كليدواژه :
مدفوع نوزادان , اثر بازدارندگي , لاكتوباسيل , infant feces , Inhibitory effect , Lactobacillus
چكيده لاتين :
Introduction: Lactobacilli are the most frequent normal microflora in human ʹs gastrointestinal tract and found in feces. The aim of this study was to isolate lactobacilli from feces of children aged between 6 to 24 months who were hreust fed, formula fed or both and determine their inhibitory effect on enteric pathogens (E. soli, Salmonella, Shigella).
Methods: Samples .from 100 infant feces were collected and cultured on MRS medium. Lactobacilli were isolated and identified by standard methods (morphology, microscopic shape, fermentation of carbohydrates and biochemical tests). ʹthe growth of isolated bacteria at different temperature, pH and the inhibitory effect by spot on the lawn, blank disk and well diffusion on enteric pathogens (E. coll. Salmonella, Shigella), resistance to common antibiotics and bile were examined.
Results: The isolated bacteria were L. fermentum, L. plantarum, L. rhamnosus, L. gasseri, L. reuteri, L. crispatus, and L. acidophilus. About 67% of lactobacilli were isolated from breast fed children, 18.75%r, from formula-fed children and 13.75%. from breast and formula fed children at the same time.
Conclusion: Our results show that the number of lactobacilli in the feces of breast- fed children is predominant. It may he substances in breast milk that help better growth of lactobacilli and by producing more inhibitory substances can change the entric pH that inhibit the growth and prevent the incidence of disease such as diarrhea. Hence, breast feeding is recommended. On the other hand, the inhibitory effect of substances from isolated lactobacilli from infant feces with breast - fed children was stable at low p11 high temperature, different concentration of bile salts, so, they might he considered as probiotic bacteria.
