The objective of this study was to identify the main chemical components of the essential oil of Cuminum cyminum L. (cumin) and of the fixed oils of Bertholletia excelsa (Brazil nut) and of Helianthus annuus (sunflower seed). As well as testing the three oils and three different commercial synthetic acaricides against engorged females of Rhipicephalus (Boophilus) microplus in order to explore their acaricidal efficacy. Six different concentrations of the oils (200, 100, 50, 25, 12.5 and 6.25 mg/mL) and the active principles were evaluated with the Adult Immersion Test (AIT). The two main chemicals components of C. cyminum L. were the cuminaldehyde and the γ-terpinene. In both B. excelsa and H. annuus were the linoleic and oleic acid. C. cyminum L. showed high acaricidal activity (100%) over the engorged females and on their reproductive characteristat from the concentration of 100 mg/mL. B. excelsa and H. annuus had low acaricidal activity (39.39% and 58.75% in the concentration of 200 mg/mL respectively). The amidine and the pyrethroid (35.12% and 1.50% respectively). It can be concluded that the oil of C. cyminum L. may be a phytoterapic alternative for the cattle's tick control.
Malassezia pachydermatis is a commensal yeast of the skin and external ear canal of dogs and cats that may become an opportunistic pathogen under some conditions. The aim of this paper was to research the diseases which predispose to the development of opportunistic M. pachydermatis in dogs with external otitis or dermatopathies. The samples were collected by sterile swabs or by the carpet technique. Samples were obtained from the external ear canal and cutaneous tegument and were seeded in Sabouraud dextrose agar added with chloramphenicol and cycloheximide. Following, they were incubated at 32ºC for seven days for yeast identification. M. pachydermatis isolation was successful in 49 (70%) of the 70 samples investigated. Underlying diseases diagnosed in these animals included ceruminous otitis, skin fold pyoderma, seborrhoeic dermatitis, atopic dermatitis, pressure point pyoderma, parasitic otitis, acanthosis nigricans, hot spot and bacterial otitis. The results confirm that the presence of this yeast can cause the perpetuation of these diseases and be a treatment complication factor.
Antimicrobials are routinely used in human and veterinary medicine. With repeated exposure, antimicrobials promote antibiotic resistance, which poses a threat to public health. In this study, we aimed to determine the susceptibility patterns, virulence factors, and phylogroups of E. coli isolates during the killing process in a bovine slaughterhouse. We analyzed 336 samples (from water, surfaces, carcasses, and feces), and 83.3% (280/336) were positive for E. coli. The most common phenotypic resistances that we detected were 50.7% (142/280) for tetracycline, 44.2% (124/280) for cephalothin, 34.6% (97/280) for streptomycin, and 36.7% (103/280) for ampicillin. A total of 82.4% of the isolates had resistance for at least one antimicrobial, and 37.5% presented multiresistance. We detected a total of 69 different phenotypic resistance patterns. We detected six other resistance-related genes, the most prevalent being tetA (22.5%) and strB (15.7%). The prevalence values of the virulence genes were 5.4% in hlyA, 1.4% in stx1, and 0.7% in stx2. The frequencies of the pathogenic strains (B2 and D) were 32.8% (92/280) and 67.1% (188/280) as commensals A and B1, respectively. E. coli isolates with pathogenic potential and multiresistance may represent an important source of dissemination and a risk to consumers.
The ixodicidal activity of the methanolic extracts of Artemisia ludoviciana (Astereceae), Cordia boissieri (Boraginaceae) and Litchi chinensis (Sapindaceae) against two field populations of Rhipicephalus (Boophilus) microplus from the state of Nuevo Leon (NL) and Veracruz (VER) was evaluated. The extract of L. chinensis in the concentration of 150 mg/ml showed efficacies of 100% and 99% against engorged females and mortalities of 98% and 99% against larvae. C. boissieri in the same concentration showed efficacies of 71% and 37% against engorged adults and mortalities of 33.04% and 10.33% against larvae and A. ludoviciana had efficacies of 94% and 83% in adults and mortalities of 89.39% and 89.21% against larvae in both populations respectively. The enzymatic activity of Acetylcholinesterase (AChE), Carboxylesterase (CaE), Glutathione-S-Transferase (GST) and Alkaline Phosphatase (ALP) was measured in both populations of ticks. As a result, a significant difference between both populations was shown, being the VER population the one that exhibited a higher enzymatic activity (p ≤ 0.05). It can be concluded that the methanolic extract of the seed of L. chinensis shows potential ixodicidal activity and can be used as an alternative source of tick control, however, prior characterization, toxicity and formulation studies are necessary.
The Rhipicephalus (Boophilus) microplus tick is of great importance in livestock due to its direct and indirect effects, it has a distribution of 69.4% of the national territory, with approximate losses of up to 573.61 million dollars per year in Mexico. Chemical control is the most widely used method, however, continuous, and indiscriminate use has led to the emergence of populations of resistant ticks. In this study, the efficacy of three synthetic ixodicides, a pyrethroid, an organophosporade, and a pyrethroid- organophosporade mixture were evaluated. in a field population through the adult immersion test, obtaining efficacy rates of 28.66%, 100%, and 96%, respectively. It was obtained that the organophosphate is the only ixodicide that can be used in this population.
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