Summary
Experimental infection of gnotobiotic piglets with mycoplasma hyorhinis strains Ne 110 and S 218 demonstrated a difference in virulence between the two strains and showed that the susceptibility to infection decreased with age.
None of 19 gnotobiotic piglets infected intranasally with M. hyorhinis strain Ne 110 at 6 days of age developed clinical disease and there was no evidence of spread of infection in the body. Mycoplasmas were recovered merely from the upper and lower respiratory tract and only 1 piglet had gross pathological changes in the form of slight pneumonic lesions. Of 5 piglets infected with the same strain at 1 day of age, 1 showed evidence for the spread of infection in the body. Of 21 piglets infected with strain S 218 at 6 days of age, 15 developed clinical disease and 18 showed evidence for the spread of infection in the body. Dissemination of the infection occurred likewise in 5 piglets infected with this strain at 1 day of age. On the other hand, none of 10 piglets infected with strain S 218 at 8 weeks of age developed clinical disease. Post‐mortem examination of these animals revealed no gross pathological changes in the lung, and mycoplasmas were recovered generally from the upper respiratory tract and less frequently also from the lower respiratory tract.
Zusammenfassung
Intranasale Infektion von gnotobiotischen Ferkeln mit Mycoplasma hyorhinis: Unterschiede in der Virulenz von Stämmen und Einfluß des Alters auf die Entwicklung der Infektion
Durch die experimentelle Infektion von gnotobiotischen Ferkeln mit 2 verschiedenen Stämmen von M. hyorhinis („Ne 110” und „S 218”) konnte bewiesen werden, daß die Stämme unterschiedlich virulent sind, und daß die Empfänglichkeit von Ferkeln gegenüber einer M. hyorhinis‐Infektion mit zunehmendem Alter abnimmt.
Von 19 Ferkeln, die im Alter von 6 Tagen mit dem Stamm „Ne 110” infiziert worden waren, erkrankte kein einziges. Die Infektion blieb auf den Respirationstrakt beschränkt, d. h. Mykoplasmen konnten nur aus der Lunge und dem oberen Respirationstrakt reisoliert werden. Nur 1 Tier zeigte geringgradige pneumonische Läsionen. Bei 1 Tier von 5 Ferkeln, die am 1. Lebenstag mit dem gleichen Stamm infiziert worden waren, konnte eine Verbreitung der Mykoplasmen über den gesamten Organismus nachgewiesen werden.
Dagegen erkrankten 15 Ferkel einer Gruppe von 21 Tieren, die im Alter von 6 Tagen mit dem Stamm „S 218” infiziert worden waren. Bei 18 Tieren konnten Mykoplasmen aus den verschiedensten Organen reisoliert werden. Eine Allgemeininfektion wurde auch bei 5 Ferkeln beobachtet, die am 1. Lebenstag mit dem Stamm „S 218” infiziert worden waren.
Dagegen erkrankten 8 Wochen alte Tiere nach einer Infektion mit dem Stamm „S 218” nicht. Bei dieser Gruppe von 10 Tieren konnten pathologischanatomisch keine Lungenveränderungen gefunden werden. Die Reisolierung von Mykoplasmen gelang regelmäßig aus dem oberen Respirationstrakt und seltener aus der Lunge.
Résumé
Infection intranasale de porcelets gnotobiotiques avec Mycoplasma hyorhinis: différences dans la vir...
BackgroundRenal involvement in rheumatoid arthritis (RA) is common and has a negative impact on patient survival. Only few cases have been reported of necrotizing glomerulonephritis (GN) associated with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) in patients with RA.Case PresentationWe report a patient with RA who developed a necrotizing GN associated with ANCA-MPO, treated with rituximab (RTX). A 55-year-old man with a 27-year history of RA under secukinumab was referred to our nephrology clinic with worsening renal function associated with microhematuria and proteinuria. Our laboratory evaluation showed hypocomplementemia and positive titers for MPO-ANCA (615 U/mL). A renal biopsy demonstrated pauci-immune necrotizing GN. The patient was treated with 3 consecutive pulses of methylprednisolone followed by oral prednisolone (1 mg/Kg) and rituximab (1000 mg, repeated 14 days later). After a 10-month follow-up, the arthritis remains well-controlled, renal function stabilized, proteinuria improved and MPO-ANCA titer normalized (6.3 U/mL).ConclusionsNecrotizing GN is a rare but a serious condition and an early diagnosis is essential to treatment. This is the first case of necrotizing GN (without extra-renal manifestations of vasculitis) in a patient with active RA, successfully treated with RTX.
SUMMARYNine gnotobiotic piglets, when 8-9 days old, were exposed to an aerosol of strain TR 32 of Mycoplasma hyorhinis and killed at intervals from 14 to 37 days after infection. The aerosol of M. hyorhinis caused bronchopneumonia in 1 pig, pleurisy alone in 2 pigs, pleuropneumonia in 2 pigs and no lung changes in 4 pigs. M. hyorhinis was re-isolated from the lungs of all infected pigs, irrespective of the presence or absence of lesions, though it was only isolated from the serosa and joints when lesions were present. Four control pigs exposed to aerosols of mycoplasma medium had no lesions.
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