In vitro antimicrobial activity of Douro wines against clinical Helicobacter pylori strains / strains121In vitro antimicrobial activity of Douro wines against clinical helicobacter pylori strains / Actividad antimicrobiana in vitro de los vinos del Duero sobre cepas clínicas de Helicobacter pylori

Abstract Aim. In vitro antimicrobial activities of seven wines (5 reds and 2 whites) from the Douro region (Iberian Peninsule) against eleven clinical strains of Helicobacter pylori were evaluated. Methods. The disk diffusion method, using Columbia Agar supplemented with horse blood (CAB), were used to determine the antimicrobial properties of some wine components against H. pylori strains. Potential interactions of antioxidants contained in the wines and two antimicrobials (amoxicillin and metronidazole) were studied by the disk diffusion method. Results. All the tested strains showed growth in CAB supplemented with 9% of the tested wines but none of them grew in media supplemented with 45% and 67.5% of wine. Similarly, all the tested strains grew in media with the concentration of proanthocyanidins present in the different types of the studied wines. The Minimal Inhibitory Concentration (MIC) values of the wine antioxidant components tested (benzoic acid, catechin, quercetin, and resveratrol) indicate that resveratrol was the most powerful inhibitory substance against H. pylori. An effect of potentiation between amoxicillin and metronidazole and the antioxidants tested was also established. The interaction of amoxicillin and resveratrol or metronidazole and catechin increased the antimicrobial activity against H. pylori. Conclusions. The results obtained suggested a potential role of resveratrol as a chemopreventive agent for H. pylori infection.

Resumen Objetivo. Se evaluó las actividades antimicrobianas in vitro de siete vinos (5 tintos y 2 blancos) de la región del Duero (Peninsula Ibérica) frente a once cepas de Helicobacter pylori de origen clínico. Métodos. Para determinar las propiedades antimicrobianas de algunos componentes del vino sobre las cepas de H. pylori se utilizaron las técnicas de difusión en disco en placas de agar Columbia suplementado con sangre de caballo (CAB). La potential interacción entre las sustancias antioxidantes presentes en los vinos y dos antimicrobianos (amoxicilina y metronidazol) se determinó usando la técnica de difusión en disco. Resultados. Todas las cepas ensayadas mostraron crecimiento en CAB suplementado con el 9% de los vinos analizados, pero no se obtuvo crecimiento de ninguna de las cepas en medios suplementados con el 45% y el 67,5% de vino. Asimismo, todas las cepas ensayadas crecieron en medios con la concentración de proantocianidinas presentes en los diferentes tipos de vinos estudiados. Los valores de concentración mínima inhibitoria (CMI) de los componentes antioxidantes de los vinos ensayados (ácido benzoico, catequina, quercetina y resveratrol) indican que el resveratrol fue la sustancia más potente en la inhibición del crecimiento de H. pylori. También se estableció un efecto de potenciación entre amoxicilina y metronidazol y los antioxidantes ensayados. Las interacciones amoxicilina + resveratrol y metronidazol + catequina aumentaron la actividad antimicrobiana contra H. pylori. Conclusiones. Los resultados obtenidos sugieren un papel potencial del resveratrol como agente quimiopreventivo de la infección por H. pylori.

Leishmania infection and host-blood feeding preferences of phlebotomine sandflies and canine leishmaniasis in an endemic European area, the Algarve Region in Portugal

The Algarve Region (AR) in southern Portugal, which is an international tourist destination, has been considered an endemic region of zoonotic leishmaniasis caused by Leishmania infantum since the 1980s. In the present study, phlebotomine and canine surveys were conducted to identify sandfly blood meal sources and to update the occurrence of Leishmania infection in vectors and dogs. Four sandfly species were captured: Phlebotomus perniciosus, Phlebotomus ariasi, Phlebotomus sergenti and Sergentomyia minuta. In one P. perniciosus female, L. infantum DNA was detected. Blood meal tests showed that this species had no host preferences and was an opportunistic feeder. An overall canine leishmaniasis (CanL) seroprevalence of 16.06% was found; the seroprevalence was 3.88% in dogs housed in kennels and 40.63% in dogs that attended veterinary clinics. The simultaneous occurrence of dogs and P. perniciosus infected with L. infantum in the AR indicates that the region continues to be an endemic area for CanL. Our results reinforce the need for the systematic spatial distribution of phlebotomine populations and their Leishmania infection rates and the need to simultaneously perform pathogen monitoring in both invertebrate and vertebrate hosts to investigate the transmission, distribution and spreading of Leishmania infection.

The first detection of Leishmania major in naturally infected Sergentomyia minuta in Portugal

Phlebotomine sandflies of the genus Sergentomyia are widely distributed throughout the Old World. It has been suggested that Sergentomyia spp are involved in the transmission of Leishmania in India and Africa, whereas Phlebotomus spp are thought to be the sole vectors of Leishmania in the Old World. In this study, Leishmania major DNA was detected in one Sergentomyia minuta specimen that was collected in the southern region of Portugal. This study challenges the dogma that Leishmania is exclusively transmitted by species of the genus Phlebotomus in the Old World.