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A new type of active packaging is the combination of food-packaging materials with antimicrobial substances to control microbial surface contamination of foods. For both migrating and non-migrating antimicrobial materials, intensive contact between the food product and Packaging material is required and therefore potential food applications include especially vacuum or skin-packaged products, e.g. vacuum-packaged meat, fish, poultry or cheese. Several antimicrobial compounds have been combined with different types of carriers (plastic and rubber articles, paper-based materials, textile fibrils and food-packaging materials). Until now, however, few antimicrobial concepts have found applications as a food-packaging material. Antimicrobial packaging materials cannot legally be used in the EU at the moment. The potential use would require amendments of several different legal texts involving areas such as food additives, food packaging, hygiene, etc. The main objective of this paper is to provide a state of the art about the different types of antimicrobial concepts, their experimental development and commercialization, and to present a case study summarizing the results of investigations on the feasibility, of a low-density polyethylene (LDPE)-film containing triclosan to inhibit microbial growth on food surfaces and consequently prolong shelf-life or improve microbial food safety. In contrast with the strong antimicrobial affect in in-vitro simulated vacuum-packaged conditions against the psychrotrophic food pathogen L. monocytogenes, the 1000 mg kg(-1) containing triclosan film did not effectively reduce spoilage bacteria and growth of L. monocytogenes on refrigerated vacuum-packaged chicken breasts stored at 7degrees C

Isometamidium Chloride (ISM) is one of the principal drugs used to counteract Trypanosoma congolense infection in livestock, both as a prophylactic as well as a curative treatment. However, numerous cases of ISM resistance have been reported in different African regions, representing a significant constraint in the battle against Animal African Trypanosomiasis.In order to identify genetic signatures associated with ISM resistance in T. congolense, the sensitive strain MSOROM7 was selected for induction of ISM resistance in a murine host. Administered ISM concentrations in immune-suppressed mice were gradually increased from 0.001 mg/kg to 1 mg/kg, the maximal dose used in livestock. As a result, three independent MSOROM7 lines acquired full resistance to this concentration after five months of induction, and retained this full resistant phenotype following a six months period without drug pressure. In contrast, parasites did not acquire ISM resistance in immune-competent animals, even after more than two years under ISM pressure, suggesting that the development of full ISM resistance is strongly enhanced when the host immune response is compromised. Genomic analyses comparing the ISM resistant lines with the parental sensitive line identified shifts in read depth at heterozygous loci in genes coding for different transporters and transmembrane products, and several of these shifts were also found within natural ISM resistant isolates. These findings suggested that the transport and accumulation of ISM inside the resistant parasites may be modified, which was confirmed by flow cytometry and ex vivo ISM uptake assays that showed a decrease in the accumulation of ISM in the resistant parasites.

A quantitative real-time PCR (qPCR) assay based on the cox III gene was evaluated for the simultaneous detection and discrimination of Theileria species in buffalo and cattle blood samples from South Africa and Mozambique using melting curve analysis. The results obtained were compared to those of the reverse line blot (RLB) hybridization assay for the simultaneous detection and differentiation of Theileria spp. in mixed infections, and to the 18S rRNA qPCR assay results for the specific detection of Theileria parva. Theileria parva, Theileria sp. (buffalo), Theileria taurotragi, Theileria buffeli and Theileria mutans were detected by the cox III assay. Theileria velifera was not detected from any of the samples analysed. Seventeen percent of the samples had non-species specific melting peaks and 4.5% of the samples were negative or below the detection limit of the assay. The cox III assay identified more T. parva and Theileria sp. (buffalo) positive samples than the RLB assay, and also detected more T. parva infections than the 18S assay. However, only a small number of samples were positive for the benign Theileria spp. To our knowledge T. taurotragi has never been identified from the African buffalo, its identification in some samples by the qPCR assay was unexpected.Because of these discrepancies in the results, cox III qPCR products were cloned and sequenced. Sequence analysis indicated extensive inter- and intra-species variations in the probe target regions of the cox III gene sequences of the benign Theileria spp. and therefore explains their low detection. The cox III assay is specific for the detection of T. parva infections in cattle and buffalo. Sequence data generated from this study can be used for the development of a more inclusive assay for detection and differentiation of all variants of the mildly pathogenic and benign Theileria spp. of buffalo and cattle.

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Aims: Understanding spoilage caused by different types of spoilage organisms, associated with vacuum-packaged sliced cooked meat products (CMP). Methods and Results: First, strains were characterized in a broth at 7°C under anaerobic conditions to compare their growth rate, acidifying character and metabolite production under conditions simulating refrigerated vacuum-packaged conditions. Brochotrix thermosphacta grew faster than the lactic acid bacteria (LAB). Within the group of the LAB, all strains grew fast except Leuconostoc mesenteroides subsp. dextranicum and Leuconostoc carnosum. Secondly, the organisms were inoculated on a model cooked ham to better understand the relationship between spoilage, microbial growth, pH, metabolite production and accompanying sensory changes. Most rapidly growing strains were Leuc. mesenteroides subsp. mesenteroides followed by B. thermosphacta, while Leuc. mesenteroides subsp. dextranicum and Leuc. carnosum grew very slowly compared with the other LAB. Brochotrix thermosphacta caused sensory deviations at a lower cell number compared with the LAB. The related pH changes, metabolite production and sensory perception are presented. Conclusions: In this pure culture study, B. thermosphacta and Leuc. mesenteroides subsp. mesenteroides had the highest potential to cause rapid spoilage on CMP. Significance and Impact of the Study: A systematic study on the behaviour of spoilage organisms on a model cooked ham to establish the relationship between microbial growth, pH, metabolite formation and organoleptic deviations.