Metagenome Sequencing Reveals the Midgut Microbiota Makeup of Culex pipiens quinquefasciatus and Its Possible Relationship With Insecticide Resistance

Midgut microbiota can participate in the detoxification and metabolism processes in insects, but there are few reports on the relationship between midgut microbiota and insecticide resistance in mosquitoes. In this study, we performed metagenomic sequencing on a susceptible strain (SS), a field-collected Hainan strain (HN), and a deltamethrin-resistant strain (RR) of Culex pipiens quinquefasciatus to understand the diversity and functions of their midgut microbiota. The results revealed differences in midgut microbiota among the three strains of Cx. pipiens quinquefasciatus. At the phylum level, Proteobacteria was the most prominent, accounting for nearly 70% of their midgut microbes. At the genus level, Aeromonas made up the highest proportion. In addition, Aeromonas, Morganella, Elizabethkingia, Enterobacter, Cedecea, and Thorsellia showed significant differences between strains. At the species level, Bacillus cereus, Enterobacter cloacae complex sp. 4DZ3-17B2, Streptomyces sp. CNQ329, and some species of Pseudomonas and Wolbachia were more abundant in the two resistant strains. Principal component analysis (PCA) showed that the SS strain had significantly different metagenomic functions than the two deltamethrin-resistant strains (HN and RR strain). The HN and RR strains differed from the SS strain in more than 10 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The analysis of species abundance and functional diversity can provide directions for future studies.

Exploring the Biological and Molecular Characteristics of Resistance to Fludioxonil in Sclerotinia sclerotiorum From Soybean in China

Sclerotinia sclerotiorum is one of the most damaging and economically important necrotrophic plant pathogens, infecting more than 400 plant species globally. Although the phenylpyrrole fungicide fludioxonil has high activity against S. sclerotiorum, reports indicate that there is also substantial potential for the development of fungicide resistance. However, the current study investigating five fludioxonil-resistant laboratory mutants found a significant fitness cost associated with fludioxonil resistance resulting in significantly (P < 0.05) reduced mycelial growth and sclerotia formation on potato dextrose agar as well as significantly (P < 0.05) lower pathogenicity on detached tomato leaves, with one mutant, LK-1R, completely losing the capacity to cause infection. In addition, all of the fludioxonil-resistant mutants had significantly (P < 0.05) increased sensitivity to osmotic stress (0.5 M of potassium chloride and 1.0 M of glucose), which is consistent with the proposed fludioxonil target sites within the high osmolarity glycerol stress response mitogen-activated protein kinase (HOG1-MAPK) signaling transduction pathway. Sequence analysis of six genes from this two-component pathway, including SsHk, SsYpd, SsSk1, SsSk2, SsPbs, and SsHog, revealed several mutations that may be associated with fludioxonil resistance. For example, six separate point mutations were found in SsHk that led to changes in the predicted amino acid sequence, including A136G, F249V, G353A, E560K, M610K, and K727R. Similarly, SsPbs had three mutations (D34G, S46L, and L337E), SsSk1 and SsYpd had two (S53G and A795V for SsSk1, and E67G and Y141H for SsYpd), and SsHog and SsSk2 had one each (V220A and S763P, respectively). To our knowledge, these constitute the first reports of amino acid changes in proteins of the HOG1-MAPK pathway being associated with fludioxonil resistance in S. sclerotiorum. This study also showed a positive cross-resistance between fludioxonil and dimethachlone and procymidone, but none with tebuconazole or carbendazim, indicating that the inclusion of tebuconazole within an integrated pest management program could reduce the risk of fludioxonil resistance developing in field populations of S. sclerotiorum and ensure the sustainable production of soybeans in China into the future.

A Swin Transformer-based model for mosquito species identification

Mosquito transmit numbers of parasites and pathogens resulting in fatal diseases. Species identification is a prerequisite for effective mosquito control. Existing morphological and molecular classification methods have evitable disadvantages. Here we introduced Deep learning techniques for mosquito species identification. A balanced, high-definition mosquito dataset with 9900 original images covering 17 species was constructed. After three rounds of screening and adjustment-testing (first round among 3 convolutional neural networks and 3 Transformer models, second round among 3 Swin Transformer variants, and third round between 2 images sizes), we proposed the first Swin Transformer-based mosquito species identification model (Swin MSI) with 99.04% accuracy and 99.16% F1-score. By visualizing the identification process, the morphological keys used in Swin MSI were similar but not the same as those used by humans. Swin MSI realized 100% subspecies-level identification in Culex pipiens Complex and 96.26% accuracy for novel species categorization. It presents a promising approach for mosquito identification and mosquito borne diseases control.

Viral Metagenomics Analysis of Rodents From Two Border Provinces Located in Northeast and Southwest China

Objective

Wild animal pathogen surveillance will help to understand the next possible pandemic in advance. Rodents, which have close contact with humans, are generally regarded as a key factor for zoonotic disease control. Given the variation in rodent virus composition in diverse ecologies, we conducted a study on the viral infection of rodents of diverse species in different typical environments of Heilongjiang and Yunnan Provinces, located in northeastern and southwestern China, respectively.

Methods

Viral metagenomics sequencing and bioinformatic analysis were performed to determine the different distributions of rodent-borne viruses in typical environments of Heilongjiang and Yunnan Provinces, China. After viral culture and PCR confirmation, genomic and phylogenetic quantitative analysis was performed on the detected hantaviruses (HVs) and Beilong viruses (BeiVs).

Results

Nineteen rodents from three species and 35 rodents from five species of rodents were collected from Heilongjiang and Yunnan Provinces, respectively. Although the number and number of species of rodents trapped in the northeast were fewer than those in the southwest, viruses annotated from rodents in Heilongjiang were more diverse than those in Yunnan. Rodents carried 22 virus families in Heilongjiang and 13 families in Yunnan. Sequences assembled from Rattus norvegicus were annotated to the M, L, and S segments of HV, and all were clustered within the Seoul-type hantavirus (SEOV). There were 2 (R81Q, S698T) and 4 (K153R, M168I, I279S, and R1790K) amino acid site substitutions in M and L compared with the versions in the most homologous strains. Two BeiV isolates from Rattus norvegicus were closely related to BeiV from brown rats in Hong Kong, with high bootstrap values of >90% in the N segment and > 95% in the L segment. They were further clustered with Tailam virus, forming a distinct group in Paramyxoviridae.

Conclusion

The rodents from Heilongjiang and Yunnan located in northeast and southwest China, respectively, had different viral spectra, and only one-third (10/32) of virus families were detected in both areas. The predominant viruses were HV and BeiV in the Hantaviridae and Paramyxoviridae families, respectively. Rodent-borne viruses in the same species were similar in different geographic disparate areas owing to their similar close contact with human habitats and human activities. Additional attention should be given to the monitoring of neglected rodent-borne viruses, especially opportunistic viruses with currently low loads.

Microbe community composition differences of hand skin on similar lifestyle volunteers: a small-scale study

AIMS

Human skin is the first barrier against pathogens and environmental hazards and the highest contact frequency occurs with the hands. Environmental and personal metabolic factors may affect skin microbes. This study was conducted to clarify the diversity in the skin microbial community that was mainly due to individual skin metabolites rather than lifestyle and environmental factors.

METHODS AND RESULTS

Skin microbiota samples were collected from 11 volunteers who met similar lifestyle inclusion criteria. The V3-V4 region of the 16S rRNA gene was amplified. After library construction and sequencing, we compared the composition and diversity of the hand skin microbiota in different sexes and BMI groups with bioinformation analysis. The whole sequence data were annotated as 42 phyla, 538 families, and 1215 genera. Four dominant phyla accounted for 97% of the total including Actinobacteriota (50.18%), Firmicutes (23.85%), Proteobacteria (21.64%) and Bacteroidota (2.05%). The genera that were detected in all subjects with high relative abundance were Cutibacterium, Staphylococcus, Corynebacterium, Streptococcus, Lawsonella, Enhydrobacter, Escherichia-Shigella, Asaia and Micrococcus.

CONCLUSIONS

The diversity and richness of the microbiota of male hand skin in our study was higher than that of females. Interestingly, Cutibacterium, Staphylococcus, and Corynebacterium might serve as important skin microbiota to distinguish sexes.

[Prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric acute myeloid leukemia]

Objective: To investigate the prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric patients with t (8;21) acute myeloid leukemia (AML) . Methods: The clinical features and RUNX1-RUNX1T1 transcript levels of 55 pediatric t (8;21) AML patients, newly diagnosed from Jan. 2010 to Apr. 2016, were analyzed retrospectively. The relationship between the minimal residual disease (MRD) and prognosis was analysed by dynamic monitoring of RUNX1-RUNX1T1 transcript levels using real-time quantitative PCR (RQ-PCR) technology. Results: The RUNX1-RUNX1T1 transcript levels in bone marrow cells at diagnosis was not related to relapse. After one course of induction therapy, patients with a more than 2 Log reduction of RUNX1-RUNX1T1 transcript levels (>2 Log) had lower 5 years cumulative incidence of relapse (CIR) [ (24.3±8.4) % vs (52.6±9.7) %, χ(2)=9.046, P=0.003], relapse-free survival (RFS) [ (71.6±12.7) % vs (48.1±13.2) %, χ(2)=5.814, P=0.016], and better overall survival (OS) [ (76.9±12.5) % vs (48.9±14.7) %, χ(2)=6.346, P=0.012], compared to patients with a less than 2 Log reduction (a<2 Log) . Multivariate Cox survival analysis suggested that a>2 Log reduction in RUNX1-RUNX1T1 transcript levels after a course of induction therapy was an independent prognostic factor for RFS (HR=0.263, 95%CI 0.081-0.851, P=0.026) and OS (HR=0.214, 95% CI 0.057-0.808, P=0.023) . During consolidation therapy and follow-up period, molecular relapse of 16 cases and hematologic relapse of 13 cases were identified by continuous dynamic monitoring of RUNX1-RUNX1T1 transcript levels, with a median interval of 4.0 (1.5-5.8) months from the molecular relapse to hematologic relapse. 2 cases of molecular relapse who received timely allogeneic hematopoietic stem cell transplantation did not experience hematologic relapse. Conclusion: Dynamic monitoring RUNX1-RUNX1T1 transcript levels by RQ-PCR technique can subdivide patients into relatively low and high risk group, early screen patients at high risk of relapse and provide a scientific basis for precision stratification and risk-adapted therapy for pediatric t (8;21) AML children.

[Four cases of acute respiratory distress syndrome patients transported with veno-venous extracorporeal membrane oxygenation]

Objective: To retrospectively review 4 cases diagnosed with pediatric acute respiratory distress syndrome (ARDS) who were transported with veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) from April 2016 to March 2017. Methods: Four patients were transported to Bayi Children's Hospital Afflicted to the PLA Army General Hospital, with V-V ECMO. Their vital signs, blood-gas analysis and chest X-ray before and after transportation were compared. The length of ECMO, pediatric intensive care unit (PICU) stay and hospitalization, and the prognosis were analyzed. Results: All the four cases were transported to our hospital successfully from distances between 1 000 km to 1 210 km. The 4 cases were 4 to 6 years old with the body weight of 19 to 35 kg, of whom 3 were boys and 1 was girl. The catheters were inserted in the right jugular vein and femoral vein. The vital signs and blood-gas analysis after transportation did not change significantly compared to baseline. The length of ECMO for the four patients were 48, 754, 157 and 438 hours. They stayed in the PICU for 10, 32, 14 and 19 days, respectively. At last, 2 of them were successfully discharged from hospital without any complications; however, the other 2 died of multiple organ failure. Conclusion: Transporting ARDS patients with a satisfactory cardiac function under VV-ECMO by an experienced ECMO team is safe.

Metagenome Sequencing Reveals the Microbiome of Aedes albopictus and Its Possible Relationship With Dengue Virus Susceptibility

Dengue fever virus (DENV) is a mosquito-borne flavivirus that poses a serious risk to human health. Aedes albopictus is a widely distributed vector of dengue fever in China. Based on the impact of physiological activity, the microbiome in A. albopictus will provide a novel environment-friendly approach to control DENV transmission. We performed metagenomic sequencing on A. albopictus before and after exposure to DENV blood meal to detect microbiome variation of A. albopictus with different susceptibilities to DENV. The dominant phyla in A. albopictus microbiome were Proteobacteria and Ascomycota, and the dominant genera were Aspergillus and Metarhizium. Gammaproteobacteria bacterium, Lactobacillus harbinensis, and Neurospora crassa differed significantly after DENV infection. There were 15 different microorganisms found to be involved in mosquito immunity and metabolism, such as Alphaproteobacteria bacterium, Methyloglobulus morosus, and Shigella sonnei, which might have an impact on the DENV susceptibility of A. albopictus. It was hypothesized that the lack of specific bacteria may lead to increased susceptibility of A. albopictus to DENV. Interventions in the microbiome composition or specific bacteria of A. albopictus may affect the susceptibility to DENV and control the mosquito-borne diseases efficiently.

Microplastics affect mosquito from aquatic to terrestrial lifestyles and are transferred to mammals through mosquito bites

Microplastics (MPs) transfer from the environment to living organisms is a nonignorable global problem. As a complete metamorphosis insect, the larvae and adult Culex quinquefasciatus mosquito live in aquatic and terrestrial environments, respectively, where they easily access MPs. However, little is known about mosquitoes' potential role in MPs accumulation throughout ecosystems. Therefore, we conducted a study with different MPs particle sizes (0.1/1/10 μm) and concentrations (0.5/5/50 μg/mL) on Cx. quinquefasciatus to address this issue. Once exposed at the young larval stage, MPs could accompany the mosquitoes their entire life. The fluorescence signals of MPs in the larvae were mainly located in the intestines. Its intensity increased (from 3.72 × 106 AU to 5.45 × 107 AU) as the concentrations of MPs increases. The fluorescence signals of MPs were also detected in the blood and skin tissues of mice bitten by adult mosquitoes with MPs containing in their bodies. Mosquitos exposed to MPs showed longer larval pupation and eclosion time as well as lower adult body weight. In addition, MPs significantly reduced the lethal effect of pyrethroid insecticides (97.77 % vs. 48.88 %, p < 0.05) with 15.1 % removal of the deltamethrin concentration. After MPs exposure, the relative abundance of the Cx. quinquefasciatus gut microbiome, such as Wolbachia spp., Elizabethkingia spp., and Asaia spp., changed as the MPs size and concentration changes. Mosquitoes provide a new pathway for MPs accumulation and transfer to higher-level living organisms. Moreover, MPs significantly reduce the control effect of deltamethrin, providing new guidelines for mosquito insecticide application in MPs contamination circumstances.