Cultures Of Microorganisms Research Articles

Evaluating the clinical utility of cervical cultures in postpartum endometritis management.

To evaluate the utility of cervical cultures in the diagnosis and management of postpartum endometritis. A retrospective study was conducted on 1069 cervical cultures collected from postpartum women with suspected endometritis between 2011 and 2021. Patient demographics, obstetric history, clinical parameters, and culture results were analyzed. Microorganisms were categorized into five groups based on species and virulence. Statistical analysis was performed to identify associations between risk factors, pathogens, and disease severity. The positivity rate for distinct microorganisms in cervical cultures was 33.1%. Escherichia coli (10.8%) and Group B Streptococcus (7.5%) were the most common isolates. Prolonged labor duration and prolonged rupture of membranes were associated with Enterobacterales infections. Elevated white blood cell count was linked to Enterobacterales and beta-hemolytic Streptococci, while the former were also associated with higher rate of postpartum clinic visit. No significant differences in disease severity were found between other microorganism groups. The study suggests that while cervical cultures can identify potential pathogens in postpartum endometritis, their clinical utility is questionable due to the polymicrobial nature of the disease and the isolation of commensal microorganisms. The lack of significant differences in disease severity across various microorganism groups raises questions regarding the contribution of distinct bacterial identification in endometritis management.

Contribution of data acquired from spectroscopic, genomic and microbiological analyses to enhance mussels’ quality assessment

In this study, a large amount of heterogeneous data (i.e., microbiological, spectral and Next Generation Sequencing data) were obtained analyzing mussels of different species and origin, to acquire a comprehensive view about the quality and safety of these products. More specifically, spectral data were collected through Fourier transform Infrared (FTIR) spectroscopy, while the overall profile of microorganisms present in these samples, affecting quality and safety of mussels throughout storage, was determined through Next Generation Sequencing (NGS) using 16S rRNA metabarcoding analysis. In parallel, conventional microbiological analysis for the estimation of culturable spoilage microorganisms (total aerobes, Pseudomonas spp., B. thermosphacta, Shewanella spp. and Enterobacteriaceae) was applied. Different machine learning algorithms, namely Partial Least Square (PLS), Support Vector Machines (SVM), k-Nearest Neighbors (kNN), Random Forest (RF) Neural Networks (NN)) were applied accordingly, to assess the potential of FTIR and NGS data to provide useful information about mussels’ microbiological quality.Microbial counts ranged from 3.5 to 9.0 log CFU/g, while NGS revealed several bacterial genera such as Pseudoalteromonas, Psychrobacter, Acinetobacter, Pseudomonas, B. thermosphacta, Psychrobacter, Kistimonas, Psychrilyobacter to affect the quality of mussels, depending on the mussel species, batch and storage conditions. According to the performance metrics, the SVM algorithm in tandem with FTIR achieved the highest prediction accuracy for microbial counts in M. chilensis samples (Rsquared; 0.89, RMSE; 0,74), while in the case of predicting the abundance of microbial genera using spectroscopic data, the best performing algorithm varied by bacterial genus. Indicatively, in M. chilensis, RF, kNN and NN performed better in predicting Enterococcus, Enhydrobacterium and Pseudoalteromonas, respectively (Rsquared = 0.92, 0.93, 0.99). Associations between genomics data and specific spectral regions were further investigated, revealing certain spectral regions that are associated with mussels’ quality and safety.The application of “multi-omics” in seafood supply chain can provide insightful information about mussels’ quality and safety compared to the methodologies followed in current quality and safety management systems.

Optimization of lung tissue pre-treatment by bead homogenization for subsequent culturomics

The discovery that the lung harbors a diverse microbiome, as revealed by next-generation sequencing, has significantly altered our understanding of respiratory health and disease. Despite the association between the lung microbiota and disease, the nature of their relationship remains poorly understood, and culture isolation of these microorganisms could help to determine their role in lung physiology. Current procedures for processing samples from the lower respiratory tract have been shown to affect the viability of microorganisms, so it is crucial to develop new methods to improve their survival. This study aimed to improve the isolation and characterization of lung microorganisms using a bead-beating homogenization method in a mouse model. Microsphere diameter and bead-beating time affected the survival of the microorganisms (E. coli, S. aureus and C. albicans). Using 2.3 mm diameter microspheres for 60 s of bead-beating promoted the survival of both bacteria and yeast strains. After intratracheal instillation of these microorganisms in mice, approximately 70% of the cells were recovered after the tissue homogenization. To assess the efficiency of the proposed method, the diversity of bacteria was compared between the homogenate and lung tissue samples. Ninety-one genera were detected in the lung tissue, and 63 in the homogenate. Bacterial genera detected in the homogenate represented 84% of the total abundance of the microbiota identified in the lung tissue. Taken together, these results demonstrate that the tissue homogenization process developed in this study recovered the majority of the microorganisms present in the lung. This study presents a bead-beating homogenization method for effective cultivation of lung tissue microorganisms, which may help to improve the understanding of host–microbe interactions in the lung.

In vitro Study of Biofilm Sensitivity of to the Enzyme Complex Included in Wobenzym

Background. Bacterial films are a marker of chronic recurrent infections. Biofilms on mucous membranes block the inflammatory response of the macroorganism, suppressing the activity of immunocytes, and thereby allow microorganisms to reach high concentrations. Currently, research is being conducted to find medications that can act on biofilms. Enzymes, especially their complexes, are substances that can destroy bacterial films. Objective. Еo determine in vitro the sensitivity of bacterial biofilms formed by vaginal microorganisms to the complex of enzymes included in Wobenzym. Materials and methods. The study included 72 clinical isolates of pure microorganism cultures isolated from the vaginal biotope: Gardnerella vaginalis (3), Enterococcus faecalis (9), Escherichia coli (18), Klebsiella pneumoniae (15), Klebsiella aerogenes (3), Lactobacillus crispatus (3), Streptococcus pyogenes (3), Acinetobacter baumanii (3), Staphylococcus aureus (3), Candida albicans (3), Enterococcus faecium (3), Streptococcus agalactiae (3), Lactobacillus acidophilus (3). Bacterial biofilm formation was determined in polystyrene flat-bottom plates using a modified method of Christensen et al. (1985). The tablet form of Wobenzym was used in the study. The tablet shell was washed with saline, the tablet itself was dissolved in 10 ml of 0.9% NaCl and used for in vitro studies. The result was determined using a reader on a spectrophotometer to determine the optical density (OD) of the formed biofilm. It was believed that the drug acted on the bacterial film, reducing the OD by more than three times. Results. An in vitro study revealed clinical isolates of bacteria that formed biofilms of varying severity. Of the 72 clinical bacterial isolates, 38 formed biofilms. A pronounced effect of the complex of enzymes included in Wobenzym on biofilms formed by microorganisms such as A. baumanii, S. aureus, G. vaginalis and E. faecalis was noted. Conclusion. Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including G. vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific) vaginitis. Conclusion. The drug Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including Gardnerella vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific vaginitis).

Influence of a synthetic analogue of the active center of GM-CSF – peptide ZP2 on the growth and biofilm formation of gram-negative bacteria – causes of surgical infections

The aim is to analyze the nature of the effect of the synthetic analogue of the active center of GM- CSF – peptide ZP2 on the growth and biofilm formation (BPO) of gram–negative bacteria – pathogens of surgical infections. The study used 18 clinical isolates of gram-negative bacteria of different species (Klebsiella pneumoniae, Citrobacter freundii, Stenotrophamonas maltophilia) isolated from purulent wounds in patients with surgical pathology and showing pronounced resistance to many antibiotics used in clinical practice. The isolation of pure cultures of microorganisms was carried out by conventional methods; species were assessed by direct protein profiling using a MALDI TOF mass spectrometer. To study the effect of ZP2 peptide on bacterial growth and BPO, isolates were co-cultured with a solution of ZP2 peptide in meat-peptone broth (MPB) at a concentration of 5 micrograms/ml at 37°C for 24-48 hours. The effect of the ZP2 peptide was studied both on emerging biofilms and on those formed, according to the degree of binding of crystalline violet in sterile 96-well polystyrene plates. Next, Growth inhibition indices and coefficients of BPO of microorganisms were determined. It was found that the synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2 inhibited the growth of the studied bacterial strains, reducing the biomass of experimental cultures during the development of bacterial populations. At the same time, the species-specific effect of the ZP2 peptide on the ability of surgical strains of the studied bacteria to form biofilms has been shown. It was experimentally established that all the studied surgical strains of microorganisms were capable of biofilm formation, and the maximum severity of the trait was characteristic of S. maltophilia isolates. The synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2 caused a decrease in the ability to form biofilms in isolates S. maltophilia and destroyed already formed biofilms in all studied species of microorganisms. The experimental data obtained expand the range of potential clinical applications of the synthetic analogue of the active center of granulocyte-macrophage colony stimulating factor (GM-CSF) – peptide ZP2, and its use in new medicines can be effective in combating antibiotic-resistant pathogens of surgical infections.

The study of stabilizing food enzymes using b-cyclodextrins

Background: Today, biologically active additives, which contain hydrolytic enzymes (amylase, lipase, protease), are widely used in the digestive industry. These enzymes are often obtained from animal and vegetable raw materials, -for example, from the pancreas of a reindeer, the Fabricius bag of chickens, and Medusomyces Gisevii Lindau (Kombucha). However, in obtaining enzymes, the activity of amylase and lipase may decrease due to active forms --of proteases. Objective: The main goal of this research work was to evaluate the stabilizing effect of nanostructures–cyclodextrins on the activity of hydrolytic enzymes (protease, amylase, lipase) obtained from animal raw material (chicken bursa of Fabricius) and microorganism cultures (Kombucha). Identify the relationship at which the negative influence of external environmental factors is leveled and, as a result, enzymatic activity is maintained for a certain period of time. Methods: The protein concentration in the solution was determined using the Lowry method. A modified method by Rukhlyadiva was used to determine the amylolytic activity. The definition of lipolytic activity is based on modified Shibabi-Bishop method. To determine the amylolytic activity, a modified method by Rukhlyadiva was used. Results: The relationship between b-cyclodextrin and enzymes was determined, at which enzymatic activity is maintained for a certain period. Conclusion: Thus, cyclodextrins in solution stabilizes the activity of proteases, amylases, and lipases, which is of great practical importance in the food and pharmaceutical industries. Keywords: kombucha, pancreas, enzymes, amylase, lipase, protease, cyclodextrins

Use of Oral Gentamicin in Children with Primary Immunodeficiency and Recurrent Campylobacter coli Bacteremia: A Case Report

Immunosuppressed patients are more at risk of suffering bacteremias due to atypical microorganisms such as Campylobacter coli, which can colonize their intestinal mucosa due to the absence of IgA, the main immunoglobulin of the mucosa and which is not provided with intravenous or subcutaneous immunoglobulin treatment. We have recently had a case of a 5-year-old girl with autosomal recessive agammaglobulinemia with recurrent Campylobacter coli bacteremia and positive stool cultures for the same microorganism. She was treated with intravenous antibiotherapy and given the recurrence of bacteremia, oral gentamicin was associated with this treatment to try to achieve intestinal eradication of the germ. Oral gentamicin was well tolerated, gave no side effects, and managed to eradicate the microorganism 6 months after the end of treatment. We want to reflect the scarce literature on the use of oral gentamicin, the dose and duration of treatment, and the good evolution of our patient with the regimen used.

The Production of Water Kefir Drink with the Addition of Dried Figs in the Horizontal Rotating Tubular Bioreactor.

Water kefir is a product obtained through the fermentation of sucrose solution, usually with some kind of dried fruit addition, by a combined culture of micro-organisms which are contained within kefir grains. Its popularity is rising because of the simplicity of its preparation and its anti-inflammatory, antioxidant, probiotic, and antibacterial effects. In this research, the water kefir production was studied in 250 mL jars, as well as in a horizontal rotating tubular bioreactor (HRTB). The first part of the research was conducted in smaller-scale (jars), wherein the optimal fruit and fruit portions were determined. These experiments included the addition of dried plums, apricots, raisins, dates, cranberries, papaya, and figs into 150 mL of initial sugar solution. Also, the optimal ratio between dried fruit and sucrose solution (0.2) at the beginning of the bioprocess was determined. The second part of this research was conducted using HRTB. The experiments in the HRTB were carried out by using different operational modes (constant or interval bioreactor rotation). A total of six different bioreactor setups were used, and in all experiments, figs were added at the beginning of the bioprocess (0.2 ratio between dried figs and sucrose solution). On the basis of the obtained results, the interval bioreactor rotation mode proved to be the better HRTB mode for the production of the water kefir, as the yield of the main fermentation products was higher, and their ratios were the most adequate for the quality of water kefir drink. The optimal results were obtained via HRTB setup 3/57 (3 min rotation, 57 min pause within 1 h) and rotation speed of 3 rpm. Furthermore, it is clear that HRTB has great potential for water kefir production due to the fact that HRTB experiments showed shorter fermentation times (at least five times) than water kefir production in jars.

The bio-cathode of microbial fuel cells systems: Performance analysis under different microbial community conditions

This study aims to investigate the conversion of different microbial community compositions in the cathode chamber in a dual-chamber bioelectrochemical system. A denitrifying bacterial community, or sludge, was enriched for denitrification by microbial consortia and subsequently acclimatized within the cathodic chamber of microbial fuel cells, either within a mixed microbial community sludge microbial fuel cell (M-MFC) or a pure culture of microorganisms in a microbial fuel cell (P-MFC). The bioelectrochemical systems were treated with different nitrate concentrations in the cathodic chamber: the MFC with low concentration nitrate (MFC1, 25 mg/L nitrate; MFC2 50 mg/L nitrate), the MFC with medium concentration nitrate(MFC3, 75 mg/L nitrate; MFC4 100 mg/L nitrate), and MFC with high concentration nitrate (MFC5, 125 mg/L nitrate; MFC6 150 mg/L nitrate; MFC7 175 mg/L nitrate), and the initial COD in the anodic chamber was based on demand(C to N ratio is 5). M-MFC exhibited better-electrogenerated capability than P-MFC. However, P-MFC exhibited better nitrogen removal performance compared to M-MFC. The best performance was attained by both types of MFCs when the nitrate content was 100 mg/L. The maximum output voltages in M-MFC4 and P-MFC4 were 449 mV and 171 mV, respectively. The average conversion rate of M-MFC4 and P-MFC4 were 2.9 mg*L−1 *h−1 and 10.5 mg*L−1 *h−1, respectively. The analysis of the microbial community of two treated MFCs in the cathode chamber in the optimal state indicated that non-electrode denitrification predominantly occurs in P-MFC. The cathode chambers were mostly populated by denitrifying microorganisms. The dominant species in M-MFC were Azonexus, Zoogloea, Ignavibacterium, and Pirellula, and the dominant species in P-MFC were Comamonas, Aeromonas, and Acidovorax. The species was assessed by qPCR analysis, and the results validated the use of a bacterial consortium for domestication as a more suitable method to improve the stability and performance of the MFCs.

Influence of Modified Cassava Starches on the Rheological and Structural Properties of a Fermented Soy Beverage During Storage

AbstractTraditionally, intensive thermal treatments are applied to process soy beverages, negatively impacting product quality by reducing solubility, and viscosity, while promoting syneresis. Modified cassava starches can prevent these effects. This study evaluates the influence of adding modified cassava starches on syneresis, apparent viscosity, particle size, microstructure, and sensory acceptance of a fermented soy beverage. A commercial culture of starter microorganisms and probiotics is used in the fermentation. Four beverages are produced: one with native cassava starch, one with octenyl succinic anhydride (OSA)‐modified cassava starch, one with crosslinked acetylated distarch adipate (ADA), and one with crosslinked‐substituted cassava starch (mixed); the starch concentration is 1% in each beverage. Samples are stored for 3 weeks at 4 °C. Modified cassava starches significantly alters syneresis compared to the native starch beverage, with no difference among the other treatments. Viscosity shows significant differences among treatments. During storage, the native starch beverage shows an increase in syneresis and a reduction in viscosity, whereas the OSA‐modified starch beverage has higher viscosity but presents significant variation by the end of the 3‐week storage period. The mixed starch beverage has intermediate characteristics with high viscosity and stability during storage. In the sensory evaluation, the consumers prefer the OSA‐modified starch beverage.

Screening of Active Oil Destructors from Various Zones of Urban Soils (on the Example of Baku)

Active cultures of hydrocarbon-decomposing microorganisms from soils of various functional zones of Baku were screened. It was shown that 15 cultures of hydrocarbon-decomposing microorganisms isolated as a result of continuous screening belonged to the genera Rhodococcus, Pseudomonas, Bacillus, Mycobacterium, Actinomyces, Arthrobacter, Micrococcus and were able to use various hydrocarbons (crude oil, paraffin and aromatic hydrocarbons and petroleum products) as the only source of carbon and energy. According to the degree of decomposition, petroleum hydrocarbons were ranked in the series: a mixture of paraffins petroleum products aromatic hydrocarbons crude oil, while the most active strains of microorganisms were isolated from the soils of the industrial and transport zones of Baku, compared with the soils of the recreational zone. The isolated active strains can be considered promising for the creation of biological products to increase soil resistance to pollutants and activate the processes of self-purification of already contaminated soils.

Performance of T2Bacteria in relationship to blood cultures - a retrospective comparative study

PurposeBlood culture (BC) is the gold standard for diagnosing blood stream infections (BSI) but is limited by long turnaround times (TAT) and low detection rate. The T2 Magnetic Resonance method (T2MR) offers a rapid, culture-independent alternative. The objective of this study was to compare the performance of the T2Bacteria assay to BCs in a real-world setting.MethodsRetrospective comparative study consisting of T2Bacteria samples and BCs sampled within 72 h from the T2Bacteria sample. The primary outcome was detections by BC and T2Bacteria, respectively. The secondary outcome was difference in TAT.ResultsIn total, 640 episodes were included, consisting of 640 T2Bacteria samples and 2,117 BCs. A median of three BCs was collected for each T2Bacteria sample. Overall positivity was 101 (15.8%) by either method. In 29 (28.7%) episodes, both T2Bacteria and BC were concordantly positive. In discordant episodes, 46/101 (45.5%) episodes were T2Bacteria positive/BC negative and 26/101 (25.7%) were T2Bacteria negative/BC positive (McNemar χ2, p < 0,05). In T2Bacteria positive/BC negative episodes, eight had growth of the same microorganism in a non-BC culture. Median (IQR) TAT for BC was 35 h and 30 min (25 h 50 min − 45 h 24 min), compared to 21 h and 3 min (17 h 6 min − 27 h 30 m) for T2Bacteria (p < 0.001), with longer delays for samplings occurring outside work hours.ConclusionsThe study highlights a high discordance between T2Bacteria and BC and suggests complementary roles of the methods in BSI diagnostics. Furthermore, it is crucial to improve TAT by reducing preanalytical delays.

Antioxidant properties and bioactivity of three marine microalgae on human cancer cell lines

ABSTRACT Marine microalgae offer significant potential as sustainably cultivable microorganisms for the biorefining of a diverse array of functional metabolites. In this study, three species of marine microalgae, Tetraselmis chuii Butcher CCAP 66/21B (Chlorophyte), Phaeodactylum tricornutum Bohlin CCAP 1052/1 (Diatom) and Amphidinium carterae Hulburt CCAP 1102/8 (Dinoflagellate), were batch cultivated and their biomass retrieved for analysis in terms of pigment and fatty acid composition as well as bioactivity potential. Sequential solvent maceration of the biomass returned extracts was used to determine antioxidant capacity and assess their growth inhibition potential against A549 (a human lung carcinoma) and MCF-7 (a breast carcinoma) cell lines. The extracts of A. carterae showed higher antioxidant capacity (≤ 33.5 μmol Trolox Equivalent mg Recovered Dried Material‒1) compared to the other extracts. No major cytotoxic activity nor production of reactive oxygen species was observed using the extracts of T. chuii and P. tricornutum. However, the methanolic extraction of A. carterae inhibited the growth of both A549 and MCF-7 cells (< 4%) at 25, 50 and 100 µg ml−1 concentrations, as determined using the MTS assay and AO/PI cell staining. Microalgal metabolites have the potential for practical applications in a variety of industrial sectors. The absence of toxicity and substantial antioxidant potential of extracts of T. chuii and P. tricornutum confirm their suitability for incorporation into animal feeds or human nutrition supplements. A. carterae also appears to be a promising source of bioactives that can be further valorized via multi-compound biorefinery pipelines.

Microhabitat-differentiated distribution of culturable and antagonistic bacteria in marine ecosystem: Seawater as the original microbial provider

Abstract: Due to the typical tropical climatic characteristics, the Xisha archipelago in the South China Sea has derived typical biological treasures, particularly culturable bacteria. Microbial resources in nature will be valuable resources for industrial application only after being culturable microorganisms. Herein, the global distribution of culturable and antagonistic bacteria against aquatic pathogenic vibrios, including Vibrios parahaemolyticus, Vibrios harveyi, Vibrios alginolyticus, Vibrios campbellii, and Vibrios owensii, in thirty-nine stations of the Xisha archipelago across four main microhabitats of sediment, seawater, corals, and marine organisms were investigated by cultivation-based strategies. Vibrio was the dominant genus (68.98%) among the culturable bacteria, followed by Pseudoalteromonas (9.36%) and Alteromonas (4.91%). Only four targeted antagonistic strains with an antagonistic specificity of a certain Vibrio were obtained, namely the strains of SP52, C219 and W198, which provided a new insight of precise disease prevention/treatment by further revealing the targeted antagonistic mechanism. The correlations between the abundance of culturable bacteria and environmental factors in the whole Xisha archipelago and four microhabitats showed that salinity as the main factor significantly affected the distribution of 6 microbial genera, while total inorganic nitrogen (TIN), total carbon (TC), and PO43− significantly related to 3 genera, 2 genera, and 1 genus, respectively. Importantly, we found that microhabitat discrepancy rather than distance discrepancy of environmental factors made a greater contribution to the distribution of culturable bacteria and antagonistic bacteria and the capability of antagonistic bacteria, which was emphasized as an important factor in shaping bacterial communities. Additionally, seawater was the original microbial provider of other microhabitats in the marine ecosystem, which was the opposite of the terrestrial ecosystem in that the soil is the original microbial provider.

Microbiological identification of some culturable native strains associated with the digestive tract in Panaque cochliodon

Objective. To characterize by microbiology the native strains associated to the intestinal tract of the species Panaque cochliodon. Materials and methods. Three adult specimens captured in the Magdalena River that were transported and sacrificed under animal welfare regulations were used. Dissection of the intestinal tract was performed, obtaining samples for microbiological isolation, using culture media, purifying the microorganisms, performing metabolic biochemical tests and API 20E (Biomeriux) tests for their identification. Results. Information on the microbial population structure was obtained, reporting the phylum Proteobacteria with the species: Pantoea sp, Erwinia sp, Providencia stuarti, Providencia alcalifaciens, Serratia ficaria, Citrobacter koseri and the phylum Firmicutes with the species: Bacillus sphaericus, Bacillus subtilis, Bacillus thurigiensis, Bacillus mycoides, Bacillus coagulans and Bacillus circulans. Conclusion. The predominant culturable microorganisms in P. cohliodon belong to the phylum Proteobacteria and the phylum Firmicutes.

Effect of long-term radish (Raphanus sativus var. sativus) monoculture practice on physiological variability of microorganisms in cultivated soil

Long-term monoculture may affect soil environment biodiversity. An example of such a plant is radish (Raphanus sativus var. sativus), an economically important crop in Poland, a quick-growing vegetable with intensified harvest throughout the season. The aim of this study was to determine changes in biodiversity of soil under radish cultivation and to compare the research methods applied. The monoculture practice affected soil pH, but the organic carbon content remained stable. 16S RNA-seq analysis revealed changes in soil microbial population, with the dominant phyla Proteobacteria (37.3%), Acidobacteria (19%), and Actinobacteria (16%), and the dominant taxa Gaiella (1.59%), Devosia (1.51%) and Nocardioides (1.43%). These changes have not fully expressed in the number of culturable microorganisms, where only fungal abundance changed significantly. However, the physiological state of microbial cells (λ) indicated that oligotrophs and copiotrophs were in a vegetative (λ > 3.0) state at the beginning of the season and fungi at the end of the year. Changes in the biodiversity of soil microorganisms were visualised using Community Level Physiological Profiling, where an oscillation in Average Well Colour Development (OD560 = 0.78–1.48) was observed in successive months of radish culture, with biodiversity indices (Shannon and Substance richness) remaining similar. The greatest variation in the influence of monoculture practice on soil factors was observed for the soil enzymes activities (for dehydrogenase and peroxidase activities – 0.5 μg TPF/h/g DW and 1.5 μmolPYGL/h/g DW respectively). Alkaline phosphatases predominated among this group of enzymes, and the activity of carbon metabolism enzymes decreased over the season, except for invertases, where an increase in activity of up to 50 μg Glc/h/g DW was observed. All the parameters studied indicated changes in the soil environment. Nevertheless the microbial community remains stable during the whole experiment returning to equilibrium in a quite short time after changing conditions.

Impact of Paenibacillus elgii supernatant on screening bacterial strains with potential for biotechnological applications

The biotechnological industry faces a crucial demand for novel bioactive compounds, particularly antimicrobial agents, to address the rising challenge of bacterial resistance to current available antibiotics. Traditional strategies for cultivating naturally occurring microorganisms often limit the discovery of novel antimicrobial producers. This study presents a protocol for targeted selection of bacterial strains using the supernatant of Paenibacillus elgii, which produces abundant signal molecules and antimicrobial peptides. Soil samples were inoculated in these enriched culture media to selectively cultivate bacteria resistant to the supernatant, indicating their potential to produce similar compounds. The bacterial strains isolated through this method were assessed for their antibacterial activity. In addition, the functional annotation of the genome of one of these strains revealed several gene clusters of biotechnological interest. This study highlights the effectiveness of using this approach for selective cultivation of microorganisms with potential for biotechnological applications.

DESCRIPTIVE CHARACTERISTICS, ETIOLOGICAL AGENTS, AND RISK FACTORS FOR MORTALITY OF URINARY TRACT INFECTIONS IN OLDER ADULTS

OBJECTIVE: Urinary tract infections are common in older adults and associated with significant morbidity and mortality. This study aimed to characterize the clinical features, bacterial etiologies, antimicrobial resistance patterns, and risk factors for mortality in elderly patients hospitalized with urinary tract infection. MATERIAL AND METHODS: Data were retrospectively analyzed from 118 patients aged ≥65 years hospitalized with a diagnosis of urinary tract infection between January 2018 and December 2022. Urinary tract infections were defined according to Centers for Disease Control and Prevention criteria. Isolated microorganisms in urine cultures and antimicrobial resistance rates were determined. Risk factors associated with mortality were evaluated by logistic regression analysis. RESULTS: 50.8% of patients were female; the mean age was 72.5±7.0 years. The most common symptoms were dysuria (65.3%), anorexia (65.3%), and flank pain (57.6%). Forty-nine patients (41.5%) had nosocomial urinary tract infections. All cause in hospital mortality was observed in 48 patients (40.6%), and 22 patients (18.6%) had in-hospital mortality directly related to urinary tract infection. Urosepsis (OR: 13.518, 95% CI: 1.711-106.793, p=0.014), kidney stones (OR: 7.529, 95% CI: 1.596-35.525, p=0.011) and urinary tract infections caused by multidrug-resistant organisms (OR: 18. 612, 95% CI: 1.564-4.283, p&amp;lt;0.001) were independent risk factors for mortality, and appropriate treatment (OR: 0.090, 95% CI: -3.736--1.085, p&amp;lt;0.001) was an independent protective factor for mortality. CONCLUSIONS: Urinary tract infections in elderly adults present with a wide range of symptoms and are predominantly caused by drug-resistant Escherichia coli. Urosepsis and kidney stones are critical determinants of mortality, emphasizing the need for rapid and appropriate management strategies. Understanding the etiology, clinical features, and mortality risk factors of urinary tract infections in elderly adults is crucial for optimizing infection management in this vulnerable population.

Microbial Composition of Extracted Dental Alveoli in Dogs with Advanced Periodontitis.

Periodontitis is a serious gum infection that damages the soft tissue and destroys the bone supporting the teeth. The aim of the study was to investigate the microbiota using traditional microbiology plating and metagenomic sequencing of extracted tooth alveoli in dogs with severe periodontitis. Isolation of culturable microorganisms was performed as part of bacteriological testing to provide bacteriological diagnosis to veterinary surgeons. Metagenomic sequencing was performed using shotgun sequencing on the Illumina HiSeq system platform. The most prevalent species at sites of periodontal infection detected by metagenomic sequencing were Porphyromonas gulae, Prevotella spp., Tannerella forsythia, Porphyromonas crevioricanis, Porphyromonas cangingivalis, and Bacteroides heparinolyticus. Pasteurella, Streptococcus, and Neisseria were the most frequently isolated culturable bacteria from infected sites detected by traditional microbiologic methods. Metagenomic data revealed that these three genera accounted for only 1.6% of all microbiota at the sites of infection. Antimicrobial resistance patterns of the isolated bacteria included resistance to ampicillin, doxycycline, sulfamethoxazole-trimethoprim, ciprofloxacin, colistin, cefotaxime, and chloramphenicol. Antimicrobial-resistant genes detected using shotgun sequencing also showed resistance to aminoglycosides and macrolides. Dogs with periodontal infections carry bacteria that can cause bite infections in humans as well as multi-resistant isolates. Therefore, treatment and prophylaxis or periodontal disease of dogs is important from a One Health perspective.

“Nejayote” valorization as a culture medium for Pseudomonas fluorescens and production of antifungal extracts

Background / Objetive. Nejayote is an alkaline agroindustrial waste that is generated from the nixtamalization process of corn. The purpose of this work was to demonstrate that nejayote can be used as a culture medium for the growth of Pseudomonas fluorescens NR113647 and to produce metabolites with antifungal activity for the sustainable management of Aspergillus niger, Botrytis cinerea and Fusarium solani. Materials and Methods. Culture media were formulated with nejayote and nejayote with glycerol, with pH 6 and 12. The bacterial biomass was separated by centrifugation and filtration and the antifungal capacity of the extracts against A. niger, B. cinerea and F. solani was determined. The determination of the metabolites present in the extracts was carried out. P. fluorescens NR113647 was able to grow on all media. Results. The extracts from nejayote at pH 12 showed inhibition of the growth of all the fungi evaluated; at least five metabolites produced by P. fluorescens NR113647 and involved in the biocontrol of phytopathogens were identified. Conclusion. Nejayote can be used as a culture medium for P. fluorescens NR113647, to produce biomass and secondary metabolites with antifungal capacity; in addition, nejayote could be used for the cultivation of other microorganisms.