ABSTRACT It is estimated that Salmonella causes one million illnesses in the United States annually, with 19,000 hospitalizations and 380 deaths. There are various serotypes of this bacterium, and the serotypes Typhimurium and Enteritidis are commonly isolated from outbreaks and, in most cases, present resistance to the antibiotics utilized in clinical medicine. One of the current theories to explain the emergence of bacterial resistance is the continuous use of antibiotics as growth promoters in animal feeds. Despite the lack of evidences that antibiotic growth promoters cause bacterial resistance, the poultry industry has explored strategies to reduce or to eliminate the use of antibiotic growth promoters in the production chain, including the improvement of biosecurity programs, use of vaccines, genetic selection, and the feeding of other additives, such as organic acid blends (OAB) and competitive exclusion (CE) products. This study aimed at evaluating the effect of the continuous dietary supplementation of an OAB and a CE product on the growth performance, pH of the crop and cecal contents, control of Salmonella Enteritidis (SE) in the cecal content, and acute-phase protein serum levels in starter commercial turkeys. The additives promoting similar results as antibiotics under controlled experimental conditions should be further evaluated on commercial farms to allow their utilization under practical conditions. Supplementing commercial turkey diets with the evaluated OAB and CE product may reduce SE load. Serum OVT and AGP levels can be used as effective and fast indicators of infection, including that by SE.

ABSTRACT The present study evaluated a probiotic and a competitive exclusion product injected in ovo on day 18 of incubation together with Marek's disease vaccine in eggs of 56-week-old broiler breeders. Three experiments were carried out. The first trial evaluated the effect of treatments on hatchability, cecal colonization of Salmonella Heidelberg (SH), and intestinal mucosa immunity (immunoglobulin A levels in the intestinal fluid). The second trial evaluated the viability of the microorganisms in the products inoculated in a solution containing diluent and Marek's disease vaccine. The third trial evaluated the colonization of the cecal microbiota in non-challenged chickens during first four days of life by culturing cecal samples under aerobic and anaerobic conditions. Hatchability was not affected by the treatments. SH cecal counts were reduced in three-day-old broilers inoculated in ovo with the competitive exclusion product. Liver and spleen pool SH counts were not different among treatments. Broilers inoculated in ovo presented higher intestinal IgA titers 24 hours after SH challenge compared with the controls. When birds were not challenged, lower cecal microbial counts in aerobic culture were determined in the control group than in the probiotic group on day 3, and in the competitive exclusion group on day 2 when cultured in anaerobiosis. The products inoculated and diluted in the vaccine solution were viable at all analyzed periods when cultured in anaerobiosis. The results of this study suggest in-ovo inoculation is an effective route for the administration of the evaluated products, which effectively enhanced the broilers' immune response to a SH challenge, as shown by the increase in IgA titers, and the reduction in cecal Salmonella Heidelberg colonization with the in-ovo inoculation with the competitive exclusion product.

Due to the constant evolution of industrial poultry production and the global emergence of bacterial resistance to antibiotics there has been an increasing interest in alternatives for the treatment of poultry salmonellosis, such as phage therapy and probiotics. The present study evaluated the effects of the oral administration of the bacteriophage P22 and of a probiotic, consisting of four Lactobacillus species, on the level of circulating heterophils containing a superoxide anion of one-day-old broilers challenged with Salmonella Typhimurium for seven days. It was concluded that the treatment with a probiotic with lactobacilli of broilers experimentally infected with Salmonella spp eliminates this pathogen by increasing the circulating levels of reactive heterophils. When chicks are treated with a probiotic and a bacteriophage, the agent is eliminated with no changes in circulating reactive heterophil counts. It is also concluded that the heterophils of day-old chicks are not capable of producing superoxide anion. However, this capacity is detected after 48 h of life, indicating that heterophils mature as birds age.

Several studies point out that eggs are the main cause of human salmonellosis, particularly when poorly processed or eaten raw. In addition of causing public health problems, the presence of Salmonella hinders international food trade, and therefore, it is a health barrier. There are several predisposing factors for the contamination of internal egg content by Salmonella spp, including eggshell quality, which is related to dietary calcium (Ca) and phosphorus (P) levels. In this study, eggs from Japanese quails fed diets containing two different Ca (2.0 or 3.5%) or P (0.25 or 0.45%) levels were evaluated. Three production phases were used in the experiment: starter, intermediate, and final. The presence of Salmonella Enteriditis in the eggshell and internal content in in the periods of 0, 24, 96, and 168 hours after the experimental contamination of the eggs by immersion in broth containing Salmonella Enteriditis. The bacterium was detected in decreasing numbers in the eggshell of eggs from all treatments and during all storage periods. No significant bacterial numbers were found in the internal egg content in none of the treatments during none of the production phases. Therefore, the evaluated Ca and P levels in the diet of Japanese quails did not result in higher or lower public health risk relative to the presence of Salmonella Enteritidis in the internal egg content.

The expression of immune response as a leukocytic infiltrate by CD4+ and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks fed Lactobacillus spp or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis (SE) was studied using immunohistochemistry. Three hundred and twenty day-of-hatch broiler chicks were divided into four groups of 80 birds each and orally received L. reuteri, L. salivarius, L. acidophilus, or CM. Each group was subdivided into four subgroups of 20 birds each, classified as follows: a subgroup did not receive any oral treatment (negative control), subgroup treated with L. spp or CM, subgroup treated with L. spp or CM and challenged with SE, and subgroup only challenged with SE (positive control). The results show that the oral treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenge or not with SE stimulated bird immune response as determined by the leukocytic infiltrate by CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 days of age. CD8+ lymphocyte number was significantly higher in the intestine of chicks receiving CM and challenged with SE. The duodenum, followed by the jejunum, were the segments in which the immune response, as shown by T, CD4+ and CD8+ cells, was stimulated with the greatest intensity.

The expansion of global poultry production has increased the need to reduce or control the agents responsible for economic losses, including Salmonella spp. These bacteria are also of public health concern due to their potential to cause food poisoning, and, more recently, due to the antimicrobial resistance presented by these bacteria. Molecular biology is an important tool currently used in the diagnosis and research studies of main poultry diseases. The present studied analyzed 100 samples of Salmonella Enteritidis (SE) isolated from avian material aiming at detecting the class 1 integron gene, Integroninvolved in antimicrobial resistance, by means of polymerase chain reaction (PCR), and comparing it with plate inhibition test. Subsequently, SE samples were evaluated for their capacity to horizontally transfer this gene. There was no direct relationship between the presence of the class 1 integron gene and SE resistance to the 14 antimicrobials tested, as 80% of the studied samples were resistant to up to three antimicrobials, and did not present the aforementioned gene. However, horizontal transfer of this gene was accomplished in vitro (from Escherichia coli to Salmonella Enteritidis), demonstrating that capacity class 1 integron gene can be disseminated among enterobacteria.

This study aimed at the antibody production by intestinal mucosa of broilers chicks were orally inoculated with Lactobacillus spp. at one and/or 21 days of age, and subsequently challenged with Salmonella enterica, subspecies enterica, serotype Enteritidis (S. Enteritidis). A total number of 288 drug-free broiler chicks was divided into 6 groups (groups A, B, C, D, E, and F), according to age at Lactobacillus spp. inoculation and SE challenge. The intestinal mucosa immune response was determined as the production of immunoglobulin A against S. Enteritidis, and evaluated by the Enzyme-Linked Immunosorbent Assay (ELISA) technique in intestinal washing fluid. Groups treated with Lactobacillus spp. presented higher IgA production only when the chicks were challenged with S. Enteritidis at 21 days of age. Nevertheless, the expected stimulus for intestinal mucosa antibody production induced by Lactobacillus spp was observed in only some of the treated groups, demonstrating that the protocol utilized in the present experiment resulted in few beneficial effects for chicks, particularly during the first days of life.

Avaliou-se a contaminação da casca e do conteúdo interno de ovos inoculados com Salmonella enterica sorovar enteritidis fagotipo 4, lavados com água de torneira (AT) ou solução de amônia quaternária (AQ) e armazenados a 8ºC e 25ºC. Duzentos e cinqüenta e dois ovos foram divididos em três grupos. Os tratamentos de cada grupo consistiram de imersão em AT, AQ a 25ºC e a 43ºC. Após a secagem natural, todos os grupos foram contaminados com solução de S. enteritidis. Seguindo-se a contaminação, cada grupo tratado foi estocado a 8ºC ou 25ºC, e a presença de S. enteritidis na casca e no conteúdo interno foi avaliada após zero, 24, 96 e 168 horas. A sanitização com AQ mostrou-se eficiente na redução de S. enteritidis nas cascas dos ovos. O armazenamento dos ovos a 8ºC demonstrou ser preponderante na redução e na ausência de S. enteritidis na casca. Nos ovos lavados com AT, o armazenamento a 25ºC permitiu a permanência da bactéria nas cascas até 168 horas. Não se detectou S. enteritidis no conteúdo interno dos ovos em nenhum dos grupos.

The contamination of eggshell and internal content of eggs that were inoculated with Salmonella enterica serovar enteritidis phagetype 4, washed with tap water (TW) or quaternary ammonium compound (QA) and stored at 8ºC and 25ºC was evaluated. Two hundred and fifty two eggs were distributed in three groups. Each treatment of the different groups was constituted by the immersion in TW, QA at 25ºC and at 43ºC. After natural dry, all groups were infected by a S. enteritidis solution. Following the challenge, each group was stored at 8ºC or at 25ºC, and the presence of S. enteritidis in the eggshell and internal content was evaluated after zero, 24, 96 and 168 hours. The use of QA demonstrated efficiency in S. enteritidis reduction of eggshell. The eggs stored at 8ºC revealed preponderancy in the reduction and the absence of S. enteritidis at the eggshell. In the TW washed eggs, the storage at 25ºC allowed the eggshell bacteria maintenance until 168 hours. There was not any detection of S. enteritidis at the internal content of eggs in any of the groups.