Expression of a truncated hepatitis E virus capsid protein in the protozoan organism Leishmania tarentolae and its application in a serological assay.

Zoonotic infections with hepatitis E virus (HEV) genotype 3 are presumably transmitted via contaminated pig meat products, which raises the necessity for enhanced serological surveillance of pig herds. The aim of the study was to set up a novel protein expression system to overcome the well-known problems in (HEV-) protein expression using the standard Escherichia coli tools such as inclusion body formation and loss of protein conformation. A recombinant strain of the protozoan organism Leishmania tarentolae (L. tarentolae) was therefore established. A fragment of HEV ORF2 coding for a truncated capsid protein of a porcine HEV strain was cloned and parts of the plasmid DNA were introduced into the Leishmania genome, resulting in stably transformed cells. Via a C-terminal His-tag the recombinant HEVΔORF2 protein could be purified and concentrated directly from the medium, resulting in a total protein amount of approximately 1.4 mg/l Leishmania culture. The recombinant protein was coated on ELISA plates and was proven to be highly reactive and well-suited to be applied in a serological assay. By investigating 144 porcine sera, the in-house assay detected specific antibodies in 43.1% of the samples and demonstrated a higher sensitivity than a commercially available antibody test. Taken together, it was shown that L. tarentolae exhibits a remarkable alternative expression strategy for viral antigens with considerable advantages of a eukaryotic protein expression host.

Proposing the term purkinjeoma: protein gene product 9.5 expression in 2 porcine cardiac rhabdomyomas indicates possible purkinje fiber cell origin.

Rhabdomyomas, defined as rare benign tumors of striated muscle, predominantly occur in the myocardium. In veterinary medicine, cardiac rhabdomyomas have rarely been reported but most frequently in pigs as an incidental finding. In the present case report, multiple circumscribed nodules found in the myocardium of 2 pigs were composed of large, vacuolated, glycogen-loaded cells. They expressed vimentin and desmin, neuron-specific enolase, and atrial natriuretic peptide. In addition, these cells expressed protein gene product 9.5, a marker for neuronal tissue and Purkinje fiber cells, in contrast to adjacent myocytes. The present findings-especially, the protein gene product 9.5 immunoreactivity-provide further evidence for the Purkinje fiber cell origin of the porcine myocardial proliferation. Therefore, the term purkinjeoma or purkinjeomatosis is proposed for cardiac rhabdomyoma in pigs.

Livestock associated methicillin-resistant Staphylococcus aureus (LaMRSA) isolated from lesions of pigs at necropsy in northwest Germany between 2004 and 2007.

An increasing number of reported detections of methicillin-resistant Staphylococcus aureus (MRSA) in food animals since 2007 has led to the assumption that there is an emerging zoonotic problem with livestock associated (la)MRSA potentially aggravating the MRSA problem in humans. It was the objective of the study to investigate, whether MRSA was present in clinical specimens of pigs collected at post-mortem since 2004 and to further characterize these isolates. We studied 138 isolates of S. aureus collected between 2004 and 2007 from various pathological lesions of pigs at necropsy. Potential MRSA were identified by growth on selective chromogenic media. Isolates were confirmed as MRSA using multiplex PCR. Confirmed isolates were spa- and SCCmec-typed and were tested for antimicrobial resistance. Overall, 60 (43%) S. aureus isolates were identified as MRSA. The majority (57/60) of the MRSA isolates found in the altered porcine tissues were spa-types associated with MRSA ST398. Three MRSA were ST97 isolates, a type that has not been described as an MRSA in pigs before. Other clonal complexes (ST9, ST30) dominated among the methicillin-sensitive S. aureus. MRSA were found in similar frequency in all 4 years. We assume that MRSA in pigs may have occurred earlier than 2004 and might be not really 'emerging', but rather have been overlooked until recently. The potentially causative role of the MRSA in the lesions warrants further investigation.

[Occurrence of MRSA in pigs and in humans involved in pig production--preliminary results of a study in the northwest of Germany]. / Zum Vorkommen von MRSA bei Schweinen und bei Menschen mit beruflicher Exposition zum Schwein--Erste Ergebnisse einer Studie in Nordwestdeutschland.

In 2007, 678 pigs of all age groups out of 347 different farms from Lower Saxony and Northrhine-Westphalia and 86 persons occupationally exposed to pigs were investigated for their nasal colonisation with methicillin-resistant Staphylococcus areus (MRSA) by the Field Station for Epidemiology of the University of Veterinary Medicine Hannover and the Robert Koch-Institute. At the individual animal level, a frequency of positive results of 13% (n = 85 positive animals) and at the herd level, a frequency of positive results of 18% (n = 62 positive herds) were found. All isolates were assigned to the Multilocus Sequence Typing Type ST398. Within MRSA-positive herds, there were more MRSA-negative than MRSA-positive animals. Among the occupationally exposed persons (veterinarians, laboratory personnel and meat inspection personnel), 20 persons (23%) showed a nasal colonisation with MRSA ST398. A quite strong association between the intensity of the contact to pigs with the frequency of nasal colonisation in the occupationally exposed persons was detected. None of the animals or the humans nasally colonised by MRSA ST398 showed any clinical symptoms of a staphylococcal infection. Conclusions are drawn on the herd and intra-herd prevalence of the nasal colonisation of pigs with MRSA ST398 in pigs, but especially on which questions need to be addressed by further research.

[Results of the evaluation of food chain information for a risk-oriented meat inspection]. / Ergebnisse zur Bewertung von Lebensmittelketteninformationen als Entscheidungsgrundlage für die risikoorientierte Fleischuntersuchung.

In a scientific project 469 slaughter groups originating from 39 farmers with 37.222 pigs in total were investigated concerning the usefulness of the food chain information. A standard statement does not include enough relevant information for the official veterinarian in the slaughterhouse to do a risk-based meat inspection. Even the food chain information for the visual meat inspection, which has certain limits, shows only farms, where the animals are of good health. Groups of fattened pigs with an extreme high rate of mortality and many abnormalities mean a potential risk for food safety. So for a risk-based meat inspection it is affordable to develop information-systems with real mortality and finding rates and the use of drugs on the farm.

[Proposals for designing the food chain information for the implementation of the risk-oriented ante- and post-mortem meat inspection]. / Vorschläge zur Gestaltung der Lebensmittelketteninformationen für die Umsetzung der risikoorientierten Schlachttier- und Fleischuntersuchung.

The recent crises in the meat industry due to meat-associated risks such as salmonella, nitrofen and dioxin prove that the traditional ante- and post mortem inspection of slaughter animals and carcasses is not any longer able to recognise and prevent the risks of today. Therefore, the EU Commission has issued Reg. (EC) 853/2004 and Reg. (EC) 854/2004 that regulate the transition of the traditional meat inspection, which demands inspecting each individual carcass in the same way, to a risk-based meat inspection, which is using relevant pieces of information about the previous production stages for making risk-based decisions on the intensity of the inspection of slaughter pig batches. The new EU legislation is not any longer prescribing exactly the inspection procedure, but defines the food safety goals. The consequence is that there are still various ideas and opinions on how to implement a reasonable risk-based meat inspection, and, in particular, on how to design the "relevant food chain information". The present paper is describing the legal framework and the objectives of the risk-based meat inspection, and proposals for designing the food chain information for the implementation of the risk-based ante- and post-mortem meat inspection are made and discussed.