Bacteria from hypersaline environments: a bioactivity reservoir of anti-methicillin resistant Staphylococcus aureus
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September 14, 2018:
[Withdrawal Notice:]
The University of Tulsa Research Misconduct Investigating Committee has found that Dr. Gad improperly submitted the manuscript “Bacteria from hypersaline environments: a bioactivity reservoir of anti-methicillin resistant Staphylococcus aureus” (Gad, 2017)[1] to PeerJ Preprints. Dr Gad assigned himself as sole author. However, based on the evidence acquired by the committee, the committee found that Dr Fakhr (PhD Research Advisor of Dr. Gad) made significant contributions to the research that warrant co-authorship; in fact senior authorship. Furthermore, Dr Fakhr did not approve the final version on the manuscript. Therefore at the request of The University of Tulsa Research Misconduct Investigating Committee this preprint is Withdrawn from publication.
[1] Gad AH. 2017. Bacteria from hypersaline environments: a bioactivity reservoir of anti-methicillin resistant Staphylococcus aureus. PeerJ Preprints 5:e2910v1 https://doi.org/10.7287/peerj.preprints.2910v1
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Abstract
In the past decades, novel pharmaceutical compounds have been produced by a wide diverse groups of marine bacteria. These marine bacteria are potential reservoirs for antimicrobial products. In this study, we investigated 40 soil samples collected from the Great Salt Plain of Oklahoma GSP for anti-methicillin resistant Staphylococcus aureus bioactivities. A total number of 499 heterotrophic bacterial isolates (202 mesophilic halotolerant isolates, 125 thermophilic isolates, 84 halophilic isolates and 88 thermophile-halophile isolates) were recovered by culture dependent isolation and subjected to high-throughput screening to investigate their bioactivities against two strains of methicillin resistant Staphylococcus aureus MRSA. A total of 101 isolates (20.2%) out of 499 isolates possessed bioactivities against MRSA strains. They included; eighty (40%) isolates out of the 202 mesophilic halotolerant isolates showed anti-MRSA bioactivity. Twenty one bioactive (7%) isolates out of the 297 enrichment isolates showed anti-MRSA bioactivity. They involved; eleven bioactive (11%) isolates out of 125 of the thermophilic group and ten bioactive isolates (10%) out of 84 halophilic group isolates. No anti-MRSA bioactivity was revealed by the 88 isolates of the thermophile-halophile group. These 101 bioactive isolates (80 mesophilic halotolerant, 11 thermophilic and 10 halophilic) exhibited bioactivities against at least one Staphylococcus aureus MRSA using well diffusion technique. In regard to biogeographical distribution, a total of 29 (29%) and 72 (71%) bioactive isolates were isolated from vegetation and salt flat areas respectively. Thirty four (34%) isolates showed bioactivity against both methicillin resistant Staphylococcus aureus strains and fourteen (14%) isolates showed antimicrobial bioactivity against Staphylococcus aureus B-8-41-D-4, whereas fifty two (52%) isolates revealed antagonism against Staphylococcus aureus 4656. Furthermore, 16S rRNA-based study exposed that, Firmicutes harbored the highest number of bioactive isolates 77 (77%) including Bacillus (n=45 isolates), Halobacillus (n=13 isolates), Virgibacillus (n=7 isolates), Brevibacillus (n=7 isolates), Paenibacillus (n=1 isolates), Sediminibacillus (n=2 isolates), Oceanobacillus (n=1 isolates) and Staphylococcus (n=1 isolate). Proteobacteria- Gammaproteobacteria contained seven bioactive isolates (7%), including Halomonas (n=5 isolates), Marinobacter (n=1 isolate) and Pseudomonas (n=1 isolate). Actinobacteria were the third group and contained two bioactive isolates (2%), including, Cellulomonas (n=1 isolate) and Micrococcus (n=1 isolates). To our knowledge, this is the first study to explore the anti- methicillin resistant Staphylococcus aureus bioactivities of bacteria isolated from GSP. We consider our findings promising for further research to develop novel antimicrobial antibiotics.
Cite this as
2017. Bacteria from hypersaline environments: a bioactivity reservoir of anti-methicillin resistant Staphylococcus aureus. PeerJ Preprints 5:e2910v1 https://doi.org/10.7287/peerj.preprints.2910v1Author comment
This is a submission to PeerJ for review.
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Competing Interests
The author declares that there are no competing interests.
Author Contributions
Ahmed H. Gad conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Funding
This study was financially supported by the Office of Research and Sponsored Programs (The Student Research Grant Program) of The University of Tulsa, USA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.