Microscopic imaging of bronchoalveolar fluids of COVID-19 positive intubated patients reveals the different level of sars-cov-2 infection on oral squamosal epithelial cells

Shikha Chaudhary, Preeti Rai, Kishore Sesham, Shailendra Kumar, Prabhakar Singh, Tapas Chandra Nag, Pratima Chaudhuri, Anjan Trikha, Subhash Chandra Yadav

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


COVID-19 pandemic has been a global health emergency due to its association with severe pneumonia and high rate of mortality. In the current study, we reported the direct evidence for the variable level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infection on several types of oral epithelial cells isolated from the aspirated oropharyngeal and bronchoalveolar secretions of severely infected and intubated patients using cytology, confocal based immunofluorescence imaging (IF), scanning electron microscope (SEM) and transmission electron microscopic (TEM) studies. Cytological analysis showed the presence of keratinised and non-keratinised oral epithelial cells with viral inclusion bodies in stratum granulosum and intermedium cells. IF imaging using SARS-CoV-2 spike protein specific antibody confirmed the presence of virus inside the stratum spinosum/granulosum (keratinised) and stratum intermedium/superficial cells (non-keratinised). No SARS-CoV-2 viruses were seen in stratum corneum cells. SEM analysis also confirms the absence of virus like structure on stratum corneum surface while viruses like structure were seen on the stratum spinosum/granulosum/stratum/intermedium and stratum superficial cells. This advanced microscopic study confirms directly that the virus tends to infect and multiply in the metabolically active or sub-basal cells of oral epithelium and absent in the inactive keratinised stratum corneum from shedding zones of oral mucosa.

Original languageEnglish (US)
Pages (from-to)196-207
Number of pages12
JournalIndian Journal of Biochemistry and Biophysics
Issue number3
StatePublished - Jun 2021

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry

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