Bacteria

Slovak term: Slovenský termín

1. Microscopy unicellular organisms having a rigid cell wall. They lack a nuclear membrance, a mitotic system, and mitochondria; possess only a single piece of chromosomal deoxyribonucleic acid; and divide by binary fission. Most are nonphotosynthetic; photosynthetic forms do not contain plant-type chlorophyll (Symons et al 2000).
2. A large group of unicellular, prokaryotic microorganisms, in other words, they consist in one cell, have no separate nucleus with genetic material and their size is typically a few micrometers (WHO 2009).
3. See also : infectious diseases

Explanation

The term bacteria was coined in the 19th century by the German botanist Ferdinand Cohn (1828-98) who based it on the Greek bakterion meaning a small rod. In 1853, Cohn categorized bacteria as one of three types of microorganisms -- bacteria (short rods), bacilli (longer rods), and spirilla (spiral forms) (WHO 2009).

Example

If bacteria form a parasitic association with other organisms, they are classified as pathogens. Pathogenic bacteria are a major cause of human death and disease and cause infections such as diarrhoea1 disease, tetanus, typhoid fever, diphtheria, syphilis, cholera, foodborne illness, leprosy and tuberculosis (WHO 2009).

References

• WHO (2009) Health impact assessment glossary: E-learning modules
• Symons JM, Bradley LC and Cleveland TC (2000) The drinking water dictionary, American Water Works Association

Links

• WHO — The Health and Environment Lexicon