Molecular characterization of Yersinia enterocolitica strains to evaluate virulence associated genes

Introduction. Yersinia enterocolitica (Ye) species is divided into 6 biotypes (BT), 1A, 1B, 2, 3, 4, 5 classified based on biochemical reactions and about 70 serotypes, classified based on the structure of the lipopolysaccharide O-antigen. The BT1A is considered non-pathogenic, while the BT 1B-5 are considered pathogenic. Methods. Evaluate the distribution of eleven chromosomal and plasmid virulence genes, ail, ystA, ystB, myfA, hreP, fes, fepD, ymoA, sat, virF and yadA, in 87 Ye strains isolated from food, animals and humans, using two SYBR Green real-time PCR platforms. Results. The main results showed the presence of the ail and ystA genes in all the pathogenic bioserotypes analyzed. The ystB, on the other hand, was identified in all non-pathogenic strains biotype 1A. The target fes, fepD, sat and hreP were found in both pathogenic biotypes and in BT1A strains. The myfA gene was found in all pathogenic biotype and in some Ye BT1A strains. The virF and yadA plasmid genes were mainly detected in bioserotype 4/O:3 and 2/O:9, while ymoA was identified in all strains. Conclusions. The two molecular platforms could be used to better define some specific molecular targets for the characterization and rapid detection of Ye in different sources which important implications for food safety and animal and human health

Diabetic mouse angiopathy is linked to progressive sympathetic receptor deletion coupled to an enhanced caveolin-1 expression.

OBJECTIVE: Clinical studies have demonstrated that hyperglycaemia represents a major risk factor in the development of the endothelial impairment in diabetes, which is the first step in vascular dysfunction. Using non-obese diabetic mice, we have evaluated the role of the adrenergic system and eNOS on progression of the disease METHODS AND RESULTS: When glycosuria is high (20 to 500 mg/dL), there is a selective reduction in the response to alpha1 and beta2 agonists but not to dopamine or serotonin. When glycosuria is severe (500 to 1000 mg/dL), there is a complete ablation of the contracture response to the alpha1 receptor agonist stimulation and a marked reduced response to beta2 agonist stimulation. This effect is coupled with a reduced expression of alpha1 and beta2 receptors, which is caused by an inhibition at transcriptional level as demonstrated by RT-PCR. In the severe glycosuria (500 to 1000 mg/dL), although eNOS expression is unchanged, caveolin-1 expression is significantly enhanced, indicating that high glucose plasma levels cause an upregulation of the eNOS endogenous inhibitory tone. These latter results correlate with functional data showing that in severe glycosuria, there is a significant reduction in acetylcholine-induced vasodilatation. CONCLUSIONS: Our results show that in diabetes development, there is a progressive selective downregulation of the alpha1 and beta2 receptors. At the same time, there is an increased expression of caveolin-1, the endogenous eNOS inhibitory protein. Thus, caveolin-1 could represent a new possible therapeutic target in vascular impairment associated with diabetes

Role of verocytotoxigenic Escherichia coli in the swine production chain

Shiga toxin-producing Escherichia coli (STEC) can cause severe clinical diseases in humans, such as haemorrhagic colitis (HC) and haemolytic-uremic syndrome (HUS). Although ruminants, primarily cattle, have been suggested as typical reservoirs of STEC, many food products of other origins, including pork products, have been confirmed as vehicles for STEC transmission. Only in rare cases, pork consumption is associated with severe clinical symptoms caused by high pathogenic STEC strains. However, in these outbreaks, it is unknown whether the contamination of food products occurs during swine processing or via cross-contamination from foodstuffs of different sources. In swine, STEC plays an important role in the pathogenesis of oedema disease. In particular a Shiga toxin subtype, named stx2e, it is considered as a key factor involved in the damage of swine endothelial cells. On the contrary, stx2e-producing Escherichia coli has rarely been isolated in humans, and usually only from asymptomatic carriers or from patients with mild symptoms, such as uncomplicated diarrhoea. In fact, the presence of gene stx2e, encoding for stx2e, has rarely been reported in STEC strains that cause HUS. Moreover, stx2e-producing STEC isolated from humans and pigs were found to differ in serogroup, their virulence profile and interaction with intestinal epithelial cells. Because of the limited epidemiologic data of STEC in swine and the increasing role of non-O157 STEC in human illnesses, the relationship between swine STEC and human disease needs to be further investigated

Prevalence and characteristics of verotoxigenic Escherichia coli strains isolated from pigs and pork products in Umbria and Marche regions of Italy

AbstractIn total 1095 samples from 675 pork products, 210 swine colon contents, and 210 swine carcass sponge swabs were collected in Umbria and Marche regions of Italy and examined for the presence of Shiga toxin-producing Escherichia coli (STEC), also known as Verotoxin-producing E. coli (VTEC). After an enrichment step, each sample was analysed by real-time PCR to detect the stx1, stx2, and eae genes. stx-Positive samples were further tested for the “top five” serogroup markers (O157, O26, O103, O111, O145) and cultured onto selective media. The isolates were assigned to stx subtypes and tested for the presence of aaiC and aggR genes. Out of 420 swine samples, 38.6% faecal samples and 13.8% carcass sponge swabs were stx-positive. In total, 33 E. coli STEC isolates were obtained from 30 samples (4 carcasses and 26 colon contents) indicating a culture-positive rate of 7.1%. A higher culture-positive rate was observed in faecal samples (12.4%) than in carcass sponge swabs (1.9%). Out of 675 pork samples, 19 (2.8%) were stx-positive. No STEC strains were isolated from stx-positive pork products. We concluded that STEC isolation from foodstuffs remains difficult, despite the application of ISO/TS 13136:2012. Furthermore, in accordance with the results of studies conducted in other countries, we observed that most of swine STEC strains carried stx2e gene and lacked of virulence genes, such as eae, aaiC and aggR, indicative of potential pathogenic characteristics for humans. Although the majority of STEC isolates did not express virulence factors correlating with severe human diseases, the association between swine STEC strains and human illness requires further investigations

Prevalence, Molecular Characterization and Antimicrobial Susceptibility of Clostridioides difficile Isolated from Pig Carcasses and Pork Products in Central Italy

In the last decade, the incidence and severity of Clostridioides difficile infections (CDIs) in humans have been increasing and community-associated infections have been described. For these reasons, the interest in C. difficile in food and in food animals has increased, suggesting other possible sources of C. difficile acquisition. This study evaluated the presence of C. difficile on pig carcasses at the slaughterhouse and in pork products in Central Italy. The contamination rate on pig carcasses was 4/179 (2.3%). Regarding food samples, a total of 216 pork products were tested (74 raw meat preparations and 142 ready-to-eat food samples made by cured raw meat). The real-time PCR screening was positive for 1/74 raw meat preparation (1.35%) and for 1/142 ready-to-eat food samples (0.7%) C. difficile was isolated only from the raw meat preparation (pork sausage). All the isolated strains were toxigenic and susceptible to all the tested antibiotics. Strains isolated from carcass samples displayed A+B+CDTa+CDTb+ profile, were toxinotype IV and belonged to the same ribotype arbitrary named TV93, while the one isolated from food samples displayed A+B+CDTa-CDTb- profile and it was not possible to determine ribotype and toxinotype, because it was lost after freeze storage. It was concluded that the prevalence of C. difficile in the pork supply chain is very low

Maedi-visna virus in Turkish sheep: a preliminary serological survey using ELISA tests

The maedi-visna virus (MVV) is distributed worldwide and, to date, no epidemiological surveys have been carried out using ELISA testing in Turkey. The aims of this study were as follows: i) to verify the diagnostic performance of a home-made ELISA test (HM-ELISA) using Turkish ovine sera in comparison with other commercially available ELISA tests, and ii) to perform a preliminary epidemiological survey in Istanbul province. The MVV seroprevalence in Istanbul province was 15.3%. Older sheep were 5 times more likely to be positive than younger animals, ewes were 3 times more likely to be positive than rams, and all the Red Karaman and White Karaman sheep tested were seronegative. The performance of the HM-ELISA and that of the other commercial tests using Turkish ovine serum samples was similar; therefore, the HM-ELISA test is suitable for use in extensive epidemiological surveys and eradication programs in Turkey

Yersinia pseudotuberculosis, serogroup 0:1A, infection in two Amazon parrots (Amazona aestiva and Amazona oratrix) with hepatic hemosiderosis

Abstract: Necropsies were conducted on a female blue-fronted Amazon (Amazona aestiva) and a female yellow-headed Amazon (Amazona oratrix) that died following depression, ruffled feathers, diarrhea and biliverdin in the urine. Gross and microscopic examinations revealed multifocal necrosis in the liver, spleen, lungs, kidney, intestine and heart caused by acute bacteremia. Yersinia pseudotuberculosis, serogroup O:1a, was isolated by culturing from the visceral lesions in the liver, intestine and spleen. Virulence gene analysis showed the presence of the inv gene and the complete pathogenicity island: IS100, psn, yptE, irp1, irp2 ybtP-ybtQ, ybtX-ybtS, int asnT-Int. Histopathologic findings and chemical analysis also demonstrated hepatic hemosiderosis. As has been demonstrated in other species, we suggest that hemosiderosis may also predispose Amazona spp. to systemic infection with Yersinia pseudotuberculosis following enteric disease

Yersinia pseudotuberculosis infection, serogroup O:1a, in two Amazon Parrots (Amazona aestiva – Amazona oratrix ) and its relationship with high iron levels in liver.

Yersinia pseudotuberculosis infection, serogroup O:1a, in two Amazon Parrots (Amazona aestiva – Amazona oratrix ) and its relationship with high iron levels in liver. Livio Galosi1, Silvana Farneti2, Giacomo Rossi1, Susan Cork3, Stefano Ferraro4, Gian Enrico Magi1, Silvia Scarpona1, Stefano Petrini2, Andrea Valiani2, Vincenzo Cuteri1, Anna Rita Attili1 1 Scuola di Bioscienze e Medicina Veterinaria, Polo di Medicina Veterinaria, Università degli Studi di Camerino, Matelica (MC), Italy 2 Istituto Zooprofilattico Sperimentale Umbria e Marche, Perugia, Italy 3 Department of Ecosystem & Public Health, Faculty of Veterinary Medicine, University of Calgary, Alberta, Canada 4 Scuola di Scienze e Tecnologia, Sezione di Chimica, Università degli Studi di Camerino, Camerino (MC), Italy On two died Amazon Parrots (Amazona aestiva and Amazona oratrix) that had shown depressed sensorium, ruffled feathers, biliverdin in the urine and diarrhea, necropsy and bacteriological analysis were carried out. Macroscopic and microscopic examinations revealed multifocal necrosis in liver, spleen, lungs, kidney, gut and heart caused by acute bacteremia. Yersinia pseudotuberculosis, serogroup O:1a, was isolated from the visceral lesions. Virulence gene analysis showed the presence of inv gene and the complete pathogenicity island: IS100, psn, yptE, irp1, irp2 ybtP-ybtQ, ybtX-ybtS, int asnT-Int. Histopathological findings and chemical analysis also reflected an excess of iron accumulation in liver. The relation between iron accumulation and systemic Pseudotuberculosis has been demonstrated in human medicine and in other species of birds. This work highlights also this relationship in Amazon Parrots