Pharmaceutical Microbiology


Written by MicroDok

Antibiotics are substances produced by certain types of microbes (bacteria and fungi inclusive), and which at minute concentrations “selectively” kill or inhibit the growth of pathogenic microbes. Antibiotics are a type of antimicrobial agents. While all antibiotics are antimicrobial agents, not all antimicrobial agents are antibiotics. Other examples of antimicrobial agents include preservatives and detergents and antiseptics.

Preservatives are antimicrobial agents that are incorporated into food or drug formulations to prevent microbial contamination and spoilage. They either kill microbes or prevent their proliferation (multiplication) in the food or product containing them. Disinfectants are antimicrobial agents used for disinfection of environments, inanimate materials or utensils. They are expected to kill microbes, preferably rapidly. Antiseptics are antimicrobial agents used for the disinfection of living tissues. They are generally classified as either skin antiseptics (used for surface disinfection, wound dressing, hand washes) or oral antiseptics (such as mouth washes and throat lozenges). Some disinfectants also function as antiseptics usually in a much dilute concentration.

Over the years, pathogenic microorganisms (i.e., disease-causing microorganisms) have developed unique methods of evading destruction or killing by potent antimicrobial agents. This biological phenomenon put forward by microbes to ward off the onslaughts of antibiotics and/or antimicrobial agents is generally known as antimicrobial (antibiotic) resistance. Antimicrobial resistance could be generally described as the ability of microbes to resist destruction by antimicrobial agents. Antimicrobial resistance could also mean the ability of pathogenic microbes to survive in the presence of potent concentrations of antimicrobial agents to which they were previously susceptible.

Rational use of antibiotics requires that patients receive medications appropriate to their clinical needs, in doses that meet their own individual requirements, for an adequate period of time, and at the lowest cost to them and their community. The inappropriate use of antibiotics has often been identified as a problem in effective health care delivery. High levels of antibiotic use, often clinically unnecessary, have led to a steady increase in antibiotic resistance which can cause life-threatening infections. More so, the non-clinical use of antibiotics especially in the rearing of animals and in poultry as well as for other veterinary purposes have also contributed to the growing global problem of antibiotic resistance.

Any use of antibiotics has the potential to stimulate the development of resistance in the microbial world. And this is because it is microorganism’s innate ability to respond to changes especially untoward changes in their environment, and this may include problematic changes such as exposure to antimicrobial agents. When the microbe responds positively to this change (i.e. exposure to antibiotics), it means that the organism is susceptible to the antibiotics, and in this case the drug is effective and can be used to kill or inhibit the growth of the bacteria. However, when the bacteria responds negatively to the antibiotics, it means that the bacteria is resistant to the antimicrobial agents and does not in any way responds to the potent efficacy of the drug. At this point, the organism is said to be resistant to the antibiotics because it is no longer susceptible to an antibiotic concentration to which it was hitherto susceptible.

Antibiotics are threats to microorganisms. They are meant to curtail the nefarious activities of pathogenic microbes. However, the individual decision (by the prescriber or dispenser, the consumer or both) to use antimicrobial agents or antibiotics often ignore the societal perspective of depleting a common good whereby antimicrobial use can be compared to the use of a natural resource such as crude oil or even water. In both cases, individual use or misuse potentially impact on the availability of either of these resources. This also impacts the overall utilization of these resources by other consumers.

The overuse of antimicrobial agents or antibiotics plays an important role in the emergence of antimicrobial resistance (AMR). On the order hand, the under-use of antibiotics via inappropriate choice, inadequate dosing, poor adherence to antibiotic prescription, poor patient’s compliance to antibiotic therapy and the availability and usage of substandard antimicrobials also plays an important role in the emergence and spread of AMR in the community or hospital environment. One of the major AMR containment strategies is therefore to increase appropriate use and to reduce inappropriate usage of antibiotics both in the hospital and non-hospital environment.

The education of clinicians, nurses, laboratory staff, patients, researchers, students, pharmacists, the academic, government and the general public on the judicious and rational use of antimicrobial agents and antibiotics is very paramount in the fight against AMR everywhere. AMR flourishes where antibiotics are abused, misused and dispensed at levels lower than the recommended treatment guidelines. In such cases, instead of the antibiotics wiping out the infection entirely (by killing the infectious disease agent or inhibiting its growth in vivo), the antibiotics or antimicrobial agents only kills or inhibits the growth of susceptible microbes while allowing the resistant microbes to thrive and continue to cause havoc in the patient or individual undergoing antibiotic therapy. In many developing countries, antibiotics are still obtainable or purchased over-the-counter (OTC) even without a proper doctor’s prescription. Such a practice, which is a type of self medication, encourages the emergence and transmission of AMR.

This is why it is important for the government to come up with legislation to control the free and open sale and usage of antibiotics by the public. More so, the government and private sector should invest in the detection of drug resistant microbes, and also go a step further to support policies that will help to create awareness on the matter, as well as invest more into the health sector of their people.

Use antibiotics wisely in order to keep resistant microbes at bay!

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