Lepidoptera insects have a novel development process comprising several metamorphic stages during their life cycle compared with vertebrate animals. Unlike most Lepidoptera insects that live on nectar during the adult stage, the Bombyx mori silkworm adults do not eat anything and die after egg-laying. In addition, the midguts of Lepidoptera insects produce antimicrobial proteins during the wandering stage when the larval tissues undergo numerous changes. The exact mechanisms responsible for these phenomena remain unclear.

Candida albicans can switch from commensal to pathogenic mode, causing mucosal or disseminated candidiasis. The host relies on pattern-recognition receptors including Toll-like receptors (TLRs) and C-type lectin receptors (CLRs) to sense invading fungal pathogens and launch immune defense mechanisms. However, the complex interplay between fungus and host innate immunity remains incompletely understood. Here we report that C. albicans upregulates expression of a small secreted cysteine-rich protein Sel1 upon encountering limited nitrogen and abundant serum. Sel1 activates NF-κB and MAPK signaling pathways, leading to expression of proinflammatory cytokines and chemokines. Comprehensive genetic and biochemical analyses reveal both TLR2 and TLR4 are required for the recognition of Sel1. Further, SEL1-deficient C. albicans display an impaired immune response in vivo, causing increased morbidity and mortality in a bloodstream infection model. We identify a critical component in the Candida-host interaction that opens a new avenue to tackle Candida infection and inflammation.

Leptospirosis, caused by pathogenic Leptospira spp., is recognized as an important emerging zoonotic disease throughout the world. In this study, multiple approaches were used to characterize the recently discovered serovar Heyan strain L231. This strain can infect guinea pigs and belonged to the pathogenic species L. weilii. Genome sequencing analysis revealed the draft genome of 4.2 M bp with a G+C content of 40.67% for strain L231, and a total of 4,794 ORFs were identified. The strain L231 genome was found to have a larger LPS biosynthesis locus than that of strains L. interrogans serovar Lai and L. borgpetersenii serovar Hardjobovis. Phylogenomic reconstructions showed that the evolutionary position of L. weilii serovar Heyan was different from that of other serovars from serogroup Manhao. These findings may lead us to a better understanding of Leptospira pathogenesis and evolution.

Hypocrealean fungi (Ascomycota) are known for their diversity of lifestyles. Their vital influences on agricultural and natural ecosystems have resulted in a number of sequenced genomes, which provide essential data for genomic analysis. Totally, 45 hypocrealean fungal genomes constructed a phylogeny. The phylogeny showed that plant pathogens in Nectriaceae diverged earliest, followed by animal pathogens in Cordycipitaceae, Ophiocordycipitaceae and Clavicipitaceae with mycoparasites in Hypocreaceae. Insect/nematode pathogens and grass endophytes in Clavicipitaceae diverged at last. Gene families associated with host-derived nutrients are significantly contracted in diverged lineages compared with the ancestral species. Introgression was detected in certain lineages of hypocrealean fungi, and the main functions of the genes located in the introgressed regions are involved in host recognition, transcriptional regulation, stress response and cell growth regulation. These results indicate that contraction of gene families and introgression might be main mechanisms to drive lifestyle differentiation and evolution and host shift of hypocrealean fungi.

Milk microbiota has a great influence on the safety and quality of dairy products. However, few studies have investigated the variations of bacterial composition in raw milk. In this study, raw milk samples were collected in 12 successive months, and their bacterial compositions were determined by 16 S rRNA gene sequencing. The highest diversity of bacterial composition was detected in June, while the lowest was in December. Firmicutes, Proteobacteria and Actinobacteria were the most abundant phyla and exhibited a counter-balanced relationship. Pseudomonas, Lactococcus and Acinetobacter were the most prevalent genera (>1%), and a tiny core microbiota (Acinetobacter and Pseudomonas) was observed. Temperature and humidity were the determining factors for most variation in bacterial compositions at both the phylum and genus levels. Higher abundances of Pseudomonas, Propionibacterium and Flavobacterium were correlated with low temperature. Furthermore, Pseudomonas/Propionibacterium and Lactobacillus/Bifidobacterium were two pairs of genera that had synergistic effects. Associations between the microbiota and milk quality parameters were analyzed. The abundances of Propionibacterium and Pseudoalteromonas were negatively correlated to total bacterial count, which meant that they helped to maintain milk quality, while a series of environmental microorganisms contributed to the spoilage of raw milk.

The extracellular signal-regulated kinase (ERK) pathway has been reported to play a pivotal role in mediating spinal cord injury (SCI) progression. The present study aimed to investigate the effects of phosphorylated ERK1/2 (p-ERK1/2) inhibition on SCI-induced astrocyte activation and inflammation and its possible mechanism in rats. Here, female Sprague-Dawley rats were randomly assigned to four groups: (1) Sham group, (2) SCI group, (3) TGN-020 group (aquaporin-4, AQP4, blocking agent), (4) PD98059 group (ERK blocking agent). A well SCI model was established by compressing the thoracic vertebra 10 level (weight 35 g, time 5 min) in rats. Western blotting and immunofluorescence staining were used to measure the expression of associated proteins after SCI. HE staining and Nissl staining were performed to detect the morphological changes of spinal cords and the number of surviving neurons following SCI, respectively. The Basso-Beattie-Bresnahan open-field rating scale was used to evaluate functional locomotor recovery following SCI in rats. Our results demonstrated that SCI significantly induced the upregulation of aquaporin-4, p-ERK1/2, glial fibrillary acidic protein, proliferating cell nuclear antigen, and proinflammatory cytokines (tumor necrosis factor-α, interleukin-6 and interleukin-1β). However, treatment with TGN-020 or PD98059 could effectively inhibit astrocyte proliferation and proinflammatory cytokine release, preserve the number of surviving ventral horn neurons, and subsequently improve the locomotor function of rats after SCI. Interestingly, the SCI-induced elevation of AQP4 expression was downregulated by p-ERK1/2 inhibition, suggesting that blocking ERK1/2 phosphorylation could attenuate astrocyte activation and inflammatory processes through negative regulation of AQP4. Therefore, p-ERK1/2 blockade may be employed as a therapeutic target for SCI.

To investigate species diversity and prevalence of antifungal resistance among clinical isolates of Aspergillus spp. in Shanghai, China.

Nanoplastics, one component of plastic pollution, can enter human bodies via inhalation and thus threaten human health. However, the knowledge about the uptake and exocytosis of nanoplastics in cells of human lung organs is still very limited. Herein, we investigated the endocytosis, distribution, and exocytosis of polystyrene nanoparticles (PS NPs) of 50 nm (G50PS) and 100 nm (R100PS) in A549 cells and BEAS-2B cells. We found that both the cellular uptake of PS NPs increased positively with exposure time and dose, and A549 cells ingested more PS NPs than BEAS-2B cells did. In addition, the intracellular content of G50PS was higher than that of R100PS except at a higher dose and longer time. The ingested PS NPs were distributed mainly in lysosomes, while many G50PS appeared around the cell membrane, and R100PS also accumulated in mitochondria in BEAS-2B cells. As for the exocytosis, R100PS was more difficult to excrete than G50PS. Lysosomes in A549 cells and actin and microtubule in BEAS-2B cells were involved in the exocytosis of the PS NPs. These findings provide detailed information about the translocation of nanoplastics in lung cells, which is valuable for the safety assessment of nanoplastics in the environment.

The Asian honeybee Apis cerana is one of two bee species that have been commercially kept with immense economic value. Here we present the analysis of genomic sequence and transcriptomic exploration for A. cerana as well as the comparative genomic analysis of the Asian honeybee and the European honeybee A. mellifera. The genome and RNA-seq data yield new insights into the behavioral and physiological resistance to the parasitic mite Varroa the evolution of antimicrobial peptides, and the genetic basis for labor division in A. cerana. Comparison of genes between the two sister species revealed genes specific to A. cerana, 54.5% of which have no homology to any known proteins. The observation that A. cerana displayed significantly more vigilant grooming behaviors to the presence of Varroa than A. mellifera in conjunction with gene expression analysis suggests that parasite-defensive grooming in A. cerana is likely triggered not only by exogenous stimuli through visual and olfactory detection of the parasite, but also by genetically endogenous processes that periodically activates a bout of grooming to remove the ectoparasite. This information provides a valuable platform to facilitate the traits unique to A. cerana as well as those shared with other social bees for health improvement.

The idea that healthy uterine cavity is sterile is challenged nowadays. It is still debatable whether the bacteria present in the uterine cavity during pregnancy are residents or invaders. To reveal microbiome composition and its characteristics in the womb of pregnant women, 41 decidual tissue samples and 64 amniotic fluid samples were taken from pregnant Chinese women. DNA extraction was followed by pyrosequencing of the hypervariable V4 region of the 16S rDNA gene to characterize womb microbiome. Both types of samples had low diversity microbiome with Enterobacteriaceae being the dominant phylotypes at family level. To characterize the nature of colonization during pregnancy, the presence of endogenous biomass was confirmed by cultivation. Surprisingly, all of the 50 amniotic fluid samples studied were culture-negative, whereas 379 out of 1,832 placenta samples were culture-positive. Our results suggested that womb contained microbiome with low diversity. Culture-based investigation of amniotic fluid and placenta samples confirmed the presence of cultivable microorganisms in the placenta but not in amniotic fluid. Thus it suggests that bacterial colonization does occur during healthy pregnancy.

Triazole resistance in A. fumigatus is an increasing worldwide problem that causes major challenges in the management of aspergillosis. New antifungal drugs are needed with novel targets, that are effective in triazole-resistant infection. In this study, we retrospectively evaluated potency of the novel drug olorofim compared to contemporary antifungal agents against 111 clinical A. fumigatus isolates collected from Huashan Hospital, Shanghai, China, using EUCAST methodology, and reviewed the literature on triazole resistant A. fumigatus published between 1966 and 2020 in China. Olorofim was active in vitro against all tested A. fumigatus isolates with MIC90 of 0.031mg/L (range 0.008-0.062 mg/L). For 4 triazole-resistant A. fumigatus (TRAF) isolates, the olorofim MIC ranged between 0.016-0.062mg/L. The reported rates of TRAF in China is 2.5% - 5.56% for clinical isolates, and 0-1.4% for environmental isolates.TR34/L98H/S297T/F495I is the predominant resistance mechanism, followed by TR34/L98H. Non TR-mediated TRAF isolates, mostly harboring a cyp51A single point mutation, showed greater genetic diversity than TR-mediated resistant isolates. Resistance due toTR34/L98H and TR34/L98H/S297T/F495I mutations among TRAF isolates might have evolved from separate local isolates in China. Continuous isolation of TRAF in China underscores the need for systematic resistance surveillance as well as the need for novel drug targets such as olorofim.

In contrast to the well-characterized gut microbiomes, the composition and function of the insect body-surface microbiotas are still elusive and highly underexplored. Here we report the dynamic features of the Drosophila melanogaster surface microbiomes. It was found that the microbiomes assembled on fly surfaces could defend insects against fungal parasitic infections. The substantial increase of bacterial loads occurred within 10 days of fly eclosion, especially the expansion of Gilliamella species. The culturable bacteria such as Lactiplantibacillus plantarum could effectively inhibit fungal spore germinations, and the gnotobiotic addition of the isolated bacteria could substantially delay fungal infection of axenic flies. We found that the fly tarsal segments were largely accumulated with bacterial cells, which could accelerate cell dispersal onto different body parts to deter fungal spore germinations. Our findings will facilitate future investigations of the surface microbiotas affecting insect physiologies.

Diverse β-carboline (βC) alkaloids are produced by microbes, plants, and animals with myriad bioactivities and drug potentials. However, the biosynthetic mechanism of βCs remains largely elusive, especially regarding the hydroxyl and glucosyl modifications of βCs. Here, we report the presence of the bacterial-like Pictet-Spenglerase gene Fcs1 in the entomopathogenic Beauveria fungi that can catalyze the biosynthesis of the βC skeleton. The overexpression of Fcs1 in Beauveria bassiana led to the identification of six βC methyl glycosides, termed bassicarbosides (BCSs) A-F. We verified that the cytochrome P450 (CYP) genes adjacent to Fcs1 cannot oxidize βCs. Alternatively, the separated CYP684B2 family gene Fcs2 was identified to catalyze βC hydroxylation together with its cofactor gene Fcs3. The functional homologue of Fcs2 is only present in the Fcs1-containing fungi and highly similar to the Fcs1-connected yet nonfunctional CYP. Both evolved quicker than those from fungi without Fcs1 homologues. Finally, the paired methyl/glucosyl transferase genes were verified to mediate the production of BCSs from hydroxy-βCs. All these functionally verified genes are located on different chromosomes of Beauveria, which is in contrast to the typical content-clustered feature of fungal biosynthetic gene clusters (BGCs). We also found that the production of BCSs selectively contributed to fungal infection of different insect species. Our findings shed light on the biosynthetic mechanism of βC glycosides, including the identification of a βC hydroxylase. The results of this study also propose an evolving process of fungal BGC formation following the horizontal transfer of a bacterial gene to fungi.

Gut microbiota is closely related to type 2 diabetes mellitus (T2DM). The gut microbiota of patients with T2DM is significantly different from that of healthy subjects in terms of bacterial composition and diversity. Here, we used the fermentation products of Paenibacillus bovis sp. nov. BD3526 to study the disease progression of T2DM in Goto-kakisaki (GK) rats. We found that the symptoms in GK rats fed the fermentation products of BD3526 were significantly improved. The 16S rRNA sequencing showed that the fermentation products of BD3526 had strong effects on the gut microbiota by increasing the content of Akkermansia. In addition, the interaction of the genus in the gut of the BD3526 group also significantly changed. Additional cytokine detection revealed that the fermentation products of BD3526 can reduce the inflammatory factors in the intestinal mucus of GK rats and thereby inhibit the inflammatory response and ameliorate the symptoms of T2DM.

Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus) is an important species of Lactic Acid Bacteria (LAB) used for cheese and yogurt fermentation. The genome of Lb. bulgaricus 2038, an industrial strain mainly used for yogurt production, was completely sequenced and compared against the other two ATCC collection strains of the same subspecies. Specific physiological properties of strain 2038, such as lysine biosynthesis, formate production, aspartate-related carbon-skeleton intermediate metabolism, unique EPS synthesis and efficient DNA restriction/modification systems, are all different from those of the collection strains that might benefit the industrial production of yogurt. Other common features shared by Lb. bulgaricus strains, such as efficient protocooperation with Streptococcus thermophilus and lactate production as well as well-equipped stress tolerance mechanisms may account for it being selected originally for yogurt fermentation industry. Multiple lines of evidence suggested that Lb. bulgaricus 2038 was genetically closer to the common ancestor of the subspecies than the other two sequenced collection strains, probably due to a strict industrial maintenance process for strain 2038 that might have halted its genome decay and sustained a gene network suitable for large scale yogurt production.

Edwardsiella bacteria are leading fish pathogens causing huge losses to aquaculture industries worldwide. E. tarda is a broad-host range pathogen that infects more than 20 species of fish and other animals including humans while E. ictaluri is host-adapted to channel catfish causing enteric septicemia of catfish (ESC). Thus, these two species consist of a useful comparative system for studying the intricacies of pathogen evolution. Here we present for the first time the phylogenomic comparisons of 8 genomes of E. tarda and E. ictaluri isolates. Genome-based phylogenetic analysis revealed that E. tarda could be separate into two kinds of genotypes (genotype I, EdwGI and genotype II, EdwGII) based on the sequence similarity. E. tarda strains of EdwGI were clustered together with the E. ictaluri lineage and showed low sequence conservation to E. tarda strains of EdwGII. Multilocus sequence analysis (MLSA) of 48 distinct Edwardsiella strains also supports the new taxonomic relationship of the lineages. We identified the type III and VI secretion systems (T3SS and T6SS) as well as iron scavenging related genes that fulfilled the criteria of a key evolutionary factor likely facilitating the virulence evolution and adaptation to a broad range of hosts in EdwGI E. tarda. The surface structure-related genes may underlie the adaptive evolution of E. ictaluri in the host specification processes. Virulence and competition assays of the null mutants of the representative genes experimentally confirmed their contributive roles in the evolution/niche adaptive processes. We also reconstructed the hypothetical evolutionary pathway to highlight the virulence evolution and niche adaptation mechanisms of Edwardsiella. This study may facilitate the development of diagnostics, vaccines, and therapeutics for this under-studied pathogen.

Although the Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) has been available for more than 75 years, one third of the world's population is still infected with Mycobacterium tuberculosis and approximately 2 million people die of TB every year. To reduce this immense TB burden, a clearer understanding of the functional genes underlying the action of BCG and the development of new vaccines are urgently needed.

The antifungal therapy caspofungin is a semi-synthetic derivative of pneumocandin B0, a lipohexapeptide produced by the fungus Glarea lozoyensis, and was the first member of the echinocandin class approved for human therapy. The nonribosomal peptide synthetase (NRPS)-polyketide synthases (PKS) gene cluster responsible for pneumocandin biosynthesis from G. lozoyensis has not been elucidated to date. In this study, we report the elucidation of the pneumocandin biosynthetic gene cluster by whole genome sequencing of the G. lozoyensis wild-type strain ATCC 20868.

Metarhizium robertsii is a versatile fungus with saprophytic, plant symbiotic and insect pathogenic lifestyle options. Here we show that M. robertsii mediates the saprophyte-to-insect pathogen transition through modulation of the expression of a membrane protein, Mr-OPY2. Abundant Mr-OPY2 protein initiates appressorium formation, a prerequisite for infection, whereas reduced production of Mr-OPY2 elicits saprophytic growth and conidiation. The precise regulation of Mr-OPY2 protein production is achieved via alternative transcription start sites. During saprophytic growth, a single long transcript is produced with small upstream open reading frames in its 5' untranslated region. Increased production of Mr-OPY2 protein on host cuticle is achieved by expression of a transcript variant lacking a small upstream open reading frame that would otherwise inhibit translation of Mr-OPY2. RNA-seq and qRT-PCR analyses show that Mr-OPY2 is a negative regulator of a transcription factor that we demonstrate is necessary for appressorial formation. These findings provide insights into the mechanisms regulating fungal lifestyle transitions.

Preeclampsia is a pregnancy-specific disorder of new-onset hypertension and proteinuria after 20 weeks' gestation, often resulting in poor outcome. Previous studies demonstrated that apelin is an endogenous active peptide with visodilation and anti-oxidative stress capabilities. The present study investigated the effects of apelin in a rat model of preeclampsia induced by reduced uterine perfusion pressure (RUPP). Rats with RUPP displayed hypertension and poor pregnancy outcomes, such as decreased fetal and placental weight. Of note, apelin treatment significantly ameliorated the symptoms of preeclampsia, improved the impaired endothelial nitric oxide synthase/nitric oxide signaling and attenuated activation of oxidative stress in RUPP rats. Apelin may be a potential agent for preventing and treating preeclampsia.