Journal of Microbiology

Journal Articles

Lactobacillus acidophilus KBL409 Ameliorates Atopic Dermatitis in a Mouse Model: Woon-ki Kim , You Jin Jang , SungJun Park , Sung-gyu Min , Heeun Kwon , Min Jung Jo , GwangPyo Ko; J. Microbiol. 2024;62(2):91-99. Published online February 22, 2024; DOI: https://doi.org/10.1007/s12275-024-00104-5

24 View
1 Download
1 Citations

Abstract: Atopic dermatitis (AD) is a chronic inflammatory skin disease with repeated exacerbations of eczema and pruritus. Probiotics can prevent or treat AD appropriately via modulation of immune responses and gut microbiota. In this study, we evaluated effects of Lactobacillus acidophilus (L. acidophilus) KBL409 using a house dust mite (Dermatophagoides farinae)-induced in vivo AD model. Oral administration of L. acidophilus KBL409 significantly reduced dermatitis scores and decreased infiltration of immune cells in skin tissues. L. acidophilus KBL409 reduced in serum immunoglobulin E and mRNA levels of T helper (Th)1 (Interferon-γ), Th2 (Interleukin [IL]-4, IL-5, IL-13, and IL-31), and Th17 (IL-17A) cytokines in skin tissues. The anti-inflammatory cytokine IL-10 was increased and Foxp3 expression was up-regulated in AD-induced mice with L. acidophilus KBL409. Furthermore, L. acidophilus KBL409 significantly modulated gut microbiota and concentrations of short-chain fatty acids and amino acids, which could explain its effects on AD. Our results suggest that L. acidophilus KBL409 is the potential probiotic for AD treatment by modulating of immune responses and gut microbiota of host.

Sulforaphane kills Mycobacterium tuberculosis H37Ra and Mycobacterium smegmatis mc2155 through a reactive oxygen species dependent mechanism: Yongjie Zhao , Shengwen Shang , Ya Song , Tianyue Li , Mingliang Han , Yuexuan Qin , Meili Wei , Jun Xi , Bikui Tang; J. Microbiol. 2022;60(11):1095-1105. Published online September 1, 2022; DOI: https://doi.org/10.1007/s12275-022-2284-8

17 View
0 Download
2 Citations

Abstract: Mycobacterium tuberculosis (M. tuberculosis) is a highly pathogenic intracellular pathogen that causes tuberculosis (TB), the leading cause of mortality from single infections. Redox homeostasis plays a very important role in the resistance of M. tuberculosis to antibiotic damage and various environmental stresses. The antioxidant sulforaphane (SFN) has been reported to exhibit anticancer activity and inhibit the growth of a variety of bacteria and fungi. Nonetheless, it remains unclear whether SFN exhibits anti-mycobacterial activity. Our
results
showed that the SFN against M. tuberculosis H37Ra exhibited bactericidal activity in a time and dose-dependent manner. The anti-tubercular activity of SFN was significantly correlated with bacterial reactive oxygen species (ROS) levels. In addition, SFN promoted the bactericidal effect of macrophages on intracellular bacteria in a dose-dependent manner, mediated by increasing intracellular mitochondrial ROS levels and decreasing cytoplasmic ROS levels. Taken together, our data revealed the previously unrecognized antimicrobial functions of SFN. Future studies focusing on the mechanism of SFN in macrophages against M. tuberculosis are essential for developing new host-directed therapeutic approaches against TB.

Effective mucosal live attenuated Salmonella vaccine by deleting phosphotransferase system component genes ptsI and crr: Yong Zhi , Shun Mei Lin , A-Yeung Jang , Ki Bum Ahn , Hyun Jung Ji , Hui-Chen Guo , Sangyong Lim , Ho Seong Seo; J. Microbiol. 2019;57(1):64-73. Published online October 2, 2018; DOI: https://doi.org/10.1007/s12275-019-8416-0

11 View
0 Download
13 Citations

Abstract: Salmonella enterica is a major human pathogen that causes invasive non-typhoidal Salmonellosis (iNTS), resulting in significant morbidity and mortality. Although a number of pre-clinical and clinical studies have reported on the feasibility of developing a safe and effective vaccine against iNTS, there have been no licensed Salmonella vaccines available to protect against NTS strains. Vaccine formulations of highest priority for NTS are live attenuated vaccines, which can elicit effective induction of intestinal mucosal and intracellular bacteria-specific cell mediated immune responses. Since glucose is crucial for intracellular survival and replication in host cells, we constructed strains with mutations in components of the glucose uptake system, called the phosphotransferase system (PTS), and compared the relative virulence and immune responses in mice. In this study, we found that the strain with mutations in both ptsI and crr (KST0556) was the most attenuated strain among the tested strains, and proved to be highly effective in inducing a mucosal immune response that can protect against NTS infections in mice. Thus, we suggest here that KST0556 (ΔptsIΔcrr) is a potential live vaccine candidate for NTS, and may also be a candidate for a live delivery vector for heterologous antigens. Moreover, since PTS is a well-conserved glucose transporter system in both Gramnegative and Gram-positive bacteria, the ptsI and crr genes may be potential targets for creating live bacterial vectors or vaccine strains.

Review

Reovirus and Tumor Oncolysis: Manbok Kim , Young-Hwa Chung , Randal N. Johnston; J. Microbiol. 2007;45(3):187-192.; DOI: https://doi.org/2544 [pii]

18 View
0 Download

Abstract: REOviruses (Respiratory Enteric Orphan viruses) are ubiquitous, non-enveloped viruses containing 10 segments of double-stranded RNA (dsRNA) as their genome. They are common isolates of the respiratory and gastrointestinal tract of humans but are not associated with severe disease and are therefore considered relatively benign. An intriguing characteristic of reovirus is its innate oncolytic potential, which is linked to the transformed state of the cell. When immortalized cells are transfected in vitro with activated oncogenes such as Ras, Sos, v-erbB, or c-myc, they became susceptible to reovirus infection and subsequent cellular lysis, indicating that oncogene signaling pathways are exploited by reovirus. This observation has led to the use of the virus in clinical trials as an anti-cancer agent against oncogenic tumors. In addition to the exploitation of oncogene signaling, reovirus may further utilize host immune responses to enhance its antitumor activity in vivo due to its innate interferon induction ability. Reovirus is, however, not entirely benign to immunocompromised animal models. Reovirus causes so-called “black feet syndrome” in immunodeficient mice and can also harm neonatal animals. Because cancer patients often undergo immunosuppression due to heavy chemo/radiation-treatments or advanced tumor progression, this pathogenic response may be a hurdle in virus-based anticancer therapies. However, a genetically attenuated reovirus variant derived from persistent reovirus infection of cells in vitro is able to exert potent anti-tumor activity with significantly reduced viral pathogenesis in immunocompromised animals. Importantly, in this instance the attenuated reovirus maintains its oncolytic potential while significantly reducing viral pathogenesis in vivo.

Characterization of an Attenuated Japanese Encephalitis Virus Adapted to African Green Nomkey Kidney Cells, Vero: Chung, Yong Ju , Hong, Sun Pyo , Moon, Sang Beom , Shin, Young Cheol , Kim, Soo Ok; J. Microbiol. 1998;36(3):189-195.

11 View
0 Download

Abstract: Live attenuated Japanese encephalitis (JE) virus SA14-14-2 produced in primary dog kidney cells (PDK) was adapted to African green monkey kidney cells, Vero. In an effort to gain insight into the molecular basis of the biological characteristics of the isolated SA14-14-2 (Vero) strain, the 1,500 nucleotide sequence encoding the envelope (E) gene which possesses major neutralizing epitopes was determined and dompared with the sequences of two other attenuated JE virus strains, SA14-14-2 (PHK) and SA14-14-2 (PDK). The amino acid sequence of the C-terminal region (a.a. 280-500) of the SA14-14-2 (Vero) E gene was found to be identical to those of strains SA14-14-2 (PHK) and SA14-14-2 (PDK), while the N-terminal region (a.a. 1-279) showed sequence variation. The distribution of mutations in the N-terminal region was nearly the same among the three attenuated strains, suggesting that the N-terminal sequences might be related with virus-host cell specificity. However, it was found that Lys and Val (a.a.138 and 176, respectively), known to be responsible for attenuation, are still conserved in SA14-14-2 (Vero). Animal testing showed that SA14-14-2 (Vero) has a neurovirulence phenotype similar to that of the parent SA14-14-2 (PDK) strain in suckling mice. The SA14-14-2 (Vero) grew very efficiently in Vero cells enough to support vaccine production. The growth characteristics of SA14-14-2 (Vero) in Vero cell and conservation of attenuation determinant of neurovirulence support that SA14-14-2 (Vero) could be developed as a new vaccine strain for human use.

First
Prev
Page of 1
Next
Last

Search