Severe acute respiratory syndrome coronavirus 2 RNA contamination of inanimate surfaces and virus viability in a health care emergency unit.

OBJECTIVES: To detect possible severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA contamination of inanimate surfaces in areas at high risk of aerosol formation by patients with coronavirus disease 2019 (COVID-19). METHODS: Sampling was performed in the emergency unit and the sub-intensive care ward. SARS-CoV-2 RNA was extracted from swabbed surfaces and objects and subjected to real-time RT-PCR targeting RNA-dependent RNA polymerase and E genes. Virus isolation from positive samples was attempted in vitro on Vero E6 cells. RESULTS: Twenty-six samples were collected and only two were positive for low-level SARS-CoV-2 RNA, both collected on the external surface of continuous positive airway pressure helmets. All transport media were inoculated onto susceptible cells, but none induced a cytopathic effect on day 7 of culture. CONCLUSIONS: Even though daily contact with inanimate surfaces and patient fomites in contaminated areas may be a medium of infection, our data obtained in real-life conditions suggest that it might be less extensive than hitherto recognized.

Electron spin-echo envelope modulation study of multicrystalline Cu(2+)-insulin: effects of Cd(2+) on the nuclear quadrupole interaction of the Cu(2+)-coordinated imidazole remote nitrogen.

A comparison of electron spin-echo envelope modulation (ESEEM) spectra from multi-crystalline Cu(2+)-insulin with and without additional Cd(2+) show a dramatic change in the quadrupole coupling parameters of the remote nitrogens of the two histidine imidazoles that ligate to copper. Without Cd(2+), the quadrupole parameters are like those observed in blue copper proteins and in copper substituted lactoferrin. With Cd(2+) soaked into the Cu(2+)-insulin crystals, the quadrupole parameters are similar to those found in galactose oxidase. Theoretical simulations of ESEEM spectra guided by structure modeling suggest that these changes originate from differences in the hydrogen bonding environments of the imidazole remote nitrogen. In addition, a compilation of results from previous ESEEM studies of copper proteins reveals that the asymmetry parameter, eta, may be an indicator of type of hydrogen bond the imidazole remote nitrogen makes. When eta > or = 0.9, the nitrogen hydrogen bonds to water, whereas when eta < 0.9, the nitrogen hydrogen bonds to the protein.