scholarly journals Distinct Mechanisms of Dissemination of NDM-1 Metallo-β-Lactamase in Acinetobacter Species in Argentina

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Mark D. Adams ◽  
Fernando Pasteran ◽  
German M. Traglia ◽  
Jasmine Martinez ◽  
Fanny Huang ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Gene ◽  
Genome Sequencing ◽  
Acinetobacter Species ◽  
Content Type ◽  
Resistance Determinants ◽  
Carbapenem Resistant ◽  
Gene Island

ABSTRACT A 4-year surveillance of carbapenem-resistant Acinetobacter spp. isolates in Argentina identified 40 strains carrying blaNDM-1. Genome sequencing revealed that most were Acinetobacter baumannii, whereas seven represented other Acinetobacter spp. The A. baumannii genomes were closely related, suggesting recent spread. blaNDM-1 was located in the chromosome of A. baumannii strains and on a plasmid in non-A. baumannii strains. A resistance gene island carrying blaPER-7 and other resistance determinants was found on a plasmid in some A. baumannii strains.

scholarly journals Evolution of Carbapenem-Resistant Acinetobacter baumannii Revealed through Whole-Genome Sequencing and Comparative Genomic Analysis

2014 ◽  
Vol 59 (2) ◽  
pp. 1168-1176 ◽  
Author(s):  
Henan Li ◽  
Fei Liu ◽  
Yawei Zhang ◽  
Xiaojuan Wang ◽  
Chunjiang Zhao ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Resistance Genes ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACTAcinetobacter baumanniiis a globally important nosocomial pathogen characterized by an evolving multidrug resistance. A total of 35 representative clinicalA. baumanniistrains isolated from 13 hospitals in nine cities in China from 1999 to 2011, including 32 carbapenem-resistant and 3 carbapenem-susceptibleA. baumanniistrains, were selected for whole-genome sequencing and comparative genomic analysis. Phylogenetic analysis revealed that the earliest strain, strain 1999BJAB11, and two strains isolated in Zhejiang Province in 2004 were the founder strains of carbapenem-resistantA. baumannii. Ten types of AbaR resistance islands were identified, and a previously unreported AbaR island, which comprised a two-component response regulator, resistance-related proteins, and RND efflux system proteins, was identified in two strains isolated in Zhejiang in 2004. Multiple transposons or insertion sequences (ISs) existed in each strain, and these gradually tended to diversify with evolution. Some of these IS elements or transposons were the first to be reported, and most of them were mainly found in strains from two provinces. Genome feature analysis illustrated diversified resistance genes, surface polysaccharides, and a restriction-modification system, even in strains that were phylogenetically and epidemiologically very closely related. IS-mediated deletions were identified in the type VI secretion system region, thecsuEregion, and core lipooligosaccharide (LOS) loci. Recombination occurred in the heme utilization region, and intrinsic resistance genes (blaADCandblaOXA-51-likevariants) and three novelblaOXA-51-likevariants (blaOXA-424,blaOXA-425, andblaOXA-426) were identified. Our results could improve the understanding of the evolutionary processes that contribute to the emergence of carbapenem-resistantA. baumanniistrains and help elucidate the molecular evolutionary mechanism inA. baumannii.

scholarly journals Spread of Carbapenem-Resistant Acinetobacter baumannii Global Clone 2 in Asia and AbaR-Type Resistance Islands

2013 ◽  
Vol 57 (11) ◽  
pp. 5239-5246 ◽  
Author(s):  
Dae Hun Kim ◽  
Ji-Young Choi ◽  
Hae Won Kim ◽  
So Hyun Kim ◽  
Doo Ryeon Chung ◽  
...  
Keyword(s):  
Hong Kong ◽  
Acinetobacter Baumannii ◽  
Clonal Complex ◽  
Carbapenem Resistance ◽  
Surveillance Study ◽  
Structural Variations ◽  
Content Type ◽  
Resistance Determinants ◽  
Carbapenem Resistant ◽  
Resistance Island

ABSTRACTIn this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistantAcinetobacter baumannii(CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan.blaOXA-24was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistantA. baumanniiin Asia.

scholarly journals Whole-Genome Sequencing for Investigating a Health Care-Associated Outbreak of Carbapenem-Resistant Acinetobacter baumannii

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 201
Author(s):  
Sang Mee Hwang ◽  
Hee Won Cho ◽  
Tae Yeul Kim ◽  
Jeong Su Park ◽  
Jongtak Jung ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Snp Analysis ◽  
Whole Genome ◽  
Phylogenetic Tree Analysis ◽  
Web Based ◽  
Hospital Outbreak ◽  
Carbapenem Resistant ◽  
Bioinformatics Tools

Carbapenem-resistant Acinetobacter baumannii (CRAB) outbreaks in hospital settings challenge the treatment of patients and infection control. Understanding the relatedness of clinical isolates is important in distinguishing outbreak isolates from sporadic cases. This study investigated 11 CRAB isolates from a hospital outbreak by whole-genome sequencing (WGS), utilizing various bioinformatics tools for outbreak analysis. The results of multilocus sequence typing (MLST), single nucleotide polymorphism (SNP) analysis, and phylogenetic tree analysis by WGS through web-based tools were compared, and repetitive element polymerase chain reaction (rep-PCR) typing was performed. Through the WGS of 11 A. baumannii isolates, three clonal lineages were identified from the outbreak. The coexistence of blaOXA-23, blaOXA-66, blaADC-25, and armA with additional aminoglycoside-inactivating enzymes, predicted to confer multidrug resistance, was identified in all isolates. The MLST Oxford scheme identified three types (ST191, ST369, and ST451), and, through whole-genome MLST and whole-genome SNP analyses, different clones were found to exist within the MLST types. wgSNP showed the highest discriminatory power with the lowest similarities among the isolates. Using the various bioinformatics tools for WGS, CRAB outbreak analysis was applicable and identified three discrete clusters differentiating the separate epidemiologic relationships among the isolates.

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 Serum Albumin and Ca2+Are Natural Competence Inducers in the Human Pathogen Acinetobacter baumannii

2016 ◽  
Vol 60 (8) ◽  
pp. 4920-4929 ◽  
Author(s):  
German Matias Traglia ◽  
Brettni Quinn ◽  
Sareda T. J. Schramm ◽  
Alfonso Soler-Bistue ◽  
Maria Soledad Ramirez
Keyword(s):  
Acinetobacter Baumannii ◽  
Natural Transformation ◽  
Hospital Environment ◽  
Human Pathogen ◽  
Nosocomial Pathogen ◽  
Natural Competence ◽  
Exogenous Dna ◽  
Content Type ◽  
Resistance Determinants ◽  
Main Protein

ABSTRACTThe increasing frequency of bacteria showing antimicrobial resistance (AMR) raises the menace of entering into a postantibiotic era. Horizontal gene transfer (HGT) is one of the prime reasons for AMR acquisition.Acinetobacter baumanniiis a nosocomial pathogen with outstanding abilities to survive in the hospital environment and to acquire resistance determinants. Its capacity to incorporate exogenous DNA is a major source of AMR genes; however, few studies have addressed this subject. The transformation machinery as well as the factors that induce natural competence inA. baumanniiare unknown. In this study, we demonstrate that naturally competent strain A118 increases its natural transformation frequency upon the addition of Ca2+or albumin. We show thatcomEAandpilQare involved in this process since their expression levels are increased upon the addition of these compounds. An unspecific protein, like casein, does not reproduce this effect, showing that albumin's effect is specific. Our work describes the first specific inducers of natural competence inA. baumannii. Overall, our results suggest that the main protein in blood enhances HGT inA. baumannii, contributing to the increase of AMR in this threatening human pathogen.

scholarly journals Semimechanistic Pharmacokinetic/Pharmacodynamic Modeling of Fosfomycin and Sulbactam Combination against Carbapenem-Resistant Acinetobacter baumannii

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Sazlyna Mohd Sazlly Lim ◽  
Aaron J. Heffernan ◽  
Jason A. Roberts ◽  
Fekade B. Sime
Keyword(s):  
Acinetobacter Baumannii ◽  
Treatment Options ◽  
Pharmacodynamic Modeling ◽  
Synergistic Activity ◽  
Bacterial Burden ◽  
Target Attainment ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Time Kill

ABSTRACT Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are now considered potential treatments for CR-AB. This study aimed to explore the utility of fosfomycin-sulbactam combination (FOS/SUL) therapy against CR-AB isolates. Synergism of FOS/SUL against 50 clinical CR-AB isolates was screened using the checkerboard method. Thereafter, time-kill studies against two CR-AB isolates were performed. The time-kill data were described using a semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Monte Carlo simulations were then performed to estimate the probability of stasis, 1-log kill, and 2-log kill after 24 h of combination therapy. The FOS/SUL combination demonstrated a synergistic effect against 74% of isolates. No antagonism was observed. The MIC50 and MIC90 of FOS/SUL were decreased 4- to 8-fold, compared to the monotherapy MIC50 and MIC90. In the time-kill studies, the combination displayed bactericidal activity against both isolates and synergistic activity against one isolate at the highest clinically achievable concentrations. Our PK/PD model was able to describe the interaction between fosfomycin and sulbactam in vitro. Bacterial kill was mainly driven by sulbactam, with fosfomycin augmentation. FOS/SUL regimens that included sulbactam at 4 g every 8 h demonstrated a probability of target attainment of 1-log10 kill at 24 h of ∼69 to 76%, compared to ∼15 to 30% with monotherapy regimens at the highest doses. The reduction in the MIC values and the achievement of a moderate PTA of a 2-log10 reduction in bacterial burden demonstrated that FOS/SUL may potentially be effective against some CR-AB infections.

scholarly journals Combating Carbapenem-ResistantAcinetobacter baumanniiby an Optimized Imipenem-plus-Tobramycin Dosage Regimen: Prospective Validation via Hollow-Fiber Infection and Mathematical Modeling

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Cornelia B. Landersdorfer ◽  
Rajbharan Yadav ◽  
Kate E. Rogers ◽  
Tae Hwan Kim ◽  
Beom Soo Shin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Acinetobacter Baumannii ◽  
Hollow Fiber ◽  
Dosage Regimen ◽  
Infection Model ◽  
Bacterial Killing ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACTWe aimed to prospectively validate an optimized combination dosage regimen against a clinical carbapenem-resistantAcinetobacter baumannii(CRAB) isolate (imipenem MIC, 32 mg/liter; tobramycin MIC, 2 mg/liter). Imipenem at constant concentrations (7.6, 13.4, and 23.3 mg/liter, reflecting a range of clearances) was simulated in a 7-day hollow-fiber infection model (inoculum, ∼107.2CFU/ml) with and without tobramycin (7 mg/kg q24h, 0.5-h infusions). While monotherapies achieved no killing or failed by 24 h, this rationally optimized combination achieved >5 log10bacterial killing and suppressed resistance.

scholarly journals Draft Genome Sequences of Two Acinetobacter baumannii Isolates from a Fatal Case of Necrotizing Fasciitis

2020 ◽  
Vol 9 (13) ◽  
Author(s):  
Brock A. Arivett ◽  
Angella Charnot-Katsikas ◽  
Cindy Bethel ◽  
Steven E. Fiester ◽  
Luis A. Actis
Keyword(s):  
Necrotizing Fasciitis ◽  
Acinetobacter Baumannii ◽  
Fatal Case ◽  
Draft Genome ◽  
Bacterial Pathogen ◽  
Genome Sequences ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Control And Prevention ◽  
Total Dna

Carbapenem-resistant Acinetobacter baumannii is a bacterial pathogen with serious implications for human health and is recognized as an urgent threat by the Centers for Disease Control and Prevention (CDC). Total DNA from two A. baumannii clinical isolates collected over 3 days from a fatal case of necrotizing fasciitis has been sequenced to >30× coverage.

scholarly journals Accumulation of Antibiotic Resistance Genes in Carbapenem-Resistant Acinetobacter baumannii Isolates Belonging to Lineage 2, Global Clone 1, from Outbreaks in 2012–2013 at a Tehran Burns Hospital

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Masoumeh Douraghi ◽  
Johanna J. Kenyon ◽  
Parisa Aris ◽  
Mahla Asadian ◽  
Sedighe Ghourchian ◽  
...  
Keyword(s):  
Middle East ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Carbapenem Resistance ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
East Region ◽  
Lineage 2 ◽  
Middle East Region

ABSTRACT The worldwide distribution of carbapenem-resistant Acinetobacter baumannii (CRAB) has become a global concern, particularly in countries where antibiotic prescription is not tightly regulated. However, knowledge of the genomic aspects of CRAB from many parts of the world is still limited. Here, 50 carbapenem-resistant A. baumannii isolates recovered at a single hospital in Tehran, Iran, during several outbreaks in 2012 and 2013 were found to be resistant to multiple antibiotics. They were examined using PCR mapping and multilocus sequence typing (MLST). All Iranian strains belonged to sequence type 328 in the Institut Pasteur MLST scheme (ST328IP), a single-locus variant of ST81IP, and all Iranian strains contained two carbapenem resistance genes, oxa23 and oxa24. The oxa23 gene is in the transposon Tn2006 in AbaR4, which interrupts the chromosomal comM gene. Phylogenetic analysis using whole-genome sequence (WGS) data for 9 isolates showed that they belonged to the same clade, designated the ST81/ST328 clade, within lineage 2 of global clone 1 (GC1). However, there were two groups that included either KL13 or KL18 at the K locus (KL) for capsular polysaccharide synthesis and either a tet39 or an aadB resistance gene, respectively. The genetic context of the resistance genes was determined, and the oxa24 (OXA-72 variant) and tet39 (tetracycline resistance) genes were each in a pdif module in different plasmids. The aadB gene cassette (which encodes gentamicin, kanamycin, and tobramycin resistance) was harbored by pRAY*, and the aphA6 gene (which encodes amikacin resistance) and sul2 gene (which encodes sulfamethoxazole resistance) were each harbored by a different plasmid. The sequences obtained here will underpin future studies of GC1 CRAB strains from the Middle East region. IMPORTANCE Carbapenem-resistant Acinetobacter baumannii strains are among the most critical antibiotic-resistant bacteria causing hospital-acquired infections and treatment failures. The global spread of two clones has been responsible for the bulk of the resistance, in particular, carbapenem resistance. However, there is a substantial gap in our knowledge of which clones and which specific lineages within each clone are circulating in many parts of the world, including Africa and the Middle East region. This is the first genomic analysis of carbapenem-resistant A. baumannii strains from Iran. All the isolates, from a single hospital, belonged to lineage 2 of global clone 1 (GC1) but fell into two groups distinguished by genes in the locus for capsule biosynthesis. The analysis suggests a potential origin of multiply antibiotic-resistant lineage 2 in the Middle East region and highlights the ongoing evolution of carbapenem-resistant GC1 A. baumannii strains. It will enhance future studies on the local and global GC1 population structure.

scholarly journals Draft Genome Sequence of a blaNDM-1- and blaPME-1-Harboring Pseudomonas aeruginosa Clinical Isolate from Pakistan

2019 ◽  
Vol 8 (17) ◽  
Author(s):  
Sidra Irum ◽  
Robert F. Potter ◽  
Rubina Kamran ◽  
Zeeshan Mustafa ◽  
Meghan A. Wallace ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Genome Sequencing ◽  
Draft Genome ◽  
Whole Genome ◽  
Beta Lactamase ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
Carbapenem Resistant ◽  
Airway Colonization

We performed Illumina whole-genome sequencing on a carbapenem-resistant Pseudomonas aeruginosa strain isolated from a cystic fibrosis patient with chronic airway colonization. The draft genome comprises 6,770,411 bp, including the carbapenemase bla NDM-1 and the extended-spectrum beta-lactamase bla PME-1.

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