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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 -
Microorganisms Feb 2023Waste oil pollution and the treatment of oily waste present a challenge, and the exploitation of microbial resources is a safe and efficient method to resolve these...
Waste oil pollution and the treatment of oily waste present a challenge, and the exploitation of microbial resources is a safe and efficient method to resolve these problems. Lipase-producing microorganisms can directly degrade waste oil and promote the degradation of oily waste and, therefore, have very significant research and application value. The isolation of efficient oil-degrading strains is of great practical significance in research into microbial remediation in oil-contaminated environments and for the enrichment of the microbial lipase resource library. In this study, WCO-9, an efficient oil-degrading bacterium, was isolated from an oil-contaminated soil using olive oil as the sole carbon source, and its enzyme activity of ρ-nitrophenyl decanoate (ρ-NPD) decomposition was 3000 U/L. The WCO-9 strain could degrade a variety of edible oils, and its degradation capability was significantly better than that of the control strain, ATCC 17908. Comparative pan-genome and lipid degradation pathway analyses indicated that isolated from the same environment shared a similar set of core genes and that the species accumulated more specific genes that facilitated resistance to environmental stresses under different environmental conditions. WCO-9 has accumulated a complete set of oil metabolism genes under a long-term oil-contamination environment, and the compact arrangement of abundant lipase and lipase chaperones has further strengthened the ability of the strain to survive in such environments. This is the main reason why WCO-9 is able to degrade oil significantly more effectively than ATCC 17908. In addition, WCO-9 possesses a specific lipase that is not found in homologous strains. In summary, WCO-9, with a complete triglyceride degradation pathway and the specific lipase gene, has great potential in environmental remediation and lipase for industry.
PubMed: 36838372
DOI: 10.3390/microorganisms11020407 -
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 -
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 -
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 -
Applied Biochemistry and Biotechnology Jan 2022Mastitis is a widespread disease in dairy cattle occurring throughout the world. The increased use of antibiotics brings about the development of antibiotic-resistant...
Mastitis is a widespread disease in dairy cattle occurring throughout the world. The increased use of antibiotics brings about the development of antibiotic-resistant microbes. The application of antibiotics in dairy farming led to increased antibiotic resistance and represents a major obstacle for the treatment of mastitis. Recent advancements in nanotechnology led to the development of nanocolloids to overcome disadvantages posed by conventional antimicrobial agents. Hence, a novel, environmentally friendly, cost-effective, biocompatible, and long-term antibacterial represents a promising solution for medicine and farming. Hence, polyherbal nanocolloids (PHNc) was formulated by using the extracts of Syzygium aromaticum, Cinnamomum verum, Emblica officinalis, Terminalia belerica, Terminalia chebula, and Cymbopogon citratus and physicochemically characterized. From mastitis milk samples, microorganisms were isolated including Acinetobacter junii, Klebsiella pneumoniae, Pseudomonas stutzeri, and Acinetobacter baumannii and screened for antibiotic susceptibility. All the isolated strains were tested with PHNc and compared with antibiotics. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and biofilm assays were performed at different concentrations, and antibacterial effects were quantified. In our results, PHNc showed potent bacteriostatic, bactericidal, and antibiofilm activity against all the strains. Our results indicated that PHNc can reduce the virulence factors responsible for infection by different bacterial strains. This study confirmed that PHNc had the potential to inhibit the growth of pathogenic Gram-negative and Gram-positive strains and could be utilized as an alternative to antibiotics to inhibit multidrug-resistant microbial pathogens in cattle.
Topics: Animals; Anti-Infective Agents; Bacteria; Cattle; Drug Resistance, Multiple, Bacterial; Female; Mastitis, Bovine; Plant Extracts
PubMed: 34762270
DOI: 10.1007/s12010-021-03748-w -
Microbial Pathogenesis Jan 2020Lipopeptide biosurfactants (LPBs) are amphiphilic compounds produced by microorganisms exhibiting various biological activities. The main aim of the present study was to...
Lipopeptide biosurfactants (LPBs) are amphiphilic compounds produced by microorganisms exhibiting various biological activities. The main aim of the present study was to assess the in vitro antimicrobial, anti-biofilm, and cytotoxic effects of LPB produced by Acinetobacter junii (AjL). We determined AjL minimum inhibitory concentration (MIC) against both Gram-positive and Gram-negative bacteria as well as two fungal strains. Also, the anti-biofilm activity of AjL against the biofilm produced by clinically isolated bacterial strains was investigated. The AjL non-selectively showed activity against both Gram-positive and Gram-negative bacterial strains. The obtained results of the present study exhibited that the AjL in concentrations nearly below critical micelle concentration (CMC) has an effective antibacterial activity. It was found that the MIC values of AjL were lower than standard antifungal and it exhibited nearly 100% inhibition against Candida utilis. The attained results of the biofilm formation revealed that AjL disrupted the biofilm of Proteus mirabilis, Staphylococcus aureus, and Pseudomonas aeruginosa at 1250 μg/ml and 2500 μg/ml concentrations. The attained results of cytotoxic effect (determined by WST-1 assay) of the AjL revealed IC of 7.8 ± 0.4 mg/ml, 2.4 ± 0.5 mg/ml, and 5.7 ± 0.1 mg/ml, against U87, KB, and HUVEC cell lines, respectively. The results indicated that AjL has a potential application in the relatively new field of biomedicine.
Topics: Acinetobacter; Antimicrobial Cationic Peptides; Bacteria; Biofilms; Cell Survival; Dose-Response Relationship, Drug; Fungi; Human Umbilical Vein Endothelial Cells; Humans; Lipopeptides; Microbial Sensitivity Tests; Staphylococcus aureus; Surface-Active Agents
PubMed: 31629797
DOI: 10.1016/j.micpath.2019.103806 -
Bioresource Technology Dec 2019The study aimed to evaluate biopolymer production using two bacterial strains, Acinetobacter junii BP25 and Aeromonas hydrophila ATCC 7966, and their co-culture. Batch...
The study aimed to evaluate biopolymer production using two bacterial strains, Acinetobacter junii BP25 and Aeromonas hydrophila ATCC 7966, and their co-culture. Batch experiments were evaluated using acetate and butyrate as carbon sources in feast and famine strategy. Feast phase was studied using carbon, nitrates and phosphate in the ratio of 100:8:1 and famine phase was limited with the phosphate and nitrates. Co-culture resulted in highest specific growth rate (0.30 h) in the feast phase and the famine phase accounted the maximum polyhydroxybutyrate (PHB) accumulation (2.46 g PHB/L), followed by Acinetobacter junii BP25 (0.25 h and 1.82 g PHB/L) and Aeromonas hydrophila ATCC 7966 (0.17 h and 1.12 g PHB/L). Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR) structural analysis confirmed as PHB. PHB production using the co-culture could be integrated with biohydrogen process using volatile fatty acids (VFA) as a carbon source in the biorefinery framework.
Topics: Acinetobacter; Aeromonas hydrophila; Bioreactors; Butyrates; Coculture Techniques; Hydroxybutyrates; Polyesters; Spectroscopy, Fourier Transform Infrared
PubMed: 31494436
DOI: 10.1016/j.biortech.2019.122062 -
AMB Express Jun 2020Deltamethrin and its major metabolite 3-phenoxybenzoic acid (3-PBA) have caused serious threat to the environment as well as human health, yet little is known about...
Deltamethrin and its major metabolite 3-phenoxybenzoic acid (3-PBA) have caused serious threat to the environment as well as human health, yet little is known about their degradation pathways by bacterial co-cultures. In this study, the growth and degradation kinetics of Acinetobacter junii LH-1-1 and Klebsiella pneumoniae BPBA052 during deltamethrin and 3-PBA degradation were established, respectively. When the inoculum proportion of the strains LH-1-1 and BPBA052 was 7.5:2.5, and LH-1-1 was inoculated 24 h before inoculation of strain BPBA052, 94.25% deltamethrin was degraded and 9.16 mg/L of 3-PBA remained within 72 h, which was 20.36% higher and 10.25 mg/L lesser than that in monoculture of LH-1-1, respectively. And the half-life of deltamethrin was shortened from 38.40 h to 24.58 h. Based on gas chromatography-mass spectrometry, 3-phenoxybenzaldehyde, 1,2-benzenedicarboxylic butyl dacyl ester, and phenol were identified as metabolites during deltamethrin degradation in co-culture. This is the first time that a co-culture degradation pathway of deltamethrin has been proposed based on these identified metabolites. Bioremediation of deltamethrin-contaminated soils with co-culture of strains LH-1-1 and BPBA052 significantly enhanced deltamethrin degradation and 3-PBA removal. This study provides a platform for further studies on deltamethrin and 3-PBA biodegradation mechanism in co-culture, and it also proposes a promising approach for efficient bioremediation of environment contaminated by pyrethroid pesticides and their associated metabolites.
PubMed: 32495133
DOI: 10.1186/s13568-020-01043-1 -
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