ABSTRACT
Milk is an important source of nutrient to humans and animals. It is meant to be the first and the only food for the offspring of mammals as it is capable to serve as food. This study evaluated the microbial quality of raw milk from dairy farm. About three raw milk samples were collected from Fulani cattle settlement, Umuahia, Abia State. The samples were analyzed using the microbiological techniques for isolation and identification of isolates. The microbial load of the samples ranged from 8.2x105 CFU/ml to 6.0 x 105 CFU/ml. About five (5) bacterial genera were isolated which comprised of 3 (25%) Lactobacillus spp., 3 (25%) Listeria spp., 3 (25%) Salmonella spp., 2 (16.7%) Proteus spp. And 1 (8.3%) The presence of bacteria responsible for intoxication such as Staphylococcus aureus may be a public health problem if no precaution is taken against this contamination.
TABLE
OF CONTENTS
Title
page i
Certification ii
Dedication iii
Acknowledgment iv
Table
of contents v
List
of tables vii
Abstract viii
CHAPTER ONE
1.0 Introduction
1
1.1 Aims
and objectives of the study 5
CHAPTER
TWO
2.0 Literature
review 6
2.1 Definition
and composition of milk 6
2.2 General
overview of milk production and safety in a dairy farm 6
2.3 Source
of microbial contamination of milk 7
2.4 Milkborne
infections and pathogenic micro-organisms 8
2.5 Hygiene,
handling and microbial evaluation of raw milk 8
2.6 Prevention
and control of microbial contamination of milk 9
2.7 Antimicrobial
residues, bacterial resistance and their effects
to
animals and humans 9
2.8 Milk-borne
infections and pathogenic microorganisms 11
2.9 Nigerian policy on food hygiene and safety
13
2.9.1 National legislations 13
2.10 Dairy
development in Nigeria 14
CHAPTER THREE
3.0 Materials
and methods 16
3.1 Study
area and sample collection 16
3.2 Sampling
of milk/size 16
3.3 Milk
sample handling 16
3.4 Media
preparation 16
3.5 Inoculation
and incubation of the sample 17
3.6 Identification
and characterization of isolates 17
3.6.1 Gram
staining technique 17
3.7 Biochemical
tests 18
3.7.1 Catalase
test 18
3.7.2 Oxidase
test 18
3.7.3 Indole
test 18
3.7.4 Citrate
utilization test 19
3.7.5 Motility
test 19
3.7.6 Coagulase
test 19
CHAPTER FOUR
4.0 Results 20
CHAPTER FIVE
5.0 Discussion 24
5.1 Conclusion
25
5.2 Recommendation
26
REFERENCES
LIST OF
TABLES
TABLES TITLE PAGES
1
Characterization and Identification
of the bacterial isolates
from the raw milk 21
2 Total
heterotrophic bacterial count (THBC) 22
3 Prevalence
of bacteria isolated from raw milk 23
CHAPTER ONE
1.0 INTRODUCTION
Milk
is an important source of nutrients to human and animals. It is meant to be the
first and the only food for the offspring of mammals as is almost complete food
(Pandey and Voskuil, 2011). Almost 87% of milk is composed of water and the
remaining part comprises total solids (carbohydrates, fat, proteins and
minerals) contained in a balanced form and digestible elements for building and
maintaining the human and animal body. Other milk ingredients include
immuno-globulins which protect the newly born against a number of diseases
(Pandey and Voskuil, 2011). Milk has a complex biochemical composition and its
high water activity and nutritional value serves as an excellent medium for
growth and multiplication of many kinds of microorganisms when suitable conditions
exists (Parekh and Subhash, 2008).
Milk
meant for human consumption must be free from any pathogenic organisms (Bertu et
al., 2010). Microbial contamination in milk may cause milk-borne diseases
to humans while others are known to cause milk spoilage. Many milk-borne
epidemics of human diseases are spread through milk contamination. Sources of
microbial contamination in milk include primary microbial contamination from
the infected or sick lactating animal. The secondary causes of microbial contamination
occurs along the milk value chain which may include contamination during
milking by milkers, milk handlers, unsanitary utensils and/or milking
equipments and water supplies used in sanitary activities. Other secondary
sources of microbial contamination occur during milk handling, transportation
and storage. There is tertiary microbial contamination which occurs mainly due
to re-contamination of milk after being processed due to unhygienic conditions
and/or poor or improper handling and storage of milk during consumption (Parekh
and Subhash, 2008). The quality of milk is determined by its composition and
overall hygiene. However, consumption of contaminated food like milk may lead
to food-borne diseases (FBDs).
The WHO has described FBDs as illnesses of an infectious
or toxic nature caused by, or thought to have been caused by the consumption of
food and water (Adams and Motarjemi, 1999), which conceivably represents the
most common health problem of recent days, thus reducing significantly economic
productivity (Mukhola, 2000). It is estimated that up to a third of people in
developed countries are affected by FBDs (WHO, 2009). FBDs are caused by the
consumption of foods exposed to hazards that may be biological or pathogenic
(e.g. viruses, bacteria, parasites), chemical (e.g. heavy metals and toxins),
and others physical (e.g. glass fragments, bone chips) (Schmidt et al.,
2003). Etiological information suggests that the frequency of occurrence from
microbial or pathogenic origin is by far higher (WHO, 2009). According to the
WHO, 62% of all human pathogens are zoonotic (Taylor et al., 2001). This
is in agreement with the WHO that 75% of all emerging human diseases originate
from animal reservoirs (Vallat, 2007). Consequently, animal sourced foods have
been found guilty for the majority of FBDs (De Buyser et al., 2001) and
incidences increase with increasing access to such foods especially without
adequate hygiene, inspection for safety or satisfactory heating to kill
pathogens (McCrindle, 2008).
Specifically, human may be infected with milk-borne
pathogens through consumption of infected raw or unpasteurized milk and milk
products (Bertu et al., 2010). Sometimes consumption of contaminated or
spoiled milk and dairy products may cause milk-borne diseases in humans.
Indeed, FBDs are a serious threat to people in Africa, responsible for 33-90%
cases of deaths in children (Flint et al., 2005). Although milk and milk
products are a minor constituent in most diets but contaminated milk are
responsible for up to 90% of all dairy related diseases of humans (De Buyser et
al., 2001). A study by Shirima et al. (2003) documented several
pathogens resulting to milk-borne zoonotic diseases including brucellosis,
tuberculosis and enterotoxaemia. The risk of infection by milk-borne zoonotic
diseases is one of the reasons for public health regulations, which discourages
the informal milk markets and consumption of raw or unpasteurized milk
(Kang’ethe et al., 2000).
Pathogenic
microorganisms commonly isolated from milk and milk products pose a serious
threat to human health. Some of these pathogens include Escherichia coli,
Staphylococcus aureus, Salmonella spp., Listeria moncytogens, Brucella
abortus, Mycobacterium spp., Campylobacter spp., Leptospira spp.,
Clostridium spp., Pseudomonas aeruginosa and Proteus spp.
(Shirima et al., 2003; Al-Tahiri, 2005; Donkor et al., 2007; Lei et
al., 2008; AlAll et al., 2012). Raw milk is known to be a major
vehicle that serves as means of transmission of these milk-borne pathogens to humans.
On the other hand, raw milk apart from being potential
carrier of pathogens can also cause serious health risk to consumers due to
antimicrobial residues (Omore et al., 2005; Kivaria et al., 2006a).
Antibiotic residues are remnants or small amounts of antimicrobial drugs or
their active metabolites which remain in milk after treating lactating cows
(Shitandi, 2004; Syit, 2008). Antimicrobial agents especially antibiotics are
normally used in dairy cattle for treatment and prevention of bacteria and associated
infections (Syit, 2008; Nonga et al., 2010; Sharma et al., 2011).
Inappropriate use of these antibiotics by small-scale livestock keepers at farm
level may lead to various bacterial pathogens developing resistance to most
commonly used antibiotics which in turn increases bacterial resistant to almost
all existing antibiotics (Kivaria et al., 2006b; Sharma et al.,
2011). The outcome of random use of antimicrobial agents in animals is
expansion of antimicrobial resistant bacteria that may be transferred from
animals to humans through contact, contaminated environment or milk and milk
products (Syit, 2008; Sharma et al., 2011). The side effects associated
with antibiotic residues in milk include the risk of allergic reactions to
sensitive people, increased selection of resistant bacteria pathogens towards
commonly used antibiotics for human illnesses and inhibition of starter
cultures used in production of different milk products (Aboge et al.,
2000; Shitandi, 2004; Kurwijila et al., 2006). Presence of antibiotic
residues in milk may be the result of failure to observe the mandatory
withdrawal periods, incorrect dosage levels and/or illegal or extra-label use
of drugs (Syit, 2008).
Despite the existence of milk evaluation control
measures and regulations at different points before processing and consumption,
majority of milk such as over 75% of milk marketed in many developing regions
(including East Africa) is sold raw or unpasteurized through informal channels
(Bertu et al., 2010; Oliver and Murinda, 2011). Milk is consumed raw at
household and/or village level especially to pastoral and agro-pastoral
communities who do not believe that milk could be a potential source of human
infections and they are not ready for any kind of treatment (Bertu et al.,
2010). This poses health risks to consumers and the general public especially
for those who consume raw or unpasteurized milk and milk products. Concerns
about human health risks from the market pathways need to be addressed in the
context of consumer practices, such as boiling, to reduce or eliminate
potential infection by milk-borne health hazards without discouraging the
markets through which the majority of smallholders’ dairies and livestock
keepers sell their milk (Kang’ethe et al., 2000).
This
study has quantified and identified some bacteria species that are common
contaminants of milk from small-scale livestock keepers. It further attempted
to establish the risk factors for microbial contamination of milk at farm
level. The study further determined the susceptibility of the bacterial
isolates to commonly used antibiotics in veterinary and human practices.
Information that have been obtained from this study will be useful in knowing
the status of microbial contamination in milk, the common species of bacteria
involved and their susceptibility to antibiotics. Also the public will be
enlightened and educated on the importance of knowing the microbial quality of
milk they consume and this can give the evidence-based advice on the likely
dangers of consuming raw or unpasteurized milk.
1.1 AIMS AND OBJECTIVES
i.
To isolate, characterize
and identify microorganisms associated with raw milk (cow).
ii.
To access the total
bacterial load of raw cow milk from farm.
Click “DOWNLOAD NOW” below to get the complete Projects
FOR QUICK HELP CHAT WITH US NOW!
+(234) 0814 780 1594
Buyers has the right to create
dispute within seven (7) days of purchase for 100% refund request when
you experience issue with the file received.
Dispute can only be created when
you receive a corrupt file, a wrong file or irregularities in the table of
contents and content of the file you received.
ProjectShelve.com shall either
provide the appropriate file within 48hrs or
send refund excluding your bank transaction charges. Term and
Conditions are applied.
Buyers are expected to confirm
that the material you are paying for is available on our website
ProjectShelve.com and you have selected the right material, you have also gone
through the preliminary pages and it interests you before payment. DO NOT MAKE
BANK PAYMENT IF YOUR TOPIC IS NOT ON THE WEBSITE.
In case of payment for a
material not available on ProjectShelve.com, the management of
ProjectShelve.com has the right to keep your money until you send a topic that
is available on our website within 48 hours.
You cannot change topic after
receiving material of the topic you ordered and paid for.
Login To Comment