Journal of Microbiology

Journal Articles

Infection Dynamics of Dengue Virus in Caco-2 Cells Depending on Its Differentiation Status.: Jayoung Nam, Jisu Lee, Geon A Kim, Seung-Min Yoo, Changhoon Park, Myung-Shin Lee; J. Microbiol. 2024;62(9):799-809. Published online August 30, 2024; DOI: https://doi.org/10.1007/s12275-024-00161-w

Abstract: Dengue virus (DENV), from the Flaviviridae family, is the causative agent of dengue fever and poses a significant global health challenge. The virus primarily affects the vascular system and liver; however, a growing body of evidence suggests its involvement in the gastrointestinal (GI) tract, contributing to clinical symptoms such as abdominal pain, vomiting, and diarrhea. However, the mechanisms underlying DENV infection in the digestive system remain largely unexplored. Prior research has detected viral RNA in the GI tissue of infected animals; however, whether the dengue virus can directly infect human enterocytes remains unclear. In this study, we examine the infectivity of human intestinal cell lines to the dengue virus and their subsequent response. We report that the Caco-2 cell line, a model of human enterocytes, is susceptible to infection and capable of producing viruses. Notably, differentiated Caco-2 cells exhibited a lower infection rate yet a higher level of virus production than their undifferentiated counterparts. These findings suggest that human intestinal cells are a viable target for the dengue virus, potentially elucidating the GI symptoms observed in dengue fever and offering a new perspective on the pathogenetic mechanisms of the virus.

Screening for Probiotic Properties of Strains Isolated from Feces of Various Human Groups: Sathyaseelan Sathyabama , Rajendran Vijayabharathi , Palanisamy Bruntha devi , Manohar Ranjith kumar , Venkatesan Brindha Priyadarisini; J. Microbiol. 2012;50(4):603-612. Published online July 21, 2012; DOI: https://doi.org/10.1007/s12275-012-2045-1

Abstract: The present study searched for potential probiotic strains from various human fecal samples. A total of 67 aerobic and 38 anaerobic strains were isolated from 5 different categories of human feces. Systematic procedures were used to evaluate the probiotic properties of the isolated strains. These showed about 75–97% survivability in acidic and bile salt environments. Adhesion to intestinal cell line Caco-2 was also high. The isolates exhibited hydrophobic properties in hexadecane. The culture supernatants of these strains showed antagonistic effects against pathogens. The isolates were resistant to a simulated gastrointestinal environment in vitro. Of the 4 best isolates, MAbB4 (Staphylococcus succinus) and FIdM3 (Enterococcus fecium), were promising candidates for a potential probiotic. S. succinus was found to be a probiotic strain, which is the second such species reported to date in this particular genus. A substantial zone of inhibition was found against Salmonella spp., which adds further support to the suggestion that the probiotic strain could help prevent intestinal infection. This study suggested that the human flora itself is a potential source of probiotics.

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