Impact of invA-PCR and culture detection methods on occurrence and survival of salmonella in the flesh, internal organs and lymphoid tissues of experimentally infected pigs

This study evaluated the suitability of invA gene amplification by PCR as an effective means of detecting Salmonella species in pigs experimentally infected with S. Typhimurium DT104. A controlled infection study using 24 pigs was performed in order to compare efficacy, precision and detection rates of the invA-based PCR method originally described by Rahn, K. De Grandis, S.A., Clarke, R.C., McEwan, S.A., Galan, J.E., Ginocchio, C., Curtiss, R. 3rd, C.L. Gyles, (Mol. Cell. Probes 1992; 6: 271-279) as a new in-house invA-based PCR method for the specific detection of Salmonella spp. in pork and different tissue samples of slaughter pigs. Finally, PCR results were compared with culture detection rates obtained by isolation procedures following the ISO 6579:2000, the 'gold standard'. After slaughtering, 14 different tissue samples of each pig were investigated to verify the usefulness of the two invA-based PCR methods in different matrices of slaughter pigs. The results demonstrate that the application of the widely used invA-based primer pair (139 + 141) may result in questionable products if samples gained from selective enrichment in the Rappaport-Vassiliadis medium were investigated. These questionable products can lead to false-positive results, if no additional hybridization procedure is attached or if unspecialized persons use this method in routine laboratory practice. The newly developed in-house PCR method used is based on the 3'-prime region of invA, especially designed and harmonized for the detection of Salmonella in different matrices of slaughtered pigs after bacterial enriched broth culture. In this study, this PCR revealed no questionable products and, furthermore, the specificity of the amplificate could be tested by means of the restriction enzyme NdeI. In comparison with the culture detection procedure, the new PCR method has a sensitivity of 100% and a specificity of 96%. Thus, this method might be used as a meaningful tool in eliminating Salmonella-positive carcasses at slaughterhouse level and thus, keeping them out of the food chain.     

Shedding consistency of strongyle-type eggs in Dutch boarding horses

Faeces of 484 horses were sampled twice with an interval of 6 weeks while anthelmintic therapy was halted. Faecal eggs counts revealed that 267 (55.2%) horses had consistently low numbers of eggs per gram faeces (EPG) (EPG < 100 or = 100), 155 (32.0%) horses had consistently high EPGs (EPG > 100). Horses with consistently high EPGs were more often mares with access to pasture, aged less than 6 or more than 23 years, that were dewormed at intervals longer than 6 months, and were treated for the last time more than 3 months before the start of the study. Horses with consistently low EPGs were more often male horses with no or limited access to pasture, that were dewormed at maximally 6-month intervals, and were aged between 6 and 23 years. The results are an indication that some horses have consistently low EPGs and perhaps could be used as non-treated animals in a selective anthelmintic treatment scheme aimed at the prevention of the development of anthelmintic resistance.     

Immunohistochemical demonstration of Leu-7 (HNK-1), Neurone-specific Enolase (NSE) and Protein-Gene Peptide (PGP) 9.5 in the developing camel (Camelus dromedarius) heart

The development of the heart-conducting system has been controversially discussed. The common opinion that these specialized myocytes originate from mesodermal precursors has been challenged when nerve-specific antigens (Leu-7, NF, GIN2) were demonstrated in embryonic hearts of various species, suggesting a neural crest contribution to the embryonic conducting tissue. Anti-Leu-7 (HNK-1) antibodies were reported to reliably mark the conducting system in developing rat, chicken and human hearts. The present investigation was carried out on the hearts of 15 camel fetuses at 35, 45, 60, 75 and 100 cm crown-rump length (three specimens for each stage), in addition to three adult hearts. We investigated the antigenicity of cardiac structures for Leu-7, NSE (Neurone specific Enolase) and PGP (Protein Gene Peptide) 9.5. In all specimens investigated, both NSE and PGP 9.5 were expressed by cardiac nerves and conducting system components. The sinuatrial and atrioventricular nodes, the atrioventricular bundle as well as subendocardial and intramyocardial Purkinje fibers were stained. In contrast, the developing conducting system did not react with anti-Leu-7 antibody, although Leu-7 antigenicity was strongly expressed by the developing cardiac nerves. In adult camel hearts, the same pattern of immunoreactivity for the markers studied was still retained. Our results show that the expression of marker proteins for the developing conducting system is species-specific. Therefore, these markers are of little significance in discussions on the possible neurogenic nature of the heart conducting tissue.     

Legal consideration of permit issuance under Article 11 par. 1 no. 3 letter(d) of the German Animal Welfare Act

The article looks at the legal situation concerning the permission for commercial activities with animals due to Article 11 par. 1 no.3 (d) of the German Animal Welfare Act, in particular in combination with activities at changing places. Regardingly the German legislator has recently (especially since 1998) started to approach the problems of animal welfare by adopting specific regulations, e. g. by enacting an obligation to inform the authority of the planned change of place of activity. Currently the legislator discusses an extension of the enabling act for an ordinance by the Federal Government on the central register for circusses. Standardized data collection and transmission shall contribute to an effective control of the companies' compliance with animal welfare law. Article 11 par. 2a of the German Animal Welfare Act is an important regulation concerning activities at changing places. It allows to combine the permission with time limits, conditions and impositions of duties. Such collateral clauses can be set down to keep an animal stock book or--in a wider sense--a documentation of the company's activities to guarantee an effective control by the authority. In the case of American rodeo shows it is to mention that collateral clauses to introduce more animal welfare are imposed by the local authorities responsible for the area where the shows will take place rather than by the authority which actually has given the permission. The authorities have to distinguish subsequent collateral clauses or directives on one hand and the revocation of the permission on the other hand, since in this case the requirements are more strict. The recent preliminary judicial decisions of the administrative courts concerning this legal problem are contradictory so that they cannot serve as a guideline for the authorities.     

Horses' behavior and heart rate in a preference test for shorter and longer riding bouts

A Y-maze preference test was used to investigate whether horses prefer a shorter riding treatment over a longer riding treatment. In a pilot study (n = 4 horses), the maze was positioned with the 2 arms each pointing toward one of the short sides of the indoor arena, and in the main study (n = 14), the maze was rotated by 90°. Horses were 11 ± 4.4 years old and ridden regularly for at least 5 times/wk. They were conditioned to associate 1 exit of the maze with 1 lap of riding (R1), covering a distance of approximately 40 m at the walk or trot according to a predetermined schedule, and the other exit with 2 such laps (R2). Immediately afterward, riders dismounted, horses were led into the maze, and horses were let loose to make their choice in the maze. After exiting the maze, the rider mounted again and rode according to the chosen treatment. This procedure was repeated on the same day until statistical significance (P < 0.05) of preference was reached or up to a maximum of 35 trials. In addition, behavioral observations and heart rates were recorded. In the pilot study, all horses, regardless of the associated treatment, chose the left arm, which, unfortunately, pointed toward the arena's exit door. If horses were not caught immediately after exiting the maze (n = 5 occasions), they walked or trotted straight to the door. In the main study, 4 horses significantly preferred R1, 2 horses significantly preferred R2, and 8 horses had no significant preference. Heart rates were significantly (P < 0.05) higher during R2 (87.4 ± 2.6 bpm) than during R1 (79.5 ± 2.4 bpm). Except for tail swishing, no significant differences were found for the frequency of occurrence of behavior patterns between R1 and R2. Over the course of repeated trials, some horses became increasingly reluctant to enter and walk through the maze, and most showed increasing resistance to being remounted (e.g., sidestepping). Overall, the experimental setup did not seem to be appropriate to answer the research question. It is likely that the repeated mounting and dismounting caused discomfort or confused many of the horses to an extent that they did not actively select a treatment but rather searched for ways to evade further mounting (and riding). In conclusion, horses did not show a clear preference for either shorter or longer riding bouts, but their behavioral reactions indicate that they perceived mounting as uncomfortable and that their motivation to rejoin their herd-mates and/or to obtain feed in the barn was greater than their motivation to being ridden at all. Nevertheless, pronounced individual differences also seem to exist, with some horses showing little aversion to, and perhaps enjoyment of, being ridden, whereas others clearly preferring not to be ridden.     

Babesia canis canis in dogs from Hungary: detection by PCR and sequencing

Canine babesiosis in Hungary has always been a severe and frequent disease, attributed to infection with Babesia canis transmitted by Dermacentor reticulatus. Identification of the disease agent has been based merely on size and morphology of the intraerythrocytic parasites and no evidence has been found concerning the subspecies (genotype) of B. canis. Therefore, a molecular survey on natural Babesia infection of dogs in Hungary using PCR and sequence analysis was attempted to clarify the subspecies (genotype) and to obtain information on the occurrence of B. canis. A total of 44 blood samples from dogs showing clinical signs of babesiosis were collected. A piroplasm-specific PCR amplifying the partial 18S rRNA gene yielded an approximately 450 bp PCR product in 39 (88.6%) samples. Thirteen positive samples originated from Budapest and 26 from 21 other locations. Five PCR products were chosen randomly for sequencing. The partial 18S rDNA sequences were submitted to GenBank (accession numbers AY611729; AY611730; AY611731; AY611732 and AY611733). The sequences showed 100% homology to one another or differed by one nucleotide. BLAST search against GenBank revealed the highest similarity (99.8 or 100%) with Babesia canis canis. The implication of these data, for the further study and diagnosis of canine babesiosis is discussed.     

Outbreak of Mycobacterium tuberculosis infection among captive Asian elephants in a Swedish zoo

Between 2001 and 2003, there was an outbreak of tuberculosis in a Swedish zoo which involved elephants, giraffes, rhinoceroses and buffaloes. Cultures of trunk lavages were used to detect infected elephants, tuberculin testing was used in the giraffes and buffaloes, and tracheal lavage and tuberculin testing were used in the rhinoceroses. The bacteria isolated were investigated by spoligotyping and restriction fragment length polymorphism. Five elephants and one giraffe were found to have been infected by four different strains of Mycobacterium tuberculosis.