Outbreak of extended-spectrum ß-lactamase-producing Klebsiella oxytoca infections associated with contaminated handwashing sinks(1).

Klebsiella oxytoca is primarily a health care-associated pathogen acquired from environmental sources. During October 2006-March 2011, a total of 66 patients in a hospital in Toronto, Ontario, Canada, acquired class A extended-spectrum ß-lactamase-producing K. oxytoca with 1 of 2 related pulsed-field gel electrophoresis patterns. New cases continued to occur despite reinforcement of infection control practices, prevalence screening, and contact precautions for colonized/infected patients. Cultures from handwashing sinks in the intensive care unit yielded K. oxytoca with identical pulsed-field gel electrophoresis patterns to cultures from the clinical cases. No infections occurred after implementation of sink cleaning 3×/day, sink drain modifications, and an antimicrobial stewardship program. In contrast, a cluster of 4 patients infected with K. oxytoca in a geographically distant medical ward without contaminated sinks was contained with implementation of active screening and contact precautions. Sinks should be considered potential reservoirs for clusters of infection caused by K. oxytoca.

Use of the Vitek-1 and Vitek-2 systems for detection of constitutive and inducible macrolide resistance in group B streptococci.

A prospective study of erythromycin and clindamycin resistance was performed with 304 consecutive group B streptococci (GBS) isolates. According to two automated susceptibility testing systems, Vitek-1 and Vitek-2, and double-disk agar diffusion, 79.9% were susceptible to both erythromycin and clindamycin. However, for macrolide-lincosamide-streptogramin B-inducible isolates, the accuracies of the Vitek-1 and Vitek-2 systems were 5.6 and 94.4%. In light of these results, we recommend that GBS be routinely tested using the double-disk diffusion method.