Kubica Sebastian, Szulińska Weronika, Kruszniewska-Rajs Celina, Kimsa-Dudek Magdalena, Olender Alina, Bogut Agnieszka, Szukała Magdalena, Dąbrowski Wojciech, Pietrzak Daniel, Gagoś Mariusz, Gola Joanna Magdalena
Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, 40-055, Poland.
Chair and Department of Medical Microbiology, Medical University of Lublin, 20-093, Lublin, Poland.
Folia Microbiol (Praha). 2025 Jul 14. doi: 10.1007/s12223-025-01298-w.
The epidemiology data for candidiasis indicate an increase in Candida glabrata infections. Moreover, several reports have shown an increasing number of drug-resistant cases of these infections. The source of drug resistance can often be traced to genetic mutations in genes related to a drug's mechanism of action. Therefore, we conducted whole genome sequencing of several drug-resistant isolates of Candida glabrata collected from patients hospitalized in Eastern Poland to assess whether mutations in selected genes correlated with susceptibility analysis results. The fungal species from patient samples were identified, and the isolated Candida glabrata were subjected to antifungal drug susceptibility testing. The results were interpreted according to the EUCAST and CLSI recommendations. Susceptibility to 5-flucytosine was assessed using the ATB FUNGUS kit. Libraries were prepared according to the NEXTERA XT DNA Library Prep and subsequently sequenced. The outcomes indicated common resistance to two of the three analyzed echinocandins, as well as two cases of simultaneous resistance to echinocandins and selected azole-based drugs. We detected several previously reported mutations in selected resistance-related genes, as well as five that are first described here: ERG5 (M267I), ERG6 (R57K), PDH1 (K438Q, V434I, F600V, V1192S), FCY1 (M129T), and FCY2 (I384F). Neither of the identified nonsynonymous mutations was correlated with the drug resistance demonstrated in the susceptibility testing. Furthermore, we can exclude the possibility of acquired drug resistance, thereby raising questions about the possibility of unknown mechanisms of resistance to azole-based and echinocandin drugs.
念珠菌病的流行病学数据表明光滑念珠菌感染有所增加。此外，几份报告显示这些感染的耐药病例数量在增加。耐药性的来源通常可追溯到与药物作用机制相关基因的基因突变。因此，我们对从波兰东部住院患者中收集的几株光滑念珠菌耐药菌株进行了全基因组测序，以评估所选基因的突变是否与药敏分析结果相关。对患者样本中的真菌种类进行了鉴定，并对分离出的光滑念珠菌进行了抗真菌药敏试验。结果根据欧洲抗菌药物敏感性试验委员会（EUCAST）和美国临床和实验室标准协会（CLSI）的建议进行解读。使用ATB FUNGUS试剂盒评估对5-氟胞嘧啶的敏感性。根据NEXTERA XT DNA文库制备试剂盒制备文库，随后进行测序。结果表明，在所分析的三种棘白菌素中，有两种存在普遍耐药性，还有两例同时对棘白菌素和某些唑类药物耐药。我们在所选的耐药相关基因中检测到了几个先前报道的突变，以及五个在此首次描述的突变：ERG5（M267I）、ERG6（R57K）、PDH1（K438Q、V434I、F600V、V1192S）、FCY1（M129T）和FCY2（I384F）。所鉴定的非同义突变均与药敏试验中显示的耐药性无关。此外，我们可以排除获得性耐药的可能性，从而引发了关于对唑类和棘白菌素类药物未知耐药机制可能性的疑问。
