|Year : 2020 | Volume
| Issue : 4 | Page : 290-295
An overview of common organisms associated with community-acquired urinary tract infections and their antibiotic sensitivity: Experience from Government Medical College and associated SMHS Hospital
Iqra Majid1, Nahid Nehvi1, Saqib Rishi2, Sheikh Mohd Saleem3
1 Department of Microbiology, Government Medical College, Srinagar, Jammu and Kashmir, India
2 Department of Microbiology, Government Medical College, Anantnag, Jammu and Kashmir, India
3 Department of Community Medicine, Government Medical College, Srinagar, Jammu and Kashmir, India
|Date of Submission||05-May-2020|
|Date of Decision||26-May-2020|
|Date of Acceptance||04-Jun-2020|
|Date of Web Publication||19-Oct-2020|
Dr. Sheikh Mohd Saleem
Department of Community Medicine, Government Medical College, Srinagar, Jammu and Kashmir
Source of Support: None, Conflict of Interest: None
Background: Appropriate knowledge about the organism and antibiotic susceptibility are the key factors to be known by the health-care professionals for effective treatment of symptomatic urinary tract infection (SUTI). This forms the basis of our study to document the common microbial agents responsible for SUTI and antibiotic susceptibility pattern of pathogens causing SUTI. Materials and Methods: Urine specimens from the patients attending the outpatient department (OPD) and hospitalized patients were collected as per standard microbiological laboratory procedures. Urine specimens were inoculated on blood and MacConkey medium. Plates were incubated overnight at 37°C and the next day were visualized for any visible growth. The characteristic colony character and colony count was taken into consideration. The organisms were later confirmed using conventional biochemical techniques after doing Gram staining. Results: On culture of 2473 specimens, 1940 (78.44%) were sterile and 533 (21.55%) urine specimens yielded significant bacterial growth. Among the 533 positive culture uropathogens isolated, 191 (35.8%) specimens were of males, whereas 342 (64.2%) specimens were of females. The mean ± standard deviation of the age of the patients was 46.1 ± 13.49. Most of the positive specimens, i.e., 316 (59.3%), were from the patients who were >40 years old. The prevalence of Escherichia coli was highest (52.2%), Enterococcus (17.3%), Pseudomonas (7.3%), and Klebsiella (6.0%). Enterococcus (83.7%), methicillin-resistant Staphylococcus aureus(MRSA) (90%), E. coli(93.2%), and Klebsiella (37.5%) isolates were found to be susceptible to nitrofurantoin, whereas Enterococcus (95.7%) and MRSA (95%) isolates were susceptible to antibiotics such as linezolid. All isolates from Morganella species were susceptible to amikacin and gentamicin. Conclusion: E. coli was the most common uropathogen isolated from the urinary specimens, followed by Enterococcus and Pseudomonas among patients who reported with symptoms of UTI in OPD.
Keywords: Antibiotic sensitivity, community-acquired urinary tract infection, urinary tract infection
|How to cite this article:|
Majid I, Nehvi N, Rishi S, Saleem SM. An overview of common organisms associated with community-acquired urinary tract infections and their antibiotic sensitivity: Experience from Government Medical College and associated SMHS Hospital. Curr Med Issues 2020;18:290-5
|How to cite this URL:|
Majid I, Nehvi N, Rishi S, Saleem SM. An overview of common organisms associated with community-acquired urinary tract infections and their antibiotic sensitivity: Experience from Government Medical College and associated SMHS Hospital. Curr Med Issues [serial online] 2020 [cited 2021 Jul 26];18:290-5. Available from: https://www.cmijournal.org/text.asp?2020/18/4/290/298597
| Introduction|| |
Urinary tract infection (UTI) is the second most common infectious disease affecting about 150 million people each year. UTI is a common infection, especially among females, and accounts for a larger proportion of population getting infected with it on a daily basis. It is the most common infection diagnosed in community, outpatient departments (OPDs), as well as in hospitalized patients. UTI may result in significant loss of workdays, economic loss, morbidity, and mortality in the sufferers. The challenge to treat this common infection has substantially resulted in prescribing broad-spectrum antibiotics to most of the patients resulting in high economic burden and antibiotic resistance.
UTI is defined as a microbial invasion of any of the tissues of the urinary tract extending from the renal cortex to urethral meatus. UTI encompasses a variety of clinical entities, including asymptomatic bacteriuria, cystitis, prostatitis, and pyelonephritis. Bacteriuria is a frequently used term that denotes the presence of bacteria in urine. The probability of the presence of bacteriuria can be ascertained by quantifying the number of bacteria in voided urine or in urine obtained through urethral catheterization. Significant bacteriuria is a term used to describe the number of bacteria in voided urine that usually exceed the number caused by contamination from the anterior urethra (i.e., ≥105 bacteria/ml). The implication being that in the presence of at least 105 bacteria/ml of urine, the infection must be seriously considered.
Uncomplicated UTI refers to an infection in a nonpregnant outpatient woman without any anatomic abnormalities or instrumentation of the urinary tract. Complicated UTI, on the other hand, is an infection in a urinary tract with functional or structural abnormalities, including indwelling catheters and calculi. In general, infection in men, pregnant women, children, and patients with nosocomial infections may be considered complicated. UTIs are generally caused by multidrug-resistant organisms. Some authors consider upper tract infection as complicated., UTIs can also recur in the form of relapses or recurrent infections. Relapse of bacteriuria refers to a recurrence of bacteriuria with the same infecting microorganism that was present before therapy was started. This is caused by the persistence of the organism in the urinary tract. Recurrent UTI clinical definition refers to ≥2 infections in 6 months or ≥3 infections in 1 year. Re-infection may occur with the same microorganism, which may have persisted in the perineal or enteric flora and can be mistaken for a relapse.
In this study, we shall discuss about symptomatic UTI (SUTI) which is regarded as the second most commonly diagnosed infection in the community. Gonzalez et al. in their study estimated the global burden of UTI to be 150 million people. The cause behind such a huge burden is the pathogenesis of the SUTI itself as there are various factors including host factors and bacterial virulence which give rise to this infection. SUTI is usually treated empirically as the uropathogen largely has origin from the colonic flora and is easy to predict. Some common known organisms responsible to play their role in causation of the infection include Escherichia More Details coli and Klebsiella species. Other pathogens such as Enterococcus species, Proteus species, Pseudomonas aeruginosa, and staphylococci have also been isolated and have been deemed provital in causing SUTI.
Aims and objectives
For the effective management of SUTI, the use of antibiotics has been the first line of treatment to eliminate the pathogens to avoid complications. Appropriate knowledge about the organism, epidemiological characteristics, and antibiotic susceptibility are the key factors to be known by the health-care professionals for effective treatment of SUTI. The antibiotic susceptibility patterns, however, vary according from region to region due to different antibiotic prescription practices. This forms the basis of our study to document the common microbial agents responsible for SUTI and antibiotic susceptibility pattern of pathogens causing SUTI. The finding of our study will be helpful for health-care professionals to know the common organisms responsible for causing SUTI in Kashmir Valley and antibiotic susceptibility to frame region-specific antibiotic policy for effective management of SUTI.
| Materials and Methods|| |
This prospective observational study was carried out in the Postgraduate Department of Microbiology, Government Medical College, Srinagar. It is one of the largest tertiary care hospitals of Kashmir Valley catering the health-care needs of the people. The study was conducted for a period of 1 year from January 2018 to December 2018 and included all the patients attending the medical OPD with symptoms suggestive of UTI. The patients were recruited from the medical OPD using a purposive sampling method. A total of 4484 specimens were received during the study period. We included specimens of patients who reported to the OPD of our hospital with symptoms of UTI (burning micturition, frequency, flank pain, fever, chills, and rigor) or those who were admitted with these symptoms for a short stay in the emergency department (not more than 24 h). Specimens from the hospitalized patients, patients with indwelling catheters, and those who were already on antibiotic therapy were excluded from the study.
Urine specimens from the patients attending the OPD and hospitalized patients were collected as per the protocol mentioned below. Female patients were instructed to collect the specimen after proper positioning of the thigh, spreading the labia apart, and cleaning the area and then collect the midstream urine for the specimen. Males were instructed to retract the prepuce, clean the area, and then collect the midstream urine for the specimen. Each patient was asked to collect a clean-catch midstream specimen of about 20 ml in a sterile container which was provided to them. All the samples were collected during daytime so as to prevent any transportation, storage, or processing issues. Each specimen container was labeled and transported (within 1 h) to the departmental laboratory for culture and antibiotic sensitivity. The culture was done first in order to prevent contamination of specimens which may occur during the handling of specimens for other procedures/tests. A measured amount of urine was taken with a calibrated nichrome loop designed to take a known volume of 0.01–0.001 ml of urine. Urine specimens were inoculated on blood and MacConkey medium. Plates were incubated overnight at 37°C and the next day were visualized for any visible growth. The characteristic colony character and colony count was taken into consideration. The organisms were later confirmed using conventional biochemical techniques after doing Gram staining. The Gram staining gave us an idea whether infection is caused by Gram-positive, Gram-negative bacteria. Yeasts were identified by Gram staining. The clinicians were informed accordingly, so that targeted antimicrobial treatment could be started. Further, antimicrobial susceptibility to different drugs was determined by Gram staining, and the antibiotic panel for Gram-positive bacteria/Gram-negative bacteria/yeasts was put depending on the results of Gram staining. Antimicrobial susceptibility of all the isolates recovered was performed on Mueller-Hinton agar plates by Kirby–Bauer disk diffusion method according to CLSI guidelines. All the discs were procured from Hi-Media, Mumbai. The cost of all the test, reagents, and culture media used during the study was procured by the Department of Microbiology, and no such financial implications were put on patients recruited.
The recorded data were compiled and entered in a spreadsheet (Microsoft Excel) and then exported to data editor of SPSS version 20.0(SPSS Inc., Chicago, Illinois, USA). Continuous variables were expressed as mean ± standard deviation (SD) and categorical variables were summarized as frequencies and percentages. Graphically, the data were presented by bar and flow diagrams.
The study did not have any ethical issues related to human or animal experiments. Consent was taken from each patient before recruitment, and their confidentiality was maintained as per the study protocol. Ethical clearance was obtained from the institutional ethical board before the commencement of the study through proposal submitted no. MC/2403/2018.
| Results|| |
Over the study period, 4484 urine specimens were received in the Postgraduate Department of Microbiology. A total of 2473 (55.15%) specimens satisfying the inclusion criteria were included in the study. On culture of 2473 specimens, 1940 (78.44%) were sterile and 533 (21.55%) urine specimens yielded significant bacterial growth. Total specimens received from female patients were 1510, of which 342 (22.64%) showed a positive culture of uropathogen, whereas specimens received from male patients were 963, of which 191 (19.83%) showed a positive culture of uropathogen [Figure 1] and [Table 1].
|Table 1: Positive isolates and gender distribution of the patients with symptomatic urinary tract infection|
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Among the 533 positive culture uropathogens isolated, 191 (35.8%) specimens were of males, whereas 342 (64.2%) specimens were of females. The age distribution and gender proportion of the patients with SUTI are shown in [Table 2]. The mean ± SD of the age of the patients was 46.1 ± 13.49. Most of the positive specimens, i.e., 316 (59.3%), were from the patients who were > 40 years old. There has been a significant gender difference among the cases with a higher number of cases reported in females than in males [Table 2].
|Table 2: Age distribution and gender proportion of the patients with community-acquired urinary tract infection|
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The distribution of uropathogen isolated from patients with SUTI and the presence of resistance among bacterial isolates is shown in [Table 3]. The prevalence of E. coli was highest (52.2%), Enterococcus (17.3%), Pseudomonas (7.3%), and Klebsiella (6.0%), respectively. Antibiotic drugs such as nitrofurantoin, piperacillin-tazobactam, ceftriaxone, cefoperazone-sulbactam, amikacin, and gentamicin were found to be most effective against E. coli, whereas gentamicin, linezolid, and vancomycin were affective against Enterococcus. The percentage of isolated cultures for antibiotic susceptibility for Gram-positive and Gram-negative organisms has been described in [Table 4]. Enterococcus (83.7%), methicillin-resistant Staphylococcus aureus (MRSA) (90%), E. coli (93.2%), and Klebsiella (37.5%) isolates were found to be susceptible to nitrofurantoin, whereas Enterococcus (95.7%) and MRSA (95%) isolates were susceptible to antibiotics such as linezolid. Moreover, all isolates from Morganella species were susceptible to amikacin and gentamicin.
|Table 3: Distribution of uropathogen isolated from patients with symptomatic urinary tract infection and their antibiotic susceptibility testing|
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|Table 4: Antibiotic susceptibility testing in Gram-positive and Gram-negative organisms|
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| Discussion|| |
For the appropriate management of any disease of infectious origin, it is vital for the treating clinicians to know the local prevalence of the microorganism responsible for causing that particular disease. Worldwide, it has been observed that there is a disparity in the occurrence of pathogens and their antibiogram, for which continuous surveillance is essential. All these factors will aid in choosing better and appropriate antibiotic to the patients seeking care for their diseases. We conducted this study with the objectives to find the common microbial agents and antibiotic susceptibility pattern of pathogens causing SUTI.
After analysis of the specimen, isolated growth of different organisms responsible for causing the symptoms was found in 533 specimens. The rest of the specimens showed no growth at all. In this study, we described the uropathogen and their antibiotic susceptibility of those 533 positive specimens. Total specimens received from male patients were 963, of which 191 (19.84%) showed a positive culture of uropathogen, whereas 342 (22.64%) specimens of 1510 showed a positive culture of uropathogen in females. Females were more commonly affected than the males. It may be due to the reasons already discussed elsewhere and may include factors such as anatomically short urethra in females and its close proximity with the anus, colonization of urethral resident flora, and the vaginal introitus. Other reasons may include inappropriate genital and sexual practices, especially among the females. Among the males, especially above 50 years old, the cause of their UTI may be attributed to the prostatic enlargement, residual urine, or neurogenic bladder.
The most common organism isolated in our study was Escherichia coli accounting for about 52.2% of cases, followed by Pseudomonas (7.3%) and Klebsiella (6.0%) among the Gram-negative organisms, respectively. The results of our study are comparable with the other studies conducted by Bahadin et al., Akram et al., and Kavita et al., where they found Escherichia coli as the most common uropathogen isolated from the specimens of patients with symptoms of UTI. Among the Gram-positive organisms, Enterococcus and MRSA were isolated in 17.3% and 3.8% of cases, respectively. Gram-positive organisms usually cause UTI among individuals who are elderly, pregnant, or who have other risk factors for UTI such as urinary catheterization or urogenital anomalies. The evidence of this comes from the literature which say that Gram-negative bacilli have multiple factors which make them more virulent for disease causation, one of them being its unique property to adhere with the host epithelium. This leads to colonization of bacteria in the uroepithelium with the help of adhesions, pili, fimbriae, and P-1 blood group phenotype receptor.
Another objective of our study was to determine the antibiotic susceptibility of the isolated organisms to get a better picture of the ongoing resistance to antimicrobials in the current era. Resistance to antimicrobials usually occurs as a result of alteration in the target receptor and decreased drug entry into the bacterial cell wall. Some bacteria may even inherit special mutant genes by which they show resistance to particular antimicrobials. Due to the irrational antibiotic prescription by local pharmacy shops, the cases of antibiotic resistance have come up in the recent past even in patients with SUTI. A similar finding of antibiogram showing least susceptibility rate in the observed specimens has been reported in our study. E. coli was most susceptible to nitrofurantoin, imipenem, amikacin, and cotrimoxazole while least susceptible to ampicillin, chloramphenicol, and Nalidixic acid (NX). This is in agreement with various studies conducted in Indian communities by Bahadin et al., Akram et al., and Kavita et al.
In the recent past, the most common antibiotic group prescribed for SUTI in common practice was quinolones and their excessive usage over these years has led to considerable resistance among the uropathogen. In our study, higher rates of resistance were observed against ciprofloxacin and ofloxacin by E. coli, Pseudomonas, and Klebsiella. In most of the studies done in the past, E. coli was found to be resistant to most of the quinolones group. In our study, E. coli and Klebsiella showed less resistance to cotrimoxazole, whereas Pseudomonas showed very high resistance to cotrimoxazole. Globally, studies have reported a resistance pattern of cotrimoxazole, ranging from 11 to 34% which is still less than reported by our study.,
In countries such as India, decreased susceptibility and higher resistance for antimicrobials may be attributed to exposure to substandard and poor quality antimicrobials, pathogens with mutated genes, lack of environmental sanitation and personal hygiene, usage of antimicrobials in agricultural industry, indiscriminate use of antimicrobials in the hands of local pharmacies, use of antibiotics for viral infections, and antibiotic use as over the counter drugs. These factors have contributed to antibiotic resistance in the community.
Our study isolated uropathogen which showed multidrug resistance pattern for almost all the available antimicrobials in the market. The same pattern of multidrug resistance has been reported by Hasan et al. and Mathai et al. However, Ibrahim et al. and Eshetie et al. demonstrated higher degrees of multidrug resistance in E. coli in their respective studies. We recommend that the irrational use of antimicrobial for any disease, especially viral infections, should be stopped. Proper surveillance measures should be kept in place to check the antimicrobial susceptibility pattern of the isolates. Standard treatment guidelines and antibiotic use policy should be framed for each medical college and hospital by special committees in consultation with the Department of Microbiology of that college/hospital. Health-care professionals should be sensitized about the irrational use of antimicrobials, growing antibiotic resistance, and other issues governing the empirical therapy.
| Conclusion|| |
Escherichia coli was the most common uropathogen isolated from the urinary specimens, followed by Enterococcus and Pseudomonas among patients who reported with symptoms of UTI in OPD. The highest isolation rate of uropathogen was observed among female patients with UTI. The most important concern to be reported was of antibiotic resistance among the uropathogen for most of the common empirically used antibiotics. E. coli showed varying degrees of resistance to most of the antimicrobials.
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Conflicts of interest
There are no conflicts of interest.
Research quality and ethics statement
The authors of this manuscript declare that this scientific work complies with reporting quality, formatting, and reproducibility guidelines set forth by the EQUATOR Network. The authors also attest that this clinical investigation was determined to require Institutional Review Board/Ethics Committee review, and the corresponding protocol/approval number is IRB Min no: 169/ETH/GMC dated October 20, 2018. We also certify that we have not plagiarized the contents in this submission and have done a Plagiarism Check.
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[Table 1], [Table 2], [Table 3], [Table 4]