1.Could bacteriophages isolated from the sewage be the solution to methicillin-resistant Staphylococcus aureus?
Cheng Siang Tan ; Nurul Aqilah Aqiludeen ; Ruixin Tan ; Annabel Gowbei ; Alexander Beemer Mijen ; Santhana Raj Louis ; Siti Fairouz Ibrahim
The Medical Journal of Malaysia 2020;75(2):110-116
Introductions: The emergence of multidrug-resistant
bacteria such as Methicillin-Resistant Staphylococcus
aureus (MRSA) complicates the treatment of the simplest
infection. Although glycopeptides such as vancomycin still
proves to be effective in treating MRSA infections, the
emergence of vancomycin-resistant strains limits the long
term use of this antibiotic. Bacteriophages are ubiquitous
bacterial viruses which is capable of infecting and killing
bacteria including its antibiotic-resistant strains.
Bactericidal bacteriophages use mechanisms that is distinct
from antibiotics and is not affected by the antibioticresistant phenotypes.
Objectives: The study was undertaken to evaluate the
possibility to isolate bacteriolytic bacteriophages against
S.aureus from raw sewage water and examine their efficacy
as antimicrobial agents in vitro.
Methods: Bacteriophages were isolated from the raw
sewage using the agar overlay method. Isolated
bacteriophages were plaque purified to obtain homogenous
bacteriophage isolates. The host range of the
bacteriophages was determined using the spot test assay
against the 25 MRSA and 36 MSSA isolates obtained from
the Sarawak General Hospital. Staphylococcus
saprophyticus, Staphylococcus sciuri and Staphylococcus
xylosus were included as non-SA controls. The identity of
the bacteriophages was identified via Transmission Electron
Microscopy and genomic size analysis. Their stability at
different pH and temperature were elucidated.
Results: A total of 10 lytic bacteriophages infecting S.aureus
were isolated and two of them namely ΦNUSA-1 and
ΦNUSA-10 from the family of Myoviridae and Siphoviridae
respectively exhibited exceptionally broad host range
against >80% of MRSA and MSSA tested. Both
bacteriophages were specific to S.aureus and stable at both
physiologic pH and temperature.
Conclusion: This study demonstrated the abundance of
S.aureus specific bacteriophages in raw sewage. Their high
virulence against both MSSA and MRSA is an excellent
antimicrobial characteristic which can be exploited for
bacteriophage therapy against MRSA.