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Toxins May 2024Herbal medicines are widely used for clinical purposes worldwide. These herbs are susceptible to phytopathogenic fungal invasion during the culturing, harvesting,...
Herbal medicines are widely used for clinical purposes worldwide. These herbs are susceptible to phytopathogenic fungal invasion during the culturing, harvesting, storage, and processing stages. The threat of fungal and mycotoxin contamination requires the evaluation of the health risks associated with these herbal medicines. In this study, we collected 138 samples of 23 commonly used herbs from 20 regions in China, from which we isolated a total of 200 phytopathogenic fungi. Through morphological observation and ITS sequencing, 173 fungal isolates were identified and classified into 24 genera, of which the predominant genera were (27.74%) and (20.81%), followed by (11.56%), (7.51%), and (6.84%). Quantitative analysis of the abundance of both and in herbal medicines via RT-qPCR revealed that the most abundant fungi were found on the herb , reaching 300,000 copies/μL for and 700 copies/μL for . The in vitro mycotoxin productivities of the isolated and strains were evaluated by using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and it was found that the species mainly produced the acetyl forms of deoxynivalenol, while species mainly produced altertoxins. These findings revealed widely distributed fungal contamination in herbal medicines and thus raise concerns for the sake of the quality and safety of herbal medicines.
Topics: China; Drug Contamination; Fungi; Mycotoxins; Plants, Medicinal; Fusarium; Drugs, Chinese Herbal; Alternaria; Tandem Mass Spectrometry
PubMed: 38787081
DOI: 10.3390/toxins16050229 -
Marine Drugs May 2024Chemical investigation of marine fungus SYSU-MS0024 cultured on solid-rice medium led to the isolation of three new alkaloids, including a pair of epimers,...
Chemical investigation of marine fungus SYSU-MS0024 cultured on solid-rice medium led to the isolation of three new alkaloids, including a pair of epimers, nigrosporines A () and B (), and a pair of enantiomers, (+)-nigrosporine C (+)-, and (-)-nigrosporine C (-)-, together with eight known compounds (-). Their structures were elucidated based on extensive mass spectrometry (MS) and 1D/2D nuclear magnetic resonance (NMR) spectroscopic analyses and compared with data in the literature. The absolute configurations of compounds - were determined by a combination of electronic circular dichroism (ECD) calculations, Mosher's method, and X-ray single-crystal diffraction technique using Cu Kα radiation. In bioassays, compound exhibited moderate inhibition on NO accumulation induced by lipopolysaccharide (LPS) on BV-2 cells in a dose-dependent manner at 20, 50, and 100 μmol/L and without cytotoxicity in a concentration of 100.0 μmol/L. Moreover, compound also showed moderate acetylcholinesterase (AChE) inhibitory activities with IC values of 103.7 μmol/L. Compound exhibited moderate antioxidant activity with EC values of 167.0 μmol/L.
Topics: Alkaloids; Cholinesterase Inhibitors; Animals; Mice; Ascomycota; Cell Line; Nitric Oxide; Antioxidants; Molecular Structure; Acetylcholinesterase; Magnetic Resonance Spectroscopy; Lipopolysaccharides
PubMed: 38786605
DOI: 10.3390/md22050214 -
Mycobiology 2024145 fungal isolates were obtained from three sampling sites situated within the Nam River basin, located in the southern region of South Korea. Through ITS sequence...
145 fungal isolates were obtained from three sampling sites situated within the Nam River basin, located in the southern region of South Korea. Through ITS sequence analysis, the fungal isolates were identified to comprise 55 species of ascomycetes and 11 species of basidiomycetes. The 55 species of ascomycetes exclusively belong to the phylum Pezizomycotina, comprising 33 species of Dothideomycetes, 6 species of Eurotiomycetes, and 16 species of Sordariomycetes. Regarding their plant pathogenicity, an investigation into the fungi's ability to penetrate solid media revealed as displaying the highest growth, followed by , various species, species, and . Further research associating this penetration ability with fungal pathogenicity is deemed necessary. Among the 10 fungal species exhibiting penetration abilities, an examination of their capability to degrade biological polymers revealed that two strains of displayed exceptional polymer degradation. These strains exhibited remarkable abilities in decomposing malachite green and crystal violet, both recalcitrant dyes. This study underscores the potential utilization of fungal diversity in freshwater environments as a foundational approach to address freshwater pollution issues.
PubMed: 38690029
DOI: 10.1080/12298093.2024.2324575 -
Plant Disease Apr 2024Dragon fruit (Selenicereus monacanthus), renowned for its economic value and dual utility in both culinary and medicinal applications, is predominantly cultivated in...
Dragon fruit (Selenicereus monacanthus), renowned for its economic value and dual utility in both culinary and medicinal applications, is predominantly cultivated in China. In July 2023, a stem spot disease was found on dragon fruit ("Zi honglong" cultivar) plants with 37% incidence, in Huajiang Town (N25°40', E105°39'), Guanling County, Anshun City, Guizhou Province. The symptoms appeared as yellow spots surrounded by watery stains, then the spots expanded to suborbicular, which finally led stem to wither. Twelve symptomatic stem samples were collected in a 1.3-hectare plantation and cut into small pieces (5 mm × 5 mm), sterilized the surface with 75% ethanol for 30 seconds, washed 3 times with disinfected distilled water, moved to potato dextrose agar (PDA) medium, and incubated at 28°C for 5 days. Once the mycelium had developed, they were transferred to another PDA medium and cultured at 28°C for a period of 3-5 days. Totally fifteen identical strains were isolated, their colonies were white and round in shape; hyphae were smooth, hyaline; conidia were globose or subglobose, smooth, aseptate, 5.8-11.9 × 4.2-10.6 μm (av. = 8.8 × 7.4 μm, n = 30), light brown in early stage and gradually turning black over time; sterile cells were terminal on hyphae, pale to dark brown, uhceiform or oval, 17.5-21.6 × 4.6-8.7 μm (av. = 19.4 × 5.8 μm, n = 30). The morphologic characteristics of the isolates matched Nigrospora chinensis described by Wang et al. (2017). The PCR amplification was carried out by 3 primers ITS1/ITS4 (Vilgalys et al. 1990; White et al. 1990), EF1-728/EF2 (O'Donnell et al. 1998; Carbone et al. 1999) and BT2A/BT2B (Glass et al. 1995) belonged to the internal transcribed spacer (ITS), translation elongation factor-1 (TEF1) and β-tubulin (TUB2) gene loci, respectively. The sequences of a representative strain (GUCC 524) had 99.38% (ITS: 483/486 bp, PP391347 vs KX985970), 99.79% (TEF1: 482/483 bp, PP400678 vs KY019427) and 99.73% (TUB2: 372/373 bp, PP400677 vs KY019497) identities with those of N. chinensis (strain LC 3085). The phylogenetic tree constructed by three gene combinations showed that GUCC 524 was significantly clustered with N. chinensis. Ten 6-month-old dragon fruit ("Zi honglong" cultivar) seedlings were engrafted with 10 μL conidial suspension (1×105 conidia/mL), packaged with sealed film, two of them were inoculated with sterile distilled water as controls, and placed in a greenhouse at 28℃ for 10 days, inoculated plants showed yellow spots analogous to field symptoms, no symptoms were found in control plants. This experiment was repeated three times. Morphological character and molecular identification based on 3 gene loci of the strains isolated from the inoculated stems, were consistent with those of the original isolated strains. Therefore, based on morphological identification, phylogenetic analysis and pathogenicity test, the pathogen was identified as N. chinensis. Our study firstly reported N. chinensis as a pathogen causing stem spot disease on dragon fruit. N. chinensis is an important agent resulting for economic losses, previously reported on Camellia sinensis (Wang et al. 2017), Saccharum officinarum (Raza et al. 2019), Aucuba japonica (Qin et al. 2021). This report establishes a pivotal reference point for the progression of scientific strategies in preventing and controlling this disease associated with N. chinensis.
PubMed: 38679592
DOI: 10.1094/PDIS-02-24-0485-PDN -
Plant Disease Apr 2024Euonymus japonicus Thunb., belonging to the family Celastreace and native to East Asia, is a widely cultivated evergreen ornamental woody plant with important ecological...
Euonymus japonicus Thunb., belonging to the family Celastreace and native to East Asia, is a widely cultivated evergreen ornamental woody plant with important ecological and economic values. In May 2023, serious leaf blight of E. japonicus occurred in the campus green space at Guiyang University, Guizhou Province, China (26°55'85"N, 106°78'04"E). Early symptom appeared as small, circular light brown spots on the edges or tips of the leaves. Then, the spot developed visible necrosis, initially light brown to dark brown halos with clear margins. Subsequently, severely infected leaves appear totally wilt, and significantly decrease their ornamental values. In a 0.07-ha field, the disease incidence reached to 40-55%. To identify the pathogen, ten typical symptomatic E. japonicus leaves were collected. They were initially immersed in 75% ethanol for 3 min, and by sodium hypochlorite (4% NaClO) solution for 45 s, and ultimately rinsed with sterile distilled water (dH2O) five times for not less than 1 min each time, then, placed the leaves on potato dextrose agar (PDA) medium and cultured for 5 days at 25°C in constant temperature incubator. Cultures were purified to yield eight isolates. Early colonies are white and regularly rounded, gradually turning dark brown to black with fluffy mycelium. Conidia were single celled, smooth, black, spherical or ellipsoidal. The conidia size of the representative strain, GY-2 and GY-3, was averagely 12.3-17.3 µm × 10.8-17 µm (n = 50). The conidiogenous cells were monoblastic, hyaline, globose or ampulliform. Morphology-based identification revealed the strain as Nigrospora spp. (Wang et al., 2017). For further confirmation, PCR of GY-2 and GY-3 DNA was performed with the primers ITS1/ITS4 (White et al., 1990), Bt2a-F/Bt2b-R (Glass and Don-aldson 1995), and TEF1-728F/TEF1-986R (Carbone and Kohn 1999). Sequences of the ITS region, TUB and TEF1 genes from the strain GY-2 and GY-3 were deposited in GenBank. (GY-2: OR999377, PP112221 and PP150467; GY-3: PP406871, PP421045 and PP421046, respectively). BLAST analysis showed GY-2 100%, 100%, and 98.36%; GY-3 99.43%, 98.21% and 100% (ITS region, TEF1, and TUB) identity to N. hainanensis sequences (accession numbers. NR_153480.1, KY019415.1, and KY019464.1; KX986094.1, OP611475.1, and KY019597.1). Additionally, tandem sequences of ITS, TUB and TEF1 constructed by MEGA 7.0 confimed the homology through the phylogenetic tree. Pathogenicity tests were conducted on healthy plants grown, each 5 mm diameter of active growing mycelium plug of isolate GY-2 was attached to 15 leaves from five healthy 2-year-old E. japonicu plants. The same number of leaves in the control group were treated with non-inoculated plugs only. All the plants were incubated at 25°C and 75% relative humidity with a 16-h/8-h photoperiod. After 10 days, no symptoms appeared on the leaves of the control group. In contrast, symptomatic blight appeared on all leaves inoculated with GY-2. Pathogenicity tests were performed five times. Pure strains were re-isolated from diseased leaves and, confirmed to be N. hainanensis based on the above methods. Recently, Nigrospora oryzae was reported as causal agent of leaf spots on Euonymus japonicus in China (Xu et al., 2023). To our knowledge, this study is the first report of N. hainanensis causing leaf blight on E. japonicu. Identification of the etiological agent may provide assistance for sustainable management in the future.
PubMed: 38679589
DOI: 10.1094/PDIS-01-24-0172-PDN -
American Journal of Ophthalmology Case... Jun 2024We report a rare case of microbial keratitis caused by .
PURPOSE
We report a rare case of microbial keratitis caused by .
OBSERVATIONS
A 72-year-old Japanese woman was injured by plant debris and developed oval corneal ulcers and hypopyon in the anterior chamber. After 5 days, she complained of pain, redness, and vision loss in her left eye and was treated with antibacterial eye drops and an ointment (1.5 % levofloxacin hydrate, cefmenoxime hydrochloride, and sterilization and disinfection eye drops; SAN-IODE and ofloxacin ophthalmic ointment). Examination revealed a worsening oval corneal ulcer with Descemet's folds and a faint hypopyon. Considering the infection from soil or plants and the poor response to intensive antibacterial eye drops, topical antifungal eye drops, i.e., 1 % voriconazole eye drops, and 1 % natamycin ointment were applied. Direct microscopy of the corneal scraping with Gram staining was performed and the result was negative. Cultures from corneal scrapings showed the growth of dark colonies after several days. The colony was identified as by sequencing of the fungal internal transcribed spacer region. Pain and vision loss improved with improvement in corneal ulcers. The antifungal treatment was administered for 37 days. Discontinuation of the eye drops after 1 month did not result in keratitis recurrence. At the final follow-up at 70 days, the best-corrected visual acuity was 20/25, with persistent small corneal opacity.
CONCLUSIONS AND IMPORTANCE
Here, we report a case of fungal keratitis caused by . Microbiological identification of the causes of rare infections is difficult in clinical laboratories, necessitating the use of advanced molecular techniques based on amplification and sequencing of appropriate phylogenetic markers. responds to topical voriconazole and natamycin.
PubMed: 38665418
DOI: 10.1016/j.ajoc.2024.102062 -
Marine Life Science & Technology Feb 2024Marine microorganisms have long been recognized as potential sources for drug discovery. Griseofulvin was one of the first antifungal natural products and has been used...
UNLABELLED
Marine microorganisms have long been recognized as potential sources for drug discovery. Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades. In this study, 12 new griseofulvin derivatives [(±)--, (+)-, (±)-, -, and -] and two new griseofulvin natural products ( and ) together with six known analogues [(-)-, -, and ] were isolated from the mangrove-derived fungus sp. QQYB1 treated with 0.3% NaCl or 2% NaBr in rice solid medium. Their 2D structures and absolute configurations were established by extensive spectroscopic analysis (1D and 2D NMR, HRESIMS), ECD spectra, computational calculation, DP4 + analysis, and X-ray single-crystal diffraction. Compounds - represent the first griseofulvin enantiomers with four absolute configurations (2, 6'; 2, 6'; 2, 6'; 2, 6'), and compounds - represent the first successful production of brominated griseofulvin derivatives from fungi via the addition of NaBr to the culture medium. In the antifungal assays, compounds and demonstrated significant inhibitory activities against the fungi , , and with inhibition zones varying between 28 and 41 mm (10 μg/disc). The structure-activity relationship (SAR) was analyzed, which showed that substituents at C-6, C-7, C-6' and the positions of the carbonyl and double bond of griseofulvin derivatives significantly affected the antifungal activity.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s42995-023-00210-0.
PubMed: 38433970
DOI: 10.1007/s42995-023-00210-0 -
Plant Disease Feb 2024Rhododendron simsii (indoor azalea) is widely cultivated for its high ornamental value (Xu et al. 2021). In April to May 2023, a leaf spot disease occurred in a field...
Rhododendron simsii (indoor azalea) is widely cultivated for its high ornamental value (Xu et al. 2021). In April to May 2023, a leaf spot disease occurred in a field study at the Baili Azalea Forest Area (27°12'N, 105°48'E), Guizhou Province, China. About 500 plants were investigated, and the results showed that the incidence of leaf spot was 20 ~ 30%. To study this disease, 10 plants showing severe symptoms were collected. Initially, the symptoms were round or irregularly shaped brown spots (1 to 10 mm). With time, the spots enlarged and merged. Symptomatic leaves were washed with sterile distilled water, and 5 × 5 mm pieces of the infected tissues were removed. After surface sterilization (30 s with 75% ethanol, 2 min with 3% NaOCl, then washed three times with sterilized distilled water), the leaf pieces were dried and placed on potato dextrose agar (PDA) and incubated at 25℃ for 5 days. Fungal colonies developed from leaf tissues, and the germinated spores were transferred onto PDA for further purification and morphological observation. Three isolates (GUBJ23, GUBJ24, and GUBJ12) with similar morphology were obtained from five affected leaves. The representative strain GUBJ23 was selected for further study. On PDA the mycelium was initially white but with sporulation turned gray and then black. Black, single-celled conidia, spherical to sub-spherical, from 11.80 to 21.39 × 13.38 to 21.83 μm (n = 50) in diameter were borne singly on hyaline vesicles at the tips of conidiophores. These morphological characteristics were similar to those of Nigrospora sphaerica (Wang et al. 2017). To confirm the identification, primer pairs for the internal transcribed spacer (ITS) region (ITS5/ITS4), β-tubulin (TUB2) (Bt-2a/Bt-2b), and the translation elongation factor 1-alpha (TEF1-α) (EF1-728F/EF1-986R), were used for PCR amplification of DNA from strain GUBJ23 (Carbone and Kohn 1999; Glass et al. 1995; White et al. 1990). The resulting sequences were deposited in GenBank with accession numbers OR818025 (ITS), OR835150 (TUB2), and OR835147 (TEF1-α). BLAST searches of the sequences revealed 99.80% identity (503/504 bp) of the ITS sequence, 100.00% identity (395/395 bp) of the TUB2 sequence, and 100.00% identity of the TEF1-α sequence (241/241 bp) with N. sphaerica LC7294 (accessions KX985932, KY019602, and KY019397, respectively.) Based on a combined dataset of ITS, TEF1-α, and TUB2 sequences, a phylogenetic tree was constructed using the maximum likelihood method and confirmed that isolates GUBJ23, GUBJ24, and GUBJ12 were N. sphaerica (Wang et al. 2017). Leaves of three healthy R. simsii plants were spray-inoculated with a spore suspension (105 conidia/mL), and an additional three plants were sprayed with sterile water. These plants were incubated at 25℃ in 75% relative humidity. After 5 to 7 days of inoculation, 0.5 to 1.8 mm spots appeared on the leaves. At 10 to 14 days after inoculation, grayish brown, semicircular or irregular lesions appeared on the leaves, usually with a diameter of 0.8 to 3 mm. The symptoms were like symptoms seen on naturally infected leaves, while the control leaves remained asymptomatic. The pathogen was re-isolated from diseased leaves and identified by morphological characterization and molecular analyses (ITS, TUB and TEF1-α), and the reisolated pathogen was identical to N. sphaerica. Thus completing Koch's postulates. According to previous research, N. sphaerica is a widely distributed phytopathogenic fungus that has a wide host range (Wang et al. 2017). This study is the first to identify N. sphaerica as the cause of leaf spot disease in R. simsii. Given the popularity of R. simsii as a pot plant and landscape shrub in Asia and othr regions, the occurrence of leaf spot disease seriously affects its ornamental and economic value. Therefore, it is crucial to establish and implement effective disease management practices to reduce impact of the disease.
PubMed: 38414195
DOI: 10.1094/PDIS-12-23-2611-PDN -
Saudi Journal of Biological Sciences Apr 2024Endophytic fungi that inhabit medicinal plants are microbial resources renowned for having compounds analogous to those produced by their host plants. This study aimed...
Endophytic fungi that inhabit medicinal plants are microbial resources renowned for having compounds analogous to those produced by their host plants. This study aimed to describe the diversity of endophytic fungi found in Kunth. To better understand the diversity of foliar endophytic fungi found in the leaves of the medicinal plant , we isolated and characterized endophytic by using both morphological and molecular methods employing ITS markers. The antimicrobial activity of endophytic fungi against common human pathogens and was also investigated. A Total of 16 endophytic fungi were successfully isolated from leaves and classified into five orders of Pezizomycotina based on the phylogenic analyses; (56%) (19%) (6%) (13%) and (6%). The antimicrobial activity of crude extracts from fungal endophyte against , and revealed that three isolates; were the most potent, while and displayed no growth inhibition property against the tested organism. The diversity indices were calculated by using the Shannon-Wiener, Margalef, and Simpson indices. The diversity indices analysis revealed an abundance of species diversity, where the dominant species were , and This study describes the diversity of endophytic fungi found in and emphasizes their potential as a source of novel bioactive compounds. More research on phytochemical composition and antimicrobial activity is ongoing to correlate the traditional uses and scientific findings.
PubMed: 38404537
DOI: 10.1016/j.sjbs.2024.103958 -
Journal of Fungi (Basel, Switzerland) Feb 2024Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease...
Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease collected along the Yangtze River. A phylogenetic analysis based on internal transcribed spacer (ITS), translation elongation factor 1 alpha (), and beta tubulin () sequences revealed one isolate (SS-2-JB-1B) grouped with , one (QY) with , twenty-two with , and one isolate (QY-2) grouped in its own clade, which are related to but clearly different from . Nineteen tested isolates, including sixteen strains from the clade and the three isolates of the other three clades, caused disease on detached rice leaves. The three isolates that did not belong to were also able to cause disease in rice seedlings, suggesting that they were rice pathogens. Isolate QY-2 differed from the other isolates in terms of colony morphology, cell size, and susceptibility to fungicides, indicating that this isolate represents a new species that we named . Our analysis showed that , , and the new species, , can cause rice leaf spot disease in the field. This research provides new knowledge for understanding rice leaf spot disease.
PubMed: 38392829
DOI: 10.3390/jof10020156