A urinary tract infection (UTI) is an infection in any part of the urinary system involving the kidneys, ureters, bladder and urethra (Foxman, 2010). Worldwide, the incidence of UTIs has been estimated at approximately 150 million people per year (Gupta, et al., 2001). Regarding hospital admissions, complicated UTIs and UTIs involving the upper urinary tract are more common in hospitalized patients (Ahmmed, et al., 2021).
Structure of E. coli
These four reactions help distinguish enterobacteriaceae from non-fermenting gram-negative rods such as Pseudomonas aeruginosa. These uropathic strains are characterized by pili containing adhesion proteins that bind to specific receptors on the urinary tract epithelium. Uropathogens are specially adapted to the urinary tract and have properties that help them grow and form large colonies in this environment.
Transmission of E. coli
The binding site on these receptors consists of galactose dimers and the pili are also called P fimbriae or pyelonephritis associated pili (PAP). Due to their lack of symptoms, they can establish long-term colonization of the host's intestinal tract and in some cases can be more effective intestinal colonizers than typical faecal commensal strains (Wold, et al., 1992). In some patients, colonized sexual partners or other household members may act as a reservoir from which a virulent ExPEC strain can re-establish in the patient, resulting in recurrent infection (Foxman, et al., 1997).
Laboratory diagnosis
Treatment of UTI
- The aminopenicillins
- Piperacillin/ Tazobactam
- Cephalosporins
- Carbapenems
- Aminoglycosides
- Quinolones
- Tigecycline
- Nitrofurantoin
- Colistin
- Trimethroprim-Sulfamethoxazole (TMP-SMX)
This drug is the prototype of the group and its structural formula is presented below. In combination with a β-lactamase inhibitor, it has the broadest antibacterial spectrum of the penicillins (Schoonover, et al., 1995). Imipenem is not absorbed orally and the drug is rapidly broken down by a dipeptidase found in the brush border of the proximal renal tubule.
Prevention and control
Resistance pattern in humans
In Europe, the incidence of antibiotic resistance for UTI-causing pathogens is higher in southern countries compared to northern ones (Kandil, et al., 2016). This could be related to the fact that the four largest consumers of antibiotics (Italy, France, Greece, Cyprus) are in the south (Adriaenssens et al., 2011). The burden of antibiotic resistance is much greater in Asia, as certain antibiotic-resistant bacteria are more prevalent in certain locations and are now spreading globally.
For S. aureus, methicillin-resistant strains (MRSA) accounted for 25.5% of community-acquired infections and 67.4% of hospital-acquired infections (Lai et al., 2014). For enterococci, vancomycin-resistant enterococci (VRE) have become a threat particularly in nosocomial infections throughout Asia (Song et al., 2009). A meta-analysis on the prevalence of antibiotic resistance in Asian countries identified several drugs to which microorganisms have developed resistance.
However, according to the WHO, the treatment of urinary tract infections has become very complicated in recent years due to an increase in antibiotic resistance and a decrease in the pace of development of new antibiotics (Chokshi, et al., 2019). Furthermore, resistance to carbapenem drugs is steadily developing, with more than 50% of uropathogens already resistant to meropenem (Sugianli, et al., 2021). Some of the major reasons for such antibiotic resistance are irrational prescription of antibiotics by doctors, unnecessary or inappropriate use of antibiotics, self-medication among patients, and the situation is further aggravated by indiscriminate use of antibiotics in agriculture (Biswas, et al. al. , 2014; Sutradhar, et al., 2014).
Antibiotics such as imipenem, amikacin, tazobactam, gentamycin and mecillinam were found to be the most effective antibiotics against the urological pathogens (Majumder, et al., 2019).
Resistant pathogen in environment
Wildlife has also contributed generously to the antibiotic resistance dilemma with high percentages of resistant organisms common among wild animals. Cephalosporin resistance is as high as 51% in wild birds and chloramphenicol-resistant organisms have only been found in insects such as houseflies. High percentages of organisms that were resistant to macrolides were also found, both in wild life and in insects (Ramey & Ahlstrom, 2020).
Resistant pathogen in food producing animals
Antibiotics are used in food-producing animals not only to prevent infection, but also to promote growth when administered at low subtherapeutic levels. Although the use of antibiotics to promote growth was banned in Europe in 2006, this measure was not implemented elsewhere, so antibiotics are still used today in many countries around the world. It is believed that the highest rate of antibiotic use is in chickens, as the most resistant strains have been isolated from them.
The highest resistance rates in animals have been found for tetracyclines, trimethoprim/sulfamethoxazole and ampicillin. One study attempted to identify the Plasmid-Mediated Quinolone Resistant (PMQR) genes in poultry and pigs (Ogbolu, et al., 2011). All strains in this study also carried the blaTEM-1 gene for β-lactamase and one strain was positive for CTX-M-15 (Fortini, et al., 2011).
These plasmids were also isolated from calves in France (Haenni, et al., 2016) and feed samples in Portugal (Tse & Yuen, 2016). Polymyxin is considered a last-resort antibiotic in humans, but it has been widely used in animals, resulting in the potential development of resistant strains (Rhouma, et al., 2016). Increased rates of resistance to tetracycline and sulfamethoxazole were found, but more alarming was the detection of genes for third-generation cephalosporin resistance.
In Bangladesh, commercial poultry production is increasing rapidly and it is considered to be at high risk for the emergence of resistance to antibiotics.
Antimicrobial resistance against Escherichia coli
This is due to excessive use of probiotics and unregulated and unnecessary use of over-the-counter antibiotics in livestock through their food and water supply. The antibiotic resistance bacteria and the antibiotic resistance genes are then spread to the surrounding environment through the urine and feces of these livestock (Bengtsson-Palme & Larsson, 2015).
Prevention and control of antimicrobial resistant strains
MATERIALS AND METHODS
- Description of the study area
- Study Design
- Study period
- Collection of data
- Sample collection
- Isolation and identification of E. coli and susceptibility testing
- Data analysis
- Descriptive analysis
- Risk factor analysis
It is located between the Chittagong Hill Tracts and the Bay of Bengal, lying on the banks of the Kornophuli River. About 75% of the country's total exports and 80% of the total imports take place through the city of Chattogram. Therefore, many cases are referred to this diagnostic center for proper evaluation of the samples.
The study was a cross-sectional study that was conducted in Chattogram city using secondary data collected from the above mentioned laboratory. Data such as age and gender were collected by laboratory personnel from the patient when they came to submit a urine sample for culture and sensitivity. The isolated pure colony was then separated from the blood agar or SDA plate and then inoculated once more into a Vitek ID tube.
Using sterile cotton swabs, a homogeneous suspension of the organism was prepared by transferring a few colonies isolated from the plates to the saline tube. Data that were collected electronically from the data warehouse within the laboratory were compiled into a Microsoft excel spreadsheet. A univariate analysis was performed against the dependent variable for age and gender of the study subjects.
A Chi-square test was performed to identify significant risk factors for the sensitivity and resistance patterns of the antibiotics.
RESULTS 4.1 Antimicrobial resistance based on gender
Univariate analysis of antimicrobial resistance against age group
A chi-square test was used to compare ages for each of the twenty-two antibiotics. When comparing antibiotic sensitivity patterns with age of subjects, no significant difference in sensitivity patterns between age groups was observed for all antibiotics except ceftazidime.
Prevalence of antimicrobial resistance among the study population
Although ceftazidime shows a p-value of 0.046, the number of cases was very low with only two cases showing resistance in the 21-40 age group. From the figure above, it is evident that ampicillin, nalidixic acid, azithromycin, ciprofloxacin, trimethoprim and almost all cephalosporins (except cefoperazone) are resistant in at least 50% of cases. About 20% of cases were also resistant to carbapenems (meropenem, imipenem and ertapenem), nitrofurantoin, amikacin and tigecycline.
Multi drug resistant strains of E. coli in the study population
The highest frequency was observed in the panel containing the antibiotics ampicillin-cefuroxime-ceftriaxone-nalidixic acid-ciprofloxacin. The combination of drugs that had the highest number of resistant strains was ampicillin-cefuroxime-ceftriaxone-. The most common combination panel was ampicillin- cefuroxime-ceftriaxone- cefepimen-nalidixic acid- ciprofloxacin-trimethoprim with thirty isolates resistant to this combination.
The panel to which the majority of bacteria were resistant is ampicillin-cefuroxime-ceftriaxone-cefepime-gentamicinnalidixic acid-ciprofloxacin-trimethoprim, and 11 sample isolates were resistant to this panel.
DISCUSSION
The highest incidence of such cases was found in India, followed by Hong Kong and then Singapore (Mowla, et al., 2011). Where antibiotics are available to humans or animals without a prescription, the emergence and spread of resistance is exacerbated. Similarly, in countries lacking standard treatment guidelines, overprescribing of antibiotics by health workers and veterinarians and overuse by the public are common (Ayukekbong, et al., 2017).
The BRIC countries (Brazil, Russia, India and China) plus South Africa were responsible for three-quarters of this growth, while annual antibiotic consumption per person varied by more than a factor of 10 across all middle- and high-income countries (Van Boeckel, et al., 2014). To reduce or delay the development of resistant strains, we must first reduce the spread of resistance genes from environmental bacteria to human pathogens. Improved surveillance of antibiotic-resistant infections and implementing strict laws to prevent and control infections can be initiated to regulate and encourage the appropriate use of quality medicines.
The health sector can encourage further investment in research to develop new antibiotics or other tools. AMR is a problem that affects the world worldwide and has real consequences for human health (Jee et al., 2018). In developing countries such as Bangladesh, the growing threat of antimicrobial resistance is high due to high population density, inadequate sanitation, and excessive use of antimicrobials in the clinical, animal, and agricultural sectors (Ayukekbong et al., 2017).
Additionally, regular monitoring should be done for UTI causative agents and their resistance patterns.
CONCLUSION
LIMITATIONS
RECOMMENDATIONS
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Antimicrobial susceptibility of organisms causing community-acquired urinary tract infections in Gauteng Province, South Africa. Antibiotic Resistance in Urinary Tract Infection in a Tertiary Care Hospital in Bangladesh - A Follow-up Study. Emergence of multidrug-resistant extended-spectrum β-lactamase-producing Eshcherichia coli associated with urinary tract infections in Bangladesh.
Bacterial uropathogens in urinary tract infections and their antibiotic susceptibility pattern in a tertiary care hospital.
