[A case of autoimmune hepatitis with tuberculosis caused by prednisolone from undeterminable enzyme-linked immunospot assay].

An 88-year-old woman was referred to our hospital for autoimmune hepatitis in 2016. She was treated with prednisolone. In 2018, she was rehospitalized owing to hepatitis relapse. Steroid pulse therapy was performed. She exhibited good recovery of hepatitis, but was transferred to a convalescent ward in a general hospital because of decreased activity of daily life. After a month later, she had high fever and cough. She was diagnosed as having tuberculosis because of positive Mycobacterium tuberculosis polymerase chain reaction. At our first medical examination in 2016, we performed enzyme-linked immunospot and the result was undeterminable. There is an increase in the opportunities to use immunosuppressant and biologic agents for elderly patients. Our case report should contribute to future medical care for elderly patients who are at risk of latent tuberculosis infection.

Dynamic integration and excision of filamentous phage XacF1 in Xanthomonas citri pv. citri, the causative agent of citrus canker disease.

Inovirus XacF1 (7325 nucleotides) is integrated into the genome of Xanthomonas citri pv. citri (Xcc) strains at the host dif site (attB) by the host XerC/D recombination system. The XacF1 attP sequence is located within the coding region of ORF12, a possible phage regulator. After integration, this open reading frame (ORF) is split into two pieces on the host genome. We examined dynamic integration/excision of XacF1 in Xcc strain MAFF 301080 and found that the integration started at 4 h postinfection (p.i.) and peaked at 12 h p.i. Thereafter, the ratio of integrated to free forms remained constant, suggesting equilibrium of integration and excision of XacF1 in the host genome. However, the integrated state became very unstable following a 5'-deletion of ORF12 in XacF1, suggesting that ORF12 plays a key role in the integration cycle of XacF1 in Xcc strains.