Successful treatment of multi-drug resistant Pseudomonas aeruginosa infection using ‘Break-point Checkerboard Plate’

Abstract

Infection is one of the major causes of death in patients on hemodialysis. We report the successful treatment of multi-drug resistant Pseudomonas aeruginosa (MDRP) using a ‘Break-point Checkerboard Plate (BC plate)’. A 71-year-old male was transferred to our hospital to treat fever of undetermined origin. Hemodialysis therapy had been initiated because of diabetic nephropathy and acute kidney injury due to sigmoid volvulus 6 months previously. He also underwent ileostomy and tracheostomy. His food was given through a nasogastric tube. He had suffered from mild to moderate fever since admission. Abdominal computed tomography revealed a retroperitoneal abscess. Chemotherapy and drainage were started. Gastrografin enema also revealed a minor intraperitoneal leak from the rectum. Despite the disappearance of the abscess and minor leak, the fever remained. Perirectal inflammation was observed, and MDRP was detected in the discharge from the drain placed into the rectum. MDRP is difficult to treat with a single antimicrobial agent in Japan. Treatment of MDRP requires combination therapy, although the antimicrobial effect is unclear. The BC plate is a 96-well plate combined with 2 of 8 antimicrobial agents diluted to breakpoint concentrations. We selected aztreonam and amikamycin judging from the BC plate results. We added fosfomycin to enhance the antibiotic effect due to its effects on drug penetration through biofilm produced by Pseudomonas aeruginosa. After these treatments, the culture of MDRP from the discharge became negative and the fever resolved. In the treatment of MDRP, the BC plate method is beneficial for the selection of antibiotic agents.