Introduction: Urinary tract Infection (UTI) represents one of the most common diseases encountered in medical practice today and occuring from the neonate to geriatric age group.1 UTI exists when pathogenic microorganisms are detected in the urine, urethra, bladder, kidney or prostate. In most instances, growth of >105 organisms/ml from a properly collected midstream “clean-catch” urine sample indicates infection.2 Bacterial infections of the urinary tract, whether hospital acquired or community acquired, occur in all age groups in both genders, and usually require urgent treatment.3 UTI’s often results in serious complications like secondary bacteremia and sepsis leading to a rise in mortality in addition to enormous hospital costs.4 The resistant bacterial strains are emerging and spreading throughout the world, mainly because of the extreme genetic plasticity of the micro organisms themselves, the mobility of world population and the heavy selective pressures of antimicrobial use.5 In all UTI cases, there is a need to initiate empirical antimicrobial treatment before obtaining the microbiological results.6 The initiation of antimicrobial therapy in community acquired UTI is empirical, so knowledge of the most common etiological agents isolated and resistance pattern of the isolated pathogens is essential to provide clinically appropriate and cost effective therapy. There exists a great need for antimicrobial resistance surveillance at the local, national & international levels.7 Material and methods: Source of data The present study was conducted in the department of Microbiology, Bowring and Lady Curzon Hospital attached to Bangalore Medical College and research centre, Bengaluru from june 2009 to feb 2010. A total of 600 suspected cases of UTI attending the outpatient department and inpatients were studied for a period of one year. Inclusion Criteria Clinically suspected cases of urinary tract infection of both sexes and all age groups admitted in the wards and cases attending the outpatient department. Exclusion Criteria Patients who were treated with the antibiotics were excluded from the study. Collection of the sample Fresh midstream urine samples were collected in universal sterile containers from all cases. The samples were transported and processed in the laboratory without delay. Processing Microscopic examination A clean grease free slide was taken and a drop of uncentrifuged urine was placed on it and covered with the coverslip. It was examined under the low power and high power of the microscope for the presence of pus cells and motile bacteria [Fig 1]. Culture Each sample was plated onto 5% Sheep blood agar and MacConkey agar plates using a calibrated loop, delivering 0.01ml of the sample. Plates were incubated aerobically at 370c overnight and observed for the presence of significant bacteriuria (>105 org/ml) [Fig 2]. Plates showing significant bacteriuria were further processed for identification using standard methods.8 Those plates showing insignificant bacteriuria and no growth (<105 org/ml) were discarded. Identification of bacterial pathogens was made on the basis of gram stain, hanging drop and biochemical tests like catalase, oxidase, IMViC reactions, TSI, urease, mannitol motility & fermentation, nitrate reduction and sugar fermentation tests[Fig 3]. Antibiotic susceptibility testing: The conventional sensitivity method used in this study was modified Kirby- Bauer disc diffusion method. Isolates were grown in peptone water at 370 C and turbidity was matched with 0.5 McFarland standard. The lawn culture was done on Mueller Hinton agar plate and antibiotic discs were placed[Fig 4]. The plates were incubated at 370C overnight and the zones of inhibition were interpreted according to CLSI guidelines9. Antibiotic susceptibility & culture media were evaluated regularly using ATCC strain (25922) of Escherichia coli. The antibiotic discs and its strength used are6 : Ampicillin 10 µg Amikacin 30 µg Amoxiclav 20/10 µg Carbenicillin 100 µg Cefotaxime 30µg Cefpodoxime 10µg Ciprofloxacin 5 µg Cotrimoxazole 1.25/23.75 µg Gatifloxacin 5 µg Gentamicin 10 µg Imipenem 10 µg Norfloxacin 10 µg Nitrofurantoin 300 µg Nalidixic acid 30 µg Pipera/tazobac 100 µg Rapid method of susceptibility testing by MINI API The rapid method used to test susceptibility pattern is MINI API by BIOMERIEUX [Fig 5]. It consists of rapid ATB strips [Fig 6] made up of transparent, rigid, thermoformed plastic and contains 16 cupules. Each strip carries a screen- printed code which is automatically recognized by the strip reader. Each cupule contains a dehydrated antibiotic at a given concentration. The first cupule serves as the growth control and contains no antibiotic. The strips are inoculated with a bacterial suspension prepared in a semisolid medium specific to ATB tests. The strips are incubated for 4 hours and is placed on the reader and read automatically. The reader recognizes the strip code, carries out the measurements and transfers them to the computer, which establishes the corresponding profile (intermediate, Resistant, sensitive).10 Results: Out of 600 cases, 320 (51.6%) were females and 280 (48.3%) were males. Male to female ratio was 1:1.14. 24.16% of the patients belonged to the age group of ≤10 years (71males and 74 females). 20.5% were of the age group 11-20years (60 males and 63 females). 16.3% were of the age group 21-30 years (45 males and 53 females). 12.6% were of the age group 31-40 years (38 males and 38 females). Suspected UTI cases above 40 years was relatively insignificant. Age Males Females Total No % No % No % ≤10 71 11.8 74 12.3 145 24.16 11-20 60 10.0 63 10.5 123 20.5 21-30 45 7.5 53 8.88 98 16.3 31-40 38 6.3 38 6.30 76 12.6 41-50 31 5.16 34 5.6 65 10.83 51-60 21 3.5 29 4.83 50 8.3 >60 14 2.3 29 4.83 43 7.1 280 46.56 320 53.44 600 100 Table A: Age and sex distribution of the study group significant bacteria with pyuria is seen in 55 cases (9.1%), significant bacteriuria without pyuria in 13 cases (2.1%), Pyuria without significant bacteriuria was seen in 1 case (0.16%) and 88.5% cases with no pyuria and bacteriuria. Findings Total Pyuria & bacteriuria 55 9.1 7.1 – 11.7 Bacteriuria alone 13 2.1 1.3 – 3.7 Pyuria alone 01 0.16 0.03 – 0.9 88.5 85.7 – 90.8 No pyuria & no 531 % 95% CI bacteriuria Total no screened 600 100 Table B: Results of microscopy and culture 32.7% cases were from inpatients and 67.3% from outpatient department. Out of 196 inpatients, 23 cases (11.73%) showed culture positive . Out of 394 outpatients, 46 cases (11.6%) showed culture positive. A total of 69 uropathogens were isolated. Escherichia coli was the commonest uropathogen isolated (73.9%), followed by Klebsiella pneumoniae (24.6%) and Citrobacter freundii (1.4%). Type of organism No Percentage 95% CI Escherichia coli 51 73.9 65.6-85.2 Klebsiella pneumoniae 17 24.6 13.6-32.8 Citrobacter freundii 01 1.4 0.3-0.78 Total 69 100 Table C: Uropathogens isolated in the study Escherichia coli was 100% sensitive to amikacin & imipenam and was least sensitive to nalidixic acid (5.8%) & carbenicillin (11.7%). Klebsiella pneumoniae was highly sensitive to imipenem (100%), piperacillin/tazobactum (82.3%), amikacin (70.5%) and least sensitive to ampicillin (5.8%), carbenicillin (5.8%). Citrobacter was sensitive to imipenem alone. ATCC strain of Esch.coli showed sensitivity to all the antibiotics used in this study. Escherichia coli Klebsiella spp Citrobacter freundii No % No % No % Ampicillin 10 19.6 01 5.8 0 0 Amikacin 51 100 12 70.5 0 0 Amoxiclav 21 41.1 03 17.6 0 0 Carbenicillin 06 11.7 01 5.8 0 0 Cefotaxime 17 33.3 03 17.6 0 0 Cefpodoxime 13 25.4 03 17.6 0 0 Ciprofloxacin 09 17.6 05 29.4 0 0 Gatifloxacin 08 15.6 07 41.1 0 0 Gentamicin 22 43.1 05 29.4 0 0 Cotrimoxazole 21 41.1 06 35.2 0 0 Imipenam 51 100 17 100 1 100 Nalidixic acid 03 5.8 02 11.7 0 0 Norfloxacin 08 15.6 06 35.2 0 0 Nitrofurantoin 34 66.6 06 35.2 0 0 Pipera/tazobac 48 94.1 14 82.3 0 0 Table D: Antibiotic sensitivity pattern of uropathogens isolated in the study Discussion: Laboratory diagnosis of UTI using urine cultures is based on the semi-quantitative counts of organisms and identification of the isolates. It is important to note that urine cultures are reserved for patients with complicated UTI or those who failed or relapsed after empirical therapy. In the outpatient setting, symptomatic patients with uncomplicated UTI are usually treated empirically. However, other investigations may be helpful and each primary care physician has his own strategy. If empiric treatment is based on history alone then one would be treating at least 40% of patients without UTI. This is because through history taking, the pretest probability of a UTI hardly exceeds sixty percent.10 In the present study, UTI’s were more common in ≤ 10 years age group (20.2%), is not in comparision with other studies as the number of cases referred were more from the pediatric department (24.16%). Mohammed Akram et al11 and Anbumani et al4 reported 20-49 years as the commonest age group affected. females were more commonly affected (53.44%) than males (46.56%), is in comparision with the study of Nwanze et al 12 (60%). Females are more commonly affected because of the short urethra, its proximity to anus and its termination beneath the labia. All this factors predisposes for the colonization of colonic gram negative bacilli 13. Significant bacteriuria was seen in 11.5% of the study group, is in comparision with the study of Mohammed akram et al 11( 11.1%), Dimitrov TS et al14 (11.74%). Escherichia coli was the commonest uropathogen (73.9%) isolated, is in comparision with the study of Katarzyna et al 6 (73%) and Semra Kurutupe et al7 (73.2%).The pattern of antibiotic susceptibilities, although subject to frequent changes, its assessment is important for clinical and epidemiological purposes. This is because the resistance of various organisms to antimicrobials poses a challenge to treat UTI since it decreases the effectiveness of treatment and increases morbidity, mortality and cost of care. Escherichia coli was highly sensitive to amikacin (100%) and imipenem (100%).Similar findings were seen in the studies.15,16 It was less sensitive to ampicillin (19.6%), similar to the reports of Hadiza et al15 (18%), is less compared to the study of Katarzyna et al6 (55%). Sensitivity to cotrimoxazole was 41.1%, similar to the reports of Mohammed H Abu et al 17 (40.4%), is less compared to the study of Katarzyna et al6(80.9%) and Yvonne et al16(73.5%). Sensitivity to norfloxacin was 15.6%. Similar findings was not found in other studies. This may be due to frequent and inadvertent use of antibiotics empirically without any laboratory investigations. Conclusion: In the present study, the antibiotic sensitivity pattern gave a serious cause for concern because the predominant uropathogens were less sensitive to commonly used antibiotics. In occasions of complicated or recurrent UTI’s, the success of treatment depends on prompt administration of appropriate antibiotics. Since the sensitivity pattern of uropathogens are subjected to change during the course of time, it is important to do local hospital based periodical assessment of it. This would allow early and appropriate management of UTI’s. The rapid method for antibiotic susceptibility testing by MINI API is technically simple, reliable(results are similar to disk diffusion method), early reporting (within 48 hours), and cost effective when compared to time consuming, technically demanding and expensive conventional method. Acknowledgement: I would like to thank all the technicians of department of microbiology, Bowring hospital for their constant help and support during the entire study. References: 1. Tambekar DH, Dhanorkar DV, Gulhane SR, Khandelwal VK, Dunhane MN. Antibacterial susceptibility of some urinary tract pathogens. Afr J Biotechnol 2006 Sep;5(17):1562-1565. 2. Joseph O Ehinmidu. Antibiotics susceptibility patterns of urine bacterial isolates. 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