The investigation and clinical reflection of the production frequency of ESBL and carbapenemase and enzyme types in enterobacteriaceae family members mediated pediatric urinary tract infections

Urinary tract infection (UTI) is a common and crucial clinical problem in childhood. Enterobacteriaceae, producing extended-spectrum beta-lactamase (ESBL) and resistant to third-generation cephalosporins are becoming widely common in the pediatric population. The aim of this study was to investigate the frequency of ESBL and carbapenemase production and enzyme types in Enterobacteriaceae family members, which underlie pediatric urinary tract infections. 268 Enterobacteriaceae strains isolated from patients for whom urine culture tests were requested in Pediatric Polyclinic and/or Clinic because of suspected UTI were included in the study. ESBL and carbapenemase enzyme production were evaluated in these isolates. Additionally, clinical features and treatment methods of 109 ESBL positive UTI patients were retrospectively reviewed in hospital registry. For the determination of ESBL in Enterobacteriaceae isolates, phenotypic test combined disk method was initially used. Genotype of ESBL positive isolates were evaluated by conventional polymerase chain reaction (PCR) test. Of 109 patients with UTI, 72 (66.1%) were female and 37 (33.9%) were male; The mean age was found to be 75.15 ± 65.41 (1-206) months. Fifty-eight (55.2%) patients were treated as outpatients and 51 (44.8%) patients were hospitalized and received parenteral treatment. Whereas Cefixime was the most commonly preferred agent among oral empiric antibiotics (67.5%), cephalosporins were the most common empirical parenteral antibiotics (75%). The treatment duration of the patients who had changed antibiotic treatment after following culture test was found to be statistically longer than the patients without change (p <0.001). Among the ESBL-producing Enterobacteriaceae isolates (n: 109), E. coli (n = 85, 78%) and K. pneumoniae (n = 18, 16.5%) were the most common causative agents. Carbapenem resistance was determined by phenotypic tests in 13 (4.9%) of 268 isolates. Since 11 of the samples were determined to be contaminated, no further analysis applied. Phenotypic carbapenem resistance was found to be 1.8% (n = 2) in isolates with UTI only. Of the 268 ESBL-positive isolates, 197 strains were tested for enzyme types. The most frequently isolated strain was E. coli (n = 143, 72.5%). CTX-M was found in 149 (75.6%), TEM in 103 (52.2%), SHV in 8 (4%), and IMP in 1 (0.5%) of these isolates. The enzyme isolates of 1 patient with carbapenem resistance were TEM+IMP. Genotypically, carbapenem resistance was 0.4% for all isolates and 0.9% for UTI alone. Clinical and laboratory response was observed in 43% of patients with cephalosporin treatment though ESBL was positive (n = 24). However, the inoculum effect of cephalosporins should be considered in ESBL positive infections, and close laboratory and clinical response monitoring is required. Of the 268 urine specimens isolated from ESBL, 159 were considered to be contamination; however, this rate was higher than the rates reported by other studies if considered to be caused by intestinal flora. Hence, further studies are required to obtain our regional data with a well-standardized randomized-controlled study for ESBL positive Enterobacteriaceae carriage and colonization. In conclusion, it is clear that the identification of the presence and types of carbapenemase enzymes, which brings treatment options almost to zero, at local and national level, will contribute to rational antibiotic use. Adequate infection control, rapid detection of resistant bacteria and antibiotic responsibility are important in order to stop the spread of ESBL-producing bacteria. Keywords: Child, Enzyme Isolates, ESBL, Carbapenem, Urinary Tract Infection