The atypical isolates of Aeromonas salmonicida are becoming increasingly important as the frequency of isolation of bacteria belonging to this group continues to rise. The primary object of this ...study was to compare and evaluate the results obtained in various laboratories concerning the biochemical identification of atypical Aer. salmonicida before and after standardization of media and methods. Five laboratories examined 25 isolates of Aer. salmonicida from diverse fish species and geographical locations including the reference strains of Aer. salmonicida subsp. salmonicida (NCMB 1102) and Aer. salmonicida subsp. achromogenes (NCMB 1110). Without standardization of the methods, 100% agreement was obtained only for two tests: motility and ornithine decarboxylase. The main reason for the discrepancies found was the variation of the incubation time prior to reading the biochemical reactions. After standardization, improvement was obtained with the identification; however, disagreement was still observed between the different laboratories. These findings demonstrate the difficulties involved in a proper identification of atypical Aer. salmonicida and also that data presented in the literature on various strains of Aer. salmonicida are not readily comparable. This paper seems to be the first on standardization of microbiological tests for identification of fish pathogens and the results obtained show the need for standardization of methods both within and between laboratories.
Reference strains and 31 clinical isolates of M. paratuberculosis, mainly from goats, were analysed for restriction fragment length polymorphism (RFLP). Restriction digests of bacterial DNA were ...hybridized with a repetitive insertion sequence, IS900, to obtain banding patterns for comparison of strains. Twenty-five of the 31 field-strains hybridized with IS900, and five hybridization patterns were identified. It was not possible to identify specific patterns for goat strains of M. paratuberculosis. Four hybridization patterns were similar, whereas the fifth pattern of a sheep strain diverged considerably in position and number of bands. Six goat strains failed to hybridize with IS900, and the absence of IS900 was verified by the polymerase chain reaction and hybridization with an oligonucleotide probe. The six IS900-negative goat strains had diverging phenotypic properties, and the identification of these strains is discussed. The present study shows that M. paratuberculosis strains infecting goats are genetically similar to cattle strains and that IS900 is a specific genetic element for identification of M. paratuberculosis.
Results on the production of 4He and ▪ nuclei in Pb–Pb collisions at sNN=2.76TeV in the rapidity range |y|<1, using the ALICE detector, are presented in this paper. The rapidity densities ...corresponding to 0–10% central events are found to be dN/dyHe4=(0.8±0.4(stat)±0.3(syst))×10−6 and ▪, respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (Tchem=156MeV) as for light hadrons. The measured ratio of ▪ is 1.4±0.8(stat)±0.5(syst).
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