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Papers by Ramon Aboytes

Riverbank filtration (RBF) is a process during which surface water is subjected to subsurface flo... more Riverbank filtration (RBF) is a process during which surface water is subjected to subsurface flow prior to extraction from wells. During infiltration and soil passage, surface water is subjected to a combination of physical, chemical, and biological processes such as filtration, dilution, sorption, and biodegradation that can significantly improve the raw water quality (Tufenkji et al, 2002; Kuehn and Mueller,

Water Research, 2005

Microbial monitoring was conducted over a period of more than 1 year at three full-scale riverban... more Microbial monitoring was conducted over a period of more than 1 year at three full-scale riverbank filtration (RBF) facilities, located in the United States along the Ohio, Missouri, and Wabash Rivers. Results of this study demonstrated the potential for RBF to provide substantial reductions in microorganism concentrations relative to the raw water sources. Cryptosporidium and Giardia were detected occasionally in the river waters but never in any of the well waters. Average concentrations and log reductions of Cryptosporidium and Giardia could not be accurately determined due to the low and variable concentrations in the river waters and the lack of detectible concentrations in the well waters. Average concentrations of aerobic and anaerobic spore-forming bacteria, which have both been proposed as potential surrogates for the protozoans, were reduced at the three facilities by 0.8 to 43.1 logs and 0.4 to 44.9 logs, respectively. Average concentrations of male-specific and somatic bacteriophage were reduced by 42.1 logs and X3.2 logs, respectively. Total coliforms were rarely detected in the well waters, with 5.5 and 6.1 log reductions in average concentrations at the two wells at one of the sites relative to the river water. Average turbidity reductions upon RBF at the three sites were between 2.2 and 3.3 logs. Turbidity and microbial concentrations in the river waters generally tracked the river discharge; a similar relationship between the well water concentrations and river discharge was not observed, due to the low, relatively constant well water turbidities and lack of a significant number of detections of microorganisms in the well waters. Further research is needed to better understand the relationships among transport of pathogens (e.g., Cryptosporidium, Giardia, viruses) and potential surrogate parameters (including bacterial spores and bacteriophage) during RBF and the effects of water and sediment characteristics on removal efficiency.

Revista Mexicana de Ciencias Pecuarias, 1985

Las enfermedades transmitidas por garrapatas que afectan a los animales domesticos son de gran im... more Las enfermedades transmitidas por garrapatas que afectan a los animales domesticos son de gran importancia economica debido a las perdidas que producen, ademas de ser el mayor obstaculo para una eficiente produccion animal en las regiones tropicales y su

La anaplasmosis bovina es una enfermedad hemoparasitaria transmitida por 9arrapatas del genero Bo... more La anaplasmosis bovina es una enfermedad hemoparasitaria transmitida por 9arrapatas del genero Boophilus spp., moscas, mosquitos hematofagos y Tabanus spp, ampliamente difundida en las zonas tropicales y subtropicales, asi como en la altiplanicie de Mexic

Estudio realizado para observar los cambios en la hematologia y respuesta inmunologica en bovinos... more Estudio realizado para observar los cambios en la hematologia y respuesta inmunologica en bovinos inoculados en forma experimental con una clona irradiada de B. bovls cultivada ln vitro.

Revista Mexicana de Ciencias Pecuarias, 1996

Ramon Aboytes Torres RESUMEN Con objeto de estimar la prevalencia de Anaplasma marginale en ganad... more Ramon Aboytes Torres RESUMEN Con objeto de estimar la prevalencia de Anaplasma marginale en ganado bovino de la zona norte del estado de Veracruz, se analizaran 785 sueros por media de la prueba de f;jacion de complemenlo, EI tamano de muestra se calculo en 37 bovinos por rancho, Eltotal de mueslras se obluvoa partir de animales de diferentes edades y razas, de21 ranchos localizados en 18 municipios, La seroprevalencia general fue del 56% con una variabilidad del12 a190% ,Se observ~ que Ia seroprevalencia aumenta con la edad. Can respecto allamano de halo se encontro que en ranchos con mas de 300 bovin~s existe mayor porcentaje de seropositivos (72%). La anaplasmosis bovina es endemica en el norte del eslado de Veracruz, debiendose observar medidas preventivas previas a la introduccion de animales susceptibles 0 procedentes de zonas libres de anaplasmosis,

Los parasitos sanguineos pertenecientes al genero Babesia que afectan al ganado bovino selecciona... more Los parasitos sanguineos pertenecientes al genero Babesia que afectan al ganado bovino seleccionan como celulas hospedadoras a los eritrocitos en apariencia maduros y originan cuadros clinicos de anemia severa, (Smith,1980). La distribucion de estos paras

Revista Mexicana de Ciencias Pecuarias, 1984

La Anaplasmosis y la Babesiosis, son dos enfermedades producidas por hemoparasitos que afectan al... more La Anaplasmosis y la Babesiosis, son dos enfermedades producidas por hemoparasitos que afectan al ganado bovino en las zonas tropicales y subtropicales, originando cuadros clinicos de anemias severas en los animales susceptibles, los agentes etiologicos s

Comparative Immunology, Microbiology and Infectious Diseases, 2000

The present study was performed to dose-titrate an Anaplasma marginale experimental immunogen der... more The present study was performed to dose-titrate an Anaplasma marginale experimental immunogen derived from partially purified initial bodies from three geographically different Mexican strains. Three five-bovine groups were inoculated twice on days zero and 21 with A. marginale initial bodies equivalent to 1.5 x 10(10) (group I), 3 x 10(10) (group II) or 6 x 10(10) (group III) infected erythrocytes mixed with STDCM adjuvant. A similar group served as non-vaccinated controls. All four groups were challenged with 1 x 10(8) infected erythrocytes from a donor cow with an increasing rickettsemia of strain MEX-15 on day 87 post-vaccination. The prepatent period was very similar for all four groups. All five non-vaccinated controls presented typical acute anaplasmosis syndrome reaching a mean of 30.9% rickettsemia and a loss of 73.4% in the packed cell volume (PCV). Two of five controls died of acute anaplasmosis. Within the vaccinated groups only one animal (group II) suffered acute disease and died. Although all the other vaccinated animals were free of clinical signs, they developed very low rickettsemias (3.2, 3.8 and 4.3%) and PCV losses of 49.9, 47.8, and 49.3% for groups I, II and III. The starting mean weight was very similar for all four groups. All animals lost weight following challenge but losses for groups I and II were lower and significantly different from group IV losses (P < or = 0.1). Although there were no significant differences among vaccinated groups, group III was more severely affected. Taken altogether, these results show a 93.3% protection against both illness and death for all groups; and 100% protection for groups I and III, and 80% for group II.

Vet. Méx, 2000

The present work was designed to evaluate the virulence of Mexican Anaplasma marginale isolates M... more The present work was designed to evaluate the virulence of Mexican Anaplasma marginale isolates MEX-15-099 (MEX15) and MEX-31-096 (MEX31). Two groups of four steers were inoculated with a dose of 1 × 10 6 infected erythrocytes of either of the isolates per animal. Experimental animals were monitored for 65 days from the inoculation date. Rectal temperature, packed cell volume (PCV), rickettsemia (PIE) and presence of specific antibodies detected by the ELISA, were registered. MEX15-infected steers reached maximal rickettsemia between 8.8% and 34.7%, while MEX31 steers only maximal values between 0.1% and 16.3%. Only MEX15 steers suffered fever > 40ºC coincidential with the amplification of the rickettsemia. A PCV loss of 68.2 ± 8.9% was registered for the MEX15 steers, which was statistically different (P< 0.05) to the 50.1 ± 8.9% loss registered for the MEX31 steers. Except for one MEX31 animal, all other animals developed O.D. readings between 0.355 and 0.829. Only the MEX15-infected animals presented clinical signs of anaplasmosis, whereas only one of the infected with the MEX31 isolate did. Under the conditions of this study, isolate MEX15 appeared more virulent than isolate MEX31.

Annals of the New York Academy of Sciences, 2008

Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the viru... more Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the virulence of this isolate by experimental inoculation of 113 susceptible cattle at increasing doses, after which only one animal required treatment for clinical disease. Subsequently, 104 cattle received a live vaccine of this strain by inoculation, which induced immunoprotection after heterologous challenged exposure with a different A. marginale isolate. In this study 14% of the immunized cattle required treatment as compared with the control nonimmunized cattle, in which 56% required treatment. The A. marginale vaccine strains used for the immunization studies had MSP1a variable regions that were different from those used for the challenge exposure.

Journal - American Water Works Association

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Journal American Water Works Association, 2004

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Water Research, 2005

Microbial monitoring was conducted over a period of more than 1year at three full-scale riverbank... more Microbial monitoring was conducted over a period of more than 1year at three full-scale riverbank filtration (RBF) facilities, located in the United States along the Ohio, Missouri, and Wabash Rivers. Results of this study demonstrated the potential for RBF to provide substantial reductions in microorganism concentrations relative to the raw water sources. Cryptosporidium and Giardia were detected occasionally in the

Archives of medical research, 1994

Bovine babesiosis, caused by parasites of the genus Babesia, is one of the world's most sever... more Bovine babesiosis, caused by parasites of the genus Babesia, is one of the world's most severe tick-borne problems of cattle in temperate to tropical areas. In the Americas Babesia bovis and B. bigemina are the causative agents, with the former considered to produce the greatest economic impact. The great complexity of the relationships causal agent-vector-host has severely hindered the efforts towards the production of a safe, long-lasting, solid-protection inducing vaccine. Recent important contributions that have encouraged the study of these agents include the development of in vitro cultivation systems, procedures for the isolation of single infected-erythrocytes, density gradient-based centrifugation systems for the isolation and concentration of both infected erythrocytes and merozoites, isozyme detection and differentiation systems that help discriminate between parasite species, and development of DNA-based diagnostics and characterization protocols. Currently, the stud...

Journal of Water Supply: Research and Technology-Aqua

Research was conducted to explore the effect of underground travel on the character of the natura... more Research was conducted to explore the effect of underground travel on the character of the natural organic matter (NOM) originating from river water sources during riverbank filtration (RBF) at three Midwestern US drinking water utilities. Measurements of biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) showed significant reductions (50 to 90%) in the biodegradable portion of NOM at two of the sites. Specific UV-absorbance (SUVA) values suggested preferential reduction (26% reduction in SUVA) in UV-absorbing NOM at one of the sites but negligible changes in SUVA were observed at the other two sites. XAD-8 characterization was carried out on the river and well waters to investigate possible changes in the character of the NOM. The distribution of dissolved organic carbon (DOC) between the XAD-8 adsorbing (‘hydrophobic’) and non-adsorbing (‘hydrophilic’) fractions was similar between the river and well waters (40 to 70% hydrophilic and 30 to 60% hydrophobic), indicating no significant, consistent, preferential removal of either fraction upon ground passage. SUVA measurements on the separate XAD-8 fractions similarly showed no significant change during bank filtration. Disinfection by-product (DBP) formation testing was performed on the various fractions, keeping the ratio of chlorine:DOC:bromide constant. DBP formation testing showed no preferential formation between the hydrophobic and hydrophilic fractions in either the river or well waters. While the overall concentrations of organic DBP precursors are effectively reduced during bank filtration, the reductions appear to be largely the result of the reduction in NOM concentration rather than a consistent change in NOM character.

Riverbank filtration (RBF) is a process during which surface water is subjected to subsurface flo... more Riverbank filtration (RBF) is a process during which surface water is subjected to subsurface flow prior to extraction from wells. During infiltration and soil passage, surface water is subjected to a combination of physical, chemical, and biological processes such as filtration, dilution, sorption, and biodegradation that can significantly improve the raw water quality (Tufenkji et al, 2002; Kuehn and Mueller,

Water Research, 2005

Microbial monitoring was conducted over a period of more than 1 year at three full-scale riverban... more Microbial monitoring was conducted over a period of more than 1 year at three full-scale riverbank filtration (RBF) facilities, located in the United States along the Ohio, Missouri, and Wabash Rivers. Results of this study demonstrated the potential for RBF to provide substantial reductions in microorganism concentrations relative to the raw water sources. Cryptosporidium and Giardia were detected occasionally in the river waters but never in any of the well waters. Average concentrations and log reductions of Cryptosporidium and Giardia could not be accurately determined due to the low and variable concentrations in the river waters and the lack of detectible concentrations in the well waters. Average concentrations of aerobic and anaerobic spore-forming bacteria, which have both been proposed as potential surrogates for the protozoans, were reduced at the three facilities by 0.8 to 43.1 logs and 0.4 to 44.9 logs, respectively. Average concentrations of male-specific and somatic bacteriophage were reduced by 42.1 logs and X3.2 logs, respectively. Total coliforms were rarely detected in the well waters, with 5.5 and 6.1 log reductions in average concentrations at the two wells at one of the sites relative to the river water. Average turbidity reductions upon RBF at the three sites were between 2.2 and 3.3 logs. Turbidity and microbial concentrations in the river waters generally tracked the river discharge; a similar relationship between the well water concentrations and river discharge was not observed, due to the low, relatively constant well water turbidities and lack of a significant number of detections of microorganisms in the well waters. Further research is needed to better understand the relationships among transport of pathogens (e.g., Cryptosporidium, Giardia, viruses) and potential surrogate parameters (including bacterial spores and bacteriophage) during RBF and the effects of water and sediment characteristics on removal efficiency.

Revista Mexicana de Ciencias Pecuarias, 1985

Las enfermedades transmitidas por garrapatas que afectan a los animales domesticos son de gran im... more Las enfermedades transmitidas por garrapatas que afectan a los animales domesticos son de gran importancia economica debido a las perdidas que producen, ademas de ser el mayor obstaculo para una eficiente produccion animal en las regiones tropicales y su

La anaplasmosis bovina es una enfermedad hemoparasitaria transmitida por 9arrapatas del genero Bo... more La anaplasmosis bovina es una enfermedad hemoparasitaria transmitida por 9arrapatas del genero Boophilus spp., moscas, mosquitos hematofagos y Tabanus spp, ampliamente difundida en las zonas tropicales y subtropicales, asi como en la altiplanicie de Mexic

Estudio realizado para observar los cambios en la hematologia y respuesta inmunologica en bovinos... more Estudio realizado para observar los cambios en la hematologia y respuesta inmunologica en bovinos inoculados en forma experimental con una clona irradiada de B. bovls cultivada ln vitro.

Revista Mexicana de Ciencias Pecuarias, 1996

Ramon Aboytes Torres RESUMEN Con objeto de estimar la prevalencia de Anaplasma marginale en ganad... more Ramon Aboytes Torres RESUMEN Con objeto de estimar la prevalencia de Anaplasma marginale en ganado bovino de la zona norte del estado de Veracruz, se analizaran 785 sueros por media de la prueba de f;jacion de complemenlo, EI tamano de muestra se calculo en 37 bovinos por rancho, Eltotal de mueslras se obluvoa partir de animales de diferentes edades y razas, de21 ranchos localizados en 18 municipios, La seroprevalencia general fue del 56% con una variabilidad del12 a190% ,Se observ~ que Ia seroprevalencia aumenta con la edad. Can respecto allamano de halo se encontro que en ranchos con mas de 300 bovin~s existe mayor porcentaje de seropositivos (72%). La anaplasmosis bovina es endemica en el norte del eslado de Veracruz, debiendose observar medidas preventivas previas a la introduccion de animales susceptibles 0 procedentes de zonas libres de anaplasmosis,

Los parasitos sanguineos pertenecientes al genero Babesia que afectan al ganado bovino selecciona... more Los parasitos sanguineos pertenecientes al genero Babesia que afectan al ganado bovino seleccionan como celulas hospedadoras a los eritrocitos en apariencia maduros y originan cuadros clinicos de anemia severa, (Smith,1980). La distribucion de estos paras

Revista Mexicana de Ciencias Pecuarias, 1984

La Anaplasmosis y la Babesiosis, son dos enfermedades producidas por hemoparasitos que afectan al... more La Anaplasmosis y la Babesiosis, son dos enfermedades producidas por hemoparasitos que afectan al ganado bovino en las zonas tropicales y subtropicales, originando cuadros clinicos de anemias severas en los animales susceptibles, los agentes etiologicos s

Comparative Immunology, Microbiology and Infectious Diseases, 2000

The present study was performed to dose-titrate an Anaplasma marginale experimental immunogen der... more The present study was performed to dose-titrate an Anaplasma marginale experimental immunogen derived from partially purified initial bodies from three geographically different Mexican strains. Three five-bovine groups were inoculated twice on days zero and 21 with A. marginale initial bodies equivalent to 1.5 x 10(10) (group I), 3 x 10(10) (group II) or 6 x 10(10) (group III) infected erythrocytes mixed with STDCM adjuvant. A similar group served as non-vaccinated controls. All four groups were challenged with 1 x 10(8) infected erythrocytes from a donor cow with an increasing rickettsemia of strain MEX-15 on day 87 post-vaccination. The prepatent period was very similar for all four groups. All five non-vaccinated controls presented typical acute anaplasmosis syndrome reaching a mean of 30.9% rickettsemia and a loss of 73.4% in the packed cell volume (PCV). Two of five controls died of acute anaplasmosis. Within the vaccinated groups only one animal (group II) suffered acute disease and died. Although all the other vaccinated animals were free of clinical signs, they developed very low rickettsemias (3.2, 3.8 and 4.3%) and PCV losses of 49.9, 47.8, and 49.3% for groups I, II and III. The starting mean weight was very similar for all four groups. All animals lost weight following challenge but losses for groups I and II were lower and significantly different from group IV losses (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; or = 0.1). Although there were no significant differences among vaccinated groups, group III was more severely affected. Taken altogether, these results show a 93.3% protection against both illness and death for all groups; and 100% protection for groups I and III, and 80% for group II.

Vet. Méx, 2000

The present work was designed to evaluate the virulence of Mexican Anaplasma marginale isolates M... more The present work was designed to evaluate the virulence of Mexican Anaplasma marginale isolates MEX-15-099 (MEX15) and MEX-31-096 (MEX31). Two groups of four steers were inoculated with a dose of 1 × 10 6 infected erythrocytes of either of the isolates per animal. Experimental animals were monitored for 65 days from the inoculation date. Rectal temperature, packed cell volume (PCV), rickettsemia (PIE) and presence of specific antibodies detected by the ELISA, were registered. MEX15-infected steers reached maximal rickettsemia between 8.8% and 34.7%, while MEX31 steers only maximal values between 0.1% and 16.3%. Only MEX15 steers suffered fever > 40ºC coincidential with the amplification of the rickettsemia. A PCV loss of 68.2 ± 8.9% was registered for the MEX15 steers, which was statistically different (P< 0.05) to the 50.1 ± 8.9% loss registered for the MEX31 steers. Except for one MEX31 animal, all other animals developed O.D. readings between 0.355 and 0.829. Only the MEX15-infected animals presented clinical signs of anaplasmosis, whereas only one of the infected with the MEX31 isolate did. Under the conditions of this study, isolate MEX15 appeared more virulent than isolate MEX31.

Annals of the New York Academy of Sciences, 2008

Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the viru... more Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the virulence of this isolate by experimental inoculation of 113 susceptible cattle at increasing doses, after which only one animal required treatment for clinical disease. Subsequently, 104 cattle received a live vaccine of this strain by inoculation, which induced immunoprotection after heterologous challenged exposure with a different A. marginale isolate. In this study 14% of the immunized cattle required treatment as compared with the control nonimmunized cattle, in which 56% required treatment. The A. marginale vaccine strains used for the immunization studies had MSP1a variable regions that were different from those used for the challenge exposure.

Journal - American Water Works Association

RefDoc Bienvenue - Welcome. Refdoc est un service / is powered by. ...

Journal American Water Works Association, 2004

RefDoc Bienvenue - Welcome. Refdoc est un service / is powered by. ...

Water Research, 2005

Microbial monitoring was conducted over a period of more than 1year at three full-scale riverbank... more Microbial monitoring was conducted over a period of more than 1year at three full-scale riverbank filtration (RBF) facilities, located in the United States along the Ohio, Missouri, and Wabash Rivers. Results of this study demonstrated the potential for RBF to provide substantial reductions in microorganism concentrations relative to the raw water sources. Cryptosporidium and Giardia were detected occasionally in the

Archives of medical research, 1994

Bovine babesiosis, caused by parasites of the genus Babesia, is one of the world's most sever... more Bovine babesiosis, caused by parasites of the genus Babesia, is one of the world's most severe tick-borne problems of cattle in temperate to tropical areas. In the Americas Babesia bovis and B. bigemina are the causative agents, with the former considered to produce the greatest economic impact. The great complexity of the relationships causal agent-vector-host has severely hindered the efforts towards the production of a safe, long-lasting, solid-protection inducing vaccine. Recent important contributions that have encouraged the study of these agents include the development of in vitro cultivation systems, procedures for the isolation of single infected-erythrocytes, density gradient-based centrifugation systems for the isolation and concentration of both infected erythrocytes and merozoites, isozyme detection and differentiation systems that help discriminate between parasite species, and development of DNA-based diagnostics and characterization protocols. Currently, the stud...

Journal of Water Supply: Research and Technology-Aqua

Research was conducted to explore the effect of underground travel on the character of the natura... more Research was conducted to explore the effect of underground travel on the character of the natural organic matter (NOM) originating from river water sources during riverbank filtration (RBF) at three Midwestern US drinking water utilities. Measurements of biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) showed significant reductions (50 to 90%) in the biodegradable portion of NOM at two of the sites. Specific UV-absorbance (SUVA) values suggested preferential reduction (26% reduction in SUVA) in UV-absorbing NOM at one of the sites but negligible changes in SUVA were observed at the other two sites. XAD-8 characterization was carried out on the river and well waters to investigate possible changes in the character of the NOM. The distribution of dissolved organic carbon (DOC) between the XAD-8 adsorbing (‘hydrophobic’) and non-adsorbing (‘hydrophilic’) fractions was similar between the river and well waters (40 to 70% hydrophilic and 30 to 60% hydrophobic), indicating no significant, consistent, preferential removal of either fraction upon ground passage. SUVA measurements on the separate XAD-8 fractions similarly showed no significant change during bank filtration. Disinfection by-product (DBP) formation testing was performed on the various fractions, keeping the ratio of chlorine:DOC:bromide constant. DBP formation testing showed no preferential formation between the hydrophobic and hydrophilic fractions in either the river or well waters. While the overall concentrations of organic DBP precursors are effectively reduced during bank filtration, the reductions appear to be largely the result of the reduction in NOM concentration rather than a consistent change in NOM character.