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UNLABELLED: To gain insights into the diversity of Pseudomonas syringae sensu lato affecting sweet cherry in California, we sequenced and analyzed the phylogenomic and genomic architecture of 86 fluorescent pseudomonads isolated from symptomatic and asymptomatic cherry tissues. Fifty-eight isolates were phylogenetically placed within the P. syringae species complex and taxonomically classified into five genomospecies: P. syringae pv. syringae, P. syringae, Pseudomonas cerasi, Pseudomonas viridiflava, and A. We annotated components of the type III secretion system and phytotoxin-encoding genes and correlated the data with pathogenicity phenotypes. Intact probable regulatory protein HrpR was annotated in the genomic sequences of all isolates of P. syringae pv. syringae, P. syringae, P. cerasi, and A. Isolates of P. viridiflava had atypical probable regulatory protein HrpR. Syringomycin and syringopeptin-encoding genes were annotated in isolates of all genomospecies except for A and P. viridiflava. All isolates of P. syringae pv. syringae caused cankers, leaf spots, and fruit lesions in the field. In contrast, all isolates of P. syringae and P. cerasi and some isolates of P. viridiflava caused only cankers. Isolates of genomospecies A could not cause any symptoms suggesting phytotoxins are essential for pathogenicity. On detached immature cherry fruit pathogenicity assays, isolates of all five genomospecies produced symptoms (black-dark brown lesions). However, symptoms of isolates of genomospecies A were significantly (P < 0.01) less severe than those of other genomospecies. We also mined for genes conferring resistance to copper and kasugamycin and correlated these data with in vitro antibiotic sensitivity tests. IMPORTANCE: Comprehensive identification of phytopathogens and an in-depth understanding of their genomic architecture, particularly virulence determinants and antibiotic-resistant genes, are critical for several practical reasons. These include disease diagnosis, improved knowledge of disease epidemiology, pathogen diversity, and determination of the best possible management strategies. In this study, we provide the first report of the presence and pathogenicity of genomospecies Pseudomonas cerasi and Pseudomonas viridiflava in California sweet cherry. More importantly, we report a relatively high level of resistance to copper among the population of Pseudomonas syringae pv. syringae (47.5%). This implies copper cannot be effectively used to control bacterial blast and bacterial canker of sweet cherries. On the other hand, no isolates were resistant to kasugamycin, an indication that kasugamycin could be effectively used for the control of bacterial blast and bacterial canker. Our findings are important to improve the management of bacterial blast and bacterial canker of sweet cherries in California.

Infectious bronchitis virus (IBV) is a respiratory virus causing atropism in multiple body systems of chickens. Recently, the California 1737/04 (CA1737/04) IBV strain was identified as one of the circulating IBV variants among poultry operations in North America. Here, the pathogenicity and tissue tropism of CA1737/04 IBV strain in specific-pathogen-free (SPF) hens were characterized in comparison to Massachusetts (Mass) IBV. In 30 weeks-old SPF hens, Mass or CA1737/04 IBV infections were carried out, while the third group was maintained as a control group. Following infection, we evaluated clinical signs, egg production, viral shedding, serology, necropsy examination, and histopathology during a period of 19 days. Also, certain tissue affinity parameters were investigated, which involved the localization of viral antigens and the detection of viral RNA copies in designated tissues. Our findings indicate that infection with CA1737/04 or Mass IBV strain could induce significant clinical signs, reduced egg production, and anti-IBV antibodies locally in oviduct wash and systemically in serum. Both IBV strains showed detectable levels of viral RNA copies and induced pathology in respiratory, renal, enteric, and reproductive tissues. However, the CA1737/04 IBV strain had higher pathogenicity, higher tissue tropism, and higher replication in the kidney, large intestine, and different segments of the oviduct compared to the Mass IBV strain. Both IBV strains shed viral genome from the cloacal route, however, the Mass IBV infected hens shed higher IBV genome loads via the oropharyngeal route compared to CA1737/04 IBV-infected hens. Overall, the current findings could contribute to a better understanding of CA1737/04 IBV pathogenicity in laying hens.

AbstractPinus bungeana belonging to the genus Pinus is a pine tree species endemic to China. It plays vital roles in afforestation, forest regeneration, landscaping, forest ecosystems, and environmental protection. However, P. bungeana has been listed as a rare and endangered species in recent years due to population fragmentation. The occurrence of lethal diseases on the trees has made the situation even worse. This study aimed to identify the pathogen causing the trunk canker on P. bungeana trees in Qingdao, China. The morphological identification of the pathogen relied primarily on the morphology of conidia. Molecular identification was performed using the combined sequences of ITS, Tef and Tub2 genes. The eight isolates were all identified as Diplodia sapinea. The pathogenicity of the eight isolates was examined both in vitro and in vivo. The results showed that all the fungal isolates caused severe canker symptoms on the inoculated P. bungeana branches. Moreover, D. sapinea was re-isolated from the inoculated branches. This study is novel in reporting D. sapinea causing trunk canker on P. bungeana trees in China. [ABSTRACT FROM AUTHOR]

Feline coronavirus (FCoV) is an enveloped, positive‐sense RNA virus, which is widespread among feline populations, and can cause a fatal serious disease called feline infectious peritonitis (FIP). According to the differences of antigen and genetic composition, FCoV consists of two genotypes, FCoV I and FCoV II. In this study, we have isolated and identified a FCoV I strain named HL2019. Based on the complete genome of HL2019, phylogenetic analysis showed that HL2019 strain formed in the cluster FCoV I which is more closed to human coronavirus 229E (HCoV 229E) and HCoV NL63, while the FCoV I stains is distantly related to FCoV II strains. Analyzing with RDP4 and Simplot software showed that the virus HL2019 is recombinant by the FCoV I China/ZJU1709 and FCoV I Netherlands/UU16 strains. Furthermore, the pathogenicity of HL2019 was evaluated in 9–12‐month‐old cats. Two of three challenged cats developed serious clinical signs and died at 28‐day postchallenge (dpc). Real‐time polymerase chain reaction (PCR) analysis showed that HL2019 has broad tissue tropism, especially in the duodenum with viral load up to 104 copies/mg. In summary, our data show that we have successfully isolated a strain of FCoV I named HL2019 that is highly pathogenic to cats. [ABSTRACT FROM AUTHOR]

Background: Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), a key agricultural pest, impacts a broad spectrum of crop species, such as cotton, maize, rice, sorghum, and a range of vegetables. Chemical pesticides and transgenic maize are commonly used to protect crops against this major pest. However, biological control offers a safer and more sustainable solution for long-term FAW management. Entomopathogenic fungi (EPF), a substitute for synthetic insecticides, have been proven to be an effective biocontrol agent for managing pest populations. The present study objective is to isolate and identify the EPF, Purpureocillium lilacinum from soil using morphological and molecular techniques and evaluate its pathogenicity against FAW eggs and various larval stages under different spore concentrations. Results: The micro-morphological characteristics fluctuated in growth behavior, appearance, and color under diverse growth media and temperatures. Molecular analysis, which involved constructing a phylogenetic tree from ITS and TEF gene regions, confirmed that PT-02 was P. lilacinum. The pathogenicity of the fungus was tested on FAW eggs, neonates, and larvae at multiple concentrations (1 × 108, 1 × 107, and 1 × 106 spores/ml), resulting in variation mortality. The egg mortality rate at 1 × 108, 1 × 107, and 1 × 106 spores/ml was 98, 98 and 96%, respectively. The neonate mortality rate was 100%, while first and second instars larvae mortality ranged from 10–36% across three concentrations, seven days after treatment (DAT). The median lethal concentration (LC50) values of P. lilacinum PT-02 against FAW eggs, first and second instars, were 3.02 × 107, 1.38 × 108, and 2.56 × 108 spore/ml, respectively. Conclusions: The findings revealed that the native strain of P. lilacinum exhibited strong virulence against FAW, suggesting its potential use as an effective biocontrol agent for managing field pest populations. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS) is one of the most significant diseases affecting the pig industry worldwide and is caused by the PRRS virus (PRRSV), which has complex genetic variation due to frequent mutations, indels, and recombination. The emergence of PRRSV L1C.5 in 2020 in the United States has raised worldwide concerns about PRRSV with the RFLP 1-4-4 pattern and lineage 1C. However, studies on the pathogenic characteristics, epidemiological distribution, and effectiveness of vaccines against PRRSV with L1C and RFLP1-4-4 pattern in China are still insufficient. In this study, a novel recombinant variant of PRRSV with RFLP 1-4-4 and lineage 1C features, different from L1C.5 in the United States, was isolated in China in 2021. In pathogenicity experiments in specific pathogen-free piglets or farm piglets, 60–100% of artificially infected experimental piglets died with high fever and respiratory symptoms. Inflammatory cytokine and chemokine levels were upregulated in infected piglets. A commercially modified live vaccine against highly pathogenic PRRSV did not provide effective protection when the vaccinated piglets were challenged with the novel L1C-1-4-4 variant. Therefore, this strain merits special attention when devising control and vaccine strategies. These findings suggest that extensive joint surveillance is urgently needed and that vaccine strategies should be updated to prevent the disease from spreading further. [ABSTRACT FROM AUTHOR]

Since 2020, a novel goose-derived reovirus, characterized by goose hemorrhagic hepatitis, has emerged in the goose breeding industry of Guangdong province, China, leading to significant economic losses in the poultry sector. To study the genetic variation of novel goose reovirus (NGRV) in Guangdong province, this experiment utilized goose embryonic fibroblast cells for virus isolation. RT-PCR was conducted to identify, amplify, clone, and sequence the complete genome of the NGRV isolated from Zhaoqing. The genomic sequences were compared with reference strains to construct a phylogenetic tree. Moreover, animal pathogenicity, excretion patterns, and pathological sections were examined. The results showed that liver and spleen samples from geese suspected of NGRV infection were used for isolation, resulting in the identification of a reovirus presumed to originate from geese, designated as GD218. In terms of genomic structure and sequence homology, GD218 closely resembles the novel duck reovirus, differing significantly from earlier isolated NDRV strains (J18, NP03, SD12, etc.) in genetic composition (nt: 80.6–97.9%, aa: 94.3–98.9%). However, it is similar to strains isolated after 2018, such as XT18, SY, QR, YL, LY20, etc. (nt: 95.3–98.9%, aa: 98.6–99.7%). Therefore, based on phylogenetic analysis, GD218 is hypothesized to be a novel type of goose-origin reovirus homologous to the novel duck reovirus. [ABSTRACT FROM AUTHOR]

Bovine rotavirus (BRV) is the main cause of acute gastroenteritis in calves, resulting in significant economic losses to the cattle industry worldwide. Additionally, BRV has multiple genotypes, which could enable cross-species transmission, thereby posing a significant risk to public health. However, there is a problem of multiple genotypes coexisting in BRV, and the cross-protection effect between different genotypes of rotavirus strains is not effective enough. Therefore, mastering clinical epidemic genotypes and using epidemic genotype strains for vaccine preparation is an effective means of preventing and controlling BRV. In this study, BRV strain DQ2020 in MA104 cells was identified by transmission electron microscopy (TEM), reverse transcription polymerase chain reaction (RT-PCR), and colloidal gold immunochromatographic test strips. The whole genome of BRV strain DQ2020 was sequenced and pathogenicity in suckling mice was assessed. The results showed that after 10 passages in MA104 cells, BRV strain DQ2020 induced cytopathic effects. Wheel-shaped virus particles (diameter, ~80 nm) were observed by TEM. A target band of 382 bp was detected by RT-PCR, a positive band was detected with the colloidal gold immunochromatographic test strips, and significant green fluorescence was observed by indirect immunofluorescence (IFA). The highest median tissue culture infectious dose of strain DQ2020 after 9 passages in MA104 cells was 10−4.81 viral particles/0.1 mL. Based on phylogenetic analysis of 11 gene fragments, the genotype of BRV strain DQ2020 was G6-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3, confirming transmission of the G6-P[1] genotype in Chinese cattle herds. Further analysis showed that the isolated strain was a reassortant of bovine (VP7, VP6, NSP3, and NSP5), human (VP4, VP1, VP2, VP3, NSP2, and NSP4), and ovine (NSP1) rotaviruses. BRV strain DQ2020 caused damage to the intestinal villi of suckling mice and diarrhea, confirming pathogenicity. In summary, this study identified a reassortant strain of bovine, human, and ovine rotavirus that is pathogenic to lactating mice, and conducted whole genome sequence analysis, providing valuable insights for the genetic evolution of the virus and the development of vaccines. [ABSTRACT FROM AUTHOR]

Introduction: Rice kernel smut, caused by Tilletia horrida, is becoming an increasingly serious disease in hybrid rice planting, leading to production losses and quality decline of male-sterile rice varieties. Successful infection requires an efficient energy source that the pathogen obtains from rice plants, such as carbohydrates. Glycoside hydrolases (GHs), one of the largest sub-families in the cell wall-degrading enzyme family, play a key role in the infection progress of pathogens. To investigate their roles in facilitating infection, in this study, we identified and characterized genes encoding GH family proteins of T. horrida and further explored the functions and structures of these genes. Materials and methods: Through genome-wide sequencing and bioinformatics analyses, 52 GH genes were identified from T. horrida, named ThGhd_1 to ThGhd_52. The subcellular location, conserved motifs, and structures of ThGhds were identified by bioinformatics analyses. Results: Phylogenetic analysis revealed that ThGhds with similar domains clustered together, although some proteins clustered in different branches, which might reflect functional diversity. Protein-protein interaction network analysis revealed that ThGhds interact with partner proteins involved in reactive oxygen species signaling, protein kinase activity, and plant hormone signal transduction pathways. RNA-sequencing analysis showed that the expression of ThGhd genes responded differently at different infection time points, with dynamic changes detected during the T. horrida infection process, indicating that these genes are involved in interactions with rice and have potential roles in pathogenic mechanisms. Conclusions: The results of this study provide valuable resources for the structure elucidation of GH family proteins of T. horrida and can help to further elucidate their roles in pathogenesis. [ABSTRACT FROM AUTHOR]

Egress represents a crucial process employed by Neospora caninum in the establishment of infection. Dense granule proteins (GRAs), secreted by the dense granule, play significant roles in modifying the parasitophorous vacuole, maintenance of morphology, and regulating host-cell interactions. However, their precise involvement in tachyzoite egress remains inadequately characterized. In this study, we identified a homologous gene, Ncgra41, corresponding to the dense granule protein 41 (GRA41) of Toxoplasma gondii, which is associated with egress, utilizing NCBI and ToxoDB databases. NcGRA41 is localized extracellularly within dense granules and intracellularly within parasitic vacuoles. Deletion of NcGRA41 did not affect tachyzoites invasion or proliferation but significantly reduced egress capacity and pathogenicity in mice. The phenotypic characteristics were restored in a complementary strain. Further investigation revealed that the absence of NcGRA41 reduced gliding motility and the transcription level of the subtilisin-like protein (SUB1). A microneme secretion assay demonstrated a significant decrease in NcMIC1 secretion, along with reduced expression levels of NcMIC1, NcMIC4, and NcMIC8. These findings demonstrate that NcGRA41, a novel dense granule protein in N. caninum, modulates tachyzoites egress and influences pathogenicity by regulating microneme secretion. [ABSTRACT FROM AUTHOR]

Background: Wilms tumor 1 (WT1; NM_024426) causes Denys–Drash syndrome, Frasier syndrome, or isolated focal segmental glomerulosclerosis. Several WT1 intron variants are pathogenic; however, the pathogenicity of some variants remains undefined. Whether a candidate variant detected in a patient is pathogenic is very important for determining the therapeutic options for the patient. Methods: In this study, we evaluated the pathogenicity of WT1 gene intron variants with undetermined pathogenicity by comparing their splicing patterns with those of the wild-type using an in vitro splicing assay using minigenes. The three variants registered as likely disease-causing genes: Mut1 (c.1017-9 T > C(IVS5)), Mut2 (c.1355-28C > T(IVS8)), Mut3 (c.1447 + 1G > C(IVS9)), were included as subjects along the 34 splicing variants registered in the Human Gene Mutation Database (HGMD)®. Results: The results showed no significant differences in splicing patterns between Mut1 or Mut2 and the wild-type; however, significant differences were observed in Mut3. Conclusion: We concluded that Mut1 and Mut2 do not possess pathogenicity although they were registered as likely pathogenic, whereas Mut3 exhibits pathogenicity. Our results suggest that the pathogenicity of intronic variants detected in patients should be carefully evaluated. [ABSTRACT FROM AUTHOR]

Bioherbicides are expected to be a supplement to integrated pest management, assisting in the control of problematic weed species. For instance, bioherbicides (Phoma and BioPhoma) were recently registered in Canada and the USA for the control of some perennial dicotyledonous weeds in lawns. These products are based on strains of the fungus Didymella macrostoma (syn. Phoma macrostoma) that causes white tip disease (WTD) in Canada thistle (Cirsium arvense). In this study, WTD was reported for the first time in the Russian Federation. Analysis of the internal transcribed spacer (ITS) region of nuc rDNA and secondary metabolite profiling confirmed the identity of Russian WTD isolates to Canadian biocontrol strains identified as D. macrostoma. Multilocus phylogenetic analysis based on sequencing of the ITS region, partial large subunit nuc rDNA region (28S), RNA polymerase II second largest subunit gene (rpb2), and partial β-tubulin gene (tub2) has differentiated the WTD isolates from C. arvense and D. macrostoma isolates from other plant hosts. Based on phylogenetic, morphological, and chemotaxonomic features, these WTD isolates were described as a new species named Didymella baileyae, sp. nov. This study also demonstrated the low pathogenicity of the ex-type D. baileyae isolate VIZR 1.53 to C. arvense seedlings and its asymptomatic development in the leaves of aboveground shoots. The organic extracts from mycelium and culture filtrate of D. baileyae, as well as macrocidin A and macrocidin Z, displayed phytotoxicity both to C. arvense leaves and seedlings. Macrocidin A was only detected in the naturally infected leaf tissues of C. arvense showing WTD symptoms. Macrocidins A and Z demonstrated low antimicrobial and cytotoxic activities, exhibiting no entomotoxic properties. The data obtained within this study on the pathogenicity and metabolites of D. baileyae may be important for the rational evaluation of its prospects as a biocontrol agent. [ABSTRACT FROM AUTHOR]

Background: Avian leukosis virus subgroup J (ALV‐J) primarily affects poultry, particularly chickens, leading to tumourigenesis and immunosuppression, which results in substantial economic losses. It is important to note that ALV‐J is commonly found in indigenous chicken breeds in China, and the virus's vertical transmission characteristics present a significant threat to the preservation of local chicken breeds. Objectives: The study aimed to investigate the characteristics and effects of the recombinant ALV‐J strain LY2021J, with a focus on its genetic composition and its potential influence on virulence and pathogenicity. Methods: LY2021J was isolated using DF‐1 cells and validated by enzyme‐linked immunosorbent assay (ELISA) and IFA. The proviral genome was amplified using segmented PCR and then spliced together using DNASTAR software. Genome‐wide genes, including gag, pol, gp85, and long terminal repeat (LTR), were compared. Recombination sites were analysed using RDP5 and SimPlot software. Pathogenicity was evaluated by monitoring symptoms and conducting examinations on SPF chickens. Results: The outbreak of ALV‐J in China has caused significant economic losses in the poultry industry. Although largely controlled in white‐feather broilers and egg‐laying chickens, ALV‐J has spread to yellow‐feather broilers and local breeds. A strain, LY2021J, isolated from Hetian chickens, showed lower mortality despite severe dysplasia. Genetic analysis revealed high similarity between LY2021J and the Chinese strains JS14NT01 and NX0101, suggesting a shared origin. Recombination with strain ev‐1 and specific 3′ UTR deletions may explain LY2021J's reduced virulence. Continued monitoring and prevention strategies are essential to mitigate ALV‐J's impact. [ABSTRACT FROM AUTHOR]

Ustilago crameri is a pathogenic basidiomycete fungus that causes foxtail millet kernel smut (FMKS), a devastating grain disease in most foxtail millet growing regions of the world. Carbohydrate-Binding Modules (CBMs) are one of the important families of carbohydrate-active enzymes (CAZymes) in fungi and play a crucial role in fungal growth and development, as well as in pathogen infection. However, there is little information about the CBM family in U. crameri. Here, 11 CBM members were identified based on complete sequence analysis and functional annotation of the genome of U. crameri. According to phylogenetic analysis, they were divided into six groups. Gene structure and sequence composition analysis showed that these 11 UcCBM genes exhibit differences in gene structure and protein motifs. Furthermore, several cis-regulatory elements involved in plant hormones were detected in the promoter regions of these UcCBM genes. Gene ontology (GO) enrichment and protein–protein interaction (PPI) analysis showed that UcCBM proteins were involved in carbohydrate metabolism, and multiple partner protein interactions with UcCBM were also detected. The expression of UcCBM genes during U. crameri infection is further clarified, and the results indicate that several UcCBM genes were induced by U. crameri infection. These results provide valuable information for elucidating the features of U. crameri CBMs' family proteins and lay a crucial foundation for further research into their roles in interactions between U. crameri and foxtail millet. [ABSTRACT FROM AUTHOR]

Citrus tristeza virus (CTV) is a causal agent of diseases that have challenged the global citrus production for more than a century. The disease named 'tristeza', which means 'sadness' in Portuguese and Spanish, has spread by aphids and vegetative propagation, resulting in costly pandemics that reshaped the world citrus production by forcing the adaption of disease‐tolerant rootstocks. Furthermore, management of the second major CTV‐induced disease, stem pitting, became a unique example of the use of cross‐protection on a large nationwide scale, allowing many citrus growing regions to control the disease that could not be managed through horticultural practices. The information gathered in this review commemorates a hundred years of research on the virus and the respective diseases, which began with classical horticultural approaches and advanced toward the cutting‐edge molecular biology studies. In this regard, it is proper to mention that CTV research greatly benefited from close international collaboration between research institutions and scientists from the affected and nonaffected citrus areas. Moreover, despite the considerable initial losses caused by tristeza, the world's fresh fruit and juice concentrate citrus industries reemerged as highly productive following the research advancements, a situation that changed throughout Florida and Brazil in the past two decades or so with the outbreak of the devastating citrus greening (Huanglongbing) bacterial disease. This review encompasses past and recent advances in the CTV research positioning the citrus‐CTV pathosystem as a pivotal model system for investigating virus interactions with perennial woody hosts. The review will also serve as an updated version of the respective section on CTV in the Description of Plant Viruses that the Association of Applied Biologists manages. We dedicated this review to the 85th Birthday celebration of Prof. Moshe Bar‐Joseph, a world‐renowned plant pathologist whose half‐a‐century‐long career devoted to citrus diseases yielded many important, pioneering discoveries on CTV and other closteroviruses. Many of those are highlighted in this review. Prof. Bar‐Joseph retired from the Volcani Center, Agricultural Research Organization in Israel several years ago, yet he continues to be actively engaged in research and provides his expertise to citrus pathologists around the world in the present days. [ABSTRACT FROM AUTHOR]

Giant freshwater prawn (Macrobrachium rosenbergii (MR)) is a significant aquafarm species commercially cultured in Taiwan. Intensive farming practices have led to the outbreak of Lactococcus garvieae (LG), which causes Lactococcosis in MR. Recently, LG has re‐emerged and the number of mortalities in prawn farms has increased in Taiwan. However, there is no preventative strategy described and a lack of knowledge on virulence factors and pathogenesis from LG in MR. The most virulent strain of L. garvieae from M. rosenbergii was screened in vivo among seven isolates selected for infectivity testing injecting 0.1 mL of 108 CFU/mL bacterial concentration. Among the seven isolates screened, L. garvieae 109‐6 resulted in 100% mortality within 3 days post‐infection. Furthermore, 109‐6 L. garvieae LD50 dosage from in MR was found to be 106 CFU/mL. Subsequently, the most virulent strain 109‐6 was sequenced using MinIon Nanopore sequencing. Results indicated that the LG genome yielded a protein‐coding of 3857 with 59 tRNA and 16 rRNA and no plasmid. Interestingly, the distribution of subsystems in the annotated genome revealed genes related to virulence, defence, and disease among LG 50 genes. Altogether, the virulent strain and its genome data revealed distinctive features of LG, which hinted toward its pathogenicity and could facilitate for better preventive strategies. [ABSTRACT FROM AUTHOR]

Summary: The retromer complex is a conserved sorting machinery that maintains cellular protein homeostasis by transporting vesicles containing cargo proteins to defined destinations. It is known to sort proteins at the vacuole membranes for retrograde trafficking, preventing their degradation in the vacuole. However, the detailed mechanism of retromer recruitment to the vacuole membrane has not yet been elucidated.Here, we show that the vacuolar SNARE complex MoPep12‐MoVti1‐MoVam7‐MoYkt6 regulates retromer‐mediated vesicle trafficking by recruiting the retromer to the vacuole membrane, which promotes host invasion in Magnaporthe oryzae.Such recruitment is also essential for the retrieval of the autophagy regulator MoAtg8 and enables appressorium‐mediated host penetration. Furthermore, the vacuolar SNARE subunits are involved in suppressing the host defense response by regulating the deployment of retromer‐MoSnc1‐mediated effector secretion.Altogether, our results provide insights into the mechanism of vacuolar SNAREs‐dependent retromer recruitment which is necessary for pathogenicity‐related membrane trafficking events in the rice blast fungus. [ABSTRACT FROM AUTHOR]

In an open-air market in southern Italy, we noticed 'Lady finger' banana fruit imported from Costa Rica showing a severe rot, whose symptoms consisted of necrotic peel lesions with variable shape and size. Fusarium sacchari and F. proliferatum were consistently isolated from symptomatic fruit. In pathogenicity tests on 'Lady finger' banana fruit, F. proliferatum was more virulent than F. sacchari. Quantitative Time-of-Flight Mass Spectrometric analysis of secondary metabolites produced by isolates of these two Fusarium species on three different matrices (banana peel, barley and maize kernels) identified 11 mycotoxins. Seven of them (Fusaproliferin, Fumonisins A1, Fumonisins A2 and Fumonisins B1, Hydrolysed Fumonisin B1, Fusarin C and Moniliformin) were detected in matrices contaminated by F. proliferatum isolates. Fumonisin A1 was the prevalent mycotoxin in both maize kernels and banana peel, while Fumonisin A2 prevailed in barley kernels. Similarly, seven mycotoxins (the cyclic hexadepsipeptides Enniatins B2, B3 and B4, Fumonisins A1 and B2, Hydrolysed Fumonisin B1 and Fusarin C) were detected in matrices contaminated by F. sacchari isolates, but they were only in part the same as those produced by F. proliferatum isolates. Fusarin C prevailed in all three matrices colonized by F. sacchari. Fumonisin A1 was detected exclusively in maize kernels while Enniatins B3 and B4, Fumonisin B2 and Hydrolysed Fumonisin B1 were detected exclusively in barley kernels. Overall, F. proliferatum produced a higher amount of mycotoxins than F. sacchari. Moreover, in banana peel both species produced a lower number and amount of mycotoxins than in the other two matrices. [ABSTRACT FROM AUTHOR]

The rice blast disease, caused by the fungus Magnaporthe oryzae, is a significant agricultural problem that adversely impacts rice production and food security. Understanding the precise molecular pathways involved in the interaction between the pathogen and its host is crucial for developing effective disease management strategies. This study examines the crucial function of the nucleolin MoNsr1 in regulating M. oryzae physiological functions. DMoNsr1 deletion mutants showed reduced fungal growth, asexual sporulation, and pathogenicity compared to the wild-type. Mutants exhibited impaired conidial germination and appressoria formation, reducing infection progression. Additionally, DMoNsr1 deletion mutant had less turgor pressure, confirming that MoNsr1 is essential for cell wall biogenesis and resistant to external stresses. Furthermore, DMoNsr1 deletion mutant showed enhanced sensitivity to oxidative stress, reactive oxygen species, and cold tolerance. Our results offer a thorough understanding of the function of MoNsr1 in the virulence and stressresilient capability in M. oryzae. These findings provide insights into the novel targets and contribute to the emergence of innovative approaches for managing rice blast disease. [ABSTRACT FROM AUTHOR]

Bovine coronavirus (BCoV), a persistent threat to global cattle industry, has caused significant economic losses worldwide. In this study, a viral strain was isolated from the intestinal content of a diseased calve, and identified by cytopathic effects observation, indirect immunofluorescence assay and electron microscopy. Results showed that BCoV NXWZ2310 belonging to the GIIb genotype and has a three-amino-acid deletion in the serine-rich region of the N gene. Importantly, the BCoV NXWZ2310 strain exhibited strong pathogenicity, causing nasal discharge and watery diarrhea in calves for 8 and 10 days, respectively. Viral shedding was detected in nasal, throat and rectal swabs at levels reaching 106.228 copies/mL, 105.0 copies /mL and 106.692 copies/mL, respectively. Pathological examination showed that NXWZ2310 resulted in parenchymal lesions of the pulmonary lobe and significant intestinal lesions. Both the lungs and intestines displayed marked microscopic lesions with clear viral antigens present. BCoV NXWZ2310 strain with N-gene deletion mutations, caused severe respiratory and digestive disease in calves. Therefore, effective strategies are needed for the prevention and control of this isolate. [ABSTRACT FROM AUTHOR]

Introduction: Getah virus (GETV) is a multi-host virus found in pigs, horses, and blue foxes. Clinically, GETV can cause fever, diarrhea, and reproductive disorders in pigs, representing significant threats to pig breeding. At present, few studies have examined the pathogenicity of GETV in pigs of different ages. Methods: In the present study, a new strain, named GETV-QJ, was isolated from clinically ill pigs, and whole genome sequencing analysis was performed. Besides the pathogenicity of piglets and pregnant sows of this strain was further studied. Results: the results illustrated that the strain belonged to group III. The strain had 93.6%-96.3% homology with other subtypes, and its homology with the same subtype strain ranged 96.5%-99%. Further studies on the pathogenicity of the virus indicated that this strain caused severe diarrhea, fever, and intestinal and lung damage in 7-day-old piglets, resulting in their death. The piglet survival rate was 0%. In pregnant sows, this strain did not cause fever, death, or abortion, but it induced viremia, which affected the farrowing performance of sows and led to reduced piglet survival. Discussion: In this study, we isolated a highly virulent group III and comprehensively established a pathogenic model of GETV in piglets and sows, providing a reference and guidance for the prevention and control of this infection. [ABSTRACT FROM AUTHOR]

With the prevalence of sequentially-emerged sublineages including BA.1, BA.2 and BA.5, SARS-CoV-2 Omicron infection has transformed into a regional epidemic disease. As a sublineage of BA.5, the BA.5.2.48 outbroke and evolved into multi-subvariants in China without clearly established virological characteristics. Here, we evaluated the virological characteristics of two isolates of the prevalent BA.5.2.48 subvariant, DY.2 and DY.1.1 (a subvariant of DY.1). Compared to the normal BA.5 spike, the double-mutated DY.1.1 spike demonstrates efficient cleavage, reduced fusogenicity and higher hACE2 binding affinity. BA.5.2.48 demonstrated enhanced airborne transmission capacity than BA.2 in hamsters. The pathogenicity of BA.5.2.48 is greater than BA.2, as revealed in Omicron-lethal H11-K18-hACE2 rodents. In both naïve and convalescent hamsters, DY.1.1 shows stronger fitness than DY.2 in hamster turbinates. Thus regional outbreaking of BA.5.2.48 promotes the multidirectional evolution of its subvariants, gaining either enhanced pathogenicity or a fitness in upper airways which is associated with higher transmission. [ABSTRACT FROM AUTHOR]

BackgroundMethodsResultsConclusionAxenfeld-Rieger syndrome (ARS, OMIM:602482) is a genetic disease characterized by ocular and systemic features. Clinical features of ARS are highly variable among patients and associated with mutations of human PITX2 and FOXC1 genes. Herein, we present an ARS in two cases (proband and his mother) with a novel variant in the PITX2.A 3-month-old boy was admitted with an abnormal eye development at birth. Physical examination and ophthalmologic examination findings revealed an abnormal development of the anterior segments, ectropion of redundant skin in the umbilicus, single-sided deafness, teeth eruption failure, patent foramen ovale, and a mid-facial flattening. The proband’s mother has been blind since the age of 12. We conducted genetic tests for the family via whole exome sequencing (WES) and quantitative PCR (qPCR) to identify the genetic etiology in the family. We also conducted a retrospective review of the ARS type I phenotype caused by the PITX2 mutations.WES and qPCR results of the proband and his parents suggested that both the child and his mother carry a 1.31kbp deletion (chr4: g.111538559_111539864del [GRCh37]) spanned the exon 4 of PITX2, resulting in the typical and rare phenotype of ARS type I. It can conclude that truncating variants in the exon 3-4 of PITX2are the more common mechanism to cause the malfunction of the gene with a broader phenotypic spectrum.The study has filled in a new clinical manifestation of the PITX2 and enriched the phenotype of ARS. The retrospective analysis of phenotype of PITX2 mutations provided a comprehensive understanding of the disease. [ABSTRACT FROM AUTHOR]

Duck plague virus (DPV) causes the highly pathogenic duck plague, and the envelope glycoprotein I (gI), as one of the key virulence genes, has not yet had its critical virulence sites identified through screening. This study used reverse genetics technology to target the gI, specifically within the DPV genome. Four DPV mutants with gI N-glycosylation site mutations were designed and constructed, and these mutant strains were successfully rescued. Our results confirmed that three asparagine residues of gI (N69, N78, and N265) are N-glycosylation sites, and western blot analysis substantiated that glycosylation at each predicted N-glycosylation site was compromised. The deglycosylation of gI leads to the protein misfolding and subsequent retention in the endoplasmic reticulum (ER). The subsequent deglycosylated gI is carried into the Golgi apparatus (GM130) in the interaction of gE. Compared to the parental virus, the mutated virus shows a 66.3% reduction in intercellular transmission capability. In ducks, the deglycosylation of gI significantly reduces DPV replication in vivo, thereby weakening the virulence of DPV. This study represents the first successful creation of a weak DPV virus strain by specific mutation at the N-glycosylation site. The findings provide a foundational understanding of DPV pathogenesis and form the basis for developing live attenuated vaccines against the disease. [ABSTRACT FROM AUTHOR]

Infectious bronchitis virus (IBV) can cause serious harm to poultry industry. It is belong to Coronaviridae which is highly variable. A kind of emerging recombinant IBV (ahysx-1) has been detected in chicken from China in 2016. To understand the epidemiology and characterization of the emerging recombinant IBV, 35,455 samples of chickens from the 15 provinces in China were collected and detected. One hundred and ninety-six out of the 537 flocks (positive rate, 36.49%), and 908 out of 35,455 samples (positive rate, 2.56%) were positive in the detection. The results showed that the emerging recombinant IBV was pandemic in China. Thirteen emerging recombinant IBV isolates were selected and continuous subcultured to the fourth generation and analyzed by Next-generation sequencing. Compared with the reported sequence of ahysx-1, the genomic analysis showed that multiple position insertions and deletions were in 1a gene, 3b gene, M gene and N gene. The identity of the S gene nucleotide sequence between all the 13 emerging recombinant IBV isolates and reference stain ahysx-1 were 98.1-99.1%, while the identity of amino acid sequence were 98.0-99.8%. To better understand the recombination mechanism of the emerging recombinant IBV, the genomic sequence of the 13 isolates were compared with turkey coronavirus or guinea fowl coronavirus. The results suggest that all the 13 emerging recombinant IBV isolates were likely to be the recombination of turkey coronavirus or guinea fowl coronavirus with IBV. Turkey coronavirus or guinea fowl coronavirus as minor parents are the donors of S gene. The major parents donors of the genome backone of these recombination events were lineages GI-19 or GVI-1 of IBV. One isolate (IBV/chicken/Henan/H1173/2021) was selected for pathogenicity analysis. The results showed that IBV/chicken/Henan/H1173/2021 was avirulent to SPF embryonated eggs, but could cause intestinal symptoms in of chicks. This study provides a foundation for understanding the epidemic situation and characterization of the emerging recombinant IBV. It is of great significance for the prevention and control of avian coronavirus infection. [ABSTRACT FROM AUTHOR]

Introduction: Neisseria meningitidis is a gram-negative bacterium responsible for life-threatening invasive infections known as invasive meningococcal disease and is associated with high fatality rates and serious lifelong disabilities among survivors. Methods: This study aimed to characterize N. meningitidis isolates cultured from blood and cerebrospinal fluid collected between 2009 and 2021 in Lithuania, assess their genomic relationships with European strains, and evaluate the possibility of using a cost-effective method for strain characterization, thus improving the national molecular surveillance of invasive meningococcal disease. In total, 321 N. meningitidis isolates were collected and analyzed using multilocus restriction typing (MLRT). Amplification of the penA gene and restriction fragment length polymorphism analysis were performed to identify the modified penA genes. Based on the MLRT genotyping results, we selected 10 strains for additional analysis using whole-genome sequencing. The sequenced genomes were incorporated into a dataset of publicly available N. meningitidis genomes to evaluate genomic diversity and establish phylogenetic relationships within the Lithuanian and European circulating strains. Results: We identified 83 different strains using MLRT genotyping. Genomic diversity of N. meningitidis genomes analysed revealed 21 different sequence types (STs) circulating in Lithuania. Among these, ST34 was the most prevalent. Notably, three isolates displayed unique combinations of seven housekeeping genes and were identified as novel STs: ST16969, ST16901, and ST16959. The analyzed strains were found to possess virulence factors not commonly found in N. meningitidis. Six distinct penA profiles were identified, each with different frequencies. In the present study, we also identified N. meningitidis strains with new penA, NEIS0123, NEIS1320, NEIS1525, NEIS1600, and NEIS1753 loci variants. In our study, using the cgMLST scheme, Minimum Spanning Tree (MST) analysis did not identify significant geographic relationships between Lithuanian N. meningitidis isolates and strains from Europe. Discussion: Discussion: To our knowledge, this is the first study to employ whole genome sequencing (WGS) method for a comprehensive genetic characterization of invasive N. meningitidis isolates from Lithuania. This approach provides a more detailed and precise analysis of genomic relationships and diversity compared to prior studies relying on traditional molecular typing methods and antigen analysis. [ABSTRACT FROM AUTHOR]

Candida tropicalis (C. tropicalis) is a zoonotic pathogen that is widespread in the environment and in recent years an increasing number of dairy cows have been infected with the fungus causing mastitis in cows.In this study, 37 milk samples from the udders of cows with clinical mastitis were collected from a dairy farm in Guangxi Province, China, from which C. tropicalis was isolated and identified, and then the isolated fungi were subjected to genome frame map sequencing, genome functional analysis as well as comparative genome analysis of the sequencing results, and combined with the virulence test of the fungi and drug sensitivity test of the fungi determined in infected mice, the resistance genes and pathogenicity of the fungi were Analysis of resistance genes and pathogenicity.Our study results revealed the isolation and characterisation of C. tropicalis from diseased cows, with a genome length of approximately 14.27 Mb. Functional annotation of the genome identified 4068 genes associated with C. tropicalis. The strain exhibited a chemoresistance mutation in the gene cyp51,a virulence-enhancing mutation in the gene VTC4, and mutations in genes linked to drug resistance. Pathogenicity tests demonstrated that C. tropicalis could induce damage to the internal organs of mice, leading to different levels of cyanosis in the abdominal cavity, white necrotic foci on the surface of internal organs, lung hemorrhage, and enlargement of the spleen and thymus.Histological sections also revealed varying degrees of hemorrhage and degenerative changes in the cells of different organs in the mice. Drug sensitivity tests showed that the fungus was highly sensitive to nystatin and ketoconazole, moderately sensitive to amphotericin B, and insensitive to antibiotics such as itraconazole, gentamicin, and penicillin. In conclusion, C. tropicalis isolated from dairy cows in the Guangxi region in this study was pathogenic and resistant to azoles such as itraconazole and fluconazole, and this study provides a theoretical basis for the further screening of novel resistance genes in C. tropicalis, as well as providing a certain reference for the drugs used for the treatment of fungal cow mastitis in this region. [ABSTRACT FROM AUTHOR]

AbstractIn February 2021, elongated grey lesions with reddish margin were observed on sudangrass (Sorghum × drummondii) leaves, in the municipality of Guasave, Sinaloa, Mexico. These symptoms resembled those of leaf blight caused by Bipolaris and Exserohilum on other grasses. Two fungal isolates were recovered from symptomatic leaves, and their identities were confirmed based on a polyphasic approach. The morphological and phylogenetic analysis of the actin gene (act) and internal transcribed spacer region (ITS) of both isolates revealed their identity as Exserohilum turcicum. A pathogenicity test with a representative isolate confirmed this fungus as the causal agent of leaf blight on sudangrass, as symptoms previously observed in the field were developed on the inoculated plants. The E. turcicum isolate was recovered from the diseased sudangrass plants, fulfilling Koch’s postulates. This is the first report of E. turcicum causing leaf blight on sudangrass in Mexico. [ABSTRACT FROM AUTHOR]

Host‐specific pathogens have long been suggested to act as a major driver of species diversity in tropical forests. However, determining the degree of host specificity of potential pathogens coupled to key cellular characteristics of infection is difficult and time‐consuming. These challenges have delayed progress in relating the functional specificity of pathogenic fungi to ecological consequences. We tested the pathogenicity of 27 (of 215) fungi that were isolated from surface sterilized roots of seedlings from four common tree species in a diverse subtropical forest. Inoculation experiments showed that six fungi exhibited strong pathogenicity on the host seedlings. Five of these only infected their specific hosts (i.e. host‐specific pathogen species). Green fluorescent protein labelling revealed that in three host‐specific pathogens fungal hyphae were able to grow into the vascular tissues only in their specific host plant, in contrast to other fungal‐host combinations that exhibit non‐pathogenic interactions. This fluorescent labelling technique allows direct tracking of the progress of fungal infection in different host tissues. Synthesis. By coupling the green fluorescent protein technique with standard host inoculation experiments, we determined the developmental differences between infections by pathogenic and non‐pathogenic fungi in a relatively simple and straightforward way. Our work provides a useful tool for rapidly screening and categorizing host–fungal interactions, reflecting the functional basis of host specificity of pathogenic fungi. More broadly, this technique can contribute to understanding the roles of pathogens in species coexistence and biodiversity maintenance in forest communities. [ABSTRACT FROM AUTHOR]

Fusarium wilt, caused by the soilborne fungal pathogen Fusarium oxysporum f. sp. lactucae (FOL), is an economically important disease of lettuce (Lactuca sativa) throughout the world. Four pathogenic races of FOL are reported, though only race 1 is known to exist in the United States. Recently, Californian lettuce growers have expressed increasing concern about Fusarium wilt, as some race 1‐resistant cultivars have exhibited susceptibility, and some susceptible cultivars have displayed reduced disease severity. To determine whether such changes in disease patterns are responses to potentially novel variants, we collected infected plants from commercial fields in the Salinas Valley and Santa Maria regions, isolated the fungus, and conducted a series of pathogenicity tests using a set of FOL race differential cultivars over 2 years (2022 and 2023) in controlled conditions. Pathogenicity tests revealed two new FOL variants that elicited novel disease reaction patterns on the set of differential cultivars that have not been previously described. Isolates Fol621 and Fol621s were less aggressive on race 1‐susceptible Banchu Red Fire, designated Variant‐1. Isolate VSP‐0916 incited severe Fusarium wilt on race 1‐resistant Costa Rica No. 4, designated Variant‐2. Moreover, VSP‐0916 exhibited high aggressiveness and the ability to induce disease in other race 1‐resistant cultivars. This study is the first documentation, to our knowledge, of the occurrence of FOL‐inciting Fusarium wilt on race 1‐resistant lettuce in the United States. Our work provides valuable information critical for the development of Fusarium wilt management strategies, including broad‐spectrum resistance breeding efforts against multiple FOL races. [ABSTRACT FROM AUTHOR]

Brown circular stem canker symptom was observed on common bean plants in Mahallat county, Markazi province, Iran, in the summer of 2022. Five identical associated fungal isolates were recovered from the infected plants. Morphological and molecular characterization of the representative isolate (UTR38) using the partial sequence of beta-tubulin, and as well as RNA polymerase II second largest subunit loci was done. The associated fungus was identified as Paramyrothecium roridum. Pathogenicity of the isolate UTR38 was conducted on six-week-old seedling stems of the P. vulgaris cultivar Sunray. The inoculated fungus was also reisolated from the inoculated plants to fulfill the Koch's postulates. According to the results, this is the first report of P. roridum as the causal agent of stem canker disease in P. vulgaris in Iran and worldwide. [ABSTRACT FROM AUTHOR]

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Simple Summary: Pigs are now facing an increasing number of emerging and re-emerging viral agents that can cause significant economic losses. Identifying and studying the pathogenicity of these viral agents helps to prevent and control the spread of diseases. Getah virus (GETV) is a neglected zoonotic virus that causes reproductive disorders in sows and diarrhea in newborn piglets. To date, reports on GETV in pigs have focused mainly on reproductive disorders. In this study, we found GETV was frequently detected in piglets associated with diarrhea during epidemiological surveillance in Jiangxi Province in China. Piglets infected with GETV manifested as diarrhea, which could lead to death in suckling piglets. A GETV strain was isolated and characterized. The complete genome, pathogenesis, and pathogenicity of the isolated strain was investigated. Clinical signs, gross lesions, and histological changes were observed in suckling piglets inoculated with the isolated GETV strain. The results of this study add to the knowledge of the epidemiology, viral genetics, pathogenicity, and pathogenicity of porcine GETV. Getah virus (GETV) is a mosquito-borne virus belonging to the genus Alphavirus in the family Togaviridae. Its infection poses an increasing threat to animals and public health in China. In this study, an epidemiological survey of GETV on 46 pig farms in Jiangxi Province, China, was performed; GETV isolation and characterization were carried out, including a complete sequence determination and phylogenetic analysis; and pathogenicity of the GETV was experimentally investigated by inoculating newborn piglets with the isolated GETV strain. Epidemiological studies conducted on the organs of infected pigs, aborted piglets, and the blood of aborted sows sampled from pig farms in Jiangxi Province, China, demonstrated that 44 out of the 46 pig farms were positive for GETV, which is a positivity rate of 95.65% (44/46). Of the 411 samples tested, 47.93% (197/411) were found positive for GETV. A GETV strain called GETV-JX-CHN-22 was obtained, which showed stable proliferation in Vero cells. One-step growth curve results showed that the GETV-JX-CHN-22-P7 (passage 7) isolate reached a peak titer of 108.3 TCID50/mL at 24 hpi. An analysis of the whole-genome sequencing results showed that GETV-JX-CHN-22 (prototype) and GETV-JX-CHN-22-P7 shared nucleotide sequence similarities of 95.3% to 99.6% with 73 reference strains of GETV in GenBank. Genetic evolution analysis revealed that GETV-JX-CHN-22 and GETV-JX-CHN-22-P7 belonged to the GIII group, the same group members of most strains were reported in China. Animal inoculation experiments indicated that piglets exhibited typical symptoms and pathological changes of GETV infection after 24 h inoculation, which reproduced the pathogenicity of GETV field strain infections in piglets. To our knowledge, this study is the first report on the detection and isolation of porcine GETV associated with diarrhea from pig farms in Jiangxi Province, China. It is of great importance to study the infection spectrum, transmission mechanism, and public health significance of GETV. The results provide foundations for the genomic and biological (pathogenic) characteristics of the circulating GETV in Jiangxi Province, China. [ABSTRACT FROM AUTHOR]

Polyamines (PAs), which are aliphatic polycationic compounds with a low molecular weight, are found in all living organisms and play essential roles in plant–pathogen interactions. Putrescine, spermidine, and spermine, the most common PAs in nature, respond to and function differently in plants and pathogens during their interactions. While plants use certain PAs to enhance their immunity, pathogens exploit PAs to facilitate successful invasion. In this review, we compile recent studies on the roles of PAs in plant–pathogen interactions, providing a comprehensive overview of their roles in both plant defense and pathogen pathogenicity. A thorough understanding of the functions of PAs and conjugated PAs highlights their potential applications in fungicide development. The creation of new fungicides and compounds derived from PAs demonstrates their promising potential for further research and innovation in this field. [ABSTRACT FROM AUTHOR]

Background: Streptococcus agalactiae (Group B streptococcus, GBS) induces a serious infection that can harm not only aquatic life but also humans and other animals. In a fish farm in southern Egypt, Nile tilapia (Oreochromis niloticus) has developed an epidemic with clinical symptoms resembling piscine streptococcosis. Results: Initial microscopic inspection of the affected fish brain and kidney indicated the presence of Gram-positive cocci. S. agalactiae was effectively isolated and identified using nucleotide homology of the 16S rRNA and species-specific PCR. The partial 16S rRNA sequence was deposited in the GenBank database at the NCBI and given the accession number MW599202. Genotyping using RAPD analysis indicated that the isolates in the present study belonged to the same genotypes and had the same origin. The challenge test, via immersion (9.2 × 107, 9.2 × 106, and 9.2 × 105 CFU/ml for 1 h) or intraperitoneal injection (4.6 × 107, 4.6 × 106, and 4.6 × 105 CFU/fish), elicited clinical symptoms resembling those of naturally infected fish with a mortality rate as high as 80%. The ability to create a biofilm as one of the pathogen virulence factors was verified. Zinc oxide nanoparticles and the ethanolic leaf extracts of nine medicinal plants demonstrated considerable antibacterial activities against the tested S. agalactiae strain with low minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC). The ethanolic leaf extracts from Lantana camara and Aberia caffra showed potent antibacterial activity with MBC values of 0.24 and 0.485 mg/ml, and MIC values of 0.12 & 0.24 mg/ml, respectively. Conclusion: This study isolated S. agalactiae from O. niloticus mortalities in a fish farm in Assiut, Egypt. The pathogen persists in fish environments and can escape through biofilm formation, suggesting it cannot be easily eliminated. However, promising findings were obtained with in vitro control employing zinc oxide nanoparticles and medicinal plant extracts. Nevertheless further in vivo research is needed. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi have been widely used as the main mycoinsecticide for controlling agricultural and forest pests. The effector molecules of these mycopathogens have evolved to adapt to their hosts. The role of fungal effectors in evading the host immune system in insects remains mainly unclear. We characterized the widely distributed fungal effector necrosis‐inducing‐like secreted protein 1 (NLS1) in the entomopathogenic fungus Metarhizium robertsii. Our findings revealed the presence of M. robertsii NLS1 (MrNLS1) in host hemocytes during the early stage of hemocoel infection. MrNLS1 knock down (ΔMrNLS1) reduced fungal pathogenicity during infection and altered the expression of host immune genes. The molecular docking results and the yeast 2‐hybrid assay confirmed that MrNLS1 interacts with the host defense protein Hdd11. The phylogenetic analysis indicated that Hdd11 is conserved across a broad range of Lepidoptera species. Knock down of hdd11 in Helicoverpa armigera, Bombyx mori, and Galleria mellonella markedly suppressed their immune responses against M. robertsii. However, no significant difference was observed in the mean lethal time between hdd11‐knockdown Lepidoptera species infected with ΔMrNLS1 and those infected with wild‐type M. robertsii. Therefore, in Lepidoptera insects, Hdd11 is essential for fungal defense. In conclusion, M. robertsii infects Lepidoptera insects by targeting host Hdd11 through its protein MrNLS1, thereby suppressing the host immune response. Our findings clarify the molecular mechanisms underlying fungal infection pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Inorganic polyphosphate (polyP)-targeted polyphosphate kinase 1 (PPK1) has attracted much attention by virtue of its importance in bacterial pathogenicity and persistence, as well as its exclusive presence in microorganisms. However, only very few drugs have been found to be efficacious in inhibiting the Acinetobacter baumannii (A. baumannii) PPK1 protein. Results: In this study, we identified Scutellarein (Scu), a potent PPK1 inhibitor that could significantly influence PPK1-regulated motility, biofilm formation, and bacterial persistence, which was further validated by the results of transcriptome analysis. Mechanistic explorations revealed that Scu achieved its enzyme inhibitory activity predominantly through direct engagement with the active center of PPK1. Moreover, the survival rate of Galleria mellonella larvae was increased by about 35% with 20 mg/kg of Scu treatment. The remarkable therapeutic benefits of Scu were also observed in the mouse pneumonia model, shown mainly by reduced bacterial colonization, pathological lesions, and inflammatory factors. Conclusion: Our results revealed that Scu could attenuate the pathogenicity and persistence of A. baumannii by interfering with its important kinase PPK1. [ABSTRACT FROM AUTHOR]

Bovine rotavirus (BRV) is the main cause of acute gastroenteritis in calves, resulting in significant economic losses to the cattle industry worldwide. Additionally, BRV has multiple genotypes, which could enable cross-species transmission, thereby posing a significant risk to public health. However, there is a problem of multiple genotypes coexisting in BRV, and the cross-protection effect between different genotypes of rotavirus strains is not effective enough. Therefore, mastering clinical epidemic genotypes and using epidemic genotype strains for vaccine preparation is an effective means of preventing and controlling BRV. In this study, BRV strain DQ2020 in MA104 cells was identified by transmission electron microscopy (TEM), reverse transcription polymerase chain reaction (RT-PCR), and colloidal gold immunochromatographic test strips. The whole genome of BRV strain DQ2020 was sequenced and pathogenicity in suckling mice was assessed. The results showed that after 10 passages in MA104 cells, BRV strain DQ2020 induced cytopathic effects. Wheel-shaped virus particles (diameter, *80 nm) were observed by TEM. A target band of 382 bp was detected by RT-PCR, a positive band was detected with the colloidal gold immunochromatographic test strips, and significant green fluorescence was observed by indirect immunofluorescence (IFA). The highest median tissue culture infectious dose of strain DQ2020 after 9 passages in MA104 cells was 10-4.81 viral particles/0.1 mL. Based on phylogenetic analysis of 11 gene fragments, the genotype of BRV strain DQ2020 was G6-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3, confirming transmission of the G6-P[1] genotype in Chinese cattle herds. Further analysis showed that the isolated strain was a reassortant of bovine (VP7, VP6, NSP3, and NSP5), human (VP4, VP1, VP2, VP3, NSP2, and NSP4), and ovine (NSP1) rotaviruses. BRV strain DQ2020 caused damage to the intestinal villi of suckling mice and diarrhea, confirming pathogenicity. In summary, this study identified a reassortant strain of bovine, human, and ovine rotavirus that is pathogenic to lactating mice, and conducted whole genome sequence analysis, providing valuable insights for the genetic evolution of the virus and the development of vaccines. [ABSTRACT FROM AUTHOR]

Background and Objectives: Researchers have focused on Staphylococcus aureus because it is transmitted through food, such as milk and dairy products, and causes human diseases. Prevalence, antimicrobial resistance, presence, and distribution of methicillin-resistant S. aureus (MRSA) virulence genes isolated from raw milk and dairy products were evaluated. Materials and Methods: 300 samples of dairy products were collected from Shahrekord, Iran. S. aureus was identified using biochemical tests and screened for sensitivity to 13 antibiotics to identify resistance genes. In addition, SCCmec typing was performed. Results: Out of 300, S. aureus was found in 82 samples. Raw milk had the highest contamination with S. aureus (60 of 82), followed by cheese (15 of 82), and butter (7 of 82). At least one resistance gene was present in every isolate of S. aureus. Virulence factors and enterotoxin-coding genes, such as sea, seb, sec, and sed were highly distributed. Conclusion: The results of this study revealed the presence of toxin-producing MRSA strains in raw milk and dairy products. MRSA in dairy farms is an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for controlling the presence of S. aureus, especially MRSA, in dairy products. [ABSTRACT FROM AUTHOR]

MicroRNA‐like RNAs (milRNAs) play a significant role in the infection process by plant‐pathogenic fungi. However, the specific functions and regulatory mechanisms of fungal milRNAs remain insufficiently elucidated. This study investigated the function of Foc‐milR138, an infection‐induced milRNA secreted by Fusarium oxysporum f. sp. cubense (Foc), which is the causal agent of Fusarium wilt of banana. Initially, through precursor gene knockout and phenotypic assessments, we confirmed that Foc‐milR138 acts as a virulent milRNA prominently upregulated during the early stages of Foc infection. Subsequent bioinformatic analyses and transient expression assays in Nicotiana benthamiana leaves identified a host receptor‐like kinase gene, MaLYK3, as the direct target of Foc‐milR138. Functional investigations of MaLYK3 revealed its pivotal role in triggering immune responses of N. benthamiana by upregulating a suite of resistance genes, bolstering reactive oxygen species (ROS) accumulation and callose deposition, thereby fortifying disease resistance. This response was markedly subdued upon co‐expression with Foc‐milR138. Expression pattern analysis further verified the specific suppression of MaLYK3 by Foc‐milR138 during the early root infection by Foc. In conclusion, Foc secretes a virulent milRNA (Foc‐milR138) to enter the host banana cells and inhibit the expression of the plant surface receptor‐like kinase MaLYK3, subverting the disease resistance activated by MaLYK3, and ultimately facilitating pathogen invasion. These findings shed light on the roles of fungal milRNAs and their targets in resistance and pathogenicity, offering promising avenues for the development of disease‐resistant banana cultivars. [ABSTRACT FROM AUTHOR]

In October 2023, a disease outbreak in pufferfish (Takifugu obscurus) farms in Zhongshan City, Guangdong, China, caused high mortality. Diseased fish (mean length: 15 ± 1 cm) exhibited swimming disorders, fin rot, hemorrhage, and an enlarged spleen. Histopathological observations generally revealed inflammation, necrosis, and congestion in the spleen, kidneys, and brain tissues. The most severe pathological changes included interstitial edema and tubular atrophy in the kidneys, hemosiderin deposition in the spleen, massive red blood cell infiltration, and a decrease in lymphocytes. A single strain of bacteria (Tol-1) was isolated from the diseased pufferfish and identified as a Gram-positive streptococcus strain, exhibiting α-hemolysis on sheep blood agar plates. Through biochemical characterization, 16S rDNA sequencing, morphological analysis, and specific primer-based identification, the Tol-1 strain was identified as Lactococcus garvieae, serotype I. Antimicrobial susceptibility testing indicated that Tol-1 was sensitive to Chloramphenicol, Ampicillin, Cephalexin, and Doxycycline, but resistant to Kanamycin, Gentamicin and Ciprofloxacin. In addition, 15 common virulence factors were detected in the Tol-1 strain, including adhPav, adhPsaA, adhC I–II, adh, and hly 1–3. Pufferfish (mean length: 17 ± 1 cm) subjected to artificial infection via intraperitoneal injection (IP) with the Tol-1 strain exhibited clinical symptoms and histopathological damage similar to those observed in naturally infected fish. An infection dose of 1 × 105 CFU/fish resulted in 80% mortality. The study fulfilled Koch's postulates, indicating that the disease outbreak in pufferfish was caused by L. garvieae, which exhibited a high mortality rate in pufferfish despite the subtle clinical symptoms. These results serve as a warning for pufferfish farming areas and provide a scientific basis for future prevention and control efforts. [ABSTRACT FROM AUTHOR]

Black spot caused by Alternaria alternata is one of the most common postharvest diseases in fruit and vegetables. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of nitric oxide (NO) on the pathogenicity of A. alternata and its underlying mechanism was studied. The results showed that treatment with 0.5 mM L−1 of sodium nitroprusside (SNP) (NO donor) increased the lesion diameter of A. alternata in vivo and in vitro, which was 22.8% and 13.2% higher than that of the control, respectively. Exogenous NO treatment also induced endogenous NO accumulation by activating nitric oxide synthase (NOS). In addition, NO triggered an increase in reactive oxygen species (ROS) levels. NO enhanced activities and gene expression levels of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). Moreover, NO stimulated cell wall degrading enzymes by activating the corresponding gene expression in vivo and in vitro. These results suggested that exogenous NO promoted the pathogenicity of A. alternata by inducing ROS accumulation and activating antioxidants and cell wall degrading enzymes. The present results could establish a theoretical foundation for the targeted control of the black spot disease in pear fruit. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium spp.) is the most important fibre crop worldwide. Black root rot and Fusarium wilt are two major diseases of cotton caused by soil-borne Berkeleyomyces rouxiae and Fusarium oxysporum f. sp. vasinfectum (Fov), respectively. Phenotyping plant symptoms caused by soil-borne pathogens has always been a challenge. To increase the uniformity of infection, we adapted a seedling screening method that directly uses liquid cultures to inoculate the plant roots and the soil. Four isolates, each of B. rouxiae and Fov, were collected from cotton fields in Australia and were characterised for virulence on cotton under controlled plant growth conditions. While the identities of all four B. rouxiae isolates were confirmed by multilocus sequencing, only two of them were found to be pathogenic on cotton, suggesting variability in the ability of isolates of this species to cause disease. The four Fov isolates were phylogenetically clustered together with the other Australian Fov isolates and displayed both external and internal symptoms characteristic of Fusarium wilt on cotton plants. Furthermore, the isolates appeared to induce varied levels of plant disease severity indicating differences in their virulence on cotton. To contrast the virulence of the Fov isolates, four putatively non-pathogenic Fusarium oxysporum (Fo) isolates collected from cotton seedlings exhibiting atypical wilt symptoms were assessed for their ability to colonise cotton host. Despite the absence of Secreted in Xylem genes (SIX6, SIX11, SIX13 and SIX14) characteristic of Fov, all four Fo isolates retained the ability to colonise cotton and induce wilt symptoms. This suggests that slightly virulent strains of Fo may contribute to the overall occurrence of Fusarium wilt in cotton fields. Findings from this study will allow better distinction to be made between plant pathogens and endophytes and allow fungal effectors underpinning pathogenicity to be explored. [ABSTRACT FROM AUTHOR]

In eukaryotes, the retromer complex is critical for the transport of cargo proteins from endosomes to the trans-Golgi network (TGN). Despite its importance, there is a lack of research on the retromer-mediated transport of cargo proteins regulating the growth, development, and pathogenicity of filamentous fungi. In the present study, transcriptome analysis showed that the expression levels of the retromer complex (CcVPS35, CcVPS29 and CcVPS26) were significantly elevated during the early stages of Corynespora cassiicola invasion. Gene knockout and complementation analyses further highlighted the critical role of the retromer complex in C. cassiicola infection. Subcellular localization analysis showed that the retromer complex was mainly localized to the vacuolar membrane and partially to endosomes and the TGN. Further research found that the retromer core subunit CcVps35 can interact with the cargo protein CcSnc1. Subcellular localization showed that CcSnc1 is mainly located at the hyphal tip and partially in endosomes and the Golgi apparatus. Deletion of CcVPS35 resulted in the missorting of CcSnc1 into the vacuolar degradation pathway, indicating that the retromer can sort CcSnc1 from endosomes and transport it to the TGN. Additionally, gene knockout and complementation analyses demonstrated that CcSnc1 is critical for the growth, development, and pathogenicity of C. cassiicola. In summary, the vesicular transport pathway involving the retromer complex regulates the sorting and transport of the cargo protein CcSnc1, which is important for the growth, development and pathogenicity of C. cassiicola. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is one of the emerging staple crops in Pakistan, with Punjab producing over 95% of the country's potatoes. Wilt is an emerging threat to the potato crop worldwide, including in Pakistan. We identified and characterized Fusarium species associated with potato wilt in Pakistan through morphological and molecular analyses. Samples were collected during the 2020–2022 potato seasons from five major potato-growing regions: Sahiwal, Chichawatni, Pakpattan, Kamalia, and Faisalabad. Morphological characterization, internal transcribed spacer (ITS) sequencing, specific translation elongation factor 1-alpha (TEF) sequencing, and phylogenetic analysis were used to identify six different Fusarium species: F. oxysporum, F. equiseti, F. incarnatum, F. fujikuroi, F. annulatum and F. thapsinum. Pathogenicity tests in a greenhouse revealed that F. oxysporum and F. equiseti were responsible for Fusarium wilt in all sampled regions, with F. oxysporum being more prevalent in wilted samples. This is the first report of F. equiseti on wilted potatoes in Pakistan. In vitro biocontrol tests using Trichoderma harzianum showed 89% inhibition against F. equiseti and 65% inhibition against F. oxysporum. These findings on F. equiseti will aid in developing future control strategies, including biocontrol measures for Fusarium wilt in potatoes. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is a devastating fungal disease caused by Fusarium graminearum. Pectin lyase, a pectinase, acts on the α-1,4-glycosidic linkage of galacturonic acid primarily by β-elimination. In this study, three pectin lyase genes (FgPel1, 2, 3) in F. graminearum were selected, and deletion mutants (ΔFgPel1, 2, 3) were constructed by homologous recombination for functional characterization. The gene deletions affected the morphology and growth rate of F. graminearum on pectin medium at various concentrations, with the growth rate of ΔFgPel1 being more significant. The growth of ΔFgPel1 colonies slowed at pH 4, with optimal growth at pH 6.5, whereas ΔFgPel2 and ΔFgPel3 exhibited greater inhibition at pH 8. Colony morphology and diameter of the deletion mutants showed no significant differences compared to the wild-type strain PH-1, and there was no effect on conidial production or germination rate. Pathogenicity assays demonstrated that gene deletion significantly reduced the ability of F. graminearum to infest corn silks and wheat ears, and that ΔFgPel2 showed a more pronounced reduction in pathogenicity on wheat spikes. In summary, the pectin lyase genes (FgPel1, 2, 3) are involved in pectin utilization and are influenced by external pH conditions, which attenuate the pathogenicity of F. graminearum without affecting its vegetative growth or asexual spore formation. These findings elucidate the roles of these genes and provide a basis for controlling FHB. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is one of the most agriculturally and economically important crops in the world. Wheat fungal diseases are becoming more severe and frequent due to global climate change, threatening wheat yields and security. While fungal diseases such as fusarium head blight, stripe rust, and powdery mildew have been extensively studied, the newly emerged fungal pathogens in wheat are still under-researched. In May 2023, black mold symptoms were observed on wheat spikes in Xinxiang City, Henan Province, China. However, the causal agent of this disease was not known. We employed a combination of morphological examination and molecular techniques to identify the pathogen. The internal transcribed spacer (ITS) region, translation elongation factor 1-alpha (tef1), and actin (act) genes of the fungus were partially sequenced (accession no. OR186209, PQ271633 and PQ271632) and showed 99.59–100% identity with the previously reported Cladosporium cladosporioides, which affects wheat, pokeweed, and black-eyed pea. The pathogenicity of this fungus was confirmed by fulfilling Koch's postulates. Through a rigorous screening process, we found Simplicillium aogashimaense, Trichothecium roseum, and Bacillus velezensis as effective biocontrol agents, with B. velezensis demonstrating the most potent antagonistic activity against the Cladosporium mold. This discovery showed the potential of B. velezensis as a biocontrol agent for wheat disease management. The findings underscore the importance of the present study in advancing the control of this disease. [ABSTRACT FROM AUTHOR]

Transcriptional regulation mediated by the balance of histone acetylation and deacetylation is fundamental in responding to environmental cues by impacting chromatin remodeling. Histone deacetylases (HDACs) are enzymes that remove acetyl groups from histone and non-histone proteins, thus restoring a tight chromatin structure. In pathogenic fungi, HDACs have been implicated in growth, secondary metabolite biosynthesis, and virulence. However, the role of HDACs in the mycotoxin fumonisin B1 (FB1)-producing fungus Fusarium verticillioides is poorly understood. In this study, we systematically characterized six F. verticillioides HDACs. An increased level of H4K16ac was observed in the deletion mutant of FvHOS2, which was associated with vegetative growth, conidiation, and virulence when infecting sugarcane and maize. FvRpd3 appeared to be essential for vegetative growth, while FvHda1 promoted growth, and both contributed to conidiation and pathogenicity. In contrast, FvSirt4 displayed a negative correlation with these processes. Additionally, the FB1 production was positively affected by FvHos2 and FvRpd3, but negatively impacted by Fvhda1, FvSir2, FvHst2, and FvSirt4 through the regulation of different key fumonisin biosynthetic (FUM) genes. Further findings indicate an association between FvSirt4 and FvSkb1, which is a histone methylase that positively regulates FB1 and pathogenicity. Moreover, as a global transcriptional regulator, over 2365 genes (~15% of the genome) enriched in multiple metabolic pathways were significantly downregulated in the ΔFvhos2 mutants relative to the wild type. Overall, our results suggest distinct roles of HDACs in regulating the growth, virulence, mycotoxin FB1 production, and gene expression in F. verticillioides. [ABSTRACT FROM AUTHOR]