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 ?
Affinivax and Astellas entered into an exclusive worldwide license agreement in February 2017 to develop and commercialize a vaccine targeting Streptococcus pneumoniae (pneumococcus).
A study in Turkey has indicated that trimethoprim/sulfamethoxazole and erythromycin resistance rates of 61 pneumococcus strains isolated between 2008-2010 were 67.2% and 55.8%, respectively (5).
SCD causes chronic hemolysis, hemolytic crisis, and infections that may precipitate hemolysis.2 Progressive vaso-occlusive damage to the spleen leads to a state of functional asplenia together with other immune system dysfunctions.3 People with SCD are at high risk for complications of influenza and pneumococcal infections because they are susceptible to bacterial infections caused by encapsulated organisms (including Streptococcus pneumoniae and Haemophilus influenzae) due to their impaired splenic function, increased airway hyperactivity, and risk of acute chest syndrome following respiratory infections.4 Vaccination against pneumococcus, influenza, and haemophilus influenzae Type-B (HiB) is recommended for patients with SCD.5-7
To analyze NVT penicillin-nonsusceptible pneumococcus (PNSP) detected in patients with invasive pneumococcal disease, we used data from the Active Bacterial Core surveillance (ABCs) system, a population- and laboratory-based collaborative system between the Centers for Disease Control and Prevention and state health departments and academic institutions in 10 states (California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee).
In bivariate analyses (Table 2), individuals aged 65 to 69 and 70 to 74 years had higher percentages of influenza, pneumococcus, and tetanus vaccination, compared to those between 60-64 years.
Effective vaccine for pneumonia caused by pneumococcus exists - yet children who are likely to be at a high risk of pneumonia are least likely to get the protection.
She was however not vaccinated against pneumococcus during that hospitalization.
Pneumococcus (Streptococcus pneumoniae) causes potentially life-threatening diseases including pneumonia and meningitis.
The singer, who is now recovering at home, had bacterial pneumonia caused by the streptococcus pneumoniae bacteria (also known as pneumococcus).
The Bill and Melinda Gates Foundation is helping create and implement the Advance Market Commitment (AMC) for Pneumococcal Vaccines, which aims to stimulate the late-stage development and manufacture of suitable and affordable vaccines against pneumococcus for developing countries.
It is estimated that there are 44,000 cases of this kind of invasive pneumococcal disease that gets beyond the lungs, into the bloodstream and into other parts of the body, and pneumococcus is said to be responsible for approximately 5,000 deaths each year in the United States.
Q: Is the vaccine against pneumococcus a reality yet?