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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 -
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 -
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 -
Brazilian Journal of Microbiology :... Jan 2019This study explores the potential of lead resistant bacterium Acinetobacter junii Pb1 for adsorption/accumulation of lead using various techniques. In the present work,...
This study explores the potential of lead resistant bacterium Acinetobacter junii Pb1 for adsorption/accumulation of lead using various techniques. In the present work, growth of A. junii Pb1 was investigated in the presence of a range of Pb(II) concentrations (0, 100, 250, 500, and 1000 mg l). Lead was found to have no toxic effect on the growth of A. junii Pb1 at 100 and 250 mg l concentrations. However, further increase in Pb(II) concentration (500 mg l) showed increase in lag phase, though growth remained unaffected and significant growth inhibition was observed when concentration was increased to 1000 mg l. Same was confirmed by the observations of flow cytometry. Further, the effect of Pb(II) on A. junii Pb1 was evaluated by using fluorescence microscopy, spectrofluorimetry, and flow cytometry. The spectrofluorimetry and fluorescence microscopy results revealed the accumulation of Pb(II) inside the bacterial cells as evident by green fluorescence due to lead binding fluorescent probe, Leadmium Green AM dye. Flow cytometry observations indicate an increase in cell size and granularity of exposure to lead. Thus, present work provides a new understanding of Pb(II) tolerance in A. junii Pb1 and its potential use in remediation of lead from contaminated soil.
Topics: Acinetobacter; Biodegradation, Environmental; Flow Cytometry; Lead
PubMed: 30637583
DOI: 10.1007/s42770-019-00041-1 -
Research in Microbiology Jun 2023Water sources (surface water, drinking water, rivers, and ponds) are significant reservoirs for transmitting antibiotic-resistant bacteria. In addition, these waters are...
Water sources (surface water, drinking water, rivers, and ponds) are significant reservoirs for transmitting antibiotic-resistant bacteria. In addition, these waters are an important public health problem because they are suitable environments for transferring antibiotic resistance genes between bacterial species. Our study aimed to assess the prevalence of Extended-spectrum beta-lactamase (ESBL) producing isolates in water samples, the susceptibility of the isolates to the specified antibiotics, the determination of biofilm ability, antibiotic resistance genes, and the molecular typing of the isolates. For this purpose, Polymerase chain reaction (PCR) and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analyses were used. Out of 70 isolates, 15 (21%) were ESBL producing, and sent for the MALDI-TOF analysis, where Escherichia coli, Acinetobacter calcoaceticus, Enterobacter bugandensis, Acinetobacter pittii, Pseudomonas aeruginosa, Acinetobacter junii, Pseudomonas oleovorans, and Enterobacter ludwigigii were identified. Moreover, colistin resistance genes (mcr 1/2/6, mcr 4, mcr 5, mcr 3/7, and mcr 8), ESBL-encoding genes (bla, bla, and bla) and carbapenemase genes (bla, bla, and bla) using molecular analysis (PCR) were confirmed. The colistin resistance gene was detected at 80% (12/15) in the isolates obtained. The distribution of these isolates according to resistance genes was found as mcr 1/2/6 4 (20%), mcr 3/7 3 (13%), and mcr 5 (40%). Additionally, the isolates harbored bla(6.6%) and bla (6.6%) genes. However, bla, bla, bla, and bla genes were not detected in any isolates. According to the Congo red agar method, seven (46.6%) isolates showed negative biofilm ability, and eight (53.3%) showed moderate biofilm ability. However, the microplate method detected weak biofilm in 53.3% of the isolates. In conclusion, this study provides evidence for the existence of multidrug-resistant bacteria that co-exist with mcr and ESBL genes in water sources. These bacteria can migrate to other environments and pose increasing threats to public health.
Topics: Colistin; Anti-Bacterial Agents; beta-Lactamases; Escherichia coli; Bacteria; Drug Resistance, Multiple, Bacterial; Water; Escherichia coli Proteins; Microbial Sensitivity Tests
PubMed: 37004897
DOI: 10.1016/j.resmic.2023.104056 -
Heliyon Feb 2023The utilization and improper use of crude oil can have irreparable damage on the environment and human populations. This study sought to isolate hydrocarbon utilizing...
The utilization and improper use of crude oil can have irreparable damage on the environment and human populations. This study sought to isolate hydrocarbon utilizing bacteria from 1% v/v pristine seawater and 1% v/v crude oil using enrichment culture techniques. Whole genome sequencing of DNA using the Oxford Nanopore sequencing technique with Fastq WIMP as the workflow at 3% abundance was undertaken. The results showed that the most abundant isolates identified using this technique at specific sampling sites were, (51.9%) (15.8%) (21.6%) (23.4%) (24.7%) (23.0%) (40.0%) and (14.2%). Cumulatively, the most abundant isolates in the 8 sampling sites were (17.91%), (11.68%) (7.68%) (7.67%) (3.40%) (3.10%). Spearman's rank correlation analysis to examine the strength of relationship between the physicochemical parameters and type of bacteria isolated, revealed that salinity (0.8046) and pH (0.7252) were the highest. Isolated bacteria from pristine seawater, especially have shown their capacity for bioremediating oil spill pollution in oceanic environments in Ghana.
PubMed: 36785818
DOI: 10.1016/j.heliyon.2023.e13075 -
Microbiology Spectrum Dec 2022New Delhi metallo-β-lactamase (NDM)-producing clinical strains in Acinetobacter spp. have been recently reported in many countries and have received considerable...
New Delhi metallo-β-lactamase (NDM)-producing clinical strains in Acinetobacter spp. have been recently reported in many countries and have received considerable attention. The vast majority of cases occur on conjugative plasmids, which play a vital role in disseminating . To characterize the conjugative plasmids bearing genes in Acinetobacter spp., we analyzed the variants of , conjugative transfer regions, genetic contexts of , and the phylogenetic pattern of the 62 predicted -positive plasmids, which were selected from 1,191 plasmids of Acinetobacter species from GenBank. We identified 30 conjugative plasmids from the 62 -harboring plasmids in Acinetobacter species, with the sites similar to plasmid pNDM-YR7 in our study, genes coding for relaxases of the MOB family, genes encoding type IV coupling proteins (T4CPs) of the TrwB/TraD subfamily, and VirB-like type IV secretion system (T4SS) gene clusters. The genome sizes of all 30 pNDM-YR7-like plasmids ranged from 39.36 kb to 49.65 kb, with a median size of 44.56 kb. The most common species of Acinetobacter containing the -positive conjugative plasmids was A. baumannii, followed by Acinetobacter lwoffii and Acinetobacter indicus. Notably, pNDM-YR7 is the first report on a -positive conjugative plasmid in Acinetobacter junii. Moreover, all 30 -positive conjugative plasmids in Acinetobacter species were found to contain genetic contexts with the structure IS--IS--. Our findings provide important insights into the phylogeny and evolution of -positive plasmids of Acinetobacter species and further address their role in acquiring and spreading genes in Acinetobacter species. Conjugative plasmids harboring the gene play a vital role in disseminating carbapenem resistance. In this study, we first report a conjugative plasmid, pNDM-YR7, in Acinetobacter junii. Based on the genomic characteristics of the -positive pNDM-YR7, we performed typing and comparative analysis of -positive plasmids using the 1,191 plasmids of Acinetobacter species available in the NCBI RefSeq database. We analyzed the characteristics of -positive plasmids, including the variants of , genetic features associated with , conjugative transfer regions, and the phylogenetic pattern of the -positive plasmids. All 30 -positive conjugative plasmids were found to contain an IS--IS-- region. This study provides novel insights into the phylogeny and evolution of -harboring conjugative plasmids and contributes to the repertoire of knowledge surrounding -positive plasmids in the genus Acinetobacter.
Topics: Phylogeny; Acinetobacter; Plasmids; beta-Lactamases; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 36301090
DOI: 10.1128/spectrum.02102-22 -
Microbiology Resource Announcements Mar 2019We report here the draft genome sequence of Acinetobacter junii MHI21018, isolated in 2009 from bovine colostrum. The draft genome sequence is composed of 3,267,995 bp,...
We report here the draft genome sequence of Acinetobacter junii MHI21018, isolated in 2009 from bovine colostrum. The draft genome sequence is composed of 3,267,995 bp, has a GC content of 38.54%, and was assembled into 114 contigs (contig size, >500 bp) with an value of 72,566 bp.
PubMed: 30863829
DOI: 10.1128/MRA.01700-18