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Different Biotypes (different + biotype)
Selected AbstractsPhenotypical characteristics of Shiga-like toxin Escherichia coli isolated from sheep dairy productsLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2007I. Caro Abstract Aims: To analyse phenotypical characteristics of Shiga toxin-producing Escherichia coli (STEC) strains from ovine origin. Methods and Results: A total of 13 STEC strains (eight O157 and five non-O157) isolated from sheep dairy products were used in this study. Biochemical traits, motility, haemolytic activity, resistance to tellurite,cefixime, maximum growth temperature and antibiotic resistance were determined. The STEC strains were grouped into nine biochemical and physiological biotypes (five for the O157 and four for the non-O157 strains). All STEC strains showed resistance to bacitracin, cloxacilin, penicillin and tylosin. Conclusions: Different biotypes and antibiotic resistance patterns of STEC isolated from sheep dairy products were observed. Significance and Impact of the Study: This work will be a contribution to the better characterization of STEC isolated from sheep dairy products, which have, to date, been scarcely studied, and to the better understanding of the risks associated with its consumption. [source] Discrimination of Staphylococcus aureus biotypes by pulsed-field gel electrophoresis of DNA macro-restriction fragmentsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003J.A. Hennekinne Abstract Aims: To examine whether pulsed-field gel electrophoresis (PFGE) of DNA macro-restriction fragments could provide better discrimination among the different biotypes previously described within the species Staphylococcus aureus than the traditional biochemical approach. Methods and Results: Seventy three Staph. aureus strains from various sources (human, animal or food origin) and belonging to eight biotypes, including the poultry-like biotype, tentatively designated as an ,abattoir' biotype, were genotyped by PFGE after SmaI digestion of DNA. The PFGE patterns were compared using the average linkage matching method (UPGMA) with the Dice coefficient. A total of 61 PFGE patterns were observed, showing between 31 and 100% similarity. In most cases, strains with the same biotype were grouped specifically into one, two or three separate sub-clusters. Strains from the ,abattoir' biotype were clustered in one separate sub-cluster. Conclusions: The PFGE typing is useful to distinguish the traditional biotypes of Staph. aureus and has a more discriminatory power than the biochemical typing. Significance and Impact of the Study: The PFGE typing confirms the ,abattoir' biotype as a separate group on a genetic level and is well suited to investigate modes of staphylococcal contamination of food. [source] Relationship between saprotrophic growth in soil of different biotypes of Pochonia chlamydosporia and the infection of nematode eggsANNALS OF APPLIED BIOLOGY, Issue 1 2009I.A. Siddiqui Abstract The ecology of Pochonia chlamydosporia in soil and its interaction with both plant and nematode hosts are important for the successful exploitation of the fungus as a biological control agent. Differences in saprotrophism and parasitism were assessed for biotypes of P. chlamydosporia, which had originated from the eggs of cyst or root-knot nematodes. Colonisation in soils of different textures (compost, sandy loam and loamy sand) measured by the numbers of colony-forming units, differed greatly. Most biotypes were more abundant in sterilised soil of the different textures compared with non-sterilised soils. The proportion of nematode eggs parasitised in a baiting technique demonstrated that biotypes had host preferences. Those biotypes that originated from root-knot nematodes (RKN-biotypes) infected significantly more Meloidogyne hapla eggs than Globodera pallida eggs, whereas biotypes from cyst nematodes (CN-biotypes) parasitised more G. pallida eggs than M. hapla eggs. Differences in virulence between biotypes in an in vitro assay in which the fungi were placed directly onto the egg masses of M. hapla and those differences observed in the baiting technique showed similar trends. There was a negative linear correlation between the growth of the eight biotypes in soil and the proportion of eggs they infected in compatible interactions (i.e. fungal biotype originated from the same nematode genus as the target eggs). Those biotypes that infected most nematode eggs colonised soil the least extensively, suggesting that virulence may have a fitness cost. However, the relationship between saprotrophic growth and virulence is complex. The relative abundance of the different biotypes in soil in Petri dish assays was similar to that under glasshouse conditions using potato but not tomato as the plant host. Chlamydospores of some biotypes applied to soil significantly reduced (>50%) the population densities of M. hapla on tomato and of G. pallida on potato plants. Some biotypes that were both effective and virulent are good candidates for biological control of specific nematode pests. Data presented here and elsewhere indicate that RKN-biotypes have different host preferences to CN-biotypes; the specific primers based on the vcp1 gene from P. chlamydosporia rapidly confirmed the host origin of seven of the eight biotypes. [source] Molecular detection and identification of Rickettsia endosymbiont in different biotypes of Bemisia tabaciCLINICAL MICROBIOLOGY AND INFECTION, Issue 2009G. Gueguen No abstract is available for this article. [source] | ||||||||||