Evaluation of the cold chain of fresh-cut endive from farmer to plate

In this study, the cold chain and its impact on food stuff microbiology was evaluated for fresh-cut endive. A survey was carried out to analyze endive temperature throughout the supply chain from producer, via processor and distributor to the restaurant. Data loggers accompanying the endive on its route provided a temperature profile of the endive. The effect of the outdoor temperature on initial cooling was evaluated and critical points regarding cold chain management in the supply chain were identified. Our experiments indicate that the cold chain is generally properly maintained. In parallel with temperature monitoring, indicator microorganisms were assessed at different points in the supply chain to examine the effects of endive temperature, temperature fluctuations, and the outdoor temperature on microbial food safety. Small temperature fluctuations in the supply chain had a small effect on the total level of aerobic mesophilic bacteria. However, at the best before-date, total coliforms and Enterobacteriaceae levels were significantly higher in endive samples subject to temperature fluctuations in the supply chain, compared to endive stored in optimal conditions. To our knowledge, this is the first study that combines microbiological analysis with the temperature profile of fresh-cut produce in a realistic food supply chain.     

Genetic analysis of production and feed efficiency traits in an Orlopp turkey line (Meleagris gallopavo)

1. Genetic parameters for production and feed efficiency traits in the Orlopp line of turkeys were estimated to determine breeding goals and future potential of the line in a long-term genetic improvement programme.

2. Body weight, egg production and fertility traits were recorded and feed conversion ratio (FCR) was assessed from 16–20 weeks of age.

3. Moderate heritabilities were found for feed intake and body weight gain (0.25 to 0.31). Average FCR was 3.14, with heritability of 0.10. Body weight, breast conformation score and egg production traits showed moderate heritabilities (0.22 to 0.52), while both fertility and hatch of fertile eggs were low (0.04 and 0.09, respectively).

4. Genetic correlations between breast confirmation score, 10- and 18-week body weights were moderate, 0.50 and 0.45, respectively. Average egg weight also showed moderate genetic correlations with 10- and 18-week body weights (0.59 and 0.42).     

Influence of calcium chloride on the cardio‐respiratory effects of a bolus of enoximone in isoflurane anaesthetized ponies

ObejctiveTo investigate the influence of calcium chloride (CaCl₂) on the cardio–respiratory effects of enoximone in isoflurane anaesthetized ponies.Study designProspective consecutive experimental trial.AnimalsSix healthy ponies, weighing 287 ± 55 kg were included in this study.MethodsAfter sedation (romifidine, 80 μg kg^?1), anaesthesia was induced with midazolam (0.06 mg kg^?1) and ketamine (2.2 mg kg^?1) and maintained with isoflurane in oxygen. The ponies’ lungs were ventilated to maintain normocapnia. After 90 minutes, a bolus of enoximone (0.5 mg kg^?1) was administered, followed by a CaCl₂ infusion (0.5 mg kg^?1 minute^?1 over 10 minutes) (treatment EC). Sodium, potassium, ionized and total calcium concentrations, cardiovascular variables and blood–gases were measured in the 120 minutes after treatment. Using a mixed model anova, the results were compared to those of a previous report [Vet Anaesth Analg, 34 (2007) 416], evaluating the effects of 0.5 mg kg^?1 enoximone in the same ponies and under identical circumstances (treatment E). Both an overall comparison and comparisons at specific time points after treatment were performed (α = 0.05).ResultsAlthough ionized and total calcium concentrations were higher during treatment EC, the cardio–respiratory effects of enoximone were comparable for both treatments. A small but significant difference in packed cell volume was detected.Conclusions and clinical relevanceCalcium chloride did not enhance the effects of enoximone in normocalcaemic anaesthetized ponies.     

Genotypic and phenotypic characterization of the European A2 isolates of <Emphasis Type="Italic">Phytophthora ramorum</Emphasis>

Phytophthora ramorum, a recently described North American and European pathogen, has three clonal lineages. The NA1 and NA2 lineages are found in North American forests and nurseries, while the EU1 lineage appears mainly in European nurseries. P. ramorum is heterothallic, having two mating types A1 and A2. All NA1 and NA2 isolates are of A2 mating type. When first collected, all EU1 isolates were of A1 mating type, with the exception of one A2 isolate collected in Belgium in 2002. Screening 410 other Belgian isolates for mating type revealed two additional EU1-A2 isolates collected in 2002 and 2003. PCR-RFLP, AFLP and SSR markers were used to determine the nature of the mating type change. The three isolates show no indications of sexual recombination or mitotic crossing over, indicating that mutation or mitotic gene conversion is the most likely explanation for the mating type change. We compared the pathogenicity and sporulation characteristics of the EU1-A2 isolates to those of EU1-A1 and NA1-A2 isolates on four host plants. Despite small differences in pathogenicity on some hosts, the EU1-A2 isolates were similarly aggressive to each other and to the EU1-A1 isolates and more aggressive than the NA1-A2 isolates. Sporulation characteristics were also comparable among EU1-A2 isolates and between EU1-A1 and EU1-A2 isolates, except for EU1-A2 isolate BBA 26/02. The limited genotypic and phenotypic differences between EU1-A2 isolates probably evolved after the mating type change, which may have occurred several years before the isolates were detected. There are strong indications that the EU1-A2 population has been eradicated from Belgium.     

Vibrio anguillarum as a fish pathogen: virulence factors, diagnosis and prevention

Vibrio anguillarum, also known as Listonella anguillarum, is the causative agent of vibriosis, a deadly haemorrhagic septicaemic disease affecting various marine and fresh/brackish water fish, bivalves and crustaceans. In both aquaculture and larviculture, this disease is responsible for severe economic losses worldwide. Because of its high morbidity and mortality rates, substantial research has been carried out to elucidate the virulence mechanisms of this pathogen and to develop rapid detection techniques and effective disease‐prevention strategies. This review summarizes the current state of knowledge pertaining to V. anguillarum, focusing on pathogenesis, known virulence factors, diagnosis, prevention and treatment.     

Columnaris disease in fish: a review with emphasis on bacterium-host interactions

Flavobacterium columnare (F. columnare) is the causative agent of columnaris disease. This bacterium affects both cultured and wild freshwater fish including many susceptible commercially important fish species. F. columnare infections may result in skin lesions, fin erosion and gill necrosis, with a high degree of mortality, leading to severe economic losses. Especially in the last decade, various research groups have performed studies aimed at elucidating the pathogenesis of columnaris disease, leading to significant progress in defining the complex interactions between the organism and its host. Despite these efforts, the pathogenesis of columnaris disease hitherto largely remains unclear, compromising the further development of efficient curative and preventive measures to combat this disease. Besides elaborating on the agent and the disease it causes, this review aims to summarize these pathogenesis data emphasizing the areas meriting further investigation.     

Expression of verocytotoxic Escherichia coli antigens in tobacco seeds and evaluation of gut immunity after oral administration in mouse model

Verocytotoxic Escherichia (E.) coli strains are responsible for swine oedema disease, which is an enterotoxaemia that causes economic losses in the pig industry. The production of a vaccine for oral administration in transgenic seeds could be an efficient system to stimulate local immunity. This study was conducted to transform tobacco plants for the seed-specific expression of antigenic proteins from a porcine verocytotoxic E. coli strain. Parameters related to an immunological response and possible adverse effects on the oral administration of obtained tobacco seeds were evaluated in a mouse model. Tobacco was transformed via Agrobacteium tumefaciens with chimeric constructs containing structural parts of the major subunit FedA of the F18 adhesive fimbriae and VT2e B-subunit genes under control of a seed specific GLOB promoter. We showed that the foreign Vt2e-B and F18 genes were stably accumulated in storage tissue by the immunostaining method. In addition, Balb-C mice receiving transgenic tobacco seeds via the oral route showed a significant increase in IgA-positive plasma cell presence in tunica propria when compared to the control group with no observed adverse effects. Our findings encourage future studies focusing on swine for evaluation of the protective effects of transformed tobacco seeds against E. coli infection.     

"家禽肠道疾病及其预防措施"专栏(九) 利用靶向释放型丁酸钠制剂应对肉鸡肠道健康和垫料问题

肠壁的受损为细菌引发肉鸡健康问题和垫料问题提供了可趁之机.最近的研究表明,丁酸在保护肠壁的完整性方面可发挥重要的作用,通过靶向释放包被技术,丁酸可达到肠道指定的部位,以此来减少坏死性肠炎的感染.