Master of Science
Nhat Ha Minh Truong
Center for Bioscience and Biotechnology, VNUHCM-University of Science, Ho Chi Minh City, Vietnam
Title: Genomic characterization and developing detection assays of Aeromonas spp. in striped catfish with Motile Aeromonas septicemia
Nhat Ha Minh Truong1,2†, Dung Tran Thi Ngoc3†, Quynh Nguyen3, Phat Vinh Voong3, Vinh Chau3, Nhi Huynh Thanh Nguyen1,2, Tuan Hoa Minh Nguyen1,2, Phuong Hong Vo2,4, Luan Thanh Nguyen5, Trinh Thi Phuong Ha5, Lan Phu Huong Nguyen3, Phuoc Hong Le4, Duy Pham Thanh3, Hoang Duc Nguyen1,2*
1 Center for Bioscience and Biotechnology, VNUHCM-University of Science, Ho Chi Minh City, Vietnam
2 Vietnam National University Ho Chi Minh City, Vietnam
3 Oxford University Clinical Research Unit, Vietnam
4 Research Institute for Aquaculture No.2
5 Gene Solutions Company, Ho Chi Minh City, Vietnam
Striped catfish farming in the Mekong Delta faces substantial disease pressure, particularly from Motile Aeromonas Septicemia (MAS), previously attributed to A. hydrophila. The reclassification of A. dhakensis as a species in 2013 has imposed the need for re-evaluation of MAS causing pathogens. We performed a large-scale whole-genome sequencing (WGS) analysis of 87 Aeromonas isolates collected from catfish farms (2012–2022). Species identification revealed diverse MAS-associated Aeromonas, dominated by A. dhakensis (54.0%, 47/87) and A. hydrophila (26.7%, 23/87), alongside other Aeromonas species (19.5%, 17/87). While A. dhakensis ST656 and A. hydrophila ST251 were prevalent, several novel sequence types were unprecedentedly detected. Traditional methods (aerA PCR, MALDI-TOF) failed to distinguish A. dhakensis or detect novel STs, underscoring the need for improved diagnostics. Gene content analysis has revealed distinct virulence factors and antimicrobial resistance factor between A. hydrophila and A. dhakensis, with ST251 and ST656 carried a much highest amount of factors, respectively. Thus, a core genome between the two STs was calculated. 2202 core genes were discovered, 78 of which were in either outer membrane or extracellular protein and therefore could become potential vaccine candidates. Finally, we sought to ultilize pangenome analysis to determine unique markers for each species for a rapid real-time PCR assays. Thus, we developed a SYBR-based real-time PCR assay comprising: (1) a singleplex PCR specific to A. hydrophila and (2) a multiplex PCR detecting both A. dhakensis and the Aeromonas genus with over 95% specificity on both A. hydrophila and A. dhakensis across STs. Given the emergence of diverse MAS-causing Aeromonas, the research provided detailed description of Aeromonas genomic variations, while offering a rapid tool for disease surveillance and management in catfish aquaculture.
Biography of the presenting author
Nhat H.M. Truong is a PhD student in Microbiology at the University of Science, Vietnam National University Ho Chi Minh City. He graduated with a Bachelor of Science in Biotechnology (Medical major) in 2018 and his Thesis in Biotechnology in 2022 at University of Science, Vietnam National University Ho Chi Minh City. Since 2019, he has been a researcher at the Center for Bioscience and Biotechnology, University of Science Ho Chi Minh City.
His current project focuses on analysing molecular epidermiology, virulence factor, antimicrobial resistant factors, and developing PCR detection assays for Aeromonas causing hemorrhage in striped catfish. His main interests are bioinformatics and molecular biology.
Presenting author details
Full name: Nhat H.M. Truong
Contact number: +84938138818
Email: thmnhat25496@gmail.com
Category: Oral presentation