Molecular evidence of Rickettsia typhi infection in dogs from a rural community in Yucatán, México.
BACKGROUND
Rickettsia typhi causes murine or endemic typhus, which is transmitted to humans primarily through flea bites contaminated with feces. Synanthropic and domestic animals also contribute to the infection cycle of R. typhi. Cases of murine typhus in humans were reported in the rural community of Bolmay, Yucatán, México, between 2007 and 2010.


OBJECTIVE
To identify the presence of R. typhi and estimate the frequency of infection in dogs from Bolmay, México, a locality with previous reports of murine typhus in humans.


METHODS
Whole blood samples were taken from 128 dogs. Total DNA was extracted for use in the polymerase chain reaction (PCR) to amplify fragments of the 17 kDa and omp B genes and confirms the presence of Rickettsia spp. The reaction products were sequenced, and alignment analysis was performed using the BLAST tool.


RESULTS
The frequency of R. typhi infection in dogs was 5.5 % (7/128). The alignment identified 99% and 100% homology to the R. typhi 17 kDa and omp B genes, respectively.


CONCLUSIONS
We confirmed the presence of R. typhi in dogs in the studied community but at a low frequency. However, there is potential risk of transmission to humans.
Coordinación de Zoonosis, Servicios de Salud de Yucatán, Mérida, México. daly-martinez@hotmail.com.
Daly
D
Martínez-Ortiz
Marco
M
Torres-Castro
Edgar
E
Koyoc-Cardeña
Karina
K
López
Alonso
A
Panti-May
Iván
I
Rodríguez-Vivas
Adriano
A
Puc
Karla
K
Dzul
Jorge
J
Zavala-Castro
Anuar
A
Medina-Barreiro
Juan
J
Chablé-Santos
Pablo
P
Manrique-Saide
D000818:Animals; D004285:Dogs; D005243:Feces; D008800:Mexico; D016133:Polymerase Chain Reaction; D012282:Rickettsia Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D012286:Rickettsia typhi / Q000737:chemistry* / Q000302:isolation & purification; D005423:Siphonaptera / Q000382:microbiology*; D014437:Typhus, Endemic Flea-Borne / Q000382:microbiology / Q000473:pathology* / Q000635:transmission
México; Rickettsia typhi; dogs