Pattern of antibiotic sensitivity and resistance of uropathogenes among pediatric patients with urinary tract infection

Objectives: studying the microbiological profile by isolation of the types of bacteria that are most frequently causing UTI in pediatric patients and assessing the antibiotic resistance profile of ١٠ different antibiotics that are used for treatment of such infection. . Methods: Urine samples from ٩٠٠ symptomatic UTI cases attending Ibn Alatheer Teaching Hospital from May ٢٠١٠ to September٢٠١١ were collected . Urinary isolates were identified by conventional methods and antibiotic resistance testing was performed by Kirby Bauer's disc diffusion method. Results: We identify ٦ species of uropathogens responsible for UTI in pediatric patients . Females are more susceptible to the UTI than males, however they usually infected by the same bacterial species. E. coli is the most predominant uropathogen in pediatric UTI. The isolated uropathogenes showed a heavy resistance pattern toward many antibiotics like Cotrimoxazole (٨٤.١%) Amoxicilline(٧٢.٦%), Nalidixi acid(٥٧.٤%). Cephalosporin (particularly cefotaxime) , Augmentin, gentamycine and nitrofurantoin exhibit adequate antibiotic activity against uropathogens while Ciprofloxacin and Amikacine subjected to the least resistant pattern of commonly used antibiotics. Conclusion: E. coli is still the most common type of bacteria causing UTI in male and female pediatric patients. Pediatric urine culture isolates are becoming increasingly resistant to commonly used antibiotics. Empirical treatment with Cotrimoxazole, Amoxicillin, or Nalidixic acid as initial drug is relatively ineffective. Cefotaxim and gentamycin can be considered as effective line for treatment of UTI . Amikacine and Ciprofloxacine are less likely to be subjected to drug resistance.

rinary tract infection (UTI) is a common cause of fever and one of the most common cause of childhood infection that usually associated with high rate of morbidity ١,٢ .Serious long term complications like renal scarring, hypertension, or chronic renal failure can be caused by inadequately treated conditions ٣,٤ .The resistance is a significant problem not only in complicated UTI but also in community acquired UTI ٤,٥ .
The increasing prevalence of antimicrobial resistance in both out and hospital patients with UTI is of worldwide concern and can vary according to geographical and regional location ٦,٧ resulting in increased illness, death and healthcare cost ٨ .Many strains of bacteria that are usually causing UTI have developed resistance to various types of antimicrobial agents like Amoxicillin, Ampicillin ٩,١٠ Nitrofurantoin, Pipercillin, nalidixic acid ١١,١٢ Chloramphenicol, Erythromycin, ١٢, ١٣ Tetracycline ١٤ and even third generation Cephalosporines ١٥ .

Although
Ampicillin and Amoxicillin have been considered the mainstay of oral treatment for community acquired UTI in many years, these agents can no longer be recommended as reliable agents since a substantial percentage of common uropathogens particularly E-coli are resistant to these antibiotics ١٦ .There is also growing concern regarding the resistance of urinary tract pathogens to the first generation cephalosporines and sulfonamides because of the increasing number of therapeutic failure after empiric treatment ١٧,١٨ .This trend is a part of the overall change in pattern of antimicrobial resistance.It is especially worrisome in children with UTI in whom quinolones are not accepted for routine use leaving fewer treatment options than in adult UTI ١٩ .
To ensure appropriate treatment, knowledge of the organisms that cause UTI and their antibiotic susceptibility is mandatory to eliminate the symptoms, eradicate the infection, prevent the urosepsis and to reduce the likely hood of renal damage ٢٠,٢١,٢٢ .With the increase in over-the counter U availability of drugs , antibiotic resistance is on the rise so knowledge about antibiotic resistance is very important for the prevention of resistance amongst microbes as the treatment given without considering the prevalent microbe and its antibiotic resistance pattern results in the selection of more resistant strains ٢٣ .The aim of this study was to identify the uropathogenes recovered in children with community acquired UTI and to study the pattern of antibiotic susceptibility of such pathogens and the prevalence of resistance among such uropathogenes .

Materials and methods
Out of ٩٠٠ urine samples collected a total of ٥٤٠ sample were fulfill our criteria.The urine samples were collected from pediatric patients (٢٤٠ males, ٣٠٠females) at age less than ١٢ years who suspected to have UTI attending Ibn Al-Atheer Teaching Hospital between May ٢٠١٠ and September ٢٠١١.Exclusion criteria include antibiotic usage within week , large fluid intake (less than one hour) before hospital attendance , and those with comorbidities such as anatomic and/or functional problems involving the urinary tract .The clean catch midstream urine samples that obtained after proper cleaning of the perianal and urethral were analyzed within ٦ hrs of collection in order to ensure that the pathogenic organisms present in the urine were isolated and also to avoid contamination and overpopulation of the pathogenic organisms.Prior to inoculation, the samples were properly shaken in order to have an even distribution of the microorganisms.The urine samples were cultured on plates of Blood agar and MacConkey agar media and the sample plates were incubated at ٣٧°C for ١٨-٢٤ hours.The cultures were subjected to identification of the organisms by using microscopical and macroscopical examinations and routine biochemical tests ٢٤ .
Standardized culture of each isolate was prepared and incubated at ٣٧°C overnight.The standardized overnight culture of each isolate was used to flood the surface of Mueller-Hinton agar plates.The standard antibiotic discs were then aseptically placed at reasonable equidistance on the inoculated Muller-Hinton agar plate and the plate allowed to stand on the bench for ١ hour.The plates were then incubated at ٣٧°C for ١٨ hrs.The diameter of the zone of inhibition produced by each antibiotic disc was measured, recorded and the isolates were classified as "resistant", or "sensitive" based on the standard interpretation chart.( the intermediately sensitive are considered to be resistant) ٢٥ .Statistical analysis: The data were analyzed using SPSS software (version ١٣, SPSS Inc., USA).Wilcoxon Rank Sum test with significance level of ≤ ٠.٠٥ was used to compare the proportions( the results showing values less than ٠.٠١ is considered highly significant) ٢٦ .

Results:
A group of ٩٠٠ pediatric patient aged less than ١٢ year and suspected to have UTI were enrolled in this study.Of this group only ٥٤٠ patients shown to have culture proven UTI , ٢٤٠ (٤٤.٤%) of them are males and ٣٠٠ (٥٥.٦%) are females.

Discussion
Constant survey of antimicrobial resistance plays a very important role in the empiric treatment of UTI.In a health care setting, a very little extra studies on antimicrobial resistance survey can facilitate to provide extremely practical information of the resistance pattern ٢٧ .The present study reveals the resistance pattern of uropathogens isolated from community acquired UTI .Amoxycillin, Cefadroxil, Nalidixic acid and Cotrimoxazole were the antimicrobials that had heavy resistance from organisms that belonged to Enterobacteriaceae family.Among the ٦ species of uropathogens that were identified in the study, E.coli (٦٧.٨%) emerged as the most predominant organism followed by Staph.aureus spp (١١.٧%),Strep.faecalis (٨.٩%), Proteus spp.(٦%), Klebseilla spp.(٣.٣%) and P.aeroginosa (٢.٢%).These results were in agreement with other previous studies ٢٨,٢٩,٣٠ .Our study also revealed that females were more susceptible to UTI than males which was also similar to other studies ١٥,٣١, ٣٢ .The major factor that make the females population more

Total of male & Female
resistant sensitive prone to UTI are their anatomical and physiological characteristics ٣٣ .Despite that both sexes are infected by the same uropathogenes , the prevalence of resistant pathogens showed a relative difference.
Antimicrobial resistance offered by different uropathogens is one of the barricades that might hinder a successful treatment.Antimicrobial resistance pattern varies with time which might increase or decrease ١٤ .This study also indicated the different pattern of antimicrobial resistance in different families of uropathogen, specially in Enterobacteriaceae family as shown in Table ٣ .E.coli identified in this study were highly resistant to Cotrimoxazol (٨١.٤%) and Amoxycillin (٧٢.١%).E.coli offered almost similar pattern of resistance towards Cefadroxil (٥٩.٦%) and Nalidixic acid (٥٠%).The possible cause of such resistance is the wide spread use of these antibiotics specially those related to β-lactam agents in pediatric population.Studies that were conducted in India reported that, the isolates of E.coli showed high resistance towards ampicillin and amoxycillin which were in agreement with this study ٣٤,٣٥ .The high resistance to amoxicillin by Klebsiella spp was seen in many other studies ٢٩,٣١ .The frequency of Klebsiella , Proteus and P. aeroginosa isolates were found to be low in this study which was consistent with some studies ٣٦,٣٧,٣٨ .However, they comparatively showed a higher resistance pattern toantibiotics included in our study, but it showed a very little resistance toward ciprofloxacin and amikacin .On going with our results some recent studies also revealed a low resistance to ciprofloxacin and amikacin ٣٩,٤٠ however, these studies found a heavy resistance to nalidixic acid unlike our results which reveal a relatively good sensitivity to nalidixic acid.
Aminoglycosides were in use for quite a long period in the history of infectious diseases.They have not considerably developed much resistance against all uropathogens.The current study showed that Pseudomonas spp has developed considerable resistance against gentamycin but a very good sensitivity to amikacin in male and female patients, and this may also be related to the greater use of gentamycin in our community.
Several studies conducted in Spain , France and Nepal٣٦,٣٧,٣٩ found that the Gram +ve bacteria (Staph.aureus and Strep.faecalis) showed moderate pattern of resistance to the antibiotics that commonly used in the empiric therapy of UTI except for cotrimoxazole, amoxicillin, and cefotaxim.
Nitrofurantoin surprisingly appear to have adequate activity against uropathogens suggesting that it is suitable for prophylaxis.This may be due to multiple mechanisms of action, requiring organisms to develop more than a single mutation in order to develop resistance , also it is less widely used than other antibiotics.However, this urinary antiseptic fails to achieve therapeutic concentration in the blood stream; because of pharmacokinetic profile , it is not recommended to treat febrile infant or child in whom renal involvement is suspected.١Conclusion E. coli is the most common uropathogene found in pediatric patients.Pediatric urine culture Fig. ( Fig. ( Fig-٣-Overall antibiotic sensitivity(irrespective of isolate).

Table ( ٢
) Types of bacteria and antibiotic sensitivity in female patients ٥٠%)