scholarly journals Isolasi Lactobacillus sp dari susu segar kemasan dan uji antimikroba terhadap bakteri patogen Salmonella sp dan Streptococcus mutan

2021 ◽  
Vol 3 (1) ◽  
pp. 18-22
Author(s):  
Adhayani Lubis ◽  
Oliviti Natali ◽  
Ade Arhamni ◽  
Masyitah Masyitah ◽  
Ariyanto Ariyanto ◽  
...  

Nilai gizi yang tinggi pada susu merupakan media yang baik untuk pertumbuhan berbagai macam mikroorganisme, baik yang menguntungkan maupun yang dapat membahayakan manusia. Penelitian ini bertujuan menganalisis kemampuan Lactobacillus sp  yang diisolasi dari susu segar terhadap bakteri patogen Gram (+) dan Gram (-) yaitu Salmonella sp, Streptococcus mutan secara in vitro. Hasil penelitian menunjukkan total populasi BAL pada susu segar kemasan adalah 200x108 CFU/g. Pada pewarnaan Gram menujukkan hasil pewarnaan Gram yang positif, sedangkan pada uji katalase menjukkan reaksi yang negatif dan uji aktivitas antimikroba yang menggunakan metode difusica kram MRS broth. Susu segar kemasan mampu menghambat Salmonella sp dengan zona hambat tertinggi adalah 11,925 mm sedangkan pada Streptococcus mutans mampu menghambat dengan zona tertinggi yaitu 13,45 mm.

Author(s):  
Wen-Yang Lin ◽  
Yi-Wei Kuo ◽  
Ching-Wei Chen ◽  
Yu-Fen Huang ◽  
Chen-Hung Hsu ◽  
...  

AbstractOral-nasal mucosal immunity plays a crucial role in protecting the body against bacterial and viral invasion. Safe probiotic products have been used to enhance human immunity and oral health. In this study, we verified the beneficial effects of mixed viable probiotic tablets, consisting of Lactobacillus salivarius subsp. salicinius AP-32, Bifidobacterium animalis subsp. lactis CP-9, and Lactobacillus paracasei ET-66, and heat-killed probiotic tablets, consisting of L. salivarius subsp. salicinius AP-32 and L. paracasei ET-66, on oral immunity among 45 healthy participants. Participants were randomly divided into viable probiotic, heat-killed probiotic, and placebo groups. The administration of treatment lasted for 4 weeks. Saliva samples were collected at Weeks 0, 2, 4, and 6, and Lactobacillus, Bifidobacterium and Streptococcus mutans populations and IgA concentration were measured. IgA concentrations, levels of TGF-beta and IL-10 in PBMCs cells were quantified by ELISA method. Results showed that salivary IgA levels were significantly increased on administration of both the viable (119.30 ± 12.63%, ***P < 0.001) and heat-killed (116.78 ± 12.28%, ***P < 0.001) probiotics for 4 weeks. Among three probiotic strains, AP-32 would effectively increase the levels of TGF-beta and IL-10 in PBMCs. The oral pathogen Streptococcus mutans was significantly reduced on viable probiotic tablet administration (49.60 ± 31.01%, ***P < 0.001). The in vitro antibacterial test confirmed that viable probiotics effectively limited the survival rate of oral pathogens. Thus, this clinical pilot study demonstrated that oral probiotic tablets both in viable form or heat-killed form could exert beneficial effects on oral immunity via IL-10, TGB-beta mediated IgA secretion. The effective dosage of viable probiotic content in the oral tablet was 109 CFUs/g and the heat-killed oral tablet was 1 × 1010 cells/g.


Biofouling ◽  
2021 ◽  
pp. 1-9
Author(s):  
Arval Viji Elango ◽  
Sahana Vasudevan ◽  
Karthi Shanmugam ◽  
Adline Princy Solomon ◽  
Prasanna Neelakantan

2012 ◽  
Vol 58 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Jinzhi He ◽  
Shida Wang ◽  
Tingxi Wu ◽  
Yangpei Cao ◽  
Xin Xu ◽  
...  
Keyword(s):  

2012 ◽  
Vol 78 (7) ◽  
pp. 2120-2127 ◽  
Author(s):  
Lei Liu ◽  
Huichun Tong ◽  
Xiuzhu Dong

ABSTRACTComplex interspecies interactions occur constantly between oral commensals and the opportunistic pathogenStreptococcus mutansin dental plaque. Previously, we showed that oral commensalStreptococcus oligofermentanspossesses multiple enzymes for H2O2production, especially lactate oxidase (Lox), allowing it to out-competeS. mutans. In this study, through extensive biochemical and genetic studies, we identified a pyruvate oxidase (pox) gene inS. oligofermentans. Apoxdeletion mutant completely lost Pox activity, while ectopically expressedpoxrestored activity. Pox was determined to produce most of the H2O2in the earlier growth phase and log phase, while Lox mainly contributed to H2O2production in stationary phase. Bothpoxandloxwere expressed throughout the growth phase, while expression of theloxgene increased by about 2.5-fold when cells entered stationary phase. Since lactate accumulation occurred to a large degree in stationary phase, the differential Pox- and Lox-generated H2O2can be attributed to differential gene expression and substrate availability. Interestingly, inactivation ofpoxcauses a dramatic reduction in H2O2production from lactate, suggesting a synergistic action of the two oxidases in converting lactate into H2O2. In anin vitrotwo-species biofilm experiment, thepoxmutant ofS. oligofermentansfailed to inhibitS. mutanseven thoughloxwas active. In summary,S. oligofermentansdevelops a Pox-Lox synergy strategy to maximize its H2O2formation so as to win the interspecies competition.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fatemeh Ostadhossein ◽  
Parikshit Moitra ◽  
Esra Altun ◽  
Debapriya Dutta ◽  
Dinabandhu Sar ◽  
...  

AbstractDental plaques are biofilms that cause dental caries by demineralization with acidogenic bacteria. These bacteria reside inside a protective sheath which makes any curative treatment challenging. We propose an antibiotic-free strategy to disrupt the biofilm by engineered clustered carbon dot nanoparticles that function in the acidic environment of the biofilms. In vitro and ex vivo studies on the mature biofilms of Streptococcus mutans revealed >90% biofilm inhibition associated with the contact-mediated interaction of nanoparticles with the bacterial membrane, excessive reactive oxygen species generation, and DNA fragmentation. An in vivo examination showed that these nanoparticles could effectively suppress the growth of S. mutans. Importantly, 16S rRNA analysis of the dental microbiota showed that the diversity and richness of bacterial species did not substantially change with nanoparticle treatment. Overall, this study presents a safe and effective approach to decrease the dental biofilm formation without disrupting the ecological balance of the oral cavity.


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