Pojava i određivanje Thermoanaerobacterium i Thermoanaerobacter u konzerviranoj hrani u limenkama

In order to determine the reason for loss of vacuum in canned food, obligately anaerobic, spore forming thermophilic organisms were isolated from shelf-stable canned food containing vegetables, noodles and potatoes as main ingredients. Thermophilic bacteria from 44 canned food samples that had been stored under anaerobic conditions at 37 °C for at least 7 days were isolated. In addition, organic fertilizer used for the cultivation of some of the foods’ ingredients was examined and anaerobic, thermophilic bacteria could also be isolated from this source. Identification of bacterial strains was carried out by partial and complete 16S-rRNA-gene sequencing. Some of the obtained gene sequences showed a high level of similarity to existing 16S-rRNA gene sequences towards strains of the genera Thermoanaerobacter, Thermoanaerobium and Thermoanaerobacterium respectively, which have not yet been reported to be of importance as food spoilers. In the course of identification of these thermophilic bacteria we developed genera specific PCR-based approaches for detecting isolates belonging to the genera Thermoanaeroacterium and Thermoanaerobacter. Direct capturing of free DNA from contaminated samples using oligonucleotides coupled with paramagentic beads allowed the reduction of the detection time to six hours with a lower limit of 104 cells/mL.Da bi se odredio uzrok nestanka vakuuma u limenkama konzervirane hrane, obligatni anaerobi, termofilni organizmi koji stvaraju spore, izolirani su iz hrane u limenkama s glavnim sastojcima: povrće, rezanci i krumpir. Izolirane su termofilne bakterije iz 44 uzorka limenki uskladištenih pod anaerobnim uvjetima pri 37 °C barem 7 dana. Osim toga, ispitana su organska gnojiva upotrijebljena za uzgoj navedenog povrća pa su i iz tog izvora izolirane anaerobne termofilne bakterije. Identifikacija bakterijskih sojeva provedena je djelomičnim i potpunim sekvencioniranjem 16S-rRNA gena. Neke od dobivenih genskih sekvencija pokazale su visoki stupanj sličnosti s postojećim sekvencijama 16S-rRNA gena sojeva rodova Thermoanaerobacter, Thermoanaerobium i Thermoanaerobacterium. Do sada još nije bila ustanovljena važnost tih sojeva kao onečišćavača hrane. Tijekom identifikacije navedenih termofilnih bakterija autori su razvili genetički specifičan pristup utemeljen na PCR za određivanje izolata koji pripadaju rodovima Thermoanaerobacterium i Thermoanaerobacter. Izravno vezanje slobodne DNA iz onečišćenih uzoraka, koristeći oligonukleotide povezane s paramagnetskim zrncima omogućilo je smanjenje vremena detekcije na 6 sati s donjom granicom od 104 stanica/mL

SxsA, a novel surface protein mediating cell aggregation and adhesive biofilm formation of Staphylococcus xylosus

Biofilm formation of staphylococci has been an emerging field of research for many years. However, the underlying molecular mechanisms are still not fully understood and vary widely between species and strains. The aim of this study was to identify new effectors impacting biofilm formation of two Staphylococcus xylosus strains. We identified a novel surface protein conferring cell aggregation, adherence to abiotic surfaces, and biofilm formation. The S. xylosus surface protein A (SxsA) is a large protein occurring in variable sizes. It lacks sequence similarity to other staphylococcal surface proteins but shows similar structural domain organization and functional features. Upon deletion of sxsA, adherence of S. xylosus strain TMW 2.1523 to abiotic surfaces was completely abolished and significantly reduced in TMW 2.1023. Macro- and microscopic aggregation assays further showed that TMW 2.1523 sxsA mutants exhibit reduced cell aggregation compared with the wildtype. Comparative genomic analysis revealed that sxsA is part of the core genome of S. xylosus, Staphylococcus paraxylosus, and Staphylococcus nepalensis and additionally encoded in a small group of Staphylococcus cohnii and Staphylococcus saprophyticus strains. This study provides insights into protein-mediated biofilm formation of S. xylosus and identifies a new cell wall-associated protein influencing cell aggregation and biofilm formation.Peer Reviewe

Bacteriocin production by lactic acid bacteria (LAB) isolated from traditional cheese

Lactic Acid Bacteria (LAB) are a group of bacteria that are found as natural microbiota in various ecosystems. They are used ato producea huge variety of fermented foods, they occur in pharmaceutical formulations and as probiotics in functional foods. They can produce a number of antimicrobial metabolites, including organic acids and other organic components, hydrogen peroxide and bacteriocins. The aim of this study was the evaluation of antibacterial activity of LAB isolated during production and maturation of traditional Rugova cheese. Samples for analysis were collected from different points of Rugova region and were transported to the laboratory under constant cooling conditions. The bacterial isolation was performed using standard methods and the isolates of LAB were identified down to the species level using a Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). Out of 140 tested isolates 105 had the ability to produce bacteriocins. The large number of bacteriocin producers demonstrates the great assertiveness of the natural LAB microbiota over potentially existing pathogens. Thus, the ability of bacteriocin production by LAB isolated from Rugova cheese can be taken as a measure of quality and safety of this traditional product

Effect of High Pressure and Heat on Bacterial Toxins

Even though the inactivation of microorganisms by high pressure treatment is a subject of intense investigations, the effect of high pressure on bacterial toxins has not been studied so far. In this study, the influence of combined pressure/temperature treatment (0.1 to 800 MPa and 5 to 121 °C) on bacterial enterotoxins was determined. Therefore, heat-stable enterotoxin (STa) of cholera toxin (CT) from Vibrio cholerae, staphylococcal enterotoxins A-E, haemolysin BL (HBL) from Bacillus cereus, and Escherichia coli (STa) were subjected to different treatment schemes. Structural alterations were monitored in enzyme immunoassays (EIAs). Cytotoxicity of the pressure treated supernatant of toxigenic B. cereus DSM 4384 was investigated with Vero cells. High pressure of 200 to 800 MPa at 5 °C leads to a slight increase of the reactivity of the STa of E. coli. However, reactivity decreased at 800 MPa and 80 °C to (66±21) % after 30 min and to (44±0.3) % after 128 min. At ambient pressure no decrease in EIA reactivity could be observed after 128 min. Pressurization (0.1 to 800 MPa) of heat stable monomeric staphylococcal toxins at 5 and 20 °C showed no effect. A combined heat (80 °C) and pressure (0.1 to 800 MPa) treatment lead to a decrease in the immuno-reactivity to 20 % of its maximum. For cholera toxin a significant loss in latex agglutination was observable only at 80 °C and 800 MPa for holding times higher than 20 min. Interestingly, the immuno-reactivity of B. cereus HBL toxin increased with the increase of pressure (182 % at 800 MPa, 30 °C), and high pressure showed only minor effects on cytotoxicity to Vero cells. Our results indicate that pressurization can increase inactivation observed by heat treatment, and combined treatments may be effective at lower temperatures and/or shorter incubation time

Effect of High Pressure and Heat on Bacterial Toxins

Even though the inactivation of microorganisms by high pressure treatment is a subject of intense investigations, the effect of high pressure on bacterial toxins has not been studied so far. In this study, the influence of combined pressure/temperature treatment (0.1 to 800 MPa and 5 to 121 °C) on bacterial enterotoxins was determined. Therefore, heat-stable enterotoxin (STa) of cholera toxin (CT) from Vibrio cholerae, staphylococcal enterotoxins A-E, haemolysin BL (HBL) from Bacillus cereus, and Escherichia coli (STa) were subjected to different treatment schemes. Structural alterations were monitored in enzyme immunoassays (EIAs). Cytotoxicity of the pressure treated supernatant of toxigenic B. cereus DSM 4384 was investigated with Vero cells. High pressure of 200 to 800 MPa at 5 °C leads to a slight increase of the reactivity of the STa of E. coli. However, reactivity decreased at 800 MPa and 80 °C to (66±21) % after 30 min and to (44±0.3) % after 128 min. At ambient pressure no decrease in EIA reactivity could be observed after 128 min. Pressurization (0.1 to 800 MPa) of heat stable monomeric staphylococcal toxins at 5 and 20 °C showed no effect. A combined heat (80 °C) and pressure (0.1 to 800 MPa) treatment lead to a decrease in the immuno-reactivity to 20 % of its maximum. For cholera toxin a significant loss in latex agglutination was observable only at 80 °C and 800 MPa for holding times higher than 20 min. Interestingly, the immuno-reactivity of B. cereus HBL toxin increased with the increase of pressure (182 % at 800 MPa, 30 °C), and high pressure showed only minor effects on cytotoxicity to Vero cells. Our results indicate that pressurization can increase inactivation observed by heat treatment, and combined treatments may be effective at lower temperatures and/or shorter incubation time

Genomic analysis reveals Lactobacillus sanfranciscensis as stable element in traditional sourdoughs

Sourdough has played a significant role in human nutrition and culture for thousands of years and is still of eminent importance for human diet and the bakery industry. Lactobacillus sanfranciscensis is the predominant key bacterium in traditionally fermented sourdoughs

Increased breath naphthalene in children with asthma and wheeze of the All Age Asthma Cohort (ALLIANCE).

Background
Exhaled breath contains numerous volatile organic compounds (VOCs) known to be related to lung disease like asthma. Its collection is non-invasive, simple to perform and therefore an attractive method for the use even in young children. We analysed breath in children of the multicenter All Age Asthma Cohort (ALLIANCE) to evaluate if "breathomics" have the potential to phenotype patients with asthma and wheeze, and to identify extrinsic risk factors for underlying disease mechanisms.
Methods
A breath sample was collected from 142 children (asthma: 51, pre-school wheezers: 55, healthy controls: 36) and analysed using gas chromatography-mass spectrometry (GC/MS). Children were diagnosed according to GINA guidelines and comprehensively examined each year over up to seven years. Forty children repeated the breath collection after 24 or 48 months. 
Results
Most breath VOCs differing between groups reflect the exposome of the children. We observed lower levels of lifestyle-related VOCs and higher levels of the environmental pollutants, especially naphthalene, in children with asthma or wheeze. Naphthalene was also higher in symptomatic patients and in wheezers with recent inhaled corticosteroid use. No relationships with lung function or TH2 inflammation were detected.
Conclusion
Increased levels of naphthalene in asthmatics and wheezers and the relationship to disease severity could indicate a role of environmental or indoor air pollution for the development or progress of asthma. Breath VOCs might help to elucidate the role of the exposome for the development of asthma.
The study was registered at ClinicalTrials.gov (NCT02496468).
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Validierung eines Fragebogens zu Problemen der Krankheitsakzeptanz bei Diabetes mellitus: Diabetes Acceptance Scale (DAS)

Fragestellung: Probleme der Diabetesakzeptanz sind assoziiert mit non-adhärentem Selbstbehandlungsverhalten und hyperglykämischer Blutzuckereinstellung. Zur Erfassung von Diabetesakzeptanzproblemen existierte bisher allerdings nur ein recht limitiertes Messinstrument, der Acceptance and Action Diabetes Questionnaire (AADQ). Um differenziertere Messungen zu ermöglichen, wurde die Diabetes Acceptance Scale (DAS) entwickelt, deren Validierung hier berichtet wird. Methodik: Die DAS ist eine 28-Item-Selbstberichtsskala mit Subskalen zur diabetesbezogenen „Akzeptanz/Integration“, „Behandlungsmotivation“, „Abwehr/Vermeidung“ und „emotionalen Belastung“ sowie einer Summenskala zur Gesamt-Diabetesakzeptanz; Entwicklung beschrieben in Diabetologie und Stoffwechsel 2015; 10 – P137. 460 Diabetespatienten (50% Typ-1, 48% Typ-2, 2% Typ-3; 50% weiblich; Alter 52 ± 15 Jahre; BMI 30 ± 7 kg/m2; Diabetesdauer 15 ± 12 Jahre; HbA1c 7,8 ± 1,4%) bearbeiteten die DAS sowie Fragebögen zu Diabetesakzeptanzproblemen (AADQ), diabetesbezogener Belastung (PAID-5), depressiver Stimmung (PHQ-9) und Diabetes-Selbstbehandlungsverhalten (DSMQ). Gleichzeitig wurde der HbA1c-Wert bestimmt. Anhand dieser Daten wurden Kennwerte der Reliabilität (Cronbachs α) und Validität (kriterienbezogene Korrelationen) der DAS untersucht. Ergebnisse: Alle DAS-Skalen zeigten durchweg hohe Reliabilität (Subskalen: α= 0,89 – 0,93; Summenskala: α= 0,96). Höhere DAS-Summenwerte (bessere Diabetesakzeptanz) waren hoch korreliert mit weniger Diabetesakzeptanzproblemen nach AADQ (r=-0,65), geringerer diabetesbezogener Belastung (r=-0,69) und weniger Depressivität (r=-0,56); alle P< 0,001. Weiter korrelierten höhere DAS-Summenwerte mit günstigeren Selbstbehandlungsverhaltensweisen nach DSMQ (diabetesgerechte Ernährung: r= 0,56; Medikamentenadhärenz: r= 0,54; Blutzuckerselbstkontrolle: r= 0,42; körperliche Betätigung: r= 0,26; Arztkontakt: r= 0,51) sowie einer besseren Blutzuckereinstellung (HbA1c-Wert: r=-0,42); alle P< 0,001. Schlussfolgerungen: Die Ergebnisse sprechen für eine hohe Reliabilität und Validität der Diabetes Acceptance Scale. Die Skala erscheint als sehr gutes Messinstrument zur Erkennung von Problemen der Diabetesakzeptanz sowie zur besseren Erforschung dieser gravierenden psychologischen Problematik