Inoculation of Mycoplasma mycoides Mycoides by endotracheal intubation produces a milder disease than by contact transmission

Abstract

Cattle infected by endotracheal intubation with Mycoplasma mycoides subspecies mycoides (Mmm) have been used in trials of Contagious Bovine Pleuropneumonia (CBPP) pathogenesis. Its advantage is that the precise moment of infection is known, unlike with the in-contact transmission when the exact time of inoculation in each animal is not known. In this study, the two methods of inoculation were directly compared, by analysing clinical signs and pathological outcome in three controlled trials. Intubation produced smaller lung lesions and a much milder disease, mainly the chronic form of CBPP, than contact transmission. The mode of inoculation may influence disease outcome and this should be taken into consideration when studying the pathogenesis of the disease and vaccine efficacy.

Keywords: CBPP; Mycoplasma mycoides; intubation; in-contact transmission