Detection and partial characterization of a bacteriocin-like substance produced by Lactobacillus fermentum CS57 isolated from human vaginal secretions.
Lactobacilli (150) from human vaginal secretions were tested for the production of antimicrobial substances which can provide a physiological defense against the pathogenic microorganisms in the vaginal area. Sixteen of the isolates (10.6%) showed antibacterial activity against one or several closely related microorganisms used as indicators. Lactobacillus fermentum CS57 was the best producer and secretes a bacteriocin-like substance (BLS) with antagonistic activity against Streptococcus agalactiae and Candida albicans. The compound was susceptible to the proteolytic enzymes and was heat labile. The mode of action was identified as bactericidal. The crude activity of the L. fermentum CS57 BLS was linked to a substance with a molecular weight larger than 30 kDa. Plasmid analysis of L. fermentum CS57 revealed the presence of a plasmid band with molecular weight of 54.7 kb. All L. fermentum CS57 non-producer variants (BLS-) obtained by curing experiments, showed loss of plasmid band and were susceptible to the BLS of the original strain. Therefore antimicrobial activity and immunity production seem to be linked to genes located on that same plasmid. Taking into account our results, L. fermentum CS57 could be considered a candidate for potential use as probiotic for the prophylaxis of vaginal human infections.
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy. Electronic address: carla.sabia@unimore.it.
Carla
C
Sabia
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Immacolata
I
Anacarso
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Alberto
A
Bergonzini
Provincial Laboratory of Clinical Microbiology, S. Agostino-Estense Hospital, Modena, Italy.
Raffaele
R
Gargiulo
Provincial Laboratory of Clinical Microbiology, S. Agostino-Estense Hospital, Modena, Italy.
Mario
M
Sarti
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Carla
C
Condò
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Patrizia
P
Messi
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Simona
S
de Niederhausern
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Ramona
R
Iseppi
Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
Moreno
M
Bondi
D000328:Adult; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000898:Antibiosis; D001430:Bacteriocins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D005260:Female; D006801:Humans; D052197:Limosilactobacillus fermentum / Q000302:isolation & purification* / Q000378:metabolism*; D008875:Middle Aged; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000378:metabolism; D055550:Protein Stability; D013292:Streptococcus agalactiae / Q000187:drug effects; D013696:Temperature; D014621:Vagina / Q000382:microbiology; D055815:Young Adult
D000890:Anti-Infective Agents; D001430:Bacteriocins; D010447:Peptide Hydrolases
Antimicrobial activity; Bacteriocin-like substance; Streptococcus agalactiae; Vaginal lactobacilli