Opportunistic Bacterial Pathogens, Molds and Mycotoxins, Viruses, Parasites, and Fish and Shellfish Toxins

2013 ◽  
pp. 435-454
Keyword(s):  
Bacterial Pathogens ◽  
Shellfish Toxins ◽  
Fish And Shellfish

scholarly journals Antagonistic activity of terrestrial Streptomyces sp. VITNK9 against Gram negative bacterial pathogens affecting the fish and shellfish in aquaculture

2018 ◽  
Vol 53 (2) ◽  
pp. 171 ◽  
Author(s):  
Mohammed Ishaque Nabila ◽  
Krishnan Kannabiran
Keyword(s):  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Vibrio Harveyi ◽  
Bacterial Pathogens ◽  
Vibrio Anguillarum ◽  
Antagonistic Activity ◽  
Edwardsiella Tarda ◽  
Streptomyces Sp ◽  
Aeromonas Caviae ◽  
Fish And Shellfish

A total of 72 morphologically different actinomycetes isolates were isolated from samples collected at different regions of Vellore, Tamil Nadu, India and screened for its antibacterial activity against fish and shellfish pathogens. All actinomycetes isolates were screened for antibacterial activity by cross streak method against the selected fish and shellfish bacterial pathogens including Aeromonas caviae, Aeromonas hydroplila, Edwardsiella tarda, Vibrio anguillarum and Vibrio harveyi. Secondary screening of antagonistic isolates by well diffusion method leads to the identification of potential isolate. Culture conditions for the potential isolate were optimized for maximal growth and yield of the ethyl acetate (EA) crude extract. The potential isolate was characterized by molecular taxonomy and phylogeny and identified as Streptomyces species and named as Streptomyces sp. VITNK9. The 16S rDNA nucleotide sequence was searched through the GenBank database and showed 83% similarity to Streptomyces vinaceusdrappus. The EA extract prepared from Streptomyces sp. VITNK9 showed moderate antagonistic activity accessed by the formation of zone of growth inhibition against, Aeromonas caviae (15.33 mm), Aeromonas hydrophila (17.66 mm), Edwardsiella tarda (18.33 mm), Vibrio anguillarum (14.33 mm) and Vibrio harveyi (14.33 mm). The MIC value of EA extract was ranged between 0.03-0.125 mg mL-1. The GC-MS spectrum of the ethyl acetate extract revealed the presence of two major compounds, pyrrolo [1,2-A] pyrazine-1,4-Dione (56.67%) and Hexahydro-3-(2-Methylpropyl) (27.91%), respectively. The results of the study suggest that Streptomyces sp. VITNK9 is a potential source for antagonistic secondary metabolites against fish and shellfish bacterial pathogens.

The Diagnosis of Viral Disease by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 270-273
Author(s):  
William B. McCombs ◽  
Cameron E. McCoy
Keyword(s):  
Electron Microscopy ◽  
Hospital Stay ◽  
Viral Infections ◽  
Medical Profession ◽  
Bacterial Pathogens ◽  
Viral Disease ◽  
Viral Pathogens ◽  
Academic Interest ◽  
The Past

Recent years have brought a reversal in the attitude of the medical profession toward the diagnosis of viral infections. Identification of bacterial pathogens was formerly thought to be faster than identification of viral pathogens. Viral identification was dismissed as being of academic interest or for confirming the presence of an epidemic, because the patient would recover or die before this could be accomplished. In the past 10 years, the goal of virologists has been to present the clinician with a viral identification in a matter of hours. This fast diagnosis has the potential for shortening the patient's hospital stay and preventing the administering of toxic and/or expensive antibiotics of no benefit to the patient.

A novel bioassay to identify anti-virulence leads against gram-positive bacterial pathogens

Planta Medica ◽  
2015 ◽  
Vol 81 (11) ◽  
Author(s):  
DA Todd ◽  
DB Zich ◽  
AR Horswill ◽  
NB Cech
Keyword(s):  
Bacterial Pathogens ◽  
Gram Positive

Risk and Regulation: Methylmercury Exposure and Fish Consumption

2010 ◽  
Vol 6 ◽  
Author(s):  
Jonathan M Gendzier
Keyword(s):  
Environmental Protection Agency ◽  
Fish Consumption ◽  
Government Regulation ◽  
Mercury Emissions ◽  
Methylmercury Exposure ◽  
Exposure Levels ◽  
Aquatic Food ◽  
Reference Doses ◽  
Fish And Shellfish ◽  
Global Cycle

Exposure to organic mercury (methylmercury) occurs almost universally due to ingestion via contaminated fish and shellfish tissue. Ultimate sources of mercury consist of air release by domestic industrial combustion, mining, and international mercury emissions transported via a global cycle. Deposition of mercury from air to surface waters results in methylation to organic methylmercury and bioaccumulation in the aquatic food web. Health effects from methylmercury exposure consist mainly of neurological and neurodevelopmental effects, with fetuses particularly sensitive. Thus regulation of methylmercury exposure has concentrated on acceptable exposure levels and reference doses aimed toward protecting developing fetuses. The risk of methylmercury exposure in humans is regulated largely by the federal government, especially by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA imposes limits on mercury emissions and seeks to research methylmercury levels in fish and humans. The EPA sets a reference dose for methylmercury exposure. The FDA conducts uses date on methylmercury levels in fish to advise consumers on how to make informed decisions regarding fish consumption. There are numerous shortcoming to government regulation of this issue. Further scientific research, improved implementation of available data and scientific conclusions, and improved public communication of risk would all lead to more effective treatment of the risk of methylmercury exposure via ingestion of fish and shellfish. This could include more effective monitoring systems of human and fish methylmercury levels, research into the process of bioaccumulation, and implementation of stricter fish labeling standards, as well as research into higher-risk subpopulations allowing for targeted standards and recommendations.

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