Spectrum of Brevundimonas vesicularis infections in neonatal period: a case series at a tertiary referral center

Abstract

To report infections caused by Brevundimonas vesicularis and the treatment regimens administered based on antibiotic studies of this Gram-negative bacterium in the neonatal period. Eight hospitalized neonates with positive blood cultures for Brevundimonas spp. were studied. Demographic data, clinical and laboratory findings, nutritional regimens, presence of primary disease, and the antibiotic regimens administered during the treatment of these neonates were noted. Antimicrobial susceptibility tests were performed on isolates of the positive cultures. Four neonates were preterm, and four were full-term infants. The underlying diseases--with the exception of being a neonate--were congenital heart disease (4 patients), respiratory distress syndrome (2), multiple congenital cerebral anomalies (1), and meconium aspiration syndrome (1). Septicemia was observed in all eight patients, while three also had concurrent meningitis. Multidrug resistance to the antimicrobials, including piperacillin-tazobactam, ceftazidime, and aztreonam, were identified in all eight infants; however, susceptibility to amikacin and imipenem was retained. All study patients responded to the antibiotic treatments and subsequent cultures were sterile. One patient died due to other causes. We consider that until larger series are available, B. vesicularis should be regarded as virulent. Consequently, in this era of multi-resistant Gram-negative bacteria, serious B. vesicularis infections in neonates should be treated with a broad-spectrum agent, such as third-generation cephalosporin until the results of susceptibility testing are available. Our case reports demonstrate that the susceptibility of this organism to all aminoglycosides and third-generation cephalosporin is not uniform, but that most of the isolates are susceptible to imipenem. More treatment experience and more exact results from antimicrobial susceptibility testing are required to improve on present treatment regimens for invasive B. vesicularis infections.