Bacterial Colonies Research Articles

Induction of biofilm in extended-spectrum beta-lactamase Staphylococcus aureus with drugs commonly used in pharmacotherapy

Staphylococcus aureus is a bacterial pathogen that causes bloodstream infections, pneumonia, and skin abscesses and is the primary pathogen responsible for medical devices associated with biofilm infections, accounting for approximately 70 % of cases. Therefore, the World Health Organization (WHO) has designated this microorganism as a top priority due to its role in causing over 20,000 bacteremia-related deaths in the US each year. The issue of pathogen resistance to antibiotics, mainly by a biofilm, further complicates these infections since biofilms render the bacterial colony impervious to antibiotics. However, many natural and synthetic substances also induce bacterial biofilm formation. Therefore, we investigated whether the most common active pharmaceutical ingredients (APIs) could induce biofilm formation in two clinical isolates of extended-spectrum beta-lactamase Staphylococcus aureus, one of them also methicillin-resistant (A2M) and two medical devices.We detected biofilm inducers, inhibitors, and destabilizers. Microbial strain, medical devices, API structure, and concentration influenced the modulatory effects of biofilm. In all devices tested, including microplates, FR18 duodenal probe, and respiratory probe, the clinic isolate methicillin-resistant S. aureus A2M exhibited lower susceptibility to biofilm formation than S. aureus A1. The anti-inflammatory acetaminophen, the hypocholesterolemic lovastatin, and the diuretic hydrochlorothiazide all induced biofilm. However, verapamil, an antihypertensive, and cetirizine, an antihistamine, inhibited biofilm on S. aureus A2M, while propranolol, another antihypertensive, inhibited biofilm on S. aureus A1. Additionally, diclofenac, an analgesic, and cetirizine destabilized the biofilm, resulting in more free bacteria and possibly making them more susceptible to external agents such as antibiotics. Nonetheless, further epidemiologic analyses and in vivo assays are needed to confirm these findings and to establish a correlation between drug use, the onset of bacterial infections in patients, and the use of medical devices.This work provides information about the probable clinical implications of drugs in patients using medical devices or undergoing surgical procedures. Inhibitory APIs could also be used as drug repurposing or templates to design new, more potent biofilm inhibitors.

Microbial Diversity Assessment in Soil from Dumping Sites: Isolation, DNA Extraction and Electrophoretic Analysis

This study aims to investigate the microbial diversity present in soil samples collected from various dumping sites, which are known for their complex and heterogeneous waste environments. The primary objective is to isolate and characterize the microbial communities inhabiting these soils, providing insights into their composition and potential ecological roles. Soil samples were collected by digging 5 cm deep at multiple dumping locations to ensure a representative sampling of the microbial populations. The collected soil samples underwent a serial dilution process, extending up to 10^-9 and 10^-10 dilutions, to facilitate the isolation of individual microbial colonies. These diluted samples were then inoculated onto Standard Potato Dextrose Agar (PDA) media, a nutrient-rich medium conducive to microbial growth. Following an incubation period, distinct bacterial colonies were observed and isolated for further analysis. DNA was extracted from the isolated bacterial colonies using a standard DNA extraction protocol. The quality and purity of the extracted DNA were assessed through gel electrophoresis, a technique that separates DNA fragments based on their size. Remarkably, the electrophoretic analysis revealed clear and distinct DNA bands along with RNA bands, indicating successful extraction of high-quality microbial DNA. Notably, this was achieved without the use of proteinase treatment, which is typically employed to remove protein contaminants from DNA samples. The results of this study underscore the robustness of the methodologies employed in isolating and characterizing microbial DNA from soil samples collected at dumping sites. The presence of distinct DNA and RNA bands highlights the effectiveness of the DNA extraction process, even in the absence of proteinase treatment. These findings provide valuable insights into the microbial diversity within dumping site soils, suggesting a rich and varied microbial community that may play significant roles in soil health and waste decomposition.

Enhancing Bactericidal Properties of Ti6Al4V Surfaces through Micro and Nano Hierarchical Laser Texturing.

Orthopedic and dental implants made from Ti6Al4V are widely used due to their excellent mechanical properties and biocompatibility. However, the long-term performance of these implants can be compromised by bacterial infections. This study explores the development of hierarchically textured surfaces with enhanced bactericidal properties to address such challenges. Hierarchical surface structures were developed by combining microscale features produced by a microsecond laser and superimposed submicron features produced using a femtosecond laser. Microscale patterns were produced by the pulsed laser surface melting process, whereas submicrometer laser-induced periodic surface structures were created on top of them by femtosecond laser processing. Escherichia coli bacterial cells were cultured on the textured surface. After 24 h, a staining analysis was performed using SYTO9 and PI dyes to investigate the samples with a confocal microscope for live dead assays. Results showed bacterial colony formation onto the microscale surface textures with live bacterial cells, whereas the hierarchical surface textures display segregated and physically damaged bacterial cell attachments on surfaces. The hierarchical surface textures showed ∼98% dead bacterial cells due to the combined effect of its multiscale surface features and oxide formation during the laser processing steps. The efficacy of hierarchical surface textures in enhancing the antibacterial behavior of Ti6Al4V implants is evident from the conducted research. Such laser-based surface treatments can find potential applications in different industrial sectors.

The Effects of Dental Hygiene Instruments on Streptococcus sanguinis Adhesion to Titanium Implant Abutments.

Maintenance of dental implant with different hygiene methods or instruments may cause a surface alteration. It directly affects bacterial colonization and adhesion on titanium implant surfaces that result in peri-implant diseases. This study aimed to compare the Streptococcus sanguinis (S. sanguinis) adhesion on titanium implant abutments after instrumentation with a rubber cup with pumice and erbium, chromium-doped: yttrium, scandium, gallium, and garnet (Er, Cr: YSGG) laser using scanning electron microscope (SEM) observation and colony-forming unit (CFU) measurement. Twenty-one MegaGentitanium implant abutments were randomly distributed into three groups. Seven abutments were respectively selected for the control/untreated (C) group, while the other two groups were treated with rubber cups with pumice (P) and Er, Cr: YSGG laser (L). All samples were cultured with S. sanguinis for bacterial colonization and adhesion. One sample for each group was selected for SEM observation, while the other samples were prepared for CFU calculation. For SEM results, at 2,000× magnification, machining marks were intact in the C group, roughened in the L group, and smoothened in the P group. At 5,000× and 10,000× magnifications, moderate colonies of S. sanguiniswere revealed in C and L groups, while sparse bacterial colonies were detected in the P group. However, for CFU results, statistical analysis showed no significant value (p>0.05) comparing all three groups. P instrumentation revealed a lesser amount of S. sanguinis adhesion in SEM photographs, but no statistical significance of CFU results was noted for all three groups.

The effect of laser therapy for the treatment of dentin hypersensitivity on surface roughness and bacterial adhesion

The aim of the study was to measure the degree of dentine surface roughness caused by five distinct lasers used to treat dentine hypersensitivity, as well as to evaluate the subsequent bacterial colonization on these irradiated surfaces. Sixty human maxillary premolar teeth without caries or restoration which were extracted for periodontal reasons were used in this study. Five different types of lasers were applied to the root dentin surface. Tested samples were divided into six groups of 10 samples each; control, diode (810 nm), diode (980 nm), Nd: YAG, Er: YAG, and Er, Cr: YSGG laser groups. The arithmetic mean of the surface roughness values (Ra) and the average roughness over a measurement area (Sa) were measured pre- and post-application using any of the laser types. Swab samples were then collected from the dentin surface. Following a 24-hour incubation period at 37 °C, the colony forming units were counted using a stereoscope. The results demonstrated a statistically significant difference in the surface roughness values pre- and post-application (Ra and Sa, respectively) in the Er, Cr: YSGG laser group (p = 0.037,p = 0.007). No significant difference was observed in the other groups (p > 0.05). There was no statistically significant difference in the number of bacterial colonies observed between the test and control groups. Diode and Nd: YAG lasers showed either a decrease or no change in surface roughness; however, the hard tissue lasers (Er: YAG, Er, Cr: YSGG) showed an increase. The Er: YAG and Nd: YAG laser groups exhibited decreased bacterial adhesion compared to the other groups.

ANTIMICROBIAL WOUND DRESSINGS FOR FULL-THICKNESS INFECTED BURN WOUNDS.

Infection of wounds delays healing, increases treatment costs, and leads to major complications. Current methods to manage such infections include antibiotic ointments and antimicrobial wound dressings, both of which have significant drawbacks, including frequent reapplication and contribution to antimicrobial resistance. In this work, we developed wound dressings fabricated with a medical-grade polyurethane coating composed of natural plant secondary metabolites, cinnamaldehyde, and alpha-terpineol. Our wound dressings are easy to change and do not adhere to the wound bed. They kill gram-positive and -negative microbes in infected wounds due to the Food and Drug Administration-approved for human consumption components. The wound dressings were fabricated by dip coating. Antimicrobial efficacy was determined by quantifying the bacteria colonies after a 24 h of immersion. Wound healing and bacterial reduction were assessed in an in vivo full-thickness porcine burn model. Our antimicrobial wound dressings showed a > 5-log reduction (99.999%) of different gram-positive and gram-negative bacteria, while maintaining absorbency. In the in vivo porcine burn model, our wound dressings were superior to bacitracin in decreasing bacterial burden during daily changes, without interfering with wound healing. Additionally, the dressings had a significantly lower adhesion to the wound bed. Our antimicrobial wound dressings reduced the burden of clinically relevant bacteria more than commercial antimicrobial wound dressings. In an in vivo infected burn wound model, our coatings performed as well or better than bacitracin. We anticipate that our wound dressings would be useful for the treatment of various types of acute and chronic wounds.

Highly sensitive SERS nanoplatform based on aptamer and vancomycin for detection of S. aureus and its clinical application

Staphylococcus aureus (S. aureus) is the most common pathogen in human purulent infections, which can cause local purulent infections, as well as pneumonia, pseudomembranous enteritis, pericarditis, and even systemic infections. The conventional methods including bacteria colony counting, polymerase chain reaction and enzyme-linked immunosorbent assay can't fully meet the requirement of highly sensitive detection of S. aureus due to their own disadvantages. Therefore, it's an urgent need to develop new platform to detect S. aureus in the early infection stage. In this study, a new surface-enhanced Raman scattering (SERS)-based nanoplatform based on dual-recognition of aptamer (Apt) and vancomycin (Van) was developed for the highly sensitive detection of S. aureus. The SERS nanoplatform consisted of two functional parts: aptamer-conjugated Fe3O4 magnetic nanoparticles (Fe3O4-Apt MNPs) for bacteria enrichment and vancomycin modified-Au nanoparticles (Van-Au NPs) as the SERS probes for S. aureus quantitative detection. Upon the target bacteria enrichment, the SERS signals of the supernatant after magnetic separation could be obtained and analyzed under different concentrations of S. aureus. The limit of detection of the proposed assay was found to be 3.27 CFU/mL. We believe that the proposed SERS-based nanoplatform has great potential as a powerful tool in the early detection of specific bacteria.

Development of dual-effect AW/Ag/CHI bioactive and antibacterial coating for orthopedic implant surfaces

Titanium implants, which are widely used in orthopedic implant applications, require surface treatments due to their low osteoinduction properties and the risk of postoperative infection. In this study, apatite wollastonite (AW)-based coatings with chitosan (CHI) and silver (Ag) added were applied to the titanium surface using dip coating and drop casting techniques. The obtained coating surfaces were characterized by FESEM, EDS, XRD, FTIR, and TGA–DSC. Biomineralization behaviors were examined by immersing the resulting coatings in simulated body fluid with pH 7.2–7.4. The antibacterial activities of the coatings obtained using S. aureus and E. coli bacterial colonies were examined. Following the successful coating of AW nanoparticles on the Ag and CHI implant substrate, the Ca/P ratio of the coated surface was obtained as 1.4–1.92% after the biomineralization process performed at 37° for 7 days. Ag particles were successfully distributed homogeneously with a 40–50-nm diameter in Ag-doped coatings. It was concluded that the successfully produced composite coating with bioactive and antibacterial properties is a suitable candidate material for metallic implant surfaces.Graphical abstract

Chitosan/polyvinyl alcohol food packaging incorporated with purple potato anthocyanins and nano-ZnO: Application on the preservation of hairtail (Trichiurus haumela) during chilled storage

The objective of this work was to evaluate the potential application of chitosan/PVA food packaging films incorporating nano-ZnO and purple potato anthocyanins for preserving chilled hairtail pieces. The hairtail pieces were packaged with chitosan/PVA (CP) and chitosan/PVA/nano-ZnO/purple potato anthocyanins (CPZP), respectively, and Control named without any packaging. The changes in pH, total volatile basic nitrogen (TVB-N), total bacterial colony (TVC), thiobarbituric acid (TBA), color value, and sensory evaluation scores of hairtail pieces were periodically determined. Notably, pH, TVC, TVB-N and TBA values of CPZP group on day 15 were 11.67 %, 23.71 %, 80.73 %, and 35.07 %, respectively, lower than Control group. In addition, CPZP group also performed the best in color and sensory evaluation. These results indicated that CPZP, an active food packaging, could extend the shelf-life of hairtail at least 6 days. Overall, chitosan/PVA food films incorporated with nano-ZnO and purple potato anthocyanins (180 mg/100 mL) provides a potential application in food preservation.

IFN-β Overexpressing Adipose-Derived Mesenchymal Stem Cells Mitigate Alcohol-Induced Liver Damage and Gut Permeability.

Alcoholic liver disease (ALD) is a form of hepatic inflammation. ALD is mediated by gut leakiness. This study evaluates the anti-inflammatory effects of ASCs overexpressing interferon-beta (ASC-IFN-β) on binge alcohol-induced liver injury and intestinal permeability. In vitro, ASCs were transfected with a non-viral vector carrying the human IFN-β gene, which promoted hepatocyte growth factor (HGF) secretion in the cells. To assess the potential effects of ASC-IFN-β, C57BL/6 mice were treated with three oral doses of binge alcohol and were administered intraperitoneal injections of ASC-IFN-β. Mice treated with binge alcohol and administered ASC-IFN-β showed reduced liver injury and inflammation compared to those administered a control ASC. Analysis of intestinal tissue from ethanol-treated mice administered ASC-IFN-β also indicated decreased inflammation. Additionally, fecal albumin, blood endotoxin, and bacterial colony levels were reduced, indicating less gut leakiness in the binge alcohol-exposed mice. Treatment with HGF, but not IFN-β or TRAIL, mitigated the ethanol-induced down-regulation of cell death and permeability in Caco-2 cells. These results demonstrate that ASCs transfected with a non-viral vector to induce IFN-β overexpression have protective effects against binge alcohol-mediated liver injury and gut leakiness via HGF.

Antibacterial Efficacy of Hiora: An Ayurvedic Mouthwash in Children.

Mouthwashes, as a form of antimicrobial delivery system, rank among the safest and most effective vehicles, particularly in the case of young children. This is attributed to their ability to distribute therapeutic components across all accessible oral surfaces, including interproximal areas. To evaluate the antibacterial efficacy of recently introduced Ayurvedic (Hiora) and triclosan-based mouthwashes among children. A total of 45 healthy children aged 10-15 years were randomly assigned to three groups: Herbal mouthwash (Hiora), triclosan-based mouthwash (Kidodent), and normal saline as the control group. Saliva samples were collected pre-rinse, 2 minutes, 30 minutes, and 60 minutes post-rinsing with the study mouthwashes. These samples were then inoculated onto Petri dishes containing blood agar culture media, followed by incubation under both aerobic and anaerobic conditions at 37°C for 48 hours. The resulting bacterial colonies of Streptococcus spp. and Lactobacillus spp. were counted (CFU/ml x 105). Statistical analysis, including ANOVA, Newman Keul's Post-hoc test, and a two-tailed 't' test, was conducted to determine the significance of the results. The Ayurvedic Hiora mouthwash demonstrated the most substantial reduction in salivary bacterial colony counts of Streptococcus spp. and Lactobacillus spp. with statistically significant results (p<0.01). The Ayurvedic Hiora mouthwash exhibited the highest antibacterial effectiveness, followed by the triclosan-based mouthwash in decreasing order, with saline showing the least efficacy.

Humic acid-mediated mechanism for efficient biodissolution of used lithium batteries

Resource recovery of valuable metals from spent lithium batteries is an inevitable trend for sustainable development. In this study, external regulation was used to enhance the tolerance and stability of strains in the leaching of spent lithium batteries to radically improve the bioleaching efficiency. The leaching of Li, Ni, Co and Mn increased to 100 %, 85.06 %, 74.25 % and 69.44 % respectively after targeted cultivation with HA as compared to the undomesticated strain. In the process of microbial leaching of spent lithium batteries, the metabolites in the Ⅰ, Ⅳ, and Ⅴ regions of the metabolism of the undomesticated bacterial colony had a positive correlation to the dissolution of spent lithium batteries. The metabolites of Ⅰ, Ⅱ, and Ⅴ regions were directly affected by the HA domesticated flora on the dissolution of spent lithium batteries. The excess metabolism of protein substances can significantly promote the reduction of Ni, Co, Mn leaching, and at the same time in the role of a large number of humic substances complexed the toxic metal ions in the system, to ensure the activity of the bacterial colony. It can be seen that the bacteria were domesticated by humic acid, which promoted the bacteria's own metabolism, and the super-metabolised EPS promoted the solubilisation of spent lithium batteries.

Growing bacterial colonies harness emergent genealogical demixing to regulate organizational entropy

Spatiotemporal organization of individuals within growing bacterial colonies is a key determinant of intraspecific interactions and colony-scale heterogeneities. The evolving cellular distribution, in relation to the genealogical lineage, is thus central to our understanding of bacterial fate across scales. Yet, how bacteria self-organize genealogically as a colony expands has remained unknown. Here, by developing a custom-built label-free algorithm, we track and study the genesis and evolution of emergent self-similar genealogical enclaves, whose dynamics are governed by biological activity. Topological defects at enclave boundaries tune finger-like morphologies of the active interfaces. The Shannon entropy of cell arrangements reduce over time; with faster-dividing cells possessing higher spatial affinity to genealogical relatives, at the cost of a well-mixed, entropically favorable state. Our coarse-grained lattice model demonstrates that genealogical enclaves emerge due to an interplay of division-mediated dispersal, stochasticity of division events, and cell-cell interactions. The study reports so-far hidden emergent self-organizing features arising due to entropic suppression, ultimately modulating intraspecific genealogical distances within bacterial colonies.

Phase ordering in binary mixtures of active nematic fluids.

We use a continuum, two-fluid approach to study a mixture of two active nematic fluids. Even in the absence of thermodynamically driven ordering, for mixtures of different activities we observe turbulent microphase separation, where domains form and disintegrate chaotically in an active turbulent background. This is a weak effect if there is no elastic nematic alignment between the two fluid components, but is greatly enhanced in the presence of an elastic alignment or substrate friction. We interpret the results in terms of relative flows between the two species which result from active anchoring at concentration gradients. Our results may have relevance in interpreting epithelial cell sorting and the dynamics of multispecies bacterial colonies.

Enhancement of pork marinating efficiency through pulsed electric field pretreatment: Integration of parameter optimization, kinetic modeling and quality characteristics

Marination is an important part of meat processing, the disadvantage is that the process of marinating is slow and prone to losing nutrients. In this study, pork tenderloins were pretreated with pulsed electric field (PEF) before being immersed in the marinade at 4 °C. The aim was to investigate the effect of PEF pretreatment (PEFP) on the marination process, specifically mass transfer and the quality of the pork. Additionally, the response surface method (RSM) was employed to explore the optimal conditions for PEFP. Results showed that under the best condition (2 kV/cm, 141.2 Hz and 2.3% duty cycle), the NaCl content of pork cured for 6 h reached 3.31%, which could effectively shorten the marinating time of pork (up to 40%). After marinating for 6 h with PEFP, the weight, moisture, and salt changes increased significantly. The effective diffusion coefficient (De) was raised to 1.71 × 10−10 (PEFP) from 1.36 × 10−10 (control) and the kinetic model of mass transfer over time has good linear correlation. The scanning electron microscopy (SEM) results indicate that PEFP altered the muscle fibre structure of pork to some extent, resulting in loosely arranged muscle fibre bundles. The total bacterial colony count results showed that PEFP had a good sterilization effect on microorganisms in pork. Furthermore, PEFP does not alter the colour or pH of marinated pork while improving its tenderness. These results showed that PEFP could effectively promote salt diffusion to shorten marinating time and improve meat tenderness.

Oral care methods to reduce salivary bacteria in infants undergoing cardiac surgery: A randomized controlled trial

Background/purposeComplications, such as postoperative pneumonia, can occur after pediatric cardiac surgery; however, studies on related changes in perioperative oral bacterial counts are scarce. Herein, we investigated the changes in oral bacterial counts before and after surgery in infants who underwent cardiac surgery, as well as after oral care using an antiseptic mouthwash. Materials and methodsA total of 102 infants who underwent congenital heart disease surgery were enrolled in this study. Preoperative oral care was provided using water and a sponge brush. Bacterial cultures were used to determine salivary bacterial counts before and after oral care. Postoperatively, the infants were randomized into a water group (WA group), benzethonium chloride mouthwash group (BZ group), or povidone-iodine mouthwash group (PV–I group), and their salivary bacterial counts, before and after oral care, were measured. ResultsThe preoperative salivary bacterial colony counts did not change after oral care; however, the postoperative bacterial counts were significantly lower, possibly because of the use of systemic antibiotics. Bacterial counts before and after oral care were not significantly different between the WA and BZ groups; however, bacterial counts were significantly decreased in the PV-I group after oral care. ConclusionOverall, the results of this study show that systemic administration of antibiotics reduces postoperative salivary bacterial counts in infants undergoing cardiac surgery, and oral care with PV-I can further reduce bacterial counts.

ISOLASI DAN UJI AKTIVITAS BAKTERI PELARUT FOSFAT DARI RHIZOSFER TANAMAN PADI (Oryza sativa L.) PADA FASE VEGETATIF DAN GENERATIF

Phosphorus (P) is a very important macronutrient for plant growth and development. Plants cannot fully absorb phosphate in the soil, only 25% can be absorbed by plants while Al binds 75% in the soil. Plants absorb P from the soil in the form of phosphate ions, especially in the form of H2PO4- and HPO42- which are present in soil solutions. H2PO4 ion is more common in acidic soils, while higher pH (&gt; 7) forms HPO42- is more dominant. The lack of P dissolved in the soil causes the plant to get P intake from other sources such as fertilizers. Efforts to increase the efficiency of Phosphate dissolution, currently the use of Phosphate solubilizing microbes have begun to be developed. This study aims to determine the number of isolated bacterial colonies, the ability of phosphate-solubilizing bacteria, and the levels of P-available before and after giving phosphate-solubilizing bacterial isolates. This research was conducted at the Laboratory of Plant Pests and Diseases and in the Laboratory of Soil and Environmental Conservation, Faculty of Agriculture, Universitas Muslim Indonesian, Makassar, Indonesia, from November to December 2020. The materials used in this study were HVS paper, aluminum foil, plastic wrap, labels, rubber, Pikovskaya media, sterile distilled water, plastic, cotton, tissue, 70% alcohol, rubbing alcohol, NA (Natrium Agar) media, soil samples from the vegetative and generative phases of rice rhizosphere from Tebba Village, Salomekko District, Bone Regency. This research method is a qualitative exploratory research based on data analysis. The results of this study indicated that the vegetative phase 3 rice isolates with 10-5 dilution had the highest number of colonies, namely 9,200,000 CFU /ml. Plant generative phase 3 rice isolate at 10-5 dilution had the highest average phosphate solubility with an IPF value of 5.56. Plant generative phase 3 rice isolate had the highest average P-available before and after the addition of Phosphate Solubilizing Bacteria isolates, namely 3.83 ppm, and after the addition of Phosphate Solubilizing Bacteria isolates increased to 9.58 ppm.

High-resolution 3D spatial distribution of complex microbial colonies revealed by mass spectrometry imaging

IntroductionBacterial living states and the distribution of microbial colony signaling molecules are widely studied using mass spectrometry imaging (MSI). However, current approaches often treat 3D colonies as flat 2D disks, inadvertently omitting valuable details. The challenge of achieving 3D MSI in biofilms persists due to the unique properties of microbial samples. ObjectivesThe study aimed to develop a new biofilm sample preparation method that can realize high-resolution 3D MSI of bacterial colonies to reveal the spatial organization of bacterial colonies. MethodsThis article introduces the moisture-assisted cryo-section (MACS) method, enabling embedding-free sectioning parallel to the growth plane. The MACS method secures intact sections by controlling ambient humidity and slice thickness, preventing molecular delocalization. ResultsCombined with matrix-assisted laser desorption ionization mass spectrometry (MALDI)-MSI, the MACS method provides high-resolution insights into endogenic and exogenous molecule distributions in Pseudomonas aeruginosa (P. aeruginosa) biofilms, including isomeric pairs. Moreover, analyzed colonies are revived into 3D models, vividly depicting molecular distribution from inner to outer layers. Additionally, we investigated metabolite spatiotemporal dynamics in multiple colonies, observing changes over time and distinct patterns in single versus merged colonies. These findings shed light on the repel-merge process for multi-colony formation. Furthermore, our study monitored chemical responses inside biofilms after antibiotic treatment, showing increased antibiotic levels in the outer biofilm layer over time while maintaining low levels in the inner region. Moreover, the MACS method demonstrated its universality and applicability to other bacterial strains. ConclusionThese results unveil complex cell activities within biofilm colonies, offering insights into microbe communities. The MACS method is universally applicable to loosely packed microorganism colonies, overcoming the limitations of previously reported MSI methods. It has great potential for studying bacterial-infected cancer tissues and artificial organs, making it a valuable tool in microbiological research.

Identifikasi Bakteri Patogen Gram Negatif pada Alat Praktikum Mikrobiologi di Laboratorium Central Stikes Maharani Malang

Stacks of laboratory equipment and lack of routine sterilization can contribute to the growth and contamination of pathogenic bacteria. This research aimed to determine the types of gram-negative pathogenic bacteria present in the microbiology practicum equipment at the Central STIKes Maharani Malang Laboratory. This type of research is descriptive research with an analytical research design. The sampling technique uses purposive sampling. This research involves taking swab samples on the surface of practical microbiology equipment, isolating bacterial colonies using MCA (Mac Conkey Agar) media, making pure cultures on MCA slanted agar media, macroscopic observations, and biochemical tests. Bacteria were grown on MCA media for 2x24 hours. The results of research using gram staining showed gram-negative bacteria, rod-shaped, spread, and red. Biochemical tests showed glucose (+g), lactose (+), mannitol (+), maltose (+), sucrose (+), H2S (-), indole (-), Mr (Methyl Red) (-), Vp ( Voges Praskaeur) (+), citrate (+), motility (-), the bacterial species Klebsiella pneumoniae was found. The second result shows glucose (+g), lactose (+), mannitol (+), maltose (+), sucrose (+), H2S (-), indole (+), Mr (Methyl Red) (+), Vp ( Voges Praskaeur) (-), citrate (-), motility (-), found Escherichia coli bacterial species. This study concluded that it was found that gram-negative bacteria were rod-shaped, spread, and red. Meanwhile, from biochemical tests using glucose, lactose, mannitol, maltose, sucrose, ındol, MR, VP, and citrate, Klebsiella pneumoniae and Escherichia coli bacteria were found.

Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes.

The Gardnerella genus, comprising at least 13 species, is associated with the polymicrobial disorder bacterial vaginosis (BV). However, the details of BV pathogenesis are poorly defined, and the contributions made by individual species, including Gardnerella spp., are largely unknown. We report here that colony phenotypes characterized by size (large and small) and opacity (opaque and translucent) are phase variable and are conserved among all tested Gardnerella strains, representing at least 10 different species. With the hypothesis that these different variants could be an important missing piece to the enigma of how BV develops in vivo, we characterized their phenotypic, proteomic, and genomic differences. Beyond increased colony size, large colony variants showed reduced vaginolysin secretion and faster growth rate relative to small colony variants. The ability to inhibit the growth of Neisseria gonorrhoeae and commensal Lactobacillus species varied by strain and, in some instances, differed between variants. Proteomics analyses indicated that 127-173 proteins were differentially expressed between variants. Proteins with increased expression in large variants of both strains were associated with amino acid and protein synthesis and protein folding, whereas those increased in small variants were related to nucleotide synthesis, phosphate transport, ABC transport, and glycogen breakdown. Furthermore, whole genome sequencing analyses revealed an abundance of genes associated with variable homopolymer tracts, implicating slipped strand mispairing in Gardnerella phase variation and illuminating the potential for previously unrecognized heterogeneity within clonal populations. Collectively, these results suggest that phase variants may be primed to serve different roles in BV pathogenesis.IMPORTANCEBacterial vaginosis is the most common gynecological disorder in women of childbearing age. Gardnerella species are crucial to the development of this dysbiosis, but the mechanisms involved in the infection are not understood. We discovered that Gardnerella species vary between two different forms, reflected in bacterial colony size. A slow-growing form makes large amounts of the toxin vaginolysin and is better able to survive in human cervix tissue. A fast-growing form is likely the one that proliferates to high numbers just prior to symptom onset and forms the biofilm that serves as a scaffold for multiple BV-associated anaerobic bacteria. Identification of the proteins that vary between different forms of the bacteria as well as those that vary randomly provides insight into the factors important for Gardnerella infection and immune avoidance.