1.1 Introduction
Gases, dust particles, water vapour and air contain microorganisms. There are vegetable cells and spores of bacteria, fungi and algae, viruses and protozoa cysts. Since air is often exposed to sunlight, it has a higher temperature and less moisture if not protected from desiccation. Most of these microbial forms will die. Air serves as transport or dispersal medium for microorganism they occur in relatively small number in air when compared with soil or water. The Micro-flora of air can be studied under two headings outdoor and indoor Micro-flora.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Air does not have an indigenous and flora, though a number of micro-organism are present in the air. Air is not a natural environment for microorganisms as it doesn’t contain enough moisture and nutrients to support their growth and reproduction. Quite a number of sources have been studied in this connection and almost all of them have been found to be responsible for the air microflora. One of the most common sources of air microflora is the soil. Soil microorganisms when distributed by the wind blow librated into the air and remain suspended therefore along period of time. Man made actions like digging or ploughing the soil may be release soil born microbes into the air.
Outdoor Micro-flora: The air in the atmosphere, which is found outside the buildings, is referred to as outside air. The dominant microflora of outside air are fungi. The two common genera of fungi are cladosporiul and sporobolomyces, besides this two general, under general found in air are Aspergillus, Alternaria, Phytophthora and Erysiphe. The outdoor air also contains besidispores, ascopres of yeast, fragments of mycelium and canidia of molds. Among the bacterial genera Bacillus and clostridium, sarcina, mirococcus, corynebacterium and Achromobacter are widely found in the outside air, the number and kind of microorganism may very from place to place, depending upon the human population densities.
Indoor Micro-flora: The air found inside the building is referred to as indoor air. The commonest genera of fungi in indoor air are penicillium, Aspergillus, the Commonest genera of bacteria found in indoor air are Staphylococci, Bacillus and Clostridium. In case of occupants being infected, the composition shows slight variations with latitude and to a lesser extent with attitude. The ozone owes its existence in the atmosphere to photosynthesis from oxygen under the influence of solar ultraviolet radiations. (Dr. Shiva, 2009).
There is no microbes are native to the atmosphere rather they represent allochthonous populations’ transperted from aquatic and terrestrial habits into the atmosphere. Microbe of air within 300 – 1,000 or more feet of the Earth’s surface are the organisms of soil that have become attached to fragments of dried leaves, strain or dust particles, being blown away by the wind. Species vary greatly in their sensitivity to a given value of relative humidity, temperature and radiation exposure.
More microbes are found in air over land masses than far at sea. Spores of fungi especially Alterneria, Cladosporium, Penicillium and Aspergillus are more numberous than other forms over sea within about 400 miles of land in both polar and tropical air masses at all altitudes up to about 10,000 feet.
Microbes found in air over populated land areas below altitude of 500 feet in clear weather include spores of Becillus and Clostridium ascos-pores of yeasts, fragments of mycelium and spores of molds and streptomycetaceae, pollen pootozoan cysts, algae, micrococcus, corynebacterium etc.
In the dust and air of schools and hospital wards or the rooms of persons suffering from infectious disease, microbe such as tubercle bacilli, streptococci, pneumococci and staphylocci have been demonstrated. These respiratory bacteria are dispersed in air in the droplets of saliva and mucus produced by coughing, sneezing, talking and laughing.
Viruses of respiratory tract and some enteric are also transmitted from the objects contaminated with infectious secretions that after drying become infectiou dust. Droplet are usually formed by sneezing, coughing and talking. Each droplet consists of saliva and mucus and each may contain thousands of microbes. It has been estimated that the number of bacteria in a single sneeze may be between 10,000 and 100,000. Small droplets in a warm dry atmosphere are dry before they reach the floor and thus quickly become droplet nuclei.
Many plant pathogens are also transported from one field to another through air and the spread of many fungal diseases of plants can be predicted by measuring the concentration of airborne fungal spores. Human bacterial pathogen which cause important airborne disease such as diphtheria, meningitis, pneumonia, tuberculosis, and whcoping cough are described in the chapter “Bacterial Disease man”.
Therefore, in Microbiology Laboratory where the research was carried out, the activities that was conducted is to know the Isolation and identification of air Micro-flora.
1.3 Statement of Problems
Microorganisms are discharged into the air as infectious droplets, droplet nuclei and dust. Droplets are usually generated by sneezing, coughing or talking, which involve saliva and mucus while droplet nuclei are formed when small liquid droplets evaporate. Dusts are released into the air during activities such as sweeping, tillage of the soil, movement of heavy vehicles, blasting of stone and air turbulence (Mende et al., 2021). Air currents may also bring microorganisms from plant, animal and other solid surfaces into the air (Olaitan et al., 2006). Microorganisms suspended in air are only rarely found in Free State (Seino et al., 2005).
Air current influence the time which either the microorganisms or the particles laden with microorganisms remain suspended in the air. In still air, the particles tend to settle down. Air current is important in the dispersal of microorganisms as it carries them over a long distance. Air current produces turbulence which causes vertical distribution of air flora. No microbes are indigenous to the atmosphere rather they represent allochthonous populations transported from aquatic and terrestrial habitats into the atmosphere (Arora et al., 2012).
1.4 Aim and Objectives of Study
The aim of the study is to determine the Isolation and identification of air Micro-flora in Microbiology Laboratory. In achieving this aim, the following specific objectives were laid out as follows:
- To determine sources of microflora contaminants in selected microflora laboratories in Nigeria.
- To isolate and identify the bacterial and fungal contaminants in microbiology laboratories based on morphological and biochemical characteristics.
- To evaluate the genetic identity of persistent bacteria in laboratories after disinfection with sodium hypochlorite.
- To determine the number species and occurrence of bacteria and fungi in the air of Microbiology Laboratory
- To provide recommendation on ways of minimizing contamination of the air in Microbiology Laboratory
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- What are the sources of microflora contaminants in microflora laboratories in Nigeria?
- Are the bacterial and fungal contaminants encountered in microbiology laboratories different morphologically?
- Are the persistent bacteria to hypochlorite based disinfection genotypically similar to standard bacteria strains?
1.6 Research Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
- H0: There is no significant bacterial and fungal contamination encountered in microbiology laboratories in Nigeria
- H1: There is a significant bacterial and fungal contamination encountered in microbiology laboratories in Nigeria
1.7 Significance of Study
The information from this study will help to contain the Laboratory Acquired Infections) LAI associated with microbial contaminations in microbiology laboratories. The research findings will also assist personnel in laboratories to be careful when performing standard manipulations of microbiological specimens in cell cultures. This will help in reducing the costs associated with the application of the technology in laboratories. The information will form a basis of training the personnel on capacity development in monitoring and evaluation of microflora contaminants in laboratories. Then effecting or upgrading policy on Standard Operating Procedures (SOPs) will be developed in the laboratories.
1.8 Scope of Study
The study focuses on the Isolation and identification of air Micro-flora in Microbiology Laboratory in Nigeria.
1.9 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
