SARS-CoV-2, other respiratory viruses and bacteria in aerosols: Report from Kuwait's hospitals

The role of airborne particles in the spread of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is well explored. The novel coronavirus can survive in aerosol for extended periods, and its interaction with other viral communities can cause additional virulence and infectivity. This baseline study reports concentrations of SARS-CoV-2, other respiratory viruses, and pathogenic bacteria in the indoor air from three major hospitals (Sheikh Jaber, Mubarak Al-Kabeer, and Al-Amiri) in Kuwait dealing with coronavirus disease 2019 (COVID-19) patients. The indoor aerosol samples showed 12-99 copies of SARS-CoV-2 per m³ of air. Two non-SARS-coronavirus (strain HKU1 and NL63), respiratory syncytial virus (RSV), and human bocavirus, human rhinoviruses, Influenza B (FluB), and human enteroviruses were also detected in COVID-positive areas of Mubarak Al Kabeer hospital (MKH). Pathogenic bacteria such as Mycoplasma pneumonia, Streptococcus pneumonia and, Haemophilus influenza were also found in the hospital aerosols. Our results suggest that the existing interventions such as social distancing, use of masks, hand hygiene, surface sanitization, and avoidance of crowded indoor spaces are adequate to prevent the spread of SARS-CoV-2 in enclosed areas. However, increased ventilation can significantly reduce the concentration of SARS-CoV-2 in indoor aerosols. The synergistic or inhibitory effects of other respiratory pathogens in the spread, severity, and complexity of SARS-CoV-2 need further investigation.

Role of PGrs and inhibitors in induction and control of somatic embryogenesis in Themeda quadrivalvis

Somatic embryogenesis could be achieved in Themeda quadrivalvis (Linn.) O. Ktze -fodder grass species on MS medium supplemented with 2,4-D. Incorporation of putrescine in the medium stimulated embryogenesis, however its lower concentration stimulated production of non-regenerative callus. Other polyamines such as spermine and spermidine could not evoke similar response. Ascorbic acid used as antioxidant could not prevent browning in embryogenic cultures, however it stimulated embryogenesis. Inhibition of auxin polar transport by use of TIBA and HFCA reduced the embryogenic response significantly and produced distorted or abnormal embryos. Antiethylene substances such as AgNO3 and CoCl2 added in the medium adversely affected the process of embryogenesis and counteracting the stimulatory role of ethylene.