Potential Pathogen Transmission Research Articles

A survey of Phlebotomine sand flies across their northern distribution range limit in Western Europe

Abstract Sand flies are vectors of Leishmania spp. protozoa, phleboviruses and Bartonella bacilliformis. In this study we surveyed areas of central-western Europe, encompassing the northern limit of the known sand fly distribution, and investigated the relationship between their presence and environmental variables. In this area, very limited occurrence data exists, none of them recent. Sampling was performed in July and August 2023 using CDC-light traps, sticky traps and human landing captures, at 179 selected sites in 48 municipalities. A total of 55 sand fly specimens were collected at 11% (20/179) of the sites sampled – including 16 sites in France, 2 in Luxembourg and 1 in Germany – comprising the first published records for Luxembourg and the Trier-Saarburg County of Germany. No sand flies were detected in Belgium or in the Netherlands. Two species were captured: Phlebotomus mascittii (37 females, 2 males) and Ph. perniciosus (1 female, 15 males). The latter species was only found in Savoie, the southernmost region sampled in France, while the former species was detected as far north as latitude 50°N. Logistic regression modelling indicated that the probability of sand fly presence gradually decreased with increasing latitude and altitude (P < 0.05), and it was not associated to other analysed landscape features in the proximity of the traps. The study confirms and provides new evidence for the presence of sand flies in areas of Western Europe and highlights the need to be aware of potential autochthonous transmission of sand fly-borne pathogens in these areas.

A review of Musca sorbens (Diptera: Muscidae) and Musca domestica behavior and responses to chemical and visual cues.

Musca flies (Diptera: Muscidae) have been found culpable in the mechanical transmission of several infectious agents, including viruses, bacteria, protozoans, and helminths, particularly in low-income settings in tropical regions. In large numbers, these flies can negatively impact the health of communities and their livestock through the transmission of pathogens. In some parts of the world, Musca sorbens is of particular importance because it has been linked with the transmission of trachoma, a leading cause of preventable and irreversible blindness or visual impairment caused by Chlamydia trachomatis, but the contribution these flies make to trachoma transmission has not been quantified and even less is known for other pathogens. Current tools for control and monitoring of house flies remain fairly rudimentary and have focused on the use of environmental management, insecticides, traps, and sticky papers. Given that the behaviors of flies are triggered by chemical cues from their environment, monitoring approaches may be improved by focusing on those activities that are associated with nuisance behaviors or with potential pathogen transmission, and there are opportunities to improve fly control by exploiting behaviors toward semiochemicals that act as attractants or repellents. We review current knowledge on the odor and visual cues that affect the behavior of M. sorbens and Musca domestica, with the aim of better understanding how these can be exploited to support disease monitoring and guide the development of more effective control strategies.

Genomic signatures of hybridization between Ixodes ricinus and Ixodes persulcatus in natural populations.

Identifying hybridization between common pathogen vectors is essential due to the major public health implications through risks associated with hybrid's enhanced pathogen transmission potential. The hard-ticks Ixodes ricinus and Ixodes persulcatus are the two most common vectors of tick-borne pathogens that affect human and animal health in Europe. Ixodes ricinus is a known native species in Finland with a well-known distribution, whereas I. persulcatus has expanded in range and abundance over the past 60 years, and currently it appears the most common tick species in certain areas in Finland. Here we used double-digest restriction site-associated DNA (ddRAD) sequencing on 186 ticks (morphologically identified as 92 I. ricinus, and 94 I. persulcatus) collected across Finland to investigate whether RAD generated single nucleotide polymorphisms (SNPs) can discriminate tick species and identify potential hybridization events. Two different clustering methods were used to assign specific species based on how they clustered and identified hybrids among them. We were able to discriminate between the two tick species and identified 11 putative hybrids with admixed genomic proportions ranging from approximately 24 to 76 percent. Four of these hybrids were morphologically identified as I. ricinus while the remaining seven were identified as I. persulcatus. Our results thus indicate that RAD SNPs are robust in identifying both species of the ticks as well as putative hybrids. These results further suggest ongoing hybridization between I. ricinus and I. persulcatus in their natural populations in Finland. The unique ability of RAD markers to discriminate between tick species and hybrids adds a useful aspect to tick evolutionary studies. Our findings align with previous studies and suggest a shared evolutionary history between the species, with instances of individuals possessing a considerable proportion of the other species' genome. This study is a significant step in understanding the formation of hybridization zones due to range expansion potentially associated with climate change.

Monitoring and analysis of pathogenic microorganisms and resistance genes.

The objectives are to improve the rapid identification method of microbial risk and cut off the route of transmission of resistance genes. When new pathogenic microorganisms are found, intervention can be carried out as early as possible to identify the risk of potential pathogen transmission, and timely cut off the transmission route. Hospital air samples were collected to analyse the distribution of environmental pathogenic microorganisms and the characteristics of ARGs resistance genes. The air samples were collected from 12 sampling sites in the Affiliated Hospital of Yangzhou University. In the infusion room, general ward and intensive care unit, no significant difference was found in microorganisms, and no significant difference was found in microbial resistance genes. There were some differences in resistance genes between east and west districts. Combined with the detection of pathogenic microorganisms and resistance genes in our hospital, it is necessary to improve the daily disinfection measures such as air conditioning and fresh air equipment, cut off the infection route, block the transmission of resistance genes, and monitor pathogens and resistance genes in airborne diseases.

Donor screening for fecal microbiota transplantation with a direct stool testing-based strategy: a prospective cohort study

Fecal microbiota transplantation (FMT) is effective against recurrent Clostridioides difficile infection (rCDI), but its safety is jeopardized by the potential transmission of pathogens, so international guidelines recommend either a quarantine or a direct stool testing. Whereas reports of the quarantine-based approach are emerging, data on the direct testing-based approach are not available. Our aim is to report outcomes of a donor screening framework for FMT including direct stool testing.In this prospective cohort study, all donor candidates recruited at our FMT centre underwent a four-step screening process to be enrolled as actual donors. Each collected stool donation was then evaluated with a direct stool testing including a molecular assay for gut pathogens and a culture assay for multi-drug resistant organisms (MDRO).From January 2019 to June 2023, 72 of 227 candidates (32%) were considered eligible and provided 277 stool donations. Ninety-nine donations (36%) were discarded for positivity to intestinal pathogens, most commonly enteropathogenic Escherichia coli (n = 37) and Blastocystis hominis (n = 20). Overall, 337 stool aliquots were obtained from 165 approved donations. All suspensions were used for patients with rCDI, and no serious adverse events or clinically evident infections were observed at 12 weeks after procedures.In our study, screening of donor faeces including direct stool testing led to the discard of a considerable rate of stool donations but was also extremely safe. This approach may represent a reliable strategy to guarantee the safety of FMT programs, especially in countries with high prevalence of MDRO.

Distribution of antibiotic resistant bacteria and genes in sewage and surrounding environment of Tórshavn, Faroe Islands

Several studies have investigated the effects of swimming in sewage-polluted recreational beach water, highlighting the associated health hazards. To mitigate potential pathogen transmission, it is imperative that the polluted water is released away from recreational waters and foreshores, where children tend to play. At present, domestic sewage in the Faroe Islands solely undergoes primary wastewater treatment within primary settling tanks before being discharged into the ocean. Effluents are a major anthropogenic source of antibiotic resistance genes and antibiotic resistant bacteria, which are released into the environment. The aim of this study was to investigate antibiotic resistant Gram-negative bacteria and antibiotic resistance genes in influents and effluents of wastewater subjected solely to primary treatment, along with their release into the environment during both summer and winter. Water samples were collected from influents and effluents as well as with increasing distance away from the wastewater outlet and from nearby tidepools. Samples were cultured on MacConkey agar with four different antibiotics for detection of antibiotic-resistant bacteria and antibiotic resistance genes were quantified by droplet digital PCR. All multi-drug resistant bacteria were identified using the API 20E kit. We observed an overall decrease of the abundance of Gram-negative bacteria from the effluents compared to influents, however, we observed the opposite trend in the antibiotic resistance genes. Antibiotic resistant bacteria and antibiotic resistance genes in addition to multi-drug resistant bacteria were found in the surrounding oceanic and several terrestrial tidepool samples. Of the multi-drug resistant bacteria, we found, e.g., Escherichia coli, P. aeruginosa, and A. hydrophila species, which can be pathogenic, potentially causing an infection if encountering a host. These results indicate a relatively wide pollution range of the effluents from the septic tank and treated sewage released into the environment, posing a potential hazard for both humans and wildlife.

Effectiveness of respiratory protective equipment on source control of exhaled pollutants

Respiratory protective equipment (RPE) is used either to protect the wearer (protection effect during inhalation) or to protect others from potential transmission of pathogens from the wearer (source control effect during exhalation). Inhalation and exhalation are two processes that generate microenvironments with different characteristics inside the RPE. In order to quantitatively evaluate the source control effectiveness (SCE) of RPE, the gap size between the RPE and the face was measured using volunteers, and the tracer-gas-based method and aerosol-based method were applied to visualize and quantify the dispersion of exhaled pollutants through the face mask and the gap using a manikin. The tracer-gas-based method (using CO2) largely overestimated the concentration of exhaled pollutants in front of the RPE. The SCE of RPE was 76–99% for aerosols and 79–92% for tracer gas. The top gap of the face mask was the dominant leakage route of exhaled pollutants. When the size of the top gap increased from 8 mm to 20 mm, the SCE for aerosols smaller than 1 μm decreased by about 15%. The SCE of the combined RPE with an N95 mask and a face shield was about 7% higher than that for an N95 mask alone. Increasing the pulmonary ventilation rate from 6 to 13 L/min and the respiratory cycle from 3 to 5 s decreased the SCE of RPE by 16% and 9%, respectively, indicating the importance of considering the activity level. The data obtained provides a basis for evaluating and improving the performance of RPE.

Preparing Collared Peccary (Pecari tajacu Linnaeus, 1758) for Reintroduction into the Wild: A Screening for Parasites and Hemopathogens of a Captive Population.

The reintroduction of captive animals to the wild helps restore endangered species, but it risks pathogen transmission, harming wild populations. Such transmission can impact the genetic diversity and long-term viability of these populations. This study assessed parasite diversity and load in captive Pecari tajacu, a species native to the Americas and culturally significant to Brazilian indigenous culture, prior to reintroduction. Samples from 24 peccaries were analyzed for ectoparasites, hemopathogens, and stool parasites with direct and molecular analysis. Findings showed that various parasites were present. Two peccaries (8.3%) were infested by the adult tick Amblyomma sculptum. Six (25.0%) tested positive for Trypanosoma evansi, four (16.7%) for hemobacteria of the family Anaplasmataceae, twelve (50.0%) for hemotropic Mycoplasma, and seven (29.2%) for Leishmania braziliensis. Stool samples indicated multiple parasites, with sixteen (66.7%) peccaries infected by Strongylida order parasites, Spiruridae in three (12.5%), and Ascaris suum in one (4.2%) animal. Cysts of Balantidium sp. were found in twenty (83.3%), Entamoeba polecki in five (20.8%), and Iodamoeba bütschlii in two (8.3%) peccaries. To our current knowledge, this is the first global report of Leishmania braziliensis, Iodamoeba bütschlii, and Entamoeba polecki in P. tajacu, irrespective of the environment, including both captivity and wild conditions. Some of these parasites are common in domestic animals, and others are zoonotic, indicating potential interspecies pathogen transmission.

Future research perspective on the interfacial physics of non-invasive glaucoma testing in pathogen transmission from the eyes.

Non-contact tonometry (NCT) is a non-invasive ophthalmologic technique to measure intraocular pressure (IOP) using an air puff for routine glaucoma testing. Although IOP measurement using NCT has been perfected over many years, various phenomenological aspects of interfacial physics, fluid structure interaction, waves on corneal surface, and pathogen transmission routes to name a few are inherently unexplored. Research investigating the interdisciplinary physics of the ocular biointerface and of the NCT procedure is sparse and hence remains to be explored in sufficient depth. In this perspective piece, we introduce NCT and propose future research prospects that can be undertaken for a better understanding of the various hydrodynamic processes that occur during NCT from a pathogen transmission viewpoint. In particular, the research directions include the characterization and measurement of the incoming air puff, understanding the complex fluid-solid interactions occurring between the air puff and the human eye for measuring IOP, investigating the various waves that form and travel; tear film breakup and subsequent droplet formation mechanisms at various spatiotemporal length scales. Further, from an ocular disease transmission perspective, the disintegration of the tear film into droplets and aerosols poses a potential pathogen transmission route during NCT for pathogens residing in nasolacrimal and nasopharynx pathways. Adequate precautions by opthalmologist and medical practioners are therefore necessary to conduct the IOP measurements in a clinically safer way to prevent the risk associated with pathogen transmission from ocular diseases like conjunctivitis, keratitis, and COVID-19 during the NCT procedure.

Transfluthrin diffusers do not protect two-person US military tents from mosquitoes in open field and canopy warm-temperate habitats

Spatial repellents are volatile or volatilized chemicals that may repel arthropod vectors in free space, preventing bites and reducing the potential for pathogen transmission. In a 21-week field study, we investigated the efficacy of passive transfluthrin-impregnated diffusers placed in two-person United States (US) military tents located in canopy and open field habitats in north Florida to prevent mosquitoes from entering. Mosquito collections with US Centers for Disease Control and Prevention traps baited with light and carbon dioxide were conducted weekly for weeks 0–4, every two weeks for weeks 5–10, and monthly for weeks 11–21. Our results demonstrated that these transfluthrin-impregnated devices did not function as spatial repellents as expected and did not create a mosquito-free zone of protection. Instead, we observed consistently higher collections of mosquitoes from tents with transfluthrin-impregnated diffusers, and higher rates of mosquito mortality in collections from tents with transfluthrin diffusers, compared to untreated control tents. Based on these findings we do not recommend the use of passive transfluthrin-impregnated diffusers for mosquito protection in two-person US military tents in warm-temperate environments similar to north Florida.

ASSESSMENT OF Staphylococcus aureus PREVALENCE IN VEGETABLES SOLD AT LOCAL MARKETS IN BENIN CITY: IMPLICATIONS FOR FOOD SAFETY.

Vegetables are an essential part of people's diet globally but they could aid the transmission of potential pathogens and channel the dissemination of resistance genes. This study aimed at evaluating the prevalence and antibiogram profile of Staphylococcus aureus in vegetables obtained from local markets in Benin City, Nigeria. A total of 50 fresh vegetables were collected from five local markets and investigated. These include 15 green leafs (Amaranthus tricolor), 15 water leafs (Talinum fruticosum), and 20 pumpkin leafs (Telfairia occidentalis). The samples were screened for Staphylococcus aureus using cultural, biochemical and Analytical Profile Index (API) Staph 32 identification protocols. The phenotypic characterization of antibiotic resistance was evaluated using the Kirby-Bauer disc diffusion technique. The distribution of Staphylococcus aureus as observed was green leafs [3/14 (21.4%)], water leafs [6/14 (42.9%)] and pumpkin leafs [5/14 (35.7%)]. The distribution of Staphylococcus aureus based on market location was showed the highest occurrence at the Oba market (40%) and New Benin market (40%) while the least occurrence was observed at New-market (10%). Overall, the total Staphylococcus aureus positive samples were 14/50 (28.0%) in all markets. The antibiotic-resistance profile of Staphylococcus aureus demonstrated by the isolates showed that the highest resistance was recorded for penicillin while no resistance was observed for nitrofurantoin and gentamicin. The multiple antibiotic resistance (MAR) index of Staphylococcus aureus in this study ranged from 0.14 – 0.71. Findings from this study and observed retail practices in local markets ascertained the possibility of vegetables getting contaminated via unhygienic agronomic and food handling practices.

Nutritional stress compromises mosquito fitness and antiviral immunity, while enhancing dengue virus infection susceptibility

Diet-induced nutritional stress can influence pathogen transmission potential in mosquitoes by impacting life history traits, infection susceptibility, and immunity. To investigate these effects, we manipulate mosquito diets at larval and adult stages, creating two nutritional levels (low and normal), and expose adults to dengue virus (DENV). We observe that egg number is reduced by nutritional stress at both stages and viral exposure separately and jointly, while the likelihood of laying eggs is exclusively influenced by adult nutritional stress. Adult nutritional stress alone shortens survival, while any pairwise combination between both-stage stress and viral exposure have a synergistic effect. Additionally, adult nutritional stress increases susceptibility to DENV infection, while larval nutritional stress likely has a similar effect operating via smaller body size. Furthermore, adult nutritional stress negatively impacts viral titers in infected mosquitoes; however, some survive and show increased titers over time. The immune response to DENV infection is overall suppressed by larval and adult nutritional stress, with specific genes related to Toll, JAK-STAT, and Imd immune signaling pathways, and antimicrobial peptides being downregulated. Our findings underscore the importance of nutritional stress in shaping mosquito traits, infection outcomes, and immune responses, all of which impact the vectorial capacity for DENV transmission.

Echolocation call characterization of insectivorous bats from caves and karst areas in southern Luzon Island, Philippines

Bats are excellent bioindicators and are increasingly used to assess ecosystem health and monitor changes in the environment. Due to increased awareness of the potential transmission of pathogens from bats to humans and recognizing the limitations of traditional bat sampling methods, the use of of non-invasive sampling techniques such as bat recorders were recommended for field-based monitoring studies. In the Philippines, however, bat bioacoustics is still a growing field, and the scarcity of acoustic data hinders the use of echolocation calls to conduct accurate inventories and population monitoring of echolocating bats. Here, we recorded and characterized echolocation calls of insectivorous bats from caves and karst areas located in southern Luzon Island, Philippines. In addition, we compared our results with other studies performed within and outside the country to identify possible regional and local variation in acoustic characters for some species. A total of 441 echolocation calls were recorded from six bat families: Hipposideridae (five species), Rhinolophidae (five species), Vespertilionidae (three species), Miniopteridae (two species), Megadermatidae (one species), and Emballonuridae (one species). Discriminant function analyses (DFA) with leave-one-out cross validation correctly classified bats emitting calls dominated with a constant frequency (CF) component (rhinolophids and hipposiderids) with >97% success and those producing frequency modulated (FM) calls (Miniopteridae and Vespertilionidae) with 88.9% success. We report echolocation calls for Philippine population of two species (Megaderma spasma and Hipposideros lekaguli) for the first time. Moreover, we present geographical variations in call frequencies for some species by comparing previously reported acoustic data elsewhere across the species’ range. This underscores the importance of establishing a readily accessible and comprehensive local reference library of echolocation calls which would serve as a valuable resource for examining taxonomic identities of echolocating bats, particularly those whose calls exhibit biogeographic variations.

Characterization of complete mitochondrial genome of three Horse flies of the genus Tabanus (Diptera: Tabanidae): comparative analysis.

Tabanidae (Horse-Flies or Deer-Flies) are one of the most economically important as well as medically significant haematophagous insect family within the order Diptera. Members of this group are also responsible for the mortality of substantial number of live-stock every year. Due to their pathogen transmission potential and vector competencies makes them an important insect group to study. Till now, mitochondrial genome of 18 species of tabanids were available. The complete mitogenome of three species T. diversifrons (15,809bp), T. rubidus (15,878bp) and T. tenens (15,872bp) were generated by Next generation sequencing method. They consist 37 genes, with a positive AT skew and a negative GC skew. The gene order of these three species is similar to the typical gene arrangement of infra-order Tabanomorpha. Most of the tRNAs showed typical clover-leaf secondary structure except trnS1, which lacks the DHU arm. The sliding window analysis showed that thenad4L is the most conserved while atp8, and nad6 are the most variable genes. Moreover, the ratios of non-synonymous to synonymous substitution rates indicated that all PCGs under the purifying selection. Phylogeny revealed Chrysops and Haematopota are monophyletic while species of Hybomitra are nested within the polyphyletic clade of Tabanus. T. diversifrons exhibits sister relationship with Atylotus miser. Two morphologically divergent species T. rubidus and T. tenens are found to be genetically similar and indistinguishable by mitochondrial genome. The hypervariable genes like atp8 and nad6 can be used as molecular markers for the identification of recently diverged lineages of family Tabanidae. Further, to address uncertainties arising from the two morphological divergent species, it is imperative to obtain data from nuclear gene markers.

Seasonal changes in network connectivity and consequences for pathogen transmission in a solitary carnivore

Seasonal variation in habitat use and animal behavior can alter host contact patterns with potential consequences for pathogen transmission dynamics. The endangered Florida panther (Puma concolor coryi) has experienced significant pathogen-induced mortality and continues to be at risk of future epidemics. Prior research has found increased panther movement in Florida’s dry versus wet seasons, which may affect panther population connectivity and seasonally increase potential pathogen transmission. Our objective was to determine if Florida panthers are more spatially connected in dry seasons relative to wet seasons, and test if identified connectivity differences resulted in divergent predicted epidemic dynamics. We leveraged extensive panther telemetry data to construct seasonal panther home range overlap networks over an 11 year period. We tested for differences in network connectivity, and used observed network characteristics to simulate transmission of a broad range of pathogens through dry and wet season networks. We found that panthers were more spatially connected in dry seasons than wet seasons. Further, these differences resulted in a trend toward larger and longer pathogen outbreaks when epidemics were initiated in the dry season. Our results demonstrate that seasonal variation in behavioral patterns—even among largely solitary species—can have substantial impacts on epidemic dynamics.

Biosecurity: A holistic One-Health concept for enhancing the health, welfare, and productivity of commercial poultry - A point of view. Proceeding of The First International Avian Influenza Summit, University of Arkansas- October 16-17, 2023”

The poultry industry plays a pivotal role in meeting global demands for protein-rich food. However, it faces significant challenges due to emerging infectious diseases, environmental concerns, and ethical considerations surrounding animal welfare. This abstract presents a comprehensive perspective on the integration of biosecurity measures within the framework of One Health, with the aim of enhancing the overall health, welfare, and productivity of commercial poultry operations. The concept of One Health emphasizes the interconnectedness of human, animal, and environmental health. Applied to the poultry industry, this approach acknowledges the potential transmission of pathogens between animals, humans, and the environment, emphasizing the need for coordinated strategies. Biosecurity emerges as a central component, encompassing a multifaceted set of preventive measures designed to mitigate risks and safeguard the health of poultry populations. Key elements of an effective biosecurity program include physical barriers, hygiene protocols, vaccination strategies, and rigorous disease monitoring and surveillance. These measures are bolstered by the implementation of strict quarantine protocols for newly introduced birds, as well as restricted access to farms and controlled movements within the premises. Moreover, biosecurity extends beyond the farm gate, involving collaboration with veterinarians, government agencies, and industry stakeholders to establish best practices and response plans. Improving the welfare of commercial poultry is another critical aspect of this holistic approach. This involves providing optimal living conditions, access to clean water, balanced nutrition, and appropriate space allowances. Enrichment strategies, such as environmental enhancements and behavioral opportunities, contribute to the overall well-being of the birds, reducing stress and enhancing their natural behaviors. Furthermore, the integration of biosecurity and One Health principles positively impacts the productivity of commercial poultry operations. Reduced disease incidence leads to lower mortality rates and increased flock performance, translating to higher production efficiency. Additionally, improved welfare conditions contribute to reduced behavioral issues, resulting in better growth rates and feed conversion ratios. In conclusion, the adoption of biosecurity measures within the framework of One Health offers a comprehensive strategy for enhancing the health, welfare, and productivity of commercial poultry. This integrated approach not only mitigates the risks posed by emerging diseases but also addresses environmental and ethical concerns associated with poultry production. By embracing this holistic concept, stakeholders in the poultry industry can achieve sustainable and responsible production practices, ensuring the long-term viability of this crucial sector in global food security.

Technology development and industrialization trends of circulating nutrient solution supply systems: a review

Hydroponics, a soil-free plant cultivation technique, delivers nutrients directly to roots through a nutrient-rich solution. This method offers advantages over traditional soil-based approaches and has gained attention for its potential to revolutionize controlled agriculture. The review aimed to offer a summary of technological advancements and industrialization patterns in systems supplying circulating nutrient solutions. An intelligent nutrient management system enhances plant growth and productivity. The utilization of a circulating hydroponic cultivation setup can reduce environmental pollution and lower production expenses. As a result, circulating nutrient solution management systems are gaining global popularity, such as in the Netherlands, circular hydroponic cultivation has been advanced to over 95%. A limitation of circulation-type nutrient solution cultivation is the potential transmission and rapid formulation of pathogens during the recycling of discharged nutrient solutions. Addressing this concern, filtration and sterilization processes can offer viable solutions. To accelerate hydroponic farming, an integrated approach could be pursued, strengthen nutrient circulation management technology. This approach could aid in the implementation of such systems in countries like the Republic of Korea, where adoption of circulating hydroponic systems remains under 5%. The trend of technological advancement and industrial growth has been conducted through patent analysis and resources that have subsequently lead the way for the advancement of extensive hydroponic farming establishments. The cyclic hydroponic cultivation in the Republic of Korea was introduced in 2010, and based on the patent information, this endeavor gained momentum from 2020 onward. Furthermore, the analysis underscores the considerable potential of circulating nutrient solution supply systems as viable approaches for promoting sustainable and efficient food production. As a result, forthcoming research and innovation need to be tailored to the local context and prioritize user-centered methodologies, ultimately facilitating the integration and establishment of hydroponic systems in the Republic of Korea.

Manufacturing Processes of a Purified Microbiome Therapeutic Reduce Risk of Transmission of Potential Bacterial Pathogens in Donor Stool.

Although fecal microbiota transplant has been used to prevent recurrent Clostridioides difficile infection (rCDI), documented pathogen transmission highlight inherent safety risks of minimally-processed stool. We describe manufacturing processes for fecal microbiota spores, live (VOWSTTM; VOS, formerly SER-109), a microbiota-based oral therapeutic of Firmicutes spores. Bacterial inactivation kill curves were obtained after ethanol exposure for four model organisms spiked into process intermediates. Bacterial log reduction factors ranged from 6.5 log10 to 7.4 log10 and lysis of spiked organisms occurred rapidly within 30 seconds. These experiments demonstrate substantial and rapid inactivation of representative organisms, supporting the potential benefit of VOS manufacturing processes to mitigate risk.

Horizontal transmission of Salmonella Typhimurium among German cockroaches and its possible mechanisms.

German cockroaches (Blattella germanica) can be both mechanical and biological (amplifying) vectors of enteric pathogens, including Salmonella enterica serovar Typhimurium (S. Typhimurium), which they acquire by feeding upon contaminated substances. Blattella germanica is also a gregarious species that shelters in groups and partakes in unique feeding behaviors such as conspecific coprophagy, necrophagy, and emetophagy. These properties create an interphase for potential horizontal transmission of pathogens among cockroach populations through the fecal-oral route, which could in turn enhance transmission to humans and other animals. Here, we performed a series of experiments to determine: (1) whether horizontal transmission of S. Typhimurium infection takes place in B. germanica, (2) the prevalence of the phenomenon, and (3) the route(s) through which it may occur. We reveal that true horizontal transmission of S. Typhimurium occurs among B. germanica. That is, uninfected cockroaches acquire infection of the gut when co-housed with orally infected conspecifics, albeit at low frequency. Furthermore, we provide definitive evidence that coprophagy and necrophagy are routes of transmission but could not exclude sharing of food or water as contributing routes. On the contrary, transmission by emetophagy appears less likely as oral regurgitates from infected cockroaches contained S. Typhimurium for less than one day after ingesting the bacteria. Together, our data enhance current understanding of the ecology of vector-borne S. Typhimurium transmission by cockroaches, implicating conspecific horizontal transmission as a phenomenon that contributes to maintaining infected cockroach populations independently of contact with primary sources of the pathogen. Although the relative importance of horizontal transmission of pathogens in cockroaches in the field remains to be determined, these results also highlight the important role that food and water sources in the local environment may play in cockroach-borne pathogen transmission and emphasize the importance of sanitation for not only abating infestations but also mitigating pathogen transmission.

Mitigation of Respirable Aerosol Particles from Speech and Language Therapy Exercises

Phonation and speech are known sources of respirable aerosol in humans. Voice assessment and treatment manipulate all the subsystems of voice production, and previous work (Saccente-Kennedy et al., 2022) has demonstrated such activities can generate >10 times more aerosol than conversational speech and 30 times more aerosol than breathing. Aspects of voice therapy may therefore be considered aerosol generating procedures and pose a greater risk of potential airborne pathogen (eg, SARS-CoV-2) transmission than typical speech. Effective mitigation measures may be required to ensure safe service delivery for therapist and patient. To assess the effectiveness of mitigation measures in reducing detectable respirable aerosol produced by voice assessment/therapy. We recruited 15 healthy participants (8 cis-males, 7 cis-females), 9 of whom were voice-specialist speech-language pathologists. Optical Particle Sizers (OPS) (Model 3330, TSI) were used to measure the number concentration of respirable aerosol particles (0.3 µm-10 µm) generated during a selection of voice assessment/therapy tasks, both with and without mitigation measures in place. Measurements were performed in a laminar flow operating theatre, with near-zero background aerosol concentration, allowing us to quantify the number concentration of respiratory aerosol particles produced. Mitigation measures included the wearing of Type IIR fluid resistant surgical masks, wrapping the same masks around the end of straws, and the use of heat and moisture exchange microbiological filters (HMEFs) for a water resistance therapy (WRT) task. All unmitigated therapy tasks produced more aerosol than unmasked breathing or speaking. Mitigation strategies reduced detectable aerosol from all tasks to a level significantly below, or no different to, that of unmasked breathing. Pooled filtration efficiencies determined that Type IIR surgical masks reduced detectable aerosol by 90%. Surgical masks wrapped around straws reduced detectable aerosol by 96%. HMEF filters were 100% effective in mitigating the aerosol from WRT, the exercise that generated more aerosol than any other task in the unmitigated condition. Voice therapy and assessment causes the release of significant quantities of respirable aerosol. However, simple mitigation strategies can reduce emitted aerosol concentrations to levels comparable to unmasked breathing.