, Shin Watanabe, Kyoko Kuwahara-Arai, Khwar Nyo Zin, Ni Ni Zaw, May Yee Aung, San Mya, Khin Nyein Zan, Teruo Kirikae, Htay Htay Tin

DOI: 10.1128/AAC.00475-19

 

ABSTRACT

Pseudomonas asiatica is recently proposed species of the genus Pseudomonas. This study describes eight isolates of carbapenem-resistant P. asiatica harboring blaNDM-1 and blaVIM-2, genes encoding metallo-β-lactamase (MBL). These isolates were obtained from urine samples of patients hospitalized in Myanmar. These isolates were resistant to carbapenems but susceptible to colistin. All eight isolates were positive for a carbapenemase inactivation method, CIMTrisII, and seven were positive on an immunochromatographic assay for NDM-type MBL. One isolate was highly resistant to aminoglycosides. Whole genome sequencing showed that seven isolates harbored blaNDM-1 and one harbored blaVIM-2, with these genes located on the chromosome. One isolate harbored blaNDM-1 and rmtC, a gene encoding 16S rRNA methylase. Five types of genomic environments surrounding blaNDM-1 and blaVIM-2 were detected in these eight isolates, with four isolates having the same type. These data indicate that P. asiatica harboring genes encoding carbapenemases, including blaNDM-1 and blaVIM-2, are spreading in medical settings in Myanmar.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Aminoglycosides; Pseudomonas asiatica; Myanmar.

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Potentiation of #betalactam #antibiotics and β-lactam/β-lactamase inhibitor combinations against #MDR and #XDR #Pseudomonas aeruginosa using non-ribosomal #tobramycin–cyclam conjugates (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Potentiation of β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations against MDR and XDR Pseudomonas aeruginosa using non-ribosomal tobramycin–cyclam conjugates

Temilolu Idowu, Derek Ammeter, Gilbert Arthur, George G Zhanel, Frank Schweizer

Journal of Antimicrobial Chemotherapy, dkz228, https://doi.org/10.1093/jac/dkz228

Published: 28 May 2019

 

Abstract

Objectives

To develop a multifunctional adjuvant molecule that can rescue β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations from resistance in carbapenem-resistant Pseudomonas aeruginosa clinical isolates.

Methods

Preparation of adjuvant was guided by structure–activity relationships, following standard protocols. Susceptibility and chequerboard studies were assessed using serial 2-fold dilution assays. Toxicity was evaluated against porcine erythrocytes, human embryonic kidney (HEK293) cells and liver carcinoma (HepG2) cells via MTS assay. Preliminary in vivo efficacy was evaluated using a Galleria mellonella infection model.

Results

Conjugation of tobramycin and cyclam abrogates the ribosomal effects of tobramycin but confers a potent adjuvant property that restores full antibiotic activity of meropenem and aztreonam against carbapenem-resistant P. aeruginosa. Therapeutic levels of susceptibility, as determined by CLSI susceptibility breakpoints, were attained in several MDR clinical isolates, and time–kill assays revealed a synergistic dose-dependent pharmacodynamic relationship. A triple combination of the adjuvant with ceftazidime/avibactam (approved), aztreonam/avibactam (Phase III) and meropenem/avibactam enhances the efficacies of β-lactam/β-lactamase inhibitors against recalcitrant strains, suggesting rapid access of the combination to their periplasmic targets. The newly developed adjuvants, and their combinations, were non-haemolytic and non-cytotoxic, and preliminary in vivo evaluation in G. mellonella suggests therapeutic potential for the double and triple combinations.

Conclusions

Non-ribosomal tobramycin–cyclam conjugate mitigates the effect of OprD/OprF porin loss in P. aeruginosa and potentiates β-lactam/β-lactamase inhibitors against carbapenem-resistant clinical isolates, highlighting the complexity of resistance to β-lactam antibiotics. Our strategy presents an avenue to further preserve the therapeutic utility of β-lactam antibiotics.

Topic: antibiotics – pseudomonas aeruginosa – immunologic adjuvants – pharmaceutical adjuvants – aztreonam – ceftazidime – lactams – ribosomes – infection – tobramycin – meropenem – toxic effect – potentiation – avibactam – carbapenem resistance

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Pseudomonas aeruginosa; Tobramycin; Aztreonam; Avibactam; Ceftazidime.

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Reduced #ceftazidime and #ertapenem susceptibility due to production of #OXA-2 in #Klebsiella pneumoniae ST258 (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Reduced ceftazidime and ertapenem susceptibility due to production of OXA-2 in Klebsiella pneumoniaeST258

Alina Iovleva, Roberta T Mettus, Christi L McElheny, Mustapha M Mustapha, Daria Van Tyne, Ryan K Shields, A William Pasculle, Vaughn S Cooper, Yohei Doi

Journal of Antimicrobial Chemotherapy, dkz183, https://doi.org/10.1093/jac/dkz183

Published: 24 May 2019

 

Abstract

Background

OXA-2 is a class D β-lactamase that confers resistance to penicillins, as well as narrow-spectrum cephalosporins. OXA-2 was recently reported to also possess carbapenem-hydrolysing activity. Here, we describe a KPC-2-encoding Klebsiella pneumoniae isolate that demonstrated reduced susceptibility to ceftazidime and ertapenem due to production of OXA-2.

Objectives

To elucidate the role of OXA-2 production in reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 clinical isolate.

Methods

MICs were determined by the agar dilution method. WGS was conducted to identify and compare resistance genes between isolates. Expression of KPC-2 was quantified by quantitative RT–PCR and immunoblotting. OXA-2 was expressed in Escherichia coli TOP10, as well as in K. pneumoniae ATCC 13883, to define the relative contribution of OXA-2 in β-lactam resistance. Kinetic studies were conducted using purified OXA-2 enzyme.

Results

K. pneumoniae 1761 belonged to ST258 and carried both blaKPC-2 and blaOXA-2. However, expression of blaKPC-2 was substantially reduced due to an IS1294insertion in the promoter region. K. pneumoniae 1761, K. pneumoniae ATCC 13883 and E. coli TOP10 carrying blaOXA-2-harbouring plasmids showed reduced susceptibility to ertapenem and ceftazidime, but meropenem, imipenem and cefepime were unaffected. blaOXA-2 was carried on a 2910 bp partial class 1 integron containing aacA4-blaOXA-2-qacEΔ1-sul1 on an IncA/C2plasmid, which was not present in the earlier ST258 isolates possessing blaKPC-2 with intact promoters. Hydrolysis of ertapenem by OXA-2 was confirmed using purified enzyme.

Conclusions

Production of OXA-2 was associated with reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 isolate.

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Beta-lactams; Carbapenem; Ceftazidime; Ertapenem; Meropenem; Imipenem; Cefepime.

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Non-lytic #antibiotic #treatment in community-acquired #pneumococcal #pneumonia does not attenuate inflammation: the #PRISTINE trial (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Non-lytic antibiotic treatment in community-acquired pneumococcal pneumonia does not attenuate inflammation: the PRISTINE trial

Geert H Groeneveld, Tanny J van der Reyden, Simone A Joosten, Hester J Bootsma, Christa M Cobbaert Jutte, J C de Vries, Ed J Kuijper, Jaap T van Dissel

Journal of Antimicrobial Chemotherapy, dkz207, https://doi.org/10.1093/jac/dkz207

Published: 18 May 2019

 

Abstract

Background

The inflammatory response in pneumococcal infection is primarily driven by immunoreactive bacterial cell wall components [lipoteichoic acid (LTA)]. An acute release of these components occurs when pneumococcal infection is treated with β-lactam antibiotics.

Objectives

We hypothesized that non-lytic rifampicin compared with lytic β-lactam antibiotic treatment would attenuate the inflammatory response in patients with pneumococcal pneumonia.

Methods

In the PRISTINE (Pneumonia treated with RIfampicin aTtenuates INflammation) trial, a randomized, therapeutic controlled, exploratory study in patients with community-acquired pneumococcal pneumonia, we looked at LTA release and inflammatory and clinical response during treatment with both rifampicin and β-lactam compared with treatment with β-lactam antibiotics only. The trial is registered in the Dutch trial registry, number NTR3751 (European Clinical Trials Database number 2012-003067-22).

Results

Forty-one patients with community-acquired pneumonia were included; 17 of them had pneumococcal pneumonia. LTA release, LTA-mediated inflammatory responses, clinical outcomes, inflammatory biomarkers and transcription profiles were not different between treatment groups.

Conclusions

The PRISTINE study demonstrated the feasibility of adding rifampicin to β-lactam antibiotics in the treatment of community-acquired pneumococcal pneumonia, but, despite solid in vitro and experimental animal research evidence, failed to demonstrate a difference in plasma LTA concentrations and subsequent inflammatory and clinical responses. Most likely, an inhibitory effect of human plasma contributes to the low immune response in these patients. In addition, LTA plasma concentration could be too low to mount a response via Toll-like receptor 2 in vitro, but may nonetheless have an effect in vivo.

Topic: antibiotics – rifampin – inflammation – immune response – community acquired  pneumonia – biological markers – cell wall – lactams – plasma – pneumococcal infections – pneumonia, pneumococcal – treatment outcome – inflammatory response – community – toll-like receptor 2 – attenuation

Issue Section: ORIGINAL RESEARCH

Keywords: Antibiotics; S. pneumoniae; Pneumonia; Beta-lactams; Rifampin.

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