Pneumococcus


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Related to Pneumococcus: streptococcus, pneumococcal vaccine, Streptococcus pneumoniae

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 ?
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.
Close contact, one person to another, is the way the pneumococcus gets from one person to another, usually within three feet--the breathing zone--and then of course we hug and kiss our relatives and friends and that all provides an opportunity for the pneumococcus to spread.
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.
5) For this reason polysaccharide vaccines are still used to prevent disease due to meningococcus and pneumococcus, as older children and adults continue to be at risk of disease due to these pathogens.
What Are Children Dying From: WHO REPORT 2004 Diphtheria YF, Diphteria, Polio, Hepatitis B 0% Tetanus 5% Pertussis 7% Measles 13% Hib 9% Rotavirus 10% Pneumococcus 17% Meningococcus A/C JE 1% TB 9% HIV 9% Malaria 28% (Source: World Health Report 2004) Note: Table made from pie chart.
Outbreaks caused by the pneumococcus strain of bacteria are extremely rare and this outbreak was the first of its kind involving children in a school to be reported in the UK.
He said these were rare circumstances and that the pneumococcus germ was different to the meningococcous germthat usually causes meningitis.
The two cohorts were balanced for a variety of baseline variables including age, sex, health plan region, index date, number of hospitalizations, and vaccinations for influenza and pneumococcus during the 6 months prior to diagnosis.
1) The main pathogen responsible for this mortality is the pneumococcus, Streptococcus pneumoniae, and its treatment is complicated by the evolution of resistance to antibiotics.