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Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features.Clinical Microbiology Reviews Apr 1996
Review
Topics: Acinetobacter; Acinetobacter Infections; Anti-Bacterial Agents; Bacteriological Techniques; Cross Infection; Drug Resistance, Microbial; Humans
PubMed: 8964033
DOI: 10.1128/CMR.9.2.148 -
Journal of Infection in Developing... Feb 2017The increasing prevalence of foodborne diseases observed in developing countries has been linked to a rise in the consumption of raw foods. However, unlike the classical... (Review)
Review
The increasing prevalence of foodborne diseases observed in developing countries has been linked to a rise in the consumption of raw foods. However, unlike the classical pathogens that are commonly implicated in foodborne illnesses, members of the genus Acinetobacter are rarely associated with diarrheal disease, probably because of the difficulty in isolating these Gram-negative bacteria from food sources. Nevertheless, several species of Acinetobacter, especially A. baumannii, possess many of the characteristics associated with successful pathogens and exhibit a prodigious ability to acquire the multiple-drug resistance (MDR) phenotype. In this mini-review, we summarize the epidemiological data relating to MDR Acinetobacter and consider evidence suggesting that contaminated dairy products, along with raw fruit and vegetables, constitute extra-hospital reservoirs of this underrated pathogen, and may represent an increased risk to immunocompromised individuals and young children in healthcare settings.
Topics: Acinetobacter; Acinetobacter Infections; Drug Resistance, Multiple, Bacterial; Foodborne Diseases; Humans
PubMed: 28248670
DOI: 10.3855/jidc.8418 -
International Journal of Molecular... Sep 2022This review briefly summarizes the data on the mechanisms of development of the adaptability of to various living conditions in the environment and in the clinic. A... (Review)
Review
This review briefly summarizes the data on the mechanisms of development of the adaptability of to various living conditions in the environment and in the clinic. A comparative analysis of the genomes of free-living and clinical strains of , as well as the genomes of and has been carried out. It has been shown that plasmids, both large and small, play a key role in the formation of the adaptability of to their living conditions. In particular, it has been demonstrated that the plasmids of various strains of differ from each other in their structure and gene composition depending on the lifestyle of their host bacteria. Plasmids of modern strains are enriched with antibiotic-resistant genes, while the content of genes involved in resistance to heavy metals and arsenic is comparable to plasmids from modern and ancient strains. It is concluded that plasmids may ensure the survival of host bacteria under conditions of various types of environmental and clinical stresses. A brief overview of the main mechanisms of horizontal gene transfer on plasmids inherent in strains is also given.
Topics: Acinetobacter; Acinetobacter baumannii; Anti-Bacterial Agents; Arsenic; Metals, Heavy; Plasmids
PubMed: 36142804
DOI: 10.3390/ijms231810893 -
Clinical Microbiology Reviews Apr 2014The OXA β-lactamases were among the earliest β-lactamases detected; however, these molecular class D β-lactamases were originally relatively rare and always plasmid... (Review)
Review
The OXA β-lactamases were among the earliest β-lactamases detected; however, these molecular class D β-lactamases were originally relatively rare and always plasmid mediated. They had a substrate profile limited to the penicillins, but some became able to confer resistance to cephalosporins. From the 1980s onwards, isolates of Acinetobacter baumannii that were resistant to the carbapenems emerged, manifested by plasmid-encoded β-lactamases (OXA-23, OXA-40, and OXA-58) categorized as OXA enzymes because of their sequence similarity to earlier OXA β-lactamases. It was soon found that every A. baumannii strain possessed a chromosomally encoded OXA β-lactamase (OXA-51-like), some of which could confer resistance to carbapenems when the genetic environment around the gene promoted its expression. Similarly, Acinetobacter species closely related to A. baumannii also possessed their own chromosomally encoded OXA β-lactamases; some could be transferred to A. baumannii, and they formed the basis of transferable carbapenem resistance in this species. In some cases, the carbapenem-resistant OXA β-lactamases (OXA-48) have migrated into the Enterobacteriaceae and are becoming a significant cause of carbapenem resistance. The emergence of OXA enzymes that can confer resistance to carbapenems, particularly in A. baumannii, has transformed these β-lactamases from a minor hindrance into a major problem set to demote the clinical efficacy of the carbapenems.
Topics: Acinetobacter; Acinetobacter Infections; Anti-Bacterial Agents; Enterobacteriaceae; Enterobacteriaceae Infections; Gene Transfer, Horizontal; Humans; beta-Lactam Resistance; beta-Lactamases
PubMed: 24696435
DOI: 10.1128/CMR.00117-13 -
Journal of Infection in Developing... Nov 2019In the last decade, Acinetobacter species have taken a major public health concern. This is mainly due the increased resistance to a wide range of antibiotics causing... (Review)
Review
INTRODUCTION
In the last decade, Acinetobacter species have taken a major public health concern. This is mainly due the increased resistance to a wide range of antibiotics causing treatment challenges. In view of the constant population mobilization and the economic crisis that Lebanon is currently facing, it becomes a necessity to re-evaluate the real threat of Acinetobacter spp and its implication in the one health.
METHODOLOGY
This review was conducted through the analysis of 45 research papers and reports pertaining to Acinetobacter spp performed in Lebanon. More than 82% of the papers consulted were published in international journals and more than 70 percent of them had received impact factor.
RESULTS
An in depth description of the involvement of this organism in human infection and its role as potential pathogen or simple colonizer was performed. In addition, the different aspects of resistance, mostly to carbapenems and colistin was studied and summarized. While in animals and environment, susceptible strains were mostly isolated, OXA-23/OXA-24 were predominant in humans. Recently, NDM-1 producing Acinetobacter spp was detected in a Syrian refugee which then was reported in Lebanese patients. The bacterial identification procedures are non-systematic and not always reliable in the Lebanese studies presenting sometimes discrepancies an inconsistency.
CONCLUSION
Acinetobacter is commonly isolated Lebanon. In view of the spread of resistance among these isolated and their dissemination, Infection control measures attempting to control the spread of this genus in and outside hospitals are lacking and thus require more attention and stewardship activities.
Topics: Acinetobacter; Acinetobacter Infections; Acinetobacter baumannii; Animals; Anti-Bacterial Agents; Carbapenems; Developing Countries; Drug Resistance, Bacterial; Emigrants and Immigrants; Humans; Lebanon; Socioeconomic Factors
PubMed: 32087065
DOI: 10.3855/jidc.11341 -
Journal of Microbiology, Immunology,... Feb 2017Patients with Acinetobacter pittii and Acinetobacter nosocomialis bacteremia have lower mortality rates than those with Acinetobacter baumannii bacteremia. However, it... (Comparative Study)
Comparative Study
BACKGROUND/PURPOSE
Patients with Acinetobacter pittii and Acinetobacter nosocomialis bacteremia have lower mortality rates than those with Acinetobacter baumannii bacteremia. However, it is unknown whether these organisms differ in outcomes of bacteremic patients. We conducted this study to answer this question.
METHODS
In this retrospective study conducted at a teaching hospital in Taiwan, we enrolled all 86 patients who had developed A. pittii bacteremia and those with A. nosocomialis bacteremia from 2000 to 2008 while matching for age, sex, Acute Physiology and Chronic Health Evaluation II score, and appropriate antimicrobial therapy. After adjustment, we accessed the clinical characteristics and 14- and 28-day mortalities.
RESULTS
We found that the patients with A. pittii bacteremia had multiple comorbidities less often and received invasive procedures less frequently. The 14-day mortality rate of patients with A. pittii or A. nosocomialis bacteremia was 14% and 7%, respectively, whereas their 28-day mortality rate was 17% and 9%, respectively. Using the mortality rate in patients with A. nosocomialis bacteremia as a reference, the odds ratios for the 14- and 28-day crude morality in those with A. pittii were 2.16 [95% confidence interval (CI), 0.77-6.05] and 2.06 (95% CI, 0.82-5.15), respectively, whereas the adjusted odds ratios for 14- and 28-day mortality were 1.89 (95% CI, 0.56-6.14) and 1.67 (95% CI, 0.59-4.78) respectively.
CONCLUSION
Our 8-year study showed that the mortality rate of A. pittii bacteremia was higher but the difference was not statistically significant.
Topics: Acinetobacter; Acinetobacter Infections; Bacteremia; Female; Hospitals, Teaching; Humans; Male; Middle Aged; Retrospective Studies; Survival Analysis; Taiwan
PubMed: 25735795
DOI: 10.1016/j.jmii.2015.01.003 -
Microbiology Spectrum Feb 2022Carbapenem resistance is increasing among Gram-negative bacteria, including the genus Acinetobacter. This study aimed to characterize, for the first time, the...
Carbapenem Resistance in Acinetobacter nosocomialis and Acinetobacter junii Conferred by Acquisition of and Genetic Characterization of the Transmission Mechanism between Acinetobacter Genomic Species.
Carbapenem resistance is increasing among Gram-negative bacteria, including the genus Acinetobacter. This study aimed to characterize, for the first time, the development of carbapenem resistance in clinical isolates of Acinetobacter junii and Acinetobacter nosocomialis conferred by the acquisition of a plasmid-borne gene and also to characterize the dissemination of this gene between species of Acinetobacter. Carbapenem-resistant A. nosocomialis HUAV-AN66 and A. junii HUAV-AJ77 strains were isolated in the Arnau de Vilanova Hospital (Spain). The genomes were sequenced, and analysis were performed to characterize the genetic environment and the OXA-24/40 transmission mechanism. Antibiotic MICs were determined, and horizontal transfer assays were conducted to evaluate interspecies transmission of OXA-24/40. Carbapenems MICs obtained were ≥64 mg/L for HUAV-AN66 and HUAV-AJ77. Genome analysis revealed the presence in both strains of a new plasmid, designated pHUAV/OXA-24/40, harboring the carbapenem-resistance gene and flanked by sequences XerC/XerD. pHUAV/OXA-24/40 was successfully transferred from A. nosocomialis and A. junii to a carbapenem-susceptible A. baumannii strain, thus conferring carbapenem resistance. A second plasmid (pHUAV/AMG-R) was identified in both clinical isolates for the successful horizontal transfer of pHUAV/OXA-24/40. carrying plasmids of the GR12 group and showing high identity with pHUAV/OXA-24/40 were identified in at least 8 Acinetobacter species. In conclusion the carbapenemase OXA-24/40 is described for the first time in A. nosocomialis and A. junii. In both isolates the gene was located in the GR12 pHUAV/OXA-24/40 plasmid. GR12 plasmids are implicated in the dissemination and spread of carbapenem resistance among Acinetobacter species. Acinetobacter baumannii is one of the most relevant pathogens in terms of antibiotic resistance. The main resistance mechanisms are the carbapenem-hydrolyzing class D β-lactamases (CHDLs), especially OXA-23 and OXA-24/40. In addition to A. baumannii, there are other species within the genus Acinetobacter, which in general exhibit much lower resistance rates. In this work we characterize for the first time two clinical isolates of Acinetobacter nosocomialis and Acinetobacter junii, isolated in the same hospital, carrying the carbapenemase OXA-24/40 and displaying high resistance rates to carbapenems. By means of bioinformatics analysis we have also been able to characterize the mechanism by which this carbapenemase is horizontally transferred interspecies of Acinetobacter spp. The dissemination of carbapenemase OXA-24/40 between non- Acinetobacter species is concerning since it prevents the use of most β-lactam antibiotics in the fight against these resistant isolates.
Topics: Acinetobacter; Acinetobacter Infections; Anti-Bacterial Agents; Bacterial Proteins; Carbapenems; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Genome, Bacterial; Genomics; Humans; Microbial Sensitivity Tests; Plasmids; beta-Lactamases
PubMed: 35138195
DOI: 10.1128/spectrum.02734-21 -
Frontiers in Cellular and Infection... 2018
Topics: Acinetobacter; Anti-Bacterial Agents; Bacteremia; Biofilms; Drug Resistance, Bacterial; Gene Expression Regulation, Bacterial; Humans; Interspersed Repetitive Sequences; Protein Translocation Systems; Pseudomonas; Quorum Sensing; Risk Factors; Virulence; Virulence Factors
PubMed: 29594065
DOI: 10.3389/fcimb.2018.00068 -
Microbes and Environments 2011Acinetobacter are a major concern because of their rapid development of resistance to a wide range of antimicrobials, and rapid profundity in transformation, surviving... (Review)
Review
Acinetobacter are a major concern because of their rapid development of resistance to a wide range of antimicrobials, and rapid profundity in transformation, surviving desiccation and persisting in the environment for a very long time. The organisms are associated with bacteraemia, pulmonary infections, meningitis, diarrhea and notorious nosocomial infections with mortality rates of 20 to 60%. Transmission is via person-to-person contact, water and food contamination, and contaminated hospital equipment. The increasing virulence and rapid development of multidrug resistance by these organisms highlights the need to search for alternatives for chemotherapy. A poor understanding of the organisms and dearth of information about their occurrence especially in developing countries informed the need for this review paper.
Topics: Acinetobacter; Acinetobacter Infections; Animals; Anti-Bacterial Agents; Bacteremia; Cross Infection; Drug Resistance, Multiple, Bacterial; Humans; Virulence
PubMed: 21502736
DOI: 10.1264/jsme2.me10179 -
Bacteriological Reviews Dec 1973
Review
Topics: Acinetobacter; Alcaligenes; Antigens, Bacterial; Cross Reactions; Immunodiffusion; Moraxella; Terminology as Topic
PubMed: 4203395
DOI: 10.1128/br.37.4.522-561.1973