Pneumococcus

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Related to pneumococcal: pneumococcal vaccine, pneumococcal pneumonia, rotavirus, Pneumococcal disease

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.

References in periodicals archive ?
Early EIP data served a major baseline for assessing the benefits of introduction of 7-valent pneumococcal conjugate vaccine (PCV7, Prevnar; Pfizer, Pearl River, NY, USA) in 2000.
Research shows that another kind of pneumococcal vaccine--called a pneumococcal conjugate vaccine (PCV)--can prevent pneumococcal disease including pneumonia in children.
Impact of pneumococcal conjugate vaccines on pneumococcal disease
Nuhu stressed: "Pneumococcus (otherwise known as Streptococcus pneumoniae) is a gram-positive bacterium that causes a group of diseases known as Pneumococcal disease.
Key clinical point: Adults who are 65 years and older should routinely receive 13-valent pneurnococcal conjugate vaccine (PCV13) in series with 23-valent pneumococcal polysaccharide vaccine (PPSV23).
As with all types of meningitis, the onset of pneumococcal meningitis is often sudden.
The introduction of the pneumococcal vaccine is an important milestone in the fight to reduce the burden caused by pneumonia in Pakistan.
The currently available pneumococcal polysaccharide vaccine, is manufactured by both Merck (Pneumovax 23) and Lederie Laboratories (Pnu-Immune 23), and includes 23 purified capsular polysaccharide antigens (serotypes 1 ,2,3,4,5,6B,7F,8,9N,9V,10A,11A,12F,14 , 15B,17F,18C,19A,19F,20,22F,23F and 33F).
Pneumococcal diseases, including pneumonia, in adults who are 50 years and older represent a significant personal and societal health burden in the US, said the company release.
Premature babies and children with medical conditions that put them at high risk of becoming seriously ill with pneumococcal disease will now be offered a vaccine that provides protection against 13 instead of seven strains.
During a scientific seminar to introduce the vaccine on Tuesday, a senior Ministry of Health official said the Pneumococcal Conjugated Vaccine was expanded to include 13 serotypes from the existing seven that was already part of the NIP in 2009.