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Spotted fever group (SFG) rickettsiae are obligatory intracellular bacteria that cause disease in humans and other animals. Ixodid ticks are the principal vectors of SFG rickettsiae. The present study aimed to determine the prevalence and species identity of SFG rickettsiae in ticks and horses from urban and rural areas of western Cuba using PCR assays. Tick samples, collected from 79 horses, consisted of 14 Amblyomma mixtum adults, 111 Dermacentor nitens adults and 19 pools of D. nitens nymphs (2-5 individuals/pool). The PCR results revealed the presence of Rickettsia spp. in 64% of the A. mixtum adults, 16% of the D. nitens adults, and 11% of the pooled samples of D. nitens nymphs. In contrast, Rickettsia spp. was not detected in any of the 200 horse blood samples included in this study. DNA sequence data of the rickettsial 17 kDa antigen gene showed that Rickettsia amblyommatis was present in A. mixtum; and Rickettsia felis in D. nitens. This is the first report of R. felis in D. nitens in Cuba. The present study extends our knowledge of the potential vector spectrum and distribution of SFG rickettsiae pathogens in western Cuba.

Introducción. Babesia caballi, Theileria equi y varias especies de rickettsias son agentes de enfermedades transmitidas por vectores que afectan a los equinos. El objetivo del presente estudio fue detectar infecciones por B. caballi y T. equi en caballos e identificar rickettsias en caballos y garrapatas en la región occidental de Cuba. Métodos. Se estandarizaron 2 ensa- yos de nPCR para la detección de B. caballi y T. equi. Se colectaron muestras de sangre de caballos, y garrapatas. Se realizó identificación por frotis sanguíneo y detección e identifica- ción molecular de B. caballi, T. equi y Rickettsia sp. Resultados. Se observaron formaciones intraeritrocíticas compatibles con B. caballi y T. equi. El nPCR mostró que el 25 % de las Anales de la Academia de Ciencias de Cuba; Vol. 12, 1 (2022): enero-abril ISSN 2304-0106 | RNPS 2308muestras fueron positivas para B. caballi, 73 % para T. equi y 20 % mostraron coinfección. Los resultados se confirmaron con la secuenciación parcial de los genes bc 48 (B. caballi) y ema-1 (T. equi). La secuenciación del gen ARNr 18S de T. equi demostró la presencia de al menos 2 genotipos de aislados de T. equi en Cuba. El ensayo de PCR en tiempo real y la secuenciación revelaron la presencia de Rickettsia amblyommatis en A. mixtum y Rickettsia felis en D. nitens. Como conclusiones estos resultados constituyen la primera evidencia molecular de B. caballi y T. equi en equinos y el primer reporte de Rickettsia felis en D. nitens en Cuba, lo que amplía el conocimiento sobre la distribución de patógenos y el espectro de vectores potenciales contribuyendo al fortalecimiento de los programas de manejo y control.

The present study aimed to determine the prevalence of zoonotic vector-borne pathogens, including Anaplasma platys, Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Ehrlichia canis and Rickettsia spp. in shelter dogs from Cuba. Blood samples were collected from 100 shelter dogs and examined by molecular methods. Overall, 85 (85%, 95% CI: 77.88&ndash, 92.12) dogs tested positive for at least one vector-borne pathogen using species-specific qPCR assays. Among the positive samples, E. canis was the most prevalent 62% (95% CI: 52.32&ndash, 71.68), followed by A. platys 40% (95% CI: 30.23&ndash, 49.77) and Rickettsia felis 27% (95% CI: 18.15&ndash, 35.85), whereas 36% (95% CI: 26.43&ndash, 45.57) showed co-infections. All samples were negative for A. phagocytophilum and B. burgdorferi s.l. The presence of 248 Rhipicephalus sanguineus ticks collected from the dogs was not statistically associated with the occurrence of infections. Thrombocytopenia was the most frequent haematological alteration found in PCR-positive dogs, it was statistically associated with the presence of E. canis, as well as co-infections (p &lt, 0.05). The phylogenetic analyses of A. platys and E. canis based on 16S rRNA, groEL and gltA genes showed a low genetic diversity between Cuban strains. The present study demonstrates the high prevalence of vector-borne pathogens with zoonotic potential in shelter dogs from Cuba.

Ticks and the vast array of pathogens they transmit, including bacteria, viruses, protozoa, and helminths, constitute a growing burden for human and animal health worldwide. In Cuba, the major tropical island in the Caribbean, ticks are an important cause of vector-borne diseases affecting livestock production, pet animal health and, to a lesser extent, human health. The higher number of tick species in the country belong to the Argasidae family and, probably less Pathogens 2020, 9, 616 2 of 24 known, is the presence of an autochthonous tick species in the island, Ixodes capromydis. Herein, we provide a comprehensive review of the ticks and tick-borne pathogens (TBPs) affecting animal and human health in Cuba. The review covers research results including ecophysiology of ticks, the epidemiology of TBPs, and the diagnostic tools used currently in the country for the surveillance of TBPs. We also introduce the programs implemented in the country for tick control and the biotechnology research applied to the development of anti-tick vaccines.

Canine hepatozoonosis caused by Hepatozoon canis is a worldwide distributed tick-borne disease of domestic and wild canids that is transmitted by ingestion of Rhipicephalus sanguineus sensu lato (s.l.) ticks. The present study was aimed to determine the prevalence of Hepatozoon infections in 80 stray dogs from Havana Province in Cuba, and to confirm the species identity and phylogenetic relationships of the causative agent. Samples were screened by microscopical examination of thin blood smears for the presence of Hepatozoon spp. gamonts and by genus-specific SYBR green-based real-time PCR assay targeting the 18S rRNA gene. Direct microscopy examination revealed Hepatozoon gamonts in the peripheral blood of 8 dogs (10.0%; 95% CI: 4.80–18.0%), while 38 animals (47.5%; 95% CI: 36.8–58.4%) were PCR-positive, including all microscopically positive dogs. Hence, the agreement between the two detection methods was ‘poor’ (κ = 0.20). Hematological parameters did not differ significantly between PCR-positive and PCR-negative dogs (p > 0.05). The DNA sequences of the 18S rRNA gene of the Hepatozoon spp. from Cuban dogs showed a nucleotide identity >99% with those of 18S rRNA sequences of Hepatozoon canis isolates from Czech Republic, Brazil and Spain. Phylogenetic analysis revealed that obtained sequences clustered within the Hepatozoon canis clade, different from the Hepatozoon felis or Hepatozoon americanum clades. The present study represents the first molecular characterization of Hepatozoon canis in stray dogs within Cuba.