Individual and combined effects of Salmonella typhimurium lipopolysaccharide and fumonisin B1 in broiler chickens.

The aim of this research was to evaluate the individual and combined effects of Salmonella typhimurium lipopolysaccharide (sLPS) and fumonisin B(1) (FB) on performance, relative weight of liver, biological parameters, and histological evaluation of several tissues from four hundred thirty-two 1-d-old male broiler chickens divided into 9 treatments according to the dose of FB (0, 100, or 200 mg/kg, from d 1 to d 28) and sLPS (0, 250, or 500 µg/application per bird, every other day, from d 15 to 27) administered. At the end of the experiment (28 d), significant effects caused by sLPS, FB, and the interaction of sLPS × FB were observed on several parameters. Histopathological evaluations showed significant lesions in liver and kidney caused by sLPS, FB, and their association. According to these results, both sLPS and FB (isolated or in association) cause significant effects on performance and biological parameters of broilers at 28 d of age.

Inoculation of newly hatched broiler chicks with two Brazilian isolates of Salmonella Heidelberg strains with different virulence gene profiles, antimicrobial resistance, and pulsed field gel electrophoresis patterns to intestinal changes evaluation.

Salmonella Heidelberg is one of the 3 most frequently isolated serovars from human Salmonella cases in Canada, and the fourth most commonly reported Salmonella serovar in human foodborne disease cases in the United States. Since 1962, Salmonella Heidelberg has been isolated and reported in poultry and poultry products in Brazil. The poultry industry has focused efforts on reducing salmonellae incidence in live production in an effort to reduce Salmonella in the processing plant. A better understanding of the initial infection in chicks could provide approaches to control Salmonella contamination. The objective of the present study was to evaluate 2 Salmonella Heidelberg strains that differed in the presence of virulence genes invA, agfA, and lpfA; antimicrobial resistance profiles; and epidemiologic profiles on aspects of pathogenicity and intestinal morphology. Newly hatched broiler chicks were inoculated with 2 strains (SH23 and SH35) of Salmonella Heidelberg and cecal morphometry, histopathology, electron microscopy, and bacterial counts in the liver and cecum were assessed. The SH23 and SH35 strains resulted in different changes in villi height and crypt depth and inflammatory cell infiltration in the cecum. The SH35 group had higher liver and cecum bacterial cell counts when compared with SH23 strains.

Occurrence and characterization of Campylobacter in the Brazilian production and processing of broilers.

Twenty-two commercial broiler flocks and their carcasses, totaling 546 samples (450 collected from a poultry farm and 96 from a slaughterhouse), were surveyed for the presence of Campylobacter. The positive results for Campylobacter among the analyzed samples were homogeneous, yielding 81.8% for cecal droppings, 80.9% for feces, and 80.4% for cloacal swabs. Pre-enrichment and direct plating showed that 77.85% and 81.8% of cloacal swabs, respectively, were positive for Campylobacter compared to 99.0% and 97.9% of carcasses testing positive with the pre-enrichment and direct plating methods. The Campylobacter count averaged 7.0 log10 colony-forming units (CFU)/g in cecal droppings, 5.15 log10 CFU/carcass after defeathering, and 4.24 log10 CFU/carcass after chilling. The samples were identified by the API Campy system as Campylobacter jejuni subsp. jejuni (68.8%), Campylobacter coli (8.3%), Campylobacter jejuni subsp. doylei (6.3%), Campylobacter upsaliensis (4.2%), and Campylobacter fetus subsp. fetus (2.1%). The analyzed broiler flocks were positive for Campylobacter in 81.8% of the cases, thus characterizing the occurrence of this pathogen in a broiler-producing region in southern Brazil. These results highlight the importance of programs targeted at the reduction of Campylobacter in poultry products, in order to minimize the risks for consumers.