Volume 63, Issue 1, 15 March 2002, Pages 19–24
Colonization rate of bacteria in the throat of healthy infants
Matitiahu Berkovitch et al. (2002). Colonization rate of bacteria in the throat of healthy infants. International Journal of Paediatric Otorhinolaryngology 63,19-24.
Nucleic Acids Research, 2003, Vol. 31, No. 22 6516-6523.The complete genome sequence and analysis of
Corynebacterium diphtheriae
A. M. CerdenÄo-TaÂrraga et. al

A. M. CerdenÄo-TaÂrraga et. al. (2003). The complete genome sequence and analysis of Corynebacterium diphtheriae . Nucleic Acids Research 31, 6516-6523.
(A. M. CerdenÄo-TaÂrraga et. al., 2003)

Corynebacterium diphtheriae is a Gram-positive,non-spore forming, non-motile, pleomorphic rod belonging to the genus Corynebacterium and the actinomycete group of organisms. The organism produces a potent bacteriophage-encoded protein exotoxin, diphtheria toxin (DT), which causes the symptoms of diphtheria. This potentially fatal infectious disease is controlled in many developed countries by an effective immunisation programme.
Corynebacterium diphtheria was shown to be the cause of the acute, communicable disease diphtheria after being isolated from diphtheritic pseudomembranes in the late 19th century
The virulent and toxigenic strains are lysogenic, and produce an exotoxin formed by two polypeptide chains, which is itself produced when a bacterium is transformed by a gene from the β prophage.[9]
Nonpathogenic species of Corynebacterium are used for very important industrial applications, such as the production of amino acids,[19][20] nucleotides, and other nutritional factors (Martín, 1989); bioconversion of steroids;[21] degradation of hydrocarbons;[22] cheese aging;[23] and production of enzymes (Khurana et al., 2000). Some species produce metabolites similar to antibiotics:bacteriocins of the corynecin-linocin type,[15][24][25] antitumor agents,[26] etc.
Unlike Gram-negative bacteria, the Gram-positive Corynebacterium species lack lipopolysaccharides that function as antigenic endotoxins in humans.
The virulent and toxigenic strains are lysogenic, and produce an exotoxin formed by two polypeptide chains, which is itself produced when a bacterium is transformed by a gene from the β prophage.[9]

In addition to streptococcal pharyngitis (strep throat), certain Streptococcus species are responsible for many cases of pink eye,[4] meningitis,bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are nonpathogenic, and form part of the commensal human microbiome of the mouth, skin, intestine, and upper respiratory tract. Furthermore, streptococci are a necessary ingredient in producing Emmentaler ("Swiss") cheese.
Streptococcal Infections of Skin and Soft Tissues
Alan L. Bisno, M.D., and Dennis L. Stevens, M.D., Ph.D. N Engl J Med 1996; 334:240-246January 25, 1996

Bisno, A. L. & Stevens, D. L. (1996). Streptococcal Infections of Skin and Soft Tissues. The new England Journal of Medicine 334, 240-246.
(Bisno, A. L. & Stevens, D. L., 1996)
S. pyogenes is one of the most common human pathogens. Responsible for a wide array of illnesses, most common is acute pharyngitis. Vairety of skin and soft tissue infections
Species of Streptococcus are classified based on their hemolytic properties.[5] Alpha hemolytic species cause oxidization of iron in hemoglobin molecules within red blood cells, giving it a greenish color on blood agar. Beta hemolytic species cause complete rupture of red blood cells. On blood agar, this appears as wide areas clear of blood cells surrounding bacterial colonies. Gamma-hemolytic species cause no hemolysis. (lab manual).

S. agalactiae is a member of the gastrointestinal normal flora in some humans and can spread to secondary sites - genitourinary tract of women 20-30%. This is of clinical importance: S. agalactiae can be transferred to a neonate passing through the birth canal and can cause serious group B streptococcal infection. It colonizes in the gastrointestinal and urinary tract in healthy adults as well as the genital tract in healthy women
Enterococcus faecalis – formerly classified as part of the Group D Streptococcus system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals.[
E.faecalis is a gram positive commensal bacteria that is found in the gastrointestinal tracts of humans and other mammals. E.faecalis was once classified as a group D Streptococcus system. S.agalactiae is also part of the gastrointestinal normal flora in some humans. However, it has become very popular in the years due to the serious group B streptococcal infections it causes as it spread into secondary sites such as the genitourinary tract of women (Bisno, A. L. & Stevens, D. L., 1996). Bile is present in the stomach (gastrointestinal tract) this possibly explains why these two species of bacteria could grow in the MAC plate.

Abe Widra
J. Bacteriol. 1959, 78(5):664-670
METACHROMATIC GRANULES of microorganisms
Widra, A. (1959). Metachromatic granules of microorganisms. J. Bacteriol 78, 664-670.
(Widra, 1959)
Special stains like Alberts's stain andPonder's stain are used to demonstrate the metachromatic granules formed in the polar regions. The exact nature and function of the metachromatic (volutin) granules seen in many microorganisms is still a matter of conjecture although polymetaphosphates (polymers of highenergy anhydride-linked phosphates) are a known constituent. The metachromatic granules (volutin) of microorganisms are usually considered to be a reserve source of food; their formation during periods of phosphate uptake has been noted (Lewis, 1941; Nagel, 1948).

Diphtheria caused by toxigenic strains of Corynebacterium diphtheriae is a disease which has reached epidemic proportions within the European region. Rapid microbiological confirmation of aclinical diagnosis is crucial for epidemiological control purposes and as specific treatment is effective only if administered during the early stages. Currently, the only in vitro method readily available to the majority of diagnostic laboratories is the Elek immunoprecipitation test.
JOURNAL OF CLINICAL MICROBIOLOGY,
Feb. 1997, p. 495–498 Vol. 35, No. 2 Copyright q 1997, American Society for Microbiology
A Modified Elek Test for Detection of Toxigenic Corynebacteria in the Diagnostic Laboratory
KATHRYN H. ENGLER et. al
Engler, K. et al. (1997). A Modified Elek Test for Detection of Toxigenic Corynebacteria in the Diagnostic Laboratory. Journal of clinical microbiology 35, 495-498.
(Engler et al., 1997)