New records of Rhipicephalus linnaei infected by Rickettsia massiliae from Central Mexico.

BACKGROUND: On the American continent, Rhipicephalus sanguineus s.l. comprises two species: Rhipicephalus linnaei and R. sanguineus s.s. Each species has been identified as a potential vector of at least one of five species of pathogenic bacteria of the genus Rickettsia. In particular, Rickettsia massiliae is one of three species with the greatest importance in public health at the continental level. In Mexico, this species is reported exclusively in the Nearctic states of Baja California and Chihuahua. AIM: For this reason, the aim of this work was to provide new records of R. massiliae for the centre of the country derived from active acarological surveillance. MATERIALS AND METHODS: During the period of February-October 2019, 29 dogs from six municipalities in the state of Morelos were sampled. Hosts were visually inspected, and ticks were recovered and identified morphologically and molecularly by amplification of the 16S rDNA gene. Subsequently, five genes from members of the genus Rickettsia were amplified and sequenced. RESULTS: A total of 229 (117♀, 98♂ and 14 N) ticks identified as R. linnaei were recovered, two of which were positive for R. massiliae strains related to those recovered from Argentina and the United States. CONCLUSIONS: This work provides the second record of R. massiliae infecting R. linnaei in Mexico and the Americas, increasing the geographic distribution of this Rickettsia species in the Neotropical region, and providing information on the possible role of R. linnaei as a potential vector of this microorganism.

Tick-associated diseases identified from hunting dogs during the COVID-19 pandemic in a Mayan community in Yucatan, Mexico.

Background: Hunting activity in the Mayan communities has increased due to COVID-19 and domestic dogs have gained more importance. Due to their proximity to humans, domestic dogs are a bridge between tick-borne diseases (TBDs) and humans and their peri-domestic environment. In Mexico, and especially in rural regions, there were not adequate records of TBDs during the SARS-CoV-2 pandemic. Aim: Identify TBD of ticks collected during the COVID-19 pandemic in a rural community. Methods: Tick capture was carried out in March 2021, in Teabo, Yucatan. Ticks were removed using from domestic dogs and placed in ethanol. Collected ticks were morphologically identified and underwent DNA extraction and a partial segment of the mitochondrial 16S-rDNA gene was amplified to corroborate the tick species. The DNA was screened for the presence of Anaplasma spp., Borrelia spp., Ehrlichia spp., and Rickettsia spp. Purified amplification products were submitted for sequencing and the results were compared to those deposited in GenBank using BLAST. Results: We collected 33 ectoparasites, Ixodes affinis, Rhipicephalus sanguineus, Rhipicephalus microplus, and Amblyomma mixtum on 11 hunting dogs. The most frequent ectoparasite was R. sanguineus (66%). We detected the presence of DNA of Rickettsia endosymbiont in I. affinis and Anaplasma platys in R. sanguineus. Rickettsia endosymbiont presented a similarity of 100% with the partial sequence of R. endosymbiont of I. affinis isolate IACACTM001 16S ribosomal RNA gene and the sequence of A. platys had a similarity of 100% with the partial sequence of the isolate 23-33TX 16S ribosomal RNA gene of A. platys from dogs from Texas, USA and with the partial sequence of the isolate L134 16S ribosomal RNA gene of Ehrlichia canis from dogs from Piura, Peru. Conclusion: We confirmed for the first time the presence of A. platys in R. sanguineus and R. endosymbiont in I. affinis ticks from dogs in the state of Yucatan.

Analysis of the genomic diversity of human papillomavirus type 31 in cervical samples reveals the presence of novel sublineages in clade C.

Human papillomavirus 31 (HPV31) is the fourth most frequent high-risk HPV (HR-HPV) genotype identified in cervical cancer (CC) worldwide and in Mexico. It has been recently classified into three lineages (A, B, and C) and eight sublineages (A1, A2, B1, B2, and C1 - C4). Here, we report the complete genomic sequences of 14 HPV31 isolates from cervical samples, and these were compared with viral genome sequences from the GenBank database for phylogenetic and genetic distance analysis. The formation of two novel clades within the C lineage (proposed as C5 and C6) was observed, with a well-defined variant-specific mutational pattern. The smallest average pairwise distance was 0.71% for lineages A and B, 0.94% for lineages A and C, and 1.01% for lineages B and C, and between sublineages, these values were 0.21% for clade A, 0.29% for clade B, and 0.24% for clade C. The isolates were grouped into the sublineages A1, B2, C1-C3, and C6. This is the first report on the whole-genome diversity of HPV31 in Mexico.

Full genome sequence of the first SARS-CoV-2 detected in Mexico.

SARS-CoV-2 was first detected in the city of Wuhan, Hubei Province, China. In this report, we describe the complete genome sequence of the first imported SARS-CoV-2, detected in a Mexican patient who had traveled to Bergamo, Italy. Phylogenetic analysis showed that this isolate belongs to subclade A2a (lineage G) and is closely related to isolates from Finland, Germany and Brazil, all of which were from patients with a history of travel to Italy. This is the first report of the complete genome sequence of this virus in Mexico.