Geobacillus stearothermophilus and Bacillus atrophaeus spores exhibit linear inactivation kinetic performance when treated with an industrial scale vaporized hydrogen peroxide (VH2O2) sterilization process.

AIMS: This study aims to determine the inactivation kinetics of Geobacillus stearothermophilus and Bacillus atrophaeus biological indicators, treated with vaporized hydrogen peroxide (VH2O2) at an industrial scale. There is an assumption that sterilization processes generate linear kinetic plots of treated biological indicators that are used for informing probability-based decision-making by the MedTech industry for effective sterilization treatments; however, this has not been reported for sterilization using VH2O2. METHODS AND RESULTS: Survivor curves were generated, and sterilization performances were separately determined using G. stearothermophilus and B. atrophaeus biological indicators following the development of appropriate process challenge devices (PCDs). Regression analysis revealed that the inactivation kinetics for VH2O2-treated microorganisms exhibited log linear profiles. The use of scanning electron microscope (SEM) revealed no significant topographical changes in the outer surface of these VH2O2-treated spores. CONCLUSIONS: Both biological indicators exhibited log linear inactivation kinetics when treated with an industrial scale vaporized hydrogen peroxide (VH2O2) sterilization process. Therefore, this novel finding corroborates and proves the appropriateness of using VH2O2 as a sterilization method in accordance with applicable ISO standards.

Principles of Parametric Release: Emphasis on Data Collection and Interpretation.

Parametric release, which relies on use of process data for product release, provides many benefits. However, adoption by the sterilization industry has been slow, with release typically involving biological indicator (BI) growth responses/ dosimetry readings. The current article highlights how the data provided by the process (described through examples for ethylene oxide [EO], vaporized hydrogen peroxide [VHP], and radiation) may be better used to inform parametric release implementation. The examples involving EO and VHP demonstrated the ability of the sterilization equipment to deliver validated parameters repeatedly after the load presented was validated. For instances in which load variability has not been addressed in performance qualification, BI testing or even measurement of EO concentration cannot reliably or fully inform the impact of such variance on the validated process. "Direct" monitoring of EO concentration is a current requirement in ISO 11135:2014. Nonetheless, the findings presented here show that EO and VHP concentrations can be determined by the calculated method, rendering the use of a concentration measurement probe somewhat superfluous. In alignment with European Union good manufacturing practice Annex 17, a key requirement of parametric release is to have sufficient data to demonstrate the repeatability of the validated process. Similar to gas technologies, radiation processing strives to implement parametric release but is limited by the currently available means of measuring all critical parameters, such as photon delivery.

Proteolytic Lactococcus lactis and Lipolytic Enterococcus durans of Dairy Origin as Meat Functional Starter Cultures.

RESEARCH BACKGROUND: As fermentation is an integral feature of both, dry sausage and cheese production, this has led to the evaluation of bacterial cultures Lactococcus lactis ssp. cremoris (LL8307) and Enterococcus durans (ED0207) originally isolated from artisanal Croatian hard type cheese to diversify the range of flavours of dry fermented sausages and to increase their microbiological safety. Both strains were chosen for their high or medium acidifying, proteolytic and/or lipolytic activity and bioprotective potential after step-by-step selection of wild isolates. Therefore, this study aims to evaluate the survival rate of selected starter cultures in wild boar meat sausages during the ripening period of 40 days at a local small-scale facility under artisanal conditions as well as their influence on sausage quality parameters. EXPERIMENTAL APPROACH: Safety, biotechnological and probiotic properties of twenty-three enterococcal and lactococcal isolates of dairy origin were studied. Based on the results, two best candidates were selected and added to the meat batter during the artisanal wild boar meat sausage preparation where their survival rate, effect on physicochemical, microbiological and sensorial properties and histamine content were evaluated. RESULTS AND CONCLUSIONS: As revealed by repetitive element-polymerase chain reaction (rep-PCR), native starter cultures survived up to 15 days of ripening and were either absent from (LL8307) or reduced by 80% (ED0207) in final products. The application of native starter cultures rapidly decreased pH (p<0.05), leading to the significantly lower load of E. coli, coliforms and Enterobacteriaceae in ready-to-eat sausages prepared by the addition of starter cultures (3.04-3.94 log CFU/g) than in the control (3.88-5.00 log CFU/g). Analysis of hedonic test data revealed that some of the sensory traits (odour, flavour, juiciness) of treatments with starter cultures were highly liked by the higher percentage of consumers. The results suggest that these starter cultures would represent a valuable tool to improve the homogeneity of artisanal manufacture and hygienic quality of fermented sausages and can be safely used for food application. NOVELTY AND CCIENTIFIC CONTRIBUTION: This is the first study to explore in depth the biotechnological potential of bacterial cultures isolated from artisanal Croatian cheese as functional starter cultures for high-quality game meat sausage production.

The survival rate and efficiency of non-encapsulated and encapsulated native starter cultures to improve the quality of artisanal game meat sausages.

This study addresses the application of native, multiple strain starter cultures for standardization of game meat sausages production. The designed starter cultures consisting of two indigenous Lactobacillus sakei and one Leuconostoc mesenteroides strains. These strains were used in both, the encapsulated and non-encapsulated form, in the game meat dough, individually or in combination, with eight treatments in total. Microbiological and physicochemical characteristics of the sausages were monitored throughout the manufacturing process, while sensory properties, biogenic amine content, and volatile compounds were evaluated in the final products. As revealed by rep-PCR, native starter cultures, encapsulated or non-encapsulated, had survived the whole sausage production process; however, to varying degrees. The application of indigenous decarboxylase negative Lb. sakei strains significantly (P < 0.05) reduced tyramine content, rapidly decreased pH and promoted the number reduction of Enterobacteriaceae and elimination of E. coli, L. monocytogenes and coliforms in ready-to-eat products. A total of 84 volatile compounds were identified by SPME-GC-MS in the eight treatment batches of game meat sausages, with only minor differences between the treatments. No significant differences in sensory traits (P > 0.05) between tested treatments were found, although treatment with the Lb. sakei strains received the highest scores for the sensory traits including cross-section, odour, hardness, aroma, and overall acceptability. Combination of multi-strain Lb. sakei starter cultures resulted in growth prevention of undesirable microbiota, reduction of tyramine content and increased the acceptability parameters of full-ripened sausages, which make them good candidates for industrial as well as artisanal application.

The Influence of Meat Batter Composition and SausageDiameter on Microbiota and Sensory Traits of ArtisanalWild Boar Meat Sausages.

In this study, the influence of meat batter composition and sausage diameter on the development of microbiota and sensory traits of traditional, spontaneously fermented wild boar meat sausages are evaluated. This research also demonstrates how principal component analysis (PCA) can be used to relate product sensory properties to particular microbial genotype and to select potential starter or adjunct culture. Generally, similar microbiological results were obtained in all types of products. The undesirable microbiota was either not detected at any sausage production stage or its number decreased below the detection limit in ripened sausages. The low growth rate of lactic acid bacteria (LAB) was consistent with the obtained pH and slow acidification rate. Although no differences in the composition of LAB species were noticed between sausage types (50S=50% wild boar meat in small casing, 50L=50% wild boar meat in large casing, 100S=100% wild boar meat in small casing), a clear separation based on LAB genotypes could be observed. Upon quantitative descriptive analysis, significant differences in sensory attributes between sausage types were established. According to the PCA, the overall acceptability traits of sausages are closely linked to one Leuconostoc mesenteroides genotype (LM_4). Of all tested technological properties, LM_4 strains showed remarkable acidification ability, lowering the pH from pH=5.41 to 3.74, and pronounced proteolytic activity on skimmed milk as well as antagonistic activity against Staphylococcus aureus (DSM 20231) and Brochothrix thermosphacta (LMG 17208). Lipolytic and haemolytic activities were not detected, and all analyzed strains were susceptible to tested antibiotics and possessed no biogenic amine genes.

Characterization of Enterococcal Community Isolated from an Artisan Istrian Raw Milk Cheese: Biotechnological and Safety Aspects.

In this study, prevalence, biotechnological and safety profiles of 588 Enterococcus isolates isolated from raw milk and Istrian cheese during different stages of ripening were analyzed. Despite the low and variable presence of enterococci in milk ((3.65±2.93) log CFU/mL), highly comparable enterococcal populations were established after 30 days of cheese ripening ((7.96±0.80) log CFU/g), confirming Enterococcus spp. as a major part of the core microbiota of Istrian cheese. The dominant species were E. faecium (53.8%) and E. faecalis (42.4%), while minor groups, consisting of E. durans (2.84%) and E. casseliflavus (0.95%), also occurred. A pronounced intraspecies variability was noticed based on molecular fingerprinting, with 35 strains (genotypes) detected. Most of the genotypes were farm-specific with one third being shared between the farms. This genotype variability reflected particular differences of Istrian cheese production, mainly variable salt concentration, ripening temperature and air humidity as well as microclimatic or vegetation conditions. There was considerable variation between the strains of the same species regarding wide range of biotechnologically important traits as well as their ability to survive in simulated gastrointestinal conditions. A considerable number of strains were resistant to critically important antibiotics such as tetracycline (43.56%), erythromycin (35.79%) and vancomycin (23.48%). Polymerase chain reaction-based detection did not identify any of the common genetic determinants for vancomycin and erythromycin resistance; for tetracycline tetM gene was detected. The presence of virulence genes including agg, efaAfs, gelE, cylM, cylB, cylA, esp, efaAfm, cob and cpd was frequently recorded, especially among E. faecalis strains.

Gait characteristics in older adults with diabetes and impaired fasting glucose: The Rotterdam Study.

AIMS: To investigate the association of diabetes mellitus and impaired fasting glucose with gait in the general middle-aged and elderly population. METHODS: We performed a cross-sectional study on 3019 participants from the population-based Rotterdam Study (aged >45years, 54% women). The presence of diabetes mellitus and impaired fasting glucose was evaluated by measuring serum glucose levels and by documenting anti-diabetic treatment. Participants underwent gait analysis using an electronic walkway. Thirty gait variables were summarized into five independent gait domains for normal walking (Rhythm, Variability, Phases, Pace and Base of Support), one for turning (Turning) and one for walking heel to toe (Tandem), which were averaged into Global Gait. Linear regression analyses were performed to determine the association of diabetes, impaired fasting glucose and continuous glucose levels within the normal range with gait. RESULTS: Diabetes mellitus was associated with worse Global Gait (Z-score difference -0.19, 95% confidence interval (CI) -0.30; -0.07), worse Pace (-0.20, 95% CI -0.30; -0.10) and worse Tandem (-0.21, 95% CI -0.33; -0.09), after adjusting for age, sex, height and weight. The association with Tandem remained significant after additional adjustment for cardiovascular risk factors. Impaired fasting glucose and continuous glucose levels within the normal range were not associated with any of the gait domains. CONCLUSION: In our population-based study diabetes mellitus was associated with worse Global Gait, which was mostly reflected in Pace and Tandem. These associations were partly driven by other cardiovascular risk factors, emphasizing the importance of optimal control of cardiovascular risk factor profiles in patients with diabetes.

The impact of restless legs syndrome on physical functioning in a community-dwelling population of middle-aged and elderly people.

OBJECTIVE: To investigate whether restless legs syndrome (RLS) is associated with impaired physical functioning using subjective and objective assessments. METHODS: From 2006-2013, 5,960 participants (mean age 67.2; 57.5% females) of the prospective population-based Rotterdam Study, aged 45 years and over, were cross-sectionally investigated for presence of restless legs syndrome using a questionnaire. Physical functioning was assessed subjectively with the Stanford Health Assessment Questionnaire (basic activities of daily living) and the Instrumental Activities of Daily living scale (instrumental activities of daily living). Additionally, physical functioning was assessed objectively by quantifying fine motor performance with the Purdue Pegboard Test and by quantifying gait with an electronic walkway. RESULTS: Restless legs syndrome was present in 13.7% of the participants. Persons with restless legs had more impairment in basic (difference in score 0.65, 95% CI 0.41;0.90) and instrumental activities of daily living (difference in score 0.28, 95% CI 0.09;0.48) than persons without restless legs. This association was strongest when symptoms were present two or more times a week (basic activities of daily living score difference 1.69, 95% CI 1.28;2.09). The association between restless legs syndrome and activities of daily living attenuated after adjusting for sleep quality or depressive symptoms. There was no association with the Purdue Pegboard Test score nor with gait. CONCLUSIONS: Individuals with restless legs syndrome experienced significantly more impairment in activities of daily function than persons without restless legs. This seemed to be (partly) mediated by poor sleep quality and depressive symptoms. No association was found with objectively assessed physical functioning.