Simulated Pediatric Blood Cultures to Assess the Inactivation of Clinically Relevant Antimicrobial Drug Concentrations in Resin-Containing Bottles.

Liliana Giordano,Brunella Posteraro,Grazia Angela Morandotti,Giulia Menchinelli,Teresa Spanu,Flora Marzia Liotti,Maurizio Sanguinetti,Tiziana D’Inzeo,Giulia De Angelis

doi:10.3389/fcimb.2021.649769

Abstract

The bacteremia level as well as the administration of antibiotics before blood collection may significantly affect the recovery of bacterial pathogens from pediatric blood cultures in BacT/Alert Virtuo or Bactec FX BC systems, which remain the common techniques to diagnose bacteremia in pediatric patients. We simulated pediatric blood cultures with low or intermediate bacteremia level to evaluate BacT/Alert PF Plus and Bactec Peds Plus blood culture bottles for resin-based inactivation of 16 antibiotic–bacterium combinations. Overall, 105/192 (54.7%) of BacT/Alert PF Plus bottles and 69/192 (36.0%) of Bactec Peds Plus bottles allowed organisms to grow when exposed to antibiotics. In particular, both BacT/Alert PF Plus and Bactec Peds Plus bottles proved to be effective with piperacillin/tazobactam and Pseudomonas aeruginosa or with oxacillin and methicillin-susceptible Staphylococcus aureus (100% growth), whereas no effectiveness was apparent with ceftriaxone and Escherichia coli, Streptococcus agalactiae, or Streptococcus pneumoniae or with cefepime and E. coli (0% growth). In some relevant instances (e.g., with vancomycin and methicillin-resistant S. aureus or Streptococcus pneumoniae), BacT/Alert PF Plus bottles were superior to Bactec Peds Plus bottles. Together, these findings underscore the potentiality of resin-containing bottles to enhance diagnosis of bacteremia in pediatric patients on antimicrobial therapy. This is particularly true with one of the evaluated BC systems and with simulated intermediate bacteremia level only.

Highlights

Bloodstream infection (BSI) remains a major cause of morbidity and mortality in pediatric patients (Weiss et al, 2015), especially in neonates (Shane et al, 2017) and hematology/oncology patients (Dandoy et al, 2019)
Among 576 simulated BacT/Alert Pediatric FAN (PF) Plus or Bactec Peds Plus blood culture (BC) bottles, 384 bottles were tested with bacterial organisms in the presence of clinically relevant peak (192 bottles) or trough (192 bottles) antibiotics’ concentrations, whereas 192 bottles were tested in the absence of antibiotics
Excluding ceftriaxone—no organisms were recovered when exposed to this drug (Table 1)—recovery results in BacT/Alert PF Plus versus Bactec Peds Plus bottles were shown by thirteen antibiotic– organism combinations (Figure 1C)

Summary

Introduction

Bloodstream infection (BSI) remains a major cause of morbidity and mortality in pediatric patients (Weiss et al, 2015), especially in neonates (Shane et al, 2017) and hematology/oncology patients (Dandoy et al, 2019). Besides being a prerequisite for targeted antibiotic administration (Liu et al, 2017), BC may allow for cessation of unnecessary empirical antimicrobial therapy in case of negative results (Dien Bard and McElvania TeKippe, 2016). Low-level [i.e., ≤10 CFU per milliliter (CFU/ ml) of blood] bacteremia (Kellogg et al, 2000) as well as inadequate blood volume sampling (based on body weight) (Huber et al, 2020) may significantly compromise the recovery of BSI pathogens (including fastidious organisms) from pediatric BC bottles (Dien Bard and McElvania TeKippe, 2016). The only recently published bacteremia simulating study in the pediatric setting (Dien Bard and McElvania TeKippe, 2016) has compared BacT/ Alert PF (bioMé rieux) and Bactec Peds Plus (Becton Dickinson) BC bottles for their efficacy against eight organism-appropriate antibiotics (Sullivan et al, 2013). Studies investigating the effect of antibioticinactivating substances using the newer BacT/Alert PF Plus BC bottle are lacking

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