Animal Diseases Research Articles

Genetic diversity of Theileria spp. in deer (Artiodactyla: Cervidae) from Brazil.

Babesia spp. and Theileria spp. are tick-borne apicomplexan protozoa that can cause disease in animals and humans. Deer are considered reservoirs for a wide variety of Piroplasmida species, including some potentially zoonotic. This study aimed to investigate the occurrence and genetic diversity of piroplasmids in wild deer sampled in four Brazilian states (São Paulo, Mato Grosso do Sul, Paraná and Goiás). For this purpose, extracted DNA samples from 181 deer buffy coat samples (138 Blastocerus dichotomus, 26 Subulo gouazoubira, 4 Mazama jucunda, 3 Mazama rufa and 10 Ozotocerus bezoarticus) were subjected to a nested PCR (nPCR) assay based on the 18S rRNA gene in order to perform a screening for piroplasmids and characterized based on the near-complete 18S rRNA, hsp70 and cox-3 genes. As a result, 75.14% (136/181) samples were positive for piroplasmids. Of these, 108 (79.41%), 101 (74.26%) and 67 (49.26%) were positive to near complete 18S rRNA, hsp70 and cox-3 genes, respectively. Phylogenetic analyses based on three molecular markers showed similar topology to each other. All sequences obtained in the present study were positioned into the Theileria sensu stricto clade, forming a distinct clade, albeit close to T. cervi. Most sequences grouped together into a large clade divided into subclades, which were often related to deer genus/species, showing that Theileria lineages seemed to show specificity according to deer genus/species. Two 18S rRNA sequences (one obtained from S. gouazoubira and another from M. jucunda) were positioned into a different clade, apart from other sequences detected in this study, indicating that different species of Theileria occur in deer from Brazil. Two subclusters were observed in the phylogenetic analysis based on the hsp70 gene: the first containing only sequences detected in marsh deer and the second grouping sequences detected in brocket deer (Mazama spp. and S. gouazoubira). The latter was also divided into smaller clades that grouped Theileria genotypes according to deer species (M. jucunda, M. rufa and S. gouazoubira). This study provides the first molecular evidence of Theileria infection in M. jucunda, as well as co-infection by distinct Theileria (sub)species/genotypes in the same deer was evidenced. Finally, this study expanded the knowledge on the diversity of Theileria spp. infecting deer from South America.

Identification and Characterization of Linear Epitopes of Monoclonal Antibodies Against African Horse Sickness Virus Serotype 1 VP2 Protein

African horse sickness (AHS) is an acute, fatal, contagious disease of animals of the family Equidae and is caused by infection with the African horse sickness virus (AHSV). Based on the outer capsid protein VP2, AHSV is classified into nine serotypes (AHSV−1 to −9) with little or no serological cross-reactivity between them. In 2020, AHS outbreaks caused by AHSV−1 were reported in Thailand and Malaysia, marking the first occurrences of AHS in Southeast Asia. However, little is known about the antigenic profile of AHSV−1 VP2. In this study, a recombinant VP2 protein was expressed in Escherichia coli and used as an immunogen, and three monoclonal antibodies (mAbs), designated 7D11, 10A9, and 9E7, against AHSV−1 VP2, were generated. These three mAbs were then successfully used in IFA, WB, and ELISA for the detection of AHSV−1 VP2. Two overlapping linear epitopes, 670NEFDFE675 (E670–675) recognized by 9E7 and 670NEFDF674 (E670–674) recognized by 7D11 and 10A9, were identified through truncation of GST-fused VP2. Amino acid sequence alignment shows that the 670NEFDFE675 motif is completely conserved within AHSV−1 but is highly divergent in other AHSV serotypes. Our studies provide an important tool for basic research into AHSV−1 and for the diagnosis of AHSV−1.

A Passion for Small Things and Staying Primed: My Career in Virology and Immunology.

A love of science and animals, perseverance, and happenstance propelled my career in veterinary virology and immunology. I have focused on deadly enteric and respiratory viral infections in neonatal livestock and humans with an aim to understand their prevalence, pathogenesis, interspecies transmission, and immunity and develop vaccines. Research on animal coronaviruses (CoVs), including their broad interspecies transmission, provided a foundation to understand emerging zoonotic fatal human respiratory CoVs [severe acute respiratory syndrome, Middle East respiratory syndrome, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)] and reverse zoonosis of SARS-CoV-2 to animals. A highlight of my early research was the discovery of the gut-mammary gland-sIgA axis, documenting a common mucosal immune system. The latter remains pivotal to designing maternal vaccines for passive immunity in neonates. Our discovery and innovative cell propagation of fastidious human and animal rotaviruses and caliciviruses and their infectivity in germ-free animals has provided cell-adapted and animal disease models for ongoing virologic and immunologic investigations and vaccines. Nevertheless, besides the research discoveries, my lasting legacy remains the outstanding mentees who have enriched my science and my life.

Bactericidal activities and biochemical features of 16 antimicrobial peptides against bovine-mastitis causative pathogens.

Mastitis, often caused by bacterial infection, is an inflammatory condition affecting the mammary glands. The condition is particularly prevalent in dairy cattle. Current treatment of bovine mastitis heavily relies on the use of antibiotics. To identify alternative solutions to antibiotic use, we evaluated the antimicrobial activity of 14 cathelicidins reported from 10 animal species. In conjunction, we assessed two bacteriocins against the bovine-mastitis causative bacterial panel, consisting of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus equi. Among the antimicrobial peptides (AMPs), cc-CATH3, ML-CATH, and PD-CATH proved to be highly active (minimum inhibitory concentration of 2-41μg/mL, 0.2-10.3μM) against all bacterial strains in the panel and field isolates from milk, with elevated somatic cell counts (≥ 500,000 cells/mL). Of the AMPs tested in this study, ML-CATH presented the highest level of effectiveness in controlling mastitis-associated bacterial strains while also possessing minimal cytotoxicity and functional stability against pH change and a high salt condition. The results of in silico analyses on the biochemical features of 12 helical cathelicidins revealed that the charge of AMPs appears to be a major determinant in killing Gram-negative bacteria. Furthermore, we observed a unique motif, "N(n≥3)-P(n≥1)-N(n≥3)", from the sequences of PMAP-36, cc-CATH3, ML-CATH, and PD-CATH that exhibits potent antimicrobial activity against a broad spectrum of bacteria compared to others. Our findings support the proposition that AMPs could serve as effective antimicrobial alternatives to conventional antibiotics in treating complex animal diseases caused by microbial infection, such as bovine mastitis.

Soil Mediated Helminthiasis: A Study on Neglected Tropical Disease in Wild Animals in Haryana

Background: Soil mediated/ transmitted helminthiasis (STH/SMH) is a neglected tropical disease and includes Ascarids, Trichuris and Hookworms, which prominently affects population living either in the low sanitary condition or in close proximity with the animals. Recent years have witnessed elevation in the Trichuris infection, with India ranking first globally. Variety of factors including low sanitation, close contact with animals, increased man and wild conflict contribute towards STH. However, co-relation of STH/SMH infection from wildlife have not been studied. Methods: The study was conducted for a period of 1 year from August, 2021 to September, 2022. Trichuris infection was present in 72 out of 131 carcasses of wild animals with prevalence rate of 35%. The prevalence percentage of Trichuris infection in different sub categories of wild animals was calculated. Seasonal prevalence rate was calculated with increased cases reported in summer season followed by monsoon. Additionally, fecal samples, worms and intestinal samples for further studies were collected. Result: Wild animals act as bridge for transmission of various zoonotic diseases. However, zoonotic potential of parasitic diseases are neglected in wild animals with no systematic literature. Based on our study we illustrate that wild animals hold considerate potential plausibly demonstrating an iceberg phenomenon. Wildlife is an essential component in the epidemiology of many, if not most, zoonoses, wildlife should be taken into account in the risk analysis framework.

Screening and Characterization of Sialic Acid-Binding Variable Lymphocyte Receptors from Hagfish

Sialic acid is a diverse group of monosaccharides often found on the termini of N- and O-linked glycans as well as being components of glycoconjugates. Hypersialylation has been associated with the progression of chronic inflammation-mediated diseases such as cardiovascular disease and cancer. Given its role in infection and disease-related processes, sialic acid is a promising target for therapeutic approaches that utilize carbohydrate-binding molecules. In this study, we screened for sialic acid-recognizing variable lymphocyte receptors (VLRBs) or ccombodies from inshore hagfish (Eptatretus burgeri) using a synthetic Neu5Ac-glycoconjugate as an antigen in immunoassay. Resulting ccombodies, 2D8, 5G11, 4A1, and 5F8 were further characterized in terms of their binding activity and specificity. A competitive ELISA using free haptens showed strong inhibition using either N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc). The half-maximal inhibitory concentrations (IC50) for Neu5Ac ranged from 7.02 to 17.06 mM, with candidates 4A1 and 5G11 requiring the least and highest amounts, respectively. IC50 values for Neu5Gc ranged from 8.12 to 13.91 mM, for 4A1 and 5G11, respectively. Candidate ccombodies also detected naturally occurring sialic acid from known sialoglycoproteins using a dot blot assay. Neu5Gc-5G11 and Neu5Ac-2D8 yielded the strongest and weakest docking interactions with affinity values of −5.9 kcal/mol and −4.9 kcal/mol, respectively. Hydrogen bonding and hydrophobic interactions were predicted to be the predominant noncovalent forces observed between the ccombodies and sialic acid. This study demonstrates that glycan-binding VLRBs from hagfish hold promise in augmenting the glycobiologists’ toolkit in investigating the roles of glycans in human and animal health and disease.

Nomenclature for human and animal fungal pathogens and diseases: a proposal for standardized terminology.

Medically important pathogenic fungi invade vertebrate tissue and are considered primary when part of their nature life cycle is associated with an animal host and are usually able to infect immunocompetent hosts. Opportunistic fungal pathogens complete their life cycle in environmental habitats or occur as commensals within or on the vertebrate body, but under certain conditions can thrive upon infecting humans. The extent of host damage in opportunistic infections largely depends on the portal and modality of entry as well as on the host's immune and metabolic status. Diseases caused by primary pathogens and common opportunists, causing the top approximately 80% of fungal diseases [D. W. Denning, Lancet Infect Dis, 24:e428-e438, 2024, https://doi.org/10.1016/S1473-3099(23)00692-8], tend to follow a predictive pattern, while those by occasional opportunists are more variable. For this reason, it is recommended that diseases caused by primary pathogens and the common opportunists are named after the etiologic agent, for example, histoplasmosis and aspergillosis, while this should not be done for occasional opportunists that should be named as [causative fungus] [clinical syndrome], for example, Alternaria alternata cutaneous infection. The addition of a descriptor that identifies the location or clinical type of infection is required, as the general name alone may cover widely different clinical syndromes, for example, "rhinocerebral mucormycosis." A list of major recommended human and animal disease entities (nomenclature) is provided in alignment with their causative agents. Fungal disease names may encompass several genera of etiologic agents, consequently being less susceptible to taxonomic changes of the causative species, for example, mucormycosis covers numerous mucormycetous molds.

A multiplex qPCR followed by high-resolution melting analysis for the detection of blood-feeding sources in Culex sp. mosquitoes.

Culex species, such as Culex quinquefasciatus and Culex nigripalpus display a range of feeding habits and act as vectors for pathogens that can cause diseases in both humans and animals. Understanding their feeding habits is pivotal for enhancing disease prevention strategies. The present study introduces the application of two multiplex real-time PCR (qPCR) followed by high-resolution melting (HRM) as a cost-effective and time-efficient alternative. This investigation involved the development of two multiplex qPCR-HRM: assay 1 detects human, dog and chicken, while assay 2 detects cat, cattle and horse in Culex sp. engorged female mosquitoes. The qPCR-HRM reactions showed a detection limit of one copy of genomic DNA when performed as single and multiplex qPCR-HRM. The reaction efficiencies were 97.96% for human, 100.60% for dog, 99.03% for chicken, 99.92% for feline, 99.18% for cattle and 97.68% for horse. The qPCR-HRM method, employing multiplex 1 and 2, was applied to field-collected mosquitoes and demonstrated the ability to detect DNA from multiple blood sources within a single sample. By analysing both multiplexes, it was possible to identify up to five distinct blood sources in Cx. quinquefasciatus and Cx. nigripalpus, and up to two sources in Culex coronatus. Sequencing corroborated the qPCR-HRM results, confirming the presence of DNA from one to four different blood sources with 100% accuracy. The development of these molecular methods may contribute for identification of blood-feeding patterns in mosquitoes. It contributes to studies on the dissemination and transmission of pathogens among various animals and humans, thereby bridging the gap between epidemiology and vector monitoring.

Antioxidant Potential of Medicinal Plants in the Treatment of Scabies Infestation

Oxidative stress, characterized by an overproduction of reactive oxygen species that overwhelm the body’s physiological defense mechanisms, is a key factor in the progression of parasitic diseases in both humans and animals. Scabies, a highly contagious dermatological condition caused by the mite Sarcoptes scabiei var. hominis, affects millions globally, particularly in developing regions. The infestation leads to severe itching and skin rashes, triggered by allergic reactions to the mites, their eggs, and feces. Conventional scabies treatments typically involve the use of scabicidal agents, which, although effective, are often associated with adverse side effects and the increasing threat of resistance. In light of these limitations, there is growing interest in the use of medicinal plants as alternative therapeutic options. Medicinal plants, rich in bioactive compounds with antioxidant properties, offer a promising, safer, and potentially more effective approach to treatment. This review explores the role of oxidative stress in scabies pathogenesis and highlights how medicinal plants can mitigate this by reducing inflammation and oxidative damage, thereby alleviating symptoms and improving patient outcomes. Through their natural antioxidant potential, these plants may serve as viable alternatives or complementary therapies in the management of scabies, especially in cases where resistance to conventional treatments is emerging.

ReportFishDisease: a GPS-enabled mobile application for supporting e-governance in aquatic animal disease management through systematic disease reporting and surveillance

ReportFishDisease: a GPS-enabled mobile application for supporting e-governance in aquatic animal disease management through systematic disease reporting and surveillance

A Micro-Flow Liquid Chromatography-Mass Spectrometry Method for the Quantification of Oxylipins in Volume-Limited Human Plasma.

Oxylipins are well-known lipid mediators in various inflammatory conditions. Their endogenous concentrations range from low picomolar to nanomolar, and there are growing demands to determine their concentrations in low-volume matrices for pathological studies, including blood, cerebrospinal fluids from animal disease models, infants, and microsampling devices. Most of the published quantification methods for comprehensive profiling of oxylipins still require more than 50µL plasma as a starting volume to detect these low levels. The aim of our study is to develop a sensitive and reliable method for the quantification of oxylipins in volume-limited human plasma samples. We established and validated a micro-liquid chromatography (LC)-mass spectrometry (MS)/MS method that requires only 5µL of human plasma for the determination of 66 oxylipins. The optimized micro-LC-MS/MS method utilized a flow rate of 4µL/min with a 0.3-mm inner diameter column. With an injection volume of 3µL, our method provides limits of detection in the range from 0.1 to 91.9pM, and limits of quantification range from 0.3 to 306.2pM. The sensitivity enhancement compared to conventional flow ranged from 1.4 to 180.7 times for 51 compounds depending on their physical-chemical properties. After validation, the method was applied to analyze 40 plasma samples from a healthy aging study to demonstrate robustness and sensitivity.

Public, Private and Public-Private Partnerships (PPP) to Implement a One Health Approach to Combat Antimicrobial Resistance in Colombia

Abstract The establishment of public-private partnerships (PPPs) within Colombia, Latin America, is a recent, innovative effort within the nation’s agricultural industry to tackle antimicrobial resistance (AMR) under a One Health approach. PPPs are a formal alliance between representatives from the public and private sectors that aim to promote cross-sectoral collaboration, stewardship and accountability. Members agree on shared objectives and responsibilities, resources and risks to establish monitoring, prevention and mitigation activities against AMR within the farming industry. Key learnings of this initiative within the context of Colombia include: maximisation of results when monitoring is assigned to the private sector, and this may apply to other lower-middle-income countries (LMICs); objectives are better achieved when they are pre-defined according to time, budget and human resource constraints of member institutions; and confidentiality agreements must be consistent with the sensitive nature of surveillance information. Barriers to implementation were also identified, such as frequent changes of government personnel at decision making levels that make governance planning and adaptation challenging, while legal formalities and bureaucracy hinder formalisation of agreements. The success of this PPP is a useful example for other LMICs to aid in the control and prevention of animal diseases, promotion of food safety and reduction in poor animal health which limit commerce, while at the same time, minimising production loss and ensuring the provision of a fair income for producers. Information © The Authors 2024

Spiral of Silence: Consumer Attention, Media Emotion, and Pork Price Fluctuations

This study utilized web crawling and text analysis to collect weekly data from July 2018 to March 2022. Using the spiral of silence theoretical framework, it explores the relationship between consumer online attention during sudden animal epidemics and pork price volatility. The research found that consumer online attention, influenced by animal disease outbreaks, significantly intensifies pork price volatility both directly and indirectly through changes in media sentiment and consumer expectations. On the one hand, the sentiment in official media reports partially mediates the relationship between consumer attention and pork price volatility. As consumer attention increases, positive sentiment in official media also rises, exerting an indirect stabilizing effect on pork prices. On the other hand, consumer expectations also have a partial mediating role, and the volume of negative news reports from unofficial media significantly amplifies the impact of consumer attention on pork price volatility. These findings provide valuable insights into the relationship between consumer online attention and market fluctuations in the agricultural sector and offer practical recommendations for enhancing demand-side management strategies.

Characterization and complete genome sequence of highly lytic phage active against methicillin-resistant Staphylococcus aureus (MRSA) isolated from Egypt

BackgroundMethicillin-Resistant Staphylococcus aureus (MRSA) is one of the most resistant bacteria to antibiotics. S. aureus is an important, widespread pathogen that can cause a variety of infectious diseases in humans and animals. Phages have been recognized as natural, safe, highly specific and effective alternatives agents to antibiotics for preventing and treating bacterial infections caused by MRSA. Therefore, this study aims at the characterization of a novel isolated lytic phage, vB_SauP_ASUmrsa123.MethodsIsolates of Staphylococcus aureus MRSA were obtained on Mannitol Salt Agar and Baird Parker Agar plates and confirmed using VITEK 2. Sewage and clinical samples were used to isolate specific phages for S. aureus MRSA, and plaque assays were used for host range determination on Luria-Bertani (LB) media. The phage morphology of the isolated phage was determined by transmission electron microscopy. The phage’s whole genome sequencing was identified.ResultsA total of 25 isolates of Staphylococci were obtained from different clinical sources and showed typical colonies on Baird-Parker and Mannitol Salt Agar plates. The VITEK 2 automated system revealed that all 25 isolates were confirmed as S. aureus (MRSA). Two of the most antibiotics-resistant isolates were further confirmed using 16S ribosomal RNA sequencing. A lytic phage was detected against the MRSA isolates tested In Vitro, namely vB_SauP_ASUmrsa123. The phage belonged to Rountreeviridae family based on morphological properties observed by TEM and the host range of the isolated phage was tested on the 25 clinical MRSA isolates in Vitro. The one-step growth curve of the isolated phage showed that the latent period was about 55 min, and the burst size was estimated at 167 PFU. The whole genome sequencing and annotation of genes revealed that phage vB_SauP_ASUmrsa123 contained a linear dsDNA with a size of about 17,155 bp with predicted 24 ORFs. Analysis of its genome provides valuable information approximately the variety of phages belonging to the staphylococcal phages class I.ConclusionA lytic Podo Phage vB_SauP_ASUmrsa123 was identified against S. aureus MRSA isolates and its genome was sequenced. The phage was found to be eligible for potential application in biocontrol.

A novel sensing probe based on AuNPs-Apt for the detection of enrofloxacin

Enrofloxacin (ENR), as a synthetic broad-spectrum antibiotic is widely utilized in veterinary medicine to treat animal diseases and promote livestock growth, it can inhibit bacterial DNA gyrase subunit A, thereby preventing bacterial DNA replication and exerting its antibacterial effect. However, excessive use of enrofloxacin poses significant risks to ecological balance and human health due to residual contamination. We have developed a novel ENR aptamer sensor based on the gold nanoparticles/aptamer (AuNPs-Apt) complexes, in which AuNPs were synthesized via the seed method and functionalized with aptamers. The optical properties, particle size, functional groups and morphology of the AuNPs-Apt probe were characterized by transmission electron microscope, Fourier transform infrared spectrometer and UV-vis spectrophotometer, respectively. The aptamer biosensor can specifically identify enrofloxacin, with a wide detection range (0.05-100μg ml-1) and a good linear relationship (R2=0.99) within the detection range. In addition, the biosensor also has the advantages of short detection time, low biological toxicity, good stability, and low detection cost. Therefore, it shows a great prospect for practical application in the field of detecting enrofloxacin residues.

Identification and mapping of objects targeted for surveillance and their role as risk factors for brucellosis in livestock farms in Kazakhstan.

Objects for Targeted Surveillance (OTS) are infrastructure entities that can be considered as focal points and conduits for transmitting infectious animal diseases, necessitating ongoing epidemiological surveillance. These entities encompass slaughterhouses, meat processing plants, animal markets, burial sites, veterinary laboratories, etc. Currently, in Kazakhstan, a funded research project is underway to establish a Geographic Information System (GIS) database of OTSs and investigate their role in the emergence and dissemination of infectious livestock diseases. This initial investigation examined the correlation between brucellosis outbreaks in cattle and small ruminant farms in the southeastern region of Kazakhstan and the presence of OTSs categorized as "slaughterhouses," "cattle markets," and "meat processing plants. The study area (namely Qyzylorda, Turkestan, Zhambyl, Almaty, Zhetysu, Abay and East Kazakhstan oblasts), characterized by the highest livestock density in the country, covers 335 slaughterhouses (with varying levels of biosecurity), 45 livestock markets and 15 meat processing plants. Between 2020 and 2023, 338 cases of brucellosis were reported from livestock farms in this region. The findings of the regression model reveal a statistically significant (p<0.05) positive association between the incidence of brucellosis cases and the number of OTSs in the region. Conversely, meat processing plants and livestock markets did not exhibit a significant influence on the prevalence of brucellosis cases. These results corroborate the hypothesis of an elevated risk of brucellosis transmission in regions with slaughterhouses, likely attributable to increased animal movements within and across regions, interactions with vehicles and contact with slaughterhouse staff. These outcomes mark a pivotal advancement in the national agricultural development agenda. The research will be extended to encompass the entire country, compiling a comprehensive OTS database.

Phenotypic, Molecular Identification and Virulence Assessment of Cronobacter spp Isolated from Clinical Samples of Children Under Two Years in Mosul City/Iraq

Cronobacter spp. is known to be a foodborne causative agent for a variety of diseases in both humans and animals. This study focused on isolating Cronobacter species from 150 clinical samples of children under two years (60 from blood and stool samples, 30 from CSF samples) collected from Ibn al Atheer and Al Khanssa Hospitals. The phenotypic identification of bacterial isolates were performed through culture, microscopic, and biochemical examinations and vitek-2 system. The results revealed a mixture of bacteria in 6.5% of the clinical specimens. The identity of isolates was 99% using the vitek-2 system for identifying Cronobacter sakazakii, Cronobacter malonaticus, Cronobacter muytjensii, and Cronobacter pulveris. Out of 150 specimens there were 8 (5.33 %) of specimens gave positive for Cronobacter spp which included: C. sakazaki 2/60 blood specimens (3.3%), C. sakazaki 2/60 stool specimens (3.3%), C. malonaticus 2/60 stool specimens (3.3%), 1/60 C. muytjensii and C. pulveris 1/60 (3.3%). The eight isolates phenotypically identified as Cronobacter were confirmed at the molecular level through 16S rRNA sequencing and submitted to NCBI under the accession numbers (OR825874, OR825875, PP126443, PP126444, PP126445, PP126455). The virulence profile of these isolates showed that 7/8 (87.5%) of Cronobacter strains exhibited haemolysin activity, 5/8 strains (62.5%) were able to produce the protease enzyme and 2/8 (25%) of Cronobacter strains were positive for lipase and lecithinase. All strains lacked the ability to produce a slime layer. The results also showed the ability of Cronobacter strains to produce biofilm by using the tube method and microtiter plate method but with different levels.

Skrjabingylus chitwoodorum in a rabies-positive striped skunk in Texas.

We describe here a case of the sinus roundworm, Skrjabingylus chitwoodorum, found incidentally in a rabies-positive striped skunk (Mephitis mephitis) in Texas, USA. Skunks serve as a natural definitive host for this metastrongylid nematode in North America, in which infections result in observable damage to the host cranium, where adult parasites reside. Additionally, skunks are considered the primary reservoir of rabies in Texas. In November 2022, the animal was discovered in northern Texas displaying neurologic signs before euthanasia and submission to the Oklahoma Animal Disease Diagnostic Laboratory for rabies testing. Direct fluorescent antibody testing indicated that the animal was rabies-positive, and, upon tissue collection, numerous adult nematodes were recovered from the cranium and identified as S. chitwoodorum by morphology and amplification of the mitochondrial cytochrome c oxidase subunit I gene. Histologically, we found lymphohistiocytic meningitis in several loci and chronic sinusitis rostral to the cribriform plate. Due to behavioral abnormalities, we additionally tested for Toxoplasma gondii via PCR, but no parasite DNA was detected. Concurrent infection by S. chitwoodorum and rabies virus may contribute to neurologic signs in skunks.

The impact of aquatic animal disease information on consumer evaluation of the origin of juvenile shrimp for aquaculture

The impact of aquatic animal disease information on consumer evaluation of the origin of juvenile shrimp for aquaculture

Development of a whole-cell SELEX process to select species-specific aptamers against Aspergillus niger

BackgroundSpores produced by the filamentous fungus Aspergillus niger are abundant in a variety of environments. The proliferation of this fungus in indoor environments has been associated to health risks and its conidia can cause allergic reaction and severe invasive disease in animals and humans. Therefore, the detection and monitoring of Aspergillus conidia is of utmost importance to prevent serious fungal infections and contaminations. Among others, aptamers could serve as biosensors for the specific detection of fungal spores.ResultsIn this study, DNA aptamers specific to conidia of A. niger were developed by optimizing a whole-cell SELEX approach. Three whole-cells SELEX experiments were performed in parallel with similar conditions. Quantification of recovered ssDNA and melting curve analyses were applied to monitor the ongoing SELEX process. Next-generation sequencing was performed on selected recovered ssDNA pools, allowing the identification of DNA aptamers which bind with high affinity to the target cells. The developed aptamers were shown to be species-specific, being able to bind to A. niger but not to A. tubingensis or to A. nidulans. The binding affinity of two aptamers (AN01-R9-006 and AN02-R9-185) was measured to be 58.97 nM and 138.71 nM, respectively, which is in the range of previously developed aptamers.ConclusionsThis study demonstrates that species-specific aptamers can be successfully developed via whole-cell SELEX to distinguish different Aspergillus species and opens up new opportunities in the field of diagnostics of fungal infections.