Detection of Campylobacter spp. in chilled and frozen broiler carcasses comparing immunoassay, PCR and real time PCR methods / Detecção de Campylobacter spp. em carcaças de frango de corte resfriadas e congeladas pelos métodos imunoenzimático, PCR e PCR em tempo real

ABSTRACT: In order to detect and identify Campylobacter spp. in broiler chicken carcasses, and to compare detection methods, 43 chilled and 43 frozen carcasses were collected and analyzed. Three methodologies were evaluated: an automated Enzyme Linked Fluorescent Assay (ELFA) VIDAS®30, Polymerase Chain Reaction (PCR) and real-time PCR. Only four chilled carcasses (4.6%) were considered positive for Campylobacter spp. by VIDAS®30 and no sample was positive when the conventional PCR technique was used. However, real-time PCR showed a higher incidence of contamination by Campylobacter spp. in broiler carcasses, with 45 (52.3%) positive samples. C. jejuni was the species most frequently reported in the samples (88.8%). No differences in the frequencies of Campylobacter spp. were observed between the chilled and frozen broiler carcasses. In conclusion, real-time PCR was the most sensitive method for the detection of Campylobacter spp. in chilled or frozen broiler carcasses, which were mainly contaminated by C. jejuni.

RESUMO: Com o objetivo de detectar e identificar Campylobacter spp. em carcaças de frango de corte utilizando três metodologias distintas - ensaio imunoenzimático VIDAS®30, Reação em Cadeia da Polimerase (PCR) e PCR em tempo real - foram coletadas e analisadas 43 carcaças de frango resfriadas e 43 congeladas. Quatro carcaças refrigeradas (4,6%) foram consideradas positivas para Campylobacter spp. pelo VIDAS®30 e nenhuma amostra positiva foi identificada quando utilizada a técnica de PCR. Porém, ao analisar as carcaças pela metodologia da PCR em tempo real, foi observada uma maior incidência de Campylobacter spp., com 45 amostras (52,3%) positivas, sendo que Campylobacter jejuni foi a espécie mais frequentemente encontrada nas amostras (88,8%). Não foi observada diferença na frequência do micro-organismo entre carcaças de frangos resfriadas e congeladas. Concluiu-se que a técnica de PCR em tempo real apresentou maior sensibilidade na detecção de Campylobacter spp. em carcaças de frangos de corte e que foi encontrada elevada presença de carcaças contaminadas, especialmente por C. jejuni.

Determination of the residue levels of nicarbazin and combination nicarbazin-narasin in broiler chickens after oral administration.

The depletion times of the anticoccidial nicarbazin administered individually and of nicarbazin and narasin administered in combination were evaluated by determining the presence and levels of 4,4'-dinitrocarbanilide (DNC), the marker residue for nicarbazin, and narasin residues in the muscle tissues of broiler chickens subjected to a pharmacological treatment. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was used. The results showed the presence of all anticoccidial residues; however, the DNC levels were higher when the nicarbazin was administered individually than when it was used in association with narasin throughout the experimental period. After six days of withdrawal, the DNC level following nicarbazin administration alone was lower than the maximum residue level (MRL) of 200 µg kg-1. However, when the nicarbazin was co-administered with narasin, the concentrations of DNC were lower than the MRL after four days of withdrawal. These results may be justified because the dosage of nicarbazin, when administrated individually, is greater than when it is used in combination with narasin. The levels of narasin were lower than the MRL of 15 µg kg-1 throughout the evaluation period. It was concluded that nicarbazin is rapidly metabolized from the broiler muscles up to six days of withdrawal since the DNC levels were lower than the maximum residue level (MRL) and the concentrations of narasin were lower than the MRL throughout the evaluation period.

Effects of the use of soybean oil and animal fat in the diet of laying hens on production performance and egg quality / Efeito do uso de oleo de soja e gordura animal na dieta de poedeiras sobre desempenho produtivo e qualidade do ovo

The effects of different dietary lipids on the fatty acid profiles of eggs produced by 20 and 54 wk old Dekalb laying hens were investigated. Laying hens were subjected to three defined treatments according to the source of lipid added to their diets: soybean oil, beef tallow, and a control diet (without the addition of oil). The experimental design was in a 3x2 factorial arrangement (three treatments and two different ages). The fatty acid composition of the yolks in the eggs produced by the laying hens was analyzed. The eggs produced by laying hens on the soybean oil diet had a large amount of polyunsaturated fatty acids (PUFA) omega-6 (n-6) and omega-3 (n-3) in their yolks (23.55, 2.30 percent respectively), whereas egg yolks from hens who were given beef tallow had higher percentages of monounsaturated fatty acids (47.53 percent) compared to soybean oil (47.53 percent) and the control diet (38.72 percent). The percentages of trans fats present in the egg yolks in all treatments were considered very low (0.91; 0,11; 0.05 percent). Young layers are more efficient at depositing n-3 fatty acids (1.40 percent), specially C22:6 (0.76 percent) with the best ratio n6:n-3 (13.97) compared to old layers (1.35; 0.72; 14.81 percent respectively). Based on these results, it was concluded that the amount of fatty acids present in the egg yolks can be modified by the sources of lipids included in the diet and that independent of the sources of lipid in the diet and the age of the chicken, egg yolks have insignificant amounts of trans fatty acids.

Foram avaliados os efeitos de diferentes dietas lipídicas na composição de ácidos graxos (AG) de ovos produzidos por poedeiras Dekalb de 20 e 54 semanas de idade. As poedeiras foram submetidas a três tratamentos definidos de acordo com a fonte lipídica adicionada nas rações: óleo de soja, sebo bovino e ração controle (sem adição de óleo). O delineamento experimental foi inteiramente casualizado em arranjo fatorial 3x2 (três tratamentos e duas idades das galinhas). Foram analisadas as composições em ácidos graxos das gemas dos ovos produzidos pelas poedeiras. O perfil de ácidos graxos das gemas dos ovos, produzidos pelas aves alimentadas com rações contendo óleo de soja, apresentaram na sua composição grande quantidade de ácidos graxos poliinsaturados (PUFA) ômega 6 (n-6) and Omega 3 (n-3) (23,55; 2,30 por cento respectivamente), enquanto as gemas dos ovos de poedeiras que receberam sebo bovino apresentaram maiores porcentagens de AG monoinsaturados (47,53 por cento) na sua composição, comparados com dieta contendo óleo de soja (47,53 por cento) e dieta controle (38,72 por cento). As porcentagens de gordura trans presente nas gemas dos ovos de todos os tratamentos foram consideradas muito baixas (0,91; 0,11; 0,05 por cento). Poedeiras novas são mais eficientes em depositar AG n-3 (1,40 por cento), especialmente C22:6 (0,76 por cento) na gema do ovo, com melhor razão n6:n:3 (13,97) comparado com poedeiras velhas (1,35; 0,72; 14,81 por cento respectivamente). Com base nesses resultados, foi concluído que a quantidade de ácidos graxos presentes na gema dos ovos podem ser modificadas de acordo com as fontes de lipídios oferecidas nas dietas e que, independente da adição de diferentes fontes lipídicas na ração e da idade das galinhas, as gemas dos ovos possuem quantidades insignificantes de gorduras trans.