scholarly journals CsrA Coordinates Compatible Solute Synthesis in Acinetobacter baumannii and Facilitates Growth in Human Urine

2021 ◽  
Author(s):  
Josephine Joy Hubloher ◽  
Kim Schabacker ◽  
Volker Müller ◽  
Beate Averhoff
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Compatible Solute ◽  
Human Pathogen ◽  
Content Type ◽  
Clinical Environments ◽  
Resistant Strains ◽  
Opportunistic Human Pathogen ◽  
Mrna Binding ◽  
Optimal Adaptation

The opportunistic human pathogen Acinetobacter baumannii has become one of the leading causes of nosocomial infections around the world due to the increasing prevalence of multidrug-resistant strains and their optimal adaptation to clinical environments and the human host. Recently, it was found that CsrA, a global mRNA binding posttranscriptional regulator, plays a role in osmotic stress adaptation, virulence, and growth on amino acids of A. baumannii AB09-003 and 17961.

scholarly journals Complete Genome Sequence of the Nosocomial Pathogen Acinetobacter nosocomialis Strain M2

2019 ◽  
Vol 8 (44) ◽  
Author(s):  
Bailey Pehde ◽  
Nicholas Lizer ◽  
Michael Carruthers
Keyword(s):  
Acinetobacter Baumannii ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Acinetobacter Calcoaceticus ◽  
Human Pathogen ◽  
Nosocomial Pathogen ◽  
Content Type ◽  
Opportunistic Human Pathogen

Acinetobacter nosocomialis is an opportunistic human pathogen that is part of the Acinetobacter calcoaceticus/Acinetobacter baumannii (ACB) complex. Here, we report the complete genome sequence of Acinetobacter nosocomialis strain M2.

scholarly journals Draft Genome Sequences of Three Human Pathogenic Acinetobacter baumannii Strains

2019 ◽  
Vol 8 (14) ◽  
Author(s):  
Masoumeh Madhi ◽  
Troels Ronco ◽  
Alka Hasani ◽  
Rikke H. Olsen
Keyword(s):  
Intensive Care ◽  
Acinetobacter Baumannii ◽  
Intensive Care Units ◽  
Nosocomial Infections ◽  
Draft Genome ◽  
Human Pathogen ◽  
Genome Sequences ◽  
Content Type ◽  
Opportunistic Human Pathogen

Acinetobacter baumannii is an opportunistic human pathogen with the ability to develop multiple resistances against the main antibiotic classes. It causes nosocomial infections, especially in intensive care units.

scholarly journals H-NS Plays a Role in Expression of Acinetobacter baumannii Virulence Features

2013 ◽  
Vol 81 (7) ◽  
pp. 2574-2583 ◽  
Author(s):  
Bart A. Eijkelkamp ◽  
Uwe H. Stroeher ◽  
Karl A. Hassan ◽  
Liam D. H. Elbourne ◽  
Ian T. Paulsen ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Molecular Mechanisms ◽  
Protein A ◽  
Multidrug Resistant ◽  
Regulatory Control ◽  
Type I ◽  
Type Vi Secretion System ◽  
Content Type ◽  
Cellular Lipids ◽  
Resistant Strains

ABSTRACTAcinetobacter baumanniihas become a major problem in the clinical setting with the prevalence of infections caused by multidrug-resistant strains on the increase. Nevertheless, only a limited number of molecular mechanisms involved in the success ofA. baumanniias a human pathogen have been described. In this study, we examined the virulence features of a hypermotile derivative ofA. baumanniistrain ATCC 17978, which was found to display enhanced adherence to human pneumocytes and elevated levels of lethality towardCaenorhabditis elegansnematodes. Analysis of cellular lipids revealed modifications to the fatty acid composition, providing a possible explanation for the observed changes in hydrophobicity and subsequent alteration in adherence and motility. Comparison of the genome sequences of the hypermotile variant and parental strain revealed that an insertion sequence had disrupted anhns-like gene in the variant. This gene encodes a homologue of the histone-like nucleoid structuring (H-NS) protein, a known global transcriptional repressor. Transcriptome analysis identified the global effects of this mutation on gene expression, with major changes seen in the autotransporter Ata, a type VI secretion system, and a type I pilus cluster. Interestingly, isolation and analysis of a second independent hypermotile ATCC 17978 variant revealed a mutation to a residue within the DNA binding region of H-NS. Taken together, these mutants indicate that the phenotypic and transcriptomic differences seen are due to loss of regulatory control effected by H-NS.

scholarly journals Colistin and Fusidic Acid, a Novel Potent Synergistic Combination for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections

2015 ◽  
Vol 59 (8) ◽  
pp. 4544-4550 ◽  
Author(s):  
Lynette M. Phee ◽  
Jonathan W. Betts ◽  
Binutha Bharathan ◽  
David W. Wareham
Keyword(s):  
Acinetobacter Baumannii ◽  
Fusidic Acid ◽  
Multidrug Resistant ◽  
Content Type ◽  
Low Concentrations ◽  
Resistant Strains ◽  
Time Kill ◽  
Susceptibility Breakpoint ◽  
Selection Of

ABSTRACTThe spread of multidrug-resistantAcinetobacter baumannii(MDRAB) has led to the renaissance of colistin (COL), often the only agent to which MDRAB remains susceptible. Effective therapy with COL is beset with problems due to unpredictable pharmacokinetics, toxicity, and the rapid selection of resistance. Here, we describe a potent synergistic interaction when COL was combined with fusidic acid (FD) againstA. baumannii. Synergyin vitrowas assessed against 11 MDRAB isolates using disc diffusion, checkerboard methodology (fractional inhibitory concentration index [FICI] of ≤ 0.5, susceptibility breakpoint index [SBPI] of >2), and time-kill methodology (≥2 log10CFU/ml reduction). The ability of FD to limit the emergence of COL resistance was assessed in the presence and absence of each drug alone and in combination. Synergy was demonstrated against all strains, with an average FICI and SBPI of 0.064 and 78.85, respectively. In time-kill assays, COL-FD was synergistic and rapidly bactericidal, including against COL-resistant strains. Fusidic acid prevented the emergence of COL resistance, which was readily selected with COL alone. This is the first description of a novel COL-FD regimen for the treatment of MDRAB. The combination was effective at low concentrations, which should be therapeutically achievable while limiting toxicity. Further studies are warranted to determine the mechanism underlying the interaction and the suitability of COL-FD as an unorthodox therapy for the treatment of multidrug-resistant Gram-negative infections.

scholarly journals Clinical Use of Colistin Induces Cross-Resistance to Host Antimicrobials in Acinetobacter baumannii

mBio ◽  
2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Brooke A. Napier ◽  
Eileen M. Burd ◽  
Sarah W. Satola ◽  
Stephanie M. Cagle ◽  
Susan M. Ray ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Innate Immune ◽  
Cross Resistance ◽  
Negative Consequences ◽  
Content Type ◽  
Bacterial Membranes ◽  
Before And After ◽  
New Antibiotics ◽  
Resistant Strains

ABSTRACTThe alarming rise in antibiotic resistance has led to an increase in patient mortality and health care costs. This problem is compounded by the absence of new antibiotics close to regulatory approval.Acinetobacter baumanniiis a human pathogen that causes infections primarily in patients in intensive care units (ICUs) and is highly antibiotic resistant. Colistin is one of the last-line antibiotics for treatingA. baumanniiinfections; however, colistin-resistant strains are becoming increasingly common. This cationic antibiotic attacks negatively charged bacterial membranes in a manner similar to that seen with cationic antimicrobials of the innate immune system. We therefore set out to determine if the increasing use of colistin, and emergence of colistin-resistant strains, is concomitant with the generation of cross-resistance to host cationic antimicrobials. We found that there is indeed a positive correlation between resistance to colistin and resistance to the host antimicrobials LL-37 and lysozyme among clinical isolates. Importantly, isolates obtained before and after treatment of individual patients demonstrated that colistin use correlated with increased resistance to cationic host antimicrobials. These data reveal the overlooked risk of inducing cross-resistance to host antimicrobials when treating patients with colistin as a last-line antibiotic.IMPORTANCEIncreased use of the cationic antibiotic colistin to treat multidrug-resistantAcinetobacter baumanniihas led to the development of colistin-resistant strains. Here we report that treatment of patients with colistin can induce not only increased resistance to colistin but also resistance to host cationic antimicrobials. This worrisome finding likely represents an example of a broader trend observed in other bacteria against which colistin is used therapeutically such asPseudomonas aeruginosaandKlebsiella pneumoniae. Furthermore, these data suggest that the possible future use of an array of cationic antimicrobial peptides in development as therapeutics may have unintended negative consequences, eventually leading to the generation of hypervirulent strains that are resistant to innate host defenses. The potential for the induction of cross-resistance to innate immune antimicrobials should be considered during the development of new therapeutics.

scholarly journals Whole-Genome Sequencing of Multidrug-Resistant Campylobacter fetus subsp. fetus NWU_ED24, Isolated from a Bovine Sheath Wash Sample

2020 ◽  
Vol 9 (40) ◽  
Author(s):  
Mpinda Edoaurd Tshipamba ◽  
Kazeem Adekunle Alayande ◽  
Ngoma Lubanza ◽  
Mulunda Mwanza
Keyword(s):  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Whole Genome ◽  
Spontaneous Abortions ◽  
Human Pathogen ◽  
Content Type ◽  
Campylobacter Fetus ◽  
Intestinal Infections ◽  
Fetus Subsp ◽  
Opportunistic Human Pathogen

ABSTRACT Campylobacter fetus subsp. fetus is an opportunistic human pathogen that is frequently identified as a cause of intestinal infections as well as bloodstream infections. This bacterium is well known to cause spontaneous abortions in sheep and cows. The strain reported in this study was isolated from a preputial wash sample from a bull in South Africa.

scholarly journals Role of OmpA in the Multidrug Resistance Phenotype of Acinetobacter baumannii

2013 ◽  
Vol 58 (3) ◽  
pp. 1806-1808 ◽  
Author(s):  
Younes Smani ◽  
Anna Fàbrega ◽  
Ignasi Roca ◽  
Viviana Sánchez-Encinales ◽  
Jordi Vila ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Protein A ◽  
Multidrug Resistant ◽  
Nosocomial Pathogen ◽  
Content Type ◽  
Resistance Phenotype ◽  
Resistant Strains ◽  
First Time

ABSTRACTAcinetobacter baumanniihas emerged as a nosocomial pathogen with an increased prevalence of multidrug-resistant strains. The role of the outer membrane protein A (OmpA) in antimicrobial resistance remains poorly understood. In this report, disruption of theompAgene led to decreased MICs of chloramphenicol, aztreonam, and nalidixic acid. We have characterized, for the first time, the contribution of OmpA in the antimicrobial resistance phenotype ofA. baumannii.

scholarly journals Disruption of Biofilm Formation by the Human Pathogen Acinetobacter baumannii Using Engineered Quorum-Quenching Lactonases

2013 ◽  
Vol 58 (3) ◽  
pp. 1802-1805 ◽  
Author(s):  
Jeng Yeong Chow ◽  
Yuanyong Yang ◽  
Song Buck Tay ◽  
Kim Lee Chua ◽  
Wen Shan Yew
Keyword(s):  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Directed Evolution ◽  
Nosocomial Infections ◽  
Biofilm Formation ◽  
Quorum Quenching ◽  
Multidrug Resistant ◽  
Human Pathogen ◽  
Content Type ◽  
Biofilm Disruption

ABSTRACTAcinetobacter baumanniiis a major human pathogen associated with multidrug-resistant nosocomial infections; its virulence is attributed to quorum-sensing-mediated biofilm formation, and disruption of biofilm formation is an attractive antivirulence strategy. Here, we report the first successful demonstration of biofilm disruption in a clinical isolate ofA. baumanniiS1, using a quorum-quenching lactonase obtained by directed evolution; this engineered lactonase significantly reduced the biomass ofA. baumannii-associated biofilms, demonstrating the utility of this antivirulence strategy.

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