Microbial landscape in hospital patients with new coronavirus disease (COVID-19), antibiotic resistance comparison vs. Pre-covid stage: a prospective study

Background. The new coronavirus infection has manifested untypically compared to other acute respiratory agents, posing a major challenge to researchers worldwide. Despite low incidence of bacterial complications, microbial coinfection plays an important role in the onset and development of severe COVID-19 to hamper diagnosis, treatment and prognosis.

Objectives. A study of microbial landscape in secondary complications of COVID-19 and prevailing microbial-agent antibiotic resistance dynamics in COVID-19 vs. patients with pre-COVID community-acquired pneumonia.

Methods. We analysed 1,113 bacterial sputum cultures in COVID-19 patients from 21 hospital of Krasnodar Krai. The study sample comprised 524 strains isolated from COVID-19 patients in bacteriological assays. The comparison sample included 643 positive sputum strains isolated from community-acquired pneumonia patients developing disease in outcome of acute respiratory infection in 2015–2018. The microbial aetiology landscape and strain antibiotic resistance have been compared in COVID-19 vs. patients with community-acquired pneumonia.

Results. Gram-negative bacteria predominated in COVID-19 cultures (58%), followed by Gram-positive bacteria (15%) and fungi (27%). Acinetobacter baumannii (35%) and Klebsiella pneumoniae (33%) were about equally represented in Gram-negative flora, Pseudomonas aeruginosa (19%) and other microorganisms were half as common. Streptococcus pneumonia and Staphylococcus aureus accounted for 48 and 15% Gram-positive strains, respectively. Sputum-isolated fungi were mainly identifi ed as Candida albicans (89%). The Streptoccocus pneumoniae detection rate dropped to 7% in 2020 relative of other flora, which is 10 times less vs. pre-COVID rates, whilst the fungal rate increased dramatically. Antibiotic resistance increased in most isolated microbial strains.

Conclusion. A Gram-negative-dominated aetiology of lower respiratory tract lesions, as well as higher risk of fungal and other opportunistic coinfections should be taken into account in patient treatment for a complicated coronavirus infection. A higher antibiotic resistance is induced by active indication-ignorant use of antibiotics, including pre-hospital treatment. A suitable treatment regimen in COVID-19 should avoid undue antibiotic prescriptions in every patient.