Faculty Opinions recommendation of Functional analysis of insertion sequence ISAba1, responsible for genomic plasticity of Acinetobacter baumannii.

2009 ◽  
Author(s):  
Mark D Adams
Keyword(s):  
Functional Analysis ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Genomic Plasticity

scholarly journals Functional Analysis of Insertion Sequence ISAba1, Responsible for Genomic Plasticity of Acinetobacter baumannii

2009 ◽  
Vol 191 (7) ◽  
pp. 2414-2418 ◽  
Author(s):  
Pauline D. Mugnier ◽  
Laurent Poirel ◽  
Patrice Nordmann
Keyword(s):  
Functional Analysis ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Target Site ◽  
Genomic Plasticity ◽  
Translational Frameshifting ◽  
Encoding Gene

ABSTRACT ISAba1 is an insertion sequence that is widely distributed in Acinetobacter baumannii. We demonstrated here that ISAba1 and the composite transposon Tn2006 are capable of transposition, generating 9-bp target site duplications. The expression of the ISAba1 transposase-encoding gene was downregulated by translational frameshifting.

scholarly journals ISAba825, a Functional Insertion Sequence Modulating Genomic Plasticity andblaOXA-58Expression inAcinetobacter baumannii

2010 ◽  
Vol 55 (2) ◽  
pp. 917-920 ◽  
Author(s):  
Pablo Ravasi ◽  
Adriana S. Limansky ◽  
Ramiro E. Rodriguez ◽  
Alejandro M. Viale ◽  
María A. Mussi
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Carbapenem Resistance ◽  
Genomic Plasticity ◽  
Hybrid Promoter ◽  
Resistance Modulation ◽  
Target Sequences

ABSTRACTISAba825, an insertion sequence found inactivatingAcinetobacter baumannii carO, was tagged with a kanamycin (Kn) resistance cassette. ISAba825::Kn effectively transposed inA. baumannii, showing preference for short, AT-enriched target sequences, generating 6- to 9-bp target duplications. Additionally, we detected the presence of ISAba825 upstream of a plasmid-borneblaOXA-58gene, generating a hybrid promoter largely enhancing its expression and leading to carbapenem resistance. Overall, a role for ISAba825 in carbapenem resistance modulation inA. baumanniiis proposed.

scholarly journals Clonal diversity of Acinetobacter baumannii from diabetic patients in Saudi Arabian hospitals

2014 ◽  
Vol 63 (11) ◽  
pp. 1460-1466 ◽  
Author(s):  
Abdulrahman A. Alsultan ◽  
Elsayed Aboulmagd ◽  
Benjamin A. Evans ◽  
Sebastian G. B. Amyes
Keyword(s):  
Health Care ◽  
Saudi Arabia ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Clonal Diversity ◽  
Diabetic Patients ◽  
Major Health ◽  
Intensive Care Patients ◽  
Carbapenem Resistant ◽  
Vitek 2

Carbapenem-resistant Acinetobacter baumannii (CR-AB) represents a major health-care problem, causing high rates of morbidity and mortality. This study investigated the clonality of CR-AB isolated from diabetic patients from different regions in Saudi Arabia, as well as the relatedness of the β-lactamase genes. A total of 64 non-repetitive CR-AB clinical isolates were collected from 16 different regions in Saudi Arabia from intensive care patients. Isolates were identified phenotypically by the Vitek 2 compact system and genotypically by amplification of the bla OXA-51-like gene. The target sequences were amplified by PCR and the clonal diversity of the isolates was explored by PFGE. Resistance studies revealed that the prevalence of imipenem and meropenem resistance was 92 % and 96 %, respectively, while the vast majority of the isolates were susceptible to tigecycline and colistin. In addition, bla VIM and bla OXA-23 were the most prevalent genes in the isolates under investigation, while ISAba1 was the most dominant insertion sequence. PFGE results showed 13 clusters; clone H was dominant, comprising 20 isolates from four hospitals, followed by clones C and F, comprising 11 isolates each from three and six hospitals, respectively. Moreover, the current study signified the clonal diversity of CR-AB in Saudi Arabia and showed the ability of some clones to infect patients in many different cities.

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

Folia Medica ◽  
2017 ◽  
Vol 59 (4) ◽  
pp. 413-422 ◽  
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.

scholarly journals Functional Analysis of the Acinetobacter baumannii XerC and XerD Site-Specific Recombinases: Potential Role in Dissemination of Resistance Genes

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 405
Author(s):  
David L. Lin ◽  
German M. Traglia ◽  
Rachel Baker ◽  
David J. Sherratt ◽  
Maria Soledad Ramirez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Functional Analysis ◽  
Acinetobacter Baumannii ◽  
Potential Role ◽  
Covalent Attachment ◽  
Recombination Reaction ◽  
Site Specific ◽  
Site Specific Recombination ◽  
E Coli ◽  
Resistant Genes

Modules composed of a resistance gene flanked by Xer site-specific recombination sites, the vast majority of which were found in Acinetobacter baumannii, are thought to behave as elements that facilitate horizontal dissemination. The A. baumannii xerC and xerD genes were cloned, and the recombinant clones used to complement the cognate Escherichia coli mutants. The complemented strains supported the resolution of plasmid dimers, and, as is the case with E. coli and Klebsiella pneumoniae plasmids, the activity was enhanced when the cells were grown in a low osmolarity growth medium. Binding experiments showed that the partially purified A. baumannii XerC and XerD proteins (XerCAb and XerDAb) bound synthetic Xer site-specific recombination sites, some of them with a nucleotide sequence deduced from existing A. baumannii plasmids. Incubation with suicide substrates resulted in the covalent attachment of DNA to a recombinase, probably XerCAb, indicating that the first step in the recombination reaction took place. The results described show that XerCAb and XerDAb are functional proteins and support the hypothesis that they participate in horizontal dissemination of resistant genes among bacteria.

scholarly journals Erratum for Oliveira et al., “Functional Analysis and Antivirulence Properties of a New Depolymerase from a Myovirus That Infects Acinetobacter baumannii Capsule K45”

2020 ◽  
Vol 94 (9) ◽  
Author(s):  
Hugo Oliveira ◽  
Ana Rita Costa ◽  
Alice Ferreira ◽  
Nico Konstantinides ◽  
Sílvio B. Santos ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Acinetobacter Baumannii

scholarly journals Scarless excision of an insertion sequence restores capsule production and virulence in Acinetobacter baumannii

2021 ◽  
Author(s):  
Clémence Whiteway ◽  
Adam Valcek ◽  
Chantal Philippe ◽  
Mojca Strazisar ◽  
Tim De Pooter ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Stress Conditions ◽  
Capsule Production ◽  
Genome Dynamics

AbstractWe identify a new mechanism mediating capsule production and virulence in the WHO and CDC priority ESKAPE pathogen Acinetobacter baumannii. Non-capsulated and avirulent bacteria can revert into a capsulated and virulent state upon scarless excision of an ISAba13 insertion sequence under stress conditions. Reversion events fully restore capsule production and in vivo virulence. This increases our knowledge about A. baumannii genome dynamics, and the regulation of capsule production, virulence and resistance.

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