Bovine CAPN1 maps to a region of BTA29 containing a quantitative trait locus for meat tenderness

Micromolar calcium activated neural protease (CAPN1) was investigated as a potential candidate gene for a quantitative trait locus (QTL) on BTA29 affecting meat tenderness. A 2,948-bp bovine cDNA containing the entire coding region of the gene was obtained, showing 91% identity to human CAPN1. The 716 AA protein predicted from this sequence shows 97% similarity (95% identity) to the 714 AA human protein. Analysis of the gene structure revealed that CAPN1 mRNA is encoded by at least 19 exons, and 11,055 bp of the gene were sequenced, including 17 introns. Two single nucleotide polymorphisms (SNP) were detected in intron 12 and were used to map bovine CAPN1 to the telomeric end of the BTA29 linkage group. This approximately coincides with the position of the QTL, demonstrating that CAPN1 protease is a positional candidate gene potentially affecting variation in meat tenderness in a bovine resource mapping population.     

Methods for checking up screening tests for detection of shiga toxin producing Escherichia coli (STEC) using PCR

Methods for making check ups of STEC-Screening-PCRs by using internal and external systems are given. A control-DNA with identical primer binding sites in relation to the target-DNA (stx-genes) was produced and by HPLC-chromatography quantified. It was used in an internal system. But we had to use too high concentrations of this DNA for making the check up in each sample. A false negative result could be shown in samples with a low stx content as a result of this coamplification process. Therefore we used an external system. A control-DNA with heterologous primer binding sites in relation to the stx-screening-PCR and the special primers were given in each vessel. The optimized system was used for making investigations of some faecal samples from cattle.     

New records of trypanorhynch cestodes from the Gulf of Mexico, including Kotorella pronosoma (Stossich, 1901) and Heteronybelinia palliata (Linton, 1924) comb. n

Four trypanorhynchs, Kotorella pronosoma (Stossich, 1901), Nybelinia cf. bisulcata (Linton, 1889), Nybelinia scoliodoni (Vijayalakshmi, Vijayalakshmi et Gangadharam, 1996), and Dasyrhynchus pacificus Robinson, 1965 are reported for the first time from the Gulf, which is now known to harbour at least 34 different species. In addition to the range extension for the trypanorhynchs listed above, 21 new host records are reported involving 13 cestode species. Characters of the genus Kotorella Euzet et Radujkovic, 1989 are emended, Nybelinia narinari MacCallum, 1917 is considered ajunior synonym of Kotorellapronosoma (Stossich, 1901), and Heteronybelinia palliata (Linton, 1924) comb. n. is redescribed. The usefulness of the bulb ratio as a means to distinguish different tentaculariid species is discussed, and the importance of shallow water localities for the life cycle of trypanorhynch cestodes is emphasised.     

Airborne Gram‐Negative Bacterial Flora in Animal Houses

The concentration and the species composition of airborne gram‐negative bacteria were studied in four cattle houses, one pig house and one poultry barn. On average only between 0.02 and 5.2 % of the total number of culturable aerobic bacteria were identified as gram‐negative bacteria. Obligate anaerobic gram‐negative bacteria were not isolated at all. In the airborne gram‐negative bacterial flora the following bacterial families dominated: the Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae. Within the family of the Enterobacteriaceae the species Escherichia coli and Enterobacter agglomerans were predominant. In animal houses using straw as bedding material Ent. agglomerans was most frequent, whereas in animal houses without litter E. coli was mainly found. Airborne Neisseriaceae were isolated very frequently in cow barns with Acinetobacter lowffii as the primary species. Airborne Pseudomonadaceae were found in high concentrations during periods of high air humidity. The results presented may also give some indications on the origin and sources of airborne endotoxins in animal housing.     

Effect of Ultraviolet Disinfection of Hydroponic Solutions on Pythium Root Rot and Non-target Bacteria

Dispersal of root pathogens is a major concern in closed hydroponic cultures. To limit dispersal, ultraviolet (UV) disinfection technology has been used to remove pathogens but its effect on non-target bacterial populations is largely unknown. In this study, the circulating solution was disinfected with various UV doses (i.e., 19, 38, 59, 88mJcm^–2) before recirculation. At the beginning of the experiment, the hydroponic solution was inoculated with Pythium aphanidermatum at 6.7±1.5CFUmL^–1. Four months later the population density of P. aphanidermatum reached 1030CFUmL^–1 in the control and 1028, 970, 610, and 521CFUmL^–1 in the solutions treated by the above UV doses. In all UV-treated solutions, significant (P<0.05) reduction of both Pythium and bacterial populations was noted. For the former, its reduction did not result in decrease of Pythium root rot nor increase of tomato fruit yield. For the latter, its reduction showed a concomitant decrease of the populations in the rhizosphere. The bacterial populations in the rhizosphere were 6.77×10⁹CFUmg^–1 fresh roots at the beginning of the experiment and were 7.89×10⁸, 9.93×10⁷, 7.33×10⁷, and 3.51×10⁷CFUmg^–1 fresh roots at the end of the experiment in the control, UV38, UV59, and UV88 treatments, respectively. The bacterial density also decreased with time in the control (UV0) although at a low rate. The results suggest that the attempt to control Pythium root rot by UV irradiation of recirculating solutions to remove P. aphanidermatum also affects the non-target bacterial populations in the rhizosphere. The interaction between the target pathogen and non-target bacterial flora in UV-treated hydroponics needs further investigation.