Multilocus sequence analysis reveals extensive genetic variety within Tenacibaculum spp. associated with ulcers in sea-farmed fish in Norway. | LitMetric
Skin ulcer development in sea-reared salmonids, commonly associated with Tenacibaculum spp., is a significant fish welfare- and economical problem in Norwegian aquaculture. A collection of 89 Tenacibaculum isolates was subjected to multilocus sequence analysis (MLSA). The isolates were retrieved from outbreaks of clinical disease in farms spread along the Norwegian coast line from seven different fish species over a period of 19 years. MLSA analysis reveals considerable genetic diversity, but allows identification of four main clades. One clade encompasses isolates belonging to the species T. dicentrarchi, whereas three clades encompass bacteria that likely represent novel, as yet undescribed species. The study identified T. maritimum in lumpsucker, T. ovolyticum in halibut, and has extended the host and geographic range for T. soleae, isolated from wrasse. The overall lack of clonality and host specificity, with some indication of geographical range restriction argue for local epidemics involving multiple strains. The diversity of Tenacibaculum isolates from fish displaying ulcerative disease may complicate vaccine development.
Objective: To investigate the molecular typing characteristics, drug resistance status and drug resistance gene carrying of food-borne Staphylococcus aureus in Ningxia.
Methods: Staphylococcus aureus isolated from food safety risk monitoring project in Ningxia in the past ten years were collected, drug resistance was detected using microbroth dilution method, enterotoxins were detected by real-time PCR. The strains were genotyped by pulsed field gel electrophoresis(PFGE) using SmaI endonuclease.
Background: Infection with Chlamydia trachomatis (CT) can have distinct clinical presentations, such as trachoma, or lymphogranuloma venereum (LGV). Certain populations are at greater risk for LGV acquisition and transmission, which requires a longer duration of therapy than other urogenital CT sexually transmitted infections (STIs). Commercial assays are not available in the United States to distinguish LGV from non-LGV serovars.
is a species-rich and cosmopolitan fungal family including species of plant pathogens, endophytes or saprobes, and parasites of humans and animals. The taxonomy of has recently been revised using a polyphasic approach. However, much remains unknown about the diversity of species and their host associations.
More than 2 000 yeast strains isolated from 1 200 samples mostly collected from Tibet and Yunnan provinces in China were identified as 462 species according to the internal transcribed spacer including the 5.8S rDNA (ITS) and the D1/D2 domains of the large subunit rDNA (LSU) sequence analyses. Among them, 70 new basidiomycetous yeast species were proposed based on the multi-locus phylogenetic analyses including the D1/D2 domains, the ITS, the small subunit rDNA (SSU), the largest subunit of RNA polymerase II (), the second largest subunit of RNA polymerase II () and translation elongation factor 1-α (), as well as the phenotypic comparisons.
The application of traditional morphological and ecological species concepts to closely related, asexual fungal taxa is challenging due to the lack of distinctive morphological characters and frequent cosmopolitan and plurivorous behaviour. As a result, multilocus sequence analysis (MLSA) has become a powerful and widely used tool to recognise and delimit independent evolutionary lineages (IEL) in fungi. However, MLSA can mask discordances in individual gene trees and lead to misinterpretation of speciation events.
