Occurrence of human-associated yeasts in bivalve shellfish from Long Island Sound

Abstract

Candida parapsilosis, C. tropicalis, and Torulopsis glabrata were the human-associated yeasts most frequently isolated from quahogs, oysters, and mussels collected from four estuarine areas along the northern shore of Long Island Sound. Some inconsistency and seasonal variation in the occurrence of these and other yeast species were noted. In particular, C. albicans densities were greatest during colder months in the more heavily polluted waters. A total of 347 yeasts were isolated and cultured at 37°C and, of these, 219 or 62% were human-associated forms. Generally, these yeasts in the animals sampled reflected the overall pollution status of the estuary from which they were taken. This study represents a clear demonstration of potentially pathogenic yeasts in a valuable marine resource. The occurrence of human pathogenic microorganisms in native populations of bivalve molluscs is well-documented (4-6, 9, 14, 20, 25, 27, 35, 37-39, 42). In addition, a variety of shellfish species have been shown to accumulate and eliminate coliforms (10, 11, 24), other bacteria (26), and virtlses (15, 30) under experimental conditions. These reports, in addition to outbreaks of viral hepatitis traced to the consumption of raw shellfish (7), indicate that recreationally and economically valuable bivalve molluscs represent a potential health hazard in some areas. Considering the filtering capacities of molluscan shellfish for particles in the yeast cell size range (23) and the known presence and survival of human pathogenic yeasts in coastal

Marine yeasts—a review

“…It was speculated that these yeasts might serve as food, but feeding experiments showed that they could not be utilized as a sole food source by the crabs. Buck et al ,20 investigating bivalve shellfish in Long Island Sound, noted that, in general, the liquid portion of the shellfish contained more yeasts than the internal viscera.…”

High prevalence of fluconazole resistant Candida tropicalis among candiduria samples in China: An ignored matter of concern

“…There are two potential explanations on the origin and/or evolution of high azole resistance in candiduria C. tropicalis isolates. First, apart from being part of the human normal microbiota, C. tropicalis is also found in other animals and in wide-range of environment such was water and sands (Buck et al, 1977;Zuza-Alves et al, 2016. Therefore, it is possible that azole resistant C. tropicalis isolates originated from the natural environment spread to humans as colonizers and become a source of invasive infections.…”

Synergistic Antifungal Activities of Thymol Analogues with Propolis

“…Propolis (bee glue), a valuable byproduct of apiculture, found in honeybee hives, has been suggested to possess antifungal activities [11,12]. This encouraged us to study the antifungal activity of some thymol analogues individually, and in combination with propolis, against Candida albicans (ATCC 36232), Saccharomyces cerevisiae (ATCC 2366), and Penicillium rastrickii (ATCC 10490), which are involved in meat spoilage, and certain animal and human diseases [13,14]. The minimum inhibitory concentration (MIC) for propolis, thymol and its analogues against such fungal species varied depending on the tested compound and the sensitivity of the target strain of fungus.…”