Bovine mastitis, a worldwide impact disease: Prevalence, antimicrobial resistance, and viable alternative approaches.

Bovine mastitis is globally considered one of the most important diseases within dairy herds, mainly due to the associated economic losses. The most prevalent etiology are bacteria, classified into contagious and environmental, with Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Escherichia coli and Klebsiella pneumoniae being the most common pathogens associated with mastitis cases. To date these pathogens are resistant to the most common active ingredients used for mastitis treatment. According to recent studies resistance to new antimicrobials has increased, which is why developing of alternative treatments is imperative. Therefore the present review aims to summarize the reports about bovine mastitis along 10 years, emphasizing bacterial etiology, its epidemiology, and the current situation of antimicrobial resistance, as well as the development of alternative treatments for this pathology. Analyzed data showed that the prevalence of major pathogens associated with bovine mastitis varied according to geographical region. Moreover, these pathogens are classified as multidrug-resistant, since the effectiveness of antimicrobials on them has decreased. To date, several studies have focused on the research of alternative treatments, among them vegetal extracts, essential oils, or peptides. Some other works have reported the application of nanotechnology and polymers against bacteria associated with bovine mastitis. Results demonstrated that these alternatives may be effective on bacteria associated with bovine mastitis.

Coffee Pulp: A Natural Alternative for Control of Resistant Nematodes in Small Ruminants.

Goat production in Mexico is an important economic activity that is affected by different gastrointestinal nematode (GIN) species. GINs resistant to commercial anthelmintics have been reported. Plant extracts or agro-industrial by-products, such as coffee pulp, have been proposed as control alternatives, given their secondary metabolite content. The aim of the present study was to determine the anthelmintic activity of the hydroalcoholic extract of coffee pulp against benzimidazole-resistant GINs. Stool samples were collected from goats, from which GIN eggs were identified and quantified. Molecular techniques confirmed the genus of GINs and their benzimidazole resistance profile. The percentage of egg hatching inhibition (% EHI) and larval mortality (% LM) with the hydroalcoholic extract of coffee pulp was determined at concentrations from 200 to 0.39 mg/mL. The genera Haemonchus spp. and Trichostrongylus spp. were identified, and the presence of the ß-tubulin gene mutation, associated with benzimidazole (BZ) resistance, was determined. Hydroalcoholic extract of coffee pulp inhibited 100% of egg hatching at 200 and 100 mg/mL, with no larvicidal effect at the evaluated concentrations.

Phytochemical Compounds and Pharmacological Properties of Larrea tridentata.

For centuries, traditional medicine from plants (phytotherapy) was the only treatment for infectious and non-infectious diseases. Although it is still practiced in several countries with excellent therapeutic results, it is frequently underestimated because, unlike Western medicine, it is not based on an empirical scientific foundation. However, interest in the search for plant-based therapeutic resources has been stimulated by disciplines such as phytochemistry and the side effects of conventional pharmacological therapies. For example, Larrea tridentata is a perennial shrub used in traditional medicine in northern Mexico and the southern United States to treat infertility, rheumatism, arthritis, colds, diarrhea, skin problems, pain, inflammation and excess body weight. Scientific research has revealed its beneficial effects-antioxidant, antitumor, neuroprotective, regenerative, antibacterial, antiviral, antifungal, anthelmintic, antiprotozoal and insecticidal-although reports indicate that some compounds in Larrea tridentata may be hepatotoxic and nephrotoxic. Therefore, the aim of this review was to highlight the updates regarding phytochemical compounds and the pharmacological properties of Larrea tridentata.

nor 3'-Demethoxyisoguaiacin from Larrea tridentata Is a Potential Alternative against Multidrug-Resistant Bacteria Associated with Bovine Mastitis.

Bovine mastitis is one of the most common diseases in dairy cows, and it causes significant economic losses in dairy industries worldwide. Gram-positive and Gram-negative bacteria can cause bovine mastitis, and many of them have developed antimicrobial resistance. There is an urgent need for novel therapeutic options to treat the disease. Larrea tridentata-derived compounds represent an important potential alternative treatment. The aim of the present study was to isolate and characterize antibacterial compounds from Larrea tridentata against multidrug-resistant bacteria associated with bovine mastitis. The L. tridentata hydroalcoholic extract (LTHE) exhibited antibacterial activity. The extract was subjected to a bipartition, giving an aqueous fraction (moderate antibacterial activity) and an organic fraction (higher antibacterial activity). Chromatographic separation of the organic fraction enabled us to obtain four active sub-fractions. Chemical analyses through HPLC techniques were conducted for the LTHE, fractions, and sub-fraction Ltc1-F3, from which we isolated two compounds, characterized by 1H and 13C NMR analyses. Compound nor-3 demethoxyisoguaiacin exhibited the best antibacterial activity against the evaluated bacteria (MIC: 0.01-3.12 mg/mL; MBC: 0.02-3.12 mg/mL). The results indicated that nor-3 demethoxyisoguaiacin can be used as an alternative treatment for multidrug-resistant bacteria associated with mastitis.

Antibacterial Potential of Caesalpinia coriaria (Jacq) Willd Fruit against Aeromonas spp. of Aquaculture Importance.

Aquaculture is an important source of food and livelihood for hundreds of millions of people around the world, however, aquaculture systems are affected by different factors, among them the appearance of resistant or multiresistant bacteria to antimicrobials. The secondary metabolites of plants have been proposed as alternatives for the treatment of these bacteria. The aim of the present study was to determine the antibacterial activity of Caesalpinia coriaria fruit hydroalcoholic extract and gallic acid over Aeromonas hydrophila, Aeromonas veronii,  and Aeromonas dhakensis to identify new molecules for the treatment of diseases caused by Aeromonas spp. The C. coriaria fruit hydroalcoholic extract (HECc) was obtained by hydroalcoholic maceration and subjected to bipartition with ethyl acetate and water to obtain an aqueous fraction (Ac-FrCc) and an organic fraction (Ac-FrEtCc); gallic acid was purchased commercially. The Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), MBC/MIC ratio, and cytotoxicity of HECc, its fractions, and gallic acid were determined. The results indicate that HECc fractions (Ac-FrCc and Ac-FrEtCc) and gallic acid have bactericidal activity against A. hydrophila and A. dhakensis, but only gallic acid showed bactericidal activity against A. veronii. The HECc and Ac-FrCc showed no toxicity, Ac-FrEtCc showed low toxicity, and gallic acid showed medium toxicity. The HECc, Ac-FrCc, and Ac-FrEtCc may be alternatives for the treatment of diseases caused by the genus Aeromonas, however, in vivo assays are necessary to corroborate these results.

Características de replicación y supervivencia del virus de viremia primaveral de la carpa (SVCV) aislado en México / Replication and survival traits of spring viremia of carp virus (SVCV) isolated in Mexico

RESUMEN Objetivo. Realizar el aislamiento del virus de la viremia primaveral de la carpa (SVCV) en ejemplares de carpa común (Cyprinus carpió), evaluar su crecimiento en diferentes tipos de células, así como la supervivencia viral a diferentes temperaturas. Materiales y métodos. Diez carpas de entre 400 500 gramos de una laguna del centro de México fueron procesadas para el diagnóstico de SVCV mediante aislamiento en cultivo de células y RT-PCR semianidado. El virus obtenido se inoculó en células EPC, BF-2, CHSE-214 y RTG-2 para determinar diferencias de crecimiento de SVCV. Además, se evaluó la supervivencia del virus conservado a temperatura ambiente (TA 20-25°C), refrigeración (REF 4°C) y congelación (CONG -80°C) hasta once meses. Los órganos internos se procesaron para análisis histológico. Resultados. Los peces analizados no presentaron signos externos sugestivos de enfermedad, pero interna e histopatológicamente se observaron lesiones sugestivas de infección sistémica. SVCV fue aislado en células EPC y BF-2 y confirmado por RT-PCR semianidado. SVCV únicamente indujo CPE en células EPC y BF-2 y fue negativo en RTG-2 y CHSE-214. El virus conservado a TA perdió viabilidad después de cuatro meses post infección (mpi), siendo total a seis mpi; mientras REF y CONG fueron estables durante los once meses de estudio. Conclusiones. La infección subclínica por SVCV fue confirmada en carpas que presentaron lesiones histológicas asociadas a esta infección. SVCV únicamente causó CPE en células EPC y BF-2 y el virus conservó su viabilidad a 4°C y -80°C hasta once meses; mientras que a TA se perdió en seis meses.

ABSTRACT Objective. To perform the isolation of spring viremia of carp virus (SVCV) in common carp (Cyprinus carpió) and evaluate its growth in different cell types and viral survival at different temperatures. Materials and methods. Ten carps of between 400-500 grams of a lagoon in central Mexico were processed for diagnosis of SVCV by isolation in cell culture and by RT-PCR. The virus obtained was inoculated into EPC, BF-2, CHSE-214 and RTG-2 cells to determine differences in virus growth; the survival of virus stored at room temperature (TA 20-25°C), refrigeration (REF 4°C) and freezing (CONG -80°C) up to eleven months was also evaluated. Internal organ samples were processed for histological analysis. Results. The fish analyzed did not show external signs suggestive of disease but internally and histopathologically lesions suggestive of systemic infection were observed. SVCV was isolated in EPC and BF-2 cells and confirmed by semi-nested RT-PCR. SVCV only induced CPE in EPC and BF-2 cells and was negative in RTG-2 and CHSE-214. The virus conserved at TA lost viability after four months post-infection (mpi), being total at six mpi; while REF and CONG were stable during the eleven months. Conclusions. Subclinical SVCV infection was confirmed in carp that presented histological lesions associated with this infection; SVCV only caused CPE in EPC and BF-2 cells; and the virus kept in refrigeration and at -80°C retained its viability up to eleven months; while TA was lost in six months.

First Identification and Characterization of Lactococcus garvieae Isolated from Rainbow Trout (Oncorhynchus mykiss) Cultured in Mexico.

Lactococcosis is a hyperacute hemorrhagic septicemia disease caused by Lactococcus garvieae, which is an emerging pathogen in global fish farming. Between 2016 and 2018, rainbow trout (Oncorhynchus mykiss) from five farms that presented outbreaks were sampled as part of a Mexican surveillance program for the detection of fish diseases. Fourteen L. garvieae isolates were recovered from sampled fish, as confirmed by biochemical tests, 16S rRNA gene sequencing, and clinical and histological insights. The biochemical and protein profiles of the isolates obtained were homogeneous. Repetitive extragenic palindromic-(REP)-and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) analyses established weak genetic heterogeneity. Rainbow trout challenged with two of the isolates used at different bacterial concentrations (10-2 and 10-4 CFU/mL) showed melanosis, and hemorrhages were observed in the fins, liver, kidney, and spleen. Isolates were obtained from all of the organs sampled, including from surviving fish, as either pure or mixed cultures. The present study is the first to confirm the presence of L. garvieae as the agent of severe lactococcosis outbreaks in the two primary Mexican states for trout farming.

In Vitro Antibacterial Potential of Salix babylonica Extract against Bacteria that Affect Oncorhynchus mykiss and Oreochromis spp.

Aquaculture development is limited by bacteria associated with several diseases; antibiotics are used for the treatment of these affections, but bacteria have developed resistance to these drugs. It is important to develop effective treatments that allow the production of antibiotic-free food. The aim of the present study is to evaluate the in vitro antibacterial effects of Salix babylonica hydro-alcoholic extract (SbHE) against Aeromonas hydrophila, Listonella anguillarum, Edwarsiella tarda, and Streptococcus iniae, bacteria that affect Oncorhynchus mykiss and Oreochromis spp. production. SbHE was obtained through the maceration technique. Reference strains were used and their sensitivity to antibiotics was determined. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of SbHE were determined. Results showed that three of four evaluated bacteria were multidrug resistant, except S. iniae. SbHE showed antibacterial activity against all bacteria. Results indicate an MIC of 1.56 to 25 mg/mL and an MBC of 3.12 to 100 mg/mL. The greatest inhibitory activity occurred against L. anguillarum obtaining a MIC of 1.56 mg/mL and an MBC of 3.12 mg/mL. Results indicate that SbHE has bactericidal activity against A. hydrophila, L.anguilalurm, and S. iniae as well as bacteriostatic activity against E. tarda and could be an alternative treatment against these bacteria.

Comportamiento epidemiológico de la leptospirosis en México durante el periodo 2013-2019 / Epidemiologic behavior of leptospirosis in México during the period 2013-2019

RESUMEN Objetivo Determinar el comportamiento temporal y espacial de la leptospirosis en México durante el periodo 2013-2019. Materiales y Métodos Se utilizó la información depositada en los boletines epidemiológicos del Sistema Nacional de Vigilancia Epidemiológica de México. Para determinar el comportamiento espacial se construyeron canales endémicos y análisis de series de tiempo. Para determinar el comportamiento espacial, se utilizó el modelo estadístico espacial Scan. Resultados Se determinó que los casos de leptospirosis en México se presentan todo el año; sin embargo, los picos endémicos se observaron en los meses de agosto, septiembre y octubre. Con respecto al comportamiento espacial, no se determinó ninguna agrupación estadísticamente; no obstante, los estados con la mayor prevalencia fueron: Sinaloa, con 146.7 casos por cada millón de habitantes, y Tabasco, con 142 casos por cada millón de habitantes. Discusión La leptospirosis es una enfermedad influenciada por los hábitos y las costumbres de la población, al igual que por variables climatológicas que favorecen el contacto con el agente etiológico. Esto coincide con lo reportado por otros estudios que han determinado que la incidencia de leptospirosis aumenta durante la época de lluvia y que esta enfermedad se relaciona con actividades de recreación en zonas tropicales. Conclusiones La leptospirosis es una enfermedad zoonótica emergente de gran importancia en México, que se presenta con mayor frecuencia en época de lluvias. Los estados de Sinaloa y Tabasco son los más afectados.(AU)

ABSTRACT Objetive To determine the temporal and spatial behavior of leptospirosis in Mexico during the period 2013-2019. Materials and Methods It was used the information deposited in the epidemiological bulletins of National System of Epidemiological Surveillance of Mexico. To determine spatial behavior, endemic channels and time series analyzes were constructed. The spatial statistical model Scan was used to determine the spatial behavior. Results It was determined that leptospirosis cases in Mexico occur throughout the year, however endemic peaks were observed during the months of August, September and October. Regarding to spatial behavior, it was not statistically determined any aggrupation, nevertheless the States with the highest prevalence were Sinaloa with 146.7 cases per million of habitants and Tabasco with 142 cases per million of habitants. Discussion Leptospirosis is a disease which is affected by habits and customs of the populations, as well as by climatological events, favoring the contact with the etiological agent, which coincides with that reported in other studies, in which it was determined that leptospirosis incidence increases during the rainy season, likewise, it was reported that this disease is related to recreational activities in tropical areas. Conclusions To date leptospirosis is an important emerging zoonotic disease in Mexico, the disease occurs more frequently during rainy season, being Sinaloa and Tabasco the most affected States by this disease.(AU)

Antibacterial and Hemolytic Activity of Crotalus Triseriatus and Crotalus Ravus Venom.

Rattlesnakes have venoms with a complex toxin mixture comprised of polypeptides and proteins. Previous studies have shown that some of these polypeptides are of high value for the development of new medical treatments. The aim of the present study is to evaluate, in vitro, the antibacterial and hemolytic activity of Crotalus triseriatus and Crotalus ravus venoms. A direct field search was conducted to obtain Crotalus triseriatus and Crotalus ravus venom samples. These were evaluated to determine their antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa through the techniques of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Hemolytic activity was also determined. Antibacterial activity was determined for treatments (Crotalus triseriatus 2) CT2 and (Crotalus ravus 3) CR3, obtaining a Minimum Inhibitory Concentration of 50 µg/mL and a Minimum Bactericidal Concentration of 100 µg/mL against Pseudomonas aeruginosa. CT1 (Crotalus triseriatus 1), CT2, and CR3 presented hemolytic activity; on the other hand, Crotalus ravus 4 (CR4) did not show hemolytic activity. The results of the present study indicate for the first time that Crotalus triseriatus and Crotalus ravus venoms contain some bioactive compounds with bactericidal activity against Pseudomonas aeruginosa which could be used as alternative treatment in diseases caused by this pathogenic bacterium.

[Epidemiologic behavior of leptospirosis in México during the period 2013-2019]. / Comportamiento epidemiológico de la leptospirosis en México durante el periodo 2013-2019.

OBJETIVE: To determine the temporal and spatial behavior of leptospirosis in Mexico during the period 2013-2019. MATERIALS AND METHODS: It was used the information deposited in the epidemiological bulletins of National System of Epidemiological Surveillance of Mexico. To determine spatial behavior, endemic channels and time series analyzes were constructed. The spatial statistical model Scan was used to determine the spatial behavior. RESULTS: It was determined that leptospirosis cases in Mexico occur throughout the year, however endemic peaks were observed during the months of August, September and October. Regarding to spatial behavior, it was not statistically determined any aggrupation, nevertheless the States with the highest prevalence were Sinaloa with 146.7 cases per million of habitants and Tabasco with 142 cases per million of habitants. DISCUSSION: Leptospirosis is a disease which is affected by habits and customs of the populations, as well as by climatological events, favoring the contact with the etiological agent, which coincides with that reported in other studies, in which it was determined that leptospirosis incidence increases during the rainy season, likewise, it was reported that this disease is related to recreational activities in tropical areas. CONCLUSIONS: To date leptospirosis is an important emerging zoonotic disease in Mexico, the disease occurs more frequently during rainy season, being Sinaloa and Tabasco the most affected States by this disease.

OBJETIVO: Determinar el comportamiento temporal y espacial de la leptospirosis en México durante el periodo 2013-2019. MATERIALES Y MÉTODOS: Se utilizó la información depositada en los boletines epidemiológicos del Sistema Nacional de Vigilancia Epidemiológica de México. Para determinar el comportamiento espacial se construyeron canales endémicos y análisis de series de tiempo. Para determinar el comportamiento espacial, se utilizó el modelo estadístico espacial Scan. RESULTADOS: Se determinó que los casos de leptospirosis en México se presentan todo el año; sin embargo, los picos endémicos se observaron en los meses de agosto, septiembre y octubre. Con respecto al comportamiento espacial, no se determinó ninguna agrupación estadísticamente; no obstante, los estados con la mayor prevalencia fueron: Sinaloa, con 146.7 casos por cada millón de habitantes, y Tabasco, con 142 casos por cada millón de habitantes. DISCUSIÓN: La leptospirosis es una enfermedad influenciada por los hábitos y las costumbres de la población, al igual que por variables climatológicas que favorecen el contacto con el agente etiológico. Esto coincide con lo reportado por otros estudios que han determinado que la incidencia de leptospirosis aumenta durante la época de lluvia y que esta enfermedad se relaciona con actividades de recreación en zonas tropicales. CONCLUSIONES: La leptospirosis es una enfermedad zoonótica emergente de gran importancia en México, que se presenta con mayor frecuencia en época de lluvias. Los estados de Sinaloa y Tabasco son los más afectados.

Salix babylonica L. as a Natural Anticoccidial Alternative in Growing Rabbits.

Coccidiosis in rabbit production is responsible for high morbidity, mortality, and economic losses. The use of natural antimicrobial substances in rabbits represents a promising way to improve their health and production. The aim of the present study was to assess the activity of Salix babylonica hydroalcoholic extract (SBHE) on the elimination of Eimeria spp. in rabbits. The phytochemical compounds and chemical composition of SBHE were determined. The cytotoxicity of SBHE was determined by a microwell assay using Artemia salina. Twenty-five New Zealand rabbits, 28 days old and 872 ± 171 g body weight (BW), were used in a completely randomized design. The rabbits were assigned to five groups of five rabbits, control group (A) received only basal diet (BD), B group received BD + 25 mg/kg BW of SBHE, C group received BD + 50 mg/kg BW of SBHE, D group received BD + 100 mg/kg BW of SBHE, and E group received BD + coccidiostat Baycox® (75 mg/kg body weight) for 28 days. Feces samples were collected at days 0, 7, 14, 21, and 28; morphological and morphometric identifications of Eimeria were carried out by the flotation technique and counting of oocysts by the McMaster technique. The rabbits were found naturally infected with Eimeria spp. The SBHE present phytochemicals with anticoccidial activity, and the cytotoxicity test indicate that this extract is nontoxic. This study demonstrates that oral administration of SBHE at 25 and 50 mg/kg BW reduced the release of oocysts per gram of feces. This effect was observed at day 14 and had the most significant effect at day 28 for both concentrations. The results indicate that SBHE could be a natural alternative for the control of coccidiosis in rabbit production.

Chemical Constituents of Salix babylonica L. and Their Antibacterial Activity Against Gram-Positive and Gram-Negative Animal Bacteria.

The principle of animal wellbeing, which states that animals should be free from pain, injury, and disease, is difficult to maintain, because microorganisms are most frequently found to be resistant or multi-resistant to drugs. The secondary metabolites of plants are an alternative for the treatment of these microorganisms. The aim of this work was to determine the antibacterial effect of Salix babylonica L. hydroalcoholic extract (SBHE) against Escherichia coli, Staphylococcus aureus and Listeria monocytogenes, and identify the compounds associated with the activity. The SBHE showed activity against the three strains, and was subjected to a bipartition, obtaining aqueous fraction (ASB) with moderate activity and organic fraction (ACSB) with good activity against the three strains. The chromatographic separation of ACSB, allowed us to obtain ten fractions (F1AC to F10AC), and only three showed activity (F7AC, F8AC and F10AC). In F7AC, five compounds were identified preliminary by GC-MS, in F8AC and F10AC were identified luteolin (1) and luteolin 7-O-glucoside (2) by HPLC, respectively. The best antibacterial activity was obtained with F7AC (Listeria monocytogenes; MIC: 0.78 mg/mL, MBC: 0.78 mg/mL) and F8AC (Staphylococcus aureus; MIC: 0.39 mg/mL; MBC: 0.78 mg/mL). The results indicated that the compounds obtained from SBHE can be used as an alternative treatment against these microorganisms and, by this mechanism, contribute to animal and human health.

Determinación de clorhidrato de clembuterol en orina de bovinos en tres rastros municipales del estado de México / Determination of Clenbuterol Hydrochloride in Bovine Urine in Three Municipal Slaughterhouses of the State of Mexico / Determinação de cloridrato de clenbuterol em urina de bovinos em três trilhas municipais do estado do México

Resumen El objetivo del presente trabajo fue determinar el porcentaje de bovinos para abasto positivos a clorhidrato de clembuterol (CCL), con base en muestras de orina de bovinos sacrificados en 3 rastros del estado de México. Para esto se colectaron muestras en los rastros municipales de Toluca (59), Ixtlahuaca (52) y Atlacomulco (40), y se obtuvo un total de 151 muestras. El análisis de las muestras se realizó a través de la prueba de ELISA y para el reporte de resultados se utilizó estadística descriptiva. De las muestras analizadas 105 fueron positivas (69,53 %), por rastro la positividad, fue de 48, 30 y 27 respectivamente. Al establecer diferentes rangos de concentración a CCL, en el rango de 200 a 1999 pg g-1 se ubicaron 46 muestras; 6 muestras, en el rango de 2000 a 3525 pg g-1; 3, en el rango de 3526 a 5050 pg g-1; 1 muestra, entre 5051 y 6575 pg g-1, y 95 se ubicaron entre 6575 y >8100 pg g-1. El rastro con mayor porcentaje de positividad fue el de Toluca, con base en los rangos establecidos, y las concentraciones más elevadas también se observaron en el mismo rastro. El límite mínimo de detección de CCL de 2000 pg g-1 permite considerar que, con base tanto en la concentración como en su cinética, las cantidades detectadas en el estudio sirven como un indicador importante de residualidad a través de este tipo de muestra.

Abstract The present work aimed to determine the percentage of bovines that tested positive for clenbuterol hydrochloride (CCL), based on urine samples of cattle slaughtered in 3 slaughterhouses of the State of Mexico. To the effect, samples were collected in the municipal slaughterhouses of Toluca (59), Ixtlahuaca (52), and Atlacomulco (40), resulting in a total of 151 samples. Sample analysis was carried out using the ELISA test, and descriptive statistics were used to report the results. 105 of the analyzed samples were positive (69.53%); by slaughterhouse, positivity was 48, 30, and 27, respectively. When establishing different ranges of CCL concentration, 46 samples were in the range of 200 to 1999 pg g-1; 6 samples were in the range of 2000 to 3525 pg g-1; 3 were in the range of 3526 to 5050 pg g-1; 1 sample was between 5051 and 6575 pg g-1, and 95 samples were between 6575 and >8100 pg g-1. The slaughterhouse with the highest percentage of positivity was that of Toluca, based on the established ranges, and the highest concentrations were also observed there. The minimum limit for the detection of CCL (2000 pg g-1) allows considering that, based on both concentration and kinetics, the quantities detected in the study serve as an important indicator of residuality in this type of sample.

Resumo O objetivo do presente trabalho foi determinar a porcentagem de bovinos para fornecimento, positivos ao cloridrato de Clenbuterol (CCL), baseados em amostras de urina de bovinos abatidos em três trilhas do estado de México. Para isso, foram coletadas amostras nas trilhas municipais de Toluca (59), Ixtlahuaca (52) e Atlacomulco (40), e obtivera-se um total de 151 amostras. A análise das amostras realizou-se através do teste de ELISA e para o relatório de resultados foi usada estatística descritiva. Das amostras analisadas 105 foram positivas (69,53 %), pelo traço a positividade foi de 48, 30 e 27 respetivamente. Ao estabelecer diferentes faixas de concentração a CCL, 46 amostras foram colocadas na faixa de 200 a 1999 pg g-1; 6 amostras na faixa de 2000 a 3525 pg g-1; 3 na faixa de 3526 a 5050 pg g-1; 1 amostra entre 5051 e 6575 pg g-1, e 95 entre 6575 e >8100 pg g-1. A trilha com maior porcentagem de positividade foi a de Toluca, baseada nas faixas estabelecidas e as concentrações mais altas observaram-se na mesma trilha. O limite mínimo de detecção de CCL de 2000 pg g-1 permite considerar que, baseado na concentração e na cinética, as quantidades detectadas no estudo servem como indicador importante de residualidade através deste tipo de amostra.

First detection of spring viraemia of carp virus in common carp (Cyprinus carpio L.) affected by a septicaemic disease in Mexico.

Spring viraemia of carp (SVC) is an infectious disease responsible for severe economic losses for various cyprinid species, particularly common carp (Cyprinus carpio carpio). The causative agent is the SVC virus (SVCV), a member of the Sprivivirus genus, Rhabdoviridae family, and a List 1 pathogen notifiable by the World Organization for Animal Health. This study describes the diagnosis of an SVCV pathogen isolated in October 2015 from wild common carp inhabiting a natural lagoon in central Mexico. While neither an epidemic nor fish mortalities were reported, the collected killed specimens exhibited clinical signs of disease (e.g., exopthalmia, moderate abdominal distension and haemorrhaging, as well as internal haemorrhages and adhesions). Histological results of injuries were consistent with the pathology caused by SVCV. This finding was supported by the isolation of a virus in EPC and BF-2 cells and subsequent RT-PCR confirmation of SVCV. The phylogenetic analyses of partial SVCV glycoprotein gene sequences classified the isolates into the Ia genogroup. These findings make this the first report of SVCV detection in Mexico, extending the southern geographical range of SVCV within North America. However, since this pathogen was detected in fish inhabiting a natural body of water without tributaries or effluents, it is difficult to estimate the risk of SVCV for other wild/feral cohabitating cyprinid species in the lagoon. The status of this virus is also unknown for other bodies of water within this region.

Anti-staphylococcal properties of Eichhornia crassipes, Pistacia vera, and Ziziphus amole leaf extracts: Isolates from cattle and rabbits.

The desideratum aim of the present context was to assess the biopotency of methanolic extracts of Eichhornia crassipes (E. crassipes), Pistacia vera (P. vera), and Ziziphus amole (Z. amole) leaves against various staphylococcal strains, and to quantify the phenolics as well as saponin content in them. The antibacterial activity of various concentrations (62.5-1000 µg/mL) of plant extracts was tested against control clinical strains (Staphylococcus aureus ATCC 25923, S. aureus ATCC 29213, and S. aureus ATCC 43300), methicillin-resistant S. aureus (MRSA1 and MRSA2), oxacillin sensitive S. aureus (SOSA1 and SOSA2), and coagulase-negative Staphylococcus epidermidis (CoNS1, CoNS2, and CoNS3) using disc diffusion assay. Leaf extracts of the three plants exhibited pronounced growth inhibitory characteristics against staphylococci in a dose dependent manner. E. crassipes extract depicted the highest relative percentage inhibition values against control clinical strains (68.6 ± 0.5%), while P. vera (68.6 ± 0.3%) and Z. amole (74.79 ± 0.3%) extracts showed pronounced relative inhibition values against staphylococcal strains isolated from cattle. Total phenols and saponin content of leaf extracts were investigated by standard in vitro methods. The methanolic extracts of these plants were found to comprise substantial content of phenolics and saponin at varying levels. The highest value of phenolics was estimated in P. vera extract (60.0 ± 1.3 mg gallic acid/g extract), followed by Z. amole (33.6 ± 1.4 mg gallic acid/g extract), and E. crassipes (23.0 ± 1.3 mg gallic acid/g extract). Saponin content for P. vera, Z. amole, and E. crassipes extracts were estimated as 41.0 ± 1.3, 35.8 ± 1.3, and 25.0 ± 1.2 mg diosgenin/g extract, respectively. The outcome of this study suggested the exploitation of methanolic extract of P. vera, Z. amole, and E. crassipes leaves for their possible application in ethnomedicine, particularly as drugs preparation against staphylococcal infections. In conclusion, the study indicates the biopotency of these plants against pathogenic MRSA present in cattle, and SOSA as well as CoNS bacteria present in rabbits, which could be a serious issue for livestock.

Molecular Identification of Mycobacterium Species of Public Health and Veterinary Importance from Cattle in the South State of México.

Mycobacterium genus causes a variety of zoonotic diseases. The best known example is the zoonotic tuberculosis due to M. bovis. Much less is known about "nontuberculous mycobacteria (NTM)," which are also associated with infections in humans. The Mexican standard NOM-ZOO-031-1995 regulates the presence of M. bovis in cattle; however, no regulation exists for the NTM species. The objective of this study was to isolate and identify nontuberculous mycobacteria species from cattle of local herds in the south region of the State of Mexico through the identification and detection of the 100 bp molecular marker in the 23S rRNA gene with subsequent sequencing of the 16S rRNA gene. Milk samples (35) and nasal exudate samples (68) were collected. From the 108 strains isolated, 39 were selected for identification. Thirteen strains isolated from nasal exudates amplified the 100 bp molecular marker and were identified as M. neoaurum (six strains), M. parafortuitum (four strains), M. moriokaense (two strains), and M. confluentis (one strain). Except M. parafortuitum, the other species identified are of public health and veterinary concern because they are pathogenic to humans, especially those with underlying medical conditions.

Efecto del clorhidrato de clembuterol en la ganancia de peso y lesiones histológicas en ratones / Effect of clenbuterol hydrochloride on weight gain and histological lesions in mice / Efeito do cloridrato de clembuterol no aumento de peso e lesões histológicas em ratos

Resumen El clorhidrato de clembuterol (CCL) es un p-agonista promotor del crecimiento en animales para abasto, pero su uso ilícito ha generado repercusiones en salud pública. Se realizó un modelo biológico con ratones, con el objeto de evaluar el efecto del CCL sobre la ganancia de peso y las lesiones histológicas que ocasiona. Los ratones fueron alimentados con carne de conejo, que previamente fue suplementada con CCL. Treinta y cinco días posexposición se registró el peso corporal; se obtuvo la concentración muscular y sérica de CCL a través de la prueba de ELISA, y se colectaron tejidos (hígado y corazón) para análisis histopatológico. Los valores obtenidos de los animales experimentales (G1 y G2) se analizaron mediante un diseño experimental completamente al azar con dos tratamientos (n = 10), sometidos a un análisis de varianza y comparación de medias con la prueba de Tukey (p < 0,05). Se registró un incremento de peso corporal de 7 g en el G1, contra 4,0 g del G2. El peso del hígado fue de 2,58 g y 1,79, respectivamente (p < 0,05). En el G1 la concentración muscular de CCL fue 5324 pg g-1 y en suero sanguíneo de 4378 pg g-1. Solo se observaron cambios histológicos en tejidos de los ratones del G1. El hígado mostró tumefacción celular, mitosis moderada, picnosis y degeneración hidrópica; en corazón, engrosamiento de fibras, pleomorfismo e hileración nuclear. El CCL favoreció el incremento de peso en los ratones expuestos, y provocó alteraciones estructurales en hígado y corazón.

Abstract Clenbuterol hydrochloride (CLB) is a growth-promoting p-agonist in animals for supply, but its illicit use has generated repercussions on public health. A biological model with mice was developed to evaluate the effect of CLB on weight gain and histological lesions. Mice were fed rabbit meat, which was previously supplemented with CLB. Body weight was recorded 35 days post-exposure; muscular and serum concentration of CLB was obtained through the ELISA test, and tissues were collected from liver and heart for histopathological analysis. Values obtained from the experimental animals (G1 and G2) were analyzed by a completely randomized experimental design with two treatments (n = 10), subjected to an analysis of variance and comparison of means with the Tukey test (p<0.05). There was an increase of 7 g in body weight in G1, compared to 4.0 g in G2. Liver weight was 2.58 g and 1.79, respectively (p<0.05). In G1, CLB concentration in muscle was 5324 pg.g-1, and 4378 pg.g-1 in blood serum. Only histological changes were observed in the tissues of Gl mice. Liver showed cellular swelling, moderate mitosis, pyknosis and hydropic degeneration; in addition, fiber thickening, pleomorphism and nuclear atypia were observed in the heart. CLB contributed to weight gain in exposed mice and caused structural alterations in liver and heart.

Resumo O cloridrato de clembuterol (CCL) é um b-agonista promotor do crescimento em animais para abate, porém o seu uso ilícito tem gerado repercussões em saúde pública. Fezse um modelo biológico com ratos, com o objeto de avaliar o efeito do CCL sobre o ganho de peso e as lesões histológicas que ocasiona. Os ratos foram alimentados com carne de coelho, que previamente foi suplementada com CCL. Trinta e cinco dias pós-exposição se registrou o peso corporal; obteve-se a concentração muscular e sérica de CCL através da prova de ELISA, e foram coletados tecidos (fígado e coração) para análise histopatológica. Os valores obtidos dos animais experimentais (Gl e G2) foram analisados mediante um desenho experimental completamente ao acaso com dois tratamentos (n = 10), submetidos a uma análise de variações e comparação de médias com a prova de Tukey (p < 0,05). Registrou-se um aumento de peso corporal de 7 g no G1, contra 4,0 g do G2. O peso do fígado foi de 2,58 g e 1,79, respectivamente (p < 0,05). No G1 a concentração muscular de CCL foi 5324 pg g-1 e em soro sanguíneo de 4378 pg g-1. Somente foram observadas mudanças histológicas em tecidos dos ratos do G1. O fígado apresentou inchaço celular, mitose moderada, picnose e degeneração hidrópica; no coração, engrossamento de fibras, pleomorfismo e filamento nuclear. O CCL favoreceu o aumento de peso nos ratos expostos, e provocou alterações estruturais em fígado e coração.

Riesgos a la salud por el uso de clorhidrato de clembuterol: una revisión / Health Risks Due to the Use of Clenbuterol Hydrochloride: a Review / Riscos à saúde pelo uso de cloridrato de clembuterol: uma revisão

En este trabajo se analiza y valora la información sobre las características y riesgos del uso de clorhidrato de clembuterol (CCL) por su potencial efecto tóxico, debido a su inclusión en la alimentación animal (bovinos, cerdos, ovinos y aves) con la finalidad de mejorar parámetros productivos-reproductivos, pero que descuidan la inocuidad alimenticia. Por eso es necesario revalorar los peligros potenciales que puede ocasionar al emplearse tanto en medicina humana como en veterinaria. El CCL es un (β-adrenérgico sintético, polvo blanco, anhidro, muy soluble en agua y altamente estable a temperatura ambiente. Es utilizado en forma clandestina en animales de engorde destinados al consumo humano. Terapéuticamente, se utiliza como un medicamento broncodilatador (pacientes con asma); en competencias deportivas se ha detectado su uso ilegal (dopaje), y en fisicoculturismo es utilizado por su efecto anabólico. Su administración en el ganado para abasto modifica e incrementa el crecimiento de masas musculares, y disminuye la acumulación de grasa; se acumula en diferentes órganos. En personas con antecedente del consumo de hígado de bovino contaminado con CCL se ha registrado temblor, dolor muscular, mareos, cefalea y taquicardia. En México, de manera ilegal y clandestina, hay distribución, comercialización y uso de CCL; sin embargo, el trabajo de las organizaciones ganaderas para el registro de unidades de producción libres de esta sustancia garantizará el consumo de los productos cárnicos. Proponer el uso de otras sustancias de las cuales hasta el momento no se tiene indicios de toxicidad propiciará una productividad sustentable, segura e inocua en las unidades de producción pecuaria.

This paper analyzes and evaluates information about the characteristics and risks of using Clenbuterol hydrochloride (CCL) for their potential toxic effects, due to its inclusion in animal food (cattle, pigs, sheep and poultry) to improve productive-reproductive parameters, but neglecting food safety. Therefore, it is necessary to reassess the potential dangers that may result when used in both human and veterinary medicine. The (β-adrenergic synthetic CCL, white powder, anhydrous, highly water soluble and highly stable at room temperature is used in a clandestine manner to fatten animals for human consumption. Therapeutically, it is used as a bronchodilator drug (asthma patients); its illegal use (doping) has been detected in sports competitions, and it is used for bodybuilding due to its anabolic effect. Its use in cattle for slaughter modifies and increases the growth of muscle mass and reduces fat accumulation, which accumulates in different organs. In people with a history of bovine liver consumption contaminated with CCL, there has been registration of: tremor, muscle pain, dizziness, headache, and tachycardia. In Mexico, in an illegal and clandestine manner, there is distribution, marketing and use of CCL; however, the work of livestock organizations in registering production units free of this substance will ensure the consumption of meat products. Moreover, to propose the use of other substances which so far have no signs of toxicity will lead to a sustainable, secure and safe productivity in livestock units.

Neste trabalho se analisa e avalia a informação sobre as características e riscos do uso de cloridrato de clembuterol (CCL) pelo seu potencial efeito tóxico, devido à sua inclusão na alimentação animal (bovinos, cerdos, ovinos e aves) com a finalidade de melhorar parâmetros produtivo-reprodutivos, mas que descuidam a inocuidade alimentícia. Por isso é necessário reavaliar os perigos potenciais que pode ocasionar ao empregar-se tanto em medicina humana como veterinária. O CCL β-adrenérgico sintético, pó branco, anidro, muito solúvel em água e altamente estável a temperatura ambiente. É utilizado em forma clandestina em animais de corte destinados ao consumo humano. Terapeuticamente, se utiliza como um medicamento bronco dilatador (pacientes com asma); em competências esportivas tem sido detectado o seu uso ilegal (dopagem), e em físico culturismo é utilizado por seu efeito anabólico. Sua administração no gado para abasto modifica e incrementa o crescimento de massas musculares, e diminui a acumulação de gordura; acumulando-se em diferentes órgãos. Em pessoas com antecedente do consumo de fígado de bovino contaminado com CCL tem se registrado: tremor, dor muscular, tonturas, cefaleia e taquicardia. No México, de maneira ilegal e clandestina, há distribuição, comercialização e uso de CCL; contudo, o trabalho das organizações pecuaristas para o registro de unidades de produção livres desta substância garantirá o consumo dos produtos de carne. Assim como também, propor o uso de outras substâncias das quais até o momento não se tem indícios de toxicidade propiciará uma produtividade sustentável, segura e inócua nas unidades de produção pecuária.

Resistencia antibiótica de genotipos de cepas de Salmonella spp de cerdos sacrificados en rastros del Estado de México / Antibiotic resistance of Salmonella spp strain genotypes isolated from pigs slaughtered at abattoirs in the Estado de Mexico

Multiresistant Salmonella serovar Typhimurium strains are a worldwide problem in animal and human health. The aim of this study was to determine the frequency of some Salmonella spp resistance genes (cmlA/tetR, PSE-1, TEM, Sip B/C) in strains isolated from pigs slaughtered at abattoirs in the Estado de Mexico. Of 87 analyzed strains 22 (25.28%) had phenotypical resistance to chloramphenicol (30 μg), 15 (17.24%) to ampicillin (10 μg) and 54 (62.07%) to sulfamethoxazole (60 μg). The phenotypical and genotypical relation of the 87 strains was: of the 22 chloramphenicol resistant strains only 14 (63.63%) expressed the cmlA/tetR resistance gene, and of the 65 strains non-resistant to chloramphenicol only 36 (55.38%) expressed the cmlA/tetR resistance gene. Regarding the 15 ampicillin resistant strains only 2 (13.33%) were carriers of the PSE-1 gene and 7 (46.66%) presented the TEM gene; both genes confer genotypical ampicillin resistance. Of 72 non-resistant ampicillin strains, 11 (15.27%) carried the TEM gene which confers ampicillin resistance. Two Salmonella strains (2.28%) belonged to phagotype DT104. Strains not showing phenotypical resistance but carrying resistance genes have not been exposed to selection by competition, although they possess the mechanism to express such resistance.

La aparición de cepas multirresistentes de Salmonella Typhimurium es un problema mundial, tanto en salud animal como en salud pública. El objetivo del presente trabajo fue determinar la frecuencia de algunos genes de resistencia (cmlA/tetR, PSE-1, TEM, Sip B/C) en cepas de Salmonella spp aisladas de cerdos en rastros del Estado de México. De las 87 cepas analizadas, 22/87 (25.28%) mostraron resistencia al cloranfenicol (30 μg), 15/87 (17.24%) a la ampicilina (10 μg) y 54/87 (62.07%) fueron resistentes al sulfametoxazol (60 μg). La relación fenotípica y genotípica de las 87 cepas analizadas fue: de las 22 cepas que presentaron resistencia fenotípica al cloranfenicol, sólo 14/22 (63.63%) expresaron el gen de resistencia cmlA/tetR, y de las 65 cepas que manifestaron sensibilidad al cloranfenicol, 36/65 (55.38%) expresaron el gen de resistencia cmlA/tetR. De las 15 cepas que expresaron resistencia a la ampicilina, sólo 2/15 (13.33%) mostraron el gen PSE-1, y 7/15 (46.66%) presentaron el gen TEM, ambos genes confieren resistencia genotípica a la ampicilina. De las 72 cepas que manifestaron sensibilidad a la ampicilina, 11 (15.27%) mostraron el gen TEM, el cual da resistencia a la ampicilina. De las 87 cepas de Salmonella sólo 2/87 (2.28%) expresaron el fagotipo DT104. Las cepas que son portadoras de genes de resistencia, pero no la manifiestan fenotípicamente, no han sido expuestas a una selección por competencia, por lo tanto, no expresan la resistencia fenotípica, pero cuentan con el mecanismo necesario para expresarla.