Distribution of Pathogenic Bacteria in Health Care Associated Sepsis in Preterm Infants and Ten Years Variation in Their Drug Resistance

Shen-wang Ni,1,* Li Wang,2,* Yang Wang,2 Ji-lu Shen1 1Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Anhui Public Health Clinical Center, Hefei, 230022, People’s Republic of China; 2Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ji-lu Shen, Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Anhui Public Health Clinical Center, No. 218 Jixi Road, Shushan District, Hefei, 230022, People’s Republic of China, Email [email protected]: To identify the causative bacteria of healthcare-associated sepsis in preterm infants and analyze their antibiotic resistance trends over ten years, providing evidence for infection prevention strategies.Materials and Methods: We retrospectively analyzed blood culture data from preterm infants (< 37 weeks) with healthcare-associated sepsis (onset > 72 hours after birth) admitted between January 2014 and December 2023. Pathogen distribution and antibiotic resistance patterns were compared between two periods (2014– 2018 vs 2019– 2023).Results: Among 9928 preterm infants, 3.3% (332 cases) had positive blood cultures, with incidence increasing from 1.4% (2014– 2018) to 2.7% (2019– 2023). Gram-negative bacteria remained predominant (48.00% to 61.07%), led by Klebsiella pneumoniae. Gram-positive bacteria increased significantly (5.33% to 31.30%), primarily coagulase-negative staphylococci, while fungal infections decreased (46.67% to 7.63%). Resistance to third-generation cephalosporins persisted in K. pneumoniae (~80%) and increased in Enterobacter cloacae (60% to 90%). Emerging carbapenem resistance was observed in E. coli (0% to 33.33%) and K. pneumoniae (5.25% to 4.08%), with Enterobacter cloacae showing a significant rise (0% to 60%). ESBL-producing strains rose from 13.33% to 30.53%. All Gram-positive isolates remained susceptible to linezolid, except one vancomycin-resistant Staphylococcus capsulatus.Conclusion: The incidence of healthcare-associated sepsis in preterm infants increased significantly, with rising carbapenem resistance in Gram-negative bacteria and a marked increase in coagulase-negative staphylococci. These trends underscore the need for enhanced infection control and judicious antibiotic use guided by blood culture results.Keywords: sepsis, preterm infants, health care associated infections, pathogenic bacteria, drug resistance