Candidatus Rickettsia colombianensi in ticks from reptiles in Córdoba, Colombia

Detection of Rickettsia spp. in questing ticks (Acari: Ixodidae) from forest fragments adjacent to agricultural and livestock farms in Casanare, Colombia

This study aimed to describe the diversity of ixodid tick species in rural forest areas of Yopal and Aguazul, Department of Casanare, Colombia, and to evaluate the presence of tick-borne Rickettsia sp., potentially impacting animal and human health. A cross-sectional study was conducted on questing ticks collected from forested farm areas that keep livestock and/or conduct agricultural activities. All ticks were subjected to DNA extraction and tested by PCR amplifying fragments of three rickettsial genes: gltA, htrA, and ompA. A total of 852 individual ticks (larvae, nymphs, and adults) and 15 additional larvae clusters were collected and identified as Amblyomma mixtum, Amblyomma cf. parvum, Amblyomma dissimile, Amblyomma spp., and Dermacentor spp. Rickettsia organisms were detected by PCR in 7.0% (16/230) of the individual larvae, 0.2% (1/488) of the nymphs, and 1.5% (2/134) of the adults. "Candidatus Rickettsia colombianensi" and Rickettsia amblyommatis were detected in 1.52% (13/852) and 0.47% (4/852) of the ticks, respectively. In addition, a novel genotype, Rickettsia sp. genotype Yopal, phylogenetically closest to Rickettsia canadensis, was identified in two A. mixtum males. Several tick and Rickettsia species were found in the study areas, suggesting the need for an in-depth study of nonspecific acute tropical febrile illness in the Department of Casanare and across Colombia. Priority areas for future studies include investigating the molecular, clinical, and epidemiological features of the presentation of tick species and the possible participation of "Ca. R. colombianensi," R. amblyommatis, and "Rickettsia sp. Yopal genotype of A. mixtum" to understand their role in human rickettsiosis in the study region.

Molecular survey of Rickettsia spp. in ticks infesting wild animals in six departments in Colombia

Ticks are a globally distributed group of hematophagous ectoparasites that parasitize terrestrial vertebrates such as amphibians, reptiles, birds, and mammals. Ticks are vectors and reservoirs of pathogens that play an important role in wildlife and human health. Rickettsia is one of the bacteria transmitted by ticks, which some pathogenic species can cause rickettsiosis, a zoonotic disease that can cause serious harm to humans and animals. More information is necessary on the interactions between ticks and wildlife despite the fifty-seven ticks species already identified in Colombia. The objective of the present study was to determine the associations between ticks parasitizing wildlife and bacteria of the genus Rickettsia in six departments of Colombia. One hundred eighty-five ticks (80 larvae, 78 nymphs, and 27 adults) were collected from 55 wildlife species (amphibians, birds, mammals, and reptiles). Nine tick species were identified, and Rickettsia bellii, Rickettsia felis, 'Candidatus Rickettsia colombianensi' and Rickettsia parkeri were detected. Our results contribute to the current knowledge of tick-associated rickettsiae and the role of wildlife in their transmission dynamics.

New hard tick (Acari: Ixodidae) reports and detection of Rickettsia in ticks from Sierra Nevada de Santa Marta, Colombia

The Sierra Nevada de Santa Marta (SNSM), located in northern Colombia, is considered a geographical island with high levels of biodiversity and endemism. However, little is known about tick species and their associated microorganisms at the SNSM. In this study we sampled host-seeking ticks in areas of the town of Minca within the SNSM. We collected 47 ticks identified as Amblyomma pacae, Amblyomma longirostre, Amblyomma ovale, Amblyomma mixtum, Haemaphysalis juxtakochi, Ixodes sp. cf. Ixodes affinis and Ixodes sp. Of these ticks, we tested for Rickettsia spp. by amplifying the gltA, SCA1, and 16S rRNA genes via PCR. Rickettsia amblyommatis was detected in one pool of 3 larvae and in a female of A. pacae. Additonally, we isolated Rickettsia sp. belonging to the group of spotted fevers in larvae of A. longirostre. This study reports new findings of six species of ticks and two species of Rickettsia within the SNSM.

Spotted Fever Group Rickettsia spp. Molecular and Serological Evidence among Colombian Vectors and Animal Hosts: A Historical Review

Spotted fever group Rickettsia spp. (SFGR) are a large group of tick-borne bacteria causing important emerging and re-emerging diseases that affect animals and humans. While SFGR are found worldwide, a lack of surveillance and misdiagnosis particularly affect South American countries. Colombia is a high burdened country in South America, yet rickettsioses are not deemed a nationally reportable condition limiting disease-specific public health resources. As mortality rates are high for one Rickettsia pathogen species, there is a great need to better understand the epidemiological and ecological factors that increase SFGR transmission risk regionally. This literature review provides an overview of Colombia-based SFGR studies connecting knowledge about both vectors and hosts.

Molecular surveillance of microbial agents from cattle-attached and questing ticks from livestock agroecosystems of Antioquia, Colombia

Ticks are obligate ectoparasites and vectors of pathogens affecting health, agriculture, and animal welfare. This study collected ticks from the cattle and questing ticks of 24 Magdalena Medio Antioquia region cattle farms. Genomic DNA was extracted from the specimens (individual or pools) of the 2088 adult ticks collected from cattle and 4667 immature questing ticks collected from pastures. The molecular detection of Babesia, Anaplasma, Coxiella and Rickettsia genera was performed by polymerase chain reaction amplification and subsequent DNA sequencing. In a total of 6755 Rhipicephalus microplus DNA samples, Anaplasma marginale was the most detected with a frequency of 2% (Confidence Interval- CI 1.68-2.36), followed by Babesia bigemina with 0.28% (CI 0.16-0.44), Coxiella spp. with 0.15% (CI 0.07-0.27), and Rickettsia spp. with 0.13% (CI 0.06-0.25). Molecular analysis of the DNA sequences obtained from the tick samples revealed the presence of Coxiella-like endosymbiont and R. felis. These results demonstrated the diversity of microorganisms present in R. microplus ticks predominantly associated with cattle and questing ticks from livestock agroecosystems, suggesting their role as reservoirs and potential biological vectors of these microorganisms on the studied sites. Also, it emphasizes the need to combine acarological surveillance with clinical diagnoses and control strategies on regional and national levels.