Isolation and characterization of Bordetella pseudohinzii in mice in China

We report on the first detection and isolation of B. pseudohinzii (Bordetella pseudohinzii) in laboratory mice in China. Forty-one B. pseudohinzii strains were isolated from 3094 mice in 33 different laboratory animal facilities in southern China. The isolates were identified through culture and genome sequenceing. Phylogenetic analysis based on the sequences of 16S rRNA and OmpA genes demonstrated that these strains were on the same clade as other B. pseudohinzii strains isolated from mice. Experimental infected mice presented an asymptomatic infection. B. pseudohinzii replicated in both the respiratory tract and the digestive tract. Most importantly B. pseudohinzii shed via feces and infected a group of sentinel mice in a separate cage via cage padding contaminated with B. pseudohinzii-positive feces, indicating that B. pseudohinzii could transmit efficiently among mice and contaminate environmental facilities. Our study highlights the importance of routine monitoring of the pathogen in laboratory mice and provides vital insights into the transmission of Brodetellae in rodents and human.