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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.

Surveillance and outbreak investigations are important epidemiological tools for assessing the frequency, distribution, and determinants of infections. The primary goal of these activities is to identify measures to reduce the burden of disease. This chapter describes examples of surveillance and approaches to outbreak investigations that have formed the basis of fungal infection control measures. However, considerable knowledge gaps exist, new threats are emerging (including antifungal resistance), and healthcare advances are making more people susceptible to severe fungal infections. Expanded surveillance efforts, timely outbreak detection, and effective outbreak investigations are needed to further reduce the burden of fungal infections. This will require confronting challenges that have held back fungal disease epidemiology, including limited clinical suspicion of fungal infections by clinical providers, difficulties in diagnosing fungal infections due to suboptimal diagnostic methods, limited availability of antifungal susceptibility testing and molecular subtyping, and a lack of mandated fungal disease surveillance in most countries.

Recent reports have demonstrated a decline in bacterial bloodstream infections (BSIs) following adherence to central line insertion practices; however, declines have been less evident for BSIs due to Candida species.