The factors of bile tolerance (as one among the fundamental characteristics of probiotic bacteria) were determined in lactococci by using plasmid variants. Bile tolerance of Lactococcus lactis wild-type (WT) strains 527 and N7 (determined by viability counts on bile-containing agar) was equivalent to the corresponding plasmid-free derivatives. In contrast, L. lactis WT strain DRC1 had lower bile tolerance than its plasmid-free derivative DRC1021. Plasmid pDR1-1B, extracted from strain DRC1, was introduced into strain DRC1021 by co-transformation with the vector plasmid pGKV21 as an indicator. Strain DRC121 (DRC1021 harboring pGKV21) had good bile tolerance as did strain DRC1021, while strain DRC13 (DRC1021 harboring both pDR1-1B and pGKV21) did not. Fatty acid (FA) composition was different between strains DRC121 and DRC13. The plasmid pDR1-1B or plasmid profile and FA composition are key factors for bile tolerance of strain DRC1, and therefore changing the plasmid profile might be a way of modulating bile tolerance in lactococci.

• MeSH
• biologické modely MeSH
• Lactococcus lactis chemie   účinky léků   genetika   fyziologie   MeSH
• mastné kyseliny chemie   metabolismus   MeSH
• plazmidy genetika   metabolismus   MeSH
• žluč MeSH
• žlučové kyseliny a soli farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• mastné kyseliny MeSH
• žlučové kyseliny a soli MeSH

A quantitative approach has been proposed to evaluate the competitive inhibition of Escherichia coli and Salmonella typhi by live and heat-inactivated laboratory isolated Lactobacillus sp. on adhesion to monolayer of Caco-2 cells. Three species of Lactobacillus (L. casei, L. acidophilus, L. agilis) isolated from human neonate feces and two commercial probiotic strains (L. casei, L. acidophilus) have been compared for probiotic activity. All lactobacilli were able to attach to the Caco-2 cells, however, the degree of adhesion was bacterial strain-dependent. The adhesion indices of the two commercial probiotic strains were not significantly different from the values obtained for the other two similar fecal strains (p > 0.01). The inhibition of attachment of the pathogenic bacteria by inactivated cells of fecal L. acidophilus was examined and compared to the results of live bacteria. The inhibition pattern was similar for live and heat-inactivated L. acidophilus (p > 0.01). The number of attached pathogenic bacteria to the Caco-2 cells decreased when the number of L. acidophilus increased from 10(6) to 10(9) CFU/mL. The heat-inactivated L. acidophilus displayed similar probiotic activity compared to the live bacteria.

• MeSH
• bakteriální adheze * MeSH
• Caco-2 buňky MeSH
• Escherichia coli fyziologie   MeSH
• feces mikrobiologie   MeSH
• Lactobacillus izolace a purifikace   fyziologie   MeSH
• lidé MeSH
• novorozenec MeSH
• probiotika izolace a purifikace   MeSH
• Salmonella typhi fyziologie   MeSH
• střeva mikrobiologie   MeSH
• vysoká teplota MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Twelve lactobacilli isolates from mucosa of 3-5-week-old weaned pigs were found to exert good antimicrobial activity against common porcine pathogens (S. aureus, B. cereus, E. coli, C. perfringens). Two of them produced in addition to lactic acid also considerable amounts of acetic acid, and 6 of them produced hydrogen peroxide and metabolites other than organic acids. Isolates 4/26 and 2/25 (identified as L. crispatus or L. amylovorus) were inhibitory against most strains of S. aureus, B. cereus and E. coli, and especially the strain 4/26 survived well in simulated gastric and intestinal juice. Diarrhea-causing E. coli O8K88H9 Ent(+) was successfully inhibited by the growing culture as well as by the catalase-treated and neutralized supernatant of L. reuteri 12/26. Mucin degradation and multiple resistance to antibiotics were not observed.

• MeSH
• antibiotická rezistence MeSH
• Bacillus cereus účinky léků   MeSH
• Clostridium perfringens účinky léků   MeSH
• Escherichia coli účinky léků   MeSH
• feces mikrobiologie   MeSH
• ileum mikrobiologie   MeSH
• kultivační média speciální farmakologie   MeSH
• kultivační média chemie   farmakologie   MeSH
• kyselina mléčná farmakologie   MeSH
• Lactobacillus účinky léků   izolace a purifikace   metabolismus   MeSH
• muciny metabolismus   MeSH
• nemoci prasat prevence a kontrola   MeSH
• odstavení MeSH
• peroxid vodíku metabolismus   MeSH
• přirozená imunita MeSH
• probiotika MeSH
• Staphylococcus aureus účinky léků   MeSH
• střevní sliznice mikrobiologie   MeSH
• Sus scrofa mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kultivační média speciální MeSH
• kultivační média MeSH
• kyselina mléčná MeSH
• muciny MeSH
• peroxid vodíku MeSH