scholarly journals Antimicrobial Activity of Bacteria Isolated From the Rhizosphere and Phyllosphere of Avena Fatua and Brachiaria Reptans Growing in Heavy-Metal Polluted Environment

Author(s):  
Muskan Ali ◽  
Sadia Walait ◽  
Muhammad Farhan Ul Haque ◽  
Salma Mukhtar

Abstract Environmental pollution especially heavy metal contaminated soils adversely affect the microbial communities associated with the rhizosphere and phyllosphere of plants growing in these areas. In the current study, we identified and characterized the rhizospheric and phyllospheric bacterial strains from Avena fatua and Brachiaria reptans with the potential for antimicrobial activity and heavy metal resistance. A total of 18 bacterial strains from the rhizosphere and phyllosphere of A. fatua and 19 bacterial strains from the rhizosphere and phyllosphere of B. reptans were identified based on 16S rRNA sequence analysis. Bacterial genera, including Bacillus, Staphylococcus, Pseudomonas and Enterobacter were dominant in the rhizosphere and phyllosphere of A. fatua and Bacillus, Marinobacter, Pseudomonas, Enterobacter, and Kocuria were the dominating bacterial genera from the rhizosphere and phyllosphere of B. reptans. Most of the bacterial strains were resistant to heavy metals (Cd, Pb and Cr) and showed antimicrobial activity against different pathogenic bacterial strains. The whole genome sequence analysis of Pseudomonas putida BR-PH17 was performed by using Illumina sequencing approach. The BR-PH17 genome contained a chromosome with size of 5774330 bp and a plasmid DNA with 80360 bp. In this genome, about 5368 predicted protein coding sequences with 5539 total genes, 22 rRNAs and 75 tRNA genes were identified. Functional analysis of chromosomal and plasmid DNA revealed a variety of enzymes and proteins involved in antibiotic resistance and biodegradation of complex organic pollutants. These results indicated that bacterial strains identified in this study could be utilized for bioremediation of heavy metal contaminated soils and as a novel source of antimicrobial drugs.

2016 ◽  
Vol 113 (38) ◽  
pp. 10690-10695 ◽  
Author(s):  
Zuowei Wu ◽  
Balamurugan Periaswamy ◽  
Orhan Sahin ◽  
Michael Yaeger ◽  
Paul Plummer ◽  
...  

Infections due to clonal expansion of highly virulent bacterial strains are clear and present threats to human and animal health. Association of genetic changes with disease is now a routine, but identification of causative mutations that enable disease remains difficult. Campylobacter jejuni is an important zoonotic pathogen transmitted to humans mainly via the foodborne route. C. jejuni typically colonizes the gut, but a hypervirulent and rapidly expanding clone of C. jejuni recently emerged, which is able to translocate across the intestinal tract, causing systemic infection and abortion in pregnant animals. The genetic basis responsible for this hypervirulence is unknown. Here, we developed a strategy, termed “directed genome evolution,” by using hybridization between abortifacient and nonabortifacient strains followed by selection in an animal disease model and whole-genome sequence analysis. This strategy successfully identified SNPs in porA, encoding the major outer membrane protein, are responsible for the hypervirulence. Defined mutagenesis verified that these mutations were both necessary and sufficient for causing abortion. Furthermore, sequence analysis identified porA as the gene with the top genome-wide signal of adaptive evolution using Fu’s Fs, a population genetic metric for recent population size changes, which is consistent with the recent expansion of clone “sheep abortion.” These results identify a key virulence factor in Campylobacter and a potential target for the control of this zoonotic pathogen. Furthermore, this study provides general, unbiased experimental and computational approaches that are broadly applicable for efficient elucidation of disease-causing mutations in bacterial pathogens.


2020 ◽  
Vol 47 (5) ◽  
pp. 3973-3985 ◽  
Author(s):  
Gorkhmaz Abbaszade ◽  
Attila Szabó ◽  
Balázs Vajna ◽  
Rózsa Farkas ◽  
Csaba Szabó ◽  
...  

2022 ◽  
Author(s):  
Fangyuan Xu ◽  
Liqiang Liu ◽  
Jun Liu ◽  
Wei He ◽  
Kang Liao

Abstract Wild apricot in Yili wild fruit forest in Xinjiang have been seriously affected by leaf spot-hole disease, with the incidence reaching 100%. To identify the pathogen of apricot perforation in the Yili wild fruit forest, two bacterial strains with strong virulence were obtained by the dilution separation method. The bacterial strains were gram-negative bacteria with yellow colonies, smooth surfaces and neat edges. The results of the pathogenicity test showed that the bacteria could cause symptoms of leaf spot-hole disease in wild apricot, similar to the symptoms in the field, and could cause HR in tobacco. Based on the 16S rDNA gene sequence and multilocus sequence analysis of fusA, gyrB, leuS, pyrG, rpoB and rlpB, combined with the physiological and biochemical characteristics, the isolated strain was identified as Pantoea agglomerans. The pathogen causing bacterial leaf spot-hole disease in wild apricot was determined to be P. agglomerans in the wild fruit forest of Yili, Xinjiang. The whole genome of the pathogen strain GL9-2 was sequenced based on the Illumina HiSeq500 and PacBio RS platforms. The genome size was 4765392 bp, and the G+C value was 55.27%. There was one chromosome and two plasmids in the genome, and 4353 CDs were identified. The annotation results showed that 52 glycoside hydrolase-related genes, 38 bacterial secretory system-related genes and 600 toxin-related genes were predicted.


2017 ◽  
Vol 5 (21) ◽  
Author(s):  
Marco Antonio Rogel-Hernandez ◽  
Gabriela Guerrero ◽  
Clara Ivette Rincón-Molina ◽  
Víctor Manuel Ruiz-Valdiviezo ◽  
Crhistian Cisneros-Pérez ◽  
...  

ABSTRACT Acinetobacter lactucae OTEC-02 was isolated from hydrocarbon-contaminated soils. Whole-genome sequence analysis was performed to learn more about the strain’s ability to degrade different types of recalcitrant toxic monoaromatic hydrocarbons. The genome of this bacterium revealed its genomic properties and versatile metabolic features, as well as a complete prophage.


Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 473
Author(s):  
Dilyana Gospodonova ◽  
Iliana Ivanova ◽  
Todorka Vladkova

The aim of this study was to prepare TiO2/Ag/Cu magnetron co-sputtered coatings with controlled characteristics and to correlate them with the antimicrobial activity of the coated glass samples. The elemental composition and distribution, surface morphology, wettability, surface energy and its component were estimated as the surface characteristics influencing the bioadhesion. Well expressed, specific, Ag/Cu concentration-dependent antimicrobial activity in vitro was demonstrated toward Gram-negative and Gram-positive standard test bacterial strains both by diffusion 21 assay and by Most Probable Number of surviving cells. Direct contact and eluted silver/coper nanoparticles killing were experimentally demonstrated as a mode of the antimicrobial action of the studied TiO2/Ag/Cu thin composite coatings. It is expected that they would ensure a broad spectrum bactericidal activity during the indwelling of the coated medical devices and for at least 12 h after that, with the supposition that the benefits will be over a longer time.


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