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Two hundred and thirty-three blood samples of water buffalo were collected on four farms in Veracruz state and Tabasco state, Mexico, to detect and confirm the identities of

American bison (Bison bison) is listed as near-threatened and in danger of extinction in Mexico. Recent studies have demonstrated the presence of several emerging pathogens at the Janos Biosphere Reserve (JBR), inhabited by one wild herd of American bison. Blood samples were collected from 26 American bison in the JBR. We tested for the presence of Anaplasma marginale, Babesia bigemina, B. bovis, Borrelia burgdorferi sensu lato, and Rickettsia rickettsii DNA using nested and semi-nested PCR protocols performing duplicates in two different laboratories. Results showed three animals (11.5%) positive for B. burgdorferi s. l., three more (11.5%) for Rickettsia rickettsii, and four (19.2%) for B. bovis. Two individuals were co-infected with B. burgdorferi s. l. and B. bovis. We found no animals positive for A. marginale and B. bigemina. This is the first report in America of R. rickettsii in American bison. American bison has been described as an important reservoir for pathogens of zoonotic and veterinary importance, thus, the presence of tick-borne pathogen DNA in the JBR American bison indicates the importance of continuous wildlife health surveys.

Canine hepatozoonosis is a tick-borne disease caused by apicomplexan hemoparasites of the genus Hepatozoon spp. (Apicomplexa: Hepatozoidae). We report a clinical case of hepatozoonosis in a domestic Siberian husky dog, Canis lupus familiaris (Linnaeus). The dog was a male of 2 years remitted to the University Veterinary Hospital because it appeared lame in the hind limbs. During clinical evaluation it presented ataxia, loss of proprioception in both hind limbs, hyperreflexia of the right hind limb, and hyporeflexia of the left hind limb. Intervertebral disc disease was ruled out with radiographic and magnetic resonance imaging. Serological tests for infectious diseases such as ehrlichiosis, anaplasmosis (SNAP 4Dx Plus® test, IDEXX Laboratories), and leptospirosis (SNAP® Lepto Test, IDEXX Laboratories) were negative. Four biopsy samples of the biceps femoris muscle were taken. Histopathological diagnosis reported “onion skin” cysts 200 to 300 µm, suggestive of Hepatozoon americanum. Clinical confirmation of Hepatozoon spp. at the border of Mexico with Texas and New Mexico could impact differential diagnosis of neuromuscular disease in the area, especially in dogs where the causes of muscular pain and weakness and lameness are non-diagnostic.

Background Nowadays, Ehrlichia canis receives increasing attention because of its great morbidity and mortality in animals. Dogs in the subclinical and chronic phases can be asymptomatic, and serological tests show cross-reactivity and fail to differentiate between current and past infections. Moreover, there could be low parasitaemia, and E. canis might be found only in target organs, hence causing results to be negative by polymerase chain reaction (PCR) on blood samples. Methods We evaluated by PCR the prevalence of E. canis in blood, liver, spleen, lymph node and bone marrow samples of 59 recently euthanised dogs that had ticks but were clinically healthy. Results In total, 52.55% of the blood PCRs for E. canis were negative, yet 61.30% yielded positive results from tissue biopsies and were as follows: 63.15% from bone marrow; 52.63% from liver; 47.36% from spleen; and 15.78% from lymph node. In addition, 33% had infection in three tissues (spleen, liver and bone marrow). Conclusions Our results show the prevalence of E. canis from tissues of dogs that were negative by blood PCR. Ehrlichia canis DNA in tissue was 30% lower in dogs that tested negative in PCR of blood samples compared to those that were positive. However, it must be taken into account that some dogs with negative results were positive for E. canis in other tissues.

Background: Nowadays, Ehrlichia canis receives increasing attention because of its great morbidity and mortality in animals. Dogs in the subclinical and chronic phases can be asymptomatic, and serological tests show cross-reactivity and fail to differentiate between current and past infections. Moreover, there could be low parasitaemia, and E. canis might be found only in target organs, hence causing results to be negative by polymerase chain reaction (PCR) on blood samples.Methods: We evaluated by PCR the prevalence of E. canis in blood, liver, spleen, lymph node and bone marrow samples of 59 recently euthanised dogs that had ticks but were clinically healthy.Results: In total, 52.55% of the blood PCRs for E. canis were negative, yet 61.30% yielded positive results from tissue biopsies and were as follows: 63.15% from bone marrow; 52.63% from liver; 47.36% from spleen; and 15.78% from lymph node. In addition, 33% had infection in three tissues (spleen, liver and bone marrow).Conclusions: Our results show the prevalence of E. canis from tissues of dogs that were negative by blood PCR. Ehrlichia canis DNA in tissue was 30% lower in dogs that tested negative in PCR of blood samples compared to those that were positive. However, it must be taken into account that some dogs with negative results were positive for E. canis in other tissues.

In this study, we report Babesia bigemina proliferation in culture medium free of components of animal origin supplemented with a lipid mixture. Babesia bigemina continuously proliferated in VP-SFM with a higher percent parasitized erythrocyte as compare to using other animal component-free culture media. Compared with Advanced DMEM/F12 (ADMEM/F12), VP-SFM had a similar percent parasitized erythrocyte (PPE). Supplementation of VP-SF with a lipid acid mixture improved B. bigemina proliferation in vitro culture, with a maximum PPE of 11.3%. Growth of B. bigemina in a perfusion bioreactor using VP-SFM medium supplemented with lipid mixture resulted in a PPE above 28%. In conclusion, we demonstrated that B. bigemina proliferated in an animal component-free medium supplemented with the fatty acid mixture. This innovation to B. bigemina in vitro culture method presented herein is an important source of biological material for live vaccine production and understanding the mechanisms and molecules involved in parasite attachment and invasion of bovine erythrocytes.

Currently, ticks are second in transmission of pathological agents to humans, and in the veterinary field are ranked first. Thus, pathogens that might be in contact with human and animal populations, especially farm animals such as horses, Equus caballus (Linnaeus), should be identified. Two species of soft ticks in the Argasidae family, Otobius megnini (Duges) and Ornithodoros turicata (Duges), and one hard tick of the Ixodidae family, Rhipicephalus sanguineus (Latreille) were identified. DNA of pathogens Theileria equi (Laveran), Babesia caballi (Nuttall and Strickland), and Anaplasma phagocytophilum (Foggie) that have been reported in species of hard ticks but not soft ticks were identified. Overall, 144 blood samples from horses at Ciudad Juarez, Chihuahua, Mexico, were processed for DNA extraction, and analyzed by end-point or nested PCR to identify pathogens. The prevalence of T. equi was 6.9% (10/144) and 5.9% (3/51) in blood samples and soft tick samples, respectively; the prevalence of B. caballi was 2.8% (4/144) in blood samples and 5.9% (3/51) in soft ticks. There was one case of coinfection with both pathogens, and one blood sample tested positive for A. phagocytophilum, indicating a prevalence of 0.8% (1/124). The results suggested that soft ticks evaluated are potential vectors and might play a role in transmission of the pathogens.

Para evaluar la transmisión por garrapatas Rhipicephalus microplus (R. microplus) de una clona atenuada de Babesia bovis (BOR) y una cepa atenuada de Babesia bigemina (BIS), doce bovinos se dividieron en cuatro grupos e infestados de forma escalonada con larvas de R. microplus libres de Babesia spp. Un becerro de cada grupo se inoculó con 1x108 eritrocitos infectados (EI) con BIS, BOR, y cepas virulentas de B. bigemina y B. bovis, respectivamente. Se realizaron dos inoculaciones seriadas adicionales (pases/jeringa) y se colectaron hembras R. microplus cuya repleción coincidió con presencia de EI en los bovinos inoculados, y cuya progenie fue utilizada para infestar un grupo de bovinos receptores (pases/garrapata). Los tres pases sucesivos por jeringa evidenciaron EI en los bovinos que recibieron las cepas atenuadas y virulentas de B. bigemina y B. bovis. Se identificaron quinetos de Babesia en garrapatas alimentadas sobre bovinos infectados con cepas virulentas de B. bigemina y B. bovis. No se identificaron quinetos en garrapatas alimentadas sobre bovinos inoculados con cepas atenuadas. Todos los receptores infestados con progenie de garrapatas alimentadas sobre bovinos infectados con cepas virulentas, resultaron positivos a Babesia. Contrariamente, los receptores de garrapatas derivadas de bovinos inoculados con cepas atenuadas resultaron negativos, excepto por los infestados con garrapatas derivadas del tercer pase realizado con BIS y BOR. Las cepas atenuadas podrían conferir un margen de seguridad mayor como inmunógenos, al no ser transmitidas por R. microplus y no revertir a la virulencia al menos después de dos pases sucesivos en bovinos.

Of 20 blood samples from nilgais from Mexico, five were polymerase chain reaction-positive for Babesia bigemina and one for Babesia bovis. Positive samples had the expected 170 (B. bigemina) and 291 (B. bovis) base pairs and were identical to Gen- Bank B. bigemina accession S45366 and B. bovis M38218.

"En este estudio se realizó el análisis de Etiquetas de Secuencias Expresadas (EST) obtenidas a partir de 2208 clonas de Escherichia coli, con plásmidos recombinantes conteniendo insertos de cDNA de Babesia bigemina. Las secuencias se analizaron mediante búsqueda de homología en las bases de datos de genes. El análisis de homología en secuencia permitió identificar 470 clonas (agrupadas en 267 clusters) conteniendo EST con similitud de secuencia estadísticamente no significativa con algún gen de Babesia spp o de otro organismo Apicomplexa, sugiriendo la presencia de genes nuevos de B. bigemina; Se identificaron 21 clonas con EST correspondientes a 6 secuencias de genes previamente reportados para B. bigemina; además de 1285 clonas (conformando 159 clusters de genes distintos) de identidad significativa con proteínas hipotéticas o correspondientes a genes ya reportados en el genoma secuenciado de Babesia bovis; 32 clonas con EST homólogas a 16 genes distintos de Theileria spp; 51 clonas (26 genes distintos) con similitud en secuencia a genes de Plasmodium spp; 25 clonas con EST de moderada similitud con 13 genes distintos genes de Toxoplasma gondii; y 4 clonas con EST de mayor identidad con 4 genes diferentes de Cryptosporidium spp. Los resultados obtenidos permiten elaborar una base de datos sobre EST del estadio intraeritrocítico de Babesia bigemina, información básica esencial para la caracterización molecular del parásito, que permite llevar a cabo la identificación y regulación de nuevas regiones génicas codificadoras y, eventualmente el establecimiento de nuevas estrategias de control de la babesiosis bovina causada por B. bigemina."

The effect of Lactobacillus casei on INIFAP's mixed vaccine against bovine babesiosis (VAC) was assessed in bovines in an endemic babesiosis area. It was previously reported that L. casei increases the efficiency of the Mexican mixed vaccine against bovine babesiosis under controlled conditions. The results of the present study demonstrated the effectiveness of simultaneous vaccination of bovines with L. casei and the mixed vaccine against bovine babesiosis in eliciting a protective immune response under extreme conditions in the field. Twenty Babesia spp free bovines were allocated into three groups: un-vaccinated (Control, n = 9), vaccinated with VAC (n = 5), and vaccinated simultaneously with VAC and Lactobacillus casei (LC-VAC, n = 6). All animals were kept in a tick and Babesia spp free field at Coatepec, Veracruz during 24 days before moving them to Paso delToro, Veracruz, for a natural exposition to Babesia spp transmitted by Riphicephalus (Boophilus) microplus ticks. Protection against Babesia spp was observed in bovines belonging to VAC and LC-VAC groups, while control animals showed severe clinical babesiosis. Bovines in VAC-LC group showed less clinical signs between days 12-16 after challenge as compared with animals in VAC group. All bovines showed both Babesia spp after challenge. Levels of IgG anti-Babesia in animals from both vaccinated groups, determined by indirect immunofluorescence test, always were higher to Babesia bovis than to B. bigemina after vaccination and challenge. It was demonstrated the efficiency of simultaneous vaccination of bovines with VAC and L. casei, in eliciting a better protective immune response against naturally transmitted Babesia spp under extreme field conditions.