Potential Pathogens Research Articles

Comparative Study of Staphylococcus aureus Biofilm Formation among Clinical Isolates and Nasal Colonisers

Staphylococcus aureus (S. aureus) a noted versatile facultative commensal with pathogenic potential. This facultatively anaerobic cocci lives a commensal lifestyle in about a quarter of the world’s population awaiting a breach in the immune barrier to establish as a debilitating pathogen. This bacterium produces biofilms which acts as adhesive molecule enhancing the bacterial virulence and gives it an ability to withstand antibiotics, thereby causing tremendous burden on the healthcare community in terms of patient mortality and morbidity. This study assesses the biofilm producing ability among clinical isolates of staphylococci in comparison to colonizing staphylococci isolated from anterior nares of healthcare personnel. The present cross-sectional observational study was conducted in a tertiary care hospital in Mysore, India. In this study, 50 pathogenic isolates of S. aureus were assessed for phenotypic biofilm production. Additionally, 100 healthcare personnel were screened for nasal colonisation with S. aureus and the colonizing isolates were also screened for phenotypic biofilm formation. Phenotypic biofilm formation was evident among 22% of the pathogenic isolates. 23% of clinical S. aureus isolates demonstrated methicillin resistance (MRSA). There was no significant association of MRSA status with biofilm production (p > 0.05). Out of the 100 healthcare professionals screened for nasal carriage of S. aureus, 30% were colonized with S. aureus. Biofilm production among colonizing S. aureus isolates was found to be 26.6%. Methicillin resistance was a whopping 40% among the colonising strains. MRSA carriage was found to be highest among those healthcare personnel who had worked for an average of 20-30 years in the hospital environment. The Present study showed no significant association of biofilm production with the pathogenic potential of the S. aureus isolates (p > 0.05). Additionally, there was no significant association of methicillin resistance with the pathogenicity of the isolate. In conclusion, the interplay of virulence genes, biofilm forming ability, drug resistance of the isolate in coordination with the host immune status dictate the fate of the colonising as well as clinical isolates of S. aureus.

Assessing the Amending and Fertilizing Properties of Digestates From Anaerobic Digestion of Faecal Sludge in Burkina Faso, West Africa

The aim of this work is to contribute to the agronomic utilization of digestate from the anaerobic treatment of faecal sludge at the Office National de l’Eau et de l’Assainissement (ONEA) Kossodo plant in Burkina Faso. Digestates were sampled and dried in the laboratory (25±2 °C). Physico-chemical and microbiological parameters were determined using standard methods. The degree of maturity of the digestate was determined using respirometry and humification tests. The effects of digestate on plants and on environment were studied using phytotoxicity, emergence, growth tests and microbiological analysis. The results revealed a pH of 8.54, electrical conductivity of 7300 µS/cm, 25.42% dry matter, 83.31% organic matter, and 489.8 g/kg total organic carbon. The C/N ratio was 9.7 and the NO3/NH4 ratio was 23.34, indicating mature compost despite other indicators suggesting that the digestate was only partially stabilized. Nutrient contents were 50.48 g/kg total nitrogen, 0.02 g/kg total phosphorus, and 4.72 g/kg total potassium. Water-soluble minerals included 1.97 g/kg ammonium, 45.99 g/kg nitrate, 0.02 g/kg nitrite, 0.35 g/kg phosphate, and 5.90 g/kg sulfate. Phytotoxicity tests showed that cabbage seeds had a germination rate of 89% with digestate filtrate compared to 100% in the control, while tomato seeds had a 100% germination rate with digestate filtrate. The germination indices were 137.58 for tomato and 82.10 for cabbage. Tests on tomato plant growth showed significant effects on biomass, height, leaf number, and branch number, with the 50% digestate proportion demonstrating the highest values. Microbiological analysis detected total aerobic flora at 4.75E+07 CFU/g, yeasts and molds at 7.77E+04 CFU/g, and coliforms at various levels, with potential pathogens such as S. aureus and Salmonella sp. reaching 6.14E+04 and 2.65E+06 CFU/g respectively. The presence of these pathogens suggests a need for further treatment of digestate to ensure safety before field application.

Enhancing variant of uncertain significance (VUS) interpretation in neurogenetics: collaborative experiences from a tertiary care centre

BackgroundThe findings of variants of uncertain significance (VUS) on a clinical genetic testing report pose a challenge for attending healthcare professionals (HCPs) in patient care. Here, we describe the outcomes...

Mature compost enhanced the harmlessness level in co-composting swine manure and carcasses in large-scale silo reactors

This study aimed to investigate the impact of incorporating mature compost on the harmlessness and maturity level of composting from swine manure and carcasses from industrialized pig farms in continuously running large-scale silo reactor systems. The potential human or animal bacterial pathogens and core bacterial community in composting were analyzed by high-throughput sequencing of 16S rRNA gene amplicons. The results showed that the addition of mature compost in the GD group significantly increased the temperature of all depths, the accumulated temperature of compost, and the germination index (75.43%) compared to that in the HN group without mature compost. High-throughput sequencing revealed that the dominated genera in GD were Ureibacillus, Lactobacillus, Corynebacterium, Staphylococcus, and Jeotgalicoccus, and the addition of mature compost could significantly increase the relative abundance of Ureibacillus (16.82%) that was associated with the biodegradation of organics. A total of 421 potential bacterial pathogens were detected, and the dominated genera of pathogens were Streptococcus, Staphylococcus, and Anaerococcus. The potential pathogen in the GD group with mature compost was reduced from 7.16 to 0.77%, which was significantly lower than that (2.97%) in the HN group. Together, these findings revealed that mature compost addition in large-scale reactor composting could accelerate the harmless and humification process, providing an effective and environmentally friendly scheme to deal with the main organic wastes in intensive pig farms.

The Microbiological Quality of Raw Ovine Milk in the Banat Region of Romania with a Focus on Escherichia coli and Its Pathogenic Potential and Antimicrobial Resistance

This study investigated the bacteriological quality of raw ovine milk produced by farms located in the Banat region of Romania. Additionally, the pathogenic potential and antimicrobial resistance of the isolated Escherichia coli strains were evaluated. A total of 95.8% (69/72) of the screened bulk tank milk samples, collected at the farm level immediately after milking, demonstrated appropriate total aerobic mesophilic bacteria (TMB) counts, varying from 3.32 to 6.09 log10 CFU/mL. However, 4.2% (3/72) of the samples were above the regulatory limit of 6.18 log10 CFU/mL. E. coli was identified in 66.6% of the examined samples, and from the total number (n = 48) of isolates, 18.8% harbored the stx2 gene, highlighting pathogenic potential. Antimicrobial susceptibility testing with the Vitek2 system of the isolated E. coli strains revealed resistance against ampicillin (45.8%), gentamicin (20.8%), ticarcillin–clavulanic acid (18.8%), cephalexin (18.8%), amoxicillin–clavulanic acid (8.3%), and trimethoprim–sulfamethoxazole (2.1%). Additionally, 64.6% of the strains showed intermediate resistance against amoxicillin–clavulanic acid, while no resistance was recorded against imipenem. Five (18.5%) strains were multidrug-resistant. This study’s results underline hygienic sanitary deficiencies during the milking phase and indicate that raw ovine milk can be contaminated with pathogenic and multidrug-resistant E. coli strains, highlighting a potential risk to public health. Further studies are encouraged to better understand the risk posed to the consumer via the consumption of ovine milk and derived products.

Screening for mitochondrial tRNA variants in 200 patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a common autoimmune disease with unknown etiology. Recently, a growing number of evidence suggested that mitochondrial dysfunctions played active roles in the pathogenesis of SLE, but its detailed mechanism remains largely undetermined. The aim of this study was to analysis the frequencies of mitochondrial tRNA (mt-tRNA) variants in Chinese individuals with SLE. We carried out a mutational screening of mt-tRNA variants in a cohort of 200 patients with SLE and 200 control subjects by PCR-Sanger sequencing. The potential pathogenicity of mt-tRNA variants were evaluated by phylogenetic conservation and haplogroup analyses. In addition, trans-mitochondrial cybrid cell lines were established, mitochondrial functions including ATP, reactive oxygen species (ROS), mitochondrial DNA (mtDNA) copy number, mitochondrial membrane potential (MMP), superoxide dismutase (SOD) and mt-RNA transcription were analyzed in cybrids with and without these putative pathogenic mt-tRNA variants. We identified five possible pathogenic variants: tRNAVal G1606A, tRNALeu(UUR) A3243G, tRNAIle A4295G, tRNAGly T9997C, and tRNAThr A15924G that only found in SLE patients but were absent in controls. Interestingly, these variants were located at extremely conserved nucleotides of the corresponding tRNAs and may alter tRNAs' structure and function. Furthermore, cells carrying these tRNA variants had much lower levels of ATP, mtDNA copy number, MMP and SOD than controls, by contrast, the levels of ROS increased significantly (p<0.05 for all). Furthermore, a significantly reductions in mt-ND1, ND2, ND3, ND5 and A6 mRNA expression were observed in cells with these mt-tRNA variants, while compared with controls. Thus, failures in tRNAs metabolism caused by these variants would impair mitochondrial translation, and subsequently lead to mitochondrial dysfunction that was involved in the progression and pathogenesis of SLE. Our study suggested that mt-tRNA variants were important causes for SLE, screening for mt-tRNA pathogenic variants was recommended for early detection and prevention for this disorder.

Virulence Profiles of Salmonella enterica Isolated from Three Food Matrices Collected from Retail Markets.

Salmonella enterica is one of the most common foodborne pathogens associated with the consumption of contaminated porcine, dairy, and avian products. Nontyphoidal Salmonella is a major cause of bacterial diarrhea, responsible for ∼150 million cases and 60,000 deaths annually. The main goal of this study was to determine the prevalence of Salmonella spp. and to establish the virulence profile (VP) from genes (avrA, invE, ssaD, sseF, ssaQ, ttrC) and plasmid genes (pefA, spvB, spvC) in isolates obtained from cheese, chicken, and pork sold in food markets in Barrancabermeja, Colombia. A survey was conducted on 100 samples each matrix. The detection of Salmonella spp. followed the ISO 6579:2017 standards modified, and isolates were confirmed using the invA gene. In addition, single polymerase chain reaction assays were developed to detect the nine virulence genes. Salmonella spp. was found in 62%, 32%, and 14% of pork, chicken, and cheese samples, respectively. A total of 277 isolates were biochemically, serologically, and molecularly compatible with Salmonella spp. The most representative serogroups were C and B. Forty-seven combinations of virulence gene were detected; 53.5% of the pork isolates, 46.2% of the cheese isolates, and 39% of the chicken isolates were distributed among VP1, VP2, and VP3 suggesting a higher pathogenic potential. In addition, seven isolates harbored plasmid-encoded virulence genes (spvB and spvC), which are associated with increased invasiveness. The results revealed a higher prevalence of Salmonella spp. in pork and chicken compared with other studies conducted in Colombia. The serogroups identified include serovars that more frequently affect humans Salmonella Enteriditis, Salmonella Newport, and Salmonella Typhimurium. The isolations have the majority of the virulence genes studied. These findings highlight the need to improve control measures and educate food handlers to minimize the presence of Salmonella spp. and its potential transmission.

Rhipicephalus simus ticks: new hosts for phleboviruses.

Ticks are widespread arthropods that transmit microorganisms of veterinary and medical significance to vertebrates, including humans. Rhipicephalus simus, an ixodid tick frequently infesting and feeding on humans, may play a crucial role in transmitting infectious agents across species. Despite the known association of many Rhipicephalus ticks with phleboviruses, information on R. simus is lacking. During a study in a riverine area in Lusaka Zambia, ten R. simus ticks were incidentally collected from the grass and bushes and subjected to metagenomic next generation sequencing (mNGS) in 2 pools of 5. Analysis detected a diverse microbial profile, including bacteria 82% (32/39), fungi 15.4% (6/39), and viruses 2.6% (1/39). Notably, viral sequence LSK-ZM-102022 exhibited similarity to tick phleboviruses, sharing 74.92% nucleotide identity in the RdRp gene and 72% in the NP gene with tick-borne phlebovirus (TBPV) from Greece and Romania, respectively. Its RNA-dependent RNA polymerase (RdRp) encoding region carried conserved RdRp and endonuclease domains characteristic of phenuiviridae viruses. Phylogenetic analysis positioned LSK-ZM-102022 in a distinct but lone lineage within tick phleboviruses basal to known species like brown dog tick phlebovirus and phlebovirus Antigone. Pair-wise genetic distance analysis revealed similar findings. This study emphasizes the urgency of further research on the ecology, transmission dynamics, and pathogenic potential of LSK-ZM-102022 and related TBPVs, crucial for local and global preparedness against emerging tick-borne diseases.

Commercial Day-Old Chicks in Nigeria Are Potential Reservoirs of Colistin- and Tigecycline-Resistant Potentially Pathogenic Escherichia coli

Background: Frequent use of colistin (COL) and tetracyclines in the Nigerian poultry sector potentially triggers bacterial resistance against COL and tigecycline (TIG), which are last-line antibiotics used to treat multidrug-resistant infections. Aim/Objectives: This study aimed to isolate COL- and TIG-resistant E. coli from commercial day-old chicks distributed to poultry farmers in Nsukka Southeastern Nigeria, assess the production of extended-spectrum β-lactamase (ESBL) and carbapenemase by the isolates, and establish their pathogenic potentials. Materials and Methods: Non-duplicate cloacal swabs were systematically collected from 250 randomly selected day-old chicks. MacConkey agar with 1 µg/mL of COL and 16 µg/mL of tetracycline was used for the isolation of putative COL- and tetracycline-resistant E. coli, respectively. E. coli isolates were confirmed biochemically using the API20E Gram-negative identification kit and molecularly by polymerase chain reaction targeting the uidA gene. Phenotypic COL resistance was established using COL agar and COL disc elution tests, while TIG insusceptibility was determined with disc diffusion. ESBL and carbapenemase production was assessed by double-disc synergy and modified carbapenem inactivation methods, respectively. Pathogenic potentials were determined using phenotypic methods. Results: COL- and TIG-resistant E. coli was recovered from 95 (38.0%) and 62 (24.8%) swabs from the 250 chicks, respectively. None of the isolates were potential ESBL or carbapenemase producers. The COL-resistant isolates displayed pathogenic potentials such as biofilm formation, haemagglutination, cell surface hydrophobicity, surface layer, and gelatinase activities at rates of 30.7%, 8.4%, 33.7%, 23.5%, and 17.6%, respectively. Meanwhile, the TIG-resistant isolates exhibited their respective potentials at rates of 47.0%, 21.0%, 35.5%, 58.1%, and 43.6%. Red, dry, and rough (RDAR) was the predominant curli fimbriae, and the cellulose morphotype portrayed by both the COL- and TIG-unsusceptible potential biofilm-producing isolates. Conclusions: This study demonstrates that a significant percentage of commercial day-old chicks distributed to farmers in Nsukka, southeastern Nigeria, are colonized by potentially pathogenic COL- and TIG-resistant E. coli, which could spread to humans and the environment.

MetaCompare 2.0: Differential ranking of ecological and human health resistome risks.

While numerous environmental factors contribute to the spread of antibiotic resistance genes (ARGs), quantifying their relative contributions remains a fundamental challenge. Similarly, it is important to differentiate acute human health risks from environmental exposure, versus broader ecological risk of ARG evolution and spread across microbial taxa. Recent studies have proposed various methods for achieving such aims. Here, we introduce MetaCompare 2.0, which improves upon original MetaCompare pipeline by differentiating indicators of human health resistome risk (HHRR, potential for human pathogens of acute resistance concern to acquire ARGs) from ecological resistome risk (ERR, overall mobility of ARGs and potential for pathogen acquisition). The updated pipeline's sensitivity was demonstrated by analyzing diverse publicly-available metagenomes from wastewater, surface water, soil, sediment, human gut, and synthetic microbial communities. MetaCompare 2.0 provided distinct rankings of the metagenomes according to both HHRR and ERR, with both scores trending higher when influenced by anthropogenic impact or other stress. We evaluated the robustness of the pipeline to sequence assembly methods, sequencing depth, contig count, and metagenomic library coverage bias. The risk scores were remarkably consistent despite variations in these technological aspects. We packaged the improved pipeline into a publicly-available web service (http://metacompare.cs.vt.edu/) that provides an easy-to-use interface for computing resistome risk scores and visualizing results.

Phylogenomics of novel clones of Aeromonas veronii recovered from a freshwater lake reveals unique biosynthetic gene clusters.

Lakes and other aquatic ecosystems can harbor harmful bacteria that can make people sick and resist antibiotics, posing a significant global health risk. In this study, we investigated Aeromonas veronii, a Gram-negative bacteria found in Lake Wilcox in Ontario. We used various techniques, including whole-genome sequencing (WGS), to analyze the bacteria and found that many of the isolates had the potential to cause human disease. We also discovered significant genetic diversity among the isolates, indicating that the lake may be a reservoir for multiple human pathogenic strains. All isolates carried genes that confer resistance to antibiotics, and some virulence genes were associated with human pathogenic isolates. This study highlights the importance of monitoring aquatic ecosystems for harmful bacteria to better understand their evolution, potential for human pathogenicity, and the ecological roles of their genetic elements. This knowledge can inform strategies for preventing the spread of antibiotic-resistant bacteria and protecting public health.

Characterization of the Blood Bacterial Microbiota in Lowland Tapirs (Tapirus terrestris), a Vulnerable Species in Brazil

Microbiome studies targeting hypervariable regions of the 16S rRNA gene are suitable for understanding interactions between animals and their associated bacteria. While many studies focus on the gut microbiome, assessments of blood microbiota remain scarce despite the prevalence of blood-borne pathogens in vertebrates. This study aimed to investigate the bacterial community in blood samples from 79 living and 7 road-killed lowland tapirs (Tapirus terrestris), a vulnerable species, sampled in two biomes in midwestern Brazil: Pantanal and Cerrado. Animals were categorized by condition (living or road-killed), sex, age, and biome. V3–V4 16S rRNA fragments were obtained from 86 blood samples and 4 negative controls. After filtering contaminants, 13,742,198 sequences representing 2146 ASVs were analyzed. Alpha diversity significantly differed by condition, while beta diversity differed by condition, site, and age (adults vs. sub-adults). For living animals (79/86 samples), alpha diversity showed no significant differences, but beta diversity differed by age. Different vector-borne bacterial pathogens, including Anaplasmataceae, Bartonella, and Borrelia spp., were detected. Additionally, evidence of transient translocation of microbial communities from other body regions to the bloodstream was observed. Amplification of bacterial 16S rRNA from blood samples of wild T. terrestris provided novel information about the diversity of blood-borne microbiota of lowland tapirs, members of a poorly studied mammalian family. Next-generation sequencing proved to be a valuable tool for screening potential vector-borne pathogens in this host.

Comparative analysis of the postadmission and antemortem oropharyngeal and rectal swab microbiota of ICU patients

Shotgun metabarcoding was conducted to examine the microbiota in a total of 48 samples from 12 critically ill patients, analyzing samples from both the oropharynx and rectum. We aimed to compare their postadmission microbiota, characterized as moderately dysbiotic, with the severely dysbiotic antemortem microbiota associated with patients’ deaths. We found that, compared with postadmission samples, patient antemortem swab samples presented moderate but not significantly decreased diversity indices. The antemortem oropharyngeal samples presented an increase in biofilm-forming bacteria, including Streptococcus oralis, methicillin-resistant Staphylococcus aureus (MRSA), and Enterococcus faecalis. Although the septic shock rate was 67%, no significant differences were detected in the potential pathogen ratios when the microbiota was analyzed. A notable strain-sharing rate between the oropharynx and intestine was noted. By comparing postadmission and antemortem samples, microbial biomarkers of severe dysbiosis were pinpointed through the analysis of differentially abundant and uniquely emerging species in both oropharyngeal and rectal swabs. Demonstrating strong interconnectivity along the oral-intestinal axis, these biomarkers could serve as indicators of the progression of dysbiosis. Furthermore, the microbial networks of the oropharyngeal microbiota in deceased patients presented the lowest modularity, suggesting a vulnerable community structure. Our data also highlight the critical importance of introducing treatments aimed at enhancing the resilience of the oral cavity microbiome, thereby contributing to better patient outcomes.

Previously defined variants of uncertain significance may play an important role in epilepsy and interactions between certain variants may become pathogenic.

Epilepsy is a chronic neurological disorder related to various etiologies, and the prevalence of active epilepsy is estimated to be between 4 and 10 per 1000 individuals having a significant role in genetic mutations. Next-Generation Sequencing (NGS) panels are utilized for genetic testing, but a substantial proportion of the results remain uncertain and are not considered directly causative of epilepsy. This study aimed to reevaluate pediatric patients diagnosed with epilepsy who underwent genetic investigation using NGS panels, focusing on inconclusive variant findings or multiple variants of uncertain significance (VUSs). A subgroup of pediatric patients aged 0-25 years, diagnosed with epilepsy, who underwent genetic investigation with an NGS epilepsy panel at the Child Neurology Unit, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, between 2018 and 2022 through Invitae, was reevaluated. Patients with inconclusive variant findings or multiple VUSs in their test results were included. Genetic data were analyzed to identify potentially pathogenic variants and frequent genetic combinations. Two unrelated potentially pathogenic variants were identified in the SCN9A and QARS1 genes. A frequent genetic combination, RANBP2&RYR3, was also observed among other combinations. The RANBP2 gene consistently co-occurred with RYR3 variants in uncertain results, suggesting potential pathogenicity. Analysis of unaffected parents' data revealed certain combinations inherited from different parents, suggesting specific gene combinations as possible risk factors for the disease. This study highlights the importance of reevaluating genetic data from pediatric epilepsy patients with inconclusive variant findings or multiple VUSs. Identification of potentially pathogenic variants and frequent genetic combinations, such as RANBP2&RYR3, could aid in understanding the genetic basis of epilepsy and identifying potential hotspots. We have performed a retrospective analysis on a subpopulation of pediatric patients diagnosed with epilepsy. We found that specific genetic variants were repeatable, indicating their potential pathogenicity to the disease.

Comparative Genomic and Secretome Analysis of Phytophthora capsici Strains: Exploring Pathogenicity and Evolutionary Dynamics

Phytophthora capsici is a destructive oomycete pathogen that poses a significant threat to global agriculture by infecting a wide range of economically important crops in the Solanaceae and Cucurbitaceae families. In Canada, the pathogen has been responsible for substantial losses in greenhouse and field-grown crops. Despite extensive worldwide research on P. capsici, little is known about the effector content and pathogenicity of the Canadian isolates. In this study, we sequenced and analyzed the genomes of two Canadian P. capsici strains, namely 55330 and 55898, and conducted a comparative secretome analysis with globally referenced strains LT1534 and LT263. The Canadian strains displayed smaller genomes at 57.3 Mb and 60.2 Mb compared to LT263 at 76 Mb, yet retained diverse effector repertoires, including RxLR and CRN effectors, and exhibited robust pathogenic potential. Our analysis revealed that while the Canadian strains have fewer unique effector clusters compared to LT263, they possess comparable CAZyme profiles, emphasizing their capacity to degrade plant cell walls and promote infection. The differences in effector content likely reflect host adaptation, as P. capsici infects a variety of plant species. This study provides valuable insights into the genetic features of Canadian P. capsici isolates and offers a foundation for future efforts in developing targeted disease-management strategies.

Wastewater-associated plastispheres: A hidden habitat for microbial pathogens?

Wastewater treatment plants (WWTPs) receive wastewater from various sources. Despite wastewater treatment aiming to remove contaminants, microplastics persist. Plastic surfaces are quickly colonized by microbial biofilm ("plastispheres"). Plastisphere communities are suggested to promote the spread and survival of potential human pathogens, suggesting that the transfer of plastispheres from wastewater to the environment could pose a risk to human and environmental health. The study aimed to identify pathogens in wastewater plastispheres, specifically food-borne pathogens, in addition to characterizing the taxonomic diversity and composition of the wastewater plastispheres. Plastispheres that accumulated on polypropylene (PP), polyvinyl chloride (PVC), and high-density polyethylene propylene (HDPE) surfaces exposed to raw and treated wastewater were analyzed via cultivation methods, quantitative reverse transcription PCR (RT‒qPCR) and 16S rRNA amplicon sequencing. RT‒qPCR revealed the presence of potential foodborne pathogenic bacteria and viruses, such as Listeria monocytogenes, Escherichia coli, norovirus, and adenovirus. Viable isolates of the emerging pathogenic species Klebsiella pneumoniae and Acinetobacter spp. were identified in the plastispheres from raw and treated wastewater, indicating that potential pathogenic bacteria might survive in the plastispheres during the wastewater treatment. These findings underscore the potential of plastispheres to harbor and disseminate pathogenic species, posing challenges to water reuse initiatives. The taxonomic diversity and composition of the plastispheres, as explored through 16S rRNA amplicon sequencing, were significantly influenced by the wastewater environment and the duration of time the plastic spent in the wastewater. In contrast, the specific plastic material did not influence the bacterial composition, while the bacterial diversity was affected. Without efficient wastewater treatment and proper plastic waste management, wastewater could act as a source of transferring plastic-associated pathogens into the food chain and possibly pose a threat to human health. Continued research and innovation are essential to improve the removal of microplastics and associated pathogenic microorganisms in wastewater.

Metagenomics reveals the divergence of gut microbiome composition and function in two common pika species (Ochotona curzoniae, Ochotona daurica) in China.

Gut microbiome plays crucial roles in animal adaptation and evolution. However, research on adaptation and evolution of small wild high-altitude mammals from the perspective of gut microbiome is still limited. In this study, we compared difference in intestinal microbiota composition and function in Plateau pikas (Ochotona curzoniae) and Daurian pikas (Ochotona daurica) using metagenomic sequencing. Our results showed that microbial community structure had distinct differences in different pika species. Prevotella, Methanosarcina, Rhizophagus and Podoviridae were abundant bacteria, archaea, eukaryotes and viruses in Plateau pikas, respectively. However, Prevotella, Methanosarcina, Ustilago and Retroviridae were dominated in Daurian pikas. Functional pathways related to carbohydrate metabolism that refer to utilization of pectin, hemicellulose and debranching enzymes were abundant in Plateau pikas, while the function for degradation of chitin, lignin and cellulose was more concentrated in Daurian pikas. Pika gut had abundant multidrug resistance genes, followed by glycopeptide and beta-lactamase resistance genes, as well as high-risk ARGs, such as mepA, tetM and bacA. Escherichia coli and Klebsiella pneumoniae may be potential hosts of mepA. This research provided new insights for adaptation and evolution of wild animals from perspective of gut microbiome, and broadened our understanding of high-risk ARGs and potential pathogens of wild animals.

Environmental Drivers of the Divergence of Harveyi Clade Pathogens with Distinctive Virulence Gene Profiles

Fish and shellfish pathogens of the Harveyi clade of the Vibrio genus cause significant losses to aquaculture yields and profits, with some of them also causing infections in humans. The present study aimed to evaluate the presence of Harveyi clade fish and shellfish pathogens and their possible diversification in response to environmental drivers in southeastern USA waters. The presence and abundance of potential pathogens were evaluated via the detection and quantitation of six Harveyi-clade-specific virulence genes (toxR, luxR, srp, vhha, vhh, and vhp; VGs) in environmental DNA with clade-specific primers. The environmental DNA was obtained from water and sediments collected from three Georgia (USA) cultured clam and wild oyster grounds. In sediments, the VG concentrations were, on average, three orders of magnitude higher than those in water. The most and least frequently detected VGs were vhp and toxR, respectively. In water, the VGs split into two groups based on their seasonal trends. The first group, composed of luxR, vhp, vhha, and vhh, peaked in August and remained at lower concentrations throughout the duration of the study. The second group, composed of toxR and srp, peaked in June and disappeared between July and December. The first group revealed a high adaptation of their carriers to an increase in temperature, tolerance to a wide range of pH, and a positive correlation with salinity up to 25 ppt. The second group of VGs demonstrated a lower adaptation of their carriers to temperature and negative correlations with pH, salinity, potential water density, conductivity, and dissolved solids but a positive correlation with turbidity. No such trends were observed in sediments. These data reveal the role of VGs in the adaptability of the Harveyi clade pathogens to environmental parameters, causing their diversification and possibly their stratification into different ecological niches due to changes in water temperature, acidity, salinity, and turbidity. This diversification and stratification may lead to further speciation and the emergence of new pathogens of this clade. Our data urge further monitoring of the presence and diversification of Harveyi clade pathogens in a global warming scenario.

Coenzyme A fueling with pantethine limits autoreactive T cell pathogenicity in experimental neuroinflammation

BackgroundImmune cell metabolism governs the outcome of immune responses and contributes to the development of autoimmunity by controlling lymphocyte pathogenic potential. In this study, we evaluated the metabolic profile of myelin-specific murine encephalitogenic T cells, to identify novel therapeutic targets for autoimmune neuroinflammation.MethodsWe performed metabolomics analysis on actively-proliferating encephalitogenic T cells to study their overall metabolic profile in comparison to resting T cells. Metabolomics, phosphoproteomics, in vitro functional assays, and in vivo studies in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), were then implemented to evaluate the effect of metabolic targeting on autoreactive T cell pathogenicity. Finally, we confirmed the translational potential of our targeting approach in human pro-inflammatory T helper cell subsets and in T cells from MS patients.ResultsWe found that autoreactive encephalitogenic T cells display an altered coenzyme A (CoA) synthesis pathway, compared to resting T cells. CoA fueling with the CoA precursor pantethine (PTTH) affected essential immune-related processes of myelin-specific T cells, such as cell proliferation, cytokine production, and cell adhesion, both in vitro and in vivo. Accordingly, pre-clinical treatment with PTTH before disease onset inhibited the development of EAE by limiting T cell pro-inflammatory potential in vivo. Importantly, PTTH also significantly ameliorated the disease course when administered after disease onset in a therapeutic setting. Finally, PTTH reduced pro-inflammatory cytokine production by human T helper 1 (Th1) and Th17 cells and by T cells from MS patients, confirming its translational potential.ConclusionOur data demonstrate that CoA fueling with PTTH in pro-inflammatory and autoreactive T cells may represent a novel therapeutic approach for the treatment of autoimmune neuroinflammation.

Influencing the attitude towards hand hygiene and face masks by pathogen visualisation during the COVID-19 pandemic

ABSTRACT Pupils need to develop habits of using self-protective and non-pharmaceutical measures in the face of health-threatening conditions. This study set out to investigate pupils’ attitudes towards health-protective measures, such as handwashing and face masks, during the COVID-19 pandemic and compared their connotative meanings after experiencing GloGermTM activities, which visualise the micro world and the way microorganisms spread. The study involved 241 students aged 11–15 who completed a semantic differential before and after participating in practical activities. Factor analysis and non-parametric tests were used to characterise and identify shifts in the pupils’ attitudes. The findings show a noticeable shift in attitude, particularly among girls, towards wearing face masks. The factors identified include connotative meanings such as giving credit to potency, achieving quick results, acknowledging purpose, experiencing uncertainty before the intervention, and evaluating the purpose after the intervention. Personal comfort was also identified as a factor that persisted before and after the intervention. Infectious diseases and pandemic awareness are crucial in today’s world and will remain so in the future. We believe that modelling safe experiences with potential pathogens, particularly in promoting healthy behaviours, can reduce health threats. The results indicate that such an approach has the potential to influence attitudes.