Search Results (136)

Objectives: Norovirus outbreaks occur in densely populated environments, such as long-term care facilities, hospitals, and schools. On 22 October 2022, an outbreak of acute gastroenteritis was reported at a kindergarten in Korea. An epidemiologic investigation was conducted to identify the source of the infection and prevent further spread. Methods: Rectal swab and environmental samples were collected for bacterial and viral testing. A retrospective cohort study was conducted among 114 kindergarteners at the kindergarten. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated to assess associations of contact with the primary case, as well as food and water consumption. Results: Of the kindergarteners, 28 out of 114 (24.6%) met the case definition. The primary case occurred on 19 October, and subsequent cases began on 21 October. Sharing the same four-year-old class as the primary case (RR, 2.56; 95% CI, 1.35–4.87), being in the same regular class (RR, 2.37; 95% CI, 1.27–4.41), being on the same floor during after-school class (RR, 3.49; 95% CI, 1.74–7.00), and attending the same English class (RR, 1.98; 95% CI, 1.05–3.72) were statistically significant. Consumption of drinking water on the third floor and fourth floor on 20 October had significantly higher and lower RRs, respectively. Norovirus was detected in 9 out of 18 rectal swab samples (50.0%). Conclusions: This norovirus outbreak at the kindergarten was presumed to have been caused by person-to-person transmission from the primary case. Isolation and restriction of symptomatic children in kindergartens should be thoroughly implemented. Additionally, enhanced surveillance among family members of affected individuals is necessary to prevent further outbreaks. Full article

Vibrio parahaemolyticus is the leading bacterial cause of gastroenteritis associated with aquatic food consumption globally. This study aimed to determine the prevalence of V. parahaemolyticus in aquatic foods from Huzhou and to identify the serotypes, antimicrobial resistance, virulence factors, and genetic relatedness of the strains. A total of 306 isolates were detected from 1314 aquatic food samples from 2022 to 2024. The results indicated that the most prevalent serotypes were O1:KUT (17.0%), O2:K28 (13.7%), and O2:KUT (13.1%). Multilocus sequence typing analysis divided the 306 isolates into 175 sequence types (STs), and the predominant sequence type was ST864 (3.3%). Antimicrobial susceptibility tests showed that 2.6% of isolates were multidrug resistant. High resistance was observed to ampicillin (64.7%) and streptomycin (44.4%). A total of seven antimicrobial categories of resistance genes were identified, and the resistance gene bla_CARB was detected in all isolates. The virulence genes tdh and trh were found in 16 (5.2%) and 12 (3.9%) isolates, respectively. In addition, we observed that all the 306 V. parahaemolyticus isolates encode type III secretion systems 1. The phylogenomic analysis based on the whole-genome sequence revealed that the 306 isolates were divided into four clusters. Our findings broaden perspectives on V. parahaemolyticus genetic diversity and enhance our ability to assess the potential risks of its spread. Full article

Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide which usually presents as mild, and self-limiting disease in immunocompetent individuals. However, in immunocompromised patients, such as those with common variable immunodeficiency, C. jejuni can cause severe recurrent infections requiring antibiotic treatment. Our study reports a case of a 37-year-old male patient with CVID, who had multiple episodes of C. jejuni intestinal infections over a 3.5-year period. A total of 27 stool samples were collected and analyzed between December 2020 and July 2024 during acute febrile diarrheal episodes, with C. jejuni isolated in 15 samples. Antimicrobial susceptibility testing (AST) during the course of the disease revealed three different antimicrobial resistance profiles including multi-drug-resistant phenotype. Whole genome sequencing was performed on three representative isolates, all identified as MLST type 367, ST-257 complex, with minimal genetic divergence, indicating a clonal origin. Genes and point mutations conferring resistance to macrolides, fluoroquinolones, beta-lactams, and tetracycline were identified in different C. jejuni isolates, along with key virulence factors linked to adherence, invasion, motility, and immune evasion. The genetic analysis of macrolide phenotypic resistance revealed different resistance mechanisms. Genotypic and phenotypic analyses of the same C. jejuni clone from single patient, and identified multidrug resistance pattern, present the first documented case of in vivo resistance development of C. jejuni in Croatia. This case highlights the role of prolonged antibiotic pressure in driving resistance evolution and underscores the need for careful antimicrobial stewardship and genomic monitoring in immunocompromised patients. Further research is needed to correlate phenotypic resistance with genetic determinants in Campylobacter spp. Full article

Acanthamoeba, a free-living amoeba ubiquitous in environmental water, has been considered as the environmental reservoir of certain bacterial pathogens, including Campylobacter jejuni, an intracellular human pathogen causing self-limiting gastroenteritis. Acanthamoeba-C. jejuni interaction mechanisms may help clarify how the otherwise fastidious bacterium C. jejuni survives in environmental waters. In this study, we constructed single deletion mutants of C. jejuni strain 81–176 for the 10 selected genes (motAB, ciaB, kpsE, virB11, cheY, flaAB, cstII, docB, sodB, and cadF) previously shown to be important for the interaction (invasion and intracellular survival) of C. jejuni with mammalian hosts. We used a modified gentamicin protection assay to quantify the internalization and intracellular survival of these mutants and the wild type with the two species of Acanthamoeba (A. castellanii and A. polyphaga). Both internalization and intracellular survival were significantly lower for all mutants compared to the wild type with both amoeba strains, except for ΔcstII in the internalization assay with A. castellanii (p < 0.05). The results of this study highlight that the mechanisms used by C. jejuni to interact with mammalian hosts are conserved in its interactions with amoeba hosts. This understanding may be useful in developing effective strategies to reduce the transmission of C. jejuni to chickens through drinking water. Full article

Background/Objective: Acute gastroenteritis is a major cause of diarrheal illnesses throughout the United States. The purpose of this article is to review the current knowledge in diagnostic and therapeutic aspects. Methods: A comprehensive literature review was conducted using PubMed and Google Scholar, focusing on articles published within the last ten years. Results: There are multiple etiologies of gastroenteritis that affect the general population. Out of the many causes, norovirus continues to be a leading cause of acute diarrheal illness worldwide. Rotavirus was also a common form of diarrhea worldwide, but the development of routine vaccination has largely reduced its incidence. Bacterial gastroenteritis continues to be a significant burden on healthcare facilities worldwide. Supportive care remains the cornerstone of treatment, while using antibiotics remains crucial in severe bacterial forms of gastroenteritis. Conclusions: Acute gastroenteritis remains a significant global health concern requiring a multifaceted approach for effective management. Enhanced diagnostic techniques, vaccine development, and robust public health measures are essential in controlling the spread of gastroenteritis. Full article

Background: Considerable mortality and morbidity rates linked to AGE are well documented in the literature. Many inflammatory markers have been studied in the context of research on AGE as tools to predict the clinical course of the disease and determine the need for the use of antimicrobials. This study focuses on CRP, PCT, and WBC counts as inflammatory markers of AGE. Methods: A retrospective chart review study was conducted at King Abdullah Specialized Children’s Hospital, Jeddah. Using a non-probability consecutive sampling technique, all patients under the age of 14 diagnosed with gastroenteritis over four years (2020–2024) were included. Results: The sample population consisted of 84 individuals. Pathogen prevalence was identified in only 15%. Salmonella was the most frequently identified bacterial pathogen. While the WBC count and ESR were reassuring in most cases, the CRP and PCT measurements were almost always elevated. Compared to the stronger association observed with WBC counts, the correlation between PCT levels and ED visits were less significant. Higher CRP levels were associated with an increased use of antibiotics. Conclusion: The results of this study highlight that CRP is useful in identifying patients who are likely to have bacterial AGE and require antibiotics. Moreover, the WBC count is a helpful tool in predicting those likely to present to the ED again. Full article

Background and objectives: Acute gastroenteritis (AGE) remains a significant cause of morbidity in children, particularly in low- and middle-income countries. Viral pathogens, including rotavirus (RoV), norovirus (NoV), and adenovirus (HAdV), are among the leading causes of AGE. This study aimed to determine the prevalence of viral, bacterial, and parasitic enteric pathogens associated with AGE among hospitalized children in Northern Jordan. Materials and Methods: A total of 195 stool samples were collected from hospitalized children with AGE during the winter seasons of 2022–2024. Multiplex real-time qPCR assays were performed to detect common pathogens. The prevalence of each pathogen was determined, and co-infections were analyzed. Clinical symptoms, demographic characteristics, and associations between specific pathogens and disease severity were evaluated. Results: Viral pathogens were the predominant cause of AGE, with NoV detected in 53 cases (27.2%; of which 19.0% were NoV GI and 8.2% NoV GII), followed by RoV (24.1%), HAdV (20.0%), HAstV (13.3%), and SaV (12.3%). Co-infections were observed in several cases, particularly among viral infections evoked by RoV, HAdV, and NoV GI. Bacterial and parasitic infections were less prevalent, with Salmonella and Campylobacter spp. detected in 23.1% and 13.8%, respectively. Additionally, Cryptosporidium was identified in two cases (0.5%). Conclusions: Viral pathogens, particularly NoV, RoV, and HAdV, are the leading causes of AGE among hospitalized children in Jordan. Co-infections among viral pathogens were common, whereas bacterial and parasitic infections played a limited role in the disease burden. These findings emphasize the importance of continued surveillance and vaccination efforts, particularly for RoV, to reduce AGE-related hospitalizations in children. Full article

Fucoidan is a sulfated fucan marine polysaccharide with potential therapeutic applications, including antibacterial activity and the control of virulence factors associated with quorum sensing. This study investigates the bioactivity of fucoidan derived from the brown algae Ascophyllum nodosum, as well as their fucoidan oligosaccharides (OFuc; <3 kDa), on the growth, motility, biofilm formation, and adhesion of Campylobacter jejuni, the leading cause of bacterial gastroenteritis worldwide. The results showed that fucoidan decreased the growth rate of C. jejuni at concentrations greater than 25 µg/mL, while no effect was observed with different concentrations (5–100 µg/mL) of OFuc. Neither compound affected bacterial motility. Both fucoidan and OFuc inhibited abiotic biofilm formation and diminished pathogen adhesion in a concentration-dependent manner. The study also found that C. jejuni recognized the fucoidan molecule through an enzyme-like lectin assay (ELLA) showing a lectin-like adhesin-carbohydrate recognition. Overall, these results suggest the potential of fucoidan from A. nodosum for controlling abiotic biofilm formation in the food industry, and they open new avenues for research into the use of fucoidan as a molecule aimed at blocking infections caused by C. jejuni. Full article

Background/Aim: Bacterial and viral gastroenteritis present with overlapping symptoms, including vomiting, diarrhea, and abdominal pain. Stool tests have been used to differentiate between them; however, stool cultures are time-consuming and stool polymerase chain reaction (PCR) tests are expensive. The role of the clinical value of procalcitonin (PCT) and C-reactive protein (CRP) as diagnostic markers of bacterial gastroenteritis remains to be investigated. This study evaluated the diagnostic value of PCT for the early diagnosis of bacterial gastroenteritis. Methods: The medical records of patients diagnosed with gastroenteritis by the emergency department with positive stool PCR results confirming the diagnosis between 1 January 2020 and 31 July 2024 were retrospectively reviewed. Demographic characteristics and laboratory findings, including PCT and CRP levels, were analyzed. The area under the curve (AUC) for the diagnosis of bacterial gastroenteritis was assessed to determine the diagnostic potential of PCT and CRP. Results: Among the 1882 cases identified, 1435 met the inclusion criteria. CRP exhibited a sensitivity of 79.0% and specificity of 78.6% (AUC: 0.848, 95% CI: 0.815–0.881) in diagnosing bacterial gastroenteritis. In comparison, PCT showed lower sensitivity (60.3%) and specificity (62.6%) (AUC: 0.660, 95% CI: 0.614–0.706). However, in patients aged >17 years with fever (≥38 °C), PCT demonstrated an improved AUC of 0.767 (95% CI: 0.603–0.932; p = 0.019). Conclusions: CRP demonstrated moderate sensitivity in predicting bacterial gastroenteritis; however, its false-negative rate suggests limitations in clinical decision-making. While PCT may assist clinicians in identifying bacterial gastroenteritis in febrile adult patients, its diagnostic accuracy remains suboptimal, necessitating further validation through larger studies. Full article

Salmonellosis is the second most common foodborne bacterial gastroenteritis in humans in Finland and worldwide. In Finland, a national salmonella control program covering cattle, pigs, and poultry, as well as the meat and eggs obtained from them, has been in place since the country joined the EU in 1995. To identify trends in the incidence of salmonellosis and to reflect on their causes, we analyzed Salmonella case data from the Finnish Infectious Disease Register (FIDR) from 1995 to 2022 and outbreak data from the national food and waterborne outbreak register (the FWO register) in the period 2010–2022. From 1995–1999 to 2015–2019, the incidence of salmonellosis decreased by 66% and 63% for domestic and travel-related cases, respectively. Most salmonellosis cases (72%) were travel-related, and, of them, 27% were infected in Southeast Asia. The most common serovars were S. Typhimurium and S. Enteritidis (38% and 19% of domestic cases, and 7% and 39% of travel-related cases). During 2010–2022, Salmonella sp. was reported as a cause in 31 foodborne outbreaks. In 14 of them, the source was identified at foodstuff level, and 12 sources were of foreign origin. The results of this study indicate that the national salmonella control program may have prevented domestic human infections in Finland. Full article

This study aimed to evaluate the therapeutic effect of Terminalia chebula (TC) on Tibetan yak-origin Salmonella-induced diarrhea and dysentery in mice. The levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α), anti-inflammatory cytokines (IL-4 and IL-10), and the oxidative stress markers malondialdehyde (MDA), superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), reduced glutathione (GSH-PX), and catalase (CAT) in the serum of mice were measured using ELISA kits. Using microbial diversity sequencing and non-targeted metabolomics detection techniques, the relevant mechanisms of TC treatment in a mouse Salmonella infection model were evaluated. The results showed the following: TC can effectively reduce the diarrhea rate; alleviate weight loss caused by Salmonella invasion; reduce the pro-inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α in serum; and increase the concentrations of the anti-inflammatory cytokines IL-4 and IL-10. TC can improve the body’s antioxidant levels to heal the damage caused by oxidative stress and lipid peroxidation. The histological section results show that TC can significantly improve gastric and intestinal tissue lesions and has no toxic effects on the liver and kidneys. 16S rRNA and ITS sequencing analysis suggests that Lactobacillus, Enterorhabdus, Alistipes (bacterial community), Lodderomyces, Saccharomyces, and Penicillium (fungal community) may be key functional microbial communities in TC. Non-targeted metabolomics also suggests that the antibacterial treatment of dysentery with chebulic acid may be related to regulation of the Ras signaling pathway, long-term potentiation, the MAPK signaling pathway, metabolic pathways, and gut microbiome composition. Conclusion: TC has clear clinical efficacy in treating bacterial diarrhea, presenting anti-inflammatory and antioxidant effects. Its roles in regulating the gut microbiome and metabolic pathways and products were determined as the main reason for its therapeutic effect in a mouse gastroenteritis model caused by Salmonella infection. Full article

The msbB gene, encoding a lipid A phosphatease, is crucial for lipopolysaccharide (LPS) synthesis in Gram-negative bacteria and plays a critical role in their virulence. This study investigated the role of msbB in Vibrio parahaemolyticus, a significant marine pathogen causing gastroenteritis in humans and infections in aquatic animals. We constructed an msbB deletion mutant (ΔmsbB) and a complementary strain (CΔmsbB) using homologous recombination. The growth, outer membrane permeability, stress and antibiotic sensitivity, biofilm formation, swarming motility, and virulence of the wild-type (WT), ΔmsbB, and CΔmsbB strains were assessed. Additionally, the pathogenicity of ΔmsbB was evaluated using L. vannamei shrimp models. The results showed that the msbB gene was successfully deleted and complemented, and its deletion did not impair bacterial growth. However, the ΔmsbB strain exhibited an increased outer membrane permeability, reduced resistance to stresses and antibiotics, defective biofilm formation, and a reduced swarming motility. In a Tetrahymena co-culture, the ΔmsbB strain showed attenuated virulence. In shrimp infected with the ΔmsbB strain, the cumulative mortality rate was 22%, significantly lower than the 62% observed in the WT strain. Moreover, the expression levels of immune-related genes in the shrimp hepatopancreas were significantly lower in the ΔmsbB group, indicating a significant reduction in infection capability and pathogenicity. These findings indicate that the msbB gene is critical for the virulence of V. parahaemolyticus and suggest that msbB is a potential target for therapeutic interventions and vaccine development against V. parahaemolyticus infections. Full article

Bacteria in the genus Vibrio, including at least 152 species, thrive in marine and estuarine environments and are frequently detected in aquatic products worldwide. Of these, 12 species have been implicated in human infectious diseases, such as the life-threatening pandemic cholera, acute gastroenteritis, and severe sepsis. Nevertheless, molecular mechanisms of their pathogenesis are not fully uncovered yet. Prophages are found prevalent in Vibrio spp. genomes, carrying a number of genes with various functions. In this review, we deciphered the evolutionary relationship between prophages and Vibrio species and highlighted the impact of prophages on the bacterial pathogenicity, environmental fitness, and genome evolution, based on 149 newly discovered intact prophages located in the genomes of 82 Vibrio spp., which we searched and collected from Web of Science Core Collection in the most recent 5 years. The effects of prophages on resistance to superinfection, strain competition, and their regulation were also discussed. This review underscored crucial roles of prophages in shaping Vibrio spp. genomes and their implications for food safety and public health. Full article

Campylobacter is one of the leading bacterial causes of gastroenteritis worldwide. It frequently contaminates poultry and other raw meat products, which are the primary sources of Campylobacter infections in humans. Plasmids, known as important mobile genetic elements, often carry genes for antibiotic resistance, virulence, and self-mobilization. They serve as the main vectors for transferring genetic material and spreading resistance and virulence among bacteria. In this study, we identified 34 new plasmids from 43 C. jejuni and C. coli strains isolated from retail meat using long-read and short-read genome sequencing. Pangenomic analysis of the plasmid assemblies and reference plasmids from GenBank revealed five distinct groups, namely, pTet, pVir, mega plasmids (>80 kb), mid plasmids (~30 kb), and small plasmids (<6 kb). Pangenomic analysis identified the core and accessory genes in each group, indicating a high degree of genetic similarity within groups and substantial diversity between the groups. The pTet plasmids were linked to tetracycline resistance phenotypes in host strains. The mega plasmids carry multiple genes (e.g., aph(3’)-III, type IV and VI secretion systems, and type II toxin–antitoxin systems) important for plasmid mobilization, virulence, antibiotic resistance, and the persistence of Campylobacter. Together, the identification and comprehensive genetic characterization of new plasmids from Campylobacter food isolates contributes to understanding the mechanisms of gene transfer, particularly the spread of genetic determinants of virulence and antibiotic resistance in this important pathogen. Full article

Background: Thermophilic Campylobacter species are among the main culprits behind bacterial gastroenteritis globally and have grown progressively resistant to clinically important antimicrobials. Many studies have been carried out to explore innovative and alternative strategies to control antibiotic-resistant campylobacters in animal reservoirs and human hosts; however, limited studies have been performed to develop efficient control schemes against Campylobacter biofilms. Methods: This study investigated the antimicrobial and antibiofilm activities of some herbal extracts against multidrug-resistant (MDR) Campylobacter species recovered from different sources using phenotypic and molecular techniques. Results: The overall Campylobacter species prevalence was 21.5%, representing 15.25% and 6.25% for C. jejuni and C. coli, respectively. Regarding C. jejuni, the highest resistance rate was observed for amoxicillin–clavulanic acid and colistin (85.25% each), followed by cefotaxime (83.61%) and tetracycline (81.97%), whereas C. coli isolates showed absolute resistance to cefotaxime followed by erythromycin (92%) and colistin (88%). Remarkably, all Campylobacter isolates were MDR with elevated multiple antimicrobial resistance (MAR) indices (0.54–1). The antimicrobial potentials of green tea (Camellia sinensis), rosemary (Rosmarinus officinalis) and ginger (Zingiber officinale) extracts against MDR Campylobacter isolates were assessed by the disk diffusion assay and broth microdilution technique. Green tea extract showed a marked inhibitory effect against tested isolates, exhibiting growth inhibition zone diameters of 8 to 38 mm and a minimum inhibitory concentration (MIC) range of 1.56–3.12 mg/mL, unlike the rosemary and ginger extracts. Our findings reveal a respectable antibiofilm activity (>50% biofilm formation inhibition) of green tea against the preformed biofilms of Campylobacter isolates. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) results showed a significant decrease (p < 0.05) in the expression levels of biofilm biosynthesis gene and its regulator (FlaA and LuxS, respectively) in Campylobacter isolates treated with the green tea extract in comparison with untreated ones. Conclusion: This is the first in vitro approach that has documented the inhibitory activity of green tea extract against MDR-biofilm-producing Campylobacter species isolated from different sources. Further in vivo studies in animals’ models should be performed to provide evidence of concept for the implementation of this alternative candidate for the mitigation of MDR Campylobacter infections in the future. Full article