No abstract

The results of the present study emphasize the need for pre- experimental examination of rats. They also show that diet and bedding conditions have the potential of seriously influencing outcomes of studies of periodontal disease in rats.

Aim: A novel automated serial dried blood spot (DBS) sampler, ‘Fluispotter’, was tested for its sampling performance. Materials & methods: An LC–MS/MS method was developed for the analysis of cortisol in DBS samples serially spotted by Fluispotter. The cortisol concentrations in 148 paired DBS and plasma samples were compared across a hematocrit (HCT) range of 22–55%. Results: The interassay accuracy and precision were <10%. Overall assay bias was negligible across the HCTs tested when analyzing the whole-spot DBS samples. The accuracy and precision of the blood volume in 10 μl DBS samples spotted by Fluispotters and micropipettes were within 3%. Deming regression and Bland-Altman analysis showed a good agreement of DBS-predicted and measured plasma cortisol. Conclusion: The Fluispotter performed serial sampling with high accuracy and precision of the sample blood volume.

SummaryAntiobiogrammes were made of a number of isolates of Staphylococcus aureus, Escherichia coli and Pasteurella pneumotropica derived from rodent, rabbit or minipig colonies never treated with antibiotics. For S. aureus no differences between rats and mice were found in the percentage of resistant isolates. Gentamicin and erythromycin were found to be the most efficient, while the highest percentages of resistance were found to be against penicillins and sulphonamides. In general, the results from antibiogrammes on E. coli were rather uniform, with only slight differences between isolates from different species, except that more vancomycin and tetracycline-resistant minipig isolates were found. In almost all isolates of E. coli, resistance was shown against penicillin, fucidin, macrolides, lincosamides and tiamulin. For a number of antibiotics, mouse isolates of P. pneumotropica were more frequently found to be sensitive than rat isolates. The resistance patterns of E. coli from the minipigs were quite similar to resistance patterns found in farm pigs, but apart from this, the resistance patterns of the bacterial species tested did not resemble human or farm animal patterns in any of the animal species, and, therefore, these studies do not support the theory that S. aureus and E. coli in laboratory animal colonies derive from the normal flora of the human caretakers. The fact that rodent species of E. coli, in contrast to human and farm animal species, are sensitive to ampicillin, tetracyclines, and the combination of sulphonamides and trimethoprim, might be due to the fact that these antibiotics are not used in rodent populations.