Advertisement

Microbial Toxicity Studies

  • Anju Agrawal
  • Krishna Gopal
Chapter

Abstract

Microbial toxins are toxins produced by microorganisms, including bacteria, viruses and fungi. Microbial toxins are important virulence determinants responsible for microbial pathogenicity and/or evasion of the host immune response. Bacterial toxin is a type of toxin that is generated by bacteria. They are classified as either exotoxin or endotoxin. Exotoxins are generated by the bacteria and actively secreted. Endotoxins are part of the bacteria itself. Subtilase cytotoxin (SubAB) is the recently recognised prototype of a new AB5 toxin family secreted by Shiga toxigenic Escherichia coli (STEC). Pasteurella multocida toxin (PMT) is the major pathogenic determinant of Pasteurella multocida. The species P. multocida causes various diseases of animals and humans. The toxin is the causative agent of the economically important atrophic rhinitis in swine. Microorganisms do not form a separate taxonomic group like vertebrates or angiosperms since they are only defined as creatures which are too small to be seen by the naked eye. There are however taxonomic groups like the gram-positive bacteria or the cyanobacteria that contain only microbial species. Microorganisms do not grow more rapidly than plants or animals. The predominant microorganisms in soil, sediments and surface water do not grow rapidly. They have doubling times in the order of magnitude of weeks. Therefore, there is no need to treat microorganisms differently from animals or plants, when performing ecotoxicological risk assessment. The most common way to study the effects of toxic materials on microorganisms is to monitor growth inhibition on agar medium by a viable plate count. Dilutions of natural water samples are plated on agar medium that contains different concentrations of the toxicants and the reduction in colony-forming units (CFUs) relative to control plates containing no toxicant are then observed. The plate count technique is based on the principle that each viable organism will give rise to one colony. This method is simple, economically suitable for statistical analysis and amenable to the examination of large number of water samples. Toxicity of a chemical in an aquatic environment is coupled to its chemical and biological fate. Some very toxic chemicals are innocuous to the environment because their degradation to nontoxic by-products is rapid. Biodegradation is one of the principal fates of these chemicals, and humans depend on the metabolic diversity of microbial populations to ensure that many synthetic organic materials do not accumulate in the environment.

Keywords

Particulate Organic Carbon Quality Guideline Bacterial Toxin Sediment Quality Guideline Botulinum Neurotoxin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Bennett JW (2010) An overview of the genus Aspergillus. In: Aspergillus: molecular biology and genomics. Caister Academic Press, Norfolk, http://www.open-access-biology.com/aspergillus/aspergillusch1.pdf. ISBN 978-1-904455-53-0Google Scholar
  2. Bourquin AW, Pritchard PH, Mahaffey WR (1978) Effects of Kepone on estuarine microorganisms. Dev Ind Microbiol 19:489–497Google Scholar
  3. Cover TL, Atherton JC (2009) Helicobacter pylori VacA toxin. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  4. Daley RJ, Hobie JE (1975) Direct counts of aquatic bacteria by a modified epifluorescence technique. Limnol Oceanogr 20:875–882CrossRefGoogle Scholar
  5. Definition of bacterial toxin – NCI Dictionary of Cancer Terms. http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=45610. Retrieved 13 Dec 2008
  6. Fisher B, Harvey RP, Champe PC (2007) Lippincott’s illustrated reviews: microbiology, Lippincott’s Illustrated Reviews Series. Lippincott Williams & Wilkins, Hagerstown, p 348. ISBN 0-7817-8215-5Google Scholar
  7. Fratamico PM et al (eds) (2008) Foodborne pathogens: microbiology and molecular biology. Horizon Scientific Press, Norfolk. ISBN 978-1-898486-52-7Google Scholar
  8. Grimes DJ, Morrison SM (1975) Bacterial bioconcentration of chlorinated hydrocarbon insecticides from aqueous systems. Microb Ecol 2:43–59CrossRefGoogle Scholar
  9. Hazelbauer GL (2012) Bacterial chemotaxis: the early years of molecular studies. Ann Rev Microbiol 66:285–303Google Scholar
  10. Herrero A, Flores E (eds) (2008) The cyanobacteria: molecular biology, genomics and evolution. Caister Academic Press, Norfolk. ISBN 978-1-904455-15-8Google Scholar
  11. Ko WH, Lockwood JL (1968) Accumulation and concentration of chlorinated hydrocarbon pesticides by microorganisms in soil. Can J Microbiol 14:1075CrossRefGoogle Scholar
  12. Kogure K, Simidu U, Taga N (1979) A tentative direct microscopic method for counting living marine bacteria. Can J Microbiol 25:415–420CrossRefGoogle Scholar
  13. Kukreja R, Singh BR (2009) Botulinum neurotoxins: structure and mechanism of action. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  14. Langley R et al (2009) Staphylococcal immune evasion toxins. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  15. Machida M, Gomi K (eds) (2010) Aspergillus: molecular biology and genomics. Caister Academic Press, Norfolk. ISBN 978-1-904455-53-0Google Scholar
  16. Mahaffey WR, Pritchard PH, Borquin AW (1982) Effect of Kepone on growth and respiration of several estuarine microorganisms. Appl Environ Microbiol 43:1419–1424Google Scholar
  17. Maldonado-Arocho F et al (2009) Anthrax toxin. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  18. Orndroff SA, Colwell RR (1980) Effect of Kepone on estuarine microbial activity. With Bacillus subtilis. Microb Ecol 6:357–368CrossRefGoogle Scholar
  19. Orth JHC (2009) Pasteurella multocida toxin. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  20. Paton AW, Paton JC (2009) Subtilase cytotoxin. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  21. Proft T (ed) (2009) Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  22. Satchell KJF, Geissler B (2009) The multifunctional-autoprocessing RTX toxins of vibrios. In: Microbial toxins: current research and future trends. Caister Academic Press, Norfolk. ISBN 978-1-904455-44-8Google Scholar
  23. Trudgill PW, Widdus R, Ross JR (1971) Effects of organochlorine insecticides on bacterial growth, respiration and viability. J Gen Microbiol 69:1–5Google Scholar
  24. Widdus R, Trudgill PW, Turnell DC (1971) Effects of technical chlordane on growth and energy metabolism of Streptococcus faecalis and Mycobacterium phlei: a comparison with Bacillus subtilis. J Gen Microbiol 69:21–23Google Scholar
  25. Young CY, Mitchell R (1973) Negative chemotaxis of marine bacteria to toxic chemicals. Appl Microbiol 25:972–975Google Scholar
  26. Zar JH (1974) Biostatistical analysis. Prentice Hall, Englewood Cliffs, pp 151–162Google Scholar

Copyright information

© Springer India 2013

Authors and Affiliations

  • Anju Agrawal
    • 1
  • Krishna Gopal
    • 2
  1. 1.Department of ZoologyS N Sen B V P G College CSJM UniversityKanpurIndia
  2. 2.Aquatic Toxicology DivisionCSIR-Indian Institute of Toxicology ResearchLucknowIndia

Personalised recommendations