ABSTRACT
Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.
Subject(s)
Animals , Bacteriocins/metabolism , Goats , Lactococcus lactis/isolation & purification , Lactococcus lactis/metabolism , Milk/microbiology , Probiotics , Bacterial Adhesion , Bile/metabolism , Food Safety/methods , Hydrogen-Ion Concentration , Lactococcus lactis/drug effects , Listeria monocytogenes/physiology , Microbial Viability/drug effectsABSTRACT
Lactococcus lactis cremoris infections are very rare in humans. We experienced liver abscess and empyema due to L. lactis cremoris in an immunocompetent adult. A 42-yr-old man was admitted with fever and abdominal pain. Abdominal computed tomography (CT) revealed a liver abscess and chest CT showed loculated pleural effusion consistent with empyema. L. lactis cremoris was isolated from culture of the abscess material and blood. The patient was treated with pus drainage from liver abscess, video-assisted thoracoscopic decortications for empyema, and antibiotics including cefotaxime and levofloxacin. The patient was completely recovered with the treatment. To our knowledge, this is the first report of a L. lactis cremoris infection in Korea.
Subject(s)
Adult , Humans , Male , Anti-Bacterial Agents/therapeutic use , Cefotaxime/therapeutic use , Drainage , Empyema/diagnosis , Gram-Positive Bacterial Infections/complications , Lactococcus lactis/drug effects , Liver Abscess/diagnosis , Microbial Sensitivity Tests , Ofloxacin/therapeutic use , Thoracic Surgery, Video-Assisted , Tomography, X-Ray ComputedABSTRACT
Os bacteriófagos podem causar a destruiçäo das bactérias láticas. Foram estudadas 35 formulaçöes de meios de cultura para Lactococcus com a capacidade de reduzir a infecçäo pelos bacteriófagos. Diferentes concentraçöes de polifosfatos ou misturas de polifosfatos e citrato, ambas associadas ou näo a fatores de crescimento bacteriano, foram testadas. Os parâmetros utilizados para comparaçäo entre os meios foram: capacidade tamponante, crescimento de L. lacts subsp. lactis ITAL 353 e a capacidade de inibir a multiplicaçäo do bacteriófago virulento 025. O leite desnatado a 12% foi usado como controle. Verificou-se que todos os meios possuíam boa capacidade tamponante. As concentraçöes acima de 6% de polifosfatos inibiram o crescimento bacteriano, exceto onde estavam presentes de 1% a 1,5% de extrato de levedura. Quatro meios contendo 5% de polifosfatos e um meio contendo também 5% de polifosfatos e 0,4% de citrato foram considerados adequados para inbir a multiplicaçäo de bacteriófagos e promover bom crescimento bacteriano