Isolation from Sewage Influent and Characterization of Novel Staphylococcus aureus Bacteriophages with Wide Host Ranges and Potent Lytic Capabilities

Abstract

Staphylococcus aureus is a gram-positive pathogen that causes a variety of diseases, including bovine mastitis, which has severe economic consequences. Standard antibiotic treatment results in selection of resistant strains, leading to a need for alternative treatments, such as bacteriophage therapy. Forty-nine S. aureus isolates were obtained from the milk of mastitic cows for use in screening of staphylococcal phages. Fifteen isolates which were positive for both coagulase and hemolysin were assayed by PCR for variation in the X region and the immunoglobulin G-binding region of the protein A gene (spa) and in the carboxy terminus of the coagulase gene (coa) and for the presence of enterotoxin C, G, H, and I genes. The host ranges of 52 phages isolated from sewage influent were determined by performing spot tests with the 15 S. aureus isolates, and two phages were subsequently chosen for further analysis. ⌽SA039 had the widest host range, producing clear plaques on 13 of the 15 isolates (87%), while ⌽SA012 produced clear plaques on 8 isolates (53%) and was the only phage that produced a clear plaque on a nonmastitic S. aureus strain. Transmission electron microscopy revealed that the phages were similar sizes and belonged to the Myoviridae family. Measurement of optical densities during coculture with S. aureus isolates confirmed the breadth of the ⌽SA039 host range and showed that ⌽SA012 had potent lytic capability. ⌽SA012-resistant bacteria did not appear for three of seven isolates tested (43%) after 65 h of incubation. These two phages are proposed as candidates for phage therapy of bovine mastitis.In the dairy industry, mastitis is a widespread problem responsible for important decreases in milk production. Economic losses of $100 million per year have been estimated for farms in Hokkaido, one of the largest milk-producing areas in Japan (28). Mastitis can be caused by over 150 different microorganisms, and one of the most important of these organisms is Staphylococcus aureus (22). After diagnosis of mastitis, the standard treatment regimen consists of isolating the diseased cow and treating it with antibiotics. However, this approach has drawbacks, such as its high cost and the eradication of harmless or beneficial organisms due to the lack of specificity of antibiotics. Additionally, the incidence of antibioticresistant bacteria has increased in recent years (4). As a result, there has been renewed interest in the use of other natural or engineered antimicrobial agents as an alternative or supplementary treatment for staphylococcal diseases such as mastitis (11,21,26). One group of alternatives with great potential involves bacteriophages (phages) and their derivatives, and a number of promising candidates have been described (2,5,7,13,17,18,27), notably bacteriophage K.One of the main obstacles to successful treatment of mastitis using phages is the fact that most phages are able to infect only a very narrow range of hosts. Given the plural etiology of many mastitis cases, it is desirable to find a phag...

Isolation and characterization of lytic phages TSE1-3 against Enterobacter cloacae

“…However the development of resistant bacteria environmentally isolated Enterobacter cloacae (accession no: KF975427) strain were isolated and characterized. The TSE phages were isolated from sewage exhaust which has been reported as a good source for bacteriophage isolation [13]. The TSE phages under study showed a narrow host range, a characteristic of majority of bacteriophages already reported [15].…”

Prevalence of Staphylococcus aureus and Lack of Its Lytic Bacteriophages in the Anterior Nares of Patients and Healthcare Workers at a Rural Clinic

“…23 The lytic phages are likely to modulate the rate of prevalence for one or more bacteria in different microbiological niches in the body. While lytic bacteriophages against S. aureus and MRSA have been isolated from different sources such as milk, 24 sewage influent, 25 cow slurry, 26 and septic wounds, 27 it is not known if they are prevalent in the anterior nares.…”

Removal of pathogenic bacteria from sewage-treated effluent and biosolids for agricultural purposes

“…There is a wide spectrum of pathogenic bacteria that has been detected in the treated sewage and biosolids, many of which are enteric in nature (Toze 1997 (Kowal 1983;US EPA 1988;Synnott et al 2009;Dungeni et al 2010;Ellafi et al 2010;Coronel-Olivares et al 2011). Markosyan et al (2002) Salmonella spp.…”