A retrospective study: management of Rhizobium radiobacter-associated bloodstream infections in pediatric hematology and oncology patients.

OBJECTIVE

Rhizobium spp. strains (formerly classified as Agrobacterium based on 16S rDNA analysis) are aerobic, motile, oxidase-positive, non-spore-forming gram-negative bacilli. Clinical manifestations associated with Rhizobium radiobacter infections vary widely, with bacteremia typically linked to intravenous catheter use.

METHODS

This study analyzes the clinical and laboratory characteristics of 11 pediatric hematology and oncology patients at a tertiary referral hospital who had Rhizobium radiobacter-associated bloodstream infections over a 3-month period.

RESULTS

Nine of the patients were male, and hematologic malignancy was the primary diagnosis in seven patients. Common risk factors included hospitalization within the last month, chemotherapy treatment, and the presence of an indwelling central venous catheter in all cases. Rhizobium radiobacter growth was detected an average of 13.5±16.6 days (range 1-54 days) after hospital admission, with 36% of patients being neutropenic at the time of culture positivity. Rhizobium radiobacter growth was detected in both catheter and peripheral blood cultures in six patients, whereas the microorganism was isolated exclusively from catheter cultures in four patients. Ten patients received antibiotic lock therapy, predominantly with amikacin (90%). Systemic antibiotic treatment involved a combination of beta-lactam and aminoglycoside antibiotics in 10 patients. Culture sterility was achieved in nine patients by the third day of antibiotic treatment. There were no cases of catheter extraction, thrombophlebitis, cardiac vegetation, reproductive complications, or mortality.

CONCLUSION

In this first pediatric case series utilizing antibiotic lock therapy, effective treatment, strict isolation, and surveillance screenings led to favorable clinical outcomes for Rhizobium radiobacter-associated bloodstream infections in children with hematologic and oncologic conditions.