Background: Minimum inhibitory concentration (MIC) breakpoints of selected cephalosporins and carbapenems against Enterobacteriaceae have been revised by major guidelines including CLSI and EUCAST mainly according to available pharmacokinetic/pharmacodynamic data. A decrease of breakpoint may obviate the need to detect specific resistance mechanisms such as extended-spectrum -lactamase (ESBL) and carbapenemase, which may be less correlated to treatment outcome than does the actual MIC of each agent.
Objective: To analyze cephalosporin and carbapenem MIC distributions among ESBL-producing Enterobacteriaceae at a university hospital against revised interpretative breakpoints.
Methods: MIC distributions of selected cephalosporins and carbapenems among 505 isolates of genotypically confirmed ESBL-producing Enterobacteriaceae were determined by E-testTM method and analyzed according to interpretative breakpoints comparing between CLSI and EUCAST guidelines.
Results: ESBL-producing Enterobacteriaceae demonstrated a wide range of cephalosporin MIC (≤1 to ≥64). Up to 9.7% of isolates displayed MIC lower than a revised cephalosporin breakpoint. Most isolates remained susceptible to imipenem and meropenem while as high as 24.6% were not susceptible to ertapenem. Lowered breakpoints may result in a change in categorical interpretations.
Conclusion: ESBL-producing isolates could be reported as susceptible to a cephalosporin with revised breakpoints although clinical use is uncertain. A higher proportion of isolates would be reported as nonsusceptible to cephalosporins or carbapenems with lowered breakpoints and thus increasing use of broadspectrum antimicrobial agents should be monitored.
Abstract Background: Vibrio vulnificus infection is prevalent among tropical coastal regions and septicemia due to this bacterium is often rapidly fatal. Our review of V. vulnificus cases in Thailand included microbiological and clinical analyses which have rarely been documented. They included a rare complication of rhabdomyolysis which has never been reported in this country.
Objective: We reported a case series of V. vulnificus septicemia at a university hospital in Thailand during a 12-year period including two fatal cases with rhabdomylysis due to V. vulnificus infection.
Methods: Our case series of patients with V. vulnificus septicemia was retrospectively reviewed to determine clinical presentations, risk factors, microbiologic data, hospital courses, treatment, and outcomes.
Results: Twenty-nine patients, predominantly male, were identified. Most patients had underlying cirrhosis or related chronic liver diseases and 20 cases (69%) died rapidly. Cellulitis and necrotizing fasciitis were common presenting symptoms. Consumption of undercooked shellfish may be a local risk factor. Inadequate surgical intervention may be related to a high mortality rate. Two fatal cases with autopsy-proven acute massive rhabdomyolysis were described, which emphasized urgent appropriate management.
Conclusion: This 29-case series identified that V. vulnificus septicemia had a high mortality rate. Chronic liver diseases are known underlying factors. Acute massive rhabdomyolysis is very rare as a fatal complication of V. vulnificus infection.