In vitro Assessment of Temperature and pH Dependent Growth Patterns of Campylobacter jejuni and coli

Introduction: Campylobacter spp. are among the main bacterial causes of acute gastroenteritis worldwide. Despite their fragile nature, they survive in the environment and food chain, likely overcoming several stressful challenges. However, little is known about their response to adverse conditions. Purpose: The aim of this study was to investigate the survival of Campylobacter jejuni and coli at various temperatures (32, 37, 42, and 47 \ub0C) and pH ranges (5, 7, and 9) in laboratory media. Methods: ATCC strains of Campylobacter jejuni (BAA-1062) and coli (43481) were cultured separately in tryptic soy broth (TSB). In order to adapt bacteria to a mild stress, broth cultures were further inoculated in TSB at pH 6 and 8. After 24 h, the pH 6 culture was inoculated in TSB at pH 5, while the pH 8 culture in TSB at pH 9. Aliquots of these broths were incubated at 32, 37, 42 and 47 \ub0C. A pH 7 culture was used as control and samples were taken at 0, 2, 4, and 24 h, spread plated onto Campy Cefex agar, and incubated for 48 h at 42 \ub0C. Results: Extreme thermal and pH conditions (i.e. 32 and 47 \ub0C, pH 5 and 9) resulted in variable behavior of Campylobacter spp. Although Campylobacter jejuni and coli populations at pH 5 and 9 were significantly (p0.05) the growth patterns of Campylobacter spp. and no interactions between strain, pH, incubation temperature, and sampling time were detected. Significance: Results suggest that Campylobacter jejuni and coli do not respond well to multiple stresses, but have the ability to adapt to low and high pH. Therefore they can resist typical sanitation practices and persist in the environment leading to human illnesses

Effect of season and dietary energy concentration on composition and strength of skin in naked neck fowl

WOS: 000077643300006PubMed ID: 99253151. Two experiments, in spring and summer, were conducted to evaluate the effect of dietary energy concentration on the composition and strength of the skin of naked neck fowl. The heterozygous naked neck birds were also compared with their normally feathered sibs under summer temperatures. 2. The average temperatures were 21.2 degrees C and 27.1 degrees C in spring and summer experiments, respectively. Three concentrations of dietary energy were fed to the birds. The diets used were: a low energy diet of 12.12 MJ ME/kg; a medium energy diet of 12.96 MJ ME/kg; and a high energy diet of 13.79 MJ ME/kg. Two protein concentration per energy treatment, 230 and 200 g/kg, respectively were used from 0 to 3 and 3 to 7 weeks of age. 3. A significant season sex interaction showed that the skin of males had higher protein and collagen and lower dry matter and fat content than that of females, when grown under summer conditions. No sex differences were present under spring conditions. 4. The differences between sexes was not significant in spring but males had stronger skin than females in summer. Neither ambient temperature nor dietary energy concentration significantly affected skin displacement of naked neck birds. 5. In comparing the naked neck and their normally feathered sibs in the summer experiment, it was found that naked neck birds had lower skin fat content and higher skin protein content than normally feathered birds

Age-related effects of catching, crating, and transportation at different seasons on core body temperature and physiological blood parameters in broilers

This study was designed to determine the physiological effects of 3 preslaughter treatments (catching, crating, and transportation) on male and female broiler chickens slaughtered at 35, 42, 49, and 56 d of age. At each age, 18 birds (3 birds per sex and pen; 3 replicate pens) were sampled after catching, crating, and transportation for 1 h for core body (rectal) temperature (Rt), blood pH, gases (partial Co-2 and O-2 pressures), ions (Na+, K+, Ca++, HCO3-), hemoglobin, plasma glucose, albumin, uric acid, creatine kinase (CK) activity, and white blood cell differential counts. The experiment was repeated under fall and summer environmental conditions

Litter materials and the incidence of carcass lesions in broilers chickens

The aim of this study was to evaluate the effects of different litter materials on litter compaction, broiler feathering and the incidence of carcass lesions. In the experiment, 3240 one-day-old Ross® chicks were selected by sex and distributed according to a completely randomized experimental design in a 2 x 6 factorial arrangement (two sex and six litter materials). The following litter materials were used: wood shavings, rice husks, chopped Napier grass, 50% sugar cane bagasse plus 50% wood shavings, 50% sugar cane bagasse plus 50% rice husks, and pure sugar cane bagasse. Litter compaction was weekly assessed using a penetrometer. On days 21, 35 and 42 of the experimental period, feathering on the back and legs was scored according to a 0 - 10 scale. On day 42, birds were slaughtered and the presence of bruises, scratches and footpad lesions was recorded. Litter material had no effect on bird feathering. Carcass lesions (scratches, bruises and footpad lesions) were influenced by the litter material evaluated. Birds reared on sugarcane bagasse and chopped Napier grass presented more scratches, bruises and footpad lesions than the others. Dermatitis was more evident in birds reared on sugarcane bagasse, chopped Napier grass and the combination of litter materials. It was found that males presented higher incidence of dermatitis and footpad lesions than females. Each litter material presented different compaction degrees, which increased along the experimental period. Sugarcane bagasse, chopped Napier grass and the combination of bedding materials presented the highest degree of compaction, compared with wood shavings and rice husks

Histomorphology of bursa of Fabricius: effects of stock densities on commercial broilers

During the past few years, there has been considerable interest on the effects of stocking density on broiler behavior and immunity. Stress may cause immunodeficiency by affecting cell and humoral responses, as well as body weight decrease, and foot-pad dermatitis. The aim of this study was to study histomorphological changes of the bursa of Fabricius in broilers submitted to three different stocking densities (10, 15, and 20 birds/m²) from one to 42 days of age. Three birds from each group were sacrifieced on days 7 and 42. The bursa was collected, fixed, and processed for histomorphometric assessment using a Kontrom KS 400 image analyzer. Data were analyzed by Biostat 3.0 (Tukey Test). The results of average cortical area percentage in bursal follicles of 6-week-old birds were 45.12a (10 birds/m²), 30.43b (15 birds/m²), and 23.77b (20 birds/m²). Average body weight was 2.58a kg (10 birds/m²), 2.56a Kg (15 birds/m²), and 2.47b Kg (20 birds/m²), respectively. The percentage of foot-pad dermatitis in 6-week-old birds was 3.33a (10 birds/m²), 17.76b (15 birds/m²), and 49.17c (20 birds/m²). These differences were statistically significant at a P<0.05 level. Under these experimental conditions,, it was concluded that the best stocking density to produce broilers is between 10-15 birds per square meter