[Epidemiology of caprine brucellosis in the Central Zone of the State of Veracruz]. / Epidemiología de la brucelosis caprina en la Zona Centro del Estado de Veracruz.

INTRODUCTION: Brucellosis is a disease of high morbidity that affects several animal species, is transmitted to humans and, therefore, is a zoonosis. It is caused by bacteria of the genus Brucella. In this study we aim to determine seroprevalence, risk factors, and spatial distribution of caprine brucellosis in 14 municipalities in the central region of the state of Veracruz. MATERIALS AND METHODS: This cross-stratified multistage study was conducted between 2009 and 2012. It included 572 animals of 81 production units selected by consensus according to the value tables of ​​Cannon and Roe. The diagnosis was by Card Testing and Radial Immunodiffusion. The seroprevalence was determined with the VassarStats® risk factor program and odds. RESULTS: The overall seroprevalence was 0.52% (95% CI: 0.13-1.65) and production units 2.47% (95% CI: 0.43-9.46). They were identified as risk factor for infection, production units in feedlot system and Card Testing seroconversion to vaccine against brucellosis; and as a protective factor, vaccination. CONCLUSIONS: Seroprevalence and distribution of goat brucellosis is low, the intensive system is a risk, and according with the Health Ministry in order that human cases are scarce.

Seroprevalence of Toxoplasma gondii infection in water buffaloes (Bubalus bubalis) in Veracruz State, Mexico and its association with climatic factors.

BACKGROUND: Infection with Toxoplasma gondii in water buffaloes (Bubalus bubalis) is of epidemiological importance because of the risk for transmission to humans. We sought to determine the seroprevalence of T. gondii infection in 339 water buffaloes in Veracruz State, Mexico using the modified agglutination test (MAT, cut off 1:25). Seroprevalence association with general characteristics of buffaloes and their environment was also investigated. RESULTS: Antibodies to T. gondii were found in 165 (48.7%) of the 339 buffaloes with MAT titers of 1:25 in 104, 1:50 in 52, and 1:100 in 9. Bivariate analysis showed that seroprevalence of T. gondii infection was similar in buffaloes regardless of their general characteristics i.e., age, sex, and breed. In contrast, the seroprevalence in buffaloes varied significantly with environmental characteristics including altitude, mean annual temperature, and mean annual rainfall of the municipalities studied. Multivariate analysis showed that T. gondii seropositivity in buffaloes was associated with a mean annual rainfall between 1266-1650 mm (OR = 1.84; 95% CI: 1.15-2.94; P = 0.01). CONCLUSIONS: Results indicate that environmental characteristics may influence the seroprevalence of T. gondii infection in buffaloes. This is the first report on the seroprevalence of T. gondii infection in buffaloes in Mexico. Further research is needed to assess the risk for infection in humans associated with the ingestion of raw or undercooked meat from buffaloes infected with T. gondii.

High prevalence of Toxoplasma gondii antibodies in dogs in Veracruz, Mexico.

BACKGROUND: Little is known concerning the prevalence of Toxoplasma gondii infection in dogs in Mexico. Here, we investigated antibodies to T. gondii and associated risk factors in 101 dogs from an animal shelter in Veracruz State, Mexico. Canine sera were assayed for T. gondii IgG antibodies by using the modified agglutination test (MAT, cut off 1:25). RESULTS: Sixty eight (67.3%) of 101 dogs were seropositive with titers of 1:25 in 16, 1:50 in 8, 1:100 in 9, 1:200 in 10, 1:400 in 10, 1:800 in 10, 1:1600 in 3, and 1:3200 or higher in 2. None of the dogs' characteristics studied including age, sex, breed, and history of deworming, rabies vaccination and contact with cats was associated with seroprevalence of T. gondii infection. CONCLUSION: Using the dogs as sentinel animals, the results indicate high contamination with T. gondii of the environment in Veracruz, Mexico. Results have public health implications, and further studies in Veracruz should be conducted to establish the sources of environmental contamination with T. gondii and to determine optimal preventive measures against T. gondii infection in humans.

Acaricidal activity of Mexican plants against Rhipicephalus microplus resistant to amitraz and cypermethrin.

This study evaluates the acaricidal activity of Mexican native plants against a Rhipicephalus microplus population resistant to both amitraz and cypermethrin. To explore the activities of plants, the larvicidal effects of 72 Kupchan fractions (Hex, DCM, AcOEt and MeOH:H2O) of 18 plant species collected in Veracruz, Mexico were studied. The evaluation of the Kupchan fractions against double resistant R. microplus indicated that the fractions of Annona globiflora (Hex, LC50 = 0.007% w/v; DCM, LC50 = 0.007% w/v), Annona scleroderma (Hex, LC50 = 0.08% w/v; DCM, LC50 = 0.02% w/v), and Litchi chinensis (Hex, LC50 = 0.79% w/v; DCM, LC50 = 0.54% w/v) showed the greatest larvicidal activities. To identify the presence of additive, synergistic, or antagonistic effects, the acaricidal activity of binary mixtures of the most active fractions of A. globiflora, A. scleroderma, L. chinensis and Citrus sinensis were also evaluated. The latter was chosen as it is easy to obtain due to its substantial presence in agricultural activity locally and globally. The results showed synergistic interaction of the fraction Hex of C. sinensis with the fractions of Hex and DCM of L. chinensis. The most active larvicidal fractions were tested against engorged ticks of R. microplus by adult immersion test at concentration of 2.5% w/v. The Hex and DCM fractions from A. globiflora and A. scleroderma were the most active, causing 100% mortality. The Hex and DCM fractions of L. chinensis exhibited approximately 50% mortality, while the other evaluated fractions did not show efficacy at this concentration. Therefore, it is evident that the fractions of these plants have the potential to be used in either combined or single form as effective alternatives in the control of R. microplus zoonoses.

Studies on the bioactive flavonoids isolated from Azadirachta indica.

Two novel natural metabolites, 3-O-butyl-(-)-epicatechin (1) and 3-O-butyl-(-)-epigallocatechin (2), as well as several known substances, (-)-epicatechin (3), (+)-gallocatechin (4), (-)-epigallocatechin (5), azadirachtin A (6), trilinolein (7) and octadecanoic acid-tetrahydrofuran-3,4-diyl ester (8), were isolated from the bark of Azadirachta indica. The structures of all compounds were established by comprehensive and comparative spectroscopic analysis of NMR and ESI-HRMS data. The new metabolites 1 and 2 represent one of the few examples of natural compounds with a butyl ether group moiety. The acaricidal activity of the compounds was tested using a standard Shaw larval immersion assay. All the compounds, except 7, possess a LD50 value less than or equal to 7.2 mM.