MICROBIOLOGICAL PROFILE OF URINARY TRACT INFECTION IN CHILDREN WITH VESICOURETERIC REFLUX AND COMPARISON OF E COLI AND NON-E COLI INFECTIONS

Dr. Shaista Nazir, Prof. Syed Khursheed Ahmad, Dr. Tariq Nazir Lone , Dr. Gowhar Nazir Mufti , Dr. Asifa Bhat, Dr. Shazia Benazir, Dr. Dekyong Angmo and Dr. Lenah Bashir. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

1438 commonly in boys (3.7%) than in girls (2%). Thereafter, the UTI has been reported to be among 3 per cent girls and 1.1 per cent boys 2 . Vesicouretric reflux (VUR) refers to the retrograde passage of urine from the bladder into the ureter. A much higher incidence of VUR (between 30% to 40%) is reported in patients undergoing evaluation for UTI. Boys with VUR tend to present at a relatively young age (25% if younger than 3 months), and younger children tend to have the most severe degrees of reflux 3 .
Antimicrobials are important in UTI in the management of acute pyelonephritis and antimicrobial prophylaxis in children with VUR especially in children younger than 2 years. It is important to know the common pathogens and their antimicrobial resistance patterns in a given population so that the clinician can start the treatment before the antimicrobial sensitivity patterns are known. Susceptibility patterns of the bacterial isolates vary with geographic region and act as a reference for guiding the empirical therapy. The aetiology of paediatric UTI and the antibiotic susceptibility of urinary pathogens in both the community and hospitals have been changing, and drug resistance has become a major problem 4 . With this background, the present study was conducted to observe the profile of the paediatric UTI, to find out the bacterial pathogens involved and their antimicrobial susceptibility pattern in patients with VUR and consecutive renal scarring in these patients at a tertiary care centre in North India.

Materials and Methods:-
This was a prospective study carried out at the Departments of Microbiology and Paediatric Surgery at our Institute from Aug 2014 to Feb 2016. All patients from 0-15 years of age diagnosed with urinary tract infection and vesicoureteral reflux attending the OPD and admitted in the hospital were included in the study. Urine sample was collected by collecting midstream urine, catheterization or suprapubic aspiration. It was screened for infection by microscopic examination for presence of pus cells. Presence of pus cells more than 10/HPF was taken as significant. Urine was inoculated on Hicrome agar using a calibrated loop. The plates were streaked to obtain isolated colonies. After this, the cultures were incubated at 35 o C for 24 hours. Next day, the plates were examined for colony morphology, significant colony count, and their characteristics.Antimicrobial susceptibility of the isolates was performed by Kirby-Bauer disc diffusion method. The zones of growth inhibition around each of the antibiotic discs were measured to the nearest millimetre. The diameter of the zone is related to the susceptibility of the isolate and to the diffusion rate of the drug through the agar medium. The zone diameters of each drug were interpreted using the criteria published by the Clinical and Laboratory Standards Institute (CLSI). 5 Patients were administered antibiotics as per culture sensitivity for 5-7 days, and a repeat culture was obtained to check for resolution of infection.
All patients were subjected to ultrasonography to look for kidney size, hydronephrosis, ureteric dilatation, etc. Patients with febrile UTI and recurrent urinary tract infection were subject to VCUG after resolution of infection as per American Academy of Paediatrics (AAP) guidelines, in order to look for presence of VUR, which was graded according to the international classification of vesicoureteral reflux 6 .. All patients with VUR were also subject to a DMSA scan to look for the presence of renal scars. The patients were followed in the Department of Pediatric Surgery monthly for a minimum of 6 months. Data regarding patients' characteristics, the most common isolates, their sensitivity, grades of reflux, and presence of renal scars were analysed statistically and conclusions drawn.

Discussion:-
Urinary tract infection (UTI) is a common problem at the pediatric age. Various studies show that by the age of 7 years, 8% of girls and 2% of boys have suffered an episode of UTI. Although predominant in females in overall pediatric age, it is more common in boys of preschool age. 7 Although UTI is known to affect more females than males overall, our study found overall male predominance. Similar observations have been made by NeelamTaneja et al.and Eltigani MA et al. 8 This male predominance could partially be explained by parents paying more attention to the male child in seeking medical treatment.Most studies on vesicoureteric reflux (VUR) suggest that general occurrence in healthy children is around 1-2%. However, different studies have shown a wide range of prevalence from 0-30% 9 . This variation may be attributed to different yardsticks and sensitivity in different imaging methods. The issue is further confounded by the inclusion of non-uniform age groups in the study.
Klebsiella showed 40% sensitivity to amikacin and 30% to nitrofurantoin in our study. Sharma et al. 16 (2011) found 100% sensitivity to amikacin and 83.3% to nitrofurantoin. Kumariet al. 17 (2005) found that 96.0% of Klebsiella were sensitive to amikacin. This variation in sensitivity pattern in Klebsiella may either be due to increasing resistance of organisms or due to limited number of isolates. Nitrofurantoin and cotrimoxazole are frequently used in urinary tract infections as chemoprophylaxis among children with vesicoureteric reflux. Our data suggests that nitrofurantoin has better activity, and bacteria have lower resistance to this drug, and should therefore be used for prophylaxis in children, especially among patients with VUR. Cotrimoxazole used to be given as an empirical therapy for UTI, as it was highly effective. However, in our study, cotrimoxazole was the least effective antibiotic against overall isolates.Hence we do not recommend it to be used as an empirical agent for prophylaxis for UTI in children. Our study showed low sensitivity of the organisms to quinolones. We found ciprofloxacin to be only 37% effective overall and 31.9% sensitive for E. coli. Although quinolones are not used in children, the finding is worrisome, and probably due to the overuse of quinolones in the community. Other studies show a similar pattern of resistance in isolates of E. coli against quinolones. Bijendra Raj et al. 18 (2014) found sensitivity of 10% against ciprofloxacin. This shows that quinolones should not be used empirically to treat UTI.
Voiding cystourethrography (VCUG) is the screening urologic imaging study of choice for detecting VUR. Vesicoureteral reflux can be a risk factor for renal scarring in the presence of UTI through the transport of microbes from the urinary bladder to the kidneys. The acquisition of renal scarring through the association of reflux, urinary infection, and intrarenal reflux has been observed clinically and experimentally. 19,20 Nuclear scintigraphy can detect areas of acute renal inflammation and chronic scarring, and this capability has changed imaging of pediatric UTIs. In our study, DMSA findings showed that 23.5% of the children (33 0f 140) had renal scarring. Scarring was associated with low-grade VUR in 21% (16 out of 73) cases and with high-grade VUR in 60% (17 out of 28) cases. Scarring was significantly associated with high-grade VUR (p=0.006). These findings are consistent with other studies. Falakaflaki B et al. 21 (2014) observed scars in 33.3% (12 out of 36) cases in low-grade reflux and 76.9% (10 out of 13) cases in high-grade refluxon a sample of 49 UTI patients with VUR . Ljiljana Jaukovic et al. 22 (2009), in 118 UTI patients with VUR, observed renal scars in 26% (22 of 84) in low-grade reflux and 56% (19 of 34) of cases in high-grade reflux. These studies and our data clearly show that scarring is more common in higher grade of reflux.
Between 65% and 90% of urinary tract infections (UTIs) in children are caused by Escherichia coli. Other pathogens include Klebsiella species, Proteus species, Pseudomonas aeruginosa, and Enterococcus species. Very few studies have compared the clinical and bacteriological characteristics in E. coli and non-E. coli infections. S Friedman et al. 23 (2006) compared the clinical and laboratory characteristics of infants and children with urinary tract infection caused by E. coli (n=107) and other pathogens (n=32). They found a significantly higher association of non-E. coli disease with urinary tract anomalies, younger age, and previous antibiotic treatment. Underlying urinary tract anomalies were noted in 18 patients, of whom 14 (77%) were infected by non-E. coli pathogens. The most frequent anomaly was grade III-IV vesicoureteral reflux (50%), followed by hydronephrosis (22.7%). We studied the clinical features in E. coli and non-E. coli urinary tract infections in our patients. Our results showed non-E. coli infections to be more common in males, even though the difference was not significant. Renal scarring was more common in patients with non-E. coli infections compared to patients with E. coli infections; the difference was insignificant (p=0.27). Our data was consistent with the study by Falakaflaki B 21 (2014), who compared renal scarring in E. coli and non-E. coli infections, and found no significant difference in renal scaring between the two groups.