Bacteriophages: Effectiveness & limitations in modern era

Bacteriophages are the most commonly found entities on the earth and considered as bacterial predators.

From beginning of life large number of diseases effecting human health some of them are bacterial, viral and protozoal. Though, bacteria are an important part of our normal flora and life seems to be impossible without the role of many prokaryotes but, the tenancy of various species can have harmful effects and cause many lethal diseases.

Being a developing country, Pakistan is facing various economic as well as health issues. Approximately, two million children, less than five years of age, die of pneumonia and similar number die of diarrhea every year.

Antibiotics have played an important role in overcoming of this issue but the bacteria have got resistant against many antibiotics, which is currently the major point of concern.

Bacteriophages are bacterial viruses were discovered by an English bacteriologist Frederick William Twort in 1915 and the term was implied by Felix d’Herelle. Like other viruses, their genetic makeup consists of either DNA or RNA encapsidated by a protein coat. A tail having fibers attached to the capsid helps in attachment to the host bacterial surface. Phages hijack the host and propagate infection in possibly two methods, either lytic cycle or through lysogenic cycles. When the phages multiply within bacteria kill the host and the life cycle is known as lytic cycle.

While some phages called as temperate phages can integrate their genome into host chromosomes, replicating with the host for many generations and the cycle is called as lysogenic cycle which may turn into lytic on the induction by ultraviolet radiations or other harsh conditions.

Effectiveness of Bacteriophages:

An increase in the number of antibiotic-resistant bacterial strains has been a major point of concern in the modern medicine. The effectiveness of the phages relies in the following facts;

1. Bacteria do not show resistance against the phage lysis mechanism
2. Phage therapy can be the most effective method to treat bacterial infections.
3. Bacteriophages have the ability of auto dosing, which means that they increase in number on their own where the hosts present.
4. They show less toxicity.
5. They confer less toxicity to the normal flora.
6. There can be versatile methods for their development and application.
7. The phages, unlike antibiotics, do not have side effects.

Limitations:

There can be problems and confusions about the development of phage therapy, for example

• Phage selection.
• Limited phage-host range.
• Unfamiliarity with the phages.

The oral administration of bacteriophages is considered easy, but the point of concern maybe there in order to neutralize the stomach acid before the ingestion to limit the phage damage or to make the survival of bacteria possible which can die at such low ph.

In Pakistan, major work on phage therapy has been done in the University of Karachi and National University of Science and Technology. The phage therapy is not new but its use in humans is not well studied and well researched, that’s why the concerns are there which we may overcome in the future.

Conclusion:

Bacteriophages, due to their number of properties as antibacterial agents, may become a complete alternative to chemical antibiotics.On the other hand, the concerns about phage therapy are also present which can be managed by a combination of proper phage selection, effective formulation and application along with greater clinician understanding and familiarity with product application