Bacterial Culture Research Articles

A colorimetric biosensor with infrared sterilization based on CuSe nanoparticles for the detection of E. coli O157:H7 in food samples.

Escherichia coli O157:H7 is a major threat to public health. At present, the detection methods for E. coli O157:H7 mainly include traditional bacterial culture, immunology (enzyme-linked immune-sorbent assay) and molecular biology techniques (polymerase chain reaction). These methods have the limitations of professional operation, waste of time and energy, and high cost. Therefore, we have developed a simple, fast, bactericidal colorimetric biosensor to detect E. coli. O157:H7. The entire process was completed in 80 minutes. The method has been successfully applied to milk and mineral water samples with satisfactory results, proving that the method is an effective method for real-time detection and inactivation of bacteria.

Herbidomicins, two pairs of polyketide tautomers produced by an actinomycete of the genus Herbidospora.

Herbidospora is one of the underexplored actinomycete genera from which only a limited number of secondary metabolites are reported. In our continuing investigation on less explored actinomycetes, a liquid culture of Herbidospora sp. RD 11066 was found to contain unknown metabolites that had no match in our in-house UV database. Chromatographic separation and following structural analysis using NMR and MS identified these metabolites to be chromanone and chromene derivatives, which were respectively composed of an inseparable mixture of two isomeric forms. The former polyketides, designated to be herbidomicins A1 (1) and A2 (2), are positional isomers in terms of a methyl substituent on an aromatic ring that mutually interconvert by acetal exchange by two phenolic hydroxy groups. The latter pair, herbidomicins B1 (3) and B2 (4), is Z/E-isomers regarding an enol ether double bond. Herbidomicins 1-4 were weakly antifungal against a dermatophytic fungus Trichophyton rubrum and were moderately cytotoxic against murine leukemia P388 cells.

Predictive Model for Extended-Spectrum β-Lactamase-Producing Bacterial Infections Using Natural Language Processing Technique and Open Data in Intensive Care Unit Environment: Retrospective Observational Study.

Machine learning has advanced medical event prediction, mostly using private data. The public MIMIC-3 (Medical Information Mart for Intensive Care III) data set, which contains detailed data on over 40,000 intensive care unit patients, stands out as it can help develop better models including structured and textual data. This study aimed to build and test a machine learning model using the MIMIC-3 data set to determine the effectiveness of information extracted from electronic medical record text using a named entity recognition, specifically QuickUMLS, for predicting important medical events. Using the prediction of extended-spectrum β-lactamase (ESBL)-producing bacterial infections as an example, this study shows how open data sources and simple technology can be useful for making clinically meaningful predictions. The MIMIC-3 data set, including demographics, vital signs, laboratory results, and textual data, such as discharge summaries, was used. This study specifically targeted patients diagnosed with Klebsiella pneumoniae or Escherichia coli infection. Predictions were based on ESBL-producing bacterial standards and the minimum inhibitory concentration criteria. Both the structured data and extracted patient histories were used as predictors. In total, 2 models, an L1-regularized logistic regression model and a LightGBM model, were evaluated using the receiver operating characteristic area under the curve (ROC-AUC) and the precision-recall curve area under the curve (PR-AUC). Of 46,520 MIMIC-3 patients, 4046 were identified with bacterial cultures, indicating the presence of K pneumoniae or E coli. After excluding patients who lacked discharge summary text, 3614 patients remained. The L1-penalized model, with variables from only the structured data, displayed a ROC-AUC of 0.646 and a PR-AUC of 0.307. The LightGBM model, combining structured and textual data, achieved a ROC-AUC of 0.707 and a PR-AUC of 0.369. Key contributors to the LightGBM model included patient age, duration since hospital admission, and specific medical history such as diabetes. The structured data-based model showed improved performance compared to the reference models. Performance was further improved when textual medical history was included. Compared to other models predicting drug-resistant bacteria, the results of this study ranked in the middle. Some misidentifications, potentially due to the limitations of QuickUMLS, may have affected the accuracy of the model. This study successfully developed a predictive model for ESBL-producing bacterial infections using the MIMIC-3 data set, yielding results consistent with existing literature. This model stands out for its transparency and reliance on open data and open-named entity recognition technology. The performance of the model was enhanced using textual information. With advancements in natural language processing tools such as BERT and GPT, the extraction of medical data from text holds substantial potential for future model optimization.

Directed Evolution of Acoustic Reporter Genes Using High-Throughput Acoustic Screening.

A major challenge in the fields of biological imaging and synthetic biology is noninvasively visualizing the functions of natural and engineered cells inside opaque samples such as living animals. One promising technology that addresses this limitation is ultrasound (US), with its penetration depth of several cm and spatial resolution on the order of 100 μm. Within the past decade, reporter genes for US have been introduced and engineered to link cellular functions to US signals via heterologous expression in commensal bacteria and mammalian cells. These acoustic reporter genes (ARGs) represent a novel class of genetically encoded US contrast agent, and are based on air-filled protein nanostructures called gas vesicles (GVs). Just as the discovery of fluorescent proteins was followed by the improvement and diversification of their optical properties through directed evolution, here we describe the evolution of GVs as acoustic reporters. To accomplish this task, we establish high-throughput, semiautomated acoustic screening of ARGs in bacterial cultures and use it to screen mutant libraries for variants with increased nonlinear US scattering. Starting with scanning site saturation libraries for two homologues of the primary GV structural protein, GvpA/B, two rounds of evolution resulted in GV variants with 5- and 14-fold stronger acoustic signals than the parent proteins. We anticipate that this and similar approaches will help high-throughput protein engineering play as large a role in the development of acoustic biomolecules as it has for their fluorescent counterparts.

Characterization of Clostridioides difficile Persister Cells and Their Role in Antibiotic Tolerance

Clostridioides difficile is a Gram-positive pathogen known for its toxin production and spore formation. It is primarily responsible for most cases of antibiotic-associated diarrhea. Bacterial persisters are a small subset of the population that exhibits transient tolerance to bactericidal substances, and they are of significant medical concern due to their association with the emergence of antibiotic resistance and difficult-to-treat chronic or recurrent infections. Vancomycin, the predominant antibiotic utilized in the management of C. difficile infection, is extensively applied in the realm of clinical practice. Previous studies have demonstrated a persister-like phenotype with treatments involving this antibiotic. However, the mechanism in C. difficile remains largely unknown, primarily due to the challenge of isolating this small population at any given time. To better characterize C. difficile persister cells, we present a study that enables the enrichment and characterization of persister cells from bacterial cultures in both the exponential and stationary phases. Moreover, we could differentiate between triggered (induced using antibiotics such as vancomycin) and spontaneous (stochastic) persister cells. Additionally, we observed the involvement of toxin-antitoxin systems and Clp proteases in persister cell formation.

Broad-Spectrum Efficacy and Modes of Action of Two Bacillus Strains against Grapevine Black Rot and Downy Mildew

Black rot (Guignardia bidwellii) and downy mildew (Plasmopara viticola) are two major grapevine diseases against which the development of efficient biocontrol solutions is required in a context of sustainable viticulture. This study aimed at evaluating and comparing the efficacy and modes of action of bacterial culture supernatants from Bacillus velezensis Buz14 and B. ginsengihumi S38. Both biocontrol agents (BCA) were previously demonstrated as highly effective against Botrytis cinerea in grapevines. In semi-controlled conditions, both supernatants provided significant protection against black rot and downy mildew. They exhibited antibiosis against the pathogens by significantly decreasing G. bidwellii mycelial growth, but also the release and motility of P. viticola zoospores. They also significantly induced grapevine defences, as stilbene production. The LB medium, used for the bacterial cultures, also showed partial effects against both pathogens and induced plant defences. This is discussed in terms of choice of experimental controls when studying the biological activity of BCA supernatants. Thus, we identified two bacterial culture supernatants as new potential biocontrol products exhibiting multi-spectrum antagonist activity against different grapevine key pathogens and having a dual mode of action.

Revealing the Mechanical Impact of Biomimetic Nanostructures on Bacterial Behavior

Naturally inspired nanostructured surfaces, by mechanically inhibiting bacterial adhesion or killing bacteria, effectively prevent the emergence of antibiotic resistance, making them a promising strategy against healthcare-associated infections. However, the current mechanical antibacterial mechanism of nanostructures is not clear, thus limiting their potential application in medical devices. This work mainly investigates the mechanical influence mechanism of biomimetic nanostructure parameters on bacterial adhesion and growth status. The results of 12 h bacterial culture showed that compared to flat surfaces, nanostructures reduced the adhesion of both E. coli and S. aureus bacteria by 49%~82%. The bactericidal efficiency against E. coli increased by 5.5%~31%, depending on the shape of the nanostructures. Nanostructures with smaller tip diameters exhibited the best anti-bacterial adhesion effects. Nanostructures with sharp tips and larger interspaces showed greater bactericidal effects against E. coli. Surfaces with larger tip diameters had the poorest antibacterial effects. Subsequently, a finite element model was established to quantitatively analyze the mechanical interactions between bacteria and nanostructures. It was found that different nanostructures affect bacterial adhesion and growth by altering the contact area with bacteria and inducing stress and deformation on the cell wall. Nanostructures with smaller tip diameters reduced the attachment area to bacteria, thereby reducing bacterial adhesion strength. Nanostructures with larger interspaces induced greater stress and deformation on the cell wall, thereby enhancing bactericidal efficiency. Finally, experimental verification with L929 cells confirmed that nanostructures do not cause mechanical damage to the cells. These studies deepen our understanding of the antibacterial mechanism of biomimetic nanostructures and provide new insights for the design of optimal nanostructures.

Multi-centric evaluation of Truenat MTB and MTB-RIF Dx assays for diagnosis of extrapulmonary tuberculosis

Extra-pulmonary TB (EPTB) is difficult to diagnose due to paucibacillary nature of disease. Current study evaluated accuracy of Truenat MTB and MTB-Rif Dx (TN), for detection of Mycobacterium tuberculosis and resistance to rifampicin. Samples were collected from 2103 treatment naive adults with presumptive EPTB, and tested by smear microscopy, liquid culture (LC) (MGIT-960) and GeneXpert MTB/RIF (GX) (Microbiological Reference Standards, MRS). TN results were compared to MRS and Composite Reference Standards (CRS, Microbiology, histopathology, radiology, clinical features prompting decision to treat, response to treatment). CRS grouped patients into 551 confirmed, 1096 unconfirmed, and 409 as unlikely TB. TN sensitivity and specificity was 73.7% and 90.4% against GX. Against LC, Overall sensitivity of GX was 67.6%, while that of TN was 62.3%. Highest sensitivity by TN was observed in pus samples (89%) and highest specificity (92%) in CSF samples, similar to GX. TN sensitivity was better in fluid and biopsy samples and slightly inferior for lymph node aspirates compared to GX. TN sensitivity for RIF resistance detection was slightly superior to GX. TN and GX results were further compared to Clinical Reference Standards. TN detected 170 TB patients initiated on treatment missed by GX, while GX detected 113 such patients missed by TN. Of 124 samples with RIF resistance discordance between GX and TN, GX reported 103/124 as sensitive, 3/124 as indeterminate and 18 as resistant (13/18 samples had low/very low DNA load) while TN reported RIF resistance indeterminate in 103/111 low/very low DNA load samples. Due to paucibacillary nature of EPTB samples, culture yield was poor and phenotypic drug susceptibility testing failed to resolve the discordance. The study establishes TN at par with GX and can be utilized for quick and accurate diagnosis of EPTB.

Evaluating the effects of temperature and agitation on biofilm formation of bacterial pathogens isolated from raw cow milk

ObjectivesTo study the effect of agitation and temperature on biofilm formation (cell aggregates embedded within a self-produced matrix) by pathogenic bacteria isolated from Raw cow milk (RCM).MethodsA 40 RCM samples were gathered from eight dairy farms in Riyadh, Saudi Arabia. After bacterial culturing and isolation, gram staining was performed, and all pathogenic, identified using standard criteria established by Food Standards Australia New Zealand (FSANZ), and non-pathogenic bacteria were identified using VITEK-2 and biochemical assays. To evaluate the effects of temperature and agitation on biofilm formation, isolated pathogenic bacteria were incubated for 24 h under the following conditions: 4 °C with no agitation (0 rpm), 15 °C with no agitation, 30 °C with no agitation, 30 °C with 60 rpm agitation, and 30 °C with 120 rpm agitation. Then, biofilms were measured using a crystal violet assay.ResultsOf the eight farm sites, three exhibited non-pathogenic bacterial contamination in their raw milk samples. Of the total of 40 raw milk samples, 15/40 (37.5%; from five farms) were contaminated with pathogenic bacteria. Overall, 346 bacteria were isolated from the 40 samples, with 329/346 (95.1%) considered as non-pathogenic and 17/346 (4.9%) as pathogenic. Most of the isolated pathogenic bacteria exhibited a significant (p < 0.01) increase in biofilm formation when grown at 30 °C compared to 4 °C and when grown with 120 rpm agitation compared to 0 rpm.ConclusionHerein, we highlight the practices of consumers in terms of transporting and storing (temperature and agitation) can significantly impact on the growth of pathogens and biofilm formation in RCM.

Screening Potential Nitrification Inhibitors through a Structure–Activity Relationship Study—The Case of Cinnamic Acid Derivatives

Using a nitrification inhibitor to decrease nitrification rates in soil represents a promising strategy to improve nitrogen fertilizer use efficiency. Nonetheless, rapid screening of nitrification inhibitors remains challenging. In this study, we propose a strategy to screen potential nitrification inhibitors through a structure–activity relationship (SAR) study based on a rapid determination of nitrification inhibition. To demonstrate this, the nitrification inhibition potentials of cinnamic acid derivatives against Nitrosomonas europaea growth were evaluated in a liquid culture. The SAR study showed that hydroxyl and fluoride groups were the favorable substituents on the benzene ring, and the ester group and double bond in the side chain were essential for maintaining high inhibition efficacy. Three compounds with notable inhibitory efficacy (EC50 = 8–25 μM) were further assessed in agricultural soil, and they displayed a noteworthy reduction in nitrification rate and bacterial amoA gene numbers. Based on the results, we identified methyl cinnamate, methyl 4-hydroxycinnamate, and methyl 4-fluorocinnamate as promising candidates for nitrification inhibition.

Perichondritis of the auricle: bacterial or fungal? (A case series).

Suppurative perichondritis of the auricle is a common disease that can easily cause malformations if it develops into an uncontrolled infection. In nearly half of the cases, otolaryngologists cannot identify the pathogens involved. In the present work, we described two cases of pyogenic perichondritis, with negative on conventional culture. However, using metagenomic next-generation sequencing (mNGS), we detected fungal infections in the patients and after the patients were given anti-fungal treatment, the patients achieved a good prognosis. These cases highlighted the possibility that fungi might be the involved pathogens in patients who have had multiple negative bacterial cultures, and mNGS should be applied in these cases. mNGS could be used as a supplement to traditional culture methods.

Comparison of the diversity of anaerobic-cultured gut bacterial communities on different culture media using 16S rDNA sequencing

The gut microbiome is a dense and diverse community of different microorganisms that deeply influence human physiology and that have important interactions with pathogens. For the correct antibiotic treatment of infections, with its twin goals of effective inhibition of the pathogen and limitation of collateral damage to the microbiome, the identification of infectious organisms is key. Microbiological culturing is still the mainstay of pathogen identification, and anaerobic species are among the most demanding bacterial communities to culture. This study aimed to evaluate the impact of growth media on the culture of an-aerobic bacteria from human stool samples. Stool samples from eight human subjects were cultured each on a yeast extract cysteine blood agar (HCB) and modified peptone-yeast extract-glucose (MPYG) plate and subjected to Illumina NGS analysis after DNA extraction and amplification. The results showed tight clustering of sequencing samples belonging to the same human subject. Various differences in bacterial richness and evenness could be observed between the two media, with HCB plates supporting the growth of a more diverse microbial community, and MPYG plates improving the growth rates of certain taxa. No statistical significance was observed between the groups. This study highlights the importance of choosing the appropriate growth media for anaerobic bacterial culture and adjusting culture conditions to target specific pathological conditions. HCB plates are suitable for standard microbiological diagnostics, while MPYG plates may be more appropriate for targeting specific conditions. This work emphasizes the role of next-generation sequencing in supporting future research in clinical microbiology.

Optimization of the production of Exopolysaccharide (EPS) from biofilm-forming bacterial consortium using different parameters

Bacterial cells produce a variety of exopolysaccharide (EPS) throughout their life cycle. EPS plays a crucial role in the formation of biofilms and the control of environmental processes in microbial communities. The bacterial community benefits from biofilms in several ways, including nutrient compartmentation and storage, environmental stress resistance and synergism. The generation of EPS by consortium-associated bacteria, which involves a variety of microorganisms, is versatile and efficient for use in industrial and environmental processes, such as biotechnology and pollution degradation. The qualitative and quantitative chemical characteristics of the consortium's EPS are mostly determined by the type of culture utilized, nutrient type, temperature, and pH. The main goal of the study was to find out how EPS biosynthesis works in a bacterial consortium culture. To achieve maximum EPS regeneration, pH, temperature, carbon, and nitrogen sources were optimized. A consortium of three bacterial strains i.e. Klebsiella pneumonia strain, Pseudomonas aeruginosa strain and Burkholderia cepacian strain that were distinguished by their capacity to produce biofilms were developed as part of the study. The maximum total EPS production was detected after 8 days of incubation at pH 7.5 (15.5g/L) and a temperature of 35 °C (12.60g/L). The optimum EPS production was identified as 17.84g/L and 21.07g/L when ammonium sulfate and glucose were employed as nitrogen and carbon supplements, respectively. The protein concentration of the EPS was 3067µg/mL, which was more than the carbohydrate (263.10µg/mL) and DNA (7.60µg/mL) content. The total protein/carbohydrate ratio of the EPS detected in the present study was 11.65, which was much higher than in prior investigations. FTIR analysis of EPS confirmed the functional groups of carbohydrates, proteins, lipids and DNA, viz., C=O, COOH, NH, OH, CH and OCH3. The study's findings revealed that enhancing the consortium's EPS molecules involves lowering biofilm-related infections and improving the efficacy of antimicrobial treatments in wastewater.

Sexual activity, vaginal symptoms, maternal perineal hygiene behavior, and constipation on ano-vaginal colonization of group B streptococcus in near term pregnancy

BackgroundMaternal Group B Streptococcus (GBS) colonization is influenced by many factors but results are inconsistent. Consideration of antenatal risk factors may help inform decision making on GBS microbiological culture screening where universal screening is not standard of care. We sought to identify independent predictors of GBS colonization at 34–37 weeks gestation incorporating vaginal symptoms, perineal hygiene measures, sexual activity, and a potential novel factor, constipation.MethodsIn this prospective cross-sectional study, 573 women at 34–37 weeks gestation had an ano-vaginal swab taken and sent for selective culture for GBS. Women were asked about vaginal bleeding, discharge, irritation and candidiasis, antibiotic use during pregnancy, ano-vaginal hygiene practices such as douching and perineal cleansing after toileting, sexual intercourse related activities, and a potential novel factor for GBS carriage, constipation. Maternal basic demographics and obstetric-related characteristics were also collected. Bivariate analyses were performed to identify associates of GBS colonization. All variables with p < 0.05 found on bivariate analysis were then included into a model for multivariable binary logistic regression analysis to identify independent risk factors for GBS colonization.ResultsGBS colonization was found in 235/573 (41.0%) of participants. Twenty six independent variables were considered for bivariate analysis. Eight were found to have p < 0.05. Following adjusted analysis, six independent predictors of GBS colonization were identified: ethnicity, previous neonatal GBS prophylaxis, antenatal vaginal irritation, antibiotic use, recent panty liner use, and frequency of sexual intercourse. Vaginal discharge and perineal cleansing were not associated after adjustment. Recent douching and constipation were not associated on bivariate analysis.ConclusionThe identification of independent predictors of GBS colonization in late pregnancy may inform the woman and care provider in their shared decision making for microbiological screening at 35–38 weeks gestation in locations where universal GBS screening is not standard of care.Ethics oversightThis study was approved by the Medical Ethics Committee of University Malaya Medical Centre (UMMC) on August 9, 2022, reference number 2022328-11120.

Use of diagnostic tests in elderly patients consulting the emergency department. Analysis of the emergency department and elder needs cohort (EDEN-8)

ObjectiveAnalyse the association between the use of diagnostic tests and the characteristics of older patients 65 years of age or more who consult the emergency department (ED). MethodsWe performed an analysis of the EDEN cohort that includes patients who consulted 52 Spanish EDs. The association of age, sex, and ageing characteristics with the use of diagnostic tests (blood tests, electrocardiogram (ECG), microbiological cultures, X-ray, computed tomography, ultrasound, invasive techniques) was studied. The association was analysed by calculating the adjusted odds ratios (aOR) and their 95 % confidence intervals (CI) using a logistic regression model. ResultsA total of 25,557 patients were analysed. There was an increase in the use of diagnostic tests based on age, with an aOR for blood test of 1.805 (95 %CI 1.671 – 1.950), ECG 1.793 (95 %CI 1.664 – 1.932) and X-ray 1.707 (95 %CI 1.583 – 1.840) in the group of 85 years or more. The use of diagnostic tests is lower in the female population. Most ageing characteristics (cognitive impairment, previous falls, polypharmacy, dependence, and comorbidity) were independently associated with increased use of diagnostic tests. ConclusionsAge, and the characteristics of ageing itself are generally associated with a greater use of diagnostic tests in the ED.

Limosilactobacillus reuteri and Its Probiotic Potential against Cariogenic Bacteria

Bacteriotherapy is a promising option in addressing dental caries, a persistent global public health challenge with multifactorial origin, including dysbiosis. Despite the exploration of various probiotics, outcomes remain inconclusive. Objective: This study aimed to assess the inhibitory potential of L. reuteri and other potential probiotics like S. salivarius and S. oralis on the growth, adhesion, colonization, and viability of major cariogenic pathogens, comparing their probiotic efficacy. Methods: An in vitro experimental study was conducted, encompassing direct competition assays in solid and liquid co-culture tests and the characterization of adhesion to dental enamel and cell viability by life or death assay. Results: L. reuteri exhibited the significant inhibition of S. sobrinus and S. mutans growth in both solid and liquid cultures, with statistically notable differences. Scanning electron microscopy and confocal microscopy demonstrated reduced cariogenic biofilm formation when combined with L. reuteri, corroborated by diminished bacterial viability and decreased dental enamel coverage. These findings underscore L. reuteri’s potential as an effective agent in caries prevention. Conclusion: The study suggests L. reuteri could serve as an effective probiotic in bacteriotherapy against dental caries. It displayed substantial inhibitory activity in vitro against cariogenic bacteria, impeding biofilm formation and adhesion, thereby impacting cell viability.

Chromosome-Scale Genome Assembly Provides Insights into Fresh Pine Wood Decay Strategies of the Wolfiporia hoelen

The sclerotia of Wolfiporia hoelen (Fr.) Y.C. Dai &amp; V. Papp is an important traditional Chinese medicine with diverse pharmacological properties. This study utilized a combination of PacBio Long-Read Sequencing, Illumina Short-Read Sequencing, and Hi-C Sequencing to generate a high-quality chromosome-level genome assembly of a W. hoelen strain Minling A5. There were 112 contigs in the genome, with 62.95 Mb in total length and 4.21 Mb in length for the contig N50. The average GC content was 51.89%. Based on Hi-C data, we corrected the CCS data and scaffolded them into 14 pseudo-chromosomes. The genome contained 44.37% repetitive sequences and 12,670 protein-coding genes, 86.53% (10,963) of which could be functionally annotated in at least one of the KOG, GO, Pfam, Swissprot, TrEMBL, NR, and KEGG databases. In addition, 240 transfer RNAs, 97 ribosomal RNAs, and 103 other non-coding RNAs were identified in the W. hoelen genome. A total of 755 pseudogenes were also identified, with an average length of 2665.51 bp. Further, there were 398, 100, 2837, 519, and 2068 genes annotated by CAZymes, TCDB, PHI, P450, and DFVF databases, respectively. One notable attribute of W. hoelen is its capacity to thrive in a substrate of fresh pine sawdust. Through an analysis of the growth on various pure wood sawdust culture media, we found that the growth of W. hoelen and Sparassis latifolia on pine sawdust was similar to that on broad-leaved wood sawdust, while the growth of Pleurotus ostreatus, P. eryngii, and Cyclocybe aegerita was slower than that on broad-leaved wood sawdust. By the functional annotation analysis of orthogroups in these five mushroom-forming fungi, it was determined that 645 orthogroups were specifically common in W. hoelen and S. latifolia. The genes in these specific orthogroups were significantly enriched in 12 pathways, including steroid biosynthesis, biosynthesis of antibiotics, and tyrosine metabolism. The high-quality genome and comparative genome analysis results significantly contribute to advancing our foundational knowledge of W. hoelen biology, while also offering valuable insights for the development of innovative biotechnological approaches aimed at enhancing the efficient and sustainable utilization of Pinus.

Скрининг и характеристика антиоксидантных свойств психрофильных микроводорослей и цианобактерий Балтийского моря

At present, the issue of obtaining a complex of biologically active substances with antioxidant activity from psychrophilic Psychrophilic microalgae and cyanobacteria are a prospective source of biologically active antioxidant substances. New antioxidant complexes could expand the scope of their industrial application. The research objective was to identify psychrophilic microalgae and cyanobacteria from the Baltic Sea in order to study their antioxidant properties. The research featured psychrophilic microalgae and cyanobacteria obtained from the Curonian Lagoon and the Baltic Bay in the Baltic Sea, Kaliningrad Region, Russia, in March – May 2022. The authors used the Pasteur method and the flow cytometry method to isolate pure cultures of psychrophilic microalgae and cyanobacteria. The method of spectrophotometry made it possible to study the antioxidant activity by analyzing radical scavenging, reducing ability, and chelating. The psychrophilic microalga Skeletonema pseudocostatum demonstrated the highest antioxidant activity in all three methods: 17.62 μmol/g trolox equivalents according to the ABTS method, 58.16 μmol/g trolox equivalents according to the DPPH method, and 3.91 μmol/g trolox equivalents according to the FRAP method. The psychrophilic microalga Thalassiosira pseudonana exhibited the following values of antioxidant activity: 12.08, 12.42, and 3.13 μmol/g trolox equivalents, respectively. The antioxidant activity of the psychrophilic microalgae Fragilariopsis kerguelensis was 13.53, 11.84, and 1.09 μmol/g trolox equivalents, respectively. The antioxidant activity of the psychrophilic cyanobacterium Aphanizomenon gracile was 15.73, 19.89, and 2.47 μmol/g trolox equivalents, respectively. The antioxidant activity of the psychrophilic cyanobacterium Anabaena cylindrica was 12.62, 13.16, and 2.16 μmol/g trolox equivalents, respectively. The samples of psychrophilic microalgae and cyanobacteria obtained from natural environment in the Russian Baltic Sea demonstrated good antioxidant properties, which makes them a potential raw material for new pharmaceutical substances.

Ancillary Benefit of Microbiology Culture Diagnostic Stewardship: Decreasing Healthcare’s Climate Impact

Abstract We calculated weights of blood, urine, and endotracheal tube culture supplies and quantified greenhouse gas emissions emitted for disposal of these supplies. Of note, disposal related emissions for a positive blood and endotracheal tube culture are each equivalent to driving 0.6 and 0.4 miles, respectively, in a gasoline-powered vehicle.

Cross-sectional study investigating the components and quality of colostrum and colostrum replacement products fed to Ontario dairy goat kids

Colostrum replacement products for use in goat kids are sourced from bovine colostrum and often used by producers to supplement or replace maternal colostrum to prevent infections. To compare the colostrum replacement products fed on-farm to caprine colostrum a cross-sectional study was undertaken. Ontario dairy goat producers were asked to collect first milking colostrum from their goats and samples of the reconstituted commercial replacement product currently in use. The frozen samples were thawed and submitted for testing of fat, protein and lactose content, IgG1 concentration and aerobic bacterial culture. Compared with caprine colostrum, the reconstituted replacement products were lower in protein (11.7%; P = 0.0007), and fat (4.6%; P < 0.0001) and higher in lactose (5.4%; P < 0.0001) on average. The average IgG1 concentration in goat colostrum (53.5 g/L; range: 16.6-1985.8) was significantly higher than in colostrum replacement products (33.7 g/L; range: 10.7-55.3) (P < 0.0001). The Brix cut-point for good quality goat colostrum (50 g/L) was calculated at 23% (sensitivity = 69.6%, specificity = 88.0%) for goat colostrum and 26% for the colostrum replacement product (sensitivity = 87.5%, specificity = 100%). The average aerobic count for goat colostrum was lower (2.95 log10 cfu/mL) than the colostrum replacement product samples that were cultured (3.85 log10 cfu/mL; P < 0.0001). Further investigation into colostrum replacement products, including on-farm storage of opened powdered product and mixing and storage of reconstituted product, is warranted. Variability in the levels of IgG1, aerobic bacterial growth and fat, protein and lactose content in colostrum replacement products also requires further exploration to determine their effects on kid health.