scholarly journals Organic acids and 2,4-Di-tert-butylphenol: major compounds of Weissella confusa WM36 cell-free supernatant against growth, survival and virulence of Salmonella Typhi

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8410
Author(s):  
Wattana Pelyuntha ◽  
Chaiyavat Chaiyasut ◽  
Duangporn Kantachote ◽  
Sasithorn Sirilun
Keyword(s):  
Lactic Acid ◽  
Typhoid Fever ◽  
Organic Acids ◽  
Systemic Disease ◽  
Salmonella Typhi ◽  
Effector Proteins ◽  
Inappropriate Use ◽  
Protective Actions ◽  
Cell Free Culture Supernatant ◽  
Weissella Confusa

Background Salmonella Typhi (S. Typhi), the causative agent of typhoid fever, causes serious systemic disease in humans. Antibiotic treatment is required for the S. Typhi infection, while the inappropriate use of antibiotics causes increased drug-resistant S. Typhi. Hence, alternative therapies through non-antibiotic approaches are urgently needed. The use of beneficial lactic acid bacterium and/or its metabolites to control typhoid fever represent a promising approach, as it may exert protective actions through various mechanisms. Method In this study, the cell-free culture supernatant (CFCS) of Weissella confusa WM36 was evaluated via the antibacterial activity, and its metabolites were identified. In addition, the effects of CFCS on Salmonella virulence behaviors were also investigated. Result Based on strong inhibition the growth of S. Typhi DMST 22842, organic acids (lactic acid and acetic acid) and 2,4-Di-tert-butylphenol (2,4 DTBP), were the main antibacterial metabolites presented in CFCS of strain WM36. Minimum inhibitory concentration (MIC) at 40% WM36–CFCS dramatically reduced the S. Typhi population to more than 99.99% at 4 h and completely inhibited biofilm formation, while sub-MIC at 20% (v/v) and MIC could reduce 100% of motility. Additionally, sub-MIC at only 10% (v/v) WM36–CFCS did down-regulate the expression of virulence genes which are responsible for the type-III secretion system, effector proteins, and quorum sensing system in this pathogen. Conclusion W. confusa WM36 and its metabolites are shown to be a promising candidates, and an effective approach against typhoid Salmonella burden.

scholarly journals Typhoid toxin provides a window into typhoid fever and the biology of Salmonella Typhi

2016 ◽  
Vol 113 (23) ◽  
pp. 6338-6344 ◽  
Author(s):  
Jorge E. Galán
Keyword(s):  
Typhoid Fever ◽  
Systemic Disease ◽  
Salmonella Typhi ◽  
Health Concern ◽  
Human Pathogen ◽  
Prevention Strategies ◽  
Public Health Concern ◽  
Life Threatening ◽  
Typhoid Toxin ◽  
Insight Into

Salmonella Typhi is the cause of typhoid fever, a disease that has challenged humans throughout history and continues to be a major public health concern. Unlike infections with most other Salmonellae, which result in self-limiting gastroenteritis, typhoid fever is a life-threatening systemic disease. Furthermore, in contrast to most Salmonellae, which can infect a broad range of hosts, S. Typhi is a strict human pathogen. The unique features of S. Typhi pathogenesis and its stringent host specificity have been a long-standing puzzle. The discovery of typhoid toxin not only has provided major insight into these questions but also has offered unique opportunities to develop novel therapeutic and prevention strategies to combat typhoid fever.

scholarly journals Brewers’ spent grain as substrate for dextran biosynthesis by Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Prabin Koirala ◽  
Ndegwa Henry Maina ◽  
Hanna Nihtilä ◽  
Kati Katina ◽  
Rossana Coda
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Materials ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
Fermentation Time ◽  
Viscosity Increase ◽  
Spent Grain ◽  
Leuconostoc Pseudomesenteroides ◽  
Weissella Confusa

Abstract Background Lactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers´ spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed. Results The starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h. Conclusions Selected lactic acid bacteria starters produced significant amount of dextran in brewers’ spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.

scholarly journals Screening of GABA-Producing Lactic Acid Bacteria from Thai Fermented Foods and Probiotic Potential of Levilactobacillus brevis F064A for GABA-Fermented Mulberry Juice Production

2020 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Jirapat Kanklai ◽  
Tasneem Chemama Somwong ◽  
Patthanasak Rungsirivanich ◽  
Narumol Thongwai
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Monosodium Glutamate ◽  
Salmonella Typhi ◽  
Shigella Dysenteriae ◽  
Fermented Foods ◽  
Gamma Aminobutyric Acid ◽  
Fermented Sausage ◽  
Gaba Content ◽  
Mulberry Juice

Gamma-aminobutyric acid (GABA), the inhibitory neurotransmitter, can be naturally synthesized by a group of lactic acid bacteria (LAB) which is commonly found in rich carbohydrate materials such as fruits and fermented foods. Thirty-six isolates of GABA-producing LAB were obtained from Thai fermented foods. Among these, Levilactobacillus brevis F064A isolated from Thai fermented sausage displayed high GABA content, 2.85 ± 0.10 mg/mL and could tolerate acidic pH and bile salts indicating a promising probiotic. Mulberry (Morus sp.) is widely grown in Thailand. Many mulberry fruits are left to deteriorate during the high season. To increase its value, mulberry juice was prepared and added to monosodium glutamate (MSG), 2% (w/v) prior to inoculation with 5% (v/v) of L. brevis F064A and incubated at 37 °C for 48 h to obtain the GABA-fermented mulberry juice (GABA-FMJ). The GABA-FMJ obtained had 3.31 ± 0.06 mg/mL of GABA content, 5.58 ± 0.52 mg gallic acid equivalent/mL of antioxidant activity, 234.68 ± 15.53 mg cyanidin-3-glucoside/mL of anthocyanin, an ability to inhibit growth of Bacillus cereus TISTR 687, Salmonella Typhi DMST 22842 and Shigella dysenteriae DMST 1511, and 10.54 ± 0.5 log10 colony-forming units (CFU)/mL of viable L. brevis F064A cell count. This GABA-FMJ was considered as a potential naturally functional food for human of all ages.

scholarly journals Stool shedding of Salmonella Typhi in children with blood culture-confirmed typhoid fever

2020 ◽  
Vol 101 ◽  
pp. 123
Author(s):  
M. Srinivasan ◽  
S. Giri ◽  
S. Kulandaipalayam Natarajan ◽  
N. Kumar ◽  
V.R. Mohan ◽  
...  
Keyword(s):  
Blood Culture ◽  
Typhoid Fever ◽  
Salmonella Typhi
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