Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis.

Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.

Aspergillus flavus, mainly causing fungal rhinosinusitis in Sudan, poses health risks due to aflatoxin production. This study revealed diverse levels of aflatoxin and gene expression of clinical isolates by pheno- and genotypic methods, emphasizing the need for vigilant monitoring in the region.

Proposal to transfer Bacillus massiliigorillae to the genus Peribacillus as Peribacillus massiliigorillae comb. nov., and Bacillus sinesaloumensis to the genus Ferdinandcohnia as Ferdinandcohnia sinesaloumensis comb. nov.

The present study was carried out to clarify the taxonomic position of Bacillus massiliigorillae and Bacillus sinesaloumensis. The 16S rRNA gene sequences extracted from the Bacillus sinesaloumensis Marseille-P3516T (FTOX00000000) and Bacillus massiliigorillae G2T (CAVL000000000) genomes showed 98.5 and 99.1% similarity with the type strains of Ferdinandcohnia humi and Peribacillus endoradicis, respectively. The amino acid identity (AAI) values of Bacillus sinesaloumensis Marseille-P3516T were higher with Ferdinandcohnia members, while Bacillus massiliigorillae G2T with Peribacillus members. In phylogenomic and phylogenetic trees, Bacillus sinesaloumensis Marseille-P3516T and Bacillus massiliigorillae G2T clade with members of the genera Ferdinandcohnia and Peribacillus, respectively. Based on the above results, we propose to transfer Bacillus massiliigorillae to the genus Peribacillus as Peribacillus massiliigorillae comb. nov., and Bacillus sinesaloumensis to the genus Ferdinandcohnia as Ferdinandcohnia sinesaloumensis comb. nov.

Proposal for transfer Bacillus alkalicola to the genus Evansella as Evansella alkalicola comb. nov.

The taxonomic position of Bacillus alkalicola was evaluated using phylogenetic and genome-based comparisons. In phylogenetic (based on 16S rRNA gene sequence) and phylogenomic (based on concatenation of protein-marker genes) trees, Bacillus alkalicola clade with the members of the genus Evansella. The amino acid identity (AAI) values suggested to reclassify Bacillus alkalicola as a member of the genus Evansella. The average nucleotide identity (ANI) value between Bacillus alkalicola and the members of the genus Evansella was lower than the threshold values for bacterial species delineation. Based on the results, we propose to transfer Bacillus alkalicola to the genus Evansella as Evansella alkalicola comb. nov. The type strain is Zby6T (=CGMCC 1.10368T=JCM 17098T=NBRC 107743T).

Proposal to transfer Bacillus lacisalsi Dong et al. 2021 to the genus Alteribacter as Alteribacter lacisalsi comb. nov.

In the present study, the taxonomic position of Bacillus lacisalsi YSP-3T was evaluated using phylogenetic and genome-based comparison. B. lacisalsi YSP-3T showed the highest 16S rRNA gene sequence similarity to Alteribacter natronophilus M30T (98.4 %), followed by Alteribacter aurantiacus K1-5T (97.5 %) and Alteribacter populi FJAT-45347T (97.2 %). In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic (based on 71 bacterial single-copy genes) trees, B. lacisalsi YSP-3T clustered with the members of the genus Alteribacter. The amino acid identity (AAI) values between B. lacisalsi YSP-3T and the members of the genus Alteribacter were >65 %, which is above the cut-off level (65-95 %) for genus delineation. The average nucleotide identity (ANI) values between B. lacisalsi YSP-3T and the members of the genus Alteribacter were <95 %, which is lower than the threshold value (95-96 %) for bacterial species delineation. The AAI value suggested that B. lacisalsi YSP-3T was a member of the genus Alteribacter while the ANIb value suggested it as a novel species of the genus Alteribacter. Based on the results, we propose to transfer Bacillus lacisalsi to the genus Alteribacter as Alteribacter lacisalsi comb. nov.

Cheese whey supports high riboflavin synthesis by the engineered strains of the flavinogenic yeast Candida famata.

BACKGROUND: Riboflavin is a precursor of FMN and FAD which act as coenzymes of numerous enzymes. Riboflavin is an important biotechnological commodity with annual market sales exceeding nine billion US dollars. It is used primarily as a component of feed premixes, a food colorant, a component of multivitamin mixtures and medicines. Currently, industrial riboflavin production uses the bacterium, Bacillus subtilis, and the filamentous fungus, Ashbya gossypii, and utilizes glucose and/or oils as carbon substrates. RESULTS: We studied riboflavin biosynthesis in the flavinogenic yeast Candida famata that is a genetically stable riboflavin overproducer. Here it was found that the wild type C. famata is characterized by robust growth on lactose and cheese whey and the engineered strains also overproduce riboflavin on whey. The riboflavin synthesis on whey was close to that obtained on glucose. To further enhance riboflavin production on whey, the gene of the transcription activator SEF1 was expressed under control of the lactose-induced promoter of the native ß-galactosidase gene LAC4. These transformants produced elevated amounts of riboflavin on lactose and especially on whey. The strain with additional overexpression of gene RIB6 involved in conversion of ribulose-5-phosphate to riboflavin precursor had the highest titer of accumulated riboflavin in flasks during cultivation on whey. Activation of riboflavin synthesis was also obtained after overexpression of the GND1 gene that is involved in the synthesis of the riboflavin precursor ribulose-5-phosphate. The best engineered strains accumulated 2.5 g of riboflavin/L on whey supplemented only with (NH4)2SO4 during batch cultivation in bioreactor with high yield (more than 300 mg/g dry cell weight). The use of concentrated whey inhibited growth of wild-type and engineered strains of C. famata, so the mutants tolerant to concentrated whey were isolated. CONCLUSIONS: Our data show that the waste of dairy industry is a promising substrate for riboflavin production by C. famata. Possibilities for using the engineered strains of C. famata to produce high-value commodity (riboflavin) from whey are discussed.

The role of hexose transporter-like sensor hxs1 and transcription activator involved in carbohydrate sensing azf1 in xylose and glucose fermentation in the thermotolerant yeast Ogataea polymorpha.

BACKGROUND: Fuel ethanol from lignocellulose could be important source of renewable energy. However, to make the process feasible, more efficient microbial fermentation of pentose sugars, mainly xylose, should be achieved. The native xylose-fermenting thermotolerant yeast Ogataea polymorpha is a promising organism for further development. Efficacy of xylose alcoholic fermentation by O. polymorpha was significantly improved by metabolic engineering. Still, genes involved in regulation of xylose fermentation are insufficiently studied. RESULTS: We isolated an insertional mutant of O. polymorpha with impaired ethanol production from xylose. The insertion occurred in the gene HXS1 that encodes hexose transporter-like sensor, a close homolog of Saccharomyces cerevisiae sensors Snf3 and Rgt2. The role of this gene in xylose utilization and fermentation was not previously elucidated. We additionally analyzed O. polymorpha strains with the deletion and overexpression of the corresponding gene. Strains with deletion of the HXS1 gene had slower rate of glucose and xylose consumption and produced 4 times less ethanol than the wild-type strain, whereas overexpression of HXS1 led to 10% increase of ethanol production from glucose and more than 2 times increase of ethanol production from xylose. We also constructed strains of O. polymorpha with overexpression of the gene AZF1 homologous to S. cerevisiae AZF1 gene which encodes transcription activator involved in carbohydrate sensing. Such transformants produced 10% more ethanol in glucose medium and 2.4 times more ethanol in xylose medium. Besides, we deleted the AZF1 gene in O. polymorpha. Ethanol accumulation in xylose and glucose media in such deletion strains dropped 1.5 and 1.8 times respectively. Overexpression of the HXS1 and AZF1 genes was also obtained in the advanced ethanol producer from xylose. The corresponding strains were characterized by 20-40% elevated ethanol accumulation in xylose medium. To understand underlying mechanisms of the observed phenotypes, specific enzymatic activities were evaluated in the isolated recombinant strains. CONCLUSIONS: This paper shows the important role of hexose sensor Hxs1 and transcription factor Azf1 in xylose and glucose alcoholic fermentation in the native xylose-fermenting yeast O. polymorpha and suggests potential importance of the corresponding genes for construction of the advanced ethanol producers from the major sugars of lignocellulose.

Phylogeny of Graphostromatacea with two new species (Biscogniauxia glaucae sp. nov. and Graphostroma guizhouensis sp. nov.) and new record of Camillea broomeana isolated in China.

In the process of studying the diversity of Xylariales in China, three species owning characteristics of Graphostromataceae were observed in China. Morphology of the described species with illustrations and their phylogeny based on regions of internal transcribed spacers (ITS), the second-largest subunit of the RNA polymerase II (RPB2), ß-tubulin (TUB2) and α-actin (ACT) are provided. Two new species and one new record from China are identified. Morphologically, Biscogniauxia glaucae sp. nov. differs from B. atropunctata var. maritima, B. citriformis var. macrospora, B. fuscella and B. mediterranea by its stromata with raised margins, clear outlines, punctate ostioles openings and ascospores which are equilateral with broadly rounded ends, a straight spore-length germ slit on the more concave side, lacking appendages and sheathes. Graphostroma guizhouensis is identified as a new species based on the multi-gene phylogenetic tree. Camillea broomeana with scanning electron microscope description of ascospores is illustrated as a new record from China. Cryptostroma is proposed in Graphostromataceae based on molecular data. Vivantia is accepted in Graphostromataceae based on its morphological characteristics and Nodulisporiurn anamorphs which are similar to those of Biscogniauxia.

Taxonomy of the Trichophyton mentagrophytes/T. interdigitale Species Complex Harboring the Highly Virulent, Multiresistant Genotype T. indotineae.

A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the Trichophyton mentagrophytes/T. interdigitale complex is ongoing in India. The correct identity of the etiologic agent is a much-debated issue. In order to define species limits, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification. Molecular characteristics show that T. mentagrophytes s. str. and T. interdigitale s. str. can be distinguished with difficulty from each other, but are unambiguously different from the Indian genotype, T. indotineae by sequences of the HMG gene. The entities were confirmed by multilocus analysis using tanglegrams. Phenotypic characters of morphology and physiology are not diagnostic, but statistically significant differences are observed between the molecular siblings. These properties may be drivers of separate evolutionary trends. Trichophyton mentagrophytes represents the ancestral, homothallic cloud of genotypes with a probable geophilic lifestyle, while T. indotineae and T. interdigitale behave as anthropophilic, clonal offshoots. The origin of T. indotineae, which currently causes a significant public health problem, is zoonotic, and its emergence is likely due to widespread misuse of antifungals.

Development of new dominant selectable markers for the nonconventional yeasts Ogataea polymorpha and Candida famata.

Nonconventional yeast Candida famata and Ogataea polymorpha are interesting organisms for basic and applied studies. O. polymorpha is methylotrophic thermotolerant yeast capable of xylose alcoholic fermentation whereas C. famata is capable of riboflavin overproduction. Still, the new tools for molecular research of these species are needed. The aim of this study was to develop the new dominant selective markers for C. famata and O. polymorpha usable in metabolic engineering experiments. In this work, the BSD gene from Aspergillus terreus coding for blasticidin S deaminase, O. polymorpha AUR1 gene required for sphingolipid synthesis and IMH3 gene, which encodes IMP dehydrogenase, were tested as the new dominant selective marker genes. Our results showed that AUR1 and IMH3 genes could be used as dominant selective markers for O. polymorpha with frequencies of transformation of 40 and 20 transformants per microgram of DNA, respectively. The IMH3 gene was successfully used as the marker for construction of O. polymorpha strains with increased ethanol production from xylose due to overexpression of TAL1, TKL1 and AOX1 genes. The BSD gene from A. terreus, conferring resistance to blasticidin, was found to be efficient for selection of C. famata transformants.

Role of the regulatory genes SEF1, VMA1 and SFU1 in riboflavin synthesis in the flavinogenic yeast Candida famata (Candida flareri).

Riboflavin or vitamin B2 is an essential dietary component for humans and animals that is the precursor of flavin coenzymes flavin mononucleotide and flavin adenine dinucleotide involved in numerous enzymatic reactions. The flavinogenic yeast Candida famata overproduces riboflavin under iron starvation; however, regulation of this process is poorly understood. Regulatory gene SEF1 encoding transcription activator has been identified. Its deletion blocks yeast ability to overproduce riboflavin under iron starvation. It was shown here that the SEF1 promoters from other flavinogenic (Candida albicans) and non-flavinogenic (Candida tropicalis) yeasts fused with the open reading frame (ORF) of SEF1 gene from C. famata are able to restore riboflavin oversynthesis in sef1Δ mutants. It is known that in the pathogenic flavinogenic yeast C. albicans, Sfu1 (GATA-type transcription factor) represses SEF1. Here, we found that deletion of SFU1 gene in wild-type C. famata leads to riboflavin oversynthesis. Moreover, it was shown that disruption of VMA1 gene (coding for vacuolar ATPase subunit A) also results in riboflavin oversynthesis in C. famata.

Lysinibacillus cavernae sp. nov., isolated from cave soil.

A Gram-staining positive, motile, rod-shaped and subterminal endospore-forming bacterium, designated strain SYSU K30005T, was isolated from a soil sample collected from a karst cave in Libo county, Guizhou province, south-western China. Strain SYSU K30005T showed the highest 16S rRNA gene sequence similarity with Lysinibacillus fusiformis (98.6%) and Lysinibacillus sphaericus (98.2%). In phylogenetic tree, strain SYSU K30005T clade with the members of the genus Lysinibacillus. Based on the phylogenetic and 16S gene sequence result, strain SYSU K30005T was affiliated to the genus Lysinibacillus. The growth of SYSU K30005T was observed at 15-37 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 0-4% (w/v) NaCl (optimum in 3.5% NaCl). Cell wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30005T were ribose, galactose and mannose and MK-7 was the only quinone. The fatty acids (> 5% of total fatty acids) were iso-C15:0, anteiso-C15:0, iso-C16:0 and iso-C17:0. The polar lipids profile included diphosphatidylglycerol, phosphatideylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G + C content was 37.2 mol%. The average nucleotide identity values between SYSU K30005T and its closest relatives were below the cut-off level (95-96%) for species delineation. The results support the conclusion that strain SYSU K30005T represents a novel species of the genus Lysinibacillus, for which we proposed the name Lysinibacillus cavernae sp. nov. The type strain is SYSU K30005T (= KCTC 43130T = CGMCC 1.17492T).

Gordonia crocea sp. nov. and Gordonia spumicola sp. nov. isolated from sludge of a wastewater treatment plant.

Two novel actinobacteria, designated NBRC 107696T and NBRC 107697T, were isolated from sludge samples from a wastewater treatment plant and their taxonomic positions were investigated by a polyphasic approach. The cells of the strains were aerobic, rod-shaped, non-motile and non-endospore-forming. The strains contained glutamic acid, alanine and meso-diaminopimelic acid in the peptidoglycan. Galactose and arabinose were detected as cell-wall sugars. The predominant menaquinone was identified as MK-9(H2) and the major fatty acids were C16  :  0, C18 : 1ω9c and C16 : 1ω7c. The DNA G+C contents of NBRC 107696T and NBRC 107697T were 68.07 and 68.99 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequence comparisons revealed that NBRC 107696T and NBRC 107697T were a clade with members of the genus Gordonia. The highest 16S rRNA gene sequence similarity values were obtained with Gordonia araii IFM 10211T (98.9 %) for NBRC 107697T, and Gordonia malaquae IMMIB WWCC-22T, Gordonia neofelifaecis AD-6T and Gordonia humi CC-12301T (98.1 %) for NBRC 107696T, respectively. The digital DNA-DNA relatedness data coupled with the combination of genotypic and phenotypic data indicated that the two strains are representatives of two novel separate species. The names proposed to accommodate these two strains are Gordonia spumicola sp. nov. and Gordonia crocea sp. nov., and the type strains are NBRC 107696T (=IFM 10067T=TBRC 11239T) and NBRC 107697T (=IFM 10881T=TBRC 11240T), respectively.

Lysinibacillus antri sp. nov., isolated from cave soil.

A Gram-stain-positive, motile, rod-shaped and endospore-forming strain, SYSU K30002T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-west China. SYSU K30002T grew at 28-40 °C (optimum, 37 °C), at pH 5.0-8.0 (optimum, pH 7.0) and in the presence of 0-4 % (w/v) NaCl (optimum in the absence of NaCl). The cell-wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30002T were ribose, galactose and mannose, and MK-7 was the menaquinone. The major fatty acids were iso-C15 : 0, C16 : 1 ω7c alcohol and iso-C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. The G+C content of the genomic DNA was 36.1 mol%. The average nucleotide identity values between SYSU K30002T and its closest relatives were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and genome comparisons, strain SYSU K30002T represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillusantri sp. nov. is proposed. The type strain is SYSU K30002T (=KCTC 33955T=CGMCC 1.13504T).

Description of Paenibacillus antri sp. nov. and Paenibacillus mesophilus sp. nov., isolated from cave soil.

Two Gram-positive, rod-shaped, motile, endospore-forming strains, SYSU K30003T and SYSU K30004T, were isolated from cave soil sampled in Xingyi County, Guizhou Province, south-west PR China. The 16S rRNA gene sequence results indicated that strains SYSU K30003T and SYSU K30004T had highest sequence similarities to Paenibacillus thermoaerophilus DSM 26310T (93.2 %) and Paenibacillus haemerocallicola KCTC 33185T (97.8 %), respectively. Optimum growth for both strains occurred at pH 7.0 and 37 °C. Both strains contained meso-2,6-diaminopimelic acid in their cell-wall peptidoglycan and MK-7 was the only isoprenoid quinone detected. The polar lipid profile of strain SYSU K30004T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two aminophospholipids, an unidentified glycolipid, unidentified phospholipids and two unidentified polar lipids. The polar lipid profile of strain SYSU K30003T contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified glycolipid. The major fatty acids (>5 %) of strain SYSU K30003T were anteiso-C15:0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0, while those of strain SYSU K30004T were anteiso-C15:0, C16:0, anteiso-C17 : 0, iso-C15 : 0, iso-C16:0 and iso-C17 : 0. The genome G+C contents of strains SYSU K30003T and SYSU K30004T were 59.0 and 53.6 mol%, respectively. The average nucleotide identity values between strains SYSU K30003T and SYSU K30004T and other closely related Paenibacillus members were below the cut-off level (95-96 %) for species identification. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains SYSU K30003T and SYSU K30004T represent two novel species of the genus Paenibacillus, for which the names Paenibacillus antri sp. nov. and Paenibacillus mesophilus sp. nov. are proposed. The type strains are SYSU K30003T (=KCTC 33956T=CGMCC 1.13505T) and SYSU K30004T (=KCTC 33957T=CGMCC 1.13872T).

Vulcaniibacterium gelatinicum sp. nov., a moderately thermophilic bacterium isolated from a hot spring.

The present study aimed to determine the taxonomic positions of strains designated R-5-52-3T, R-5-33-5-1-2, R-5-48-2 and R-5-51-4 isolated from hot spring water samples. Cells of these strains were Gram-stain-negative, non-motile and rod-shaped. The strains shared highest 16S rRNA gene sequence similarity with Vulcaniibacterium thermophilum KCTC 32020T (95.1%). Growth occurred at 28-55 °C, at pH 6-8 and with up to 3 % (w/v) NaCl. DNA fingerprinting, biochemical, phylogenetic and 16S rRNA gene sequence analyses suggested that R-5-52-3T, R-5-33-5-1-2, R-5-48-2 and R-5-51-4 were different strains but belonged to the same species. Hence, R-5-52-3T was chosen for further analysis and R-5-33-5-1-2, R-5-48-2 and R-5-51-4 were considered as additional strains of this species. R-5-52-3T possessed Q-8 as the only quinone and iso-C15:0, iso-C11:0, C16 : 0 and iso-C17 : 0 as major fatty acids. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified polar lipids and two unidentified phospholipids. The genomic G+C content was 71.6 mol%. Heat shock proteins (e.g. Hsp20, GroEL, DnaK and Clp ATPases) were noted in the R-5-52-3T genome, which could suggest its protection in the hot spring environment. Pan-genome analysis showed the number of singleton gene clusters among Vulcaniibacterium members varied. Average nucleotide identity (ANI) values between R-5-52-3T, Vulcaniibacterium tengchongense YIM 77520T and V. thermophilum KCTC 32020T were 80.1-85.8 %, which were below the cut-off level (95-96 %) recommended as the ANI criterion for interspecies identity. Thus, based on the above results, strain R-5-52-3T represents a novel species of the genus Vulcaniibacterium, for which the name Vulcaniibacterium gelatinicum sp. nov. is proposed. The type strain is R-5-52-3T (=KCTC 72061T=CGMCC 1.16678T).

Pseudomonas Saliphila sp. nov., a Bacterium Isolated from Oil-Well Production Water in Qinghai Oilfield of China.

Strain 16W4-4-3 T was isolated from the oil-well production water in Qinghai Oilfield, China. Cells were Gram-stain-negative, rod-shaped, catalase- and oxidase-positive, facultatively anaerobic and motile by single polar flagellum. The 16S rRNA gene sequences of strain 16W4-4-3 T showed the highest similarities with Pseudomonas profundi M5T (98.8%), P. pelagia CL-AP6T (98.0%), P. salina XCD-X85T (97.7%), and P. sabulinigri J64T (97.5%). The phylogenetic trees based on multilocus sequence analyses with concatenating 16S rRNA, gyrB, rpoD and rpoB genes suggested that this strain should be affiliated to the genus Pseudomonas but remotely related from other species. In addition, whole genome analyses revealed that the digital DNA-DNA hybridization values and average nucleotide identities of strain 16W4-4-3 T against its close relatives were all below 28.8% and 86.5%, respectively. Furthermore, the isolate had totally different whole cell protein profile as compared to those of other species. Major fatty acids were summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C17:0cyclo. Major isoprenoid quinone was ubiquinone (Q-9), and major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The DNA G + C content was 58.5 mol%. Therefore, phenotypic, phylogenetic, genomic, chemotaxonomic, and proteomic traits showed that the isolate represented a novel species of the genus Pseudomonas, the name Pseudomonas saliphila sp. nov. is proposed. Type strain is 16W4-4-3 T (= CGMCC 1.13350 T = KCTC 72619 T).

Species borderlines in Fusarium exemplified by F. circinatum/F. subglutinans.

Fusarium species are known as cross-kingdom pathogens, causing infections in both plants and animals. This ecological variation challenges the species concept of closely similar lineages in the genus. The present paper describes various types of genetic interaction between strains of two neighboring model species with different predilection, F. circinatum and F. subglutinans. Parameters include sequencing of the translation elongation factor 1α (TEF1) and the second largest subunit of RNA polymerase (RPB2), sexual crossing, and vegetative compatibility groups (VCGs). Successful interspecific crosses resulted in either recombination or in homothallic fruiting, the latter being limited to F. subglutinans MAT1 parents. Crossings were skewed, as Fusarium circinatum recombined more often than F. subglutinans. We hypothesize that genetic exchange in Fusarium species is finely regulated with an arsenal of options, which are applied when partners are phylogenetically closely related, leading to fluent species borderlines.

Virulence and antifungal susceptibility of microsatellite genotypes of Candida albicans from superficial and deep locations.

A set of 185 strains of Candida albicans from patients with vulvovaginal candidiasis (VVC) and from non-VVC clinical sources in southwest China was analysed. Strains were subjected to genotyping using CAI microsatellite typing and amplification of an intron-containing region of the 25S rRNA gene. Microsatellite genotypes of strains from non-VVC sources showed high polymorphism, whereas those of VVC were dominated by few, closely similar genotypes. However, among non-VVC strains, two genotypes were particularly prevalent in patients with lung cancer. 25S rDNA genotype A was dominant in VVC sources (86.7%), whereas genotypes A, B, and C were rather evenly distributed among non-VVC sources; known genotypes D and E were not found. In an experimental mouse model, isolates from lung cancer and AIDS patients proved to have higher virulence than VVC strains. Among 156 mice infected with C. albicans, 19 developed non-invasive urothelial carcinoma. No correlation could be established between parameters of virulence, source of infection, and incidence of carcinoma. C. albicans strains from VVC were less susceptible to itraconazole than the strains from non-VVC sources, whereas there was small difference in antifungal susceptibility between different 25S rDNA genotypes of C. albicans tested against amphotericin B, itraconazole, fluconazole, and flucytosine.

Bacillus antri sp. nov., isolated from cave soil.

A Gram-stain-positive, strictly aerobic, rod-shaped, motile, endospore-forming strain, SYSU K30001T, was isolated from a soil sample collected from a cave in Xingyi county, Guizhou province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU K30001T belonged to the genus Bacillus, with the highest sequence similarity to the type strain of Bacillus panaciterrae (98.1 %). Growth occurred at pH 6.0-9.0 (optimum, pH 7.0), at 28-55 °C (optimum, 28 °C) and in the presence of 0-3 % (w/v) NaCl (optimum in the absence of NaCl). Strain SYSU K30001T contained meso-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-7 as the only isoprenoid quinone present. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid. The major fatty acids were iso-C15 : 0, iso-C17 : 1ω10c, anteiso-C14 : 0 and iso-C17 : 0. The genome G+C content was 39.8 mol%. The average nucleotide identity values between SYSU K30001T and B. panaciterrae DSM 19096T were 72.1 % (ANIb) and 83.1 % (ANIm), which were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and molecular characterizations, strain SYSU K30001T represents a novel species of the genus Bacillus, for which the name Bacillus antri sp. nov. is proposed. The type strain is SYSU K30001T (=KCTC 33954T=CGMCC 1.13871T).

Revision of the medically relevant species of the yeast genus Diutina.

Diutina (Candida) rugosa is emerging as a causative agent of human infections. Recently some close relatives have been described, that is, D. mesorugosa, D. pseudorugosa, and D. neorugosa, some of which have also been implicated in human infection. Phylogenetic relationships of 24 clinical isolates of the D. rugosa complex are reconstructed using multilocus sequence analysis of five housekeeping genes, supplemented with phenotypic studies of CandiSelect™ 4 Agar and nutritional physiology. Diutina mesorugosa could not meaningfully be distinguished from D. rugosa and is regarded as a synonym. Diutina neorugosa and D. pseudorugosa represent separate, distantly related species within the genus Diutina, but have as yet not been encountered in clinical settings.