Occurrence and Diagnostic Evaluation of Colistin Resistance among Pediatric patients

Background: The world is now facing a formidable from the emergence of bacteria that are resistant to almost all available antibiotics. There won't be any new antibiotics to combat these "superbugs", there is now renewed interest in reviving older antibiotics that were for clinical use, especially the polymyxins (colistin and polymyxin B), to be used as "last resort" antimicrobials. Objectives: This work aims to detect colistin resistance in Gram negative bacteria using broth microdilution, colistin broth disc elution, and PCR for mcr-1 colistin resistance gene. Methodology: Samples were collected from 50 hospitalized pediatric patients. Antibiotic susceptibility was assessed by disk diffusion and VITEK-2. Colistin susceptibility tests by disk elution and broth microdilution and mcr-1 gene PCR. Results: Mean age of our patients was (65.9±54.9) days. Most common isolates were Klebsiella spp. (86%). All isolates were resistant to b-lactams, Colistin resistance was 40%. The mcr-1 were revealed in 12 isolates. No impact of mcr-1 on antibiotic sensitivity. Higher percentage of cases with positive mcr-1 were resistant by colistin Broth micro dilution. Sensitivity and specificity of Colistin broth disc elution were 100%. No statistical significance difference in age, Colistin previous administration, or mechanical ventilation as regards result of broth Micro dilution. Conclusion: Our study underlines critical need of improved infection control strategies, antimicrobial stewardship, to fight multidrug-resistant infections in pediatrics. Patient outcomes are seriously threatened by the great resistance rates to several antibiotics, especially last-resort treatments as colistin. Future studies are needed to clarify the genetic factors of colistin resistance.