LEUCONOSTOC LACTIS SEPSIS IN A CHILD WITH CHROMOSOMAL 18 ABNORMALITY RECEIVING ENTERAL NUTRITION

Abstract

Leuconostoc lactis, a Gram-positive facultative anaerobe considered safe in food fermentation, is an unusual opportunistic pathogen in humans. We report a 3-year old with mosaic trisomy 18 (18q12.2q21.3, monosomy 18q12.1q12.2 and monosomy 21.31q22.3) receiving enteral nutrition via gastrostomy tube (Peptamen Jr. 1.0, Nestle, Arlington, VA, USA) who presented with septicemia. On the day of admission, she had oxygen desaturation (80%) and an episode of twitching of her extremities with eye deviation. Her vital signs revealed temperature of 36.6 C, heart rate 64, respiratory rate 30–60s and blood pressure 91/39. Laboratory studies were notable for white blood cell count 13.02 nL, lactic acid 2.3 mmol/L and unremarkable C-reactive protein, procalcitonin and comprehensive metabolic panel. Respiratory support had to be rapidly escalated to intubation. Blood culture reported Gram-positive cocci after 18 h of incubation. Chest radiograph showed bilateral infiltrates. She was started on vancomycin and cefepime. On the third day of hospitalisation, cerebrospinal fluid studies were normal with negative meningitis/ encephalitis and broad-range polymerase chain reaction panels and bacterial cultures. Other unrevealing studies included: respiratory pathogen, severe acute respiratory syndrome coronavirus 2, and Pneumocystis jirovecii polymerase chain reactions, and respiratory and urine cultures. Blood culture was identified as L. lactis and susceptibilities sent to a reference laboratory (Mayo Laboratory, Rochester, MN, USA) showed a penicillin minimum inhibitory concentration of 1 mcg/mL. Antibiotics were changed to intravenous ampicillin for 14 days. Subsequent blood cultures were negative. Her immune evaluation showed normal T&B cells subsets and immunoglobulins except for undetectable IgM. L. lactis, commonly used as starters in milk and cheese fermentation and as probiotic supplement, can be pathogenic in immunocompromised patients and/or children with short gut syndrome. The child’s chromosomal abnormality with unbalanced paracentric inversion of chromosome 18, which involves two deletions and one duplication with chromosome 18q, has not been previously described in the medical literature. Associations of her chromosomal abnormality with an underlying immunodeficiency are unknown. Leuconostoc spp. catheter-related bacteremia in children with disrupted bowel mucosa receiving parenteral and enteral nutrition has been the most prevalent risk factor associated with sepsis. Different from previously reported cases, our patient required only enteral feeds and did not present with gastrointestinal symptoms. Antibiotic management is best addressed by susceptibility testing. Leuconostoc spp. are intrinsically resistant to vancomycin, and high minimum inhibitory concentrations to penicillin render them tolerant to therapy. Empiric antibiotics to consider include third-generation cephalosporins, alone or in combination with gentamicin. Promoting awareness of the potential complications associated with translocation of microorganisms found in food adjuncts used in children is warranted.