Rothia mucilaginosa was primarily known as contaminant and non-pathogenic but this bacteria is being isolated as an alarming pathogen from the pathological specimens of respiratory tract infections, endocarditis and prosthetic device related infections. Rothia sp. are frequently identified in a tertiary hospital of Bangladesh for a last couple of years. Biochemical reactions to different carbohydrates, proteins and amino acids substrates play major role for identification and speciating different Rothia sp. A cross-sectional descriptive study was performed at laboratory services department; microbiology of Khwaja Yunus Ali Medical College and Hospital, Sirajganj with 22 isolates of R. mucilaginosa. BD phoenix M50 system was used for observing fermentation status of carbohydrate and protein, amino acid substrates and kirby-bauer disc diffusion method was performed to investigate the antimicrobial susceptibility. A total 20 carbohydrate substrates were used and all isolates showed variable reaction to almost 50% of the carbohydrate. There were 20 protein, amino acid substrates and isolated 22 Rothia sp. reacted variably to almost 50% of these substrates. Amikacin, meropenem, imipenem and moxifloxacin showed maximum sensitivity in vitro. All isolates were resistant to penicillins, cloxacillin and cefoxitin. 27.2% isolates were susceptible to vancomycin. This study raises a critical issue regarding establishing the role of Rothia sp. as a primary pathogen. Further studies are required to identify virulence factors and their role in pathogenicity.

Tania Rahman received her MBBS degree from Sir Salimullah Medical College, Dhaka, Bangladesh. She then obtained an M.Phil degree in microbiology from Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh. She began her professional career in 2017 as an assistant professor and has since been promoted to associate professor in the department of microbiology at Khwaja Yunus Ali Medical College and Hospital, Sirajganj, Bangladesh. She loves teaching students in the academic section. She also serves in the laboratory services department of Khwaja Yunus Ali Hospital, which is her real area of fascination. She has attended workshops on scientific writing and biostatistics and received certificates of participation. She was also a participant in an advanced training workshop on molecular techniques organized by ideSHi, Bangladesh. Additionally, she received a CME (Continuing Medical Education) certificate from the Centre for Medical Education, Bangladesh.