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Bioresource Technology Jan 2022A heterotrophic nitrification- aerobic denitrification (HNAD) bacterium, Acinetobacter junii ZHG-1, was isolated, meanwhile, the optimal conditions for the strain were...
A heterotrophic nitrification- aerobic denitrification (HNAD) bacterium, Acinetobacter junii ZHG-1, was isolated, meanwhile, the optimal conditions for the strain were evaluated, moreover, the influence mechanism of the C/N ratio on the HNAD process was investigated from the perspective of electron transport and energy level. The increasing of C/N ratio enhanced the reduced/oxidized nicotinamide adenine dinucleotide (NADH/NAD) ratio, NADH concentration, electron transport system activity (ETSA), ATP content, as well as enzymes activities, consequently, the HNAD performance of the strain can be improved, however, when the C/N ratio was higher than 30, the activities of enzymes relating to the HNAD process and the ETSA had reached the maximum, which might limit the further improvement of the nitrogen removal with the increasing of C/N ratio. As the interaction between different biochemical reactions in HNAD process, more efforts should be devoted to the influent mechanism of different environmental factors on the HNAD process.
Topics: Acinetobacter; Aerobiosis; Denitrification; Heterotrophic Processes; Nitrification; Nitrites; Nitrogen
PubMed: 34653622
DOI: 10.1016/j.biortech.2021.126116 -
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 -
Marine Pollution Bulletin Nov 2021This study investigates bacterial diversity and potential pathogens in the international ships' ballast water at Tanjung Pelepas Port, Malaysia, using 16S rRNA amplicon...
This study investigates bacterial diversity and potential pathogens in the international ships' ballast water at Tanjung Pelepas Port, Malaysia, using 16S rRNA amplicon sequencing. Thirty-four bacterial phylum, 305 families, 577 genera, and 941 species were detected in eight ballast water samples of different origins. The similarity of the bacterial composition between samples was found to be random and not tied to geographical locations. The bacterial abundance did not seem to be affected by related physicochemical except for temperature. Ballast water samples with a temperature lower than 25 °C showed a relatively lower bacterial abundance. A total of 33 potential pathogens were detected from all ballast water samples. Pseudomonas spp., Tenacibaculum spp., Flavobacteriaceae spp., Halomonas spp., and Acinetobacter junii are the potential pathogens with more than 10% OTU prevalence. This study would provide beneficial information for further enhancing ballast water microorganism guidelines in Malaysia.
Topics: Acinetobacter; Humans; Malaysia; RNA, Ribosomal, 16S; Ships; Water
PubMed: 34391012
DOI: 10.1016/j.marpolbul.2021.112850 -
Frontiers in Microbiology 2021New Delhi metallo-β-lactamase, a metallo-β-lactamase carbapenemase type, mediates resistance to most β-lactam antibiotics including penicillins, cephalosporins, and...
New Delhi metallo-β-lactamase, a metallo-β-lactamase carbapenemase type, mediates resistance to most β-lactam antibiotics including penicillins, cephalosporins, and carbapenems. Therefore, it is important to detect genes in children's clinical samples as quickly as possible and analyze their characteristics. Here, a recombinase-aided amplification (RAA) assay, which operates in a single one-step reaction tube at 39°C in 5-15 min, was established to target genes in children's clinical samples. The analytical sensitivity of the RAA assay was 20 copies, and the various bacterial types without genes did not amplify. This method was used to detect genes in 112 children's stool samples, 10 of which were tested positive by both RAA and standard PCR. To further investigate the characteristics of carbapenem-resistant bacteria carrying in children, 15 carbapenem-resistant bacteria (, , , , , , and ) were isolated from the 10 samples. Notably, more than one bacterial type was isolated from three samples. Most of these isolates were resistant to cephalosporins, cefoperazone-sulbactam, piperacillin-tazobactam, ticarcillin-clavulanic acid, aztreonam, co-trimoxazole, and carbapenems. and were the two main types in these samples. These data show that the RAA assay has potential to be a sensitive and rapid gene screening test for clinical samples. The common existence of and multi-drug resistance genes presents major challenges for pediatric treatment.
PubMed: 34367092
DOI: 10.3389/fmicb.2021.691289 -
Environmental Science and Pollution... Dec 2021The direct discharge of azo dyes and/or their metabolites into the environment may exert toxic, mutagenic, and carcinogenic effects on exposed fauna and flora. In this...
The direct discharge of azo dyes and/or their metabolites into the environment may exert toxic, mutagenic, and carcinogenic effects on exposed fauna and flora. In this study, we analyzed the metabolites produced during the degradation of an azo dye namely Reactive Black 5 (RB5) in the bacterial-augmented floating treatment wetlands (FTWs), followed by the investigation of their underlying toxicity. To this end, a FTWs system was developed by using a common wetland plant Phragmites australis in the presence of three dye-degrading bacteria (Acinetobacter junii strain NT-15, Pseudomonas indoloxydans strain NT-38, and Rhodococcus sp. strain NT-39). We found that the FTW system effectively degraded RB5 into at least 20 different metabolites with the successful removal of color (95.5%) from the water. The fish toxicity assay revealed the nontoxic characteristics of the metabolites produced after dye degradation. Our study suggests that bacterially aided FTWs could be a suitable option for the successful degradation of azo dyes, and the results presented in this study may help improve the overall textile effluent cleanup processes.
Topics: Animals; Azo Compounds; Biodegradation, Environmental; Coloring Agents; Naphthalenesulfonates; Water Pollutants, Chemical; Wetlands
PubMed: 34231138
DOI: 10.1007/s11356-021-15130-8 -
International Journal of Environmental... Jun 2021The increasing number of endoscopic procedures performed and their increasing invasiveness mean that endoscopy of the gastrointestinal tract is associated with the risk...
The State of Microbiological Cleanliness of Surfaces and Equipment of an Endoscopic Examination Laboratory-Data from a Reference Tertiary Clinical Endoscopy Center in Southern Poland.
The increasing number of endoscopic procedures performed and their increasing invasiveness mean that endoscopy of the gastrointestinal tract is associated with the risk of transmitting pathogenic microorganisms through infected equipment or contact with other patients and medical staff. In order to ensure protection of the health of both patients and medical staff, endoscopy laboratories should meet high hygiene standards. The results of tests of the microbiological cleanliness of surfaces and equipment of an endoscopic examination laboratory performed in the period from January to December 2019 at the Provincial Clinical Hospital No. 2 in Rzeszow were assessed retrospectively. Samples for testing were collected by swabbing from places where microbiological contamination was the most likely and cleaning was the most difficult. In the analyzed period, a total of 86 samples were collected for microbiological tests, of which positive results accounted for 6.9%. Positive results were obtained mainly from swabs collected from wet surfaces (66.7%). Most of the isolated microorganisms were Gram-negative bacteria (66.7% of all positive tests) and they were: , and . The condition of the microbiological cleanliness of the surfaces and equipment of the endoscopic examination laboratory was satisfactory. A very low level of microbiological contamination of the tested items indicates occasional shortcomings in the decontamination processes. Since microorganisms isolated from the collected samples may be the cause of infection in patients and medical personnel, it is necessary to verify the decontamination procedures applied and to continue periodic microbiological monitoring of their effectiveness.
Topics: Acinetobacter; Endoscopy; Equipment Contamination; Humans; Laboratories; Poland; Retrospective Studies
PubMed: 34208169
DOI: 10.3390/ijerph18126346 -
Journal of Immunology (Baltimore, Md. :... Jun 2021Group 3 innate lymphoid cells (ILC3s) in the gut mucosa have long been thought to be noncytotoxic lymphocytes that are critical for homeostasis of intestinal epithelial...
Group 3 innate lymphoid cells (ILC3s) in the gut mucosa have long been thought to be noncytotoxic lymphocytes that are critical for homeostasis of intestinal epithelial cells through secretion of IL-22. Recent work using human tonsillar cells demonstrated that ILC3s exposed to exogenous inflammatory cytokines for a long period of time acquired expression of granzyme B, suggesting that under pathological conditions ILC3s may become cytotoxic. We hypothesized that inflammation associated with bacterial exposure might trigger granzyme B expression in gut ILC3s. To test this, we exposed human colon lamina propria mononuclear cells to a panel of enteric bacteria. We found that the Gram-negative commensal and pathogenic bacteria induced granzyme B expression in a subset of ILC3s that were distinct from IL-22-producing ILC3s. A fraction of granzyme B ILC3s coexpressed the cytolytic protein perforin. Granzyme B expression was mediated, in part, by IL-15 produced upon exposure to bacteria. ILC3s coexpressing all three IL-15R subunits (IL15Rα/β/γ) increased following bacterial stimulation, potentially allowing for presentation of IL-15 during bacterial exposure. Additionally, a large frequency of colonic myeloid dendritic cells expressed IL-15Rα, implicating myeloid dendritic cells in presentation of IL-15 to ILC3s. Tonsillar ILC3s minimally expressed granzyme B when exposed to the same bacteria or to rIL-15. Overall, these data establish the novel, to our knowledge, finding that human colonic ILC3s can express granzyme B in response to a subset of enteric bacteria through a process mediated by IL-15. These observations raise new questions about the multifunctional role of human gut ILC3s.
Topics: Acinetobacter; Colon; Gastrointestinal Microbiome; Granzymes; Humans; Immunity, Innate; Interleukin-15; Lymphocytes; Ruminococcus; Salmonella typhimurium
PubMed: 34117105
DOI: 10.4049/jimmunol.2000239 -
MicrobiologyOpen Mar 2021The intestinal symbiotic bacteria of Aedes albopictus play a potential role in host resistance to insecticides. In this study, we sequenced the full-length of 16S rRNA... (Comparative Study)
Comparative Study
The intestinal symbiotic bacteria of Aedes albopictus play a potential role in host resistance to insecticides. In this study, we sequenced the full-length of 16S rRNA and analyzed the differences in the intestinal microbiota between deltamethrin-resistant and -sensitive Ae. albopictus. Symbiotic bacteria were cultured and analyzed using six types of culture media in aerobic and anaerobic environments. We found significant differences in the diversity and abundance of the intestinal microbiota of the two strains of Ae. albopictus. The symbiotic bacteria cultured in vitro were found to be mainly facultative anaerobes. The cultured bacteria such as Serratia oryzae and Acinetobacter junii may function to promote the development of insecticide resistance. This work indicates that intestinal bacteria may contribute to the enhancement of insecticide resistance of Ae. albopictus It also highlights the analytical advantage of full-length 16S rRNA sequencing to study the intestinal microbiota of mosquitoes.
Topics: Aedes; Animals; Bacteria; Biodiversity; DNA, Bacterial; Gastrointestinal Microbiome; Insecticide Resistance; Insecticides; Larva; Nitriles; Pyrethrins; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Symbiosis
PubMed: 33970535
DOI: 10.1002/mbo3.1177 -
Research in Microbiology 2021The K92 capsular polysaccharide (CPS) from Acinetobacter baumannii B8300 was studied by sugar analysis, Smith degradation, and one- and two-dimensional H and C NMR...
A novel ItrA4 d-galactosyl 1-phosphate transferase is predicted to initiate synthesis of an amino sugar-lacking K92 capsular polysaccharide of Acinetobacter baumannii B8300.
The K92 capsular polysaccharide (CPS) from Acinetobacter baumannii B8300 was studied by sugar analysis, Smith degradation, and one- and two-dimensional H and C NMR spectroscopy. The elucidated CPS includes a branched pentasaccharide repeat unit containing one d-Galp and four l-Rhap residues; an atypical composition given that all A. baumannii CPS structures determined to date contain at least one amino sugar. Accordingly, biosynthesis of A. baumannii CPS types are initiated by initiating transferases (Itrs) that transfer 1-phosphate of either a 2-acetamido-2-deoxy-d-hexose, a 2-acetamido-2,6-dideoxy-d-hexose or a 2-acetamido-4-acylamino-2,4,6-trideoxy-d-hexose to an undecaprenyl phosphate (UndP) carrier. However, the KL92 capsule biosynthesis gene cluster in the B8300 genome sequence includes a gene for a novel Itr type, ItrA4, which is predicted to begin synthesis of the K92 CPS by transferring D-Galp 1-phosphate to the UndP lipid carrier. The itrA4 gene was found in a module transcribed in the opposite direction to the majority of the K locus. This module also includes an unknown open reading frame (orf), a gtr166 glycosyltransferase gene, and a wzi gene predicted to be involved in the attachment of CPS to the cell surface. Investigation into the origins of orf-gtr166-itrA4-wzi revealed it might have originated from Acinetobacter junii.
Topics: Acinetobacter Infections; Acinetobacter baumannii; Adult; Amino Sugars; Bacterial Capsules; Bacterial Proteins; Humans; Magnetic Resonance Spectroscopy; Male; Multigene Family; Polysaccharides, Bacterial; Transferases (Other Substituted Phosphate Groups)
PubMed: 33667610
DOI: 10.1016/j.resmic.2021.103815 -
Scientific Reports Jan 2021In this study, sediments were collected from two different sites in the deep-sea hydrothermal region of the South Atlantic Ocean. Two microbial enrichment cultures (H7S...
In this study, sediments were collected from two different sites in the deep-sea hydrothermal region of the South Atlantic Ocean. Two microbial enrichment cultures (H7S and H11S), which were enriched from the sediments collected at two sample sites, could effectively degrade petroleum hydrocarbons. The bacterial diversity was analyzed by high-throughput sequencing method. The petroleum degradation ability were evaluated by gas chromatography-mass spectrometry and gravimetric analysis. We found that the dominant oil-degrading bacteria of enrichment cultures from the deep-sea hydrothermal area belonged to the genera Pseudomonas, Nitratireductor, Acinetobacter, and Brevundimonas. After a 14-day degradation experiment, the enrichment culture H11S, which was obtained near a hydrothermal vent, exhibited a higher degradation efficiency for alkanes (95%) and polycyclic aromatic hydrocarbons (88%) than the enrichment culture H7S. Interestingly, pristane and phytane as biomarkers were degraded up to 90% and 91% respectively by the enrichment culture H11S, and six culturable oil-degrading bacterial strains were isolated. Acinetobacter junii strain H11S-25, Nitratireductor sp. strain H11S-31 and Pseudomonas sp. strain H11S-28 were used at a density ratio of 95:4:1 to construct high-efficiency oil-degrading consortium H. After a three-day biodegradation experiment, consortium H showed high degradation efficiencies of 74.2% and 65.7% for total alkanes and PAHs, respectively. The degradation efficiency of biomarkers such as pristane and high-molecular-weight polycyclic aromatic hydrocarbons (such as CHR) reached 84.5% and 80.48%, respectively. The findings of this study indicate that the microorganisms in the deep-sea hydrothermal area are potential resources for degrading petroleum hydrocarbons. Consortium H, which was artificially constructed, showed a highly efficient oil-degrading capacity and has significant application prospects in oil pollution bioremediation.
PubMed: 33446871
DOI: 10.1038/s41598-021-80991-5