The Evaluation of the Level of Bacterial Contamination of the Stethoscopes Used in Aria Hospital (2009)

Stethoscope is one of the most frequently-used tools in hospitals that is in direct contact with many patients and can therefore be a vector in the dissemination of bacterial infections. The aim of this study is to evaluate the rate of bacterial contamination in the stethoscopes that were used in Aria Hospital in 2009. This is a cross sectional study which has been done on 70 stethoscopes used in Aria hospital in 2009. The samples were taken from the stethoscopes employed by medical students (both Externs and Interns) as well as the ones used in the other sectors of the hospital. The samples were collected from the diaphragm surface of the stethoscopes with the aid of a sterile swab, inoculated into Trypton Soy Broth media and incubated for 24 hours. Next, the samples were inoculated into blood agar and MacConkey agar where they were evaluated using gram staining and biochemical assays. Tests of sensitivity to antibiotics were also carried out using Kirby- Bauer method. Thirty six out of a total of 70 stethoscopes (51.42%) were contaminated, 27 (38.57%) of which were identified as infected with Coagulase negative Staphylococcus (gram positive cocci). 5 (7.14%) of them were contaminated with Enterobacter (gram negative bacilli), 2 (2.85%) with Bacillus (gram positive bacilli), 1(1.42%) with E-coli (gram negative bacilli) and 1(1.42%) with Kelebciella (gram negative bacilli). The isolatesof Coagulase negative Staphylococcus showed the highest level of susceptibility to Imipenem, Cloxacillin and Vancomycin while the most effective antibiotics for gram negative bacillus were Imipenem and Ceftriaxon. Stethoscopes presented a high rate of contamination and their use without precautions can spread nosocomial infections. As for the suggested empirical treatments, Imipenem, Cloxacillin and Vancomycin can be used.