Silkworm pathogenic bacteria infection model for identification of novel virulence genes

Kaito, Chikara; Kurokawa, Kenji; Matsumoto, Yasuhiko; Terao, Yutaka; Kawabata, Shigetada; Hamada, Shigeyuki; Sekimizu, Kazuhisa

doi:10.1111/j.1365-2958.2005.04596.x

Cited by 160 publications

(210 citation statements)

References 30 publications

(38 reference statements)

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“…Furthermore, a large number of silkworms can be produced at low cost. We demonstrated that antibiotics used clinically to treat infected humans are effective in silkworms, and that the ED 50 values of the antibiotics used in the silkworm infection model are consistent with those obtained in mammalian animal models (Hamamoto et al, 2004(Hamamoto et al, , 2005Hamamoto & Sekimizu, 2005;Kaito et al, 2002Kaito et al, , 2005. Silkworms have enzymes, P450s and conjugating enzymes (Hamamoto et al, 2005;Li et al, 2005;Luque et al, 2002) that are involved in metabolizing antibiotics.…”

Section: Introductionsupporting

confidence: 73%

A silkworm–baculovirus model for assessing the therapeutic effects of antiviral compounds: characterization and application to the isolation of antivirals from traditional medicines

Orihara

Hamamoto

Hiroshi

et al. 2008

Journal of General Virology

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Ganciclovir, foscarnet, vidarabine and ribavirin, which are used to treat viral infections in humans, inhibited the proliferation of a baculovirus (Bombyx mori nucleopolyhedrovirus) in BmN4 cells, a cultured silkworm cell line. These antiviral agents inhibited the proliferation of baculovirus in silkworm body fluid and had therapeutic effects. Using the silkworm infection model, the antiviral activity of Kampo medicines was screened and it was found that cinnamon bark, a component of the traditional Japanese medicine Mao-to, had a therapeutic effect. Based on the therapeutic activity, the antiviral substance was purified. Nuclear magnetic resonance analysis of the purified fraction revealed that the antiviral activity was due to cinnzeylanine, which has previously been isolated from Cinnamomum zeylanicum. Cinnzeylanine inhibits the proliferation of herpes simplex virus type 1 in Vero cells. These results suggest that the silkworm-baculovirus infection model is useful for screening antiviral agents that are effective for treating humans infected with DNA viruses.

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Section: Introductionsupporting

confidence: 73%

A silkworm–baculovirus model for assessing the therapeutic effects of antiviral compounds: characterization and application to the isolation of antivirals from traditional medicines

Orihara

Hamamoto

Hiroshi

et al. 2008

Journal of General Virology

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“…2). RNase Y was shown to affect production of virulence factors either through expression of the accessory gene regulatory locus, agr or independently (Kaito et al, 2005;Nagata et al, 2008). Recently Marincola et al (2012) performed a transcriptomic analysis to decipher the effect of RNase Y on global gene regulation.…”

Section: Ribonucleases As Possible Co-factors Of Srnasmentioning

confidence: 99%

The importance of regulatory RNAs in Staphylococcus aureus

Tomasini

François

Howden

et al. 2014

Infection, Genetics and Evolution

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a b s t r a c t RNA molecules with regulatory functions in pathogenic bacteria have benefited from a renewed interest these two last decades. In Staphylococcus aureus, recent genome-wide approaches have led to the discovery that almost 10-20% of genes code for RNAs with critical regulatory roles in adaptive processes. These RNAs include trans-acting RNAs, which mostly act through binding to target mRNAs, and cis-acting RNAs, which include regulatory regions of mRNAs responding to various metabolic signals. Besides recent analysis of S. aureus transcriptome has revealed an unprecedented existence of pervasive transcription generating a high number of weakly expressed antisense RNAs along the genome as well as numerous mRNAs with overlapped regions. Here, we will illustrate the diversity of trans-acting RNAs and illustrate how they are integrated into complex regulatory circuits, which link metabolism, stress response and virulence.

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“…Ribonucleases (RNases) play a critical role in RNA metabolism and have been largely associated with the regulation of factors involved in bacterial pathogenicity [3,4]. In particular, the single-stranded specific endoribonuclease Y (RNase Y) is crucial for the virulence of Gram-positive pathogens such as Staphyloccocus aureus, Clostridium perfringens and Streptococcus pyogenes [5–9]. In S. aureus , RNase Y stabilizes the mRNA coding for the two-component system SaeRS, which acts as a general regulator of virulence [8,10].…”

Section: Introductionmentioning

confidence: 99%

RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

et al. 2018

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Endoribonuclease Y (RNase Y) is a crucial regulator of virulence in Gram-positive bacteria. In the human pathogen Streptococcus pyogenes, RNase Y is required for the expression of the major secreted virulence factor streptococcal pyrogenic exotoxin B (SpeB), but the mechanism involved in this regulation remains elusive. Here, we demonstrate that the 5′ untranslated region of speB mRNA is processed by several RNases including RNase Y. In particular, we identify two RNase Y cleavage sites located downstream of a guanosine (G) residue. To assess whether this nucleotide is required for RNase Y activity in vivo, we mutated it and demonstrate that the presence of this G residue is essential for the processing of the speB mRNA 5′ UTR by RNase Y. Although RNase Y directly targets and processes speB, we show that RNase Y-mediated regulation of speB expression occurs primarily at the transcriptional level and independently of the processing in the speB mRNA 5′ UTR. To conclude, we demonstrate for the first time that RNase Y processing of an mRNA target requires the presence of a G. We also provide new insights on the speB 5′ UTR and on the role of RNase Y in speB regulation.

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Silkworm pathogenic bacteria infection model for identification of novel virulence genes

Cited by 160 publications

References 30 publications

A silkworm–baculovirus model for assessing the therapeutic effects of antiviral compounds: characterization and application to the isolation of antivirals from traditional medicines

A silkworm–baculovirus model for assessing the therapeutic effects of antiviral compounds: characterization and application to the isolation of antivirals from traditional medicines

The importance of regulatory RNAs in Staphylococcus aureus

RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

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