An unusual identification ofRickettsia parkeriin synanthropic rodents and domiciliated dogs of a rural community from Yucatán, Mexico

Abstract

AbstractRickettsia parkeribelongs to the spotted fever group (SFG) of theRickettsiagenus. This bacterium causes mild rickettsiosis in humans and is mainly transmitted byAmblyommaticks. Its medical importance is emerging in the Americas, including Mexico. Synanthropic rodents and domiciled dogs participate as accidental hosts in epidemiological cycles ofRickettsiaof the SFG. The aim is to report the presence ofR. parkeriin synanthropic rodents and domiciled dogs from a rural community of Yucatán, Mexico. Rodents were captured, and plasma samples were taken from dogs in 48 households from Ucú, Yucatán, Mexico. A spleen sample (rodents) and plasma (dogs) were used in the propagation ofRickettsia on Vero cells. These infected cells were used in the extraction of genomic DNA.RickettsiaDNA was identified using a semi‐nested PCR (snPCR); some products were sent for sequencing. The recovered sequences were analysed with bioinformatics programs, and a phylogenetic tree was built to determine theRickettsiaspecies. One hundred animals were sampled: 36 synanthropic rodents and 64 dogs. The snPCR evidenced the presence ofRickettsiaDNA in 10 rodents (10/36, 27.8%) and 18 dogs (18/64, 28.1%), which represents a global frequency of 28% (28/100) in this study. The bioinformatics analysis yielded homology toR. parkeriand was demonstrated in the phylogenetic tree. The first evidence of the presence ofR. parkeriin synanthropic rodents (Mus musculus) from Mexico is presented; likewise, the participation of domestic dogs in the transmission cycle of this bacterium with potential importance in public health is confirmed.