Question

Font Paragraph Ch. 16-Skin & Eye Diseases The patient was a 44 year -old male with a past medical history significant for hypertension, non-insulin-dependent diabetes, bigh cholesterol, and heavy smoking Q packas/day). He presested to the emergency room with complaints of chest pain and was found to have suffered a myocardial infarction (heart attack). A cardiac catheterization on hospital day 3 showed three arterial occlusions, and he underwent a triple-bypass on hospital day 5. On day 7 he developed septic shock with acute respiratory and renal failure, requiring intubation. He had afever at that time of39.3° C and two blood cultures were obtained. Achest x-ray showed left lung pleural effusion and a chest tube was inserted to drain the effusion. On day 11, pus was leaking from the stemal wound. Cultures derived from the wound and from the chest tube grew the organism noted in figures 1 and 2. A Kirby-Bauer disk diffussion assay is shown in figure 3. Figure 2: Organism grown on 5% BAP Figure 1: Organism under 1000x Figure 3: K-B disk diffusion assay. The organism is shown to be resistant gentamycin, oxacillin penicillin, and erythromycin. The organism is sensitive to sacomxcuR and TMP/SMX

Answer 1

1. The organism causing this condition is Streptococcus pneumoniae. This organism is a main causative agent for nosocomial pneumococcal bloodstream infections . The potential predisposing conditions for nosocomial bloodstream infections are invasive procedures like intubation, indwelling catheter insertion, central line catheter insertion ,etc in the previous seven days of admission in hospital. Heart failure patients, upper respiratory tract infections are at risk of acquiring this organism .

2.Streptococcus pneumoniae remains sensitive to Vancomycin . We can find two circular areas zones where bacteria has stopped growing in agar plate. The observed zones contain vancomycin and  Trimethoprim (TMP) Sulfamethoxazole (SMX) so the microorganism is considered to be sensitive to both those antibiotics.

3.Sepsis was considered to have been nosocomially acquired if it appeared 48 h after admission to the hospital and if no evidence of infection was present at admission. Here the patient has acquired this infection after a week of admission in hospital . And also other five patients have been diagnosed with this same organism . Hospitalization is a risk factor for nasopharyngeal colonization with S. pneumoniae.

Streptococcus pneumoniae is found to be the leading cause of community acquired pneumonia. Streptococcus pnuemoniae infections increases with overcrowding. So in community this organism infects lot .

Eventhough Streptococcus pneumonia has high incidence as community acquired pathogen , this as a nosocomial infection has high mortality rate even with high antimicrobial therapy.

4. Perform a toxicity assay and polymerase chain reaction (PCR) to identify the genes responsible for streptococcus exotoxin production . This can find out what strains are responsible for the infections. Also as the days of admission as inpatient increases , the risk for acquiring nosocomial infections increase. Patients who undergo open heart surgery are immuno-compromised , so they are at risk or susceptible to numerous hospital acquired infections.

5. Antimicrobial therapy and pneumococcal conjugate vaccine should be provided as prophylaxis. Healthcare workers should wash hands frequently and also before & after performing procedures on patients. Follow aseptic techniques.