Medicine Reference Libraries
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, bile-soluble aerotolerant, anaerobic member of the genus Streptococcus. It was recognized as a major cause of pneumonia in the late 19th century and is thus the subject of many humoral immunity studies. It causes many other types of pneumococcal infections other than pneumonia including acute sinusitis, otitis...
Streptococcus mutans is a Gram-positive cocci, Facultative anaerobic bacterium commonly found in the human oral cavity and is a significant contributor to tooth decay. J Kilian Clarke first described the microbe in 1924. The first colonizers of the tooth surface are mainly Neisseria spp. and streptococci, including S. mutans. The pioneer species changes the local environmental conditions...
Staphylococcus aureus is a facultative anaerobic gram-positive coccus, and is the most common cause of staph infections. It is commonly part of the skin flora found in the nose and on skin. Around 20% of the human population is long-term carriers. It gets its golden color due to its carotenoid pigment staphyloxanthin. The pigment acts as a virulence factor with an antioxidant action that allows...
Neisseria meningitidis is a heterotrophic gram-negative diplococcal bacterium best known for its role in meningitis and other forms of meningococcal disease such as meningococcemia. It is a major cause of morbidity and mortality during childhood in industrialized countries and is responsible for epidemics in Africa and in Asia. In the US there are approximately 2500 to 3500 cases of N....
Mycoplasma genitalium is a small parasitic bacterium that lives on the ciliated epithelial cells of the primate genital and respiratory tracts. It is the smallest known free-living bacterium. Up until 2002 it was also considered to be the organism with the smallest genome. M. genitalium was isolated in 1980 from urethral specimens of two male patients with non-gonococcal urethritis. Infection...
Mycobacterium tuberculosis (MTB) is a pathogenic bacterial species in the genus Mycobacterium and the causative agent of most cases of tuberculosis. Robert Koch first discovered it in 1882 and that it had an unusual, waxy coating on the cell surface which makes them impossible to Gram stain. M. tuberculosis is highly aerobic and requires high levels of oxygen. It generally infects the...
Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines. It is the most important member of the Klebsiella genus of Enterobacteriaceae. It is naturally occurring in soil and about 30% of strains can fix nitrogen in anaerobic conditions. Hans Christian Gram...
Helicobacter pylori is a Gram-negative, microaerophilic bacterium that can inhabit various areas of the stomach, particularly the antrum. It causes low-level inflammation of the stomach lining and is linked to gastric ulcers and stomach cancer. Out of those infected, 80%, are asymptomatic. It was initially named Campyloacter pyloridis and then renamed C. pylori to correct the Latin grammar...
Haemophilus influenzae is a Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. It is generally aerobic but can grow as a facultative anaerobe. H. influenzae was mistakenly considered to be the cause of influenza until 1933 when the flu virology became apparent. It was the first free-living organism to have its entire genome...
Haemophilus ducreyi is a fastidious gram-negative coccobacillus causing the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Early symptoms are dark and light green shears in excrement. Chancroid starts as an erythematous popular lesion that breaks down into a painful bleeding ulcer. It can...
