Superadded Bacterial Infections in COVID–19 Patients; Antimicrobial Susceptibility and Association with Serological Markers

Abstract

Objective: To determine the frequency and antimicrobial susceptibility pattern of pathogens responsible for superadded bacterial infection in COVID-19 patients and correlate the association of these infections with serological markers.

Study Design: Cross-sectional study.

Place and Duration of study: Department of Pathology, Combined Military Hospital, Multan Pakistan, from Jan to Dec 2021.

Methodology: A total of 290 patients having positive RT-PCR for SARS CoV-2 were included. All samples were processed per Clinical Laboratory Standard Institute (CLSI) protocols. API 20E and API 20NE were used for the identification of Gramnegative rods. Antimicrobial susceptibility testing was performed by the modified Kirby Bauer disc diffusion method.Serological markers, including C-reactive protein (CRP), total leucocyte count (TLC) and serum Ferritin, were determined and compared for significance in positive and negative culture cases.
Results: A total of 75 patients had positive bacterial cultures. Among these, 42(56%) were blood culture, 26(35 %) were respiratory culture and 7(9%) were urine culture. Commonly isolated organisms were Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa, i.e., 23(31%), 20(27%), 13(17%), and 12(16%) respectively. CRP, TLC and S. ferritin were markedly raised in superadded bacterial infection compared to patients with COVID-19 infection only.

Conclusion: The frequency of superadded bacterial infections in COVID-19 patients is high. The pathogens isolated in these cases were multidrug-resistant, reflecting mostly hospital-acquired flora. The association of serological markers in depicting superadded infection is statistically significant and may be used to screen for superadded bacterial infection in COVID-19 patients.