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PROJECT TOPICS ON PREVALENCE AND ANTIBIOTIIC SUSCEPTIBILTY PATTERN OF METHICILLIN – RESISTANT STAPHYLOCOCCUS AUREUSAMONG THE INTERNALLY DISPLACED PERSONS IN MAIDUGURI, NIGERIA.

PROJECT TOPICS ON PREVALENCE AND ANTIBIOTIIC SUSCEPTIBILTY PATTERN OF METHICILLIN – RESISTANT STAPHYLOCOCCUS AUREUSAMONG THE INTERNALLY DISPLACED PERSONS IN MAIDUGURI, NIGERIA.

ABSTRACT

 

Antimicrobial resistance has been noticed as one of the paramount microbial threats in the twenty first century. Staphylococcus aureus has always been a stumbling block for antimicrobial chemotherapy and methicillin resistance of S. aureus remains to be a significant problem and a global threat to human race due to its multidrug resistance propensity and avalanche of diseases associated with it.

Methicilin-Resistant Staphylococcus aureus is troublesome in homeless shelters that are crowded and confined with poor hygiene practice, (a typical of internally displaced persons camp) which may proliferate, thus putting inhabitants at increased risk of contracting MRSA. This study determined the prevalence of MRSA among the internally displaced persons (IDP) in Maiduguri, Nigeria.

In this study, 400 nasal swabs were collected from IDP‘s in some selected camps within Maiduguri metropolis. The swabs were inoculated on blood agar and mannitol salt agar. Fifty one S. aureus were isolated giving a prevalence of 12.75%.The isolates were further characterised by phenotypic and molecular methods, for detection of MRSA. Out of the fifty one S. aureus isolates, 46 (90.20%) isolates were identified by Cefoxitin disc diffusion as MRSA. Eight representative of MRSA isolates were confirmed by PCR.

Forty six (46) MRSA and five (5) MSSA isolates exhibited multi resistant pattern to the commonly used antibiotics. The antibiotic susceptibility test of S. aureus showed a high level of resistance to Oxacilin and Cefoxitin (90.20%) followed by Penicilin (84.31). Relatively high level of resistance was observed to Tetracycline (50.98%) but no resistance was observed to chloramphenicol and Ofloxacin. Polymerase chain reactiondetected mecA gene from the eight methicillin-resistant phenotypes which were selected randomly from the five IDP camps.The prevalence of S. aureus and MRSA isolated from nasal swab of IDPs was found to be 12.75% and 90.20% respectively.

CHAPTER ONE

                                                                     INTRODUCTION

 

1.1 Background of the Study

Staphylococcus aureus is one of the species of the genus Staphylococcus. It is a gram positive, non-motile, catalase positive, coagulase positive, facultative anaerobe, involved in causing a number of diseases including boils, pustules, impetigo, osteomyelitis, mastitis, septicaemia, meningitis, pneumonia and toxic shock syndrome. For humans, this organism is an important cause of food borne intoxication, pneumonia, post-operative wound infections, and nosocomial bacteremia (Umaru et al., 2011). Staphylococcus aureus is considered the most resistant of all non-spore forming pathogens, with well-developed capacities to withstand high salt concentrations (7.5 – 10%), extremes in pH and high temperatures (up to 60OC for 60minutes), it also remains viable after months of air–drying and resists the effects of many disinfectants and has overcome most of the therapeutic agents that have been developed in recent years and hence, antimicrobial chemotherapy for this species has always been empirical (Jun et al., 2004). Its mechanism of resistance to beta lactam and the fluoroquinolones has been documented (Kloos, 1998).

Staphylococcus aureus colonises the skin and nasal carriage occurs in about 25-30% of healthy people (Chambers, 2009). It is a versatile human pathogen responsible for nosocomial (Hospital acquired) and community acquired (CA) infection, with clinical manifestation of superficial and systemic diseases, associated with high morbidity and mortality rates. The unique characteristic of S.aureus is the production of virulence factors responsible for the establishment of staphylococcal diseases and propensity to develop resistance to multiple antibiotics ( Tenoveret al., 2000; Chambers, 2009).It has also been reported that S. aureus strains have a wide variety of multi-drug

resistant genes on plasmids, which can be exchanged and spread among different species of staphylococcus and can be transferred to new bacterial hosts by any of transduction, conjugation or transformation (Lujanet al., 2007). Staphylococcus aureus is known to be notorious in their acquisition of resistance to new drugs and continues to defy control measures (Talaro and Talaro, 2002). Many strains of S. aureus carry a wide variety of multi-drug resistance genes on plasmids. Staphylococcus aureus are frequently resistant to penicillinase-reistant penicillin‘s. An organism exhibiting this type of resistance is referred to as methicillin (oxacillin)-resistant S. aureus (MRSA). Such organisms are also frequently resistant to most of the commonly used antimicrobial agents, including the amino-glycosides, macrolides, chloramphenicol, tetracycline and fluoroquinolones (Tenover and Gaynes, 2002; Ikeagwu et al., 2008;Umaru et al.,2011).

Methicillin-resistant Staphylococcus aureus (MRSA) is major nosocomial pathogens with identifiable risk factors, which includes hospitalization, surgery, residence in chronic Healthcare facilities and injection drug users (Lowy, 1998). Consequential effect of S. aureus multidrug resistance includes prolonged hospitalization of patients, difficulty in patient management and treatment, and problem in infection control (Kleven, 2007).Methicillin resistance is clinically very important because a single genetic element confers resistance to the beta-lactam antibiotics which include penicillin‘s, cephalosporins and carbapenem‘s among others (Grundmannet al., 2006).

The resistance to methicillin was due to a penicillin binding protein coded for by a mobile genetic element termed the methicillin resistance gene mecA (Diekema and Pfaller, 2000). Methicillin resistance is mainly due to the expression of the mecA gene, which specifies penicillin binding protein 2a (PBP2a), a transpeptidase with a low affinity for β-lactams (Garza -Gonzalez, 2010; Zong et al., 2011). The mecA gene is carried by a mobile genetic element (MGE) termed the staphylococcal cassette chromosome (SCCmec) (Zong et al., 2011). Though the SSCmec origin remains unknown, it has been suggested that mecA may act as potential SCCmec donor accounting for the rise of new MRSA clones. Eleven SCCmec elements have been described to date. SCCmec I-IV (Ito et al., 2012) and V-XI, but few reports exist on the detection of mecA gene and characterization of SCCmec types in Nigeria (Ghebremedhin 2009; Shittu et al., 2011).

Over the period of 20 to 30 years, MRSA strains have been present in hospitals and the community. The organism is often sub-categorized as hospital acquired MRSA (HA-MRSA) or community acquired MRSA (CA-MRSA)(Schwalm III et al., 2011). These two groups, although have similar microbiological characteristics; differ for risk factors, genetic structure, virulence determinants and antibiotic resistance (Wang et al., 2010). Some have defined CA-MRSA by criteria related to the patients suffering from an MRSA infection while other authors have defined CA-MRSA by genetic characteristics of the bacteria themselves (Okuma et al., 2002).

Community acquired-Methicillin resistant Staphyloccus aureus strains were first reported in the late 1990s, these cases were defined by a lack of exposure to the health care settings. Several years later, it became clear that CA-MRSA infections were caused by strains of MRSA that differed from the older and better studied health care-associated strains (Okuma et al., 2002). Community acquired-Methicillin resistant staphylococcus aureus infections occurs in otherwise healthy people without a recent history of hospitalization or clinical presentation, and are usually associated with skin and soft tissue infection.

Risk factors for CA- MRSA include crowding, frequent contact, compromised skin, contaminated surfaces and shared items, and poor hygiene. Hospital acquired-Methicillin resistant staphylococcus aureus infections occurs most commonly in immune compromised individuals in hospitals and health care centers. Risk factors for HA- MRSA include hospitalization, surgery, dialysis, long-term care, indwelling devices, and history of previous MRSA infection. The bulk of MRSA related clinical infections are caused by HA- MRSA, which are considered ―nosocomial‖ (Hanselman et al., 2006; Klevens et al., 2007).

From virtually zero prevalence level in 1961, (Jevons, 1961) it has been detected worldwide with varied level influenced by geographical location, type of health institution and studied population.In Europe, MRSA prevalence ranges from over 50% in Portugal and Italy to below 2% in Switzerland and the Netherlands, where infection control measures have been shown to work (Queand Moreillon, 2010). In Asia, the prevalence lies around 50%, with extremely high rates in Hong Kong (75%) and Japan (72%) (Queand Moreillon, 2010).In Africa, MRSA prevalence varies with different countries, high in some and low in others (Bell and Turridge, 2002). Despite this epidemiological data on MRSA in some African countries, available data are still relatively limited when compared to information from developed countries, which may be attributable to high level of awareness of MRSA infections and its clinical and societal consequences.

The epidemiology of MRSA is fast changing and has become one of the established pathogen in both hospital and community. Methicillin-Resistant Staphylococcus aureus infection and colonization has been reported in humans in Nigeria, in both hospital and outside the hospital environment. In Nigeria, several reports of human MRSA infections have been documented. Ike (2003) reported a prevalence rate of 43% at Jos University Teaching Hospital while Onanuga et al. (2005; 2006) showed a prevalence rate of 71.7% and 69% from urine samples in Abuja and Zaria respectively among healthy women. The prevalence rate of 20% was also recorded in Zaria from non-hospital sources (Olonitola et al., 2007a). Also Taiwo et al. (2004), FusiNgwa et al. (2007), and Olowe et al. (2007) in separate studies reported a prevalence rate of 34.7%, 54.9% and 47.8% in Ilorin (University of Ilorin Teaching Hospital), Lagos (Paediatric Unit, Lagos University Teaching Hospital and Oshogbo (Ladoke Akintola University of Technology, College of HealthSciences) respectively. Adelowo et al. (2014) reported a prevalence of 47.6 % from patients attending University of Maiduguri Teaching Hospital.

Recommended : CAUSES AND EFFECTS OF INSECURITY IN NIGERIA: THE CHALLENGES AND RELEVANCE OF THE NIGERIAN POLICE FORCE AS A PANACEA

The internally displaced persons (IDPs) are persons or group of persons who have been forced or obliged to flee or to leave their homes or places of habitual residence, in particular as a result of or in order to avoid the effects of armed conflict, situations of generalized violence, violations of human-made disasters and who have not crossed an internationally recognized state border (UN, 2004; Ocha, 2015). The National Emergency Management Agency (NEMA) had reported that Boko Haram terrorists had forced residents of various communities to take refuge in different camps across northern Nigeria and more than one third of such camps were domiciled in the northeast, while more than half of them are in Maiduguri, the Borno State capital (NEMA, 2014).

PROJECT TOPICS ON PREVALENCE AND ANTIBIOTIIC SUSCEPTIBILTY PATTERN OF METHICILLIN – RESISTANT STAPHYLOCOCCUS AUREUSAMONG THE INTERNALLY DISPLACED PERSONS IN MAIDUGURI, NIGERIA.

1.2 Statement of the Research Problem

Staphylococcus aureus is a major component of normal flora of the skin and nostrils which probably explains its high prevalence as contaminants and can easily be discharged by several human activities like sneezing, talking and contact with moist skin (Ita and Ben, 2004). Pathogens spread among people with direct or indirect contact of hands and with animate and inanimate objects (Mathai, 2010;Tekerekoğlu et al., 2013).

There is increasing global concern for the spread of antibiotic resistant bacteria particularly MRSA.Associated with this concern is the use of antimicrobial agents in promoting the emergence and rise in the prevalence of these resistant pathogens (Mansori and Khaleghi, 1997; Lee, 2003; Ikeagwu et al., 2008).MRSA infections are of special concern because these infections are associated with prolonged hospital stay, increased hospital costs, and have a few therapeutic options for affected patients (Saxen et al., 2003).

1.3 Justification

Recent studies suggest that the infection due to MRSA is not only hospital-acquired but community acquired as well (Chandrashekhar et al., 2012). Methicillin-Resistant Staphylococcus aureus now represent a global problem, some large outbreaks have been reported from different parts of the world, where it had caused severe infections including septicaemia, endocarditis and meningitis (WHO, 1996).

A study by Dickinson (2002) in England and Wales has concluded an increase in the trend of death due to MRSA infection (Dickinson, 2002). Infections caused by MRSA can be expensive in terms of antibiotic therapy, isolation facilities and materials and length of hospital stay (Dickinson, 2002; Kumari et al., 2008). According to a World Health Organization literature (1996), the global financial burden because of MRSA infection has been worked out to be $20,000 to $ 114,000 for outbreaks and from $28,000 to $1, 600, 000 for endemic infections per year (Chandrashekhar et al., 2012).The common sources of these infections are human patients and carriers (Collier et al.,1998; Chandrashekhar et al., 2012).

In addition to dire consequences of infections, MRSA strains are important for their resistance to many other commonly used antibiotics and the emergence of resistance to vancomycin, the drug that has been used to treat MRSA infections for more than three decades. Reports of emergence of vancomycin resistance in S. aureus from India (Assadullah et al., 2003; Tiwari et al 2008; Saha et al., 2008) further justify the necessity for this research.Methicillin-Resistant Staphylococcus aureus is especially troublesome in hospitals and nursing homes or long-term care facilities where patientswith open wounds, invasive devices, and weakened immune system are at greater risk of infection than the general public (Hardy et al., 2004).

Prisons, military barracks and homeless shelters can be crowded and confined and poor hygiene practices may proliferate, thus putting inhabitants at increased risk of contracting MRSA. The internally displaced are at greater risk of contracting MRSA infections because they are overcrowded and there is poor hygiene practice among most of them which can facilitate the spread of MRSA. Therefore,the results of this study showing cases of MRSA among the internally displaced persons will be of benefit to Medical Personnel handling the internally displaced persons, Infections prevention and control workers, and researchers on Staphylococcal infections. In north eastern Nigeria, there is still paucity of epidemiological information on MRSA (Adelowo et al., 2014) while information on its prevalence among the IDPs is non-existent. Therefore, this work will serve as a data base on the study of MRSA among the IDPs in Maiduguri, Nigeria.

1.4 Aim and Objectives

1.4.1 Aim

The aim of this study was to determine the prevalence and antibiotic susceptibility pattern of Methicillin-Resistant Staphylococcus aureus among the internally displaced persons in Maiduguri.

1.4.2 Objectives

The specific objectives were to:

  1. Isolate and characterize aureusfrom the anterior nares of the IDP‘s using conventional microbiological techniques.
  2. Carry out an in vitro antibiotic susceptibility test of the aureusisolates.
  3. Screen the isolates for methicillin resistance.
  4. Detect mecA gene among the methicillin resistant phenotypes using Polymerase Chain Reaction.

 

See Also : PREVALENCE OF SCHISTOSOMIASIS IN RELATION TO THE OCCURRENCE OF INTERMEDIATE SNAIL HOST IN PARTS OF ZANGON-KATAF LOCAL GOVERNMENT AREA OF KADUNA STATE, NIGERIA

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