scholarly journals AVALIAÇÃO DO EFEITO PROBIÓTICO DE Lactobacillus rhamnosus V5 CONTRA SALMONELLA ENTERICA sorovariedade Typhimurium.

2019 ◽  
pp. 231-240
Author(s):  
Carina Terumi Tsuruda ◽  
Patrícia Canteri De Souza ◽  
Erick Kenji Nishio ◽  
Ricardo Sérgio Couto de Almeida ◽  
Luciano Aparecido Panagio ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Lactobacillus Rhamnosus

scholarly journals Influence of Bacterial Competitors on Salmonella enterica and Enterohemorrhagic Escherichia coli Growth in Microbiological Media and Attachment to Vegetable Seeds

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 285
Author(s):  
Da Liu ◽  
Ronald Walcott ◽  
Kevin Mis Solval ◽  
Jinru Chen
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Lactobacillus Rhamnosus ◽  
Probiotic Bacterium ◽  
Enterohemorrhagic Escherichia Coli ◽  
Biocontrol Agents ◽  
Human Pathogens ◽  
Bacterial Strains ◽  
Pathogen Populations

Interests in using biological agents for control of human pathogens on vegetable seeds are rising. This study evaluated whether probiotic bacterium Lactobacillus rhamnosus GG, bacterial strains previously used as biocontrol agents in plant science, as well as a selected plant pathogen could compete with foodborne human pathogens, such as Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC), for growth in microbiological media and attachment to vegetable seeds; and to determine whether the metabolites in cell-free supernatants of competitive bacterial spent cultures could inhibit the growth of the two pathogens. The results suggest that the co-presence of competitive bacteria, especially L. rhamnosus GG, significantly (p < 0.05) inhibited the growth of Salmonella and EHEC. Cell-free supernatants of L. rhamnosus GG cultures significantly reduced the pathogen populations in microbiological media. Although not as effective as L. rhamnosus GG in inhibiting the growth of Salmonella and EHEC, the biocontrol agents were more effective in competing for attachment to vegetable seeds. The study observed the inhibition of human bacterial pathogens by competitive bacteria or their metabolites and the competitive attachment to sprout seeds among all bacteria involved. The results will help strategize interventions to produce vegetable seeds and seed sprouts free of foodborne pathogens.

scholarly journals pH-, Lactic Acid-, and Non-Lactic Acid-Dependent Activities of Probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium

2005 ◽  
Vol 71 (10) ◽  
pp. 6008-6013 ◽  
Author(s):  
Domitille Fayol-Messaoudi ◽  
Cédric N. Berger ◽  
Marie-Hélène Coconnier-Polter ◽  
Vanessa Liévin-Le Moal ◽  
Alain L. Servin
Keyword(s):  
Lactic Acid ◽  
Growth Phase ◽  
Salmonella Enterica ◽  
Lactobacillus Rhamnosus ◽  
Stationary Growth Phase ◽  
Exponential Growth Phase ◽  
Killing Activity ◽  
Serovar Typhimurium ◽  
Probiotic Strains ◽  
Probiotic Lactobacilli

ABSTRACT The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.

scholarly journals Propriedades probióticas in vitro de Lactobacillus spp. isolados de queijos minas artesanais da Serra da Canastra - MG

2014 ◽  
Vol 66 (5) ◽  
pp. 1592-1600 ◽  
Author(s):  
C.R.G. Andrade ◽  
M.R. Souza ◽  
C.F.A.M. Penna ◽  
L.B. Acurcio ◽  
F.M. Sant'Anna ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Lactobacillus Plantarum ◽  
Enterococcus Faecalis ◽  
Salmonella Enterica ◽  
Lactobacillus Rhamnosus ◽  
Lactobacillus Spp

O objetivo deste estudo foi determinar o potencial probiótico in vitro de Lactobacillus spp. isolados de queijos minas artesanais da Serra da Canastra, considerando-se o antagonismo entre amostras isoladas frente a microrganismos indicadores, a susceptibilidade a antimicrobianos, a sensibilidade ao ácido gástrico e a sensibilidade a sais biliares. Todas as bactérias ácido-lácticas testadas apresentaram resistência ao ácido gástrico (pH 2,0) e aos sais biliares (0,3%), bem como atividade antagonista contra Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica var. Typhimurium, Enterococcus faecalis e bactérias ácido-lácticas isoladas dos próprios queijos - Lactobacillus plantarum (D27) e Lactobacillus rhamnosus (B25). Todas as amostras foram sensíveis à eritromicina e tetraciclina e resistentes à ciprofloxacina, gentamicina, oxacilina, estreptomicina e vancomicina. L. plantarum(B17) apresentou melhor potencial probiótico, pois obteve resultados satisfatórios em todas as propriedades avaliadas. Mais estudos são necessários para verificar a presença e a capacidade de transmissão de genes de resistência antimicrobiana a outros microrganismos e para avaliar o potencial dos microrganismos in vivo. As bactérias selecionadas poderão ser utilizadas na elaboração de queijos em que sejam mantidos o sabor e a tradição do queijo minas artesanal do estado de Minas Gerais.

scholarly journals A Lactobacillus rhamnosus strain induces protection in different sites after Salmonella enterica subsp. enterica serovar Typhimurium challenge in gnotobiotic and conventional mice

2014 ◽  
Vol 66 (2) ◽  
pp. 347-354 ◽  
Author(s):  
A.H. Mendonça ◽  
M.M.O.P. Cerqueira ◽  
J.R. Nicoli ◽  
S.M.M. Sousa ◽  
R.M.D. Nardi ◽  
...  
Keyword(s):  
Protective Effect ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Lactobacillus Rhamnosus ◽  
Colony Forming Unit ◽  
Human Newborn ◽  
Probiotic Treatment ◽  
Serovar Typhimurium ◽  
And Control

The ability of a Lactobacillus rhamnosus strain isolated from a healthy breast-fed human newborn to reduce the pathological consequences for the host due to an experimental oral infection with Salmonella enterica subsp. enterica serov. Typhimurium in vivo was determined using gnotobiotic and conventional mice. Conventional mice received 0.1mL probiotic milk (8.0 log colony-forming unit) daily for 10 days before the oral pathogenic challenge (5.0 log colony-forming unit). Then probiotic treatment was continued until the end of the experiment. Probiotic treatment in germ-free mice consisted of a single dose of the probiotic milk at the beginning of the experiment and a challenge with S. Typhimurium 10 days later (3.0 log colony-forming unit). A protective effect was observed in both gnotobiotic and conventional animals in terms of histopathologic and morphometric data, but in different anatomical sites. This protection was observed in liver and intestines, respectively, for gnotobiotic and conventional mice. However, S. Typhimurium populations were similar in the feces of both treated and control gnotobiotic mice. We conclude that a protective effect of L. rhamnosus against experimental S. Typhimurium was observed. This protection was not due to the reduction of the population of pathogenic bacteria in the intestine.

scholarly journals Evaluación del efecto antimicrobiano de una mezcla de probióticos frente a Cronobacter sakazakii y Salmonella enterica en preparados para lactantes reconstituidos para lactantes

2020 ◽  
Vol 34 ◽  
pp. 27-37
Author(s):  
C. Candel-Pérez ◽  
R. García-Iborra ◽  
J. García-Alonso ◽  
Mª Carmen Martínez-Gracia
Keyword(s):  
Salmonella Enterica ◽  
Incubation Temperature ◽  
Lactobacillus Rhamnosus ◽  
Antimicrobial Effect ◽  
Cronobacter Sakazakii ◽  
Inhibitory Mechanism ◽  
Bifidobacterium Infantis ◽  
Ph Values ◽  
Infant Formulae ◽  
Temperature Interaction

Cronobacter sakazakii y Salmonella enterica son considerados patógenos capaces de causar sepsis y meningitis en lactantes. Se han descrito casos de infección por estos patógenos asociados al consumo de preparados para lactantes contaminados. La inclusión de probióticos en los preparados, además de su papel en la modulación de la microbiota intestinal, podría ser útil para contrarrestar la contaminación de microorganismos patógenos de estos productos una vez reconstituidos y, por lo tanto, reducir el riesgo de infección. El objetivo de esta investigación fue evaluar el efecto antimicrobiano de una mezcla de probióticos (Lactobacillus rhamnosus y Bifidobacterium infantis) frente a Cronobacter sakazakii y Salmonella enterica en preparados reconstituidos para lactantes. Las muestras (con o sin probióticos) se inocularon con C. sakazakii o S. enterica y se incubaron a 30 o 40ºC durante 72 horas. Los resultados muestran que la presencia de probióticos en los preparados lácteos no tiene un marcado efecto en el crecimiento de los patógenos. Sin embargo sí se ve potenciado su efecto inhibitorio frente a C. sakazakii por la interacción entre la temperatura de incubación y los probióticos. Los probióticos empleados fueron viables durante todo el período de incubación, por lo que el agotamiento de los nutrientes se descartó como posible mecanismo de inhibición. La disminución del pH en los preparados lácteos inoculados no explica de manera satisfactoria un comportamiento tan diferente entre ambos patógenos. Por lo tanto, se sugiere como posible mecanismo inhibidor la liberación de bacteriocinas específicas con acción contra C. sakazakii pero sin efecto contra Salmonella. Se deben realizar estudios adicionales para probar esta hipótesis.   Cronobacter sakazakii and Salmonella enterica have been implicated in outbreaks causing sepsis and meningitis in infants. Several infection cases have been associated with the consumption of contaminated powdered infant formulae. Besides its role in modulating gut microbiota, the inclusion of probiotics in infant formulae may be useful to counteract pathogen contamination in these products and thus to reduce the risk of infection. The aim of this research was to evaluate the antimicrobial effect of a mixture of the probiotics Lactobacillus rhamnosus and Bifidobacterium infantis against Cronobacter sakazakii and Salmonella enterica in reconstituted follow-on formulae. For that, infant formulae (with or without probiotics) were inoculated with either C. sakazakii or S. enterica and incubated at 30 or 40ºC for 72 hours. Overall, the results showed the presence of probiotics inhibiting the growth of C. sakazakii together with incubation temperature (interaction between both factors). Probiotics were viable throughout the incubation period so that nutrient exhaustion could be ruled out as the mechanism of C. sakazakii inhibition. Thus, the acidification of media observed during the study was hypothesized to be responsible for pathogen growth inhibition. However, since in the case of formulae inoculated with Salmonella the behavior of probiotics and pH values was similar to C. sakazakii, the decrease of pH does not satisfactorily explain such a different behavior. So, it is suggested that the production of specific bacteriocins by probiotics against C. sakazakii but not against Salmonellla could be the underlying inhibitory mechanism. Further studies should be carried out to test this hypothesis.

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