scholarly journals Genetic Characterization and Passage Instability of a Hybrid Plasmid Co-Harboring bla IMP-4 and bla NDM-1 Reveal the Contribution of Insertion Sequences During Plasmid Formation and Evolution

2021 ◽  
Author(s):  
Xi Li ◽  
Jintao He ◽  
Yan Jiang ◽  
Minfei Peng ◽  
Yunsong Yu ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Genetic Characterization ◽  
Hybrid Plasmid ◽  
Insertion Sequences ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Formation And Evolution

In this study, we characterized a novel plasmid from a carbapenem-resistant K. michiganensis (CRKM) isolate, which harbors two metallo-β-lactamases (MBLs), IMP-4 and NDM-1, is capable of transconjugation and contains three replicons. Our results first expand the diversity of plasmids co-harboring carbapenemase genes in Enterobacterales , which exhibits epidemic importance in bacterial resistance.

scholarly journals Application of CRISPR/Cas9-Based Genome Editing in Studying the Mechanism of Pandrug Resistance in Klebsiella pneumoniae

2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Qiaoling Sun ◽  
Yu Wang ◽  
Ning Dong ◽  
Lingwei Shen ◽  
Hongwei Zhou ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genome Editing ◽  
Genetic Characterization ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACT In this study, a CRISPR/Cas9-mediated genome editing method was used to study the functions of the mgrB, tetA, and ramR genes in mediating colistin and tigecycline resistance in carbapenem-resistant Klebsiella pneumoniae (CRKP). Inactivation of the tetA or ramR gene or the mgrB gene by CRISPR/Cas9 affected bacterial susceptibility to tigecycline or colistin, respectively. This study proved that the CRISPR/Cas9-based genome editing method could be effectively applied to K. pneumoniae and should be further utilized for genetic characterization.

scholarly journals Emergence of Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae Coharboring a blaNDM-1-Carrying Virulent Plasmid and a blaKPC-2-Carrying Plasmid in an Egyptian Hospital

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohamed Abd El-Gawad El-Sayed Ahmed ◽  
Yanxian Yang ◽  
Yongqiang Yang ◽  
Bin Yan ◽  
Guanping Chen ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genetic Basis ◽  
Tertiary Care ◽  
Antibiotic Resistance Genes ◽  
Hybrid Plasmid ◽  
World Health ◽  
Care Hospital ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Depth Analysis

ABSTRACT The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates in Egyptian hospitals has been reported. However, the genetic basis and analysis of the plasmids associated with carbapenem-resistant hypervirulent K. pneumoniae (CR-HvKP) in Egypt have not been presented. Therefore, we attempted to decipher the plasmid sequences that are responsible for transferring the determinants of carbapenem resistance, particularly blaNDM-1 and blaKPC-2. Out of 34 K. pneumoniae isolates collected from two tertiary hospitals in Egypt, 31 were CRKP. Whole-genome sequencing revealed that our isolates were related to 13 different sequence types (STs). The most prevalent ST was ST101, followed by ST383 and ST11. Among the CRKP isolates, one isolate named EBSI036 has been reassessed by Nanopore sequencing. Genetic environment analysis showed that EBSI036 carried 20 antibiotic resistance genes and was identified as a CR-HvKP strain: it harbored four plasmids, namely, pEBSI036-1-NDM-VIR, pEBSI036-2-KPC, pEBSI036-3, and pEBSI036-4. The two carbapenemase genes blaNDM-1 and blaKPC-2 were located on plasmids pEBSI036-1-NDM-VIR and pEBSI036-2-KPC, respectively. The IncFIB:IncHI1B hybrid plasmid pEBSI036-1-NDM-VIR also carried some virulence factors, including the regulator of the mucoid phenotype (rmpA), the regulator of mucoid phenotype 2 (rmpA2), and aerobactin (iucABCD and iutA). Thus, we set out in this study to analyze in depth the genetic basis of the pEBSI036-1-NDM-VIR and pEBSI036-2-KPC plasmids. We report a high-risk clone ST11 KL47 serotype of a CR-HvKP strain isolated from the blood of a 60-year-old hospitalized female patient from the intensive care unit (ICU) in a tertiary care hospital in Egypt, which showed the cohabitation of a novel hybrid plasmid coharboring the blaNDM-1 and virulence genes and a blaKPC-2-carrying plasmid. IMPORTANCE CRKP has been registered in the critical priority tier by the World Health Organization and has become a significant menace to public health. The emergence of CR-HvKP is of great concern in terms of both disease and treatment. In-depth analysis of the carbapenemase-encoding and virulence plasmids may provide insight into ongoing recombination and evolution of virulence and multidrug resistance in K. pneumoniae. Thus, this study serves to alert contagious disease clinicians to the presence of hypervirulence in CRKP isolates in Egyptian hospitals.

scholarly journals Bacterial Resistance to Antisense Peptide Phosphorodiamidate Morpholino Oligomers

2012 ◽  
Vol 56 (12) ◽  
pp. 6147-6153 ◽  
Author(s):  
Susan E. Puckett ◽  
Kaleb A. Reese ◽  
Georgi M. Mitev ◽  
Valerie Mullen ◽  
Rudd C. Johnson ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Acyl Carrier Protein ◽  
Essential Gene ◽  
Resistant Mutant ◽  
Resistant Isolate ◽  
Carrier Protein ◽  
Bacterial Gene ◽  
Content Type ◽  
Bacterial Gene Expression ◽  
Phosphorodiamidate Morpholino Oligomers

ABSTRACTPeptide phosphorodiamidate morpholino oligomers (PPMOs) are synthetic DNA mimics that bind cRNA and inhibit bacterial gene expression. The PPMO (RFF)3RXB-AcpP (where R is arginine, F, phenylalanine, X is 6-aminohexanoic acid, B is β-alanine, and AcpP is acyl carrier protein) is complementary to 11 bases of the essential geneacpP(which encodes acyl carrier protein). The MIC of (RFF)3RXB-AcpP was 2.5 μM (14 μg/ml) inEscherichia coliW3110. The rate of spontaneous resistance ofE. colito (RFF)3RXB-AcpP was 4 × 10−7mutations/cell division. A spontaneous (RFF)3RXB-AcpP-resistant mutant (PR200.1) was isolated. The MIC of (RFF)3RXB-AcpP was 40 μM (224 μg/ml) for PR200.1. The MICs of standard antibiotics for PR200.1 and W3110 were identical. The sequence ofacpPwas identical in PR200.1 and W3110. PR200.1 was also resistant to other PPMOs conjugated to (RFF)3RXB or peptides with a similar composition or pattern of cationic and nonpolar residues. Genomic sequencing of PR200.1 identified a mutation insbmA, which encodes an active transport protein. In separate experiments, a (RFF)3RXB-AcpP-resistant isolate (RR3) was selected from a transposome library, and the insertion was mapped tosbmA. Genetic complementation of PR200.1 or RR3 withsbmArestored susceptibility to (RFF)3RXB-AcpP. Deletion ofsbmAcaused resistance to (RFF)3RXB-AcpP. We conclude that resistance to (RFF)3RXB-AcpP was linked to the peptide and not the phosphorodiamidate morpholino oligomer, dependent on the composition or repeating pattern of amino acids, and caused by mutations insbmA. The data further suggest that (RFF)3R-XB PPMOs may be transported across the plasma membrane by SbmA.

scholarly journals Multicenter Clinical and Molecular Epidemiological Analysis of Bacteremia Due to Carbapenem-Resistant Enterobacteriaceae (CRE) in the CRE Epicenter of the United States

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Michael J. Satlin ◽  
Liang Chen ◽  
Gopi Patel ◽  
Angela Gomez-Simmonds ◽  
Gregory Weston ◽  
...  
Keyword(s):  
New York ◽  
Empirical Therapy ◽  
Carbapenem Resistance ◽  
The United States ◽  
Resistance Mechanisms ◽  
Rapid Diagnostics ◽  
Multicenter Studies ◽  
Content Type ◽  
Medical Centers ◽  
Carbapenem Resistant

ABSTRACT Although the New York/New Jersey (NY/NJ) area is an epicenter for carbapenem-resistant Enterobacteriaceae (CRE), there are few multicenter studies of CRE from this region. We characterized patients with CRE bacteremia in 2013 at eight NY/NJ medical centers and determined the prevalence of carbapenem resistance among Enterobacteriaceae bloodstream isolates and CRE resistance mechanisms, genetic backgrounds, capsular types (cps), and antimicrobial susceptibilities. Of 121 patients with CRE bacteremia, 50% had cancer or had undergone transplantation. The prevalences of carbapenem resistance among Klebsiella pneumoniae, Enterobacter spp., and Escherichia coli bacteremias were 9.7%, 2.2%, and 0.1%, respectively. Ninety percent of CRE were K. pneumoniae and 92% produced K. pneumoniae carbapenemase (KPC-3, 48%; KPC-2, 44%). Two CRE produced NDM-1 and OXA-48 carbapenemases. Sequence type 258 (ST258) predominated among KPC-producing K. pneumoniae (KPC-Kp). The wzi154 allele, corresponding to cps-2, was present in 93% of KPC-3-Kp, whereas KPC-2-Kp had greater cps diversity. Ninety-nine percent of CRE were ceftazidime-avibactam (CAZ-AVI)-susceptible, although 42% of KPC-3-Kp had an CAZ-AVI MIC of ≥4/4 μg/ml. There was a median of 47 h from bacteremia onset until active antimicrobial therapy, 38% of patients had septic shock, and 49% died within 30 days. KPC-3-Kp bacteremia (adjusted odds ratio [aOR], 2.58; P = 0.045), cancer (aOR, 3.61, P = 0.01), and bacteremia onset in the intensive care unit (aOR, 3.79; P = 0.03) were independently associated with mortality. Active empirical therapy and combination therapy were not associated with survival. Despite a decade of experience with CRE, patients with CRE bacteremia have protracted delays in appropriate therapies and high mortality rates, highlighting the need for rapid diagnostics and evaluation of new therapeutics.

scholarly journals Effect of Short-Term Carbapenem Restriction on Antimicrobial Susceptibility of Resistant Gram-Negative Bacilli in an ICU

2020 ◽  
Vol 41 (S1) ◽  
pp. s200-s201
Author(s):  
Mariana Melo ◽  
Raquel Bandeira ◽  
lio de Castro Giselle Dias ◽  
Braulio Couto
Keyword(s):  
High Mortality ◽  
Bacterial Resistance ◽  
Statistical Significance ◽  
Public Health Problem ◽  
Resistance Rate ◽  
Second Phase ◽  
Short Term ◽  
Intervention Phase ◽  
Carbapenem Resistant ◽  
The Impact

Background: Carbapenem-resistant GNB infections are a serious public health problem worldwide, particularly due to the high mortality associated with them and the low number of therapeutic options. One approach to this challenge is the development of antimicrobial stewardship programs. Objective: We evaluated the impact of a carbapenem restriction program on reducing of bacterial resistance in an intensive care unit (ICU). Methods: A retrospective study conducted in 2 phases in the 80-bed ICU of an acute-care public hospital in Minas Gerais, Brazil. The preintervention phase lasted 16 months (January 2018–April 2019) and the second phase (carbapenem restriction), after the intervention, lasted 4 months (May–August 2019). The intervention was defined as carbapenem-sparing and the use of meropenem was authorized in 3 situations: (1) treatment of serious infections documented by extended-spectrum β-lactamase–producing Enterobacteriacea (ESBL); (2) therapeutic failure with the use of another antimicrobial; and (3) infectious disease recommendation. Data were obtained through consultation of electronic medical records and microbiological results, as standardized by the CLSI, for patients with a >48-hour stay in the ICU and who met the criteria for healthcare-associated infection (HAI) according to the CDC NHSN definition. Results: Before the intervention, on average, 50 cultures were obtained with positive results for multidrug-resistant GNB–MER-GNB (SD, 12.2) and in the intervention phase, this number was 31 cultures (SD, 12.8; P = .010). Average carbapenem consumption decreased significantly with corresponding increase in cefepime consumption in the same period (Fig. 1). The ATB (DDD per 1,000 patient days) before the intervention for carbapenems was 110.6 (SD, 97.1) and for cefepime was 8.2 (SD, 5.9). In the intervention phase, the ATB for carbapenems was 44.7 (SD, 38.5; P = .015) and for cefepime it was 32.0 (SD, 20.3; P < .001). In terms of multidrug resistance rate, before the intervention, 95 of 149 of Acinetobacter (64%) were resistant and during the intervention, 13 of 30 Acinetobacter (43%) were resistant (P = .043). Other GNB (Klebsiella, Proteus, Escherichia coli, and Pseudomonas) reduced the resistance rate, but without statistical significance. We observed a reduction in the HAI rate per MDR-GNB (Fig. 2): before the intervention, it was 22.7 (SD, 5.5) and during the intervention phase it was 16.5 (SD, 7.7; P = .07), although this change did not reach statistical significance. Nevertheless, the ICU Klebsiella infection rate did significantly decrease; it was 5.5 (SD, 1.9) before the intervention and 2.4 (SD, 1.8) after the intervention (P = .009). Conclusions: Short-term carbapenem restriction may be an effective strategy to reduce the incidence of carbapenem-resistant GNB infections in the ICU. The scarce arsenal available for the treatment of MDR-GNB and the high mortality rate justify the growing need for stewardship programs in Brazilian ICUs.Funding: NoneDisclosures: None

scholarly journals Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae Mediated by Chromosomal Integration of Plasmid DNA

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Astrid V. Cienfuegos-Gallet ◽  
Liang Chen ◽  
Barry N. Kreiswirth ◽  
J. Natalia Jiménez
Keyword(s):  
Klebsiella Pneumoniae ◽  
Plasmid Dna ◽  
Clonal Expansion ◽  
Genetic Alterations ◽  
Sequence Type ◽  
Chromosomal Integration ◽  
Colistin Resistance ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Single Locus Variant

ABSTRACT Here we describe the spread of colistin resistance in clinical isolates of carbapenem-resistant Klebsiella pneumoniae in Medellín, Colombia. Among 32 isolates collected between 2012 and 2014, 24 showed genetic alterations in mgrB. Nineteen isolates belonged to sequence type 512 (ST512) (or its single locus variant [SLV]) and harbored an 8.1-kb hsdMSR insertion corresponding to ISKpn25, indicating a clonal expansion of the resistant strain. The insertion region showed 100% identity to several plasmids, suggesting that the colistin resistance is mediated by chromosomal integration of plasmid DNA.

scholarly journals Complete Sequence of pOZ176, a 500-Kilobase IncP-2 Plasmid Encoding IMP-9-Mediated Carbapenem Resistance, from Outbreak Isolate Pseudomonas aeruginosa 96

2013 ◽  
Vol 57 (8) ◽  
pp. 3775-3782 ◽  
Author(s):  
Jianhui Xiong ◽  
David C. Alexander ◽  
Jennifer H. Ma ◽  
Maxime Déraspe ◽  
Donald E. Low ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Complete Sequence ◽  
Open Reading Frames ◽  
Content Type ◽  
Conserved Sequence ◽  
Carbapenem Resistant ◽  
Class 1 ◽  
Usage Analysis ◽  
Type 3

ABSTRACTPseudomonas aeruginosa96 (PA96) was isolated during a multicenter surveillance study in Guangzhou, China, in 2000. Whole-genome sequencing of this outbreak strain facilitated analysis of its IncP-2 carbapenem-resistant plasmid, pOZ176. The plasmid had a length of 500,839 bp and an average percent G+C content of 57%. Of the 618 predicted open reading frames, 65% encode hypothetical proteins. The pOZ176 backbone is not closely related to any plasmids thus far sequenced, but some similarity to pQBR103 ofPseudomonas fluorescensSBW25 was observed. Two multiresistant class 1 integrons and several insertion sequences were identified. TheblaIMP-9-carrying integron containedaacA4→blaIMP-9→aacA4, flanked upstream by Tn21 tnpMRAand downstream by a completetnioperon of Tn402and amermodule, named Tn6016. The second integron carriedaacA4→catB8a→blaOXA-10and was flanked by Tn1403-liketnpRAand asul1-type 3′ conserved sequence (3′-CS), named Tn6217. Other features include three resistance genes similar to those of Tn5, a tellurite resistance operon, and twopiloperons. The replication and maintenance systems exhibit similarity to a genomic island ofRalstonia solanacearumGM1000. Codon usage analysis suggests the recent acquisition ofblaIMP-9. The origins of the integrons on pOZ176 indicated separate horizontal gene transfer events driven by antibiotic selection. The novel mosaic structure of pOZ176 suggests that it is derived from environmental bacteria.

scholarly journals First Description of Two Sequence Type 2 Acinetobacter baumannii Isolates Carrying OXA-23 Carbapenemase in Pagellus acarne Fished from the Mediterranean Sea near Bejaia, Algeria

2016 ◽  
Vol 60 (4) ◽  
pp. 2513-2515 ◽  
Author(s):  
Soumia Brahmi ◽  
Abdelaziz Touati ◽  
Axelle Cadière ◽  
Nassima Djahmi ◽  
Alix Pantel ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Mediterranean Sea ◽  
Sequence Type ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Selective Agar ◽  
Agar Media ◽  
The Mediterranean ◽  
First Time

ABSTRACTTo determine the occurrence of carbapenem-resistantAcinetobacter baumanniiin fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producingA. baumanniistrains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [aac(6′)-Ib andaac(3′)-I genes].

scholarly journals Activity of Simulated Human Dosage Regimens of Meropenem and Vaborbactam against Carbapenem-Resistant Enterobacteriaceae in an In Vitro Hollow-Fiber Model

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Mojgan Sabet ◽  
Ziad Tarazi ◽  
Debora Rubio-Aparicio ◽  
Thomas G. Nolan ◽  
Jonathan Parkinson ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Hollow Fiber ◽  
Phase 1 ◽  
Phase 3 ◽  
Fiber Model ◽  
Content Type ◽  
Development Of Resistance ◽  
Carbapenem Resistant ◽  
Dosage Regimens

ABSTRACT The objective of these studies was to evaluate the exposures of meropenem and vaborbactam that would produce antibacterial activity and prevent resistance development in carbapenem-resistant Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae strains when tested at an inoculum of 108 CFU/ml. Thirteen K. pneumoniae isolates, three Enterobacter cloacae isolates, and one Escherichia coli isolate were examined in an in vitro hollow-fiber model over 32 h. Simulated dosage regimens of 1 to 2 g of meropenem with 1 to 2 g of vaborbactam, with meropenem administered every 8 h by a 3-h infusion based on phase 1 or phase 3 patient pharmacokinetic data, were studied in the model. A dosage of 2 g of meropenem in combination with 2 g of vaborbactam was bactericidal against K. pneumoniae, E. cloacae, and E. coli strains, with meropenem-vaborbactam MICs of up to 8 mg/liter. When the vaborbactam exposure was adjusted to the levels observed in patients enrolled in phase 3 trials (24-h free AUC, ∼550 mg · h/liter, versus 320 mg · h/liter in the phase 1 studies), 2 g of meropenem with 2 g of vaborbactam was also bactericidal against strains with meropenem-vaborbactam MICs of 16 mg/liter. In addition, this level of vaborbactam also suppressed the development of resistance observed using phase 1 exposures. In this pharmacodynamic model, exposures similar to 2 g of meropenem in combination with 2 g of vaborbactam administered every 8 h by a 3-h infusion in phase 3 trials produced antibacterial activity and suppressed the development of resistance against carbapenem-resistant KPC-producing strains of Enterobacteriaceae.

scholarly journals Contaminated Handwashing Sinks as the Source of a Clonal Outbreak of KPC-2-Producing Klebsiella oxytoca on a Hematology Ward

2014 ◽  
Vol 59 (1) ◽  
pp. 714-716 ◽  
Author(s):  
Eva Leitner ◽  
Gernot Zarfel ◽  
Josefa Luxner ◽  
Kathrin Herzog ◽  
Shiva Pekard-Amenitsch ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Genetic Relatedness ◽  
Klebsiella Oxytoca ◽  
Klebsiella Pneumonia ◽  
Environmental Isolates ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACTWe investigated sinks as possible sources of a prolongedKlebsiella pneumoniacarbapenemase (KPC)-producingKlebsiella oxytocaoutbreak. Seven carbapenem-resistantK. oxytocaisolates were identified in sink drains in 4 patient rooms and in the medication room. Investigations for resistance genes and genetic relatedness of patient and environmental isolates revealed that all the isolates harbored theblaKPC-2andblaTEM-1genes and were genetically indistinguishable. We describe here a clonal outbreak caused by KPC-2-producingK. oxytoca, and handwashing sinks were a possible reservoir.

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