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Background: Shigellosis is an acute gastroenteritis infection and one of Ethiopia's most common causes of morbidity and mortality, especially in children under five. Antimicrobial resistance (AMR) has spread quickly among Shigella species due to inappropriate antibiotic use, inadequacies of diagnostic facilities, and unhygienic conditions. This study aimed to characterize Shigella sonnei (S. sonnei) using whole genome sequence (WGS) analysis in Addis Ababa, Ethiopia. Methods: The raw reads were quality-filtered and trimmed, and a minimum length of 50bp was retained and taxonomically classified using MiniKraken version 1. The whole genome data were aligned with Antibiotic Resistance Gene (ARG) sequences of the Comprehensive Antibiotic Resistance Database (CARD) by Resistance Gene Identifier (RGI). Plasmids were analyzed using the PlasmidFinder tool version 2.1. Additionally, AMR and virulence genes were screened at the Centre for Genomic Epidemiology (CGE) web-based server. Results: All isolates in our investigation contained genes encoding blaEC-8 and blaZEG-1. Here, 60.7% of the isolates were phenotypically sensitive to cefoxitin among the blaEC-8 genes detected in the genotyping analysis, whereas all isolates were completely resistant to amoxicillin and erythromycin phenotypically. The study also identified genes that conferred resistance to trimethoprim (dfrA). Plasmid Col156 and Col (BS512) types were found in all isolates, while IncFII and Col (MG828) plasmids were only identified in one isolate. Conclusion: This study found that many resistant genes were present, confirming the high variety in S. sonnei strains and hence a divergence in phylogenetic relationships. Thus, combining WGS methods for AMR prediction and strain identification into active surveillance may be beneficial for monitoring the spread of AMR in S. sonnei and detecting the potential emergence of novel variations. [ABSTRACT FROM AUTHOR]

Modern lifestyle changes, especially the consumption of a diet high in salt, sugar, and fat, have contributed to the increasing incidence and prevalence of chronic metabolic diseases such as diabetes, obesity, and gout. Changing lifestyles continuously shape the gut microbiota which is closely related to the occurrence and development of metabolic diseases due to its specificity of composition and structural diversity. A large number of pathogenic bacteria such as Yersinia, Salmonella, Shigella, and pathogenic E. coli in the gut utilize the type III secretion system (T3SS) to help them resist host defenses and cause disease. Although the T3SS is critical for the virulence of many important human pathogens, its relationship with metabolic diseases remains unknown. This article reviews the structure and function of the T3SS, the disruption of intestinal barrier integrity by the T3SS, the changes in intestinal flora containing the T3SS in metabolic diseases, the possible mechanisms of the T3SS affecting metabolic diseases, and the application of the T3SS in the treatment of metabolic diseases. The aim is to provide insights into metabolic diseases targeting the T3SS, thereby serving as a valuable reference for future research on disease diagnosis, prevention, and treatment. [ABSTRACT FROM AUTHOR]

Background: Shigellosis continues to pose a significant public health problem in Africa; however, there is a lack of comprehensive knowledge regarding its prevalence, serogroup distribution, and antimicrobial resistance profiles. Therefore, the objective of this systematic review and meta-analysis was to determine the overall prevalence of Shigella, the distribution of species, and the patterns of antimicrobial resistance across Africa. Methods: Following PRISMA guidelines, a systematic search strategy was conducted using the PubMed, Web of Science and Scopus databases from January 31, 2024 to February 10, 2024. The study quality was assessed using the Joanna Briggs Institute checklist, and data were analyzed using the R statistical language and the R package 'meta'. The random effects model was employed to estimate the pooled prevalence, while heterogeneity was assessed using the I2 statistic and prediction interval. Results: A total of 116 studies from 29 African countries were included in this meta-analysis, involving the examination of 99,510 samples. The overall pooled estimate of Shigella prevalence was determined to be 5.9% (95% CI: 4.9 – 7.0%). Regional prevalence showed prevalences of Southern Africa (6.9 [95% CI: 3.0 – 12.2%]), Northern Africa (6.7% [95% CI: 4.1 – 9.8%]), Eastern Africa (6.2% [95% CI: 4.9 – 7.6%]), Central Africa (4.5% [95% CI: 2.6 – 6.8%]) and Western Africa (4.0% [95% CI: 2.5 – 5.9%]). Shigella prevalence was found to be higher in children (6.6%, 95% CI: 3.2 – 11.1%) than in adults (3.6%, 95% CI: 1.6 – 6.3%). The most prevalent species was S. flexneri (53.6%, 95% CI: 46.1%—61.0%), followed by S. sonnei (11.5%, 95% CI: 7.7%—15.7%), S. dysenteriae (10.1%, 95% CI: 6.2 – 14.5%) and S. boydii (7.7%, 95% CI: 4.7 – 11.1%). Among the currently recommended first-line antibiotics, ciprofloxacin and ceftriaxone showed resistance prevalences of 10.0% (95% CI: 4.5%—16.9%) and 8.5% (95% CI: 2.4—16.9%) respectively. Conclusion: This review highlights the burden of shigellosis in Africa. S. flexneri remains the most prevalent species associated with shigellosis cases with S. sonnei being the second most dominant. The antimicrobial resistance patterns observed in the study suggest local antimicrobial patterns in choosing antibiotics for the treatment of Shigellosis. Recommendation: There is the need to explore alternative treatments for shigellosis with particular focus on vaccine development. There is also the need for more genomic epidemiology studies exploring the dissemination and risk of drug-resistant S. sonnei clones in Africa. [ABSTRACT FROM AUTHOR]

Background We report data from stage 1 of an ongoing 2-staged, phase 1/2 randomized clinical trial with a 4-component generalized modules for membrane antigens-based vaccine against Shigella sonnei and Shigella flexneri 1b, 2a, and 3a (altSonflex1-2-3; GSK). Methods Europeans aged 18–50 years (N = 102) were randomized (2:1) to receive 2 injections of altSonflex1-2-3 or placebo at 3- or 6-month interval. Safety and immunogenicity were assessed at prespecified time points. Results The most common solicited administration-site event (until 7 days after each injection) and unsolicited adverse event (until 28 days after each injection) were pain (altSonflex1-2-3, 97.1%; placebo, 58.8%) and headache (32.4%; 23.5%), respectively. All serotype-specific functional IgG antibodies peaked 14–28 days after injection 1 and remained substantially higher than prevaccination at 3 or 6 months postvaccination; the second injection did not boost but restored the initial immune response. The highest seroresponse rates (≥4-fold increase in titers over baseline) were obtained against S. flexneri 2a (enzyme-linked immunosorbent assay [ELISA] after injection 1, 91.0%; after injection 2 [day 113; day 197], 100%; 97.0% and serum bactericidal activity [SBA] after injection 1, 94.4%; after injection 2, 85.7%; 88.9%) followed by S. sonnei (ELISA after injection 1, 77.6%; after injection 2, 84.6%; 78.8% and SBA after injection 1, 83.3%; after injection 2, 71.4%; 88.9%). Immune responses against S. flexneri 1b and S. flexneri 3a, as measured by both ELISA and SBA, were numerically lower compared to those against S. sonnei and S. flexneri 2a. Conclusions No safety signals or concerns were identified. altSonflex1-2-3 induced functional serotype-specific immune responses, allowing further clinical development in the target population. Clinical Trials Registration. NCT05073003. [ABSTRACT FROM AUTHOR]

Among the pathogens that cause infectious diarrhea in China, Shigella is the most prominent. Shigellosis affects both adults and children, particularly those in developing nations, with nearly 190 million annual cases and a third resulting in fatalities. The recently emerged CRISPR/Cas system has also been increasingly applied for the detection of different biological targets. The lateral flow assay (LFA) has the advantages of short detection time, simple operation, high sensitivity, and low cost, and it provides an ideal platform for on-site detection. In this study, a recombinase polymerase amplification–CRISPR/Cas12a–LFA test for Shigella flexneri was constructed. The established method had good specificity and sensitivity, and the qualitative accuracy of 32 tested strains reached 100%. The detection limit of genomic DNA reached 8.3 copies/μL. With the advantages of high accuracy and portability, this diagnostic apparatus represents a novel method of identification and detection of Shigella flexneri, particularly in settings that lack complex laboratory infrastructure. [ABSTRACT FROM AUTHOR]

Shigellosis, caused by the Gram-negative bacterium Shigella, is a major global health challenge. Despite extensive research over the past two decades, no commercial vaccine is available to prevent Shigella infection. Developing multi-epitope vaccines offers a promising and innovative approach to tackling infectious diseases. In this study, we produced a multi-epitope vaccine candidate using E. coli BL21 (DE3) plysS bacteria and purified the vaccine protein with Ni-NTA affinity chromatography. We then prepared alginate nanoparticles containing the vaccine protein, with a particle size of 122 ± 6 nm, PDI 0.17, SPAN 0.83, and zeta potential of -27 ± 2 mV. Successful protein loading was confirmed through nanodrop and ATR-FTIR analyses. To evaluate the immunogenicity of the encapsulated vaccine, mice were orally vaccinated, and their serum was analyzed for IgG, IL-4, and IFN-γ levels cytokines. The results showed a significant increase in IgG level in the vaccinated group compared to controls. Additionally, the vaccinated group exhibited a notable increase in IL-4 and IFN-γ cytokines, indicating a robust Th-cell-mediated immune response essential for combating Shigella. Our nano-vaccine demonstrated high efficacy in activating both humoral and cellular immunity, effectively protecting against the bacteria. The alginate-based oral vaccine candidate thus emerges as a promising strategy for developing a multi-epitope vaccine candidate against Shigella. [ABSTRACT FROM AUTHOR]

Shigellosis remains a significant global health challenge, particularly in Asia and Africa, where it is a major cause of morbidity and mortality among children. Despite the urgent need, the development of a licensed Shigella vaccine has been hindered, partly due to the lack of suitable animal models for preclinical evaluation. In this study, we used an intragastric adult rhesusmacaque challenge model to evaluate the safety, immunogenicity, and efficacy of five live-attenuated Shigella dysenteriae 1 vaccine candidates, all derived fromthe 1617 parent strain. The vaccine strains includedWRSd1, a previously tested candidate with deletions in virG(icsA), stxAB, and fnr, and four other strains--WRSd2, WRSd3, WRSd4, and WRSd5--each containing deletions in virG and stxAB, but retaining fnr. Additionally, WRSd3 and WRSd5 had further deletions in the Shigella enterotoxin gene senA and its paralog senB, with WRSd5 having an extra deletion in msbB2. Rhesus monkeys were immunized three times at two-day intervals with a target dose of 2 × 1010 CFU of the vaccine strains. Thirty days after the final immunization, all monkeys were challenged with a target dose of 2 × 109 CFU of the S. dysenteriae 1 1617 wild-type strain. Safety, immunogenicity, and efficacy were assessed through physical monitoring and the evaluation of immunologic and inflammatory markers following immunization and challenge. Initial doses of WRSd1, WRSd3, and WRSd5 led to mild adverse effects, such as vomiting and loose stools, but all five vaccine strains were well tolerated in subsequent doses. All strains elicited significant IgA and IgG antibody responses, as well as the production of antibody-secreting cells. Notably, none of the vaccinated animals exhibited shigellosis symptoms such as vomiting or loose/watery stool post-challenge, in stark contrast to the control group, where 39% and 61% of monkeys exhibited these symptoms, respectively. The aggregate clinical score used to evaluate Shigella attack rates post-challenge revealed a 72% attack rate in control animals, compared to only 13% in vaccinated animals, indicating a relative risk reduction of 81%. This study highlights the potential of this NHP model in evaluating the safety, immunogenicity, and efficacy of live-attenuated Shigella vaccine candidates, offering a valuable tool for preclinical assessment before advancing to Phase 1 or more advanced clinical trials. [ABSTRACT FROM AUTHOR]

Shigella spp. are highly pathogenic members of the Enterobacteriaceae family, causing ∼269 million cases of bacillary dysentery and >200,000 deaths each year. Like many Gram-negative pathogens, Shigella rely on their type three secretion system (T3SS) to inject effector proteins into eukaryotic host cells, driving both cellular invasion and evasion of host immune responses. Exposure to the bile salt deoxycholate (DOC) significantly enhances Shigella virulence and is proposed to serve as a critical environmental signal present in the small intestine that prepares Shigella’s T3SS for efficient infection of the colonic epithelium. Here, we uncover critical mechanistic details of the Shigella-specific DOC signaling process by describing the role of a π-helix secondary structure element within the T3SS tip protein invasion plasmid antigen D (IpaD). Biophysical characterization and high-resolution structures of IpaD mutants lacking the π-helix show that it is not required for global protein structure, but that it defines the native DOC binding site and prevents off target interactions. Additionally, Shigella strains expressing the π-helix deletion mutants illustrate the pathogenic importance of its role in guiding DOC interaction as flow cytometry and gentamycin protection assays show that the IpaD π-helix is essential for DOC-mediated apparatus maturation and enhanced invasion of eukaryotic cells. Together, these findings add to our understanding of the complex Shigella pathogenesis pathway and its evolution to respond to environmental bile salts by identifying the π-helix in IpaD as a critical structural element required for translating DOC exposure to virulence enhancement. [ABSTRACT FROM AUTHOR]

Shigella is an important human-adapted pathogen for which there is an increasing incidence of antimicrobial resistance and no effective vaccine. Modelling Shigella infection of humans has historically been difficult, but new technologies and animal models have emerged to recapitulate key hallmarks of shigellosis. The use of organ-on-chip technology, zebrafish infection models, transgenic mouse models, and human challenge studies all uniquely contribute to our understanding of Shigella infection biology. Recent advances have illuminated our understanding of Shigella pathogenesis, guiding vaccine strategies and moving us closer to human health impact. Shigella is an important human-adapted pathogen which contributes to a large global burden of diarrhoeal disease. Together with the increasing threat of antimicrobial resistance and lack of an effective vaccine, there is great urgency to identify novel therapeutics and preventatives to combat Shigella infection. In this review, we discuss the development of innovative technologies and animal models to study mechanisms underlying Shigella infection of humans. We examine recent literature introducing (i) the organ-on-chip model, and its substantial contribution towards understanding the biomechanics of Shigella infection, (ii) the zebrafish infection model, which has delivered transformative insights into the epidemiological success of clinical isolates and the innate immune response to Shigella , (iii) a pioneering oral mouse model of shigellosis, which has helped to discover new inflammasome biology and protective mechanisms against shigellosis , and (iv) the controlled human infection model, which has been effective in translating basic research into human health impact and assessing suitability of novel vaccine candidates. We consider the recent contributions of each model and discuss where the future of modelling Shigella infection lies. [ABSTRACT FROM AUTHOR]

Shigellosis is a gastrointestinal disease causes high morbidity and mortality worldwide, however, there is no anti- Shigella vaccine. The use of antibiotics in shigellosis treatment exacerbates antibiotic resistance. Antibodies, particularly egg yolk antibody (IgY), offer a promising approach to address this challenge. This study aimed to investigate the prophylactic effect of IgY produced against a recombinant chimeric protein containing the immunogens IpaD, IpaB, StxB, and VirG from Shigella. The chimeric protein, comprising IpaD, IpaB, StxB, and VirG, was expressed in E. coli BL21 and purified using the Ni-NTA column. Following immunization of chickens, IgY was extracted from egg yolk using the PEG-6000 method and analyzed through SDS-PAGE and ELISA techniques. Subsequently, the prophylactic efficacy of IgY was assessed by challenging of mice with 10 LD50 of S. dysenteriae and administering different concentrations of IgY (1.25, 2.5, 5, and 10 mg/kg) under various time conditions. The recombinant protein, weighing 82 kDa, was purified and confirmed by western blotting. The IgY concentration was determined as 9.5 mg/ml of egg yolk and the purity of the extracted IgY was over 90 %. The results of the ELISA showed that at least 19 ng of pure antibody identified recombinant protein and reacts with it. The challenge test employing IgY and Shigella demonstrated a direct correlation between the survival rate and antibody concentration, with increased concentrations leading to decreased mortality rates. Treatment of mice with 10 mg/kg IgY leads to 80 % survival of the mice against 10 LD50 S. dysenteriae. Our findings suggest that IgY may offer therapeutic potential in treating Shigella infections and combating antibiotic resistance. • shigella is a significant problem in developing countries. • IgY can cause prophylaxis and neutralize bacteria. • IgY produced against IpaD, IpaB, StxB and VirG of shigella could cause high prophylaxis against bacteria. • IgY is a suitable prophylaxis candidate due to easy production and cost-effectiveness advantages. [ABSTRACT FROM AUTHOR]

Bacterial diseases of the gastrointestinal (GI) tract continue to be a major worldwide cause of human morbidity and mortality. Among various enteric pathogens, Shigella spp. are some of the most common and deadly bacterial pathogens. They are responsible for ~125 million worldwide cases of shigellosis, and ~14,000 deaths annually, the majority in children under the age of 5 and occurring in developing countries. Preventing and treating shigellosis with conventional drugs (e.g., vaccines and antibiotics) has proven to be very difficult. Here, we assessed the safety and tolerability of ShigActive™, a lytic bacteriophage preparation targeting Shigella spp., in a randomized, placebo-controlled, double-blind Phase 1 clinical trial. Ten participants randomized 4:1 received ShigActive™ or placebo co-administered with sodium bicarbonate orally three times daily for 7 days. Solicited and unsolicited adverse events (AEs) were observed for 29 days. Fifty percent of the subjects receiving ShigActive™ reported mild GI-related symptoms, while one participant experienced moderate fatigue. No serious or medically attended AEs occurred through day 90. Additionally, no significant differences in GI-associated inflammatory mediators or fecal microbiome changes were observed between placebo- and ShigActive™-treated subjects, or from a participants' baseline value. The results of this first-in-human (FIH) randomized, controlled Phase 1 trial of ShigActive™ demonstrate that it is safe and well tolerated when orally administered with no significant differences compared to placebo controls. [ABSTRACT FROM AUTHOR]

Abstract Background Shigellosis continues to pose a significant public health problem in Africa; however, there is a lack of comprehensive knowledge regarding its prevalence, serogroup distribution, and antimicrobial resistance profiles. Therefore, the objective of this systematic review and meta-analysis was to determine the overall prevalence of Shigella, the distribution of species, and the patterns of antimicrobial resistance across Africa. Methods Following PRISMA guidelines, a systematic search strategy was conducted using the PubMed, Web of Science and Scopus databases from January 31, 2024 to February 10, 2024. The study quality was assessed using the Joanna Briggs Institute checklist, and data were analyzed using the R statistical language and the R package ‘meta’. The random effects model was employed to estimate the pooled prevalence, while heterogeneity was assessed using the I2 statistic and prediction interval. Results A total of 116 studies from 29 African countries were included in this meta-analysis, involving the examination of 99,510 samples. The overall pooled estimate of Shigella prevalence was determined to be 5.9% (95% CI: 4.9 – 7.0%). Regional prevalence showed prevalences of Southern Africa (6.9 [95% CI: 3.0 – 12.2%]), Northern Africa (6.7% [95% CI: 4.1 – 9.8%]), Eastern Africa (6.2% [95% CI: 4.9 – 7.6%]), Central Africa (4.5% [95% CI: 2.6 – 6.8%]) and Western Africa (4.0% [95% CI: 2.5 – 5.9%]). Shigella prevalence was found to be higher in children (6.6%, 95% CI: 3.2 – 11.1%) than in adults (3.6%, 95% CI: 1.6 – 6.3%). The most prevalent species was S. flexneri (53.6%, 95% CI: 46.1%—61.0%), followed by S. sonnei (11.5%, 95% CI: 7.7%—15.7%), S. dysenteriae (10.1%, 95% CI: 6.2 – 14.5%) and S. boydii (7.7%, 95% CI: 4.7 – 11.1%). Among the currently recommended first-line antibiotics, ciprofloxacin and ceftriaxone showed resistance prevalences of 10.0% (95% CI: 4.5%—16.9%) and 8.5% (95% CI: 2.4—16.9%) respectively. Conclusion This review highlights the burden of shigellosis in Africa. S. flexneri remains the most prevalent species associated with shigellosis cases with S. sonnei being the second most dominant. The antimicrobial resistance patterns observed in the study suggest local antimicrobial patterns in choosing antibiotics for the treatment of Shigellosis. Recommendation There is the need to explore alternative treatments for shigellosis with particular focus on vaccine development. There is also the need for more genomic epidemiology studies exploring the dissemination and risk of drug-resistant S. sonnei clones in Africa.

Abstract Shigellosis, caused by the Gram-negative bacterium Shigella, is a major global health challenge. Despite extensive research over the past two decades, no commercial vaccine is available to prevent Shigella infection. Developing multi-epitope vaccines offers a promising and innovative approach to tackling infectious diseases. In this study, we produced a multi-epitope vaccine candidate using E. coli BL21 (DE3) plysS bacteria and purified the vaccine protein with Ni-NTA affinity chromatography. We then prepared alginate nanoparticles containing the vaccine protein, with a particle size of 122 ± 6 nm, PDI 0.17, SPAN 0.83, and zeta potential of -27 ± 2 mV. Successful protein loading was confirmed through nanodrop and ATR-FTIR analyses. To evaluate the immunogenicity of the encapsulated vaccine, mice were orally vaccinated, and their serum was analyzed for IgG, IL-4, and IFN-γ levels cytokines. The results showed a significant increase in IgG level in the vaccinated group compared to controls. Additionally, the vaccinated group exhibited a notable increase in IL-4 and IFN-γ cytokines, indicating a robust Th-cell-mediated immune response essential for combating Shigella. Our nano-vaccine demonstrated high efficacy in activating both humoral and cellular immunity, effectively protecting against the bacteria. The alginate-based oral vaccine candidate thus emerges as a promising strategy for developing a multi-epitope vaccine candidate against Shigella.

Abstract Background Shigellosis, also known as bacillary dysentery, is an acute infection of the intestine. The symptoms can vary from mild watery diarrhoea to severe inflammatory bacillary dysentery, which is characterized by fever, intense abdominal cramps, and the presence of blood and mucus in the stools. While the disease typically resolves on its own, it can become life-threatening in immunocompromised individuals or in the absence of adequate medical care. Main body of the abstract Shigella is the primary cause of bacillary dysentery worldwide. It is comprised of four distinct species—S. dysenteriae, S. flexneri, S. boydii, and S. sonnei—each with unique genomic characteristics and disease-causing abilities. Shigella spp. have developed resistance to multiple drugs and have also adapted well to the gut environment over time. They have become well-suited to infecting the human gut epithelial cells and causing dysentery. Consequently, numerous studies have investigated the potential application of nanotechnology in the treatment of shigellosis by leveraging its capability for drug delivery and targeted therapy, thereby improving effectiveness while reducing side effects. Short conclusion It is crucial to maintain ongoing surveillance and develop new strategies to effectively manage this issue. In this review, we shed light on the present comprehension of distinct Shigella spp. and their potential contribution to the pathogenesis of shigellosis, along with their interaction with the gut microbiota. We also provide insight into how nanotechnology may be a major factor in preventing shigellosis in the future.

While the incidence of shigellosis has decreased in developed nations due to improved living conditions and healthcare systems, it remains prevalent in economically developing regions. In recent years, a resurgence of shigellosis has been observed in the United States, Europe, and Taiwan, primarily among men having sex with men and people living with human immunodeficiency virus, along with a rise in antimicrobial resistance. This study aims to review the historical epidemiological trends and drug resistance in shigellosis, with a focus on Taiwan. A comprehensive search was conducted using various databases and sources, including non-English literature in Japanese and Chinese. In developed countries, Shigella sonnei and Shigella flexneri are the most common species, while Shigella dysenteriae infections are sporadic. In Taiwan, the classification and prevalence of Shigella species have evolved over time, with S. flexneri and S. sonnei being the predominant strains. Fluoroquinolone resistance and azithromycin non-susceptibility are the ongoing threat. In conclusion, shigellosis remains a significant global health concern, with recent increases in certain populations and antimicrobial resistance. Further research is necessary to understand the clinical significance and risk factors associated with asymptomatic carriers and to assess the impact of behavioral modifications and interventions in high-risk populations.

We meta-analyzed the diagnostic accuracy of rapid diagnostic tests (dipsticks) and loop-mediated isothermal amplification (LAMP) method to detect Shigella species.We searched MEDLINE, Embase, Web of Science and Google Scholar from inception to 2023 for studies reporting on the performance of Shigella dipstick and LAMP tests compared with culture or polymerase chain reaction (PCR).Our search identified 2618 studies, of which fourteen met the inclusion criteria for the systematic review. Ten studies covering 4056 tests (from twelve countries) were included in the meta-analysis. The overall pooled sensitivity and specificity were 98% (95% CI: 94–100) and 97% (95% CI: 92–99), respectively. Pooled sensitivity and specificity of dipsticks were 95% and 98%, respectively. In contrast, LAMP showed higher pooled sensitivity (100%) and diagnostic odds ratio (431752), but similar specificity (97%).LAMP and dipstick tests exhibited promising performance, suggesting that they could be useful for assisting in the diagnosis of shigellosis.

Background: Shigellosis, also known as bacillary dysentery, is an acute infection of the intestine. The symptoms can vary from mild watery diarrhoea to severe inflammatory bacillary dysentery, which is characterized by fever, intense abdominal cramps, and the presence of blood and mucus in the stools. While the disease typically resolves on its own, it can become life-threatening in immunocompromised individuals or in the absence of adequate medical care. Shigella is the primary cause of bacillary dysentery worldwide. It is comprised of four distinct species—S. dysenteriae, S. flexneri, S. boydii, and S. sonnei—each with unique genomic characteristics and disease-causing abilities. Shigella spp. have developed resistance to multiple drugs and have also adapted well to the gut environment over time. They have become well-suited to infecting the human gut epithelial cells and causing dysentery. Consequently, numerous studies have investigated the potential application of nanotechnology in the treatment of shigellosis by leveraging its capability for drug delivery and targeted therapy, thereby improving effectiveness while reducing side effects. Short conclusion: It is crucial to maintain ongoing surveillance and develop new strategies to effectively manage this issue. In this review, we shed light on the present comprehension of distinct Shigella spp. and their potential contribution to the pathogenesis of shigellosis, along with their interaction with the gut microbiota. We also provide insight into how nanotechnology may be a major factor in preventing shigellosis in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND. The use of high-throughput technologies has enabled rapid advancement in the knowledge of host immune responses to pathogens. Our objective was to compare the repertoire, protection, and maternal factors associated with human milk antibodies to infectious pathogens in different economic and geographic locations. METHODS. Using multipathogen protein microarrays, 878 milk and 94 paired serum samples collected from 695 women in 5 high and low-to-middle income countries (Bangladesh, Finland, Peru, Pakistan, and the United States) were assessed for specific IgA and IgG antibodies to 1,607 proteins from 30 enteric, respiratory, and bloodborne pathogens. RESULTS. The antibody coverage across enteric and respiratory pathogens was highest in Bangladeshi and Pakistani cohorts and lowest in the U.S. and Finland. While some pathogens induced a dominant IgA response (Campylobacter, Klebsiella, Acinetobacter, Cryptosporidium, and pertussis), others elicited both IgA and IgG antibodies in milk and serum, possibly related to the invasiveness of the infection (Shigella, enteropathogenic E. coli "EPEC", Streptococcus pneumoniae, Staphylococcus aureus, and Group B Streptococcus). Besides the differences between economic regions and decreases in concentrations over time, human milk IgA and IgG antibody concentrations were lower in mothers with high BMI and higher parity, respectively. In Bangladeshi infants, a higher specific IgA concentration in human milk was associated with delayed time to rotavirus infection, implying protective properties of antirotavirus antibodies, whereas a higher IgA antibody concentration was associated with greater incidence of Campylobacter infection. CONCLUSION. This comprehensive assessment of human milk antibody profiles may be used to guide the development of passive protection strategies against infant morbidity and mortality. FUNDING. Bill and Melinda Gates Foundation grant OPP1172222 (to KMJ); Bill and Melinda Gates Foundation grant OPP1066764 funded the MDIG trial (to DER); University of Rochester CTSI and Environmental Health Sciences Center funded the Rochester Lifestyle study (to RJL); and R01 AI043596 funded PROVIDE (to WAP). [ABSTRACT FROM AUTHOR]

As the most common cause of bacillary dysentery or shigellosis, Shigella sonnei (S nonnei) has spread throughout the world. Invasion of the colorectal epithelial cells by this facultative intracellular bacterium occurs via various virulence factors. The increase in the resistance rate highlights the need for novel interventions, particularly increasing the urgency of the development of Shigella vaccines that may offer an effective solution. A multiepitope protein vaccine (MEPV) construct previously designed using bioinformatics tools against Shigella species, was applied in vivo in BALB/C mice. The designed vaccine construct was expressed in a bacterial host, purified, and finally confirmed by Western blot analysis. The immunogenicity of the purified MEPV was assessed against S sonnei via intranasal and subcutaneous administration routes, followed by evaluating its protective efficiency. We observed that interferon-gamma, interleukin-4, and immunoglobulin G levels were increased in all experimental groups. Therefore, The MEPV effectively protected the mice against S sonnei. [ABSTRACT FROM AUTHOR]

This article examines the connection between elevated wheat IgG4 antibody levels and autism spectrum disorder (ASD) in children. The study discovered that children with ASD and high levels of wheat IgG4 antibodies had changes in their gut microbiota and were more susceptible to certain pathogens. These children also experienced alterations in gut microbial carbohydrate-activating enzymes, which impacted their ability to metabolize dietary fiber. These findings suggest a potential relationship between food hypersensitivities, gut microbiota, and ASD. The document discusses the results of a study on the association between food-specific IgG4 antibodies and intestinal infections in children with ASD. The study found that increased IgG4 levels for foods like wheat, milk, yogurt, sheep milk, and eggs were linked to a higher presence of E. coli in fecal samples. The researchers propose that targeting individuals with high levels of food-specific IgG4 antibodies may be more effective in developing dietary interventions for children with ASD. Further research is planned to investigate the presence of immune complexes in the intestinal mucosa. [Extracted from the article]

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(1) Shigella spp. (Shigella) is known for causing dysentery with blood in stool, but most children infected with Shigella have non-dysentery Shigella-associated diarrhea (NDSD). The World Health Organization recommends the use of antibiotics when diarrhea is bloody, leaving most NDSD cases untreated. The absence of dysentery may not indicate a low risk of death and severe morbidity. Rapid diagnosis and treatment of shigellosis in vulnerable, young children may be lifesaving. INSIGHT aims to determine the potential benefit of identifying NDSD cases (n = 296) and their outcomes compared to cases of Shigella dysentery [DS (n = 148)] and non-Shigella watery diarrhea [WD (n = 148)]. (2) Children seeking care at hospitals in Bangladesh will be enrolled and followed for 1 year (NDSD and DS) or 90 days (WD). We will determine the impact of NDSD on morbidity, mortality, gut health, nutritional status, and cognitive development compared to DS and WD in children and whether the simple "Rapid LAMP-based Diagnostic Test (RLDT)" can accelerate the detection and treatment of shigellosis in the clinical settings of rural Bangladesh. (3) INSIGHT will determine the impact of NDSD in children and determine if the treatment guidelines of shigellosis need to be revisited to improve clinical outcomes and the development of these children. [ABSTRACT FROM AUTHOR]

Diarrheal diseases are important causes of morbidity and mortality, worldwide. The occurrence of multiple pathogens in stool samples of symptomatic and asymptomatic individuals in resource-limited countries have been repeatedly described. In this study, we assessed the differentiated effects of combined pathogen detections on recorded symptoms. A case-control study was conducted among 620 under-five-year-old children in rural northeastern Tanzania with emphasis of multiple detection. The median age of children was 11 months (IQR = 7, 20), and 52.1% were male. Cases (50.2%, n = 157) were less likely than controls (64.5%, n = 198) to have multiple colonization with gastrointestinal tract (GIT) pathogens. The children's age was positively associated with the likelihood of harboring multiple GIT pathogens [OR, 1.02, 95% CI = 1.01, 1.04]. Shigella spp./enteroinvasive Escherichia coli (EIEC) [OR = 2.80, 95% CI 1.62, 4.83] and norovirus [OR = 2.04, 95% CI 1.23, 3.39] were more common in cases and were strongly associated with diarrhea, while enteroaggregative E. coli (EAEC) [OR = 0.23, 95%CI 0.17–0.33] were more common in controls. Diarrheal diseases in under-five children from rural Tanzania are likely to be due to infections with Shigella spp./EIEC, and norovirus with strongly age-dependent associations. [ABSTRACT FROM AUTHOR]

Background. The objective of this systematic review and meta-analysis was to estimate the proportions of individuals infected with Campylobacter, Escherichia, Salmonella, Shigella, or Yersinia who develop reactive arthritis. Methods. A systematic review was conducted, encompassing English-language articles published before January 2024, sourced from the Embase, PubMed, Scopus, and Web of Science databases. This review included observational studies that reported the occurrence of reactive arthritis (ReA) among patients with Campylobacter, Escherichia, Salmonella, Shigella, or Yersinia infections. Data extraction was carried out independently by two reviewers. Subsequently, a random-effects meta-analysis was performed, with heterogeneity assessed using the I2 value. Additionally, meta-regression was employed to investigate the potential influence of study-level variables on the observed heterogeneity. Results. A total of 87 studies were identified; 23 reported on ReA development after Campylobacter infection, 7 reported on ReA after Escherichia infection, 30 reported ReA onset after salmonellosis, 14 reported ReA after shigellosis, and 13 reported ReA after Yersinia infection. The proportion of Campylobacter patients who developed ReA was 0.03 (95% CI [0.01, 0.06], I2 = 97.62%); the proportion of Escherichia patients who developed ReA was 0.01 (95% CI [0.00, 0.06], I2 = 92.78%); the proportion of Salmonella patients was 0.04 (95% CI [0.02, 0.08], I2 = 97.67%); the proportion of Shigella patients was 0.01 (95% CI [0.01, 0.03], I2 = 90.64%); and the proportion of Yersinia patients who developed ReA was 0.05 (95% CI [0.02, 0.13], I2 = 96%). Conclusion. A significant proportion of Salmonella, Shigella, and Yersinia cases resulted in ReA. Nonetheless, it is important to interpret the findings cautiously due to the substantial heterogeneity observed between studies. [ABSTRACT FROM AUTHOR]

Background: Worldwide, more than 125 million people are infected with Shigella each year and develop shigellosis. In our previous study, we provided evidence that Shigella sonnei infection triggers activation of the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome in macrophages. NLRP3 inflammasome is responsible for regulating the release of the proinflammatory cytokines interleukin (IL)-1β and IL-18 through the protease caspase-1. Researchers and biotech companies have shown great interest in developing inhibitors of the NLRP3 inflammasome, recognizing it as a promising therapeutic target for several diseases. The leaves of Cinnamomum osmophloeum kaneh, an indigenous tree species in Taiwan, are rich in cinnamaldehyde (CA), a compound present in significant amounts. Our aim is to investigate how CA affects the activation of the NLRP3 inflammasome in S. sonnei-infected macrophages. Methods: Macrophages were infected with S. sonnei, with or without CA. ELISA and Western blotting were employed to detect protein expression or phosphorylation levels. Flow cytometry was utilized to assess H2O2 production and mitochondrial damage. Fluorescent microscopy was used to detect cathepsin B activity and mitochondrial ROS production. Additionally, colony-forming units were employed to measure macrophage phagocytosis and bactericidal activity. Results: CA inhibited the NLRP3 inflammasome in S. sonnei-infected macrophages by suppressing caspase-1 activation and reducing IL-1β and IL-18 expression. CA also inhibited pyroptosis by decreasing caspase-11 and Gasdermin D activation. Mechanistically, CA reduced lysosomal damage and enhanced autophagy, while leaving mitochondrial damage, mitogen-activated protein kinase phosphorylation, and NF-κB activation unaffected. Furthermore, CA significantly boosted phagocytosis and the bactericidal activity of macrophages against S. sonnei, while reducing secretion of IL-6 and tumour necrosis factor following infection. Conclusion: CA shows promise as a nutraceutical for mitigating S. sonnei infection by diminishing inflammation and enhancing phagocytosis and the bactericidal activity of macrophages against S. sonnei. [ABSTRACT FROM AUTHOR]

The gut-brain-axis has a role in mental health disorders. In people with generalized anxiety disorder, GAD, 1 1 GAD: generalized anxiety disorder. normal flora Escherichia-Shigella , are significantly elevated. Fecal microbiota transplant, FMT, 2 2 FMT: fecal microbiota transplant. has been used to alter the gut composition in unhealthy individuals. There may be a role for FMT in the treatment of GAD to improve the gut-brain-axis. A systematic review of literature was conducted on articles published in PubMed, CINAHL Plus, Scopus, Cochrane Library, and Wed of Science from 2000 to 2022 that analyzed FMT as a modality to alter the gut microbiome in which Escherichia-Shigella levels were quantified and reported. Of 1916 studies identified, 14 fit criteria and were included. Recipients undergoing FMT procedures had at least one enteric diagnosis and increased percentages of Escherichia-Shigella pre-FMT. Five studies on recurrent Clostridioides difficile infection, three irritable bowel syndrome, two ulcerative colitis, one ulcerative colitis and recurrent Clostridioides difficile infection, one acute intestinal and chronic graft-vs-host disease, one pouchitis, and one slow transit constipation. 10 articles (71.4 %) showed decreased levels of Escherichia-Shigella post-FMT compared to pre-FMT. Four studies claimed the results were significant (40 %). Limitations include potential bias in study selection, study methods of analysis, and generalization of results. The gut-brain-axis has a role in GAD. Those with GAD have significantly higher Escherichia-Shigella compared to those without GAD. FMT has the potential to decrease Escherichia-Shigella in patients with GAD to positively alter the gut-brain-axis as a potential for future GAD treatment. • Levels of specific enteric bacteria are increased in generalized anxiety disorder. • Fecal microbiota transplant (FMT) can be used to alter the gut microbiome. • A review was completed to assess FMT's ability to alter levels of Escherichia-Shigella. • 71 % of reviewed studies showed that FMT was able to decrease levels of both bacteria. • FMT should be researched as a treatment modality for generalized anxiety disorder. [ABSTRACT FROM AUTHOR]

We meta-analyzed the diagnostic accuracy of rapid diagnostic tests (dipsticks) and loop-mediated isothermal amplification (LAMP) method to detect Shigella species. We searched MEDLINE, Embase, Web of Science and Google Scholar from inception to 2023 for studies reporting on the performance of Shigella dipstick and LAMP tests compared with culture or polymerase chain reaction (PCR). Our search identified 2618 studies, of which fourteen met the inclusion criteria for the systematic review. Ten studies covering 4056 tests (from twelve countries) were included in the meta-analysis. The overall pooled sensitivity and specificity were 98 % (95 % CI: 94–100) and 97 % (95 % CI: 92–99), respectively. Pooled sensitivity and specificity of dipsticks were 95 % and 98 %, respectively. In contrast, LAMP showed higher pooled sensitivity (100 %) and diagnostic odds ratio (431752), but similar specificity (97 %). LAMP and dipstick tests exhibited promising performance, suggesting that they could be useful for assisting in the diagnosis of shigellosis. • Shigella infection can result in growth deficits among children. • We investigated the diagnostic accuracy of Shigella dipsticks tests and LAMP. • Ten studies were included in the meta-analysis. • Dipsticks pooled sensitivity and specificity: 95 % and 98 %, respectively. • LAMP pooled sensitivity and specificity: 100 % and 97 %, respectively. [ABSTRACT FROM AUTHOR]

Large outbreaks of Shigella sonnei among children in Haredi Jewish (ultra-Orthodox) communities in Brooklyn, New York have occurred every 3–5 years since at least the mid-1980s. These outbreaks are partially attributable to large numbers of young children in these communities, with transmission highest in child care and school settings, and secondary transmission within households. As these outbreaks have been prolonged and difficult to control, we developed an agent-based model of shigellosis transmission among children in these communities to support New York City Department of Health and Mental Hygiene staff. Simulated children were assigned an initial susceptible, infectious, or recovered (immune) status and interacted and moved between their home, child care program or school, and a community site. We calibrated the model according to observed case counts as reported to the health department. Our goal was to better understand the efficacy of existing interventions and whether limited outreach resources could be focused more effectively. We evaluated how well disseminating hand washing education in child care programs can reduce the number of infected children. The model indicated that intervention efficacy may be as high as 24% when all intervention parameters are at optimal values but only approximately 7% for a more realistic, less stringent scenario. We ranked intervention parameters according to their permutation importance using a random-forest regression analysis. The most important parameter was the minimum number of reported cases in a child care program that triggers a visit to disseminate hand washing education, followed by the use of non-antibacterial soap in hand washing education, the number of additional visits to child care programs, and the probability of successfully obtaining information on child care program attendance via patient interview. Additional strategies should be considered, such as working with community partners to assist with hand hygiene education at facilities during an outbreak. [ABSTRACT FROM AUTHOR]

Introduction: Intratumoral microbes play an important role in the development of colorectal cancer (CRC). However, studying intratumoral microbes in CRC faces technical challenges, as tumor microbe communities are often contaminated by fecal microbes due to the structure of the gut folds and villi. The present study aimed to develop a new method for isolating tumor cellassociated microbiota and comparing microbial populations from different compartments. Materials and methods: The distribution of intestinal bacteria was detected using immunohistochemistry combined with 5R-16s rRNA gene sequencing to explore the effects of the sampling site and number of washes on the detection of microbiota. The 5R-16s rRNA gene sequencing was performed using 44 samples from 11 patients with CRC, including CRC tumor tissues (TT), normal tissues adjacent to CRC (NT), tumor cells (TC), and normal cells (NC). TC and NC were obtained from the TT and NT using an enzymatic digestion method. The microbiota and their potential functions in the four groups were analyzed and compared to determine the differential microbiota related to CRC. Results: Bacteria were mainly distributed in the feces covering intestinal tissues and in the epithelial cells and macrophages within the tissues. Different sampling sites and number of washes led to detection of different microbiota distributions. Although the cleaningmethod could be controlled, sampling sites varied and led to different microbiota distributions. The phyla of Firmicutes and Bacteroidetes were highly abundant in the conventionally used tissue samples, whereas Proteobacteria was the most abundant phyla in the cell samples isolatedwith the newmethod (i.e., after cell enzymatic hydrolysis). Detection of CRC cell-associated microbiota using a cell enzymatic digestion method showed that some bacteria, such as Fusobacterium, Eikenella, Shewanella, and Listeria, were more abundant in TT than NT, whereas the abundance of Akkermansia was lower in TT than NT. The tumor/normal ratios of some bacteria, such as Gemella, Escherichia, Shigella, and Blautia, were different between the cell and tissue samples. Conclusion: The cell enzymatic digestion method reduced fecal bacterial contamination, enabling low biomass intratumoral microbiota to be detected and allowing prediction of bacterial distributions. [ABSTRACT FROM AUTHOR]

Shigella spp. are responsible for bacillary dysentery or shigellosis transmitted via the fecal–oral route, causing significant morbidity and mortality, especially among vulnerable populations. There are currently no licensed Shigella vaccines. Shigella spp. use a type III secretion system (T3SS) to invade host cells. We have shown that L-DBF, a recombinant fusion of the T3SS needle tip (IpaD) and translocator (IpaB) proteins with the LTA1 subunit of enterotoxigenic E. coli labile toxin, is broadly protective against Shigella spp. challenge in a mouse lethal pulmonary model. Here, we assessed the effect of LDBF, formulated with a unique TLR4 agonist called BECC470 in an oil-in-water emulsion (ME), on the murine immune response in a high-risk population (young and elderly) in response to Shigella challenge. Dual RNA Sequencing captured the transcriptome during Shigella infection in vaccinated and unvaccinated mice. Both age groups were protected by the L-DBF formulation, while younger vaccinated mice exhibited more adaptive immune response gene patterns. This preliminary study provides a step toward identifying the gene expression patterns and regulatory pathways responsible for a protective immune response against Shigella. Furthermore, this study provides a measure of the challenges that need to be addressed when immunizing an aging population. [ABSTRACT FROM AUTHOR]

Objective: Nowadays, viruses are the leading cause of acute gastroenteritis, while Rotavirus (RV) is the most common cause of acute viral gastroenteritis. In this study, the RV antigen positive diagnosis of gastroenteritis patients hospitalized in the pediatric service of the socio-demographic, clinical and laboratory features was aimed to be interpreted by comparison with literature data. Method: Socio-demographic data of patients hospitalized with the diagnosis of RV gastroenteritis, clinical and laboratory findings were retrospectively evaluated the hospital's file was obtained from the records. Results: The study of children hospitalized with acute gastroenteritis caused a mean age of 17.68 months from 740 patients who were enrolled, and 270 patients who were positive for RV and RV ratio was found to be 36%. Although the cases were most frequently seen in the spring, the most common months were February, March and April. The most frequent application causes were diarrhea and vomiting and the most common age group was the age group of 6 months-2 years of age. Five patients developed complications were detected. Laboratory findings in 101 patients with C-reactive protein positive (37.4%), 213 patients (78.8%) serum aspartate aminotransferase levels were high, in 94 patients (34.8%) had elevated alanine aminotransferase levels. Conclusion: Most cases of gastroenteritis were admitted to the service accounted for RV diarrhea and especially important cause of diarrhea is seen in winter and spring seasons. Therefore, the RV detection in cases of gastroenteritis is important to predict patient's clinic and prevent unnecessary use of antibiotics. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study was to analyze the fatty acid content, antioxidant, and antimicrobial activities of Argemone mexicana seed oil growing wild in north East Ethiopia. Materials and Methods: Oils of A mexicana L. were obtained by means of Screw press from seeds. Methyl esters were derived from the oily mixtures by trans-esterification process and were analyzed by GC/ FID and GC/MS systems. This oil was investigated for antioxidant activity using a DPPH radical-scavenging assay and was also tested against a panel of microorganisms. Results: Linolenic acid (49.00%) and oleic acid (28.91%) were the most abundant fatty acids in leaves and stems, respectively. The oil showed moderate to highest antimicrobial activity against Bacillus subtilis, Candida albicans, Shigella dysentery, Staphylococcus aureus, Pseudomonas aeroginosa, and Escherichia coli. The oil also demonstrated the highest antioxidant activity with the percentage of inhibition of 92.5% at a concentration of 1.5 mg/mL, and its IC50 and AAI were 22.4 µg/mL and 4.93 µg/mL, respectively. Conclusion: The results obtained from the present study indicated that the oil of A mexicana seed oil contained a high source of polyunsaturated fatty acids. These results also showed that the extracted oil from this plant has significant antimicrobial and antioxidant activities. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of the results of joint work of Russian and Congolese infectious disease specialists and epidemiologists to decipher the etiology and causes of the outbreak of intestinal infections in Dolisie (Republic of the Congo) in the summer of 2023. It has been found that the increase in the incidence of intestinal infections was caused mainly by the agents of typhoid fever and dysentery; tropical malaria was a combined pathology. No cases of cholera patient detection were registered. Failure of water supply system, domestic disrepair, and low public awareness about prevention of intestinal infections contributed to the active transmission of pathogens. The combination of epidemic process manifestations testified to the aquatic nature of the outbreak. Also, cases of pathogen transmission through contact household route were recorded, food transmission was not excluded. Patients with severe and complicated forms of typhoid fever and shigellosis accounted for 50 % of those hospitalized. There was delay in seeking medical care. The available regimens of antibacterial therapy were ineffective, since there was no possibility of laboratory confirmation of the diagnosis with determination of sensitivity to drugs. Uncontrolled treatment facilitated the emergence of antibiotic resistance in pathogens, prolonged bacterial release and subsequent spread of infection. Infectious disease specialists and epidemiologists of the Rospotrebnadzor provided consulting and practical assistance to Congolese colleagues, developed and presented recommendations for optimizing anti-epidemic and therapeutic measures, taking into account the results of assessment of the causes for onset and development of the outbreak.

Foodborne diseases are a global problem that is spreading day by day. These diseases are one of the most common causes of death in children and the elderly. This study was conducted to investigate the prevalence of water and foodborne diseases in Kurdistan province for six months from April to September 2022. Stool samples from patients were collected in the laboratory in a special container containing 10% formalin preservative. 134 stool samples from 28 food outbreaks from Kurdistan province were analyzed for the type of infected bacteria. The research results were analyzed in SPSS-19 software. Among the 28 outbreaks in Kurdistan province during the two seasons of spring and summer, the highest number of outbreaks was in the summer season with 20 and then in the spring season with 8 outbreaks. The dominant age group was children under 10 years (%21) old and people between 20-30 years old, and the dominant gender group was men. The most common clinical symptoms were nausea, vomiting, abdominal cramps, bloody diarrhea and non-bloody diarrhea. It is important to know the type of bacteria that cause water and foodborne diseases in reducing outbreaks and treatment costs and applying necessary measures for control and prevention.

Shigella dysenteriae has been recognized as the second most prevalent pathogen associated with diarrhea that contains blood, contributing to 12.9% of reported cases, and it is additionally responsible for approximately 200,000 deaths each year. Currently, there is no S. dysenteriae licensed vaccine. Multidrug resistance in all Shigella spp. is a growing concern. Current vaccines, such as O-polysaccharide (OPS) conjugates, are in clinical trials but are ineffective in children but protective in adults. Thus, innovative treatments and vaccines are needed to combat antibiotic resistance. In this study, we used immuno-informatics to design a new multiepitope vaccine and identified S. dysenteriae strain SD197's membrane protein targets using in-silico methods. The target protein was prioritized using membrane protein topology analysis to find membrane proteins. B and T-cell epitopes were predicted for vaccine formulation. The epitopes were shortlisted based on an IC50 value <50, antigenicity, allergenicity, and a toxicity analysis. In the final vaccine construct, a total of 8 B-cell epitopes, 12 MHC Class I epitopes, and 7 MHC Class II epitopes were identified for the Lipopolysaccharide export system permease protein LptF. Additionally, 17 MHC Class I epitopes and 14 MHC Class II epitopes were predicted for the Lipoprotein-releasing ABC transporter permease subunit LolE. These epitopes were selected and linked via KK, AAY, and GGGS linkers, respectively. To enhance the immunogenic response, RGD (arginine-glycine-aspartate) adjuvant was incorporated into the final vaccine construct. The refined vaccine structure exhibits a Ramachandran score of 91.5% and demonstrates stable interaction with TLR4. Normal Mode Analysis (NMA) reveals low eigenvalues (3.925996e-07), indicating steady and flexible molecular mobility of docked complexes. Codon optimization was carried out in an effective microbial expression system of the Escherichia coli K12 strain using the recombinant plasmid pET-28a (+). Finally, the entire in-silico analysis suggests that the suggested vaccine may induce a significant immune response against S. dysenteriae, making it a promising option for additional experimental trials. [ABSTRACT FROM AUTHOR]

Background: Cryptosporidium spp. cause watery diarrhea in humans and animals, especially in infants and neonates. They parasitize the apical surface of the epithelial cells in the intestinal lumen. However, the pathogenesis of Cryptosporidium-induced diarrhea is not fully understood yet. Methodology/principal findings: In this study, we infected C57BL/6j neonatal mice with C. parvum IIa and IId subtypes, and examined oocyst burden, pathological changes, and intestinal epithelial permeability during the infection. In addition, transcriptomic analyses were used to study the mechanism of diarrhea induced by the C. parvum IId subtype. The neonatal mice were sensitive to both C. parvum IIa and IId infection, but the IId subtype caused a wide oocyst shedding window and maintained the high oocyst burden in the mice compared with the IIa subtype. In addition, the mice infected with C. parvum IId resulted in severe intestinal damage at the peak of infection, leading to increased permeability of the epithelial barrier. The KEGG, GO and GSEA analyses revealed that the downregulation of adherens junction and cell junction molecules at 11 dpi. Meanwhile, E-cadherin, which is associated with adherens junction, was reduced at the protein level in mouse ileum at peak and late infection. Conclusions/significance: C. parvum IId infection causes more severe pathological damage than C. parvum IIa infection in neonatal mice. Furthermore, the impairment of the epithelial barrier during C. parvum IId infection results from the downregulation of intestinal junction proteins. Author summary: Cryptosporidiosis is a leading cause of moderate to severe diarrhea in children under 2 years of age. However, the pathogenesis of Cryptosporidium infection is not well understood. In this study, we used neonatal mice and a virulent C. parvum IId subtype as an infection model to study the mechanism of diarrhea associated with cryptosporidiosis. The results showed that the C. parvum IId subtype caused intense infection and severe pathological changes. At the peak of infection, mice had reduced intestinal digestion and absorption, and increased intestinal permeability. Transcriptomic data indicated that multiple pathways were involved in regulation of C. parvum IId infection. In particular, the adherens junction and cell junction assembly were downregulated. This was further supported by the reduction of E-cadherin expression during both peak and recovery periods. These data suggest that neonatal mice infect with C. parvum experience extensive damage of the intestinal barrier, resulting in diarrhea at the peak of infection. [ABSTRACT FROM AUTHOR]

Shigella dysenteriae, is a Gram-negative bacterium that emerged as the second most significant cause of bacillary dysentery. Antibiotic treatment is vital in lowering Shigella infection rates, yet the growing global resistance to broad-spectrum antibiotics poses a significant challenge. The persistent multidrug resistance of S. dysenteriae complicates its management and control. Hence, there is an urgent requirement to discover novel therapeutic targets and potent medications to prevent and treat this disease. Therefore, the integration of bioinformatics methods such as subtractive and comparative analysis provides a pathway to compute the pan-genome of S. dysenteriae. In our study, we analysed a dataset comprising 27 whole genomes. The S. dysenteriae strain SD197 was used as the reference for determining the core genome. Initially, our focus was directed towards the identification of the proteome of the core genome. Moreover, several filters were applied to the core genome, including assessments for non-host homology, protein essentiality, and virulence, in order to prioritize potential drug targets. Among these targets were Integration host factor subunit alpha and Tyrosine recombinase XerC. Furthermore, four drug-like compounds showing potential inhibitory effects against both target proteins were identified. Subsequently, molecular docking analysis was conducted involving these targets and the compounds. This initial study provides the list of novel targets against S. dysenteriae. Conclusively, future in vitro investigations could validate our in-silico findings and uncover potential therapeutic drugs for combating bacillary dysentery infection. [ABSTRACT FROM AUTHOR]

To determine the incidence of antimicrobial-resistant emerging pathogens, Clostridium difficile, and its associated risk factors in tertiary care setups of Pakistan. This cross-sectional prospective study was conducted from January 2019 to December 2020, to determine the prevalence and antimicrobial resistance patterns of C. difficile strains isolated from 450 stool specimens of patients suffering from diarrhea hospitalized in tertiary care hospitals in Peshawar, Pakistan. The stool samples of the patients were processed for culture and detection of toxin A and toxin B by enzyme-linked immunosorbent assay (ELISA) and tpi PCR. The drug sensitivity test was performed for antibiotics including ampicillin, cefixime, cefepime, amoxicillin, nalidixic acid, sulpha/TMP (SXT), chloramphenicol, metronidazole, vancomycin, ciprofloxacin, levofloxacin, and imipenem. Of 450 stool specimens, 108 (24%) were positive for C. difficile by stool culture, whereas 115 (25.5%) were only positive for C. difficile toxins based on ELISA and PCR (128 (28.6%). Of 108, 90.7% (n = 98) isolates were resistant to one antibiotic, and 90 (83.4%) were resistant to three or more antimicrobials. The highest resistance rates were found against penicillin (83.3%) followed by amoxicillin (70%), nalidixic acid (61%), and metronidazole (38%), and the lowest resistance was found against vancomycin (6.4%) and imipenem (3.7%). CDI was statistically significantly correlated with increased age, use of antibiotics, abdominal surgeries, use of proton pump inhibitors and H2a, and presence of comorbidities. The high frequency of C. difficile in Peshawar, Pakistan, indicates that CDI is an important nosocomial infection in different hospitals. The results will be helpful for clinicians to redesign control and therapeutic strategies in hospitals. [ABSTRACT FROM AUTHOR]

Background: A number of studies have detected relationships between weather and diarrhea. Few have investigated associations with specific enteric pathogens. Understanding pathogen-specific relationships with weather is crucial to inform public health in low-resource settings that are especially vulnerable to climate change. Objectives: Our objectives were to identify weather and environmental risk factors associated with diarrhea and enteropathogen prevalence in young children in rural Bangladesh, a population with high diarrheal disease burden and vulnerability to weather shifts under climate change. Methods: We matched temperature, precipitation, surface water, and humidity data to observational longitudinal data from a cluster-randomized trial that measured diarrhea and enteropathogen prevalence in children 6 months-5.5 years from 2012–2016. We fit generalized additive mixed models with cubic regression splines and restricted maximum likelihood estimation for smoothing parameters. Results: Comparing weeks with 30°C versus 15°C average temperature, prevalence was 3.5% higher for diarrhea, 7.3% higher for Shiga toxin-producing Escherichia coli (STEC), 17.3% higher for enterotoxigenic E. coli (ETEC), and 8.0% higher for Cryptosporidium. Above-median weekly precipitation (median: 13mm; range: 0-396mm) was associated with 29% higher diarrhea (adjusted prevalence ratio 1.29, 95% CI 1.07, 1.55); higher Cryptosporidium, ETEC, STEC, Shigella, Campylobacter, Aeromonas, and adenovirus 40/41; and lower Giardia, sapovirus, and norovirus prevalence. Other associations were weak or null. Discussion: Higher temperatures and precipitation were associated with higher prevalence of diarrhea and multiple enteropathogens; higher precipitation was associated with lower prevalence of some enteric viruses. Our findings emphasize the heterogeneity of the relationships between hydrometeorological variables and specific enteropathogens, which can be masked when looking at composite measures like all-cause diarrhea. Our results suggest that preventive interventions targeted to reduce enteropathogens just before and during the rainy season may more effectively reduce child diarrhea and enteric pathogen carriage in rural Bangladesh and in settings with similar meteorological characteristics, infrastructure, and enteropathogen transmission. Author summary: Location-specific weather factors influence the fate, transport, and transmission of enteropathogens that cause diarrhea. We sought to identify hydrometeorological risk factors associated with childhood diarrhea and specific enteropathogens in rural Bangladesh. In this setting, higher temperatures and precipitation were associated with higher diarrhea in children under 5 years old and with several enteropathogens including bacteria, viruses, and parasites. Higher precipitation was associated with the lower prevalence of some enteric viruses. Our data suggest that interventions targeted to reduce pathogen transmission just before and during the rainy season might be most effective to reduce diarrhea in this setting. [ABSTRACT FROM AUTHOR]

Background: Diarrhea caused by Salmonella and Shigella species are the leading cause of illness especially in developing countries. These infections are considered as the main public health problems in children, including Ethiopia. This study aimed to assess the prevalence, associated factors, and antimicrobial susceptibility patterns of Salmonella and Shigella species in Sheik Hassan Yabere Referral Hospital Jigjiga, Eastern Ethiopia from August 05 to November 15, 2022. Method: A cross-sectional study was conducted among 239 under-five children with diarrhea selected through a convenient sampling technique. A structured questionnaire was used to collect associated factors. A stool sample was collected and processed for the identification of Salmonella and Shigella species using MacConkey adar, Xylose Lysine Deoxycholate agar (Oxoid Ltd) and Biochemical tests. The antimicrobial susceptibility pattern of isolates was performed using the Kirby-Bauer disc diffusion technique. The data was entered into Epi-data version 4.6 and exported to the statistical package of social science version 22 for analysis. The association between outcome and independent variables was assessed using bivariate, multivariable, and chi-square and P-value < 0.05 was considered as statistical significance. Result: Overall prevalence of Salmonella and Shigella species was 6.3% (95% CI, 5.7–6.9%), of which 3.8% (95 CI, 3.2–4.4%) were Salmonella species and 2.5% (95% CI, 1.95-3%) were Shigella species. Unimproved water source (AOR = 5.08, 95% CI = 1.45, 17.25), open field (AOR = 2.3, 95% CI = 1.3, 5.03), rural residence (AOR = 1.8, 95% CI = 1.4, 7.5), Hand-washing practice (p = 0.001), and raw meat consumption (p = 0.002) were associated with occurrence of Salmonella and Shigella species. Salmonella and Shigella isolates were resistant to Ampicilin (100%). However, Salmonella isolates was sensitive to Norfloxacin (100%). About 22.2% and 16.7% of Salmonella and Shigella isolates were multi-drug resistant, respectively. Conclusion: Prevalence of Salmonella and Shigella species were lower than most studies done in Ethiopia. Hand-washing habit, water source type, Open field waste disposal habit, raw meat consumption and rural residence were associated with Salmonellosis and shigellosis. All isolated Salmonella were sensitive to norfloxacin. The evidence from this study underscores the need for improved water, sanitation and hygiene (WASH) system and the imperative to implement drug susceptibility tests for the treatment of Salmonella and Shigella infection. [ABSTRACT FROM AUTHOR]

Pathogen infections including Shigella flexneri have posed a significant threat to human health for numerous years. Although culturing and qPCR were the gold standards for pathogen detection, time-consuming and instrument-dependent restrict their application in rapid diagnosis and economically less-developed regions. Thus, it is urgently needed to develop rapid, simple, sensitive, accurate, and low-cost detection methods for pathogen detection. In this study, an immunomagnetic beads-recombinase polymerase amplification-CRISPR/Cas12a (IMB-RPA-CRISPR/Cas12a) method was built based on a cascaded signal amplification strategy for ultra-specific, ultra-sensitive, and visual detection of S. flexneri in the laboratory. Firstly, S. flexneri was specifically captured and enriched by IMB (Shigella antibody-coated magnetic beads), and the genomic DNA was released and used as the template in the RPA reaction. Then, the RPA products were mixed with the pre-loaded CRISPR/Cas12a for fluorescence visualization. The results were observed by naked eyes under LED blue light, with a sensitivity of 5 CFU/mL in a time of 70 min. With no specialized equipment or complicated technical requirements, the IMB-RPA-CRISPR/Cas12a diagnostic method can be used for visual, rapid, and simple detection of S. flexneri and can be easily adapted to monitoring other pathogens. [ABSTRACT FROM AUTHOR]

Background: The method currently available to diagnose shigellosis is insensitive and has many limitations. Thus, this study was designed to identify specific antigenic protein(s) among the cell surface associated proteins (SAPs) of Shigella that would be valuable in the development of an alternative diagnostic assay for shigellosis, particularly one that could be run using a stool sample rather than serum. Methods: The SAPs of clinical isolates of S. dysenteriae, S. boydii, Shigella flexneri, and S. sonnei were extracted from an overnight culture grown at 37 °C using acidified-glycine extraction methods. Protein profiles were observed by SDS-PAGE. To determine if antibodies specific to certain Shigella SAPs were present in both sera and stool suspensions, Western blot analysis was used to detect the presence of IgA, IgG, and IgM. Results: Immunoblot analysis revealed that sera from patients infected with S. flexneri recognized 31 proteins. These SAP antigens are recognized by the host humoral response during Shigella infection. Specific antibodies against these antigens were also observed in intestinal secretions of shigellosis patients. Of these 31 S. flexneri proteins, the 35 kDa protein specifically reacted against IgA present in patients' stool suspensions. Further study illustrated the immunoreactivity of this protein in S. dysenteriae, S. boydii, and S. sonnei. This is the first report that demonstrates the presence of immunoreactive Shigella SAPs in stool suspensions. The SAPSs could be very useful in developing a simple and rapid serodiagnostic assay for shigellosis directly from stool specimens. [ABSTRACT FROM AUTHOR]

Introduction: Shigella is the etiologic agent of a bacillary dysentery known as shigellosis, which causes millions of infections and thousands of deaths worldwide each year due to Shigella's unique lifestyle within intestinal epithelial cells. Cell adhesion/invasion assays have been extensively used not only to identify targets mediating host-pathogen interaction, but also to evaluate the ability of Shigella-specific antibodies to reduce virulence. However, these assays are time-consuming and labor-intensive and fail to assess differences at the single-cell level. Objectives and methods: Here, we developed a simple, fast and high-content method named visual Adhesion/Invasion Inhibition Assay (vAIA) to measure the ability of anti-Shigella antibodies to inhibit bacterial adhesion to and invasion of epithelial cells by using the confocal microscope Opera Phenix. Results: We showed that vAIA performed well with a pooled human serum from subjects challenged with S. sonnei and that a specific anti-IpaD monoclonal antibody effectively reduced bacterial virulence in a dose-dependent manner. Discussion: vAIA can therefore inform on the functionality of polyclonal and monoclonal responses thereby supporting the discovery of pathogenicity mechanisms and the development of candidate vaccines and immunotherapies. Lastly, this assay is very versatile and may be easily applied to other Shigella species or serotypes and to different pathogens. [ABSTRACT FROM AUTHOR]

Shigellosis is a severe gastrointestinal disease that annually affects approximately 270 million individuals globally. It has particularly high morbidity and mortality in low-income regions; however, it is not confined to these regions and occurs in high-income nations when conditions allow. The ill effects of shigellosis are at their highest in children ages 2 to 5, with survivors often exhibiting impaired growth due to infection-induced malnutrition. The escalating threat of antibiotic resistance further amplifies shigellosis as a serious public health concern. This review explores Shigella pathology, with a primary focus on the status of Shigella vaccine candidates. These candidates include killed whole-cells, live attenuated organisms, LPS-based, and subunit vaccines. The strengths and weaknesses of each vaccination strategy are considered. The discussion includes potential Shigella immunogens, such as LPS, conserved T3SS proteins, outer membrane proteins, diverse animal models used in Shigella vaccine research, and innovative vaccine development approaches. Additionally, this review addresses ongoing challenges that necessitate action toward advancing effective Shigella prevention and control measures. [ABSTRACT FROM AUTHOR]

Background Bacterial pathogens cause substantial diarrhea morbidity and mortality among children living in endemic settings, yet antimicrobial treatment is only recommended for dysentery or suspected cholera. Methods AntiBiotics for Children with severe Diarrhea was a 7-country, placebo-controlled, double-blind efficacy trial of azithromycin in children 2–23 months of age with watery diarrhea accompanied by dehydration or malnutrition. We tested fecal samples for enteric pathogens utilizing quantitative polymerase chain reaction to identify likely and possible bacterial etiologies and employed pathogen-specific cutoffs based on genomic target quantity in previous case-control diarrhea etiology studies to identify likely and possible bacterial etiologies. Results Among 6692 children, the leading likely etiologies were rotavirus (21.1%), enterotoxigenic Escherichia coli encoding heat-stable toxin (13.3%), Shigella (12.6%), and Cryptosporidium (9.6%). More than one-quarter (1894 [28.3%]) had a likely and 1153 (17.3%) a possible bacterial etiology. Day 3 diarrhea was less common in those randomized to azithromycin versus placebo among children with a likely bacterial etiology (risk difference [RD]likely, −11.6 [95% confidence interval {CI}, −15.6 to −7.6]) and possible bacterial etiology (RDpossible, −8.7 [95% CI, −13.0 to −4.4]) but not in other children (RDunlikely, −0.3% [95% CI, −2.9% to 2.3%]). A similar association was observed for 90-day hospitalization or death (RDlikely, −3.1 [95% CI, −5.3 to −1.0]; RDpossible, −2.3 [95% CI, −4.5 to −.01]; RDunlikely, −0.6 [95% CI, −1.9 to.6]). The magnitude of risk differences was similar among specific likely bacterial etiologies, including Shigella. Conclusions Acute watery diarrhea confirmed or presumed to be of bacterial etiology may benefit from azithromycin treatment. Clinical Trials Registration NCT03130114. [ABSTRACT FROM AUTHOR]