Achromobacter xylosoxidans, an emerging pathogen in catheter-related infection in dialysis population causing prosthetic valve endocarditis: a case report and review of literature.

INTRODUCTION: Dialysis catheter-related infection is a major cause of morbidity and mortality in patients on dialysis. In recent years, there have been reported cases of infections with opportunistic environmental organism, Achromobacter xylosoxidans (AX) causing bacteremia in patients on dialysis. However, no previous such reports on prosthetic valve endocarditis in a dialysis patient with Achromobacter xylosoxidans were found after a Medline search. We report such a case and review the literature. CASE: A 69-year-old diabetic man with bioprosthetic aortic valve replacement developed end-stage renal disease following infective endocarditis with Staphylococcus epidermidis. Even though he was treated successfully for his endocarditis, he developed further bacteremia with AX from his peripherally inserted central catheter (PICC) and the line was removed. He had further episodes of bacteremia with AX while having dialysis with tunneled line and the line was also removed. He was re-admitted with pyrexia and vegetations both in mitral and prosthetic aortic valve confirmed with transesophageal echo. His antimicrobial therapy with etrapenum, tigecycline and cotrimoxazole failed. He had both mitral and prosthetic aortic valve replacements but postoperatively developed multiorgan failure and died despite the intensive support. DISCUSSION: Achromobacter xylosoxidans is an aerobic, Gram-negative bacillus and considered to be an opportunistic pathogen with low virulence. Infective endocarditis is a potentially lethal complication of bacteremia. The choice of appropriate antibiotic is crucial in these cases. AX strains are highly resistant to antibiotics. The organism is usually susceptible to antipseudomonal penicillins, carbapenems and trimethoprim-sulfamethoxazole. CONCLUSION: AX is an emerging pathogen in catheter-related infection in the dialysis population and, therefore, needs vigilance and prompt treatment. Antimicrobial treatment should include susceptibility and synergy testing. Removal of central intravenous catheter should also be considered at the time of early presentation in patients at high risks of developing infective endocarditis.

Positron emission tomography does not add to computed tomography for the diagnosis and staging of pancreatic cancer.

BACKGROUND: Positron emission tomography (PET) has been proposed for pancreatic cancer diagnosis and staging. METHODS: 112 patients with suspected pancreatic cancer underwent 18F-fluoro-2-deoxy-D-glucose gamma camera PET and computed tomography (CT), of whom 62 also had laparoscopic ultrasonography and 70 underwent abdominal exploration for potential resection. The final diagnosis was malignancy in 78 and benign disease in 34 patients (25 with chronic pancreatitis). RESULTS: The diagnostic sensitivity and specificity for PET were 73 and 60% compared to 89 and 65% for CT respectively (Cohen's kappa = 0.59). In 30 patients CT was equivocal with cancer in 14 and benign disease in 16. PET correctly diagnosed 13 of these patients (cancer in 6 and benign disease in 7), interpreted 4 as equivocal (cancer in 3 and benign disease in 1) but was incorrect in the remaining 13 patients (cancer in 5 and benign disease in 8). The sensitivity and specificity for detecting small volume metastatic disease were 20 and 94% for CT and 22 and 91% for PET, respectively. CONCLUSION: PET had a similar accuracy to that of CT for imaging pancreatic cancer but it did not provide any additional information in patients with equivocal CT findings and currently would seem of little benefit for the staging of pancreatic cancer.