RESUMEN

Purpose: Waterborne pathogens pose a significant threat to public health, emphasizing the continuous necessity for advancing robust detection techniques, particularly in preventing outbreaks associated with these pathogens. This study focuses on cholera, an infectious disease caused by Vibrio cholerae, serogroups O1 and O139, often transmitted through contaminated water and food, raising significant public health concerns in areas with poor sanitation and limited access to clean water. Methods: We developed a colorimetric biosensor using aptamer-functionalized gold nanoparticles to identify Vibrio cholerae O139 and address this issue. The detection mechanism relies on the color change of gold nanoparticles (AuNPs) from red to blue-purple induced by NaCl after the pathogen incubation and aptamer-target binding. Initial steps involved synthesizing and characterizing AuNPs, then exploring the impact of aptamer and NaCl concentrations on AuNP agglomeration. Optimization procedures for aptamer concentration and salt addition identified the optimal conditions for detection as 120 pM aptamers and 1 M NaCl. Results: The aptasensor demonstrated a robust linear relationship, detecting V. cholerae concentrations from 103 to 108 CFU/mL, with a limit of detection (LOD) of 587 CFU/mL. Specificity tests and accurate sample analyses confirmed the efficiency of the AuNPs aptasensor, showcasing its reliability and speed compared to traditional culture examination methods. Moreover, we extended the aptasensor to a paper-based sensing platform with similar detection principles. Conclusion: The change in color upon target binding was captured with a smartphone and analyzed using image processing software. The paper-based device detected the target in less than 2 min, demonstrating its convenience for on-field applications.

RESUMEN

Vibrio cholerae is a cholera-causing pathogen known to instigate severe contagious diarrhea that affects millions globally. Survival of vibrios depend on a combination of multicellular responses and adapt to changes that prevail in the environment. This process is achieved through a strong communication at the cellular level, the process has been recognized as quorum sensing (QS). The severity of infection is highly dependent on the QS of vibrios in the gut milieu. The quorum may exist in a low/high cell density (LCD/HCD) state to exert a positive or negative response to control the regulatory pathogenic networks. The impact of this regulation reflects on the transition of pathogenic V. cholerae from the environment to infect humans and cause outbreaks or epidemics of cholera. In this context, the review portrays various regulatory processes and associated virulent pathways, which maneuver and control LCD and HCD states for their survival in the host. Although several treatment options are existing, promotion of therapeutics by exploiting the virulence network may potentiate ineffective antibiotics to manage cholera. In addition, this approach is also useful in resource-limited settings, where the accessibility to antibiotics or conventional therapeutic options is limited.

RESUMEN

Background: Data on non-O1/non-O139 Vibrio cholera (NOVC) infection in liver disease is limited. We studied the clinical features and outcome of patients with cirrhosis with non-NOVC bacteraemia and/or spontaneous bacterial peritonitis (SBP) when compared to non-extended spectrum beta lactamase (non-ESBL) Escherichia coli (E. coli). Methods: Hospital information system of patients with cirrhosis admitted with bacteraemia and/or SBP from 2010 to 2020 was searched to include patients with NOVC infection. Non-ESBL E. coli bacteraemia/bacterascites were chosen as a comparator group, matched for the date of admission within 5 days of index case. Propensity score matching (PSM) was done for patient's age and Child score to compare outcome at discharge between NOVC-infected and E. coli-infected cirrhotic patients. Results: There were 2545 patients admitted with bacteraemia and/or SBP during the study period; 29 had NOVC isolated (M:F = 23:6; age: 39, 18-54 years; median, range; model for end-stage liver disease [MELD] score: 25, 12-38; Child score: 11, 10-12.5) from either blood (26), ascites (3), or both (8). Of these, 26 isolates were pan-sensitive to antibiotic sensitivity tests. Fifty-three patients with non-ESBL E. coli were isolated (M: F = 43:10; age: 48; 18-69 years; MELD score: 25, 20-32; Child score:12,11-13) from blood (31), ascites (17), or both (5) within the selected time frame. Of these, 48 isolates were sensitive to the empirical antibiotics initiated.After PSM, in comparison with 29 non-ESBL E. coli patients (age: 41, 18-55 years; MELD score: 24, 19-31; Child score: 12, 11-13), NOVC patients had higher incidence of circulatory failure at admission (14 [49 %] vs 4 [13 %]; P: 0.01) and significantly higher in-hospital mortality (15 [52 %] vs 6 [20 %];P: 0.028]. Conclusions: Bacteraemia due to non-O1/non-O139 strains of V. cholera, is an uncommon cause of bacteraemia or bacterascites in patients with cirrhosis and is associated with high incidence of circulatory failure and significant mortality.

RESUMEN

Cholera meningitis is a rare complication of Vibrio cholerae (V. cholerae) infection. We present a case of cholera meningitis caused by toxigenic V. cholerae O1 in a 34-year-old male with sickle cell disease (SCD). The patient presented with fever, diarrhea, and altered mental status. Cerebrospinal fluid (CSF) analysis showed 5,231 cells/µL (53.9% neutrophils), a protein level of 462 mg/dL, and a glycorrhachia level of 26 mg/dL. V. cholerae O1 was isolated on CSF culture. Despite the patient undergoing antimicrobial therapy, brain imaging revealed basal ganglia ring-enhancing lesions suggestive of tuberculomas. Antituberculosis treatment and steroids led to clinical improvement. This report highlights the need to consider V. cholerae meningitis in patients with SCD who present with diarrhea and altered mental status. Prompt diagnosis and appropriate antimicrobial therapy are keys to improving patient outcomes.

RESUMEN

Objective: This study aimed to investigate whether the VCA0560 gene acts as an active diguanylate cyclase (DGC) in Vibrio cholerae and how its transcription is regulated by Fur and HapR. Methods: The roles of VCA0560 was investigated by utilizing various phenotypic assays, including colony morphological characterization, crystal violet staining, Cyclic di-GMP (c-di-GMP) quantification, and swimming motility assay. The regulation of the VCA0560 gene by Fur and HapR was analyzed by luminescence assay, electrophoretic mobility shift assay, and DNase I footprinting. Results: VCA0560 gene mutation did not affect biofilm formation, motility, and c-di-GMP synthesis in V. cholerae, and its overexpression remarkably enhanced biofilm formation and intracellular c-di-GMP level but reduced motility capacity. The transcription of the VCA0560 gene was directly repressed by Fur and the master quorum sensing regulator HapR. Conclusion: Overexpressed VCA0560 functions as an active DGC in V. cholerae, and its transcription is repressed by Fur and HapR.

Asunto(s)

Asunto(s)

RESUMEN

Objective: Cholera is a challenging ancient disease caused by Vibrio cholera (V. cholera). Antibiotics that prevent cell wall synthesis are among the first known antibiotic groups. Due to its high consumption, V. cholera has developed resistance to the majority of antibiotics in this class. Resistance to recommended antibiotics for the treatment of V. cholera has also increased. In light of the decrease in consumption of certain antibiotics in this group that inhibit cell wall synthesis and the implementation of new antibiotics, it is necessary to determine the antibiotic resistance pattern of V. cholera and to employ the most effective treatment antibiotic. Method: An comprehensive systematic search for relevant articles was conducted in PubMed, Web of Science, Scopus, and EMBASE through October 2020. Stata version 17.1 utilized the Metaprop package to execute a Freeman-Tukey double arcsine transformation in order to estimate weighted pooled proportions. Results: A total of 131 articles were included in the meta-analysis. Ampicillin was the most investigated antibiotic. The prevalence of antibiotic resistance was in order aztreonam (0%), cefepime (0%), imipenem (0%), meropenem (3%), fosfomycin (4%), ceftazidime (5%), cephalothin (7%), augmentin (8%), cefalexin (8%), ceftriaxone (9%), cefuroxime (9%), cefotaxime (15%), cefixime (37%), amoxicillin (42%), penicillin (44%), ampicillin (48%), cefoxitin (50%), cefamandole (56%), polymyxin-B (77%), carbenicillin (95%) respectively. Discussion: Aztreonam, cefepime, and imipenem are the most efficient V. cholera cell wall synthesis inhibitors. There has been an increase in resistance to antibiotics such as cephalothin, ceftriaxone, amoxicillin, and meropenem. Over the years, resistance to penicillin, ceftazidime, and cefotaxime, has decreased.

RESUMEN

The two-component regulatory system (TCS) is a major regulatory system in bacteria that occurs in response to environmental changes and involves the sensor histidine kinase (HK) protein and response regulator (RR) protein. Among the TCSs, PhoR/PhoB is crucial for bacteria to adapt to changes in environmental phosphate concentrations. In addition, recent studies have shown that PhoR binding to the MgtC virulence factor activates phosphate transport for normal pathogenesis. In this work, we determined the crystal structure of the catalytic ATP binding domain of the PhoR sensor histidine kinase from Vibrio cholera, compared the structure with the known HK protein structures and discussed the potential binding interface with MgtC.

Asunto(s)

RESUMEN

Bacteriophage therapy targeting the increasingly resistant Vibrio cholerae is highly needed. Hence, studying the phenotypic behavior of potential phages under different conditions is a prerequisite to delivering the phage in an active infective form. The objective of this study was to characterize phage VP4 (vB_vcM_Kuja), an environmental vibriophage isolated from River Kuja in Migori County, Kenya in 2015. The phenotypic characteristics of the phage were determined using a one-step growth curve, restriction digestion profile, pH, and temperature stability tests. The results revealed that the phage is stable through a wide range of temperatures (20-50°C) and maintains its plaque-forming ability at pH ranging from 6 to 12. The one-step growth curve showed a latent period falling between 40 and 60 min, while burst size ranged from 23 to 30 plaque-forming units/10 µl at the same host strain. The restriction digestion pattern using EcoRI, SalI, HindIII, and XhoI enzymes showed that HindIII could cut the phage genome. The phage DNA could not be restricted by the other three enzymes. The findings of this study can be used in future studies to determine phage-host interactions.

Asunto(s)

RESUMEN

BACKGROUND: Vibrio cholerae, the causative agent of cholera, has been responsible for global epidemics and many other problems over the centuries. It is one of the main public health issues in less-developed and developing countries and is considered one of the deadliest infectious agents. Therefore, precise and susceptible detection of V. cholerae from environmental and biological samples is critical. Aptamers provide a rapid, sensitive, highly specific, and inexpensive alternative to traditional methods. OBJECTIVE: The present study develops a new protocol inspired by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) to implement an in silico aptamer selection against V. cholerae, which can also be employed in the case of other pathogenic microorganisms. METHODS: First, we built an oligonucleotide pool and screened it based on the secondary structure. Following that, we modeled the tertiary structures of filtered sequences and performed RNAprotein dockings to assess binding affinities between RNA sequences and Outer Membrane Protein U (OmpU), an effective marker in distinguishing epidemic strains of V. cholerae, which constitute up to 60% of the total outer membrane protein. Finally, we used molecular dynamics simulation to validate the results. RESULTS: Three sequences (ChOmpUapta) were proposed as final aptameric candidates. Analysis of the top-ranked docking results revealed that these candidate aptamers bound to all subunits of OmpU at the extracellular side with high affinity. Moreover, ChOmpUapta-3 and ChOmpUapta-2 were fully stable and formed strong bonds under dynamic conditions. CONCLUSION: We propose incorporating these candidate sequences into aptasensors for V. cholerae detection.

Asunto(s)

RESUMEN

OBJECTIVE@#This study aimed to investigate whether the VCA0560 gene acts as an active diguanylate cyclase (DGC) in Vibrio cholerae and how its transcription is regulated by Fur and HapR.@*METHODS@#The roles of VCA0560 was investigated by utilizing various phenotypic assays, including colony morphological characterization, crystal violet staining, Cyclic di-GMP (c-di-GMP) quantification, and swimming motility assay. The regulation of the VCA0560 gene by Fur and HapR was analyzed by luminescence assay, electrophoretic mobility shift assay, and DNase I footprinting.@*RESULTS@#VCA0560 gene mutation did not affect biofilm formation, motility, and c-di-GMP synthesis in V. cholerae, and its overexpression remarkably enhanced biofilm formation and intracellular c-di-GMP level but reduced motility capacity. The transcription of the VCA0560 gene was directly repressed by Fur and the master quorum sensing regulator HapR.@*CONCLUSION@#Overexpressed VCA0560 functions as an active DGC in V. cholerae, and its transcription is repressed by Fur and HapR.

Asunto(s)

RESUMEN

Vibrio cholerae includes strains responsible for the cholera disease and is a natural inhabitant of aquatic environments. V. cholerae possesses a unique polar flagellum essential for motility, adhesion, and biofilm formation. In a previous study, we showed that motility and biofilm formation are altered in the presence of subinhibitory concentrations of polymyxin B in V. cholerae O1 and O139. In this study, we performed an experimental evolution to identify the genes restoring the motility in the presence of a subinhibitory concentration of polymyxin B. Mutations in five genes have been identified in three variants derived from two different parental strains A1552 and MO10: ihfA that encodes a subunit of the integration host factor (IHF), vacJ (mlaA) and mlaF, two genes belonging to the maintenance of the lipid asymmetry (Mla) pathway, dacB that encodes a penicillin-binding protein (PBP4) and involved in cell wall synthesis, and ccmH that encodes a c-type cytochrome maturation protein. We further demonstrated that the variants derived from MO10 containing mutations in vacJ, mlaF, and dacB secrete more and larger membrane vesicles that titer the polymyxin B, which increases the bacterial survival and is expected to limit its impact on the bacterial envelope and participate in the flagellum's retention and motility.

RESUMEN

Vibrio cholerae, a noninvasive mucosal pathogen, is endemic in more than 50 countries. Oral cholera vaccines, based on killed whole-cell strains of Vibrio cholerae, can provide significant protection in adults and children for 2-5 years. However, they have relatively limited direct protection in young children. To overcome current challenges, in this study, a potential conjugate vaccine was developed by linking O-specific polysaccharide (OSP) antigen purified from V. cholerae O1 El Tor Inaba strain PIC018 with Qß virus-like particles efficiently via squarate chemistry. The Qß-OSP conjugate was characterized with mass photometry (MP) on the whole particle level. Pertinent immunologic display of OSP was confirmed by immunoreactivity of the conjugate with convalescent phase samples from humans with cholera. Mouse immunization with the Qß-OSP conjugate showed that the construct generated prominent and long-lasting IgG antibody responses against OSP, and the resulting antibodies could recognize the native lipopolysaccharide from Vibrio cholerae O1 Inaba. This was the first time that Qß was conjugated with a bacterial polysaccharide for vaccine development, broadening the scope of this powerful carrier.

Asunto(s)

RESUMEN

Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus are the most significant aquatic pathogens of the genera Vibrio, account for most Vibrio-associated outbreaks worldwide. Rapid identification of these pathogens is of great importance for disease surveillance, outbreak investigations and food safety maintenance. Traditional culture dependent methods are time-consuming and labor-intensive whereas culture-independent polymerase chain reaction (PCR) based assays are reliable, consistent, rapid and reproducible. This review covers the recent development and applications of PCR based techniques, which have accelerated advances in the analysis of nucleic acids to identify three major pathogenic vibrios. Emphasis has been given to analytical approaches as well as advantages and limits of the available methods. Overall, this review article possesses the substantial merit to be used as a reference guide for the researchers to develop improved PCR based techniques for the differential detection and quantification of Vibrio species.

Asunto(s)

RESUMEN

The rapid diagnosis of cholera contributes to adequate outbreak management. This meta-analysis assesses the diagnostic accuracy of cholera rapid tests (RDTs) to detect Vibrio cholerae O1. METHODS: Systematic review and meta-analysis. We searched four databases (Medline, EMBASE, Google Scholar, and Web of Science up to 8 September 2021) for studies that evaluated cholera RDTs for the detection of V. cholerae O1 compared with either stool culture or polymerase chain reaction (PCR). We assessed the studies' quality using the QUADAS-2 criteria. In addition, in this update, GRADE approach was used to rate the overall certainty of the evidence. We performed a bivariate random-effects meta-analysis to calculate the pooled sensitivity and specificity of cholera RDTs. RESULTS: Overall, 20 studies were included in this meta-analysis. Studies were from Africa (n = 11), Asia (n = 7), and America (Haiti; n = 2). They evaluated eight RDTs (Crystal VC-O1, Crystal VC, Cholkit, Institut Pasteur cholera dipstick, SD Bioline, Artron, Cholera Smart O1, and Smart II Cholera O1). Using direct specimen testing, sensitivity and specificity of RDTs were 90% (95% CI, 86 to 93) and 86% (95% CI, 81 to 90), respectively. Cholera Sensitivity was higher in studies conducted in Africa [92% (95% CI, 89 to 94)] compared with Asia [82% (95% CI, 77 to 87)]. However, specificity [83% (95% CI, 71 to 91)] was lower in Africa compared with Asia [90% (95% CI, 84 to 94)]. GRADE quality of evidence was estimated as moderate. CONCLUSIONS: Against culture or PCR, current cholera RDTs have moderate sensitivity and specificity for detecting Vibrio cholerae O1.

RESUMEN

Cholera is a severe small intestine bacterial disease caused by consumption of water and food contaminated with Vibrio cholera. The disease causes watery diarrhea leading to severe dehydration and even death if left untreated. In the past few decades, V. cholerae has emerged as multidrug-resistant enteric pathogen due to its rapid ability to adapt in detrimental environmental conditions. This research study aimed to design inhibitors of a master virulence gene expression regulator, HapR. HapR is critical in regulating the expression of several set of V. cholera virulence genes, quorum-sensing circuits and biofilm formation. A blind docking strategy was employed to infer the natural binding tendency of diverse phytochemicals extracted from medicinal plants by exposing the whole HapR structure to the screening library. Scoring function criteria was applied to prioritize molecules with strong binding affinity (binding energy < -11 kcal/mol) and as such two compounds: Strychnogucine A and Galluflavanone were filtered. Both the compounds were found favourably binding to the conserved dimerization interface of HapR. One rare binding conformation of Strychnogucine A was noticed docked at the elongated cavity formed by α1, α4 and α6 (binding energy of -12.5 kcal/mol). The binding stability of both top leads at dimer interface and elongated cavity was further estimated using long run of molecular dynamics simulations, followed by MMGB/PBSA binding free energy calculations to define the dominance of different binding energies. In a nutshell, this study presents computational evidence on antibacterial potential of phytochemicals capable of directly targeting bacterial virulence and highlight their great capacity to be utilized in the future experimental studies to stop the evolution of antibiotic resistance evolution.

Asunto(s)

RESUMEN

Genomic information can be used to predict major pathogenic traits of pathogens without the need for laboratory experimentation. However, no Vibrio cholerae genome-based trait identification tools currently exist. The aim of this study was to develop a web-based prediction tool to identify Vibrio pathogenic traits using publicly available 796 whole-genome sequences of V. cholerae. Using this application, 68 structural O-antigen gene clusters belonging to 49 serogroups of V. cholerae were classified, and the composition of the genes within the O-antigen cluster of each serogroup was identified. The arrangement and location of the CTX prophage and related elements of the seventh cholera pandemic strains were also revealed. With the versatile tool, named VicPred, we analyzed the assemblage of various SXTs (sulfamethoxazole/trimethoprim resistance element) and major genomic islands (GIs) of V. cholerae, and the increasing trend in drug-resistance revealing high resistance of the V. cholerae strains to certain antibiotics. The pathogenic traits of newly sequenced V. cholerae strains could be analyzed based on these characteristics. The accumulation of further genome data will expedite the establishment of a more precise genome-based pathogenic traits analysis tool.

RESUMEN

In September 2019, after a reported death due to acute diarrheal disease in Shahpur village, Panchkula district, Haryana state, India, we conducted an outbreak investigation to identify the etiological agent, estimate the burden of disease, and make recommendations to prevent future outbreaks. The suspected cholera case was a resident of Shahpur huts, ≥1 year of age having ≥3 loose stools within a 24-h period between September 1 and 28, 2019 and a laboratory-confirmed cholera case, whose stool specimen tested positive for Vibrio cholerae. We identified 196 suspected cholera cases with a median age of 18 years (range: 1-65 years); 54% (106) being female. The overall attack rate was 8% (196/2,602), and the case fatality rate was 1% (2/196). Tested samples of water from tanks (n = 6), sewage effluent (n = 2), and 22% (4/18) of stool specimens collected from suspected cases were positive for V. cholerae. Strengthening surveillance, improving water, and sanitation systems are recommended to prevent future cholera outbreaks.

Asunto(s)

RESUMEN

OBJECTIVES: Few studies have evaluated determinants of multidrug-resistant (MDR) Vibrio cholerae O1 in older children and adults. This study aimed to characterize the prevalence of MDR V. cholerae O1 and associated risk factors among patients over five years of age in Bangladesh. METHODS: Stool culture and antimicrobial susceptibility testing were performed as a part of a larger study at Dhaka Hospital in Bangladesh from March 2019-March 2020. Univariate statistics and multiple logistic regression were used to assess the association between a range of variables and MDR V. cholerae O1. RESULTS: MDR was found in 175 of 623 (28.1%) V. cholerae O1 isolates. High levels of resistance were found to erythromycin (99.2%), trimethoprim-sulfamethoxazole (99.7%), and ampicillin (88.9%), while susceptibility was high to tetracyclines (99.7%), azithromycin (99.2%), ciprofloxacin (99.8%), and cephalosporins (98.6%). MDR was associated with prior antibiotic use, longer transport time to hospital, higher income, non-flush toilet use, greater stool frequency, lower blood pressure, lower mid-upper arm circumference, and lower percent dehydration. CONCLUSIONS: MDR V. cholerae O1 was common among patients over five in an urban hospital in Bangladesh. Significant factors associated with MDR may be actionable in identifying patients with a high likelihood of MDR.

Asunto(s)

RESUMEN

Broad-spectrum amino acid racemases (Bsrs) enable bacteria to generate non-canonical D-amino acids (NCDAAs), whose roles and impact on microbial physiology, including modulation of cell wall structure and dissolution of biofilms, are just beginning to be appreciated. Here we used a diverse array of structural, biochemical and molecular simulation studies to define and characterize how BsrV is post-translationally regulated. We discovered that contrary to Vibrio cholerae alanine racemase AlrV highly compacted active site, BsrV's is broader and can be occupied by cell wall stem peptides. We found that peptidoglycan peptides modified with NCDAAs are better stabilized by BsrV's catalytic cavity and show better inhibitory capacity than canonical muropeptides. Notably, BsrV binding and inhibition can be recapitulated by undigested peptidoglycan sacculi as it exists in the cell. Docking simulations of BsrV binding the peptidoglycan polymer generate a model where the peptide stems are perfectly accommodated and stabilized within each of the dimers active sites. Taking these biochemical and structural data together, we propose that inhibition of BsrV by peptidoglycan peptides underlies a negative regulatory mechanism to avoid excessive NCDAA production. Our results collectively open the door to use "à la carte" synthetic peptides as a tool to modulate DAAs production of Bsr enzymes.