Ramos Lívia S, Figueiredo-Carvalho Maria Helena G, Silva Laura N, Siqueira Nahyara L M, Lima Joice C, Oliveira Samuel S, Almeida-Paes Rodrigo, Zancopé-Oliveira Rosely M, Azevedo Fabio S, Ferreira Adriana L P, Branquinha Marta H, Santos André L S
Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-901, RJ, Brazil.
Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro 21040-360, RJ, Brazil.
J Fungi (Basel). 2022 May 27;8(6):574. doi: 10.3390/jof8060574.
Although considered rare, the emergent species complex, formed by (), () and var. (), is highlighted due to its profile of increased resistance to the available antifungal drugs. In the present work, 25 clinical isolates, recovered from human infections during 2011-2020 and biochemically identified by automated system as , were initially assessed by molecular methods (amplification and sequencing of gene) for precise species identification. Subsequently, the antifungal susceptibility of planktonic cells, biofilm formation and susceptibility of biofilms to antifungal drugs and the secretion of key molecules, such as hydrolytic enzymes, hemolysins and siderophores, were evaluated by classical methodologies. Our results revealed that 7 (28%) isolates were molecularly identified as , 7 (28%) as and 11 (44%) as . Sixteen (64%) fungal isolates were recovered from blood. Regarding the antifungal susceptibility test, the planktonic cells were resistant to (i) fluconazole (100% of and Chv, and 72.7% of isolates), itraconazole and voriconazole (85.7% of and Chv, and 72.7% of isolates); (ii) no breakpoints were defined for posaconazole, but high MICs were observed for 85.7% of and , and 72.7% of isolates; (iii) all isolates were resistant to amphotericin B; and (iv) all isolates were susceptible to echinocandins (except for one isolate of ) and to flucytosine (except for two isolates of ). Biofilm is a well-known virulence and resistant structure in species, including the complex. Herein, we showed that all isolates were able to form viable biofilms over a polystyrene surface. Moreover, the mature biofilms formed by the species complex presented a higher antifungal-resistant profile than their planktonic counterparts. Secreted molecules associated with virulence were also detected in our fungal collection: 100% of the isolates yielded aspartic proteases, hemolysins and siderophores as well as phospholipase (92%), esterase (80%), phytase (80%), and caseinase (76%) activities. Our results reinforce the multidrug resistance profile of the species complex, including Brazilian clinical isolates, as well as their ability to produce important virulence attributes such as biofilms and different classes of hydrolytic enzymes, hemolysins and siderophores, which typically present a strain-dependent profile.
尽管被认为罕见，但由（）、（）和变种（）形成的新兴物种复合体因其对现有抗真菌药物的耐药性增加而受到关注。在本研究中，从2011年至2020年期间人类感染中分离出25株临床菌株，并通过自动化系统进行生化鉴定为，最初通过分子方法（基因扩增和测序）进行精确的物种鉴定。随后，采用经典方法评估浮游细胞的抗真菌药敏性、生物膜形成以及生物膜对抗真菌药物的敏感性，以及关键分子如水解酶、溶血素和铁载体的分泌情况。我们的结果显示，7株（28%）菌株经分子鉴定为，7株（28%）为，11株（44%）为。16株（64%）真菌菌株从血液中分离得到。关于抗真菌药敏试验，浮游细胞对（i）氟康唑耐药（100%的和Chv，以及72.7%的菌株）、伊曲康唑和伏立康唑耐药（85.7%的和Chv，以及72.7%的菌株）；（ii）泊沙康唑未定义断点，但85.7%的和以及72.7%的菌株观察到高MIC值；（iii）所有菌株对两性霉素B耐药；（iv）所有菌株对棘白菌素敏感（一株菌株除外），对氟胞嘧啶敏感（两株菌株除外）。生物膜是包括物种复合体在内的物种中一种众所周知的毒力和耐药结构。在此，我们表明所有菌株都能够在聚苯乙烯表面形成有活力的生物膜。此外，由物种复合体形成的成熟生物膜比其浮游对应物呈现出更高的抗真菌耐药性。在我们的真菌菌株收集中还检测到了与毒力相关的分泌分子：100%的菌株产生天冬氨酸蛋白酶、溶血素和铁载体，以及磷脂酶（92%）、酯酶（80%）、植酸酶（80%）和酪蛋白酶（76%）活性。我们的结果强化了物种复合体的多重耐药性，包括巴西临床分离株，以及它们产生重要毒力属性如生物膜和不同类别的水解酶、溶血素和铁载体的能力，这些通常呈现出菌株依赖性特征。
