Assessment of a new selective chromogenic Bacillus cereus group plating medium and use of enterobacterial autoinducer of growth for cultural identification of Bacillus species.

A new chromogenic Bacillus cereus group plating medium permits differentiation of pathogenic Bacillus species by colony morphology and color. Probiotic B. cereus mutants were distinguished from wild-type strains by their susceptibilities to penicillin G or cefazolin. The enterobacterial autoinducer increased the sensitivity and the speed of enrichment of B. cereus and B. anthracis spores in serum-supplemented minimal salts medium (based on the standard American Petroleum Institute medium) and buffered peptone water.

Enumeration of probiotic bacilli spores in animal feed: interlaboratory study.

Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80 degrees C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (10(9) colony-forming units [CFU]/g) and low (10(5) CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the repeatability relative standard deviation (RSD(r)) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSD(r) values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.

[Not Available]. / Untersuchung von Weizen sächsischer Herkunft auf Fusarien und die Toxine Deoxynivalenol (DON) und Zearalenon (ZEA).

98 wheet samples harvested in 1998 from three different experimental plots in saxony where investigated on the species of fusarium and the mycotoxins DON, ZEA and nivalenol (NIV). Analysis of DON was done by fast-Elisa-test and HPLC-MS. There was a good correlation between the two methods but a tendency of higher values determined by Elisa. NIV was also determined by HPLC-MS and ZEA by HPLC-fluorescence.

[The effect of a Bordetella live vaccine on the occurrence and manifestation of atrophic rhinitis suum and the aerogenous infection burden in field strains of the agent]. / Untersuchungen zum Einfluss eines Bordetellen-Lebendimpfstoffes auf das Auftreten und die Ausprägung der Rhinitis atrophicans suum sowie den aerogenen Infektionsdruck durch Feldstämme des Erregers.

A field study was carried out in a large scale unit for swine breeding and fattening with the object to influence the high morbidity rate of Atrophic Rhinitis and pneumonia with the help of a Bordetella live vaccine. The results show that it is possible to decrease the infectious pressure by B. bronchiseptica and to reduce the pathomorphological signs of Atrophic Rhinitis in consequence of the application of the live vaccine. The pathologic-anatomical investigations of nasal turbinates in immunized slaughtered fattening pigs show a significant lower morbidity concerning Atrophic Rhinitis and a higher percentage of pigs without changes at conchae nasales and septum nasi. We find also a lower contamination of the air with B. bronchiseptica field strains during vaccine application. The results also explain that a high infectious pressure by B. bronchiseptica and the possibility of communication between unvaccinated and vaccinated groups of pigs counteract a better efficiency of the vaccine. The decrease of the morbidity rate of Atrophic Rhinitis appears so much more important because toxicogenic Pasteurella multocida strains were isolated from nasal swabs of vaccinated pigs during the investigations. But these strains influenced the Atrophic Rhinitis frequency only accidentally. All results as a whole point out that in pig houses with a high animal density one has to pay more attention to virulent B. bronchiseptica strains than it was been done till now.