Monitoring the cell number of Lactococcus lactis subsp. cremoris FC in human feces by real-time PCR with strain-specific primers designed using the RAPD technique.
Strain-specific PCR primers for Lactococcus lactis subsp. cremoris FC were developed using the randomly amplified polymorphic DNA (RAPD) technique. RAPD was used to generate strain-specific markers. A 1164-bp RAPD marker found to be strain-specific was sequenced, and a primer pair specific for L. lactis subsp. cremoris FC was designed. The specificity of this primer pair was tested with 23 L. lactis subsp. cremoris strains and 20 intestinal bacterial species, and was found to be strain-specific. Subsequently, this primer pair was subjected to the quantification of L. lactis subsp. cremoris FC in the feces of subjects fed fermented milk containing this strain. After administration, L. lactis subsp. cremoris FC was detected in the feces of all 7 subjects, with the maximum number being between 10(5) and 10(9) cells g(-1) of feces. Furthermore, this strain was detected in only one feces sample 2 weeks after administration was stopped. These results suggest that L. lactis subsp. cremoris FC can survive passage through the gastrointestinal tract.
Maruo
Toshinari
T
Fujicco Co., Ltd, 6-13-4 Minatojima-nakamachi, Chuo-ku, Kobe, Hyogo 650-8558, Japan. t-maruo@fujicco.co.jp
Sakamoto
Mitsuo
M
Toda
Toshiya
T
Benno
Yoshimi
Y
D000328:Adult; D001483:Base Sequence; D015415:Biomarkers; D015169:Colony Count, Microbial; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007778:Lactobacillus / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D008297:Male; D010802:Phylogeny; D019936:Probiotics / Q000008:administration & dosage*; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods; D012680:Sensitivity and Specificity; D013045:Species Specificity
D015415:Biomarkers; D017931:DNA Primers; D004269:DNA, Bacterial