ABSTRACT
Efficient bio-medical waste management is a major challenge in Africa, and Nigeria in particular. Uncontrolled and excessive use of antibiotics by human may cause an increase in the prevalence and distribution of resistance genes in the environmental samples such as biomedical wastes. Antibiotics resistance is a global problem currently threatening the treatment of infections in plants, animals and humans. This study investigated the antibiotics resistant pattern of bacterial isolates from waste dump sites in Federal Medical Centre, Aba Road, Umuahia, Abia State. The isolates present in the samples were isolated and identified using cultural and biochemical techniques. The isolates were subjected to antimicrobial susceptibility to determine the resistant pattern of the isolates to some antimicrobial agents. Exactly fifty (50) samples from different dump sites from Federal Medical Centre, Umuahia were analyzed. A total of 41 bacterial species were isolated from the 50 samples. Bacillus spp occupied 36.9% of the total number of the isolates, Escherichia coli occupied 17.1%, Streptococcus spp occupied 22.0%, and Klebsiellaspp occupied 7.3% of the total number of isolates. The isolates showed multidrug resistance to Chloramphenicol, Septrin, Augmentin, Amoxycillin and Streptomycin. From the result, Bacillus spp showed the highest resistance to almost all the antibiotics tested. All the Bacillus spp isolates (100%) were resistant to Augmentin,93.3% of Bacillus spp showed resistance to Amoxycillin, 53.3% were resistant to Streptomycin, 86.7% were resistant to Chloramphenicol, 13.3% were resistant to Gentamicin while 6.7% were resistant to Pefloxacin. All the Bacillus sppisolates were sensitive to Ciprofloxacin. Among the isolates, Klebsiellaspp showed the least resistant to the antibiotics tested, only Augmentin, Amoxycillin and Chloramphenicol were resistance recorded. The high resistant to antibiotics as observed in this study is very alarming and thus highlights the global problem of antibiotics resistance to the public health.
TABLE OF CONTENTS
Title page i
Dedication ii
Acknowledgements iii
Certification iv
Table of Contents v
List of Tables viii
List of Figures ix
Abstract x
CHAPTER ONE
1.0 Introduction 1
1.1 Statement
of Problem 3
1.2 Justification 3
1.3 Aim
and Objectives 4
CHAPTER TWO
2.0 Literature Review 5
2.1 Antibiotic Resistance 6
2.1.1 Emergence
of Resistance 7
2.2 Problems
of Antibiotic Resistance 9
2.3 Genetic
Basis of Antibiotic Resistance 10
2.3.1 Inherent
Resistance 10
2.3.2 Mutational
resistance 10
2.4 Mechanisms
for Emergence Resistance 11
2.4.1 Plasmid
Mediated Resistance 11
2.4.2 Reduced
Membrane Permeability 12
2.4.3 Modification
of Target Resistance Site 12
2.4.4 Rapid
Extrusion or Effluxpumps 13
2.4.5 Chromosome
Mediated-Resistance 13
2.5 Mechanism
of Resistance Transfer 14
2.5.1 Horizontal
transfer of antibiotic resistance genes 14
2.6 Specific
Mechanisms of Resistance 17
2.6.1 Staphylococcus
aureus 17
2.6.2 Escherichia
coli 18
2.6.3 Pseudomonas
aeruginosa 18
2.7 Waste 20
CHAPTER THREE
3.0 Materials
and Method 23
3.1 Collection
of Samples 23
3.2 Media
Preparation 23
3.3 Isolation
Characterization and Identification of Bacterial Isolates 23
3.4 Biochemical
Test 24
3.4.1 Gram
Staining 24
3.4.2 Motility
Test 24
3.4.3 Catalase
Test 25
3.4.4 Coagulase
Test (Slide test) 25
3.4.5 Citrate
Utilization Test 25
3.4.6 Indole
Test 26
3.4.7 Urease
Test 26
3.4.8 Triple
Sugar Iron Test (TSI) 27
3.4.9 Endospore
formation stain 27
3.5 Antibiotics
susceptibility test 27
CHAPTER FOUR
4.0 Result 29
CHAPTER FIVE
5.0 Discussions 38
5.1 Conclusion 39
5.2 Recommendations 40
References
LIST OF TABLES
Table Title Page
4.1: Prevalence
of bacteria isolates from different dumpsite at Federal Medical 30
Centre, Aba Road, Umuahia, Abia State, Nigeria.
4.2:
Antibiotic susceptibility pattern of
the isolates from Federal Medical Centre, Aba
road, Umuahia, Abia State Nigeria. 31
4.3:
Percentage resistance of the isolates
on different antimicrobial agents. 35
LIST
OF FIGURES
Figure Title Page
4.1: Average percentage resistance of the
isolates to different antimicrobial agents. 36
4.2: Multidrug resistance of the isolates
from different dumpsites at Federal Medical 37
Centre, Aba road, Umuahia, Abia
State Nigeria.
CHAPTER ONE
1.0 INTRODUCTION
Efficient
bio-medical waste management is a major challenge in Africa, and Nigeria in
particular (Fongwa, 2002). Uncontrolled and excessive use of antibiotics by
human may cause an increase in the prevalence and distribution of resistance
genes in the environmental samples such as bio-medical waste (Iversen et al., 2002).
In
the early 1970s, physicians were finally forced to abandon the belief that,
given the vast array of effective antimicrobial agents, virtually all-bacterial
infections were treatable. This optimism was shaken by the emergence of
resistance to multiple antibiotics among such pathogens as Staphylococcus
aureus, Pseudomonas aeruginosa and a host of others (Lowy, 2003).
Multidrug
resistance is now the norm among these pathogens. Staphylococcus aureus is perhaps the pathogen of greatest
concern because of its intrinsic virulence, its ability to cause a diverse
array of life threatening infections, and its capacity to adapt to different
environmental conditions (Lowy, 2003). Pseudomonas aeruginosa is a highly
relevant opportunistic pathogen. One of the most worrisome characteristics of Pseudomonas
aeruginosa is its low antibiotic susceptibility. Escherichia coli is
responsible for more than 80% of urinary tract infections (UTI) (Wikipedia,
2007), and is noted for producing an enzyme (β- lactamase) which degrades
penicillin during clinical trials, and currently resists a vast number of other
antibiotics (Sherman, 2006).
Antibiotic
resistance is the ability of a microorganism to resist the effect of an antibiotic;
these organisms thwart antibiotics by interfering with their mechanism of
action. Resistance to antibiotics has spread fast to a number of commonly used
antibiotics such that “in the 1990s, we have come to a point for certain
infections that we do not have agents available”. (Lewis, 1995).
Antimicrobial
drug resistance in bacterial pathogens is of National and International concern
(WHO, 2001; CDC, 2001). Although the misuse of antimicrobial agents is accepted
as a major driving force behind the spread of resistance, the nature of this
relationship is complex. Resistance to antibiotics is sometimes acquired by a
change in the genetic make-up of a bacterium, which can occur by either a
genetic mutation or by transfer of antibiotic resistance genes between bacteria
in the environment (Williams, 2002).
Infectious
diseases are becoming more difficult and more expensive to treat, because our
current antibiotics are becoming less useful against antibiotic resistant
pathogenic bacteria. When antibiotics fail to work, the consequences include
extra consultation with the doctor, hospitalization or extended hospital stays,
a need for more expensive antibiotics to replace the older ineffective ones,
loss of workdays, and sometimes, death (APUA, 1999).
The
increased use of antibiotics in health care, as well as in agriculture and
animal husbandry, is in turn contributing to the growing problem of antibiotic
resistant bacteria. The antibiotic does not technically cause resistance, but
allows a situation where an already existing variant can flourish (APUA, 1999).
Products such as disinfectants, sterilants, and heavy metals used in industries
and in household products along with antibiotics, are creating selective
pressure in the environment that lead to mutations in microorganisms (Baquero et
al., 1998).
In
environment with multiple stresses, such as antibiotics and heavy metals, it
would be ecologically favorable, in terms of survival, for a bacterium to
acquire resistance to both stresses. If the resistance is carried on plasmid,
those bacteria with clusters of resistance genes on plasmids are likely to
simultaneously pass on those genes to other bacteria, with a better chance of
survival (Lawrence, 2000).
1.1 Statement of Problem
Antibiotic
resistance is a global problem currently threatening the treatment of
infections in plants, animals and humans. Bacteria with elevated antibiotic
resistance levels present a potential public health risk because infections
with these organisms do not respond to one or more of the drugs commonly used
to treat them. According to CDC, (2000), drug resistant pathogens are a growing
menace to all people, regardless of age, gender, or socioeconomic background.
There
is also, the risk of transferring antibiotic resistance to bacterial populations
in the environment because antimicrobial resistance genes and their genetic
vectors, once evolved in bacteria of any kind anywhere, can spread indirectly
through the world’s interconnecting commensal, environmental, and pathogenic
bacteria anywhere else (O’Brien, 2002).
1.2 Justification
The
proliferation of dumpsites and open drainages within hospital and the lack of
efficient waste collection and treatment processes is of public health concern
because microorganisms and heavy metals among others are the major pollutants
of dumpsites and wastewater.
Therefore,
there is need to study the antibiotic resistance pattern of bacterial isolates
from hospital dump sites.
In
view of the increasing resistance among various pathogens to common
antibiotics, including broad-spectrum antibiotics, there is need to research
into preventable causes of antibiotic resistance in order to lower the
incidence of drug resistance.
Antimicrobial
resistance is driving up health care cost, increasing the severity of disease,
and increasing the death rates from certain infections (NIAID, 2006). A number
of clinically important microbes have developed resistance to available
antimicrobials including Staphylococcus aureus and Pseudomonas
aeruginosa which cause skin, bone, lung and bloodstream infections and Escherichia
coli which causes urinary tract infections (Wikipedia, 2007).
1.3 Aim and Objectives
The aim of this study is to ascertain
the antibiotic resistance pattern of bacterial isolates from waste dump site in
Federal Medical Centre Umuahia.
The
objectives of this work are therefore:
1.
To isolate and identify bacteria pathogens from hospital dump site.
2.
To determine antibiotic resistance pattern of the bacterial isolates.
3.
To deduce the public health importance of the antibiotic resistant bacterial
isolates.
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