A highly polymorphic degenerate microsatellite for molecular strain typing of Candida krusei.

Simple sequence repeats, due to their high variability, are widely used for molecular epidemiology of pathogenic micro-organisms. However, their usefulness is restricted by their high instability and low information content. Here, a locus, CKTNR, in the fungal pathogen Candida krusei is described which displays considerable sequence, as well as length, heterogeneity. Alleles of this locus, which contains a degenerate trinucleotide repeat, appear to be stable. The CKTNR polymorphism could serve as the basis for a molecular typing system of C. krusei. Furthermore, analysis of the CKTNR allele distribution suggested that C. krusei reproduces mainly clonally.

Frequency of change of ventilator circuit in premature infants: Impact on ventilator-associated pneumonia.

OBJECTIVE: Ventilator-associated pneumonia (VAP) is associated with substantial mortality. The frequency of changing the ventilator circuit (VC) might influence the occurrence rate of VAP. In premature infants receiving ventilatory support, the question regarding the frequency of changing VC is as yet unsettled. DESIGN: A prospective, randomized, and controlled trial in 60 premature neonates receiving ventilatory support. INTERVENTIONS: We investigated the impact of two VC change regimens on VAP in premature infants, either every 24 hrs or every 72 hrs. In each patient, the humidifier, inspiratory tube, and expiratory tube were changed and cultured at the assigned intervals along with cultures of tracheal aspirates. Blood cultures were obtained whenever there was clinical evidence of pneumonia or sepsis. MEASUREMENTS AND MAIN RESULTS: The two study groups did not differ significantly in gestational age, birth weight, gender, duration of mechanical ventilatory support, surfactant therapy, duration of hospitalization, mortality rate, rate of bloodstream infection, or rate of colonization of tracheal aspirate, humidifier, and expiratory tube by microbes. The inspiratory tube was significantly less colonized in the 72-hr group as compared to the 24-hr group (p <.05). The rate of VAP per 1000 ventilator days was not higher in the 72-hr group, compared with the 24-hr group (23.3 vs. 37.7; not significant). Switching from a 24-hr to a 72-hr change policy would save our neonatal intensive care unit a yearly sum of $14,000 (US). CONCLUSIONS: Extending the VC-change interval in premature infants from 24 hrs to 72 hrs is safe and cost-effective.