EFFECT OF SOME DISINFECTANTS AGAINST STAPHYLOCOCCUS AUREUS

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Bacteria are ubiquitous microorganisms that inhabit various environments, including household surfaces. While many bacteria are harmless or even beneficial, some species are pathogenic and capable of causing diseases when they come into contact with humans, food, or open wounds. Common household bacteria such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa can be transmitted through contaminated surfaces, utensils, and hands, leading to infections ranging from mild skin irritations to severe gastrointestinal and respiratory illnesses (LeChevallier and Au, 2004). The use of disinfectants is a common and effective strategy to control bacterial contamination in domestic environments. Disinfectants are chemical agents specifically formulated to kill or inhibit the growth of microorganisms on inanimate surfaces. They include chlorine-based compounds, alcohols, phenolics, quaternary ammonium compounds, and hydrogen peroxide, each with unique mechanisms of action (McDonnell and Russell, 1999).

In households, surfaces such as kitchen counters, bathroom sinks, doorknobs, and floors can harbor diverse bacterial populations due to frequent human contact and exposure to organic matter. Regular cleaning with disinfectants significantly reduces the microbial load, thereby minimizing the risk of infections. However, the efficacy of a disinfectant depends on several factors, including concentration, contact time, type of microorganism, and presence of organic matter (Rutala and Weber, 2016).

With the growing concern about microbial resistance and the potential health risks of ineffective cleaning, it is essential to evaluate the effectiveness of commonly used disinfectants on household bacteria. Such studies help consumers make informed decisions about safe and efficient cleaning practices.

1.2 Statement of the Problem

Despite widespread use, not all disinfectants are equally effective against household bacteria. Inappropriate selection or improper use of these agents may lead to incomplete eradication of bacteria, which can contribute to microbial resistance and persistent contamination. Furthermore, the market is saturated with various disinfectant brands claiming high efficiency, but without standardized household-based testing, their actual performance remains uncertain. This creates a knowledge gap regarding the comparative effectiveness of disinfectants commonly available to consumers.

1.3 Aim of the Study

The aim of this study is to determine the effect of some disinfectants on Staphylococcus aureus isolated from household surfaces.

1.4 Objectives of the Study

The specific objectives were to:

i.          isolate Staphylococcus aureus present on  household surfaces.

ii.        determine the  effects  of  Dettol , Izal and Hypo against Staphylococcus.

iii.      compare the effects of the three selected disinfectantson S. aureus

1.5 Research Questions

i.          How effective are selected disinfectants in inhibiting the growth of these bacteria?

ii.        Can we isolate S. aureus from household surfaces?

iii.      Which disinfectant demonstrates the highest antimicrobial activity?

1.6 Significance of the Study

This study Provides scientific data on the effectiveness of commonly used household disinfectants.

Help households choose appropriate disinfectants for maximum hygiene.

Contribute to public health by promoting practices that reduce the spread of pathogenic bacteria.

Serve as a reference for future studies on antimicrobial resistance and household sanitation.

1.7 Scope and Delimitation of the Study

The study  focused on bacterial isolates obtained from common household surfaces such as kitchen sinks, toilet seats, door handles, and countertops. Only three selected available disinfectants were tested, and the study limited to bacterial; viruses and fungi not considered.

1.8 Justification of the Study

With increased awareness about hygiene, especially in the post-COVID-19 era, disinfectant use has become a routine practice. However, without evidence-based data on their effectiveness against specific household bacteria, users may waste resources or fail to achieve proper sanitation. This research addresses the need for empirical testing of disinfectants to ensure safety and efficiency in domestic environments.