Pasteurella multocida causes atrophic rhinitis in swine and fowl cholera in birds, and is a secondary agent in respiratory syndromes. Pathogenesis and virulence factors involved are still poorly understood. The aim of this study was to detect 22 virulence-associated genes by PCR, including capsular serogroups A, B and D genes and to evaluate the antimicrobial susceptibility of P. multocida strains from poultry and swine. ompH, oma87, plpB, psl, exbD-tonB, fur, hgbA, nanB, sodA, sodC, ptfA were detected in more than 90% of the strains of both hosts. 91% and 92% of avian and swine strains, respectively, were classified in serogroup A. toxA and hsf-1 showed a significant association to serogroup D; pmHAS and pfhA to serogroup A. Gentamicin and amoxicillin were the most effective drugs with susceptibility higher than 97%; however, 76.79% of poultry strains and 85% of swine strains were resistant to sulphonamides. Furthermore, 19.64% and 36.58% of avian and swine strains, respectively, were multi-resistant. Virulence genes studied were not specific to a host and may be the result of horizontal transmission throughout evolution. High multidrug resistance demonstrates the need for responsible use of antimicrobials in animals intended for human consumption, in addition to antimicrobial susceptibility testing to P. multocida.

Concerns about foodborne salmonellosis have led many countries to introduce microbiological criteria for certain food products. If such criteria are not well-grounded in science, they can be an unjustified obstacle to trade. Raw poultry products are an important part of the global food market. Import / export ambiguities, as well as regulatory confusion resulting from different Salmonella requirements, were the impetus for convening an international group of scientific experts from 16 countries to discuss the scientific and technical factors that affect the setting of a microbiological criterion for Salmonella contamination of raw chicken. A particular concern for the group was the use of criteria implying a ‗zero tolerance' for Salmonella and suggesting complete absence of the pathogen. The notion can be interpreted differently by various stakeholders and was considered inappropriate because there is neither an effective means of eliminating Salmonella from raw poultry nor any practical method for verifying its absence.Therefore, it may be more useful at present to set food-safety metrics that involve reductions in hazard levels. Using terms such as ‗zero tolerance' or ‗absence of a microbe' in relation to raw poultry should be avoided unless defined and explained by international agreement.Risk assessment provides a more meaningful approach than a zero-tolerance philosophy and new metrics, such as performance objectives that are linked to human health outcomes, should be utilized throughout the food chain to help in defining risk and identifying ways to reduce adverse effects on public health.PAGE 4 IntroductionThe association between poultry and Salmonella has a long history. More than 50 years ago, pullorum disease and fowl typhoid were common causes of mortality in chicken and turkey flocks, and development of the industry was delayed until these diseases were brought under control (147). Subsequently, a different problem emerged with the increasing isolation of nonhost-specific salmonellae from both poultry products and cases of human salmonellosis.Because of an apparent linkage between the two, fuelled by the intensive nature of poultry production and processing, which was seen to facilitate pathogen transmission, global efforts to control Salmonella in the poultry industry have increasingly gathered pace and particularly in the years following the pandemic spread of Salmonella Enteritidis in the late 1980s. However, fulfillment of this goal has not been easy. In the production of raw foods, such as chicken meat, there are multiple constraints in attempting to eliminate microbial health hazards, and these are both socio-economic and scientific (i.e., biological, technological and analytical). Food animal production and processing in different parts of the world are faced with similar challenges, such as the frequent presence of potentially pathogenic microorganisms that rarely cause disease in food animals but may do so in humans, along with the very nature of an industry in which environmental co...

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Salmonella spp. are one of the most important agents of foodborne disease in several countries, including Brazil. Poultry-derived products are the most common food products, including meat and eggs, involved in outbreaks of human salmonellosis. Salmonella has the capacity to form biofilms on both biotic and abiotic surfaces. The biofilm formation process depends on an interaction among bacterial cells, the attachment surface and environmental conditions. These structures favor bacterial survival in hostile environments, such as slaughterhouses and food processing plants. Biofilms are also a major problem for public health because breakage of these structures can cause the release of pathogenic microorganisms and, consequently, product contamination. The aim of this study was to determine the biofilm production capacity of Salmonella serotypes at four different temperatures of incubation. Salmonella strains belonging to 11 different serotypes, isolated from poultry or from food involved in salmonellosis outbreaks, were selected for this study. Biofilm formation was investigated under different temperature conditions (37°, 28°, 12° and 3°C) using a microtiter plate assay. The tested temperatures are important for the Salmonella life cycle and to the poultry-products process. A total of 92.2% of the analyzed strains were able to produce biofilm on at least one of the tested temperatures. In the testing, 71.6% of the strains produced biofilm at 37°C, 63% at 28°C, 52.3% at 12°C and 39.5% at 3°C, regardless of the serotype. The results indicate that there is a strong influence of temperature on biofilm production, especially for some serotypes, such as S. Enteritidis, S. Hadar and S. Heidelberg. The production of these structures is partially associated with serotype. There were also significant differences within strains of the same serotype, indicating that biofilm production capacity may be strain-dependent.

The present study was carried out to evaluate the occurrence of Salmonellae in raw broiler parts and to determine the antimicrobial resistance profile of the isolated strains. Twenty-four (39.3%) broiler parts samples were positive for Salmonella and twenty-five Salmonella strains were isolated, since two different serovars were detected in one single positive sample. Salmonella Enteritidis was the most prevalent serovar. Among Salmonella Enteritidis isolates, 95.2% belonged to Phage Type 4 (PT4) (20/21) and 4.8% to PT7 (1/21). Twenty-two (88%) strains of Salmonella were resistant to at least one antimicrobial agent, generating eight different resistance patterns. The S. Typhimurium (n: 1) and S. Hadar (n: 3) isolates presented multiple resistance. Three S. Enteritidis isolates were susceptible to all antimicrobials tested, two were resistant only to tetracycline. The high prevalence of Salmonella in the broiler parts strenghtens the importance of the use of good manufacturing practices (GMP), and HACCP. The results also emphasize the need for the responsible use of antimicrobials in animal production.