Treatment of carbapenem resistant enterobacteriaceae pneumonia with a tetracycline and aminoglycoside antibiotic combination: case report
Start Date
10-5-2016 1:00 PM
Description
Infections caused by carbapenem-resistant Enterobacteriaceae (CRE) present an emerging andcontinuously evolving public health threat in acute care settings in the developed world. This concern is further compounded by non-standard antibiotic regimens and high mortality associated with infections caused by CRE. Retrospective and prospective studies have evaluated various antibiotic regimens in the management of infections caused by CRE. Antibiotics currently used in the management of CRE infections include polymyxins, fosfomycin, aminoglycosides, and tigecycline. Carbapenem-containing regimens have shown improved outcomes in comparison to monotherapy in patients who have Enterobacteriaceae with a minimum inhibitor concentration (MIC) range for carbapenem resistance less than 8 mg/L. However, carbapenem-containing regimens have not shown improvement in infections caused by Enterobacteriaceae with MIC for carbapenems over 8 mg/L.The 84 year old Caucasian male presented to the emergency room of a community general medical and surgical hospital with 202 beds. He presented with shortness of breath, vomiting,and an irritated tracheostomy site. His past medical history was significant for diabetes, cerebrovascular accident, cataracts, anemia, hip replacement, chronic obstructive pulmonary disease (COPD), and dysphagia. Of note, he also had a history of aspiration pneumonia within the previous 90 days, recent tracheostomy, indwelling central line, urinary catheter, and gastrostomy tube. Baseline laboratory and vital signs indicated leukocytosis of 18,000 cells/microliters, lactic acidosis (2.7 mmol/L), hypotension with a blood pressure of 92/53 mm Hg, and a blood urea nitrogen level of 47 mg/dl. Further, a chest x-ray showed right lower lobe pneumonia and beige secretions were found upon aspiration of the lungs. Based on the history and presentation of the patient an empiric antimicrobial regimen was started with vancomycin and imipenem/cilastatin. On day 5, the sputum culture was complete and demonstrated growth of carbpenem resistant (MIC greater or equal to 16 mg/L) Klebsiella pneumoniae (K. pneumoniae). The susceptibilities further indicated that the CRE was sensitive to tetracycline(MIC equal to 4 mg/L) and aminoglycosides (MIC equal to 4 mg/L). The antibiotic regimen was thereby switched to doxycycline and gentamicin. On day 8, x-ray of the chest showedimprovement of right lower lobe pulmonary effusion. After 3 weeks in the hospital the patient was released to long term acute care continued on oral doxycycline until follow up could occur 5-7 days later. Doxycycline and gentamicin have been shown to have in vitro activity against carbapenem resistant K. pneumoniae isolates, further their combination shows synergy in doxycycline susceptible but carbapenem resistant K. pneumoniae isolates. Still, clinical data is limited in the use of this combination in patients with pneumonia caused by carbapenem resistant K. pneumoniae. The successful management of this patient with doxycycline and gentamicin demonstrates the potential for a cost effective alternative combination regimen for treating CRE infections.
Treatment of carbapenem resistant enterobacteriaceae pneumonia with a tetracycline and aminoglycoside antibiotic combination: case report
Infections caused by carbapenem-resistant Enterobacteriaceae (CRE) present an emerging andcontinuously evolving public health threat in acute care settings in the developed world. This concern is further compounded by non-standard antibiotic regimens and high mortality associated with infections caused by CRE. Retrospective and prospective studies have evaluated various antibiotic regimens in the management of infections caused by CRE. Antibiotics currently used in the management of CRE infections include polymyxins, fosfomycin, aminoglycosides, and tigecycline. Carbapenem-containing regimens have shown improved outcomes in comparison to monotherapy in patients who have Enterobacteriaceae with a minimum inhibitor concentration (MIC) range for carbapenem resistance less than 8 mg/L. However, carbapenem-containing regimens have not shown improvement in infections caused by Enterobacteriaceae with MIC for carbapenems over 8 mg/L.The 84 year old Caucasian male presented to the emergency room of a community general medical and surgical hospital with 202 beds. He presented with shortness of breath, vomiting,and an irritated tracheostomy site. His past medical history was significant for diabetes, cerebrovascular accident, cataracts, anemia, hip replacement, chronic obstructive pulmonary disease (COPD), and dysphagia. Of note, he also had a history of aspiration pneumonia within the previous 90 days, recent tracheostomy, indwelling central line, urinary catheter, and gastrostomy tube. Baseline laboratory and vital signs indicated leukocytosis of 18,000 cells/microliters, lactic acidosis (2.7 mmol/L), hypotension with a blood pressure of 92/53 mm Hg, and a blood urea nitrogen level of 47 mg/dl. Further, a chest x-ray showed right lower lobe pneumonia and beige secretions were found upon aspiration of the lungs. Based on the history and presentation of the patient an empiric antimicrobial regimen was started with vancomycin and imipenem/cilastatin. On day 5, the sputum culture was complete and demonstrated growth of carbpenem resistant (MIC greater or equal to 16 mg/L) Klebsiella pneumoniae (K. pneumoniae). The susceptibilities further indicated that the CRE was sensitive to tetracycline(MIC equal to 4 mg/L) and aminoglycosides (MIC equal to 4 mg/L). The antibiotic regimen was thereby switched to doxycycline and gentamicin. On day 8, x-ray of the chest showedimprovement of right lower lobe pulmonary effusion. After 3 weeks in the hospital the patient was released to long term acute care continued on oral doxycycline until follow up could occur 5-7 days later. Doxycycline and gentamicin have been shown to have in vitro activity against carbapenem resistant K. pneumoniae isolates, further their combination shows synergy in doxycycline susceptible but carbapenem resistant K. pneumoniae isolates. Still, clinical data is limited in the use of this combination in patients with pneumonia caused by carbapenem resistant K. pneumoniae. The successful management of this patient with doxycycline and gentamicin demonstrates the potential for a cost effective alternative combination regimen for treating CRE infections.