Bacterial Contamination of the Wristwatches Among Clinical and Preclinical Undergraduate Medical Students

Background: Wristwatches and white coats have been found to harbor a great number of bacteria. Hence, it has raised our concern about the contribution of wristwatches to iatrogenic infections in patients. The aim of this study was to determine the type of microbial contamination present on the wristwatches of clinical and preclinical medical students. Methods: Sterile cotton swabs dipped in saline were used to collect samples from the wristwatches of 50 undergraduate medical students (25 clinical and 25 preclinical) of MMMC (Manipal Campus). The sample was cultured on blood agar and MacConkey's agar plates. Bacterial colonies were identified by Gram stain and biochemical tests. Antibiotic sensitivity tests were performed by Kirby-Bauer disk diffusion method. Results: All the samples collected from wristwatches of preclinical students had coagulase-negative Staphylococcus (CONS), and 12% of samples had growth of Staphylococcus aureus. Likewise, clinical students’ wristwatch also had CONS and S. aureus (24%). However, few clinical students’ wristwatch samples yielded the growth of Escherichia coli (12%), Pseudomonas aeruginosa (4%), and Acinetobacter species (4%). Staphylococcus aureus isolates were methicillin resistant. Escherichia coli strains were observed to be extended spectrum beta-lactamase-producing strains. All gram-negative bacteria were sensitive to carbapenem. Conclusions: Although wristwatches of both clinical and preclinical students had normal flora such as CONS and S. aureus, few clinical students carried drug resistant E. coli, P. aeruginosa, and Acinetobacter species, which are dangerous pathogens in the health care settings. Therefore, wristwatches seem to be a potential source of cross-infection in a clinical setting. The results indicate that there is a need for better compliance of hand hygiene maintenance.