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The aim of the study was to analyse selected aspects of the natural variability of selected varieties of Vitis vinifera. Grapevine is one of the most popular and desirable crops in the world due to the great tradition of wine production, but grape extracts also have a wide range of pharmaceutical effects on the human body. It is important to identify different varieties for the conservation of genetic resources, but also for commercial and cultivation purposes. The variability of conserved DNA-derived polymorphism profiles, as well as microbial characteristics, were analysed in this study. Six different varieties of Vitis vinifera L. were used in the study: Cabernet Savignon, Chardonney, Welschriesling, Weisser Riesling, Gewurztramines and Gruner Veltliner. Genetic polymorphism was analysed by CDDP markers for WRKY genes. Polymorphic amplicon profiles were generated by all primer combinations used in the study. Gruner Veltliner and Welschriesling were the most similar, with a similarity value at 0.778. Microbiological quality of grape and antimicrobial activity against Gram-positive and Gram-negative bacteria and yeasts were analysed further. The plate diluting method for microbial quality and the disc diffusion method for antimicrobial activity were evaluated. The number of total count of bacteria ranged between 3.12 in Cabernet Sauvignon to 3.62 log cfu/g in Grűner Veltliner. The best antimicrobial activity showed Gewurztramines against Salmonella enterica, Yersinia enterocolitica, Pseudomonas aeroginosa, Staphylococcus aureus, Listeria monocytogenes, Candida albicans, Candida krusei, and Candida tropicalis. The best antimicrobial activity was found against Enterococcus faecalis in variety Weisser Riesling. [ABSTRACT FROM AUTHOR]

We have recently demonstrated a novel anaerobic NADH-dependent haem breakdown reaction, which is carried out by a range of haemoproteins. The Yersinia enterocolitica protein, HemS, is the focus of further research presented in the current paper. Using conventional experimental methods, bioinformatics, and energy landscape theory (ELT), we provide new insight into the mechanism of the novel breakdown process. Of particular interest is the behavior of a double phenylalanine gate, which opens and closes according to the relative situations of haem and NADH within the protein pocket. This behavior suggests that the double phe-gate fulfills a regulatory role within the pocket, controlling the access of NADH to haem. Additionally, stopped-flow spectroscopy results provide kinetic comparisons between the wild-type and the selected mutants. We also present a fully resolved crystal structure for the F104AF199A HemS monomer, including its extensive loop, the first such structure to be completely resolved for HemS or any of its close homologues. The energy landscapes approach provided key information regarding the gating strategy employed by HemS, compensating for current limitations with conventional biophysical and molecular dynamics approaches. We propose that ELT become more widely used in the field, particularly in the investigation of the dynamics and interactions of weak-binding ligands, and for gating features, within protein cavities., (© 2025 The Author(s). Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

Abstract Yersiniosis is an infectious zoonotic disease caused by two enteropathogenic species of Gram-negative genus Yersinia: Yersinia enterocolitica and Yersinia pseudotuberculosis. Pigs and other wild and domestic animals are reservoirs for these bacteria. Infection is usually spread to humans by ingestion of contaminated food. Yersiniosis is considered a rare disease, but recent studies indicate that it is overlooked in the diagnostic process therefore the infections with this bacterium are not often identified. Reliable diagnosis of Yersiniosis by culturing is difficult due to the slow growth of the bacteria easily overgrown by other more rapidly growing microbes unless selec-tive growth media is used. Phage adhesins recognizing bacteria in a specific manner can be an excellent diagnostic tool, es-pecially in the diagnosis of pathogens difficult for culturing. In this study, it was shown that Gp17, the tail fiber protein (TFP) of phage φYeO3-12, specifically recognizes only the pathogenic Yersinia enterocolitica serotype O:3 (YeO:3) bacteria. The ELISA test used in this work confirmed the specific interaction of this protein with YeO:3 and demonstrated a promising tool for developing the pathogen recognition method based on phage adhesins.

The key to the successful development of animalhusbandry is the epizootic welfare of the country. Forimplementation the set of preventive measures it is requiresa perfect system for diagnosing infectious diseases, includingbrucellosis. Despite the fact that Ukraine is consideredofficially free from this zoonosis among farm animals, thesituation regarding it in the wild fauna of our country remainsinsufficiently studied.This article presents the results of serological studies of548 sera samples of wild boars from 16 regions of Ukraine,collected during 2019 – 2020. The research was conductedon the basis of the State Scientific and Research Institute ofLaboratory Diagnostics and Veterinary and Sanitary Expertise(SSRILDVSE, Kyiv, Ukraine) by using the complementfixation test (CFT) and enzyme-linked immunosorbent assay(ELISA). In addition, all positive samples were further testedon yersiniosis with differential purposes.The systematization of obtained results show thatantibodies to Brucella spp. in sera samples from wild boarsin Ukraine were detected by CFT in 57 samples (10.4 % ofthe total number), by ELISA – in 83 (15.1 %). In general,antibodies to these pathogens were diagnosed in samplesfrom 13 regions (most often from Zhytomyr, Lviv andChernihiv).Positive samples by CFT and/or ELISA werefurther tested for the presence of antibodies to Yersiniaenterocolitica because, according to the literature andguidelines for diagnostic kits, possibility of crossreactions between brucellosis and yersiniosis. As a resultof differential studies, from the 83 positive on brucellosissamples, 42 also showed antibodies to Y. enterocolitica.Taking into account the cross-reactions between tests forbrucellosis and yersiniosis, antibodies to Brucella spp.during the analyzed period were found in 7.5 % of animals(in 41 of 548 samples).The prospect of this work is to further studies of theepizootic situation regarding brucellosis in the wild faunaof Ukraine. The obtained results indicate the circulationof antibodies to this zoonosis among wild boars in ourcountry.

ABSTRACT Stringent response plays an important role in the response of Enterobacteriaceae pathogens to rapid environmental changes. It has been shown that synergistic and antagonistic actions exist between the signaling molecules (p)ppGpp and DksA in several foodborne pathogens; however, the biological function of these molecules and their interactions in Yersinia are still unclear. This study systematically investigated the role of stringent response in Yersinia enterocolitica, a typical foodborne Enterobacteriaceae pathogen, by deleting the (p)ppGpp and DksA biosynthesis genes. (p)ppGpp and DksA copositively regulated most phenotypes, such as motility, antibiotic resistance, and tolerance to oxidative stress, whereas they exhibited independent and/or divergent roles in the growth and biofilm synthesis of Y. enterocolitica. Gene expression analysis revealed that (p)ppGpp- and DksA-deficiency reduced the transcription of flagellar synthesis genes (fliC and flgD) and biofilm synthesis genes (bssS and hmsHFRS), which could potentially contribute to changes in motility and biofilm formation. These results indicate that stringent response regulators (p)ppGpp and DksA have a synergistic role and independent or even completely opposite biological functions in regulating genes and phenotypes of Y. enterocolitica. Our findings revealed the biofunctional relationships between (p)ppGpp and DksA and the underlying molecular mechanisms in the regulation of the pathogenic phenotype of Y. enterocolitica. IMPORTANCE The synergetic actions between the stringent response signaling molecules, (p)ppGpp and DksA, have been widely reported. However, recent transcriptomic and phenotypic studies have suggested that independent or even opposite actions exist between them. In this study, we demonstrated that the knockout of (p)ppGpp and DksA affects the polymorphic phenotype of Yersinia enterocolitica. Although most of the tested phenotypes, such as motility, antibiotic resistance, and tolerance to oxidative stress, were copositively regulated by (p)ppGpp and DksA, it also showed inconsistencies in biofilm formation ability as well as some independent phenotypes. This study deepens our understanding of the strategies of foodborne pathogens to survive in complex environments, so as to provide theoretical basis for the control and treatment of these microorganisms.

Germs from Yersinia genus have a vast ecologic niche, being met at different domestic and wild animal species, but also in food, water and soil. The majority of yersinis live in the digestive tract of human and numerous animal species, especially rodents, but also in soil, plant debris, waters etc. Numerous species of Yersinia genus could produce characteristic infections in human, the main source of infections is represented by rodents and hematophagous insects or, more frequently, by water or contaminated food. In a 1999 study, Mead and coauthors established that the Yersinia enterocolitica prevalence in food, in USA, is around 90%. Foods of animal origin more frequently contaminated with Yersinia enterocolitica are: pork, poultry, beef and lamb meat, milk, ice-cream, sea fruits etc., among them pork meat and milk represents the sources of the most numerous toxi-infection outbreaks in human, in different world regions. Bacteria determine infections which interest the digestive tract in numerous animal species and human, with diarrhea, lymphadenitis, pneumonia and abortion are the most important symptoms. Yersinia enterocolitica enter the human body regularly by oral ingestion, and localize itself with predilection in the distal portion of the ileum and at the ileocaecal appendix and proximal colon level, were determine a terminal ileitis with lymphadenitis, acute enterocolitis, and secondary accompanied with nodosum erythema, poliartritis that could be complicated with septicemia, sometimes leading to death.

The species from Yersinia genus are widespread in nature, they could be isolated from warm-blooded and cold-blooded animals, from foods, water and soil. Among genus species, Yersinia enterocolitica is most frequently isolated from human and animals. The resistance of Yersinia enterocolitica is similar to Yersinia pseudotuberculosis. Moreover, it resists to refrigeration temperature (+4°C). It is susceptible to streptomycin, chloramphenicol, tetracyclines, polymyxin B and colistin sulfate. Also, Yersinia enterocolitica is easily inactivated by sodium nitrite and sodium nitrate added in foodstuffs. It still shows some resistance to these salts, in solution, and could tolerate a 5% NaCl concentration in culture media. Toora shows that adding a 5% NaCl in food could lead to a growing rate reduction. In our research we study the behavior of Yersinia enterocolitica strains isolated from swine feces, on different isolation and identification media, chlorine tolerance, but also the behavior against eleven anti-infectious substances (nalidixic acid, furazolidone, erythromycin, tetracycline, gentamicin, streptomycin, ampicillin, kanamycin, cefalotin, trimethoprim and enrofloxacin).

During the experimental stages, the researches aimed to establish the prevalence of Y. enterocolitica bacteria on swine, in the butchering flow. The experiments developed on a large number of test specimens (800), sampled starting with the moment of animals receiving and until the final product was obtained. For isolation and identification there were used a modified method, proposed by The International Organization for Standardization, and CIN and SSDC isolating cultures as well. Following the effectuated researches, in accordance with the international ones, we can conclude that, in the present, the butchering process allows the strict observance of the hygiene and disinfection conditions with the purpose of limiting the dispersion of Yersinia enterocolitica, which favors the phenomenon of inter-contamination.

The human pathogen Yersinia enterocolitica strain W22703 is characterized by its toxicity towards invertebrates that requires the insecticidal toxin complex (Tc) proteins encoded by the pathogenicity island Tc-PAIYe. Molecular and pathophysiological details of insect larvae infection and killing by this pathogen, however, have not been dissected. Here, we applied oral infection of Galleria mellonella (Greater wax moth) larvae to study the colonisation, proliferation, tissue invasion, and killing activity of W22703. We demonstrated that this strain is strongly toxic towards the larvae, in which they proliferate by more than three orders of magnitude within six days post infection. Deletion mutants of the genes tcaA and tccC were atoxic for the insect. W22703 ΔtccC, in contrast to W22703 ΔtcaA, initially proliferated before being eliminated from the host, thus confirming TcaA as membrane-binding Tc subunit and TccC as cell toxin. Time course experiments revealed a Tc-dependent infection process starting with midgut colonisation that is followed by invasion of the hemolymph where the pathogen elicits morphological changes of hemocytes and strongly proliferates. The in vivo transcriptome of strain W22703 shows that the pathogen undergoes a drastic reprogramming of central cell functions and gains access to numerous carbohydrate and amino acid resources within the insect. Strikingly, a mutant lacking a phage-related holin/endolysin (HE) cassette, which is located within Tc-PAIYe, resembled the phenotypes of W22703 ΔtcaA, suggesting that this dual lysis cassette may be an example of a phage-related function that has been adapted for the release of a bacterial toxin. Author summary: Interactions of bacteria with invertebrates took place over a long period of time, and it is assumed that these animals are not only a reservoir for human pathogens, but have also shaped their evolution. We here report that Y. enterocolitica colonizes the midgut of G. mellonella via the insecticidal toxin complex Tc and subsequently migrates through the epithelial cell layer within the first 18 hours of infection. Once reaching the hemolymph, the pathogen grows to high cell densities to finally kill the insect. The massive proliferation is fostered by a set of differentially regulated genes that constitutes an adaptation of Y. enterocolitica to the nutrient-rich environment encountered within the insect larvae. A successful infection not only depends on the insecticidal Tc, but also requires the activity of a phage-related lysis cassette that is involved in Tc release, probably without affecting bacterial cell integrity. We conclude that the investigation of oral invertebrate infections contributes to a better understanding of microbial pathogenicity. [ABSTRACT FROM AUTHOR]

Yersiniosis, caused by Yersinia enterocolitica, is the third most rampant zoonotic disease in Europe; the pathogen shows high antibiotic resistance. Herbs have multiple anti–microbial components that reduce microorganism resistance. Therefore, an extract of Picrorhiza kurroa (P. kurroa) was evaluated for potential antimicrobial activity. We report that the ethanolic extract of P. kurroa showed effective antimicrobial activity (zone of inhibition: 29.8 mm, Minimum inhibitory concentration (MIC): 2.45 mg/mL, minimum bactericidal concentration (MBC): 2.4 mg/mL) against Yersinia enterocolitica. Potential bioactive compounds from P. kurroa were identified using LC–MS, namely, cerberidol, annonidine A, benzyl formate, picroside–1, and furcatoside A. P. kurroa showed effective antimicrobial potential in skim milk at different pH, acidity, and water activity levels. P. kurroa affected the physiology of Yersinia enterocolitica and reduced the number of live cells. Yersinia enterocolitica, when incubated with P. kurroa extract, showed lower toxin production. Picroside–1 was isolated and showed higher antimicrobial potential in comparison to the standard antibiotic. Picroside–1 lysed the Yersinia enterocolitica cells, as observed under scanning electron microscopy. Docking revealed that picroside–1 (ligand) showed both hydrophilic and hydrophobic interactions with the dihydrofolate reductase (DHFR) protein of Yersinia enterocolitica and that DHFR is a possible drug target. The high activity and natural origin of Picroside–1 justify its potential as a possible drug candidate for Yersinia enterocolitica. [ABSTRACT FROM AUTHOR]

At the A. E. Favorsky Irkutsk Institute of Chemistry, a series of silatrane-sulfonamide hybrids 1a-d and 2a-d was synthesized. The antibacterial activity of 1a, 1b, 1d, 2a, and 2b against test strains of bacteria Yersinia pestis EV NIIEG, Yersinia enterocolitica 628/1, Listeria monocytogenes 766, and Starhylococcus aureus ATCC 6538-P (FDA 209-Р) was evaluated. The minimum inhibitory concentration for silatrane-sulfonamide hybrids was 100-200 mg/liter. Silatrane-sulfonamide hybrid 1d was the most active against all tested strains: minimum inhibitory concentration 100 mg/liter. Exposure to silatrane-sulfonamide hybrids in a doses of 100-200 mg/liter inhibited culture growth by 50-75%. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica and Y. pseudotuberculosis are Gram-negative, facultative anaerobic bacteria that cause yersiniosis—one of the most important zoonotic diseases of the digestive tract. The aim of this study was to determine the prevalence of potentially human-pathogenic Y. enterocolitica and Y. pseudotuberculosis strains in free-living and farmed fallow deer, and to evaluate their sensitivity to chemotherapeutics. A total of 372 rectal swabs were analyzed, including 262 from free-living and 110 from farmed fallow deer. Due to the psychrophilic properties of Yersinia, two samples were collected from each animal. Seven Y. enterocolitica strains were isolated from free-living fallow deer, while two strains were isolated from farmed fallow deer. Yersinia pseudotuberculosis strains were not identified. All isolated Y. enterocolitica strains were ystB-positive, and phylogenetic analysis based on the nucleotide sequences of this gene revealed the presence of two phylogenetic groups. Yersinia enterocolitica strains isolated from fallow deer belonged to biotype 1A, and serotyping analysis demonstrated that the vast majority did not agglutinate with any diagnostic sera. All strains were multiple drug resistant and were not sensitive to at least four of the tested chemotherapeutics (amoxicillin with clavulanic acid, ampicillin, cefalexin, and streptomycin). One Y. enterocolitica strain isolated from a free-living animal was resistant to nine out of the 13 analyzed chemotherapeutics and was intermediately sensitive to the four remaining chemotherapeutics. The highest sensitivity was noted in case of ciprofloxacin (five strains) and trimethoprim-sulfamethoxazole (three strains). Only one strain isolated from a free-living animal was sensitive to three out of the 13 examined antibiotics, whereas the remaining strains were sensitive to only one drug or were not sensitive to any of the chemotherapeutics used. The results of this study indicate that multiple drug-resistant Y. enterocolitica strains can be carried by free-living and farmed fallow deer. This observation gives serious cause for concern because the meat of fallow deer and other ruminants is often consumed semi-raw (steak) or raw (tartar steak). [ABSTRACT FROM AUTHOR]

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Simple Summary: Red foxes (Vulpes vulpes) are largely present in Italian wooded areas and often reach urban environments. These animals are susceptible to several bacterial and protozoan pathogens that are able to affect dogs and humans. Foxes may harbor arthropod-borne microorganisms, enteropathogens and leptospirae, and thus represent a potential source of infections for other animals. Previous surveys in fox populations have usually focused on few of these pathogens, whereas in the present investigation, the occurrence of several bacterial and protozoan pathogens have been investigated: Salmonella spp., Yersinia spp., Listeria monocytogenes, Brucella spp., Ehrlichia canis, Anaplasma phagocytophilum, Coxiella burnetii, Leptospira spp., Neospora caninum, Hepatozoon canis, Babesia spp. and microsporidia. Even though the survey was based on a small number of animals, the results suggested that red foxes in Central Italy are involved in the epidemiology of some infections. Most surveys of pathogens in red foxes (Vulpes vulpes) have focused on particular agents. The aim of this study was to verify, with bacteriological and molecular analyses, the occurrence of the main bacterial and protozoan pathogens that are able to infect canids, in red foxes regularly hunted in Central Italy. Spleen, brain, kidney and fecal samples from red foxes were submitted to bacteriological and/or molecular analyses to detect Salmonella spp., Yersinia spp., Listeria monocytogenes, Brucella spp., Ehrlichia canis, Anaplasma phagocytophilum, Coxiella burnetii, Leptospira spp., Neospora caninum, Hepatozoon canis, Babesia spp. and microsporidia. Two (9.1%) strains of Yersinia enterocolitica biotype 1 and 2 (9.1%) of Yersinia frederiksenii were isolated from 22 fecal samples. Among the 22 spleen samples, seven (31.8%) were PCR-positive for H. canis and 3 (13.6%) for Babesia vulpes. Kidneys from two (2.9%) foxes, among 71 tested, were PCR-positive for L. interrogans. Even though the analyses were carried out on a small number of animals, the results suggested that red foxes from the selected geographic area may act as reservoirs of some investigated pathogens. [ABSTRACT FROM AUTHOR]

This study was done to find exopolysaccharide (EPS)‐producing lactic acid bacteria (LAB) against foodborne pathogens. Isolated LAB were screened to find the ones with the ability to produce antibacterial EPS against foodborne pathogens. Among tested EPSs, EPS of AS20(1) isolate showed inhibitory effects on the growth of Listeria monocytogenes (MIC = 0·935 mg ml−1, MBC = 0·935 mg ml−1), Yersinia enterocolitica (MIC = 12·5 mg ml−1, MBC = 50 mg ml−1) and Bacillus cereus (MIC = 6·25 mg ml−1, MBC = 12·5 mg ml−1). According to 16S rRNA sequencing, AS20(1) showed the closest similarity to Lacticaseibacillus paracasei (100%). This antibacterial EPS showed negligible toxicity (4·4%–5·2%) against red blood cells. Lacticaseibacillus paracasei AS20(1) showed probiotic properties, including high acid resistance, hydrophobicity (47·5%), autoaggregation and coaggregation with foodborne pathogens. Also, L. paracasei AS20(1) showed no haemolysis activity and antibiotic resistance. Characterization of antibacterial EPS revealed that it is a heteropolysaccharide with various functional groups, amorphous structure, and smooth surface, sheet and compact structure, which can be suitable for food packaging. L. paracasei AS20(1) and its antimicrobial EPS can be used to make functional food. [ABSTRACT FROM AUTHOR]

Aims: The purpose of the study was to evaluate the occurrence of Yersinia enterocolitica in different types of wastewater and to characterize the isolates by biotyping, serotyping, and antimicrobial susceptibility testing. In addition, cultivation protocols were evaluated. Methods and Results: The occurrence of Y. enterocolitica was determined in treated and untreated municipal wastewater, as well as in hospital, slaughterhouse, and cowshed wastewater. Y. enterocolitica was detected in 84.1% of the wastewater samples, while the main sources were untreated municipal and slaughterhouse wastewater. In contrast, the lowest incidence was found in hospital wastewater. An exclusive occurrence of biotype 1A (98.3%) was detected. Pathogenic bio‐serotypes 4/O:3 and 3/O:3 were isolated only from slaughterhouse wastewater. The highest resistance rates were observed for ampicillin (92.5%) and amoxicillin‐clavulanic acid (36.8%). Conclusions: Y. enterocolitica was commonly detected in wastewater, although the prevalence varied depending on the origin of the wastewater. No single cultivation protocol was able to recover Y. enterocolitica isolates from such a complex matrix as wastewater. Significance and Impact of the Study: Our study provided data that can contribute to the evaluation of wastewater as a source of Y. enterocolitica and to understanding the threat of wastewater isolates to human health. [ABSTRACT FROM AUTHOR]

In this study, different parts of Phytolacca americana L. (Pokeweed) fruit from Türkiye were investigated for their antioxidant, antibacterial, antibiofilm and anticancer potentials. The radical scavenging activities, reducing power and total phenolic content were determined to appraise of the antioxidant potentials. The antibacterial and antibiofilm activities of the extracts against Enterococcus faecalis, Yersinia enterocolitica, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium were evaluated by using agar-well diffusion, minimum inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) assays. In addition of latening the onset of apoptosis depending on dose, the potential of the anti-proliferative effects was investigated on MDA-MB-231 and MCF-7 cells. The highest free radical scavenging activity and phenolic content were found in the seed extract. Seed extract showed the highest inhibition zones and significant antibacterial activity at 2.5-5 mg/mL MIC concentrations against tested bacterial strains. More significantly, seed extract was found effective on inhibition of early phase biofilm formation at 2.5-10 mg/mL. BIC concentrations against tested bacterial strains. Next, the main mechanisms of cell death of the seed extract in MDA-MB-231 and MCF-7 cells were investigated. Accordingly, when apoptosis was evaluated morphologically, late apoptosis was observed in cells that showed both Hoechst 33342 and Propidium Iodide (PI) positivity in a dose-dependent manner. This study showed that P. americana seed extract can contribute to alternative medicine studies and have potential power in pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Although the use of the probiotic bacterium Lactobacillus for the treatment and prevention of diseases caused by various pathogenic bacteria has received increasing attention in recent years, its mechanism remains incompletely understood. Levilactobacillus brevis 23017 is a select probiotic strain that can regulate the immunity of host animals and resist pathogen infections. In this study, we analyzed the effect of L. brevis 23017 on Yersinia enterocolitica intestinal infection in a BALB/c mouse model and discussed its underlying mechanism. We found that in the mouse model, L. brevis 23017 prevented the damage of villi in the small intestine and decelerated weight loss after Y. enterocolitica infection. Moreover, we focused on the mechanism of the protective effect of L. brevis 23017 from the perspective of the damage and repair of the intestinal mucosal barrier. We observed that L. brevis 23017 maintained a normal mucosal barrier by altering the expression of tight junction proteins. Notably, our results indicated that L. brevis 23017 effectively promoted the secretion of the intestine-specific secretory immunoglobulin A (SIgA) by B cells via regulating cytokines and oxidative damage levels. This mechanism may be the reason for its protective role in Y. enterocolitica infection. In addition, our results demonstrated that the mechanism of L. brevis 23017 was related to antibacterial colonization and inflammation regulation and closely related to antioxidative stress and SIgA promotion. The protective effect of L. brevis 23017 on mice was related to the signaling pathway protein p38 MAPK and the phosphorylation levels of NF-κB. Our study provided novel insight into the mechanism of Lactobacillus against pathogenic bacterial infections. Such insight is of great importance for the prevention, diagnosis, and treatment of related diseases. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica O:3 (YeO3) is considered to be associated with reactive arthritis (ReA), and its lipopolysaccharide (LPS) has been detected in synovial fluids from patients. Interestingly, YeO3 wild-type LPS was processed by host cells, resulting in truncated LPS molecules presenting the core region. Previously, we reported the immunogenicity but not adjuvanticity of YeO3 LPSs of wild (S) type, Ra, Rd, or Re chemotypes in mice. Here, we demonstrate the presence of YeO3 LPS chemotype-specific antibodies in all analyzed synovial fluids (SF) from patients with juvenile idiopathic arthritis (JIA). Interestingly, the high titer of antibodies specific for the Kdo-lipid A region was found in most tested SF. In contrast, only a few were positive for antibodies recognizing O-specific polysaccharides. Western blot analysis revealed the presence of antibodies reacting with fast-migrating LPS fractions and enterobacterial common antigen (ECA) in synovial fluid samples. Our data also suggest the importance of LPS-associated ECA for the antigenicity of endotoxin. Furthermore, we confirmed in vitro that Yersinia LPS processing leads to the exposure of its core region and enhanced potency of complement lectin pathway activation. [ABSTRACT FROM AUTHOR]

Drug repurposing is considered a promising strategy to fight antimicrobial resistance (AMR). Methotrexate (Mtx), a classical anticancer drug, could strongly inhibit bacterial dihydrofolate reductase (DHFR). However, its poor permeability into bacteria and potent human cytotoxicity make it unsuitable as an antibacterial. Herein, we reported the conjugation of Mtx with a siderophore to construct "Trojan horse" antibacterials. The most potent conjugate 8 with nanomolar minimum inhibitory concentration (MIC) values exhibited over 1.00×103‐fold improved activity against Gram‐positive Streptococcus pneumoniae (S. pneumoniae) and Gram‐negative Yersinia enterocolitica (Y. enterocolitica) compared with Mtx, while possessing 2.31×103‐fold reduced human cytotoxicity, resulting in 2.08×106‐fold improvements in the therapeutic index. This proof‐of‐principle study verifies that siderophore conjugation is an effective strategy for developing new antibacterials from anticancer drugs. [ABSTRACT FROM AUTHOR]

In the last decades, the wildlife–human interface has been increasing due to several anthropogenic factors. Therefore, it is crucial to be aware of the impact of these new dynamics on the health of wild animals and their associated zoonotic disease risks. This study aimed to characterize the faecal microbiota of two populations of red deer (Cervus elaphus) by metabarcoding, with a particular focus on potential human and veterinary pathogens, and to perform an assessment of antibiotic resistance genes (ARGs) occurrence. The faecal microbiota of red deer was assessed by metabarcoding using the 16S rRNA marker, and OTUs of the genera Treponema, Yersinia, Clostridium, Mycobacterium, and Rickettsia were identified. Two of them affiliated with species more commonly regarded as pathogens (Clostridium piliforme and Yersinia enterocolitica). The quantification of ARGs was performed by quantitative real‐time PCR, using a metagenomic approach, and the most abundant genes were found to be blaTEM, sul1, tetracycline resistance genes (tetW, tetO, and tetQ) and ermF. From these, tetO and tetW are rank II ARGs, which were recently considered future threats for human health. Our results suggest the need for screening programs for the occurrence of pathogens and ARGs in wildlife and particularly in‐game species. [ABSTRACT FROM AUTHOR]

This study aims to isolate and characterize efficient biohydrogen generating facultative anaerobic bacteria from various samples, viz., biogas plant (BGP), municipal sewage (MS), and dairy industry treatment plant (DTP). The physiochemical properties of various untreated anaerobic sludge samples reflect the anoxic state and appropriateness of the substrate for separating biohydrogen generating bacteria. The biohydrogen producing bacterial strains were separated from methanogens using the heat-treatment method. The facultative anaerobic bacterial load of heat-treated test samples was determined viz., 27.2±0.57×106 (BGP), 21.8±0.43×106 (MS), and 18.6±0.92×106 (DTP) CFU mL-1 (Colony forming unit), which decreased from the total anaerobic bacterial load of untreated anaerobic sludge viz., 32.1±0.28×106 (BGP), 42.2±0.16×106 (MS), and 34.7±0.12×106 (DTP) CFU mL-1. The 28 predominant bacterial isolates strains were isolated from the heat-treated test samples. All 28 bacterial strains were identified using microscopic and biochemical techniques. Biohydrogen producing potential bacterial strains were screened using the Hungate technique with glucose as a carbon source. Among them, 12 strains were capable of producing biohydrogen, among these 5 strains being excellent biohydrogen producers. Based on the16s rRNA molecular sequencing, the 5 selected biohydrogen generating organisms were authenticated as viz., Salmonella bongori (MZ636759), Escherichia coli (MZ636716), Staphylococcus hominis (MZ636713), Yersinia enterocolitica (OM009292), and Shewanella oneidensis (MZ636800). The gas composition study by GC-TCD in a fermentative medium shows that Shewanella oneidensis (MZ636800) could produce the best biohydrogen (111.4±8.3 mLH 2/L), followed by Salmonella bongori (MZ636759) with 98.1±2.9 mL H2/L and Escherichia coli (MZ636716) with 86.7±6.2 mLH 2/L. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica has clinical significance due to its etiological role in yersiniosis and gastroenteritis. This study was designed to assess anti-bacterial and anti-biofilm effects of equol on Y. enterocolitica via phenotypic and genetic analyses. To determine its anti-bacterial activity, minimum inhibitory concentrations (MICs) of equol against clinically isolated Y. enterocolitica strains were analyzed. Subsequently, it was confirmed that the sub-MIC90 value of equol could inhibit biofilm formation and reduce preformed biofilm. Furthermore, it was found that equol could reduce the expression of biofilm-related (hmsT) gene in Y. enterocolitica. This study also demonstrated that equol not only reduced levels of bacterial motility, but also decreased the expression of a motility-related (flhDC) gene in Y. enterocolitica. XTT [2,3-bis (2-metoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction analysis revealed that equol attenuated cellular metabolic activities in Y. enterocolitica biofilm. Additionally, changes in biomass and cell density in equol-treated biofilms were visualized using a confocal laser scanning microscope. In conclusion, this study suggests that equol is a potential anti-bacterial and anti-biofilm agent to treat Y. enterocolitica. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica is one of the intestinal pathogens that are transferred to human through water and food, especially infected meat. Food contamination with this bacterium causes diarrhea, vomiting, stomach pain, appendicitis syndrome, like fever and septicemia. This study aimed study the red meat supplied in Shiraz for Yersinia enterocolitica contamination. In this study, 200 samples of meat supplied in Shiraz were prepared, and were classified based on packaging and non-packaging, storage method and retention time of cart and were investigated for Yersinia enterocolitica contamination. Samples were transferred to PBS enriched environment containing sorbitol sugar and bile salts. These samples were stored in a refrigerator at 4°C for three weeks and then cultured on selected culture medium of Yersinia enterocolitica. Then, microbiological and biochemical subtraction tests were performed on samples. According to study, 13% of the collect meat samples (26 samples) was infected with Yersinia enterocolitica. The results showed no significant difference in the frequency of contamination among different groups of the samples. The studies show that a significant amount of red meat can be contaminated with bacteria when meat foods are not heated enough during cooking, and subsequent storage in the refrigerator provides the opportunity to amplification of this bacterium. Moreover, due to the lack of apparent signs of spoilage, this bacterium causes gastroenteritis and other gastrointestinal complications in consumers.

Antimicrobial resistance is a threat to public health. Fresh foods, especially ready-to-eat (RTE) products, can serve as vehicle for resistance dissemination if eaten directly without further processing by the consumer. This study investigated the presence of Enterobacterales resistant to clinically relevant antibiotics in RTE products acquired from 3 Portuguese supermarkets. Food samples (n = 42) were processed and plated in selective medium, followed by the identification of the isolates as well as the determination of the antibiotic resistance profile. Environmental bacteria resistant to beta-lactams and colistin were detected. Furthermore, the detection of Yersinia enterocolitica and Klebsiella oxytoca isolates was of special relevance. [ABSTRACT FROM AUTHOR]

The iron-regulatory hormone hepcidin is induced early in infection, causing iron sequestration in macrophages and decreased plasma iron; this is proposed to limit the replication of extracellular microbes, but could also promote infection with macrophage-tropic pathogens. The mechanisms by which hepcidin and hypoferremia modulate host defense, and the spectrum of microbes affected, are poorly understood. Using mouse models, we show that hepcidin was selectively protective against siderophilic extracellular pathogens (Yersinia enterocolitica O9) by controlling non-transferrin-bound iron (NTBI) rather than iron-transferrin concentration. NTBI promoted the rapid growth of siderophilic but not nonsiderophilic bacteria in mice with either genetic or iatrogenic iron overload and in human plasma. Hepcidin or iron loading did not affect other key components of innate immunity, did not indiscriminately promote intracellular infections (Mycobacterium tuberculosis), and had no effect on extracellular nonsiderophilic Y enterocolitica O8 or Staphylococcus aureus Hepcidin analogs may be useful for treatment of siderophilic infections.

Yersinia enterocolitica infections impose a significant public health and socioeconomic burden on human population in many countries. The current study investigated the prevalence, antimicrobial resistance profile and molecular diversity of Y. enterocolitica in meat and meat products across various retail outlets in selected provinces of South Africa (SA). In a cross-sectional study, a total of 581 retail meat and meat products were collected from four cities across three provinces of SA. Samples were from beef and pork products, which included 292 raw intact, 167 raw processed, and 122 ready-to-eat (RTE) meats. Samples were analysed using classical microbiological methods for isolation, identification and biotyping of Y. enterocolitica. Conventional polymerase chain reaction (PCR) was performed for confirmation, serotyping, screening of virulence (n = 11) and antimicrobial resistance (n = 18) genes. Phenotypic antimicrobial resistance profiles were determined against 12 antibiotics discs, using disc diffusion method. The overall prevalence of 12% (70/581) was reported across all cities with contamination proportion reported in samples collected from raw intact 15% (43/292), followed by raw processed 11% (18/167) and RTE meats 7% (9/122). All positive isolates were of biotype 1A with 7% (5/70) belonging to bioserotype 1A/O:8. Most of the isolates harboured ymoA, ystB, fepD, ail, fepA, invA and myfA virulence genes. High antimicrobial resistance frequency was observed for ampicillin (94%), cephalothin (83%) and amoxicillin (41%), respectively. Of the 18 tested antimicrobial resistance genes, blaTEM was the most predominant (40%) followed by cmlA (21%). This study reveals the presence of antimicrobial resistant Y. enterocolitica possessing virulent genes of public health importance in products of animal origin, therefore, health monitoring and surveillance of this pathogen is required.

Brazil has the greatest plant diversity in the world. Many species exhibit a wide range of phytochemical compounds which can be exploited in food, agronomic, pharmacological and medicinal plant industries. Therefore, the chemical composition and in vitro bioactivities of volatile oil from Psidium firmum fresh leaves (PfVO) were investigated for the first time. GC-FID and GC-MS analyses revealed 28 compounds in PfVO. The major ones were α-selinene (20.8%), β-caryophyllene (16.5%) and nerolidol (10.4%). Results showed that PfVO affected the growth of Leishmania amazonensis promastigote forms in a dose-dependent manner; its IC50 value was 14.05 µg/mL. PfVO also exhibited antibacterial activity against Salmonella enteritidis, Yersinia enterocolitica, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes; MIC values ranged from 25 μg/mL to 250 μg/mL. Moreover, PfVO promoted normal cell growth inhibition at 61.02 ± 1.97 µg/mL. Antiproliferative activity was observed against human tumor cell lines; IC50 values of MCF-7 cells, HeLa cells and M059J cells were 47.91 µg/mL, 73.78 µg/mL and 41.94 µg/mL, respectively. Results provided strong evidence of the promising potential of PfVO as a nature-based antileishmanial, antibacterial and antiproliferative agent.

Abstract Background We report an unusual case of infective colitis by Yersinia enterocolitica complicated by microliver abscesses mimicking multiple liver metastases in a 79 yr old female without any risk factors for bacteriaemia by this pathogen. Case presentation The patient was admitted to the Internal Medicine with Stroke Care ward of University Policlinico “P. Giaccone” in Palermo because of the appearance of diarrhoea. After the antimicrobial treatment for infective colitis, the clinicians observed a persistently increased white blood cells (WBC) count and multiple hepatic lesions; after having excluded any neoplastic disease and inflammatory bowel disease (IBD), blood cultures positive for Y. enterocolitica allowed to establish the final diagnosis was infective micro liver abscesses consequent to infective colitis due to Y. enterocolitica, which were successfully treated with cefixime and doxycycline. Conclusions This case report should make clinicians reflect on how complex the differential diagnosis between microliver abscesses and metastasis could be and the possibility of bacteriaemia by Y. enterocolitica even without iron overload conditions.

To date, Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis are the three Yersinia species generally agreed to be pathogenic in humans. However, there are a limited number of studies that suggest some of the “non-pathogenic” Yersinia species may also cause infections. For instance, Yersinia frederiksenii used to be known as an atypical Y. enterocolitica strain until rhamnose biochemical testing was found to distinguish between these two species in the 1980s. From our regional microbiology laboratory records of 18 hospitals in Eastern Ontario, Canada from 1 May 2018 to 1 May 2021, we identified two patients with Y. frederiksenii isolates in their stool cultures, along with their clinical presentation and antimicrobial management. Both patients presented with diarrhea, abdominal pain, and vomiting for 5 days before presentation to hospital. One patient received a 10-day course of sulfamethoxazole-trimethoprim; his Y. frederiksenii isolate was shown to be susceptible to amoxicillin-clavulanate, ceftriaxone, ciprofloxacin, and sulfamethoxazole-trimethoprim, but resistant to ampicillin. The other patient was sent home from the emergency department and did not require antimicrobials and additional medical attention. This case series illustrated that diarrheal disease could be associated with Y. frederiksenii; the need for antimicrobial treatment should be determined on a case-by-case basis.

[Display omitted] • Detection of Yersinia enterocolitica in bivalve mollusks by a reference test (ISO 10273:2017). • Validation "in house" of the molecular method employed to detect pathogenic Yersinia enterocolitica in bivalve mollusks. • Detection of Yersinia enterocolitica in real samples of bivalve mollusks. Yersinia enterocolitica (Ye) is a foodborne pathogen isolated from humans, food, animals, and the environment. Yersiniosis is the third most frequently reported foodborne zoonosis in the European Union. Ye species are divided into six biotypes 1A, 1B, 2, 3, 4, and 5, based on biochemical reactions and about 70 serotypes. Biotype 1A is non-pathogenic, 1B is highly pathogenic, and biotypes 2–5 have moderate or low pathogenicity. The reference analysis method for detecting pathogenic Ye species underestimates the presence of the pathogen due to similarities between Yersinia enterocolitica -like species and other Yersiniaceae and/or Enterobacteriaceae , low concentrations of distribution pathogenic strains and the heterogeneity of Yersinia enterocolitica species. In this study, the real-time PCR method ISO/TS 18867 to identify pathogenic biovars of Ye in bivalve molluscs was validated. The sensitivity, specificity and accuracy of the molecular method were evaluated using molluscs experimentally contaminated. The results fully agree with those obtained with the ISO 10273 method. Finally, we evaluated the presence of Ye in seventy commercial samples of bivalve molluscs collected in the Gulf of Naples using ISO/TS 18867. Only one sample tested resulted positive for the ail gene, which is considered the target gene for detection of pathogenic Ye according to ISO/TS 18867. Additionally, the presence of the ystB gene, used as target for Ye biotype 1A, was assessed in all samples using a real-time PCR SYBR Green platform. The results showed amplification ystB gene aim two samples. [ABSTRACT FROM AUTHOR]

We aimed to characterise Yersinia enterocolitica from human clinical specimens in Switzerland using epidemiological, microbiological and whole-genome sequencing (WGS) data. 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. 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 Tn 2670 -like transposon containing catA1 , aadA12, sul1, and qacE Δ1 (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. 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. • Whole genome sequencing proved a powerful tool to subtype Yersinia enterocolitica. • Y. enterocolitica BT 1A strains were genetically highly diverse. • Y. enterocolitica BT 2/O:3 strains were all ST12 and clustered closely. • Y. enterocolitica BT 4/O:3 strains mostly belonged to ST18 but were more diverse. • Two highly clonal BT 4/O:3 subpopulations had wide spatio-temporal distribution. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica is a human pathogen transmitted via the faecal–oral route among animals and humans and is a major foodborne public health hazard. This study explores the role of Y. enterocolitica transmission at the livestock–wildlife interface and investigates the potential role wild and peridomestic rodents play as a source of this zoonotic pathogen. The total of 342 faecal samples collected from the seven rodent species and one insectivore was examined using an optimized protocol to culture and identify Y. enterocolitica. Positive samples were also bioserotyped for grouping and determination of sample pathogenicity. Wildlife species sampled in this study were separated into two sample groups: randomly sampled (brown rats, house mice, wood mice, bank voles, field voles and the common shrew), as well as targeted sampling (red and grey squirrels). The overall prevalence of Y. enterocolitica in the randomly sampled population was 3.73%. Brown rats were chosen as sentinel species and tested to determine if location (pig farm vs non‐pig farm) was a significant factor affecting Y. enterocolitica prevalence. In this study, location was not significant. All positive samples were found to be of biotype 1A, deemed non‐pathogenic. Three of the samples were serotype 09, six were serotype 27 and five had an unidentifiable serotype. This study represents the first time Y. enterocolitica has been identified in these species of wildlife within mainland Britain. In addition, this study's findings are entirely novel and overall with regard to field voles and common shrews. However, the role of wild and peridomestic rodents in the transmission of pathogenic Y. enterocolitica remains unknown, as this study was unable to detect the presence of pathogenic Y. enterocolitica strains in these species. [ABSTRACT FROM AUTHOR]

The study assessed microbial safety and polycyclic aromatic hydrocarbon concentrations (PAHs) of intermediate moisture smoked African giant snail (Achatina achatina) meat. Snail samples were smoked after treatments with 25% glycerol, 0.5% potassium sorbate and 3% NaCl. One hundred (100) smoked snail samples were used for the analysis. Four (4) samples were used for preliminary analysis with one sample for each infusion method. The 96 remaining samples were divided into four (4) groups of 24 samples per group based on the four infusion methods and each group was divided into six (6) batches of four (4) samples. Microbiological analyses were carried out on the smoked snail samples to determine the presence of pathogenic bacteria, Campylobacter jejuni (CJ), Listeria monocytogenes (LM), Mycobacterium tuberculosis (MT), Salmonella spp. (SP), Escherichia coli (EC), and Yersinia enterocolitica (YE) using standard methods and PAH concentrations were determined by using Gas Chromatography-Mass Spectrophotometric method. The results showed that there was presence LM, EC, and YE from the smoked snail samples. The sixteen different PAHs: Naphthalene (Nap), Acenaphthylene (Acp), Acenaphthene (Acn), 1,2-Benzanthracene, (1,2 BAnt), fluorene (Flu), Pyrene (Pyr), phenanthrene (Phe), anthracene (Ant), fluoranthene (Flr), benz [a] anthracene (B[a]A), chrysene (Chr), benzo [b] fluoranthene (B[b]F), benzo [k] fluoranthene (B[k]F), benzo [a] pyrene (B[a]P), Dibenzo[a,h]anthracene (DB[a,h]A) and benzo [ghi] perylene (B[ghi]P) were detected. The PAHs concentrations in the samples were very high and above maximum permissible level of 2.0 µg/kg for BaP. The concentrations of PAH4; 4PAHs (B[a]P + Chr + B[b]F + B[a]A) in all the samples despite curing were high and greater than the maximum acceptable level of 12 µg/kg stipulated by European Commission Regulation (EU) No 835/2011 of 19 August 2011 for B[a]P in grilled or smoked meat products. [ABSTRACT FROM AUTHOR]

Phage vB_YenS_P400 isolated from deer, is a virulent siphovirus of Y. enterocolitica, whose circularly permutated genome (46,585 bp) is not substantially related to any other phage deposited in public nucleotide databases. vB_YenS_P400 showed a very narrow host range and exclusively lysed two Y. enterocolitica B4/O:3 strains. Moreover, lytic activity by this phage was only discernible at room temperature. Together with the finding that vB_YenS_P400 revealed a long latent period (90 to 100 min) and low burst size (five to ten), it is not suitable for applications but provides insight into the diversity of Yersinia phages. [ABSTRACT FROM AUTHOR]

We investigated the prevalence of Campylobacter jejuni, Campylobacter coli, Salmonella, en-terohemorrhagic Escherichia coli, enterotoxigenic Escherichia coli, Yersinia enterocolitica, and Escherichia albertii in domestic chicken and pork sold at retail stores in Saitama Prefecture, Japan. Campylobacter was detected in 35.7% (60/168)of chicken samples and 7.3% (14/190)of pork samples. C. jejuni and C. coli were predominant in chicken and pork, respectively. Salmonella was found in 58.1% (100/172)of chicken samples and 19.9% (41/206)of pork samples. Moreover, Salmonella Schwarzengrund was the major serovar observed in chicken isolates, whereas S. Ty-phimurium monophasic variant was in pork isolates. Furthermore, ETEC was found in 0.6% (1/160)of chicken samples and 2.4% (5/206)of pork samples. Y. enterocolitica was absent from all (83/83)chicken samples but was present in 9.3% (18/193)of pork samples, with a prevalence in pork tongues as high as 21.0% (13/62 samples). However, EHEC and E. albertii were not detected in our study. Therefore, the results of this study indicate that chicken was highly contaminated with Campylobacter sp. and Salmonella, and pork was with Y. enterocolitica serotype o3, Campylobacter sp., Salmonella, and ETEC. [ABSTRACT FROM AUTHOR]

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New point-of-care (POC) diagnosis of bacterial infections are imperative to overcome the deficiencies of conventional methods, such as culture and molecular methods. In this study, we identified new aptamers that bind to the virulence factor Yersinia adhesin A (YadA) of Yersinia enterocolitica using cell-systematic evolution of ligands by exponential enrichment (cell-SELEX). Escherichia coli expressing YadA on the cell surface was used as a target cell. After eight cycles of selection, the final aptamer pool was sequenced by high throughput sequencing using the Illumina Novaseq platform. The sequencing data, analyzed using the Geneious software, was aligned, filtered and demultiplexed to obtain the key nucleotides possibly involved in the target binding. The most promising aptamer candidate, Apt1, bound specifically to YadA with a dissociation constant (Kd) of 11 nM. Apt1 was used to develop a simple electrochemical biosensor with a two-step, label-free design towards the detection of YadA. The sensor surface modifications and its ability to bind successfully and stably to YadA were confirmed by cyclic voltammetry, impedance spectroscopy and square wave voltammetry. The biosensor enabled the detection of YadA in a linear range between 7.0 × 104 and 7.0 × 107 CFU mL−1 and showed a square correlation coefficient >0.99. The standard deviation and the limit of detection was ~2.5% and 7.0 × 104 CFU mL−1, respectively. Overall, the results suggest that this novel biosensor incorporating Apt1 can potentially be used as a sensitive POC detection system to aid the diagnosis of Y. enterocolitica infections. Furthermore, this simple yet innovative approach could be replicated to select aptamers for other (bacterial) targets and to develop the corresponding biosensors for their detection. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the antimicrobial potential of different extracts of Simira ecuadorensis, a characteristic plant of Ecuador, and to validate its potential as a food preservative. Four extracts referred to as ethanol, ethanol-water (50:50 v/v), spray-dried, and freeze-dried were obtained under different processes. Initially, their antimicrobial activities were evaluated against a wide group of microorganisms consisting of 20 pathogenic and spoilage microbial strains found in foods through the agar diffusion method. Then, the extracts with the best yields and antimicrobial properties against microorganisms of greatest interest were selected to determine their effect on model foods preserved under normal commercial conditions through challenge tests. Spray-dried and ethanol-water extracts were tested for their ability to inhibit C. jejuni in chicken model products, where is a common pathogen and Shew. putrefaciens in fish model products as it is a spoilage microorganism frequently found in fish. One solid and one liquid were chosen as model foods: burger and broth, respectively. Campylobacter jejuni and Shewanella putrefaciens were effectively inhibited by the four extracts with minimum inhibitory concentration (MIC) of 80 mg/mL. Bacillus cereus, Yersinia enterocolitica, Clostridium perfringens, and Leuconostoc mesenteroides were also inhibited by ethanolic extract. The ethanol-water extract showed greater antimicrobial activity in fish products, whereas spray-dried extract had low growth inhibition of C. jejuni in chicken burgers; however, it was quite effective on C. jejuni in broth. The spray-dried extract significantly decreased the pH of the chicken burgers, while the ethanolic extract had a slight impact on the pH of the fish burgers. The presence of antibacterial effects revealed that the S. ecuadorensis extracts could be potentially used in food preservation and as a natural antimicrobial. [ABSTRACT FROM AUTHOR]

Focusing on resistance trends and transmission patterns of pathogenic microorganisms is a major priority for national surveillance programs. The use of whole-genome sequencing for antimicrobial susceptibility testing (WGS-AST) is a powerful alternative to traditional microbiology laboratory methods. Yersinia enterocolitica antimicrobial resistance (AMR) in the Ningxia Hui Autonomous Region has yet to be described thoroughly in current studies. We assessed and monitored the development of Y. enterocolitica AMR in the Ningxia Hui Autonomous Region during 2007-2019 based on WGS-AST. Resistance genotypes were predicted based on WGS. Antimicrobial resistance testing using classical microbiology determined resistance to 13 antimicrobial agents in 189 Y. enterocolitica isolates from Ningxia. The highest resistance level was 97.88% for cefazolin, followed by ampicillin (AMP) (44.97%), ciprofloxacin (CIP) (25.40%), streptomycin (STR) (11.11%), and tetracycline (TET) (10.58%). Isolates emerged as chloramphenicol (CHL) and trimethoprim/sulfamethoxazole (SXT) resistant. The primary plasmid types were IncFII(Y) and ColRNAI. The TET, STR, and SXT resistance were mediated by the tetA, aph(6)-Id, aph(30 0)-Ib, and sul2 genes located on the IncQ1 plasmid. The resistant strains were predominantly biotype 4/O:3/ST429 and the hosts were pigs and patients. The number of multidrug-resistant (MDR) strains was of concern, at 27.51%. At present, the prediction of antimicrobial resistance based on WGS requires a combination of phenotypes. From 2007 to 2019, Y. enterocolitica isolates from the Ningxia Hui Autonomous Region showed a relatively high rate of resistance to cefazolin (CZO) and some resistance to AMP, CIP, STR, and TET. CIP, SXT, and TET showed a relatively clear trend of increasing resistance. Plasmids carrying multiple drug resistance genes are an important mechanism for the spread of antimicrobial resistance. Isolates with low pathogenicity were more likely to present an AMR phenotype than non-pathogenic isolates. [ABSTRACT FROM AUTHOR]

Yersinia enterocolitica is a dangerous foodborne human pathogen that mainly causes gastroenteritis. Ideal methods for the detection of pathogens in food should be rapid, sensitive, specific, and cost effective. To this end, novel in vitro nucleic acid identification methods based on clustered, regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) endonuclease have received increasing attention. In this study, a simple, visual, and ultrasensitive method, based on CRISPR/Cas12a with recombinase polymerase amplification (RPA), was developed for the detection of Y. enterocolitica. The results show that a specific attachment invasion locus gene (ail) can be rapidly detected using a CRISPR/Cas12a-RPA-based system. Application of the method to raw pork, which was artificially infected with Y. enterocolitica, achieved an estimated detection limit of 1.7 CFU/mL in less than 45 min, and this was 100 times lower compared with qPCR. The results indicated that the CRISPR/Cas12a-RPA system has good potential for monitoring pathogenic Y. enterocolitica in the chilled meat supply chain. [ABSTRACT FROM AUTHOR]

Several honeybee products are known for their functional properties, including important antioxidant and antimicrobial actions. The present study examines the antioxidant activity (AA), total polyphenolic content (TPC), and antibacterial action of honey and propolis samples collected from the Greek island of Samothrace, which were applied in vitro either individually or in combination in selected concentrations. To accomplish this, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the Folin–Ciocalteu assays were employed to determine the AA and TPC, respectively, while the antibacterial action was investigated against each one of four important pathogenic bacterial species causing foodborne diseases (i.e., Salmonella enterica, Yersinia enterocolitica, Staphylococcus aureus, and Listeria monocytogenes) using the agar well diffusion assay. Compared to honey, propolis presented significantly higher AA and TPC, while its combined application with honey (at ratios of 1:1, 3:1, and 1:3) did not increase these values. Concerning the antibacterial action, Y. enterocolitica was proven to be the most resistant of all the tested bacteria, with none of the samples being able to inhibit its growth. S. enterica was susceptible only to the honey samples, whereas L. monocytogenes only to the propolis samples. The growth of S. aureus was inhibited by both honey and propolis, with honey samples presenting significantly higher efficacy than those of propolis. Νo synergism in the antibacterial actions was observed against any of the tested pathogens. Results obtained increase our knowledge of some of the medicinal properties of honey and propolis and may contribute to their further exploitation for health promotion and/or food-related applications (e.g., as preservatives to delay the growth of pathogenic bacteria). [ABSTRACT FROM AUTHOR]

Yersiniosis is the third most reported food-borne zoonosis in Europe. The aim of the present study was to perform the search for Yersinia enterocolitica in food samples collected from Apulia and Basilicata regions (Southern Italy) and to characterize any isolates by classical and modern analytical methods. A total of 130 samples were analyzed between July 2018 and July 2019: most of them were raw milk and dairy products made from it. Furthermore, 8 out of 130 samples were individual milk samples collected from bovines reared in a Brucella-free farm which showed false positive serological reaction for brucellosis due to the presence of pathogenic Y. enterocolitica O:9 biotype 2 in faeces. The Real Time PCR targeting the ail gene and the culture method were performed to detect pathogenic Y. enterocolitica. Isolates were subjected to API 20E (Biomerieux) and MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time-of-Flight) for species identification. All samples were negative for the ail gene. The culture method allowed to isolate suspicious colonies from 28 samples. The API 20E system and the MALDI-TOF MS technique identified 20 Y. enterocolitica and 1 Y. intermedia in a concordant way. The remaining 7 strains were all identified as Y. enterocolitica by the API 20E system, while the MALDI-TOF MS recognized 4 Y. intermedia, 1 Y. bercovieri and 2 Y. massiliensis. Genotypic characterization of the discordant strains was performed by rMLST and it confirmed the MALDI-TOF MS' results. Only non-pathogenic Y. enterocolitica biotype 1A strains were found, although with a non-negligible prevalence (P = 0.15 with CI 95% = ± 0.06). This study indicates a poor circulation of pathogenic Y. enterocolitica in food products made and marketed in the investigated areas. However, the small number of samples, insufficient for some food categories such as meat and vegetable, does not allow to exclude the presence of pathogenic strains at all. [ABSTRACT FROM AUTHOR]

The effects of sumac, cumin, black pepper and red pepper diethyl ether extracts on the growth of eight foodborne pathogens (FBP) and their biogenic amine (BA) production were investigated in histidine decarboxylase broth. The antimicrobial effect was determined by the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations. Sumac extract showed the highest antimicrobial activity against FBP. Enterococcus faecalis and Aeromonas hydrophila were the most susceptible strains to sumac extract. The MBC of spice extracts on the FBP was generally above 50 mg/mL. Cumin extract was the most effective in decreasing bacterial loads, inhibiting significantly the microbial growth of Staphylococcus aureus, Pseudomonas aeruginosa, Campylobacter jejuni and A. hydrophila. Histamine production ranged from 0.14 (Yersinia enterocolitica) to 39.29 mg/L (S. aureus). Cumin extract significantly inhibited the histamine formation by S. aureus and Salmonella paratyphi A. Black and red pepper extracts promoted the histamine formation by most of FBP under scrutiny. Red pepper extract generally increased formation of BA, while sumac and cumin extracts proved to be the most effective antimicrobials and BA formation inhibitors. This research study allowed to conclude that sumac and cumin extracts can be used as natural preservatives in the agro-food industry. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a multiplex bead assay using a Brucella rLPS antigen, a Brucella suis smooth antigen, and a Yersinia enterocolitica O:9 antigen that not only discriminates Brucella-infected from Brucella-uninfected pigs and wild boar, but also overcomes the cross reactivity with Y. enterocolitica O:9. Sera from 126 domestic pigs were tested: 29 pigs were Brucella infected, 80 were non-infected and 17 were confirmed to be false positive serological reactors (FPSR). Sera from 49 wild boar were tested: 18 were positive and 31 were negative. Using the rLPS antigen, 26/29 Brucella-infected domestic pigs and 15/18 seropositive wild boar were positive, while 75/80 non-Brucella infected domestic pigs, all FPSR, and all seronegative wild boar were negative. Using the smooth B. suis 1330 antigen, all Brucella-infected domestic pigs, 9/17 FPSR and all seropositive wild boar were positive, while all non-infected pigs and 30/31 seronegative wild boar were negative. The ratio of the readouts from the smooth B. suis antigen and Y. enterocolitica O:9 antigen enabled discriminating all Brucella infected individuals from the FPSR domestic pigs. These results demonstrate the potential of this assay for use in the surveillance of brucellosis, overcoming the cross-reactivity with Y. enterocolitica. [ABSTRACT FROM AUTHOR]