Toscana virus encephalitis in Southwest Germany: a retrospective study

Background Toscana virus (TOSV) is an arthropod-borne virus transmitted by phlebotomine sandflies (Phlebotomus sp.) widespread throughout the Mediterranean having the potential to cause meningoencephalitis in humans. In Germany, the vectors of TOSV are introduced recently and become endemic especially in Southwestern Germany. As TOSV is not investigated regularly in patients with meningoencephalitis, cases of TOSV-neuroinvasive disease may remain mostly undetected. Methods We conducted a retrospective cohort study on patients with meningoencephalitis without identification of a causal pathogen from 2006 to 2016. Serologic assessment for anti-TOSV-IgG and IgM was performed on serum and CSF. Demographic, clinical and CSF data from TOSV-positive patients were compared to a cohort of patients with meningoencephalitis due to enterovirus. Informed consent was obtained from all included patients. Results We found 138 patients with meningoencephalitis without identified causal pathogen. From 98 of these patients CSF and serum was available for further testing. Additionally, we included 27 patients with meningoencephalitis due to enterovirus. We identified two patients with serological confirmed TOSV-neuroinvasive disease (TOSV-IgM and IgG positive, 2%) and two patients with possible TOSV-neuroinvasive disease (isolated TOSV-IgM positive, 2%). Overall, TOSV-neuroinvasive was detected in 4% of our cases with suspected viral meningoencephalitis. None of them had a history of recent travel to an endemic area. Conclusions We found cases of TOSV-neuroinvasive disease in our German cohort of patients with meningoencephalitis. As no recent history of travel to an endemic area was reported, it remains probable that these cases resemble autochthonous infections, albeit we cannot draw conclusions regarding the origin of the respective vectors. TOSV could be considered in patients with meningoencephalitis in Germany.

Prevalence of Echinococcus Species in Wild Foxes and Stray Dogs in Qinghai Province, China

Echinococcosis is a zoonotic parasitic disease that is highly endemic to the Qinghai province of China. Limited data are available on the prevalence of the causal pathogen, Echinococcus spp., in definitive hosts in this region. Thus, the aim of this study was to evaluate the prevalence of Echinococcus spp. in wild foxes and stray dogs in Qinghai province. Five hundred and twenty-eight feces from wild foxes and 277 from stray dogs were collected from 11 counties in the Golog, Yushu, and Haixi prefectures and screened for Echinococcus spp. using copro-DNA polymerase chain reaction (PCR). In total, 5.5% of wild foxes and 15.2% of stray dogs tested positive for Echinococcus spp. The prevalence rates of Echinococcus spp. in wild foxes in Golog, Yushu, and Haixi were 7.3%, 5.2%, and 1.9%, respectively. In stray dogs, these rates were 13.3%, 17.3%, and 0%, respectively. Sequencing analysis determined that Echinococcus multilocularis was the most prevalent species, occurring in 4.0% and 12.6% of wild foxes and stray dogs, respectively. Echinococcus shiquicus was observed in 1.5% of wild foxes and 0.7% of stray dogs. Echinococcus granulosus was observed only in wild dogs, with a prevalence rate of 1.8%. To our knowledge, this is the first report on the prevalence of E. shiquicus in dogs in Qinghai province. The current results improve our understanding of the transmission and dissemination of human echinococcosis and suggest that exposure to the eggs of E. multilocularis harbored by wild foxes and stray dogs may pose a great risk of alveolar echinococcosis to humans in Qinghai province.

Centenary of Soil and Air Borne Wheat Karnal Bunt Disease Research: A Review

Karnal bunt (KB) of wheat (Triticum aestivum L.), known as partial bunt has its origin in Karnal, India and is caused by Tilletia indica (Ti). Its incidence had grown drastically since late 1960s from northwestern India to northern India in early 1970s. It is a seed, air and soil borne pathogen mainly affecting common wheat, durum wheat, triticale and other related species. The seeds become inedible, inviable and infertile with the precedence of trimethylamine secreted by teliospores in the infected seeds. Initially the causal pathogen was named Tilletia indica but was later renamed Neovossia indica. The black powdered smelly spores remain viable for years in soil, wheat straw and farmyard manure as primary sources of inoculum. The losses reported were as high as 40% in India and also the cumulative reduction of national farm income in USA was USD 5.3 billion due to KB. The present review utilizes information from literature of the past 100 years, since 1909, to provide a comprehensive and updated understanding of KB, its causal pathogen, biology, epidemiology, pathogenesis, etc. Next generation sequencing (NGS) is gaining popularity in revolutionizing KB genomics for understanding and improving agronomic traits like yield, disease tolerance and disease resistance. Genetic resistance is the best way to manage KB, which may be achieved through detection of genes/quantitative trait loci (QTLs). The genome-wide association studies can be applied to reveal the association mapping panel for understanding and obtaining the KB resistance locus on the wheat genome, which can be crossed with elite wheat cultivars globally for a diverse wheat breeding program. The review discusses the current NGS-based genomic studies, assembly, annotations, resistant QTLs, GWAS, technology landscape of diagnostics and management of KB. The compiled exhaustive information can be beneficial to the wheat breeders for better understanding of incidence of disease in endeavor of quality production of the crop.

UPLC-QTOF-MS-Based Untargeted Study of Metabolites Secreted by Sclerotinia Sclerotiorum Pathogen Under Axenic Condition

The stem rot disease has emerged globally as a major disease threat to the productivity and seed quality of oilseed Brassica. The generalist causal pathogen Sclerotinia sclerotiorum (Lib.) de Bary shows large variability in their aggressiveness and pathogenicity. Revealing the metabolic profile and signaling components of the pathogen in host-pathogen interaction are fundamental in understanding host resistance to the disease. In this study, the metabolites released by the pathogenic strains of S. sclerotiorum under the axenic culture have been identified using the untargeted high-resolution UPLC-QTOF-ESI-MS/MS. The analysis of the ethyl acetate extracts of the S. sclerotiorum culture revealed ten major secondary metabolites namely, sclerin, sclerotinin-B, sclerone, melanin, bostrycoidin, botcinin-D, botcinin-A, gliovirin, scleramide, and botcinic acid. The later six metabolites are being reported for the first time in the culture extract of the S. sclerotiorum pathogen. The phylogenetic analysis based on the overlapping and unique informative peaks in the chromatograms, the six S. sclerotiorum strains were grouped into three major clads. The clustering based on metabolic profiles does not substantiate the diversity based on morphology or virulence differences on the host. The findings of the study signified the metabolites secreted under the axenic conditions are varies based on their growth and developmental stages and may not necessarily be the determining factors for their differential aggressiveness and virulence over the host.

Ramularia leaf spot in barley

Ramularia leaf spot is an emerging pathogen across barley growing regions of the world. It's rise from minor to major disease has been rapid over the last twenty years. The causal pathogen, Ramularia collo-cygni is poorly understood but it has been shown to have a complex life cycle and the ability to exist on many hosts in an endophytic state. The rate of development of fungicide resistance in the fungus is also extremely fast and many of the major single site fungicides are no longer effective in many countries. With multisite fungicides having their approval or reconsidered and no consistent varietal resistance available, control of the disease is increasing challenging. This chapter reviews the latest research into Ramularia biology and control and highlights the areas where recent advances have been made.

Crude Extracts and Alkaloids Derived from Ipomoea-Periglandula Symbiotic Association Cause Mortality of Asian Citrus Psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important economic pest of citrus crops because it vectors the causal pathogen of huanglongbing (HLB; aka citrus greening). Population suppression of D. citri with insecticides has been disproportionally relied on for HLB management and a greater diversity of more sustainable tools is needed. Periglandula spp. is a fungal endosymbiont (family Clavicipitaceae) that forms a mutualistic relationship with members of plants in family Convolvulaceae. This association results in the production of ergot alkaloids that were previously documented as having psyllicidal properties. We investigated the mortality and behavior of D. citri exposed to crude extracts from morning glories in the plant family Convolvulaceae, as well as synthetic ergot alkaloids. Nymphs and adults were exposed to the crude plant extracts from Periglandula positive species of Convolvulaceae, as well as five synthetic ergot alkaloids. Treatments were prepared by exposing clippings of citrus to 100 ng/µL of crude extract from Periglandula-positive species of Ipomoea (I. imperati, I. leptophylla, I. pandurata and I. tricolor), and Turbina corymbosa, and from one Periglandula-negative species (I. alba) (100 ng/µL). Mortality of adult and nymphal D. citri was significantly higher than the control after exposure to extracts from I. tricolor and I. imperati. The synthetic ergot alkaloids, lysergol (10–100 ng/µL), ergonovine maleate (100 ng/µL), agroclavine (10–100 ng/µL), and ergosine (10–100 ng/µL) increased mortality of D. citri nymphs, while ergosine (100 ng/µL) and agroclavine (100 ng/µL) increased mortality of adults compared to water controls. Fewer D. citri adults settled on plants treated with crude extracts or synthetic ergot alkaloids than on water controls at 48 h after release. D. citri that fed on citrus leaves treated with 10 ng/μL solution of crude extract from the Periglandula-positive species Ipomoea (I. imperati, I. leptophylla, I. pandurata, I. tricolor), and Turbina corymbosa excreted significantly less honeydew compared with a negative water control and extract from Periglandula-negative species (I. alba). Our results indicate that crude extracts and ergot alkaloids exhibit toxic and sub-lethal effects on D. citri that could be useful for management of this pest.

Hyperparasitism on Plasmopara viticola by Simplicillium lanosoniveum

A previously unknown association between Plasmopara viticola, the causal pathogen of grape downy mildew, and the mycoparasite strain F2 was described in this paper. F2 could be consistently isolated from the mildew of diseased spots on grape leaves of Kyoho (Vitis labrusca × V. vinifera cv. Kyoho) infected with P. viticola, but neither from the surfaces of healthy grape leaves nor within lesions of other diseases. It could be observed that strain F2 was capable of coiling around sporangiophores and sporangia of P. viticola under microscope, causing hyphae deformation, decreasing the pathogen growth, and reducing the number of sporangia. This fungal strain was identified as Simplicillium lanosoniveum on the basis of morphological characterizations and 28S rDNA sequencing. To our knowledge, this is the first report of S. lanosoniveum with hyperparasitic characteristics on P. viticola, and the hyperparasite has potential application in the control of grape downy mildew.

Characterisation and Pathogenicity of Aspergillus tamarii Causing Banana Fruit Rot

Banana fruit rot is a common postharvest disease of the banana fruit. The appearance of rot symptoms on the surface of the fruits reduces the quality and marketability of banana. From rot lesions on banana fruits, three Aspergillus isolates were isolated. Based on morphological characteristics and sequences of Internal Transcribed Spacer, β-tubulin and calmodulin, the isolates were identified as A. tamarii. Pathogenicity tests of the isolates, conducted using mycelial plugs with wounded and unwounded treatments, showed A. tamarii as the pathogen of banana fruit rot. Rot symptoms were highly severe on wounded banana fruits compared to unwounded fruits, and therefore, wounded banana fruits are more susceptible to A. tamarii infection. To the best of our knowledge, this is the first report of A. tamarii as a causal pathogen of banana fruit rot. This study indicated A. tamarii is one of postharvest rot pathogens of banana.

Autophagy and Host Defense in Nontuberculous Mycobacterial Infection

Autophagy is critically involved in host defense pathways through targeting and elimination of numerous pathogens via autophagic machinery. Nontuberculous mycobacteria (NTMs) are ubiquitous microbes, have become increasingly prevalent, and are emerging as clinically important strains due to drug-resistant issues. Compared to Mycobacterium tuberculosis (Mtb), the causal pathogen for human tuberculosis, the roles of autophagy remain largely uncharacterized in the context of a variety of NTM infections. Compelling evidence suggests that host autophagy activation plays an essential role in the enhancement of antimicrobial immune responses and controlling pathological inflammation against various NTM infections. As similar to Mtb, it is believed that NTM bacteria evolve multiple strategies to manipulate and hijack host autophagy pathways. Despite this, we are just beginning to understand the molecular mechanisms underlying the crosstalk between pathogen and the host autophagy system in a battle with NTM bacteria. In this review, we will explore the function of autophagy, which is involved in shaping host–pathogen interaction and disease outcomes during NTM infections. These efforts will lead to the development of autophagy-based host-directed therapeutics against NTM infection.

Detection of the G143A Mutation in the Cytochrome b Gene of Corynespora cassiicola Isolates from Soybean in Tennessee

Corynespora cassiicola is the causal pathogen of target spot in soybean and cotton grown in the United States. With target spot increasing in importance, fungicides are becoming an important tool for control of this disease. Unfortunately, there are reports of C. cassiicola isolates in other crops being resistant to some fungicide classes. The objective of this study was to identify if resistance to quinone outside inhibitor (QoI) fungicides is present in Tennessee soybean and cotton isolates of C. cassiicola. Four isolates of C. cassiicola were evaluated at a range of doses for the fungicide pyraclostrobin. Isolates were also sequenced to determine if the G143A mutation was present in the cyt b gene. Two isolates previously reported to be resistant to QoIs were also used as positive checks. Two isolates of C. cassiicola from Tennessee soybean were found to have the G143A mutation. EC50 values for the two isolates ranged from 15.7 to 121 μg/ml. As a result of this study, C. cassiicola isolates have exhibited resistance to QoI fungicides in Tennessee soybean.