Molecular systematics support the revival of Mycobacterium salmoniphilum (ex Ross 1960) sp. nov., nom. rev., a species closely related to Mycobacterium chelonae Mycobacterial infections in fish are usually attributed to strains of Mycobacterium marinum, Mycobacterium chelonae and Mycobacterium fortuitum. Bacteria identified as M. chelonae have been isolated numerous times from salmonid fishes. Recently, this bacterium has been associated with salmon mortalities in the aquaculture industry. An M. chelonae-like species from salmon, 'Mycobacterium salmoniphilum', was described in 1960. However, the species name lost standing in nomenclature when it was omitted from the 1980 Approved Lists of Bacterial Names because the species could not be distinguished with confidence from M. fortuitum. In the 1980s, mycobacteria isolated from salmon were characterized as a distinct subspecies, 'Mycobacterium chelonae subsp. piscarium'. Again, the uncertainty of the validity of the species resulted in the subsequent withdrawal of the name. Since then, most studies have considered isolates from salmon to be M. chelonae. Nucleotide sequence analysis of the small-subunit rRNA, hsp65 and rpoB genes was used to examine the taxonomic relatedness of type cultures and authentic isolates in our culture collection available from earlier studies. The M. chelonae-like strains from salmon were phylogenetically distinct from other Mycobacterium strains and members of the M. chelonae complex. Moreover, the cell-wall-bound mycolic acids were not representative of known mycolate patterns for M. chelonae-complex organisms. These results supported the status of the species as a separate taxon and effect the valid publication of the name 'M. salmoniphilum' as Mycobacterium salmoniphilum (ex Ross 1960) sp. nov., nom. rev., with the type strain SC T (5ATCC 13578 T 5DSM 43276 T).

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This study showed the emergence of MRSA with SCCmec type III and with spa types t12311, t10740, t1234, t1991, and t2651 with different phenotypic and genotypic antimicrobial resistance in the west of Iran. We found different SCCmec and spa types distributed among nosocomial and non-nosocomial MRSA in the west of Iran.

Traditional identification of mycobacteria based on cultural and biochemical tests can take several weeks and may fail to provide a precise identification. Polymerase Chain Reactionrestriction analysis (PRA) of the gene encoding heat shock protein 65 kDa (hsp65) gene has been proposed as a rapid and inexpensive alternative approach. Despite being widely used for differentiation of mammalian mycobacteria, this method has only been applied in the identification of a small number of aquatic mycobacteria. The present study aimed to evaluate the potential use of PRA of hsp65 for the identification of aquatic mycobacteria compared with sequence analysis. Seventy one mycobacterial isolates including, 10 type/ reference strains and the remainder field isolates, were subjected to PRA of a 441 bp fragment of this gene. For 68 representative isolates, sequence analysis was performed. All rapidly and slowly growing mycobacteria had best matches with 99.3% to 100% similarity with their corresponding species in the databanks.PRA proved to be a simple and rapid method for identifying aquatic mycobacteria.However, the incidence of similar or identical restriction patterns for some species of mycobacteria, and in particular, identification of new species of mycobacteria is a major problem using such a method. In contrast, the nucleic acid sequencing of the hsp65 gene yielded unambiguous results. Mycobacteriosis (fish tuberculosis) is a progressive disease of a wide range of wild and captive marine and freshwater fish species (Chinabut, 1999). The zoonotic nature of the organism, the massive economical losses which have occurred to the aquaculture industry due to this disease and the lack of effective treatment highlight the need for mycobacteria to be rapidly detected and identified to species level. IntroductionTraditional identification of mycobacteria based on cultural and biochemical tests may take several weeks, and sometimes even then fail to provide a precise identification. In addition, the procedures of these tests are time consuming and complicated. Therefore, various molecular based methods have been developed for the rapid detection and identification of mycobacteria species. There are currently several commercially available methods, including the AccuProbe system (Genprobe, San Diego, Calif), INNO-LiPA (Innogenetics, Ghent, Belgium), or GenoType Mycobacterium assay (Hain, Lifescience, Germany). Although such tests provide desirable sensitivity and specificity, they are limited to the identification of a small number of mycobacteria. Among other molecular methods, Polymerase Chain Reaction (PCR) -RestrictionEnzyme Analysis (PRA), and sequence analysis have been applied to several mycobacteria genes. In this regard, PCR of the 441 bp of heat shock protein 65 kD gene (hsp65), followed by restriction fragment pattern analysis by BstEII and HaeIII enzymes proposed by Telenti et al. (1993), has provided a rapid method for identifying mycobacteria and closely related species (Brunello et al., 2001; Devallois et ...