À família das Myrtaceae possui mais de 5.000 espécies e está amplamente distribuído pelo mundo, dentre estas se destaca o gênero Psidium que são araçazeiros e produtores de frutos. A Psidium refum conhecida popularmente como araçá roxo é uma árvore frutífera endêmica do Brasil não cultivada sendo encontrada em seu habitat natural. Inúmeras espécies da família Myrtaceae produzem óleo essencial e apresentam atividades biológicas, maioria dos óleos essenciais de Myrtaceae analisados até o momento são caracterizados pela predominância de monoterpenos, sesquiterpenos e fenilpropanóides. Estes óleos essenciais possuem atividades antimicrobianas contra diversas bactérias como Staphylococcus aureus, Escherichia coli Staphylococcus epidermidis, Micrococcus luteus entre outras. Em relação a atividade antioxidante da espécie Psidium a poucos trabalhos na literatura descrevendo sua ação. O estudo da composição química dos óleos essenciais das espécies Psidium guajava, Psidium cattleianum e Psidium guineense vem sendo amplamente estudados para a atividade acaricidas. Entretanto os trabalhos encontrados na literatura do gênero da Psidium rufum estão relacionados a estudos morfológicos, não existindo pesquisas relacionadas as suas atividades biológicas. Assim as espécies pertencentes ao gênero Psidium possuem um grande potencial para estudos para evidencias a atividades biológicas de seus óleos.

Objetivo: avaliar a atividade acaricida e larvicida do óleo essencial das folhas de Psidium rufum frente a fêmeas ingurgitadas e larvas de Rhipicephalus microplus. Metodologia: o óleo essencial das folhas frescas de P. rufum foi extraído por hidrodestilação (2h) e analisado por cromatografia em fase gasosa acoplada à espectrometria de massas (CG-EM). As atividades acaricida e larvicida foram realizadas pela técnica de imersão de adultos e imersão larval (Larval Paket Test) utilizando o óleo essencial nas concentrações de 300 a 0,001 mg/mL. Como controle positivo foi utilizado uma solução comercial (cipermetrina 15%; clorpirifós 25%; citronelal 1%) a 0,005%, e como controle negativo uma solução aquosa de polissorbato (80) a 2,0%. As concentrações letais (CL50 e CL99) foram determinadas pela análise de Probitos. Resultados: no óleo essencial, foram identificados 55 compostos, sendo a classe majoritária os sesquiterpenos hidrocarbonetos (70,07%), e como majoritários o 1,8-cineole (19,00%); seguido do α-longipinene (18,62%). Os resultados evidenciaram que o óleo essencial de P. rufum a 6.20 mg/mL foi efetivo para controlar 73% da eclodibilidade de ovos reduzindo a oviposição e o número de carrapatos adultos e larvas. A CL99 para as larvas foi 2,50 mg/mL, e para as fêmeas ingurgitadas CL99 de 513,57 mg/mL. Conclusão: o óleo essenciaL das folhas de P. rufum demonstrou potencial para controlar R. microplus no ciclo de vida que corresponde a fase larval, indicando tratar-se de uma planta promissora para o desenvolvimento e aplicação de produtos contra carrapatos bovinos.

Lately, bacterial drug resistance has become an important worldwide problem in one health, where bacteria have undergone mutation becoming increasingly resistant. The major problem of bacterial drug resistance is the difficulty with eliminating microorganisms from different wounds and infected patients, and the therapeutic option is most often ineffective as a result of the repeated and inappropriate use of antimicrobials. The objective of this work was to detect and identify enterobacteria, to evaluate their resistance profile and the production of extended-spectrum b-lactamases in draft horse isolates from the municipality of Umuarama, Parana, Brazil. A nasal, oral, and ear cavity swab was collected from 38 horses (used for animal traction) for isolation and bacterial identification, phenotypic antibiotic susceptibility testing, and the phenotypic test for the detection of extended-spectrum b-lactamasesproducing strains. In 12 swabs bacterial isolation was possible. Strains of Escherichia coli, Serratia rubidaea, Citrobacterdiversus, Kluyvera species, and Providenciaalcalifaciens were isolated. one hundred percent multidrug resistance was detected, and the antimicrobials that encountered the highest resistance were ertapenem (100%), cefotaxime (100%), cefoxitin (100%), ampicillin (100%), amoxicillin (100%), chloramphenicol (100%), and aztreonam (91.67%) and no extended-spectrum b-lactamases -producing strain was detected. The results of this work reveal the presence of strains of the Enterobacteriaceae family associated with high bacterial resistance in horses used for animal traction in the municipality of Umuarama, State of Parana, Brazil, and these results confirm that these horses can be considered reservoirs of multidrug-resistant microorganisms. This situation can be considered an important problem of one health.

The aim of this study was to evaluate the antibacterial and antioxidant activities of essential oil (EO) from fresh leaves of Psidium rufum. The EO was extracted by hydrodistillation and identified by gas chromatography coupled to mass spectrometry. The antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antioxidant activity was determined by β-carotene/linoleic acid co-oxidation system, 2,2-diphenyl-1-picrylhydrazyl radical scavenging and iron reduction methods. Hydrocarbon sesquiterpenes were the predominant class, indicating 1,8 cineole, α-longipinene as major. The EO was tested against the bacteria Staphylococcus aureus and Pseudomonas aeruginosa (MIC = 2,500 µg/mL and MBC = 20,000 µg/mL); Enterococcus faecalis (MIC = 2,500µg/mL and MBC > 20,000µg/mL) and Escherichia coli (MIC > 20,000µg/mL and MBC > 20,000µg/mL). The EO showed antioxidant potential due to β-carotene/linoleic acid co-oxidation system, with 76.63% of oxidation inhibition (1.0mg/mL) and due to the iron reduction power (5,38 μmol Fe 2+ /mg sample). The results are promising in recommending this species for the development of food, cosmetic and pharmaceutical products.

Losses due to low reproductive efficiency can economically affect production in a small dairy farm. The aim of this study was to detect the presence of anti-Leptospira, anti-Toxoplasma gondii, and anti-Neospora caninum antibodies in dairy cows with history of reproductive problems at a small dairy farm in Umuarama, Paraná, Brazil. The evaluated herd presented with history of abortion and return to estrus. Of the 37 samples analyzed, 10 (27%) were positive in microscopic serum agglutination, with titers ranging from 100 to 400, 21 (56.75%) were positive for Toxoplasma gondii in the indirect immunofluorescence test (IIFT), with titers ranging from 16 to 256, and four (10.8%) were positive for Neospora caninum in IIFT, with titers ranging from 25 to 50. No variables were associated with any infection. Leptospirosis, toxoplasmosis, and neosporosis are widespread in herds and may have a negative impact on reproductive parameters of dairy cattle. Periodic serological evaluations are important, as they may guide the choice of preventive disease control measures in the herd and also alert and educate small producers and the local population on the possible presence of zoonoses spread by these infectious agents, in addition, it can be concluded that infectious diseases can have negative implications on the reproductive parameters of dairy cattle causing return to heat and abortion.