Antimicrobial Susceptibility Pattern and ESBL Production among Uropathogenic Escherichia coli Isolated from UTI Children in Pediatric Unit of a Hospital in Kerman, Iran

Aims: Emergence of antibiotic resistance and extended spectrum β- lactamase (ESBL) among uropathogens in the pediatric unit of hospitals created serious health care concern. This study deals with antimicrobial susceptibility and ESBL analysis of uropathogenic Escherichia coli isolated from children hospitalized in pediatric unit of a university hospital in Kerman, Iran.
Methodology: Fifty-five uropathogens positive samples were recovered from one hundred thirty five samples collected from urine of the children hospitalized with sign of UTI in pediatric unit of a hospital, in Kerman, Iran from April 2011 to November 2012.
Preliminary antimicrobial susceptibility testing was carried out using agar disk-diffusion breakpoint assay and minimum inhibitory concentrations (MICs) of different antibiotics were determined by agar dilution method. ESBL production was detected by a double disk synergy test and confirmed by a phenotypic confirmatory test.
Results: Of fifty-five positive samples isolated, Escherichia coli (69%) was the leading uropathogen followed by Klebsiella spp. (18.8%), Proteus (7.27%), Staphylococcus aureus (3.63%), Citrobacter (1.8%), Enterobacter spp. (1.81%) and Enterococcus (1.8%). Antimicrobial susceptibility tests revealed that almost all uropathogenic E. coli were sensitive to carbapenems (100%) and amikacin (94.4%), while, 100% of the strains were resistant to ampicillin (MIC range ±32 µg/mL), 63.8% were resistant to amoxicillin/clavulanic acid (MIC range ±32µg/mL), 33% were resistant to trimethoprim- sulfamethoxazole (MIC range ±64.2µg/mL) and 61.1% of the strains were resistant to third generation of cephalosporins (MIC range ±8.0µg/mL) (P=0.05). The ESBL confirmatory test for uropathogenic E. coli isolates resistant to third generation of cephalosporins revealed that only 20% were produced detectable ESBL enzymes.
Conclusion: From above results it can be concluded that E. coli was the most common nosocomial pathogen associated with UTI among hospitalized children in our hospital and amikacin, carbapenems were very effective drugs for treatment of UTI in these age group, while, care must be taken when third generation of cephalosporins and trimethoprim- sulfamethoxazole are administered.