Bacteriophage ZCSE2 is a Potent Antimicrobial against Salmonella enterica Serovars: Ultrastructure, Genomics and Efficacy

Abstract

Developing novel antimicrobials capable of controlling multidrug-resistant bacterial pathogens is essential to restrict the use of antibiotics. Bacteriophages (phages) constitute a major resource that can be harnessed as an alternative to traditional antimicrobial therapies. Phage ZCSE2 was isolated among several others from raw sewage but was distinguished by broad-spectrum activity against Salmonella serovars considered pathogenic to humans and animals. Lytic profiles of ZCSE2 against a panel of Salmonella were determined together with low temperature activity and pH stability. The morphological features of the phage and host infection processes were characterized using a combination of transmission electron and atomic force microscopies. Whole genome sequencing of ZCSE2 produced a complete DNA sequence of 53,965 bp. No known virulence genes were identified in the sequence data, making ZCSE2 a good candidate for phage-mediated biological control purposes. ZCSE2 was further tested against S. Enteritidis in liquid culture and was observed to reduce the target bacterium to below the limits of detection from initial concentrations of 10 7 -10 8 Colony Forming Units (CFU)/mL. With a broad host-range against pathogenic Salmonella serovars, phage ZCSE2 constitutes a potential tool against a major cause of human and animal disease.

Phage S144, a New Polyvalent Phage Infecting Salmonella spp. and Cronobacter sakazakii

“…Interestingly, the C-terminus of the tail fiber of the Loughboroughvirus phages (S144, SE4 and ZCSE2) is more similar to the otherwise unrelated Cronobacter phages GAP31 and GAP32 [71,72] than to the Rosemountvirus phages. While phages SE4 and ZCSE2 have been proven to infect many different Salmonella serovars, no bacterial strains from other genera were tested [35,43]. Given the similarity to phage S144 including the C-terminus of the tail fiber, involved in the host recognition and binding, we suggest that also phages SE4 and ZCSE2 may infect C. sakazakii and may thus be polyvalent phages.…”

“…Taxonomically, phage S144 can be classified as a member of the recently approved Loughboroughvirus genus, containing only two other members: the Salmonella phages ZCSE2 [43] and SE4 [35]. Since these phages are highly similar to the members of the Rosemountvirus genus, we proposed a new subfamily, the 'Salusvirinae'.…”

Characteristics of a Series of Three Bacteriophages Infecting Salmonella enterica Strains

“…In fact, many papers have been published recently which described bacteriophages that might be used in phage therapy against Salmonella . They include reports on characterization of previously unknown bacteriophages having the potential for use in phage therapy [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], experimental studies with bacteriophages applied to poultry [ 21 , 22 , 23 , 24 , 25 , 26 ], and the use of bacteriophages in experimental phage therapy in mouse [ 27 , 28 , 29 , 30 ] or pig [ 31 ] models. Although promising results were obtained in these studies, and economic analyses have been performed to assess costs and benefits of the use of phage therapy for the control of Salmonella in poultry [ 9 , 32 ], it is evident that the host range of the vast majority of Salmonella phages is restricted to specific strains or serovars.…”

Bacteriophages vB_Sen-TO17 and vB_Sen-E22, Newly Isolated Viruses from Chicken Feces, Specific for Several Salmonella enterica Strains

“…The proposal of the use of phage therapy to treat Salmonella infections has been published previously in many reports. Those studies led to determination of properties of various Salmonella -specific phages [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], effects of application of phages to poultry [ 22 , 23 , 24 , 25 , 26 , 27 ], and results of experimental use of phages in therapies of infected animals [ 28 , 29 , 30 , 31 , 32 ]. In addition, economic analyses of potential use of anti- Salmonella phage therapy in poultry have also been published [ 1 , 33 ].…”

“…In addition, economic analyses of potential use of anti- Salmonella phage therapy in poultry have also been published [ 1 , 33 ]. Despite promising results of these studies, it was also indicated that most phages infecting S. enterica have a relatively narrow host range, specific to one or a few serovars or strains [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 34 ]. Thus, characterization of newly isolated bacteriophages infecting this bacterium is reasonable.…”