Pulmonary infection secondary to Blastobotrys raffinosifermentans in a cystic fibrosis patient: Review of the literature.

BACKGROUND: The genus Blastobotrys consists of at least 20 species. Disease in humans has been reported with B adeninivorans, B raffinosifermentans, B proliferans and B serpentis, mostly in immunocompromised patients and those with cystic fibrosis. OBJECTIVE: We report a lung infection secondary to B raffinosifermentans in a cystic fibrosis patient successfully treated with isavuconazole and review the literature of invasive infections caused this genus. We also evaluated clinical isolates in our laboratory for species identification and antifungal susceptibility. METHODS: Phylogenetic analysis was performed on a collection of 22 Blastobotrys isolates in our reference laboratory, and antifungal susceptibility patterns were determined for nine clinically available antifungals against 19 of these isolates. RESULTS: By phylogenetic analysis, 21 of the 22 isolates in our collection were identified as B raffinosifermentans and only 1 as B adeninivorans. Most were cultured from the respiratory tract, although others were recovered from other sources, including CSF and blood. Isavuconazole, caspofungin and micafungin demonstrated the most potent in vitro activity, followed by amphotericin B. In contrast, fluconazole demonstrated poor activity. The patient in this case responded to isavuconazole treatment for breakthrough infection due to B raffinosifermentans that was cultured from pleural fluid while on posaconazole prophylaxis post-bilateral lung transplantation for cystic fibrosis. CONCLUSIONS: Blastobotrys species are rare causes of infections in humans and primarily occur in immunocompromised hosts. In our collection, the majority of isolates were identified as B raffinosifermentans. To our knowledge, this is the first report of successful treatment of such an infection with isavuconazole.

Kodamaea ohmeri infections in humans: A systematic review.

BACKGROUND: Kodamaea ohmeri, previously known as Pichia ohmeri or Yamadazyma ohmeri, belongs to the Saccharomycetaceae family and the Ascomycetae class, is the telomorphic form of C guilliermondii var. membranaefaciens and is frequently mistaken for Candida, as they belong to the same family. It has been isolated from environmental sources, such as sand, pools, seawater and fruits, while the last decades it is recognised as a rare pathogen that causes life-threatening infections in humans. The purpose of this study was to systemically review all published cases of K ohmeri infections in the literature and describe the epidemiology, microbiology, antimicrobial susceptibility, treatment and outcomes of these infections in humans. METHODS: Systematic review of PubMed (through 27th December 2019) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of K ohmeri infections. RESULTS: A total of 35 studies, containing data of 44 patients, were included in the analysis. The most common K ohmeri infections were those of the bloodstream, infective endocarditis and onychomycosis. Previous antibiotic use, presence of a central venous catheter, parenteral nutrition and cancer were very common among patients. Mortality was high in the case of fungemias but low for other types of infections. Amphotericin B and fluconazole are the most common agents used for treatment, even though alarming MICs for fluconazole were noted. CONCLUSIONS: This systematic review thoroughly describes infections by K ohmeri and provides information on their epidemiology, clinical presentation, microbiology, antibiotic resistance patterns, treatment and outcomes.

Cytological Evaluations of Advanced Generations of Interspecific Hybrids Between Allium cepa and Allium fistulosum Showing Resistance to Stemphylium vesicarium.

Interspecific crossing is a promising approach for introgression of valuable traits to develop cultivars with improved characteristics. Allium fistulosum L. possesses numerous pest resistances that are lacking in the bulb onion (Allium cepa L.), including resistance to Stemphylium leaf blight (SLB). Advanced generations were produced by selfing and backcrossing to bulb onions of interspecific hybrids between A. cepa and A. fistulosum that showed resistance to SLB. Molecular classification of the cytoplasm established that all generations possessed normal (N) male-fertile cytoplasm of bulb onions. Genomic in situ hybridization (GISH) was used to study the chromosomal composition of the advanced generations and showed that most plants were allotetraploids possessing the complete diploid sets of both parental species. Because artificial doubling of chromosomes of the interspecific hybrids was not used, spontaneous polyploidization likely resulted from restitution gametes or somatic doubling. Recombinant chromosomes between A. cepa and A. fistulosum were identified, revealing that introgression of disease resistances to bulb onion should be possible.

Soil fungal biodiversity and pathogen identification of rotten disease in Aconitum carmichaelii (Fuzi) roots.

Aconitum carmichaelii, commonly known as Fuzi, is a typical traditional Chinese medicine (TCM) herb that has been grown for more than one thousand years in China. Although root rot disease has been seriously threatening this crop in recent years, few studies have investigated root rot disease in Fuzi, and no pathogens have been identified. In this study, fungal libraries from rhizosphere soils were constructed by internal transcribed spacer (ITS) sequencing using the HiSeq 2500 high-throughput platform. A total of 948,843 tags were obtained from 17 soil samples, and these corresponded to 195,583,495 nt. At 97% identity, the libraries yielded 12,266 operational taxonomic units (OTUs), of which 97.5% could be annotated. In sick soils, Athelia, Mucor and Mortierella were the dominant fungi, comprising 10.3%, 10.1% and 7.7% of the fungal community, respectively. These fungi showed 2.6-, 1.53- to 6.31- and 1.38- to 2.65-fold higher enrichment in sick soils compared with healthy soils, and their high densities reduced the fungal richness in the areas surrounding the rotted Fuzi roots. An abundance analysis suggested that A. rolfsii and Mucor racemosus, as the dominant pathogens, might play important roles in the invading Fuzi tissue, and Phoma adonidicola could be another pathogenic fungus of root rot. In contrast, Mortierella chlamydospora, Penicillium simplicissimum, Epicoccum nigrum, Cyberlindnera saturnus and Rhodotorula ingeniosa might antagonize root rot pathogens in sick soils. In addition, A. rolfsii was further verified as a main pathogen of Fuzi root rot disease through hypha purification, morphological observation, molecular identification and an infection test. These results provide theoretical guidance for the prevention and treatment of Fuzi root rot disease.

Potential use of cuminic acid as a botanical fungicide against Valsa mali.

Valsa canker caused by Valsa mali is commonly present in eastern Asia and cause large economic losses. Because of limited agricultural measures and chemical residues of commonly used fungicides there is an urgent need of alternative plant protecting agents. On this background the activity of cuminic acid, a plant extract from the seed of Cuminum cyminum L, was assessed. The median effective concentration (EC50) values for inhibition of mycelial growth of seven V. mali strains ranged from 3.046 to 8.342 µg/mL, with an average EC50 value of 4.956 ± 0.281 µg/mL. The antifungal activity was the direct activity of cuminic acid instead of the influence on the pH of media by cuminic acid. After treated with cuminic acid, mycelia dissolved with decreased branches and swelling; cell membrane permeability increased while pectinases activity decreased significantly. Moreover, peroxidase (POD) activity of the apple leaves increased after treated with cuminic acid. Importantly, on detached branches of apple tree, cuminic acid exhibited both protective and curative activity. These results indicated that cuminic acid not only showed the antifungal activity, but also could improve the defense capacity of the plants. Taken together, cuminic acid showed the potential as a natural alternative to commercial fungicides or a lead compound to develop new fungicides for the control of Valsa canker.

Ag doped hollow TiO2 nanoparticles as an effective green fungicide against Fusarium solani and Venturia inaequalis phytopathogens.

Chemical-based pesticides are widely used in agriculture to protect crops from insect infestation and diseases. However, the excessive use of highly toxic pesticides causes several human health (neurological, tumor, cancer) and environmental problems. Therefore nanoparticle-based green pesticides have become of special importance in recent years. The antifungal activities of pure and Ag doped (solid and hollow) TiO2 nanoparticles are studied against two potent phytopathogens, Fusarium solani (which causes Fusarium wilt disease in potato, tomato, etc) and Venturia inaequalis (which causes apple scab disease) and it is found that hollow nanoparticles are more effective than the other two. The antifungal activities of the nanoparticles were further enhanced against these two phytopathogens under visible light exposure. The fungicidal effect of the nanoparticles depends on different parameters, such as particle concentration and the intensity of visible light. The minimum inhibitory dose of the nanoparticles for V. inaequalis and F. solani are 0.75 and 0.43 mg/plate. The presence of Ag as a dopant helps in the formation of stable Ag-S and disulfide bonds (R-S-S-R) in cellular protein, which leads to cell damage. During photocatalysis generated (•)OH radicals loosen the cell wall structure and this finally leads to cell death. The mechanisms of the fungicidal effect of nanoparticles against these two phytopathogens are supported by biuret and triphenyl tetrazolium chloride analyses and field emission electron microscopy. Apart from the fungicidal effect, at a very low dose (0.015 mg/plate) the nanoparticles are successful in arresting production of toxic napthoquinone pigment for F. solani which is related to the fungal pathogenecity. The nanoparticles are found to be effective in protecting potatoes affected by F. solani or other fungi from spoiling.

Transcript profiles in sugar beet genotypes uncover timing and strength of defense reactions to Cercospora beticola infection.

Cercospora leaf spot disease, caused by the fungus Cercospora beticola, is the most destructive foliar disease of sugar beet (Beta vulgaris) worldwide. Despite the great agronomical importance of this disease, little is known about its underlying molecular processes. Technical resources are scarce for analyzing this important crop species. We developed a sugar beet microarray with 44,000 oligonucleotides that represent 17,277 cDNAs. During the four stages of C. beticola-B. vulgaris interactions, we profiled the transcriptional responses of three genotypes: susceptible, polygenic partial resistance, and monogenic resistant. Similar genes were induced in all three genotypes during infection but with striking differences in timing. The monogenic resistant genotype displayed strong defense responses at 1 day postinoculation (dpi). The other genotypes displayed defense responses in a later phase (15 dpi) of the infection cycle. The partially resistant genotype displayed a strong defense response in the late phase of the infection cycle. Furthermore, the partially resistant genotype expressed pathogen-related transcripts that the susceptible genotype lacked. These results indicate that resistance was achieved by the ability to mount an early defense response, and partial resistance was determined by additional defense and signaling transcripts that allowed effective defense in the late phase of the infection cycle.

Seasonal Variation in Frequency of Isolation of Ophiosphaerella korrae from Bermudagrass Roots in Mississippi and Pathogenicity and Optimal Growth of Selected Isolates.

Isolation frequency of Ophiosphaerella korrae (spring dead spot pathogen) from Cynodon dactylon (bermudagrass) roots at a golf course near West Point, Mississippi, was monitored over a 3-year investigation. Laboratory and greenhouse experiments were conducted to determine optimal temperatures for the growth of selected O. korrae isolates collected from the field study and to evaluate those isolates for pathogenicity potential. Isolation frequencies of the pathogen from naturally infested root samples were significantly higher in the winter and spring and lowest in the fall regardless of cultural, nutrient, and chemical treatments. Annual soil temperatures ranged between 8 and 29 degrees C, and no correlation was observed between temperature and percent isolation of O. korrae. Optimal in vitro growth of selected O. korrae isolates ranged from 21 to 25 degrees C. Root discoloration was significantly greater in the presence of O. korrae compared to non-inoculated roots in greenhouse studies. Results of this study confirm and are the first to document that O. korrae naturally infests roots throughout the bermudagrass growth cycle, but factors other than temperature and management practices may influence O. korrae in situ.

The emerging life-threatening opportunistic fungal pathogen Kodamaea ohmeri: optimal treatment and literature review.

BACKGROUND/PURPOSE: The yeast Kodamaea ohmeri rarely causes life-threatening human infections. However, risk factors, laboratory diagnoses, and treatments for K. ohmeri infection have been limited, and the optimal therapy for K. ohmeri infection has not been identified. METHODS: Twenty cases of K. ohmeri infection have been reported in the English medical literature. We present two new cases of K. ohmeri fungemia. We investigated the nature and treatment of K. ohmeri infections using minimum inhibitory concentrations of antifungal agents and by comparing the two cases with those described in the literature. RESULTS: From March 1998 to December 2008, a total of 22 patients with K. ohmeri infections were studied. Hematological malignancies and diabetes were the most common co-morbidities for K. ohmeri infections, with crude prevalence rates of 27.3% and 18.2%, respectively. The K. ohmeri isolates showed less susceptibility to fluconazole but greater susceptibility to amphotericin B [15/25 isolates (60%) vs. 25/25 isolates (100%), respectively]. Good outcomes (8/9 cases; 88.9%) were found following removal of indwelling catheters and implants. In addition, voriconazole and echinocandins, such as caspofungin and micafungin, also showed excellent minimum inhibitory concentrations against K. ohmeri. CONCLUSION: K. ohmeri should not be regarded as a contaminant of blood cultures. Favorable outcomes for this potentially life-threatening infection are promoted by the removal of indwelling catheters; furthermore, outcomes are associated with optimal antifungal regimens, especially voriconazole and echinocandins.