مجلة مركز بحوث التقنيات الاحيائية (Dec 2022)
Enhancement of anti-bactericidal and anti-biofilm activities of silver nanoparticles against multidrug-resistant enteric pathogens isolated from children with diarrhea
Abstract
Background: Gastroenteritis has a significant mortality and morbidity incidence in children globally. Antimicrobial resistance in Enterobacteriaceae is a serious public health problem, especially in developing countries. Objective: The present study aimed to evaluate the anti-bacterial and anti-biofilm activities of AgNPs alone and in combination with kanamycin against multidrug- resistant Enterobacteriaceae and P. aeruginosa isolated from diarrheal children. Materials and methods: 90 Enterobacteriaceae and P. aeruginosa isolates from diarrheal children were evaluated against 10 antibiotics. Minimum inhibitory doses of AgNPs and kanamycin were determined using broth microdilution, synergistic was determined using Checkerboard dilution tests, and the Calgary technique was used to analyze biofilm development. Results: A total of 90 stool cultures were conducted for bacteria associated with diarrhea among children attending some Baghdad hospitals. The findings revealed that bacterial diarrhea was most often caused by E. coli 31 (34.5%), followed by S. typhi 19 (21.1%), K. pneumoniae 14 (15.5%), P. aeruginosa 11 (12.2%) and S. sonnei 6 (6.7%), and significant variations between the strain's species were discovered using statistical analysis (P < 0.05). The present study's findings revealed that bacteria isolated from children with diarrhea were spread significantly in age groups of 37–48 months and significantly different between age groups (P < 0.05), with a male/female ratio of 0.57/1. Imipenem and amikacin were the most active antibiotics compared to penicillin, which was the least effective antibiotic. The combination of sublethal doses of AgNPs with sub-MIC (½MIC) of kanamycin exhibited substantial synergistic bactericidal effects against MDR-Enterobacteriaceae. AgNPs inhibited biofilm formation by 55%–65% for diarrhea-causing bacteria, while the combination of AgNPs with kanamycin demonstrated the strongest biofilm inhibition of around 80%–90% against MDR-Enterobacteriaceae with a highly significant variation (P < 0.05). Conclusions: The outcomes of the research shows that the combination of AgNPs with kanamycin has remarkable synergistic bactericidal and anti-biofilm effectiveness against MDR-Enterobacteriaceae isolated from diarrheal children.
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