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International Journal of Molecular... Jan 2023(formerly ), a non-fermentative bacterium, has been isolated from animals and human clinical specimens. It is naturally resistant to polymyxins, including colistin...
(formerly ), a non-fermentative bacterium, has been isolated from animals and human clinical specimens. It is naturally resistant to polymyxins, including colistin (CO), and may cause opportunistic infections in humans. We isolated six strains from Senegalese monkey stool. In order to determine whether an efflux pump mechanism was involved in CO resistance in we evaluated the effects of verapamil (VRP), reserpine (RSP), phe-arg β-naphthylamide dihydrochloride (PAβN) and carbonyl cyanide 3-chloro phenyl hydrazone (CCCP), four efflux pump inhibitors, on these colistin-resistant strains. Using the broth microdilution method, a CO and CCCP combination of 2 µg/mL and 10 µg/mL, respectively, significantly reduced the CO minimal inhibitory concentration (MIC) of , supporting an efflux pump mechanism. In contrast, VRP, PAβN and RSP did not restore CO susceptibility. A time kill assay showed a bactericidal effect of the CO-CCCP combination. Genomic analysis revealed a potential implication in the CO resistance mechanism of some conserved efflux pumps, such as YejABEF, NorM and EmrAB, as previously reported in other bacteria. An inhibitory effect of the CO-CCCP combination was observed on biofilm formation using the crystal violet method. These results suggest that the intrinsic CO resistance in is linked to an efflux pump mechanism and that the synergistic effect of CO-CCCP may open a new field to identify new treatments to restore antibiotic efficacy in humans.
Topics: Humans; Colistin; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Hydrazones; Anti-Bacterial Agents; Brucella; Microbial Sensitivity Tests
PubMed: 36768429
DOI: 10.3390/ijms24032106 -
New Biotechnology Jul 2018Piracetam (2-oxo-1-pyrrolidine acetamide) is a popular cognitive enhancer, which has recently been detected in waste and drinking water. Nootropic drugs are designed to...
Piracetam (2-oxo-1-pyrrolidine acetamide) is a popular cognitive enhancer, which has recently been detected in waste and drinking water. Nootropic drugs are designed to affect human metabolism and act on the nervous system, but their environmental effects have yet to be the subject of detailed studies. In this report, we present the efficient biodegradation of the cognitive enhancer, piracetam. Two bacterial strains capable of using this compound as the sole carbon source were isolated and later identified as Ochrobactrum anthropi strain MW6 and Ochrobactrum intermedium strain MW7. The compound's mineralization and the cleavage of the heterocyclic ring were shown in the experiments with C-labeled piracetam. This is also the first report of a pharmaceutical's degradation by the Ochrobactrum genus. This study presents model microorganisms that can be used in further investigation of piracetam's degradation pathways as well as enzymes and genes involved in the process.
Topics: Chromatography, High Pressure Liquid; Nootropic Agents; Ochrobactrum; Piracetam
PubMed: 28720419
DOI: 10.1016/j.nbt.2017.07.006 -
Canadian Journal of Microbiology Feb 2020Growth and productivity of rice are negatively affected by soil salinity. However, some salt-tolerant rhizosphere-inhabiting bacteria can improve salt resistance of...
Growth and productivity of rice are negatively affected by soil salinity. However, some salt-tolerant rhizosphere-inhabiting bacteria can improve salt resistance of plants, thereby augmenting plant growth and production. Here, we isolated a total of 53 plant-growth-promoting rhizobacteria (PGPR) from saline and non-saline areas in Bangladesh where electrical conductivity was measured as >7.45 and <1.80 dS/m, respectively. Bacteria isolated from saline areas were able to grow in a salt concentration of up to 2.60 mol/L, contrary to the isolates collected from non-saline areas that did not survive beyond 854 mmol/L. Among the salt-tolerant isolates, , , and , identified by comparing respective sequences of 16S rRNA using the NCBI GenBank, exhibited a higher amount of atmospheric nitrogen fixation, phosphate solubilization, and indoleacetic acid production at 200 mmol/L salt stress. Salt-tolerant isolates exhibited greater resistance to heavy metals and antibiotics, which could be due to the production of an exopolysaccharide layer outside the cell surface. L. fertilized with MS3 and grown under 200 mmol/L salt stress was found to be favoured by enhanced expression of a set of at least four salt-responsive plant genes: , , , and . Fertilization of rice with osmoprotectant-producing PGPR, therefore, could be a climate-change-preparedness strategy for coastal agriculture.
Topics: Achromobacter denitrificans; Bacillus; Bangladesh; Indoleacetic Acids; Nitrogen Fixation; Ochrobactrum; Oryza; Phosphates; RNA, Ribosomal, 16S; Rhizosphere; Salinity; Salt Stress; Salt Tolerance; Soil; Soil Microbiology
PubMed: 31714812
DOI: 10.1139/cjm-2019-0323 -
Journal of Hazardous Materials Apr 2020Currently, radioactive waste is disposed primarily by burial in a deep geological repository. Microorganisms thriving in such contaminated environment show tolerance to...
Currently, radioactive waste is disposed primarily by burial in a deep geological repository. Microorganisms thriving in such contaminated environment show tolerance to radionuclides. In the present study the bacterial flora, from soil sample collected from an area around atomic power station exposed to radionuclides and heavy metals, was cultivated and assessed for thorium (Th) tolerance. Of all the isolates, strain AM7 identified as O. intermedium was selected since it could thrive at high levels of Th (1000 mg L). AM7 was characterized physico-chemically and its culture medium was optimized using central composite design of response surface methodology for assessing its growth properties in presence of Th. The strain also showed exceptional exopolysaccharide (EPS) production and its yield was further analyzed using one factor study to investigate the influence of each medium component. On supplementing the EPS medium with Th, no significant decrease in yield was observed. FTIR spectroscopy revealed the functional groups of EPS involved in EPS-Th binding. To the best of our knowledge, this is the first report showing exceptional Th-tolerance by any bacteria. Such study will help other researchers to strategize an environment-friendly way of radwaste disposal.
Topics: Biopolymers; Microbial Consortia; Ochrobactrum; Polysaccharides, Bacterial; RNA, Ribosomal, 16S; Radiation Tolerance; Soil Pollutants, Radioactive; Thorium Compounds
PubMed: 31954311
DOI: 10.1016/j.jhazmat.2020.122047 -
Poultry Science Apr 2020This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens...
Dietary l-arginine supplementation ameliorates inflammatory response and alters gut microbiota composition in broiler chickens infected with Salmonella enterica serovar Typhimurium.
This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens subjected to Salmonella enterica serovar Typhimurium. One hundred and forty 1-day-old Arbor Acres male birds were randomly assigned to a 2 × 2 factorial arrangement including diet treatment (with or without 0.3% Arg supplementation) and immunological stress (with or without S. typhimurium challenge). Samples were obtained at 7 D after infection (day 23). Results showed that S. typhimurium challenge caused histopathological and morphological damages, but Arg addition greatly reduced these intestinal injuries. S. typhimurium challenge elevated the levels of serum inflammatory parameters, including diamine oxidase, C-reactive protein, procalcitonin, IL-1β, IL-8, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITNF) homolog. However, Arg supplementation decreased the serum procalcitonin, IL-1β, IL-8, and LITNF concentration. S. typhimurium challenge significantly increased jejunal IL-1β, IL-8, IL-10, and IL-17 mRNA expression and tended to upregulate IL-22 mRNA expression, but Arg supplementation remarkably reduced IL-8 mRNA expression, tended to downregulate IL-22 mRNA expression, and dramatically elevated IFN-γ and IL-10 mRNA expression. In addition, sequencing data of 16S rDNA indicated that the population of Proteobacteria phylum; Enterobacteriaceae family; Escherichia-Shigella, and Nitrosomonas genera; and Escherichia coli and Ochrobactrum intermedium species were more abundant, but the population of Rhodocyclaceae and Clostridiaceae_1 families and Candidatus Arthromitus genus were less abundant in the ileal digesta of birds with only S. typhimurium infection when compared with the controls. Treatment with Arg in birds subjected to S. typhimurium challenge increased the abundances of Firmicutes phylum, Clostridiaceae_1 family, Methylobacterium and Candidatus Arthromitus genera but decreased the abundance of Nitrosomonas genus and Rhizobium cellulosilyticum and Rubrobacter xylanophilus species as compared with the only S. typhimurium-challenged birds. In conclusion, Arg supplementation can alleviate intestinal mucosal impairment by ameliorating inflammatory response and modulating gut microbiota in broiler chickens challenged with S. typhimurium.
Topics: Animal Feed; Animals; Arginine; Bacterial Physiological Phenomena; Chickens; Diet; Dietary Supplements; Gastrointestinal Microbiome; Inflammation; Intestines; Male; Poultry Diseases; Random Allocation; Salmonella Infections, Animal; Salmonella typhimurium; Stress, Physiological
PubMed: 32241466
DOI: 10.1016/j.psj.2019.10.049 -
Microbiological Research Mar 2023Extensive use of neonicotinoid insecticides in recent decade had contaminated water and soil systems and poses serious environmental and health risk. Microbial...
Extensive use of neonicotinoid insecticides in recent decade had contaminated water and soil systems and poses serious environmental and health risk. Microbial degradation of toxic contaminants in the environment has been established as a sustainable tool towards its remediation. Under this context, the present study focused on the biodegradation of neonicotinoid insecticide acetamiprid, by bacterial strain Brucella intermedia PDB13 isolated from the gut of the acetamiprid exposed earthworms. To enhance acetamiprid biodegradation, suitable parameters such as pH, temperature, inoculum size and acetamiprid concentration range were optimised using Response Surface Methodology (RSM). The experimental results showed that the Brucella intermedium PDB13 can tolerate and degrade relatively high concentrations of acetamiprid (50 - 350 mg L). The results confirmed that maximum degradation of about 89.72% was achieved under optimized conditions. Further, confirmation of acetamiprid biodegradation was assessed through the occurrence of its degraded metabolites through HPLC, FTIR, and LCMS analysis. Based on this analysis, possible acetamiprid biodegradation pathway by Brucella intermedia PDB13 was proposed. Additionally, cytotoxicity, earthworm acute toxicity, and zebrafish embryo toxicity studies were also performed to assess the toxicity variations between the parent compound and its metabolites. The acetamiprid treated group resulted in cytotoxic effects apparently, with the increase in aberrant cells frequency (22.5 ± 3.3), when compared with its metabolites (2.3 ± 4.3) and control (1.9 ± 5.6) respectively. All these results evidently reported the degradation potential of Brucella intermedia PDB13, thereby establishing the scope for further advanced biodegradation studies towards mitigating the pesticide pollution.
Topics: Animals; Insecticides; Oligochaeta; Zebrafish; Neonicotinoids; Bacteria; Biodegradation, Environmental
PubMed: 36565686
DOI: 10.1016/j.micres.2022.127278 -
Parasites & Vectors Jul 2014Phlebotomine sand flies transmit the haemoflagellate Leishmania, the causative agent of human leishmaniasis. The Leishmania promastigotes are confined to the gut lumen...
BACKGROUND
Phlebotomine sand flies transmit the haemoflagellate Leishmania, the causative agent of human leishmaniasis. The Leishmania promastigotes are confined to the gut lumen and are exposed to the gut microbiota within female sand flies. Here we study the colonisation resistance of yeast and bacteria in preventing the establishment of a Leishmania population in sand flies and the ability of Leishmania to provide colonisation resistance towards the insect bacterial pathogen Serratia marcescens that is also pathogenic towards Leishmania.
METHODS
We isolated microorganisms from wild-caught and laboratory-reared female Lutzomyia longipalpis, identified as Pseudozyma sp. Asaia sp. and Ochrobactrum intermedium. We fed the females with a sugar meal containing the microorganisms and then subsequently fed them with a bloodmeal containing Leishmania mexicana and recorded the development of the Leishmania population. Further experiments examined the effect of first colonising the sand fly gut with L. mexicana followed by feeding with, Serratia marcescens, an insect bacterial pathogen. The mortality of the flies due to S. marcescens was recorded in the presence and absence of Leishmania.
RESULTS
There was a reduction in the number of flies harbouring a Leishmania population that had been pre-fed with Pseudozyma sp. and Asaia sp. or O. intermedium. Experiments in which L. mexicana colonised the sand fly gut prior to being fed an insect bacterial pathogen, Serratia marcescens, showed that the survival of flies with a Leishmania infection was significantly higher compared to flies without Leishmania infection.
CONCLUSIONS
The yeast and bacterial colonisation experiments show that the presence of sand fly gut microorganisms reduce the potential for Leishmania to establish within the sand fly vector. Sand flies infected with Leishmania were able to survive an attack by the bacterial pathogen that would have killed the insect and we concluded that Leishmania may benefit its insect host whilst increasing the potential to establish itself in the sand fly vector. We suggest that the increased ability of the sand fly to withstand a bacterial entomopathogen, due to the presence of the Leishmania, may provide an evolutionary pressure for the maintenance of the Leishmania-vector association.
Topics: Animals; Female; Host-Pathogen Interactions; Leishmania; Psychodidae; Serratia
PubMed: 25051919
DOI: 10.1186/1756-3305-7-329 -
Environmental Science and Pollution... Jul 2019Farmland soil sprayed with organophosphorus pesticides (OPs) annually was investigated for the identification and characterization of OP-degrading microorganisms. Six...
Farmland soil sprayed with organophosphorus pesticides (OPs) annually was investigated for the identification and characterization of OP-degrading microorganisms. Six bacterial strains were identified, including Brevundimonas faecalis MA-B12 and Alcaligenes faecalis subsp. parafaecalis MA-B13 for methamidophos degradation, Citrobacter freundii TF-B21 and Ochrobactrum intermedium TF-B23 for trichlorfon degradation, Ochrobactrum intermedium DV-B31 for dichlorvos degradation, and Bacillus cereus for dimethoate degradation. The optimal biodegradation conditions for OPs were obtained at pH 7.0 and incubation temperature ranging from 28 to 37 °C. In an 8-day batch test, biodegradation of the four OPs all followed first-order kinetics, with biodegradation rates ranging from 58.08 to 96.42%. Functional genes responsible for OPs degradation were obtained, including ophB, ampA, opdE, opd, opdA, and mpd. As these strains were indigenous strains isolated from farmland soils, they can be potentially used as bacterial consortium for the bioremediation of mixed OP-contaminated soils. A time-course genotoxicity assessment of the degradation products was done by a bacterial whole-cell bioreporter, revealing that biodegradation of trichlorfon, dichlorvos, and dimethoate resulted a decreased genotoxicity within 5 days, which, however, significantly increased on day 8. The result demonstrated that more toxic products may be produced during the biodegradation processes of OPs, and more attention should be put not only on the pesticides themselves, but also on the toxic effects of their degradation products. To the best of our knowledge, this is for the first time that the genotoxicity of OP degradation products was evaluated by the bioreporter assay, broadening our understanding on the genotoxic risks of OPs during biodegradation process. Graphical Abstract.
Topics: Bacillus cereus; Biodegradation, Environmental; DNA Damage; Dichlorvos; Dimethoate; Kinetics; Organophosphorus Compounds; Pesticides; Soil
PubMed: 31129897
DOI: 10.1007/s11356-019-05135-9 -
Folia Microbiologica Apr 2021In the present study, bacterial isolates were screened for arsenic resistance efficiency. Environmental isolates were isolated from arsenic-rich soil samples (i.e., from...
In the present study, bacterial isolates were screened for arsenic resistance efficiency. Environmental isolates were isolated from arsenic-rich soil samples (i.e., from Rajnandgaon district of Chhattisgarh state, India). Amplification and sequencing of 16S rRNA gene revealed that the isolates were of Bacillus firmus RSN1, Brevibacterium senegalense RSN2, Enterobacter cloacae RSN3, Stenotrophomonas pavanii RSN6, Achromobacter mucicolens RSN7, and Ochrobactrum intermedium RSN10. Arsenite efflux gene (arsB) was successfully amplified in E. cloacae RSN3. Atomic absorption spectroscopy (AAS) analysis showed an absorption of 32.22% arsenic by the RSN3 strain. Furthermore, results of scanning electron microscopy (SEM) for morphological variations revealed an initial increase in the cell size at 1 mM sodium arsenate; however, it was decreased at 10 mM concentration in comparison to control. This change of the cell size in different metal concentrations was due to the uptake and expulsion of the metal from the cell, which also confirmed the arsenite efflux system.
Topics: Achromobacter; Arsenic; Brevibacterium; Enterobacter cloacae; Ochrobactrum; RNA, Ribosomal, 16S; Soil; Soil Pollutants; Stenotrophomonas
PubMed: 33131029
DOI: 10.1007/s12223-020-00832-2 -
Journal of Environmental Science and... Jul 2017This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica,...
This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica, Veracruz, Mexico. The identified bacteria were Ochrobactrum intermedium, Pandoraea pnomenusa and Ochrobactrum sp., but SA2-09 strain was not identified. The ability of the isolates to degrade polycyclic aromatic hydrocarbons (PAHs) was evaluated at 31.61 and 54.52 mg/kg PAHs in soil, when used as crude oil in soil microcosm during 80 days of incubation at 30°C. The results demonstrated that O. intermedium biodegraded many PAHs, including the high molecular weight (HMW) PAHs fluoranthene (100% equivalent 0.24 mg/kg), benzo [b] fluoranthene (81.8% equal 0.18 mg/kg), Benzo[a]pyrene (87.0%, 0.20 mg/kg) and Benzo[g,h,i]perylene (52.7%, 0.39 mg/kg). P. pnomenusa had a degradation profile of HMW PAHs, which was similar to O. intermedium, while Ochrobactrum sp. and the strain SA-09 exhibited lower degradation rates of HMW.
Topics: Biodegradation, Environmental; Burkholderia; Mexico; Ochrobactrum; Petroleum; Phylogeny; Polycyclic Aromatic Hydrocarbons; RNA, Ribosomal, 16S; Soil Pollutants
PubMed: 28463567
DOI: 10.1080/10934529.2017.1316170