Lesion profiles and gliosis in the brainstem of 135 Swiss cows with bovine spongiform encephalopathy (BSE)

Lesion profiles are considered to be an important tool for the comparison of the various animal and human spongiform encephalopathies and to obtain information upon prion strain variations. Histological and immunohistochemical reactions (PrPsc, GFAP) in 13 brain areas at 4 levels in the brainstem from 135 BSE-positive and 45 BSE-negative cases were retrospectively evaluated. In this retrospective study a lesion profile based on histological features was worked out on the basis of BSE cases originating from Switzerland over a period of ten years. They were confirmed post mortem by histology and immunohistology. Our findings were reviewed in comparison with lesion profiles published in England. No striking differences comparing type and quality of lesions in the relevant areas between the Swiss and the English cases were evident. Moreover, the lesion profiles and the character of the lesions did not differ between animals born before or after the offal feeding ban, which supports the hypothesis that the Swiss epidemic is sustained by the same single, stable strain of the BSE agent, which is probably the same as in the English epidemic.There was a good correlation between PrPsc accumulation and spongiform changes, in particular in those areas which were morphologically most affected. Astrocytosis in BSE was quantified. A significant rise in GFAP-positive cells could be shown comparing the brain stem nuclei of BSE affected with BSE-unaffected cattle, despite considerable variation between the cases and between the nuclei. The observed astrocytosis did correlate with vacuolation of the neuropil and of perikarya as well as with PrPsc accumulation.     

Anti-oxidative/oxidative status of rat liver after ovariectomy

The lack of protective action of oestrogens which appears during menopausal period may be the reason of serious metabolic disturbances including oxidative stress. The hypothesis was stated that ovariectomy may induce the variations of antioxidant/oxidant status which can be detected in rat liver. A total of 102 healthy Wistar female rats were included in the experiment and divided into control (CON; n = 6), sham-operated (SHO; n = 48) and ovariectomized (OVX; n = 48) groups. Animals from SHO (n = 6) and OVX (n = 6) groups were killed every week during 8 weeks of experiment to detect dynamic changes in examined parameters. Anti-oxidative enzyme activities [glutathione peroxidase (GSH-Px); superoxide dismutase (SOD)] as well as total antioxidant capacity (TAC) and the intensity of lipid peroxidation, measured by the concentration of N,N,diethyl-p-phenylene diamine (DEPPD) radical, were determined in liver homogenates by the use of spectrophotometric methods. Wave-like patterns of examined parameters within 8 weeks of experiment were detected. GSH-Px activity tended to be higher in OVX animals and was significantly lower at 8th week when compared with 1st week of experiment. SOD activity was higher in SHO animals and showed significant differences between 3rd, 4th, 7th and 1st week. TAC values were significantly higher in OVX when compared with SHO groups in 2nd, 4th, 5th week and significantly lower in 3rd, 6th and 7th week of the experiment. The concentration of DEPPD radicals tended to increase in OVX group. In conclusion, ovariectomy which leads to oestrogen insufficiency is reflected as well in variation of anti-oxidative/oxidative parameters in rat liver homogenates.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

Feeding corn milling byproducts to feedlot cattle.

Corn milling byproducts are expected to increase dramatically in supply as the ethanol industry expands. Distillers grains, corn gluten feed, or a combination of both byproducts offer many feeding options when included in feedlot rations. These byproduct feeds may effectively improve cattle performance and operation profitability. When these byproducts are fed in feedlot diets, adjustments to grain processing method and roughage level may improve cattle performance. Innovative storage methods for wet byproducts and the use of dried byproducts offer small operations flexibility when using byproducts. As new byproducts are developed by ethanol plants, they should be evaluated with performance data to determine their product-specific feeding values.     

Identification of putative adhesin genes in shigatoxigenic Escherichia coli isolated from different sources

Shiga toxin-producing Escherichia coli (STEC) is an important pathogen responsible for severe human intestinal and systemic infections. The bacterial factors required for colonization of the hosts are still not well defined. In this study, the prevalence of seven putative adhesive genes that are not encoded in the locus of enterocyte effacement (LEE) in 74 STEC strains isolated from humans (n=39), food (n=6), cattle (n=11), and pigs (n=18) was investigated by PCR. In addition, Shiga toxin (stx) and intimin (eaeA including alpha, beta, gamma, delta, epsilon, zeta variants) genes were tested. The most prevalent adhesin was that encoded by toxB gene (52 of 74 isolates; 70.3%). This marker was found in all 12 strains of O157:H7 serotype and in 23 of 32 (71.9%) isolates of the O157:NM serogroup. Moreover, this gene was also present in other 17 STEC of the non-O157 serogroup. The second most prevalent adhesin was that encoded by the lpfAO157/OI-154 gene (43 isolates; 58.1%). This marker was detected in LEE-positive strains of the O157 serogroup but also in 9 LEE-negative isolates of porcine origin. Several STEC isolates tested (42 strains; 56.7%) had the efa1 gene of the Efa1 putative adhesive marker. This adhesin was almost exclusively found among eaeA-positive strains recovered from humans, food and cattle. On the other hand, iha marker was detected either in LEE-positive (29 isolates) or LEE-negative (12 strains) STEC. Only two eaeA-negative strains had the saa putative adhesive gene. These results show that STEC strains may be able to express several putative adhesins. However, further studies are needed to evaluate the role of the genes identified in the present study in the pathogenesis of human infections.     

Relative sensitivity of polymerase chain reaction assays used for detection of feline herpesvirus type 1 DNA in clinical samples and commercial vaccines

OBJECTIVE: To determine relative detection rates and detection limits for 6 published polymerase chain reaction (PCR) assays used for detection of feline herpesvirus type 1 (FHV-1) DNA. SAMPLE POPULATION: 5 vaccines licensed for use in preventing FHV-1-associated disease; 15 conjunctival biopsy specimens collected from cats with keratitis, conjunctivitis, or both; and a plaque-purified field isolate of FHV-1 cultured in vitro. PROCEDURE: Vaccines and clinical samples were assessed for FHV-1 DNA by use of all 6 assays. Detection rates were calculated by assuming that any sample in which FHV-1 DNA was detected was a true-positive result. Detection limits were estimated by use of serial dilutions of DNA extracted from cultured FHV-1 and 1 clinical sample. RESULTS: Testing by use of all 6 assays resulted in detection of FHV-1 DNA in all 5 vaccines. Testing by use of all 6 assays yielded concordant results for 9 of 15 conjunctival biopsy specimens (8 with negative results and 1 with a positive result). Calculated detection rates for clinical samples ranged from 29% to 86%. Assay sensitivity was ranked similarly by use of detection rate or detection limit. CONCLUSIONS AND CLINICAL RELEVANCE: Testing by use of all assays was equally likely to detect vaccine virus. Therefore, a positive PCR result in a cat may reflect vaccine virus rather than wild-type virus. Test sensitivity as assessed by detection limits and detection rates varied greatly. Because FHV-1 can be shed in clinically normal animals, high detection rate will not necessarily correlate with high diagnostic sensitivity.