Contents page of the issue July 2007




POULTRY
É. Ivanics, Á. Bálint, N. Pálmai, L. Márton, Á. Dán, K. Ursu, L. Szeredi, Z. Deim, D. Rigó, L. Tekes, P. Zarka, Eöné Nagy, M. Dobos-Kovács, R. Glávits: Diseases in Hungarian goose and duck flocks caused by highly pathogenic avian influenza strain (H5N1 subtype) / 387 Full text article

BOVINE
L. Könyves, V. Jurkovich, A. Tirián, Lné Tegzes, H. Fébel, J. Kutasi, E. Brydl: Comparative examination of the biological effects of Saccharomyces cerevisiae yeast cultures in dairy cows / 400

SMALL ANIMALS
A. Bánfi, K. Fodor, Á. Maróti-Agóts, Z. Diószegi: Hip dysplasia in dogs. 2. Clinics, evaluation, screening and prevention / 410
A. Neuber, Ch Horvath.: Shampoo therapy in veterinary dermatology / 418
M. Raue, R. Johne, M. März, R. Raue, H. Müller: Papillomavirus infections in dogs – review / 423

BACTERIOLOGY
A. Imre, A. Szmolka, F. Olasz, B. Nagy: The role of serovar specific plasmids in the virulence of Salmonella strains / 428

JUBILEE
For the 80th birthday of György Poth (J. Tóth) / 441

EVENTS
16th Köves-days (Hajdúszoboszló, 3-4th May 2007) (L. Visnyei) / 442

VETERINARY HISTORY
Janos Koves, establisher of the of Hungarian vaccine production was born 125 years ago (I. Kótai) / 443
Newer veterinary history memorial place, Kulcs in Fejér county (K. Oberrecht) / 445

L. Könyves – V. Jurkovich – A. Tirián – Lné Tegzes – H. Fébel – J. Kutasi – E. Brydl:
COMPARATIVE EXAMINATION OF THE BIOLOGICAL EFFECTS OF SACCHAROMYCES CEREVISIAE YEAST CULTURES IN DAIRY COWS

The aim of the study was to measure the effect of different strains of live and viable Saccharomyces cerevisiae yeast cultures (Sc) with different dosage on rumen fermentation, metabolic status, and milk production in dairy cows. Holstein-Frisian cows in early lactation were randomly assigned to 5 groups of 25 cows and fed daily rations that contained Sc as follows: Group K: control, not treated; A: 20 g (2.1x1010CFU/g) Sc; B: 5 g (1.7x1010CFU/g) Sc; C: 5 g (2.5x1010CFU/g) Sc; D:10 g (4x107CFU/g) Sc daily. In each group 12 cows were randomly selected for monitoring the metabolic status and parameters of rumen fermentation. Milk yield and milk quality indices were measured by the Hungarian Milk Recording Ltd on monthly basis with 25 cows/group. Blood, urine and rumen fluid samples were taken monthly, 3–5 hours after morning feeding; at the beginning of the experiment and once a month onward until 90th day of the experiment. Parameters of energy metabolism (blood aceto-acetic acid, NEFA, glucose), protein supply (blood and urine urea, blood total protein), acid-base metabolism (urine and rumen pH, urine NABE) and volatile fatty acid (VFA) concentration (rumen fluid total volatile fatty acid, acetate, propionate, butyrate) was determined.
At first sampling that preceeded the start of the 90 day period of feeding the experimental diet no differences were found between parameters of the control and experimental groups. There was, however, significant (P<0.001) increase in rumen pH, acetate molar ratio, acetate:propionate ratio and a decrease in the propionate and butirate molar ratio and total VFA concentration in group C and D but not in others in later phase of the investigation. There was no significant and remarkable difference in metabolic parameters during the experimental period, but there was significant (P<0.01) increase in body condition scores in treated cows. Significant (P<0.05) increase was detected in milk protein percentage in all treatment groups, but not in the control. There was no significant difference in butter fat percentage between the groups. The milk yield (4% FCM milk kg) was higher in the treated animals, compared to control, but the difference was significant (P<0.01) only in case of group D.

A. Bánfi – K. Fodor – Á. Maróti-Agóts – Z. Diószegi:
HIP DYSPLASIA IN DOGS. 2. CLINICS, EVALUATION, SCREENING AND PREVENTION

In the first part of the article the authors summarise the genetic background and the effects of environmental factors in hip dysplasia (HD) and the rearing of breeds the most affected by hip dysplasia. In the second part they present the pathogenesis of HD, examination process, making and evaluating X-ray pictures and screening. Because of hereditary nature of HD, the only way of prevention is the consequent selection, animals affected by HD must not be bred. There are drugs and surgical methods available for their treatment.

A. Imre – A. Szmolka – F. Olasz – B. Nagy:
THE ROLE OF SEROVAR SPECIFIC PLASMID IN VIRULENCE OF SALMONELLA

In the first steps of Salmonella pathogenesis (cell invasion, survival in macrophages) beside the role of several chromosomal virulence gene clusters, an important role is also assigned to the serovar specific plasmids. This paper intends to review these serovar specific virulence plasmids and their genes, based on the available literature and on the authors’ own experience.
First, it should be known that these large (50–90 kb) virulence plasmids are characteristic only to some serovars (S. Typhimurium, S. Enteritidis, S. Gallinarum, and S. Dublin), while other serovars (S. Hadar, S. Infantis) may also possess plasmids of similar size but without known virulence genes. The common trait of Salmonella virulence plasmids (spv) is the presence of the „virulence region” encoding the spvRABC genes, which may play an important role in the propagation and survival of Salmonella in the parenchymal organs and in the reticuloendothelial system of the host. A further virulence linked group of genes is called „plasmid encoded fimbriae” (pef) operon most likely playing a role in the intestinal adhesion and host specificity. Another gene governs the resistance to complement killing (rck), and is, therefore responsible for bacterial survival in the serum, due to the outer membrane protein encoded by gene. Finally, antibiotic resistance may occasionally be encoded by genes of psv providing further selection advantage to the bacteria.
Due to the wide scale use of live attenuated vaccines against salmonellosis of poultry (and swine), the serovar specific virulence plasmids are receiving increased attention as undesired components of the vaccine strains. With this in mind, the authors performed experiments on removal of the virulence plasmid of a S. Enteritidis strain. The first trials using ethidium bromide treatment have failed, but a transposon based elimination system newly, established by them has been successful. Results of the in vitro (cultured cell) and in vivo (day old chick) infection experiments indicated that the virulence traits of the plasmidless mutants of S. Enteritidis and of a S. Typhimurium strain have only been slightly reduced. These results are concordant with the fact that some wide spread Salmonella serovars are existing without the virulence plasmid. Based on the literature data and on the experimental results produced here, it can be concluded that the role of serovar specific plasmids should be more cautiously assessed in the future and this estimation should be strictly related to the strain tested and to the used model system.