Dynamics of bovine intramammary infections due to coagulase-negative staphylococci on four farms

The objectives of this study were to compare the impact of different coagulase-negative species (CNS) on udder health measured in terms of individual quarter milk somatic cell count (SCC) and duration of intramammary infection, and to get some insight into most likely routes of infection for different CNS species. This longitudinal observational study was performed on four farms that were sampled at 4-week intervals for a total of 12 visits each. Quarters infected with CNS were followed through time with milk samples being submitted for bacteriological culture and SCC determination. PCR amplification of the internal transcribed spacer region and sequencing of the sodA and rpoB genes were used for species allocation. Pulsed-field gel electrophoresis (PFGE) was performed to assess strain identity. The percentage of quarters affected per farm varied between 6 and 35%, with the most frequently isolated CNS species being Staphylococcus epidermidis, followed by Staph. simulans, Staph. chromogenes and Staph. haemolyticus. It was possible to follow 111 intramammary infections due to CNS through time. Duration of infection had a mean of 188 d and was not significantly different between CNS species. Geometric mean quarter SCC overall was 132 000 cells/ml and was also not significantly different between CNS species. Despite the possibility of a different epidemiology of infection, the impact in terms of udder health seems to be similar for different CNS species

Enterococcus spp. from Azeitao and Nisa PDO-cheeses: surveillance for antimicrobial drug resistance

Research Areas: Food Science & TechnologyABSTRACT - Enterococcus spp. were isolated from PDO-cheese of Azeitão and Nisa at six cheesemaking units (Azeitão: A1, A2, A3, A4; and Nisa: N9, N10), over four years (2016–2019). Genomic typing was performed using RAPD and distinct enterococci (n = 145) were identified at the species level by multiplex-PCR and evaluated regarding antimicrobial drug resistance (AMR). Antibiotics from nine distinct classes (aminoglycosides, macrolides, oxazolidinones, chloramphenicol, streptogramins, tetracyclines, glycopeptides, β-lactams, and quinolones) were selected for AMR surveillance and breakpoint criteria defined by EUCAST and CLSI were considered and compared. Regarding species allocation, 78 enterococci were identified as E. faecium, 37 confirmed as E. faecalis and 30 as E. durans. High levels of resistance to quinupristin-dalfopristin, tetracycline and teicoplanin were observed. Some resistances to clinically relevant antimicrobials were also detected, including β-lactams, aminoglycosides, and glycopeptides. Two isolates were considered multidrug-resistant, one according to EUCAST and the other to CLSI breakpoint criteria. Overall, considering the absence of reports regarding enterococcalrelated toxinfections or infections resulting from the consumption of PDO-cheeses, traditional foods harbouring these bacteria should be considered safe. However, the possibility of horizontal gene transfer events associated with antibiotic resistance determinants further highlights the importance for AMR surveillance along the food chain.info:eu-repo/semantics/publishedVersio

Antibiotic Resistance and Virulence Factors among Enterococci Isolated from Chourico, a Traditional Portuguese Dry Fermented Sausage

Enterococci are ubiquitous microorganisms, found as part of the normal intestinal microbiota of many animals. They can be present in food products, for example, the Portuguese dry fermented sausage chourico. Twenty enterococci were isolated from chourico in two processing units; after identification and typification by conventional-molecular methods, the isolates were screened for virulence factors and antibiotic resistance. Identification allocated all enterococci to the species Enterococcus faecalis, and PCR fingerprinting demonstrated that each isolate was specific to the processing unit and chourico from which it was recovered. Regarding the screening for virulence factors, I strain produced cytolysin and 4 were gelatinase positive, but none produced lipase. The ace gene was detected in I enterococci, ebpABC and efaA(fs). in 16 isolates each, esp in 3, fsrB in 5, gelE in 7, and cylA in I. A multiresistant phenotype was observed in 8 isolates, 6 belonging to factory A. The antibiotic resistance gene ere(B) was detected in 9 enterococci, whereas the genes tet(M), aac(6')-le-aph(2 ''), and vanA were detected in 8 isolates each. As some of the E. faecalis chourico isolates present a multiresistant profile and harbor virulence and/or resistance genes, to assess further the safety of Portuguese dry sausages, a larger number of products and processing units must by analyzed

Vascular Endothelial Dysfunction in β-Thalassemia Occurs Despite Increased eNOS Expression and Preserved Vascular Smooth Muscle Cell Reactivity to NO

The hereditary β-thalassemia major condition requires regular lifelong blood transfusions. Transfusion-related iron overloading has been associated with the onset of cardiovascular complications, including cardiac dysfunction and vascular anomalies. By using an untransfused murine model of β-thalassemia major, we tested the hypothesis that vascular endothelial dysfunction, alterations of arterial structure and of its mechanical properties would occur despite the absence of treatments.Vascular function and structure were evaluated ex vivo. Compared to the controls, endothelium-dependent vasodilation with acetylcholine was blunted in mesenteric resistance arteries of β-thalassemic mice while the endothelium-independent vasodilator (sodium nitroprusside) produced comparable vessel dilation, indicating endothelial cell impairment with preserved smooth muscle cell reactivity to nitric oxide (NO). While these findings suggest a decrease in NO bioavailability, Western blotting showed heightened expression of aortic endothelial NO synthase (eNOS) in β-thalassemia. Vascular remodeling of the common carotid arteries revealed increased medial elastin content. Under isobaric conditions, the carotid arteries of β-thalassemic mice exhibited decreased wall stress and softening due to structural changes of the vessel wall.A complex vasculopathy was identified in untransfused β-thalassemic mice characterized by altered carotid artery structure and endothelial dysfunction of resistance arterioles, likely attributable to reduced NO bioavailability despite enhanced vascular eNOS expression

Selection of staphylococci strains isolated from a Portuguese traditional fermented/dry sausage for potential use as starter cultures Selection of staphylococci strains isolated from a Portuguese traditional fermented/dry sausage for potential use as star

To cite th is article / Pou r citer cet article -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Abstract. In order to evaluate its potential use as starter cultures, 104 isolates of Staphylococcus spp. were obtained from sausages and different sampling environment points in workshops A and B, at southern region of Portugal. PCR amplification was carried out to confirm genus and species allocation. From workshop A, 47 isolates were staphylococci, the majority belonging to the specie S. equorum, while from workshop B, of the 57 isolates identified as staphylococci, most were S. xilosus. The genetic profiles of isolates were further compared using PCR fingerprinting analysis, guiding to the selection of 43 representative strains subsequently characterized for their nitrate reductase, lipolytic and proteolytic activities. Among these strains, 30% revealed proteolytic ability while 42% had lipolytic activity. 65% of the strains reduced nitrate. Subsequently, 10 strains (representatives of different fingerprinting groups) were evaluated for their ability to grow at different temperatures, pH and NaCl concentrations. S. xylosus and S. equorum showed to growth under all the studied conditions being more effective at 15°C, 20°C and pH 5.5 at 20°C, and NaCl concentrations of 10% and 15%; therefore can be guaranteed their application in technological processes with varying temperatures. In workshop A, strains P05-58 S. carnosus and P05-74 S. equorum and, from workshop B, P06-01 and P06-26 S. xylosus presented the most interesting features. Keywords. Staphylococcus coagulase negative -Fermented meat products -Starter culture -Proteolytic activity -Lipolytic activity -Nitrate reductase activity. Sélection de souches de staphylocoques isolées à partir de produits carnés traditionnels portugai

What is the main processing factor influencing Staphylococcus species diversity in different manufacturing units?

The microbiota of traditional dry-cured sausages and industrial environment was assessed to characterize the diversity of coagulase-negative staphylococci (CNS), and establish potential relationships with hygiene level or technological characteristics. Eight processing units from South Portugal were audited according to a checklist of requirements. Environmental and products’ samples at different production stages were evaluated regarding hygiene and safety criteria. CNS were recovered, characterized, and their potential use as starters evaluated. Low genetic diversity was observed for Staphylococcus xylosus, whereas Staphylococcus equorum showed diverse genetic profiles. Staphylococcus xylosus predominated in products with a long period of cold smoking, Staphylococcus saprophyticus in products with a long period of hot smoking, Staphylococcus epidermidis in products with a short period of cold smoking, and S. equorum in nonsmoked products. Most S. xylosus were resistant to tetracycline, whereas S. equorum were susceptible. Antibioresistance restricted the selection of starters due to safety recommendation