Pan-azole- and multi-fungicide-resistant Aspergillus fumigatus is widespread in the United States

Aspergillus fumigatus is an important global fungal pathogen of humans. Azole drugs are among the most effective treatments for A. fumigatus infection. Azoles are also widely used in agriculture as fungicides against fungal pathogens of crops. Azole-resistant A. fumigatus has been increasing in Europe and Asia for two decades where clinical resistance is thought to be driven by agricultural use of azole fungicides. The most prevalent mechanisms of azole resistance in A. fumigatus are tandem repeats (TR) in the cyp51A promoter coupled with mutations in the coding region which result in resistance to multiple azole drugs (pan-azole resistance). Azole-resistant A. fumigatus has been isolated from patients in the United States (U.S.), but little is known about its environmental distribution. To better understand the distribution of azole-resistant A. fumigatus in the U.S., we collected isolates from agricultural sites in eight states and tested 202 isolates for sensitivity to azoles. We found azole-resistant A. fumigatus in agricultural environments in seven states showing that it is widespread in the U.S. We sequenced environmental isolates representing the range of U.S. sample sites and compared them with publicly available environmental worldwide isolates in phylogenetic, principal component, and ADMIXTURE analyses. We found worldwide isolates fell into three clades, and TR-based pan-azole resistance was largely in a single clade that was strongly associated with resistance to multiple agricultural fungicides. We also found high levels of gene flow indicating recombination between clades highlighting the potential for azole-resistance to continue spreading in the U.S.IMPORTANCEAspergillus fumigatus is a fungal pathogen of humans that causes over 250,000 invasive infections each year. It is found in soils, plant debris, and compost. Azoles are the first line of defense antifungal drugs against A. fumigatus. Azoles are also used as agricultural fungicides to combat other fungi that attack plants. Azole-resistant A. fumigatus has been a problem in Europe and Asia for 20 years and has recently been reported in patients in the United States (U.S.). Until this study, we did not know much about azole-resistant A. fumigatus in agricultural settings in the U.S. In this study, we isolated azole-resistant A. fumigatus from multiple states and compared it to isolates from around the world. We show that A. fumigatus which is resistant to azoles and to other strictly agricultural fungicides is widespread in the U.S.

Neonatal Candida meningitis: significance of cerebrospinal fluid parameters and blood cultures

OBJECTIVE

The purpose of this study was to examine the frequency of normal cerebrospinal fluid (CSF) parameters in Candida meningitis and the proportion of candidemia associated with Candida meningitis.

STUDY DESIGN

We evaluated the initial lumbar puncture results from infants discharged from 150 Neonatal Intensive Care Units between 1997 and 2004. Candida meningitis was diagnosed by a positive CSF culture or positive Gram stain for yeast. We calculated two-tailed P-values using non-parametric testing, Mann-Whitney, Kruskal-Wallis or Fisher's exact tests where appropriate.

RESULTS

Twenty infants had culture-positive Candida meningitis. Normal CSF parameters were found in 43% (3/7) of the infants with Candida meningitis and only 37% (7/19) of them had positive blood cultures for Candida.

CONCLUSION

Normal CSF parameters do not exclude the diagnosis of neonatal Candida meningitis. The majority of infants in this cohort with Candida meningitis did not have evidence of candidemia at the time of diagnosis.