Bacterial Dysentery Research Articles

Combining Transcriptomics and Proteomics to Screen Candidate Genes Related to Bovine Birth Weight.

We established transcriptome and proteome databases for low-birth-weight (LB) and high-birth-weight (HB) calf placentae, identifying key genes and proteins associated with birth weight through bioinformatics analyses that included functional enrichment and protein-protein interactions (PPIs). Both mRNA and protein levels were validated. A total of 1494 differentially expressed genes (DEGs) and 294 differentially expressed proteins (DEPs) were identified when comparing the LB group to the HB group. Furthermore, we identified 53 genes and proteins exhibiting significant co-expression across both transcriptomic and proteomic datasets; among these, 40 were co-upregulated, 8 co-downregulated, while 5 displayed upregulation at the protein level despite downregulation at the mRNA level. Functional enrichment analyses (GO and KEGG) and protein-protein interaction (PPI) analysis indicate that, at the transcriptional level, the primary factor contributing to differences in calf birth weight is that the placenta of the high-birth-weight (HB) group provides more nutrients to the fetus, characterized by enhanced nutrient transport (SLC2A1 and SLC2A11), energy metabolism (ACSL1, MICALL2, PAG2, COL14A1, and ELOVL5), and lipid synthesis (ELOVL5 and ELOVL7). In contrast, the placenta of the low-birth-weight (LB) group prioritizes cell proliferation (PAK1 and ITGA3) and angiogenesis. At the protein level, while the placentae from the HB group exhibit efficient energy production and lipid synthesis, they also demonstrate reduced immunity to various diseases such as systemic lupus erythematosus and bacterial dysentery. Conversely, the LB group placentae excel in regulating critical biological processes, including cell migration, proliferation, differentiation, apoptosis, and signal transduction; they also display higher disease immunity markers (COL6A1, TNC CD36, CD81, Igh-1a, and IGHG) compared to those of the HB group placentae. Co-expression analysis further suggests that increases in calf birth weight can be attributed to both high-efficiency energy production and lipid synthesis within the HB group placentae (ELOVL5, ELOVL7, and ACSL1), alongside cholesterol biosynthesis and metabolic pathways involving CYP11A1 and CYP17A1. We propose that ELOVL5, ELOVL7, ACSL1, CYP11A1, and CYP17A1 serve as potential protein biomarkers for regulating calf birth weight through the modulation of the fatty acid metabolism, lipid synthesis, and cholesterol levels.

Transcriptomics analysis reveals the effect of Pulsatilla decoction butanol extract on endoplasmic reticulum and peroxisome function of Candida albicans in hyphal state

Ethnopharmacological relevanceThe traditional Chinese medicine formula known as Pulsatilla decoction was utilized to treat conditions such as bacterial dysentery, ulcerative colitis, and fungal infections like vulvovaginal candidiasis (VVC) caused by Candida albicans (C. albicans). In our prior research, it was shown that the n-butanol extract from Pulsatilla Decoction (BEPD) exhibited effective inhibition of C. albicans. Nevertheless, the exact mechanism by which BEPD hinders hyphal growth, a critical virulence factor of C. albicans, remains unclear. Aim of the studyIn the present study, the inhibitory effect and mechanism of the BEPD on C. albicans hyphal growth was predicted by transcriptome analysis, and further verified by in vitro and in vivo experiments. Materials and methodsThe BEPD was prepared and C. albicans was cultured to induce the hyphal state. Transcriptome analysis was conducted to predict the significant difference in enrichment genes and signaling pathways in the inhibitory effect of BEPD on C. albicans hyphae. Various methods, such as spot assay, time-growth curve analysis, Confocal laser scanning microscope (CLSM), scanning electron microscope (SEM), transmission electron microscope (TEM), flow cytometry, and spectrophotometer, were used to assess the effect of BEPD on hyphal structure and growth activity, lipid peroxidation level, peroxidase (CAT) activity, superoxide dismutase (SOD) activity, and apoptosis of C. albicans. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was employed to examine the expression levels of genes associated with endoplasmic reticulum and peroxisome function. The VVC model was employed to evaluate the influence of BEPD on the growth of C. albicans hyphae in vivo. ResultThe growth of C. albicans hyphae on solid culture media was significantly inhibited by BEPD. CLSM showed that the length of C. albicans hyphae was decreased and their vitality was lowered. SEM indicated that the hyphae of C. albicans were fractured, while TEM revealed damage to the organelles within the cells. GO enrichment and KEGG pathways analysis from transcriptomic data demonstrated that BEPD effectively suppressed the functioning of the endoplasmic reticulum and peroxisomes in C. albicans hyphae. RT-qPCR verified the decreased expression of genes associated with endoplasmic reticulum and peroxisome function by BEPD. Investigation of the endoplasmic reticulum revealed that BEPD elevated levels of reactive oxygen species (ROS) and apoptosis, indicating endoplasmic reticulum stress, as well as malondialdehyde (MDA), a marker of oxidative stress. Additionally, BEPD was shown to lower the activities of catalase (CAT) and superoxide dismutase (SOD). In animal trials, BEPD effectively hindered the growth of C. albicans hyphae in the vaginas of mice with VVC, thus reducing immune inflammatory damage to the vaginal mucosa of these mice. ConclusionThis study demonstrates that BEPD has an inhibitory effect on hyphae, which are an important virulence factor of C. albicans. This effect may be related to BEPD's inhibitory effect on endoplasmic reticulum (ER) and peroxisome function. The findings suggest that BEPD could potentially play a therapeutic role in C. albicans infectious diseases by inhibiting hyphae.

The effect of temperature on infectious diarrhea disease: A systematic review

This study aimed to ascertain the delayed effects of various exposure temperatures on infectious diarrhea. We performed a Bayesian random-effects network meta-analysis to calculate relative risks (RR) with 95 % confidence intervals (95 % CI). The heterogeneity was analyzed by subgroup analysis. There were 25 cross-sectional studies totaling 6858735 patients included in this analysis, with 12 articles each investigating the effects of both hyperthermia and hypothermia. Results revealed that both high temperature (RRsingle = 1.22, 95%CI:1.04–1.44, RRcum = 2.96, 95%CI:1.60–5.48, P < 0.05) and low temperature (RRsingle = 1.17, 95%CI:1.02–1.37, RRcum = 2.19, 95%CI:1.33–3.64, P < 0.05) significantly increased the risk of infectious diarrhea, while high temperature caused greater. As-sociations with strengthening in bacillary dysentery were found for high temperatures (RRcum = 2.03, 95%CI:1.41–3.01, P < 0.05; RRsingle = 1.17, 95%CI:0.90–1.62, P > 0.05), while the statistical significance of low temperatures in lowering bacterial dysentery had vanished. This investigation examined that high temperature and low temperature were the conditions that posed the greatest risk for infectious diarrhea. This research offers fresh perspectives on preventing infectious diarrhea and will hopefully enlighten future studies on the impact of temperature management on infectious diarrhea.

Genome-Wide Investigation Reveals Potential Therapeutic Targets in Shigella spp.

Shigella stands as a major contributor to bacterial dysentery worldwide scale, particularly in developing countries with inadequate sanitation and hygiene. The emergence of multidrug-resistant strains exacerbates the challenge of treating Shigella infections, particularly in regions where access to healthcare and alternative antibiotics is limited. Therefore, investigations on how bacteria evade antibiotics and eventually develop resistance could open new avenues for research to develop novel therapeutics. The aim of this study was to analyze whole genome sequence (WGS) of human pathogenic Shigella spp. to elucidate the antibiotic resistance genes (ARGs) and their mechanism of resistance, gene-drug interactions, protein-protein interactions, and functional pathways to screen potential therapeutic candidate(s). We comprehensively analyzed 45 WGS of Shigella, including S. flexneri (n = 17), S. dysenteriae (n = 14), S. boydii (n = 11), and S. sonnei (n = 13), through different bioinformatics tools. Evolutionary phylogenetic analysis showed three distinct clades among the circulating strains of Shigella worldwide, with less genomic diversity. In this study, 2,146 ARGs were predicted in 45 genomes (average 47.69 ARGs/genome), of which only 91 ARGs were found to be shared across the genomes. Majority of these ARGs conferred their resistance through antibiotic efflux pump (51.0%) followed by antibiotic target alteration (23%) and antibiotic target replacement (18%). We identified 13 hub proteins, of which four proteins (e.g., tolC, acrR, mdtA, and gyrA) were detected as potential hub proteins to be associated with antibiotic efflux pump and target alteration mechanisms. These hub proteins were significantly (p < 0.05) enriched in biological process, molecular function, and cellular components. Therefore, the finding of this study suggests that human pathogenic Shigella strains harbored a wide range of ARGs that confer resistance through antibiotic efflux pumps and antibiotic target modification mechanisms, which must be taken into account to devise and formulate treatment strategy against this pathogen. Moreover, the identified hub proteins could be exploited to design and develop novel therapeutics against MDR pathogens like Shigella.

Novel rpsK / rpsD primer-probe assay improves detection of Campylobacter jejuni and Campylobacter coli in human stool.

Campylobacter causes bacterial enteritis, dysentery, and growth faltering in children in low- and middle-income countries (LMICs). Campylobacter spp. are fastidious organisms, and their detection often relies on culture independent diagnostic technologies, especially in LMICs. Campylobacter jejuni and Campylobacter coli are most often the infectious agents and in high income settings together account for 95% of Campylobacter infections. Several other Campylobacter species have been detected in LMIC children at an increased prevalence relative to high income settings. After doing extensive whole genome sequencing of isolates of C. jejuni and C. coli in Peru, we observed heterogeneity in the binding sites for the main species-specific PCR assay (cadF) and designed an alternative rpsKD-based qPCR assay to detect both C. jejuni and C. coli. The rpsKD-based qPCR assay identified 23% more C.jejuni/ C.coli samples than the cadF assay among 47 Campylobacter genus positive cadF negative samples verified to have C. jejuni and or C. coli with shotgun metagenomics. This assay can be expected to be useful in diagnostic studies of enteric infectious diseases and be useful in revising the attribution estimates of Campylobacter in LMICs.

Risk Factors of Developing Postinfectious Irritable Bowel Syndrome in Shigellosis Patients, 5 Years After Hospitalization During the Outbreak.

Irritable bowel syndrome (IBS) can be triggered by bacterial dysentery. This study aimed to investigate postinfectious IBS and its risk factors after the shigellosis outbreak in hospitalized patients. This retrospective study was conducted in 2020-2021 in referral hospitals for Shigella gastroenteritis during the 2014 shigellosis outbreak in Isfahan. The Shigella-infected group included hospitalized shigellosis patients with clinical symptoms and positive stool culture. The control group included patients matched pairwise on age and sex to the Shigella-infected group, admitted to the same hospitals in the same period with diagnoses other than shigellosis. Both groups had no history of diagnosed IBS before the outbreak. The incidence of IBS (according to Rome-III criteria) and its related factors was compared between the 2 groups 5 years after infection. Of 619 participants, 220 (35.5%) were in the Shigella-infected group. The 5-year incidence of IBS was 31.8% and 5.7% in the Shigella-infected and control groups, respectively. Multivariate analysis showed that shigellosis was significantly associated with increased risk of IBS (odds ratio [OR], 17.18 [95% confidence interval {CI}, 9.37-31.48]). Multivariate analysis indicated education level (OR, 4.15 [95% CI, 1.47-11.73]), diarrhea lasting >4 days (OR, 1.69 [95% CI, 1.17-2.44]), and abdominal cramps during the infection (OR, 0.27 [95% CI, .77-.95]) associated with postinfectious IBS (P < .05). Hospitalized patients with Shigella gastroenteritis are at increased risk of IBS within 5 years after infection. Factors such as higher education level and the absence of abdominal cramps and diarrhea persisting for >5 days during hospitalization can further increase this risk.

Trends in Gastrointestinal Infections during the COVID-19 Pandemic and Concerns of Post-Pandemic Resurgence in Japan.

The impact of the COVID-19 pandemic was very broad and substantial, affecting a variety of fields worldwide. In Japan, the infection began spreading in March 2020. At that time, the government alerted people to cancel overseas travel, and encouraged wearing of masks, handwashing, sanitizing and keeping social distance. We sought to determine how COVID-19 infections affected other infectious diseases by investigating the trends in seven gastrointestinal infections that are listed among the 77 important infectious diseases designated by the National Institute of Infectious Diseases. We compared seven gastrointestinal infectious diseases, namely cholera, bacterial dysentery, enterohemorrhagic Escherichia coli, typhoid fever, paratyphoid fever, amoebic dysentery, and giardiasis, in terms of numbers of new cases before the COVID-19 pandemic (2012-2019) and during the pandemic (2020-2022). During the COVID-19 pandemic period (2020-2022), the incidence of the seven infections decreased significantly (p < 0.05) compared with before the pandemic (2012-2019). The sharp and significant decline in incidence of these seven infections in Japan during the COVID-19 pandemic period (2020-2022) appears to be due to restrictions on overseas travel and strict anti-infection measures, such as self-quarantine and encouragement of handwashing and sanitizing. The number of new cases of gastrointestinal infections in Japan is expected to increase in 2024 as these measures lapse. It is important for physicians to continue to monitor trends in gastrointestinal infections and educate people about proper infection prevention.

Ascorbate deficiency increases progression of shigellosis in guinea pigs and mice infection models

ABSTRACT Shigella spp. are the causative agents of bacterial dysentery and shigellosis, mainly in children living in developing countries. The study of Shigella entire life cycle in vivo and the evaluation of vaccine candidates’ protective efficacy have been hampered by the lack of a suitable animal model of infection. None of the studies evaluated so far (rabbit, guinea pig, mouse) allowed the recapitulation of full shigellosis symptoms upon Shigella oral challenge. Historical reports have suggested that dysentery and scurvy are both metabolic diseases associated with ascorbate deficiency. Mammals, which are susceptible to Shigella infection (humans, non-human primates and guinea pigs) are among the few species unable to synthesize ascorbate. We optimized a low-ascorbate diet to induce moderate ascorbate deficiency, but not scurvy, in guinea pigs to investigate whether poor vitamin C status increases the progression of shigellosis. Moderate ascorbate deficiency increased shigellosis symptom severity during an extended period of time (up to 48 h) in all strains tested (Shigella sonnei, Shigella flexneri 5a, and 2a). At late time points, an important influx of neutrophils was observed both within the disrupted colonic mucosa and in the luminal compartment, although Shigella was able to disseminate deep into the organ to reach the sub-mucosal layer and the bloodstream. Moreover, we found that ascorbate deficiency also increased Shigella penetration into the colon epithelium layer in a Gulo−/− mouse infection model. The use of these new rodent models of shigellosis opens new doors for the study of both Shigella infection strategies and immune responses to Shigella infection.

An Analytical Approach for Temporal Infection Mapping and Composite Index Development

Significant and composite indices for infectious disease can have implications for developing interventions and public health. This paper presents an investment for developing access to further analysis of the incidence of individual and multiple diseases. This research mainly comprises two steps: first, an automatic and reproducible procedure based on functional data analysis techniques was proposed for analyzing the dynamic properties of each disease; second, orthogonal transformation was adopted for the development of composite indices. Between 2000 and 2019, nineteen class B notifiable diseases in China were collected for this study from the National Bureau of Statistics of China. The study facilitates the probing of underlying information about the dynamics from discrete incidence rates of each disease through the procedure, and it is also possible to obtain similarities and differences about diseases in detail by combining the derivative features. There has been great success in intervening in the majority of notifiable diseases in China, like bacterial or amebic dysentery and epidemic cerebrospinal meningitis, while more efforts are required for some diseases, like AIDS and virus hepatitis. The composite indices were able to reflect a more complex concept by combining individual incidences into a single value, providing a simultaneous reflection for multiple objects, and facilitating disease comparisons accordingly. For the notifiable diseases included in this study, there was superior management of gastro-intestinal infectious diseases and respiratory infectious diseases from the perspective of composite indices. This study developed a methodology for exploring the prevalent properties of infectious diseases. The development of effective and reliable analytical methods provides special insight into infectious diseases’ common dynamics and properties and has implications for the effective intervention of infectious diseases.

Preliminary Investigations on the Therapeutic Efficacy and Safety of Mixed Probiotic Lactic Acid Bacteria on Albino Rats Challenged with Shigella dysenteriae

This study investigates the potential of lactic acid bacteria (LAB) from the Nigerian beverage “kunun zaki” as alternative therapeutic agents against Shigella dysenteriae infections. In light of rising antibiotic resistance, the decline in probiotic usage prompted interest in LAB’s role in countering bacterial dysentery. Shigella dysenteriae, a significant cause of dysentery in developing nations, prompted this research which aims to carry out a preliminary investigation on the therapeutic efficacy and safety of mixed probiotic lactic acid bacteria on albino rats challenged with Shigella dysenteriae. Lactic acid bacteria, known for treating infections, were isolated from the beverage and tested against Shigella dysenteriae. The study employed 15 albino rats for in vivo trials, inducing diarrhea and treating with Lactococcus lactis and Lactobacillus brevis separately (T1 and T2) and combined in a 1 : 1 ratio (T3). Clinical parameters were observed before and after treatment. This revealed that L. lactis and L. brevis administration lowered rectal temperature from an average of 42°C caused by infection to 36.5°C. Stool consistency improved from light brown loose to dark brown semisolid, signifying reduced diarrhea. Bacteriological analysis displayed significant reduction ( p &lt; 0.05 ) in Shigella counts in rat intestines across all treatments— 220 ± 2.88 C F U / g to 19.00 ± 1.77 C F U / g , 8.33 ± 0.88 C F U / g , and 65.00 ± 2.88 C F U / g for T1, T2, and T3, respectively. The mixed LAB treatment was notably effective. Lactic acid bacteria counts increased significantly in Shigella-treated rats versus the positive control. Hematology and liver function parameters showed no significant differences between treatments and untreated controls. Lactic acid bacteria from “kunun zaki” exhibited curative potential, individually or combined, against Shigella dysenteriae. These lactic acid bacteria also positively influenced gut microbiota in Shigella-infected albino rats.

Exopolysaccharide produced by Lactiplantibacillus plantarum Y12 exhibits inhibitory effect on the Shigella flexneri genes expression related to biofilm formation

Shigella is a specific enteric pathogen in humans, causing symptoms of bacterial dysentery. The biofilm formation of S. flexneri contributes to the emergence of multidrug resistance and facilitates the establishment of persistent chronic infections. This study investigated the regulatory effects of Lactiplantibacillus plantarum Y12 exopolysaccharide (L-EPS) on gene expression and its spatial hindrance effects in inhibiting the biofilm formation of S. flexneri. The transcriptome analysis revealed a significant impact of L-EPS on the gene expression profile of S. flexneri, with a total of 968 genes showing significant changes (507 up-regulated and 461 down-regulated). The significantly down-regulated KEGG metabolic pathway enriched in phosphotransferase system, Embden-Meyerhf-Parnas, Citrate cycle, Lipopolysaccharide biosynthesis, Cationic antimicrobial peptide resistance, Two-component system. Moreover, L-EPS significantly down-regulated the gene expression levels of fimbriae synthesis (fimF), lipopolysaccharide synthesis (lptE, lptB), anchor protein repeat domain (arpA), virulence factor (lpp, yqgB), antibiotic resistance (marR, cusB, mdtL, mdlB), heavy metal resistance (zraP), and polysaccharide synthesis (mtgA, mdoB, mdoC). The expression of biofilm regulator factor (bssS) and two-component system suppressor factor (mgrB) were significantly up-regulated. The RT-qPCR results indicated that a major component of L-EPS (L-EPS 2-1) exhibited the gene regulatory effect on the S. flexneri biofilm formation. Furthermore, electrophoresis and isothermal microtitration calorimetry demonstrated that the interaction between L-EPS 2-1 and eDNA is electrostatic dependent on the change in environmental pH, disrupting the stable spatial structure of S. flexneri biofilm. In conclusion, L-EPS inhibited the biofilm formation of S. flexneri through gene regulation and spatial obstruction effects.

Promising directions for vaccine development to prevent shigellosis

Shigellosis (bacterial dysentery) is an acute infectious disease caused by Shigella spp., members of the Enterobacteriaceae family. The disease has the highest mortality rate amongst bacterial enteric infections. A considerable proportion of Shigella infections occur in children under the age of five. In 2017, WHO included Shigella spp. strains into the list of “priority pathogens” that are resistant to most antibiotics and pose a threat to global public health. This provided a stimulus for the development of new antibiotics to treat shigellosis. Apart from the creation of new antimicrobial therapies for Shigella infections, an important role in fighting against shigellosis belongs to the preventative measures set out in WHO’s Immunisation Agenda 2030. These include sanitation, hygiene, consumption of clean water, and vaccination. The development of Shigella vaccines has been a priority of the WHO programme for more than 20 years. The aim of the study was to analyse promising approaches to Shigella vaccine development. According to the analysis of literature, only one vaccine against shigellosis has been approved so far—Shigellvac, the Russian polysaccharide dysentery vaccine against Shigella sonnei. This study covers a number of vaccine candidates (whole-cell, polysaccharide, polysaccharide conjugate, protein antigen-based vaccines, etc.) that are at different stages of clinical trials. The importance of researching combination (multivalent) vaccines against Shigellа spp. and other enteric pathogens is noted. However, the authors consider subunit vaccines based on Ipa proteins, providing broad cross-protection against Shigellа spp., and conjugate polyvalent vaccines for children under 5 the most promising for further development.

Elucidation of Key Interactions between VirF and the virB Promoter in Shigella flexneri Using E. coli MarA- and GadX-Based Homology Models and In Vitro Analysis of the DNA-Binding Domains of VirF and MarA.

Infection with Shigella, the organism responsible for the diarrheal disease shigellosis, leads to approximately 200,000 deaths globally annually. Virulence of this pathogen is primarily controlled by the DNA-binding transcriptional activator VirF. This AraC family protein activates transcription of two major virulence genes, virB and icsA, which lead to the pathogen's ability to invade and spread within colonic epithelial cells. While several AraC proteins have been studied, few studies of VirF's binding to its DNA promoters have been reported, and VirF's three-dimensional structure remains unsolved. Here, we used structures of two E. coli VirF homologs, GadX and MarA-marRAB, to generate homology models of the VirF DNA-binding domain in free and DNA-bound conformations. We conducted alanine scanning mutagenesis on seven residues within MarA that make base-specific interactions with its promoter, marRAB, and the corresponding residues within VirF (identified by sequence and structural homologies). In vitro DNA-binding assays studying both wild-type and mutant MarA and VirF proteins identified residues important for binding to the marRAB and virB promoters, respectively. Comparison of the effects of these DNA-binding domain mutants validated our MarA-based homology model, allowing us to identify crucial interactions between VirF and the virB promoter. Proteins with mutations to helix 3 within both MarA(W42A, R46A) and MalE-VirF(R192A, K193A) exhibited significant reductions in DNA binding, while the effects of mutations in helix 6 varied. This suggests the shared importance of helix 3 in the binding to these promoters, while helix 6 is transcription factor specific. These results can inform further development of virulence-targeting inhibitors as an alternative to traditional antimicrobial drug design. IMPORTANCE Globally, infection with Shigella flexneri is a leading cause of bacterial dysentery, particularly affecting children under the age of 5 years. The virulence of this pathogen makes it highly infectious, allowing it to spread easily within areas lacking proper sanitation or access to clean drinking water. VirF is a DNA-binding transcription factor that activates S. flexneri virulence once the bacteria infect the human colon. Development of drugs that target VirF's DNA-binding activity can be an effective treatment to combat shigellosis as an alternative or addition to traditional antibiotics. Due to the lack of structural data, analysis of VirF's DNA-binding activity is critical to the development of potent VirF inhibitors.

Identification of MHC Class II Immunopeptidomes from Shigella flexneri 2a-infected Macrophages as Potential Vaccine Candidates

BACKGROUND: Shigella is a Gram-negative rod-shaped intracellular bacterial pathogen that causes bacterial dysentery or shigellosis among children under five years old. Antibiotics have been less effective in treating shigellosis due to the multi-drug resistance of Shigella. Therefore, an effective vaccine is urgently needed to prevent this disease. The present study aims to determine the peptides presented by major histocompatibility complex (MHC) class II molecules of Shigella-infected macrophages using mass spectrometry-based immunopeptidomics approaches. The MHC class II-associated peptides derived from Shigella-infected macrophages are candidates for developing subunit-based Shigella vaccine.METHODS: THP-1-derived macrophages were infected with Shigella flexneri 2a at the multiplicity of infection equal to 10. The lysate was immunoprecipitated and analyzed by liquid chromatography–tandem mass spectrometry (LC-MS/MS). The sequences retrieved were analyzed using bioinformatics tools.RESULTS: The Shigella-infected THP-1-derived macrophages contained sample peptides from source proteins of almost all subcellular localizations. Eight peptides from S. flexneri 2a-infected macrophages were predicted to be localized at the outer membrane proteins (OMPs) of S. flexneri 2a by the PSORTb server. Two of the OMP-associated peptides were predicted as antigenic, non-allergenic, and non-toxic by respective bioinformatics tools.CONCLUSION: The findings in this study showed two selected OMPs have great potential for vaccine development against shigellosis.KEYWORDS: immunopeptidomics, mass spectrometry, vaccine development, Shigella, MHC peptides

Molecular mechanism of the effect of gegen qinlian decoction on type 2 diabetes mellitus based on network pharmacology and molecular docking

Gegen qinlian decoction (GGQLD) is a Traditional Chinese Medicine formula comprising four herbal medicines. It is commonly used to treat bacterial dysentery in the past. Modern research has repositioned this decoction and applied it to treat type 2 diabetes mellitus (T2DM) and has achieved good results. However, the molecular mechanism of GGQLD in treating T2DM is still not fully known. Hence, this study was designed to explore the effective components and potential mechanism of GGQLD in the treatment of T2DM by using network pharmacology and molecular docking technology. The herb-compound-target interaction network was constructed by retrieving and screening of active components in different herbs in GGQLD and corresponding T2DM-related target genes across multiple databases. Subsequently, STRING and Cytoscape were applied to analyze and construct PPI network. Then, GO and KEGG pathway enrichment analysis were performed to investigate biological processes and pathways involved in GGQLD. The differentially expressed analysis was used to verify whether the expression of key target genes in T2DM and non-T2DM samples was statistically significant. Finally, the binding capacity between active components and key targets was validated by molecular docking using AutoDock4. The results shows that there are 60 active components involved in 100 T2DM-related targets that are identified in GGQLD formula. PPI networks were constructed and 10 key targets (IL1B, EGFR, VEGFA, IL6, JUN, TP53, MAPK3, AKT1, CASP3 and TNF) were obtained after topological analysis. Further, GO and KEGG analysis showed that GGQLD may play an important role in treating T2DM and its complications by synergistically regulating many biological processes and pathways involved in inflammatory response, hypoxia reaction, angiogenesis, cell growth, apoptosis, senescence, and biological processes mediated by PI3K-AKT, HIF-1, EGFR signaling pathways. Gene expression microarray data analysis showed that the expression of IL1B, IL6, EGFR, TP53, VEGFA, and JUN in T2DM samples were significantly different from those in normal controls. 4 high-affinity active components of GGQLD binding with the 10 key targets, including kaempferol, quercetin, naringenin and beta-sitosterol have been identified by molecular docking. Furthermore, the molecular dynamics simulation analysis by GROMACS showed the stability of the compound-protein binding complex. Our research preliminarily revealed the material basis and relevant mechanisms of GGQLD in treating T2DM and its complications. The prediction results might facilitate the development of GGQLD or its active compounds as alternative therapy for T2DM, and provide support for further study and experimental validation.

Real-time multiplex PCR assay reveals the increased prevalence of Campylobacter spp and diarrhoeagenic Escherichia coli in humans from Vellore, South India.

Introduction. Bacterial dysentery is one of the greatest causes of morbidity and mortality worldwide. Campylobacter spp. and diarrhoeagenic Escherichia coli (DEC) are recognised as the most common causes of bacterial enteritis in developing countries including India.Hypothesis/Gap statement. Rapid and accurate identification of dysentery causing organisms using molecular methods is essential for better disease management, epidemiology and outbreak investigations.Aim. In view of the limited information available on the dysentery causing agents like Campylobacter spp., enterohemorrhagic E. coli (EHEC)/enteropathogenic E. coli (EPEC) and enteroinvasive E. coli (EIEC)/Shigella in India, this study was undertaken to investigate the presence of these pathogens in human and poultry stool samples by molecular methods.Methodology. In total, 400 human stool samples and 128 poultry samples were studied. Microaerophilic culture along with real-time multiplex PCR with the targets specific to the genus Campylobacter, Campylobacter jejuni, Campylobacter coli, EHEC, EPEC and EIEC/Shigella was performed. Further species confirmation was done using MALDI-TOF MS.Results. On microaerophilic culture, C. coli was isolated in one human sample and two C. jejuni and one C. fetus in poultry samples. On PCR analysis, among human stool samples, typical EPEC (42%) was predominantly seen followed by Campylobacter spp. (19%) and EIEC/Shigella (10%). In contrast, Campylobacter spp. (41%) was predominant in poultry samples, followed by typical EPEC (26%) and EIEC/Shigella (9%). Poly-infections with Campylobacter spp. and DEC were also observed among both sources.Conclusion. The present study documented the increased prevalence of Campylobacter spp. in humans compared with the results of previous studies from India. Typical EPEC was found to be predominant in children less than 5 years of age in this study. The high prevalence of coinfections in the current study indicates that a multiple aetiology of diarrhoea is common in our settings.

Yersinia Enterocolitica.

Yersinia Enterocolitica.

UJI TOKSISITAS EKSTRAK DAUN KENCUR (Kaempferia galanga L) DENGAN METODE BRINE SHRIMP LETHALY TEST (BSLT)

One of the plants that has potential as medicine is kencur(Kaemoferia galanga L). Many studies have asserted that the rhizome of kencur is useful for bacterial infections, cough medicine, dysentery, cold, and stomachache. Therefore, the research aimed to identify the toxic effect of kencur leaf extract on artemia salina larvae applying the BSLT (Brine shrimp lethaly test) method. It employed three concentration treatments using 10 artemia salina larvae that died after 48 hours. Futher, it was calculated by LC50with probit analysis. The result of probit analysis revealed that the value of LC50from n-hexane extract was 96,13µg/mL, ethyl acetate extract was 98,22 µg/mL and methanol extract of kencur leaf was 156,06 µg/mL. The LC50 value of the extract was in the active category, with the value of LC50was lower than 1000 ppm.

A PCR-free genosensing platform for detection of Shigella dysenteriae in human plasma samples by porous and honeycomb-like biochar decorated with ultrathin flower-like MoS2 nanosheets incorporated with Au nanoparticles

Shigella dysenteriae, a gram-negative bacterium, which results in the most infectious of bacterial shigellosis and dysenteries. In this study, an innovative gene detection platform based on label-free DNA sequences was developed to detect Shigella dysenteriae in human plasma samples. The porous and honeycomb-like structure of biochar (BC) was first synthesized through a pyrolysis process. Then, the produced biochar was effectively decorated with flower-like MoS2 nanosheets (MoS2/BC). The resulting nanocomposite was incorporated with Au nanoparticles (AuNPs) by applying chronoamperometry technique, and then the subsequent product including MoS2 nanosheets, biochar and AuNPs were immobilized on the Au electrode surface and used for modifier agent in electrochemical bio-assays. Structural and morphological study of the synthesized compounds were investigated using various characterization methods such as FE-SEM, TEM, EDS, FTIR, and XRD. Various electrochemical techniques including cyclic voltammetry (CV) and Differential pulse anodic stripping voltammetry (DPASV) have been used to investigate the applicability of the fabricated genosensing bio-assay. Under optimal conditions, LOD and LOQ were calculated 9.14 fM and 0.018 pM respectively. In addition, a linear range from 0.01 to 100 pM was obtained for single stranded-target DNA (ss-tDNA), with R2 of 0.9992. The recoveries ranged from 98.0 to 101.3%. The fabricated bio-detection assay demonstrated high selectivity for 1, 2, and 3 base mismatch sequences. In addition, a negative control of the gene detection platform which was performed to study selectivity was provided by ss-tDNA from Haemophilusinfluenzae, and Salmonella typhimurium. Moreover, it is important to mention that the organized bioassay is simply reusable and reproducible with the RSD% (relative standard deviation) ˂ 5 to next detection assays.

Роль ентеропатогенних кишкових паличок у розвитку і перебігу хронічного невиразкового коліту

Мета. Проведений аналіз даних літератури показав, що у хворих на хронічний невиразковий коліт ізолюють E. сoli, які викликають дизентерієподібні, холероподібні захворювання та ешерихіози. Тому метою наших досліджень було встановити рівень персистенції у товстій кишці хворих на хронічний невиразковий коліт енте ропатогенних ешерихій та їх значення в екологічній системі «макроорганізм — мікробіота». Матеріали та методи. Протягом 2000–2015 рр. проведено бактеріологічне обстеження вмісту порожнини товстої кишки хворих на хронічний невиразковий коліт віком 27–41 рік (середній вік 37,74 ± 3,62 року). Отримані культури перевіряли в орієнтовній реакції аглютинації з полівалентною сироваткою ОКА. Позитивні культури піддавались дослідженню з полівалентною сироваткою вузького спектра ОКВ, ОКС, ОКД та ОКЕ. Результати. У хворих, у порожнині товстої кишки яких виявлені E. сoli О18ас:К77; О26:К60; О55:К59; О128ав:К67, захворювання мало перебіг за нозологічною формою коліентериту. У тих пацієнтів, в кого виділили сероваріанти О25:К11; О144:К; О124:К72, захворювання перебігало як бактеріальна дизентерія, а О25:К11 і О128:К67 — у холероподібній формі. Обговорення. У 94,50 % хворих виявляються звичайні E. сoli, але у 55 (35,03 %) персистують ентеропатогенні ешерихії, у 41 (26,11 %) — E. сoli Hly+, у 37 (23,57 %) — E. сoli Lac–, у 18 (11,46 %) — ентеротоксигенні E. сoli, у 14 (8,42 %) — ентероінвазивні та в 11 (7,01 %) — ентерогеморагічні ешерихії. Висновки. Визначено, що основними сероваріантами умовно-патогенних ешерихій, що колонізують товсту кишку хворих на хронічний невиразковий коліт і персистують в її порожнині, є О114:К90; О25:К11; О124:К72; О128:К67; О18ас:К77, персистенція яких впливає на клінічну маніфестацію від коліту до дизентерієподібного або до холероподібного захворювання.