Prevalence Of Pathogens Research Articles

High serological and molecular prevalence of Ehrlichia canis and other vector-borne pathogens in dogs from Boa Vista Island, Cape Verde

Despite the high global impacts of canine vector-borne diseases (CVBD) due to their wide distribution and zoonotic potential, the current epidemiological situation of CVBD in many tropical and subtropical regions remains unknown. This study examines the seroprevalence and molecular prevalence of Ehrlichia canis and other pathogens causing CVBDs (Leishmania infantum, Dirofilaria immitis, Babesia spp., Anaplasma spp. and Hepatozoon canis) in dogs living on the island of Boa Vista (Cape Verde Republic). Blood samples and infesting ticks were taken from 150 dogs across the island (stray, shelter, and pet dogs). Serum samples were tested using a rapid immunochromatographic test (Uranotest® Quattro) that detects antibodies against E. canis, L. infantum, Anaplasma spp. and D. immitis antigen. Levels of serum antibodies against E. canis were measured using the immunofluorescence antibody test (IFAT). In addition, tick-borne pathogens in blood samples (Anaplasma spp., Babesia spp., Hepatozoon spp., and Ehrlichia canis) were detected by microscopy observation and/or PCR plus sequencing. The seroprevalence of E. canis was extremely high at 82% (123/150), as revealed by both immunochromatography and IFAT. Most dogs returning a seropositive test result (82.92%; 102/123) had antibody titres > 1:1280 but showed no clinical signs or notable laboratory abnormalities. Of the 123 animals testing seropositive for E. canis, 67 (54.47%) also presented antibodies against Anaplasma spp., and 13 (10.56%) showed the presence of Hepatozoon spp. gamonts in the blood smear. Ehrlichia canis infection was detected in 17.1% (25/146) of dogs tested by direct sequencing of polymerase chain reaction (PCR) products. Co-infections were detected in seven of these dogs: four dogs tested PCR-positive for both E. canis and A. platys, two dogs tested positive for E. canis and Hepatozoon spp., and one dog tested positive for E. canis, A. platys and Hepatozoon spp. Rhipicephalus sanguineus sensu lato was the only tick species found infesting the canine study population. The high prevalence of tick-borne pathogens detected in dogs from Boa Vista Island highlights a need for improved control measures designed to prevent the transmission of these pathogens.Graphical

Epidemiology and Diagnostic Accuracy of Respiratory Pathogens in Pediatric Populations: Insights From Global Studies.

Lower respiratory tract infections (LRTIs) are the most common cause for going to the doctor's at pediatric age. Respiratory infections are still of interest because they are widespread, significantly impact public health by potentially leading to pandemics, drive antimicrobial resistance through antibiotic misuse, more often spread globally due to traveling, and benefit from ongoing advancements in diagnostics and research for better management.This paper's main aim was to offer a systematic review of the literature published over the last 10 years on the etiology of LRTIs. The search strategy was based on reviewing original articles, systematic reviews, position papers, and guidelines published in MEDLINE, EMBASE, Cochrane Library, and PubMed. The review was previously registered with PROSPERO. The final review included 27 articles that met the eligibility criteria (studies identifying the etiology of inferior respiratory infections in children, according to the WHO definition, published in the last 10 years). Statistical analysis was performed using Microsoft Excel Version 2406 (Microsoft Corporation, Redmond, Washington, USA) and SPSS Statistics V.23 (IBM Corp., Armonk, New York, USA). The total number of patients was 2,193,978. Eight articles focused on children younger than five years, and two included children under the age of two.The results revealed that Mycoplasma pneumoniae and respiratory syncytial virus (RSV) are significant respiratory pathogens with seasonal peaks and age-specific prevalence and that nasopharyngeal aspirates (NPAs) are more reliable than throat swabs for confirming infections due to their higher positive predictive value (PPV).The impact of COVID-19 interventions led to reduced infections from RSV, adenovirus, and influenza viruses, but an increase in rhinovirus post-reopening, with high co-infection rates. Co-infections are common, particularly with pathogens like human bocavirus (HBoV) and RSV, underscoring the need for comprehensive diagnostic approaches. The impact of non-pharmaceutical interventions during the COVID-19 pandemic significantly reduced the prevalence of many respiratory pathogens, except for rhinovirus, which increased post-reopening. Understanding these dynamics is crucial for managing respiratory infections, especially in pediatric populations.

Feline respiratory disease complex: insights into the role of viral and bacterial co-infections.

Feline respiratory disease complex (FRDC) is a highly prevalent syndrome in cats that often result in fatal outcomes. FRDC etiology is complex, and often, multiple viral and bacterial pathogens are simultaneously associated with disease causation. There is limited information about the role of co-infections in pathogenesis and the current prevalence of pathogens in North America. We aimed to conduct a study using technical advances in molecular diagnosis and statistical modeling analysis to elucidate the occurrence of pathogens and how co-infections affect disease severity. We attained information from three diagnostic laboratories in North America regarding the occurrence of Bordetella bronchiseptica, Chlamydia felis, Mycoplasma, Felid alphaherpesvirus 1 (FeHV-1), feline calicivirus (FCV), and influenza A, along with age, seasonality, sex, and clinical signs. We also evaluated the role of co-infections in disease severity. These pathogens were also investigated in clinically normal cats (control). The most detected pathogens were Mycoplasma, FCV, and FeHV-1. Most pathogens were detected in the control group, highlighting the challenge of interpreting positive testing results. Co-infections of Mycoplasma and FCV, as well as Mycoplasma and FeHV-1, were important predictors of disease severity. Age, sex, and season had a minor impact on pathogen occurrence. This study provides new insights into FRDC and underlines the relevance of diagnostic panels to screen for a range of pathogens, providing knowledge for timely diagnosis and therapeutic interventions.

Antibiotics Consumption and Antibiotic Resistance during and Post Covid-19: Impact on Global Health

In the modern healthcare environment, the growth in multidrug-resistant pathogen prevalence has been associated with the increasing use of broad-spectrum antibiotics globally. We carried out a study to look at the trends and procedures related to antibiotic prescriptions in order to assess antibiotic use in its entirety. The overuse of antibiotics in the treatment of COVID-19 is a specific cause for focus as it raises concerns about the possible emergence of antimicrobial resistance. The study verifies a significant pattern in which COVID-19 patients received antibiotic prescriptions regardless of their reported severity, indicating a severe deficiency in clinical examination, the prescribing of antibiotics without a prescription is analyzed in perspective with changing healthcare practices including the increasing use of telemedicine. The concerns about the emergence of antimicrobial resistance while addressing the growing problem of unnecessary antibiotic use in the treatment of COVID-19. The concerns related to COVID-19 and the lack of treatment strategy led to the overuse of antibiotics without proper clinical treatment can be identified as main reason for increase in Antibiotics Consumption and Antibiotic Resistance.

The androgen receptor gene and criminal offending: Evidence derived from international data

Beginning early in fetal development, the androgen receptor (AR) gene helps regulate bodily exposure to testosterone. Most studies of individuals have found an inverse correlation between the number of CAG repeats on this gene and serious forms of physical aggression. This two-phased study was primarily undertaken to determine if a link between AR CAGn and physical aggression also exists at an ecological level of analysis. To make this assessment, we first conducted a bivariate analysis of the average number of AR CAG repeats for a large number of countries and the rates of crime victimization in those same countries. Except for motor vehicle theft, as the national average number of CAG repeats increased, crime victimization rates decreased. This inverse relationship was especially strong for violent offenses. In the second phase of this study, we sought to determine if per capita gross domestic product, pathogen prevalence, and average intelligence might be mediating some of the AR CAG repeats-criminality relationship. Mediation analysis analysis indicated that, once gross domestic product and pathogenic prevalence were controlled, average intelligence was able to eliminate most of the links between CAG repeats and crime victimization rates, especially in the case of violent offenses. These findings suggest that the AR gene is not influencing criminality primarily by altering testosterone brain exposure (as we suspected). Instead, it may affect criminality mainly by affecting cognitive ability. In fact, once average national intelligence is included in the mediation analysis model, direct relationships between CAG repeats and measures of homicide, assault, and robbery were no longer statistically significant. Findings from this two-phased study point toward the AR gene as having multiple effects on brain functioning, particularly regarding intellectual development as hypothesized by Manning [62]. Replication is obviously needed.

Natural medicine can substitute antibiotics in animal husbandry: protective effects and mechanisms of rosewood essential oil against Salmonella infection

Aniba rosaeodora essential oil (RO) has been traditionally used in natural medicine as a substitute for antibiotics due to its notable antidepressant and antibacterial properties. Salmonella, a prevalent pathogen in foodborne illnesses, presents a major challenge to current antibiotic treatments. However, the antibacterial efficacy and mechanisms of action of RO against Salmonella spp. remain underexplored. This study aims to elucidate the chemical composition of RO, evaluate its antibacterial activity and mechanisms against Salmonella in vitro, and further delineate its anti-inflammatory mechanisms in vivo during Salmonella infection. Gas chromatography-mass spectrometry (GC-MS) was utilized to characterize the chemical constituents of RO. The antibacterial activity of RO was assessed using minimal inhibitory concentration (MIC) and time-kill assays. Various biochemical assays were employed to uncover the potential bactericidal mechanisms. Additionally, mouse and chick models of Salmonella infection were established to investigate the prophylactic effects of RO treatment. RO exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacteria, with an MIC of 4 mg·mL−1 for Salmonella spp. RO treatment resulted in bacterial damage through the disruption of lipid and purine metabolism. Moreover, RO reduced injury and microbial colonization in infected mice and chicks. RO treatment also modulated the host inflammatory response by inhibiting proinflammatory pathways. In conclusion, our findings demonstrate that RO is effective against Salmonella infection, highlighting its potential as an alternative to antibiotics for antibacterial therapy.

Socio-environmental factors associated with small mammal assemblage and Leptospira prevalence in Suburban Areas of Terengganu, Malaysia

Objective: To examine the socio-environmental factors associated with the assemblage of small mammals and the prevalence of Leptospira pathogen in poor suburban communities of Terengganu, Malaysia. Methods: We trapped small mammals from 119 trapping points scattered around three suburban communities of Terengganu using sausage-baited live traps. On the average, we set up five traps for three nights at each sampling point during the trapping period. Kidneys of captured animals were harvested and processed for Leptospira investigation. Additionally, environmental survey was conducted at each trapping point to obtain information about possible variables supporting small mammal assemblage. We used a generalized linear model to evaluate the effect of different socio-environmental variables on small mammals’ assemblage. Results: A total of 89 small mammals, specifically, Rattus norvegicus (n=39), Rattus rattus (n=27), Rattus exulans (n=10), Suncus murinus (n=11), and Tupaia glis (n=2) were captured from 1 385 trap nights. Fourteen individuals (15.7%) of the captured animals tested positive for Leptospira bacteria using PCR detection. Results of our generalized linear model showed only residences bordering vacant lots as the variable positively associated with small mammal occurrence in the three study sites. Conclusions: Small mammal community, especially the often neglected species, could harbour and potentially contribute towards pathogenic Leptospira maintenance in the study sites. To adequately control small mammals’ population and subsequent human zoonoses transmission, it is critical to advocate and promote appropriate infrastructure and suburban services, together with good hygiene practices that can reduce the animals’ access to food and harborage.

Managing the microbiological safety of tilapia from farm to consumer.

Tilapia stands out as one of the most extensively farmed and consumed fish species globally, valued for its ease of preparation and relative affordability. Although tilapia is a valuable protein source, it can also function as a vector for foodborne pathogens. This literature review reveals that tilapia could carry a variety of contamination with various foodborne pathogens, including Plesiomonas shigelloides, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, Salmonella Weltevreden, Salmonella enterica, Shigella, Staphylococcus aureus, Campylobacter jejuni, Clostridium botulinum, and Listeria monocytogenes. Although guidelines from entities, such as the Global Seafood Alliance, Aquaculture Stewardship Council, and International Organization for Standardization, have been established to ensure the microbiological safety of tilapia, the unique challenges posed by pathogens in tilapia farming call for a more nuanced and targeted approach. Recognizing that contaminants could emerge at various stages of the tilapia supply chain, there is a crucial need for enhanced detection and monitoring of pathogens associated with this fish and its culturing environment. Additionally, it is essential to acknowledge the potential impact of climate change on the safety of tilapia, which may elevate the prevalence and contamination levels of pathogens in this fish. Proactive measures are essential to understand and mitigate the effects of climate change on tilapia production, ensuring the sustainability and safety of this seafood product for both present and future generations.

Surge in Mycoplasma Pneumoniae infection and Respiratory Viruses Co-infection in Children With Community-Acquired Pneumonia in the Post-Pandemic.

During the COVID-19 pandemic, multifaceted non-pharmaceutical interventions have not only reduced the transmission of SARS-CoV2 but also affected the prevalence of other respiratory pathogens. With the lifting of many restrictions, a surge in cases of pneumonia in children has been reported in many hospitals in China. The study assessed the changes in pathogen and symptoms of children with community-acquired pneumonia (CAP) before and after the adjustments of prevention and control measures of epidemic and provided recommendations for CAP in children. Children diagnosed with CAP were enrolled in the study from 2022 to 2023. A cross-sectional retrospective study was conducted in a general hospital. We analyzed the data about demographic data, clinical symptoms, pathogens, and medical treatments. The Chi-square and Mann-Whitney U-test were used to assess the statistical significance of groups. We studied 1103 children, 339 in 2022 and 764 in 2023. Compared with children in 2022, more children were diagnosed with CAP in 2023 and these children had a higher body temperature and levels of CRP and PCT, which indicated these children got severe inflammation. The positive rate of the pathogen was also higher in 2023, especially the detective rate of Mycoplasma pneumoniae. The number of children infected with more than two pathogens was higher in 2023, especially those co-infected with the virus and M. Pneumoniae. Concerning the medicine therapy, the usage of β-lactam antibiotics, Macrolide antibiotics, and antiviral drugs kept rapid growth. After the adjustment of epidemic prevention and control policies in 2023, more children got CAP with severe clinical symptoms, and more antibiotics and antiviral drugs were used. Further study is needed to explore the reasons for the increase in children with CAP and to explore the rationality of treatment.

ESKAPE Pathogens: Antimicrobial Resistance Patterns, Risk Factors, and Outcomes a Retrospective Cross-Sectional Study of Hospitalized Patients in Palestine.

Antimicrobial resistance to ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp). remains a major challenge in hospital settings. This study aimed to determine the ESKAPE antimicrobial resistance patterns and associated factors with multi-drug resistance strains among hospitalized patients in a single tertiary care medical hospital in Palestine. A single-center retrospective cross-sectional study was conducted by reviewing patients' electronic medical records and laboratory results from November 1, 2021, to November 30, 2022, at the Palestine Medical Complex in Palestine. The study included patients aged > 18 years who had been infected with ESKAPE pathogens 48 hours after hospital admission. This study included 231 patients, of whom 90.5% had MDR infections. In total, 331 clinical samples of ESKAPE pathogens were identified. A. baumannii was the most prevalent MDR pathogen (95.6%) with Carbapenem-resistant exceeding 95%, followed by K. pneumoniae (83.8%) with extended-spectrum cephalosporin resistance exceeding 90%, S. aureus (68.2) with 85% oxacillin-resistance, E. faecium (40%) with 20% vancomycin resistance, P. aeruginosa (22.6%) with 30% carbapenem resistance. Furthermore, emergent colistin resistance has been observed in A. baumannii, K. pneumoniae, and P. aerogenesis. Risk factors for MDR infection included age (p< 0.035), department (p< 0.001), and invasive procedures such as IUC (p< 0.001), CVC (p< 0.000), and MV (p< 0.008). Patients diagnosed with MDR bacteria had increased 30-day mortality (p< 0.001). The findings of this study show alarming MDR among hospitalized patients infected with ESKAPE pathogens, with resistance to first-line antimicrobial agents and emerging resistance to colistin, minimizing treatment options. Healthcare providers and the Ministry of Health must take steps, adopt policies to prevent antimicrobial resistance, adhere to infection control guidelines, implement antimicrobial stewardship programs to prevent and limit the growing health crisis, and support research to discover new treatment options.

Dental Caries: Unveiling the State-of-the-art Insights and Crafting Hypotheses for Oral Health.

The pathophysiological understanding of dental caries explains that the primary factor responsible is linked to an imbalance in microbial composition within the oral cavity, stemming from both artificial and natural sources. Streptococcus mutans (S. mutans) is the most accountable and prevalent pathogen for caries development among the diverse pool. S. mutans, an acidogenic bacterium, lowers oral pH through the metabolic conversion of dietary sugar into organic acids, leading to enamel demineralization and dental caries. Numerous antibacterial interventions have been employed in the past to address this issue. However, adopting such an approach poses the risk of exacerbating concerns related to Antimicrobial Resistance (AMR) and long-term oral cytotoxicity. In response to this, a sustainable strategy is suggested, involving the utilization of L-Arginine (L-Arg) as a probiotic nutrient supplement for non-pathogenic microbes. It will help in creating a natural competitive environment against the pathogenic microbes responsible for initiating dental caries. The hypothesis involves utilizing a combination of a nutrient supplement and the repurposed drug Piceatannol, specifically for its anti-biofilm properties. This combination synergistically improves the effectiveness of the therapy by converting the complex microbial biofilm into a planktonic state.

Identification, Antibiotic Profiling of Potential Pathogenic Bacteria from Fomites in Neonatal Intensive Care Units in a Tertiary Teaching Hospital of North Karnataka

This study was taken up to determine the prevalence of potential pathogens in most touched fomites in Neonatal Intensive Care Units (NICUs) and to determine their antibiogram. Fifty swabs each were collected from fomites from In-born (for babies born in our center) and out-born (for babies born elsewhere, brought to our center) NICUs, before and after cleaning. Samples were processed using standard Microbiological techniques. Antibiogram was determined by Kirby-Bauer disc diffusion method. From In-born NICU, before cleaning, 42 (84%) samples yielded growth with 48 bacterial isolates of which 31 (64.6%) were pathogens and after cleaning, 40 (80%) samples yielded growth with 41 bacterial isolates, of which 30 (73.1%) were pathogens. Most frequent isolates were non-fermenting gram-negative bacilli (NFGNB) and Klebsiella pneumoniae before and after cleaning, respectively. Prevalence of bacteria from In-born NICU before and after the cleaning was statistically significant (p = 0.025). From Out-born NICU, before cleaning, 42 (84%) samples yielded growth with 45 bacterial isolates, of which 25 (55.55%) were pathogens. Samples collected after cleaning; 42 (84%) samples yielded growth with 43 bacterial isolates of which 19 (44.18%) were pathogens. Most frequent isolates were NFGNB and Klebsiella pneumoniae from In-born NICU and K. pneumoniae and Escherichia coli from Out-born NICU before and after cleaning, respectively. Overall prevalence of pathogens was significant (p = 0.007). Staphylococcal isolates were resistant to Methicillin. NFGNB exhibited highest resistance (55.9%) towards Gentamicin. Significant decrease in the frequency of pathogens after cleaning indicates stringent practice of sterilization protocol would be essential in hospital environment.

Zoonotic potential of urban wildlife faeces, assessed through metabarcoding

Monitoring zoonoses in urban environments is of great relevance, where the incidence of certain pathogens may be higher and where population density makes the spread of any contagious disease more likely. In this study we applied a metabarcoding approach to study potentially zoonotic pathogens in faecal samples of 9 urban vertebrate species. We applied this methodology with two objectives. Firstly, to obtain information on potential pathogens present in the urban fauna of a large European city (Madrid, Spain) and to determine which are their main reservoirs. In addition, we tested for differences in the prevalence of these potential pathogens between urban and rural European rabbits, used as ubiquitous species. Additionally, based on the results obtained, we evaluated the effectiveness of metabarcoding as a tool for monitoring potential pathogen. Our results revealed the presence of potentially zoonotic bacterial genera in all studied host species, 10 of these genera with zoonotic species of mandatory monitoring in the European Union. Based on these results, urban birds (especially house sparrows and pigeons) and bats are the species posing the greatest potential risk, with Campylobacter and Listeria genera in birds and of Chlamydia and Vibrio cholerae in bats as most relevant pathogens. This information highlights the risk associated with fresh faeces from urban wildlife. In addition, we detected Campylobacter in >50 % of the urban rabbit samples, while we only detected it in 11 % of the rural rabbit samples. We found that urban rabbits have a higher prevalence of some pathogens relative to rural rabbits, which could indicate increased risk of pathogen transmission to humans. Finally, our results showed that metabarcoding can be an useful tool to quickly obtain a first screening of potentially zoonotic organisms, necessary information to target the monitoring efforts on the most relevant pathogens and host species.

Analyzing the Prevalence and Patterns of Antibiotic-Resistant Pathogens Causing Surgical Site Infections

Surgical Site Infections (SSIs) remain a critical healthcare challenge, contributing to increased morbidity, mortality, and healthcare costs. SSIs represent the third most common nosocomial infection globally with an incidence of 19-20%, while their prevalence in Pakistan was significantly higher, ranging up to 33.6%. The emergence of Multidrug-Resistant (MDR) organisms has worsened this issue. Objective: To determine the prevalence of antibiotic-resistant pathogens responsible for SSIs and analyze their antibiotic susceptibility patterns over the past decade. Methods: A systematic review was conducted adhering to PRISMA guidelines. Studies published between 2006 and 2023 were included. Data on the prevalence of antibiotic-resistant organisms associated with SSIs were extracted and analyzed through several databases (PubMed, Google Scholar, Sci-hub and Science Direct) using Boolean logic “AND” and “OR”, and Medical Subject Headings (MeSH Terms) and keywords. A total of 70 articles were retrieved from which 16 articles were considered eligible after applying detailed inclusion/exclusion criteria and removing the duplicates and irrelevant articles. Results: The study identified Staphylococcus aureus, coagulase-negative staphylococci, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter spp. as predominant MDR pathogens. A significant increase in the prevalence of antibiotic-resistant strains was observed over the study period. Gram-negative bacteria exhibited a higher resistance rate (66.8%) compared to Gram-positive organisms (51.1%). Conclusions: The increasing prevalence of antibiotic-resistant pathogens underscores the urgent need for comprehensive infection prevention and control measures to address the burden of SSIs. Targeted interventions, antimicrobial stewardship, and continued surveillance were essential to combat this growing challenge.

Effects of Peromyscus spp. (Rodentia: Cricetidae) presence, land use, and ecotone on Ixodes scapularis (Acari: Ixodidae) ecology in an emergent area for tick-borne disease.

As the range of Ixodes scapularis Say expands, host abundance and land use can play important roles in regions where ticks and their associated pathogens are emerging. Small mammal hosts serve as reservoirs of tick-borne pathogens, with Peromyscus leucopus Rafinesque often considered a primary reservoir. A sympatric species Peromyscus maniculatus Wagner is also a competent reservoir and is notoriously difficult to differentiate from P. leucopus. Anthropogenic land use can alter host and habitat availability, potentially changing tick exposure risk. We tested the hypotheses that tick infestation and pathogen prevalence differ between the two Peromyscus spp. and that host-seeking I. scapularis density and pathogen prevalence differ across land use and ecotone gradients. We live trapped small mammals and collected ticks across 3 land-use classifications and ecotones in Maine, an emergent area for tick-borne disease. We tested each small mammal and tick sample for Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti. While both Peromyscus spp. serve as hosts for immature ticks, P. leucopus exhibited a higher tick infestation frequency and intensity. We did not detect any significant difference in pathogen infection prevalence between the two species. The density of I. scapularis nymphs and the density of infected nymphs did not differ significantly between land-use types, though did differ across ecotones. We also noted a significant north/south gradient, with higher tick densities and pathogen prevalence at the southern end of the study area. Our study highlights the potential variability in tick density and pathogen prevalence across fine spatial scales within an emerging region for tick-borne disease.

Visual fluorescence detection of Listeria monocytogenes with CRISPR-Cas12a aptasensor.

Listeria monocytogenes (L. monocytogenes) is a prevalent food-borne pathogen that can cause listeriosis, which manifests as meningitis and other symptoms, potentially leading to fatal outcomes in severe cases. In this study, we developed an aptasensor utilizing carboxylated magnetic beads and Cas12a to detect L. monocytogenes. In the absence of L. monocytogenes, the aptamer maintains its spatial configuration, keeping the double-stranded DNA attached and preventing the release of a startup template and activation of Cas12a's trans-cleavage capability. Conversely, in the presence of L. monocytogenes, the aptamer undergoes a conformational change, releasing the double-stranded DNA to serve as a startup template, thereby activating the trans-cleavage capability of Cas12a. Consequently, as the concentration of L. monocytogenes increases, the observable brightness in a blue light gel cutter intensifies, leading to a rise in fluorescence intensity difference compared to the control. This Cas12a aptasensor demonstrates excellent sensitivity towards L. monocytogenes, with a lowest detection limit (LOD) of 57.15CFU/mL and a linear range of 4×102 to 4×107 CFU/mL (R2=0.9858). Notably, the proposed Cas12a aptasensor exhibited outstanding selectivity and recovery in beef samples, and could be employed for precise monitoring. This Cas12a aptasensor not only provides a novel fluorescent and visual rapid detection method for L. monocytogenes but also offers simplicity, speed, and stability compared to previous detection methods. Furthermore, it is suitable for on-site detection of beef samples.

Polyamide microplastics can mitigate the effects of pathogenic bacterium on the health of marine mussels

Vibrio parahaemolyticus and microplastics are prevalent in the ocean. Bacteria attach onto plastic particles, forming harmful biofilms that collectively threaten bivalve health. This study investigates the interaction between polyamide microplastics (PA: particle size 38 ± 12 µm) and V. parahaemolyticus, as well as their combined impact on thick-shelled mussels (Mytilus coruscus). We introduced 1011 CFU/L of V. parahaemolyticus into varying PA concentrations (0, 5, 50, and 500 particles/L) to observe growth over 14 h and biofilm formation after 48 h. Our findings indicate that microplastics suppress biofilm formation and virulence gene expression. Four treatments were established to monitor mussel responses: a control group without PA or V. parahaemolyticus; a group with 50 particles/L PA; a group with 1011 CFU/L V. parahaemolyticus; and a co-exposure group with both 50 particles/L PA and 1011 CFU/L V. parahaemolyticus, over a 14-day experiment. However, combined stress from microplastics and Vibrio led to immune dysregulation in mussels, resulting in intestinal damage and microbiome disruption. Notably, V. parahaemolyticus had a more severe impact on mussels than microplastics alone, yet their coexistence reduced some harmful effects. This study is the first to explore the interaction between microplastics and V. parahaemolyticus, providing important insights for ecological risk assessments.

Metabarcoding study of potential pathogens and zoonotic risks associated with dog feces in Seoul, South Korea.

A significant portion of South Korea's population, approximately a quarter, owns pets, with dogs being the most popular choice among them. However, studies analyzing the fecal organism communities of dogs in South Korea are lacking, and limited efforts have been exerted to identify pathogens with potential zoonotic implications. Therefore, this study aimed to investigate potential pathogens using metabarcoding analysis and evaluate the risk of zoonotic diseases in dog feces in Seoul, South Korea. Fecal samples were collected from both pet and stray dogs in the Mapo district of Seoul. Next-generation sequencing (NGS) was utilized, employing 16S rRNA amplicon sequencing to identify prokaryotic pathogens, and 18S rRNA amplicon sequencing for eukaryotic pathogens. The data obtained from the QIIME2 pipeline were subjected to various statistical analyses to identify different putative pathogens and their compositions. Significant variations in microbiota composition were found between stray and pet dogs, and putative prokaryotic and eukaryotic pathogens were identified. The most prevalent putative bacterial pathogens were Fusobacterium, Helicobacter, and Campylobacter. The most prevalent putative eukaryotic pathogens were Giardia, Pentatrichomonas, and Cystoisospora. Interestingly, Campylobacter, Giardia, and Pentatrichomonas were found to be significantly more prevalent in stray dogs than in pet dogs. The variation in the prevalence of potential pathogens in dog feces could be attributed to environmental factors, including dietary variances and interactions with wildlife, particularly in stray dogs. These factors likely contributed to the observed differences in pathogen occurrence between stray and pet dogs. This study offers valuable insights into the zoonotic risks associated with dog populations residing in diverse environments. By identifying and characterizing putative pathogens in dog feces, this research provides essential information on the impact of habitat on dog-associated pathogens, highlighting the importance of public health planning and zoonotic risk management.

Nestling sex and behaviour determine the host preference of insect vectors in avian nests.

Sexual differences in pathogen prevalence in wildlife often arise from varying susceptibility influenced by factors such as sex hormones and exposure to pathogens. In the case of vector-borne pathogens, host selection by insect vectors determines the exposure of hosts to infections, largely affecting the transmission of these infectious diseases. We identify the blood-feeding patterns of insect vectors in Blue Tit (Cyanistes caeruleus) nestlings in a 3-year study. Blood from both nestlings and insect vectors (Culicoides spp. and Simuliidae) captured inside nest-boxes were used to molecularly determine the sex of the host. We then compared the sex-ratios of the nestlings that had been bitten and those of the complete brood in each nest. We found that males were bitten more frequently than females in 2021, when males weighed less in comparison to other years. Additionally, we molecularly identified bitten nestlings individually by genotyping the DNA of blood obtained from both, the vector's abdomen and nestlings of each brood in 2022. Nestlings more frequently bitten by vectors were males, weighed less and were closest to the nest entrance. To our knowledge this is the first study identifying the nestling selection by insect vectors in bird nests under natural conditions. These results contribute to understanding the mechanisms of host selection by insect vectors, shedding light on pathogen transmission and offering insights into the observed sex-biased infections in wildlife populations.

Sensitive colorimetric detection of Escherichia coli in milk using Au@Ag core-shell nanoparticles

Escherichia coli (E. coli) is a prevalent pathogen that is frequently associated with the foodborne illness. It causes various infections and poses a significant threat to human health. A rapid and sensitive assay for detecting E. coli is essential for timely diagnosis. Herein, a simple and sensitive colorimetric analysis method for detecting E. coli was developed based on the formation of Au@Ag core-shell nanoparticles facilitated by p-benzoquinone (BQ). E. coli reduced p-benzoquinone to generate hydroquinone (HQ), which could reduce the added Tollens’ reagent to silver elemental and grow on the surface of gold nanoparticles (AuNPs). As the E. coli concentration increased, the silver layer thickess on the AuNPs surface growed, resulting in a stronger silver absorption peak observed at 390 nm. The color of the solution changed from red to orange, which could be used to detect E. coli by the naked eye. As a result, E. coli was detected with a linear range from 1.0 × 101 to 1.0 × 107 CFU/mL based on the absorbance intensity. In addition, this method accurately detected E. coli in real milk sample, demonstrating promising applications in foodborne pathogen detection. With satisfactory accuracy, the proposed colorimetric method holds excellent prospects in detecting pathogens in actual food samples.