Microbial Etiology and Antibiotic Resistance Patterns of Urinary Tract Pathogens in Hospitalized Infants in Bahrain: A Tertiary Care Center Experience

Introduction: Urinary tract infections (UTIs) are fairly common in infants. Early diagnosis and prompt treatment are crucial to avoid complications. However, providing appropriate antibiotic treatment is a challenge to any clinician considering the rise in the urinary pathogens that are resistant to the commonly used antibiotics especially with the emergence of extended-spectrum beta-lactamase (ESBL)-producing organisms. Consequently, this leaves the physician with limited options of antibiotic choices. This study aims to investigate the local resistance patterns of uropathogens causing UTIs in hospitalized infants in Bahrain and to provide guidance for the preferred choice of empirical antibiotic treatment. Methods: A retrospective cross-sectional study with an analysis of the medical records of infants from birth to one year of age admitted with UTIs at Salmaniya Medical Complex between June 2015 and June 2017 was conducted. Results: Data were obtained from 117 term infants (no preterm infants were included), with 80 (68.4%) being male. A total of 106 (90.6%) patients were less than six months of age. The most frequently isolated organisms were Escherichia coli found in 66 (49.6%) patients, followed by Klebsiella in 43 (32.3%). Forty-eight (36%) were ESBL-producing organisms (31 and 17 of E. coli and Klebsiella, respectively). The highest antibiotic resistance of E. coli was found against cephalosporin (55.5%), while penicillin resistance was only 19.4% and co-trimoxazole was 14.4%. Resistance rates of non-E. coli organisms were highest against cephalosporin (44.6%), followed by nitrofurantoin (19.1%) and penicillin (18.5%). The overall resistance to cephalosporin antibiotics was highest against cephalothin (a first-generation cephalosporin) (54.9%). The second highest resistance rate was demonstrated against cefuroxime (a second-generation cephalosporin) (50.5%), followed by ceftriaxone (a third-generation cephalosporin) (45.1%). Lower resistance rates were found against cefotaxime (22.3%), followed by ceftazidime (33.3%). A resistance rate of zero was found against cefepime (a fourth-generation cephalosporin). Aminoglycosides and nitrofurantoin demonstrated the lowest resistance rates among all cultured uropathogens. Among all cultures, 3.9% of the E. coli were resistant to aminoglycosides, while non-E. coli organisms showed zero resistance to aminoglycosides. Regarding the nitrofurantoin antibiotic, 19% of non-E. coli bacteria showed resistance, while only 1.7% of E. coli were resistant to this antibiotic. Zero resistance to carbapenem was found in E. coli organisms (both ESBL and non-ESBL), compared to 1.9% resistance by non-E. coli organisms (both ESBL and non-ESBL combined). Conclusion: E. coli is the predominant uropathogen causing UTI in infants with high rates of ESBL organisms in our community. Since the highest resistance was found against cephalosporins, aminoglycosides and nitrofurantoin are the preferred empirical antibiotic options for the treatment of UTIs. For infants with ESBL organisms, carbapenem antibiotics represent a good treatment option.