ABSTRACT
Background: Glyphosate [N-phosphonomethyl Glycine] is an organophosphorus pesticide with dangerous effects on the environment. In this study, the biodegradation of glyphosate herbicide by halophilic bacteria isolated from Qom Hoze-Soltan Lake has been investigated
Methods: After sampling and bacterial isolation, native halophilic strains grown in the presence of glyphosate at a wavelength of 660 nm and also the disappearance of the glyphosate in the plates at a wavelength of 220 nm were determined and the dominant bacteria were isolated. Biochemical, molecular [according to the 16S rRNA sequence], antibiotic, and the Minimum Inhibitory Concentration [MIC] test was performed for the dominant bacteria. Analysis of the remaining glyphosate herbicide was performed by HPLC analysis after derivation with FMOC-Cl
Results: According to the results of the biochemical, antibiotic and molecular 16S rRNA tests, the native halophilic isolates with the ability to biodegrade glyphosate were gram positive cocci very similar to Salinicoccus spp. The results of HPLC showed that Salinicoccus spp is able to biodegrade glyphosate herbicide
Conclusion: The native bacteria in Qom Hoze-soltan lake, Iran can be used for biodegradation of glyphosate herbicide
ABSTRACT
Background: Enterococci have emerged as a major cause of nosocomial infections and within this group, Enterococcus faecalis and Enterococcus faecium cause the majority of human and livestock enterococcal infections. In this article, we tried to determine antibiotics and metals resistance patterns of E. faecalis and E. faecium strains
Methods: One hundred sixty different strains of E. faecalis and E. faecium were collected from livestock sewage and the human fecal waste during 15 months. Then bacterial antibiotics sensitivity tests were carried out using the Agar disc diffusion method
Results: Generally, 100% of E. faecalis strains separated from human and livestock sources [i.e. sheep] showed penicillin [P]/ kanamycin [K]/ nitrofurantoin [N]/ loracarbef [L]/ Ciprofloxacin [Cc]/ ampicillin [AN]/ nalidixic acid [NA]/ sulfamethoxazole [S] antibiotics resistance patterns. In addition, 55% of isolated E. faecium showed P/S/AN/NA antibiotics resistance patterns. Each strain showed a resistance to at least two aminoglycoside antibiotics. However, E. faecalis strains from human and the livestock sources showed 94% and 100% of resistance to nitrofurantoin, respectively. The effects of different metal concentrations was evaluated in both strains. The agar dilution method was applied in this stage. Hg at 0.05 mmol/L of minimum inhibitory concentration [MIC] showed toxicity to both the human and livestock Enterococcus strains. Cadmium at 1 mmol/L and 0.5 mmol/L concentrations had the most toxicity to E. faecalis and E. faecium strains, respectively. Obviously, toxicity to bacteria is less than other metals. As a result, Zn/Ni/Cu/Co resistance pattern is suggested for both strains. Finally, antibiotics and heavy metals resistance patterns were monitored simultaneously
Conclusion: Almost all E. faecalis strains isolated from humans and livestock showed antibiotics and heavy metals resistance patterns of P/K/L/Cc/S/AN/NA/Zn/Cu/Co simultaneously. Moreover, 55% of E. faecium strains showed similar antibiotics and heavy metals resistance patterns of P/S/AN/NA/Zn/Ni/Cu/Co