Prevalence and Mechanisms of Carbapenem Resistance Among <i>Acinetobacter baumannii</i> Clinical Isolates in Egypt

Benmahmod, Abdalbagi Basheer; Said, Heba Shehta; Ibrahim, Ramdan H.

doi:10.1089/mdr.2018.0141

Cited by 52 publications

(47 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In our study, 70% of the isolates were resistant to imipenem, similar to what reported in a study conducted in 2014 [26]. Unfortunately, imipenem resistance in Egypt has recently increased to around 92% of the studied cases [27,28], indicating the decrease of carbepenem effectiveness against A. baumannii infections.…”

Section: Discussionsupporting

confidence: 89%

Acquisition of Colistin Resistance Links Cell Membrane Thickness Alteration with a Point Mutation in the lpxD Gene in Acinetobacter baumannii

et al. 2020

View full text Add to dashboard Cite

Acinetobacter baumannii is one of the most common causes of nosocomial infections in intensive care units. Its ability to acquire diverse mechanisms of resistance limits the therapeutic choices for its treatment. This especially concerns colistin, which has been reused recently as a last-resort drug against A. baumannii. Here, we explored the impact of gaining colistin resistance on the susceptibility of A. baumannii to other antibiotics and linked colistin resistance acquisition to a gene mutation in A. baumannii. The susceptibility of 95 A. baumannii isolates revealed that 89 isolates were multi-drug resistance (MDR), and nine isolates were resistant to colistin. Subsequently, three isolates, i.e., MS48, MS50, and MS64, exhibited different resistance patterns when colistin resistance was induced and gained resistance to almost all tested antibiotics. Upon TEM examination, morphological alterations were reported for all induced isolates and a colistin-resistant clinical isolate (MS34Col-R) compared to the parental sensitive strains. Finally, genetic alterations in PmrB and LpxACD were assessed, and a point mutation in LpxD was identified in the MS64Col-R and MS34Col-R mutants, corresponding to Lys117Glu substitution in the lipid-binding domain. Our findings shed light on the implications of using colistin in the treatment of A. baumannii, especially at sub-minimum inhibitory concentrations concentrations, since cross-resistance to other classes of antibiotics may emerge, beside the rapid acquisition of resistance against colistin itself due to distinct genetic events.

show abstract

Section: Discussionsupporting

confidence: 89%

Acquisition of Colistin Resistance Links Cell Membrane Thickness Alteration with a Point Mutation in the lpxD Gene in Acinetobacter baumannii

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Apart from β-lactamases, β-lactam resistance in A. baumannii is additionally ascribed to nonenzymatic mechanisms, perhaps less well elucidated than enzymatic hydrolysis, but mainly including changes in outer membrane proteins and multidrug efflux pumps [155]. The loss of the 29-kDa outer membrane porin, CarO, was associated with imipenem and meropenem resistance [172]. A recent study from Egypt revealed that ISAba1 has been inserted in carO gene leading to interruption of its expression [173].…”

Section: Nonenzymatic β-Lactam Resistance Mechanismsmentioning

confidence: 99%

Insights into Acinetobacter baumannii: A Review of Microbiological, Virulence, and Resistance Traits in a Threatening Nosocomial Pathogen

2020

View full text Add to dashboard Cite

Being a multidrug-resistant and an invasive pathogen, Acinetobacter baumannii is one of the major causes of nosocomial infections in the current healthcare system. It has been recognized as an agent of pneumonia, septicemia, meningitis, urinary tract and wound infections, and is associated with high mortality. Pathogenesis in A. baumannii infections is an outcome of multiple virulence factors, including porins, capsules, and cell wall lipopolysaccharide, enzymes, biofilm production, motility, and iron-acquisition systems, among others. Such virulence factors help the organism to resist stressful environmental conditions and enable development of severe infections. Parallel to increased prevalence of infections caused by A. baumannii, challenging and diverse resistance mechanisms in this pathogen are well recognized, with major classes of antibiotics becoming minimally effective. Through a wide array of antibiotic-hydrolyzing enzymes, efflux pump changes, impermeability, and antibiotic target mutations, A. baumannii models a unique ability to maintain a multidrug-resistant phenotype, further complicating treatment. Understanding mechanisms behind diseases, virulence, and resistance acquisition are central to infectious disease knowledge about A. baumannii. The aims of this review are to highlight infections and disease-producing factors in A. baumannii and to touch base on mechanisms of resistance to various antibiotic classes.

show abstract

“…baumannii investigated isolates (22,36,37). However, another Egyptian study couldn't find the former gene among any of their studied carbapenem resistant A. baumannii isolates (38).…”

Section: Discussionmentioning

confidence: 97%

Molecular Characterization of Carbapenem-ResistantAcinetobacter baumanniiClinical Isolates from Egyptian Patients

Hassan

Salem

Hassan

et al. 2020

Preprint

View full text Add to dashboard Cite

Author summary Carbapenem-resistant A. baumannii has become a real global health threat. The aim of the present study was to characterize and to assess the prevalence of carbapenemases among 206 CR-AB clinical isolates from Egyptian patients. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC. In this study, IS Aba1 was detected upstream 10% of blaOXA-23 positive isolates only which indicates that the spread of resistance among Acinetobacter isolates could be either chromosomal or plamid- mediated.

show abstract

Prevalence and Mechanisms of Carbapenem Resistance Among Acinetobacter baumannii Clinical Isolates in Egypt

Cited by 52 publications

References 52 publications

Acquisition of Colistin Resistance Links Cell Membrane Thickness Alteration with a Point Mutation in the lpxD Gene in Acinetobacter baumannii

Acquisition of Colistin Resistance Links Cell Membrane Thickness Alteration with a Point Mutation in the lpxD Gene in Acinetobacter baumannii

Insights into Acinetobacter baumannii: A Review of Microbiological, Virulence, and Resistance Traits in a Threatening Nosocomial Pathogen

Molecular Characterization of Carbapenem-ResistantAcinetobacter baumanniiClinical Isolates from Egyptian Patients

Contact Info

Product

Resources

About