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

Abstract

Rickettsia parkeri belongs to the spotted fever group (SFG) of the Rickettsia genus. This bacterium causes mild rickettsiosis in humans and is mainly transmitted by Amblyomma ticks. Its medical importance is emerging in the Americas, including Mexico. Synanthropic rodents and domiciled dogs participate as accidental hosts in epidemiological cycles of Rickettsia of the SFG. The aim is to report the presence of R. parkeri in 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 of Rickettsia on Vero cells. These infected cells were used in the extraction of genomic DNA. Rickettsia DNA 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 the Rickettsia species. One hundred animals were sampled: 36 synanthropic rodents and 64 dogs. The snPCR evidenced the presence of Rickettsia DNA 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 to R. parkeri and was demonstrated in the phylogenetic tree. The first evidence of the presence of R. parkeri in 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.

Prevalence and transmission of the most relevant zoonotic and vector-borne pathogens in the Yucatan peninsula: A review

“…These diseases are considered neglected according to the Pan American Health Organization [ 103 ] and represent a challenge for public health in the region. Furthermore, infections by pathogenic Rickettsia are also of concern due to their potential to affect different vectors and animal hosts and because of their impact on human health [ 40 , 45 , 46 , 104 ].…”

Actualización Sobre Aspectos Epidemiológicos De La Rickettsiosis en El Trópico De México

“…o para aislar o evidenciar las bacterias. Estas investigaciones han empleado métodos de laboratorio directos e indirectos, para revelar la infección activa en sangre, tejidos u órganos, o la presencia de anticuerpos en suero sanguíneo contra grupos de Rickettsia (Sánchez-Montes et al, 2021;Arroyo-Ramírez et al, 2023)…”

“…Específicamente en el sureste de México, que tiene una amplia región con clima tropical y cuenta con un complejo paisaje biológico-ecológicoepidemiológico-socioeconómico en donde durante todo el año ocurren numerosas interacciones epidemiológicas entre hospederos susceptibles, reservorios naturales y vectores biológicos (Manrique-Saide, 2023), se han documentado personas infectadas con R. rickettsii (Torres-Castro et al, 2022a), R. felis (Zavala-Velázquez et al, 2000), R. parkeri (Torres-Castro et al, 2022b) y R. typhi (Torres-Castro et al, 2022a). Todas estas especies de Rickettsia también se han encontrado en hospederos mamíferos como perros domiciliados (Martínez-Ortiz et al, 2016;Arroyo-Ramírez et al, 2023) y/o roedores de especies sinantrópicas y silvestres (Panti-May et al, 2015;Peniche-Lara et al, 2015;Torres-Castro et al, 2018;Arroyo-Ramírez et al, 2023). Estos registros han servido para involucrar a estos animales como portadores u hospederos accidentales en los ciclos epidemiológicos de las especies patógenas de Rickettsia endémicas en el sureste de México.…”

“…Recientemente,Torres-Castro et al (2022c) reportaron ADN de Rickettsia TG en perros de la localidad de Maxcanú, Yucatán. Finalmente,Arroyo- Ramírez et al (2023) reportaron, por segunda ocasión, la circulación de R. parkeri en perros de Ucú, Yucatán. Adicionalmente, Dzul-Rosado et al Oligoryzomys sp.…”