Mini-Review: The Diagnostic Methods of Tinea Capitis.

Tinea capitis is a widespread superficial fungal infection that affects children predominately. Microscopic examination and fungal culture are the conventional gold standards for diagnosis, but they are insensitive and time-consuming. In recent years, new diagnostic methods have been developed to facilitate the diagnosis and identification of causative pathogens. Trichoscopy examination showed high sensitivity and specificity for diagnosing tinea capitis with the characteristic signs of comma hairs, corkscrew hairs, bar code-like hairs and zigzag hairs. Reflectance confocal microscopy has also been used in the rapid diagnosis of tinea capitis in several studies. Molecular assays such as polymerase chain reaction and matrix-assisted desorption/ionization time to flight mass spectrometry are extensively utilized for rapid and accurate identification of the pathogens. Early diagnosis and treatment can aid in disease control and scarring reduction.

Tumor Necrosis Factor Receptor-Associated Factor 6 (TRAF6) Mediates Ubiquitination-Dependent STAT3 Activation upon Salmonella enterica Serovar Typhimurium Infection.

Salmonella enterica serovar Typhimurium can inject effector proteins into host cells via type III secretion systems (T3SSs). These effector proteins modulate a variety of host transcriptional responses to facilitate bacterial growth and survival. Here we show that infection of host cells with S Typhimurium specifically induces the ubiquitination of tumor necrosis factor receptor-associated factor 6 (TRAF6). This TRAF6 ubiquitination is triggered by the Salmonella pathogenicity island 1 (SPI-1) T3SS effectors SopB and SopE2. We also demonstrate that TRAF6 is involved in the SopB/SopE2-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3), a signaling event conducive to the intracellular growth of S Typhimurium. Specifically, TRAF6 mediates lysine-63 ubiquitination within the Src homology 2 (SH2) domain of STAT3, which is an essential step for STAT3 membrane recruitment and subsequent phosphorylation in response to S Typhimurium infection. TRAF6 ubiquitination participates in STAT3 phosphorylation rather than serving as only a hallmark of E3 ubiquitin ligase activation. Our results reveal a novel strategy in which S Typhimurium T3SS effectors broaden their functions through the activation of host proteins in a ubiquitination-dependent manner to manipulate host cells into becoming a Salmonella-friendly zone.

The Salmonella effector SopB prevents ROS-induced apoptosis of epithelial cells by retarding TRAF6 recruitment to mitochondria.

Microbial pathogens enter host cells by injecting effector proteins of the Type III secretion system (T3SS), which facilitate pathogen translocation across the host cell membrane. These effector proteins exert their effects by modulating a variety of host innate immune responses, thereby facilitating bacterial replication and systemic infection. Salmonella enterica serovar typhimurium (S.typhimurium) is a clinically important pathogen that causes food poisoning and gastroenteritis. The SopB effector protein of S. typhimurium, encoded by Salmonella pathogenicity islands (SPI)-1 T3SS, protects host epithelial cells from infection-induced apoptosis. However, how SopB influences apoptosis induction remains unclear. Here, we investigated the mechanism of SopB action in host cells. We found that SopB inhibits infection-induced apoptosis by attenuating the production of reactive oxygen species (ROS) in mitochondria, the crucial organelles for apoptosis initiation. Further investigation revealed that SopB binds to cytosolic tumor necrosis factor receptor associated factor 6 (TRAF6) and forms a trap preventing the mitochondrial recruitment of TRAF6, an essential event for ROS generation within mitochondria. By studying the response of Traf6(+/+) and Traf6(-/-)mouse embryonic fibroblasts to S. typhimurium infection, we found that TRAF6 promoted apoptosis by increasing ROS accumulation, which led to increased Bax/Bcl-2 ratio, Bax recruitment to mitochondrial membrane, and release of Cyt c into the cytoplasm. These findings show that SopB suppresses host cell apoptosis by binding to TRAF6 and preventing mitochondrial ROS generation.

Engineering Escherichia coli for production of 4-hydroxymandelic acid using glucose-xylose mixture.

BACKGROUND: 4-Hydroxymandelic acid (4-HMA) is a valuable aromatic fine chemical and widely used for production of pharmaceuticals and food additives. 4-HMA is conventionally synthesized by chemical condensation of glyoxylic acid with excessive phenol, and the process is environmentally unfriendly. Microbial cell factory would be an attractive approach for 4-HMA production from renewable and sustainable resources. RESULTS: In this study, a biosynthetic pathway for 4-HMA production was constructed by heterologously expressing the fully synthetic 4-hydroxymandelic acid synthase (shmaS) in our L-tyrosine-overproducing Escherichia coli BKT5. The expression level of shmaS was optimized to improve 4-HMA production by fine tuning of four promoters of different strength combined with three plasmids of different copy number. Furthermore, two genes aspC and tyrB in the competitive pathway were deleted to block the formation of byproduct to enhance 4-HMA biosynthesis. The final engineered E. coli strain HMA15 utilized glucose and xylose simultaneously and produced 15.8 g/L of 4-HMA by fed-batch fermentation in 60 h. CONCLUSIONS: Metabolically engineered E. coli strain for 4-HMA production was designed and constructed, and efficiently co-fermented glucose and xylose, the major components in the hydrolysate mixture of agricultural biomass. Our research provided a promising biomanufacturing route to produce 4-HMA from lignocellulosic biomass.

Glycosyltransferases: mechanisms and applications in natural product development.

Glycosylation reactions mainly catalyzed by glycosyltransferases (Gts) occur almost everywhere in the biosphere, and always play crucial roles in vital processes. In order to understand the full potential of Gts, the chemical and structural glycosylation mechanisms are systematically summarized in this review, including some new outlooks in inverting/retaining mechanisms and the overview of GT-C superfamily proteins as a novel Gt fold. Some special features of glycosylation and the evolutionary studies on Gts are also discussed to help us better understand the function and application potential of Gts. Natural product (NP) glycosylation and related Gts which play important roles in new drug development are emphasized in this paper. The recent advances in the glycosylation pattern (particularly the rare C- and S-glycosylation), reversibility, iterative catalysis and protein auxiliary of NP Gts are all summed up comprehensively. This review also presents the application of NP Gts and associated studies on synthetic biology, which may further broaden the mind and bring wider application prospects.

Monkeypox presenting as a chancre-like rash: A case report.

BACKGROUND: Since May 2022, outbreaks of monkeypox have occurred in many countries around the world, and several cases have been reported in China. CASE SUMMARY: A 38-year-old man presented with a small, painless, shallow ulcer on the coronary groove for 8 d. One day after the rash appeared, the patient developed inguinal lymphadenopathy with fever. The patient had a history of male-male sexual activity and denied a recent history of travel abroad. Monkeypox virus was detected by quantitative polymerase chain reaction from the rash site and throat swab. Based on the epidemiological history, clinical manifestations and nucleic acid test results, the patient was diagnosed with monkeypox. CONCLUSION: Monkeypox is an emerging infectious disease in China. Monkeypox presenting as a chancre-like rash is easily misdiagnosed. Diagnosis can be made based on exposure history, clinical manifestations and nucleic acid test results.

Macrophage activation syndrome as a complication of dermatomyositis: A case report.

BACKGROUND: Macrophage activation syndrome (MAS) can be a fatal complication of rheumatic disorders, which occurs most commonly in patients with systemic juvenile idiopathic arthritis or systemic lupus erythematosus. It has rarely been reported in patients with dermatomyositis. Here, we describe a fatal case of MAS that developed in an adult patient with dermatomyositis. CASE SUMMARY: A 44-year-old woman was admitted to our hospital with fever, generalized rash and muscle weakness. Fifteen days later, the fever persisted after the use of antibiotics, and repeat blood culture was negative. The patient then exhibited a typical Gottron sign and diffuse erythema on the face and neck, which were consistent with a diagnosis of dermatomyositis. The patient exhibited limb muscle strength of 2, and electromyography was suggestive of muscle-derived damage, which also supported a diagnosis of dermatomyositis. In addition, the patient exhibited high serum ferritin level, cytopenia, liver dysfunction, coagulopathy, enlarged spleen and hypertriglyceridemia, all of which are typical manifestations of MAS. The patient was diagnosed with dermatomyositis complicated by MAS. Although a high dose of methylprednisolone was administered for 15 d, the patient's condition continued to deteriorate and central nervous system symptoms developed. Eventually, treatment was discontinued, and the patient died. CONCLUSION: MAS is an important, potentially fatal, complication of dermatomyositis. Although MAS is rare in dermatomyositis, it should be considered in the differential diagnosis of an unexplained change of hemoglobin, platelet, fibrinogen, ferritin and triglyceride, which may complicate dermatomyositis.

Oral Prevalence of Candida Species in Patients Undergoing Systemic Glucocorticoid Therapy and the Antifungal Sensitivity of the Isolates.

BACKGROUND: Candida species are commonly detected as colonizers of the oral cavity; candidiasis or candidemia can develop in patients who are immunocompromised. Use of topical or inhaled glucocorticoids can alter the spectrum of Candida species and can promote oral candidiasis. The present study aims to evaluate the diversity of Candida species in the oral cavity and their susceptibility to antifungal agents in patients undergoing treatment with systemic glucocorticoids (SGCs) compared with non-users. METHODS: We conducted a descriptive, analytical, cross-sectional study that enrolled 120 patients with oral problems who were undergoing treatment with SGCs and who were admitted to the hospital of the First Affiliated Hospital, College of Medicine, Zhejiang University and Zhejiang Hospital, Hangzhou, China, between February 2019 and September 2019. One hundred and twenty age-and sex-matched patients were recruited as the SGC non-user control group. Demographic data included oral complaints and underlying diseases; symptoms of oral candidiasis were identified on physical examination. Candida species were collected using a concentrated oral rinse. Identification of fungal isolates was based on conventional phenotypic methods assisted by DNA sequence analysis of the internal transcribed spacer (ITS) rDNA gene region. Antifungal activities of anidulafungin, amphotericin B, micafungin, caspofungin, 5-flucytosine, posaconazole, voriconazole, itraconazole, and fluconazole were evaluated using the Sensititre YeastOneTM YO10 panel supplemented by the CLSI-M27-A3 protocol. RESULTS: Fifty-two (43.33%) out of the 120 patients undergoing with SGCs were diagnosed with oral candidiasis, compared with 14 (11.67%) of the non-users (P < 0.05). Likewise, we collected 88 strains from 73.33% of the SGC users compared with only 48 (40%) from non-users (P < 0.05). Candida albicans was detected most frequently in both groups (45.45% vs 66.67%, respectively; P = 0.033); the overall frequency of non-Candida albicans (NCA) strains isolated from patients treated with SGCs were significantly higher than that identified among non-users (51.14% vs 33.33%, respectively; P = 0.046), although there were no significant differences concerning any single species of NCA. Resistance of C. albicans to itraconazole (P = 0.004) and fluconazole (P = 0.001) was significantly higher in patients treated with SGCs than in non-users; however, echinocandins, amphotericin B, voriconazole, and posaconazole were all active against strains from both participant groups with no significant differences detected. CONCLUSION: Taken together, our findings indicate that SGC therapy may result in an increased prevalence of oral candidiasis as reflected by the clinical presentations and strains isolated; these findings were also associated with an increased frequency of NCA strains. SGC therapy was also associated with an increased frequency of C. albicans strains that were resistant to both itraconazole and fluconazole. The impact of SGC therapy on Candida species in the oral cavity requires further study.

[Effect of sho1 gene of Aspergillus fumigatus on adaptation to osmotic pressure and on sensitivity of antifungal drugs].

OBJECTIVE: To construct the sho1 gene mutant of Aspergillus fumigatus, and to investigate the function of sho1 in adaptation to environmental changes. METHODS: Saccharomyces cerivisiae sho1 gene homolog was identified by tblastn searches in A. fumigatus genome database. A PCR fragment, composed of the 5' flanking sequence (approximately 1 kb) of sho1, sho1 ORF, and its 3' flanking sequence (approximately 1 kb), was subcloned into a vector pDHt/SK2 with ApaI/XbaI enzyme to produce a recombinant plasmid PA. The selected marker pyrG cut from pLAX223 with NcoI/PstI was cloned into PA, and PB was produced. The plasmid PB was transformed into competent Agrobacterium tumefaciens EHA105 by using the freeze/thaw method. The strain of A. tumefaciens was designated as At sho1. Then triangle upsho1 was produced via ATMT. The radial growth was observed and compared between triangle up sho1 and wild type (wt) on MM, CM and BHI medium, and the sensitivity of triangle up sho1 and wt to amphotericin B, itraconazole, voriconazole, and caspofungin investigated. RESULTS: Radial growth had visible difference between triangle up sho1 and wt on MM, CM and BHI medium. triangle up sho1 mutant was sensitive to high osmotic pressure but not to low osmotic pressure. The susceptibility to antifungal drugs was similar between the triangle up sho1 and wt. CONCLUSION: Slow growth of the triangle up sho1 mutant has nothing to do with the different medium. The sho1 gene plays a role in response to osmotic pressure in A. fumigatus, but sho1 has a minor role in the susceptibility to the antifungal drugs despite the slow growth.

[Agrobacterium tumefaciens-mediated transformation of uracil auxotroph Aspergillus fumigatus is an efficient method for target gene knockout].

OBJECTIVE: To investigate the efficiency of Agrobacterium tumefaciens mediated transformation of Aspergillus fumigatus by using pyrG as a recessive selectable marker. METHODS: FAP1 and SHO1 genes target sequences, composed of a selectable marker pyrG and the flanking sequences of the FAP1 and the SHO1 genes, were cloned into a binary plasmid pDHt/sk, respectively. The produced plasmids were transformed into A. tumefaciens. The A. tumefaciens and uracil auxotroph A. fumigatus were cocultured in induction medium without uricil and uridine at 24 degrees C for 48 h. To inhibit growth of A. tumefaciens and to select transformants, the cultures were transferred to 37 degrees C and incubated for another 48 h. RESULTS: In this study, A. tumefaciens-mediated transformation of A. fumigatus produced high homologous recombination rates, which was 44% (7 of 16) for FAP1 and 35% (7 of 20) for SHO1. CONCLUSION: Our study showed that A. tumefaciens-medidated transformation by using pyrG as a recessive selectable marker is an efficient tool for target gene deletion of A. fumigatus.

[Recent advances in the study of macrolide glycosyltransferases].

Catalyzed by a family of enzymes called glycosyltransferases (GTases), glycosylation reactions are essential for the bioactivities of macrolide antibiotics which have been widely applied. Additionally, glycosylation is also an important strategy of microbial to get macrolide antibiotic resistance. Studies on the structure, function and application areas of macrolide GTases will lay the stable groundwork for the combinatorial biology. This paper introduced in detail the biological functions of macrolide glycosylation, and then made an in-depth discussion on the families and discoveries of macrolide GTases. The resistance mechanism with macrolide glycosyltion and the correlative GTases MGT have been reviewed afterwards. According to the flexible substrate specificity of macrolide GTases, the combinatorial biological applications on them were also seriously summarized here. At the end, the authors made a developmental prospect of macrolide GTases based on the studies of the research group.

"Perfect" designer chromosome V and behavior of a ring derivative.

Perfect matching of an assembled physical sequence to a specified designed sequence is crucial to verify design principles in genome synthesis. We designed and de novo synthesized 536,024-base pair chromosome synV in the "Build-A-Genome China" course. We corrected an initial isolate of synV to perfectly match the designed sequence using integrative cotransformation and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated editing in 22 steps; synV strains exhibit high fitness under a variety of culture conditions, compared with that of wild-type V strains. A ring synV derivative was constructed, which is fully functional in Saccharomyces cerevisiae under all conditions tested and exhibits lower spore viability during meiosis. Ring synV chromosome can extends Sc2.0 design principles and provides a model with which to study genomic rearrangement, ring chromosome evolution, and human ring chromosome disorders.

Enterostomy can decrease the mortality of patients with Fournier gangrene.

AIM: To determine the significance of enterostomy in the emergency management of Fournier gangrene. METHODS: The clinical data of 51 patients (49 men and 2 women) with Fournier gangrene who were treated at our hospital over the past 12 years were retrospectively analyzed. The patients were divided into two groups according the surgical technique performed: enterostomy combined with debridement (the enterostomy group, n = 28) or debridement alone (the control group, n = 23). Patients in the enterostomy group received thorough debridement during surgery and adequate local drainage after surgery, as well as administration of broad-spectrum antibiotics. The clinical data and outcomes in both groups were analyzed. RESULTS: The surgical procedures were successful in both patient groups. In the enterostomy group, 10 (35.8%) patients required skin grafting with a total of six debridement procedures. While in the control group, six (26.1%) patients required four debridement procedures. However, this difference was not statistically significant. Following surgery, the time to normal body temperature (6 d vs 8 d, P < 0.05) and average length of hospital stay (14.3 ± 7.8 d vs 20.1 ± 8.9 d, P < 0.05) were shorter in the enterostomy group. The case fatality rate was lower in the enterostomy group than that in the control group (3.6% vs 21.7%, P < 0.05). CONCLUSION: Enterostomy can decrease the case fatality rate of patients with Fournier gangrene.

Combined alkali and acid pretreatment of spent mushroom substrate for reducing sugar and biofertilizer production.

Spent mushroom substrate (SMS) was pretreated with alkaline reagents including potassium hydroxide, lime and ammonia to enhance enzymatic saccharification. Under the best pretreatment conditions (1M KOH, 80 °C, 90 min; 1M lime, 80 °C, 120 min; 10 M ammonia, 70 °C, 120 min), the total reducing sugar (TRS) yield reached 258.6, 204.2 and 251.2 mg/g raw SMS, which were respectively 6.15, 4.86, and 5.98 times of untreated SMS. The effects of pretreatment by above alkaline reagents and sulfuric acid on the composition and structure of SMS were evaluated to provide comparative performance data. A new process, combined alkali and acid (CAA) pretreatment followed by enzymatic hydrolysis, was innovatively proposed to improve the cost-effectiveness and avoid environmental problems. The SMS residue after CAA pretreatment-enzymatic hydrolysis process was converted to biofertilizer with Pichia farinose FL7 and a cell density of 3.0×10(8) cfu/g in biomass was attained.

Conversion of spent mushroom substrate to biofertilizer using a stress-tolerant phosphate-solubilizing Pichia farinose FL7.

To develop high-efficient biofertilizer, an environmental stress-tolerant phosphate-solubilizing microorganism (PSM) was isolated from agricultural wastes compost, and then applied to spent mushroom substrate (SMS). The isolate FL7 was identified as Pichia farinose with resistance against multiple environmental stresses, including 5-45°C temperature, 3-10 pH range, 0-23% (w/v) NaCl and 0-6M ammonium ion. Under the optimized cultivation condition, 852.8 mg/l total organic acids can be produced and pH can be reduced to 3.8 after 60 h, meanwhile, the soluble phosphate content reached 816.16 mg/l. The P. farinose was used to convert SMS to a phosphate biofertilizer through a semi-solid fermentation (SSF) process. After fermentation of 10 days, cell density can be increased to 5.6 × 10(8)CFU/g in biomass and pH in this medium can be decreased to 4.0. SMS biofertilizer produced by P. farinose significantly improved the growth of soybean in pot experiments, demonstrating a tremendous potential in agricultural application.

Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment.

Spent mushroom substrate (SMS) was treated with dilute sulfuric acid followed by cellulase and xylanase treatment to produce hydrolysates that could be used as the basis for media for the production of value added products. A L9 (3(4)) orthogonal experiment was performed to optimize the acid treatment process. Pretreatment with 6% (w/w) dilute sulfuric acid at 120°C for 120 min provided the highest reducing sugar yield of 267.57 g/kg SMS. No furfural was detected in the hydrolysates. Exposure to 20PFU of cellulase and 200 XU of xylanase per gram of pretreated SMS at 40°C resulted in the release of 79.85 g/kg or reducing sugars per kg acid pretreated SMS. The dilute sulfuric acid could be recycled to process fresh SMS four times. SMS hydrolysates neutralized with ammonium hydroxide, sodium hydroxide, or calcium hydroxide could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28 and a cell density of 2.9×10(11)CFU/mL could be obtained. The results provide a foundation for the development of value-added products based on SMS.