Tick-borne bacterial pathogens (TBBPs) show a worldwide distribution and represent a great impact... more Tick-borne bacterial pathogens (TBBPs) show a worldwide distribution and represent a great impact on public health. The brown dog tick (Rhipicephalus sanguineus) is a vector of several pathogens that affect dogs and sometimes humans as well. In addition, TBBPs represent a diagnostic challenge and imply financial resources and medical treatment for long periods of time. In the present study, R. sanguineus s. l. was identified as the main tick species naturally parasitizing dogs that inhabit. Juárez City, Chihuahua, in the Paso del Norte region, Mexico–US Border, representing 99.8% of the cases. Additionally, an end-point PCR was performed to search for whether pathogens in R. sanguineus s. l. can transmit in DNA extracted from ticks and dog blood samples. This is the first molecular detection of Rickettsia rickettsi infecting domestic dogs in Mexico; however, other pathogens were also identified, such as Ehrlichia canis and Anaplasma platys in both ticks and dog blood samples, while ...
Abstract. Babesiosis is a tick-borne disease caused by protozoan parasites of the genus Babesia (... more Abstract. Babesiosis is a tick-borne disease caused by protozoan parasites of the genus Babesia (Starcovici, 1893). Canine babesiosis cases occurring worldwide are associated mainly with Babesia gibsoni (Patton, 1910) and Babesia canis (Piana and Galli-Valerio, 1895), the latter reclassified into three sub-species: B. canis canis (Piana and Galli-Valerio, 1895), B. canis rossi (Nuttall, 1910), and B. canis vogeli (Reichenow, 1937). A 7-month-old male, Siberian husky dog, Canis familiaris (Linnaeus, 1758) infested with ticks was taken to a veterinary clinic at Colima, Mexico. Symptoms at clinical examination of the dog included: weakness, pale mucous membranes, decreased capillary filling time (≥4 seconds), fever (39.8°C), left abdominal distension, and pain. Radiographic images showed moderate splenomegaly. Hematological study revealed reduction in packed cell volume, hemoglobin concentration, erythrocyte count, platelet count, and leukocyte count. Microscopic examination of Giemsa-stained blood smears showed pyriform-shaped bodies inside erythrocytes, compatible with a large Babesia spp. Molecular analysis indicated a Babesia spp. in the blood. The study describes the first case reported at Colima, Mexico, where B. canis vogeli infection was confirmed in a dog.
Abstract. Canine hepatozoonosis is a tick-borne disease caused by apicomplexan hemoparasites of t... more Abstract. 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 am...
In this study, Expressed Sequence Tags (EST) were obtained and analyzed from 2208 randomly select... more In this study, Expressed Sequence Tags (EST) were obtained and analyzed from 2208 randomly selected clones containing plasmids with cDNA inserts derived from a Babesia bigemina library. The obtained sequences were extracted and subject to Blast homology search in the Genbank databases. Sequence homology analysis resulted in the identification of 470 clones (grouped in 267 distinct clusters) which contained EST with no significant sequence identity with Babesia sp genes or other Apicomplexan parasites. Presumably, these EST would correspond either to new, unreported B. bigemina transcribed genes present in the erythrocyte stages of the parasite, or to non-translated sequences of the putative genes. 21 clones were identified which contained EST corresponding to 6 genes coding for B. bigemina antigens already reported in the literature; 1285 clones (grouped in 159 clusters of distinct sequences) had significant sequence identity with genes coding for hypothetical proteins previously id...
Babesia bovis, an etiological agent of bovine babesiosis, causes a significant burden to the catt... more Babesia bovis, an etiological agent of bovine babesiosis, causes a significant burden to the cattle industry worldwide. The most efficient method to mitigate bovine babesiosis is a live vaccine produced by serial passage in splenectomized cattle. However, there are several concerns regarding live vaccine production, including variation between batches and the use of many animals. In this study, we report a B. bovis-SF strain continuously cultured in a medium free of components of animal origin enriched with a chemically defined lipid mixture (CD lipid mixture) and the use of a perfusion bioreactor to harvest a large amount of B. bovis. Six culture media were compared, including VP-SFM, CD-CHO, CD-Hydrolyzed, CD-CHO, SFM, and ADMEM/F12. We found that the VP-SFM medium performed the best for B. bovis growth, with a maximum percentage of parasitized erythrocytes (PPE) of 8.6%. The effect of six dilutions of a commercial mixture of CD lipids added to VP-SFM showed that the CD lipid mixt...
Background: Nowadays, Ehrlichia canis receives more attention because of its great morbidity and ... more Background: Nowadays, Ehrlichia canis receives more attention because of its great morbidity and mortality in animals. Dogs in the subclinical and chronic phases can be asymptomatic, and serologic 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 negative by PCR in blood. Methods: We evaluated by PCR the prevalence of E. canis in blood, liver, spleen, lymphatic nodules, and bone marrow in 59 recently euthanized 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% yield positive results in tissue biopsies as follows: 63.15% from bone marrow, 52.63% from liver, 47.36% from spleen and 15.78% from lymphatic nodules. In addition, 33% had infection in three tissues (spleen, liver and bone marrow). Conclusions: Our results show prevalence of E. canis in tissue from dogs tha...
In this study, we report Babesia bigemina proliferation in culture medium free of components of a... more 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 mo...
This study reported that Babesia bigemina (Bbig-SF) was continuously cultured in vitro in a serum... more This study reported that Babesia bigemina (Bbig-SF) was continuously cultured in vitro in a serum-free medium supplemented with a mixture of insulin-transferrin-selenite (M-ITS) and putrescine (Pu). Firstly, the effect of five different types of basal culture media supplemented with 40% bovine serum was evaluated regarding the proliferation of the protozoan parasite. Cultures with the advanced DMEM/F12 medium (A-DMEM/F12) showed the highest percentage of parasitized erythrocytes (PPE) at 8.37%. Using A-DMEM/F12, a strain of B. bigemina (Bbig-SF) was adapted for growth in bovine serum-free medium by a sequential reduction of serum and demonstrated a maximum PPE of 7.18% in the absence of serum. The next study was the evaluation of the effect of adding four different concentrations of M-ITS to the serum-free A-DMEM/F12 medium on Bbig-SF; the optimal concentrations of M-ITS were 2000, 1100, and 1.34 mg/L, which yielded a PPE of 7.23%. Next, eight levels of Pu were evaluated on Bbig-SF cultured in serum-free A-DMEM/F12. After the addition of 0.1012 mg/L of Pu, the maximum PPE was 7.61%. When the combination of serum-free A-DMEM/F12 + M-ITS (2000, 1100, and 1.34 mg/ L) + Pu (0.1012 mg/L) was evaluated, it yielded a maximum PPE of 14.80%. Finally, the combination of M-ITS + Pu in A-DMEM/F12 without serum and incorporation of a perfusion bioreactor yielded a maximum PPE of 33.45%. We concluded these culturing innovations for B. bigemina in vitro allow the optimization of small-and large-scale proliferation as a source of this protozoan parasite for future studies. Recently, Rojas et al. [15] demonstrated that by using the advanced
Con objeto de evaluar cambios en la morfología celular como signo de activación, se obtuvieron mo... more Con objeto de evaluar cambios en la morfología celular como signo de activación, se obtuvieron monocitos de sangre periférica de cuatro bovinos adultos y se cultivaron in vitro en presencia o no de Lactobacillus casei. A las 48 y 72 horas después de la exposición a la bacteria, las células se tiñeron y en el microscopio óptico se determinó la circunferencia de la membrana plasmática (CMP) y la máxima longitud del citoplasma (MLC). Los promedios obtenidos (+ EEM) de la CMP y MLC (n=20/bovino) para las células testigo (T) y tratadas con L. casei (LC), fueron para CMP: 41.54 (+ 2.08) µm para T y 61.53 (+ 2.30) µm para LC a las 48 horas (P<0.05) y de 35.80 (+ 1.49) µm para T y de 68.90 (+ 8.8) µm para LC a las 72 horas (P<0.05). Los valores promedios de la MLC obtenidos fueron de 13.08 (+ 1.05) µm para T y 19.34 (+ 0.86) mµ para LC a las 48 horas (P<0.05) y de 11.46 (+ 0.67) µm para T y 21.55 (+ 3.3) µm para LC a las 72 horas (P<0.05). Los resultados obtenidos sugieren que...
To assess transmissibility of attenuated Babesia bigemina (BIS) and Babesia bovis (BOR) strains b... more To assess transmissibility of attenuated Babesia bigemina (BIS) and Babesia bovis (BOR) strains by Rhipicephalus microplus (R. microplus), 12 steers from a tick-free area were divided in four groups and infested at different intervals with R. microplus larvae. One animal from each group was inoculated with 1x108 infected erythrocytes (IE) of attenuated BIS, BOR, virulent B. bigemina, or B. bovis field strains.
Two hundred and thirty-three blood samples of water buffalo were collected on four farms in Verac... more 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 Babesia and Anaplasma spp. sequences. Nested PCR assays were used for the amplification of specific genes encoding B. bovis rhoptry-associated protein (RAP-1), B. bigemina SpeI-AvaI restriction fragment, and Anaplasma marginale major surface protein 5 (MSP5). Using DNA sequencing and BLASTn analysis for DNA homology hemoparasite identification, the identities of the hemoparasites were established by comparing the nucleotide sequences obtained in this study with those available in the GenBank database at the National Center for Biotechnology Information (NCBI). Water buffalo infection with at least one of the hemoparasites under study was detected in 45% (105/233) of the blood samples, while a mixed infection with B. bovis and B. bigemina was detected in 6.4% (15/233) of samples. For this cross-sectional study, m...
Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa prot... more Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa protozoa of the genus Babesia that are obligate intraerythrocytic parasites. The pathogenicity of Babesia parasites for cattle is determined by the interaction with the host immune system and the presence of the parasite’s virulence genes. A Babesia bigemina strain that has been maintained under a microaerophilic stationary phase in in vitro culture conditions for several years in the laboratory lost virulence for the bovine host and the capacity for being transmitted by the tick vector. In this study, we compared the virulome of the in vitro culture attenuated Babesia bigemina strain (S) and the virulent tick transmitted parental Mexican B. bigemina strain (M). Preliminary results obtained by using the Basic Local Alignment Search Tool (BLAST) showed that out of 27 virulence genes described and analyzed in the B. bigemina virulent tick transmitted strain, only five were fully identified in ...
Bovine babesiosis is a hemoparasitic disease caused by intra-erythrocytic protozoa of the genus B... more Bovine babesiosis is a hemoparasitic disease caused by intra-erythrocytic protozoa of the genus Babesia. It is mainly transmitted by Rhipicephalus (Boophilus) microplus ticks and cause of a hemolytic devastating disease with a high economic impact in the cattle industry, particularly in the tropical and subtropical areas of the world where the tick vector is endemic. Immunization with in vitro culture-derived parasites is thus far the best procedure that can be used for the prevention or control of bovine babesiosis. It has been proved that when the vaccine parasites are established in the animals, the induced immune response is protective, able to respond to natural challenge with parasites of high virulence in the field. With this methodology, a better control of possible contamination with other pathogens is also achieved. It is therefore reasonable to recommend the use of the vaccine in susceptible animals that could be introduced into endemic areas. This article outlines only s...
The aim of the present research was to assess the immunogenicity and protective capability of a c... more The aim of the present research was to assess the immunogenicity and protective capability of a combination of the B. bovis recombinant proteins MSA-1, MSA-2c and 12D3 in cattle exposed to Babesia infection transmitted by ticks under natural conditions. The immunization phase of the study was conducted at CENID-Parasitología Veterinaria in Jiutepec, Morelos, and the challenge phase was carried out in an experimental station in Pichucalco, Chiapas, Mexico. Eighteen steers were randomly distributed into three groups of six animals each. Animals were treated on days 0 and 14 as follows: Group 1 (G1), control, with the adjuvant Montanide 70 (M70) + PBS; Group 2 (G2) with a mixture of the Babesia bovis recombinant proteins MSA-1, MSA-2c and 12D3 admixed in M70; Group 3 (G3) with a live attenuated mixed vaccine against bovine babesiosis (day 0 only). Immunization of cattle with a combination of recombinant proteins from B. bovis induced specific IgG antibodies that recognized the correspo...
The indirect fluorescent antibody test (IFAT) is the most frequently used test to conduct seroepi... more The indirect fluorescent antibody test (IFAT) is the most frequently used test to conduct seroepidemiological studies so far, and it is regarded as the "gold standard" test for the serological diagnosis of bovine babesiosis. The aim of the present study was to compare the enzyme-linked immunosorbent assay (ELISA) and the rapid immunochromatography test (ICT) for use in the serological diagnosis of cattle exposed to B. bovis in Mexico. The evaluation of test performance was carried out with 30 positive and 30 negative reference sera. A total of 72 bovine sera samples collected from cattle in a region with endemic bovine babesiosis were analyzed by ELISA and ICT, and the results were compared with those of IFAT. Kappa value (k) was also calculated to determine the agreement between tests. The sensitivity and specificity of ELISA for detecting antibodies against B. bovis were 87% (26/30) and 80% (24/30), respectively. The sensitivity and specificity of ICT for detecting antib...
Tick-borne bacterial pathogens (TBBPs) show a worldwide distribution and represent a great impact... more Tick-borne bacterial pathogens (TBBPs) show a worldwide distribution and represent a great impact on public health. The brown dog tick (Rhipicephalus sanguineus) is a vector of several pathogens that affect dogs and sometimes humans as well. In addition, TBBPs represent a diagnostic challenge and imply financial resources and medical treatment for long periods of time. In the present study, R. sanguineus s. l. was identified as the main tick species naturally parasitizing dogs that inhabit. Juárez City, Chihuahua, in the Paso del Norte region, Mexico–US Border, representing 99.8% of the cases. Additionally, an end-point PCR was performed to search for whether pathogens in R. sanguineus s. l. can transmit in DNA extracted from ticks and dog blood samples. This is the first molecular detection of Rickettsia rickettsi infecting domestic dogs in Mexico; however, other pathogens were also identified, such as Ehrlichia canis and Anaplasma platys in both ticks and dog blood samples, while ...
Abstract. Babesiosis is a tick-borne disease caused by protozoan parasites of the genus Babesia (... more Abstract. Babesiosis is a tick-borne disease caused by protozoan parasites of the genus Babesia (Starcovici, 1893). Canine babesiosis cases occurring worldwide are associated mainly with Babesia gibsoni (Patton, 1910) and Babesia canis (Piana and Galli-Valerio, 1895), the latter reclassified into three sub-species: B. canis canis (Piana and Galli-Valerio, 1895), B. canis rossi (Nuttall, 1910), and B. canis vogeli (Reichenow, 1937). A 7-month-old male, Siberian husky dog, Canis familiaris (Linnaeus, 1758) infested with ticks was taken to a veterinary clinic at Colima, Mexico. Symptoms at clinical examination of the dog included: weakness, pale mucous membranes, decreased capillary filling time (≥4 seconds), fever (39.8°C), left abdominal distension, and pain. Radiographic images showed moderate splenomegaly. Hematological study revealed reduction in packed cell volume, hemoglobin concentration, erythrocyte count, platelet count, and leukocyte count. Microscopic examination of Giemsa-stained blood smears showed pyriform-shaped bodies inside erythrocytes, compatible with a large Babesia spp. Molecular analysis indicated a Babesia spp. in the blood. The study describes the first case reported at Colima, Mexico, where B. canis vogeli infection was confirmed in a dog.
Abstract. Canine hepatozoonosis is a tick-borne disease caused by apicomplexan hemoparasites of t... more Abstract. 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 am...
In this study, Expressed Sequence Tags (EST) were obtained and analyzed from 2208 randomly select... more In this study, Expressed Sequence Tags (EST) were obtained and analyzed from 2208 randomly selected clones containing plasmids with cDNA inserts derived from a Babesia bigemina library. The obtained sequences were extracted and subject to Blast homology search in the Genbank databases. Sequence homology analysis resulted in the identification of 470 clones (grouped in 267 distinct clusters) which contained EST with no significant sequence identity with Babesia sp genes or other Apicomplexan parasites. Presumably, these EST would correspond either to new, unreported B. bigemina transcribed genes present in the erythrocyte stages of the parasite, or to non-translated sequences of the putative genes. 21 clones were identified which contained EST corresponding to 6 genes coding for B. bigemina antigens already reported in the literature; 1285 clones (grouped in 159 clusters of distinct sequences) had significant sequence identity with genes coding for hypothetical proteins previously id...
Babesia bovis, an etiological agent of bovine babesiosis, causes a significant burden to the catt... more Babesia bovis, an etiological agent of bovine babesiosis, causes a significant burden to the cattle industry worldwide. The most efficient method to mitigate bovine babesiosis is a live vaccine produced by serial passage in splenectomized cattle. However, there are several concerns regarding live vaccine production, including variation between batches and the use of many animals. In this study, we report a B. bovis-SF strain continuously cultured in a medium free of components of animal origin enriched with a chemically defined lipid mixture (CD lipid mixture) and the use of a perfusion bioreactor to harvest a large amount of B. bovis. Six culture media were compared, including VP-SFM, CD-CHO, CD-Hydrolyzed, CD-CHO, SFM, and ADMEM/F12. We found that the VP-SFM medium performed the best for B. bovis growth, with a maximum percentage of parasitized erythrocytes (PPE) of 8.6%. The effect of six dilutions of a commercial mixture of CD lipids added to VP-SFM showed that the CD lipid mixt...
Background: Nowadays, Ehrlichia canis receives more attention because of its great morbidity and ... more Background: Nowadays, Ehrlichia canis receives more attention because of its great morbidity and mortality in animals. Dogs in the subclinical and chronic phases can be asymptomatic, and serologic 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 negative by PCR in blood. Methods: We evaluated by PCR the prevalence of E. canis in blood, liver, spleen, lymphatic nodules, and bone marrow in 59 recently euthanized 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% yield positive results in tissue biopsies as follows: 63.15% from bone marrow, 52.63% from liver, 47.36% from spleen and 15.78% from lymphatic nodules. In addition, 33% had infection in three tissues (spleen, liver and bone marrow). Conclusions: Our results show prevalence of E. canis in tissue from dogs tha...
In this study, we report Babesia bigemina proliferation in culture medium free of components of a... more 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 mo...
This study reported that Babesia bigemina (Bbig-SF) was continuously cultured in vitro in a serum... more This study reported that Babesia bigemina (Bbig-SF) was continuously cultured in vitro in a serum-free medium supplemented with a mixture of insulin-transferrin-selenite (M-ITS) and putrescine (Pu). Firstly, the effect of five different types of basal culture media supplemented with 40% bovine serum was evaluated regarding the proliferation of the protozoan parasite. Cultures with the advanced DMEM/F12 medium (A-DMEM/F12) showed the highest percentage of parasitized erythrocytes (PPE) at 8.37%. Using A-DMEM/F12, a strain of B. bigemina (Bbig-SF) was adapted for growth in bovine serum-free medium by a sequential reduction of serum and demonstrated a maximum PPE of 7.18% in the absence of serum. The next study was the evaluation of the effect of adding four different concentrations of M-ITS to the serum-free A-DMEM/F12 medium on Bbig-SF; the optimal concentrations of M-ITS were 2000, 1100, and 1.34 mg/L, which yielded a PPE of 7.23%. Next, eight levels of Pu were evaluated on Bbig-SF cultured in serum-free A-DMEM/F12. After the addition of 0.1012 mg/L of Pu, the maximum PPE was 7.61%. When the combination of serum-free A-DMEM/F12 + M-ITS (2000, 1100, and 1.34 mg/ L) + Pu (0.1012 mg/L) was evaluated, it yielded a maximum PPE of 14.80%. Finally, the combination of M-ITS + Pu in A-DMEM/F12 without serum and incorporation of a perfusion bioreactor yielded a maximum PPE of 33.45%. We concluded these culturing innovations for B. bigemina in vitro allow the optimization of small-and large-scale proliferation as a source of this protozoan parasite for future studies. Recently, Rojas et al. [15] demonstrated that by using the advanced
Con objeto de evaluar cambios en la morfología celular como signo de activación, se obtuvieron mo... more Con objeto de evaluar cambios en la morfología celular como signo de activación, se obtuvieron monocitos de sangre periférica de cuatro bovinos adultos y se cultivaron in vitro en presencia o no de Lactobacillus casei. A las 48 y 72 horas después de la exposición a la bacteria, las células se tiñeron y en el microscopio óptico se determinó la circunferencia de la membrana plasmática (CMP) y la máxima longitud del citoplasma (MLC). Los promedios obtenidos (+ EEM) de la CMP y MLC (n=20/bovino) para las células testigo (T) y tratadas con L. casei (LC), fueron para CMP: 41.54 (+ 2.08) µm para T y 61.53 (+ 2.30) µm para LC a las 48 horas (P<0.05) y de 35.80 (+ 1.49) µm para T y de 68.90 (+ 8.8) µm para LC a las 72 horas (P<0.05). Los valores promedios de la MLC obtenidos fueron de 13.08 (+ 1.05) µm para T y 19.34 (+ 0.86) mµ para LC a las 48 horas (P<0.05) y de 11.46 (+ 0.67) µm para T y 21.55 (+ 3.3) µm para LC a las 72 horas (P<0.05). Los resultados obtenidos sugieren que...
To assess transmissibility of attenuated Babesia bigemina (BIS) and Babesia bovis (BOR) strains b... more To assess transmissibility of attenuated Babesia bigemina (BIS) and Babesia bovis (BOR) strains by Rhipicephalus microplus (R. microplus), 12 steers from a tick-free area were divided in four groups and infested at different intervals with R. microplus larvae. One animal from each group was inoculated with 1x108 infected erythrocytes (IE) of attenuated BIS, BOR, virulent B. bigemina, or B. bovis field strains.
Two hundred and thirty-three blood samples of water buffalo were collected on four farms in Verac... more 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 Babesia and Anaplasma spp. sequences. Nested PCR assays were used for the amplification of specific genes encoding B. bovis rhoptry-associated protein (RAP-1), B. bigemina SpeI-AvaI restriction fragment, and Anaplasma marginale major surface protein 5 (MSP5). Using DNA sequencing and BLASTn analysis for DNA homology hemoparasite identification, the identities of the hemoparasites were established by comparing the nucleotide sequences obtained in this study with those available in the GenBank database at the National Center for Biotechnology Information (NCBI). Water buffalo infection with at least one of the hemoparasites under study was detected in 45% (105/233) of the blood samples, while a mixed infection with B. bovis and B. bigemina was detected in 6.4% (15/233) of samples. For this cross-sectional study, m...
Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa prot... more Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa protozoa of the genus Babesia that are obligate intraerythrocytic parasites. The pathogenicity of Babesia parasites for cattle is determined by the interaction with the host immune system and the presence of the parasite’s virulence genes. A Babesia bigemina strain that has been maintained under a microaerophilic stationary phase in in vitro culture conditions for several years in the laboratory lost virulence for the bovine host and the capacity for being transmitted by the tick vector. In this study, we compared the virulome of the in vitro culture attenuated Babesia bigemina strain (S) and the virulent tick transmitted parental Mexican B. bigemina strain (M). Preliminary results obtained by using the Basic Local Alignment Search Tool (BLAST) showed that out of 27 virulence genes described and analyzed in the B. bigemina virulent tick transmitted strain, only five were fully identified in ...
Bovine babesiosis is a hemoparasitic disease caused by intra-erythrocytic protozoa of the genus B... more Bovine babesiosis is a hemoparasitic disease caused by intra-erythrocytic protozoa of the genus Babesia. It is mainly transmitted by Rhipicephalus (Boophilus) microplus ticks and cause of a hemolytic devastating disease with a high economic impact in the cattle industry, particularly in the tropical and subtropical areas of the world where the tick vector is endemic. Immunization with in vitro culture-derived parasites is thus far the best procedure that can be used for the prevention or control of bovine babesiosis. It has been proved that when the vaccine parasites are established in the animals, the induced immune response is protective, able to respond to natural challenge with parasites of high virulence in the field. With this methodology, a better control of possible contamination with other pathogens is also achieved. It is therefore reasonable to recommend the use of the vaccine in susceptible animals that could be introduced into endemic areas. This article outlines only s...
The aim of the present research was to assess the immunogenicity and protective capability of a c... more The aim of the present research was to assess the immunogenicity and protective capability of a combination of the B. bovis recombinant proteins MSA-1, MSA-2c and 12D3 in cattle exposed to Babesia infection transmitted by ticks under natural conditions. The immunization phase of the study was conducted at CENID-Parasitología Veterinaria in Jiutepec, Morelos, and the challenge phase was carried out in an experimental station in Pichucalco, Chiapas, Mexico. Eighteen steers were randomly distributed into three groups of six animals each. Animals were treated on days 0 and 14 as follows: Group 1 (G1), control, with the adjuvant Montanide 70 (M70) + PBS; Group 2 (G2) with a mixture of the Babesia bovis recombinant proteins MSA-1, MSA-2c and 12D3 admixed in M70; Group 3 (G3) with a live attenuated mixed vaccine against bovine babesiosis (day 0 only). Immunization of cattle with a combination of recombinant proteins from B. bovis induced specific IgG antibodies that recognized the correspo...
The indirect fluorescent antibody test (IFAT) is the most frequently used test to conduct seroepi... more The indirect fluorescent antibody test (IFAT) is the most frequently used test to conduct seroepidemiological studies so far, and it is regarded as the "gold standard" test for the serological diagnosis of bovine babesiosis. The aim of the present study was to compare the enzyme-linked immunosorbent assay (ELISA) and the rapid immunochromatography test (ICT) for use in the serological diagnosis of cattle exposed to B. bovis in Mexico. The evaluation of test performance was carried out with 30 positive and 30 negative reference sera. A total of 72 bovine sera samples collected from cattle in a region with endemic bovine babesiosis were analyzed by ELISA and ICT, and the results were compared with those of IFAT. Kappa value (k) was also calculated to determine the agreement between tests. The sensitivity and specificity of ELISA for detecting antibodies against B. bovis were 87% (26/30) and 80% (24/30), respectively. The sensitivity and specificity of ICT for detecting antib...
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Papers by Julio Figueroa