Bacteriological Profile of Early Versus Late-onset Neonatal Sepsis at Tertiary Care Hospital in Nepal

Neonatal sepsis is one of the most common causes of neonatal mortality in developing countries like Nepal, ranking third after premature birth and birth asphyxia. This study intended to study the microbial etiology and antimicrobial susceptibility pattern of neonatal sepsis and its association with different birth conditions and C-reactive protein (CRP). Methods Blood samples were collected aseptically from 120 neonates suspected of sepsis, admitted to the Neonatal Intensive Care Unit (NICU) and Neonate wards of Tribhuvan University Teaching Hospital, Kathmandu, Nepal, and processed according to the protocol of the American Society for Microbiology (ASM). For antimicrobial susceptibility testing, the standard disc diffusion technique of the Kirby-Bauer method recommended by the Clinical and Laboratory Standards Institute (CLSI) 2019 was followed. Along with blood culture, a C-reactive protein (CRP) test was also carried out from each blood sample. Results Out of 120 blood cultures, 36 (30.0%) yielded microbial growth, 20 (55.5%) in the early-onset neonatal sepsis, and 16 (44.5%) in the late-onset neonatal sepsis. Among 36 blood culture-positive neonatal sepsis, 25 (69.5%) were born through normal delivery, 11 (30.5%) via Cesarean section (C-section); 23 (63.9%) were pre-term delivered neonates, 13 (36.1%) were termed delivered neonates; 23 (63.9%) were low birth weight neonates and 13 (36.1%) were normal birth weight. Among 36 isolates, 15 (41.7%) were gram-positive and 21 (58.3%) were gram-negative organisms. A higher percentage of Coagulase-negative Staphylococcus (n=5, 35.0%) was isolated in EONS, whereas Citrobacter freundii (n=5, 31.2%) was isolated in a higher percentage in LONS. Coagulase-negative Staphylococcus (n=11, 30.6%) were isolated in higher percentages followed by Citrobacter freundii (n=8, 22.2%), Klebsiella pneumoniae (n=6, 16.7%), Acinetobacter baumanii complex (n=5, 13.9%), Staphylococcus aureus (n=4, 11.1%), Acinetobacter lwoffii (n=1, 2.8%) , and Pseudomonas aeruginosa (n=1, 2.8%). Seventeen organisms (47.2%) showed multi-drug resistance of which one was an extended-spectrum beta-lactamase (ESBL) producer. A total of 40 blood samples (33.3%) tested positive for CRP, of which 35 had positive blood culture results. Based on blood culture results, CRP's sensitivity, specificity, and accuracy in this study were 97.2%, 94.0%, and 95.0% respectively which help to rule out the true infection and potential contamination of Coagulase-negative Staphylococcus in neonatal sepsis. Conclusion Gram-positive bacteria s tood out as the major causative agent of neonatal sepsis. MDR and ESBL were also prevalent in neonatal sepsis.