Wide Host Range Research Articles

Estimates of microbiome heritability across hosts.

Microbiomes contribute to variation in many plant and animal traits, suggesting that microbiome-mediated traits could evolve through selection on the host. However, for such evolution to occur, microbiomes must exhibit sufficient heritability to contribute to host adaptation. Previous work has attempted to estimate the heritability of a variety of microbiome attributes. Here we show that most published estimates are limited to vertebrate and plant hosts, but significant heritability of microbiome attributes has been frequently reported. This indicates that microbiomes could evolve in response to host-level selection, but studies across a wider range of hosts are necessary before general conclusions can be made. We suggest future studies focus on standardizing heritability measurements for the purpose of meta-analyses and investigate the role of the environment in contributing to heritable microbiome variation. This could have important implications for the use of microbiomes in conservation, agriculture and medicine.

Genotyping of human isolates from human toxoplasmosis outbreak: Restriction Fragment Length Polymorphism and Sanger Sequencing.

Toxoplasmosis is a parasitic disease caused by infection with Toxoplasma gondii, capable of infecting a wide range of hosts. The parasite exhibits a broad genetic diversity, necessitating genotypic characterization for genotype identification and associations with epidemiological information. Therefore, the Restriction Fragment Length Polymorphism (RFLP) technique is used for characterization. This study aimed to perform genotypic characterization of isolates from pregnant women infected during a human toxoplasmosis outbreak, comparing the RFLP and Sanger Sequencing methodologies. For this purpose, six human isolates were subjected to conventional PCR, Multiplex PCR, Nested PCR, Enzymatic Digestion, and Sanger Sequencing. Additionally, the standard strains GTI (Type I), PTG (Type II), and CTG (Type III) were also subjected to the same techniques described above. Subsequently, the amplified DNA products were compared with the standard strains. As a result, it was observed that Sanger Sequencing provides the same information as RFLP PCR, as well as the possibility of cost reduction for genotypic characterization, and providing greater agility in issuing results. Additionally, Sanger Sequencing of T. gondii isolates allows for detailed evaluation of nucleotide sequences, including the assessment of SNPs and enzymatic restriction sites, which the RFLP technique does not.

Rising orthotospovirus incidence in India: Challenges and advances in management

Orthotospoviruses (OV) have emerged as a significant agricultural threat in India, posing a severe risk to critical crops, including tomato, chilli, watermelon and groundnut. This review explores the rising incidence of OV, including Groundnut Bud Necrosis Orthotospovirus (GBNV), Watermelon Bud Necrosis Orthotospovirus (WBNV), Capsicum Chlorosis Orthotospovirus (CaCV), Peanut Yellow Spot Orthotospovirus (PYSV), Iris yellow spot Orthotospovirus (IYSV) and Tomato Spotted Wilt Orthotospovirus (TSWV), along with the challenges in their management. These viruses have led to severe yield losses, sometimes causing complete crop failure due to their wide host range and the polyphagous nature of thrips. This further complicates control efforts by facilitating rapid spread across diverse crops and regions. The review highlights the multifaceted challenges in managing OV and thrips, including the lack of durable host resistance, limited diagnostic capabilities, and difficulties in controlling thrips populations. Current management strategies, including cultural practices, chemical control, biological control and resistant genotype development, have shown limited efficacy in providing long-term solutions. Recent advancements in biotechnological approaches, such as RNA interference, are discussed as promising pathways for improved virus management. The review underscores the need for genome editing techniques, such as CRISPR/Cas9, which offer the capacity to develop virus-resistant plants by targeting essential viral or vector genes to disrupt transmission cycles. Additionally, using nanoparticles for targeted delivery of antiviral compounds and novel detection tools presents another innovative solution to effectively mitigate the impact of OV on Indian agriculture.

Encapsulated Predatory Bacteria Efficiently Protect Potato Tubers from Soft Rot Disease.

Soft rot Pectobacteriaceae (SRP) are a group of destructive Gram-negative phytopathogens that can infect a wide range of plant hosts, including potatoes. There are no effective control agents available against SRP, making their management challenging. We have developed a novel approach to protect potato tubers against SRP. It makes use of encapsulated predatory Bdellovibrio bacteriovorus bacteria that, upon release from a polymeric carrier, prey upon SRP. We applied a carrageenan-trehalose-based formulation containing a B. bacteriovorus HD100 predator to prevent soft rot disease development in potato tubers, under various conditions. The dried formulation exhibited very high stability over an 18-month period at room temperature (∼25°C), in contrast to unencapsulated suspensions of the predator, in which viability decreased rapidly below detection level. The rehydrated formulation was as efficient as freshly grown unencapsulated predators and provided high protection in potted potato tubers, displaying an average of 50% reduction in disease parameters (e.g., tissue decay and disease index) under controlled conditions at 7 days postinoculation and planting. The protective effect provided by this formulation was maintained in longer-term trials (28 days) conducted in larger vessels within a net house under natural climate conditions, highlighting its potential for practical application in the field.

Genetical and Morphological Identification of Prosthogonimus pellucidus (Digenea, Prosthogonimidae) in Grus japonensis

Species of the family Prosthogonimidae are considered the most pathogenic trematodes of poultry and wild birds worldwide, causing heavy economic losses in many countries. Prosthogonimosis was a common parasitic disease of Grus japonensis (Müller, 1776) which caused inflammation of the cloaca and bursa of Fabricius and even death. Morphological identifications of Prosthogonimus species are easily confusing; therefore, molecular characterization is used for discrimination. The present study was conducted to identify Prosthogonimus species at Zhalong National Nature Reserve, northeast of China. Considering the morphological variability and wide host range of individual Prosthogonimus species, a combination of both morphological and molecular analyses is indispensable for the valid identification of this parasite and the internal transcribed spacer (ITS) region was amplified for the sequence analysis and phylogenetic analysis. The results of molecular analysis together with phylogenetic reconstruction indicated that the Prosthogonimus pellucidus (von Linstow, 1873) in this study form a single cluster with P. pellucidus, revealing potentially high diversity within the genus Prosthogonimus. Classification of Prosthogonimus species seems to be unrelated to the host and may be related to geographical location. These data provide a significant resource of molecular markers for studying the taxonomy, population genetics, and systematics of Prosthogonimidae.

Lecanicillium attenuatum infection and effects on the reproduction of Frankliniella occidentalis

ABSTRACT Frankliniella occidentalis, western flower thrips, is an invasive pest that seriously damages economic crops such as vegetables, flowers, and fruit trees because of its high fecundity, short generation cycle, and strong adaptability. Lecanicillium is an important entomopathogenic fungus, characterised by its wide host range, high pathogenicity, and environmental safety. It plays an important role in the environmentally friendly management of F. occidentalis. This study clarifies whether L. attenuatum infects F. occidentalis and affects its reproduction. The results of scanning electron microscope showed that conidia of L. attenuatum were attached to many parts of thrips adult after 1 h of treatment with 10^8 conidia/mL, and most F. occidentalis were covered by hyphae after 72–120 h. The cumulative mortality rate of the second instar larvae of the F1, F2, and F3 generations exceeded 60% on the seventh day post-infection and that of female adults was higher than 90% when treated by L. attenuatum with 10^8 conidia/mL. Simultaneously, L. attenuatum had strong sublethal effects on the surviving thrips. Indeed, the number of eggs deposited and the lifespan of female adults decreased considerably after the second instar larvae of F. occidentalis were treated with L. attenuatum, and had the impaction on the thrips offspring too. Altogether, our data suggested that L. attenuatum not only exhibited a high degree of pathogenicity towards F. occidentalis second instar larvae and adults but also affected the longevity and reproduction of surviving thrips.

Seroprevalence of Toxoplasma gondii in domestic dogs from Lima City in Peru

The protozoan Toxoplasma gondii, which can infect a wide range of warm-blooded animal hosts, including humans, causes the zoonosis toxoplasmosis. This parasite affects dogs, and infections may lead to neuromuscular problems in them. Likewise, dogs can act as sentinels for toxoplasmosis, providing valuable information on the prevalence of the parasite in a given area. Therefore, the aim of the present study was to determine the seroprevalence of T. gondii in dogs from Lima City in Peru. A total of 120 sera from domestic dogs were used to detect IgG antibodies using the modified agglutination test (MAT). Forty dogs tested positive for the MAT, indicating a seroprevalence of 33.3 % (CI95% 24.9–41.8 %). Only the variable sex demonstrated a statistical association with exposure to T. gondii in dogs, with males exhibiting odds of 2.40 (CI95% 1.10–5.37) compared to females. Since dogs are the main human pet, they could act as sentinels to estimate the situation of toxoplasmosis in humans. Our findings highlight the need to continue epidemiological surveillance of T. gondii in canine populations in various localities of Peru.

Chlamydiosis in Animals.

The Chlamydiaceae family consists of Gram-negative, obligate intracellular bacteria that replicate within the cells of a diverse range of hosts. These hosts include domesticated animals such as cats, dogs, and livestock, as well as wildlife like koalas and birds, exotic species such as reptiles and amphibians, and humans. Chlamydial infection can result in various clinical signs, including respiratory diseases, reproductive failures, ocular pathologies, and enteritis, though the infected organism may remain asymptomatic. In recent years, chlamydial nomenclature has undergone several revisions due to the wide range of hosts, the frequent discovery of novel strains, and the reclassification of existing ones. Given this and the clinical significance of these infections, ranging from asymptomatic to fatal, an updated review is essential. This article outlines key characteristics of Chlamydia species and provides an updated overview of their nomenclature, offering a concise reference for future research on chlamydial diseases.

First report of tomato ringspot virus infection of Krymsk 86 (Prunus cerasifera × P. persica), a hybrid rootstock, in California.

California produces 99% of prunes (Prunus domestica) in the U.S.A., valued at $148 million and accounting for 40% of world prune production. In the last decade, the rootstock Krymsk 86 (K86; P. cerasifera x P. persica) is increasingly used in prune production because of its high vigor, excellent anchorage and graft compatibility with a wide variety of Prunus crops. An estimated >50% of new prune plantings in the Sacramento Valley are on K86. In late spring of 2023, 'Improved French' prune trees in two Northern California counties, grafted on K86 and Lovell (P. persica) rootstocks, were declining with a pale colored canopy. One orchard was ~ 9-years-old and in the other, trees varied from ~ 20 years to newly planted. The percentage of affected trees in one orchard was 3.6% (n=1,824) and 4.6% (n=1,295) in trees on K86 and Lovell, respectively. Symptomatic trees were scattered throughout this orchard, with a higher density of affected trees in the northeast quadrant. Examination of the trunk revealed a necrotic brown line at the graft union, typical of prune brown line (PBL) disease (Mircetich and Hoy, 1981), caused by infection of rootstock by tomato ringspot virus (ToRSV), a member species of Nepovirus lycopersici (family Secoviridae. The virus is vectored by dagger nematodes (Teliz et al. 1967) and its presence was confirmed in one of the orchards. To confirm infection by ToRSV in declining trees, total RNA from leaf samples, feeder roots, and cambial tissue from bark samples from scion and rootstock of one tree each on K86 and Lovell, was obtained using RNeasy Plant Mini kit (www.qiagen.com) and tested by one step reverse transcription-polymerase chain reaction (RT-PCR) assay using primers previously described (Tang et al., 2014). The reaction conditions included RT at 54oC using random hexamers and Superscript III (Thermo Fisher Scientific, USA), followed by a denaturation step at 95°C for 5 min, and 35 amplification cycles of 95°C for 30 s, 55°C for 30 s, and 72°C for 45 sec; and a final extension of 72°C for 5 min. The expected size amplicons (176 bp) were visualized by agarose gel electrophoresis only from RNA obtained from the cambial tissue below the graft union confirming the ToRSV infection in K86 rootstock. Extracts from bark scrapings of the rootstocks of three symptomatic trees also tested positive for ToRSV with immunostrips (www.agdia.com). In subsequent RT-PCR tests, RNA extracts from cambial tissue from 9 of 10 symptomatic trees on K86 tested positive for ToRSV. The amplicons were purified using a gel extraction kit (Qiagen Inc., Valencia, CA), and subjected to Sanger sequencing (Azenta Life Sciences (South Plainfield, NJ, USA). The sequence of the ToRSV isolates 316 (GenBank accession PQ282959) and 318 (GenBank accession PQ2829560 exhibited 99.4% (175/176 base pairs) and 98.9 % (175/177) sequence identity, respectively, with ToRSV isolate Rasp1-2014 segment RNA2 (GenBank accession KM083895). Our results indicate that ToRSV can infect K86 and cause PBL. ToRSV and its nematode vectors have a wide host range that includes several crop plants and weeds, but this virus is not currently part of registration and phytosanitory certification of Prunus species in the state of California. This is the first report of ToRSV infection of the K86 rootstock. This information is important for the selection of a rootstock in prune orchards where the virus is endemic.

A new leaf spot caused by Alternaria alternata on Atractylodes lancea in Jiangsu, China.

Atractylodes lancea is an important Chinese herbal medicine, which is mainly produced in Jiangsu province, China. In June 2022, leaf spots symptom were observed on some A. lancea seedlingsgrowing in a Chinese herbal medicine resource garden of NanjingBotanical Garden, Jiangsu. Approximately 75% of 100 A. lancea seedlings suffered from the disease. Initially, gray to black spots appeared at the tip of the blade, then spread deep into the petiole, finally causing the blade to wither and fall. To isolate the pathogen, five diseased leaves were collected from five different seedlings. Leaf sections (3 to 4 mm) were excised from the margins between healthy and diseased tissues, surface sterilized in 75% alcohol for 30 s, then in 1.5% NaClO for 90 s, rinsed three times in sterilized distilled water, plated on potato dextrose agar (PDA) and incubated at 25℃in darkness. Pure cultures were obtained by monosporic isolation. Eighteen isolates were obtained, and 77.8% of isolates was identified as Alternaria spp. A representative isolate, CS4-1 was used for further investigation. The colony of CS4-1, growing on PDA was cotton-like and black to brown with gray-white aerial hyphae on their surfaces, and dark gray on the back. The conidia were solitary on conidiophores and were oval to pear-shaped, brown in color, with 1 to 4 transverse septa and 0 to 1 oblique septa, parietal cells extending into the beak, and measured 8.9 to 39.5×6.0 to 13.5 µm (n=35). These characteristics were consistent with the description of Alternaria spp. (Simmons 2007). Six DNA regions, i.e.,internal transcribed spacer (ITS),large subunit ribosomal RNA (LSU), small subunit ribosomal RNA (SSU), anonymous region OPA10-2, Alt a 1 major allergen (Alta1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH)and translation elongation factor 1-alpha (TEF1)with the respective GenBank Accession No. OP836052, OP836054, OP836051, OP851487, OP851488, OP851489, and OP851490, were amplified and sequenced with the primer pairs described by White et al. (1990) and Woudenberg et al. (2015). A neighbor-joining phylogenetic tree was generated by combining all sequenced loci in MEGA7, and CS4-1 clustered in the A. alternata clade. To test pathogenicity, 12 leaves, on three one-month-old A. lancea seedlings (four leaves from each seedling) were wounded with a sterile needle and inoculated with 20 μL of conidial suspension (1×106 spores/mL) on the left sides of leaves. The right sides of the leaves were inoculated with 20 µL sterile water and used as the control. All inoculated detached leaves and seedlings were covered with clear polyethylene bags to keep moisture and were incubated in a greenhouse at 25℃, 80% relative humidity, and a 12-h light/dark cycle. The experiment was repeated three times. After 4 days, typical gray to black spots were visible on the left sides of all inoculated leaves and the inoculated seedlings, and the right sides remained asymptomatic. Subsequently, the same fungus was reisolated and identified based on morphological and molecular traits. A. alternata has a very wide host range but has never been reported on A. lancea worldwide (nt.ars-grin.gov). Because of the medicinal value of A. lancea, further studies should be directed toward control of this disease.

Comparative Mitogenomics Analysis Revealed Evolutionary Divergence among Purpureocillium Species and Gene Arrangement and Intron Dynamics of Ophiocordycipitaceae.

The species of Purpureocillium are cosmopolitan and multitrophic fungi that can infect a wide range of invertebrate hosts. This study reports the mitogenome of P. atypicola, a specialized spider pathogenic fungus. The 112,465 bp mitogenome encoded genes typically found in fungal mitogenomes, and a total of 52 introns inserted into seven genes. A comparison with three other Purpureocillium species revealed significant differences in length and intron number, primarily due to intron variation; however, there was no dynamic variation in the introns of the cox1 gene within the same species of the Purpureocillium genus. Different mitochondrial protein-coding genes showed variable degrees of genetic differentiation among these species, but they were all under purifying selection. Additionally, frequent intron loss or gain events were detected to have occurred during the evolution of the Ophiocordycipitaceae mitogenomes, yet the gene arrangement remains conserved. A phylogenetic analysis of the combined mitochondrial gene set gave identical and well-supported tree topologies. The estimated age of the crown of Ophiocordycipitaceae and Purpureocillium were around the Early Cretaceous period (127 Mya) and Late Cretaceous period (83 Mya), respectively. The results of this study advance our understanding of the genomics, evolution, and taxonomy of this important fungal group.

Prevalence and genotyping of Toxoplasma gondii in questing Ixodes ricinus ticks from forest areas of Northern Poland.

Toxoplasma gondii occurs in a wide range of intermediate hosts, whose blood may be a meal for different tick species. A few studies have examined the role of ticks in the life cycle of T. gondii. This one includes the largest number and all stages of Ixodes ricinus collected from the widest area, covering seven recreational localities within a forest biotope in Northern Poland. This study aimed to determine the prevalence of T. gondii DNA in 2144 collected questing ticks to establish whether they may be involved in T. gondii life cycle. The additional goal was to genotype the detected T. gondii, as knowledge about its genotypes occurring in European ticks is insufficient. A further purpose was to detect coinfection with T. gondii and Borreliaceae in the collected ticks, as all of them have previously been tested for the presence of bacteria DNA. Nested PCR and sequencing of the obtained B1 gene fragment were conducted. T. gondii DNA was detected in 0.9% of all ticks (1.1% of nymphs and 0.7% of larvae). The presence of T. gondii in unfed larvae and nymphs may indicate the possibility of its vertical transmission. The prevalence of T. gondii DNA in ticks collected from individual sites was focal (0-4.3%) and seems to depend on local climatic conditions. Among all examined ticks, 0.3% were coinfected with T. gondii and Borreliella spp., vs. 0.6% of specimens with a single T. gondii infection. The obtained B1 sequences showed the greatest similarity (99.71-100%) to the sequence representing type III.

Chemoreceptor MCP4580 of Vibrio splendidus mediates chemotaxis toward L-glutamic acid contributing to bacterial virulence

Chemotaxis has an essential function in flagellar bacteria that allows them to sense and respond to specific environmental signals, enabling their survival and colonization. Vibrio splendidus is an important opportunistic pathogen that infects a wide range of hosts including fish, bivalve, and sea cucumber. Our study demonstrated that V. splendidus AJ01 exhibited chemotaxis toward L-glutamic acid (L-Glu), an abundant amino acid in the intestinal and respiratory tree tissues of the sea cucumber. Bacterial samples collected from two locations in soft agar swimming plates were subjected to RNA-sequencing (RNA-Seq) analysis to identify the methyl-accepting chemotaxis protein (MCP) respond to L-Glu. Among the 40 annotated chemoreceptors, MCP4580 was identified as the MCP that mediates L-Glu-response. Molecular docking and site-directed mutagenesis revealed that L-arginine at residue 81 (R81) and L-glutamine at residue 88 (Q88) in the ligand-binding domain (LBD) are crucial for L-Glu recognition. Bacterial two-hybrid assay (BTH) showed that MCP4580 forms dimers and interacts with the histidine kinase CheA via the coupling protein CheW1 and CheW2. Phosphorylation analysis showed that the binding of L-Glu to MCP4580 results in the inhibition of CheA phosphorylation mainly via CheW1. Notably, sea cucumbers stimulated with each mutant strain of chemotaxis protein exhibited reduced mortality, highlighting the importance of chemotaxis in V. splendidus virulence. The present study provides valuable insights into the molecular components and signal transduction involved in the chemotaxis of V. splendidus toward L-Glu, and highlights the importance of chemotaxis in its virulence.

First Report of Root Collar Canker Caused by Neoscytalidium dimidiatum on Jacaranda mimosifolia in China.

Jacaranda mimosifolia is widely cultivated as a garden ornamental tree. In July 2023, an unknown root collar canker of J. mimosifolia was discovered in green belts of Qingxiu District, Nanning, China, with a 8% incidence rate. Crowns of affected trees ranged from reddish brown leaves to deciduous or dead. Root collar tissue became necrotic matched by underbark dark brown lesions with irregular margins, and rotted at last. Six diseased plants distributed within 3000 m2 were choosed, and 24 root collar tissues were surface sterilized and placed on potato dextrose agar (PDA) plates to incubate at 28℃ for 3 to 5 days. Same colonies were consistently isolated from 18 tissues, and three isolates (M3-B1-1, M3-B1-2 and M3-B1-3) were purified for morphological and molecular determination. These isolates formed colonies with lush aerial mycelia rapidly, which covered a 90 mm plate in 72h. The colonies were initially white, then grayish-green to black. Arthrospores were colourless to light brown, short columnar, aseptate, truncate base, averaging 12.1±2.5 µm × 3.4±0.7 µm, sometimes formed arthric chains. Chlamydospores were dark brown, round or oval, aseptate, averaging 8.7±1.6 µm × 5.0±0.9 µm. Mature pycnidia and conidia produced for about 50 days on oatmeal agar medium (OMA), and conidia were colorless, oblong, aseptate, averaging 11.2±1.2 µm × 6.0±1.4 µm. These morphological characteristics were consistent with the description of Neoscytalidium dimidiatum (Penz.) Crous & Slippers (Crous et al. 2006). Genomic DNA was extracted from three isolates. The partial ITS region, TUB2 and TEF1-α genes were amplified (White et al., 1990; Glass and Donaldson 1995; Carbone and Kohn 1999). The sequences were deposited in GenBank (ITS: PP939650-PP939652; TUB2: PP942728-PP942730; TEF1-α: PP942731-PP942733). Blastn analysis revealed that ITS sequences of three isolates showed 99.8%, 100%, 100% identity (506 bp out of 507 bp, 507 bp out of 507 bp, 507 bp out of 507 bp) to N. dimidiatum C21 (KX447539), the TUB2 sequences showed 100% identity (436 bp out of 436 bp, 437 bp out of 437 bp, 437 bp out of 437 bp) to N.dimidiatum LNeo (ON099066), and the TEF1-α sequences showed 99.64% identity (276 bp out of 277 bp) to N.dimidiatum ARM230 (MK495384), respectively. Phylogenetic analysis based on concatenated ITS, TUB2 and TEF1-α sequences showed that three isolates were clustered into the same clade as N. dimidiatum. To fulfill Koch's postulates, pathogenicity of these isolates was tested on healthy two-year-old J. mimosifolia trees. Stem and root collar were wounded and placed mycelial plugs (8mm), and the inoculation sites were wrapped with parafilm or covered with nursery substrate to maintain the humidity. Four plants were inoculated with each isolate. As a control, four plants were inoculated with noncolonized PDA plugs. All treated plants were kept in a greenhouse at 28 ± 3°C and 70% relative humidity. Foliar blight and necrotic lesions around inoculation points were observed about 65 days after inoculation, and 50% of inoculated trees exhibited symptoms, whereas the control trees remained symptomless. Neoscytalidium dimidiatum was successfully reisolated from symptomatic tissue via morphological analysis. To our knowledge, this is the first report of root collar canker caused by N. dimidiatum on J. mimosifolia. Neoscytalidium dimidiatum has a wide range of hosts, including pitaya, pine, mulberry, pear, grape, locust tree (Luo et al. 2024). This finding will help in controlling of the disease epidemic.

Development and validation of a droplet digital PCR assay for Nipah virus quantitation

BackgroundNipah virus (NiV) is a zoonotic pathogen that poses a significant threat because of its wide host range, multiple transmission modes, high transmissibility, and high mortality rates, affecting both human health and animal husbandry. In this study, we developed a one-step reverse transcription droplet digital PCR (RT-ddPCR) assay that targets the N gene of NiV.ResultsOur RT-ddPCR assay exhibited remarkable sensitivity, with a lower limit of detection of 6.91 copies/reaction. Importantly, it displayed no cross-reactivity with the other 13 common viruses and consistently delivered reliable results with a coefficient of variation below 10% across different concentrations. To validate the effectiveness of our RT-ddPCR assay, we detected 75 NiV armored RNA virus samples, mimicking real-world conditions, and negative control samples, and the RT-ddPCR results perfectly matched the simulated results. Furthermore, compared with a standard quantitative real-time PCR (qPCR) assay, our RT-ddPCR assay demonstrated greater stability when handling complex matrices with low viral loads.ConclusionsThese findings show that our NiV RT-ddPCR assay is exceptionally sensitive and provides a robust tool for quantitatively detecting NiV, particularly in stimulated field samples with low viral loads or complex matrices. This advancement has significant implications for early NiV monitoring, safeguarding human health and safety, and advancing animal husbandry practices.

Epidemiology and genetic diversity of bocavirus in wild rodents in urban areas of Guangzhou, Southern China

Members of the genus Bocaparvovirus have a significant impact on human health and can infect a wide range of hosts, increasing the likelihood of crossing species barriers. Among the various mammalian hosts, rodents are widely recognized as important reservoirs for emerging and zoonotic viruses. However, despite recent reports of bocavirus infections in rodents, our current understanding of rat bocavirus (RBoV) genetic diversity and evolution is limited. In this study, rodent samples were collected from the urban areas of Guangzhou city, Southern China, to investigate the presence and genetic diversity of RBoV. Through PCR-based screening of 296 rodent spleens, 54 samples were determined to be positive for RBoV infection, and 12 nearly complete genome sequences of RBoV were recovered. Phylogenetic analysis revealed distinct lineages and sub-lineages of RBoV, and six recombination events with strong statistical support were identified, with five of these events involving sequences obtained from this study. These results highlight the genetic diversity of RBoV circulating in rodents in Guangzhou city and emphasize the importance of extensive surveillance to gain a better understanding of RBoV epidemiology, evolutionary characteristics, and potential for cross-species transmission.

Epidemiology of human and animal leptospirosis in Kenya: A systematic review and meta-analysis of disease occurrence, serogroup diversity and risk factors.

Leptospirosis is a priority zoonotic disease in Kenya, but an in-depth review of its presence in humans, animals and the environment is lacking. Therefore, we conducted this systematic review and meta-analysis to understand the epidemiological situation to date. We searched for literature in African journals online, AGRIS, Embase, the Leptospira WOAH reference laboratory library, ProMED-mail, PubMed, Scopus, Web of Science, and the institutional repositories of 33 academic institutions and included 66 publications on leptospirosis in Kenya which spanned from 1951 to 2022. The review was registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY). Most investigations were done in rural and urban areas in western, southern, central, and coastal areas in Kenya and the largely pastoral eastern and northern areas were under-represented. A wide host range of domestic animals and wildlife was revealed, and occupational exposure was an important risk factor for humans. The microscopic agglutination test (MAT) was the most frequent test, particularly common in studies conducted during the 1980s and 1990s. However, varying MAT panels and cut-off titres were observed. The overall seroprevalence in cattle was 28.2% (95% confidence intervals [CI]: 12.0-53.0; heterogeneity: I2 = 96.7%, τ2 = 1.4), and 11.0% in goats (95% CI: 5.4-21.2; heterogeneity: I2 = 78.8%, τ2 = 0.4). Molecular tests were seldom used to determine species and illustrate strain diversity. There was a lack of awareness of leptospirosis among farmers and health practitioners. The widespread presence of leptospires and inadequate diagnostic capacity demonstrate that leptospirosis is a common but underreported disease in Kenya. Raising awareness and boosting the country's diagnostic capacity is crucial to timely detection and disease control.

Insect pest Spodoptera litura (Fabricius) and its resistance against the chemical insecticides: A review

A polyphagous nocturnal pest Spodoptera litura (Fabr.) commonly called armyworm, infests about 150 plant species across 44 families worldwide, with nearly 60 plant species affected just in India. The majority of leaf tissues are consumed by the larvae and only the stem and side shoots will remain in the field. They entirely consume the interior content by boring into them, causing squares and young bolls to shed. This insect can badly affect crops and has a wide range of potential hosts, which can lead to financial losses for farmers and food shortages for consumers. The worldwide distribution of S. litura as a pest results in significant impact on productivity of many crops. They have the capability to invade new places as a wide-ranging species. Armyworm frequently reappears in India every year and causes evident destruction. Different records on the insect population outbreak have been reported from many countries all around the world. The larvae of insect pests enter the fruits and even contaminate it and this causes yield and economic losses. The low temperatures of winter season are the limiting factors that affect species. It migrates mainly to breed during the summer season but is unable to survive in winters. S. litura acquired resistance to several synthetic insecticides, which led to pest outbreaks that were irregular and caused failure of different crops. The resistance and cross-resistance of this pest against insecticide toxin make it more difficult to reduce its population below threshold level. Understanding the mechanisms of resistance is crucial for developing effective resistance management strategies that can restrict or halt the spread of resistance in these pest populations.

Unveiling the intricacies of the rice-Rhizoctonia pathosystem: a comprehensive review of host-pathogen interactions, molecular mechanisms, and strategies for sustainable management

Sheath blight disease in rice, induced by the necrotrophic basidiomycetes Rhizoctonia solani, has emerged as a significant menace to global rice cultivation, especially with the widespread adoption of high-yielding varieties. The pathogen’s capacity to endure unfavorable conditions and its wide host range contribute to the increased challenge for management. The occurrence of sheath blight in rice is intensified when high-yielding semi-dwarf cultivars are employed, coupled with dense planting and the application of substantial amounts of nitrogenous fertilizers. Managing this pathogen is a formidable challenge due to its broad host range, substantial genetic variability, and the absence of satisfactory levels of natural resistance in the existing rice germplasm. Due to the absence of complete resistance sources, the predominant approach for managing sheath blight has been through chemical control methods. It is imperative to explore solutions to combat this pathogen, in order to reduce rice yield losses and safeguard global food security. Developing genetic resistance provides an alternative to the use of potentially harmful chemical fungicides. This review crucially delivers efforts to enhance the understanding of the host–pathogen relationship, which involves identification of gene loci/markers associated with resistance responses, modification of host genome through transgenic approaches, examining the wide host range, epidemiology and its managemental approaches. Recent advancements and current research on the R. solani–rice pathosystem, along with a gap analysis, are presented.

Exposure patterns and the risk factors of Crimean Congo hemorrhagic fever virus amongst humans, livestock and selected wild animals at the human/livestock/wildlife interface in Isiolo County, upper eastern Kenya.

Crimean Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease caused by CCHF virus (CCHFV). The disease has a complex transmission cycle that involves a wide range of hosts including mammalian and some species of birds. We implemented a sero-epidemiological study in Isiolo County, Kenya, to determine relative seroprevalences of CCHFV in humans, livestock and in wild animals. In addition, we identified subject and environment level factors that could promote exposure to CCHFV. Humans (n = 580) and livestock (n = 2,137) were recruited into the study through a multistage random sampling technique, and in addition, various species of wild animals (n = 87) were also sampled conveniently. Serum samples from all recruited humans and animals were collected and screened for CCHFV antibodies using ID Screen multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The overall anti-CCHFV IgG seroprevalences in humans, cattle, goats, sheep and camels were 7.2% [95% CI: 3.1-15.8%], 53.9% [95% CI: 30.7-50.9%], 11.6% [95% CI: 7.2-22.5%], 8.6% [95% CI: 3-14%] and 89.7% [95% CI: 78-94%], respectively. On average, the sampled wild animals had CCHFV seroprevalence of 41.0% [95% CI: 29.1-49.4%]; giraffes had the highest mean CCHF seroprevalence followed by buffaloes, while impala had very low exposure levels. Statistical analyses using mixed effects logistic regression models showed that CCHFV exposure in humans was significantly associated with male gender, being over 30 years of age and belonging to a household with a seropositive herd. In livestock, a combination of animal- and environment level factors including older animals, being in an area with high normalized difference vegetation index (NDVI) and high vapour pressure deficit were significantly associated with CCHFV infection. Age, sex and species of wild animals were considered as the key risk factors in the analysis, but none of these variables was significant (P-value = 0.891, 0.401 and 0.664, respectively). Additionally, RT-qPCR analysis revealed the presence of CCHFV RNA in camels (30%), cattle (14.3%), and goats (3.8%), but not in humans, sheep, or wild animals. This study demonstrates that environmental factors, such as NDVI and vapor pressure deficit, affect CCHFV exposure in livestock, while the presence of infected livestock is the key determinant of human exposure at the household level. These findings underscore the importance of using One Health approaches to control the disease in human-livestock-wildlife interfaces. For instance, the existing CCHF surveillance measures could be enhanced by incorporating algorithms that simulate disease risk based on the environmental factors identified in the study. Additionally, tick control in livestock, such as the use of acaricides, could reduce CCHFV exposure in livestock and, consequently, in humans.