Microbiology Section, Department of Diagnostics and Public Health, University of Verona, Verona, Italy.
Pharmacology Section, Department of Diagnostics and Public Health, University of Verona, Verona, Italy.
Front Cell Infect Microbiol. 2021 Aug 12;11:683409. doi: 10.3389/fcimb.2021.683409. eCollection 2021.
To investigate the presence of bacteria and fungi in bronchial aspirate (BA) samples from 43 mechanically ventilated patients with severe COVID-19 disease.
Detection of SARS-CoV-2 was performed using Allplex 2019-nCoV assay kits. Isolation and characterisation of bacteria and fungi were carried out in BA specimens treated with 1X dithiothreitol 1% for 30 min at room temperature, using standard culture procedures.
Bacterial and/or fungal superinfection was detected in 25 out of 43 mechanically ventilated patients, generally after 7 days of hospitalisation in an intensive care unit (ICU). Microbial colonisation (colony forming units (CFU) <1000 colonies/ml) in BA samples was observed in 11 out of 43 patients, whereas only 7 patients did not show any signs of bacterial or fungal growth. was identified in 17 patients. Interestingly, 11 out of these 17 isolates also showed carbapenem resistance. The molecular analysis demonstrated that resistance to carbapenems was primarily related to OprD mutation or deletion. was the second most isolated pathogen found in 13 samples, of which 8 were carbapenemase-producer strains.
These data demonstrate the detection of bacterial superinfection and antimicrobial resistance in severe SARS-CoV-2-infected patients and suggest that bacteria may play an important role in COVID-19 evolution. A prospective study is needed to verify the incidence of bacterial and fungal infections and their influence on the health outcomes of COVID-19 patients.
调查 43 例重症 COVID-19 机械通气患者支气管吸出物（BA）样本中细菌和真菌的存在情况。
使用 Allplex 2019-nCoV 检测试剂盒检测 SARS-CoV-2。BA 标本用 1X 二硫苏糖醇 1%室温孵育 30 分钟处理，采用标准培养程序分离和鉴定细菌和真菌。
在 43 例机械通气患者中，有 25 例患者检测到细菌和/或真菌感染，通常在 ICU 住院 7 天后发生。在 43 例患者中的 11 例患者的 BA 样本中观察到微生物定植（菌落形成单位（CFU）<1000 个菌落/ml），而只有 7 例患者未显示任何细菌或真菌生长迹象。在 17 例患者中鉴定出。有趣的是，在这 17 个分离株中，有 11 个也表现出对碳青霉烯类药物的耐药性。分子分析表明，对碳青霉烯类药物的耐药性主要与 OprD 突变或缺失有关。是在 13 个样本中发现的第二种最分离的病原体，其中 8 个是产碳青霉烯酶的菌株。
这些数据表明，在严重的 SARS-CoV-2 感染患者中检测到细菌的继发感染和抗生素耐药性，提示细菌可能在 COVID-19 演变中发挥重要作用。需要进行前瞻性研究以验证细菌和真菌感染的发生率及其对 COVID-19 患者健康结局的影响。
