Project – Antimicrobial Resistance Profiles and Prescribing-Related Risk Factors Among Patients with Culture-Confirmed Urinary Tract Infections: A Study of a Selected Tertiary Hospital in Abuja.

CHAPTER ONE

INTRODUCTION

Topic: Antimicrobial Resistance Profiles and Prescribing-Related Risk Factors Among Patients with Culture-Confirmed Urinary Tract Infections: A Study of a Selected Tertiary Hospital in Abuja

1.1 Background to the Study

Antimicrobial resistance (AMR) has emerged as one of the most significant public health challenges confronting healthcare systems globally because it reduces the effectiveness of medicines used to treat bacterial and other microbial infections. Antimicrobial resistance occurs when microorganisms, including bacteria, develop the ability to survive or grow despite exposure to antimicrobial agents that would ordinarily inhibit or destroy them. This development makes infections more difficult to treat, increases the likelihood of treatment failure, prolongs illness, raises healthcare costs and increases the risk of complications and mortality. The World Health Organization (WHO, 2025), in its Global Antibiotic Resistance Surveillance Report, reported that approximately one in six laboratory-confirmed bacterial infections causing common infections worldwide in 2023 were resistant to antibiotic treatments. The report, based on more than 23 million bacteriologically confirmed cases from over 100 countries, further identified increasing resistance across several important pathogen-antibiotic combinations. Similarly, Murray et al. (2022), in their global systematic analysis of bacterial antimicrobial resistance, estimated that bacterial AMR was directly responsible for 1.27 million deaths in 2019 and associated with approximately 4.95 million deaths. These findings demonstrate that antimicrobial resistance is not simply a microbiological concern but a major threat to effective treatment, patient safety and the sustainability of healthcare delivery.

Urinary tract infections (UTIs) are among the most frequently encountered bacterial infections in clinical practice and represent an important area of concern in the management of antimicrobial resistance. A urinary tract infection occurs when microorganisms, particularly bacteria, enter and multiply within parts of the urinary system, including the urethra, bladder, ureters and kidneys. UTIs may be classified as lower urinary tract infections, such as cystitis and urethritis, or upper urinary tract infections, such as pyelonephritis, depending on the anatomical location and extent of infection. Common symptoms include painful urination, frequent urination, urgency, lower abdominal discomfort and, in more severe cases, fever and flank pain. The European Association of Urology (EAU, 2025) recognises UTIs as a significant clinical condition requiring appropriate diagnosis, risk assessment and antimicrobial treatment based on the nature and severity of infection. Similarly, Flores-Mireles et al. (2015) explained that UTIs are among the most common bacterial infections, with uropathogenic Escherichia coli being a leading cause of both uncomplicated and complicated infections. Other organisms frequently implicated include Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus species and Staphylococcus saprophyticus. The increasing resistance of these organisms to commonly prescribed antibiotics has made the management of UTIs more complicated, thereby creating the need for continuous investigation of their antimicrobial susceptibility profiles.

The antimicrobial resistance profiles of uropathogens are important because they provide information about the susceptibility or resistance of bacterial isolates to different antimicrobial agents used in treating urinary tract infections. Antimicrobial susceptibility testing helps healthcare professionals identify which antibiotics are likely to be effective against specific bacterial organisms and which drugs may result in treatment failure. Commonly prescribed antibiotics for UTIs include nitrofurantoin, trimethoprim-sulfamethoxazole, fosfomycin, ciprofloxacin, amoxicillin-clavulanate and selected cephalosporins, although their appropriateness depends on the organism, infection characteristics, patient factors and local resistance patterns. Gupta et al. (2011), in the Infectious Diseases Society of America guidelines for acute uncomplicated cystitis and pyelonephritis, emphasised the importance of local resistance patterns in selecting appropriate empirical treatment. The Clinical and Laboratory Standards Institute (CLSI, 2025) also provides standardised procedures for interpreting antimicrobial susceptibility results and categorising bacterial isolates as susceptible, intermediate or resistant. In addition, the WHO (2025) identifies surveillance of resistance among common urinary pathogens as an important component of antimicrobial resistance monitoring. Therefore, determining the resistance profiles of bacterial isolates from culture-confirmed UTIs is essential for guiding appropriate antibiotic selection, reducing ineffective treatment and supporting evidence-based clinical decisions.

Antimicrobial resistance in urinary tract infections is influenced by several biological, clinical and behavioural factors, among which antibiotic prescribing practices are particularly important. Prescribing-related risk factors include inappropriate antibiotic selection, unnecessary prescription, excessive duration of treatment, inadequate dosage, repeated empirical treatment without laboratory confirmation and failure to consider previous antibiotic exposure. The use of broad-spectrum antibiotics when narrower-spectrum agents are appropriate may also increase selective pressure, encouraging the survival and multiplication of resistant bacterial organisms. Llor and Bjerrum (2014) explained that inappropriate antibiotic use is a major contributor to the development and spread of antimicrobial resistance, particularly where antibiotics are frequently prescribed for infections without adequate clinical or microbiological justification. Similarly, Costelloe et al. (2010), in their systematic review and meta-analysis, demonstrated that antibiotic prescribing in primary care was associated with increased resistance in individual patients, with the relationship particularly evident following exposure to antibiotics commonly used for respiratory and urinary infections. These findings suggest that prescribing decisions are not merely treatment procedures but important factors that may influence the development and selection of resistant microorganisms. Consequently, investigating the relationship between antibiotic prescribing practices and resistance profiles among patients with culture-confirmed UTIs is necessary for improving antimicrobial stewardship and reducing the burden of resistant infections.

Patient-related clinical characteristics may also influence the occurrence and distribution of antimicrobial resistance among individuals with urinary tract infections. Factors such as age, sex, pregnancy, diabetes mellitus, recurrent UTIs, previous hospitalisation, catheterisation, underlying urinary abnormalities and previous exposure to antibiotics may affect the likelihood of developing infections caused by resistant organisms. For example, patients with recurrent urinary tract infections may have repeated exposure to antimicrobial treatment, which can increase selection pressure and contribute to the emergence of resistant bacterial strains. Similarly, patients with diabetes or structural abnormalities of the urinary tract may experience complicated infections that require more intensive clinical management. Flores-Mireles et al. (2015) identified host characteristics, bacterial virulence factors and interactions between uropathogens and the urinary tract as important determinants of UTI development and progression. Gupta et al. (2011) also identified patient characteristics and clinical presentation as important considerations in selecting appropriate antimicrobial treatment. Furthermore, the WHO (2025) highlights the importance of interpreting antimicrobial resistance data in relation to the characteristics of the patients and infections from which bacterial isolates are obtained. These considerations indicate that antimicrobial resistance should be examined alongside relevant patient characteristics and prescribing histories rather than treated exclusively as a laboratory outcome.

In Nigeria, antimicrobial resistance represents a major public health concern because of the high burden of infectious diseases, challenges associated with appropriate antibiotic use, limited access to microbiological diagnosis in some healthcare settings and differences in antimicrobial stewardship practices. The availability of antibiotics without adequate prescriptions, self-medication, incomplete treatment courses and the frequent use of empirical therapy may contribute to inappropriate antimicrobial exposure. The Nigeria Centre for Disease Control and Prevention (NCDC, 2017), in the National Action Plan for Antimicrobial Resistance, identified inappropriate antimicrobial use and high levels of resistance among important bacterial pathogens as major challenges requiring coordinated surveillance and stewardship interventions. The Federal Ministry of Health and Social Welfare and other relevant ministries (2024), in Nigeria’s updated National Action Plan on Antimicrobial Resistance, also highlighted the importance of strengthening laboratory surveillance, improving antimicrobial prescribing practices and addressing resistance among clinically important organisms. In a study conducted at National Hospital Abuja, Iregbu and Nwajiobi-Princewill (2013) analysed 6,763 urine samples, of which 885 (13.1%) yielded uropathogens. Escherichia coli and Klebsiella species were the predominant isolates, and considerable resistance to several commonly tested antibiotics was observed. Their findings demonstrated the importance of regular surveillance and improved antibiotic stewardship in the management of UTIs in Nigeria. This local evidence establishes the relevance of investigating antimicrobial resistance patterns and prescribing-related factors within Nigerian healthcare institutions.

Abuja, as Nigeria’s Federal Capital Territory, accommodates major healthcare institutions that provide specialised medical services to patients from different geographical, socioeconomic and clinical backgrounds. Tertiary hospitals in Abuja receive patients with uncomplicated and complicated infections, recurrent UTIs and other conditions requiring advanced diagnostic and treatment services. These institutions therefore generate important clinical and microbiological information that can support the monitoring of antimicrobial resistance and the evaluation of antibiotic prescribing practices. A study by Iregbu and Nwajiobi-Princewill (2013) at National Hospital Abuja identified significant resistance among urinary bacterial isolates and recommended continuous surveillance and improved antibiotic stewardship. Furthermore, a study by Akinyemi et al. (2022) examining multidrug-resistant Escherichia coli isolates at a tertiary hospital in Abuja reported that urine accounted for 57% of the clinical specimens from which the studied isolates were recovered. More than half of the patients had received antibiotics within the week preceding specimen collection, illustrating the relevance of previous antimicrobial exposure when investigating resistant bacterial infections. The WHO (2025) equally emphasises the importance of standardised laboratory surveillance and the use of local antimicrobial resistance information to guide treatment decisions. Against this background, the present study seeks to investigate antimicrobial resistance profiles and prescribing-related risk factors among patients with culture-confirmed urinary tract infections in a selected tertiary hospital in Abuja. The study will examine the distribution of bacterial uropathogens, their susceptibility and resistance patterns, patients’ previous antibiotic exposure and relevant prescribing practices, with the aim of generating evidence that can support appropriate antibiotic selection, effective treatment and improved antimicrobial stewardship.

1.2 Statement of the Problem

Antimicrobial resistance has become a major challenge in the treatment of urinary tract infections because bacterial organisms that were previously susceptible to commonly prescribed antibiotics are increasingly developing resistance to these medicines. This situation creates difficulties for healthcare professionals who rely on empirical antibiotic treatment, particularly when the causative organism and its susceptibility pattern are not immediately available. Patients may consequently receive antibiotics that are ineffective against the organisms responsible for their infections, resulting in persistent symptoms, prolonged illness, recurrent infections and additional treatment expenses. The WHO (2025) reported that approximately one in six laboratory-confirmed bacterial infections worldwide in 2023 were resistant to antibiotic treatments, demonstrating the growing threat posed by resistant infections. Similarly, Murray et al. (2022) established the substantial global mortality burden associated with bacterial antimicrobial resistance. In the Nigerian context, Iregbu and Nwajiobi-Princewill (2013) identified considerable resistance among bacterial isolates recovered from urine samples at National Hospital Abuja. Despite the availability of antibiotics for UTI treatment, the increasing resistance of uropathogens raises concerns about the continued effectiveness of commonly prescribed medicines and the possibility of treatment failure among patients.

Another important problem concerns inappropriate antibiotic prescribing practices and their potential contribution to the development and spread of antimicrobial resistance. Antibiotics may sometimes be prescribed without adequate microbiological confirmation, selected without sufficient consideration of local susceptibility patterns or administered for inappropriate durations. Some patients may also engage in self-medication, obtain antibiotics without proper medical consultation, reuse previously prescribed medicines or fail to complete recommended treatment courses. These practices can expose bacterial organisms to inadequate or unnecessary antimicrobial pressure, thereby encouraging the survival of resistant strains. Llor and Bjerrum (2014) identified inappropriate antibiotic use as a major driver of antimicrobial resistance, while Costelloe et al. (2010) demonstrated that antibiotic exposure was associated with increased resistance in individual patients. In Nigeria, the NCDC (2017) identified inappropriate antimicrobial use and prescribing practices as important challenges in controlling resistance. However, the extent to which previous antibiotic exposure, empirical prescribing, repeated antibiotic treatment and other prescribing-related factors are associated with resistant uropathogens among patients with culture-confirmed UTIs in the selected tertiary hospital remains an important issue requiring investigation.

Furthermore, the absence of continuous and hospital-specific information on antimicrobial resistance profiles may affect the selection of appropriate antibiotics for treating urinary tract infections. Resistance patterns may differ across hospitals, geographical locations, patient populations and bacterial species. An antibiotic that remains effective in one healthcare institution may demonstrate reduced effectiveness in another because of differences in antimicrobial exposure, prescribing practices and circulating bacterial strains. Iregbu and Nwajiobi-Princewill (2013) demonstrated differences in susceptibility among urinary bacterial isolates at National Hospital Abuja, with several organisms showing high levels of resistance to commonly tested antibiotics. Akinyemi et al. (2022) also documented multidrug-resistant E. coli isolates at a tertiary hospital in Abuja, with a considerable proportion of affected patients having received antibiotics shortly before specimen collection. These findings indicate the importance of examining resistance patterns alongside patients’ clinical and prescribing histories. Without current and hospital-specific antimicrobial susceptibility information, clinicians may continue relying on empirical treatment approaches that do not adequately reflect the resistance characteristics of circulating uropathogens.

The central problem addressed by this study is the limited hospital-specific understanding of the relationship between antimicrobial resistance profiles and prescribing-related risk factors among patients with culture-confirmed urinary tract infections in the selected tertiary hospital in Abuja. Although previous studies have established the presence of resistant uropathogens in Nigerian healthcare institutions, there remains a need to examine the current distribution of bacterial isolates, their antimicrobial susceptibility patterns and the prescribing-related factors associated with resistance within the selected hospital. In particular, the relationship between previous antibiotic exposure, repeated treatment, empirical prescribing and the occurrence of resistant urinary bacterial isolates requires further investigation. This gap limits the availability of context-specific evidence that could guide effective antibiotic selection and antimicrobial stewardship. Therefore, this study will investigate the antimicrobial resistance profiles of bacterial isolates from culture-confirmed UTIs and assess prescribing-related risk factors among affected patients in the selected tertiary hospital in Abuja.

1.3 Objectives of the Study

The main objective of this study is to examine antimicrobial resistance profiles and prescribing-related risk factors among patients with culture-confirmed urinary tract infections in a selected tertiary hospital in Abuja.

The specific objectives are to:

1. Identify the bacterial pathogens responsible for culture-confirmed urinary tract infections among patients in the selected tertiary hospital.

2. Determine the antimicrobial susceptibility and resistance profiles of bacterial isolates associated with urinary tract infections.

3. Examine prescribing-related risk factors, including previous antibiotic exposure, empirical antibiotic treatment, repeated prescriptions and inappropriate antibiotic use, among patients with culture-confirmed UTIs.

4. Assess the relationship between prescribing-related risk factors and antimicrobial resistance patterns among bacterial isolates from patients with culture-confirmed UTIs.

1.4 Research Questions

The following research questions will guide the study:

1. What are the major bacterial pathogens responsible for culture-confirmed urinary tract infections among patients in the selected tertiary hospital?

2. What are the antimicrobial susceptibility and resistance profiles of bacterial isolates associated with urinary tract infections?

3. What prescribing-related risk factors are associated with antimicrobial resistance among patients with culture-confirmed UTIs?

4. What is the relationship between prescribing-related risk factors and antimicrobial resistance patterns among bacterial isolates from patients with culture-confirmed UTIs?

1.5 Research Hypothesis

The following null hypothesis will guide the study:

H₀: There is no statistically significant relationship between prescribing-related risk factors and antimicrobial resistance profiles among bacterial isolates from patients with culture-confirmed urinary tract infections in the selected tertiary hospital in Abuja.

1.6 Significance of the Study

The findings of this study will be significant to patients, medical practitioners, microbiologists, hospital management, pharmacists, public health authorities, policymakers, researchers and students.

Patients: The study will provide information about the increasing resistance of bacterial organisms responsible for urinary tract infections. It will promote awareness of the importance of appropriate antibiotic use, laboratory investigations and adherence to prescribed treatment. The findings may also help reduce inappropriate self-medication and encourage patients to seek professional medical advice before using antibiotics.

Medical Practitioners: The findings will provide useful information to doctors and other healthcare professionals concerning the antimicrobial susceptibility patterns of bacterial isolates responsible for UTIs. This may assist clinicians in selecting appropriate antibiotics based on laboratory findings rather than relying exclusively on empirical treatment. The study may also encourage consideration of patients’ previous antibiotic exposure when making treatment decisions.

Medical Microbiologists: The study will contribute to the understanding of bacterial pathogens associated with urinary tract infections and their resistance characteristics. It will provide information that may support laboratory surveillance, antimicrobial susceptibility testing and the identification of multidrug-resistant organisms. The findings may also encourage regular evaluation of local antibiograms to support effective clinical management.

Hospital Management: The study will provide hospital administrators with evidence regarding the burden of antimicrobial resistance among patients with culture-confirmed UTIs. The findings may assist in strengthening laboratory services, improving infection prevention and control practices, and supporting antimicrobial stewardship programmes. Hospital management may also use the findings to improve collaboration between microbiology laboratories, clinicians and pharmacy departments.

Pharmacists: The study will provide useful information for hospital pharmacists involved in antibiotic dispensing, prescription review and antimicrobial stewardship. It may assist pharmacists in identifying inappropriate prescribing practices, monitoring antibiotic utilisation and promoting rational antimicrobial use. The findings may also strengthen collaboration between pharmacists and prescribers in ensuring that antibiotic selection is consistent with available susceptibility results.

Public Health Authorities: The findings will contribute to public health knowledge concerning antimicrobial resistance in Nigeria. They may support surveillance initiatives, public health education and interventions aimed at reducing inappropriate antibiotic use. The study may also provide evidence for strengthening national and institutional antimicrobial resistance control strategies.

Policymakers: The study may provide evidence to guide policies on antimicrobial stewardship, laboratory diagnosis, antibiotic prescription and the control of resistant bacterial infections. It may also support the implementation of existing national strategies for addressing antimicrobial resistance within Nigerian healthcare institutions.

Researchers and Students: The study will contribute to existing literature on antimicrobial resistance, urinary tract infections, bacterial susceptibility patterns and antibiotic prescribing practices. It will provide a reference point for future research in medical microbiology, public health, pharmacology and related disciplines. Other researchers may also use the findings to investigate antimicrobial resistance in different healthcare institutions and geographical locations.

1.7 Scope of the Study

The study will focus on antimicrobial resistance profiles and prescribing-related risk factors among patients with culture-confirmed urinary tract infections in a selected tertiary hospital in Abuja, Nigeria.

Content Scope: The study will examine the bacterial pathogens responsible for culture-confirmed UTIs, their antimicrobial susceptibility patterns, resistance profiles and the prescribing-related factors associated with antimicrobial resistance. Particular attention will be given to previous antibiotic exposure, empirical antibiotic treatment, repeated antibiotic prescriptions and inappropriate antibiotic use.

Geographical Scope: The study will be conducted in one selected tertiary hospital in Abuja, Federal Capital Territory, Nigeria. The hospital’s microbiology laboratory and relevant patient clinical records will provide the setting for obtaining the required information, subject to ethical approval and data availability.

Population Scope: The study population will comprise patients whose urine samples were subjected to microbiological culture and yielded significant bacterial growth within the defined study period. Relevant clinical and prescription information will also be considered where available.

Variable Scope: Antimicrobial resistance profiles will constitute the principal outcome variable, while prescribing-related risk factors will serve as the explanatory variables. Bacterial species, antimicrobial susceptibility results and relevant patient characteristics will also be examined.

1.8 Operational Definition of Terms

Antimicrobial Resistance (AMR): This refers to the ability of microorganisms, particularly bacteria, to survive or grow despite exposure to antimicrobial agents that would ordinarily inhibit or destroy them.

Urinary Tract Infection (UTI): This refers to an infection involving any part of the urinary system, including the urethra, bladder, ureters or kidneys, commonly caused by bacterial organisms.

Culture-Confirmed Urinary Tract Infection: This refers to a urinary tract infection supported by laboratory urine culture findings demonstrating significant bacterial growth in accordance with the laboratory’s established diagnostic criteria.

Antimicrobial Resistance Profile: This refers to the pattern of susceptibility and resistance demonstrated by bacterial isolates when tested against different antimicrobial agents.

Antimicrobial Susceptibility Testing: This refers to laboratory procedures used to determine whether bacterial organisms are susceptible, intermediate or resistant to specific antimicrobial agents.

Uropathogens: These are microorganisms, particularly bacteria, capable of causing infections within the urinary tract.

Prescribing-Related Risk Factors: These refer to antibiotic prescribing and exposure-related practices that may contribute to the selection, development or spread of antimicrobial-resistant bacterial organisms.

Empirical Antibiotic Treatment: This refers to the administration of antibiotics based on clinical assessment before the causative organism and its antimicrobial susceptibility pattern have been established through laboratory testing.

Previous Antibiotic Exposure: This refers to a patient’s history of using antimicrobial medications before the current diagnosis or collection of the urine specimen.

Multidrug Resistance (MDR): This refers to acquired non-susceptibility to at least one antimicrobial agent in three or more antimicrobial categories, according to the standard definition proposed by Magiorakos et al. (2012).

Antibiogram: This refers to a summary of antimicrobial susceptibility patterns of bacterial isolates within a particular healthcare institution over a specified period.

Antimicrobial Stewardship: This refers to coordinated interventions designed to promote the appropriate selection, dosage, route and duration of antimicrobial treatment to improve patient outcomes and reduce antimicrobial resistance.

Project – Antimicrobial Resistance Profiles and Prescribing-Related Risk Factors Among Patients with Culture-Confirmed Urinary Tract Infections: A Study of a Selected Tertiary Hospital in Abuja.