ABSTRACT 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.

ABSTRACT 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.

ABSTRACT The incidence of foodborne diseases caused by the genus Salmonella spp. in industrialized countries is often high in epidemiological surveys. Obtaining a rapid diagnostic test for identification of bacteria is crucial in order to rapidly implement control measures to contain bacterial spread, to reduce losses in animal production and to avoid risks from food-borne infections to human health. The aim of this study was to standardize duplex real-time PCR using SYBr Green I for differential and quantitative diagnosis of S. Typhimurium and S. Enteritidis. According to the experiment, the melting temperature of 85°C was observed for a 206bp amplified product when S. Enteritidis DNA was added to the reaction. S. Typhimurium DNA showed that the melting temperature of 79°C when observed for a 62bp amplified product. The standard curve showed the high sensitivity of the proposed test, since it was possible to obtain eight quantification points, starting at 108 CFU/mL and ending at 101 CFU/mL. As a result of the present study, a real-time PCR duplex reaction with high sensitivity, specificity and based on the fluorescence of SYBr Green I was standardized. In addition, this methodology aligns low cost to the faster diagnostic result, in relation to other molecular tests, making it attractive for application in routine laboratory analyzes.

ABSTRACT In poultry processing plants, disinfectants are often added to pre-chilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite) on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE) in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil) in pre-chilling tanks.

Salmonella spp. is the main originator of human foodborne diseases worldwide and is mainly transmitted by food containing eggs. In Brazil, as a result of the lack of studies and data collection very little is known about the prevalence of Salmonella spp. in laying hen flocks and commercial table eggs. Consequently the present study was elaborated and aimed at generating data about Salmonella spp. in part of the Brazilian egg production chain. Eight flocks of day-old chicks, eight flocks of adult laying hens (four vaccinated with bacterin against Salmonella Enteritidis and four unvaccinated) and commercial table eggs from four supermarkets were examined. Salmonella spp. was isolated in 50 % of the newly hatched chicks, 25 % of the adult flocks and 1.5 % of egg samples examined. S. enterica subsp. enterica 4,12:r:-, S. Mbandaka, S. enterica subsp. enterica 6,7: z10:-, S. Enteritidis and S. Havana were the serovars isolated in birds. In commercial table-eggs S. Mbandaka, S. enterica subsp. enterica 6,7: z10:- and S. Braenderup were isolated. These results show that Salmonella spp. is present in laying hen flocks and consequently in eggs destined for human consumption. Probably, some of the Salmonella serovars are being introduced in egg farms by vertical via.

In order to maintain the high production and export rates achieved by the Brazilian poultry industry, it is necessary to prevent and control certain disease agents, such as Salmonella spp. Using bacterial cultures, the aim of the present study was to investigate the prevalence of Salmonella spp. in specimens collected from broiler facilities. Local wild birds were also sampled, as well as the feces of swine housed on the poultry farm. After sample collection, the isolated serotypes were subsequently inoculated into broiler chicks to determine their effects. Positive samples were collected from the following locations in the poultry facilities: poultry litter (S. serotype 4,5,12:R:-; S. Heidelberg; S. Infantis), broiler feces (S. Heidelberg; S. serotype 6,7:R:-; S. serotype 4,5,12:R:-; S. Tennessee), water (S. Glostrup; S. serotype 6,8:d:-;), and lesser mealworms (Alphitobius diaperinus) found in the litter (S. Tennessee). Among the 36 wild birds captured, S. Heidelberg was isolated from one bird's organs and intestinal contents (Colaptes campestris), and S. Enteritidis was isolated from another bird's intestinal contents (Zenaida auriculata). Salmonella Panama and Salmonella Typhimurium were isolated from swine feces. One-day-old chicks (150) were divided into 10 groups of 15 animals each. Each group was orally inoculated with a previously isolated serotype of Salmonella. Soft stools were observed on the cage floor and around the birds' cloaca between 3 and 12 days post-infection (dpi). The different serotypes of Salmonella used to inoculate the chicks were re-isolated from the spleen, liver, and cecal content samples of the infected birds on 15 and 21 dpi.

In the present study Salmonella spp. was surveyed in four flocks of meat-type quails reared in a farm that also had processing plant on site, located in the region of Bastos, state of São Paulo, Brazil. Meconium samples of one-day-old quail chicks were collected from transport cardboard boxes. Cecal content was collected on days 7, 14, 21, 28 and 35 of rearing. At 36 days of age, birds were slaughtered in the farm's processing plant, where two samples of water from the scalding and the chilling tanks and four carcasses per flock were collected. All samples were examined for Salmonella spp. using traditional bacteriological methods. Salmonella spp. was present in meconium samples of three flocks and in cecal feces of the four flocks. This bacterium was also isolated in the chiller water and in the carcasses of three of the evaluated flocks and in the scalding water of one flock. In this study, S. enterica subspecies enterica 4, 5, 12; S. Corvalis; S. Give; S. Lexington; S. Minnesota; S. Schwarzengrund; S. Rissen and S. Typhimurium were the eight serovars identified.

The present study aimed to analyze the genetic similarity between genomic profiles of thirteen Klebsiella oxytoca and seven Klebsiella pneumoniae samples isolated from two different collections carried out in different places of dental offices. Random amplified polymorphic DNA (RAPD) technique and similarity coefficients (calculated by Sorensen-Dice and simple matching) were applied to determine their genetic profile of randomic DNA sequences. The majority of the isolates of K. pneumoniae and K. oxytoca presented similar coefficient values (e" 0.80). Thus, it was possible to identify that strain dissemination occurred mainly via the hands of the surgeon-dentists and, finally, to determine the genetic similarity of the strains from dental office environments.