Papers by Germinal Jorge Canto Alarcon
Revista Mexicana de Ciencias Pecuarias, 1986
El presente trabajo se llevo a cabo para conocer el efecto de la Ivermectina sobre la garrapata c... more El presente trabajo se llevo a cabo para conocer el efecto de la Ivermectina sobre la garrapata comun del ganado (Boophilus microplus). Se emplearon ocho bovinos Hereford infestados artificialmente con 10,000 larvas en tres ocasiones a Intervalos de nueve
Revista Mexicana de Ciencias Pecuarias, 1990
EI uso del cultivo in vitro de B. bigemina permite la obtenci6n de diferentes subpoblaclones, de ... more EI uso del cultivo in vitro de B. bigemina permite la obtenci6n de diferentes subpoblaclones, de las cuales se desoonocia su oomportamlento en bovlnos susceptlbles. En este estudlo sa evalu6 el efecto de tres alslamientos derivados de cultivo in vitro: el aislamiento original, uno irradiado yun tercero clonado e irradiado, ademas de un cuarto aislamiento obtenido de un caso de campo. Cuatro grupos de cuatro animales cada uno fueron respectlvamente inoculados por via intramus cular. Un quinto grupo de animales no infectados sirvi6 oomo grupo testlgo. Los cuatro aislamlen tos fueron capaces de multiplicarse. Solo en los bovinos Inoculados con el aislamiento de campo se observ6 una forma clinica de la enfermedad, oon marcados cambios en los valores de temperatura rectal, hematocrito, hemoglobina y oonteo de gl6bulos rojos y cuyas parasltemias fueron mayores y mas prolongadas. En oontraste, los aislamientos derivados in vitro se oonside raron menos virulentos, ya que los camblos hematol6gloos fueron menos severos que los inducidos por la cepa de campo. AJ desafio, el aislamiento de cultivo no Irradiado y el de campo Indujeron proteeci6n, no solo oontra los signos clinioos sino aparentemente tam bien oontra Is infeccl6n.
International Journal for Parasitology: Parasites and Wildlife, 2016
Mexico has a long history of parasitological studies in communities of vertebrates. However, the ... more Mexico has a long history of parasitological studies in communities of vertebrates. However, the mega diversity of the country makes fauna inventories an ongoing priority. Presently, there is little published on the parasite fauna of gray foxes (Urocyon cinereoargenteus Schereber, 1775) and this study provides new records of parasites for gray foxes in central Mexico. It is a continuation of a series of previous parasitological studies conducted with this carnivore in Mexico from 2003 to the present. A total of 24 foxes in the Parque Nacional El Cimatario (PANEC) were trapped, anaesthetized, and parasites recovered. The species found were Dirofilaria immitis, Ctenocephalides canis, C. felis, Euhoplopsillus glacialis affinis (first report for gray foxes in Mexico) Pulex simulants, and Ixodes sp. Three additional gray fox carcasses were necropsied and the parasites collected were adult nematodes Physaloptera praeputialis and Toxocara canis. The intensive study of the gray fox population selected for the 2013e2015 recent period allowed for a twofold increase in the number of parasite species recorded for this carnivore since 2003 (nine to 18 parasite species), mainly recording parasitic arthropods, Dirofilaria immitis filariae and adult nematodes. The parasite species recorded are generalists that can survive in anthropic environments; which is characteristic of the present ecological scenario in central Mexico. The close proximity of the PANEC to the city of Santiago de Queretaro suggests possible parasite transmission between the foxes and domestic and feral dogs. Furthermore, packs of feral dogs in the PANEC might have altered habitat use by foxes, with possible impacts on transmission.
PLoS ONE, 2013
''Test-and-slaughter'' has been successful in industrialized countries to control and eradicate t... more ''Test-and-slaughter'' has been successful in industrialized countries to control and eradicate tuberculosis from cattle; however, this strategy is too expensive for developing nations, where the prevalence is especially high. Vaccination with the Calmette-Guérin (BCG) strain has been shown to protect against the development of lesions in vaccinated animals: mouse, cattle and wildlife species. In this study, the immune response and the pathology of vaccinated (BCG-prime and BCG prime-CFP-boosted) and unvaccinated (controls) calves were evaluated under experimental settings. A 10 6 CFU dose of the BCG strain was inoculated subcutaneously on the neck to two groups of ten animas each. Thirty days after vaccination, one of the vaccinated groups was boosted with an M. bovis culture filtrate protein (CFP). Three months after vaccination, the three groups of animals were challenged with 5610 5 CFU via intranasal by aerosol with a field strain of M. bovis. The immune response was monitored throughout the study. Protection was assessed based on immune response (IFN-g release) prechallenge, presence of visible lesions in lymph nodes and lungs at slaughter, and presence of bacilli in lymph nodes and lung samples in histological analysis. Vaccinated cattle, either with the BCG alone or with BCG and boosted with CFP showed higher IFN-g response, fewer lesions, and fewer bacilli per lesion than unvaccinated controls after challenge. Animals with low levels of IFN-g postvaccine-prechallenge showed more lesions than animals with high levels. Results from this study support the argument that vaccination could be incorporated into control programs to reduce the incidence of TB in cattle in countries with high prevalence.
Parasitology Research, 2000
Clones of a Babesia bovis isolate known to cause particularly severe cerebral babesiosis were tes... more Clones of a Babesia bovis isolate known to cause particularly severe cerebral babesiosis were tested for virulence phenotype by inoculation of cattle. Clones were selected for phenotyping by two criteria - rate of growth in culture and hybridization of a virulence-related probe to Southern blots. Largely on the basis of associated mortality, B. bovis clones were judged to vary in their pathogenic potential.
Annals of the New York Academy of Sciences, 2004
The objective of this study was to characterize the immune response of Babesia bigemina-infected ... more The objective of this study was to characterize the immune response of Babesia bigemina-infected cows during the second trimester of pregnancy. Twelve animals were divided into four groups (I, II, III, IV); groups I and II were pregnant cows, groups III and IV were non-pregnant cows. Groups I and III were infected with a virulent strain of Babesia bigemina, the doses utilized was 1 x 10(7) infected red blood cells IM. Groups II and IV were noninfected control groups. All the infected animals were severely affected; at days 5-7 post-inoculation (DPI) they showed clinical signs: fever (40-41.5 degrees C), packed cell volume reduction, and parasitemia, and specific treatment was required. The immune response was monitored daily from 0-11 DPI. As shown by flow cytometry analysis, in infected animals the distribution in peripheral blood of the T-cells subpopulations (CD4+, CD8+, gammadelta T-cells) was not affected when compared to the control groups. By ELISA, IFN-gamma production showed a trend to increase in plasma between 6-10 DPI; noninfected cows showed the lowest optical density values. By RT-PCR, a Th1 predominant response was observed, TNFalpha, INF-gamma and iNOs were detected. In contrast IL-4 and IL-10 were weak or undetected. The results of this trial will be discussed.
Annals of the New York Academy of Sciences, 2004
To determine the optimal dose of a combined, frozen immunogen containing in vitro culture-derived... more To determine the optimal dose of a combined, frozen immunogen containing in vitro culture-derived strains of Babesia bovis and Babesia bigemina, twenty-four 14-month-old Bos taurus steers from a Boophilus microplus-free area in Northern Mexico were used in this experiment. Cattle were randomly allocated into six groups with four animals each, and were intramuscularly inoculated as follows: group 1 (control animals) were administered with normal bovine erythrocytes; group 2 received 1 x 10(7) B. bovis- and B. bigemina-infected erythrocytes as a combined fresh immunogen. Groups 3-6 were inoculated with a combined frozen immunogen containing (previous to cryopreservation at -196 degrees C) 1 x 10(7), 5 x 10(7), 1 x 10(8), and 5 x 10(8) infected erythrocytes of each parasite species, respectively. Four months after immunization, principal and control animals were translocated to a bovine babesiosis endemic zone for field challenge. This was carried out by introducing the experimental cattle to tick-infested pastures for 30 days without ixodicide treatment. Cattle were monitored from day 8 postintroduction to the field (PIF) by recording the manifestation of clinical disease, rectal temperature values (RT), packed cell volume index (PCV), and percent of parasitized erythrocytes (PPE). At challenge, all experimental cattle became infected with both Babesia bovis and B. bigemina. However, except for two animals from group 6, none of the vaccinated animals showed signs of acute clinical babesiosis; therefore, no treatment was instituted. Out of six animals showing acute clinical babesiosis (four group 1 controls and two group 6 vaccinates), two animals (one from each group) died, despite babesiacide treatment, as they manifested classical cerebral babesiosis caused by B. bovis. Regardless of the dose or type of immunogen used (combined fresh or frozen), 90% of vaccinated cattle were determined to be protected against the virulent Babesia sp. field isolates. Nevertheless, by evaluating clinical parameters, such as average of maximum drop in PVC index (28.5%), average duration of parasitemia (3 days for B. bovis; 8.5 days for B. bigemina), and average duration of RT values > or = 39.5 degrees C (2 days), animals receiving 1 x 10(8) infected erythrocytes, as combined frozen immunogen, were more efficaciously protected against challenge with virulent B. bovis and B. bigemina field isolates.
Annals of the New York Academy of Sciences, 2006
A comparative assessment of the virulence of Babesia bovis clones that adhere or not to bovine br... more A comparative assessment of the virulence of Babesia bovis clones that adhere or not to bovine brain endothelial cells was done using two clones of B. bovis: (1) a clone phenotypically characterized as virulent (2F8) and (2) a clone of reduced virulence (RAD). Of these subpopulations, we selected those that had adhesive characteristics (a) or nonadhesive characteristics (na) in cultured endothelial cells. Twenty Holstein cattle, 12 months of age or older, were used in this study, and these cattle were randomly assigned to five groups of four animals each. The clones and their respective subpopulations were inoculated via intramuscular injection at a 0.5 × 10 7 infected erythrocyte dosage. Group A was inoculated with aRAD, group B with naRAD, group C with a2F8, group D with na2F8, and group E remained as a control. All inoculated animals showed a decrease in the packed cell volume (PCV), with group D showing the largest decrease (39.53%) and longest time (7 days) with rectal temperature above 39.5 • C. Babesia was observed in stained blood smears from only six cattle. While the four parasite subpopulations were pathogenic, significant differences were not noted among them, despite that the subpopulations considered to be virulent caused the greatest reduction in PCV per individual.
Vet. Mex, 1999
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Revista Mexicana de Biodiversidad, 2015
Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commo... more Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commons CC BY-NC-ND 4.0.
Revista Mexicana De Ciencias Pecuarias, 1984
The studies reported in this thesis were conducted in order to obtain a better understanding of i... more The studies reported in this thesis were conducted in order to obtain a better understanding of immunity to Dictyocaulus viviparus infection.
Revista panamericana de salud pública = Pan American journal of public health, 2015
To determine the geospatial distribution of bovine paralytic rabies cases transmitted by Desmodus... more To determine the geospatial distribution of bovine paralytic rabies cases transmitted by Desmodus rotundus in the Mexican states of Guanajuato, Querétaro, and San Luis Potosí. This was a cross-sectional epidemiological study based on cases reported during statewide campaigns for the control of bovine paralytic rabies in Guanajuato (2008-2013), Querétaro (2005-2013) and San Luis Potosí (2001-2013). All cases were confirmed by direct immunofluorescence. Maps showing the distribution of cases by year and species were constructed using ArcMap version 10.1. To identify areas where conditions favor the appearance of cases, bioclimatic variables were combined with georeferenced cases using MaxEnt version 3.3.3. Of the 1037 cases recorded, 911 (87.9%) occurred in San Luis Potosí, 82 (7.9%) in Querétaro, and 44 (4.2%) in Guanajuato. Of the total number of cases, 87.4% occurred at altitudes of less than 1500 meters above sea level. In Guanajuato and Querétaro, 77.3% and 42.3% of the cases, re...
Therya
Lynx rufus has been reported (Figure 1). El Cimatario National Park is surrounded by peripheral s... more Lynx rufus has been reported (Figure 1). El Cimatario National Park is surrounded by peripheral suburbs of the city of Queretaro. It is located at 20.474° to 20.556° N, and-100.326° to-100.386° W, with a reported area of 2,447 ha. It is a protected natural area dominated
Journal of Ancient Diseases & Preventive Remedies
A total of 2,736 samples, sputum, urine, and other fluids, collected from 1,154 tuberculosis susp... more A total of 2,736 samples, sputum, urine, and other fluids, collected from 1,154 tuberculosis suspicious patients in Queretaro, Mexico were included in the study. Acid-fast staining and culture in selective mediums, Stonebrink and Lowenstein-Jensen, were performed in all samples. Genotyping of isolates was performed by spoligotyping and single nucleotide polimorfism (SNP) whole genome sequencing. Mycobacterium bovis spoligotypes and SNP-types obtained were compared to those of cattle found in a database. Twenty-one (1.8%) isolates of Mycobacterium were obtained by culture, all from sputum; two (13%) were identified as M. bovis by spoligotyping, SB0673 and SB0971, which are frequently found in cattle in Mexico. From the isolates´ total, 15 were whole genome sequenced, confirming two as M. bovis. The SNP patterns of the two M. bovis isolates from human were similar to those found in cattle in different parts of Mexico.
Revista Mexicana De Ciencias Pecuarias, 1986
Revista Mexicana De Ciencias Pecuarias, 1987
Revista Mexicana De Ciencias Pecuarias, 1985
Revista Mexicana De Ciencias Pecuarias, Sep 1, 2012
El control de la babesiosis bovina en muchas partes del mundo está restringido al tratamiento qui... more El control de la babesiosis bovina en muchas partes del mundo está restringido al tratamiento quimioterapéutico y al control de la población de garrapatas con agentes acaricidas. No hay programas de control basados en estudios de inmunidad de hato, control integral de la garrapata y las enfermedades que transmite, ni vacunas contra la babesiosis disponibles comercialmente. Para poder desarrollar estas herramientas es necesario utilizar tecnologías que incluyan conocimientos de genómica, proteómica y bioinformática, apoyadas en la investigación de genes con potencial diagnóstico o vacunal. El estudio de la función de los genes, y de la conservación o variabilidad son indispensables para determinar su utilidad. Es necesario, primero identificar los genes con potencial a incluirse en el desarrollo de estas herramientas, y después, evaluar su variabilidad o conservación en distintas poblaciones de parásitos. En segundo término, es necesario seleccionar regiones específicas de estos genes, que cumplan la función deseada, ya sean regiones conservadas o diferentes entre cepas. Finalmente, es necesario utilizar el método adecuado de evaluación de estos candidatos para el desarrollo de métodos de control adecuados. A pesar de que hay ciertos avances en el estudio de genes de B. bovis, hay prácticamente nula información respecto a B. bigemina. Es necesario aprovechar las nuevas estrategias genómicas y de bioinformática para identificar nuevos genes con potencial diagnóstico y de vacunación. El desarrollo de la ganadería mexicana está supeditado al establecimiento e implementación de estas herramientas.
Revista Mexicana De Ciencias Pecuarias, 1984
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Papers by Germinal Jorge Canto Alarcon