Introduction

Urinary tract infections (UTIs) represent widespread human microbial disorders involving any part of the urinary tract, such as the kidneys, bladder, urethra, and prostate .¹ UTI infection exhibits a variety of symptoms including mild burning micturition, bacteremia, sepsis and even death.² It is reported that UTI affects both genders but women in the age group 15-44 are more prone to this infection.³ Amongst the various types of urinary tract infection, cystitis (lower urinary tract infection) and pyelonephritis (upper urinary tract infection) constitute the majority of problems. The most common symptoms of lower urinary tract infection include inflammation and irritation in the lining of urethra and bladder, burning sensation or pain while urinating. Other symptoms include frequent urination often with scanty urine, sensation of having to urinate urgently, cloudy, bad smelling, or bloody urine, lower abdominal pain and sometimes mild grade fever. The most frequent upper urinary tract infections symptoms include high grade fever, nausea and vomiting, shaking chills, pain in back or side of waist. In children when compared with adults, fever, vomiting, loss of bladder control and sleep are more common symptoms.

Urinary tract infections (UTIs) are prevalent all over the world and have both direct and indirect influences on the socioeconomic parameters in the global population. Moreover, these infections contribute to significant burden of morbidity and mortality and are placed second only to respiratory tract infections.⁴ UTIs are known to affect approximately 150 million people each year worldwide.⁵

UTIs are categorized as community or hospital-acquired infections based on the setting where the infection is acquired. The community- acquired urinary tract infections are acquired in a community setting or within the first 48 hours of hospitalization.⁶ In community and hospital settings the etiology of UTIs and the antimicrobial susceptibility of uropathogens have been changing over the years.^7,8 Factors such as the changing patient population, extensive use and misuse of anti-microbial agents have contributed to changes in the bacterial profile of UTI.⁹

Knowledge of the antimicrobial resistance patterns of common uropathogens according to local epidemiology is essential for providing clinically appropriate, cost effective therapy for UTI.^10,11

This study was undertaken to assess the bacterial and demographic profile of human population presenting with symptoms of urinary tract infections over a period of one year between June 2021 to July 2022.

Methods

A retrospective analysis of data from urine bacteriology seat over a period of one year between June 2021 to July 2022 was done in the department of Microbiology, University College of Medical sciences and associated GTB Hospital, Delhi. The urine samples received for culture and sensitivity were streaked on McKonkey Agar and blood agar plates. The plates were incubated for 24 hours at 37°C. Plates showing growth suggestive of significant bacteriuria, with colony counts exceeding 10⁵cfu/ml were subjected to standard biochemical tests for identification and antimicrobial sensitivity testing by Kirby-Bauer disc diffusion method. The bacterial isolates were interpreted as 'Sensitive' or 'Resistant' on the basis of the diameters of zones of inhibition of bacterial growth as per recommendations by the disc manufacturer.

Statistical analysis

The data collected was entered into Microsoft EXCEL spreadsheet and data analysis was done using, Statistical Package for Social Sciences (SPSS) software‟, IBM manufacturer, Chicago, USA, version 20.0.

Results

In this study, a total of 21359 samples were received for urine culture and sensitivity testing. Out of these, 2265 samples were positive with an overall positivity rate of 10.60%. Table 1 shows gender wise distribution of cases. It can be seen that majority of the positive samples were from females as compared to males (Positivity rate F: M= 6.04% : 4.56 %; F:M ratio= 1.8:1)

Table 2 shows age wise distribution of positive cases. It can be seen that majority of positive samples (1559; 68.83%) were from age group between 21-60 years of age. Females formed the major group (914; 58.62%) as compared to males in this.

Table 3 shows distribution of isolates in OPD, IPD and ICU services. Overall, Gram negative bacilli were seen in 1896 samples followed by Gram positive cocci in 278 positive samples and mixed growth was seen in 92 positive samples. In OPD, IPD and ICU services, Gram negative bacilli were the predominant microorganisms isolated.

Figure 1: Distribution of isolates in OPD, IPD and ICU services.

Figure 1 shows distribution of isolates in OPD, IPD and ICU services. In Gram negative bacilli, E. coli (1204; 53.15%) is the predominant organism followed by Klebsiella spp. (315;13.90%) and Citrobacter spp.(191; 8.43%). In Gram positive cocci, Enterococcus (152;6.71%) was the predominant species followed by staphylococcus spp. (107; 4.72%).

Figure 2: Distribution of Methicillin Resistant Staphylococcus aureus (MRSA) and Methicillin Susceptible Staphylococcus aureus (MSSA) (N=107)

Figure 2 shows distribution of Methicillin Resistant Staphylococcus aureus (MRSA) and Methicillin Susceptible Staphylococcus aureus (MSSA) among 107 isolates of Staphylococcus aureus isolated from urine samples between July 2021 to June 2022.It can be seen that majority ,i.e., 66 (61.68%)out of total 107 of isolates were resistant to methicillin as compared to 41 (38.31%) isolates which were sensitive.

Discussion

In this study, a total of 21359 samples were received for urine culture and sensitivity testing. Out of these, 2265 samples were positive with an overall positivity rate of 10.60%. The majority of the positive samples were from females as compared to males (Positivity rate F: M= 6.04%: 4.56 %; F:M ratio= 1.8:1) proving the fact that there is a higher preponderance of urinary tract infections in females as compared to males. The high incidence of urinary tract infections in females may be due to shorter urethra in females, proximity of urethral opening to both the vagina and the anus, the main source of bacteria such as Escherichia coli that cause UTIs.¹² Our findings are supported by studies by M. Muthulakshmi et al and Manjula N.G. et al.^2,13

In this study, it was seen that majority of positive samples (1559; 68.83%) were from age group between 21-60 years of age. Females formed the major group (914; 58.62%) as compared to males in this. The incidence of UTI in females increases with age and sexual activity.¹⁴ Post-menopausal women have higher rates of UTIs because of pelvic prolapse, lack of oestrogen, loss of lactobacilliin the vaginal flora, increased periurethral colonization by Escherichia coli, and a higher incidence of medical illnesses such as diabetes mellitus (DM).¹⁵ Our findings are well supported by similar study by Mohapatra et al who reported higher incidence of UTIs in adult females.¹⁶

In this study, 175 (7.72%) out of 2265 total positive samples were from children between 0-10 years of age. Out of the total 175 positive samples, 107 (61.14%) were from girls and 68 (38.85%) were from boys. The reasons for childhood UTI may be due to vesicoureteral reflux with pathogenesis of renal scarring, reflux nephropathy, pyelonephritis and voiding disorders.¹⁷

Similar findings were observed in study done by Christy VR et al who reported that out of 79 suspected cases, 28 (35.44%) are culture positive in boys and in girls it was 37 (46.83%) in the age group 0-10 years.¹⁸

In this study, Gram negative bacilli were seen in 1896 positive samples followed by Gram positive cocci in 278 positive samples and mixed growth was seen in 92 positive samples from OPD, IPD and ICU services. The Gram negative bacilli were the predominant microorganisms isolated from our hospital clinical services. In Gram negative bacilli, E. coli (1204; 53.15%) is the predominant organism followed by Klebsiella spp. (315;13.90%) and Citrobacter spp.(191; 8.43%). In Gram positive cocci, Enterococcus (152; 6.71%) was the predominant species followed by staphylococcus spp. (107; 4.72%) [Table 3; Fig.1].Our finds are well corroborated by studies from Foxman, Nielubowicz et al, Kline et al and Ronald.^19-22

It was seen in our study, that majority, i.e., 66 (61.68%) out of total 107 isolates of Staphylococcus aureus were resistant to methicillin as compared to 41 (38.31%) sensitive isolates. The majority of MRSA isolates were from OPD followed by IPD and ICU (37;56.06% >24;36.36% >5;7.57%). The rising trend of methicillin resistant Staphylococcus aureus in outpatient department is worrisome as it represents the load of MRSA in community acquired urinary tract infection. The rising trend of MRSA in community acquired urinary tract infection is attributed to the widespread and irrational uses of antibiotics leading to development of resistance in Staphylococcus aureus.S imilar findings were seen in a study done by Aisling et al in an Irish setting who observed that less than one-third (32.5%) of MRSA urine samples came from hospital inpatient sources,implying that MRSA bacteriuria is more frequently a community-based phenomena.²³

The limitations of the study were that firstly it was laboratory based study and limited to the cases for which cultures were requested from the clinic. Secondly, there was no information on antibiotics administered prior to sampling for urine culture or data on subsequent treatment. Thirdly, details on the method of collection, which has a direct bearing on urine culture, were not available for all patients, limiting the analysis of the pathogens from these samples.

We recommend that a prospective study on demography of urinary tract infection is needed to understand the burden of infection in various age groups and gender along with the burden of resistant organism with particular reference to Staphylococcus aureus in the community.

Acknowledgement

The authors wish to acknowledge staff and technicians posted in urine bacteriology seat for their help in preparation of this manuscript.

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