Anais do Congresso Paranaense de Microbiologia
IV Congress of Microbiology in Paraná

The problems caused by increased antibacterial resistance due to the overuse of synthetic antimicrobials pose a serious threat to global public health. An example of this is Salmonella infections that are on the World Health Organization's list as a high priority, due to the increasing number of cases of human and animal salmonellosis. Therefore, research with plants for the discovery of natural bioactive compounds that present relevant biological properties, increasingly arouse interest in this field. Podocarpus lambertii (Pinheiro-bravo) is a typical plant in southern Brazil, indicated mainly for the recovery of degraded areas. The literature presents studies with insecticide potential and chemical characteristics of the species without indicating the part of the plant used. Thus, the study of this species is still initial and little is known from the scientific point of view of the pharmacological and chemical potential of this plant. Therefore, the objective of this research was to identify the metabolites of the methanol extract (EM) from the leaves of P. lambertii and to investigate the antibacterial activity of this extract against ten serotypes of Salmonella enterica (multiresistant) that occur more frequently in the West. Paraná region, Brazil. Salmonella serotypes were isolated from broiler aviaries (feed, flour, inputs, aviary bedding) in the region, donated by the Mercolab Veterinary Laboratory, Cascavel, Paraná, and were: Salmonella Enteritidis (Isolated e ATCC 13076 as a reference), Salmonella Infantis, Salmonella Typhimurium, Salmonella Heildelberg, Salmonella Gallinarum, Salmonella Mbandaka, Salmonella Montevideo, Salmonella Newport, Salmonella Orion and Salmonella Agona. Phytochemical prospection of EM was performed based on colorimetric reactions and/or precipitate formation after the addition of specific reagents and antibacterial activity was performed by broth microdilution test (at concentrations from 200 mg/mL to 0.09 mg/mL). The minimal inibitory concentration (MIC) and minimal concentracion bactericide (MBC) were determined. Phytochemical screening revealed the presence of four groups of compounds in EM, being flavonoids, steroids, tannins, alkaloids. MIC and MBC values ranged from 1.56 to 6.25 mg/mL and 1.56 to 25 mg/mL, respectively. EM showed high/moderate against the ten Salmonella serotypes evaluated. The results showed that EM from Podocarpus lambertii has antibacterial activity on Salmonella serotypes and the presence of secondary metabolites that can be a source of new bioactive compounds used in medical/veterinary formulations to control infections caused by these bacteria. This study evaluated for the first time the effect of methanol extract prepared from P. lambertii against Salmonella enterica serotypes isolated from broiler poultry houses.