Photohydroionisation for disinfection of poultry litter.

1. This study evaluated photohydroionisation efficiency on the disinfection of new shavings used as substrate for litter in the poultry industry, pre-inoculated with bacterial, fungal and viral agents.2. Each replicate consisted of 250 g of new shavings sterilised by autoclaving, challenged with bacterial (Escherichia coli, Staphylococcus aureus, and Salmonella enterica, serovar Abony), fungal (Saccharomyces cerevisiae) and viral inoculum (Gumboro disease virus). The experiment consisted of six replicates at four times (0, 1, 5 or 10 min exposure) of photohydroionisation. The disinfection process was performed in a bench photohydroionisation device with four ultraviolet lamps. The agents inoculated in the shavings were analysed after the disinfection process.3. The counts of enterobacteria and total bacteria showed a quadratic effect. In contrast, the counts of fungi and viruses showed a negative linear effect with an increase in the time of photohydroionisation. The enterobacteria showed a linear response plateau effect (LRP), with a minimum time point of 5.498 minutes at a minimum contamination of 0.666 CFU/g and a reduction of 82.27% of the pre-established inoculum. Total bacteria had an LRP effect with a minimum time point of 1.902 minutes at minimum contamination of 1.739 CFU/g and a reduction of 50.0% of the pre-established inoculum. An LRP effect was found for fungi, with a minimum time point of 7.931 minutes in minimum contamination of 3.380 CFU/g, and with a reduction of 11.0% of the pre-established inoculum. For viruses, there was an LRP effect with a minimum time point of 5.012 minutes in minimum contamination of 0.000 viral titre per 100 g of shavings, which was reduced by 100% of the pre-established inoculum.4. Photohydroionisation in the disinfection of new shavings used as poultry litter has partial potential as a microbiological control tool, as a complete reduction occurred only for the viruses, whereas for bacteria and fungi only partial reductions of these microorganisms were observed.

Experimental infection of chickens by a flagellated motile strain of Salmonella enterica serovar Gallinarum biovar Gallinarum.

Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid (FT), a septicaemic disease which can result in high mortality in poultry flocks. The absence of flagella in SG is thought to favour systemic invasion, since bacterial recognition via Toll-like receptor (TLR)-5 does not take place during the early stages of FT. In the present study, chicks susceptible to FT were inoculated with a wild type SG (SG) or its flagellated motile derivative (SG Fla(+)). In experiment 1, mortality and clinical signs were assessed, whereas in experiment 2, gross pathology, histopathology, systemic invasion and immune responses were evaluated. SG Fla(+) infection resulted in later development of clinical signs, lower mortality, lower bacterial numbers in the liver and spleen, and less severe pathological changes compared to SG. The CD8(+) T lymphocyte population was higher in the livers of chicks infected with SG at 4 days post-inoculation (dpi). Chicks infected with SG had increased expression of interleukin (IL)-6 mRNA in the caecal tonsil at 1 dpi and increased expression of IL-18 mRNA in the spleen at 4 dpi. In contrast, the CD4(+) T lymphocyte population was higher at 6 dpi in the livers of birds infected with SG Fla(+). Therefore, flagella appeared to modulate the chicken immune response towards a CD4(+) T profile, resulting in more efficient bacterial clearance from systemic sites and milder infection.

Dinâmica da população de coliformes durante a compostagem automatizada de dejetos líquidos de suínos / Population dynamics during composting of fecal automated pig slurry

Microrganismos presentes em dejetos de suínos podem contaminar o meio ambiente. Embora a compostagem seja preconizada como um método eficiente para reduzir este potencial poluidor dos dejetos, existem poucas informações de pesquisa sobre tal processo. O presente trabalho teve o objetivo de avaliar a eficiência da compostagem automatizada dos dejetos líquidos de suínos (DLS) na redução da população de coliformes, usados como indicadores de poluição fecal. Os DLS foram adicionados periodicamente, durante 106 dias, em substrato constituído pela mistura, em partes iguais, de maravalha e serragem. Foram efetuadas 14 adições de DLS, e em cada adição as leiras de compostagem eram revolvidas por meio de uma máquina especialmente desenvolvida para este fim. Foram avaliados dois tratamentos com três repetições, sendo um com e outro sem adição de ácido fosfórico aos dejetos, até pH 6,0. A adição de ácido visou reduzir as perdas de N por volatilização de amônia (NH3) durante a compostagem. A avaliação da população de coliformes foi feita pela técnica do número mais provável (NMP), com uso do caldo Fluorocult, incubado a 37ºC por 24h e posterior leitura em luz ultravioleta. A população de coliformes fecais não foi afetada pela adição de ácido fosfórico. O processo de compostagem automatizada foi eficiente na redução de coliformes fecais, cuja população original passou de 4,2x1010 para 1,2 x 105 ao final da compostagem (156 dias) sem adição de ácido e de 3,8x1010 para 2,3x104 na compostagem com adição de ácido. Essa remoção de coliformes fecais, promovida pela compostagem automatizada dos dejetos líquidos de suínos, corresponde a 99,99 por cento...

Microorganisms present in pig manure can contaminate the environment. Although composting is recommended as an efficient method to reduce the pollution potential of waste, there is little research information on this process. This study aimed to evaluate the efficiency of automated composting of pig slurry (PS) in reducing the population of coliforms, used as fecal pollution indicators. The PS was added periodically during 106 days in substrate, with a mixture, in equal parts, of wood shavings and sawdust. There were 14 additions of PS and at each addition the compost windrows were revolved through a machine especially developed for this purpose. Two treatments with three replications were evaluated, one with and one without the addition of phosphoric acid to the slurry up to pH 6.0. The acid addition aimed to reduce N losses through the volatilization of ammonia (NH3) during composting. Coliforms were evaluated by the technique of most probable number (MPN) using the Fluorocult broth, incubated at 37 ° C for 24 h and subsequent reading in ultra violet light. The population of fecal coliforms was not affected by the addition of phosphoric acid. The automated composting process was effective in reducing faecal coliforms, whose original population decreased from 4.2 x 1010 to 1.2 x 105 at the end of composting (156 days) without addition of acid and from 3.8 x1010 to 2,3 x104 in compost with added acid. This removal of faecal coliforms, promoted by automated composting of pig slurry, corresponds to 99.99 percent...