:: Volume 2, Issue 4 (Autumn 2015) ::
Environ. health eng. manag. 2015, 2(4): 199-202 Back to browse issues page
Antibiotics and heavy metals resistance patterns of Enterococcus faecalis and faecium bacteria isolated from the human and the livestock sources
Yaser Sharifi, Azadeh Abedzadeh, Atieh Salighe, Naser Kalhor, Mohammad Khodadad Motlagh, Ali Javadi
Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran , alijavadi1388@gmail.com
Abstract:   (4891 Views)

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.

Keywords: E. faecalis, Heavy metals, Antibiotics, Resistance
eprint link: http://eprints.kmu.ac.ir/id/eprint/24702
Full-Text [PDF 266 kb]   (1276 Downloads)    
Type of Study: Original Article | Subject: General
Received: 2016/01/20 | Accepted: 2016/01/20 | Published: 2016/01/20


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Volume 2, Issue 4 (Autumn 2015) Back to browse issues page