Microbial Patterns and Antibiotic Susceptibility in Blood Culture Isolates of Septicemia Suspected Children in the Pediatrics Ward of a Tertiary Care Hospital

Abstract

Objectives This study aims to determine microbial patterns and antibiotic susceptibility to alert clinicians to the emerging pathogens that may pose a threat to the community, especially children. Materials and Methods This retrospective cross-sectional study was conducted in the Department of Pathology, Holy Family Hospital, Rawalpindi, Pakistan, from July 2019 to December 2019. Two samples were taken from two different sites of each patient at the time of fever (> 100° F) to avoid chances of contamination. A blood sample of 5 to 10 mL was drawn from each site. In a 50 mL brain heart infusion broth (BHIB), 5 to 10% blood was injected in two different bottles and incubated for 48 hours at 37°C. After 48 hours, subculture was done by streaking the drops of blood samples taken from BHIB on blood and MacConkey agar. Cultures were incubated in aerobic conditions at 37°C for 24 to 48 hours. For testing antibiotic susceptibility, criteria defined by the Clinical and Laboratory Standards Institute (CLSI) were followed. Microbes were identified under a microscope by observing their morphological characteristics after gram staining and applying biochemical tests. Antibiotic sensitivity test was performed using standard aseptic methods. Statistical Analysis Bacterial isolates and their susceptibility patterns were represented using frequencies and percentage charts. Results Out of 423 blood cultures, growth was recorded in 92 (21.75%) of the cultures with female to male ratio 2.1:1. The gram-positive bacteria accounted for 43.48% (n = 40), whereas gram-negative bacteria covered the majority 54.36% (n = 50). Among isolates, Staphylococcus aureus (42.39%) was the most common, followed by Acinetobacter spp. (17.39%) and Pseudomonas aeruginosa (14.13%). Acinetobacter spp. showed 0% susceptibility to amikacin and cefotaxime. All the isolates were 100% resistant to amoxicillin-clavulanic acid. S. aureus showed lower sensitivity for ceftazidime (0%), clindamycin (66.67%), ciprofloxacin (0%), clarithromycin (11.76%), and ceftriaxone (0%). Tigecycline showed 100% sensitivity for all isolates tested. Conclusion Gram-negative bacteria form the majority of isolates in our setup, with Acinetobacter as the most common species among them. The resistance against cephalosporins, penicillin, and fluoroquinolones shown by Acinetobacter, Pseudomonas, Salmonella, and Klebsiella is of grave concern. Among gram-positive bacteria, S. aureus has established resistance against multiple drugs. Limited and objective use of antibiotic therapy is a much-needed strategy under new guidelines.

Keywords

• antibiotic susceptibility
• blood culture
• sepsis
• pediatrics
• clinical and laboratory standards institute (clsi)