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Antibiotics (Basel, Switzerland) Nov 2022The increasing number of multidrug-resistant Gram-negative bacteria presents a serious threat to global health. However, colistin-resistant has rarely been reported. We...
The increasing number of multidrug-resistant Gram-negative bacteria presents a serious threat to global health. However, colistin-resistant has rarely been reported. We identified a colistin-resistant clinical isolate, AJ6079, in blood. The colony of AJ6079 presented a dry phenotype, and it was difficult to form a bacterial suspension, whilst transmission electron microscopy revealed that AJ6079 possessed a thick outer membrane. The phenotypic and genomic comparisons were conducted with one colistin-susceptible , which had the same antibiotic susceptibility profile except for colistin, and had the same KL25 capsule biosynthesis locus. The AJ6079 exhibited a slower growth rate, indicating that colistin-resistant possesses a higher fitness cost. The genome of AJ6079 had a G+C content of 38.7% and contained one 3,362,966 bp circular chromosome with no plasmid or mobile colistin resistance () gene. Comparative genomic analysis revealed that the AJ6079 contained several previously unreported point mutations in colistin-resistance-related genes involving amino acid substitutions in PmrB (N5K, G147C), LpxA (I107F, H131Y), and LpxD (F20I, K263R), which might be correlated with colistin resistance in . Further research is needed for verification as the genetic background was not exactly the same between the two isolates.
PubMed: 36551350
DOI: 10.3390/antibiotics11121693 -
MSphere May 2024is an opportunistic human and animal pathogen severely understudied. Here, we conducted the largest genomic epidemiological study on this pathogen to date. Our data...
UNLABELLED
is an opportunistic human and animal pathogen severely understudied. Here, we conducted the largest genomic epidemiological study on this pathogen to date. Our data show that this bacterium has spread globally. Also, we found that some human and non-human isolates are not well differentiated from one another, implying transmission between clinical and non-clinical, non-human settings. Remarkably, human but also some non-human isolates have clinically important antibiotic resistance genes, and some of these genes are located in plasmids. Given these results, we put forward that should be considered an emerging One Health problem. In this regard, future molecular epidemiological studies about this species will go beyond human isolates and will consider animal-, plant-, and water-associated environments.
IMPORTANCE
is the most well-known species from the genus . However, other much less studied species could be important opportunistic pathogens of animals, plants and humans. Here, we conducted the largest genomic epidemiological study of , which has been described as a source not only of human but also of animal infections. Our analyses show that this bacterium has spread globally and that, in some instances, human and non-human isolates are not well differentiated. Remarkably, some non-human isolates have important antibiotic resistance genes against important antibiotics used in human medicine. Based on our results, we propose that this pathogen must be considered an issue not only for humans but also for veterinary medicine.
Topics: Acinetobacter Infections; Humans; Acinetobacter; Animals; One Health; Genome, Bacterial; Anti-Bacterial Agents; Molecular Epidemiology; Communicable Diseases, Emerging; Drug Resistance, Bacterial; Plasmids; Genomics
PubMed: 38606973
DOI: 10.1128/msphere.00162-24 -
Surgical Infections Mar 2022
Topics: Acinetobacter; Bile Duct Neoplasms; Cholangitis; Humans; Klatskin Tumor; Stents
PubMed: 34668785
DOI: 10.1089/sur.2021.264 -
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 -
Urology Case Reports Sep 2020is one of more than 50 different species belonging to the genus . This bacterium is rarely reported to cause human infections. Here we described a rare case of , which...
is one of more than 50 different species belonging to the genus . This bacterium is rarely reported to cause human infections. Here we described a rare case of , which grew in urine culture approximately one month after the patient was discharged from the hospital with antibiotics for a urinary tract infection, which caused left obstructing renal calculi requiring nephrostomy tube placement.
PubMed: 32322533
DOI: 10.1016/j.eucr.2020.101209 -
Journal of Infection and Chemotherapy :... Feb 2020Acinetobacter spp. are known to be a cause of nosocomial infections and to have diverse mechanisms of resistance to antimicrobials. Here, we report the case of a patient... (Review)
Review
Acinetobacter spp. are known to be a cause of nosocomial infections and to have diverse mechanisms of resistance to antimicrobials. Here, we report the case of a patient who presented to our emergency department with necrotizing fasciitis due to Acinetobacter junii as confirmed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS). Patients with liver cirrhosis are susceptible to gram-negative infection. Moreover, although Acinetobacter spp. infection is best known to be a cause of combat-related-skin and soft-tissue infections, we propose that medical professionals need to consider the presence of these potentially multi-drug-resistant, gram-negative pathogens when treating patients with liver cirrhosis who present with severe soft-tissue infections. To our knowledge, this is the first case report of severe-skin and soft-tissue infections caused by A. junii.
Topics: Acinetobacter; Acinetobacter Infections; Aged; Anti-Bacterial Agents; Community-Acquired Infections; Fasciitis, Necrotizing; Humans; Leg; Liver Cirrhosis; Male; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Treatment Outcome; Wounds and Injuries
PubMed: 31680035
DOI: 10.1016/j.jiac.2019.09.018 -
Journal of Environmental Management Feb 2023Growing industrialization and unchecked release of industrial waste, including heavy metals have resulted in disastrous effects on environment. Considering the problem...
Growing industrialization and unchecked release of industrial waste, including heavy metals have resulted in disastrous effects on environment. Considering the problem of heavy metal pollution, the present research was designed to study the bioremediation of chromium, a highly toxic and prominent heavy metal pollutant by Acinetobacter junii strain b2w isolated from the Mithi river, Mumbai, India. The bacterial isolate could grow without affecting its growth kinetics up to a concentration of 200 ppm of chromium and showed resistance towards 400 ppm of chromium. It was able to bioremediate 83.06% of total chromium and reduces 98.24% of Cr to C at a concentration of 10 ppm of chromium. The bacterial isolate could grow well at a wide pH range from 5 to 9, salinity of up to 3.5% and could also tolerate heavy metals such as Cd, Zn, As, Hg, Pb and Cu. Thus, indicating its possible on-ground applicability for bioremediation of chromium. Acinetobacter junii bioaccumulate chromium without disrupting the cell integrity and biosorption. However, chromium alters the functional groups on bacterial cell surface and led to decrease in sulfate-containing molecules. Further, the protein expression study has revealed that Cr significantly up-regulates proteins broadly classified under envelope stress responses, oxidative stress responses, energy metabolism and quorum sensing and growth regulator. The possible mechanisms of Cr detoxification in Acinetobacter junii strain b2w could be reduction, bioaccumulation and efflux along with neutralization of oxidative stress generated by Cr. Thus, based on bacterial bioremediation potential and its molecular response, it can be proposed that the isolated Acinetobacter junii has potential applicability for chromium bioremediation.
Topics: Chromium; Biodegradation, Environmental; Proteomics; Metals, Heavy
PubMed: 36521220
DOI: 10.1016/j.jenvman.2022.116978 -
Infection Dec 2014Rods of the Acinetobacter genus are present mainly in the external environment (e.g. water, soil) and in animals, while in humans they may comprise physiological flora....
Rods of the Acinetobacter genus are present mainly in the external environment (e.g. water, soil) and in animals, while in humans they may comprise physiological flora. The main pathogenic species is Acinetobacter baumannii complex, which constitutes a common cause of nosocomial infections, particularly in patients with underlying diseases and risk factors (e.g. prior broad-spectrum antibiotic therapy, malignancy, central venous catheter, mechanical ventilation); however, infections of the eye caused by strains of Acinetobacter spp. are very rare. We report a unique case of community-acquired corneal ulcer caused by Acinetobacter non-baumannii (possibly A. junii), in a patient with no risk factors identified. The case highlights the need for obtaining a sample from the cornea for bacteriological culture in the case of suspected ophthalmic infection as identification of the pathogen, and assessment of its susceptibility profile enables proper antibiotic therapy, improves the outcome and may constitute an eyesight-saving management.
Topics: Acinetobacter; Acinetobacter Infections; Anti-Bacterial Agents; Corneal Ulcer; Female; Humans; Middle Aged
PubMed: 25056128
DOI: 10.1007/s15010-014-0647-8 -
Acta Paediatrica (Oslo, Norway : 1992) Jul 1999Acinetobacter junii caused sepsis in six preterm infants in our neonatal unit within 48 h. Each infant with clinical signs of systemic infection and activation of the...
Acinetobacter junii caused sepsis in six preterm infants in our neonatal unit within 48 h. Each infant with clinical signs of systemic infection and activation of the acute phase response had two positive blood cultures with Acinetobacter junii. The sudden onset, the short duration of the outbreak and the fact that none of the infants were colonized by A. junii suggested a common source of A. junii administered directly into the blood. The only feature shared by all six affected newborns was an intravenous fat emulsion (Intralipid 10%), which was shown to be an excellent growth medium for A. junii. Sepsis did not occur in four infants with 20% fat emulsion or amino acids only. Vaminolact did not support growth of the outbreak strain. The immediate source of the outbreak could not be identified: samples of the actual feeds given were not available for investigation, but A. junii was not isolated from parenteral solutions with identical batch numbers used in the septic infants. We conclude that Acinetobacter junii can cause a life-threatening infection in preterm neonates. Contaminated intravenous fat emulsion is implicated as a possible source of the infection. As a part of rigid infection control, intravenous feedings should be prepared under aseptic conditions.
Topics: Acinetobacter Infections; Bacteremia; Female; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Male; Time Factors
PubMed: 10447139
DOI: 10.1080/08035259950169080 -
Microbiology Resource Announcements Aug 2021Acinetobacter junii INC8271 was isolated from a cancer patient with polymicrobial bacteremia after biliary stent placement. The complete genome sequence consisted of a...
Acinetobacter junii INC8271 was isolated from a cancer patient with polymicrobial bacteremia after biliary stent placement. The complete genome sequence consisted of a chromosome of 3,530,883 bp (GC content, 38.56%) with 3,377 genes, including those encoding 74 tRNAs and 18 rRNAs, and two intact prophage sequences. No antibiotic resistance genes were detected.
PubMed: 34410161
DOI: 10.1128/MRA.00604-21