Clinical and microbiological features of resistant gram-negative bloodstream infections in children

Bloodstream infections (BSIs) caused by Gram-negative (GN) bacteria cause significant morbidity and mortality. There is a worldwide increase in the reported incidence of resistant microorganisms; therefore, surveillance programs are important to define resistance patterns of GN microorganisms causing BSIs. The objective of this study was to describe the clinical and microbiological features of resistant GN BSIs in a tertiary pediatric hospital in Turkey.

Patients between 1 month and 18 years of age hospitalized between January 2005 and December 2012 were included in this study. The presence of ESBL and AmpC type beta-lactamase activity were evaluated using the Clinical and Laboratory Standards Institute (CLSI) disk diffusion and double-disk synergy tests.

A total of 209 resistant GN bacterial BSI episodes were identified in 192 patients. Of 192 children, 133 (69.2%) were aged ≤48 months of age. Sixty-six (31.6%) of the BSIs were considered community-acquired and 143 (68.4%) were hospital-acquired infections. The most common isolates were non-fermenting GN bacteria (n=117, 55.9%). The major causative pathogens were Pseudomonas spp. in non-fermenting GN bacteria. The resistance rates to imipenem for Pseudomonas spp. and Acinetobacter spp. were 40.5% and 41.6%, respectively. The most common isolates in fatal patients were Pseudomonas spp. followed by Escherichia coli. The overall 28-day mortality rate was 16.3%.

Although our study was performed at a single center and represents a local population, based on this study, it is concluded that surveillance programs and studies of novel antibiotics for resistant GN bacteria focusing on pediatric patients are required.