Sterility Testing Research Articles

Decreasing of hand colonization and sterility of refill antiseptic in Dr. Yap Eye Hospital, Yogyakarta

Dr. Yap Eye Hospital, Yogyakarta uses aseptic gel containing 70% ethyl alcohol to refill antiseptic containers during times of antiseptic scarcity. The study aimed to evaluate the effectiveness and sterility of the refill antiseptics in reducing the number of colonization on the hands of nurses. It was a quasi-experimental using pre- and post-control groups design involving 56 nurses who used antiseptics in a bottle sterilized by plasma device (plasma bottle) compare to those washed using detergent (detergent bottle) before being refilled. Sterility tests were performed every two wk for up to two mo. Colonization pre and post hand hygiene practices were determined as an efficacy test and compared using the Mann-Whitney test in STATA 14. Antiseptic in plasma bottles remains sterile until the week8th since refilled, longer than detergent bottles (6th weeks). The pre-handrub colorizations were 0.04-16.92 CFU/cm2 and decreased significantly post-handrub to 0.00-3.08 CFU/cm2 (p<0.0001). Significant decrease pre- vs post-handrub colonization was observed in usage of detergent bottle (0.04-31.04 vs 0.00-10.48 CFU/cm2, p=0.0007). There was no significant difference in ∆ colonization for two bottles (0.40-15.76 vs 0.04-30.92 CFU/cm2, p=0.8790). In conclusion, antiseptic in the plasma bottle remains sterile longer than in the detergent bottle since refilled. Both of them are equally effective in reducing colonization after handrub activity.

A review of current approaches for decellularization, sterilization, and hemocompatibility testing on xenogeneic pericardium

Decellularization, sterilization, and hemocompatibility are the main areas for biomaterials evaluation when the material is designed for medical implants. The glutaraldehyde fixation of xenogeneic pericardium graft is not fully capable of preventing implant rejection in the recipient. The decellularization process removes the cellular components from organs or tissue to form an extracellular matrix as a structural template, and this template can be used for tissue engineering applications. The decellularization can be performed by chemical, enzymatic or physical, or a combination of methods. Sterilization and hemocompatibility are essential for medical devices that come into contact with blood. The different sterilization treatments include gamma radiation, freeze-drying, ethylene oxide, peracetic acid, antibiotics, and ethanol. In this context, this study reviews the three major areas of decellularization, sterilization, and hemocompatibility of xenogeneic pericardium for tissue engineering applications. In this study, a brief overview of recent decellularization approaches and combinations such as chemical method, chemical and enzymatic method, and the physical and chemical method used to remove cellular material from the pericardium are discussed. In the different sterilization techniques, the sterilization efficiency and post sterilization results obtained by various research groups on pericardium scaffolds are discussed. Also, this review deals with in vitro hemocompatibility testing such as hemolysis, platelet adhesion, coagulation system, and activation of leucocytes for xenogeneic biomaterials.

Towards an automated approach for smart sterility test examination.

As new technologies emerge, deep learning applications are often integral parts of new products as features and often as differentiating benefits. This is especially notable in commercial consumer products in everyday applications, such as voice assistants or streaming content recommendation systems. Due to the power and applicability of these deep learning technologies significant efforts are being directed to the development and integration of appropriate models into science and engineering applications to supplant analogue systems that may be highly prone to human error. Here we present an innovative, low-cost approach to advance sterility assessment workflows that are required and regulated within drug release/manufacturing processes. The model system leverages off-the-shelf hardware as well as deep learning models to detect and classify different microbial contaminations in test containers. The paired hardware and software tools were evaluated in experiments using common model organisms (C. sporogenes, P. aeruginosa, S. aureus). With this approach we were able to detect all three test organisms across 40 experiments, furthermore we were capable of classifying the present organisms with an average classification accuracy of over 87%.

Development of a 3D printed surgical guide for Brugada syndrome substrate ablation.

Brugada syndrome (BrS) is a disease associated with ventricular arrhythmias and sudden cardiac death. Epicardial ablation has demonstrated high therapeutic efficacy in preventing ventricular arrhythmias. The purpose of this research is to define a workflow to create a patient-specific 3D-printed tool to be used as a surgical guide for epicardial ablation in BrS. Due to their mechanical properties and biocompatibility, the MED625FLX and TPU95A were used for cardiac 3D surgical guide printing. ECG imaging was used to define the target region on the right ventricular outflow tract (RVOT). CT scan imaging was used to design the model based on patient anatomy. A 3D patient-specific heart phantom was also printed for fitting test. Sterilization test was finally performed. 3D printed surgical models with both TPU95A and MED625FLX models were in agreement with pre-specified imputed measurements. The phantom test showed retention of shape and correct fitting of the surgical tool to the reproduced phantom anatomy, as expected, for both materials. The surgical guide adapted to both the RVOT and the left anterior descending artery. Two of the 3D models produced in MED265FLX showed damage due to the sterilization process. A 3D printed patient-specific surgical guide for epicardial substrate ablation in BrS is feasible if a specific workflow is followed. The design of the 3D surgical guide ensures proper fitting on the heart phantom with good stability. Further investigations for clinical use are eagerly awaited.

Effect of Organic Nutrient Management on Growth and Yield Attributes of Different Varieties of Rice

A field experiment was conducted during kharif season 2018 at the Research Farm of Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (MP) to evaluate the “Effect of organic nutrient management on growth and yield attributes of different varieties of rice”. The experiment was laid out in RBD involving twelve rice varieties in triplicate. A uniform dose of organic manures i.e. 1/3rd Nitrogen through each of farm yard manure, neem cake and vermicompost were applied to all the varieties. Results of the study revealed that Pusa Sugandha 3 has recorded significantly higher growth parameters viz., plant height (69.80 cm), number of tillers per hill (13.53) and dry matter production per hill (43.39 g) among all the varieties. Among yield attributes significantly higher number of effective tillers per hill (11.40), total number of grains per panicle (164.67), panicle length (25.33 cm), grain yield (3298 kg ha-1) and straw yield (5463 kg ha-1) were recorded under Pusa Sugandha 3 variety of rice. However Sahyadri and MTU 1010 reported the highest sterility percentage (17.62) and test weight (24.45 g) respectively.

Extended Stability of Vasopressin Injection in Polyvinyl Chloride Bags and Polypropylene Syringes and Its Impact on Critically Ill Patient Care and Medication Waste.

Background. Vasopressin is frequently utilized for a variety of shock states in critically ill patients. Short stability (≤24 hours) after intravenous admixture with current manufacturer labeling requires just in time preparation and may lead to delays in therapy and increased medication waste. We aimed to evaluate vasopressin stability in 0.9% sodium chloride stored in polyvinyl chloride bags and polypropylene syringes for up to 90 days. Additionally, we evaluated the impact of extended stability on the time to administration and cost savings from reduced medical waste at an academic medical center. Methods. Dilutions of vasopressin to concentrations of 0.4 and 1.0 unit/mL were performed under aseptic conditions. The bags and syringes were stored at room temperature (23°C-25°C) or under refrigeration (3°C-5°C). Three samples of each preparation and storage environment were analyzed on days 0, 2, 14, 30, 45, 60, and 90. Physical stability was performed by visual examination. The pH was assessed at each point and upon final degradation evaluation. Sterility of the samples was not assessed. Chemical stability of vasopressin was evaluated using liquid chromatography with tandem mass spectrometry. Samples were considered stable if there was <10% degradation of the initial concentration. Results. Vasopressin diluted to 0.4 and 1.0 unit/mL with 0.9% sodium chloride injection was physically stable throughout the study. No precipitation was observed. At days 2, 14, 30, 45, 60, and 90 all bags and syringes diluted to 0.4 units/mL had <10% degradation. Vasopressin diluted to 1 unit/mL and stored under refrigeration had <10% degradation at all measured days, but when stored under room temperature was found to have >10% degradation at day 30. Implementation of a batching process resulted in reduced waste ($185 300) and improved time to administration (26 vs 4 minutes). Conclusion. Vasopressin diluted to a concentration of 0.4 units/mL with 0.9% sodium chloride injection is stable for 90 days at room temperature and under refrigeration. When diluted to 1.0 unit/mL with 0.9% sodium chloride injection it is stable for 90 days under refrigeration. Use of extended stability and sterility testing to batch prepare infusions may lead to improved time to administration and cost savings from reduced medication waste.

Влияние индуцированной транспозиционной активности р элементов на возраст-зависимые изменения репродуктивной системы и эмбриональную выживаемость Drosophila melanogaster

The age-dependent change in the activity of P elements in the P-M genetic system was studied by parameters of the reproductive system (fertility, gonadal atrophy, ovarian reserve) and embryonic survival of Drosophila melanogaster. The transposition activity of P elements was controlled using tests for sterility and mutability of the sn[w] locus, the results of which showed a high mobilization of functional P sequences in all age groups. An increase in the activity of transposons with age was noted in dysgenic F1 individuals obtained from aging parents in inducing crosses, as well as in 60-day-old dysgenic offspring (according to the mutability of the sn[w] locus). It was shown that the effect of P-transpositions affected only on the viability of embryos, the profile of which decreased with the aging of their dysgenic F1 parents. On the contrary, the average fecundity of dysgenic females did not change with age and was at a low level compared to non-dysgenic females. An analysis of the obtained data suggests that the observed effects are based on different mechanisms of the biological action of aging and induced P-activity.

Salivary Gene Expression of RANK, RANKL, and OPG in Type 1 Diabetes Mellitus and Periodontal Disease Patients.

The relationship between type 1 diabetes mellitus (T1DM) and periodontal disease may exhibit by the alteration of bone metabolism. However, evidence for this relationship is scarce and inconclusive. Thus, the aims of the present study were to investigate salivary receptor activator of nuclear factor kappa-β (RANK), receptor activator of nuclear factor kappa-β ligand (RANKL), osteoprotegerin (OPG) gene expression and the RANKL:OPG ratio in T1DM and non-T1DM. Secondary objective was to determine the relationships of RANK, RANKL and OPG gene expression to clinical parameters of T1DM and periodontal disease. Twenty patients with T1DM and twenty age-matched non-T1DM were recruited. Clinical periodontal parameters were measured. Total RNA was isolated from non-stimulated saliva, and the relative gene expressions of RANK, RANKL, OPG and RANKL:OPG ratio were determined by quantitative real-time polymerase chain reaction. The T1DM group had significantly higher mean periodontal parameters than the non-T1DM group, while the mean plaque scores of both groups were not significantly different. There was a trend of higher relative gene expression of RANK, RANKL, and the RANKL:OPG ratio and lower expression of OPG in T1DM group but no statistic significant different when compared to non-T1DM. In the T1DM group, RANKL:OPG correlated with the percentage of bleeding sites, whereas RANK, RANKL, and HbA1c levels correlated with pocket depth. Bone metabolisms demonstrating by decreased OPG gene expression and upregulated of RANK, RANKL, RANKL:OPG with higher pocket depth and bleeding in T1DM may play an important role in periodontal destruction in T1DM.

Isolation and therapeutic efficacy of enteropathogenic E. coli phage cocktail against colibacillosis in neonatal goats

Phage based therapeutics have shown promising results against the infections caused by the drug resistant bacteria. To combat the problem of antibiotic resistance posed by diarrhoeagenic E. coli, here, we identified and characterized 38 E. coli phages which were isolated from 70 solid sources (goat-faeces and soil). The in vitro lytic range of phage isolates (n=38) against 439 isolates of E. coli was found between 16 and 53%. Three phage isolates with highest host range showed lytic efficacy against 53, 48 and 46% of E. coli isolates, respectively. A preparation with above three phages was developed, and the phages of the preparation were found stable at wide range of temperature, pH and chloroform treatment. Endotoxin content of the preparation was found below the threshold level and it also passed safety and sterility tests. a total of 40 diarrheic goat kids were administered orally with the therapeutic phage preparation for two days twice daily. Total 21 diarrheic goat-kids were successfully treated using the therapeutic phage preparation, whereas 19 kids could not be treated (success rate: 52.5%; 21/40). The results of the current study provide insight for using lytic bacteriophages for therapeutic interventions against drug resistant E. coli responsible for colibacillosis in neonatal goat kids

Phytochemical Screening, Proximate Analysis and Microbiological Quality of Bio-Clean II Herbal Remedy

Background: A few studies have demonstrated the medicinal benefits of Bio-Clean II herbal remedy. The aim of this study is to determine the phytochemical screening, proximate analysis and microbiological quality of Bio-Clean II. Materials and Methods: Samples of the herbal remedy were procured from the manufacturer and were analyzed using standard procedure of analysis including sterility test, Spectrophotometry, Atomic Absorption spectroscopy, and gravimetric method. All the batches of Bio-Clean II examined pass sterility test. Physicochemical characterization of the herbal remedy was as follows: pH (6.86), temperature (25oC), relative density (1.08), conductivity (272 uS/cm) and total dissolved solid (163 mg/L). Phytochemical screening of the herbal remedy revealed the presence of the following bioactive secondary metabolites in varied quantity: resin (+), Flavonoids (+++), Saponins (+), Anthraquinones (+++), Tannin (++), Alkaloids (++) and Cardiac Glycoside (++); except for Steroids which was absent (-). Trace elements analysis revealed the presence of the following in varied quantity: Iron (2.526 mg/L), Zinc (0.033 mg/L) and Iodine (0.025 mg/L), except for Copper and Cobalt which were absent. The results of the proximate analysis were as follows: % Moisture (54.25), % Carbohydrate (11.23), % Crude Protein (12.41), % Crude Fat (9.25), % Crude Fibre (10.65) and % Ash Content (2.21). The outcome of the study shows that all the samples of Bio-Clean II examined were of high microbiological quality and therefore poses no microbial threat to the safety of potential consumers; while the presence of appreciable quantities of some important phytochemical compounds and trace elements in the herbal remedy further underscores its medicinal benefits as earlier reported.

Pleural Infections: Antimicrobial Susceptibility Patterns of Bacterial Isolates and Associated Factors in Suspected Hospitalized Patients at Arba Minch General Hospital, Southern Ethiopia

Background: Pleural infection remains a clinical problem with high morbidity and mortality all over the world. Antimicrobial options are uncertain due to the lack of understanding of the bacteriology of pleural infection. Thus, the goal of this study was to determine bacteriological profiles, antimicrobial susceptibility patterns, and factors associated with pleural infection. Methods: An institution-based cross-sectional study was undertaken in Arba Minch General Hospital from 1 st January to 30 th November 2020. Socio-demographic, clinical, and behavioral data were collected using a pre-tested, structured questionnaire. Adducted amounts of pleural fluid samples were collected aseptically with sterile test tubes. Standard procedures were utilized for bacterial identification, and antimicrobial susceptibility testing was done using Kirby–Disk Bauer's diffusion method. Version 25 of the Statistical Package for the Social Sciences (SPSS) was used to analyze the data. The p-value of 0.05 was considered statistically significant. Results: A total of 152 hospitalized patients were enrolled in this study. The overall magnitude of bacterial pleural infection was 27.6%. The predominant bacteria isolated were Staphylococcus aureus with 34.9%, followed by Escherichia coli with 11.6%. Multidrug-resistant (MDR) isolates account for around 48.8% of all isolates, with Gram-positive bacterial isolates accounting for 71.4%. Methicillin-resistant was found in 26.7% and 33.3% of isolated Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS), respectively. One isolate of Enterococcus spp. was found to be vancomycin-resistant. All isolated Streptococcus pneumoniae and Streptococcus pyogenes were susceptible to penicillin, erythromycin, cotrimoxazole, and vancomycin. Likewise, isolated Pseudomonas aeruginosa was susceptible to piperacillin. The pleural infection showed a statistically significant association with age group less than or equal to 25 years old (p&lt;0.001), hospital admission for more than seven days (p&lt;0.007), chest tube drainage (p&lt;0.021), previous history of pneumonia (p&lt;0.029) and habit of alcohol drinking (p&lt;0.029). Conclusion: The overall rate of culture-confirmed pleural infection was high, and a considerable percentage of bacteria isolates showed increased resistant to routinely used antibiotics, indicating that more attention is needed to follow the spread and emergence of drug-resistant bacterial agents.

Isolation and identification of aerobic bacteria and their antibiogram profile in catheter related bloodstream infection among the hemodialysis patient in a tertiary care hospital

Background: Catheter-related bloodstream infection (CRBSI) is quite evident in hemodialysis (HD) patients. The pattern of the isolates from the catheter tip as well as blood culture and their sensitivity against antibiotics varies and set a huge challenge for the physician for its management. Aims and Objectives: The present study was undertaken to isolate and identify, causative organism in CRBSI from the HD patient and to determine the antibiotic susceptibility profile of each isolate and determines the current trend. Materials and Methods: A total (n=101) patients admitted for HD in the nephrology unit of a tertiary care hospital with preexisting comorbidities such as diabetes and hypertension (HT) were recruited according to inclusion/exclusion criteria after obtaining written consent. Blood samples from peripheral blood vessel of suspected CRBSI patients were collected as well as the catheter tip was cut and collected in sterile test tube and transported to microbiology laboratory for isolation, identification, and antibiotic susceptibility test. Results: The HD catheter tip culture was found positive in 54 (53.46%) samples out of the total 101 samples. The distribution of catheter tip culture positive patients and their association with diabetes mellitus was highest at age group &gt; 60 years with a p &lt; 0.0001. The association between catheter tip culture positive and HT was also found significant with P&lt;0.0001. After analysis of culture reports of HD catheter tip and peripheral blood, culture-positive reports were found in 15 (14.85%) patients as CRBSI. The distribution of CRBSI predominantly found in the age group of 41–50 years (33%) which was significant with P=0.004. The causative organisms for CRBSI were Gram negative under this study and multidrug resistant too. The only drug polymyxin B was 100% sensitive to Gram-negative organism whereas vancomycin and linezolid were 100% sensitive to Gram-positive organisms. Conclusion: Patients with kidney disease receiving HD with a central venous catheter experience high rates of bloodstream and catheter tip infection commonly in those suffering from diabetes, HT, and dyslipidemia. The causative organisms for CRBSI were mainly Gram negative with a concern over existence of multidrug resistance strain.

Study on Parametric Release of Ethylene Oxide Sterilization of Medical Devices

This study briefly introduces the basic theory of sterilization, the characteristics of ethylene oxide sterilization for medical devices and the key factors about sterilization effectiveness, analyzes and compares three methods used in the product release of medical devices sterilized by ethylene oxide: test for sterility, traditional release and parametric release, and focuses on the theoretical basis, feasibility, validation requirements, advantages and disadvantages of parametric release.

Development of surface modified nanoparticles of curcumin for topical treatment of diabetic retinopathy: In vitro, ex vivo and in vivo investigation

Diabetic retinopathy (DR) is the worst microvascular complication of diabetes that results in blindness. Present treatment of DR is invasive and associated with pain and inflammation. There is a need to develop painless treatment. The surface-modified PLGA (50:50) nanoparticles of Curcumin, which is a peroxisome proliferator-activated receptor-gamma agonist, were prepared to target DR by topical administration. Nanoparticles were optimized by a 32 factorial design. The Concentration of PLGA and number of HPH cycles at fixed pressure were independent variables whereas particle size. PDI and % entrapment efficiency were the dependent variables. Batch F6 with particle size, PDI, and % EE 194.7 nm, 0.231, and 90% respectively was selected as the optimized batch. The optimized batch was further subjected to spray drying and evaluated for various parameters. Residual solvent analysis was carried out by Gas chromatography. In vitro drug release study showed a biphasic drug release pattern of 70.17 ± 1.38% cumulative drug release at the end of 10 h. The release profile of curcumin from nanoparticles appeared to fit best with the Higuchi model. XRD study confirmed the molecular dispersion of the drug. The formulation showed satisfactory results in sterility testing, histology and isotonicity testing. In vivo study on rats showed dose dependent reduction in vascular endothelial growth factor (VEGF) concentration in vitreous fluid. Based on available evidences it can be concluded that the prepared formulation possesses great potential to manage diabetic retinopathy.

Self-Organization of Graft Copolymers and Retortable iPP-Based Nanoporous Films Thereof

Polyolefins might become inexpensive alternatives to the existing membranes based on polyethersulfone. Here, we disclose the production of retortable, well-defined polypropylene (PP)-based nanoporous films derived from amphiphilic graft copolymer precursors. The graft copolymers, containing a polypropylene backbone and polyester grafts, were obtained by grafting lactones, specifically δ-valerolactone and ε-caprolactone, from well-defined randomly functionalized poly(propylene-co-10-undecen-1-ol) as a macroinitiator. Depending on the composition, the graft copolymers self-assemble into droplet, cylindrical, lamellar, or interconnected two-phase morphologies. Functional mesoporous iPP-based films were fabricated by the selective degradation of the polyester blocks of the copolymers. Their structure and morphology were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM), small-angle X-ray scattering (SAXS), and solid-state NMR, while the mesoporosity was assessed by nitrogen sorption experiments. The pore size of the films is strongly influenced not only by the volume fraction of the copolymer blocks but unexpectedly also by the topology (i.e., number of grafts) of the graft copolymer, as was confirmed by computational modeling studies using the dynamic density functional theory (DDFT) engine within the Culgi software. This work provides a conclusive answer on how the morphology of iPP-based graft copolymers is tuned by the copolymer composition and the amount and length of the grafted polyester blocks. Filtration tests and flux determination demonstrated that such structurally well-defined mesoporous products could be considered for the development of ultrafiltration membranes while the chemical resistance and sterilization tests revealed their robust performance and suitability for water purification applications.

A state-of-the-art guide to the sterilization of thermoplastic polymers and resin materials used in the additive manufacturing of medical devices

Continuous development of additive manufacturing technologies has reached new areas, including medical research and healthcare applications, where precision, highly accurate reproducibility, disinfection, or even sterility of the end product is essential. The study aims to critically evaluate the effect of different sterilization and disinfection methods for most commonly used additive manufacturing technologies and materials in medical device development: PLA (polylactic acid), PETG (polyethylene terephthalate glycol), ABS (acrylonitrile butadiene styrene), and HIPS (high impact polystyrene) for material extrusion technology (FFF; fused filament fabrication), polyamide (PA2200) for powder bed fusion technology (SLS; selective laser sintering), MED610™ for PolyJet™ material jetting, and standard Formlabs™ white resin (V4) for SLA (stereolithography) technology. The materials were tested before and after different sterilization and disinfection protocols, including treatment with 70% ethanol, chlorine solution, H2O2 plasma sterilization, autoclave and dry heat sterilization, applying 10 and 20 cycles in all cases. Bacteriostatic/fungistatic and sterility tests were performed using Escherichia coli, Enterococcus faecalis, and Candida albicans as reference strains. Cytotoxicity was evaluated using A549 cells. The samples showed significant structural or aesthetic alterations detected by various mechanical tests, scanning electron microscopy, or differential scanning calorimetry (DSC-TGA). No significant cytotoxic effect was revealed during the experiment. Our results can serve as a guide for the selection of effective sterilization and disinfection methods for the most common materials used in 3D printing in medical and healthcare applications.

Assessment of the bacteriological quality and efficacy of two hand sanitizers sold within Ilishan-Remo Community of Ogun State, Nigeria

Background. Hand sanitizers have been recognized as an effective means of reducing bacterial load and transmission. It is needful to periodically assess the bacteriological status of individual products due to batch variation. Aim. This study was designed to assess the bacteriological quality and efficacy of two hand sanitizers sold within the Ilishan-Remo community of Ogun State, Nigeria, amidst the COVID-19 pandemic. Methodology. Samples of two brands of hand sanitizers were procured and assessed using standard bacteriological methods, including Sterility test, Surface viable count, Gram-stain, Motility test, Biochemical tests, Quantitative suspension test, and Agar diffusion test. Data were analyzed with paired-samples T-Test using Statistical Package for the Social Sciences -Version 20.0 (SPSS-20.0) to assess for significant variation between the effectiveness of the two hand sanitizers. P-values &lt;0.05 was considered significant. Results. The study's outcome showed the satisfactory bacteriological quality of both hand sanitizers tested. However, the mean bacterial load was not significantly reduced after sterilization using both hand sanitizers. The hand sanitizers' bactericidal activity was also considered unsatisfactory since the Log reduction was less than 5. Brand B hand sanitizer proved to be more potent than Brand A at the contact time. Each of the products displayed varying inhibitory activities against the bacterial isolates. Conclusion. The study highlighted the need to periodically assess the bacteriological quality and efficacy of hand sanitizers to guarantee the general safety of the end users and ensure proper infection control.

Clarification of large-volume bacterial cultures using a centrifuge-free protocol.

AimsTo provide a reliable, reproducible and centrifuge‐free filtration protocol for clarification of large volumes of bacterial cultures.Methods and ResultsFour experiments were designed to compare different techniques enabling clarification of Escherichia coli cultures using as a benchmark the concentration and quality of bacterial outer membrane vesicles (OMVs). The experiments were designed to examine the performance of different extraction methods on large volume (≥1 L) filtrations of bacterial culture media. Performance parameters included filtration flow rates, sterility testing and characterization of the filtrates by: (i) SDS‐PAGE, (ii) cryogenic transmission electron microscopy, (iii) nanoparticle tracking analysis and (iv) Qubit protein quantification. The experiments revealed that: (i) addition of the filter aid Diatomaceous Earth to the bacterial cultures improved filtration flow rates significantly and eliminated the need for centrifugation prior to filtration; (ii) sterile filtration was successful as no bacterial passage was identified through the membrane filter; (iii) centrifuge‐free filtrates contained an increased amount of OMVs compared to centrifuged filtrates.ConclusionsIn comparison to conventional centrifuge‐based protocols, the clarification method presented has universal applicability for a broad range of microbial extraction procedures, regardless of the volume of culture harvested. Moreover, the decreased amount of OMVs presented in the filtrates following centrifugation step provides an additional argument in favour of a centrifuge‐free approach.Significance and Impact of the StudySterile filtration is a universal method for the clarification of bacterial cultures. Common challenges related to filtration include filter clogging and long processing times, due to limited centrifugation capacity, which can affect product quality. The proposed protocol is likely to ensure a highly effective filtration process and could be a novel approach in improving the filtrate products without the need of centrifugation.

Plasma Non Thermal Sebagai Sterilisasi Masker untuk Inaktivasi Virus Corona (COVID-19)

We used non-thermal plasma generators to sterilize textile materials, especially in personal protective equipment for masks, to inactivate viruses and bacteria attached to the mask material in this study. The design of the ozone generator utilizes the non-thermal plasma method of corona discharge using a high voltage generator with an output voltage of 3.,000 V. The sterilization process was carried out with variations in sterilization time (10,15 and 20 minutes) and an active electrode height of 3 cm. This research was carried out using CT RT-PCR testing to determine the cycle threshold value contained in the nucleic acid RNA of the COVID-19 virus before and after sterilization. Changes in CT values obtained after sterilization for 20 cycle threshold (CT) values were 37.07 for the N gene and 35,67 for the ORF. Based on the sterilization test results, no data stated that the virus was harmful. Based on these results, the increase in CT numbers is directly proportional to the length of time for sterilization so that the RNA content of the COVID-19 virus decreases. To determine the effect of the sterilization process on the hydrophilic properties of the maks, the Fourier Transform Infra-Red (FTIR) test was carried out. The study results show that non-thermal plasma can sterilize masks from the coronavirus. This study concludes that the plasma method can be used to sterilize masks from the coronavirus

Comparison of the Sensitivity of Sterility Tests Based on the Analysis of 2x2 Contingency Tables

The work is devoted to statistical methods for determining the comparative sensitivity of sterility analyzers with a binary scale: 1/0, +/-. The paper considers both traditional statistical test methods namely the direct binomial test, the McNemar test, and the new, highly sensitive Yefimov Method, and Pearson-Yefimov statistical test. First, the comparative effectiveness of statistical methods for assessing the sensitivity of testers is demonstrated on a specially developed model system (the Test Bench), and then on real experimental data. The data were obtained during the validation of a new tester and a new method for analyzing samples for sterility. The new method is compared with the old one, the certified method. The sensitivity of both new and old methods (testers) was already determined earlier by a direct non-statistical method, which allowed us to compare the results of the two approaches. The factors influencing the efficiency of statistical tests are revealed and described.