Ability of Bacteriophages Isolated from Different Sources to Reduce Salmonella enterica Serovar Enteritidis In Vitro and In Vivo

Abstract

Salmonella enterica serovar Enteritidis-lysing bacteriophages isolated from poultry or human sewage sources were used to reduce Salmonella Enteritidis in vitro and in experimentally infected chicks. Cocktails of 4 different bacteriophages obtained from commercial broiler houses (CB4Ø) and 45 bacteriophages from a municipal wastewater treatment plant (WT45Ø) were evaluated. In experiment 1, an in vitro crop assay was conducted with selected bacteriophage concentrations (10(5) to 10(9) pfu/mL) to determine ability to reduce Salmonella Enteritidis in the simulated crop environment. Following 2 h at 37 degrees C, CB4Ø or WT45Ø reduced Salmonella Enteritidis recovery by 1.5 or 5 log, respectively, as compared with control. However, CB4Ø did not affect total SE recovery after 6 h, whereas WT45Ø resulted in up to a 6-log reduction of Salmonella Enteritidis. In experiment 2, day-of-hatch chicks were challenged orally with 3 x 10(3) cfu/chick Salmonella Enteritidis and treated cloacally with 1 x 10(9) WT45Ø pfu/chick 1 h postchallenge. One hour later, chicks were treated or not with a commercially available probiotic (Floramax-B11). Both treatments significantly reduced Salmonella Enteritidis recovery from cecal tonsils at 24 h following vent lip application as compared with controls, but no additive effect was observed with the combination of bacteriophages and probiotic. In experiment 3, day-of-hatch chicks were challenged orally with 9 x 10(3) cfu/chick Salmonella Enteritidis and treated via oral gavage with 1 x 10(8) CB4Ø pfu/chick, 1.2 x 10(8) WT45Ø pfu/chick, or a combination of both, 1 h postchallenge. All treatments significantly reduced Salmonella Enteritidis recovered from cecal tonsils at 24 h as compared with untreated controls, but no significant differences were observed at 48 h following treatment. These data suggest that some bacteriophages can be efficacious in reducing SE colonization in poultry during a short period, but with the bacteriophages and methods presently tested, persistent reductions were not observed.

Assessing the impact of bacteriophages in the treatment of Salmonella in broiler chickens

“…Moreover, bacteriophages have previously been used to control intracellular pathogens [27]. Some bacteriophages can be efficacious in reducing S. enteritidis colonization in poultry during a short period [18]. In our study, we were able to clear Salmonella from infected chicks after successive phage treatments applied within a short time period after infection.…”

“…Presence of Salmonella specific bacteriophages has previously been reported from excretion sewage of commercial broiler houses [24]. Meanwhile Andreatti Filho et al [18], isolated bacteriopgages from environmental drag swabs in commercial broiler houses. Spot tests were used in this study to confirm the presence of specific bacteriophages in the preparations, other studies such as Rahaman et al [17], have used similar strategies to test for the presence of specific bacteriophages.…”

“…Total DNA was extracted from caecal contents of all chicks in groups 2 & 3 and one chick from group 1 and 4 at each time point using QIAamp DNA Mini kit (Qiagen, Germany, GmbH) with modifications from the manufacturer’s recommendations (the rest of chicks in group 1 and 4 were examined by plating on XLD agar [18]). Briefly, 200 µl of the caecal content suspension was incubated with 10 µl of proteinase K and 200 µl of lysis buffer at 56°C for 10 min.…”

Bacteriophages: the possible solution to treat infections caused by pathogenic bacteria

“…Phages have also been applied on meat as well as fruits (Leverentz et al 2001) and vegetables (Viazis et al 2011) to control pathogens. They have successfully controlled bacterial infections caused by different kinds of bacteria, like Salmonella (Andreatti Filho et al 2007), Pseudomonas aeruginosa (McVay et al 2007), Staphylococcus aureus (Wills et al 2005), Clostridium difficile (Ramesh et al 1999), Escherichia coli (Huff et al 2002), and Campylobacter (Loc Carrillo et al 2005) in large animals and poultry. They significantly reduced Salmonella enterica colonization and horizontal transmission (Lim et al 2012).…”

Liposome-Encapsulated Bacteriophages for Enhanced Oral Phage Therapy against Salmonella spp

“…Thus, phage therapy has been proposed as a means to control Salmonella infection in chickens. Indeed, several studies have shown that phages effectively reduce Salmonella enterica colonization in poultry (11)(12)(13)(14)(15). The utility of phages in food preservation and safety has also been demonstrated (16)(17)(18)(19)(20)(21).…”