2.3. Stool Sample Collection and Processing

During the study, a total of 208 non-duplicate fecal samples were collected comprising of 104 each from the HS and NHS groups. After obtaining the written consent in local and English languages, each participant was provided with a clean, sterile, leak-proof, screw-capped plastic container with a plastic spoon and was instructed in the collection of a fresh stool sample. A single stool sample was collected from each student. Then, the fecal samples were processed for isolation and identification of E. coli and Klebsiella species according to standard microbiological methods recommended by the American Society for Microbiology (ASM) [9]. For this, each stool sample was inoculated onto a MacConkey agar plate and incubated aerobically at 37°C for 24 hours.