-
PloS One 2013The arenas and detailed mechanisms for transfer of antibiotic resistance genes between environmental bacteria and pathogens are largely unclear. Selection pressures from...
The arenas and detailed mechanisms for transfer of antibiotic resistance genes between environmental bacteria and pathogens are largely unclear. Selection pressures from antibiotics in situations where environmental bacteria and human pathogens meet are expected to increase the risks for such gene transfer events. We hypothesize that waste-water treatment plants (WWTPs) serving antibiotic manufacturing industries may provide such spawning grounds, given the high bacterial densities present there together with exceptionally strong and persistent selection pressures from the antibiotic-contaminated waste. Previous analyses of effluent from an Indian industrial WWTP that processes waste from bulk drug production revealed the presence of a range of drugs, including broad spectrum antibiotics at extremely high concentrations (mg/L range). In this study, we have characterized the antibiotic resistance profiles of 93 bacterial strains sampled at different stages of the treatment process from the WWTP against 39 antibiotics belonging to 12 different classes. A large majority (86%) of the strains were resistant to 20 or more antibiotics. Although there were no classically-recognized human pathogens among the 93 isolated strains, opportunistic pathogens such as Ochrobactrum intermedium, Providencia rettgeri, vancomycin resistant Enterococci (VRE), Aerococcus sp. and Citrobacter freundii were found to be highly resistant. One of the O. intermedium strains (ER1) was resistant to 36 antibiotics, while P. rettgeri (OSR3) was resistant to 35 antibiotics. Class 1 and 2 integrons were detected in 74/93 (80%) strains each, and 88/93 (95%) strains harbored at least one type of integron. The qPCR analysis of community DNA also showed an unprecedented high prevalence of integrons, suggesting that the bacteria living under such high selective pressure have an appreciable potential for genetic exchange of resistance genes via mobile gene cassettes. The present study provides insight into the mechanisms behind and the extent of multi-drug resistance among bacteria living under an extreme antibiotic selection pressure.
Topics: Anti-Bacterial Agents; Bacteria; Conjugation, Genetic; Drug Resistance, Multiple, Bacterial; Gene Transfer, Horizontal; Genome, Bacterial; Humans; Integrons; Microbial Sensitivity Tests; RNA, Ribosomal, 16S; Wastewater; Water Microbiology
PubMed: 24204801
DOI: 10.1371/journal.pone.0077310 -
Clinical Ophthalmology (Auckland, N.Z.) 2013A healthy 34-year-old man presented with Ochrobactrum intermedium endophthalmitis due to a metallic intraocular foreign body. After vitrectomy, lensectomy, removal of...
A healthy 34-year-old man presented with Ochrobactrum intermedium endophthalmitis due to a metallic intraocular foreign body. After vitrectomy, lensectomy, removal of the metallic intraocular foreign body, intravitreal vancomycin and ceftazidime, and systemic ciprofloxacin, intraocular inflammation worsened. Repeat vitreous culture confirmed persistent endophthalmitis due to multidrug-resistant O. intermedium. The endophthalmitis successfully resolved after the administration of intravitreal moxifloxacin.
PubMed: 24039392
DOI: 10.2147/OPTH.S44212 -
Applied and Environmental Microbiology Dec 2013The external environment, particularly wastewater treatment plants (WWTPs), where environmental bacteria meet human commensals and pathogens in large numbers, has been...
The external environment, particularly wastewater treatment plants (WWTPs), where environmental bacteria meet human commensals and pathogens in large numbers, has been highlighted as a potential breeding ground for antibiotic resistance. We have isolated the extensively drug-resistant Ochrobactrum intermedium CCUG 57381 from an Indian WWTP receiving industrial wastewater from pharmaceutical production contaminated with high levels of quinolones. Antibiotic susceptibility testing against 47 antibiotics showed that the strain was 4 to >500 times more resistant to sulfonamides, quinolones, tetracyclines, macrolides, and the aminoglycoside streptomycin than the type strain O. intermedium LMG 3301T. Whole-genome sequencing identified mutations in the Indian strain causing amino acid substitutions in the target enzymes of quinolones. We also characterized three acquired regions containing resistance genes to sulfonamides (sul1), tetracyclines [tet(G) and tetR], and chloramphenicol/florfenicol (floR). Furthermore, the Indian strain harbored acquired mechanisms for horizontal gene transfer, including a type I mating pair-forming system (MPFI), a MOBP relaxase, and insertion sequence transposons. Our results highlight that WWTPs serving antibiotic manufacturing may provide nearly ideal conditions for the recruitment of resistance genes into human commensal and pathogenic bacteria.
Topics: Anti-Bacterial Agents; DNA Mutational Analysis; DNA Transposable Elements; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Genome, Bacterial; India; Industrial Waste; Microbial Sensitivity Tests; Mutation, Missense; Ochrobactrum; Sequence Analysis, DNA; Wastewater
PubMed: 24038701
DOI: 10.1128/AEM.02141-13 -
Gut Pathogens Apr 2013Ochrobactrum intermedium is an emerging opportunistic pathogen of humans that is closely related to members of the genus Brucella. Earlier, we reported the case of an...
BACKGROUND
Ochrobactrum intermedium is an emerging opportunistic pathogen of humans that is closely related to members of the genus Brucella. Earlier, we reported the case of an Indian subject with non-ulcer dyspeptic symptoms whose urease positive gastric biopsy revealed the presence of Helicobacter pylori along with non-Helicobacter like bacteria, eventually cultured and identified as O. intermedium strain M86.
RESULTS
Here, we describe the unclosed draft genome of the strain M86 with a length of 5,188,688 bp and mean G+C content of 57.9%. We have also identified many putative gene clusters that might be responsible for its persistence in the gastric mucosa.Comparative analysis of genomic features of Ochrobactrum intermedium strain M86 and Ochrobactrum intermedium LMG 3301T was also done.
CONCLUSIONS
This paper attempts to gain whole-genome based insights into the putative gene determinants of O. intermedium for survival in the highly acidic stomach lumen environment .Identification of genes putatively involved in the various metabolic pathways may lead to a better understanding of the survival of O. intermdedium in acidic condition.
PubMed: 23557353
DOI: 10.1186/1757-4749-5-7 -
3 Biotech Mar 2012Hexavalent chromium-resistant Ochrobactrum intermedium BCR400 was isolated from chromium contaminated soil collected from Vadodara, Gujarat. It reduced 100 mg Cr(VI)/L...
Hexavalent chromium-resistant Ochrobactrum intermedium BCR400 was isolated from chromium contaminated soil collected from Vadodara, Gujarat. It reduced 100 mg Cr(VI)/L completely in 52 h with initial Cr(VI) reduction rate of 1.98 mg/L/h. The Cr(VI) reduction rate decreased with increase in Cr(VI) concentration from 100 to 500 mg/L. The addition of anthraquinone-2-sulphonic acid (AQS) to culture O. intermedium BCR400 significantly enhanced its chromium reduction rate. The activation energy of AQS-mediated Cr(VI) reduction (120.69 KJ/mol) was 1.1-fold lower than non-mediated Cr(VI) reduction. An increase in the activities of quinone reductase and chromate reductase in cells grown in presence of AQS/AQS + Cr(VI) suggests their role in reduction of Cr(VI) by O. intermedium. Both chromate reductase and quinone reductase activities were FAD independent, required NADH as reductant, displayed maximum activity at pH (7.0) and temperature (30 °C). Thus Cr(VI) bioremediation potential of O. intermedium can be enhanced by augmentation of system with AQS as redox mediator.
PubMed: 22582159
DOI: 10.1007/s13205-011-0038-0 -
Journal of Microbiology and... Apr 2012Chromium is generated from several industrial processes. It occurs in different oxidation states, but Cr(III) and Cr(VI) are the most common ones. Cr(VI) is a toxic,...
Chromium is generated from several industrial processes. It occurs in different oxidation states, but Cr(III) and Cr(VI) are the most common ones. Cr(VI) is a toxic, soluble environmental contaminant. Some bacteria are able to reduce hexavalent chromium to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of considerable interest. An indigenous chromium-reducing bacterial strain, Rb-2, isolated from a tannery water sample, was identified as Ochrobactrum intermedium, on the basis of 16S rRNA gene sequencing. The influence of factors like temperature of incubation, initial concentration of Cr, mobility of bacteria, and different carbon sources were studied to test the ability of the bacterium to reduce Cr(VI) under variable environmental conditions. The ability of the bacterial strain to reduce hexavalent chromium in artificial and industrial sewage water was evaluated. It was observed that the mechanism of resistance to metal was not due to the change in the permeability barrier of the cell membrane, and the enzyme activity was found to be inductive. Intracellular reduction of Cr(VI) was proven by reductase assay using cell-free extract. Scanning electron microscopy revealed chromium precipitates on bacterial cell surfaces, and transmission electron microscopy showed the outer as well as inner distribution of Cr(VI). This bacterial strain can be useful for Cr(VI) detoxification under a wide range of environmental conditions.
Topics: Biodegradation, Environmental; Chromium; Molecular Sequence Data; Ochrobactrum; Oxidation-Reduction; Phylogeny; Sewage; Water Pollutants, Chemical
PubMed: 22534304
DOI: 10.4014/jmb.1108.08029 -
Indian Journal of Microbiology Jun 2009Microbial communities in coastal subsurface sediments play an important role in biogeochemical cycles. In this study microbial communities in tidal subsurface sediments...
Microbial communities in coastal subsurface sediments play an important role in biogeochemical cycles. In this study microbial communities in tidal subsurface sediments of Balramgari in the state of Orissa, India were investigated using a culture independent approach. Two 16S rDNA cloned libraries were prepared from the closely located (100 m along the coast) subsurface sediment samples. Library I sediment samples had higher organic carbon content but lower sand percentage in comparison to Library II. A total of 310 clone sequences were used for DOTUR analysis which revealed 51 unique phylotypes or operational taxonomic units (OTUs) for both libraries. The OTUs were affiliated with 13 major lineages of domain bacteria including Proteobacteria (α, β, δ and λ), Acidobacteria, Actinobacteria, Cyanobacteria, Chloroflexi, Firmicutes, Verrucomicrobia, Bacteroidetes, Gemmatimonadetes and TM7. We encountered few pathogenic bacteria such as Aeromonas hydrophila and Ochrobactrum intermedium, in sediment from Library I. ∫-LIBSHUFF comparison depicts that the two libraries were significantly different communities. Most of the OTUs from both libraries possessed ≥85% to <97% similarity to RDP database sequences depicting the putative presence of new species, genera and phylum. This work revealed the complex and unique bacterial diversity from coastal habitat of Balramgari and shows that, in coastal habitat a variability of physical and chemical parameter has a prominent impact on the microbial community structure.
PubMed: 23100766
DOI: 10.1007/s12088-009-0034-9 -
Journal of Applied Microbiology Sep 2006To optimize a medium for nicotine degradation by Ochrobactrum intermedium DN2 in presence of yeast extract, glucose and Tween 80 using response surface methodology (RSM).
AIMS
To optimize a medium for nicotine degradation by Ochrobactrum intermedium DN2 in presence of yeast extract, glucose and Tween 80 using response surface methodology (RSM).
METHODS AND RESULTS
In this study, the effects of yeast extract, glucose and Tween 80 on nicotine degradation were investigated in flasks using a novel nicotine-degrading bacterium, O. intermedium DN2. A full factorial central composite design was applied in the design of experiments and in the analysis of the experimental data. The results showed that the most significant variable influencing nicotine degradation was yeast extract, followed by glucose, and then Tween 80. Moreover these three factors interacted with each other and combined to produce positive effects on nicotine degradation. The experimental data also allowed the development of an empirical model (P < 0.0001) describing the inter-relationship between independent and dependent variables. By solving the regression equation, the optimal values of the variables were determined as: yeast extracts 0.094%, glucose 0.101% and Tween 80 0.080%. Using the medium obtained, about 1,220 mg l(-1) of nicotine was degraded (95.55%) within 10 h at the specific biodegradation of 116.59 mg l(-1) h(-1) in 30-l bioreactor containing 25-l tobacco extract.
CONCLUSIONS
An optimal medium of nicotine degradation by the strain DN2 was obtained.
SIGNIFICANCE AND IMPACT OF THE STUDY
RSM proved to be reliable in developing the model, optimizing factors and analysing interaction effects. The results provide better understanding on the interactions between yeast extract, glucose and Tween 80 for nicotine biodegradation.
Topics: Biodegradation, Environmental; Culture Media; Glucose; Models, Biological; Nicotine; Nicotinic Agonists; Ochrobactrum; Polysorbates; Surface-Active Agents; Yeasts
PubMed: 16907819
DOI: 10.1111/j.1365-2672.2006.02929.x -
FEMS Microbiology Ecology May 2006The diversity of Ochrobactrum anthropi, Ochrobactrum intermedium, Ochrobactrum tritici and Ochrobactrum grignonense in agricultural soil and on the wheat rhizoplane was...
The diversity of Ochrobactrum anthropi, Ochrobactrum intermedium, Ochrobactrum tritici and Ochrobactrum grignonense in agricultural soil and on the wheat rhizoplane was investigated. O. anthropi was isolated both from soil and from the rhizoplane, O. intermedium and grignonense only from bulk soil, and O. tritici only from the wheat rhizoplane. On the genetic level, the immunotrapped isolates and a number of strains from culture collection mainly of clinical origin were compared with rep-PCR profiling using BOX primers, and a subset of these isolates and strains using REP primers. The isolates clustered according to their species affiliation. There was no correlation between rep clusters of O. anthropi isolates and habitat (place of isolation). The genetic diversity of Ochrobactrum at the species level as well as microdiversity of O. anthropi (number of BOX groups) was higher in soil than on the rhizoplane. Similarity values from genetic rep-PCR profiles correlated positively with DNA-DNA reassociation percentages. Isolates with >80.7% similarity in BOX profile and >86.4% in rep profile clustered within the same species. Similarity analysis of rep-PCR profiles is hence an alternative to DNA-DNA hybridization as a genomic criterion for species delineation within the genus Ochrobactrum. We used the substrate utilization system BIOLOG-GN to compare the immunotrapped isolates on the phenetic level. For the isolates from bulk soil, substrate utilization versatility (number of utilized substrates) and substrate utilization capacity (mean conversion rate of substrates) were slightly but significantly higher than for the isolates from the rhizoplane. This trend was also seen using API 20E and 20NE systems. Plate counts of total bacteria and the number of immunotrapped Ochrobactrum isolates per gram dry weight were higher for the rhizoplane than for the soil samples. The results of genetic and phenotypic analyses indicated a 'rhizosphere effect'; the diversity and metabolic capacity of Ochrobactrum isolates were higher in bulk soil, and the population density was higher on the wheat rhizoplane.
Topics: Biodiversity; Cluster Analysis; Genotype; Nucleic Acid Hybridization; Ochrobactrum; Phenotype; Polymerase Chain Reaction; Soil Microbiology; Triticum
PubMed: 16629756
DOI: 10.1111/j.1574-6941.2005.00029.x -
Journal of Clinical Microbiology Mar 2006Ochrobactrum intermedium [corrected] infection is rare in humans and is generally associated with immunocompromised hosts with indwelling foreign bodies. We report a... (Review)
Review
Ochrobactrum intermedium [corrected] infection is rare in humans and is generally associated with immunocompromised hosts with indwelling foreign bodies. We report a case of pelvic abscess with O. intermedium [corrected] after a routine appendectomy in an immunocompetent patient and review the literature on O. intermedium [corrected] infection in patients with normal immune function.
Topics: Abscess; Appendectomy; Gram-Negative Bacterial Infections; Humans; Immunocompetence; Male; Middle Aged; Ochrobactrum anthropi; Pelvic Infection; Postoperative Complications
PubMed: 16517927
DOI: 10.1128/JCM.44.3.1184-1186.2006