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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 -
Huan Jing Ke Xue= Huanjing Kexue Aug 2019Due to the problems of traditional biological nitrogen and phosphorus removal, including long process duration and high infrastructural and operational costs, the...
Due to the problems of traditional biological nitrogen and phosphorus removal, including long process duration and high infrastructural and operational costs, the simultaneous nitrogen and phosphorus removal capabilities, influencing factors and kinetic characteristics were systematically studied using the heterotrophic nitrifier NP1 which possesses efficient simultaneous nitrogen and phosphorus removal ability. The results showed that strain NP1 exhibited efficient heterotrophic nitrification ability with a maximum ammonia removal rate of 99.12%. Furthermore, only small amounts of nitrification intermediates were accumulated during the reaction process. Strain NP1 also adapted well to higher ammonia nitrogen loading. In addition, strain NP1 had efficient aerobic denitrification characteristics, and could utilize nitrite and nitrate for growth and metabolism, achieving a maximum removal rate of 91.40% and 95.10%, respectively. The heterotrophic nitrification process of strain NP1 was accompanied by simultaneous phosphorus accumulation, and the appropriate ratio of nitrogen to phosphorus was beneficial for the simultaneous removal of nitrogen and phosphorus. When the ratio of nitrogen to phosphorus was 5:1, the maximum ammonia nitrogen and phosphate removal rates reached 99.21% and 88.35%, respectively. The bacterial growth process of stain NP1 matched the Logistic model (>0.99), and the nitrogen and phosphate degradation conformed to the Compertz model (>0.99). The maximum conversion rates of nitrogen and phosphate () obtained by model fitting were in the order ammonia>nitrate>nitrite, and lag time (0) was in the order nitrate>nitrite>ammonia. According to the analysis of the degradation kinetics of the matrix and the removal rate of nitrogen and phosphorus, the optimal conditions were found to be sodium succinate, C/N=10, =30℃, and =160 r·min.
Topics: Acinetobacter; Aerobiosis; Denitrification; Heterotrophic Processes; Kinetics; Nitrification; Nitrites; Nitrogen; Phosphorus; Water Purification
PubMed: 31854780
DOI: 10.13227/j.hjkx.201901208 -
Bioresource Technology Nov 2014A novel heterotrophic nitrifying bacterium was isolated from activated sludge and was identified as Acinetobacter junii YB. The strain exhibited efficient heterotrophic...
A novel heterotrophic nitrifying bacterium was isolated from activated sludge and was identified as Acinetobacter junii YB. The strain exhibited efficient heterotrophic nitrification-aerobic denitrification ability at a broad range of ammonium loads and had the capability to utilize hydroxylamine, nitrite and nitrate as a sole nitrogen source. Based on the nitrogen removal and enzyme assay, the nitrogen removal pathway was speculated to be achieved through heterotrophic nitrification coupled with aerobic denitrification. In addition, single-factor experiments showed that efficient heterotrophic nitrification and growth of strain YB occurred with succinate as the carbon source, pH 7.5, 37 °C, and high C/N ratio and dissolved oxygen. Furthermore, the new isolate showed capacities for aggregation and hydrophobicity. Regular variations of the flocculating ability and relative hydrophobicity were observed during the whole cultivation. The ability to perform heterotrophic nitrification-aerobic denitrification and cell aggregation demonstrated the great potential of the strain YB for future applications.
Topics: Acinetobacter; Analysis of Variance; Carbon; Cell Aggregation; DNA Primers; Flocculation; Heterotrophic Processes; Microscopy, Electron, Scanning; Nitrification; Nitrogen; Sewage; Species Specificity; Spectrophotometry, Ultraviolet; Succinic Acid
PubMed: 25171329
DOI: 10.1016/j.biortech.2014.08.058 -
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 -
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 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 -
Heliyon Feb 2024This study was aimed at using microcosm experiments to assess crude oil degradation efficiency of and isolated along Ghana's coast. Uncontaminated seawater from...
This study was aimed at using microcosm experiments to assess crude oil degradation efficiency of and isolated along Ghana's coast. Uncontaminated seawater from selected locations along the coast was used to isolate bacterial species by employing enrichment culture procedures with crude oil as the only carbon source. The isolates were identified by means of the extended direct colony transfer method of the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy (MALDI-TOF MS), as , and . Remediation tests showed that yielded degradation efficiencies of 27.59 %, 41.38 % and 57.47 %. Whereas efficiencies of 21.14 %, 32.18 % and 43.68 % were recorded by representing 15, 30 and 45 days respectively. Consortia of , and also yielded 32.18 %, 48.28 % and 62.07 % for the selected days respectively. Phylogenetic characterization using ClustalW and BLAST of sequences generated from the Oxford Nanopore Sequencing technique, showed that the Ghanaian isolates clustered with and species respectively. An analysis of the sequenced data for the 1394-bp portion of the 16S rRNA gene of the isolates revealed >99 % sequence identity with the isolates present on the GenBank database. The isolates of closest identity were and with accession numbers, NR_133958.1 and KJ147060.1 respectively. and isolated from Ghana's coast under pristine seawater conditions have therefore demonstrated their capacity to be used for the remediation of crude oil spills.
PubMed: 38318038
DOI: 10.1016/j.heliyon.2024.e24994 -
Environmental Science and Pollution... Apr 2017A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene...
A new insight to adsorption and accumulation of high lead concentration by exopolymer and whole cells of lead-resistant bacterium Acinetobacter junii L. Pb1 isolated from coal mine dump.
A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene sequencing. The minimum inhibitory concentration of lead for the strain was 16,000 mg l and it showed antibiotic and multi metal resistance. In aqueous culture, at an initial lead (Pb(II)) concentration of 100 and 500 mg l, lead adsorption and accumulation by the isolate was 100 and 60%, at pH 7 at 30 °C after 48 and 120 h, respectively. The two fractions of exopolysaccharide (EPS), loosely associated EPS (laEPS) and bound EPS (bEPS), and whole cells (devoid of EPS) showed high binding affinity towards Pb(II). The binding affinity of laEPS towards Pb(II) (1071 mg Pb g) was three times higher than that of bEPS (321.5 mg Pb g) and 6.5 times higher than that of whole cells (165 mg Pb g). The binding affinity of EPS and whole cells with Pb(II), reported in the current study, is considerably higher as compared to that reported in the literature, till date. SEM analysis, showed an increase in thickness of cells on exposure to Pb(II) and TEM analysis, revealed its accumulation (interior of cell) and its adsorption (with the external cell surface). The isolate was also found to be positive for indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production which helps in promoting plant growth. Thus, this study provides a new understanding towards Pb(II) uptake by A. junii Pb1, highlighting its potential on the restoration of Pb(II) contaminated repositories.
Topics: Acinetobacter; Adsorption; Coal; Deoxyuracil Nucleotides; Lead; RNA, Ribosomal, 16S
PubMed: 28283975
DOI: 10.1007/s11356-017-8752-8