Pneumococcus


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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 ?
4 Vaccination against pneumococcus, influenza, and haemophilus influenzae Type-B (HiB) is recommended for patients with SCD.
Further long-term nationwide surveillance of serotype dynamics is required to assess the multiple ecologic factors that influence antibiotic resistance in the pneumococcus in the conjugate vaccine era.
Older adults with upper class had lower odds for influenza and pneumococcus vaccination, compared to those with lower class.
Unfortunately she had septic shock from a potentially preventable strain of the pneumococcus and had she been vaccinated, she might not have had a fatal outcome.
Imagine that each strain of the pneumococcus bacteria is a class of schoolchildren, all wearing the school uniform.
There are two vaccines against pneumococcus - one is now routinely used on children, and Dr Brown says it's very good against around 70% of pneumococcal strains.
In fact, pneumococcus is the most common bacterial cause of pneumonia, and as we may discuss a little bit further, it often complicates influenza.
A: We are working in collaboration with the Biomolecular Chemistry Centre because pneumococcus has become one of the leading causes of infectious diseases, not only for children in Cuba, but in other parts of the world.
The new vaccine will contain a substance called D4Ply, a fragment of a protein produced by nearly all the different types of pneumococcus.
A 38-YEAR-OLD man is in serious condition after he tested positive for both the H1N1 virus and pneumococcus bacteria.
ISLAMABAD, April 24, 2009 (Balochistan Times) -- Pakistan will apply for support from the Global Alliance for Vaccines and immunization to introduce free vaccination for children against pneumococcus disease.
In October 2006, a serious outbreak of five cases of pneumonia was caused by pneumococcus bacteria in the reception classes of Priory Primary School in Percy Park Road, Tynemouth.