Prevalence And Antimicrobial Susceptibility Of Gram Negative Bacteria In The Urine
Urinary tract infections (UTIs) represent a significant health concern globally, with Gram-negative bacteria being primary causative agents. This study delves into the prevalence and antimicrobial susceptibility patterns of Gram-negative bacteria isolated from urine samples, aiming to provide comprehensive insights into UTI management and antibiotic stewardship. Utilizing a systematic approach, urine samples from diverse demographics were analyzed, revealing a notable prevalence of Gram-negative pathogens, including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Furthermore, susceptibility testing unveiled concerning levels of resistance to commonly prescribed antibiotics, such as fluoroquinolones, cephalosporins, and trimethoprim-sulfamethoxazole, underscoring the urgency for tailored treatment strategies and surveillance programs to mitigate the escalating threat of antimicrobial resistance in UTIs.
In order to access the prevalence and sensitivity pattern of urinary pathogens, 60 midstream urine samples from students of Caritas University were investigated using cultural methods. Samples were examined microscopically and cultured in blood agar and Macckonkey agar. Disk diffusion method was used for antibiotic testing. Of the 60 urine samples 48 yielded significant growth with a prevalence rate of 80%. It was observed that females were more infected than the males with a prevalence rate of 56.70% and 43.30% respectively under the ages of 18-25yrs. Escherichia coli was the most predominant. The isolates were very sensitive to Gentamycin, Nitrofurantoin and Ofloxacin which were the (most sensitive) and the most resistant were Tetracycline, Cortrimozol, Cephalexin and Ampicillin. Therefore Nitrofurantoin, Gentamycin, Ofloxacin were strongly recommended for the treatment of UTI as indicated in the study.
Title page
Certification
Dedication
Acknowledgement
Abstract
Tables of contents
List of tables
CHAPATER ONE
1.0 Introduction
1.1 Aims and objectives of the study
CHAPTER TWO
2.0 Literature review
2.1 Microorganisms found in urine and their etiology
2.1.1 Bacteria
2.1.2 Viruses
2.1.3 Fungi
2.1.4 Protozoa
2.2.1 Entry of bacteria into the urinary tract
2.2.2 Routes of bacteria infection
2.2.3 Symptoms of UTI
2.2.4 Diagnosis
2.2.5 Treatment
2.2.5.1 Aims of treatment of UTI
2.2.5.2 Future strategies in treatment of bacteria/UTI
2.2.6 Prevention and control
2.3.0 Antimicrobial resistance
2.3.1 Mechanisms of drug resistance
2.3.1.1 Drug- inactivating enzyme
2.3.1.2 Alteration in the target molecule
2.3.1.3 Decrease uptake of the drugs
2.3.1.4 Increased elimination of the drugs
2.3.2 Conditions influencing the effectiveness of drugs
2.3.2.1 Population size
2.3.2.2 Population composition
2.3.2.3 Concentration and intensity of antimicrobial agent
2.3.2.4 Duration of exposure
2.3.2.5 Temperature
2.3.3 Actions of antimicrobial drugs
2.3.3.1 Inhibition of cell synthesis
2.3.3.2 Inhibition of cell membrane
2.3.3.3 Inhibition of nucleic acid synthesis
2.3.3.4 Inhibition of essential metabolites
CHAPTER THREE
3.0 Materials and methods
3.1 Sample collection
3.1.2 Antimicrobial susceptibility test
3.1.3 Urinalysis test
3.2 Gram staining
3.3 Biochemical test
3.3.1 Catalase test
3.3.2 Coagulase test
3.3.3 Motility test
3.3.4 Methyl test
3.3.5 Urease test
3.3.6 Indole test
3.3.7 Citrate utilization test
CHAPTER FOUR
4.0 Result
CHAPTER FIVE
5.1 Discussion
5.2 Conclusion
5.3 Recommendation
References
Appendix I
Appendix II
INTRODUCTION
Gram negative bacteria are bacteria that do not retain their crystal violet dye in the gram staining protocol. They are differentiated by their cell wall structure. The following characteristics are displayed by gram negative bacteria as follows
Cytoplasmic membrane
Thin peptidoglycan layer(much thinner than gram positive)
Outer membrane containing lipopolysaccharide outside the
peptidoglycan layer Porin exists in the outer membrane, which acts like pores There is a space between the layer of peptidoglycan and the secondary cell membrane, called the periplasmic space If present, flagella have four (4) supporting rings instead of two
No techoic acid or lipopolysaccharide Some examples of gram negative bacteria include; Escherichia coli, Salmonella species, Pseudomonas species, Klebsiella species, Proteus species, Helicobacter species, Mosoxella species, Cyanobacteria species, Spirochetes
species. They also constitute a serious problem in urinary tract infections in many parts of the world. Appropriate antimicrobial treatments are often critical to decreasing morbidity and mortality among hospitalized patients having the infections caused by the pathogens. Gram negative bacteria are non-spore forming bacilli that grow rapidly on ordinary laboratory media under both
aerobic and anaerobic conditions. It has been estimated that symptomatic urinary tract infects (UTI) occurs in as many as 7million visits to emergency units and 100,000 hospitalised annually. UTI has been the most common hospital acquired infections, accounting for as many as 35% of nosocomial infection. It is the second most common cause of bacteraemia in hospitalised patients (Nacem, 2000). UTI is known to occur in all populations but has a particular impact on females of all ages and males at two extremes of life,
immuno-compromised patients and anyone with function or structural abnormalities of the urinary and excretory system.
UTI is known to be the microbial invasion of any of the tissues of the urinary tract reaching from the renal cortex to the urethrameatus (Nicolle, 2000). It is also known to be the presence in two consecutive urine samples of greater than 100rods (105 ) organisms per ml of a single bacterial strain in the urinary tract. UTI can be categorized in ascending or descending. Infections which are confined to the urethral or the bladder are ascending and referred to as uretitis or cystitis respectively. On the other hand, the pathogens spread from one or other infected body site to the kidney down along the ureter to the bladder. Such descending UTI cause severe kidney infection, a condition called pyelonephritis (Parsons, 1958). This is potentially more serious; infections to the urethra are called urethritis and to the prostrate gland are called prostitis. This classification is the presence or absence of symptoms, reoccurrence or
absence or presence of complicating factors which are host factors facilitating establishment and maintenance of bacteraemia or worsening the prognosis of UTI`s engaging the kidney. Majority of pathogens are gram negative species with predominance of
members of Enterobacteriace (Neu, 1992). Escherichia coli accounts for majority of urinary tract infections in young women but other gram negative rods of different genera such as proteus species and pseudomonas aeruginosa an aerobic gram negative rod is also troublesome. As a urinary tract pathogens because of its resistance to antimicrobial medicine make it difficult to treat
successfully (Nester et al. 1998). Antibiotics are used for the control of bacterial infections in human. Generally,
gram negative bacteria are sensitive to many antimicrobial agents but strains from different patients and carriers differ in the pattern and degrees of sensitivity to different drugs. Increasing antimicrobials resistance in bacterial pathogen is a worldwide concern. The prevalence of antimicrobial resistance among urinary tract infectious agents is also increasing (Mathai et al. 2001 :
Karaloswsky et al. 2001) and its treatment has become more complicated due to increasing resistance and empirical therapy leading to treatment failures of most associated with gram negative bacteria (Blondeau et al. 1999). The present study investigated the pattern of gram negative uropathogens and their antimicrobial resistance pattern among the clinical isolates to the commercially
available antibiotics that are often prescribed in urinary tract infectious cases
1.1 Aims and objectives
To find out the prevalence of gram negative organisms in the urinary
tract among caritas university students.
To investigate their antibiotic sensitivity pattern to enable formulation of
drugs for urinary tract infection in our community.
To determine the age and sex prevalence.
To determine the prevalence of bacterial strains and their antimicrobial
susceptibility in urine.
To find the pathogenic bacteria commonly responsible with UTI and
susceptibility patterns this will help the clinicians to choose the right
empirical treatment.
Prevalence And Antimicrobial Susceptibility Of Gram Negative Bacteria In The Urine:
The prevalence and antimicrobial susceptibility of Gram-negative bacteria in urine is an important aspect of clinical microbiology and public health. Urinary tract infections (UTIs) are commonly caused by Gram-negative bacteria, and understanding their prevalence and susceptibility to antimicrobial agents is crucial for effective patient management and antibiotic stewardship. Here’s an overview of this topic:
- Prevalence of Gram-Negative Bacteria in Urine:
- Gram-negative bacteria are a common cause of urinary tract infections, accounting for a significant proportion of cases.
- Common Gram-negative bacteria isolated from urine samples include Escherichia coli (E. coli), Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Enterobacter species.
- Methods for Detection and Identification:
- Urine samples from patients with suspected UTIs are typically cultured in the laboratory to identify the causative bacteria.
- Identification of Gram-negative bacteria is often based on their colony morphology, biochemical tests, and, in some cases, molecular methods like polymerase chain reaction (PCR).
- Antimicrobial Susceptibility Testing:
- Once the bacteria are identified, antimicrobial susceptibility testing is performed to determine which antibiotics are effective against the isolated strains.
- This testing involves exposing the bacteria to various antibiotics and assessing their growth or inhibition in the presence of these drugs.
- Results are reported as susceptibility, intermediate susceptibility, or resistance to specific antibiotics.
- Common Antibiotics for UTIs Caused by Gram-Negative Bacteria:
- Commonly used antibiotics for the treatment of UTIs caused by Gram-negative bacteria include:
- Trimethoprim-sulfamethoxazole
- Ciprofloxacin
- Levofloxacin
- Nitrofurantoin
- Ceftazidime
- Ceftriaxone
- Commonly used antibiotics for the treatment of UTIs caused by Gram-negative bacteria include:
- Antibiotic Resistance:
- Resistance to antibiotics among Gram-negative bacteria is a growing concern globally.
- Overuse and misuse of antibiotics contribute to the development of resistance.
- Extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Gram-negative bacteria are examples of highly resistant strains.
- Surveillance of antibiotic resistance patterns in Gram-negative bacteria is essential for guiding treatment choices.
- Clinical Implications:
- Knowledge of the prevalence and antimicrobial susceptibility of Gram-negative bacteria in urine helps clinicians select the most appropriate antibiotics for UTI treatment.
- Empiric therapy may be initiated based on local resistance patterns while awaiting specific culture and sensitivity results.
- Antibiotic stewardship programs aim to promote responsible antibiotic use to combat resistance.
- Public Health Impact:
- Monitoring the prevalence and resistance patterns of Gram-negative bacteria in urine contributes to public health efforts to combat antimicrobial resistance.
- It helps in developing guidelines for the appropriate use of antibiotics in both community and healthcare settings.
In summary, the prevalence and antimicrobial susceptibility of Gram-negative bacteria in urine are important aspects of clinical practice and public health. Timely and accurate identification of bacterial pathogens and understanding their resistance profiles are essential for effective UTI management and antibiotic stewardship efforts.