The novel coronavirus SARS-CoV-2 is the etiological agent of COVID-19. This virus has become one of the most dangerous in recent times with a very high rate of transmission. At present, several publications show the typical crown-shape of the novel coronavirus grown in cell cultures. However, an integral ultramicroscopy study done directly from clinical specimens has not been published. Nasopharyngeal swabs were collected from 12 Cuban individuals, six asymptomatic and RT-PCR negative (negative control) and six others from a COVID-19 symptomatic and RT-PCR positive for SARS CoV-2. Samples were treated with an aldehyde solution and processed by scanning electron microscopy (SEM), confocal microscopy (CM) and, atomic force microscopy. Improvement and segmentation of coronavirus images were performed by a novel mathematical image enhancement algorithm. The images of the negative control sample showed the characteristic healthy microvilli morphology at the apical region of the nasal epithelial cells. As expected, they do not display virus-like structures. The images of the positive sample showed characteristic coronavirus-like particles and evident destruction of microvilli. In some regions, virions budding through the cell membrane were observed. Microvilli destruction could explain the anosmia reported by some patients. Virus-particles emerging from the cell-surface with a variable size ranging from 80 to 400 nm were observed by SEM. Viral antigen was identified in the apical cells zone by CM. The integral microscopy study showed that SARS-CoV-2 has a similar image to SARS-CoV. The application of several high-resolution microscopy techniques to nasopharyngeal samples awaits future use.

中文翻译：

---

SARS-CoV-2：高分辨率显微镜对受感染人鼻咽组织的初步研究

新型冠状病毒 SARS-CoV-2 是 COVID-19 的病原体。这种病毒已成为近年来最危险的病毒之一，传播速度非常快。目前，一些出版物显示了在细胞培养物中生长的新型冠状病毒的典型冠形。然而，尚未发表直接从临床标本中进行的整体超显微镜研究。鼻咽拭子采集自 12 名古巴人，其中 6 名无症状且 RT-PCR 阴性（阴性对照），另外 6 名来自 COVID-19 有症状且 RT-PCR 对 SARS CoV-2 呈阳性的人。样品用醛溶液处理，并通过扫描电子显微镜 (SEM)、共聚焦显微镜 (CM) 和原子力显微镜进行处理。冠状病毒图像的改进和分割是通过一种新的数学图像增强算法进行的。阴性对照样品的图像在鼻上皮细胞的顶端区域显示出特征性的健康微绒毛形态。正如预期的那样，它们没有显示出类似病毒的结构。阳性样本的图像显示出特征性的冠状病毒样颗粒和明显的微绒毛破坏。在一些地区，观察到病毒粒子通过细胞膜出芽。微绒毛破坏可以解释一些患者报告的嗅觉丧失。通过 SEM 观察到从细胞表面出现的大小范围从 80 到 400 nm 不等的病毒颗粒。通过CM在顶端细胞区鉴定病毒抗原。整体显微镜研究表明，SARS-CoV-2 具有与 SARS-CoV 相似的图像。