The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

A study was conducted to investigate the effects of organic acids (OA) and competitive exclusion product (CE) on growth performance, intestinal morphology, and concentration of volatile fatty acids in the cecal content. The experiment lasted for 10 wk. Four hundred twenty 1-d-old female commercial cross turkey poults (British United Turkeys, BUT Big 9) were distributed into 4 treatments with 5 replicates/pen of 21 birds each. The birds were fed a basal diet without growth promoter (control), diet with lincomycin (44 mg/kg), diet with organic acids (2 g/kg), and diet with product of CE (10(9) cfu/kg). Dietary levels of other nutrients, housing, and general management practices were similar for all treatments. On the first week (d 0-7), the BW and BW gain of the birds that fed diets with OA were lower than in the control group. In the fattening phase (d 28-70), the feed intake of the OA-treated group was lower than compared with the control. The birds that received diet with OA and CE product presented higher concentrations of propionic acid, at 14 d, and butyric acid in cecal content at 28, 56, and 70 d, compared with the control. Dietary inclusion of additives had no significant effects on intestinal villus height, crypt depth, and villus:crypt ratio. Organic acids had negative effects either on early gain or feed intake throughout the study. Because the test was conducted under controlled experimental conditions, the additives that showed results similar to those found by using antibiotics should be studied further in commercial farms to obtain results that can be incorporated into practice.

Aim: To evaluate the use of organic acids (OAs) and competitive exclusion (CE) product administered continuously in the feed and transiently in drinking water on the control of Salmonella enterica subspecie enterica serotype Enteritidis (SE) prior to slaughter. Methods and Results: The influence of treatments were evaluated on pH, population of the lactic acid bacteria (LAB) and bacteria of the family Enterobacteriaceae, concentration of volatile fatty acids and SE colonization in the crop and caecum. The birds were challenged with SE 24 h before being slaughtered, and then, the caeca and crop were removed and subjected to SE counts. Continuous administration of OAs reduced the population of bacteria from the Enterobacteriaceae family in both crop and caecum, positively influenced the butyric acid concentration and reduced SE colonization in the caecum. The diet supplemented with CE product positively influenced the quantity of LAB in the crop and caecum, elevated the butyric acid concentration and reduced both Enterobacteriaceae quantity and SE colonization in the caecum. There was no effect from administering the treatments via drinking water on the variables measured. Conclusions: Continuous supplementation in feed with OAs and CE product reduced SE colonization of the caeca. Significance and Impact of the Study: Supplementation of OAs and CE product in diet to turkeys can reduce the SE load, potentially leading to a lower contamination risk of meat during slaughter.

The protection level against Salmonella Enteritidis was evaluated in chickens after in ovo treatment with different species of Lactobacillus spp. inoculated into the air cell or by immersion in broth culture. Two hundred forty embryonated eggs were distributed into 8 groups, corresponding to treatments with Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus salivarius, and control. On d 18 of incubation, 4 groups were inoculated with 0.1 mL of inoculum in the air cell and 4 groups were immersed for 3 min in culture of each treatment. Two days after hatching, 0.5 mL of Salmonella Enteritidis culture was inoculated by the intraesophageal route. On d 5 of life, the chicks were euthanized and the ceca were processed to obtain Salmonella Enteritidis counts. There was no decrease in Salmonella Enteritidis colonization of chick ceca, regardless of treatment or route of administration. Lactobacillus spp. samples used in the treatment showed no probiotic potential in chicks when inoculated in ovo, in relation to Salmonella Enteritidis inhibition in poultry ceca.

Foodborne diseases represent a major risk to public health worldwide. Pathogenic bacteria can live in the form of biofilm within the food industry, providing a permanent source of contamination. The aim of this study was to evaluate the influence of the types of adhesion surfaces on Salmonella biofilm formation at eight different times, and analyze the action time of a bacteriophage pool on established biofilms. Most of the samples used were classified as weak biofilm producers, with serovars Enteritidis and Heidelberg showing the highest frequency of biofilm formation. Glass and stainless steel surfaces significantly favored biofilm formation at 60 and 36 h of incubation respectively, but the polyvinyl chloride surface did not favor biofilm production, suggesting that the type of material may interfere with production. The bacteriophage pool action period focused on 3 h, but treatment of 9 h on glass surface biofilms was superior to other treatments because it affected the largest number of samples. These results suggests that some surface types and Salmonella serotypes may promote biofilm formation and indicate bacteriophages as an alternative to control biofilms. But further studies are required to prove the effectiveness and safety of bacteriophage therapy as an alternative in the antimicrobial control in the processing plants.

No abstract

This study aimed to characterize the in vitro and in vivo adhesion and immunomodulatory effect of Lactobacillus strains isolated from chickens. Lactobacillus samples isolated from 65-wk-old birds were identified by PCR; their adhesion was evaluated in vitro via basement membrane-type cell matrix and in vivo through carboxyfluorescein succinimidyl amino ester staining inoculation in 1-d-old birds and duodenum, jejunum, ileum, and cecum collections at 1, 4, 12, and 24 h after inoculation. The 5 best adhesive samples at the in vitro test formed a pool for total IgA and IgG measurement in sera and intestinal fluid. The birds were divided into groups by inoculation scheme: group 1 was treated with a pool of Lactobacillus spp. at 2-d-old and challenged 1 d later with Salmonella Enteritidis and then treated again with a pool of Lactobacillus spp. at 4 d of age; group 2 was treated with a pool of Lactobacillus spp. at 2 and 4 d of age; group 3 was challenged with Salmonella Enteritidis at 3 d of age; and group 4 was a negative control. Collections were taken at 7, 14, 21, 28, and 35 d after the first inoculation. The results suggest that basement membrane matrix use represents an important technique for triage of samples for subsequent in vivo evaluation and that carboxyfluorescein succinimidyl amino ester staining is efficient for identifying this bacterial characteristic. The Lactobacillus-treated groups (1 and 2) presented the highest IgA concentrations at the end of the experiment (12,054.6 and 10,568.4 ng/mL, respectively). The group 2 IgG values in intestinal fluid exceeded those of the other 3 groups (P < 0.05), peaking at 6.419 ng/mL. In most serum collections, the Lactobacillus-treated groups (1 and 2) did not differ significantly in IgG concentrations (P > 0.05), whereas group 3 presented the highest concentration of this antibody. It is concluded that there was greater adhesion of strains in the cecum and an important correlation between in vitro and in vivo results. These results also suggest the immunomodulatory action of Lactobacillus spp. in the chicken.

Ligações entre o uso indiscriminado de antimicrobianos na produção de animais, que se destinam à alimentação humana, conferindo pressão seletiva sobre microrganismos, e uma emergência na sua existência, surgimento, disseminação e transferência de genes que conferem de resistência a drogas antimicrobianas constituí preocupação global crescente. Processos de resistência antimicrobiana ocorrem de modo natural ou adquirido, sendo a maneira adquirida a mais preocupante. Vários são os mecanismos de transferência de resistência antimicrobiana, sobretudo elementos genéticos móveis são determinantes ao desenvolvimento de cepas bacterianas resistentes. Enterobactérias são frequentemente isoladas em produtos avícolas, sendo relatada múltipla resistência antimicrobiana e surtos de doenças em humanos. O objetivo da presente revisão foi discutir e expor aspectos relacionados à transferência de resistência antimicrobiana, destacando os impactos da utilização de antimicrobianos e o processo de transferência de resistência antimicrobiana entre bactérias patogênicas, zoonóticas e comensais de aves.