Protective effect of the AT137RQ and ARQK176 PrP alleles against classical scrapie in Sarda breed sheep     

Gabriele Vaccari  Gaia Scavia  Marcello Sala  Gianmario Cosseddu  Barbara Chiappini  Michela Conte  Elena Esposito  Raniero Lorenzetti  Gabriella Perfetti  Paola Marconi  Francesco Scholl  Katia Barbaro  Antonino Bella  Romolo Nonno    Umberto Agrimi 《Veterinary research》2009,40(3)

The susceptibility of sheep to scrapie is under the control of the host’s prion protein (PrP) gene and is also influenced by the strain of the agent. PrP polymorphisms at codons 136 (A/V), 154 (R/H) and 171 (Q/R/H) are the main determinants of susceptibility/resistance of sheep to classical scrapie. They are combined in four main variants of the wild-type ARQ allele: VRQ, AHQ, ARH and ARR. Breeding programmes have been undertaken on this basis in the European Union and the USA to increase the frequency of the resistant ARR allele in sheep populations. Herein, we report the results of a multi-flock study showing the protective effect of polymorphisms other than those at codons 136, 154 and 171 in Sarda breed sheep. All ARQ/ARQ affected sheep (n = 154) and 378 negative ARQ/ARQ controls from four scrapie outbreaks were submitted to sequencing of the PrP gene. The distribution of variations other than those at the standard three codons, between scrapie cases and negative controls, was statistically different in all flocks. In particular, the AT₁₃₇RQ and ARQK₁₇₆ alleles showed a clear protective effect. This is the first study demonstrating a protective influence of alleles other than ARR under field conditions. If further investigations in other sheep breeds and with other scrapie sources confirm these findings, the availability of various protective alleles in breeding programmes of sheep for scrapie resistance could be useful in breeds with a low frequency of the ARR allele and would allow maintaining a wider variability of the PrP gene.  相似文献   

Antibiotic resistance assessment in S. aureus strains isolated from raw sheep’s milk cheese     

Spanu  V.  Virdis  S.  Scarano  C.  Cossu  F.  De Santis  E. P. L.  Cosseddu  A. M. 《Veterinary research communications》2010,34(1):87-90

In vitro activities of 16 antibiotics were tested against 36 Staphylococcus aureus (SA) strains isolated from raw sheep’s milk cheese from six dairies. The minimum inhibitory concentration (MIC) was determined using a broth microdilution method (CLSI). All 36 isolates were analyzed for the presence of the accessory gene regulator gene, agr (I–IV), and genes encoding resistance to methicillin (mecA), erythromycin (ermA), penicillin (blaZ), and vancomycin (vanA-B). The isolates were also analyzed for similarities in pulsed-field gel electrophoresis (PFGE) patterns. SA strains showed resistance to ampicillin (36.1%), penicillin (33.3%), tetracycline (11.1%), and cloxacillin (2.8%) but were susceptible (≥94.4%) to 12 out of 16 tested antimicrobials. The overall susceptibility of the strains to oxacillin, vancomycin, and erythromycin was confirmed by the absence of the mecA, vanA-B, and ermA genes. The PFGE results showed that 32 strains belonged to 10 different clusters (P1–P10) while four strains were untypeable.  相似文献   

Multiplex PCR for the identification and serotyping of L. monocytogenes isolated from sheep cheese-processing plants     

De Santis EP  Pilo AL  Cosseddu AM  Canu NA  Scarano C  Marongiu P 《Veterinary research communications》2007,31(Z1):359-363

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The pattern of toxin genes and expression of diarrheal enterotoxins in Bacillus thuringiensis strains isolated from commercial bioinsecticides     

C. Scarano  S. Virdis  F. Cossu  R. Frongia  E. P. L. De Santis  A. M. Cosseddu 《Veterinary research communications》2009,33(Z1):257-260

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Characterization of Sarda sheep carcasses used in the processing of meat products     

Mazzette R  Meloni D  De Santis EP  Santercole V  Scarano C  Cosseddu AM 《Veterinary research communications》2005,29(Z2):335-338

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