Decontamination of high-risk animal and zoonotic pathogens.

Preparedness for the decontamination of affected environments, premises, facilities, and products is one prerequisite for an immediate response to an animal disease outbreak. Various information sources provide recommendations on how to proceed in an outbreak situation to eliminate biological contaminants and to stop the spread of the disease. In order to facilitate the identification of the right decontamination strategy, we present an overview of relevant references for a collection of pathogenic agents. The choice of pathogens is based on a survey of lists containing highly pathogenic agents and/or biological agents considered to be potential vehicles for deliberate contamination of food, feed, or farm animals. European legislation and guidelines from national and international institutions were screened to find decontamination protocols for each of the agents. Identified recommendations were evaluated with regard to their area of application, which could be facilities and equipment, wastes, food, and other animal products. The requirements of a disinfectant for large-scale incidents were gathered, and important characteristics (eg, inactivating spectrum, temperature range, toxicity to environment) of the main recommended disinfectants were summarized to assist in the choice of a suitable and efficient approach in a crisis situation induced by a specific high-risk animal or zoonotic pathogen. The literature search revealed numerous relevant recommendations but also legal gaps for certain diseases, such as Q fever or brucellosis, and legal difficulties for the use of recommended disinfectants. A lack of information about effective disinfectants was identified for some agents.

Factors associated with the occurrence of MRSA CC398 in herds of fattening pigs in Germany.

BACKGROUND: The purpose of this study was to investigate the prevalence of MRSA in herds of fattening pigs in different regions of Germany, and to determine factors associated with the occurrence of this pathogen. For this purpose pooled dust samples were collected, and a questionnaire covered information regarding herd characteristics and management practices. Samples were pre-enriched in high-salt medium followed by selective enrichment containing cefoxitin/aztreonam, and culturing. Presumptive colonies were confirmed by multiplex-PCR targeting nuc-, mecA- and 16S rRNA-genes. Isolates were spa- and SCCmec-, and in selected cases, multilocus sequence-typed. Susceptibilities to 13 antimicrobials were determined by broth microdilution. Statistical analysis was carried out using backward stepwise logistic regression to calculate odds ratios with the MRSA test result as the outcome and herd characteristics as categorical covariates. RESULTS: Overall, 152 of 290 (52%) fattening pig farms tested positive for MRSA. The prevalence in the east, north- and south-west of Germany ranged from 39 to 59%.t011 (66%) and t034 (23%) were the most commonly identified spa-types, and 85% of isolates carried SCCmec Type V. Identified spa-types were all associated with clonal complex CC398. Susceptibility testing revealed that all isolates were resistant to tetracycline. High resistance rates were also found for sulfamethoxazole/trimethoprim (40%), and quinupristin/dalfopristin (32%). In addition, 83% of strains displayed multidrug resistant (> 3 substance classes) phenotypes.Logistic regression revealed herd size (large farms OR: 5.4; CI: 2.7-11.2; p < 0.05), and production type (wean-to-finish OR: 4.0; CI: 1.6-10.4; p < 0.05) as risk factors associated with a positive MRSA finding in fattening pig operations. CONCLUSIONS: MRSA CC398 is widely distributed among herds of fattening pigs in Germany. Farm management plays a crucial role in the dissemination of MRSA with herd size, and production type representing potential major indicators.

Zero tolerances in food and animal feed -- are there any scientific alternatives? A European point of view on an international controversy.

A number of zero tolerance provisions are contained in both food and animal feed law, e.g. for chemical substances whose occurrence is not permitted or is directly prohibited in food or animal feed. In the European Union, bans of this kind were introduced to give consumers and animals the greatest possible protection from substances with a possible hazard potential within the intendment of the hazard prevention principles and current precautionary measures. This also applies to substances for which an acceptable daily intake cannot be derived and a maximum residue limit cannot, therefore, be established, e.g. due to missing or inadequate toxicological data. Zero tolerances are also under discussion as trade barriers because their use has triggered numerous legal disputes. This paper draws together the results of an evaluation of alternative risk assessment methods to be used for the risk assessment of substances to which currently only zero tolerances apply. It will demonstrate that, depending on the available toxicological data, a scientifically sound risk assessment may still be possible. In this context, the two concepts - margin of exposure and threshold of toxicological concern - are very promising approaches. Until the scientific and sociopolitical discussions have been completed, it is essential that the principle of zero tolerances be upheld, especially for those substances which may be genotoxic carcinogens. In microbiology, there is no legal room for manoeuvre with regard to food safety criteria established for reasons of consumer health protection on the basis of scientific assessments.