Streptococcus (redirected from Streptococus)

Streptococcus /Strep·to·coc·cus/ (-kok´us) a genus of gram-positive, facultatively anaerobic cocci occurring in pairs or chains; it is separable into the pyogenic group, the viridans group, the enterococcus group, and the lactic group. The first group includes the ß-hemolytic human and animal pathogens, the second and third include a-hemolytic parasitic forms that are normal flora in the upper respiratory tract and the intestinal tract, respectively, and the fourth is made up of saprophytic forms associated with the souring of milk. Species include S. mu´tans, which may cause dental caries; S. pneumo´niae, an a-hemolytic species that is the most common cause of lobar pneumonia and also causes other serious, acute pyogenic disorders; S. pyo´genes, a ß-hemolytic species that causes septic sore throat, scarlet fever, and rheumatic fever; and S. san´guinis, found in dental plaque, blood, and subacute bacterial endocarditis.

---

streptococcus /strep·to·coc·cus/ (strep?to-kok´us) pl. streptococ´ci   an organism of the genus Streptococcus. streptococ´calstreptococ´cic

---

hemolytic streptococcus  any streptococcus capable of hemolyzing erythrocytes, classified as a-hemolytic type, producing a zone of greenish discoloration much smaller than the clear zone produced by the ß-hemolytic type about the colony on blood agar; and the ß-hemolytic type, producing a clear zone of hemolysis immediately around the colony on blood agar. The most virulent streptococci belong to the latter group. On immunological grounds, the ß-hemolytic streptococci may be divided into groups A through T; most human pathogens belong to groups A through G.

nonhemolytic streptococcus  any streptococcus that does not cause a change in the medium when cultured on blood agar.

viridans streptococcus  any of a group of streptococci with no defined Lancefield group antigens but not Streptococcus pneumoniae, usually a-hemolytic; part of the normal flora of the respiratory tract but also causing dental caries, bacterial endocarditis, and other disorders in immunocompromised hosts.

---

Streptococcus

n.

A genus of gram-positive, anaerobic, often pathogenic bacteria having an ovoid or spherical appearance and occurring in pairs or chains, including many erythrocytolytic and pathogenic species that cause erysipelas, scarlet fever, and septic sore throat in humans.

---

strep·to·coc·cus (strpt-kks)

n. pl. strep·to·coc·ci (-kks, -kk)

A bacterium of the genus Streptococcus.

---

strepto·coccal, strepto·coccic adj.

---

Streptococcus (plural, streptococci)

Any of several species of bacteria that are spherical in shape and form pairs or chains. Streptococci cause scarlet fever, tonsillitis, and pneumonia, and are often involved in lymphadenitis.

Mentioned in: Acute Poststreptococcal Glomerulonephritis, Conjunctivitis, Erysipelas, Lymphadenitis, Sydenham's Chorea, Throat Culture, Toxic Shock Syndrome

---

Streptococcus (strep·tō kô·ks),

n a pathogenic bacterium often found in the mucosae of the mouth, nose, and throat and occasionally in skin, muscle, or heart tissue.

---

Streptococcus

a genus of gram-positive, predominantly facultatively anaerobic cocci in the family Streptococcaceae occurring in pairs or chains. It is classifiable in several ways, none of them completely satisfactory in terms of species designation. Sherman's classification was based on tolerance tests. The system used most widely in veterinary bacteriology is Lancefield's grouping based on serological tests.

Another means of differentiating streptococci is on the basis of type of hemolysis produced around colonies grown on sheep blood agar. Alpha (a) is partial hemolysis or greening of the agar. Beta (ß) hemolysis is seen as a clear zone and gamma (?) is no hemolysis. Most of the pathogenic species are ß hemolytic.

---

Streptococcus agalactiae

causes mastitis in cattle, goats and sheep, neonatal septicemia and urogenital infections in dogs and cats.

Streptococcus avium, Streptococcus durans, Streptococcus faecalis, Streptococcus faecium and Streptococcus gallinarum

reclassified in the genus enterococcus. Now called Enterococcus avium etc.

Streptococcus bovis

an important organism in the development of lactic acidosis in cattle following carbohydrate engorgement because of its capacity to ferment starch to lactic acid.

Streptococcus canis (canus)

isolated from cases of septicemia and adenitis in puppies and kittens.

Streptococcus dysgalactiae

causes mastitis in cows, ewes and goat does and polyarthritis in lambs.

Streptococcus dysgalactiae subsp. equisimilis

causes suppurative arthritis in piglets and abscesses in lymph nodes of the head and neck of horses. Also a cause of cervicitis in mares. Previously called S. equisimilis.

Streptococcus equi subsp. equi

causes strangles in horses.

Streptococcus equi subsp. zooepidemicus

occurs as a secondary infection in most species, particularly in horses in wounds, as a cause of cervicitis and a secondary infection associated with the viral infections of the upper respiratory tract. A cause of metritis and mastitis in cattle and septicemia in lambs, pigs and poultry. Previously called S. zooepidemicus.

Streptococcus equinus

causes opportunist infections in many species.

Streptococcus parauberis, Streptococcus uberis, Streptococcus viridans

may cause mastitis in cows.

Streptococcus pneumoniae

formerly called Diplococcus pneumoniae; pneumococcus, causes pneumonia in humans, nonhuman primates, guinea pigs and calves and mastitis in cattle, and septicemia and arthritis in cats.

Streptococcus porcinus

causes cervical abscess of pigs.

Streptococcus pyogenes

a cause of lymphangitis in foals and an uncommon cause of bovine mastitis. An important pathogen of humans.

Streptococcus spp. biovar 1

causes disease in cultured finfish.

Streptococcus suis

has at least 35 capsular types many of which can cause streptococcal meningitis and arthritis in pigs. There is geographic variance in the importance of individual serotypes but types 1,2,3,4,7,8 and 11 are common pathogens. Infection with type 2 is particularly common and is a zoonosis as is type 14. Immunity to disease can be engendered by vaccination but is serotype specific.