Résumé
Introduction: Kocuria kristinae is a commensal organism, sometimes considered as a lab contaminant, but its repeated isolation from clinical samples in immunocompromised patients should raise red flags. Materials and Methods: We confirmed the infection with re-isolation of the organism from the same site before starting treatment. For the identification of Kocuria kristinae we used IDGP cards on VITEK 2 compact system. Antibiotic susceptibility test was done manually following CLSI guidelines 2018 for Coagulase-negative staphylococci. Results: A total of 510 major head neck oncosurgeries were performed during the period of two years. Out of which 120 patients had skin and soft tissue infections. Out of these infected patients, 90 were culture positive and of these Kocuria kristinae were isolated in 12 patients. Resistance to penicillin and oxacillin is seen in all isolates. Conclusion: Kocuria kristinae should not be ignored as a commensal flora or lab contaminant in immunocompromised hosts. Its Increase in resistance pattern is a matter of concern. It is an ignored opportunistic pathogen whose detailed sensitivity test should be developed to treat patients timely and effectively.
Résumé
Malachite green (MG), consisting of green crystals with a metallic lustre, is very soluble in water and is highly cytotoxic to mammalian cells in culture and also acts as a liver tumour promoter. In view of its industrial importance and possible exposure to human beings, MG poses a potential environmental health hazard. Accordingly, we have studied the effect of MG on the formation of free radicals using Electron Spin Resonance (ESR) analysis with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent. ESR analysis showed formation of reactive free radicals during exposure of MG to Syrian hamster embryo (SHE) cells. As per mechanism-based toxicology in cancer risk assessment, the chemicals that have the potential to be metabolized to active free radical species could be human cancer hazards. So, we have investigated the effect of MG on the formation of Type II and Type III morphologically transformed foci using SHE cell transformation assay. MG induced dose related transformed foci. Some of these transformed foci were taken out using selective trypsinisation and established immortal cell lines. One of these immortal cell lines was characterized extensively. This immortal cell line showed enhanced DNA synthesis in the form of BrdU incorporation, increased presence of proliferating cell nuclear antigen (PCNA), bcl-2 and p53 proteins by immunohistochemistry. When these immortal cells were injected subcutaneously into nude mice, they developed tumors which were transplantable and histopathologically sarcomas. The present studies indicate that MG could be a potential candidate for two year chemical carcinogenesis rodent bioassays.