Search results
Results from the WOW.Com Content Network
Examples of facultative intracellular bacteria include members of the genera Brucella, Legionella, Listeria, and Mycobacterium.These bacteria invade the human body and replicate inside the cells, evading the immune system and causing disease by disrupting the human's cells normal function.
Some examples of facultatively anaerobic bacteria are Staphylococcus spp., [3] Escherichia coli, Salmonella, Listeria spp., [4] Shewanella oneidensis and Yersinia pestis. Certain eukaryotes are also facultative anaerobes, including fungi such as Saccharomyces cerevisiae [ 5 ] and many aquatic invertebrates such as nereid polychaetes .
Fungal examples (that affect humans) include: Pneumocystis jirovecii [17] The mitochondria in eukaryotic cells may also have originally been such parasites, but ended up forming a mutualistic relationship (endosymbiotic theory). [18] Study of obligate pathogens is difficult because they cannot usually be reproduced outside the host.
A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle. Examples of facultative parasitism occur among many species of fungi , such as family members of the genus Armillaria .
Salmonella species are facultative intracellular pathogens. [6] Salmonella can invade different cell types, including epithelial cells, M cells, macrophages, and dendritic cells. [55] As facultative anaerobic organism, Salmonella uses oxygen to make adenosine triphosphate (ATP) in aerobic environments (i.e., when oxygen is available).
Clostridium species are endospore-forming bacteria, and can survive in atmospheric concentrations of oxygen in this dormant form. The remaining bacteria listed do not form endospores. [5] Several species of the Mycobacterium, Streptomyces, and Rhodococcus genera are examples of obligate anaerobe found in soil. [10]
Bacteria reproduce rapidly if conditions are right for growth. Most bacteria grow best in dark, warm, moist environments with food. When grown on solid media, some bacteria form colonies as they multiply, and they may grow large enough to be seen. By growing and counting colonies of fecal coliform bacteria from a sample of water, the amount of ...
When an organism is able to survive in both oxygen and anaerobic environments, the use of the Pasteur effect can distinguish between facultative anaerobes and aerotolerant organisms. If the organism is using fermentation in an anaerobic environment, the addition of oxygen will cause facultative anaerobes to suspend fermentation and begin using ...