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Infectious Medicine Jun 2024Swift and accurate detection of , which is a prominent causative pathogen associated with seafood contamination, is required to effectively combat foodborne disease and...
BACKGROUND
Swift and accurate detection of , which is a prominent causative pathogen associated with seafood contamination, is required to effectively combat foodborne disease and wound infections. The gene is relatively conserved within and is primarily involved in the expression and regulation of virulence genes with a notable degree of specificity. The aim of this study was to develop a rapid, simple, and constant temperature detection method for in clinical and nonspecialized laboratory settings.
METHODS
In this study, specific primers and CRISPR RNA were used to target the gene to construct a reaction system that combines recombinase polymerase amplification (RPA) with CRISPR‒Cas13a. The whole-genome DNA of the sample was extracted by self-prepared sodium dodecyl sulphate (SDS) nucleic acid rapid extraction reagent, and visual interpretation of the detection results was performed by lateral flow dipsticks (LFDs).
RESULTS
The specificity of the RPA-CRISPR/Cas13a-LFD method was validated using strain ATCC-17802 and six other non-parahaemolytic species. The results demonstrated a specificity of 100%. Additionally, the genomic DNA of was serially diluted and analysed, with a minimum detectable limit of 1 copy/µL for this method, which was greater than that of the TaqMan-qPCR method (10 copies/µL). The established methods were successfully applied to detect wild-type , yielding results consistent with those of TaqMan-qPCR and MALDI-TOF MS mass spectrometry identification. Finally, the established RPA-CRISPR/Cas13a-LFD method was applied to whole blood specimens from mice infected with , and the detection rate of by this method was consistent with that of the conventional PCR method.
CONCLUSIONS
In this study, we describe an RPA-CRISPR/Cas13a detection method that specifically targets the gene and offers advantages such as simplicity, rapidity, high specificity, and visual interpretation. This method serves as a valuable tool for the prompt detection of in nonspecialized laboratory settings.
PubMed: 38948389
DOI: 10.1016/j.imj.2024.100111 -
The Pan African Medical Journal 2024as cholera, due to toxigenic bacteria Vibrio cholera (serogroups O1 and O139), is a major public health threat in Africa, the aim of this work was to investigate...
INTRODUCTION
as cholera, due to toxigenic bacteria Vibrio cholera (serogroups O1 and O139), is a major public health threat in Africa, the aim of this work was to investigate potentially pathogenic Vibrionaceae bacteria firstly from human stool samples, and secondly from various environmental water points of Saint-Louis city in Senegal.
METHODS
a hospital-based study was conducted between 2013 and 2015. Stool samples were taken and cultured from daily incoming patients or hospitalized for acute diarrhea at Saint-Louis´ regional hospital. For environment, a monthly longitudinal sampling from January to October 2016 was carried out at 10 sites in the city. We used total DNA extracted from APW (alkaline peptone water) broth solutions and on suspect bacterial colonies to run PCR Multiplex targeting specific DNA fragments to detect Vibrio genus and specific species. In case of positivity, a simplex PCR was performed to test for cholera toxins Ctx, and V. parahaemolyticus TRH and TDH.
RESULTS
for 43 patients screened, bacterial culture was positive in 6% of cases but no strain of V. cholerae or other Vibrio sp. was isolated. PCR on 90 APW solutions were positive for Vibrio sp.(n = 43), V. cholera(n = 27), V. mimicus(n = 16), V. parahaemolyticus(8), V. alginolyticus(n = 4), and V. vulnificus(n = 2). Unlike for those on suspected colonies which were positive for a majority of V. parahaemolyticus (n = 40) and V. cholerae non-O1 / O139 (n = 35). Six strains of V. parahaemolyticus carried TRH gene, 3 of which expressed simultaneously virulence TRH and TDH genes. For physicochemical parameters, all temperatures varied similarly according to a unimodal seasonality, as well as salinity.
CONCLUSION
despite the presence of natural populations of Vibrionaceae, even toxigenic ones, was noted in water environment, along with favorable habitat conditions that could play a role in transmission of Vibriosis in the Saint Louis population, we did not isolate any of them from patients screened at the hospital.
Topics: Humans; Senegal; Cholera; Feces; Polymerase Chain Reaction; Diarrhea; Water Microbiology; Vibrionaceae; Vibrio; DNA, Bacterial; Vibrio cholerae; Adult; Female; Male
PubMed: 38946740
DOI: 10.11604/pamj.2024.48.5.34685 -
Fish & Shellfish Immunology Jun 2024Toll-like receptors (TLRs) represent a prominent category of pattern recognition receptors that have been extensively investigated for their pivotal role in combating... (Review)
Review
Toll-like receptors (TLRs) represent a prominent category of pattern recognition receptors that have been extensively investigated for their pivotal role in combating pathogen incursions. Despite this, there has been a notable absence of comprehensive identification and exploration of the immune response associated with the TLR family genes in C. altivelis. This study successfully identified and named fourteen genes as Catlr1-1, Catlr1-2, Catlr2-1, Catlr2-2, Catlr3, Catlr5, Catlr7, Catlr8, Catlr9, Catlr13-1, Catlr13-2, Catlr18, Catlr21, and Catlr22. A series of bioinformatic analysis were performed, encompassing analysis of protein properties, examination of gene structures, evolutionary assessments, and prediction of protein tertiary structures. The expression patterns of Catlr genes were analyzed in five immune tissues: liver, spleen, kidney, gill, and intestine, in both healthy and bacterial stimulated-fish. The results showed that different tissue and different genes showed differed expression patterns after V. harveyi infection, indicating the involvement of all Catlr members in mounting immune responses following infection in various tissues. Additionally, histological evaluations of immune tissues unveiled varying levels of damage. In conclusion, this investigation into the TLR gene family offers novel information that contribute to a more profound comprehension of the immune response mechanisms in C. altivelis.
PubMed: 38945413
DOI: 10.1016/j.fsi.2024.109720 -
Journal of Hazardous Materials Jun 2024The rapid proliferation of the halophilic pathogen Vibrio parahaemolyticus poses a severe health hazard to halobios and significantly impedes intensive mariculture. This...
The rapid proliferation of the halophilic pathogen Vibrio parahaemolyticus poses a severe health hazard to halobios and significantly impedes intensive mariculture. This study aimed to evaluate the potential application of gliding arc discharge plasma (GADP) to control the infection of Vibrio parahaemolyticus in mariculture. This study investigated the inactivation ability of GADP against Vibrio parahaemolyticus in artificial seawater (ASW), changes in the water quality of GADP-treated ASW, and possible inactivation mechanisms of GADP against Vibrio parahaemolyticus in ASW. The results indicate that GADP effectively inactivated Vibrio parahaemolyticus in ASW. As the volume of ASW increased, the time required for GADP sterilization also increased. However, the complete sterilization of 5000 mL of ASW containing Vibrio parahaemolyticus of approximately 1.0 × 10 CFU/mL was achieved within 20 min. Water quality tests of the GADP-treated ASW demonstrated that there were no significant changes in salinity or temperature when Vibrio parahaemolyticus (1.0 ×10 CFU/mL) was completely inactivated. In contrast to the acidification observed in plasma-activated water (PAW) in most studies, the pH of ASW did not decrease after treatment with GADP. The HO concentration in the GADP-treated ASW decreased after post-treatment. The NOconcentration in the GADP-treated ASW remained unchanged after post-treatment. Further analysis revealed that GADP induced oxidative stress in Vibrio parahaemolyticus, which increased cell membrane permeability and intracellular ROS levels of Vibrio parahaemolyticus. This study provides a viable solution for infection with the halophilic pathogen Vibrio parahaemolyticus and demonstrates the potential of GADP in mariculture.
PubMed: 38943886
DOI: 10.1016/j.jhazmat.2024.135015 -
International Journal of Hygiene and... Jun 2024On March 31, 2021, an outbreak of diarrhoeal disease was reported in Dangapara village of Purba Bardhaman district, West Bengal, India. The outbreak was investigated to...
BACKGROUND
On March 31, 2021, an outbreak of diarrhoeal disease was reported in Dangapara village of Purba Bardhaman district, West Bengal, India. The outbreak was investigated to estimate the magnitude, identify aetiological agents and source of infection, and guide prevention control measures.
METHODS
We did an active search for case patients at Dangapara village. We excluded children under five years of age from the epidemiological analysis. We described the outbreak by time, place, and person. We conducted a case control study with 133 controls and 65 cases. Water samples from different sources and rectal swabs from case patients were collected and sent for laboratory investigations.
RESULTS
We identified 95 case patients among 330 residents of Dangapara village (attack rate 29 %). Three stool samples were positive for Vibrio cholerae, and two pond water samples were contaminated with coliform organisms. Washing utensils [adjusted odds ratio (AOR): 69.8, (95% confidence interval (CI) 6.5-749.5)] and taking a bath in pond water [AOR: 3.4, (95% CI 1.2-9)] were associated with increased risk of illness. About 97% of cases were attributed to washing utensils in pond water. Washing hands before taking food was associated with a lower risk of developing disease with AOR: 0.1 (95% CI 0.03-0.33).
CONCLUSION
A cholera outbreak occurred among residents of Dangapara village due to theuse of contaminated pond water for washing utensils and bathing. Prompt management of cases and immediate discontinuation of pond water use stopped the outbreak.
PubMed: 38943722
DOI: 10.1016/j.ijheh.2024.114409 -
Frontiers in Medicine 2024Infection with is associated with high rates of amputation and mortality. Alterations in the global climate have heightened the risk of atypical infections caused by...
BACKGROUND
Infection with is associated with high rates of amputation and mortality. Alterations in the global climate have heightened the risk of atypical infections caused by this pathogen.
CASE PRESENTATION
In the case report we describe, a 75-year-old man residing in a coastal city contracted secondary to an insect bite.
DISCUSSION AND CONCLUSION
This case underscores the importance for clinicians of recognizing that early administration of appropriate antibiotics in patients with non-traditional routes of infection can significantly reduce rates of amputation and mortality.
PubMed: 38933117
DOI: 10.3389/fmed.2024.1419074 -
Microorganisms Jun 2024In September 2023, several hatcheries in Latin America experienced significant mortality rates, up to 90%, in zoea stage 2 of . Observations of fresh mounts revealed...
In September 2023, several hatcheries in Latin America experienced significant mortality rates, up to 90%, in zoea stage 2 of . Observations of fresh mounts revealed structures resembling lipid droplets, similar to those seen in a condition known as "las bolitas syndrome". Routine histopathological examinations identified detached cells and tissues in the digestive tracts of affected zoea, contrasting with the typical algal cell contents seen in healthy zoea. Polymerase chain reaction (PCR) testing for over 20 known shrimp pathogens indicated minimal differences between diseased and healthy batches. Both groups tested negative for acute hepatopancreatic necrosis disease (AHPND) but positive for species and Rickettsia-like bacteria in the diseased samples. Histological analyses of the affected zoea revealed characteristic tissue degeneration in the hepatopancreas, forming spheres that eventually migrated into the upper gut, midgut, and midgut caeca, a pathology identified as bolitas syndrome (BS). Microbiological assessments revealed species at concentrations of 10 CFU zoea/g in affected zoea, approximately two orders of magnitude higher than in healthy zoea. Bacterial isolation from both healthy and BS-affected zoea on thiosulphate-citrate-bile salts-sucrose (TCBS) agar and CHROMagar™ (Paris, France), followed by identification using API 20E, identified six strains of . Despite similarities to "las bolitas syndrome" in fresh mounts, distinct histopathological differences were noted, particularly the presence of sloughed cells in the intestines and variations in hepatopancreatic lobes. This study highlights the critical need for further research to fully understand the etiology and pathology of bolitas syndrome in zoea stage 2 of to develop effective mitigation strategies for hatchery operations.
PubMed: 38930568
DOI: 10.3390/microorganisms12061186 -
International Journal of Environmental... May 2024Healthcare-acquired infections are a major problem in healthcare facility settings around the world. The Democratic Republic of the Congo (DRC) has over 2 million... (Randomized Controlled Trial)
Randomized Controlled Trial
Effect of a Water, Sanitation, and Hygiene Program on Handwashing with a Cleansing Agent among Diarrhea Patients and Attendants in Healthcare Facilities in the Democratic Republic of the Congo: A Randomized Pilot of the PICHA7 Program.
Healthcare-acquired infections are a major problem in healthcare facility settings around the world. The Democratic Republic of the Congo (DRC) has over 2 million diarrhea patients hospitalized each year. These healthcare settings become high-risk environments for spreading diarrheal illnesses such as cholera. The objective of the Preventative Intervention for Cholera for 7 Days (PICHA7) program is to develop evidence-based water, sanitation, and hygiene (WASH) interventions to reduce cholera and other severe diarrheal diseases in the DRC. The study objective was to evaluate the effectiveness of PICHA7 program delivery in increasing handwashing with a cleansing agent at stool/vomit- and food-related events in a healthcare facility setting among diarrhea patients and patient attendants. A pilot of the PICHA7 program was conducted among 284 participants in 27 healthcare facilities from March 2020 to November 2021 in urban Bukavu in the South Kivu Province of the DRC. The standard arm received the standard message provided in the DRC to diarrhea patients on the use of oral rehydration solution and a basic WASH message at healthcare facility discharge. The PICHA7 arm received the PICHA7 WASH pictorial module delivered by a health promoter focused on handwashing with a cleansing agent at the bedside of the diarrhea patient in the healthcare facility and provision of a soapy water bottle (water and detergent powder). Within 24 h of intervention delivery, a three-hour structured observation of handwashing practices at stool/vomit- and food-related events (key events) was conducted in healthcare facilities of diarrhea patients and their attendants. Compared to the standard arm, there was significantly more handwashing with a cleansing agent at key events in the PICHA7 arm (40% vs. 15%) (odds ratio: 5.04; (95% confidence interval (CI): 2.01, 12.7)). These findings demonstrate that delivery of the PICHA7 WASH pictorial module and provision of a soapy water bottle to diarrhea patients and their attendants presents a promising approach to increase handwashing with a cleansing agent among this high-risk population in healthcare facilities in the eastern DRC.
Topics: Humans; Diarrhea; Hand Disinfection; Male; Adult; Hygiene; Democratic Republic of the Congo; Female; Pilot Projects; Health Facilities; Sanitation; Middle Aged; Young Adult; Adolescent; Cholera
PubMed: 38928906
DOI: 10.3390/ijerph21060659 -
Developmental and Comparative Immunology Jun 2024Infections with pathogenic Vibrio strains are associated with high summer mortalities of Pacific oysters Magalana (Crassostrea) gigas, affecting production worldwide....
Infections with pathogenic Vibrio strains are associated with high summer mortalities of Pacific oysters Magalana (Crassostrea) gigas, affecting production worldwide. This raises the question of how M. gigas cultures can be protected against deadly Vibro infection. There is increasing experimental evidence of immune priming in invertebrates, where previous exposure to a low pathogen load boosts the immune response upon secondary exposure. Priming responses, however, appear to vary in their specificity across host and parasite taxa. To test priming specificity in the Vibrio - M. gigas system, we used two closely related Vibrio splendidus strains with differing degrees of virulence towards M. gigas. These V. splendidus strains were either isolated in the same location as the oysters (sympatric, opening up the potential for co-evolution) or in a different location (allopatric). We extracted cell-free haemolymph plasma from infected and control oysters to test the influence of humoral immune effectors on bacterial growth in vitro. While addition of haemolypmph plasma in general promoted growth of both strains, priming by an exposure to a sublethal dose of bacterial cells lead to inhibitory effects against a subsequent challenge with a potentially lethal dose in vitro. Inhibitory effects and immune priming was strongest when oysters had been primed with the sympatric Vibrio strain, but inhibitory effects were seen both when challenged with the sympatric as well as against allopatric V. splendidus, suggesting some degree of cross protection. The stronger immune priming against the sympatric strain suggests that priming could be more efficient against matching local strains potentially adding a component of local adaptation or co-evolution to immune priming in oysters. These in vitro results, however, were not reflected in the in vivo infection data, where we saw increased bacterial loads following an initial challenge. This discrepancy might suggests that that it is the humoral part of the oyster immune system that produces the priming effects seen in our in vitro experiments.
PubMed: 38925430
DOI: 10.1016/j.dci.2024.105221 -
Fish & Shellfish Immunology Jun 2024C-type lectins (CTLs) are an important class of pattern recognition receptors (PRRs) that exhibit structural and functional diversity in invertebrates. Repetitive DNA...
C-type lectins (CTLs) are an important class of pattern recognition receptors (PRRs) that exhibit structural and functional diversity in invertebrates. Repetitive DNA sequences are ubiquitous in eukaryotic genomes, representing distinct modes of genome evolution and promoting new gene generation. Our study revealed a new CTL that is composed of two long tandem repeats, abundant threonine, and one carbohydrate recognition domain (CRD) in Exopalaemon carinicauda and has been designated EcTR-CTL. The full-length cDNA of EcTR-CTL was 1242 bp long and had an open reading frame (ORF) of 999 bp that encoded a protein of 332 amino acids. The genome structure of EcTR-CTL contains 4 exons and 3 introns. The length of each repeat unit in EcTR-CTL was 198 bp, which is different from the short tandem repeats reported previously in prawns and crayfish. EcTR-CTL was abundantly expressed in the intestine and hemocytes. After Vibrio parahaemolyticus and white spot syndrome virus (WSSV) challenge, the expression level of EcTR-CTL in the intestine was upregulated. Knockdown of EcTR-CTL down-regulated the expression of anti-lipopolysaccharide factor, crustin, and lysozyme during Vibrio infection. The recombinant CRD of EcTR-CTL (rCRD) could bind to bacteria, lipopolysaccharides, and peptidoglycans. Additionally, rCRD can directly bind to WSSV. These findings indicate that 1) CTLs with tandem repeats may be ubiquitous in crustaceans, 2) EcTR-CTL may act as a PRR to participate in the innate immune defense against bacteria via nonself-recognition and antimicrobial peptide regulation, and 3) EcTR-CTL may play a positive or negative role in the process of WSSV infection by capturing virions.
PubMed: 38917950
DOI: 10.1016/j.fsi.2024.109721