Isolation and molecular identification of keratinophilic fungi from public parks soil in Shiraz, Iran

Pathogenic Drug Resistant Fungi: A Review of Mitigation Strategies

Fungal pathogens cause significant human morbidity and mortality globally, where there is a propensity to infect vulnerable people such as the immunocompromised ones. There is increasing evidence of resistance to antifungal drugs, which has significant implications for cutaneous, invasive and bloodstream infections. The World Health Organization (WHO) published a priority list of fungal pathogens in October 2022, thus, highlighting that a crisis point has been reached where there is a pressing need to address the solutions. This review provides a timely insight into the challenges and implications on the topic of antifungal drug resistance along with discussing the effectiveness of established disease mitigation modalities and approaches. There is also a need to elucidate the cellular and molecular mechanisms of fungal resistance to inform effective solutions. The established fungal decontamination approaches are effective for medical device processing and sterilization, but the presence of pathogenic fungi in recalcitrant biofilms can lead to challenges, particularly during cleaning. Future design ideas for implantable and reusable medical devices should consider antifungal materials and appropriates for disinfection, and where it is relevant, sterilization. Preventing the growth of mycotoxin-producing fungi on foods through the use of appropriate end-to-end processes is advisable, as mycotoxins are recalcitrant and challenging to eliminate once they have formed.

Culturable Fungi from Urban Soils in China I: Description of 10 New Taxa

An investigation of members of the soil keratinophilic fungi community in China resulted in the identification of one new monotypic genus, Zongqia, and 10 new species, 2 of which are affiliated with Solomyces, 1 with the new genus Zongqia, 4 with Pseudogymnoascus, and 3 with Scedosporium. These novel taxa form an independent lineage distinct from other species, based on morphological and multilocus phylogenetic analyses. Descriptions, illustrations, and notes are provided for each taxon. These new taxa of the soil keratinophilic fungi add to the increasing number of fungi known from China, and it is now evident that numerous novel taxa are waiting to be described.

IMPORTANCE Keratinophilic fungi are a group that can degrade and utilize keratin-rich material. It is also because of this ability that many taxa can cause infections in animals or humans but remain poorly studied. In this study, we reported a novel genus and 10 novel species, 7 novel species belonging to the order Thelebolales and 3 to the genus Scedosporium, based on multilocus phylogenetic analyses combined with morphological characteristics. Our study significantly updates the taxonomy of Thelebolales and Scedosporium and enhances our understanding of this group of the keratin-degrading fungal community. The findings also encourage future studies on the artificially constructed keratin-degrading microbial consortia.

Prevalence of superficial-cutaneous fungal infections in Shiraz, Iran: A five-year retrospective study (2015-2019)

Background

Superficial and cutaneous fungal infections are common in tropical areas. The aim of this study was to provide a basic database of superficial and cutaneous mycoses and the most common etiological agents among patients.

Methods

Between 2015 and 2019, a total of 1807 patients suspected of superficial and cutaneous mycosis referring to the mycology laboratory of Shiraz medical school, Fars, Iran were evaluated. Specimens were taken from the patients’ affected area, and clinical samples were examined by direct microscopy and culture. The epidemiological profile of the patients was collected.

Results

A total of 750 patients were confirmed with mycoses. Positive samples totaled 750 cases consisting of the nail (373/49.7%), skin (323/43%), head (47/6.26%), and mucosal membrane (4/0.5%). The yeasts group included 304 Candida spp. (70.3%), 123 Malassezia spp. (28.47%), and 5 Rhodotorula spp. (1.1%). The filamentous fungi were distributed as 34.8% dermatophytes and 7.5% non‐dermatophyte. The clinical types of dermatophytosis were tinea unguium (110/261), tinea capitis (50/261), tinea pedis (48/261), tinea corporis (37/261), and tinea cruris (16/261). Non‐dermatophyte molds included A. flavus 17, A. niger 4, Aspergillus spp. 15, Penicillium. 10, Fusarium 6, Mucor 2, Stemphylium 1, and Alternaria 1.

Conclusion

This study provides useful data for the study trends of superficial and cutaneous fungal infections in a specific area. The mycological data confirmed higher incidence of candidiasis (mainly onychomycosis) and dermatophytosis in patients affected by fungal pathogens, which helped to better understand the epidemiological aspects of these mycoses.

Diversity of Geophilic Dermatophytes Species in the Soils of Iran; The Significant Preponderance of Nannizzia fulva

A molecular epidemiology study was conducted between 2016 and 2017 by a network of collaborators from 12 provinces in the Islamic Republic of Iran. A total of 1484 soil samples from different habitats were screened for the presence of dermatophytes by using the hair baiting technique. The primary identification of isolates was carried out by amplification and MvaI restriction fragment length polymorphism (RFLP) of the internal transcribed spacers regions of ribosomal DNA (ITS-rDNA). The identifications, especially in the cases of isolates with unknown RFLP patterns, were confirmed by sequencing of the ITS-rDNA region. As a result, 256 isolates were recovered. The isolation rate was higher in soils with pH range 7.1–8.0, collected from animal habitats (n = 78; 34%) and parks and gardens (n = 75; 32%), geographically from Mazandaran Province (n = 115; 49.5%) and seasonally in the spring (n = 129; 50.4%), all of which were statistically significant (p < 0.05). The dermatophytes comprising five species of the two genera, viz., Nannizzia fulva (n = 214), N. gypsea (n = 34), Arthroderma quadrifidum (n = 5), A. gertleri (n = 2) and A. tuberculatum (n = 1), were isolated. The geophilic dermatophytes occurred in various soils from different parts of Iran; however, surprisingly, N. fulva emerged as the dominant species, outnumbering the common geophilic species of N. gypsea. For the definitive identification of soil inhabitant dermatophytes, DNA-based identification is strongly recommended.

DNA sequence analysis of keratinophilic fungi isolated from livestock stables in the East of Iran

BACKGROUND AND PURPOSE

Keratinophilic fungi play an important role in the decomposition of keratinous substances in nature. This capacity induces dermatomycosis in both humans and livestock. The soil of livestock stables can be a reservoir of keratinophilic fungi. Therefore, the present study was conducted to isolate and identify keratinophilic fungi in the soil of the livestock stables located in Qayen, South Khorasan Province, Iran.

MATERIALS AND METHODS

This study was conducted on 62 soil samples collected from livestock stables. The samples were cultured by means of hair bait technique (HBT). The identification of the isolates was performed based on their morphological characteristics and then confirmed by polymerase chain reaction and sequencing of the ITS regions of ribosomal DNA.

RESULTS

A total of 118 isolates of 7 species from 5 genera were identified. Aphanoascus verrucosu (n=70, 59.36%) was detected as the dominant keratinophilic fungus, followed by Arthroderma quadrifidum (n=13, 11.01%), A. terreus (n=12, 10.16%), Acremonium (n=12, 10.16%), A. gertleri (n=5, 4.23%), Fusarium equiseti (n=3, 2.54%), and Uncinocarpus reesii (n=3, 2.54%).

CONCLUSION

Different keratinophilic fungi were isolated from the soil of livestock stables; however, A. verrucosu was found to be the dominant species.

Children's public health: Danger of exposure to pathogenic fungi in recreational places in the middle-west region of Brazil

BACKGROUND

Dermatophytes are keratinophilic fungi, considered etiological agents of cutaneous mycoses in man and animals. The objective of this work was to isolate dermatophytic and non-dermatophytic fungi in recreational sandboxes (rainy and dry periods) in public day-care centers located in the city of Cuiabá-MT (Middle-west of Brazil).

METHODS

Samples (n=200) were collected from the superficial layer of the sandboxes at a depth of 2-5cm in 10 public nurseries in Cuiabá-MT. Hair baits measuring 1-2cm were autoclaved and dispersed in 50g of the sample in sterile plates, incubated at 28°C, moistened with chloramphenicol solution (50mg/L). After 6 weeks the baits were inoculated on Sabouraud agar plus 50mg/L chloramphenicol and 500mg/L cycloheximide. The fungi were identified according to macroscopic and micromorphological characteristics.

RESULTS

From the collected sand samples, 1318 colonies and 56 species of fungi belonging to 22 genera were isolated. The most important genera were Paecilomyces spp. (30.42%), Penicillium spp. (19.12%), Fusarium spp. (11.46%) and Aspergillus spp. (11.15%). Dermatophytes were recovered in 50% of day-care centers in a total of 29 identified colonies, the Trichophyton genus (86.2%) being the most frequently isolated.

CONCLUSIONS

The dermatophytes in the recreational areas of day-care centers can pose a risk to the health of its users, especially for children and the employees. Work with this profile is very important to guide actions related to health surveillance.

Frequency Distribution of Keratinophilic Dermatophyte Fungi from the Soil of Different Zones in Isfahan Using Morphological and Molecular Methods

Background:

Dermatophytes are one of the most important etiologic agents of cutaneous infections in humans and animals. The present study aimed to study the frequency distribution of keratinophilic dermatophyte fungi using conventional and molecular methods in soil of Isfahan city.

Materials and Methods:

In this study, 200 soil samples were randomly selected in three northern, southern, and central parts of Isfahan using hair-baiting technique. The fungi were identified by morphology based on macroscopic and microscopic characteristics of fungi. Furthermore, the sequencing of ITS1-5.8S-ITS2 region of the ribosomal DNA of the 60 randomly isolated fungi was investigated.

Results:

The results of conventional method showed that from a total of 371 fungal colonies, the highest amount of detected colonies was in the central zone (151, 40.26%). Furthermore, in all three areas, the most common detected dermatophyte was Microsporum gypseum (38.3%). The results of the molecular analysis showed that M. gypseum identified by the morphology method was Nannizzia fulva, and also, Chrysosporium sp. with the frequency of 30% in morphology method was the second dominated fungus including Chrysosporium keratinophilum (42.6%) and Chrysosporium shanxiense (21.4%) which confirmed by sequencing method.

Conclusion:

The results showed that keratinophilic dermatophyte fungi including Nannizzia fulva, Chrysosporium sp., and Trichophyton mentagrophytes are found in the children playgrounds in Isfahan. Therefore, health-care officials should pay more attention to these hygienic issues. C. shanxiense, which is found here for the first time in Iran, has been reported only from China.

Indoor damp surfaces harbor molds with clinical significance

Background and Purpose:

Fungal contamination in damp places in buildings has become an increasing problem worldwide. Dampness facilitates the growth of fungi, which can cause adverse effects not only on the buildings but also on their occupants. The aim of this study was to identify indoor mold species in the buildings of Kerman province, Iran.

Materials and Methods:

In this study, 110 samples were obtained from surfaces of damp indoor areas in buildings randomly selected in Kerman province. The identification of fungal species was based on the macroscopic and microscopic characteristics of the isolates, such as colony morphology, hyphae, conidia, and conidiophores, as well as molecular sequence data.

Results:

Based on the results, a total of 218 fungal isolates were obtained. Apart from frequently isolated fungi, such as Alternaria, Aspergillus, and Penicillium, 13 species, including Cladosporium sphaerospermum, Cladosporium herbarum, Cladosporium halotolerans, Engyodontium album, Collariella bostrychodes, Stachybotrys xigazenensis, Ramularia eucalypti, Fusarium merismoides, Fusarium solani, Ochroconis musae, Mucor racemosus, Acremonium zonatum, and Acremonium persicinum were identified, and the selected species were described. Among these 13 species, Cladosporium was the most common species (43%) in indoor surfaces, followed by Ochroconis musae (10.8%) and Engyodontium album (7.4%). To the best of our knowledge, Stachybotrys xigazenensis was reported in the present study for the first time in Iran. In addition, E. album and O. musae were isolated for the first time from indoor surfaces in Iran.

Conclusion:

According to the results, the level of overall fungal richness across indoor surfaces was high. Some of the isolated taxa were clinically significant. It was concluded that the damp residential surfaces were potentially passive collectors of clinically significant molds.

Morpho-Molecular Characterization of Soil Inhabitant Dermatophytes from Ahvaz, Southwest of Iran, a High Occurrence of Microsporum fulvum

Occurrence and diversity of dermatophyte mycoflora in 298 soil samples from Ahvaz, Southwest of Iran was investigated by using the hair-baiting technique. The samples were collected during spring (n = 210) and autumn (n = 88) of 2015, and the fungal isolates were identified based on the macro- and micro-morphology of colonies and with further ITS-rDNA RFLP and sequencing. Totally, 60 soil samples (20.1%) were positive for dermatophyte growth whose pH varied from 7.0 to 7.9. The highest (26.6%) and the lowest (14.3%) recovery rates were from the animal resorts and the streets soils samples, respectively. Seasonally, 16.7% of the spring samples and 28.4% of the autumn samples were positive. Based on molecular identification, three species of two genera were identified viz. M. fulvum (n = 57), M. canis (n = 2) and zoophilic Trichophyton interdigitale (n = 1). As a specific goal in the study, differentiation of the species in Microsporum gypseum complex was established by measuring the mean length and width of macroconidia in some strains of M. gypseum, M. fulvum and M. incurvatum. Mean size for macroconidia length and width in three species showed that M. gypseum and M. incurvatum can morphologically be differentiated from M. fulvum but not from each other. M. fulvum was the most abundant species isolated from the soils of Ahvaz; however, to comprehensively specify the distribution pattern of geophilic dermatophytes in the soils of this city further investigations are needed. Identification based on micro-morphometric is not effective for species distinction in M. gypseum complex, while molecular procedures based on sequencing of certain DNA regions are the most reliable and applicable strategies for this purpose.

Preferential utilization and colonization of keratin baits by different myco-keratinophiles

Myco-keratinophilic species have a predilection for different keratinous substrates but show variability in their affinity towards them. Keeping this in view, a survey was conducted in the Khardung and Khardung La soils of Ladakh (India) and 28 myco-keratinophilic species belonging to 15 fungal genera (Sarocladium, Aspergillus, Beauveria, Chrysosporium, Cladosporium, Alternaria, Epicoccum, Fusarium, Gibberella, Clonostachys, Paecilomyces, Purpureocillium, Metarhizium, PenicilliumandSagenomella) were isolated by using keratin bait technique. These isolated species were tested for their preferential utilization ability and colonization on different baits by morphological assessment. Different types of keratin baits used were feathers, human hair, human nails and wool. Overall assessment revealed that feathers were colonized and utilized by all the species (100 %), followed in decreasing order by nails (89.29 %), hair (85.71 %) and sheep wool (67.86 %). So, it is concluded that feather baiting technique, could be more useful in trapping keratinophilic fungi than the hair baiting technique which is till date regarded as the best method for the isolation of myco-keratinophiles. On the basis of succession on keratinous baits, the recovered keratinophilic species were also categorized into four categories: early successional species (pioneer colonizers), late successional species (final colonizers), persistent species and no-pattern species.

The genome of newly classified Ochroconis mirabilis: Insights into fungal adaptation to different living conditions

BACKGROUND

Ochroconis mirabilis, a recently introduced water-borne dematiaceous fungus, is occasionally isolated from human skin lesions and nails. We identified an isolate of O. mirabilis from a skin scraping with morphological and molecular studies. Its genome was then sequenced and analysed for genetic features related to classification and biological characteristics.

RESULTS

UM 578 was identified as O. mirabilis based on morphology and internal transcribed spacer (ITS)-based phylogeny. The 34.61 Mb assembled genome with 13,435 predicted genes showed less efficiency of this isolate in plant cell wall degradation. Results from the peptidase comparison analysis with reported keratin-degrading peptidases from dermatophytes suggest that UM 578 is very unlikely to be utilising these peptidases to survive in the host. Nevertheless, we have identified peptidases from M10A, M12A and S33 families that may allow UM 578 to invade its host via extracellular matrix and collagen degradation. Furthermore, the lipases in UM 578 may have a role in supporting the fungus in host invasion. This fungus has the potential ability to synthesise melanin via the 1,8-dihydroxynaphthalene (DHN)-melanin pathway and to produce mycotoxins. The mating ability of this fungus was also inspected in this study and a mating type gene containing alpha domain was identified. This fungus is likely to produce taurine that is required in osmoregulation. The expanded gene family encoding the taurine catabolism dioxygenase TauD/TdfA domain suggests the utilisation of taurine under sulfate starvation. The expanded glutathione-S-transferase domains and RTA1-like protein families indicate the selection of genes in UM 578 towards adaptation in hostile environments.

CONCLUSIONS

The genomic analysis of O. mirabilis UM 578 provides a better understanding of fungal survival tactics in different habitats.

Growth of marine fungi on polymeric substrates

BACKGROUND

Marine fungi are a diverse group of opportunistic and obligate organisms isolated from marine environments. These fungi are now often included in screens for novel metabolites, while less attention has been given to their production of hydrolytic enzymes. Most enzymes derived from marine microorganisms have been obtained from marine bacteria. The enzymes produced by marine fungi may have different properties than those derived from bacteria or from terrestrial fungi. Here we assess the growth of six filamentous marine fungi on a wide range of polymeric substrates as an indication of their general capacity to produce hydrolytic enzymes.

RESULTS

Calcarisporium sp. KF525, Tritirachium sp. LF562, Bartalinia robillardoides LF550, Penicillium pinophilum LF458, Scopulariopsis brevicaulis LF580 and Pestalotiopsis sp. KF079 all grew on both casein and gelatin as N-source, indicating secretion of proteases. All species also grew on starch, laminarin, xylan, pectin and oil, indicating production of amylases, glucanases, xylanases, pectinases and lipases. Growth on cellulose occurred but was weaker than on xylan. All strains also grew to some extent on sulphated arabinogalactan, although only LF562 could utilise arabinose. Four strains grew on the sulphated ulvans, whereas only KF525 grew on agar or carrageenan. KF525 and LF562 showed limited growth on alginate. Although fucose was used as carbon source by several species, fucoidan did not support biomass production.

CONCLUSIONS

Marine fungi could be excellent sources of a wide range of hydrolytic enzymes, including those able to hydrolyse various seaweed polymers. Although the native hosts may secrete only small amounts of these enzymes, the genes may provide a rich source of novel enzymes.

Biotechnological Aspects and Perspective of Microbial Keratinase Production

Keratinases are proteolytic enzymes predominantly active when keratin substrates are available that attack disulfide bridges in the keratin to convert them from complex to simplified forms. Keratinases are essential in preparation of animal nutrients, protein supplements, leather manufacture, textile processing, detergent formulation, feather meal processing for feed and fertilizer, the pharmaceutical and biomedical industries, and waste management. Accordingly, it is necessary to develop a method for continuous production of keratinase from reliable sources that can be easily managed. Microbial keratinase is less expensive than conventionally produced keratinase and can be obtained from fungi, bacteria, and actinomycetes. In this overview, the expansion of information about microbial keratinases and important considerations in keratinase production are discussed.

Distribution of Keratinophilic Fungi in Soil Across Tunisia: A Descriptive Study and Review of the Literature

Data on the frequency and distribution of keratinophilic fungi in soil of Tunisia are scanty. The present survey aimed to describe the distribution of keratinophilic fungi in soils collected in Tunisia. Keratinophilic fungi were isolated using Vanbreuseghem's hair-baiting technique from 354 soil samples collected in 15 governorates of Tunisia and identified according to their morphology with further DNA and MALDI-TOF analysis when necessary. Keratinophilic fungi were isolated from 46.3 % of the samples from 14 governorates. Chrysosporium keratinophilum was the predominant species (30.5 %) followed by Microsporum gypseum (27.4 %). Other isolated species included C. tropicum (14.0 %), C. indicum (11.0 %), Chaetomium sp. (4.9 %), Arthroderma curreyi, Arthroderma cuniculi (3.7 % each), C. merdarium (3.1 %), Anixiopsis stercoraria, C. parvum, Paecilomyces lilacinus, Auxarthron zuffianum (2.4 % each), Fusarium oxysporum, Aphanoascus verrucosus, Gymnascella dankaliensis (1.2 % each) and 12 other species (0.6 % each). Two to five distinct fungal species were associated with 11.5 % of the positive samples. Keratinophilic fungi were more frequently isolated in rural (54.8 %) than in urban (41.1 %) areas (p = 0.012). The highest (100 %) positive culture rate was noted in soil collected in stables. Keratinophilic fungi are frequent throughout Tunisian territory, particularly in soils with a high organic matter content that should be regarded as humans and animals mycoses reservoir.

Incidence of Keratinophilic Fungi from Selected Soils of Vidarbha Region of Maharashtra State, India

One hundred and fifty samples were collected from eleven districts of Vidarbha region of Maharashtra state and screened for the presence of keratinophilic fungi using hair baiting technique for isolation. Seventy-one isolates were recovered and identified. The cultures were identified using macro- and micromorphological features. Their identification was also confirmed by the BLAST search of sequences of the ITS1-5.8S-ITS2 rDNA region against the NCBI/Genbank data and compared with deposited sequences for identification purpose. Thirteen species of eight genera were isolated, namely, Auxarthron conjugatum (2.00%), Chrysosporium indicum (14.00%), Chrysosporium evolceanui (2.66%), Chrysosporium tropicum (4.66%), Chrysosporium zonatum (1.33%), Chrysosporium state of Ctenomyces serratus (3.33%), Gymnascella dankaliensis (1.33%), Gymnascella hyalinospora (0.66%), Gymnoascoideus petalosporus (0.66%), Microsporum gypseum complex (9.33%), Trichophyton mentagrophytes (2.00%), T. terrestre (3.33%), and Uncinocarpus queenslandicus (2.00%). This study indicates that the soils of Vidarbha region of Maharashtra may be significant reservoirs of certain keratinophilic fungi.

Draft Genome Sequence of Ochroconis constricta UM 578, Isolated from Human Skin Scraping

Ochroconis constricta is a soilborne dematiaceous fungus that has never been reported to be associated with human infection. Here we report the first draft genome sequence of strain UM 578, isolated from human skin scraping. The genomic information revealed will contribute to a better understanding of this species.