Abstract

Fresh fruits are an essential part of people’s diet all over the world. Since they are typically eaten raw and often without heat treatment or thorough washing. So they serve as vectors for the transmission of pathogenic microorganisms associated with human disease. This study aimed at isolating and identifying the pathogenic bacteria Staphylococcus areus from the selected popular fresh fruits and vegetables which are known as street food.

A total of five (10) fruits were collected around the university market and its environs with aseptic conditions. Selective and nonselective media were used to isolate and identify the bacteria Staphylococcus areus. All the species were identified on the basis of their morphology, biochemical test: catalase, coagulase and Gram staining and selective differential media.

CHAPTER ONE

GENERAL INTRODUCTION

1.1 BACKGROUND OF THE STUDY

In recent years, outbreak of human infections associated with the consumption of fresh or minimally processed fruits have increased, despite their nutritional and health benefits Hedberg, C.W., K.L. MacDonald, and M.T.J.C.I.D. (1994), Beuchat, L.R. (2002). Human disease outbreaks have been recognized as being caused by contaminated fruits consumption, several studies have been published describing the bacterial contamination of intact fruits in open markets GARG, N., J. et al. (1990).

Fruits host a variety of pathogenic microorganisms that may be spread over the plants or occur in the plant tissues as micro colonies Beuchat, L.R. (2002). Some diverse factors may be affected by the variety of microbial profile of fruits including normal micro flora from the soil, animal manure derived flora, irrigation or sewage water, transportation and unconscious handling by retailers. Microbial contamination is commonly exposed to fruits by contact with dirt, dust and water and by handling at Harvest or during post-harvest processing Carmo, H., et al., (2005),  Nguyen‐the, C. & Carlin, F.J.C.R.i.F.S (1994).

Therefore, a wide range of microorganisms are present including plants and human pathogens. Due to lack of surveillance and inadequate screening of these raw in university of Buea campus and its environs, most outbreaks have become undetected and there is very little information available in the literature so far Nipa, M.N., et al., (2011)

1.2 LITERATURE REVIEW

In another study, it was found that bacterial contamination of fruits was correlated with the fact that it is typically eaten without thermal treatment. A major contributing factor to contamination is the use of untreated wastewater and manure as fertilizers for the production of fruits Olayemi, A.J. (1997). In Bangladesh, various fruits are sold in open market and most of them are eaten raw, which is suitable medium for bacterial contamination Khan, M., M. Saha, and A.J.L. Kibria, (1992). In developing countries like Bangladesh, both poverty and poor sanitation is common, fecal contamination of domestic and commercial food is likely to occur, and illness has been traced to the ingestion of fecal infected food in multiple outbreaks Rabbani, G. and Greenough III, W.J.  (1999).

The ingestion of infected fresh fruits has been related to many outbreaks of human gastro-enteritis BRACKETT, R. (1992). The untreated waste water and manure as fertilizers for the cultivation of fruits and is a significant contributor to contamination Rai, P.K. and Tripathi, B.J. (207), Amoah, P., et al., (2006). Fresh fruits can harbour large and diverse population of bacteria. However, most of research on fresh fruits has focused on their isolation and as a result; we know far less about the overall diversity and molecular characteristics of those bacterial communities Leff, J.W. and Fierer, N.J. (2013)

1.3 RATIONALE

Apples and Oranges are increasingly being sold and consumed in Molyko.  The  unhygienic handling and processing of this fruits and packaging, permits the contamination  and  proliferation  of  pathogenic  bacteria  in  this  fruits making  this  sector  a great area of concern and so far very little studies have been carried in out on apples and oranges in Buea.

1.4 HYPOTHESIS

H0: Staphylococcus areus cannot be isolated and identified in fruits.

HA: Staphylococcus areus can be isolated and identified in fruits.

1.5 OBJECTIVES:

1.5.1 General objective:

To isolate and biochemically identify Staphylococcus areus from fruits.

1.5.2 Specific objective:

1. To isolate Staphylococcus areus from fruits.
2. To biochemically identify Staphylococcus areus from fruits.

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