The Close Correlation Between COVID-19 and Bacterial Etiologies of Hospital-Acquired Infections (HAIs) As a Co-infection

This study was conducted on COVID-19 patients aged 20–60 years of both sexes, who were hospitalized at Mosul General Hospital and Tikrit Teaching Hospital during the period from 16 February to 13 July 2024. A total of 80 throat swab samples were collected to investigate bacterial co-infections accompanying COVID-19. Of these, 72 samples (90%) were positive for bacterial growth, while 8 samples (10%) were negative. Among the Gram-positive bacterial isolates, Staphylococcus aureus was the most prevalent (24 isolates; 33.33%), followed by Streptococcus pneumoniae (17 isolates; 23.61%) and Streptococcus pyogenes (14 isolates; 19.44%). S. aureus is a known pathogen responsible for a wide range of respiratory infections. S. pneumoniae, which colonizes the nasopharynx, may become pathogenic and is a leading cause of secondary respiratory tract infections. S. pyogenes possesses several virulence factors that facilitate tissue invasion and bacterial dissemination, contributing to severe co-infections (Ahmed et al., 2021). In addition to Gram-positive bacteria, Gram-negative pathogens were also identified. Pseudomonas aeruginosa was the most common among them (10 isolates; 13.88%), known for its persistence in moist environments and association with nosocomial infections. Escherichia coli (5 isolates; 6.94%) and Klebsiella pneumoniae (2 isolates; 2.77%) were also isolated, both of which are opportunistic pathogens in immunocompromised or hospitalized patients. The findings of this study revealed a concerning level of antimicrobial resistance. S. aureus showed 100% resistance to amoxicillin/clavulanic acid (Augmentin), while S. pneumoniae exhibited complete resistance to most antibiotics tested. S. pyogenes demonstrated 100% resistance to ceftriaxone, Augmentin, and ampicillin. Similarly, Gram-negative isolates showed high resistance levels to commonly used antibiotics, indicating a critical challenge in managing bacterial co-infections in COVID-19 patients.