Proteomic Characterization of Lytic Bacteriophages of Staphylococcus aureus Isolated from Sewage Affluent of India

Abstract

Staphylococcus aureus is a Gram-positive bacterium 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 need for an alternative treatment such as bacteriophage therapy. Present study describes isolation and characterization of a staphylococcal phage from sewage samples. S. aureus isolates obtained from microbial type culture collection (MTCC), Chandigarh, India, were used to screen staphylococcal phages. A phage designated as ΦMSP was isolated from sewage samples by soft agar overlay method. It produced clear plaques on tryptone soya agar overlaid with S. aureus. Transmission electron microscopy revealed that the phage had an icosahedral symmetry. It had 5 major proteins and possessed a peptidoglycan hydrolase corresponding to 70 kDa. ΦMSP infection induced 26 proteins to be uniquely expressed in S. aureus. This phage can be proposed as a candidate phage to treat staphylococcal infections.

Isolation, Characterization, and Antibacterial Activity of Bacteriophages Against Methicillin-Resistant Staphylococcus aureus in Pakistan

“…The major proteins in lanes 4 and 5 were 90, 75, 20, 185, 155, 140, 115, and 55 kDa in size. A phage protein of about 100 kDa was also reported (14). …”

“…This might be due to the fact that hospital waste water is rich in bacterial contaminants from the hospital environment, which provides an excellent host range for all types of bacteriophages. The above explains why most of the researchers in this area were able to isolate phages from hospital waste water (14). …”

“…The sewage water samples were then processed for phage isolation as described previously (14). Briefly, the samples were first centrifuged at 4,000 rpm for 20 minutes, and a supernatant was filtered using a 0.22 µm syringe filter.…”

“…Individual plaques were picked using a sterile micro-pipette tip, as follows: the tip was first inserted into the center of a well isolated plaque and was swirled to obtain a single plaque. The plaque was then suspended in saline magnesium (SM) buffer, and an overlay method was used to obtain purified plaques of each type on the lawn of the individual host bacterium, as described previously (14). For the phage count (plaque forming unit (PFU) determination), a SM buffer supplemented with gelatin was prepared, and the phages were counted, as described previously.…”

Intriguing Interaction of Bacteriophage-Host Association: An Understanding in the Era of Omics

“…Abundance profiles of proteins can be plotted using comparative metaproteomics, while the reduction or increase in the quantity of some proteins may signify a distinct purpose in an organism or during particular situations of phage infection on the bacterial host (Sangha et al, 2014). The post-infection protein expression changes can be classified as (1) function which alters rapidly on phage-infection, but can get reverted back (2) variations that develop gradually and persist consistent or cannot revert back, and (3) alterations that appear abruptly and are maintained for a longer term.…”