Isolation, identification and characterisation of three novel probiotic strains (Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036) from the faeces of exclusively breast-fed infants.
The aim of the present study was to isolate, identify and characterise novel strains of lactic acid bacteria and bifidobacteria with probiotic properties from the faeces of exclusively breast-fed infants. Of the 4680 isolated colonies, 758 exhibited resistance to low pH and tolerance to high concentrations of bile salts; of these, only forty-two exhibited a strong ability to adhere to enterocytes in vitro. The identities of the isolates were confirmed by 16S ribosomal RNA (rRNA) sequencing, which permitted the grouping of the forty-two bacteria into three different strains that showed more than 99 % sequence identity with Lactobacillus paracasei, Lactobacillus rhamnosus and Bifidobacterium breve, respectively. The strain identification was confirmed by sequencing the 16S-23S rRNA intergenic spacer regions. Strains were assayed for enzymatic activity and carbohydrate utilisation, and they were deposited in the Collection Nationale de Cultures de Microorganismes (CNCM) of the Institute Pasteur and named L. paracasei CNCM I-4034, B. breve CNCM I-4035 and L. rhamnosus CNCM I-4036. The strains were susceptible to antibiotics and did not produce undesirable metabolites, and their safety was assessed by acute ingestion in immunocompetent and immunosuppressed BALB/c mouse models. The three novel strains inhibited in vitro the meningitis aetiological agent Listeria monocytogenes and human rotavirus infections. B. breve CNCM I-4035 led to a higher IgA concentration in faeces and plasma of mice. Overall, these results suggest that L. paracasei CNCM I-4034, B. breve CNCM I-4035 and L. rhamnosus CNCM I-4036 should be considered as probiotic strains, and their human health benefits should be further evaluated.
Department of Biochemistry and Molecular Biology II, Instituto de Nutrición y Tecnología de los Alimentos José Mataix (INyTA), Centro de Investigación Biomédica (CIBM), Universidad de Granada, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain.
Sergio
S
Muñoz-Quezada
Empar
E
Chenoll
José María
JM
Vieites
Salvador
S
Genovés
José
J
Maldonado
Miriam
M
Bermúdez-Brito
Carolina
C
Gomez-Llorente
Esther
E
Matencio
María José
MJ
Bernal
Fernando
F
Romero
Antonio
A
Suárez
Daniel
D
Ramón
Angel
A
Gil
D000818:Animals; D000898:Antibiosis; D001422:Bacterial Adhesion; D001644:Bifidobacterium / Q000145:classification / Q000254:growth & development* / Q000276:immunology / Q000302:isolation & purification*; D001942:Breast Feeding; D020895:Enterocytes / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D018928:Immunity, Mucosal; D016867:Immunocompromised Host; D007231:Infant, Newborn; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development* / Q000276:immunology / Q000302:isolation & purification*; D052201:Lacticaseibacillus rhamnosus / Q000145:classification / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D008089:Listeria monocytogenes / Q000254:growth & development; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D050296:Microbial Viability; D019936:Probiotics / Q000009:adverse effects / Q000302:isolation & purification* / Q000627:therapeutic use; D012401:Rotavirus / Q000254:growth & development; D013030:Spain; D013047:Specific Pathogen-Free Organisms