Journal of Microbiology

Journal Articles

Furan-based Chalcone Annihilates the Multi-Drug-Resistant Pseudomonas aeruginosa and Protects Zebra Fish Against its Infection: Santosh Pushpa Ramya Ranjan Nayak , Catharine Basty , Seenivasan Boopathi , Loganathan Sumathi Dhivya , Khaloud Mohammed Alarjani , Mohamed Ragab Abdel Gawwad , Raghda Hager , Muthu Kumaradoss Kathiravan , Jesu Arockiaraj; J. Microbiol. 2024;62(2):75-89. Published online February 21, 2024; DOI: https://doi.org/10.1007/s12275-024-00103-6

Abstract: The emergence of carbapenem-resistant Pseudomonas aeruginosa, a multi-drug-resistant bacteria, is becoming a serious public health concern. This bacterium infects immunocompromised patients and has a high fatality rate. Both naturally and synthetically produced chalcones are known to have a wide array of biological activities. The antibacterial properties of synthetically produced chalcone were studied against P. aeruginosa. In vitro, study of the compound (chalcone derivative named DKO1), also known as (2E)-1-(5-methylfuran-2-yl)-3-(4-nitrophenyl) prop-2-en-1-one, had substantial antibacterial and biofilm disruptive action. DKO1 effectively shielded against P. aeruginosa-induced inflammation, oxidative stress, lipid peroxidation, and apoptosis in zebrafish larvae. In adult zebrafish, the treatment enhanced the chances of survivability and reduced the sickness-like behaviors. Gene expression, biochemical analysis, and histopathology studies found that proinflammatory cytokines (TNF-α, IL-1β, IL-6, iNOS) were down regulated; antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) levels increased, and histoarchitecture was restored in zebrafish. The data indicate that DKO1 is an effective antibacterial agent against P. aeruginosa demonstrated both in vitro and in vivo.

Ultrasonic Treatment Enhanced Astaxanthin Production of Haematococcus pluvialis: Yun Hwan Park , Jaewon Park , Jeong Sik Choi , Hyun Soo Kim , Jong Soon Choi , Yoon-E Choi; J. Microbiol. 2023;61(6):633-639. Published online June 13, 2023; DOI: https://doi.org/10.1007/s12275-023-00053-5

Abstract: In this study, effects of ultrasonic treatment on Haematococcus pluvialis (H. pluvialis) were investigated. It has been confirmed that the ultrasonic stimulation acted as stress resources in the red cyst stage H. pluvialis cells containing astaxanthin,
result
ing in additional astaxanthin production. With the increase in production of astaxanthin, the average diameter of H. pluvialis cells increased accordingly. In addition, to determine how ultrasonic stimulation had an effect on the further biosynthesis of astaxanthin, genes related to astaxanthin synthesis and cellular ROS level were measured. As a result, it was confirmed that astaxanthin biosynthesis related genes and cellular ROS levels were increased, and thus ultrasonic stimulation acts as an oxidative stimulus. These results support the notion on the effect of the ultrasonic treatment, and we believe our novel approach based on the ultrasonic treatment would help to enhance the astaxanthin production from H. pluvialis.

Review

The crosstalk between bacteria and host autophagy: host defense or bacteria offense: Lin Zheng , Fang Wei , Guolin Li; J. Microbiol. 2022;60(5):451-460. Published online April 29, 2022; DOI: https://doi.org/10.1007/s12275-022-2009-z

Abstract: Xenophagy is a specific selective autophagy for the elimination of intracellular bacteria. Current evidence suggests that the processes for host autophagy system to recognize and eliminate invading bacteria are complex, and vary according to different pathogens. Although both ubiquitin-dependent and ubiquitin-independent autophagy exist in host to defense invading bacteria, successful pathogens have evolved diverse strategies to escape from or paralyze host autophagy system. In this review, we discuss the mechanisms of host autophagy system to recognize and eliminate intracellular pathogens and the mechanisms of different pathogens to escape from or paralyze host autophagy system, with a particular focus on the most extensively studied bacteria.

Journal Article

[PROTOCOL]A Signature-Tagged Mutagenesis (STM)-based murine-infectivity assay for Cryptococcus neoformans: Kwang-Woo Jung , Kyung-Tae Lee , Yong-Sun Bahn; J. Microbiol. 2020;58(10):823-831. Published online September 29, 2020; DOI: https://doi.org/10.1007/s12275-020-0341-8

Abstract: Signature-tagged mutagenesis (STM) is a high-throughput genetic technique that can be used to investigate the function of genes by constructing a large number of mutant strains with unique DNA identification tags, pooling them, and screening them for a particular phenotypic trait. STM was first designed for the identification of genes that contribute to the virulence or infectivity of a pathogen in its host. Recently, this
method
has also been applied for the identification of mutants with specific phenotypes, such as antifungal drug resistance and proliferation. In the present study, we describe an STM
method
for the identification of genes contributing to the infectivity of Cryptococcus neoformans using a mutant library, in which each strain was tagged with a unique DNA sequence.

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