Rare Invasive Yeast Infections in Greek Neonates and Children, a Retrospective 12-Year Study

Although Candida species remain the leading cause of invasive fungal infections (IFI), the list of other isolated fungal pathogens is increasing. The aim of the study was to report cases of IFI caused by rare yeasts in the largest tertiary Greek pediatric hospital. A retrospective study was performed from 6/2008–6/2020 regarding IFI caused by rare species. Identification of isolates was attained by conventional, molecular, and MALDI TOF MS methods, and susceptibility testing was performed according to the Clinical and Laboratory Standards (CLSI) methodology. During a 12-year period, 14 different rare fungal species in 33 neonates and children with IFI hospitalized in intensive care and oncology units were isolated from blood, central catheters, peritoneal, pleural, or pericardial fluid specimens. It is the first time for IFI caused by Wickerhamomyces anomalus (Candida pelliculosa), Pichia fermentans (Candida lambica), Yarrowia (Candida) lipolytica, Pichia (Hansenula) kluyveri, Rhodotorula mucilaginosa, Wickerhamiella (Candida) pararugosa and Cyberlindnera (Candida) fabianii in Greek neonates and children to be reported. For most of these rare fungal species isolated in the present study, no official antifungal breakpoints have been defined, and there are no guidelines for their treatment. Clinical laboratories should be aware of uncommon and emerging yeast pathogens and be able to detect them with molecular and proteomic methods.

Isolation and Identification of Osmophilic Yeast from unripe Jackfruit (Artocarpus heterophyllus Lamk.)

Osmophilic yeast are microbes that are able to live on media with high sugar concentrations. Some types of osmophilic yeast can break down organic compounds, for example, starch. This research was aimed to isolate and identify existing osmophilic yeast in unripe jackfruits. In this research, the unripe jackfruit was left rotting and 2.5 g of the sample were taken to be solved in 25 ml 0.85% NaCl and diluted. The GYP (glucose-yeast-peptone) agar medium with the glucose concentration of 30–50% was suitable for osmophilic yeast growth. Isolate purification was performed using the streaking method from single colony. Isolates were identified based on physiological and morphological characteristics. The physiological characterization were carried out by running sugar assimilation test on the tool kit API 20C AUX, while the morphological characterization was carried out by performing macroscopic and microscopic observations. Four isolates were assumed to be Candida lambica, 3 isolates were assumed to be Candida rugosa and two isolates were assumed to be Geotrichum candidum. It was found out that 44.4% of yeast in the unripe jackfruit were Candida lambica, 33.3% was Candida rugosa and 22.2% was Geotrichum candidum. Candida lambica was the most common osmophilic yeast found in the jackfruit.

RARE CAUSATIVE AGENTS OF MAMMARY GLAND INFECTION

A brief case report on bovine subclinical mastitis caused by yeast species Candida lambica is presented in this article. Basic cultural, microscopic and biochemical traits of this rare agent implicated in bovine mammary infection are described. Identifi cation of isolates was performed using an Integral System Yeasts Plus test, a commercial kit for identifi cation of yeasts of importance in medicine. Th e available literature off ers only sporadic reportson C. lambica infection in both humans and animals.

Conversion of Ferulic Acid to 4-Vinylguaiacol by Yeasts Isolated from Frozen Concentrated Orange Juice

Yeasts were isolated from frozen concentrated orange juice, grown in Sabouraud dextrose broth at 25°C, and tested for the ability to cometabolize ferulic acid. Strains of Rhodotorula sp., Candida lambica, Trichosporon pullulans, and Candida intermedia decarboxylated ferulic acid nonoxidatively to an off-flavor compound, 4-vinylguaiacol. By decarboxylating naturally occurring ferulic acid, these and other yeasts have the potential to contribute to off flavors in improperly stored fruit juices.

Killer activity of yeasts isolated from the water environment

The killer activity of 46 strains belonging to 12 yeast and yeast-like species isolated from water or sediment samples was studied. Only two strains of the genus Cryptococcus did not show killer activity. Killer activity of yeast-like species Aureobasidium pullulans, Hyphopichia burtonii and Geotrichum candidum, and yeast species Candida krusei and Candida lambica was low. Sporobolomyces salmonicolor, Cryptococcus laurentii and Cryptococcus albidus had better activity against basidiomycetous than ascomycetous species. Hansenula anomala strains showed good activity against Geotrichum candidum strains, Cryptococcus albidus, and Sporobolomyces salmonicolor. Rhodotorula species showed activity against the majority of both ascomycetous and basidiomycetous species.Key words: yeasts, killer activity, sediment and water samples.