Molecular Microbiology
Molecular Microbiology. Information on molecular microbiology, molecular bacteriology, virology, microbes, bacteria, medical microbiology, environmental microbiology, industrial microbiology, food microbiology and all aspects of microbiology.
Microbiology
Gram-positive bacteria
Gram-positive Bacteria are generally divided into the Actinobacteria and the Firmicutes. The Actinobacteria include some of the most common soil bacteria and some pathogens, including Mycobacterium, Corynebacterium, Bacillus, Staphylococcus.
- Bacillus Bacillus subtilis is one of the best understood prokaryotes in terms of molecular biology and cell biology. Its superb genetic amenability and relatively large size have provided powerful tools to investigate a bacterium in all possible aspects. Recent improvements in technology have provided novel and amazing insights into the dynamic structure of this single cell organism. The organism is a model for differentiation, gene/protein regulation and cell cycle events in bacteria.
- Clostridium The genus Clostridium comprises a heterogeneous group of anaerobic spore-forming bacteria, including prominent toxin-producing species, such as C. difficile, C. botulinum, C. tetani and C. perfringens, in addition to well-known non-pathogens like solventogenic C. acetobutylicum. Clostridia produce a range of different clostridial toxins including two of the most potent biological toxins known to affect humans.
- Corynebacteria Corynebacteria are a diverse group of Gram-positive bacteria found in a range of different ecological niches such as soil, vegetables, sewage, skin, and cheese smear. Some are important pathogens while others are of immense industrial importance.
- Lactobacillus Lactobacillus is a genus of Gram-positive facultative anaerobic or microaerophilic bacteria. In humans they are symbiotic and are found in the gut flora. Lactobacillus species are used for the production of yogurt, cheese, sauerkraut, pickles, beer, wine, cider, kimchi, chocolate and other fermented foods, as well as animal feeds such as silage.
- Mycobacterium Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. The genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy. Mycobacteria are aerobic and nonmotile bacteria (except for the species Mycobacterium marinum which has been shown to be motile within macrophages) that are characteristically acid-alcohol fast. Mycobacteria do not contain endospores or capsules and are usually considered to be Gram-positive bacteria.
- Staphylococcus Species of Staphylococcus are important pathogens that cause a variety of diseases in humans and animals. In particular, they cause hospital acquired infections and antibiotic resistant strains (MRSA) cause major problems in hospitals.
Gram-negative bacteria
Many species of Gram-negative bacteria are pathogenic. Medically relevant Gram-negative include Acinetobacter, Helicobacter pylori, Legionella, Pasteurellaceae, Pseudomonas, Treponema, Vibrio cholerae.
- Acinetobacter The genus Acinetobacter is a group of Gram-negative, non-motile and non-fermentative bacteria belonging to the family Moraxellaceae. They are important soil organisms where they contribute to the mineralisation of, for example, aromatic compounds. Acinetobacter are able to survive on various surfaces (both moist and dry) in the hospital environment, thereby being an important source of infection in debilitated patients. These bacteria are innately resistant to many classes of antibiotics. In addition, Acinetobacter is uniquely suited to exploitation for biotechnological purposes.
- Cyanobacteria Cyanobacteria are a fascinating and versatile group of bacteria of immense biological importance. Thought to be amongst the first organisms to colonize the earth, these bacteria are the photosynthetic ancestors of chloroplasts in eukaryotes such as plants and algae. In addition they can fix nitrogen, survive in very hostile environments (e.g. down to -60°C), are symbiotic, have circadian rhythms, exhibit gliding mobility, and can differentiate into specialized cell types called heterocysts. This makes them ideal model systems for studying fundamental processes such as nitrogen fixation and photosynthesis.
- Helicobacter pylori Helicobacter pylori causes peptic ulcers, gastritis and gastric cancer. The bacterium infects up to 50% of the human population. H. pylori has very unique characteristics, such as microaerophily and nitrogen metabolism.
- Legionella Legionella is the genus of bacterium that causes Legionnaires' Disease also known as Legionellosis. These bacteria are commonly found in aquatic habitats where they can survive and multiply in different protozoa enabling the bacterium to be transmissible and pathogenic to humans.
- Pasteurellaceae The Pasteurellaceae family comprises a large and diverse family of Gram-negative bacteria with members ranging from important pathogens such as Haemophilus influenzae to commensals of the animal and human mucosa. Members of the family Pasteurellaceae cause a wide variety of diseases in humans and animals.
- Pseudomonas The bacterial genus Pseudomonas includes the opportunistic human pathogen P. aeruginosa, plant pathogenic bacteria, plant beneficial bacteria, ubiquitous soil bacteria with bioremediation capabilities and other species that cause spoilage of milk and dairy products. P. aeruginosa can cause chronic opportunistic infections that have become increasingly apparent in immunocompromised patients and the ageing population of industrialised societies.
- Treponema Treponema pallidum is a gram-negative spirochaete bacterium. There are at least four known subspecies: T. pallidum pallidum, which causes syphilis; T. pallidum pertenue, which causes yaws; T. pallidum carateum, which causes pinta; and T. pallidum endemicum, which causes bejel.
- Vibrio cholerae Vibrio cholerae is the causative agent of cholera and belongs to a group of organisms whose natural habitats are the aquatic ecosystems. The strains that cause cholera epidemics have evolved from non-pathogenic progenitor strains by acquisition of virulence genes, and V. cholerae represents a paradigm for this evolutionary process.
- Borrelia The genus Borrelia, in the spirochete phylum, is not closely related to any other bacteria and has a highly unusual genome composed of a linear chromosome and multiple circular and linear plasmids that appear to be in a constant state of rearrangement, recombination, and deletion. The determination of the genome sequence of Borrelia strains has facilitated tremendous advances in understanding this genus at the molecular and cellular level as well as the pathogenesis of Lyme disease and relapsing fever.
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