Prevalence of Yersinia enterocolitica Bioserotype 3/O:3 among Children with Diarrhea, China, 2010-2015

Pathogenicity and virulence of Yersinia

The genus Yersinia includes human, animal, insect, and plant pathogens as well as many symbionts and harmless bacteria. Within this genus are Yersinia enterocolitica and the Yersinia pseudotuberculosis complex, with four human pathogenic species that are highly related at the genomic level including the causative agent of plague, Yersinia pestis. Extensive laboratory, field work, and clinical research have been conducted to understand the underlying pathogenesis and zoonotic transmission of these pathogens. There are presently more than 500 whole genome sequences from which an evolutionary footprint can be developed that details shared and unique virulence properties. Whereas the virulence of Y. pestis now seems in apparent homoeostasis within its flea transmission cycle, substantial evolutionary changes that affect transmission and disease severity continue to ndergo apparent selective pressure within the other Yersiniae that cause intestinal diseases. In this review, we will summarize the present understanding of the virulence and pathogenesis of Yersinia, highlighting shared mechanisms of virulence and the differences that determine the infection niche and disease severity.

Characteristics and comparative genome analysis of Yersinia enterocolitica and related species associated with human infections in Switzerland 2019-2023

PURPOSE

We aimed to characterise Yersinia enterocolitica from human clinical specimens in Switzerland using epidemiological, microbiological and whole-genome sequencing (WGS) data.

METHODS

Isolates (n = 149) were collected between January 2019 and December 2023. Epidemiological data was noted and strains were characterized by biochemical and serological typing, antimicrobial susceptibility testing (AST), and WGS-based analysis.

RESULTS

Most of the isolates (86%) were from stool specimens and 52% were from male patients. The patients' median age was 28 years (range < 1-94 years). Typing assigned the isolates to bioserotype 4/O:3 (44%), biotype 1A (34%), bioserotype 2/O:9 (21%), and bioserotype 3/O:3 (1%). WGS identified Y. enterocolitica (n = 147), Y. alsatica (n = 1) and Y. proxima (n = 1). Seven isolates were multidrug resistant (MDR) and harboured plasmid pAB829 carrying aph(3″)-Ib, aph(6)-Id, and tet(Y) (n = 1), pAC120 carrying aph(6)-Id and tet(A) (n = 2), or a 12.6 kb Tn2670-like transposon containing catA1, aadA12, sul1, and qacEΔ1 (n = 4). Virulence factors (VFs) included ail (n = 99), invB, (n = 145), ystA (n = 99), ystB (n = 48) and pYV-associated VFs (n = 93). MLST and cgMLST analysis showed that BT 1A strains consisted of several STs and were highly diverse, whereas BT 2/O:9 strains were all ST12 and clustered closely, and BT 4/O:3 strains mostly belonged to ST18 but were more diverse. SNP analysis revealed two highly clonal BT 4/O:3 subpopulations with wide spatio-temporal distribution.

CONCLUSIONS

Y. enterocolitica BT 1A, BT 2/O:9 and BT 4/O:3 are frequently associated with human yersiniosis in Switzerland. WGS-based subtyping of Y. enterocolitica is a powerful tool to explore the genetic diversity and the pathogenic potential of human isolates.

A novel cgMLST for genomic surveillance of Yersinia enterocolitica infections in France allowed the detection and investigation of outbreaks in 2017-2021

Enteric yersiniosis, the third most common food-borne zoonosis in Europe, is mainly caused by the pathogen Yersinia enterocolitica. In France, the yersiniosis microbiological surveillance is conducted at the Yersinia National Reference Laboratory (YNRL). Since 2017, isolates have been characterized by whole genome sequencing (WGS) followed by a 500-gene Yersinia-cgMLST. We report here the data of the WGS-based surveillance on Y. enterocolitica isolates for the 2017-2021 period. The YNRL characterized 7,642 Y. enterocolitica strains distributed in 2,497 non-pathogenic isolates from lineages 1Aa and 1Ab, and 5,145 specimens belonging to 8 pathogenic lineages. Among pathogenic isolates, lineage 4 was the most common (87.2%) followed by lineages 2/3-9b (10.6%), 2/3-5a (1.2%), 2/3-9a (0.6%), 3-3b, 3-3c, 1B, and 3-3d (0.1% per each). Importantly, we developed a routine surveillance system based on a new typing method consisting of a 1,727-genes core genome Multilocus Sequence Typing (cgMLST) specific to the species Y. enterocolitica followed by isolate clustering. Thresholds of allelic distances (AD) were determined and fixed for the clustering of isolates: AD ≤ 5 for lineages 4, 2/3-5a, and 2/3-9a, and AD ≤ 3 for lineage 2/3-9b. Clustering programs were implemented in 2019 in routine surveillance to detect genomic clusters of pathogenic isolates. In total, 419 clusters with at least 2 isolates were identified, representing 2,504 of the 3,503 isolates characterized between 2019 and 2021. Most clusters (n = 325) comprised 2 to 5 isolates. The new typing method proved to be useful for the molecular investigation of unusual grouping of cases as well as for the detection of genomic clusters in routine surveillance.

IMPORTANCE

We describe here the new typing method used for molecular surveillance of Yersinia enterocolitica infections in France based on a novel core genome Multilocus Sequence Typing (cgMLST) specific to Y. enterocolitica species. This method can reliably identify the pathogenic Y. enterocolitica subspecies and compare the isolates with a high discriminatory power. Between 2017 and 2021, 5,145 pathogenic isolates belonging to 8 lineages were characterized and lineage 4 was by far the most common followed by lineage 2/3-9b. A clustering program was implemented, and detection thresholds were cross-validated by the molecular and epidemiological investigation of three unusual groups of Y. enterocolitica infections. The routine molecular surveillance system has been able to detect genomic clusters, leading to epidemiological investigations.

An Update in Knowledge of Pigs as the Source of Zoonotic Pathogens

The available data indicate that the human world population will constantly grow in the subsequent decades. This constant increase in the number of people on the Earth will lead to growth in food demand, especially in food of high nutritional value. Therefore, it is expected that the world livestock population will also increase. Such a phenomenon enhances the risk of transmitting pathogens to humans. As pig production is one of the most significant branches of the world's livestock production, zoonoses of porcine origins seem to be of particular importance. Therefore, in this review, we aim to introduce the latest data concerning, among other things, epidemiology and available preventive measures to control the most significant porcine zoonoses of viral, bacterial, and parasitic origin.

Public health implications of Yersinia enterocolitica investigation: an ecological modeling and molecular epidemiology study

BACKGROUND

Yersinia enterocolitica has been sporadically recovered from animals, foods, and human clinical samples in various regions of Ningxia, China. However, the ecological and molecular characteristics of Y. enterocolitica, as well as public health concerns about infection in the Ningxia Hui Autonomous Region, remain unclear. This study aims to analyze the ecological and molecular epidemiological characteristics of Y. enterocolitis in order to inform the public health intervention strategies for the contains of related diseases.

METHODS

A total of 270 samples were collected for isolation [animals (n = 208), food (n = 49), and patients (n = 13)], then suspect colonies were isolated and identified by the API20E biochemical identification system, serological tests, biotyping tests, and 16S rRNA-PCR. Then, we used an ecological epidemiological approach combined with machine learning algorithms (general linear model, random forest model, and eXtreme Gradient Boosting) to explore the associations between ecological factors and the pathogenicity of Y. enterocolitis. Furthermore, average nucleotide identity (ANI) estimation, single nucleotide polymorphism (SNP), and core gene multilocus sequence typing (cgMLST) were applied to characterize the molecular profile of isolates based on whole genome sequencing. The statistical test used single-factor analysis, Chi-square tests, t-tests/ANOVA-tests, Wilcoxon rank-sum tests, and Kruskal-Wallis tests.

RESULTS

A total of 270 isolates of Yersinia were identified from poultry and livestock (n = 191), food (n = 49), diarrhoea patients (n = 13), rats (n = 15), and hamsters (n = 2). The detection rates of samples from different hosts were statistically different (χ² = 22.636, P < 0.001). According to the relatedness clustering results, 270 isolates were divided into 12 species, and Y. enterocolitica (n = 187) is a predominated species. Pathogenic isolates made up 52.4% (98/187), while non-pathogenic isolates made up 47.6% (89/187). Temperature and precipitation were strongly associated with the pathogenicity of the isolates (P < 0.001). The random forest (RF) prediction model showed the best performance. The prediction result shows a high risk of pathogenicity Y. enterocolitica was located in the northern, northwestern, and southern of the Ningxia Hui Autonomous Region. The Y. enterocolitica isolates were classified into 54 sequence types (STs) and 125 cgMLST types (CTs), with 4/O:3 being the dominant bioserotype in Ningxia. The dominant STs and dominant CTs of pathogenic isolates in Ningxia were ST429 and HC100_2571, respectively.

CONCLUSIONS

The data indicated geographical variations in the distribution of STs and CTs of Y. enterocolitica isolates in Ningxia. Our work offered the first evidence that the pathogenicity of isolates was directly related to fluctuations in temperature and precipitation of the environment. CgMLST typing strategies showed that the isolates were transmitted to the population via pigs and food. Therefore, strengthening health surveillance on pig farms in high-risk areas and focusing on testing food of pig origin are optional strategies to prevent disease outbreaks.

Yersinia enterocolitica-Derived Outer Membrane Vesicles Inhibit Initial Stage of Biofilm Formation

Yersinia enterocolitica (Y. enterocolitica) is an important food-borne and zoonotic pathogen. It can form biofilm on the surface of food, increasing the risk to food safety. Generally, outer membrane vesicles (OMVs) are spherical nanostructures secreted by Gram-negative bacteria during growth. They play a role in biological processes because they contain biologically active molecules. Several studies have reported that OMVs secreted by various bacteria are associated with the formation of biofilms. However, the interactions between Y. enterocolitica OMVs and biofilm are unknown. This study aims to investigate the effect of Y. enterocolitica OMVs on biofilm formation. Firstly, OMVs were extracted from Y. enterocolitica Y1083, which has a strong biofilm-forming ability, at 15 °C, 28 °C and 37 °C and then characterized. The characterization results showed differences in the yield and protein content of three types of OMVs. Next, by co-culturing the OMVs with Y. enterocolitica, it was observed that the OMVs inhibited the initial stage of Y. enterocolitica biofilm formation but did not affect the growth of Y. enterocolitica. Furthermore, biofilm formation by Salmonella enteritidis and Staphylococcus aureus were also inhibited by OMVs. Subsequently, it was proved that lipopolysaccharides (LPS) in OMVs inhibited biofilm formation., The proteins, DNA or RNA in OMVs could not inhibit biofilm formation. Bacterial motility and the expression of the biofilm-related genes pgaABC, motB and flhBD were inhibited by LPS. LPS demonstrated good anti-biofilm activity against various bacteria. This study provides a new approach to the prevention and control of pathogenic bacterial biofilm.

Selected Livestock-Associated Zoonoses as a Growing Challenge for Public Health

The aim of this paper is to review the most significant livestock-associated zoonoses. Human and animal health are intimately connected. This idea has been known for more than a century but now it has gained special importance because of the increasing threat from zoonoses. Zoonosis is defined as any infection naturally transmissible from vertebrate animals to humans. As the frequency and prevalence of zoonotic diseases increase worldwide, they become a real threat to public health. In addition, many of the newly discovered diseases have a zoonotic origin. Due to globalization and urbanization, some of these diseases have already spread all over the world, caused by the international flow of goods, people, and animals. However, special attention should be paid to farm animals since, apart from the direct contact, humans consume their products, such as meat, eggs, and milk. Therefore, zoonoses such as salmonellosis, campylobacteriosis, tuberculosis, swine and avian influenza, Q fever, brucellosis, STEC infections, and listeriosis are crucial for both veterinary and human medicine. Consequently, in the suspicion of any zoonoses outbreak, the medical and veterinary services should closely cooperate to protect the public health.

Global Prevalence of Yersinia enterocolitica in Cases of Gastroenteritis: A Systematic Review and Meta-Analysis

The prevalence of Yersinia enterocolitica in gastroenteritis is often underestimated. It relates considerably to morbidity and medical expenses around the world. Understanding the cause of gastroenteritis leads to making the appropriate treatment decisions. We systematically searched PubMed, Science Direct, Embase, and Scopus to identify all published studies between Jan. 1, 2000, and Dec. 31, 2019, to assess the prevalence of Y. enterocolitica in gastroenteritis patients. A total of 5039 articles were identified that lead to the extraction of data from 47 of them. The pooled prevalence of Y. enterocolitica in cases of gastroenteritis was estimated as 1.97% (1.32–2.74%) in the culture method and 2.41% (1.07–4.22%) in the molecular method. Among the biotypes of Y. enterocolitica, 1A (62.48%) and 1B (2.14%) had the most and least prevalence, respectively. Serotype O3 Y. enterocolitica with 39.46% had the highest and O5,27 with 0.0% had the least prevalence in gastroenteritis cases. In conclusion, the findings of this systematic review show that Y. enterocolitica is prevalent in gastroenteritis in all age groups. Serotypes O3 and O9 of Y. enterocolitica had the highest prevalence and O5,27 had the least prevalence in diarrheal patients. The prevalence of Y. enterocolitica was similar in both gender and different seasons. It should be noted that to determine the role of the organism, more studies are needed especially in food-borne diseases.

Efficacy of montmorillonite and vitamin AD combined with zinc preparation in children with diarrheal disease and its effect on inflammatory factors

OBJECTIVE

To investigate the effect of montmorillonite and vitamin AD combined with zinc preparation in children with diarrheal disease and its effect on inflammatory factors.

METHODS

A total of 156 children with diarrheal diseases admitted to our hospital from January 2018 to January 2020 were enrolled and divided into two groups (n=78 for each) using random number table. The control group (CG) was treated with montmorillonite, and the observation group (OG) was additionally treated with vitamin AD and zinc. Both groups completed 7 d of treatment and 3 months of follow-up to compare the efficacy rate, time to onset of symptom relief, inflammatory factor levels, T-lymphocyte levels, adverse drug reactions, and relapse rate.

RESULTS

The efficacy rate of 7 d treatment in the OG was 94.87%, higher than that of 56.41% in the CG (P < 0.05). After intervention, the OG had normal frequency of defecation, shorter time for stool to return to normal appearance, shorter duration of antiemetic, antipyretic, antidiarrheal treatment and shorter hospital stay than those of the CG (P < 0.05). The OG exhibited lower levels of CRP, TNF-α, NO, and PCT and higher levels of SOD than the CG (P < 0.05). The OG had lower levels CD3⁺ and CD4⁺ at 7 d after treatment, lower CD8⁺ levels and higher CD4⁺/CD8⁺ levels than the CG (P < 0.05). The relapse rate at 6 months after treatment in the OG was lower than that in the CG (P < 0.05).

CONCLUSION

The combination of montmorillonite, vitamin AD and zinc preparation can achieve higher short-time efficacy, shorten the time of disappearance of symptoms, reduce the level of inflammatory factors, and improve the level of T-lymphocytes, without increasing the incidence of adverse drug reactions.

Selection of potential aptamers for specific growth stage detection of Yersinia enterocolitica

Yersinia enterocolitica remains a threat to public health, and a sensitive detection method is a prerequisite due to its complicated diagnosis associated with slow growth. Recently, aptamer-based detection systems have played a vital role in the development of simple, rapid, sensitive, and specific detection methods. Herein, highly specific ssDNA aptamers were screened against Y. enterocolitica at the different growth stages by whole cell-SELEX. Cells at different growth stages were harvested and incubated with an ssDNA library to get an enriched pool of specific aptamer candidates. After the 10th round of SELEX, the enriched pool was sequenced and grouped into seven families based on homology and similarity of the secondary structure. Flow cytometry analysis revealed that the aptamers M1, M5, and M7 with K d values of 37.93 ± 7.88 nM, 74.96 ± 21.34 nM, and 73.02 ± 18.76 nM had the highest affinity and specificity to the target, respectively. The selected aptamers showed binding to the different growth stages of Y. enterocolitica with a significant increase in the gated fluorescence. Our aptamer selection strategy is convenient, and the developed aptamer can be useful for an accurate and reliable detection system.

An overview of Yersinia enterocolitica and related species in samples of different origin from San Luis, Argentina

This study is aimed at offering an overview of the prevalence of Yersinia enterocolitica and related species in San Luis, Argentina, from samples of diverse origin received in our laboratory between 1984 and 2014, and providing an analysis of the distribution of Yersinia isolates according to their isolation sources, highlighting bioserotypes and potential reservoirs and vehicles of transmission to humans. From a total of 4572 samples of human, animal, food and environmental origins analyzed by traditional culture methods and molecular techniques, 229 (5%) samples were Yersinia positive. The highest frequency of Yersinia isolates was observed in environmental specimens (14.3%), followed by animal (9.2%), food (5%) and human (0.6%) samples. A total of 255 Yersinia isolates were characterized, including 183 Y. enterocolitica and 72 isolates of other Yersinia species. Biotype 1A associated to several serotypes was identified in Y. enterocolitica isolates from environment (100%), animals (95.5%), foods (71.7%) and human samples (40%); bioserotype 2/O:9 was identified in isolates from foods (25.5%), and biotype 3 was associated with strains from humans (60%), animals (4.5%) and foods (2.8%). This biotype included three strains O:3 and six strains O:5. The data highlight animals and foods as the main Y. enterocolitica sources in our region.

Application of data science in risk assessment and early warning

The food supply chain has been recognised by the EU as a critical infrastructure, and its complexity is the main cause of vulnerability. Depending on the food matrix, natural and/or deliberate contamination, food-borne diseases or even food fraud incidents may occur worldwide. Consequently, robust predictive models and/or software tools are needed to support decision-making and mitigating risks in an efficient and timely manner. In this frame, the fellow participated in data collection and analysis tasks, so as to provide additional predictive models. The working programme, covered a wide range of aspects related to risk assessment including identification of emerging risks (quantitative), microbiological risk assessment, authenticity assessment, spatio-temporal epidemiological modelling and database formation for hosting predictive microbial models. The training and close integration, in the open-source, in-house (German Federal Institute for Risk Assessment (BfR)) developed software tools under the framework of FoodRisk-Labs (https://foodrisklabs.bfr.bund.de.) for data analysis, predictive microbiology, quantitative microbiological risk assessment and automatic data retrieval purposes allowed for the independent use. Moreover, the fellow actively contributed to the update of the upcoming Yersinia enterocolitica risk assessment, and also in authenticity assessment of edible oils. Over the course of the year, the fellow was closely involved in international and national research projects with experts in the above-mentioned disciplines. Lastly, he consolidated his acquired knowledge by presenting his scientific work to conferences, and BfR-internal meetings.

A comprehensive review on the prevalence, pathogenesis and detection ofYersinia enterocolitica

Food safety is imperative for a healthy life, but pathogens are still posing a significant life threat. “Yersiniosis” is caused by a pathogen named Yersinia enterocolitica and is characterized by diarrheal, ileitis, and mesenteric lymphadenitis types of sicknesses. This neglected pathogen starts its pathogenic activity by colonizing inside the intestinal tract of the host upon the ingestion of contaminated food. Y. enterocolitica remains a challenge for researchers and food handlers due to its growth habits, low concentrations in samples, morphological similarities with other bacteria and lack of rapid, cost-effective, and accurate detection methods. In this review, we presented recent information about its prevalence, biology, pathogenesis, and existing cultural, immunological, and molecular detection approaches. Our ultimate goal is to provide updated knowledge regarding this pathogen for the development of quick, effective, automated, and sensitive detection methods for the systematic detection of Y. enterocolitica.

Food safety is imperative for a healthy life, but pathogens are still posing a significant life threat.

Subtractive proteomics and immunoinformatics revealed novel B-cell derived T-cell epitopes against Yersinia enterocolitica: An etiological agent of Yersiniosis

Yersinia enterocolitica is the third most common cause of gastrointestinal manifestations in Europe. Statistically, every year the pathogen accounts for 640 hospitalizations, 117,000 illnesses, and 35 deaths in the United States. The associated mortality rate of the pathogen is 50% and is virtually resistant to penicillin G, ampicillin and cephalotin. The development of new and effective therapeutic procedures is urgently needed to counter the multi-drug-resistant phenotypes imposed by the said pathogen. Based on subtractive reverse vaccinology and immunoinformatics approaches, we have successfully predicted novel antigenic peptide vaccine candidates against Y. enterocolitica. The pipeline revealed two isoforms of ompC family; meoA (ompC) and ompC2 as promising vaccine targets. Protein-protein interactions elaborated the involvement of target candidates in the major biological pathways of the pathogen. The predicted 9-mer B-cell derived T-cell epitope of proteins are found to be virulent, antigenic, non-allergic, surface exposed and conserved in all nine completely sequenced strains of the pathogen. Molecular docking predicts deep and stable binding of the epitopes in the binding pocket of the most predominant allele in human population-the DRB1*0101. These epitopes of target proteins could provide the foundation for the development of an epitope-driven vaccine against Y. enterocolitica.

Colicin FY inhibits pathogenic Yersinia enterocolitica in mice

Yersiniosis belongs to the common foodborne diseases around the world, and frequently manifests as diarrhea that can be treated with probiotics. Colicin FY is an antibacterial agent produced by bacteria and it is capable of specific growth inhibition of Yersinia enterocolitica, the causative agent of gastrointestinal yersiniosis. In this study, recombinant E. coli producing colicin FY were constructed, using both known probiotic strains EcH22 and EcColinfant, and the newly isolated murine strains Ec1127 and Ec1145. All E. coli strains producing colicin FY inhibited growth of pathogenic Y. enterocolitica during co-cultivation in vitro. In dysbiotic mice treated with streptomycin, E. coli strains producing colicin FY inhibited progression of Y. enterocolitica infections. This growth inhibition was not observed in mice with normal gut microflora, likely due to insufficient colonization capacity of E. coli strains and/or due to spatial differences in intestinal niches. Isogenic Y. enterocolitica producing colicin FY was constructed and shown to inhibit pathogenic Y. enterocolitica in mice with normal microflora. Evidence of in vivo antimicrobial activity of colicin FY may have utility in the treatment of Y. enterocolitica infections.