Cymbopogon citratus Essential Oil in Controlling of Bacteria Associated with Oral Cavity of Dogs In Vitro and Dry Pet Feed.

The aim of this study was to evaluate the antibacterial activity of Cymbopogon citratus essential oil against bacteria isolated from the oral cavity of dogs and applied directly to artificially contaminated feed. The commercial dry dog feed received the inoculum of the bacteria prevalent in the oral cavity of the dogs where C. citratus was deposited in the feed by spray. In total, 42 isolates were obtained, 38 Gram-positive and 4 Gram-negative. Staphylococcus spp. was the most prevalent bacteria in the oral cavity of dogs (76.2%). The isolates showed high levels of resistance to different antimicrobials. The minimum inhibitory concentration capable of inhibiting oral bacteria was 0.38 mg/mL. C. citratus essential oil showed positive results with a significant bacterial reduction when applied to feed, signaling the need for further studies to enable its use in the control of pathogens transmitted by animal feed.

Resistance profile and biofilm production capacity of Staphylococcus spp. beef slaughterhouse isolates and their sensitivity to Rosmarinus officinalis essential oil.

Microorganisms can interfere with meat quality, being a public health problem. The aim of this study was to characterize the antimicrobial susceptibility profile of Staphylococcus spp. isolated from utensils of a bovine slaughterhouse and to evaluate the antibacterial and antibiofilm activity of the essential oil of Rosmarinus officinalis L. (rosemary). Samples of surfaces and utensils used during slaughter in the northwest of the state of Paraná, Brazil were collected. After isolation and differentiation of the isolates by the coagulase test, the antimicrobial susceptibility test, Staphylococcus aureus identification and mecA gene research were performed. The study for biofilm production was carried out by the method of adhesion in borosilicate tube and by adhesion in polystyrene plate. Subsequently, the inhibitory activity of the R. officinalis essential oil and its ability to inhibit biofilm were investigated. Twenty-two of the samples collected were identified as coagulase-negative Staphylococcus and five as coagulase-positive Staphylococcus. There was resistance to all antibiotics tested, with clindamycin (33.33%) and rifampicin (29.6%) showing the highest rate. None of the samples was confirmed as Staphylococcus aureus or for the presence of the mecA resistance gene. The essential oil inhibited the growth of 48% of the isolates at a concentration of 16,000 µg/mL. Of these isolates, 33% were positive for biofilm production and this biofilm was also inhibited by the essential oil. This work revealed that multidrug-resistant Staphylococcus and biofilm producers are present in the slaughter environment and are susceptible to the essential oil of R. officinalis.

Origanum vulgare essential oil and carvacrol: natural alternatives against resistant bacteria / Óleo essencial de origanum vulgare e carvacrol: alternativas naturais contra bactérias resistentes / El aceite esencial de origanum vulgare y el carvacrol: alternativos naturales contra las bacterias resistentes

Bacteria that are resistant to several antibiotics are a serious One Health problem, as new alternatives for treatment do not appear at the same speed. Thus, the aim of this work was to carry out a survey of studies involving the activity of the essential oil of O. vulgare and its isolated compound carvacrol on antibiotic-resistant bacteria. To this end, a qualitative review of the literature was carried out in the PubMed database from 2015 to 2020. Both for the essential oil and for the isolated compound, the inhibitory action extends to strains often associated with difficult-to-treat infections such as oxacillin and vancomycin-resistant Staphylococcus aureus, ß-lactamase-producing strains, carbapenemases, among others. The point that distinguishes the studies is the type of methodology used in the tests, with studies with carvacrol more directed towards mechanisms of molecular action and application in cells and animals, while those with oils are more preliminary. Although these substances have potential to control resistant bacteria, more research is needed to enable their use.

Bactérias resistentes a vários antibióticos são um grave problema para a Saúde Única, pois novas alternativas de tratamento não aparecem na mesma velocidade. Assim, o objetivo deste trabalho foi realizar um levantamento de estudos envolvendo a atividade do óleo essencial de O. vulgare e seu composto isolado, carvacrol, sobre bactérias resistentes a antibióticos. Para tanto, foi realizada uma revisão qualitativa da literatura na base de dados PubMed no período de 2015 a 2020. Tanto para o óleo essencial quanto para o composto isolado, a ação inibitória se estende a cepas frequentemente associadas a infecções de difícil tratamento como Staphylococcus aureus resistente à oxacilina e vancomicina, cepas produtoras de ß-lactamase, carbapenemases, entre outras. O ponto que diferencia os estudos é o tipo de metodologia utilizada nos testes, sendo os estudos com carvacrol mais direcionados para mecanismos de ação molecular e aplicação em células e animais, enquanto os com óleos são mais preliminares. Embora essas substâncias tenham potencial para controlar bactérias resistentes, mais pesquisas são necessárias para viabilizar seu uso.

Las bacterias resistentes a diversos antibióticos son un grave problema para la Sanidad Única, ya que las nuevas alternativas de tratamiento no aparecen a la misma velocidad. Así pues, el objetivo de este trabajo fue realizar una encuesta sobre los estudios relativos a la actividad del aceite esencial de O. vulgare y su compuesto aislado, el carvacrol, sobre las bacterias resistentes a los antibióticos. Para ello, se realizó una revisión bibliográfica cualitativa en la base de datos PubMed en el periodo comprendido entre 2015 y 2020. Tanto para el aceite esencial como para el compuesto aislado, la acción inhibidora se extiende a cepas frecuentemente asociadas a infecciones de difícil tratamiento como el Staphylococcus aureus resistente a la oxacilina y a la vancomicina, cepas productoras de ß-lactamasas, carbapenemasas, entre otras. El punto que diferencia los estudios es el tipo de metodología utilizada en las pruebas, siendo los estudios con carvacrol más dirigidos a mecanismos de acción molecular y aplicación en células y animales, mientras que los de aceites son más preliminares. Aunque estas sustancias tienen potencial para controlar las bacterias resistentes, es necesario seguir investigando para que su uso sea viable.