Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

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.

Evaluation of Salmonella-Lytic Properties of Bacteriophages Isolated from Commercial Broiler Houses

Because of recent interest in bacteriophage therapy in poultry, information regarding the interaction of bacteriophages and potential host bacteria in the environment should be collected. The present studies were initiated with a rather typical commercial broiler integrator within the south-central United States to examine environmental Salmonella levels in two broiler complexes, attempt to isolate Salmonella-lytic bacteriophages, and elucidate a possible reason for differing apparent Salmonella prevalence. Significantly ( P<0.05) less Salmonella was isolated from houses in complex 1 ( 15/44 [ 34%] Salmonella-positive drag swabs) as compared to houses in complex 2 ( 22/24 [ 92%]). A total of seven Salmonella-lytic bacteriophages were isolated from Salmonella-positive environments, and two bacteriophages were isolated from a single Salmonella-negative house. During the initial bacteriophage isolation, individual bacteriophages did not replicate in the Salmonella host isolated from the same environment, and lysis of additional Salmonella hosts relied on high numbers of bacteriophage to be present. This suggests that the presence of these bacteriophages in the environment of a commercial broiler house had little to no effect on the presence of Salmonella. This study highlights the need to find additional bacteriophage sources, more effective isolation methods, and more innovative approaches to using bacteriophages to treat enteric disease.

Beef Carcass Contamination by Shiga Toxin-Producing Escherichia coli Strains in an Abattoir in Brazil: Characterization and Resistance to Antimicrobial Drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Escherichia coli phylogenetic group determination and its application in the identification of the major animal source of fecal contamination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro characterization of intra-generic inhibition of growth in Salmonella typhimurium

The intra-generic inhibition of bacterial growth observed previously in vivo and in vitro with strains of Salmonella, Citrobacter and E. coli was studied in vitro using S. typhimurium strain F98. There was complete inhibition of multiplication of S. typhimurium when it was added to stationary-phase broth cultures of different Salmonella serotypes, but only partial inhibition when added to broth cultures of E. coli. The degree of inhibition between different mutants of F98 was affected by the numbers of bacteria of the inhibiting strain, but this was not the only factor, since exponential-phase bacterial cells were less inhibitory than stationary-phase cells. The inhibitory effect was produced at temperatures between 20°C and 40°C. The complete inhibition of growth observed between F98 mutants was abolished by ampicillin, rifampicin and streptomycin, but not by nalidixic acid. Inhibition was also prevented by separating the two cultures by a dialysis membrane. A Tnpho A Insertion mutant of F98 was produced which did not show inhibition in vitro but was still inhibitory in vivo. It is suggested that this complete inhibition of bacterial multiplication between organisms of the same genus, which is greater than that produced between organisms from different genera, is mediated by a cell surface protein.

CONDICOES BACTERIOLOGICAS DE LEITE CRU E DE LEITE PASTEURIZADO NA REGIAO DE ARARAQUARA, SP, BRASIL

Milk can be an important spreading vehicle of pathogenic agents mainly for young children who are an important group of milk consumers. 135 milk samples (77 of raw milk and 58 of pasteurized milk) were analysed in order to verify the number of heterotrophic bacteria, of Staphylococcus aureus and of total coliforms, as well as to determine presence of Salmonella, Shigella, enteropathogenic Escherichia coli (EPEC) and enteroinvasive Escherichia coli (EIEC). The results were negative for Salmonella, Shigella and EIEC. EPEC serotypes 0:28, 0:111 and 0:55 were isolated in 4 of raw milk samples. The heterotrophic bacteria was found in counts over 30.000 UFC/mL in 91%, 25% and 68,75% respectively of raw milk, milk grade B and grade C. Counts over 30.000 coliforms/mL were found in 70,13%, 6,25% and 6,24% of the raw milk, B and C, respectively. 32,40% of the raw milk had counts of S. aureus over 3.000 UFC/mL.

The antibacterial effects for Salmonella Enteritidis phage type 4 of different chemical disinfectants and cleaning agents tested under different conditions

A selection of commercially available disinfectants, sanitizers and water sanitizers based on iodophor, quaternary ammonium compounds (QACs) and phenolic compounds were tested for their activity against a phage type 4 strain of Salmonella serotype Enteritidis in the presence of a variety of organic materials. In general the phenolic preparations were the most effective followed by the QACs and the iodophors. They were all inactivated to different degrees by chick fluff, chicken faeces, feed and wood shavings. The inactivation was greatest when Salmonella organisms were pre-dried in feed. Under these conditions formaldehyde and glutaraldehyde were still active. There was some evidence that induced resistance to stress conditions including culture at 42°C and anaerobic culture increased resistance to one of the water sanitizers.

Salmonella em carcaças de frango congeladas

Hundred and fifty frozen broiler carcasses of four commercial brands, purchased at retail stores for Salmonella research, were examined: 43 of the carcasses referred to each of the brands A, B, D and 21 of brand C. Thirty-two percent of the samples were found positive; 11 serotypes were identified as S. Agona, S. Anatum, S. Enteritidis, S. Hadar, S. Havana, S. Mbandaka, S. Montevideo, S. Ouakam, S. Poona, S. Schwarzengrund and S.14, 5, 12:-. Antibiogram testing of the isolated strains showed 100% resistance to ampicilin, 75.0% to cefhalotin, 52.1% to cephoxitin, 22.9% to tobramicin, 6.2% to polimixin B and to tetracyclines, 4.2% to gentamicin, and 2.1% to netilmicin, to aztreonam and to amicacin. All strains showed total sensibility to chloramphenicol and to sulfazotrim.

Experimental Salmonella enterica serovar Pullorum infection in two commercial varieties of laying hens

An experiment was carried out to investigate the biology of Salmonella Pullorum in two varieties of laying hens, from 5 days of age up to 9 months. One variety was resistant to systemic salmonellosis (light layers producing white eggs) and the other was considered susceptible (brown layers producing brown eggs). The brown birds were more affected by the infection, showing signs of clinical disease in the first month of life. Later, these signs disappeared, but postmortem examination revealed persistent gross pathological changes in the liver, spleen, heart and ovary. The rapid agglutination test detected reactors throughout the experiment, with the strongest agglutination from 1 to 7 months post-infection. S. Pullorum was isolated from some of the organs and the eggs laid throughout the experiment. The relationship between white birds and S. Pullorum was less intense, and there were no noticeable signs of disease. There were few gross pathological changes, and the bacteria were isolated infrequently and only for a brief period after infection, although contaminated eggs were laid by these birds. The strongest serological response in the white chickens occurred between the second and the fifth month post-infection.

Avaliação do extrato de Momordica charantia em Salmonella typhimurium: Mutagenicidade e antimutagenicidade

In the last years some natural products has been described as supressors of the mutagenic process in bacteria, the antimutagenics. The literature reference that in most of the countries, the population makes use of medicinal plants. The plant Momordica charantia (Cucurbitaceae) is original from Africa being used popularly as purgative, antirheumatic and for skin problems, burns and hemorrhoids. The present work had as objective to evaluate the mutagenic and antimutagenic activities of the ethanolic extract of M. charantia in Salmonella/microsome assays using TA100, TA98 and TA102 strains. It was verified that the extract did not present mutagenic activity when evaluated in different concentrations (0.64, 1.27, 2.55 and 3.84 mg/plate) but acted as antimutagenic agent against the mutations induced by the sodium azide (TA100,-S9), 4-nitro-phenylenediamine (TA98, -S9), daunomycin (TA102, +S9) 2-anthramine (TA100 and TA98, +S9) and 2-aminofluorene (TA102, +S9). When the metabolic activation (+S9) was used, the percentage of inhibition of the mutagenicity varied in the range of 31%-96%, while in absence of metabolizing system (-S9), the maximum percentage of inhibition of the mutagenicity was 44%. In that way, we can conclude that the metabolites found in the extract has potential to protect the genetic material against the damages induced by different chemical agents.

Avaliação da atividade mutagênica do resíduo sólido de uma fábrica de confecções de meias e lingerie em ensaios com Salmonella typhimurium

Cancer is one of the most hazardous effects to human health caused by the exposition to chemical agents. The search for new technological solutions in the industrial field led to a rapid increase in the productive sector, causing the workers to be exposed to millions of potentially toxic agents, substances potentially harmful to health. This study presents the mutagenic activity of sweepings from a sock and lingerie factory in Araraquara-Brazil, assayed with Salmonella typhimurium. All the extracts from the factory had mutagenic on activity the YG1024 strain, which is extremely sensitive to detect the mutagenic activity of the arilhydroxilamines, nitroarenes and aromatic amines. The extracts were non-mutagenics for the strains TA100 and TA98. The analysis of the mutagenicity of industrial residues is highly important because employees that participate in the production are directly exposed to those agents, as well as to the environment where the garbage is deposited.

SEM analysis of internal adaptation of adhesive restorations after contamination with saliva

Purpose: This study tested the null hypothesis that different treatments of saliva-contaminated substrate would not affect microgap formation at the dentin walls of bonded restorations. Materials and Methods: Forty freshly extracted human molars received standardized Class V preparations on buccal and lingual surfaces. The specimens were assigned to four experimental groups (n = 20): [G1] no contamination (control group), [G2] saliva contamination (10 s) after etching followed by 5 s air stream; [G3] saliva contamination after etching and rinsed for 10 s; and [G4] re-etching for 10 s after saliva contamination. All specimens were restored with a one-bottle adhesive (Single Bond, 3M ESPE) and microhybrid composite resin (Filtek Z250, 3M ESPE) according to the manufacturer's instructions. The specimens were thermocycled, sectioned through the center of the restoration, and then processed for SEM. Microgaps were measured at the axial wall at 1500X magnification. The data were submitted to Kruskal-Wallis nonparametric statistical analysis at p < 0.05. Results: The data revealed that different groups resulted in a statistically significant difference (p < 0.01) in gap formation. Air drying [G2] and rinsing [G3] the saliva-contaminated dentin resulted in similar microgap values (p > 0.05). However, re-etching the dentin after saliva contamination [G4] increased microgap formation (p < 0.05) when compared with the groups G1 and G2. Although air drying and rinsing produced results comparable to noncontaminated dentin, the presence of microgaps was not completely eliminated. Conclusion: Contaminated saliva did not prevent hybrid layer formation; however, it did reduce the adaptation of the restorative material to bonded surfaces.