Is Streptococcus pneumoniae catalase positive?
Is Streptococcus pneumoniae catalase positive?
All streptococci are catalase-negative. S. pneumoniae strains are sensitive to the chemical optochin (ethylhydrocupreine hydrochloride). Optochin sensitivity allows for the presumptive identification of alpha-hemolytic streptococci as S.
Why is Streptococcus pneumoniae alpha-hemolytic?
pneumoniae and other so-called alpha-hemolytic streptococci is caused by the oxidation of oxy-hemoglobin produced by hydrogen peroxide. Oxidation of oxy-hemoglobin to the nonbinding oxygen form, met-hemoglobin, might occur in the lungs during pneumococcal pneumonia.
How is Streptococcus pneumoniae distinguished from other streptococci?
Bile solubility testThe bile (sodium deoxycholate) solubility test distinguishes S. pneumoniae from all other alpha-hemolytic streptococci. S. pneumoniae is bile soluble whereas all other alpha-hemolytic streptococci are bile resistant.
How is Streptococcus pneumoniae diagnosed?
Definitively diagnosing Streptococcus pneumoniae infection generally relies on isolating the organism from blood or other normally sterile body sites. Tests are also available to detect capsular polysaccharide antigen in body fluids.
How is Streptococcus pneumoniae treated?
Pneumococcal pneumonia caused by organisms that are susceptible or intermediately resistant to penicillin responds to treatment with penicillin, one million units intravenously every 4 hours, ampicillin, 1g every 6 hours, or ceftriaxone, 1g every 24 hours. Ease of administration favors the use of ceftriaxone.
What does Streptococcus pneumoniae need to grow?
Streptococcus pneumoniae is a fastidious bacterium, growing best in 5% carbon dioxide. Nearly 20% of fresh clinical isolates require fully anaerobic conditions. In all cases, growth requires a source of catalase (e.g. blood) to neutralize the large amount of hydrogen peroxide produced by the bacteria.
What is the difference between Streptococcus pneumoniae and pneumococcal pneumonia?
Pneumonia can be caused by a variety of viruses, bacteria, and sometimes fungi. Pneumococcal pneumonia is caused by bacteria called Streptococcus pneumoniae or strep. S. pneumoniae is also called pneumococcus.
Why is it important to distinguish Streptococcus pneumoniae from other streptococci?
Reliable distinction of Streptococcus pneumoniae and viridans group streptococci is important because of the different pathogenic properties of these organisms.
How is strep pneumoniae treated?
Pneumococcal pneumonia caused by organisms that are susceptible or intermediately resistant to penicillin responds to treatment with penicillin, one million units intravenously every 4 hours, ampicillin, 1g every 6 hours, or ceftriaxone, 1g every 24 hours.
What is the cure for Streptococcus pneumoniae?
Invasive Streptococcus pneumoniae infections are treated with antibiotics. There is an increasing problem of Streptococcus pneumoniae bacteria developing drug resistance due to the overuse and misuse of antibiotics.