Phenotypic and genotypic analysis of <i>Flavobacterium psychrophilum</i> isolates from Ontario salmonids with bacterial coldwater disease

Hesami, Shohreh; Allen, Katie J. AllenK.J.; Metcalf, Devon MetcalfD.; Ostland, V. E.; MacInnes, Janet I.; Lumsden, John S.

doi:10.1139/w08-058

Cited by 24 publications

(38 citation statements)

References 40 publications

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Section: Importancementioning

confidence: 99%

“…A number of molecular biology-based assays have been employed to study the genetic diversity of F. psychrophilum in an attempt to define its host specificity, geographical associations, and virulence (15-18). However, despite these concerted efforts, the lack of standardized, reproducible, and comparable assays (18)(19)(20) left the intraspecific heterogeneity of F. psychrophilum as it relates to distribution and transmission routes incompletely understood.Multilocus sequence typing (MLST) is a robust, reproducible, and established technique to identify and characterize the strain diversity of human and animal bacterial pathogens (21, 22), including those affecting fish (23)(24)(25)(26)(27). MLST is based on the sequencing of, typically, 7 housekeeping gene loci, whereby an isolate is characterized by the allele types (ATs) found at the loci.…”

mentioning

confidence: 99%

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Genetic Diversity of Flavobacterium psychrophilum Isolates from Three Oncorhynchus spp. in the United States, as Revealed by Multilocus Sequence Typing

Vliet

Wiens

Loch

et al. 2016

Appl Environ Microbiol

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The use of a multilocus sequence typing (MLST) technique has identified the intraspecific genetic diversity of U.S. Flavobacterium psychrophilum, an important pathogen of salmonids worldwide. Prior to this analysis, little U.S. F. psychrophilum genetic information was known; this is of importance when considering targeted control strategies, including vaccine development. Herein, MLST was used to investigate the genetic diversity of 96 F. psychrophilum isolates recovered from rainbow trout (Oncorhynchus mykiss), coho salmon (Oncorhynchus kisutch), and Chinook salmon (Oncorhynchus tshawytscha) that originated from nine U.S. states. The isolates fell into 34 distinct sequence types (STs) that clustered in 5 clonal complexes (CCs) (n ‫؍‬ 63) or were singletons (n ‫؍‬ 33). The distribution of STs varied spatially, by host species, and in association with mortality events. Several STs (i.e., ST9, ST10, ST30, and ST78) were found in multiple states, whereas the remaining STs were localized to single states. With the exception of ST256, which was recovered from rainbow trout and Chinook salmon, all STs were found to infect a single host species. Isolates that were collected during bacterial cold water disease outbreaks most frequently belonged to CC-ST10 (e.g., ST10 and ST78). Collectively, the results of this study clearly demonstrate the genetic diversity of F. psychrophilum within the United States and identify STs of clinical significance. Although the majority of STs described herein were novel, some (e.g., ST9, ST10, ST13, ST30, and ST31) were previously recovered on other continents, which demonstrates the transcontinental distribution of F. psychrophilum genotypes. IMPORTANCEFlavobacterium psychrophilum is the causative agent of bacterial cold water disease (BCWD) and rainbow trout fry syndrome (RTFS) and is an important bacterial pathogen of wild and farmed salmonids worldwide. These infections are responsible for large economic losses globally, yet the genetic diversity of this pathogen remains to be fully investigated. Previous studies have identified the genetic diversity of this pathogen in other main aquaculture regions; however, little effort has been focused on the United States. In this context, this study aims to examine the genetic diversity of F. psychrophilum from the United States, as this region remains important in salmonid aquaculture.T he causative agent of bacterial cold water disease (BCWD) and rainbow trout fry syndrome (RTFS), Flavobacterium psychrophilum, is an important bacterial pathogen of wild and farmed salmonids worldwide (1). In addition to horizontal transmission, F. psychrophilum is suspected of being vertically transmitted (2-5) and appears to resist standard povidone-iodine treatment during egg disinfection (4, 6, 7), which make efforts to control this bacterium particularly problematic. Since the initial isolation of F. psychrophilum in North America (8), F. psychrophilum infections have been reported in Europe, South America, Asia, and Australia (9-11) and from all of...

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Section: Importancementioning

confidence: 99%

mentioning

confidence: 99%

Genetic Diversity of Flavobacterium psychrophilum Isolates from Three Oncorhynchus spp. in the United States, as Revealed by Multilocus Sequence Typing

Vliet

Wiens

Loch

et al. 2016

Appl Environ Microbiol

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“…Several studies (12,23) have shown that F. psychrophilum strains are highly homogeneous phenotypically. In this study, also it was observed that all five isolates showed high level of homogeneity in their biochemical and morphological characteristics.…”

Section: Discussionmentioning

confidence: 99%

“…F. psychrophilum is a Gram negative flexible, slender rod shaped bacteria (26) that produces non-diffusible yellow pigment on agar medium (12). F. psychrophilum strains generally shows a slow gliding motility (26).…”

Section: Introductionmentioning

confidence: 99%

“…The pathogen was first isolated from juvenile coho salmon (Oncorhynchus kisutc) in 1948 in USA (5). The causative agent of the disease has been isolated from most areas of the world such as Australia, Belgium, Canada, Chile, Denmark, Finland, France, Italy, Japan, Korea, Spain, Sweden and United Kingdom (8,12,26) and its economical importance in aquaculture of freshwater salmonid is emphasized all over the world (24,26). In Turkey, F. psychrophilum was isolated from rainbow trout farms in Aegean, Marmara, Mediterranean, Center Anatolia and Eastern Anatolia (11,14,18,19).…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the presence and antibiotic susceptibilities of Flavobacterium psychrophilum in rainbow trout farms (Oncorhynchus mykiss Walbaum, 1792) in The Middle and Eastern Black Sea Regions of

;ONUK¹

2012

Ankara Üniversitesi Veteriner Fakültesi Dergisi

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Cellulolytic bacteria from soils in harsh environments

Soares

Melo

Dias

et al. 2012

World J Microbiol Biotechnol

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It is believed that the exposure of organisms to harsh climate conditions may select for differential enzymatic activities, making the surviving organisms a very promising source for bioprospecting. Soil bacteria play an important role in degradation of organic matter, which is mostly due to their ability to decompose cellulose-based materials. This work focuses on the isolation and identification of cellulolytic bacteria from soil found in two environments with stressful climate conditions (Antarctica and the Brazilian semi-arid caatinga). Cellulolytic bacteria were selected using enrichments at high and low temperatures (4 or 60°C) in liquid media (trypic soy broth-TSB and minimum salt medium-MM) supplemented with cellulose (1%). Many of the isolates (119 out of 254-46.9%) displayed the ability to degrade carboxymethyl-cellulose, indicating the presence of endoglucolytic activity, while only a minority of these isolates (23 out of 254-9.1%) showed exoglucolytic activity (degradation of avicel). The obtained isolates revealed a preferential endoglucolytic activity according to the temperature of enrichments. Also, the identification of some isolates by partial sequencing of the 16S rRNA gene indicated that the Bacteroidetes (e.g., Pedobacter, Chryseobacterium and Flavobacterium) were the main phylum of cellulolytic bacteria isolated from soil in Antarctica; the Firmicutes (e.g., Bacillus) were more commonly isolated from samples from the caatinga; and Actinobacteria were found in both types of soil (e.g., Microbacterium and Arthrobacter). In conclusion, this work reports the isolation of bacteria able to degrade cellulose-based material from soil at very low or very high temperatures, a finding that should be further explored in the search for cellulolytic enzymes to be used in the bioenergy industry.

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Phenotypic and genotypic analysis of Flavobacterium psychrophilum isolates from Ontario salmonids with bacterial coldwater disease

Cited by 24 publications

References 40 publications

Genetic Diversity of Flavobacterium psychrophilum Isolates from Three Oncorhynchus spp. in the United States, as Revealed by Multilocus Sequence Typing

Genetic Diversity of Flavobacterium psychrophilum Isolates from Three Oncorhynchus spp. in the United States, as Revealed by Multilocus Sequence Typing

Investigation of the presence and antibiotic susceptibilities of Flavobacterium psychrophilum in rainbow trout farms (Oncorhynchus mykiss Walbaum, 1792) in The Middle and Eastern Black Sea Regions of

Cellulolytic bacteria from soils in harsh environments

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