Salmonella serovars are increasing in importance as significant pathogens of both human and animals. Although water and wastewater are treated to eliminate pathogenic microorganisms, they still play an important role in the transmission of
Salmonella spp. In this study, bacteriophages infecting
Salmonella spp. were isolated from wastewater and evaluated; for their potential to lyse environmental
Salmonella strains in vitro at different MOIs and temperatures; and to control the wastewater bacterial community. Three distinct phages designated sww65, sww275, and sww297; as defined by plaque morphology, electron microscopy and host range; were obtained from wastewater. Challenge tests were performed at 37, and 30 °C with the infection of the
Salmonella cultures with individual phage, a mixture of two phages, and cocktail of three phages at MOIs of 10
0, 10
2, and 10
4 PFU/CFU. At 30, and 37 °C, a cocktail of three phages reduced all of the
Salmonella cultures tested. These results required a high multiplicity of infection. However, when infected with only one phage or a mixture of two phages at MOIs of 10
0 or 10
2 PFU/CFU, an emergence of bacterial resistance was observed. The dynamic monitoring of wastewater enterobacterial community was conducted using Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR). The number of bands decreased gradually with the use of individual phage or phage cocktails. Moreover, the dynamic monitoring of
Salmonella community during wastewater treatment was performed using PCR detection of virulence gene
invA. The results correlated with the ERIC-PCR fingerprints, and suggested that
Salmonella community was affected by the phage treatment. Indeed, in wastewater, bacteriophages are reducing
Salmonella and other members of the
Enterobacteriaceae. These results indicated that dynamic changes are closely related with the process of treatment. The introduction of wide host range bacteriophages in wastewater can have a potential impact on the dynamics of the microbial communities, manifested by the reduction or the elimination of microbial species.
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