A Plasmid-Borne blaOXA-58 Gene Confers Imipenem Resistance to Acinetobacter baumannii Isolates from a Lebanese Hospital

ABSTRACT We investigated the basis of the carbapenem resistance of 17 multidrug-resistant Acinetobacter baumannii clinical isolates collected from 2004 to 2005 at the Saint George University Hospital in Beirut, Lebanon. A. baumannii isolates were clonally related and were susceptible to colistin and trimethoprim-sulfamethoxazole, susceptible or intermediate to ampicillin-sulbactam and meropenem, and resistant to all other antimicrobials. Conjugation experiments demonstrated that resistance to imipenem could be transferred along with a plasmid containing the carbapenem-hydrolyzing oxacillinase bla OXA-58 gene. The plasmid that we called pABIR was 29,823 bp in size and showed a novel mosaic structure composed of two origins of replication, four insertion sequence (IS) elements, and 28 open reading frames. The bla OXA-58 gene was flanked by IS18 and ISAba3 elements at the 5′ and 3′ ends, respectively. The production of the carbapenem-hydrolyzing oxacillinase OXA-58 was apparently the only mechanism for carbapenem resistance in A. baumannii isolates causing the outbreak at the Lebanese Hospital.

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Carbapenemase Production of Clinical Isolates Acinetobacter baumannii and Pseudomonas aeruginosa from a Bulgarian University Hospital

Folia Medica ◽

10.1515/folmed-2017-0060 ◽

2017 ◽

Vol 59 (4) ◽

pp. 413-422 ◽

Cited By ~ 1

Author(s):

Atanaska P. Petrova ◽

Irina D. Stanimirova ◽

Ivan N. Ivanov ◽

Michael M. Petrov ◽

Tsonka M. Miteva-Katrandzhieva ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Acinetobacter Baumannii ◽

Insertion Sequence ◽

Susceptibility Testing ◽

Transmembrane Protein ◽

Carbapenem Resistance ◽

University Hospital ◽

Gram Negative ◽

Main Factors ◽

Hospital Wards

AbstractBackground: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes’ production has a secondary role. Aim: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A. baumannii and P. aeruginosa. Materials and methods: Forty three A. baumannii and 43 P. aeruginosa isolates, resistant or with intermediate resistance to imipenem and/or meropenem were included in the study. They were collected from patients admitted in 14 various hospital wards between 2010 and 2014. Both phenotypic and genetic methods were used for identifi cation and antimicrobial susceptibility testing. Results: All A. baumannii demonstrated carbapenemase production determined by a modifi ed Hodge test whereas P. aeruginosa isolates did not show this phenomenon. OXA-23 genes were determined in 97.7% (42 out of 43) of A. baumannii isolates indistinguishable from the sequence of the classical ARI-1 gene. OXA-24, OXA-58 and overexpression of OXA-51 were not registered in any of the isolates. All P. aeruginosa were negative for blaVIM and blaIMP genes. Conclusion: The leading cause of carbapenem resistance in A. baumannii isolates from our hospital is the carbapenemase production due to the expression of OXA- 23 gene, whereas in P. aeruginosa - the loss of transmembrane OprD protein and the effl ux pumps’ hyperexpression are suspected to be the main mechanisms.

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Characterization of a Novel Phage ΦAb1656-2 and Its Endolysin with Higher Antimicrobial Activity against Multidrug-Resistant Acinetobacter baumannii

Viruses ◽

10.3390/v13091848 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1848

Author(s):

Kyeongmin Kim ◽

Md Maidul Islam ◽

Dooyoung Kim ◽

Sung Ho Yun ◽

Jungmin Kim ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Therapeutic Agent ◽

Catalytic Domain ◽

Hydrolytic Enzymes ◽

Multidrug Resistant ◽

Open Reading Frames ◽

Nosocomial Pathogen ◽

Prophage Induction ◽

Reading Frames

Acinetobacter baumannii is a nosocomial pathogen, which is a problem worldwide due to the emergence of a difficult-to-treat multidrug-resistant A. baumannii (MDRAB). Endolysins are hydrolytic enzymes produced by a bacteriophage that can be used as a potential therapeutic agent for multidrug-resistant bacterial infection in replacing antibiotics. Here, we isolated a novel bacteriophage through prophage induction using mitomycin C from clinical A. baumannii 1656-2. Morphologically, ΦAb1656-2 was identified as a Siphoviridae family bacteriophage, which can infect MDRAB. The whole genome of ΦAb1656-2 was sequenced, and it showed that it is 50.9 kb with a G + C content of 38.6% and 68 putative open reading frames (ORFs). A novel endolysin named AbEndolysin with an N-acetylmuramidase-containing catalytic domain was identified, expressed, and purified from ΦAb1656-2. Recombinant AbEndolysin showed significant antibacterial activity against MDRAB clinical strains without any outer membrane permeabilizer. These results suggest that AbEndolysin could represent a potential antimicrobial agent for treating MDRAB clinical isolates.

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Antibiotic resistance pattern of Acinetobacter baumannii from burns patients: increase in prevalence of blaOXA-24-like and blaOXA-58-like genes

Iranian Journal of Microbiology ◽

10.18502/ijm.v11i6.2222 ◽

2020 ◽

Cited By ~ 1

Author(s):

Niloofar Tafreshi ◽

Laleh Babaeekhou ◽

Maryam Ghane

Keyword(s):

Acinetobacter Baumannii ◽

Insertion Sequence ◽

Treatment Options ◽

Carbapenem Resistance ◽

Multidrug Resistant ◽

Resistance Pattern ◽

Drug Resistant ◽

Burn Wound ◽

Beta Lactamases ◽

First Time

Background and Objectives: Notwithstanding the increased prevalence of Acinetobacter baumannii drug-resistant isolates, treatment options are progressively limiting. This study aims to provide a recent report on antibiotic susceptibility in burn wound isolates of A. baumannii, and the importance of OXA beta-lactamases in carbapenem resistance. Materials and Methods: The susceptibility levels to different antimicrobial categories were determined among 84 A. baumannii isolates from burn wound infection between 2016 and 2018. Multiplex PCR was used to detect OXA beta-lactamases genes, including blaOXA-51, blaOXA-23, blaOXA-24 and blaOXA-58. ISAba-1 association with blaOXA-51, blaOXA-23 and blaOXA-58 was detected by PCR mapping. Results: All the isolates were determined as multidrug-resistant (MDR) and 69% as extensively drug-resistant (XDR). Different carbapenems MIC ranges (MIC50 and MIC90) were observed among the isolates harboring blaOXA-like genes and isolates with the OXA-24-like enzyme showed higher carbapenems MIC ranges. The prevalence of blaOXA-51-like, blaOXA-23-like, blaOXA-24-like and blaOXA-58-like were 100%, 53.57%, 41.66% and 30.95%, respectively. ISAba-1 insertion sequence was found to be upstream to blaOXA-23-like and blaOXA-58-like genes in 23 out of 45 (71.1%) blaOXA-23-like-positive and 4 out of 23 (15.3) blaOXA-58-like-positive isolates, respectively. Conclusion: Resistance to carbapenems as the last resort for treatment of A. baumannii infections is growing. This study, for the first time in Iran, has observed the increased frequency of blaOXA-24-like and blaOXA-58-like genes and found an association between ISAba-1 and blaOXA-58-like gene, which signifies the possible risk of increased diversity in OXA beta-lactamases and growth in carbapenem resistance

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Acquisition of a Plasmid-Borne blaOXA-58 Gene with an Upstream IS1008 Insertion Conferring a High Level of Carbapenem Resistance to Acinetobacter baumannii

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00393-08 ◽

2008 ◽

Vol 52 (7) ◽

pp. 2573-2580 ◽

Cited By ~ 53

Author(s):

Te-Li Chen ◽

Roy Chen-Chih Wu ◽

Men-Fang Shaio ◽

Chang-Phone Fung ◽

Wen-Long Cho

Keyword(s):

Acinetobacter Baumannii ◽

Clinical Isolate ◽

Shuttle Vector ◽

Carbapenem Resistance ◽

Open Reading Frames ◽

Transcription Control ◽

Genetic Construct ◽

Fold Reduction ◽

High Level ◽

Reading Frames

ABSTRACT The oxacillinase gene was reported to confer limited resistance to carbapenem in Acinetobacter baumannii. In this study, we have demonstrated that an A. baumannii clinical isolate harboring a plasmid, pTVICU53, has 11,037 bp encoding 13 open reading frames. A bla OXA-58 gene with an upstream insertion of truncated ISAba3 (ΔISAba3) and IS1008 was found in this plasmid. ΔISAba3and IS1008 provided two independent promoters for the transcription control of the bla OXA-58 gene. The transformation of pTVICU53 or a shuttle vector bearing IS1008-ΔISAba3-bla OXA-58 to different A. baumannii recipients can increase their MICs of carbapenem 64- to 256-fold. The deletion of promoters provided by IS1008 resulted in dramatic decreases in bla OXA-58 transcription and a 32- to 64-fold reduction in the carbapenem MIC. These findings highlight that A. baumannii might develop carbapenem resistance with a single transformation step, taking up a plasmid containing a genetic construct with a potentially high level of transcription of the bla OXA-58 gene.

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Molecular Epidemiology and Clone Transmission of Carbapenem-Resistant Acinetobacter baumannii in ICU Rooms

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.633817 ◽

2021 ◽

Vol 11 ◽

Author(s):

Xiufeng Zhang ◽

Fangping Li ◽

Furqan Awan ◽

Hongye Jiang ◽

Zhenling Zeng ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Insertion Sequence ◽

Core Genome ◽

Carbapenem Resistance ◽

Multidrug Resistant ◽

Chi Square ◽

The Core ◽

Carbapenem Resistant ◽

Significant Difference ◽

Chi Square Test

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major cause of nosocomial infections and hospital outbreaks worldwide, remaining a critical clinical concern. Here we characterized and investigated the phylogenetic relationships of 105 CRAB isolates from an intensive care unit from one hospital in China collected over six years. All strains carried blaOXA-23, blaOXA-66 genes for carbapenem resistance, also had high resistance gene, virulence factor, and insertion sequence burdens. Whole-genome sequencing revealed all strains belonged to ST2, the global clone CC2. The phylogenetic analysis based on the core genome showed all isolates were dominated by a single lineage of three clusters and eight different clones. Two clones were popular during the collection time. Using chi-square test to identify the epidemiologically meaningful groupings, we found the significant difference in community structure only existed in strains from separation time. The haplotype and median-joining network analysis revealed genetic differences appeared among clusters and changes occurred overtime in the dominating cluster. Our results highlighted substantial multidrug-resistant CRAB burden in the hospital ICU environment demonstrating potential clone outbreak in the hospital.

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Bias between the Left and Right Inverted Repeats during IS911 Targeted Insertion

Journal of Bacteriology ◽

10.1128/jb.00452-08 ◽

2008 ◽

Vol 190 (18) ◽

pp. 6111-6118 ◽

Cited By ~ 5

Author(s):

P. Rousseau ◽

C. Loot ◽

C. Turlan ◽

S. Nolivos ◽

M. Chandler

Keyword(s):

Insertion Sequence ◽

Regulatory Protein ◽

Open Reading Frames ◽

Inverted Repeats ◽

Functional Differences ◽

Left And Right ◽

Ordered Assembly ◽

Overlapping Open Reading Frames ◽

Reading Frames

ABSTRACT IS911 is a bacterial insertion sequence composed of two consecutive overlapping open reading frames (ORFs [orfA and orfB]) encoding the transposase (OrfAB) as well as a regulatory protein (OrfA). These ORFs are bordered by terminal left and right inverted repeats (IRL and IRR, respectively) with several differences in nucleotide sequence. IS911 transposition is asymmetric: each end is cleaved on one strand to generate a free 3′-OH, which is then used as the nucleophile in attacking the opposite insertion sequence (IS) end to generate a free IS circle. This will be inserted into a new target site. We show here that the ends exhibit functional differences which, in vivo, may favor the use of one compared to the other during transposition. Electromobility shift assays showed that a truncated form of the transposase [OrfAB(1-149)] exhibits higher affinity for IRR than for IRL. While there was no detectable difference in IR activities during the early steps of transposition, IRR was more efficient during the final insertion steps. We show here that the differential activities between the two IRs correlate with the different affinities of OrfAB(1-149) for the IRs during assembly of the nucleoprotein complexes leading to transposition. We conclude that the two inverted repeats are not equivalent during IS911 transposition and that this asymmetry may intervene to determine the ordered assembly of the different protein-DNA complexes involved in the reaction.

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Prevalence of multidrug-resistant Acinetobacter baumannii in a critical care setting: A tertiary teaching hospital experience

SAGE Open Medicine ◽

10.1177/20503121211001144 ◽

2021 ◽

Vol 9 ◽

pp. 205031212110011

Author(s):

Thabit Alotaibi ◽

Abdulrhman Abuhaimed ◽

Mohammed Alshahrani ◽

Ahmed Albdelhady ◽

Yousef Almubarak ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Mortality Rate ◽

Acinetobacter Baumannii ◽

Care Setting ◽

Multidrug Resistant ◽

University Hospital ◽

Published Data ◽

Tertiary Teaching ◽

The Mean

Background: The management of Acinetobacter baumannii infection is considered a challenge especially in an intensive care setting. The resistance rate makes it difficult to manage and is believed to lead to higher mortality. We aim to investigate the prevalence of Acinetobacter baumannii and explore how different antibiotic regimens could impact patient outcomes as there are no available published data to reflect our population in our region. Methods: We conducted a retrospective review of all infected adult patients admitted to the intensive care unit at King Fahad University Hospital with a confirmed laboratory diagnosis of Acinetobacter baumannii from 1 January 2013 until 31 December 2017. Positive cultures were obtained from the microbiology department and those meeting the inclusive criteria were selected. Variables were analyzed using descriptive analysis and cross-tabulation. Results were further reviewed and audited by blinded co-authors. Results: A comprehensive review of data identified 198 patients with Acinetobacter baumannii. The prevalence of Acinetobacter baumannii is 3.37%, and the overall mortality rate is 40.81%. Our sample consisted mainly of male patients, that is, 68.7%, with a mean age of 49 years, and the mean age of female patients was 56 years. The mean age of survivors was less than that of non-survivors, that is, 44.95 years of age. We observed that prior antibiotic use was higher in non-survivors compared to survivors. From the review of treatment provided for patients infected with Acinetobacter baumannii, 65 were treated with colistin alone, 18 were treated with carbapenems, and 22 were treated with a combination of both carbapenems and colistin. The mean length of stay of Acinetobacter baumannii–infected patients was 20.25 days. We found that the survival rates among patients who received carbapenems were higher compared to those who received colistin. Conclusion: We believe that multidrug-resistant Acinetobacter baumannii is prevalent and associated with a higher mortality rate and represents a challenging case for every intensive care unit physician. Further prospective studies are needed.

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Nucleotide Sequence and Genetic Structure of a Novel Carbaryl Hydrolase Gene (cehA) from Rhizobium sp. Strain AC100

Applied and Environmental Microbiology ◽

10.1128/aem.68.3.1220-1227.2002 ◽

2002 ◽

Vol 68 (3) ◽

pp. 1220-1227 ◽

Cited By ~ 50

Author(s):

Masayuki Hashimoto ◽

Mitsuru Fukui ◽

Kouichi Hayano ◽

Masahito Hayatsu

Keyword(s):

Nucleotide Sequence ◽

Insertion Sequence ◽

Amino Acid Sequences ◽

Open Reading Frames ◽

Homology Search ◽

Sequencing Analysis ◽

Terminal Sequence ◽

Homologous Sequences ◽

Naphthyl Acetate ◽

Reading Frames

ABSTRACT Rhizobium sp. strain AC100, which is capable of degrading carbaryl (1-naphthyl-N-methylcarbamate), was isolated from soil treated with carbaryl. This bacterium hydrolyzed carbaryl to 1-naphthol and methylamine. Carbaryl hydrolase from the strain was purified to homogeneity, and its N-terminal sequence, molecular mass (82 kDa), and enzymatic properties were determined. The purified enzyme hydrolyzed 1-naphthyl acetate and 4-nitrophenyl acetate indicating that the enzyme is an esterase. We then cloned the carbaryl hydrolase gene (cehA) from the plasmid DNA of the strain and determined the nucleotide sequence of the 10-kb region containing cehA. No homologous sequences were found by a database homology search using the nucleotide and deduced amino acid sequences of the cehA gene. Six open reading frames including the cehA gene were found in the 10-kb region, and sequencing analysis shows that the cehA gene is flanked by two copies of insertion sequence-like sequence, suggesting that it makes part of a composite transposon.

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Characterization of the Enterobacter Phage vB_EclM_CIP9

Microbiology Resource Announcements ◽

10.1128/mra.01600-19 ◽

2020 ◽

Vol 9 (13) ◽

Author(s):

Klara Wang ◽

Marielou G. Tamayo ◽

Tiffany V. Penner ◽

Bradley W. M. Cook ◽

Deborah A. Court ◽

...

Keyword(s):

Enterobacter Cloacae ◽

Opportunistic Pathogen ◽

Multidrug Resistant ◽

Open Reading Frames ◽

Resistant Isolate ◽

Content Type ◽

Hospital Acquired Infections ◽

Hospital Acquired ◽

Reading Frames

Enterobacter cloacae is an opportunistic pathogen that causes hospital-acquired infections in immunocompromised patients. Here, we describe vB_EclM_CIP9, a novel Enterobacter phage that infects a multidrug-resistant isolate of E. cloacae. Phage vB_EclM_CIP9 is a myovirus that has a 174,924-bp genome, with 296 predicted open reading frames.

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Characterization of the IS200/IS605 Insertion Sequence Family in Halanaerobium Hydrogeniformans

Genes ◽

10.3390/genes11050484 ◽

2020 ◽

Vol 11 (5) ◽

pp. 484

Author(s):

Michael Sadler ◽

Melanie R. Mormile ◽

Ronald L. Frank

Keyword(s):

Insertion Sequence ◽

Open Reading Frames ◽

Insertion Sequences ◽

Genome Plasticity ◽

Mobile Dna ◽

Dna Elements ◽

Left And Right ◽

Evolutionary Role ◽

Reading Frames

Mobile DNA elements play a significant evolutionary role by promoting genome plasticity. Insertion sequences are the smallest prokaryotic transposable elements. They are highly diverse elements, and the ability to accurately identify, annotate, and infer the full genomic impact of insertion sequences is lacking. Halanaerobium hydrogeniformans is a haloalkaliphilic bacterium with an abnormally high number of insertion sequences. One family, IS200/IS605, showed several interesting features distinct from other elements in this genome. Twenty-three loci harbor elements of this family in varying stages of decay, from nearly intact to an ends-only sequence. The loci were characterized with respect to two divergent open reading frames (ORF), tnpA and tnpB, and left and right ends of the elements. The tnpB ORF contains two nearly identical insert sequences that suggest recombination between tnpB ORF is occurring. From these results, insertion sequence activity can be inferred, including transposition capability and element interaction.

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