The antibacterial effect of infantile fecal Lactobacillus against Escherichia coli causing healthcare-associated infection

Abstract

Background: Healthcare-associated infections (HAIs) are a major public health problem worldwide. Increasing resistance of HAIs agents to conventional antibiotics also becomes a major therapeutic challenge for physicians. The aim of this research was to determine the antibacterial properties of Lactobacillus plantarum and Lactobacillus fermentum isolated from the stool of healthy infants against Escherichia coli causing HAI. Methods: Healthy infantile fecal samples and HAIs-origin samples (urine, blood, and etc.) were collected. Phenotypic isolation and characterization were done. Genotypic identification of lactic acid bacteria was performed by 16S rRNA gene sequencing. The antibiotic susceptibility test was performed using disc diffusion method. Antagonistic effect of Lactobacillus strains by well diffusion method. Results: Of 105 HAI-origin isolates, 25 were identified as E. coli., L. plantarum, and L. fermentum had more probiotic potential. E. coli isolates showed high resistance to Ceftriaxone, Cotrimoxazole, and Ciprofloxacin. Examined Lactobacillus species showed a significant inhibitory effect against E. coli isolates. Conclusion: L. plantarum had considerable inhibitory activity against E. coli isolates with HAIs-origin that were resistant to the most conventional antibiotics.