Pneumococcus

The major causative microorganism (Streptococcus pneumoniae) of lobar pneumonia. Pneumococci occur singly or as pairs or short chains of oval or lancet-shaped cocci, 0.05–1.25 micrometers each, flattened at proximal sides and pointed at distal ends. A capsule of polysaccharide envelops each cell or pair of cells. The organism is nonmotile and stains gram-positive unless degenerating.

Pneumococci have been isolated from the upper respiratory tract of healthy humans, monkeys, calves, horses, and dogs. Epizootics of pneumococcal infection have been described in monkeys, guinea pigs, and rats but are not the source of human infection. In humans, pneumococci may be found in the upper respiratory tract of nearly all individuals at one time or another. Following damage to the epithelium lining the respiratory tract, pneumococci may invade the lungs. They are the principal cause of lobar pneumonia in humans and may cause also pleural empyema, pericarditis, endocarditis, meningitis, arthritis, peritonitis, and infection of the middle ear. Approximately one of four cases of pneumococcal pneumonia is accompanied by invasion of the bloodstream by pneumococci, producing bacteremia. Although the high mortality of untreated pneumococcal infection has been reduced significantly by treatment with antibiotics, one of every six patients with bacteremic lobar pneumonia still succumbs despite optimal therapy. In addition, the number of isolates of pneumococci resistant to one or more antimicrobial drugs has been gradually but steadily increasing. For these reasons, prophylactic vaccination is recommended, especially for those segments of the population that are at high risk for fatal infection. The polyvalent vaccine contains the purified capsular polysaccharides of the 23 types that are responsible for 85% of bacteremic pneumococcal infection and has an aggregate efficacy of 65–70% in preventing infection with any of the types represented in it.

Pneumococcus

a nonspore-bearing, nonmotile bacterium. The pneumococcus is oval-shaped, measures 0.5 × 1.5μ, and occurs in pairs; hence it is classified in the genus Diplococcus. It is gram-positive and forms a mucous capsule. Pneumococci grow only on protein media. The colonies are smooth and mucous, and the optimum growth temperature is 37°C. Pneumococci are facultative aerobes; they ferment carbohydrates to form lactic acid. They are pathogenic to man, causing inflammation of the lungs, and are found in the sputum of infected persons.

pneumococcus

[noo″mo-kok´us] Streptococcus pneumoniae. adj., adj pneumococ´cal.

Strep·to·coc·cus pneu·mo·ni·ae

a species of gram-positive, lancet-shaped cocci and diplococci frequently occurring in chains; cells are readily lysed by bile salts. Virulent forms are enclosed in type-specific polysaccharide capsules, the basis for an effective vaccine. Normal inhabitants of the respiratory tract, and the most common cause of lobar pneumonia, they are the most common causative agents of meningitis, and pneumonia worldwide, and also cause otitis media, sinusitis, and other infections. It is the type species of the former genus Diplococcus. Synonym(s): Fraenkel pneumococcus, pneumococcus, pneumonococcus

pneumococcus

(no͞o′mə-kŏk′əs, nyo͞o′-)n. pl. pneumo·cocci (-kŏk′sī′, -kŏk′ī′) A nonmotile, gram-positive bacterium (Streptococcus pneumoniae) that is the most common cause of bacterial pneumonia and is a cause of meningitis and other infectious diseases.

pneu′mo·coc′cal (-kŏk′əl) adj.

Strep·to·coc·cus pneu·mo·ni·ae

(strep'tō-kok'ŭs nū-mō'nē-ē) A bacterial species of gram-positive, lancet-shaped diplococci frequently occurring in pairs or chains. Virulent forms are enclosed in type-specific polysaccharide capsules. Normal inhabitants of the respiratory tract, and the cause of lobar pneumonia, otitis media, meningitis, sinusitis, and other infections.
Synonym(s): pneumococcus.

Strep·to·coc·cus pneu·mo·ni·ae

(strep'tō-kok'ŭs nū-mō'nē-ē) A bacterial species of gram-positive, lancet-shaped diplococci frequently occurring in pairs or chains. Normal inhabitants of the respiratory tract, and the cause of lobar pneumonia, otitis media, meningitis, sinusitis, and other infections.
Synonym(s): pneumococcus.

Patient discussion about pneumococcus

Q. What Is Streptococcal Pneumonia? I have heard that I might have streptococcal pneumonia. What exactly does that mean?A. Streptococcal pneumonia is a disease caused by the streptoccus bacteria. It is one of the most common causes of pneumonia in healthy people. You can learn more about bacterial pneumonia here-
http://www.5min.com/Video/Pneumonia---Viral-or-Bacterial--9552

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Strep·to·coc·cus pneu·mo·ni·ae

Strep·to·coc·cus pneu·mo·ni·ae

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Synonyms for pneumococcus

noun bacterium causing pneumonia in mice and humans

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