Yeasts isolated from tropical fruit ice creams: diversity, antifungal susceptibility and adherence to buccal epithelial cells

Abstract

Fruit-based ice creams are products widely consumed in tropical countries and, because of their composition, can be a good source for microbial growth, including opportunistic pathogens. The aims of this study were to characterize the yeast populations present in Brazilian fruit-based ice creams, and to investigate the antifungal susceptibility to amphotericin B, fluconazole and itraconazole, and the ability of the isolates that were able to grow at 37 ºC to adhere to buccal epithelial cells (BEC). Two hundred and sixty-seven yeast isolates obtained from the ice cream samples were identified as belonging to 29 species, with counts that ranged from 1.5 to 5.2 log CFU/mL. The predominant species were Candida intermedia, Torulaspora delbrueckii, C. parapsilosis, Clavispora lusitaniae, Saccharomyces cerevisiae and Pichia kudriavzevii. At least 16 yeast species isolated in this study have been reported as opportunistic pathogens. Forty-one yeast isolates showed resistance or dose-dependent susceptibility to at least one of the antifungal drugs tested. One isolate of C. parapsilosis was resistant to all the antifungals tested and showed ability to adhere to BEC. The percentage of adhesion to BEC was high mainly for isolates of P. kudriavzevii, Meyerozyma guilliermondii, C. parapsilosis, S. cerevisiae and Debaromyces hansenii. The data suggest that the presence of these opportunistic yeasts as contaminants in ice creams may represent a potential risk to the final consumer, especially to immunocompromised individuals who may consume these products.

Occurrence and Identification of Yeasts in Production of White-Brined Cheese

“…These species formerly belonged to the genus Cryptococcus, but after a recent reclassification they were assigned to the mentioned genera [55]. In accordance with this study, a few incidences of C. curvatus have been reported in the air of dairy environments [56], whereas P. flavescens has rarely been identified in dairy matrices such as ice cream and cheese brine [38,45]. The presence of C. moniliiforme is undesirable in white-brined cheese, as it is able to form melanin-like brown pigments, leading to product discoloration [57].…”

“…It is a common spoilage organism in various types of cheeses (brined, ripened, Swiss-type, blue-veined), characterized by high proteolytic and lipolytic activities [7,11,43]. Similar to C. auris, C. parapsilosis is considered as an opportunistic human pathogen causing invasive candidiasis [11,44,45]. At the same time, C. parapsilosis is regularly encountered in other fermented products, having positive impact on their organoleptic properties.…”

Distribution of Kazachstania Yeast in Thai Traditional Fermented Fish (Plaa-Som) in Northeastern Thailand

“…Our analysis revealed that these Candida yeasts were found in fermented fish samples from two provinces (20%). However, some of yeast strains, such as C. tropicalis , C. glabrata , C. intermedia , and C. parapsilosis , have been reported as spoilage yeasts and opportunistic human pathogens [ 58 , 59 , 60 , 61 , 62 ]. They may present as a result of unsanitary manufacturing processes.…”

“…They may present as a result of unsanitary manufacturing processes. Moreover, the use of raw fish without thermal treatment contributes to the presence of pathogens in the final product [ 58 , 59 , 63 , 64 , 65 ].…”

Characterization of spoilage microbiota through next-generation sequencing and application of spectroscopy-based technologies for assessing the microbiological quality of fresh-cut produce

“…isolates appeared to be phylogenetically related to F. circinatum. Recently,Lima et al (2019) found that in tropical fruit-based ice creams (including pineapple based) the predominant species were Candida intermedia, Torulaspora delbrueckii, Candida parapsilosis, Clavispora lusitaniae, Saccharomyces cerevisiae and Pichia kudriavzevii.…”