Insights into the global molecular epidemiology of carbapenem non-susceptible clones of Acinetobacter baumannii

Karah, Nabil; Sundsfjord, Arnfinn; Towner, K. J.; Samuelsen, Ørjan

doi:10.1016/j.drup.2012.06.001

Cited by 235 publications

(269 citation statements)

References 91 publications

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“…Additionally, the occurrence of bla SIM-1 was detected in class 1 integrons among seven clinical isolates of A. baumannii from Korea [83]. While the genetic determinants of IMP, VIM and SIM-type enzymes were found on class 1 integrons of A. baumannii, bla NDM have not been found till date [84].…”

Section: Integronsmentioning

confidence: 99%

Acinetobacter baumannii: biology and drug resistance — role of carbapenemases

Nowak

Paluchowska

2015

Folia Histochem Cytobiol.

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Acinetobacter baumannii is a Gram-negative, glucose-non-fermenting, oxidase-negative coccobacillus, most commonly associated with the hospital settings. The ability to survive in adverse environmental conditions as well as high level of natural and acquired antimicrobial resistance make A. baumannii one of the most important nosocomial pathogens. While carbapenems have long been considered as antimicrobials of last-resort, the rates of clinical A. baumannii strains resistant to these antibiotics are increasing worldwide. Carbapenem resistance among A. baumannii is conferred by coexisting mechanisms including: decrease in permeability of the outer membrane, efflux pumps, production of beta-lactamases, and modification of penicillin-binding proteins. The most prevalent mechanism of carbapenem resistance among A. baumannii is associated with carbapenem-hydrolysing enzymes that belong to Ambler class D and B beta-lactamases. In addition, there have also been reports of resistance mediated by selected Ambler class A carbapenemases among A. baumannii strains. Resistance determinants in A. baumannii are located on chromosome and plasmids, while acquisition of new mechanisms can be mediated by insertion sequences, integrons, transposons, and plasmids. Clinical relevance of carbapenem resistance among strains isolated from infected patients, carriers and hospital environment underlines the need for carbapenemase screening. Currently available methods vary in principle, accuracy and efficiency. The techniques that deserve particular attention belong to both easily accessible unsophisticated methods as well as advanced techniques based on mass spectrometry or molecular biology. While carbapenemases limit the therapeutic options in A. baumannii infections, studies concerning novel beta-lactamase inhibitors offer a new insight into effective therapy.

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Section: Integronsmentioning

confidence: 99%

Acinetobacter baumannii: biology and drug resistance — role of carbapenemases

Nowak

Paluchowska

2015

Folia Histochem Cytobiol.

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“…During the last two decades A. baumannii became clinically important pathogen due to its capability for outbreaks and resistance to most antibiotics including carbapenems [1]. The outbreak of A. baumannii associated with United States military operations in Iraq generated special interest in this organism [2].…”

Section: Introductionmentioning

confidence: 99%

Identification of Imipenem-Resistant Genes in Acinetobacter baumannii Isolated from Baghdad Hospitals

Hussein¹,

Al-Mathkhury²

2014

J Med Microb Diagn

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Imipenem-resistant Acinetobacter baumannii (IRAB) represents one of the important causing agents of nosocomial infections especially in immunocompromised and Intensive Care Units (ICUs) patients. The aim of this work was to identify the Imipenem-Resistant genes in Acinetobacter baumannii isolated from Baghdad hospitals. Among 128 A. baumannii isolates, 67 isolates (58.26%) were resistant to imipenem and meropenem. Four genes for imipenem resistance (blaOXA-23 like, blaOXA-24 like, blaOXA-51like and blaOXA-58 like) were amplified and sequenced. The presence of blaOXA-23-like genes in 91.03% of IRAB isolates indicated that the blaOXA-23-like genes are the predominant mechanism for imipenem resistance in our isolates. Sequencing of PCR products showed the presence of new OXA-genes in local A. baumannii isolates including: OXA-207, OXA-239 and OXA-229 among the genes of OXA-24-like, OXA-23-like and OXA-58-like genes, respectively. In conclusion, this study identifies the genes responsible for the imipenem resistance in Baghdad which is important to understand the imipenem resistance and to suggest plans for treatment of patients in future.

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“…Also the latter genes are regulated by upstream IS genetic (ISAba) elements decisive for the resistance to carbapenems. [37,39,40] It is of note that only in ST195 and ST281 isolates we have found blaOxa-66 and blaOxa-23 regulated by IS genetic elements and also the blaTEM-19. It is to be stressed that blaOXA-23 gene encodes the most prevalent and endemic carbapenemase in Italy.…”

Section: Discussionmentioning

confidence: 94%

The whole genome sequencing of Acinetobacter-calcoaceticus-baumannii complex strains involved in suspected outbreak in an Intensive Care Unit of a pediatric hospital

Ugolotti

Marco

Bandettini

et al. 2016

JHA

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Background: To analyze the genetic characteristics of Acinetobacter-calcoaceticus-baumannii complex strains isolated in suspected outbreak in a Intensive Care Unit of a pediatric hospital in order to promptly stop the dissemination of this dangerous strain. Methods: This study described the use of whole genome obtained by Next Generation Sequencing to define the clonality of 13 Acinetobacter-calcoaceticus-baumannii complex strains and to study their Resistoma. This was required because Acinetobacter baumannii is known to be resistant to desiccation and to disinfectants and is difficult to treat and eradicate. Thus, this microorganism is a major problem that demands a rigorous outbreak monitoring program to prevent and control the spread of the dangerous strain. Results: The first result of our analysis has been to describe precisely the characteristics of isolates involved in the nosocomial infection, reduce the dimension of the more problematic isolates sustaining the outbreak and promptly facilitate the control of the strains diffusion. Indeed, our study indicated that among the 13 Acinetobacter baumannii-calcoacteticus complex strains, identified by biochemical and mass-spectrometry assays, 7 were Acinetobacter baumannii, 5 were Acinetobacter calcoaceticus, and one was Acinetobacter haemolyticus. The analysis of clonality of Acinetobacter baumannii indicated that three strains of ST744 were identical for > 99.8% among them and thus have sustained an outbreak in Intensive Care Unit. All personnel and possible environment samples were also monitored and all the procedures aimed to the prevention and control of Hospital Acquired Infections (HAI), have been strictly enforced by the Hospital Infection Control Committee. This gave the possibility to trace a strain from an environmental contamination characterized by high degree of clonality with the one isolated from a patient. On the contrary Acinetobacter calcoaceticus strains were different from each other and thus they were not responsible for any outbreak. The Resistoma analysis indicated a correspondence between phenotypic and genotypic characteristics of analyzed strains. Conclusions: Next Generation Sequencing is an appropriate technique to trace the circulation of dangerous strains sustaining nosocomial infections. The combination of the high resolution genotyping together with the definition of the antibiotic genetic determinants and the precise species identification make this technique a useful tool employed as standard practice to control HAI.

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Insights into the global molecular epidemiology of carbapenem non-susceptible clones of Acinetobacter baumannii

Cited by 235 publications

References 91 publications

Acinetobacter baumannii: biology and drug resistance — role of carbapenemases

Acinetobacter baumannii: biology and drug resistance — role of carbapenemases

Identification of Imipenem-Resistant Genes in Acinetobacter baumannii Isolated from Baghdad Hospitals

The whole genome sequencing of Acinetobacter-calcoaceticus-baumannii complex strains involved in suspected outbreak in an Intensive Care Unit of a pediatric hospital

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