Objectives: To identify antibiotic susceptibility and resistance of bacterial strains responsible for urinary tract infections in children.
Methods: The cross-sectional study was conducted from June to December 2017 at the Central Teaching Hospital, Baghdad, Iraq, and comprised patients aged between one day and 15 years who were brought to the emergency department and were diagnosed as having urinary tract infections. Urine samples were cultured on appropriate media and the isolated organisms were identified. The susceptibility of bacteria-causing urinary tract infection to different antimicrobial agents was investigated using antibiotic discs. Data was analysed using SPSS 24.
Results: Of the 155 patients, 78(50.3%) were girls and 77(49.7%) were boys. The highest number of patients 55(35.5%) were aged <1 year. The most common organism encountered in the study were Escherichia coli 78(50.followed by Klebsiella pneumonia 21(13.5%). Among the Escherichia coli isolates,54(69.2%) were resistant to ceftriaxone, 50(64.1%)to ampicillin and 38(48.7%) to ciprofloxacin.
Conclusions: Escherichia coli was found to be most predominant organism causing urinary tract infection, and it was resistant, among others, to ceftriaxone, ampicillin and ciprofloxacin.
Keywords: Antibiotic susceptibility, Antibiotic resistance, Urinary infection, Bacterial infection, Paediatrics. (JPMA 69: S-59 (Suppl. 3); 2019)
Urinary tract infection (UTI) is one of the most common bacterial infections in children and one of the major causes of admission to hospitals.1 UTIs are considered the most common infections after the upper respiratory tract infections (URTIs). 2 The prevalence of UTIs varies with age. During the 1st year of life, it is more common in males, the male-tofemale ratio being 2.8-5.4-to-1. Beyond 1-2 years, there is a female preponderance, with the male-to-female ratio being 1-to-10. In boys, most UTIs occur during the 1st yr of life and are much more common in uncircumcised boys. In girls, the first UTI usually occurs by the age of 5 year, with peaks observed during infancy and toilet training. 3The most common causative agents of UTIs are Escherichia (E.) coli, Klebsiella (K.), Pseudomonas (P.), other gram-negative enteric bacilli, such as Proteus, and other agents such as group B streptococci, staphylococci (S.), Candida (C.) albicans and microorganisms belonging to the flora of vagina and periurethral region. 1 UTIs may be asymptomatic or symptomatic and may cause mortality due to sepsis, and pyelonephritis at younger ages, and recurrent UTI especially may cause serious long-term complications such as hypertension (HTN) and end-stage renal disease (ESRD). 4 Antibiotics play an important role in the treatment of UTIs. Choosing an antibiotic depends on various factors, such as the patients' past medical history, past hospital reports of other illnesses, their spontaneous cure rates and their antibiotic-resistance charts, the frequently identified aetiological agent, its antimicrobial sensitivity testing, its pharmacokinetics its toxicity, and the patients' age etc. 5 Multidrug resistance (MDR) is defined as resistance to two or more different structural classes of antimicrobial agents. MDR has become a universal phenomenon across organisms and may complicate the management of infections. Antibiotic resistance can cause serious damage and is an important public health problem. 6 The importance of infectious agent determination and susceptibility to antibiotics and the detection of resistance status are key factors in the diagnosis and proper treatment of UTI because of the increasing antibiotic resistance. 7 The misuse of antibiotics leads to possible adverse effect, super infection, increased cost of healthcare and the emergence of highly resistant strains of bacteria in the community. 8 The biochemical and genetic aspects of antibiotic resistance mechanisms have been discussed in literature 9 (Figure).
The current study was planned to obtain data on antibiotic susceptibility and resistance of bacterial strains responsible for UTIs in children.
Patients and Methods
The cross-sectional study was conducted from June to December 2017 at the Central Teaching Hospital, Baghdad, Iraq, and comprised patients aged between one day and 15 years who were brought to the emergency department (ED) and were diagnosed as having UTI. Those included had clinical symptoms of UTI, like fever,incontinence, dysuria, abdominal pain and vomiting, along with a growth of >105 CFU/mL in urine cultures. Those excluded were patients with incomplete data, growth of multiple microorganisms in the culture, and those who had known urological problems, such as vesico-ureteric reflux. After consent was obtained from the participants by talking and taking permission from the parents or thepatients if old enough, medical files were reviewed, and age, gender, clinical findings and culture results of the patients, antibiotic sensitivities, and resistance patterns were retrospectively evaluated. Urine samples from the non-toilet trained patients, aged 1day to 36 months, were obtained by clean catch collection method. Mid-stream urine was collected from toilet-trained children. The samples had been cultured immediately, but in samples that cannot be cultured within 4 hours of collection, the sample had been refrigerated. 10 Urine samples were sent to the laboratory where they were inoculated using a 4mm caliber loop on culture medias containing blood agar with 5% sheep blood and MacConkey agar (BioMark, India), andincubated at 37°C for 18-24 hours using an incubator (Fischer Scientific, Germany). In urine cultures with significant growth, bacterial identification was performed using standard conventional methods, including Analytical Profile Index (API) 20E, API 20 staph and gram stain. 11 After identification of the microorganism, antibiotic sensitivity test was done on Mueller-Hinton agar by disc diffusion test (Mastdiscs, UK) againstsulfomethaxazole-trimetoprim (SXT) 25μg, ceftriaxone 30μg, cefixime 5μg ,ciprofloxacin 5μg, amikacin 30μg, nitrofurantoin 30μg, gentamicin 10μg, cefoxitin 30μg, cefepime 30μg, cephalothin 30μg, amoxycillinclavulanate 30μg, imipenem 5μg and ampicillin 25μg. Sensitivity and resistance were determined by measuring the diameter of zones around each drug according to Clinical Laboratory Standard Institute (CLSI) guidelines. 12 Data was first recorded in Excel and was then analysed using SPSS 24. Continuous variables were presented as means and standard deviations (SDs), while discrete variables were presented as frequencies and percentages.
Of the 155 patients, 78(50.3%) were girls and 77(49.7%) were boys. The highest number of patients 55(35.5%) were aged <1 year (Table-1).
The most common organism encountered in the study were E. coli 78(50%) followed by K. pneumonia 21(13.5%) (Table-2).
Among the Escherichia coli isolates, 54(69.2%) were resistant to ceftriaxone, 50(64.1%) to ampicillin and 38(48.7%) to ciprofloxacin (Table-3).
UTIs are some of the most common bacterial infections, affecting 150 million people each year worldwide. In 2007, in the United States alone, there were an estimated 10.5 million office visits for UTI symptoms (constituting 0.9% of all ambulatory visits) and 2-3 million ED visits. Serious sequelae include frequent recurrences, pyelonephritis with sepsis, renal damage in young children and complications caused by frequent antimicrobial use, such as high-level antibiotic resistance and Clostridium difficile colitis. 13 During infancy, boys are more likely to develop UTIs. After infancy, girls are much more likely to develop them. UTIs are more common among girls because their short urethras make it easier for bacteria to move up the urinary tract. 14 The findings of the current study agree with literature. 15,16In studies performed in various regions of the world, mostly E. coli have been isolated in UTIs. 17-21 In the current study as well, E. coli was the most common uropathogen identified either as a single or mixed culture. E. coli is the most common cause of UTI as it possesses a variety of virulence factors, which the organism uses to get attached, invade and injure the host. These virulence factors include adhesins, toxins, iron acquisition factors, lipopolysacharide capsules, and other invasins. 22The second microorganism implicated as a cause of UTI in this study was K. pneumoniae, which is in line with a study, 16 but S. aureus ranked second as a UTI cause in a study 15 and in another study, Proteus species ranked second as a UTI cause. 23These differences are related to the different risk factors associated with certain types of infections with particular microorganism such as age, comorbid conditions, and whether the infection is hospital-acquired or community-acquired. Proteus mirabilis and P. aeruginosa accounted for 11.6% of all species encountered as a UTI cause in this study. In one study. 16 Proteus accounted for 12.1%, while P. aeruginosa was the third predominant organism in another study. 24 However, Bagshaw et al. 25 recorded enterococci as the third most frequent uropathogen in intensive care unit (ICU)-acquired UTIs. This higher percentage of enterococcus species could be related to the fact that entercocccusis associated with approximately 15% cases of nosocomial UTIs in both children and adults. Nowadays, resistance is increasing and resistance pattern is changing because of careless and irregular use of antibiotics, especially in children with recurrent UTI. The resistant pattern of E.coli in the current study was nearly similar to other studies15,26-28 to the effect that most E. coli strains are resistant to ampicillin, ceftriaxone and a significant percentage were resistant to ciprofloxacin, while most E. coli species in the earlier studies were sensitive to amikacin, nitrofurantoin and nearly almost of them were sensitive to imipenem (Table-4).
It is significant to note that the current study and an earlier one 15 showed a higher resistance pattern of E. coli to SXT compared to the other studies cited above from Iraq, and this could be related to the widespread use of this antibiotic as a drug of first choice for UTIs in the country. K. pneumoniae, the second most common cause ofculture-proven UTI in the current study, was resistant to ampicillin which is in line with a study conducted in Malaysia. 29
Most of the organisms implicated as a cause of UTI showed good sensitivity to imipenem, amikacin, nitrofurantoin and gentamicin. The high rate of resistant bacteria suggests that frequent and excessive use of antibiotics should be avoided in day-to-day practice.
Source of Funding: Our budget.
Conflict of Interest: None
1. Kocak M, Buyukkaragoz B, Celebi Tayfur A, Caltik A, Koksoy AY, Cizmeci Z, et al. Causative pathogens and antibiotic resistance in children hospitalized for urinary tract infection. Pediatr Int 2016;58:467-71.
2. Farajnia S, Alikhani MY, Ghotaslou R, Naghili B, Nakhlband A. Causative agents and antimicrobial susceptibilities of urinary tract infections in the northwest of Iran. Int J Infect Dis 2009;13:140-4.
3. Elder JS. Urinary tract infections. In: Klegman RM, Stanton BF, St Geme JW, Schor NF, Behrman RE, eds. Nelson Textbook of pediatrics. 20th ed. Philadelphia: Elsevier, 2016; pp 2556-61.
4. Hansson S, Jodal ULF. Urinary tract infection. In: Barratt TM, Avner ED, Harmon WE, eds. Pediatric Nephrology. Baltimore, Maryland: Lippincott Williams & Wilkins, 1999; pp 835-850.
5. Brad G, Sab?u I, Marcovici T, Mari? I, D?escu C, Belei O, et al. Antibiotic resistance in urinary tract infections in children. JurnalulPediatrului2010;13:51-52.
6. Srinivasan S, Madhusudhan NS. Prevalence of multidrug resistant pathogens in children with urinary tract infection: a retrospective analysis. Int J Med Res Health Sci2014;3:954-8.
7. Kaya? L, Yolba? ?, Ece A, Kaya? Y, Bal?k H, Kocamaz H. Causative agents and antibiotic susceptibilities in children with urinary tract infection. J Microbiol Infect Dis 2011;1:17-21.
8. Joda AE. Are prophylactic antibiotics justified in pediatric patients with inguinal hernia repair? Med J Malaysia 2016;15:24-9.
9. Shaikh S, Fatima J, Shakil S, Rizvi SM, Kamal MA. Antibiotic resistance and extended spectrum beta-lactamases: Types, epidemiology and treatment. Saudi J Biol Sci 2015;22:90-101.
10. NICE. Urinary tract infection in under 16s: diagnosis and management.
[Online] 2007 [Cited 2017 October 10]. Available from URL:
11. Reynolds J. API-20E multitest strip: Biology. [Online] 2019 [Cited 2019 June 03]. Available from URL: https://bio.libretexts.org/Ancillary_Materials/Laboratory_Experiments/Microbiology_Labs/Microbiology_Labs_I/43%3A_API-20E_multitest_strip
12. Jenkins SG, Schuetz AN. Current concepts in laboratory testing to guide antimicrobial therapy. Mayo Clin Proc 2012; 87: 290-308.
13. Foxman B. Urinary tract infection syndromes: occurrence, recurrence, bacteriology, risk factors, and disease burden. Infect Dis Clin North Am 2014;28:1-13.
14. Weinberg GA. Urinary tract infection in children. [Online] [Cited
2017 November 13]. Available from URL: http://www.merckmanuals.com/home/children-s-healthissues/bacterial-infections-in-infants-and-children/urinary-tractinfection-uti-in-children
15. Saeed CH, AL-Otraqchi KIB, Mansoor IY. Prevalence of urinary tract infections and antibiotics susceptibility pattern among infants and young children in Erbil city. Zanco J Med Sci 2015;19:915-22.
16. Abuhandan M, Guzel B, Oymak Y, Ciftci H. Antibiotic sensitivity and resistance in children with urinary tract infection in Sanliurfa. Turk J Urol2013;39:106-10.
17. Adjei O, Opoku C. Urinary tract infections in African infants. Int J Antimicrob Agents 2004;24(Suppl 1):S32-4.
18. Ladhani S, Gransden W. Increasing antibiotic resistance among urinary tract isolates. Arch Dis Child 2003;88:444-5.
19. Wu CY, Chiu PC, Hsieh KS, Chiu CL, Shih CH, Chiou YH. Childhood urinary tract infection: a clinical analysis of 597 cases. Acta Paediatr Taiwan 2004;45:328-33.
20. Bouallegue O, Saidani M, Ben Mohamed S, Mzoughi R. [Bacteriologic features of urinary tract infections in children in the Sousse area, Tunisia]. Tunis Med 2004;82:742-6.
21. Yuksel S, Ozturk B, Kavaz A, Ozcakar ZB, Acar B, Guriz H, et al. Antibiotic resistance of urinary tract pathogens and evaluation of empirical treatment in Turkish children with urinary tract infections.Int J Antimicrob Agents 2006;28:413-6.
22. Kudinha T. The Pathogenesis of Escherichia coli Urinary Tract Infection. In: Samie A. Escherichia coli - Recent Advances on Physiology, Pathogenesis and Biotechnological Applications. Rijeka, Croatia: Intech, 2017; pp 45-70.
23. Hryniewicz K, Szczypa K, Sulikowska A, Jankowski K, Betlejewska K, Hryniewicz W. Antibiotic susceptibility of bacterial strains isolated from urinary tract infections in Poland. J Antimicrob Chemother 2001;47:773-80.
24. Shah SU, Ahmad A, Gul I, Rehman G. Etiology and antibiotic resistance pattern of community-acquired urinary tract infections in children. KJMS 2015;8:428-33.
25. Bagshaw SM, Laupland KB. Epidemiology of intensive care unitacquired urinary tract infections. CurrOpin Infect Dis 2006;19:67-71.
26. Niranjan V, Malini A. Antimicrobial resistance pattern in Escherichia coli causing urinary tract infection among inpatients. Indian J Med Res 2014;139:945-8.
27. Hadadi M, Malekzadegan Y, Heidari H, Sedigh Ebrahim-Saraie H, Motamedifar M. Antimicrobial resistance pattern in Escherichia coli isolates obtained from a specialized women and children hospital in Shiraz, Iran: a prevalence study. J Health Sci Surveillance Sys 2016;4:194-98.
28. Al-Mijalli SHS. Bacterial Uropathogens in Urinary Tract Infection and Antibiotic Susceptibility Pattern in Riyadh Hospital, Saudi Arabia. Cell Mol Med 2017;3:1-6.
29. Noor Shafina MN, Nor Azizah A, Mohammad AR, Faisal MF, Mohamad Ikhsan S, Hafizah Z, et al. Bacterial pathogens and antibiotic resistance patterns in children with urinary tract infection in a Malaysian tertiary hospital. Med J Malaysia 2015;70:153-7.