Microbiology Clinical Microbiology Procedures

Question: Discuss about the Microbiology of Clinical Microbiology Procedures. Answer: 1. As per Grams stain analysis, the obtained sputum specimen is of acceptable quality to provide clinically relevant data because it was successfully cultured in agar medium with less contamination and isolated bacterial colonies in culture. The obtained Gram stain results are clearly visible in shape with specific identification either as Gram-positive or Gram-negative bacteria. Therefore, provided sputum is suitable to provide proper clinical information (Black, 2008). 2. As per the Grams stain and colony morphologies studied in culture the suspected organism causing pneumonia is Streptococcus pneumoniae because the maximum obtained bacteria (25 per oil immersion field) is gram-positive with lancet-shaped diplococci and short-chain cocci morphology that is similar to the morphology of Streptococcus pneumoniae (Garcia, 2010). 3. The Alpha-hemolysis due to the presence of S.pneumoniae leads to the greening of the medium. Alpha hemolysis occurs due to oxidation of haemoglobin to green methemoglobin in the presence of hydrogen peroxide that is produced by the bacterium. This leads to the formation of green colour or greening of culture medium. 4. Viridian streptococci and Streptococcus anginosus are some other non-pathogenic organisms that are observed to be present in this type of specimen and causes alpha-hemolysis. These microorganisms show the capacity to undergo alpha-hemolysis in culture medium (Garcia, 2010). Bile Solubility test Bile solubility test is performed to discriminate S.pneumoniae from other alpha-hemolytic bacteria because S.pneumoniae gets dissolved in the presence of bile whereas other hemolytic streptococci show resistance. This test leads to lysis of S.pneumoniae when 2-10% bile salts are applied to colonies of this organism whereas other organisms show resistance to these bile salts and survive. Optochin Sensitivity test This test also works an identification test for S.pneumoniae because in the presence of optochin this alpha-hemolytic bacteria shows sensitivity. The other alpha-hemolytic streptococci except S.pneumoniae are optochin resistant. The optochin is a chemical used in this test; the S.pneumoniae shows sensitivity to this chemical whereas other organisms are optochin resistant. Therefore, S.pneumoniae shows susceptibility to optochin whereas other organisms don't show any susceptibility (Garcia, 2010). No, the patient is not suffering from polymicrobial pneumonia or any other disease because the blood and urine culture were negative. The other microorganisms are in a very low quantity that can be due to other infections or contaminations. Antimicrobial susceptibility test should be performed to confirm the presence of S.pneumoniae in the sputum. For performing this test penicillin can be used as an antimicrobial agent that shows antibiotic activity against streptococci and staphylococci (Black, 2008). The S.pneumoniae consists polysaccharide capsule that shows effectiveness to evade the defence mechanism of the host cell. This capsule completely covers the cell under unfavourable conditions as well as performs a major role in virulence (Black, 2008). The preventative measures for S.pneumoniae includes: - Quit smoking Rest Exercise Proper medication Good hygienic environment Immunization Antibiotics Super pat Diet and behavioural modifications (Garcia, 2010) The symptoms almost confirmed the presence of pneumonia in this patients case but the blood and urine test were performed to analyse the spread of organism and severity of infection throughout the patients body. References Garcia, L. S. (Ed.). (2010).Clinical microbiology procedures handbook. American Society for Microbiology Press. Black, J. G. (2008).Microbiology: principles and explorations. John Wiley Sons.