1. Fluconazole‐resistant Candida parapsilosis strains with a Y132F substitution in the ERG11 gene causing invasive infections in a neonatal unit, South Africa
- Author
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Rindidzani E. Magobo, Shawn R. Lockhart, Nelesh P. Govender, Jeannette Wadula, van Rensburg, Chris Janse van Rensburg, Andrew Whitelaw, Inge Zietsman, Norman Miller, Peter Smith, Johan van Greune, Adrian Brink, Anwar Hoosen, Olga Perovic, Maphoshane Nchabaleng, Heidi Orth, Yacoob Coovadia, Loekie Badenhorst, Johan Moolman, AK Peer, Chetna Govind, Ranmini Kularatne, Barry Bhagoobhai, Ben Prinsloo, Sumayya Haffejee, John Simpson, Greta Hoyland, Marthinus van Schalkwyk, Glenda Bowie, Patricia Hanise, Sandeep Vasaikar, Linda Wende, Tom Chiller, Angela Ahlquist‐Cleveland, and Jaymati Patel
- Subjects
Azoles ,0301 basic medicine ,Candida parapsilosis ,Genotype ,030106 microbiology ,Microbial Sensitivity Tests ,Dermatology ,Microbiology ,Fungal Proteins ,South Africa ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,C. parapsilosis ,Drug Resistance, Fungal ,medicine ,Humans ,Fluconazole ,Gene ,Genotyping ,Academic Medical Centers ,High prevalence ,biology ,Infant, Newborn ,Candidemia ,Infant ,General Medicine ,biology.organism_classification ,Nurseries, Hospital ,Infectious Diseases ,Amino Acid Substitution ,Fluconazole resistant ,Microsatellite ,Microsatellite Repeats ,medicine.drug - Abstract
INTRODUCTION The prevalence of azole resistance in C parapsilosis is very low in most parts of the world. However, South Africa has reported an exceptionally high prevalence of azole resistance in C parapsilosis strains isolated from candidaemia cases. We aimed to determine the possible molecular mechanisms of fluconazole resistance in C parapsilosis isolates obtained through surveillance at a large neonatal unit at a South African academic hospital. METHODS We sequenced the ERG11 and MRR1 genes of C parapsilosis isolates recovered from cases of neonatal candidemia, followed by microsatellite genotyping. A total of 73 isolates with antifungal susceptibility results were analysed. RESULTS Of these, 57 (78%) were resistant, 11 (15%) susceptible dose-dependent and 5 (7%) susceptible. The most commonly identified amino acid substitution within the ERG11 gene was Y132F in 68% (39/57) of fluconazole-resistant isolates and none in susceptible isolates. Three amino acid substitutions (R405K, G583R and A619V) and 1 nucleotide deletion at position 1331 were identified within MRR1 gene in 19 (26%) isolates. Microsatellite genotyping grouped isolates into four clusters (50 isolates). Cluster 1 accounted for 23% (17/73) of all cases, cluster 2 for 22% (16/73), cluster 3 for 14% (10/73) and cluster 4 for 10% (7/73). We found an association between cluster type and fluconazole resistance (P-value = .004). Isolates harbouring the Y132F substitution were more likely to belong to a cluster than non-Y132F isolates. CONCLUSION Fluconazole resistance in C parapsilosis strains from a single South African neonatal unit was associated with cluster type and predominantly driven by Y123F amino acid substitutions in the ERG11 gene.
- Published
- 2020
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