A randomized, double-blind, placebo-controlled study to assess the effect of an aqueous extract of Triticum aestivum on canine outer ear inflammation / Ensaio clínico, randomizado, duplo cego, para tratamento experimental de otite externa com extrato aquoso de Triticum aestivum

Outer ear otitis is a multifactorial acute or chronic inflammation of the ear canal, and treatment is often hampered by growing antibiotic resistance. Pre-clinical assessments have shown that an aqueous extract of Triticum aestiveum (wheat) can effectively reduce the symptoms associated with the disease. The purpose of this study was to assess, through a randomized, double-blind, placebo-controlled trial, the use of T. aestivum extract on canine external otitis. Thirty dogs (60 ears) met the criteria to be included in this study, and were randomly assigned a treatment group: placebo, extract, or positive control (C+). Ears were treated every day for seven days, and assessed before treatment (day zero), after treatment (day 7), and again on reassessment (day 14). Clinical assessment included: type of otitis; pinna conformation; presence or absence of itchiness, foul odor, and pain; presence of stenosis, erythema and cerumen. Furthermore, the evaluators assessed the temperature in each ear and the pH of the cerumen, and swabs were collected for bacterial and fungal isolation. All veterinarians treating and assessing the animals were blinded regarding the treatment groups. Results showed little difference in the treatment groups regarding clinical parameters. By day 7 ears treated with the C+ had elevated temperatures, when compared to the others (P<0.05), this was still true on day 14. Bacterial isolation had completely died out by day 7, however, on day fourteen the placebo group had six ears with bacterial infections, unlike the other two groups (P<0.05). The results generated herein show that a 25% wheat extract solution is effective in the reduction of clinical and microbiological parameters of external otitis, with better results when compared to a placebo, and similar results to the traditional, antibiotic/anti-inflammatory treatment.(AU)

A Otite Externa (OE) é uma inflamação aguda ou crônica do conduto auditivo dos cães apresentando várias etiologias e o uso de antimicrobianos vem apresentando resistência por inúmeras causas. O objetivo do presente estudo clínico, randomizado e duplo cego foi avaliar a utilização de Triticum aestivum no tratamento da otite externa em cães. Trinta cães com sintomas de otite externa foram distribuídos aleatoriamente em três grupos para tratamento (grupo placebo, grupo solução teste e grupo controle positivo), sendo tratados uma vez ao dia, durante sete dias e avaliados nos dias 0 (zero), sete, e 14 pós o tratamento, sendo submetidos a exame otológico, coleta de secreção auricular para cultura bacteriana e medição do pH do canal auditivo, sendo também realizada a aferição da temperatura do conduto auditivo. Como resultados foi observado que no dia sete houve um aumento da temperatura auricular do grupo controle positivo e manteve-se com a temperatura maior no dia 14 em relação aos demais grupos. Em relação a cultura bacteriana não houve diferença estatística nos grupos entre os dias zero e sete, porém na avaliação com 14 dias, percebeu-se crescimento bacteriano somente no grupo placebo. A solução com extrato aquoso de trigo 25% é eficaz na redução dos parâmetros clínicos e microbiológicos da otite externa, sendo uma nova opção para o tratamento dessa enfermidade em cães.(AU)

Protection against lethal leptospirosis after vaccination with LipL32 coupled or coadministered with the B subunit of Escherichia coli heat-labile enterotoxin.

Leptospirosis, a worldwide zoonosis, lacks an effective, safe, and cross-protective vaccine. LipL32, the most abundant, immunogenic, and conserved surface lipoprotein present in all pathogenic species of Leptospira, is a promising antigen candidate for a recombinant vaccine. However, several studies have reported a lack of protection when this protein is used as a subunit vaccine. In an attempt to enhance the immune response, we used LipL32 coupled to or coadministered with the B subunit of the Escherichia coli heat-labile enterotoxin (LTB) in a hamster model of leptospirosis. After homologous challenge with 5× the 50% lethal dose (LD(50)) of Leptospira interrogans, animals vaccinated with LipL32 coadministered with LTB and LTB::LipL32 had significantly higher survival rates (P < 0.05) than animals from the control group. This is the first report of a protective immune response afforded by a subunit vaccine using LipL32 and represents an important contribution toward the development of improved leptospirosis vaccines.

Recombinant vaccines against leptospirosis.

Leptospirosis is an important neglected infectious disease that occurs in urban environments, as well as in rural regions worldwide. Rodents, the principal reservoir hosts of pathogenic Leptospira spp., and other infected animals shed the bacteria in their urine. During occupational or even recreational activities, humans that come into direct contact with infected animals or with a contaminated environment, particularly water, are at risk of infection. Prevention of urban leptospirosis is largely dependent on sanitation measures that are often difficult to implement, especially in developing countries. Vaccination with inactivated whole-cell preparations (bacterins) has limited efficacy due to the wide antigenic variation of the pathogen. Intensive efforts towards developing improved recombinant vaccines are ongoing. During the last decade, many reports on the evaluation of recombinant vaccines have been published. Partial success has been obtained with some surface-exposed protein antigens. The combination of protective antigens and new adjuvants or delivery systems may result in the much-needed effective vaccine.

Subunit approach to evaluation of the immune protective potential of leptospiral antigens.

Leptospirosis is the most widespread zoonosis in the world. Current vaccines are based on whole-cell preparations that cause severe side effects and do not induce satisfactory immunity. In light of the leptospiral genome sequences recently made available, several studies aimed at identification of protective recombinant immunogens have been performed; however, few such immunogens have been identified. The aim of this study was to evaluate 27 recombinant antigens to determine their potential to induce an immune response protective against leptospirosis in the hamster model. Experiments were conducted with groups of female hamsters immunized with individual antigen preparations. Hamsters were then challenged with a lethal dose of Leptospira interrogans. Thirteen antigens induced protective immune responses; however, only recombinant proteins LIC10325 and LIC13059 induced significant protection against mortality. These results have important implications for the development of an efficacious recombinant subunit vaccine against leptospirosis.

Preliminary characterization of Mus musculus-derived pathogenic strains of Leptospira borgpetersenii serogroup Ballum in a hamster model.

Human and animal leptospirosis caused by Leptospira spp. belonging to serogroup Ballum has increased worldwide in the past decade. We report the isolation and serologic and molecular characterization of four L. borgpetersenii serogroup Ballum isolates obtained from Mus musculus, and preliminary virulence studies. These isolates are useful for diagnosis of leptospirosis and for epidemiologic studies of its virulence and pathogenic mechanisms.