High Rickettsial Diversity in Rodents and Their Ectoparasites From the Central Highlands of Madagascar

Rickettsioses are among emerging infectious diseases around the world. In Madagascar, little information is available regarding Rickettsia (Rickettsiales: Rickettsiaceae) diversity and their potential impacts on public health. In fact, molecular screening of ectoparasites of mammals reported the presence of three species, Rickettsia africae, Rickettsia typhi, and Rickettsia felis. The present study aims to investigate the diversity of Rickettsia in small mammals and associated ectoparasites (fleas and ticks) using a molecular approach. In September and December 2016, fieldworks were undertaken in two districts of Madagascar to capture small mammals using standard traps (Tomahawk and Sherman traps) and collect associated ectoparasites. In total, 12 taxa of ectoparasites (5 flea and 7 tick species) were collected from 89 individuals of four species of terrestrial small mammals. Rickettsia spp. were molecularly identified in one specimen of Rattus rattus (Rodentia: Muridae), one specimen of Pulex irritans (Siphonaptera: Pulicidae) as well as four specimens of Ixodes cf. colasbelcouri (Ixodida: Ixodidae). This study showed the presence of three phylogenetically distinct taxa of Rickettsia in small mammals and their ectoparasites. The current study broadens our knowledge on the diversity of Rickettsia in the Central Highlands of Madagascar and highlights for the first time the presence of Ri. felis in R. rattus and in tick, I. cf. colasbelcouri in Madagascar. Additional studies are needed to have exhaustive information on Rickettsia in small mammals and their ectoparasites, to determine their pathogenicity as well as their potential effects on public health in order to update the national policy for the control of emerging infectious diseases in Madagascar.

Melting curve analysis to differentiate Rickettsia spp. and Rickettsia felis

Rickettsiosis, caused by Rickettsia species, is one of the old arthropod-borne illness that commonly found in humans and animals. One of the barriers to rickettsiosis control is the intricacy and time-consuming nature of rickettsiosis laboratory diagnosis. This study aimed to establish quantitative real-time PCR targeting the gltA gene for the DNA differentiation of Rickettsia spp. and Ricketsia felis. The collection of cat flea was extracted to acquire the DNA of Rickettsia. Primers were designed based on the analysis of Rickettsia gltA gene sequences. The confirmation of R. felis was performed by sequencing of PCR product. BLAST analysis was done to confirm the closest similarity of the sequences. Results of this study highlighted the melting temperature was reached at 78,5 °C for Rickettsia spp. and 76.5+0.5 °C for Rickettsia felis. The melting peak temperatures were significantly different between Rickettsia spp. and R. felis (p<0.05). The findings of this work are crucial in the development of powerful diagnostic procedures for detecting and distinguishing Rickettsia spp. and R. felis species.

First Molecular Evidence of Pathogens in Fleas Collected from Dogs in Northern Vietnam

Fleas are considered as hosts for a wide range of pathogens that cause emerging and re-emerging zoonotic diseases worldwide. Data on fleas and flea-borne pathogens (FBPs) in the international literature are limited in Vietnam. This study aimed to investigate the species of fleas and the presence of pathogens of interest in fleas in northern Vietnam using PCR and sequence analysis. Out of 200 dogs enrolled in this study, 20% were infested by the flea species Ctenocephalides felis felis. In total, 62 fleas (35 females and 27 males) collected from domestic dogs were molecularly screened for the detection of pathogens. Out of the screened fleas, 39 were positive for Rickettsia felis (62.9%), 9 for Candidatus Mycoplasma hemobos (14.52%), and 6 for Mycoplasma wenyonii (9.68%). This study shows the first molecular detection of the above-mentioned pathogens in fleas collected from the studied areas and the potential risk of infection with examined FBPs in northern Vietnam.

Amblyomma aureolatum Genetic Diversity and Population Dynamics Are Not Related to Spotted Fever Epidemiological Scenarios in Brazil

Regional differences in tick-borne disease epidemiology may be related to biological variations between vector populations. Amblyomma aureolatum (Ixodida: Ixodidae), a neotropical tick, is known from several regions in Brazil. However, only in the metropolitan area of São Paulo (SP) state are there studies that establish its role as a vector of a pathogenic rickettsia (Rickettsia rickettsii). The aim of the study was to analyze the genetic diversity, population dynamics, and rickettsia infection in A. aureolatum populations from different spotted fever scenarios in Brazil. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D-loop mitochondrial markers for tick population analyses, and gltA, htrA, ompA, and ompB genes for rickettsia researches. Of the 7–17 tick haplotypes identified, 5–13 were exclusive to each population and 2–12 for each epidemiological scenario, as well as three haplotypes shared by all populations. Amblyomma aureolatum populations are expanding, and do not appear to be genetically structured vis-a-vis the different epidemiological scenarios studied. Rickettsia bellii (in SP) and Rickettsia felis (in Santa Catarina) were identified as infecting A. aureolatum. No relationship between tick haplotypes and rickettsia types were observed.

Protozoan and Microbial Pathogens of House Cats in the Province of Tekirdag in Western Turkey

Domestic felines' re-emerging infectious and neglected zoonotic diseases are a significant focus of global "One Health" efforts. This study aimed to rapidly diagnose 14 pathogens, including zoonoses by using PCR primers in 167 client-owned symptomatic cats, routinely accepted to the Veterinary Clinics of Tekirdag. The prevalence of pathogens investigated were as follows: Babesia canis canis (24%), Babesia microti (2.4%), Hepatozoon felis (10.8%), Cytauxzoon felis (6.6%), Bartonella henselae (40.1%), Anaplasma platys (30.5%), Anaplasma phagocytophilum (7.2%), Rickettsia felis (26.3%), Borrelia burgdorferi (21%), and hemotropic Mycoplasma sp. (11.4%). There was a significant difference between the prevalence of the pathogens (?2 = 152.26, df = 9, p < 0.001). There was also a statistical difference between the gender of the cats in terms of the prevalence of all pathogens considered together (?2 = 4.80, df = 1, p = 0.028), where the female cats showed a higher prevalence. This was not the case for the different age groups (?2 = 2.92, df = 1, p=0.088). The lowest infection was observed for B. microti (p < 0.001), while the highest infection was observed for B. henselae (p < 0.01). Leishmania donovani, Plasmodium spp., Ehrlichia chaffeensis, and Neoehrlichia mikurensis PCR test results were negative in all samples. In conclusion, house cats of Tekirdag are apparently highly susceptible to some neglected zoonoses important for "One Health," and their prevalence in the region is most probably underestimated. Hence, applying PCR tests to assist fast clinic diagnosis in routine, may be an efficient option to protect the public as well as the cats from severe diseases.

Historical Spatial Distribution of Zoonotic Diseases in Domestic, Synanthropic, and Wild Animals in the Mexican Territory of the Yucatan Peninsula

The Mexican territory of the Yucatan Peninsula has a tropical climate and harbors a wide variety of domestic, synanthropic, and wild animals, as well as disease vectors. To determine the distribution of recorded zoonotic diseases in the Yucatan Peninsula, scientific publications referring to these diseases in animals and containing geographic coordinates of disease occurrence, were studied. The epidemiological bulletins of the national government were also consulted to obtain information on zoonotic diseases reported in humans in the territory. The territory harbors a wide variety of tropical zoonotic pathogens, including Trypanosoma cruzi, Leptospira interrogans, Toxoplasma gondii, Leishmania mexicana, Dirofilaria immitis, and Rickettsia felis. A variety of domestic, synanthropic, and wild animals act as hosts or reservoirs in the transmission cycle of the zoonotic diseases in the Yucatan Peninsula, and some spillover into human populations has also been recorded. There are still zoonotic diseases that have rarely or never been reported in humans, but it is not clear whether this is because these diseases in humans are not common, there is a lack of viable transmission cycle or there is a lack of appropriate diagnosis. It is necessary to continue monitoring vectors, animal hosts, and humans to identify risk factors for zoonotic diseases in the Yucatan Peninsula.

Serological Survey on the Occurrence of Rickettsia spp., Neospora caninum, Bartonella henselae and Toxoplasma gondii in Cats from Tuscany (Central Italy)

Asymptomatic cats often harbor pathogens, some of which have not been largely investigated in feline populations. The aim of this study was to evaluate the occurrence of antibodies against Rickettsia conorii, Rickettsia felis, Rickettsia typhi, Neospora caninum, Bartonella henselae and Toxoplasma gondii in cats from Tuscany. Ninety-five blood serum samples, previously collected, were analyzed by indirect immunofluorescence assay. Fifty-six (58.94%) cats had antibodies to at least one investigated pathogen: 28 (29.47%) cats were positive for B. henselae, 17 (17.89%) for R. felis, 14 (14.73%) for R. conorii, 14 (14.73%) for T. gondii, 2 (2.1%) for N. caninum. No cats were positive for R. typhi. Positive reactions to two or more pathogens were detected in 18 (18.94%) cats. The occurrence of antibodies against these microorganisms suggests that cats, even though asymptomatic, may be infected by pathogens, often zoonotic, and thus may be a source of infections for other animals and humans.

Caracterización epidemiológica de casos humanos compatibles con rickettsiosis que consultaron a instituciones de salud del departamento de Caldas-Colombia, años 2016-2019

Introducción: Las rickettsiosis son enfermedades zoonóticas, algunos artrópodos cumplen el papel de vectores. la inespecificidad de los síntomas hace que su diagnóstico clínico sea difícil. La Inmunofluorescencia indirecta (IFI), se usa en el diagnóstico. En Colombia, a partir del 2003, ha resurgido el interés por realizar estudios en búsqueda de dicha patología. Objetivo: Caracterizar epidemiológicamente los casos humanos compatibles con rickettsiosis que consultan a las instituciones de salud del departamento de Caldas-Colombia, durante el periodo de tiempo comprendido en los años 2016- 2019. Métodos: Se realizó un estudio de diseño cuantitativo, observacional, descriptivo, con una muestra no probabilística constituida por 175 pacientes con síntomas compatibles con rickettsiosis que consultaron en diferentes municipios de Caldas- Colombia; se les realizo IFI para la detección de anticuerpos en fase aguda y convaleciente frente a Rickettsia rickettsii, Rickettsia typhi y Rickettsia felis. Resultados: El promedio de edad fue de 31 años, Los municipios con mayor proporción de casos son Belalcázar, Chinchiná, Filadelfia, La Dorada, La Merced, Manizales. El 66 % tenían mascotas, frecuentemente perros; el 12% manifiestan picaduras por artrópodos. Los signos y síntomas más frecuentes fueron: cefalea 69,7%, artromialgia 60%, fiebre 58,2%. La seroprevalencia por IgG fue del 60%, 47,9% y 24% para R. rickettsii, R. typhi y R. felis respectivamente. Cinco pacientes presentaron seroconversión frente a R. rickettsii y R. felis y uno frente a R. typhi. Conclusión: Hay evidencia de enfermedad rickettsial en el departamento, predominantemente asociada con rickettsias del grupo de las fiebres manchadas.