Penicillin streptomycin pen strep antibiotic antimycotic mixture

The MDCK (Madin Darby Canine Kidney) cell line, provided by the Center of Scientific Excellence for Influenza Viruses (CSEIV), National Research Centre (NRC), Egypt, were cultured at 37°C and 5% CO₂ under humified conditions using the growth medium (GM). The GM is composed of Dulbecco’s Modified Eagle’s Medium (DMEM) (DMEM; BioWhittaker, Walkersville, MD, USA) including 5% fetal bovine serum (FBS) (Gibco-BRL; New York, USA) and 1% Penicillin/Streptomycin (pen/strep) antibiotic/antimycotic mixture (GIBCO-BRL; New York, USA). In the same line, the seasonal influenza A/Egypt/NRC098/2019(H1N1) (GISAID ID: EPI_ISL_12995118) and highly pathogenic avian influenza A/chicken/Egypt/N12640A/2016 (H5N1) obtained from the virus collections of the CSEIV, NRC, Egypt, were propagated in confluent MDCK cell monolayers [31 (link), 32 (link)] and titrated using plaque infectivity assay (PIA) and Tissue Culture Infectious Dose (TCID₅₀) method [33 (link)–35 (link)].

Madin Darby Canine Kidney (MDCK) cells were kindly obtained from the cell culture collections of the Centre of Scientific Excellence for Influenza Viruses at Egyptian National Research Centre and were grown in Dulbecco’s Modified Eagle’s Medium (DMEM) (DMEM; BioWhittaker, Walkersville, MD, USA) supplemented with fetal bovine serum (FBS) (10%) (Gibco-BRL; New York, USA) and penicillin/streptomycin (pen/strep) antibiotic/antimycotic mixture (2%) (GIBCO-BRL; New York, USA) and cultured under the optimum growth conditions; 37 °C/ 5% CO₂/humified conditions.
Both the HPAIV A/chicken/Egypt/N12640A/2016(H5N1)^{22 (link)} and the seasonal influenza A/Egypt/NRC098/2019(H1N1) (GISAID ID: EPI_ISL_12995118) were provided by the Egyptian Center of Scientific Excellence for Influenza Viruses, National Research Center, Egypt and inoculated either in MDCK cells and/or specific pathogen-free (SPF) embryonated chicken eggs to propagate them as described earlier^{22 (link),23 (link)}.