Kinetics of vibriocidal antibody responses among cholera patients in Goma, the Democratic Republic of Congo.

Cholera is a diarrheal disease that continues to burden vulnerable populations globally, primarily due to lack of clean water, optimal sanitation and adequate health infrastructure. Understanding the kinetics of antibody responses elicited by toxigenic infection can inform the Sero-epidemiological estimation of disease burden and impact of vaccination efforts. While antibody kinetics have been well-described in South Asia, such studies based in Africa are lacking, despite the ongoing prevalence of cholera in that region.

Using spatial video and deep learning for automated mapping of ground-level context in relief camps.

Background: The creation of relief camps following a disaster, conflict or other form of externality often generates additional health problems. The density of people in a highly stressed environment with questionable safe food and water access presents the potential for infectious disease outbreaks. These camps are also not static data events but rather fluctuate in size, composition, and level and quality of service provision.

Enhancing sustainability in self-compacting concrete by optimizing blended supplementary cementitious materials.

Within concrete engineering, the uptake of self-compacting concrete (SCC) represents a notable trend, delivering improved workability and placement efficiency. However, challenges persist, notably in achieving optimal performance while mitigating environmental impacts, particularly in cement consumption. However, simply reducing the cement content in the mix design can directly compromise the structural-concrete requirements.

Exploring the effect of a pendent amine group poised over the secondary coordination sphere of a cobalt complex on the electrocatalytic hydrogen evolution reaction.

A Co complex (2) of a bispyridine-dioxime ligand (HL) containing a tertiary amine group in the proximity of the Co center is synthesized and characterized. One of the oxime protons of the ligand is deprotonated, and the amine group remains protonated in the solid-state structure of the Co complex (2a). The acid-base properties of 2 showed p values of 5.

Tellurium Containing Long Lived Emissive Fluorophore for Selective and Visual Detection of Picric Acid through Photo-Induced Electron Transfer.

A novel tellurium (Te) containing fluorophore, 1 and its nickel (2) and copper (3) containing metal organic complex (MOC) have been synthesized to exploit their structural and optical properties and to deploy these molecules as fluorescent probes for the selective and sensitive detection of picric acid (PA) over other commonly available nitro-explosives. Furthermore, density functional theory (DFT) and single crystal X-ray diffraction (SCXRD) techniques revealed the inclusion of "soft" Tellurium (Te) and "hard" Nitrogen (N), Oxygen (O) atoms in the molecular frameworks. Owing to the presence of electron rich "N" and "O" atoms along with "Te" in the molecular framework, 1 could efficiently and selectively sense PA with more than 80 % fluorescence quenching efficiency in organic medium and having detection limit of 4.

Seafood-Associated Outbreak of ctx-Negative Vibrio mimicus Causing Cholera-Like Illness, Florida, USA.

Vibrio mimicus caused a seafood-associated outbreak in Florida, USA, in which 4 of 6 case-patients were hospitalized; 1 required intensive care for severe diarrhea. Strains were ctx-negative but carried genes for other virulence determinants (hemolysin, proteases, and types I-IV and VI secretion systems). Cholera toxin-negative bacterial strains can cause cholera-like disease.

Ancestral Origin and Dissemination Dynamics of Reemerging Toxigenic Vibrio cholerae, Haiti.

The 2010 cholera epidemic in Haiti was thought to have ended in 2019, and the Prime Minister of Haiti declared the country cholera-free in February 2022. On September 25, 2022, cholera cases were again identified in Port-au-Prince. We compared genomic data from 42 clinical Vibrio cholerae strains from 2022 with data from 327 other strains from Haiti and 1,824 strains collected worldwide.

Vibrio cholerae Invasion Dynamics of the Chironomid Host Are Strongly Influenced by Aquatic Cell Density and Can Vary by Strain.

Cholera has been a human scourge since the early 1800s and remains a global public health challenge, caused by the toxigenic strains of the bacterium Vibrio cholerae. In its aquatic reservoirs, V. cholerae has been shown to live in association with various arthropod hosts, including the chironomids, a diverse insect family commonly found in wet and semiwet habitats.

Molecular Basis of the Toxigenic Vibrio cholerae O1 Serotype Switch from Ogawa to Inaba in Haiti.

Toxigenic Vibrio cholerae O1 serotype Ogawa was introduced involuntarily into Haiti in October 2010, and virtually all of the clinical strains isolated during the first 5 years of the epidemic were Ogawa. Inaba strains were identified intermittently prior to 2015, with diverse mutations resulting in a common phenotype. In 2015, the percentage of clinical infections due to the Inaba serotype began to rapidly increase, with Inaba supplanting Ogawa as the dominant serotype during the subsequent 4 years.

The Use of Spatial Video to Map Dynamic and Challenging Environments: A Case Study of Cholera Risk in the Mujoga Relief Camp, D.R.C.

In this paper, we provide an overview of how spatial video data collection enriched with contextual mapping can be used as a universal tool to investigate sub-neighborhood scale health risks, including cholera, in challenging environments. To illustrate the method's flexibility, we consider the life cycle of the Mujoga relief camp set up after the Nyiragongo volcanic eruption in the Democratic Republic of Congo on 22 May 2021. More specifically we investigate how these methods have captured the deteriorating conditions in a camp which is also experiencing lab-confirmed cholera cases.

Spatial Video and EpiExplorer: A Field Strategy to Contextualize Enteric Disease Risk in Slum Environments.

Disease risk associated with contaminated water, poor sanitation, and hygiene in informal settlement environments is conceptually well understood. From an analytical perspective, collecting data at a suitably fine scale spatial and temporal granularity is challenging. Novel mobile methodologies, such as spatial video (SV), can complement more traditional epidemiological field work to address this gap.

Development of a Monoclonal Antibody to a Vibriophage as a Proxy for Vibrio cholerae Detection.

Cholera is an acute watery, diarrheal disease that causes high rates of morbidity and mortality without treatment. Early detection of the etiologic agent of toxigenic Vibrio cholerae is important to mobilize treatment and mitigate outbreaks. Monoclonal antibody (mAb) based rapid diagnostic tests (RDTs) enable early detection in settings without laboratory capacity.

Thiol-based functional mimicry of phosphorylation of the two-component system response regulator ArcA promotes pathogenesis in enteric pathogens.

Pathogenic bacteria can rapidly respond to stresses such as reactive oxygen species (ROS) using reversible redox-sensitive oxidation of cysteine thiol (-SH) groups in regulators. Here, we use proteomics to profile reversible ROS-induced thiol oxidation in Vibrio cholerae, the etiologic agent of cholera, and identify two modified cysteines in ArcA, a regulator of global carbon oxidation that is phosphorylated and activated under low oxygen. ROS abolishes ArcA phosphorylation but induces the formation of an intramolecular disulfide bond that promotes ArcA-ArcA interactions and sustains activity.

Exploring convolutional neural networks and spatial video for on-the-ground mapping in informal settlements.

Background: The health burden in developing world informal settlements often coincides with a lack of spatial data that could be used to guide intervention strategies. Spatial video (SV) has proven to be a useful tool to collect environmental and social data at a granular scale, though the effort required to turn these spatially encoded video frames into maps limits sustainability and scalability. In this paper we explore the use of convolution neural networks (CNN) to solve this problem by automatically identifying disease related environmental risks in a series of SV collected from Haiti.

Characterization of the Vibriocidal Activity of Chitosan Microparticles: A Potential Therapeutic Agent for Emerging Multidrug-Resistant Cholera Infections.

Due to increasing reports of multidrug-resistant (MDR) O1, the goal of this study was to characterize the in vitro antimicrobial activity of chitosan microparticles (CMs) to evaluate their potential as a novel therapeutic agent for cholera. We examined the antimicrobial activity of CMs against toxigenic O1 using direct enumeration, microscopy, and fluorescence microplate assays. Bacterial viability kinetics were measured with different concentrations of CMs, solution pH, and salt content using a live/dead staining technique.

Draft Genome Sequence of an Environmental Vibrio cholerae Strain, 2012Env-25, Obtained Using Nanopore Sequencing Technology.

is a halophilic Gram-negative bacterial species and the etiological agent of cholera. Here, we report the draft genome sequence of an environmental strain, 2012Env-25, obtained using Oxford Nanopore Technologies (ONT) to provide insights into the ecology, evolution, and pathogenic potential of this bacterium.

Toxigenic evolution and establishment of reservoirs in aquatic ecosystems.

The spread of cholera in the midst of an epidemic is largely driven by direct transmission from person to person, although it is well-recognized that is also capable of growth and long-term survival in aquatic ecosystems. While prior studies have shown that aquatic reservoirs are important in the persistence of the disease on the Indian subcontinent, an epidemiological view postulating that locally evolving environmental contributes to outbreaks outside Asia remains debated. The single-source introduction of toxigenic O1 in Haiti, one of the largest outbreaks occurring this century, with 812,586 suspected cases and 9,606 deaths reported through July 2018, provided a unique opportunity to evaluate the role of aquatic reservoirs and assess bacterial transmission dynamics across environmental boundaries.

Conversion of a -Mediated Non-toxigenic O1 Strain to a Toxigenic Strain Using Chitin-Induced Transformation.

Toxigenic strains, including strains in serogroups O1 and O139 associated with the clinical disease cholera, are ubiquitous in aquatic reservoirs, including fresh, estuarine, and marine environments. Humans acquire cholera by consuming water and/or food contaminated with the microorganism. The genome of toxigenic harbors a cholera-toxin producing prophage (CT-prophage) encoding genes that promote expression of cholera toxin.

Micro-Space Complexity and Context in the Space-Time Variation in Enteric Disease Risk for Three Informal Settlements of Port au Prince, Haiti.

Diffusion of cholera and other diarrheal diseases in an informal settlement is a product of multiple behavioral, environmental and spatial risk factors. One of the most important components is the spatial interconnections among water points, drainage ditches, toilets and the intervening environment. This risk is also longitudinal and variable as water points fluctuate in relation to bacterial contamination.

Vibrio cholerae motility exerts drag force to impede attack by the bacterial predator Bdellovibrio bacteriovorus.

The bacterial predator Bdellovibrio bacteriovorus is evolved to attack and kill other bacteria, including the human intestinal pathogen Vibrio cholerae. Although B. bacteriovorus exhibit a broad prey range, little is known about the genetic determinants of prey resistance and sensitivity.

AIE active piperazine appended naphthalimide-BODIPYs: photophysical properties and applications in live cell lysosomal tracking.

Piperazine appended naphthalimide-BODIPYs (NPB1-NPB4) exhibiting solvatochromism and aggregation-induced emission with a large Stokes shift (up to 146 nm) have been described. Separation of naphthalimide and BODIPY fluorophores by piperazine in these conjugates creates a donor-acceptor system and induces twisted intramolecular charge transfer, in addition to photoinduced electron transfer. The crucial role of naphthalimide, the alkyl chain length, the piperazine ring, and the solid-state packing on AIE has been extensively investigated by various studies.