KMITL Expo 2026 LogoKMITL 66th Anniversary Logo

Genomic analysis, Bacteriocin dynamic production of putatively novel bacteriocin DCR3-2 inhibiting Listeria monocytogenes synthesized by Lactococcus lactis subsp. hordinae DCR3-2 isolated from Thai pickled crab (Pu-dong)

Abstract

Listeriosis is a severe foodborne illness characterized by a fatality rate exceeding 30%, attributed to the pathogen Listeria monocytogenes. This study evaluated 160 lactic acid bacteria (LAB) isolated from Thai pickled crabs for their potential as agents against L. monocytogenes and for their probiotic properties and probiogenomic characteristics. Among these strains, strain DRC3-2 exhibited activity through the synthesis of bacteriocin DRC3-2, which significantly inhibited L. monocytogenes ATCC 19115 in spot-on-lawn assays. Phenotypic and whole-genome analyses revealed that strain DRC3-2 thrived in environments with 2-6% NaCl, pH values ranging from 3 to 9, and temperatures between 25 and 45°C. Based on average nucleotide identity (ANI) and digital DNA‒DNA hybridization (dDDH) values, strain DRC3-2 was taxonomically classified as Lactococcus lactis subsp. hordinae. The production of bacteriocin DRC3-2 peaked during the late stationary phase, following its synthesis in the early exponential growth phase. BAGEL4 analysis identified the putative novel bacteriocin DRC3-2 as lactococcin A and B, with respective bit-scores of 40.05 and 36.58. In silico safety assessments confirmed the nonpathogenic nature of strain DRC3-2 in humans, highlighting its absence of antibiotic resistance genes. Finally, this investigation underscores the novel bacteriocin DRC3-2 for application in the prevention and treatment of L. monocytogenes infections.

Objective

Listeria monocytogenes เป็นเชื้อก่อโรคที่มักพบในอาหารที่มีการปนเปื้อน สามารถอยู่รอดในสภาวะที่รุนแรง เช่น อุณหภูมิต่ำ ความเป็นกรดสูง ความเข้มข้นของเกลือสูง ซึ่งทำให้มีความเสี่ยงอย่างมากในระบบย่อยอาหารของมนุษย์ ดังนั้นจึงศึกษาแบคทีเรียกรดแลคติกที่มีความสำคัญในอุตสาหกรรมอาหารและยาเนื่องจากมีคุณสมบัติเป็นโพรไบโอติก และแบคทีเรียกรดแลคติกบางชนิดที่สามารถผลิตแบคเทอริโอซินหรือเปปไทด์ต้านจุลชีพที่มีฤทธิ์ทางชีวภาพ และแบคเทอริโอซินที่มีประสิทธิภาพในการยับยั้งแบคทีเรียก่อโรค ซึ่งถือว่าเป็นทางเลือกที่น่าสนใจแทนการใช้ยาปฎิชีวนะแบบดั้งเดิม เนื่องจากช่วยลดการพัฒนาการดื้อยาของแบคทีเรีย นอกจากนี้แบคเทอริโอซินยังมีความเสถียรสูง สามารถทนต่ออุณหภูมิที่รุนแรงและสภาวะเป็นกรดได้ อีกทั้งยังไม่เป็นพิษต่อเซลล์มนุษย์ การศึกษานี้จึงมุ่งหมายเพื่อศึกษาแบคเทอริโอซินชนิดใหม่จาก Lactococcus lactis subsp. hordinae DCR3-2 ซึ่งแยกได้จากปูดอง เพื่อประเมินฤทธิ์การต้านจุลชีพของแบคทีเรียชนิดนี้ และการวิเคราะห์ทางbioinformatics เพื่อยืนยันว่าสายพันธุ์ DCR3-2 มีความปลอดภัยสำหรับมนุษย์และมีคุณสมบัติโพรไบโอติก

Other Innovations

A DESIGN GUIDELINE FOR PROTOTYPE APPLICATION OF PUBLIC TRANSPORTATION AT KING MONGKUT'S INSTITUTE OF TECHNOLOGY LADKRABANG.

คณะสถาปัตยกรรม ศิลปะและการออกแบบ

A DESIGN GUIDELINE FOR PROTOTYPE APPLICATION OF PUBLIC TRANSPORTATION AT KING MONGKUT'S INSTITUTE OF TECHNOLOGY LADKRABANG.

This research aims to study the guidelines and develop a prototype of an application for public transport users to plan their journey and increase safety in using different types of public transport to travel to King Mongkut's Institute of Technology Ladkrabang. The objectives are as follows: 1) To study the factors of user experience (UX) and user interface (UI) design that affect the users of the application for using public transport. 2) To study the needs of users of public transport applications who must travel to King Mongkut's Institute of Technology Ladkrabang. 3) To present the guidelines for designing the user experience (UX) and user interface (UI) and to produce a prototype of the application for using public transport to travel to King Mongkut's Institute of Technology Ladkrabang. The research includes a review of the literature on User Experience (UX) and User Interface (UI) design, as well as a look at examples of public transportation applications and pick-up sites near King Mongkut's Institute of Technology Ladkrabang. This study is based on qualitative research. There are examples of employing relevant applications during the interview. The target audience is students aged 18 to 35 who will give prototypes for application development to satisfy their requirements. Provide information that is actually useful to users. The research results found that the public transport vehicles that the target group used the most were the Songthaew (the pick-up truck), train, airport rail link, motorcycle taxi, taxi, and bus, respectively. Users were concerned about various safety issues and wanted to design features to increase safety and confidence in using public transport vehicles for students, such as sending locations to relevant officials in the event of an emergency or when assistance was needed, and important information about public transport vehicles that students needed, such as calculating prices, calculating travel times, bus schedules, official and clear pick-up and drop-off points, bus routes, driver registration, suggestions or route recommendations, and the time of public transport vehicles arriving at the point where users were waiting, etc. The guidelines for designing the User Experience (UX) were presented from the analysis of the target group's data, which was a prioritization of the features of the menu for recording frequently used routes, a menu showing nearby pick-up points, a menu for searching for routes and selecting using various user constraints, such as calculating travel prices or travel times, and a menu that could set fonts and color modes to support a variety of users. This was because the study of user needs for fonts found an equal demand for Thai fonts with looped (Looped font) and without looped (Loopless font), as well as a study of the application's color requirements, which required both light and dark colors to be displayed in approximately equal amounts. This includes the design of the user interface (User Interface) by designing symbols that allow users to access the desired information quickly without confusion.

Read more
BrushXchange; A toothbrush featuring a recycled plastic handle and a replaceable brush head.

คณะบริหารธุรกิจ

BrushXchange; A toothbrush featuring a recycled plastic handle and a replaceable brush head.

BrushXchange is a toothbrush brand dedicated to reducing plastic waste in Thailand by offering toothbrushes made from recycled plastic with replaceable bristles. These products help minimize waste generated by traditional toothbrushes. The design is modern and user-friendly, emphasizing durability, comfort, and affordability, making it appropriate for health-conscious and environmentally aware consumers. The brand aims to drive change in the oral care industry by providing high-quality products at accessible prices. Its marketing strategy focuses on using social media platforms like Instagram and TikTok and collaborating with organizations that promote sustainability. The product is distributed through retail stores such as Lotus’s and Tops. BrushXchange also prioritizes environmental responsibility by using recycled paper packaging and organizing sustainability campaigns. The brand's long-term goal is to become a widely recognized brand image in the eco-friendly toothbrush market in Thailand while encouraging sustainable living habits within society.

Read more
PROBIOGENOMIC ASESSMENT OF THE ABILITY OF THE POTENTAIL PROBIOTIC ENTEROCOCCUS LACTIS RRS4 ISOLATED FROM RAPHANUS SATIVUS LINN TO PROTECT VANCOMYCIN RESISTANT ENTEROCOCCUS

คณะวิทยาศาสตร์

PROBIOGENOMIC ASESSMENT OF THE ABILITY OF THE POTENTAIL PROBIOTIC ENTEROCOCCUS LACTIS RRS4 ISOLATED FROM RAPHANUS SATIVUS LINN TO PROTECT VANCOMYCIN RESISTANT ENTEROCOCCUS

The species Enterococcus lactis is closely related to E. faecium and is known for its beneficial and probiotic effects. In this study, strain RRS4 was isolated from Raphanus sativus Linn. and identified based on both phenotypic and genotypic characteristics. Strain RRS4 exhibited cell viability in environments with 2-8% NaCl, pH ranging from 4 to 9, and temperatures between 4°C and 45°C. Through comprehensive genomic analysis, strain RRS4 was confirmed to be E. lactis. E. lactis RRS4 demonstrated inhibitory effects against Vancomycin-resistant E. faecalis JCM 5803. Safety assessments via in silico methods, including KEGG annotation, indicated the absence of virulent and undesirable genes in E. lactis RRS4. VirulenceFinder analysis aligned virulence-related genes with those from three strains of E. lactis and four strains of E. faecium. While antibiotic resistance genes were found to be conserved, they did not correlate with key pathogenicity traits. Furthermore, safety evaluations highlighted that E. lactis RRS4 is generally safe, despite the presence of genes associated with antibiotic resistance. Lastly, we propose guidelines for assessing the safety of microbial strains using whole-genome analysis. These findings represent advancements in probiotic research.

Read more