Identification

Identification by genotypic methods is particularly valuable for organisms such as Actinomyces spp., which are poorly differentiated in conventional biochemical or serological tests. Species-specific oligonucleotide probes targeting ribosomal DNA have been developed both for identification of cultivars and for direct detection, but their value has been limited by the high degrees of intraspecies genetic diversity occurring within Actinomy-ces spp.[2,8] Conversely, amplified rDNA restriction analysis [ARDRA or polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP)] has proved to be a highly discriminatory, practical, and cost-effective method for differentiation of Actinomyces and other facultatively anaerobic gram-positive bacilli to the species or subspecies levels. In two small studies, the restriction endonuclease MnlI was recommended.[9,10] However, in studies of over 600 clinical and some veterinary isolates, banding patterns obtained from separate digestions by HaeIII and HpaII were ana-lyzed.[11,12] Neither enzyme alone was sufficiently discriminatory, but, in combination, differentiated all currently recognized Actinomyces, Arcanobacterium, and Actinobaculum spp., some to subspecies level, and many Propionibacterium, Lactobacillus, Bifidobacterium, Gardnerella, Mobiluncus, and Eubacterium spp. Results correlated well with those obtained by conventional methods, but the latter lacked discrimination. Several recently described species (e.g., A. funkei, A. urogenita-lis) were recognized as being distinct from existing species prior to their formal description by other workers, and a number of novel species, including A. cardiffensis, were detected. This method is now used routinely at the Anaerobe Reference Laboratory of the National Public Health Service for Wales for identification of nonsporing gram-positive bacilli referred from throughout the UK. Unfortunately, although only basic molecular expertise and equipment are necessary to perform this method, it remains impractical for use in the clinical laboratory for identification of occasional isolates.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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