Inclusion of Organic Acids in the Drinking Water and Feed for the Control of Salmonella Heidelberg in Broilers

Poultry products may be a source of foodborne human salmonellosis. The use of alternatives to antimicrobials that are not harmful to humans may reduce the presence of Salmonella spp. in poultry production. Among the products used, organic acids stand out. In the present study, three different organic acid (OA) blends were evaluated for the control of Salmonella Heidelberg (SH) in commercial broilers. Day-old chicks (n = 114) were randomly assigned to four treatments, with three replicates of 12 birds each. Birds in treatments A and B received SCFA (0.2mL/L) and SCFA + MCFA (0.2mL/L), respectively, in the drinking water, while birds in treatment C received SCFA + MCFA in the feed (2g/Kg of feed). Birds from treatment D did not receive OAs (control group). At 8 days of age, each bird was orally inoculated with SH at 108 CFU/mL, and cloacal swabs and SH enumeration of the cecal content were performed 24-, 48-, and 72-hours post-inoculation (hpi). The results show a reduction of both SH shedding and counts in the birds fed OAs at all pi times relative to the control birds. Fecal shedding was significantly lower in the OA-treated groups compared with the control group. As for SH presence in the cecum, significant differences were detected between groups C and D at 24 and 72 hpi, and between groups B and D at 72 hpi. The results of this study indicate that the use of feeding OAs to broilers may contribute to reduce the incidence of SH in the poultry production chain, allowing better flock health management, provided an efficient biosecurity program is employed.(AU)

Evaluation of propanediol and cobalamin metabolism in the intestinal colonization and systemic invasion of Salmonella Enteritidis in laying hens / [Avaliação do metabolismo do propanodiol e da cobalamina na colonização intestinal e na infecção sistêmica de Salmonella Enteritidis em poedeiras]

Embora Salmonella Enteritidis (SE) seja capaz de metabolizar 1,2-propanodiol (1,2-Pd), utilizado como fonte de carbono e de energia ao longo de uma rota dependente de vitamina B12, a importância deste composto na infeção de Gallus gallus domesticus por SE permanece desconhecida. No presente estudo, foram construídos um mutante de SE sem os genes pduCDE, que codifica a propanodiol desidratase (Pdu), e outro contendo as deleções no pduCDE e também nos genes cobS e cbiA, responsáveis pela síntese de vitamina B12. Em seguida, avaliou-se a importância do metabolismo do 1,2-Pd em SE para colonização intestinal de infecção sistêmica de poedeiras comerciais. As estirpes mutantes de SE foram capazes de colonizar o intestino, de serem excretadas nas fezes e de invadir o baço e o fígado na mesma intensidade que a estirpe selvagem, o que sugere que os produtos dos genes pduC, pduD, pduE, cobS e cbiA não são essenciais durante infecção por Salmonella Enteritidis nessa espécie.(AU)

Antimicrobial Resistance in Salmonella Serovars Isolated From an Egg-Producing Region in Brazil

Fowl paratyphoid infections are caused by different Salmonella serovars that can affect a wide range of hosts. Due to its complex epidemiology, Salmonella serovar identification is crucial for the development and implementation of monitoring and control programs in poultry farms. Moreover, the characterization of the antimicrobial resistance profiles of Salmonella strains isolated from livestock is relevant to public health because they are a common causative agent of foodborne diseases. The objective of this study was to investigate the presence of Salmonella spp. and to identify the antimicrobial resistance profiles of strains isolated in the midwestern region of São Paulo state, which accounts for the highest production of table eggs in Brazil. For this purpose, 2008 fecal samples were collected on 151 commercial layer farms and submitted to microbiological analyses. Twenty-two serovars were isolated from 80 (52.9%) farms, among which S. Mbandaka and S. Braenderup were the most prevalent. All isolates expressed resistance to at least one of the 23 antimicrobials tested, and the highest resistance rates were determined against streptomycin (93.5%) and sulfonamide (84.6%). Moreover, multidrug resistance was observed in 41% of the isolates and the maximum drug resistance profile was against ten different antimicrobials. Therefore, the identification of Salmonella serovars in poultry production provides epidemiological knowledge to develop prevention and control measures in order to ensure poultry health and to prevent human infection by multiresistant strains.(AU)

Antimicrobial Resistance in Salmonella Serovars Isolated From an Egg-Producing Region in Brazil

Fowl paratyphoid infections are caused by different Salmonella serovars that can affect a wide range of hosts. Due to its complex epidemiology, Salmonella serovar identification is crucial for the development and implementation of monitoring and control programs in poultry farms. Moreover, the characterization of the antimicrobial resistance profiles of Salmonella strains isolated from livestock is relevant to public health because they are a common causative agent of foodborne diseases. The objective of this study was to investigate the presence of Salmonella spp. and to identify the antimicrobial resistance profiles of strains isolated in the midwestern region of São Paulo state, which accounts for the highest production of table eggs in Brazil. For this purpose, 2008 fecal samples were collected on 151 commercial layer farms and submitted to microbiological analyses. Twenty-two serovars were isolated from 80 (52.9%) farms, among which S. Mbandaka and S. Braenderup were the most prevalent. All isolates expressed resistance to at least one of the 23 antimicrobials tested, and the highest resistance rates were determined against streptomycin (93.5%) and sulfonamide (84.6%). Moreover, multidrug resistance was observed in 41% of the isolates and the maximum drug resistance profile was against ten different antimicrobials. Therefore, the identification of Salmonella serovars in poultry production provides epidemiological knowledge to develop prevention and control measures in order to ensure poultry health and to prevent human infection by multiresistant strains.