Effects of Antibiotics and Disinfectants On bacteria

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The workings of bacteria have formed a fundamental part of understanding of biology. However, there are variations as to the understanding of bacteria and the role that they play in the universe. In most cases, bacteria are thought of as disease causing organisms. In fact, this is the common riding phrase in the marketing of disinfectants, wherein the effectiveness of disinfectants is defined by its ability to “eliminate” bacteria. As much as pathogenic bacteria result in ailments such as bubonic plague, tetanus, tuberculosis, gonorrhea and pneumonia among others, they are a minute component of all bacteria. It is worth noting that the average human body incorporates a higher number of bacterial cells than human cells. The bacteria assist the human body in undertaking various, necessary functions. Moreover, bacteria assist in breaking down organic matter, make up base for food web in numerous environments, and help in the provision of nitrogen to agricultural crops.

While there is differentiation of the nature of different categories of bacteria, the working of disinfectants on them is virtually the same (Russell, 2002, pp. 87). Disinfectants may act on microorganisms such as bacteria in two varied ways. They may inhibit their growth or have a lethal action on them. However, disinfection mainly concentrates on the lethal action as the desired effect.

There exists some uncertainty as to the functioning of disinfectants on active molecules. A large number of scholars have underlined the notion that antiseptics and disinfectants function in a non-specific manner, which contrasts antibiotics that incorporate unique, cellular targets in the microorganisms (Russell, 2002, pp. 88). Nevertheless, disinfectant are often complex formulations pertaining to active molecules that sometimes incorporate acidic or alkaline agents, chelating agents, co-solvents, and anticorrosive or surface active products (Salyers & Whitt, 2005. pp. 78). It is worth noting that there may exist a significant variation in the media that surround target microorganism, as well as the state in which the bacteria is present. For example, bacteria that are incorporated in complex biofilm or even isolated. These are factors that affect the working of disinfectants on bacteria. Nevertheless, there are various ways in which antibiotics affect bacteria in carrying out their lethal action.

First, antibiotics and disinfectants act on the external membrane of bacterial wall. It is worth noting that a bacterium incorporates a membrane, which protects it from its environment. The integrity of the external membrane is extremely crucial for the survival and existence of the bacterium (Russell, 2002, pp. 89). The membrane incorporates basic compounds including lipopolysaccharides and phospholipids and is stabilized by the Ca ++ and Mg++ cations. In essence, when the ionized disinfecting molecules are repelled or absorbed by the electrical charges during the initial contact and absorption stage, various actions may occur (Salyers & Whitt, 2005. pp. 76). The non-polar molecules would dissolve and become lipids. In addition, specific carrying systems may allow for the entry of other molecules via the violated membrane and, the other molecules would have the capacity to disturb the membrane’s organization by adhering to certain sites, thereby, having lethal effects on the bacteria (Hugo, 1999, pp.45).

In addition, molecules from disinfectants and antibiotics may act on the bacteria wall. It is noteworthy that the bacterial wall comes as extremely crucial to the existence of the bacteria. It is known to confer rigidity on the organism and differs significantly between Gram-negative and Gram-positive-positive bacteria. The variation results in the diversity of the affinities characterizing hydrophilic disinfectants. Nevertheless, the adherence to the bacterial wall threatens the existence of the organism (Salyers & Whitt, 2005. pp. 76).

On the same note, the antibiotics may act on the bacteria’s cytoplasmic membrane. There are two ways in which active molecules of antibiotics may penetrate the bacteria’s cytoplasmic membrane. It may penetrate through passive diffusion, which is slow and non-specific. Alternatively, it may enter via active transport, which is specific and enables for the accumulation of various products in the bacteria after binding to the membrane protein or transformation (Salyers & Whitt, 2005. pp. 76).

In some cases, the antibiotics and disinfectants act on the energy metabolism of the bacteria. They may also act on the spores of the bacteria, which are essential for its existence. The presence and impermeability of the dipicolinic acid in the bacterial spores enhances their resistance to disinfectants (Hugo, 1999, pp.45). However, active molecules of disinfectants are known to incorporate highly oxidizing products including chlorine and hydrogen peroxide. These two products have the capacity to destabilize the structure of the spores (Hugo, 1999, pp.45).

All in all, there are variations in the manner in which disinfectants and antibiotics affect bacteria depending on their compounds. Products that contain peracetic acids oxidize and even denatures lipids and proteins in microorganisms, resulting in disorganization of their membrane. Iodine, on the other hand, decreases the bacteria’s requirements of oxygen. It interferes at the respiratory chain level of microorganisms by impending the transportation of electrons via electrophilic reactions with enzymes pertaining to the respiratory chain (Salyers & Whitt, 2005. pp. 76). In addition, iodine interacts preferentially with proteins pertaining to the cytoplasm membrane that have positive or neutral charge. Products that incorporate ozone are believed to act on the bacteria through oxidation. Ozone is known to activate the bacteriophages T4 andF2 by attacking protein capsid thereby releasing and activating the nucleic acids. These actions have fatal effects on the bacteria.

Bibliography

Russell, A.D, 2002, Mechanisms of antimicrobial action of antiseptics and disinfectants: an increasingly important area of investigation, Journal of Antimicrobial Chemotherapy.

Salyers, A. A., & Whitt, D. D. (2005). Revenge of the microbes: how bacterial resistance is undermining the antibiotic miracle. Washington, D.C., ASM Press.

Hugo, W. B. (1999). Disinfection mechanisms. In Principles and Practice of Disinfection, Preservation and Sterilization, 3rd edn, Blackwell Science, Oxford.