Disinfection of the causative agent of contagious equine metritis by Nolvasan and Roccal II

Haemophilus equigenitalis, the proposed name for the bacterium that causes contaginous equine metritis (CEM) was tested for sensitivity to the disinfectant solutions Nolvasan® (2% chlorhexidine diacetate) and Roccal II® (10 alkyldimethylbenzylammonium chloride).Bacteria (10⁶) suspended in medium were inactivated in 10–20 min at 0°–2°C and in 2.5 min at 20°–22°C by a 3 : 128 dilution of Nolvasan. Roccal II, diluted 1 : 128, inactivated 10⁶ bacteria in 2.5 min at 0°–2°C and 20°–22°C.These dilutions of the disinfectants inactivated H. equigenitalis (titers of 0.1–11.0 × 10⁷/ml) in vaginal exudates from infected mares and pure cultures suspended in medium (titers of 1–5 × 10⁹/ml) in 10 min at 0°–2°C and 20°–22°C when the exudates and cultures were dried on metal carriers. The limit of detection of survivors was 3–32 bacteria/ml.It is recommended that contaminated instruments and other metal surfaces encountered during CEM infections should be decontaminated with either disinfectant for 10 min before rinsing.