Surface conditioning with bacteriophages reduces biofilm formation of Salmonella Heidelberg.

Salmonella remains one of the most common foodborne pathogens worldwide, and its resistance to antimicrobials has increased considerably over the years. In this context, was evaluated the action of three bacteriophages isolated or combined in inhibiting the adhesion and removal of Salmonella Heidelberg biofilm on a polystyrene surface. The bacteriophages UPF_BP1, UPF_BP2, UPF_BP3 and a pool of them were used for biocontrol of Salmonella Heidelberg biofilms on polystyrene surface in the action times of 3, 6 and 9 h. Individual and combined phages exhibited reductions in Salmonella Heidelberg adhesion of up to 83.4% and up to 64.0% in removal of preformed biofilm. The use of synergistic combinations between the phages is the most indicated option due to its potential to reduce biofilms. The use of the bacteriophage pool in surface conditioning is an alternative in the control of Salmonella Heidelberg biofilms.

Pesticide and trace element bioaccumulation in wild owls in Brazil.

Owls are outstanding environmental quality bioindicators due to their position at the top of the food chain and susceptibility to pollutant accumulation. Exposure to chemical contaminants is often a risk for these animals. Moreover, studies addressing the bioaccumulation of trace elements and pesticide residues in tropical nocturnal raptor species are scarce. We analyzed the 26 organs (heart, liver, and kidney) of Tyto furcata (n=3), Megascops spp. (n=5), Pulsatrix koeniswaldiana (n=1), and Asio stygius (n=1) carcasses, collected from June 2018 to May 2019 in the Southern region of Brazil. The original vegetation consisted of areas of Araucaria forests and grassy-woody steppes with gallery forests, which were greatly modified by the introduction of agriculture. In four animals and eight organs, the pesticides abamectin, atrazine, chlorpyrifos-ethyl, and diurom were analyzed through high-performance liquid chromatography coupled with a mass detector. In six animals and eighteen organs, the trace elements cadmium, lead, chromium, and nickel were identified via atomic absorption spectrophotometry. Chlorpyrifos-ethyl was detected in the livers of the genus Megascops. Chromium was found at high concentrations in all matrices analyzed for this trace element. Moreover, P. koeniswaldiana presented lead levels indicative of high exposure. The bioaccumulation of these toxics in owls described here can impact the population levels of these species, impact on its ecological function, and consequently unbalance the ecosystem. Moreover, owls are considered bioindicators; therefore, the occurrence of bioaccumulation indirectly gives us information about the quality of the environment.

Antimicrobial and Disinfectant Susceptibility of Salmonella Serotypes Isolated from Swine Slaughterhouses.

Salmonella remains one of the most common foodborne pathogens worldwide, and its resistance to antimicrobials and disinfectants has increased considerably over the years. Thus, monitoring its resistance to products commonly used in swine production is indispensable for the development of strategies to reduce the occurrence of bacterial resistance. In this context, our aim was to detect Salmonella at different points in swine slaughterhouses, identify the main serotypes, and evaluate their resistance to disinfectants and antimicrobials used in swine production. Salmonella at the processing plants was detected by conventional microbiology. Salmonella strains were tested for susceptibility to peracetic acid (0.5% and 1%), quaternary ammonium (0.5%), and seven antimicrobials. Twenty-eight percent of the samples were positive for Salmonella, with the most identified serotypes being Salmonella Derby, Salmonella Typhimurium, and monophasic Salmonella Typhimurium. All tested strains were susceptible to both concentrations of peracetic acid, but only 28% were susceptible to quaternary ammonium. Sixteen percent of the strains were susceptible to all tested antimicrobials. Only enrofloxacin was efficient in inhibiting the growth of all strains. The highest number of non-susceptible strains was to amoxicillin, followed by chloramphenicol, florfenicol, and doxycycline. Thirty-six percent of the strains were classified as multidrug-resistant. Salmonella were detected in all slaughtering processes, and important serotypes were recovered, including Salmonella Typhimurium, Salmonella Derby, monophasic Salmonella Typhimurium, and Salmonella Infantis. We observed high rates of resistance to quaternary ammonium and to important antimicrobial agents. Salmonella Typhimurium and Salmonella Infantis were the most resistant serotypes.