Single Bacterium Research Articles

Determination and analysis of spectral fluorescence cross-sections of bacteria aerosols

Fluorescence cross-sections of single bacteria provide information on the strength of fluorescence response of bacteria for particular excitation conditions and give hints about a possible distinguishability of bacteria by fluorescence techniques. In this report, the fluorescence cross-sections of dry bacteria aerosols are derived from fluorescence spectra by absolute calibration of the measuring system. The fluorescence is measured in a continuous aerosol flow. The aerosol concentration is calculated from microscopic analyses of bacteria samples taken from the aerosol flow. Established calibration methods such as Mie scattering from monodisperse spheres and Raman scattering from water are applied to the same set of fluorescence spectra. The cross-section data obtained are evaluated with regard to their independency from the applied measuring system. The results are compared to data published in the literature. Polarization effects are identified to contribute to the discrepancies between the different datasets.Graphical abstract

Chronic Exposure to Bioaerosols in PM2.5 from Garbage Stations Accelerates Vascular Aging via the NF-κB/NLRP3 Pathway.

The fine particulate matter (PM2.5) in air pollution is a critical risk factor influencing human health. Our study included 8144 participants andshowed that the risk of major adverse cardiovascular events increases by 35% (HR, 1.35; 95% CI, 1.14-1.60) for participants with thehighest quartile to PM2.5 exposure as compared to those with lowest quartile. Bioaerosols, as an important environmental exposure in PM2.5, can induce systemic chronic inflammation leading to vascular aging. Thus, the effects of bioaerosols are investigated from household garbage stations in PM2.5 on vascular aging, and the underlying mechanisms are explored. In vivo, chronic exposure to bioaerosols upregulated senescence marker expression levels while causing vascular dysfunction and remodeling. In vitro, bioaerosol exposure induced decreased proliferation, G0/G1 arrest, and impaired migration of human umbilical vein endothelial cells (HUVECs). Furthermore, a single bacterium (AS22a) from the bioaerosol community was isolated and demonstrated that it upregulated inflammatory factors and accelerated cell senescence and vascular aging by activating the NF-κB/NLRP3 signaling pathway, which may serve as a primary mechanism underlying vascular aging induced by bioaerosols in PM2.5. These findings suggest that high levels of bioaerosols in household garbage stations may adversely affect cardiovascular health.

Synergistic enhancement of polycyclic aromatic hydrocarbon degradation by Arthrobacter sp. SZ-3 and Pseudomonas putida B6-2 under high Tween80 concentration: mechanisms and efficiency.

This study investigates the advantages of combined microbial degradation of polycyclic aromatic hydrocarbons (PAHs) in reducing the inhibitory effects of high-concentration eluents commonly used in soil washing. A microbial synergistic strategy was proposed using Arthrobacter sp. SZ-3 and Pseudomonas putida B6-2 as the key bacteria in the presence of Tween 80. The results show that in systems with Tween 80, the SZ-3 strain exhibits a strong capacity to degrade three types of PAH compounds, while the B6-2 strain follows multiple degradation pathways. Mixed bacteria achieved degradation rates 60.70% higher than single bacteria at varying concentrations of Tween 80. Additionally, the average growth rates of mixed bacteria increased by 1.17-1.37 times, aligning with the changes in the functional group. Protein activity detection within each degradation system corresponded with growth quantity and the cyclic variation characteristics of ETS enzyme activity. Notably, the ETS activity of mixed bacteria was 150% higher than that of single bacteria. At a Tween 80 concentration of 500 mg/L, the degradation rates of PAHs (Phe, Flu, Pyr) by mixed bacteria were significantly higher than those by single bacteria. The catechol 1,2-dioxygenase activity of mixed bacteria was 2.30 times higher than that of single bacteria. While Tween 80 did not alter the PAH degradation pathways, it significantly influenced the accumulation amount and duration of the characteristic intermediate product. This provides a reference for the remediation of recalcitrant pollutants under conditions involving high-concentration surfactants.

Paenibacillus polymyxa J2-4 induces cucumber to enrich rhizospheric Pseudomonas and contributes to Meloidogyne incognita management under field conditions.

Root knot nematodes (RKNs) pose a great threat to agricultural production worldwide. The bacterial nematocides have received increasing attention due to their safe and efficient control against RKNs. Here, we investigated the biocontrol efficacy of Paenibacillus polymyxa J2-4 against Meloidogyne incognita in the field and analyzed the rhizosphere microbiome of cucumber under nematode infection after application of the J2-4 strain. Furthermore, a biomarker strain of Pseudomonas spp. was isolated from the J2-4-inoculated rhizosphere soil, and its nematocidal activity and growth-promoting effect on host plants were determined. In addition, chemotaxis assay of P. fluroescens ZJ5 toward root exudates was carried out. The field experiment demonstrated that P. polymyxa J2-4 could effectively suppressed gall formation in cucumber plants, with the galling index reduced by 67.63% in 2022 and 65.50% in 2023, respectively, compared with controls. Meanwhile, plant height and yield were significantly increased in J2-4 treated plants compared with controls. Metagenomic analysis indicated that J2-4 altered the rhizosphere microbial communities. The relative abundance of Pseudomonas spp. was notably enhanced in the J2-4 group, which was consistent with Linear discriminant analysis Effect Size results that Pseudomonas was determined as one of the biomarkers in the J2-4 group. Furthermore, the ZJ5 strain, one of the biomarker Pseudomonas strains, was isolated from the J2-4-inoculated rhizosphere soil and was identified as Pseudomonas fluorescens. In addition, P. fluorescens ZJ5 exhibited high nematicidal activity in vitro and in vivo, with 99.20% of the mortality rate of M. incognita at 24 h and 69.75% of gall index reduction. The biocontrol efficiency of the synthetic community of ZJ5 plus J2-4 was superior to that of any other single bacteria against M. incognita. Additionally, ZJ5 exhibited great chemotaxis ability toward root exudates inoculated with J2-4. Paenibacillus polymyxa J2-4 has good potential in the biological control against M. incognita under field conditions. Enrichment of the beneficial bacteria Pseudomonas fluorescens ZJ5 in the J2-4-inoculated rhizosphere soil contributes to M. incognita management. © 2024 Society of Chemical Industry.

Intragenic DNA inversions expand bacterial coding capacity.

Bacterial populations that originate from a single bacterium are not strictly clonal and often contain subgroups with distinct phenotypes1. Bacteria can generate heterogeneity through phase variation-a preprogrammed, reversible mechanism that alters gene expression levels across a population1. One well-studied type of phase variation involves enzyme-mediated inversion of specific regions of genomic DNA2. Frequently, these DNA inversions flip the orientation of promoters, turning transcription of adjacent coding regions on or off2. Through this mechanism, inversion can affect fitness, survival or group dynamics3,4.Here, we describe the development of PhaVa, a computational tool that identifies DNA inversions using long-read datasets.We alsoidentify 372 'intragenic invertons', a novel class of DNA inversions found entirely within genes, in genomes of bacterial and archaeal isolates. Intragenic invertons allow a gene to encode two or more versions of a protein by flipping a DNA sequence within the coding region, thereby increasing coding capacity without increasing genome size. We validate ten intragenic invertons in the gut commensal Bacteroides thetaiotaomicron, and experimentally characterize an intragenic inverton in the thiamine biosynthesis gene thiC.

Effects of temperature and lactic acid Bacteria additives on the quality and microbial community of wilted alfalfa silage

This study investigated the influence of different temperatures (35℃ High temperature and average indoor ambient temperature of 25℃) and lactic acid bacterial additives (Lactiplantibacillus plantarym, Lentilactobacillus buchneri, or a combination of Lactiplantibacillus plantarym and Lentilactobacillus buchneri) on the chemical composition, fermentation quality, and microbial community of alfalfa silage feed. After a 60-day ensiling period, a significant interaction between temperature and additives was observed, affecting the dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) of the silage feed (p < 0.05). Temperature had a highly significant impact on the pH value of the silage feed (p < 0.0001). However, the effect of temperature on lactic acid, acetic acid, propionic acid, and butyric acid was not significant (p > 0.05), while the inoculation of additives had a significant effect on lactic acid, acetic acid, and butyric acid (p > 0.05). As for the dynamic changes of microbial community after silage, the addition of three kinds of bacteria increased the abundance of lactobacillus. Among all treatment groups, the treatment group using complex bacteria had the best fermentation effect, indicating that the effect of complex lactic acid bacteria was better than that of single bacteria in high temperature fermentation. In summary, this study explained the effects of different temperatures and lactic acid bacterial additives on alfalfa fermentation quality and microbial community, and improved our understanding of the mechanism of alfalfa related silage at high temperatures.

Formation of Single-Species and Multispecies Biofilm by Isolates from Septic Transfusion Reactions in Platelet Bag Model.

During 2018-2021, eight septic transfusion reactions occurred from transfusion of platelet units contaminated with Acinetobacter spp., Staphylococcus saprophyticus, Leclercia adecarboxylata, or a combination of those environmental organisms. Whether biofilm formation contributed to evasion of bacterial risk mitigations, including bacterial culture, point-of-care testing, or pathogen-reduction technology, is unclear. We designed a 12-well plate-based method to evaluate environmental determinants of single-species and multispecies biofilm formation in platelets. We evaluated bacteria isolated from septic transfusion reactions for biofilm formation by using crystal violet staining and enumeration of adherent bacteria. Most combinations of bacteria had enhanced biofilm production compared with single bacteria. Combinations involving L. adecarboxylata had increased crystal violet biofilm production and adherent bacteria. This study demonstrates that transfusion-relevant bacteria can produce biofilms well together. More work is needed to clarify the effect of biofilms on platelet bacterial risk control strategies, but US Food and Drug Administration-recommended strategies remain acceptable.

Anti-biofilm and antioxidant activities of Sargassum muticum extracts and their preservation effect of Chinese shrimp (Penaeus chinensis)

Vibrio parahaemolyticus can enhance bacterial resistance to disinfectants and antimicrobials by forming biofilms. The development of new natural antimicrobials is essential for the control of biofilm-related contamination and infection. In this paper, we preliminarily explored the inhibitory activity of Sargassum muticum extracts (HA-PTs) against the biofilm of V. parahaemolyticus. HA-PTs exerted anti-biofilm activity by destroying the integrity of the cell membrane, curbing the motility of single and colonial bacteria, hindering the synthesis of polysaccharide intercellular adhesion, inhibiting the secretion of extracellular DNA, and reducing the metabolic activity of biofilms. Furthermore, experiments on four free radicals (DPPH•, •OH, ABTS+•, and O2−•) scavenging activity and total antioxidant capacity (FRAP method and phenanthroline method) demonstrated that HA-PTs have strong reducing properties and can capture a variety of free radicals, which in turn prevents them from participating in oxidative reactions. When HA-PTs were applied to Chinese shrimp infected with V. parahaemolyticus, it could prolong their shelf life by controlling the pH rise caused by protein degradation, inhibiting the bacterial proliferation, reducing the content of total volatile basic nitrogen produced by protein degradation, and reducing the accumulation of thiobarbiturates caused by oxidative deterioration of fats.

Building microbial consortia to enhance straw degradation, phosphorus solubilization, and soil fertility for rice growth

Straw pollution and the increasing scarcity of phosphorus resources in many regions of China have had severe impacts on the growing conditions for crop plants. Using microbial methods to enhance straw decomposition rate and phosphorus utilization offers effective solutions to address these problems. In this study, a microbial consortium 6 + 1 (consisting of a straw-degrading bacterium and a phosphate-solubilizing bacterium) was formulated based on their performance in straw degradation and phosphorus solubilization. The degradation rate of straw by 6 + 1 microbial consortium reached 48.3% within 7 days (The degradation ability was 7% higher than that of single bacteria), and the phosphorus dissolution rate of insoluble phosphorus reached 117.54 mg·L− 1 (The phosphorus solubilization ability was 29.81% higher than that of single bacteria). In addition, the activity of lignocellulosic degrading enzyme system was significantly increased, the activities of endoglucanase, β-glucosidase and xylanase in the microbial consortium were significantly higher than those in the single strain (23.16%, 28.02% and 28.86%, respectively). Then the microbial consortium was processed into microbial agents and tested in rice pots. The results showed that the microbial agent significantly increased the content of organic matter, available phosphorus and available nitrogen in the soil. Ongoing research focuses on the determination of the effects and mechanisms of a functional hybrid system of straw degradation and phosphorus removal. The characteristics of the two strains are as follows: Straw-degrading bacteria can efficiently degrade straw to produce glucose-based carbon sources when only straw is used as a carbon source. Phosphate-solubilizing bacteria can efficiently use glucose as a carbon source, produce organic acids to dissolve insoluble phosphorus and consume glucose at an extremely fast rate. The analysis suggests that the microbial consortium 6 + 1 outperformed individual strains in terms of both performance and application effects. The two strains within the microbial consortium promote each other during their growth processes, resulting in a significantly higher rate of carbon source consumption compared to the individual strains in isolation. This increased demand for carbon sources within the growth system facilitates the degradation of straw by the strains. At the same time, the substantial carbon consumption during the metabolic process generated a large number of organic acids, leading to the solubilization of insoluble phosphorus. It also provides a basis for the construction of this type of microbial consortium.

Associated bacterial and fungal infections in burn wounds: Common factors, distribution in etiology, age groups, bacterial and fungal strands – Evaluation of a single burn center experience of 20 years

IntroductionBurn intensive care unit (BICU) patients suffer from reduced immunological competence. Often bacterial and fungal infections occur as single or associated infection of the burn site. However, common factors in associated infections are discussed controversially. In this study we evaluated factors common in associated occurrence of bacterial and fungal infection in the burn population. Patients and methodsIn total 213 patients, admitted to the ICU of Cologne Merheim Clinical Center between 1988 and 2011, with associated infections were included in this study. Exclusion criteria were no bacterial, or no fungal infection, or incomplete data. Data evaluated were sex, age, type of burn injury, total body surface area (TBSA), abbreviated burn severity index (ABSI) score, 3rd degree burn, inhalation injury, length of BICU stay, antibiotic therapy, bacterial strand, fungal strand, incidence of bacteria and fungus infection, single or associated occurrence and bacteria species associated with fungus species. Statistical analysis comprised of univariate, Chi-square and Fischer Exact test, multivariate analysis, positive and negative predictive value, logistic regression analysis with the Nagelkerke, Cox/ Snell R-square. Results196 patients were included into the study, 147 male and 49 female. Total mean age was 47 years, in the fire burn group 47 years, in scalding 53 years, in electrical burn 29 years and in chemical burn 62 years. 123 male and 45 female were combusted, 15 male and 3 female scalded, 9 male had an electrical burn and 1 female a chemical burn. The mean TBSA in fire burns was 41 %, in scalding 42 %, in electrical burns 46 %, and in chemical burn 16 %. The mean ABSI in fire burn and scalding was 9, in electrical burn 8 and in chemical burn 7. The 3rd degree burns were 16 % in fire burn and 13 % in scalding and electrical burn and 0 % in chemical burn. The length of BICU stay was 49 days for fire burn, 47 days for scalding, 58 days in electrical burn and 21 days in chemical burn patients.The gram-positive bacterial strands most often found were Staphylococcus strands, gram negative Pseudomonas and Acinetobacter strands. Candida albicans was the most often present fungal strand. There was no difference in incidence between gram positive and gram-negative bacteria. In patients suffering from fire burns the most common bacteria were Staphylococcus and Pseudomonas, in scalding Acinetobacter, and in chemical burns Staphylococcus. In electrical burns no predominant bacterial strand was found. The associated occurrence of Staphylococcus and Candida albicans and Pseudomonas and Candida albicans was predominant. In patients with fire burn, 48% showed an associated infection, in scalding 21%, in electrical burn 33% and in chemical burn 100%.Combusted patients had the highest incidence of associated infection in age group 80–89 years, in scalding 40–49, 50–59 and 70–79 years, in electrical burn 20–29 years and in chemical burn 60–69 years. Most common factors of associated infections were higher age, high TBSA with 3rd degree burns and bacterial infections. Interestingly inhalation injury was highly inversely correlated to associated infection. ConclusionThe associated occurrence of bacterial and fungal wound infection is highest in burn patients with infections with Staphylococcus or Pseudomonas, the incidence is mainly found in fire burn and electrical burns. The use of oxygen in inhalation injury might prevent associated bacterial and fungal infections.

Unraveling the Metabolic Behavior and Interspecific Interaction Pattern of Lactic Acid Bacteria within Chinese Rice Wine.

The synthetic community of lactic acid bacteria (LAB) is commonly utilized in the food industry for manipulating product properties. However, the intermediate interactions and ecological stability resulting from metabolic differences among various LAB types remain poorly understood. We aimed to analyze the metabolic behavior of single and combined lactic acid bacteria in China rice wine based on microbial succession. Three-stage succession patterns with obligate heterofermentative LAB dominating prefermentation and homofermentative LAB prevailing in main fermentation were observed. Facultative heterofermentative LAB exhibited significant growth. Pairwise coculture interactions revealed 63.5% positive, 34.4% negative, and 2.1% neutral interactions, forming nontransitive and transitive competition modes. Nontransitive competitive combinations demonstrated stability over ∼200 generations through amino acid (mainly aspartic acid, glutamine, and serine) cross-feeding and lactic acid detoxification, which also showed potential for controlling biogenic amines and developing LAB starter cultures. Our findings offer insights into the mechanistic underpinnings of LAB interaction networks.

Study on Enhancement of Acid Production by Combination Fermentation of Caproic Acid-producing Bacteria and Lactic Acid-producing Bacteria

A new caproic acid bacteria 20-5 (Caproicibacterium sp.) was newly screened in the laboratory, and several high-quality lactic acid bacteria A2-3 ( Sporolactobacillus fermentans ), GCB-3 ( Pediococcus acidilactici ), KR-4 ( Lactiplantibacillus plantarum ), LY-5 ( Levilactobacillus brevis ), B2-1 ( Lactiplantibacillus plantarum ) were used for exploratory compound fermentation experiments. The compound fermentation was a caproic acid bacteria (20-5) alone plus four lactic acid bacteria ( A2-3, GCB-3, KR-4, LY-5, B2-1 ), the experimental ratio was set up four groups of compound ratio of 1 : 2,1 : 1,5 : 1,10 : 1. The optimum ratio of 20-5 to B2-1 was 10 : 1, and the total acid yield reached 26.75 g / L. The best caproic acid production capacity after compounding was the 10: 1 group of 20-5 and B2-1, and the caproic acid yield was 7.22 g / L. The average lactic acid content in the fermentation broth was 4.52 g / L after compounding. After compounding, the acid production of the 1 : 1 and 5 : 1 groups of 20-5 : A2-3 and the 10 : 1 group of 20-5 : B2-1 increased compared with that of single bacteria. In the other compound groups, the acid production capacity decreased after the compound operation, and the lactic acid production generally decreased, but the caproic acid production increased, indicating that caproic acid bacteria can use lactic acid as a carbon source for fermentation and acid production activities, so that caproic acid bacteria can produce caproic acid.

A syringe-driven PicoArray device for rapid isolation and quantification of foodborne Salmonella

Rapid and accurate detection of pathogenic Salmonella in food and environmental sources is of paramount importance to protect public health from salmonellosis. However, most current assays are labor-intensive, time-consuming, and require expensive instruments and experienced operators. In this work, we developed a PicoArray-based colony-forming unit (CFU) quantification system for rapid and ultrasensitive Salmonella detection. To enable on-site detection, we employed syringe-vacuum-assisted sample loading and oil-induced sample digitization to stochastically confine single bacteria in the picoliter-level wells of the PicoArray device (containing 40,233 wells). Such a single bacterial confinement enables the isolation and characterization of individual bacteria from a large population. In addition, the confinement of bacteria in small volumes allows rapid accumulation of metabolites, thereby eliminating the pre-incubation step and reducing the time required to detect bacteria. By combining it with a selective medium for the isolation of Salmonella and a fluorescent redox indicator (e.g., resazurin) to facilitate the detection of individual microcolonies, the PicoArray device can rapidly and precisely detect Salmonella. As a proof-of-concept, we demonstrated the ability of our platform for rapid, sensitive, and specific detection of Salmonella in spiked milk samples. Our platform offers the possibility of close monitoring of pathogens in food or drinks at the consumer end because it allows a non-trained operator to detect foodborne pathogens in the clinically relevant range in the home setting.

Remediation of arsenic- and nitrate-contaminated groundwater through iron-dependent autotrophic denitrifying culture

Groundwater contamination with arsenic and nitrate poses a pressing concern for the safety of local communities. Bioremediation, utilizing Fe(II)-oxidizing nitrate reducing bacteria, shows promise as a solution to this problem. However, the relatively weak environmental adaptability of a single bacterium hampers practical application. Therefore, this study explored the feasibility and characteristics of a mixed iron-dependent autotrophic denitrifying (IDAD) culture for effectively removing arsenic and nitrate from synthetic groundwater. The IDAD biosystem exhibited stable performace and arsenic resistance, even at a high As(III) concentration of 800 μg/L. Although the nitrogen removal efficiency of the IDAD biosystem decreased from 71.4% to 64.7% in this case, the arsenic concentration in the effluent remained below the standard (10 μg/L) set by WHO. The crystallinity of the lepidocrocite produced by the IDAD culture decreased with increasing arsenic concentration, but the relative abundance of the key iron-oxidizing bacteria norank_f_Gallionellaceae in the culture showed an opposite trend. Metagenomic analysis revealed that the IDAD culture possess arsenic detoxification pathways, including redox, methylation, and efflux of arsenic, which enable it to mitigate the adverse impact of arsenic stress. This study provides theoretical understanding and technical support for the remediation of arsenic and nitrate-contaminated groundwater using the IDAD culture.

Heterotrophic bacteria trigger transcriptome remodelling in the photosynthetic picoeukaryote Micromonas commoda.

Marine biogeochemical cycles are built on interactions between surface ocean microbes, particularly those connecting phytoplankton primary producers to heterotrophic bacteria. Details of these associations are not well understood, especially in the case of direct influences of bacteria on phytoplankton physiology. Here we catalogue how the presence of three marine bacteria (Ruegeria pomeroyi DSS-3, Stenotrophomonas sp. SKA14 and Polaribacter dokdonensis MED152) individually and uniquely impact gene expression of the picoeukaryotic alga Micromonas commoda RCC 299. We find a dramatic transcriptomic remodelling by M. commoda after 8 h in co-culture, followed by an increase in cell numbers by 56 h compared with the axenic cultures. Some aspects of the algal transcriptomic response are conserved across all three bacterial co-cultures, including an unexpected reduction in relative expression of photosynthesis and carbon fixation pathways. Expression differences restricted to a single bacterium are also observed, with the Flavobacteriia P. dokdonensis uniquely eliciting changes in relative expression of algal genes involved in biotin biosynthesis and the acquisition and assimilation of nitrogen. This study reveals that M. commoda has rapid and extensive responses to heterotrophic bacteria in ways that are generalizable, as well as in a taxon specific manner, with implications for the diversity of phytoplankton-bacteria interactions ongoing in the surface ocean.

Investigating the degradation potential of microbial consortia for perfluorooctane sulfonate through a functional "top-down" screening approach.

Perfluorooctane sulfonate (PFOS) is a prominent perfluorinated compound commonly found in the environment, known to pose various risks to human health. However, the removal of PFOS presents significant challenges, primarily due to the limited discovery of bacteria capable of effectively degrading PFOS. Moreover, single degradation bacteria often encounter obstacles in individual cultivation and the breakdown of complex pollutants. In contrast, microbial consortia have shown promise in pollutant degradation. This study employed a continuous enrichment method, combined with multiple co-metabolic substrates, to investigate a microbial consortium with the potential for PFOS degradation. By employing this methodology, we effectively identified a microbial consortium that demonstrated the capacity to reduce PFOS when exposed to an optimal concentration of methanol. The consortium predominantly comprised of Hyphomicrobium species (46.7%) along with unclassified microorganisms (53.0%). Over a duration of 20 days, the PFOS concentration exhibited a notable decrease of 56.7% in comparison to the initial level, while considering the exclusion of adsorption effects. Furthermore, by comparing the predicted metabolic pathways of the microbial consortium with the genome of a known chloromethane-degrading bacterium, Hyphomicrobium sp. MC1, using the KEGG database, we observed distinct variations in the metabolic pathways, suggesting the potential role of the unclassified microorganisms. These findings underscore the potential effectiveness of a "top-down" functional microbial screening approach in the degradation of stubborn pollutants.

Phosphorylation-amplified synchronized droplet microfluidics sensitizes bacterial growth kinetic real-time monitoring

The necessity for rapid and accurate bacterial growth monitoring is imperative across various domains, including healthcare and environmental safety. We introduce the self-synchronized droplet-amplified electrical screening cytometry (SYNC) system, a novel meld of droplet microfluidics and electrochemical amplification tailored for precise bacterial growth kinetic monitoring. SYNC encapsulates single bacteria in picolitre droplets, enabling real-time, fluorescence-free electrochemical monitoring. A specially devised phosphorylation-amplified culture medium translates bacterial metabolic activity into discernible electrical impedance changes. The dual-channel design and a rail-based structure in SYNC facilitate parallel screening and self-synchronization of droplets, addressing the limitations of conventional impedance cytometry. SYNC showcases a 5-fold enhancement in detection sensitivity and reduces 50% of the detection time compared to traditional approaches. Notably, SYNC is pioneering in providing exact initial bacterial concentrations, achieve to 104 bacteria/ml, a capability unmatched by existing real-time techniques measuring electrochemical variations. Along with its robust performance, this earmarks SYNC as a powerful tool for applications such as antibiotic susceptibility testing, food quality monitoring, and real-time water bacteria monitoring, paving the way for enhanced microbial process management and infection control.

Influence of Candida albicans-Streptococcus mutans cross-border interactions on the corrosion behaviour of Ti and Ti-Zr in artificial saliva

This study evaluated and compared the corrosion effects of Streptococcus mutans (S. mutans), Candida albicans (C. albicans), and their mixture on implant materials Ti and Ti-Zr. Corrosion tests were conducted in simulated artificial saliva. The results showed differences in biofilm structure, corrosion behavior, and mechanisms between single and mixed bacteria. The cross-kingdom interaction between S. mutans and C. albicans enhanced biofilm maturity and acidity, providing necessary conditions for pitting corrosion. C. albicans played a dominant role in the interaction between C. albicans and S. mutans. Furthermore, Ti-Zr exhibited higher corrosion resistance compared to Ti.

Silver nanoparticles biosynthesis using mixture of Lactobacillus sp. and Bacillus sp. growth and their antibacterial activity

The biosynthesis of nanoparticles offers numerous advantages, including ease of production, cost-effectiveness, and environmental friendliness. In our research, we focused on the bioformation of silver nanoparticles (AgNPs) using a combination of Lactobacillus sp. and Bacillus sp. growth. These AgNPs were then evaluated for their biological activities against multidrug-resistant bacteria. Our study involved the isolation of Bacillus sp. from soil samples and Lactobacillus sp. from raw milk in Dhamar Governorate, Yemen. The synthesized AgNPs were characterized using various techniques such as UV–visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The antibacterial properties of the AgNPs were assessed using the modified Kirby Bauer disk diffusion method against multidrug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa. Our results demonstrated that the use of a bacterial mixture for biosynthesis led to faster and more effective production of AgNPs compared to using a single bacterium. The UV–visible spectra showed characteristic peaks indicative of silver nanoparticles, while XRD analysis confirmed the crystalline nature of the synthesized particles. FTIR results suggested the presence of capping proteins that contribute to the synthesis and stability of AgNPs. Furthermore, TEM images revealed the size and morphology of the AgNPs, which exhibited spherical shapes with sizes ranging from 4.65 to 22.8 nm. Notably, the antibacterial activity of the AgNPs was found to be more pronounced against Staphylococcus aureus than Pseudomonas aeruginosa, indicating the potential of these nanoparticles as effective antimicrobial agents. Overall, our study highlights the promising antibacterial properties of AgNPs synthesized by a mixture of Lactobacillus sp. and Bacillus sp. growth. Further research is warranted to explore the potential of utilizing different bacterial combinations for enhanced nanoparticle synthesis.

Microbial Ecology of Scardovia wiggsiae and other oral microbiota in Indian children

Early childhood caries (ECC) has become a significant health problem especially in children bellow 5 years. It has been on the ascending prevalence in many countries. The novel cariogenic bacteria Scardovia wiggsiae were identified to be significantly associated with severe-early childhood caries in the presence as well as in the absence of Streptococcus mutans. The goal of this current study was to analyse the role of Scardovia wiggsiae and other cariogenic microorganisms like Selenomonas noxia, Streptococcus mutens, Fusobacterium nucleatum and Veillonella parvula in Indian children with and without ECC. Children below 72 months were enrolled in the study and are divided into two groups of 50 each. One group consists of 50 children with ECC and other 50 without ECC. The presence of S. wiggsiae, Selenomonas noxia, Streptococcus mutens, Fusobacterium nucleatum and Veillonella parvula was examined by using 16S rRNA-based Real time PCR technique in saliva samples. The prevalence of S. wiggsiae is abundantly seen in children with ECC compared to children without ECC. Children with ECC have significantly higher prevalence (P&lt;0.05) of S. wiggsiae, S. noxia, S. mutans, and F. nucleatum. In this study, higher and equal association rate is observed between S. wiggsiae and S. noxia, and S. wiggsiae and F. nucleatum in children with ECC. The study have demonstrated that not only a single cariogenic bacteria is responsible for ECC, but the population of oral microbiota may support for the development and progression of ECC.