New Delhi Metallo Beta Lactamase-1 Producing Gram-negative Bacteria in A Burn Unit: Management and Infection Control

Author(s):
Desiree Pinto; Shane Mathew; Lauren Moffatt; Taryn Travis; Jeffrey Shupp; Shawn Tejiram

Background:

Severe burn injury induces a unique immunocompromised state in affected patients. The leading cause of death in burn-injured patients is sepsis.  Infections are frequently caused by gram negative (GN) bacteria and are increasingly difficult to treat due to antibiotic resistance.  Resistance to carbapenems conferred by New Delhi metallo beta lactamase-1 (NDM-1) has become a global health concern, especially for susceptible burn-injured patients.

Hypothesis:

In this case series, we aim to describe a regional burn center’s strategy in the treatment and prevention of carbapenem resistant GN bacteria conferred by NDM-1.

Methods:

Patients admitted to a regional burn center with clinical isolates positive for NDM-1 were retrospectively reviewed from 2021 to 2023. Demographics, culture data, location of isolates, antibiotic treatment, infectious control measures, unit decontamination strategies, and clinical outcomes were collected.

Results:

Over a three-year period, seven total clinical isolates of carbapenem resistant GN bacteria conferred by NDM-1 were identified. Of these, six patients sustained burn injury sizes ranging from 15 to 65% and one patient was admitted with a desquamating rash secondary to beta-lactam antibiotics.  Clinical isolates were obtained from blood, bronchoalveolar lavage, and wound cultures. GN bacteria with NDM-1 resistance included Klebsiella pneumoniae, Enterobacter cloacae, Escherichia coli, and Acinetobacter baumannii. Infectious disease consultation was made following identification of NDM-1 resistance. Antibiotic regimens included the following, 7-day course of IV ceftazidime/avibactam (2 patients), 7-day course of IV ceftazidime/avibactam and IV aztreonam (2 patients), 7-day course of IV Amikacin and IV colistin (1 patient), 5-day course of nebulized Amikacin (1 patient), and 14-day course of IV cefidericol (1 patient). All patients demonstrated clearance on interval culture data following treatment. Unit control measures included contact precautions for NDM-1 patients up to one year, contact precautions for all patients on the unit, and both surveillance rectal and wound swabs for all patients on the unit. One patient died after developing ischemic bowel.

Conclusions:

Carbapenem resistance from NDM-1 is becoming more prevalent and represents a unique risk for patients with severe burn injury or desquamating cutaneous disease. Identifying successful antibiotic stewardship, multidisciplinary support, and decontamination practices is crucial to achieve infection clearance.