fidaxomicin and Bacteremia

We investigated the antimicrobial resistance trends and profiles of clinical anaerobic isolates in northern Taiwan. Trends in the susceptibility of five commonly encountered clinical anaerobic isolates to seven agents from 2008 to 2012 were measured using the Cochran-Armitage trend test. The minimum inhibitory concentrations (MICs) of 16 antimicrobial agents, including fidaxomicin and rifaximin, against anaerobic blood isolates from two medical centers were determined using the agar dilution method. During the study period, susceptibility data on 11,105 isolates were evaluated. Metronidazole and chloramphenicol retained excellent activities. Around 20-30 % of isolates of Bacteroides and Prevotella species were resistant to ampicillin-sulbactam, cefmetazole, flomoxef, and clindamycin. Of the 507 tested blood isolates, the rates of resistance to commonly used agents were much higher, namely, 16.2 % for amoxicillin-clavulanate, 15.6 % for ampicillin-sulbactam, 24.7 % for cefmetazole, and 36.1 % for clindamycin. Notably, 13.5 % of B. fragilis isolates were resistant to ertapenem. Also, 15.2 % of B. uniformis, 17.2 % of other Bacteroides species, 14.3 % of Prevotella species, and 14 % of Clostridium other than C. perfringens isolates were resistant to moxifloxacin. Cefoperazone-sulbactam was active against most isolates, except for Clostridium species other than perfringens (resistance rate, 18.6 %). Fidaxomicin exerted poor activities against most anaerobes tested (MIC90 of >128 μg/ml for B. fragilis and all isolates), except for C. perfringens (MIC90 of 0.03 μg/ml) and Peptostreptococcus micros (MIC90 of 2 μg/ml). However, rifaximin showed a wide range of susceptibilities against the tested anaerobes (MIC90 of 0.5 μg/ml for B. fragilis). The emergence of resistance to ertapenem and moxifloxacin among bacteremic anaerobes highlights the need for continuous monitoring.

Topics: Academic Medical Centers; Aminoglycosides; Anti-Infective Agents; Bacteremia; Bacteria, Anaerobic; Drug Resistance, Bacterial; Epidemiological Monitoring; Fidaxomicin; Humans; Microbial Sensitivity Tests; Rifamycins; Rifaximin; Taiwan

Clostridium difficile infection (CDI) and Klebsiella pneumoniae carbapenemase producing-Klebsiella pneumoniae (KPC-Kp) bloodstream infection (BSI) are emerging health-care associated (HCA) diseases of public health concern, in terms of morbidity, mortality, and insufficient response to antibiotic therapy. Both agents can be acquired in the hospital but clinical disease can develop in a community setting, after discharge. We report here a putative link between the above-mentioned healthcare associated infections that appeared as a dramatic community onset disease with a fulminant fatal outcome.. We describe the case of a 63 year old man affected by severe CDI. Even though the patient underwent 72 hours of standard CDI antibiotic treatment, the clinical course was complicated by toxic megacolon and KPC-Kp BSI. The patient died 24 hours after total colectomy.. The impact of HCA-BSIs in complicating CDI is still unknown. Intestinal inflammatory injury and disruption of intestinal flora by standard antibiotic treatment could be responsible for promoting difficult-to-treat infections in CDI. By preserving intestinal flora, Fidaxomicin could have a crucial role in preventing BSIs complicating severe CDI.

Topics: Aminoglycosides; Anti-Bacterial Agents; Bacteremia; Bacterial Proteins; beta-Lactamases; Clostridioides difficile; Clostridium Infections; Coinfection; Cross Infection; Fatal Outcome; Fidaxomicin; Hospitals; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Middle Aged