Test plates were automatically read and results were recorded with the BIOMIC Vision Image Analysis System. Species, drug, zone diameter, susceptibility category, and quality control results were collected quarterly via e-mail for analysis. Duplicate (the same patient, same species, and same susceptible-resistant biotype profile during any 7-day period) and uncontrolled test results were not analyzed. The 10 most common species of yeasts all showed less resistance to voriconazole than to fluconazole. Candida krusei showed the largest difference, with over 70% resistance to fluconazole and less than 8% to voriconazole. All species of yeasts tested were more susceptible to voriconazole than to fluconazole, assuming proposed interpretive breakpoints of >17 mm (susceptible) and <13 mm (resistant) for voriconazole. MICs reported in this study were determined from the zone diameter in millimeters from the continuous agar gradient around each disk, which was calibrated with MICs determined from the standard CLSI M27-A2 broth dilution method by balanced-weight regression analysis. The results from this investigation demonstrate the broad spectrum of the azoles for most of the opportunistic yeast pathogens but also highlight several areas where resistance may be progressing and/or where previously rare species may be "emerging."

Clostridium difficile-associated diarrhoea (CDAD) presents mainly as a nosocomial infection, usually after antimicrobial therapy. Many outbreaks have been attributed to C. difficile, some due to a new hyper-virulent strain that may cause more severe disease and a worse patient outcome. As a result of CDAD, large numbers of C. difficile spores may be excreted by affected patients. Spores then survive for months in the environment; they cannot be destroyed by standard alcohol-based hand disinfection, and persist despite usual environmental cleaning agents. All these factors increase the risk of C. difficile transmission. Once CDAD is diagnosed in a patient, immediate implementation of appropriate infection control measures is mandatory in order to prevent further spread within the hospital. The quality and quantity of antibiotic prescribing should be reviewed to minimise the selective pressure for CDAD. This article provides a review of the literature that can be used for evidence-based guidelines to limit the spread of C. difficile. These include early diagnosis of CDAD, surveillance of CDAD cases, education of staff, appropriate use of isolation precautions, hand hygiene, protective clothing, environmental cleaning and cleaning of medical equipment, good antibiotic stewardship, and specific measures during outbreaks. Existing local protocols and practices for the control of C. difficile should be carefully reviewed and modified if necessary.

The susceptibilities of 824 Bacteroides fragilis group isolates against nine antibiotics were evaluated in a Europe-wide study involving 13 countries. Species determination, by different methods, was carried out on all but one isolate. Resistance rates were evaluated according to species and geographical areas via CLSI and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. The present data were compared with those obtained 10 and 20 years ago at a European level. High-level resistance (MIC ≥ 64 mg/L) to ampicillin was observed in 44.5% of the strains, which is a significant increase relative to 20 years ago (16%). Piperacillin/tazobactam was more active than amoxicillin/clavulanic acid (3.1% and 10.4% resistance, respectively), again with a resistance increase relative to earlier studies. Dramatic increases in resistance were observed for cefoxitin, clindamycin and moxifloxacin, with rates of 17.2%, 32.4% and 13.6%, respectively. The lowest resistances were found for imipenem, metronidazole and tigecycline (1.2%, <1% and 1.7%). Nonsusceptible strains to imipenem and metronidazole were more resistant to other anti-anaerobic drugs. Differences were detected between geographical areas, with higher resistance rates for moxifloxacin in Scandinavian countries (21.4%) than in Mediterranean countries (5.4%), whereas, for clindamycin, the resistance rates were higher in Mediterranean (41.8%) and lower in Scandinavian countries (22.5%). Piperacillin/tazobactam resistance was also higher in Scandinavian countries.

Candida krusei is well known as a fungal pathogen for patients with hematologic malignancies and for transplant recipients. Using the ARTEMIS Antifungal Surveillance Program database, we describe geographic and temporal trends in the isolation of C. krusei from clinical specimens and the in vitro susceptibilities of 3,448 isolates to voriconazole as determined by CLSI (formerly NCCLS) disk diffusion testing. In addition, we report the in vitro susceptibilities of bloodstream infection isolates of C. krusei to amphotericin B (304 isolates), flucytosine (254 isolates), anidulafungin (121 isolates), caspofungin (300 isolates), and micafungin (102 isolates) as determined by CLSI broth microdilution methods. Geographic differences in isolation were apparent; the highest frequency of isolation was seen for the Czech Republic (7.6%) and the lowest for Indonesia, South Korea, and Thailand (0 to 0.3%). Overall, 83% of isolates were susceptible to voriconazole, ranging from 74.8% in Latin America to 92.3% in North America. C. krusei was most commonly isolated from hematology-oncology services, where only 76.7% of isolates were susceptible to voriconazole. There was no evidence of increasing resistance of C. krusei to voriconazole from 2001 to 2005. Decreased susceptibilities to amphotericin B (MIC at which 90% of isolates were inhibited [MIC 90 ], 4 g/ml) and flucytosine (MIC 90 , 16 g/ml) were noted, whereas 100% of isolates were inhibited by <2 g/ml of anidulafungin (MIC 90 , 0.06 g/ml), micafungin (MIC 90 , 0.12 g/ml) or caspofungin (MIC 90 , 0.25 g/ml). C. krusei is an uncommon but multidrugresistant fungal pathogen. Among the systemically active antifungal agents, the echinocandins appear to be the most active against this important pathogen.

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