Geology topics

M. Faisal

Publications and source records attributed to M. Faisal.

5 recordsLinked to original sources

USGS2013

Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish

Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery-propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment-producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.

Journal of Fish Diseases↗

USGS2011

Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North America. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with previously naïve host populations.

Diseases of Aquatic Organisms↗

USGS2010

Recovery of Renibacterium salmoninarum from naturally infected salmonine stocks in Michigan using a modified culture protocol

Renibacterium salmoninarum, the causative agent of bacterial kidney disease (BKD), is a fastidious and slow-growing bacterium that is extremely difficult to grow in vitro. Herein, we describe a modified primary culture protocol that encompasses a modified bacteriological culture medium and a tissue processing procedure. In order to facilitate the release of R. salmoninarum from granulomatous tissues, kidneys of infected fish were homogenized in a high speed stomacher. The kidney disease medium (KDM2), routinely used for primary culture of R. salmoninarum was modified by the addition of antibiotics and metabolites. When a relatively large inoculum of diluted kidney homogenate was streak-plate inoculated onto the modified KDM2, colonial growth of R. salmoninarum was achieved within 5-7. days, compared to the standard of two weeks or more. The modified procedure was then used to determine the prevalence of R. salmoninarum among representative captive and feral salmonid stocks in Michigan. Prevalence and clinical manifestations varied among species, strains of fish, and locations; however, R. salmoninarum isolates were biochemically homogenous. The improved primary culture procedure described in this study enabled selective and quick isolation of R. salmoninarum. Also, the isolates retrieved in this study constitute a unique biological resource for future studies of R. salmoninarum in the Laurentian Great Lakes. ?? 2009 University of Cairo.

Journal of Advanced Research↗

USGS2006

Isolation of viral haemorrhagic septicaemia virus from muskellunge, Esox masquinongy (Mitchill), in Lake St Clair, Michigan, USA reveals a new sublineage of the North American genotype

Viral haemorrhagic septicaemia virus (VHSV) was isolated from muskellunge, Esox masquinongy (Mitchill), caught from the NW portion of Lake St Clair, Michigan, USA in 2003. Affected fish exhibited congestion of internal organs; the inner wall of the swim bladder was thickened and contained numerous budding, fluid-filled vesicles. A virus was isolated using fish cell lines inoculated with a homogenate of kidney and spleen tissues from affected fish. Focal areas of cell rounding and granulation appeared as early as 24 h post-inoculation and expanded rapidly to destroy the entire cell sheet by 96 h. Electron microscopy revealed virions that were 170-180 nm in length by 60-70 nm in width having a bullet-shaped morphology typical of rhabdoviruses. The virus was confirmed as VHSV by reverse transcriptase-polymerase chain reaction. Sequence analysis of the entire nucleoprotein and glycoprotein genes revealed the virus was a member of the North American genotype of VHSV; however, the isolate was sufficiently distinct to be considered a separate sublineage, suggesting its origin may have been from marine species inhabiting the eastern coastal areas of the USA or Canada.

Michigan↗

USGS2001

Detection of Perkinsus marinus extracellular proteins tissues of the eastern oyster Crassostrea virginica: Potential use diagnostic assays

Perkinsus marinus , the cause of serious losses of the eastern oyster Crassostrea virginica , secretes extracellular proteins (ECP) in culture (in vitro) including serine proteases. The production of similar ECP in the eastern oyster (in vivo) and their role in pathogenicity, however, remain to be elucidated. The induction and dissemination of these proteins within infected eastern oysters could be critical to understanding the pathologic mechanisms employed as well as to providing the means for rapid and specific diagnosis. To quantify and examine the production of these proteins in the host, polyclonal antibodies were produced against ECP produced during the in vitro culture of P. marinus. By the use of a Western blot technique, these antibodies were shown to recognize a 62-kDa protein antigen expressed in lightly infected oysters, whereas three antigens (62, 38, and 28 kDa) were recognized in heavily infected oysters. Additionally, there was an antigen that is expressed in vitro (40 kDa) that was not detected in vivo and two that were detected in vivo (120 and 32 kDa) but not in vitro. An enzyme-linked immunosorbent assay (ELISA) employing these antibodies indicated that the concentration of secreted antigens is significantly related ( P < 0.05) to the number of cells of P. marinus in infected eastern oyster tissues, as determined by the standard Ray's fluid thioglycollate medium (RFTM) assay. Significant differences ( P < 0.025) between the ELISA and RFTM assays were only observed when oysters possessed less than one hypnospore per gram of tissue. Thus this ELISA proved to be an excellent diagnostic tool, generating values that correlated with the number of protozoal cells present within infected tissues.

Virginia↗