Etiologic Agent Research Articles

First report of Equine Parvovirus-Hepatitis (EqPV-H) in Argentina

The novel Equine Parvovirus-Hepatitis (EqPV-H) was first identified in the serum and liver of a horse that died of equine serum hepatitis, also known as Theiler's disease. Several reports in recent years strongly suggest that EqPV-H is the etiologic agent of Theiler's disease. Brazil is the only South American country where infection with this virus has been reported. This study investigated the presence of EqPV-H DNA in horse serum pools (n=51), commercial horse serum batches (n=5) and individual serum samples from donor horses (n=175) from Argentina. All serum samples were analyzed by quantitative polymerase chain reaction (qPCR) and samples with positive or indeterminate results were further analyzed by NS1 nested-PCR for phylogenetic studies.None of the serum pools was positive by qPCR but 9/51 pools were indeterminate (one or both test sample’s Ct values were higher than the limit of detection). The NS1 nested-PCR detected the EqPV-H DNA in 8 of these indeterminate samples (15.7 % of serum pools). Three of the commercial horse serum batches (60 %) contained EqPV-H DNA, detected either by qPCR and/or nested-PCR. From the 175 individual horse serum samples, three (1.71 %) were positive for EqPV-H by both techniques. The genetic analysis of the 12 partial NS1 sequences obtained showed that the local isolates were similar to EqPV-H sequences from Germany and China. This study provides the first evidence of the presence of EqPV-H in horses and in horse sera commercially available in Argentina and emphasizes the importance of controlling the biosecurity of commercial equine sera as well as any other blood-derived biological products of equine origin. Data availabilityViral sequences generated in this study were uploaded to the NCBI nucleotide database and are available with the accession numbers PP408676-PP408687.

Fungal Musculoskeletal Infections: Comprehensive Approach to Proper Diagnosis.

Fungal musculoskeletal infections often have subacute or indolent manifestations, making it difficult to distinguish them from other diseases and infections, given that they are relatively uncommon. Fungal infections occur by hematogenous spread, direct inoculation, or contiguous extension and may be related to different risk factors, including immunosuppression and occupational activity. The infection can manifest in isolation in the musculoskeletal system or as part of a systemic process. The fungi may be endemic to certain regions or may be found throughout the world, and this can help to narrow the diagnosis of the etiologic agent. Infections such as candidiasis, cryptococcosis, aspergillosis, and mucormycosis are often related to immunosuppression. On the other hand, histoplasmosis, paracoccidioidomycosis, coccidioidomycosis, and blastomycosis can occur in healthy patients in geographic areas where these infections are endemic. Furthermore, infections can be classified on the basis of the site of infection in the body. Some subcutaneous infections that can have osteoarticular involvement include mycetoma, sporotrichosis, and phaeohyphomycosis. Different fungi affect specific bones and joints with greater prevalence. Imaging has a critical role in the evaluation of these diseases. Imaging findings include nonspecific features such as osteomyelitis and arthritis, with bone destruction, osseous erosion, mixed lytic and sclerotic lesions, and joint space narrowing. Multifocal osteomyelitis and chronic arthritis with joint effusion and synovial thickening may also occur. Although imaging findings are often nonspecific, some fungal infections may show findings that aid in narrowing the differential diagnosis, especially when they are associated with the patient's clinical condition and history, the site of osteoarticular involvement, and the geographic location. ©RSNA, 2024.

Role of Moringa oleifera irrigation solution on the cell metabolism change of Streptococcus mutans

The principal etiological agent responsible for dental caries is Streptococcus mutans (S. mutans). The Moringa oleifera (M. oleifera) possesses antioxidant and antibacterial properties that function through the response to oxidative stress, which affects bacterial cell metabolism. This research examined M. oleifera impact on S. mutans growth, toxicity, glucan-binding protein (GBP) expression, and nucleic acid structure. Methods included spectrophotometry for growth analysis, enzyme-linked immunosorbent assay for GBP quantification, the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) MTT assay for cytotoxicity, Fourier transform infrared for nucleic acid changes, and docking simulation for ligand-receptor affinity. Results showed that M. oleifera significantly inhibited S. mutans growth at all concentrations over 24 and 48 h (optical density <0.1), comparable to <300 CFU/mL. At 72 h, 6.25% and 3.125% concentrations were most effective, with chlorhexidine also showing stability at these times. A 3.125% concentration of M. oleifera notably reduced GBP production to below 15% and caused cell toxicity. Furthermore, 25% and 3.125% concentrations significantly altered S. mutans nucleic acids, and M. oleifera showed high binding affinity to the GBP gene receptor. Thus, M. oleifera can inhibit S. mutans growth and GBP production, cause nucleic acid deformation, and strongly bind to the GBP receptor, highlighting its potential in dental caries prevention.

First detection of multiple cases related to CV-A16 strain of B1c clade in Beijing in 2022.

Coxsackievirus A16 (CV-A16) is a significant etiologic agent of hand, foot, and mouth disease (HFMD) and herpangina (HA), with the capacity to progress to severe complications, including encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis, and other critical conditions. Beijing's epidemiological surveillance system, established in 2008, encompasses 29 hospitals and 16 district disease control centers. From 2019 to 2021, the circulation of CV-A16 was characterized by the co-circulation of B1a and B1b clades. Multiple cases of HFMD linked to clade B1c has not been reported in Beijing until 2022. This study enrolled 400 HFMD and 493 HA cases. Employing real-time RT-PCR, 368 enterovirus-positive cases were identified, with 180 selected for sequencing. CV-A16 was detected in 18.89% (34/180) of the cases, second only to CV-A6, identified in 63.33% (114/180). Full-length VP1 gene sequences were successfully amplified and sequenced in 22 cases, revealing the presence of clades B1a, B1b, and B1c in 14, 3, and 5 cases, respectively. A cluster of five B1c clade cases occurred between June 29 and July 17, 2022, within a 7-km diameter region in Shunyi District. Phylogenetic analysis of five complete VP1 gene sequences and two full-genome sequences revealed close clustering with the 2018 Indian strain (GenBank accession: MH780757.1) within the B1c India branch, with NCBI BLAST results showing over 98% similarity. Comparative sequence analysis identified three unique amino acid variations (P3S, V25A, and I235V). The 2022 Shunyi District HFMD cases represent the first instances of spatiotemporally correlated CV-A16 B1c clade infections in Beijing, underscoring the necessity for heightened surveillance of B1c clade CV-A16 in HFMD and HA in this region.

Microbiological Profile and Antibiotic Resistance Pattern in Acuteexacerbations of COPD: A Study from Northern India

Background Chronic Obstructive Pulmonary Disorder (COPD) is a major cause of morbidity and one of the principal causes of death worldwide. The objective of this study is to identify the bacterial etiological agents in patients with acute exacerbations of COPDs by sputum culture and their antibiogram.MethodsThis is a prospective study comprising 100 diagnosed patients of COPD taken as GOLD Grade 4 who were admitted in the Department of Pulmonary Medicine, TB and Chest Hospital which comes under King George Hospital, Visakhapatnam.ResultsOut of 100 patients, 83 were males of which 87% were smokers. The most common organisms isolated were Gram negative bacilli in 51 patients and only 26 were Gram positive cocci. The most common Gram-negative isolate was Klebsiella pneumoniae 27 cases followed by Pseudomonas aeruginosa in 19 cases. The most common Gram-positive isolate was Streptococcus pneumoniae in 16 cases followed by Streptococcus pyogenes in 6 cases and Staphylococcus aureus in 2 cases.Conclusions Frequent exacerbations appear to be associated with worsening healthoutcomes and effort should focus on prompt and effective treatment of eachepisode. Bacterial pathogens, mostly Gram negative bacilli are found to be the chief etiological agents in AECOPD. Antibiotic therapy should be initiated early depending on the culture. Susceptibility patterns of that particular region should be determined to prevent antibiotic resistance and to decrease health costs.

HPV Detection in Breast Tumors and Associated Risk Factors in Northeastern Brazil.

Breast cancer risk factors include lifestyle, genetic-hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the clinical and sociodemographic characteristics, correlating them with various breast cancer tumor types. HPV detection involved amplifying the L1 region, with viral load measured using the E2/E6 ratio and viral activity indicated by E5 oncogene expression. Predominantly, patients over 56 years of age with healthy lifestyles showed a high incidence of invasive ductal carcinoma and triple-negative breast cancer. HPV was detected in 35.7% of cases, mostly HPV16, which is associated with high viral loads (80 copies per cell) and significant E5 expression. These results hint at a possible link between HPV and breast carcinogenesis, necessitating further studies to explore this association and the underlying viral mechanisms.

Trypanosoma cruzi Vps34 colocalizes with Beclin1 and plays a role in parasite invasion of the host cell by modulating the expression of a sub-group of trans-sialidases

Trypanosoma cruzi, the etiological agent of Chagas' disease, can infect both phagocytic and non-phagocytic cells. T. cruzi gp82 and gp90 are cell surface proteins belonging to Group II trans-sialidases known to be involved in host cell binding and invasion. Phosphatidylinositol kinases (PIK) are lipid kinases that phosphorylate phospholipids in their substrates or in themselves, regulating important cellular functions such as metabolism, cell cycle and survival. Vps34, a class III PIK, regulates autophagy, trimeric G-protein signaling, and the mTOR (mammalian Target of Rapamycin) nutrient-sensing pathway. The mammalian autophagy gene Beclin1 interacts to Vps34 forming Beclin 1–Vps34 complexes involved in autophagy and protein sorting. In T. cruzi epimastigotes, (a non-infective replicative form), TcVps34 has been related to morphological and functional changes associated to vesicular trafficking, osmoregulation and receptor-mediated endocytosis. We aimed to characterize the role of TcVps34 during invasion of HeLa cells by metacyclic (MT) forms. MTs overexpressing TcVps34 showed lower invasion rates compared to controls, whilst exhibiting a significant decrease in gp82 expression in the parasite surface. In addition, we showed that T. cruzi Beclin (TcBeclin1) colocalizes with TcVps34 in epimastigotes, thus suggesting the formation of complexes that may play conserved cellular roles already described for other eukaryotes.

Identification of Lutzomyia longipalpis' using MALDI-TOF peptide/protein profiles

Sand flies are vectors of great public health importance, since they constitute a group of hematophagous insects responsible for etiological agents transmission of zoonotic diseases such a visceral leishmaniasis. In face of the expansion of these diseases, efficient control strategies are needed which depend on comprehending the sand fly eco-epidemiology. In this regard, MALDI-TOF mass spectrometry has been used for bacteria, fungi and yeast detection studies through peptide/protein profiles. However, little is known about interference of biological factors associated with vector ecology, such as blood meal preferences and even sand fly age on the peptide/protein profiles. Thus, the present study aimed to evaluate the differences in peptide/protein profiles of the sand fly Lutzomyia longipalpis, by means of MALDI-TOF, due to the sand fly's age, sex, blood meal source and Leishmania infantum infection. Sample preparation was made removing both head and last abdomen segments keeping the thorax, its appendices and the rest of the abdomen. Five specimens per pool were used to obtain peptide/protein extract of which 1 μL solution was deposited over 1 μL MALDI matrix dried. Characteristic spectra were analyzed using principal coordinate analysis as well as indicator species analysis to discriminate differences in sand flies's peptide/protein profile by sex, age, blood meal source and L. infantum infection. The results show that the evaluated variables produced distinct peptide/protein profiles, demonstrated by the identification of specific diagnostic ions. It was found that the interference of biological factors should be taken into account when using the MALDI-TOF analysis of sand fly species identification and eco-epidemiological applications in field studies. Based on our results, we believe that it is possible to identify infected specimens and the source of blood meal in a collection of wild sand flies, serving to measure infectivity and understand the dynamics of the vector's transmission chain. Our results may be useful for epidemiological studies that look at the ecology of sand flies and leishmaniasis, as well as for raising awareness of biological characteristics’ impact on peptide/protein profiles in sand fly species identification.

Outbreak of cholera due to contaminated pond water utilisation in a rural area of West Bengal, India, 2021

BackgroundOn March 31, 2021, an outbreak of diarrhoeal disease was reported in Dangapara village of Purba Bardhaman district, West Bengal, India. The outbreak was investigated to estimate the magnitude, identify aetiological agents and source of infection, and guide prevention control measures. MethodsWe did an active search for case patients at Dangapara village. We excluded children under five years of age from the epidemiological analysis. We described the outbreak by time, place, and person. We conducted a case control study with 133 controls and 65 cases. Water samples from different sources and rectal swabs from case patients were collected and sent for laboratory investigations. ResultsWe identified 95 case patients among 330 residents of Dangapara village (attack rate 29 %). Three stool samples were positive for Vibrio cholerae, and two pond water samples were contaminated with coliform organisms. Washing utensils [adjusted odds ratio (AOR): 69.8, (95% confidence interval (CI) 6.5–749.5)] and taking a bath in pond water [AOR: 3.4, (95% CI 1.2–9)] were associated with increased risk of illness. About 97% of cases were attributed to washing utensils in pond water. Washing hands before taking food was associated with a lower risk of developing disease with AOR: 0.1 (95% CI 0.03–0.33). ConclusionA cholera outbreak occurred among residents of Dangapara village due to theuse of contaminated pond water for washing utensils and bathing. Prompt management of cases and immediate discontinuation of pond water use stopped the outbreak.

SARS-CoV-2 Nucleocapsid Protein Induces Tau Pathological Changes That Can Be Counteracted by SUMO2.

Neurologic manifestations are an immediate consequence of SARS-CoV-2 infection, the etiologic agent of COVID-19, which, however, may also trigger long-term neurological effects. Notably, COVID-19 patients with neurological symptoms show elevated levels of biomarkers associated with brain injury, including Tau proteins linked to Alzheimer's pathology. Studies in brain organoids revealed that SARS-CoV-2 alters the phosphorylation and distribution of Tau in infected neurons, but the mechanisms are currently unknown. We hypothesize that these pathological changes are due to the recruitment of Tau into stress granules (SGs) operated by the nucleocapsid protein (NCAP) of SARS-CoV-2. To test this hypothesis, we investigated whether NCAP interacts with Tau and localizes to SGs in hippocampal neurons in vitro and in vivo. Mechanistically, we tested whether SUMOylation, a posttranslational modification of NCAP and Tau, modulates their distribution in SGs and their pathological interaction. We found that NCAP and Tau colocalize and physically interact. We also found that NCAP induces hyperphosphorylation of Tau and causes cognitive impairment in mice infected with NCAP in their hippocampus. Finally, we found that SUMOylation modulates NCAP SG formation in vitro and cognitive performance in infected mice. Our data demonstrate that NCAP induces Tau pathological changes both in vitro and in vivo. Moreover, we demonstrate that SUMO2 ameliorates NCAP-induced Tau pathology, highlighting the importance of the SUMOylation pathway as a target of intervention against neurotoxic insults, such as Tau oligomers and viral infection.

Investigating the Effectiveness of Ceragenins against Acinetobacter baumannii to Develop New Antimicrobial and Anti-Adhesive Strategies.

A growing body of experimental data indicates that ceragenins (CSAs), which mimic the physicochemical properties of the host's cationic antimicrobial peptide, hold promise for the development of a new group of broad-spectrum antimicrobials. Here, using a set of in vivo experiments, we assessed the potential of ceragenins in the eradication of an important etiological agent of nosocomial infections, Acinetobacter baumannii. Assessment of the bactericidal effect of ceragenins CSA-13, CSA-44, and CSA-131 on clinical isolates of A. baumannii (n = 65) and their effectiveness against bacterial cells embedded in the biofilm matrix after biofilm growth on abiotic surfaces showed a strong bactericidal effect of the tested molecules regardless of bacterial growth pattern. AFM assessment of bacterial cell topography, bacterial cell stiffness, and adhesion showed significant membrane breakdown and rheological changes, indicating the ability of ceragenins to target surface structures of A. baumannii cells. In the cell culture of A549 lung epithelial cells, ceragenin CSA-13 had the ability to inhibit bacterial adhesion to host cells, suggesting that it interferes with the mechanism of bacterial cell invasion. These findings highlight the potential of ceragenins as therapeutic agents in the development of antimicrobial strategies against bacterial infections caused by A. baumannii.

An injectable subunit vaccine containing Elongation Factor Tu and Heat Shock Protein 70 partially protects American bison from Mycoplasma bovis infection.

Mycoplasma bovis (M. bovis) is the etiologic agent of high mortality epizootics of chronic respiratory disease in American bison (Bison bison). Despite the severity of the disease, no efficacious commercial vaccines have been licensed for the prevention of M. bovis infection in bison. Elongation factor thermal unstable (EFTu) and Heat Shock Protein 70 (Hsp70, DnaK) are highly conserved, constitutively expressed proteins that have previously been shown to provide protection against M. bovis infection in cattle. To assess the suitability of EFTu and Hsp70 as vaccine antigens in bison, the immune response to and protection conferred by an injectable, adjuvanted subunit vaccine comprised of recombinantly expressed EFTu and Hsp70 was evaluated. Vaccinates developed robust antibody and cellular immune responses against both EFTu and Hsp70 antigens. To assess vaccine efficacy, unvaccinated control and vaccinated bison were experimentally challenged with bovine herpes virus-1 (BHV-1) 4 days prior to intranasal infection with M. bovis. Vaccinated bison displayed reductions in joint infection, lung bacterial loads, and lung lesions compared to unvaccinated controls. Together, these results showed that this subunit vaccine reduced clinical disease and bacterial dissemination from the lungs in M. bovis challenged bison and support the further development of protein subunit vaccines against M. bovis for use in bison.

High-density resolution of the Kaposi's sarcoma associated herpesvirus transcriptome identifies novel transcript isoforms generated by long-range transcription and alternative splicing.

Kaposi's sarcoma-associated herpesvirus is the etiologic agent of Kaposi's sarcoma and two B-cell malignancies. Recent advancements in sequencing technologies have led to high resolution transcriptomes for several human herpesviruses that densely encode genes on both strands. However, for KSHV progress remained limited due to the overall low percentage of KSHV transcripts, even during lytic replication. To address this challenge, we have developed a target enrichment method to increase the KSHV-specific reads for both short- and long-read sequencing platforms. Furthermore, we combined this approach with the Transcriptome Resolution through Integration of Multi-platform Data (TRIMD) pipeline developed previously to annotate transcript structures. TRIMD first builds a scaffold based on long-read sequencing and validates each transcript feature with supporting evidence from Illumina RNA-Seq and deepCAGE sequencing data. Our stringent innovative approach identified 994 unique KSHV transcripts, thus providing the first high-density KSHV lytic transcriptome. We describe a plethora of novel coding and non-coding KSHV transcript isoforms with alternative untranslated regions, splice junctions and open-reading frames, thus providing deeper insights on gene expression regulation of KSHV. Interestingly, as described for Epstein-Barr virus, we identified transcription start sites that augment long-range transcription and may increase the number of latency-associated genes potentially expressed in KS tumors.

Differences in enteric pathogens and intestinal microbiota between diarrheic weaned piglets and healthy penmates

Postweaning diarrhea (PWD) is a multifactorial disease caused by different aetiological agents, like viruses or bacteria and where the role of the microbiota remains unclear. The aim of this study was to assess differences between healthy and diarrheic weaned pigs concerning the prevalence of pathogens and changes in the intestinal microbiota. Eighteen farms with PWD were selected and 277 fecal samples were collected (152 diarrheic vs 125 healthy). Presence of Rotavirus A (RVA), B (RVB), C (RVC) and Porcine Epidemic Diarrhea Virus (PEDV), virulence factors of Escherichia coli and Clostridioides difficile were analyzed by PCR. Finally, the microbiota composition was also study by 16 S rRNA sequencing on 148 samples (102 diarrheic vs 46 healthy). RVA (53.95 % vs 36 %, p=0.04) and RVB (49.67 % vs 28.8 %, p<0.001) were more frequent in diarrheic animals. Furthermore, RVA viral load was higher in diseased animals. VT2 toxin was significantly associated with diarrhea, whereas other virulence factors were not. Presence of C. difficile and PEDV was almost negligible. Regarding microbiota changes, Fusobacteriota phylum was more frequent in diarrheic samples and Ruminococcaceae family in healthy penmates. During the first week postweaning, Enterobacteriace and Campylobacteria were enriched in animals presenting diarrhea. Furthermore, Lactobacillus was detected in those individuals with no RVA infection. In conclusion, RVA seems to play a primary role in PWD. Classic E. coli virulence factors were not associated with diarrhea, indicating the need for revising their implication in disease. Moreover, Lactobacillus was found frequently in animals negative for RVA, suggesting some protective effect.

Investigation of Etiological Prevalence of Neonatal Calves with Acute Diarrhea in Şanlıurfa Province with Immunochromatographic Test

Neonatal calf diarrhea is a significant global concern, frequently causing morbidity and mortality and resulting in substantial economic losses. This study aimed to assess the prevalence of E. coli F5, Clostridium perfringens, Cryptosporidium spp., Rotavirus, Coronavirus, and Giardia spp. as contributors to diarrhea in neonatal calves in Şanlıurfa province. We also evaluated the clinical severity associated with these etiological agents. The study involved 123 neonatal calves (62 males, 61 females) aged 1-28 days from Şanlıurfa province with acute diarrhea. Calf Health Scores (CHS) were assigned based on clinical examination data. Rapid diagnostic tests were conducted on stool samples to identify E. coli F5, Clostridium perfringens, Cryptosporidium spp., Rotavirus, Coronavirus, and Giardia spp. regardless of mono or co-infection status, the rapid test results showed a prevalence of 9.76% for E. coli F5, 41.46% for C. perfringens, 30.89% for Cryptosporidium spp., 16.26% for Rotavirus, 13% for Coronavirus, and 27.64% for Giardia spp. CHS varied, with the highest score observed in E. coli F5 + Giardia spp. co-infection (CHS: 7) and the lowest in Coronavirus + Rotavirus co-infection (CHS: 4). In Şanlıurfa province, C. perfringens and Cryptosporidium spp. were identified as the most common agents. It has been determined that as the etiological factor diversity increases CHS may increase but there may be different variables that change CHS. These results are significant for developing effective diagnosis and control strategies for the prominent etiologies of diarrhea in calves.

Screening of sugarcane germplasm against Sporisorium scitamineum and its effects on setts germination and tillering

Sugarcane smut is the most damaging disease that is present almost across the globe, causing mild to severe yield losses depending upon the cultivar types, pathogen races and climatic conditions. Cultivation of smut-resistant cultivars is the most feasible and economical option to mitigate its damages. Previous investigations revealed that there is a scarcity of information on early detection and effective strategies to suppress etiological agents of smut disease due to the characteristics overlapping within species complexes. In this study, 104 sugarcane cultivars were screened by artificial inoculation with homogenate of all possible pathogen races of Sporisorium scitamineum during two consecutive growing seasons. The logistic smut growth pattern and the disease intrinsic rate were recorded by disease growth curve. Variable levels of disease incidence i.e., ranging from 0 to 54.10% were observed among these sugarcane cultivars. Besides, pathogen DNA in plant shoots of all the cultivars was successfully amplified by PCR method using smut-specific primers except 26 cultivars which showed an immune reaction in the field trial. Furthermore, the plant germination and tillering of susceptible sugarcane cultivars were greatly influenced by pathogen inoculation. In susceptible cultivars, S. scitamineum caused a significant reduction in setts germination, coupled with profuse tillering, resulting in fewer millable canes. Correlation analysis demonstrated that there was a positive relationship between reduction in setts germination and increase in the number of tillers. The present study would be helpful for the evaluation of smut resistance in a wide range of sugarcane germplasm, especially from the aspects of setts germination and tillers formation, and it also screened out several excellent germplasm for potential application in sugarcane breeding.

Sugar feeding in triatomines: a new perspective for controlling the transmission of Chagas disease.

Introduction: Triatomines are vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Currently, there is no vaccine against this disease. Thus, control of the insect vector population is the main strategy available to reduce the number of cases. Triatomines are considered obligate hematophagous, but different alternative feeding behaviors were described, such as haemolymphagy or plant feeding. Methods: To determine the preference for sugar feeding in nymphs and adults of Rhodnius prolixus, the insects were exposed a piece of cotton containing bromophenol blue plus sucrose. In addition, we offered several sugars for different species of triatomines, and tested sugar meals as a route of delivery of insecticides in first-instar nymphs of R. prolixus. The effect of sugar feeding on the physiology of these different species of triatomines was recorded. Results: First instar nymphs ingested sucrose more strongly than other stages, and showed high mortality rates. In different species of triatomines, sucrose induced an ingestion, but engorgement varied according to the species. R. prolixus nymphs showed an indiscriminate intake of various sugars, with very different physiological effects. Furthermore, ingesting different combinations of insecticides + sugar significantly reduced insect survival. Discussion: In summary, we described for the first-time sugar feeding as a widespread behavior in several species of triatomines, and the possibility of the use of toxic sugar baits for the control of these vectors. The knowledge of feeding behavior in these insects can be fundamental for the development of new strategies to control Chagas disease.

Molecular Genotyping of Circulating Enterovirus in the Lazio Region from 2012 to 2023.

Enteroviruses (EVs) are ubiquitous viruses that circulate worldwide, causing sporadic or epidemic infections, typically during the summer and fall. They cause a broad spectrum of illnesses, ranging from an unspecified febrile clinical presentation to a severe illness. EVs are recognized to be the most frequent etiological agents of aseptic meningitis in children. However, as the infection is usually mild and self-limiting, it remains underestimated, and the epidemiology of EVs is poorly understood. To date, no vaccine or effective therapy for all types of enteroviruses is available, and EVs constitute a public health concern. Here, we investigated the molecular epidemiology of EV strains circulating in the Lazio region over a 10-year time span (2012-2023) by using a sequence-typing approach and phylogenetic analysis. The epidemiological trend of EV infection has undergone changes during the SARS-CoV-2 pandemic (2020-2021), which resulted in a modification in terms of the number of diagnosed cases and seasonality. From 2022, the circulation of EVs showed a behavior typical of the pre-pandemic period, although changes in predominantly circulating strains have been noted. Both epidemic and sporadic circulation events have been characterized in the Lazio region. Further analyses are needed to better characterize any strain with higher potential pathogenic power and to identify possible recombinant strains.

A simplified molecular tool for detecting the Chagas etiological agent using a vector feces sample in field conditions

Triatomine bugs are vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease in the American continent. Here, we have tested a loop-mediated isothermal amplification (LAMP) test for a direct detection of T. cruzi in feces of Triatoma infestans, the main vector of this parasite in the Southern Cone of America. The analytical evaluation showed positive results with samples of triatomine feces artificially inoculated with DNA from strains of T. cruzi corresponding to each Discrete Typing Units (I-VI), with a sensitivity of up to one parasite per reaction. Conversely, the reaction yielded negative results when tested with DNA from Trypanosoma rangeli and other phylogenetically related and unrelated organisms. In triatomines captured under real field conditions (from urban households), and defined as positive or negative for T. cruzi using the reference microscopy technique, the LAMP test achieved a concordance of 100 %. Our results demonstrate that this LAMP reaction exhibits excellent analytical specificity and sensitivity without interference from the fecal matrix, since all the reactions were conducted without purification steps. This simple molecular diagnostic technique can be easily used by vector control agencies under field conditions.

Co-infection of Lactococcus garvieae and Aeromonas hydrophila in cultured Nile Tilapia in Kerala, India.

Co-infection of Lactococcus garvieae and Aeromonas hydrophila, has been confirmed from diseased Nile Tilapia (Oreochromis niloticus), Chithralada strain cultured in a freshwater rearing pond of Alappuzha district of Kerala, India. The aetiological agents behind the disease outbreak were bacteriologically proven and confirmed by 16SrRNA sequencing and phylogenetic analysis. PCR detection of the virulent genes, showed existence of adhesin and hemolysin in L. garvieae and aerolysin in A. hydrophila strain obtained. To fulfil Koch's postulates, challenge experiments were conducted and median lethal dose (LD50) of L. garvieae and A. hydrophila was calculated as 1 × 105.91 CFU per mL and 1 × 105.2 CFU per mL respectively. Histopathologically, eyes, spleen, and kidney were the predominantly infected organs by L. garvieae and A. hydrophila. Out of the 13 antibiotics tested to check antibiotic susceptibility, L. garvieae showed resistance to almost 7 antibiotics tested, with a resistance to Ciprofloxacin while A. hydrophila was found resistant to Streptomycin and Erythromycin. Understanding the complex interaction between Gram-positive and Gram-negative bacteria in the disease process and pathogenesis in fish host will contribute to efficient treatment strategies. As a preliminary investigation into this complex interaction, the present study is aimed at phenotypic and genotypic characterization, pathogenicity evaluation, and antibiotic susceptibility of the co-infecting pathogens in a diseased sample of freshwater-farmed Nile tilapia.