Infectious Agents Research Articles

Modeling spatiotemporal dynamics of Amblyomma americanum questing activity in the central Great Plains.

Ticks represent important vectors of a number of bacterial and viral disease agents, owing to their hematophagous nature and their questing behavior (the process in which they seek new hosts). Questing activity is notably seasonal with spatiotemporal dynamics that needs to be understood in detail as part of mediating and mitigating tick-borne disease risk. Models of the geography of tick questing activity developed to date, however, have ignored the temporal dimensions of that behavior; more fundamentally, they have often not considered the sampling underlying available occurrence data. Here, we have addressed these shortfalls for Amblyomma americanum, the most commonly encountered tick in the central Great Plains, via (1) detailed, longitudinal sampling to characterize the spatiotemporal dimensions of tick questing activity; (2) randomization tests to establish in which environmental dimensions a species is manifesting selective use; and (3) modeling methods that include both presence data and absence data, taking fullest advantage of the information available in the data resource. The outcome was a detailed picture of geographic and temporal variation in suitability for the species through the two-year course of this study. Such models that take full advantage of available information will be crucial in understanding the risk of tick-borne disease into the future.

Preliminary Insights into Sustainable Control of Solanum lycopersicum Early Blight: Harnessing Arbuscular Mycorrhizal Fungi and Reducing Fungicide Dose

Tomato (Solanum lycopersicum L.) production is constantly threatened by several fungal pathogens, such as Alternaria solani, the causal agent of early blight disease. In this study, a greenhouse experiment was set up to evaluate the biocontrol ability of arbuscular mycorrhizal fungi (AMF) against A. solani in the presence of reduced doses of fungicides (i.e., captan and copper oxychloride). Disease severity, plant growth traits, chlorophyll and phosphorus content, phenolic compounds, and antioxidant activity were assessed. The effects of fungicide dose on AMF were investigated by root colonization, spore density, and mycorrhizal dependence evaluation. AMF-inoculated and fungicide-treated plants reduced disease severity compared to fungicide-treated and non-mycorrhizal plants, in most cases, regardless of the fungicide dose. AMF improved plant growth, especially when combined with copper oxychloride. However, plant fresh weight decreased in plants treated with the lowest dose of captan (25 g 100 L−1). Overall, AMF colonization decreased in plants with high fungicide doses, while the leaf color parameters did not show differences between treatments. The results suggest reducing the fungicide dose using AMF is possible, particularly for copper oxychloride. Further studies will be required to confirm these data. This integrated approach could offer a sustainable alternative to decrease the use of chemical control.

The Detection of Chlamydia pneumoniae, Helicobacter pylori and Cytomegalovirus in Non-Atherosclerotic Arteries of Patients with Coronary Artery Disease

Atherosclerotic coronary artery disease (ACAD) is a major cause of global morbidity and mortality, characterized as an inflammatory process due to damage to blood vessel walls by risk factors like aging, hyperlipidemia, hypertension, smoking, and diabetes. Infectious agents, including Chlamydia pneumoniae (Cpn), Cytomegalovirus (CMV), and Helicobacter pylori (HP), have been implicated in ACAD’s pathophysiology. A study with 56 subjects undergoing coronary artery bypass grafting (CABG) aimed to detect Cpn, CMV, and HP DNA in unaffected artery segments and explore associations with disease progression and inflammation markers. The study found infectious agents’ DNA in 21.4% of samples, HP in eight samples, and CMV and Cpn in four samples each. Significant correlations were observed between HP and overweight or obese subjects, as well as between the presence of infectious agents and inflammation marker values. An association between HP and renal function was also noted. The findings reaffirm previous discoveries of infectious agents in non-clinically affected arteries used as CABG grafts. Correlations identified between the presence of HP, CMV, and Cpn DNA in grafts and several biomarkers of inflammation and obesity emphasize the potential role of these infectious agents in ACAD pathogenesis.

Chinese Populations of Magnaporthe oryzae Serving as a Source of Human-Mediated Gene Flow to Asian Countries: A Population Genomic Analysis

Magnaporthe oryzae, a filamentous heterothallic ascomycete fungus that serves as the causative agent of rice blast disease, is globally distributed in rice-growing regions. Populations shaped by environmental factors and human intervention play important roles in the formation of genetic structure. In this study, population structures and spatiotemporal dynamics were investigated based on large-scale whole genomic sequences of rice-infecting M. oryzae around the world. By analyzing these genetic structures, we identified divergent clades that crossed geographic boundaries. While we observed associations between the isolates and their geographic origins, we also found that there were frequent migration events occurring across Asia in main rice cultivation regions. Within Asia, China was the migration origin, facilitating gene flows to Japan and South Korea. Since the 1970s, the genetic diversity of M. oryzae populations in China has also shown a steadily increasing trend, continuing through to the 2020s. Additionally, our analysis of the evolutionary history of Asian M. oryzae populations provided insights into the population expansion that has taken place in recent decades. Overall, our findings indicate that human-mediated gene flows played a pivotal role in shaping the genetic structure of M. oryzae.

Allergic rhinitis: a brief overview of the etiopathogenesis and rehabilitation of patients

The article presents a brief overview of modern literature sources concerning the prevalence, etiopathogenetic approaches in the diagnosis and treatment of allergic rhinitis. The relevance of the problem under consideration is due to the high prevalence of this pathology, the variety of etiopathogenetic mechanisms and the variability of classifications. One of the most popular classifications is seasonal. When studying pathogenetic mechanisms, the following patterns were revealed: the nasal mucosa is the main air conditioner of the respiratory tract and the first line of defense against infectious agents transmitted by airborne droplets. These roles require maintaining and restoring epithelial integrity and the ability to initiate immune responses. When conditions or factors are present that compromise the integrity of the mucosa, the epithelium releases alarmins and other molecular patterns associated with damage that trigger repair mechanisms but can also cause protective inflammation. In allergic rhinitis, the same mechanisms can activate the development of the disease. Many authors consider various diagnostic methods for allergic rhinitis. Such as a detailed and competent collection of complaints and anamnesis, including family history, physical examination, endoscopic examination of the nasal cavity, rhinomanometry, skin prick tests, radiological studies, including computed tomography of the paranasal sinuses, intradermal tests, study of total and specific immunoglobulins E in blood serum, basophil activation test, nasal provocation test, nasal cytology and biopsy histology, acoustic rhinometry, nasal inspiratory peak flow testing, and nitric oxide measurements are used. Attention is also paid to laboratory and instrumental methods for the differential diagnosis of rhinitis of pseudoallergic origin; the following methods are used: ultrasound diagnostics of the hepatobiliary system, biochemical blood test, and immunological studies. Treatment of patients with allergic rhinitis requires an integrated and interdisciplinary approach and, of course, requires differential and personalized methods taking into account etiopathogenetic mechanisms.

Cardiac Manifestations of Lyme Disease.

Lyme disease (LD) is an inflammatory disorder caused by an infectious bacterial agent and is the most common tick-borne illness in the United States and Europe. About 1.5-10% of adults infected with LD develop cardiac complications. This review summarizes the current knowledge of the epidemiology, pathophysiology, and diagnosis of Lyme carditis (LC), as well as the different manifestations of LD in the cardiovascular system. This review will primarily highlight the effect of LD on the cardiac conduction system and also discuss its effect on the myocardium, pericardium, valves, and coronary arteries. The management and prognosis of LC will be reviewed here as well. While this is a comprehensive review of the current literature on LC, there remain many questions regarding the complex relationship between LD and the heart.

Caspase-1 in Cx3cr1-expressing cells drives an IL-18-dependent T cell response that promotes parasite control during acute Toxoplasma gondii infection.

Inflammasome activation is a robust innate immune mechanism that promotes inflammatory responses through the release of alarmins and leaderless cytokines, including IL-1α, IL-1β, and IL-18. Various stimuli, including infectious agents and cellular stress, cause inflammasomes to assemble and activate caspase-1. Then, caspase-1 cleaves targets that lead to pore formation and leaderless cytokine activation and release. Toxoplasma gondii has been shown to promote inflammasome formation, but the cell types utilizing caspase-1 and the downstream effects on immunological outcomes during acute in vivo infection have not been explored. Here, using knockout mice, we examine the role of caspase-1 responses during acute T. gondii infection globally and in Cx3cr1-positive populations. We provide in vivo evidence that caspase-1 expression is critical for, IL-18 release, optimal interferon-γ (IFN-γ) production, monocyte and neutrophil recruitment to the site of infection, and parasite control. Specifically, we find that caspase-1 expression in Cx3cr1-positive cells drives IL-18 release, which potentiates CD4+ T cell IFN-γ production and parasite control. Notably, our Cx3cr1-Casp1 knockouts exhibited a selective T cell defect, mirroring the phenotype observed in Il18 knockouts. In further support of this finding, treatment of Cx3cr1-Casp1 knockout mice with recombinant IL-18 restored CD4+ T cell IFN-γ responses and parasite control. Additionally, we show that neutrophil recruitment is dependent on IL-1 receptor accessory protein (IL-1RAP) signaling but is dispensable for parasite control. Overall, these experiments highlight the multifaceted role of caspase-1 in multiple cell populations contributing to specific pathways that collectively contribute to caspase-1 dependent immunity to T. gondii.

Comparative ecological analysis and predictive modeling of tick-borne pathogens.

Tick-borne diseases constitute the predominant vector-borne health threat in North America. Recent observations have noted a significant expansion in the range of the black-legged tick (Ixodes scapularis Say, Acari: Ixodidae), alongside a rise in the incidence of diseases caused by its transmitted pathogens: Borrelia burgdorferi Johnson (Spirochaetales: Spirochaetaceae), Babesia microti Starcovici (Piroplasmida: Babesiidae), and Anaplasma phagocytophilium Zhu (Rickettsiales: Anaplasmataceae), the causative agents of Lyme disease, babesiosis, and anaplasmosis, respectively. Prior research identified environmental features that influence the ecological dynamics of I. scapularis and B. burgdorferi that can be used to predict the distribution and abundance of these organisms, and thus Lyme disease risk. In contrast, there is a paucity of research into the environmental determinants of B. microti and A. phagocytophilium. Here, we use over a decade of surveillance data to model the impact of environmental features on the infection prevalence of these increasingly common human pathogens in ticks across New York State (NYS). Our findings reveal a consistent northward and westward expansion of B. microti in NYS from 2009 to 2019, while the range of A. phagocytophilum varied at fine spatial scales. We constructed biogeographic models using data from over 650 site-year visits and encompassing more than 250 environmental variables to accurately forecast infection prevalence for each pathogen to a future year that was not included in model training. Several environmental features were identified to have divergent effects on the pathogens, revealing potential ecological differences governing their distribution and abundance. These validated biogeographic models have applicability for disease prevention efforts.

Solanum pimpinellifolium exhibits complex genetic resistance to Pseudomonas syringae pv. tomato

Pseudomonas syringae pv. tomato (Pst) is the causal agent of bacterial speck disease in tomatoes. The Pto/Prf gene cluster from Solanum pimpinellifolium was introgressed into several modern tomato cultivars and provided protection against Pst race 0 strains for many decades. However, virulent Pst race 1 strains that evade Pto-mediated immunity now predominate in tomato-growing regions worldwide. Here we report the identification of resistance to a Pst race 1 strain (Pst19) in the wild tomato accession S. pimpinellifolium LA1589 (hereafter LA1589), using our rapid high-throughput seedling screen. LA1589 supports less bacterial growth than cultivars, and does not exhibit a hypersensitive response to Pst19. We tested an existing set of 87 Inbred Backcross Lines (IBLs) derived from a cross between susceptible Solanum lycopersicum E-6203 and Solanum pimpinellifolium LA1589 for resistance to Pst19. Using single-marker analysis, we identified three genomic regions associated with resistance. Bacterial growth assays on IBLs confirmed that these regions contribute to resistance in planta. We also mapped candidate genes associated with resistance in a cross between the Solanum lycopersicum var. lycopersicum cultivar Heinz BG-1706 and S. pimpinellifolium LA1589. By comparing candidates from the two mapping approaches, we were able to identify 3 QTL and 5 candidate genes in LA1589 for a role in resistance to Pst19. This work will assist in molecular marker-assisted breeding to protect tomato from bacterial speck disease.

Lipschütz ulcer following first dose of COVID-19 tozinameran vaccine: Report of a case and review of a World Health Organization pharmacovigilance database.

Lipschütz ulcer (LU) is a condition known for painful vulvar ulcers, typically affecting young women and often linked to infectious agents. Recent reports have indicated a potential connection between LU and COVID-19 vaccination, particularly after the second or booster doses. This study presents a case of LU following the first dose of tozinameran in a young woman who had a previous SARS-CoV-2 infection and investigates similar cases globally. An 18-year-old woman experienced vulvar pain and ulcers 2-days after her initial COVID-19 vaccine dose. After ruling out infections through serological tests, a diagnosis of LU was made, and her symptoms resolved after 10 days. A literature search and VigiBase® analysis revealed 11 cases of LU following COVID-19 vaccination, and 519 vulvovaginal ulcer cases associated with these vaccines were identified in Vigibase®, with a median onset of 2 days. Most LU cases occurred after the second dose or booster shots. The primary hypothesis for this association is a type 3 hypersensitivity reaction mediated by immune complexes, possibly triggered by prior exposure, as many cases occurred after the second dose. Interestingly, the presented case suggests that prior COVID-19 infection could serve as sensitization. In conclusion, this study highlights the potential occurrence of LU after the initial COVID-19 vaccine dose in young patients with prior COVID-19 infection. While the risk of recurrence after subsequent vaccinations or infections remains uncertain, the benefits of vaccination outweigh the risks. Clinicians and patients should be aware of this potential issue to make informed decisions regarding vaccination.

Effects of COVID-19 pandemic on epidemiological features of viral respiratory tract infections in children: a single-centre study.

The epidemiology of respiratory infections may vary depending on factors such as climate changes, geographical features, and urbanization. Pandemics also change the epidemiological characteristics of not only the relevant infectious agent itself but also other infectious agents. This study aims to assess the impact of the COVID-19 pandemic on the epidemiology of viral respiratory infections in children. We retrospectively reviewed the medical records of children aged ≤18years with laboratory-confirmed viral respiratory infections other than COVID-19 from January 2018 to March 2023. Data on demographic characteristics, month and year of admission, and microbiological results were collected. During the study period, 1,829 respiratory samples were sent for polymerase chain reaction testing. Rhinovirus was identified in 24% of the patients, mixed infections in 21%, influenza virus in 20%, and respiratory syncytial virus in 12.5%. A 38.6% decrease in viral respiratory infections was observed in 2020, followed by a 188% increase in 2021. The respiratory syncytial virus was significantly more common in the post-pandemic period (13.8%) compared to the pre-pandemic period (8.1%), but no seasonal shift in respiratory syncytial virus infection was observed. There was also a yearly increase in influenza infections in the post-pandemic period compared to the pre-pandemic period. After the COVID-19 pandemic, the frequency of parainfluenza virus infections increased during the summer months, and this finding provides a new contribution to the existing literature.

Molecular characterization and immunopathological investigation of Avian reticuloendotheliosis virus in breeder flocks in Egypt

BackgroundReticuloendotheliosis virus (REV) is an oncogenic immunosuppressive retrovirus that infects different kinds of avian species; posing significant economic losses to the poultry industry worldwide.MethodsIn Egypt, there is an unidentified disease associated with the runting-stunting syndrome with neoplasia, suspected to be REV, that has been continuously monitored in several breeder flocks. To diagnose and analyze REV by cell cultures, enzyme-linked immunosorbent assay (ELISA), histopathological investigation, the polymerase chain reaction (PCR) test, and sequencing analysis, 200 blood samples, and 50 tissue specimens were collected. The current study targets the occurrence and genetic characteristics of a viral neoplastic disease, resembling REV infection, circulating in breeder flocks from 2022 to 2023 in the Ismailia, El-Sharqia, and El-Dakahliya governorates.ResultHere, REV was isolated on chicken embryo fibroblast cell culture; exhibiting cell aggregation, rounding, and cell detachments. Collectively, only 70 serum samples were positive for anti‐REV antibodies with seroprevalence rates of 35% based on the ELISA test. The histopathological observation demonstrated lymphoreticular tumors in the liver, spleen, and other examined organs. The immunohistochemical staining method confirmed the REV-positive signals in all examined organs (liver, kidney, spleen, bursa, ovaries) except for the heart. The PCR assay of the LTR gene assessed 370 base pairs with only 5 positive samples with a percentage of 16.6%. Three positive samples were further sequenced and submitted to the Genbank under accession numbers (PP763709, PP763710, PP763711). Phylogenetic analysis of the REV-LTR gene showed that our three isolates (Sharquia-1-REV, Ismilia-2-REV, Mansoura-3-REV) are REV subtype III which predominantly circulated in breeders in Egypt. These three isolates are highest similar to American, Chinese, and Taiwanese REV reference strains, and other Egyptian strains with nucleotide identity percentages of 100%, 99%, and 99%; respectively, and on the amino acid identity level were with (99–100%), (98%, 99%), (99%, 100%); respectively.ConclusionsThis study established that REV infection was extensively distributed in the breeders and became one of the causes of the clinical outbreaks of tumors, raising awareness of REV as the causative agent of avian oncogenic disease in Egypt.

Improving Biomedical Science Literacy and Patient-Directed Knowledge of Tuberculosis (TB): A Cross-Sectional Infodemiology Study Examining Readability of Patient-Facing TB Information

BackgroundTuberculosis (TB) continues be the leading cause of death globally due to an infectious agent. There is a paucity of data describing the readability of patient-facing TB information for service users. The aim of this study was to calculate the readability of multiple global TB information sources.MethodsInformation on tuberculosis (n = 150 sources) included nine categories, Patient-facing information: WHO publications (n = 17), International governments (n = 19), Hospitals (n = 10), Non-government organisations (NGOs)/charities (n = 20), Cochrane Plain Language Summaries (n = 20); LabTestsOnlineUK (n = 4) and Scientific-facing information: Clinical trials (n = 20), Cochrane abstracts (n = 20), Scientific abstracts (n = 20). Readability was calculated using Readable software, defined by (i) Flesch Reading Ease (FRE), (ii) Flesch-Kincaid Grade Level (FKGL), (iii) Gunning Fog Index and (iv) SMOG Index and two text metrics [words/sentence, syllables/word].ResultsMean readability values for TB information for the FRE and FKGL were 35.6 ± 1.6 (standard error of mean (SEM)) (US Target ≥60; UK Target ≥90) and 12.3 ± 0.3 (US Target ≤8; UK Target ≤6), respectively, with mean words per sentence and syllables per word of 17.2 and 1.8, respectively. Cochrane Plain Language Summaries had similar readability scores to their matching scientific abstract (p = 0.15). LabTestsOnlineUK yielded a mean FRE score of 51.5 ± 1.2, a mean FKGL score of 10.2 ± 0.5 and text metric scores of 16.7 ± 2.3 and 1.6, for words per sentence and syllables per word, respectively. In descending order, TB information from international governments, hospitals and LabTestsOnlineUK were the most readable (FRE = 57.9, 54.1 and 51.5, respectively), whereas scientific abstracts and Cochrane abstracts were the most difficult to read (13.0 and 30.2, respectively).ConclusionPatient-facing TB information analysed had poor readability. Effective communication of biomedical science concepts and information relating to TB is vital for service users to enhance their health literacy of tuberculosis, thereby promoting better clinical outcomes. Biomedical scientists are important custodians of scientific information for their service user populations, including other healthcare professionals within the TB multidisciplinary (MDT) team and patient service users. When preparing TB information, this should be checked and modified in real time employing readability calculators, to align with health readability targets.

Bronchiectasis Exacerbations: Are We Doing Everything We Can?

At the European Respiratory Society (ERS) Congress 2024, two experts in bronchiectasis, Pieter Goeminne, Department of Respiratory Diseases, Vitaz Saint-Nicholas Hospitals, Belgium, and Michal Shteinberg, Pulmonology Institute and CF Center – Carmel Medical Center; Israel Institute of Technology; and The B. Rappaport Faculty of Medicine, Haifa, Israel, discussed bronchiectasis’ pathogenesis and exacerbations, along with unmet needs regarding diagnosis and treatment. Bronchiectasis is a chronic and progressive inflammatory disease with a rising prevalence. Commonly associated conditions/related comorbidities of bronchiectasis include post-infective diseases and other airway conditions (such as chronic obstructive pulmonary disease [COPD] and asthma), although the cause of bronchiectasis may remain unknown in over a third of patients. Development of bronchiectasis involves the intersection of four pathogenic components: chronic infections, airway ciliary dysfunction, chronic inflammation (mostly neutrophilic), and structural lung damage, commonly known as the ‘vicious vortex.’ In particular, bronchiectasis development, progression, and exacerbation also involve upregulated and dysregulated neutrophil function. Exacerbations in bronchiectasis are marked by symptoms of increased cough, sputum changes, decreased lung function, and fatigue, among others. Careful clinical examination and awareness of bronchiectasis symptoms are needed to properly diagnose and treat the initial condition and prevent exacerbations. Triggers for exacerbations can be endogenous, such as neutrophil or eosinophil increases, as well as exogenous, including the presence of infectious agents and pollution. Research regarding treatment for bronchiectasis is limited, but European guidelines recommend airway clearance techniques and antibiotics during exacerbations. To enable more targeted treatment for bronchiectasis from first occurrence, to limit exacerbations, and during an exacerbation, there are unmet needs for better identification of resistant genes, treatments for pathogens and inflammation, and biomarkers of exacerbation triggers.

Case-control study on associations of hemorrhagic bowel syndrome in swine with feed characteristics and intestinal pathogens

Haemorrhagic bowel syndrome (HBS) is one of the most common causes of death in fattening pigs worldwide. The objective of this descriptive study was to systematically assess predictors or causal components for the appearance of HBS using case farms (mortality rate caused by HBS ≥ 1.5%) in comparison with control farms (mortality rate caused by HBS ≤ 0.25%), focusing on feed ingredients, feed quality and size, and gastrointestinal pathogens. The inclusion of sugar beet as a feed component in liquid feeding systems was found to be associated (p = 0.03) with farms identified as HBS cases. Another predictive or causal factor found for liquid feeding systems, but only for those using meal, was particle size. A higher percentage of small particles (< 2 mm) in the meal was associated with a higher risk of being an HBS case farm (p = 0.02), while no relevant association was detected for the use of pellets. Sugar beet in the diet was also associated with the incidence of HBS.The microbial quality of the feed in dry feeding systems, specifically the number of total aerobes at the first and last outlet tubes, was associated with a higher incidence of HBS (p = 0.03). Faecal sample analysis showed a difference (p < 0.05) in the prevalence of B. pilosicoli in the herd category (case vs. control herd). In this descriptive study, five predictive or causal factors were identified for an HBS farm with a mortality rate due to HBS ≥ 1.5%. These included the number of aerobes in dry matter samples from the first and last feeders, the particle diameter of the meal used in liquid feeding systems and sugar beet as a component of liquid feeding rations, and the presence of B. pilosicoli as an infectious agent at animal level. Relevant associations reinforce the findings of the previously published Swiss study that HBS is a multifactorial syndrome involving different aspects of pig production and cannot be attributed to a single cause. Further studies are needed to develop evidenced based causal models for HBS in swine.

Effect of bacteriophage on histopathology and disease resistance of Whiteleg shrimp (Litopenaeus vannamei) infected by Vibrio parahaemolyticus

Vibrio parahaemolyticus is the causative agent of shrimp diseases, the most serious of which is acute hepatopancreatic necrosis disease (AHPND). Bacteriophage is a virus of bacteria that can parasitize and destroy bacteria, so it is considered a potential alternative to antibiotics. The study was carried out to evaluate the treatment ability of bacteriophages on Litopenaeus vannamei after being infected by V. parahaemolyticus B4XOT2.2 isolated from the bottom mud of shrimp ponds infected with AHPND. The study used the histopathological survey method on shrimp at all three ages: postlarvae, adult shrimp at the ages of 30–45 days, and 55–60 days old, which were arranged into three treatments: healthy shrimp, diseased shrimp, and bacteriophage-treated shrimp. The results showed that: the concentration of Vibrio spp. in bacteriophage-treated treatment was decreased in all three groups (postlarvae, shrimp at the ages of 30–45 days, and 55–60 days old) from 3,7x103 CFU/mL to 2,2x102 CFU/mL after two days, from 4,6x104 CFU/mL to 3,3x102 CFU/mL after two days and from 4,6x104 CFU/mL to 5,6x103 CFU/mL after three days, respectively. The pathological signs and histological features of the infected shrimp samples were similar to those typical of acute hepatopancreatic necrosis disease and recovered in shrimp tissue after being treated with bacteriophages such as the hepatopancreas was also darker, the intestines gradually filled, no hematoma around the tubules were found, in the lumen of the tube reduced sloughing cells and blood cells, no melanization was observed.

Pathogens from salmon aquaculture in relation to conservation of wild Pacific salmon in Canada.

The spread of pathogens from farmed salmon is a conservation concern for wild Pacific salmon in British Columbia (BC), Canada. Three pathogens are prevalent in farmed Atlantic salmon in BC, spill over to wild Pacific salmon, and are linked to negative impacts on wild salmon: Piscine orthoreovirus, Tenacibaculum spp., and sea lice (Lepeophtheirus salmonis). Molecular screening of infectious agents in farmed and wild salmon and environmental DNA highlights a further 4 agents that are likely elevated near salmon farms and 37 that co-occur in wild and farmed salmon. Pathogens likely affect wild salmon indirectly by mediating migration, competition, and predation. Current net-pen aquaculture practices pose these risks to numerous populations of all species of wild salmon in BC, most of which are not covered in Government of Canada science and advisory reports. Climate change, pathogen evolution, and changes to disease management and aquaculture regulations will influence future risks.

Semisynthetic Ecdysteroid Cinnamate Esters and tert-Butyl Oxime Ether Derivatives with Trypanocidal Activity.

The parasite Trypanosoma cruzi is the causative agent of Chagas disease, a neglected tropical disease that affects the lives of millions of indigenous people in Latin America. As medications to treat Chagas disease are limited to the application of benznidazole and nifurtimox, which are not ideal treatments for the chronic stage of the disease, the search for new antichagasic drug candidates is an important need. Ecdysone has previously been shown to interfere with the life cycle of T. cruzi. Here, we report the biological profiling and subsequent semisynthetic structure optimization of 47 ecdysteroids against T. cruzi with the aim of identifying selective trypanocidal ecdysteroids. Two moderately trypanocidal pharmacophores were identified: ecdysteroids containing a 6-tert-butyl oxime ether and a cinnamic ester moiety. These functional groups were combined into the structures of four new semisynthetic ecdysteroids (44-47), among which 44 exerted potent and selective trypanocidal activity (IC50 < 2 μM). Cellular infection assays showed that ecdysteroid 44 potently and efficiently inhibited amastigote replication as determined by trypomastigote release after cellular infection with an IC50 of 2.7 ± 0.1 μM. The compound was similarly potent to benznidazole (IC50 = 3.8 ± 0.7 μM) and more than 5-fold more cytotoxic toward T. cruzi over RAW264.7 host macrophages. Overall, the ecdysteroid cinnamate ester 44 is a novel trypanocidal lead structure that needs to be further characterized in follow-up studies.

Viable Trypanosoma cruzi cultured from a dead Paratriatoma lecticularia (Hemiptera: Reduviidae) encountered in a large dog kennel environment in south Texas, USA.

Trypanosoma cruzi (Chagas, 1909) is a protozoan parasite transmitted by triatomine (Hemiptera: Reduviidae) insects and is the causative agent of Chagas disease. Oral transmission of the parasite occurs through consumption of contaminated food or infected triatomines and may depend on the degree to which T. cruzi survives in triatomine abdomens. Dead triatomines may be abundant in areas with insecticide use, such as dog kennels where animals may encounter them. We attempted to culture T. cruzi from the gut material of 108 triatomines collected near dog kennels-14 found alive and 94 found dead-and also tested for T. cruzi DNA and discrete typing units using PCR. In total, 30 (27.8%) tested positive for T. cruzi using PCR, 5 alive (35.7%) and 25 dead (26.6%), with no difference in infection between insects found alive versus dead (P-value = 0.53) and more PCR positives identified in dead triatomines with intact gut contents than in dead desiccated triatomines (P-value = 0.049). One Paratriatoma lecticularia (Stål, 1859) that was found dead (1.1%, n = 94) had T. cruzi growth in culture. Given the use of bleach for external decontamination of triatomines as well as the level of bacterial and fungal contamination of cultures, both of which may have impacted the growth of T. cruzi, the apparent prevalence of viable parasites in this study should be interpreted as a conservative estimate. Vector control initiatives should consider that dead insects may still pose a risk of T. cruzi transmission to animals and humans.

Platelet Indices in Patients With Gram-Negative and Gram-Positive Sepsis: A Retrospective Cross-Sectional Study.

Different inflammatory processes and sepsis can significantly affect the number of platelets and platelet indices. Therefore, in this study, total platelet count (PLT), thrombocrit (Pct), platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) were analyzed in patients with Gram-negative and Gram-positive bacterial sepsis and in sterile blood cultures. Inclusion criteria were an increased number of inflammatory parameters (elevated values ​​of leukocytes,C-reactive protein (CRP), procalcitonin (PCT), andpositive blood culture. Exclusion criteria were patients who did not have elevated values ​​of inflammatory parameters and did not have a positive blood culture.Samples were collected from patients who had sepsis confirmed by blood cultures at the Department of Microbiology and Molecular Diagnostics at University Clinical Hospital Mostar in the period from 2019 to 2022. Three groups were analyzed, patients who had sterile blood cultures, patients with blood cultures with isolated Gram-positive bacteria, and patients with blood cultures with isolated Gram-negative bacteria. Specific infectious agents were identified for each group of patients. In addition to the above, PLT, Pct, MPV, PDW, P-LCR, PCT, CRP, the total number of leukocytes, and the number of neutrophil leukocytes were analyzed in each group. The values of PCT, CRP, and the number of neutrophile leukocytes were significantly higher in patients with Gram-negative sepsis as compared to Gram-positive sepsis and to control group. Patients with sepsis have decreased PLT and Ptc and increased values of MPV, PDW, and P-LCR. In sepsis caused by the Gram-negative bacteria, i.e., Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii, the values of the same parameters were more changed compared to sepsis caused by Gram-positive bacteria, i.e., Streptococcus pneumoniae, Enterococcus spp., and methicillin-resistant Staphylococcus aureus (MRSA). When comparing Gram-negative negative bacteria, PLT was lowest in sepsis caused by Escherichia coli, the PDW value was highest in sepsis caused by Acinetobacter baumannii, and MPV and P-LCR were the highest in sepsis caused by Klebsiella pneumoniae. Our study showed that platelet indices are significantly changed in patients with sepsis. Patients with sepsis have decreased values of PLT and Pct and increased values of MPV, PDW, and P-LCR, indicating an increase in thrombocyte production. Moreover, the results were more prominent in sepsis caused by Gram-negative bacteria compared to sepsis caused by Gram-positive bacteria.