Growth Of Bacterial Colonies Research Articles

Current knowledge on Inquilinus limosus, a scarcely researched human pathogen

AbstractInquilinus limosus belongs to the class of the Alphaproteobacteria and was first described in 2002. So far, the species has mainly been isolated from respiratory specimens of patients with cystic fibrosis. A main characteristic of Inquilinus limosus is the prolonged time until bacterial colony growth is detectable. As the defined incubation times in many laboratories are too short to detect the growth of Inquilinus limosus, it is likely that the species is less frequently detected in the clinical setting than it actually occurs. This also explains why there are currently only very few data on the incidence available. Furthermore, as an uncommon pathogen, Inquilinus limosus may be familiar to only a few specialised clinicians. Due to these reasons, only little research (e.g. case reports and research papers) have been published on this species to date. However, given that a clear human pathogenic significance can be deduced from the existing literature, we have decided to present the current state of knowledge in this review and to address further aspects for the future elucidation of the pathogenesis of Inquilinus limosus.

Cell shape affects bacterial colony growth under physical confinement

Evidence from homogeneous liquid or flat-plate cultures indicates that biochemical cues are the primary modes of bacterial interaction with their microenvironment. However, these systems fail to capture the effect of physical confinement on bacteria in their natural habitats. Bacterial niches like the pores of soil, mucus, and infected tissues are disordered microenvironments with material properties defined by their internal pore sizes and shear moduli. Here, we use three-dimensional matrices that match the viscoelastic properties of gut mucus to test how altering the physical properties of their microenvironment influences the growth of bacteria under confinement. We find that low aspect ratio (spherical) bacteria form compact, spherical colonies under confinement while high aspect ratio (rod-shaped) bacteria push their progenies further outwards to create elongated colonies with a higher surface area, enabling increased access to nutrients. As a result, the population growth of high aspect ratio bacteria is, under the tested conditions, more robust to increased physical confinement compared to that of low aspect ratio bacteria. Thus, our experimental evidence supports that environmental physical constraints can play a selective role in bacterial growth based on cell shape.

Ameliorated Viability of Lactic Acid Bacteria in Fruit Juice Isolated from Indigenous Dahi with Prebiotics (Asparagus falcatus and Zingiber officinale)

Dahi is a fermented milk product containing probiotic lactic acid bacteria. This study aimed to isolate, identify, and characterize lactic acid-producing bacteria from native Dahi and evaluate their viability in orange juice using natural prebiotics. Dahi samples were obtained from local shops in Chattogram and Bogura, Bangladesh. Lactic acid-producing bacteria were isolated using MRS (de Mann Rogosa and Sharpe) medium. The isolated bacteria were identified through colony morphology, biochemical tests, and probiotic characteristics. Molecular identification was performed using polymerase chain reaction (PCR) targeting conserved 16S rDNA regions. Isolates of the genus Lactobacillus and Lactococcus lactis sp. Lactis were confirmed and used to develop probiotic orange juice. Prebiotics (Asparagus falcatus and Zingiber officinale) were added to the juice to support probiotic growth. The inoculated cell’s viability and the juice’s physicochemical parameters were evaluated during fermentation (48 hours) and storage (28 days). All fruit juice samples showed a mean number of viable cells of at least 1×105 CFU/mL during the 48-hour fermentation and 28-day storage in the refrigerator. Using natural prebiotics positively affected the survival of lactic acid bacteria, as demonstrated by bacterial colony growth on Petri dishes. Developing probiotic fruit juice enriched with prebiotics could be an effective alternative for individuals allergic or intolerant to milk-based products. Incorporating lactic acid bacteria from native Dahi into orange juice, combined with natural prebiotics, resulted in viable probiotic cells throughout fermentation and storage.

Exploring the molecular biology of zinc-doped hydroxyapatite nanocomposites as fillers for dental materials: a self-defensive approach targeting bacterial DNA

Abstract Infections during or after the denture filling pose a serious threat to recovery later, and antibiotics are scanty for quick healing. The antibacterial potential of Zn has convinced us to fabricate its composites with hydroxyapatite (HA), which has distinct biological properties. The main aim of the study is to evaluate the antibacterial potential of Zn-doped HA and investigate its molecular interaction with bacterial strains to enhance its defensive ability against bacterial attack. This study investigates the synthesis of zinc-doped hydroxyapatite nano-powder (Zn-HA) as coating and filling materials for dental applications. The co-precipitation technique was used in this regard to obtain the purest form of nanoparticles. The as-prepared Zn-HA samples were characterized by FTIR spectroscopy to assess the interaction of functional groups between components, X-ray diffraction (XRD) to determine percentage crystallinity, SEM to explore the surface morphology of composites, and EDX to confirm the incorporation of Zn in the apatite structure. The crystalline size of Zn-HA decreases from 99 nm to 40 nm with an increase in the doping of Zncl2 from 0 to 2.5g. With increasing the concentration of Zn doping, the effectiveness of antibacterial potential was increased. Due to an increased in the concentration of doped Zn, the Zn ions effectively rupture the bacterial membrane and destroy its DNA. Meanwhile, it shows the highest antibacterial activity against Pseudomonas (20.2±0.02), Klebsiella (25.8±0.05), Bacillus (18.3±0.09), S. aureus (24±0.03), and E. coli (19.3±0.09) with Zn/HA5.It showed that by increasing the concentration of Zinc ions in hydroxyapatite, the antibacterial potential increased. This increased concentration of zinc ions in HA enhances its-defensive ability against the attack of various bacterial strains, this makes it a potential material and enhances its efficacy in dental applications like coating, filling material, or dental restoratives, in inhibiting the growth of bacterial colonies and biofilm formation in the oral cavity. In this way, Zn/HA as an efficient dental composite as a restorative material with enhanced antibacterial potential may help to mitigate the risk of dental infections, promote dental as well as oral health, and overall improve the life of dentine.

Bacterial Blocking and Repair of Intestinal Defects With Well-Alighed Lamellar MXene/Polyvinyl Alcohol Hydrogels Prepared by Bidirectional Freezing Method

To explore the bacterial blocking effect of oriented multilayer MXene/polyvinyl alcohol (PVA) nanocomposite hydrogels and their effect on the repair of intestinal defects. MXene/PVA nanocomposite hydrogels were prepared using the traditional freezing method and the bidirectional freezing ice template method. The structures of the different hydrogels were observed using scanning electron microscopy (SEM) and micro-CT reconstruction. The rheological properties of the hydrogels were measured using a dynamic rheometer, and their mechanical properties were assessed using a universal testing machine. The burst pressure of the hydrogels was determined through burst experiments, and bacterial colony growth was observed by the osmosis method to assess the bacteria blocking ability of the hydrogels in vitro. A rat model of cecal perforation was established, and the hydrogels were used for intestinal repair. Gram staining was performed to observe in vivo the bacterial blocking ability of the hydrogels, HE staining was performed to observe the intestinal inflammation, and CD31 and CD68 immunofluorescence staining and proliferating cell nuclear antigen (PCNA) staining were performed to observe the repair effect of the hydrogels on intestinal defects. SEM and micro-CT reconstruction revealed that the hydrogel prepared by the traditional freezing method exhibited a random porous structure, while the hydrogel prepared by the bidirectional freezing method showed an oriented multilayer structure. Rheological and tensile tests indicated that the oriented hydrogel had superior mechanical properties, and the burst pressure of the oriented multilayer hydrogel was as high as 27 kPa, significantly higher than that of the non-oriented hydrogel (P<0.001). Bacterial colony growth was observed by the osmosis method and it was found that, compared with the non-oriented hydrogel, the oriented multilayer hydrogel could effectively prevent the infiltration of Escherichia coli and Staphylococcus aureus in vitro. Gram staining results showed that the oriented multilayer hydrogel could effectively block intestinal bacteria from entering the abdominal cavity in vivo. HE staining results showed that the oriented multilayer hydrogel could effectively reduce intestinal inflammation in vivo. CD31 and CD68 immunofluorescence staining and PCNA staining results showed that the oriented multilayer hydrogel had a repairing effect on intestinal defects in vivo. The oriented multilayer hydrogel prepared by bidirectional freezing effectively prevents bacterial infiltration and reduces intestinal inflammation.

The biophysical basis of bacterial colony growth

The biophysical basis of bacterial colony growth

3D printed scaffolds with quercetin and vitamin D3 nanocarriers: In vitro cellular evaluation.

Increasing bone diseases and anomalies significantly challenge bone regeneration, necessitating the development of innovative implantable devices for effective healing. This study explores the potential of 3D-printed calcium phosphate (CaP) scaffolds functionalized with natural medicine to address this issue. Specifically, quercetin and vitamin D3 (QVD) encapsulated solid lipid nanoparticles (QVD-SLNs) are incorporated into the scaffold to enhance bone regeneration. The melt emulsification method is utilized to achieve high drug encapsulation efficiency (~98%) and controlled biphasic release kinetics. The process-structure-property performance of these systems allows more controlled release while maintaining healthy cell-material interactions. The functionalized scaffolds show ~1.3- and ~-1.6-fold increase in osteoblast cell proliferation and differentiation, respectively, as compared with the control. The treated scaffold demonstrates a reduction in osteoclastic activity as compared with the control. The QVD-SLN-loaded scaffolds show ~4.2-fold in vitro chemopreventive potential against osteosarcoma cells. Bacterial assessment with both Staphylococcus aureus and Pseudomonas aeruginosa shows a significant reduction in bacterial colony growth over the treated scaffold. These findings summarize that the release of QVD-SLNs through a 3D-printed CaP scaffold can treat various bone-related disorders for low or non-load-bearing applications.

Utilizing Maize Cob Media as a Replacement for Nutrient Agar Media in the Growth of Escherichia coli and Staphylococcus aureus Bacteria

Bacteria are microorganisms that require adequate media and nutrients to grow and develop. The media commonly used to grow bacteria is Nutrient agar media, but the price of Nutrient agar media is quite expensive. Corn cobs are lignocellulosic wastes that contain nutrients that can meet the nutritional requirements of bacterial growth media. This study aims to investigate the viability of corn cobs as a cost-effective alternative to Nutrient agar media. Specifically, we explore the variance in bacterial colony growth when utilizing corn cobs as a growth medium for Escherichia coli and Staphylococcus aureus bacteria. Employing a true experimental design with a posttest-only control structure, we analyze the treatment's effects using the One Way ANOVA test and Independent Sample T-test. These statistical methods enable us to discern differences between groups utilizing corncob media with and without added sugar.Our findings reveal noteworthy insights into bacterial colony growth. For Escherichia coli, the average number of colonies on corncob media with sugar was 222 CFU/ml, on corncob media without sugar, it was 164 CFU/ml, and on Nutrient agar media, it reached 361 CFU/ml. In the case of Staphylococcus aureus, colonies on corncob media with sugar averaged 871 CFU/ml, on corncob media without sugar, they averaged 657 CFU/ml, and on Nutrient agar media, they reached 942 CFU/ml.Statistical analysis using the One Way ANOVA test for both Escherichia coli and Staphylococcus aureus demonstrated p-values &lt;0.05, signifying significant differences in their growth on corncob media with sugar, corncob media without sugar, and Nutrient agar media. Furthermore, the Independent Sample T-test results for both bacterial strains yielded p-values &lt;0.05, indicating dissimilar growth patterns on corncob media with sugar compared to corncob media without sugar.In conclusion, our study underscores significant disparities in the growth of Escherichia coli and Staphylococcus aureus bacteria among Nutrient agar media, corncob media with sugar, and corncob media without sugar. Notably, we observed a marked increase in bacterial colony counts on corncob media with sugar and corncob media without sugar.

Phytochemical Analysis and Antibacterial Property of Green Okra Fruit Extract Against Enterococcus Faecalis Bacteria Tooth Root Canals

Background: Root canal treatment aims to eliminate bacteria that cause pulp abnormalities. Enterococcus faecalis is a bacteria in the infected tooth pulp, even those that have been treated. Irrigation was carried out together with biomechanical preparation using a combination of NaOCl and EDTA. The material is antibacterial, dissolves the organic and inorganic tissue of the root canal dentin, lacks odor and irritates the soft tissue. An alternative irrigation material from Jember cultivation is green okra. The fruit contains flavonoids, tannins, steroids, terpenoids. This study aims to analyze the phytochemical and antimicrobial properties of green okra fruit extract on the growth of E. Faecalis bacteria. Method: Phytochemical analysis to see the content of alkaloids, flavonoids, tannins, saponins, steroids and terpenoids. Antimicrobial analysis included the inhibition test using disc diffusion, MIC and MBC tests using the dilution method. Samples were green okra fruit extract 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, 1.563%, 2.5% NaOCl, 17% EDTA. The MIC and MBC tests were examined for Optical Density values ​​with a spectrophotometer and then subcultured to see whether there was growth of bacterial colonies. Analysis of the research data used ANOVA and LSD parametric statistical tests Result: Phytochemical content sequentially is Polyphenols, Alkaloids, Flavonoids, Saponins, Tannins, Steroids, Terpenoids. Antimicrobial properties Green okra fruit extract concentration of 6.25% had the smallest inhibition zone, the largest OD value and the highest colony count. The concentration of 100% has the largest inhibition zone, the lowest OD, there are no bacterial colonies. Antimicrobial power The concentration of 100% is close to that of 17% EDTA and 2.5% NaOCl. In the Kruskal Wallis test, there were differences in the Mann-Whitney test study group, there were significant differences between all groups Conclusion: The phytochemical content of green okra fruit extract has antimicrobial activity against E. faecalis approaching 2.5% NaOCl and 17% EDTA at 100% concentration, 6.25% MIC concentration and 12.5% ​​MBC concentration. Keywords: Phytochemical, Antibacterial, Green okra fruit extract, Enterococcus faecalis

ANTIBACTERIAL EFFECTIVENESS TEST OF KECAPI LEAVES EXTRACTS (Sandoricum koetjape) AGAINST THE GROWTH OF Porphyromonas gingivalis

Background: Chronic periodontitis is a disease of the oral cavity that is influenced by the presence of plaque bacteria caused by Porphyromonas gingivalis which can cause chronic infection of the periodontal tissue. Kecapi leaf (Sandoricum koetjape) extract contains active compounds in the form of flavonoids, saponins, alkaloids, steroids, phenolics, and triterpenoids which function as antibacterial against the growth of Porphyromonas gingivalis. Kecapi leaf extract is used as an alternative to using herbal gluconate to prevent infection caused of Porphyromonas gingivalis. Purpose: To determine the antibacterial effectiveness of kecapi leaf extract against bacterial growth of Porphyromonas gingivalis. Methods: This study used a pure experimental research (true experimental) with post-test only with control design, consists of 7 treatment groups, including: concentrated kecapi leaf extract 5%, 10%, 15%, 25%, 50%, chlorhexidine gluconate 0.2% as positive control, and distilled water as negative control. It was repeated 7 times, the antibacterial effectiveness was assessed from Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) on BHIB and NA media by dilution method. Results: MIC on kecapi leaf extract at a concentration of 5% showed the smallest result of -0.147 and the MBC value at a concentration of 50% did not show the growth of bacterial colonies. Conclusion: Kecapi leaf extract with concentrations of 5%, 10%, 15%, 25%, 50%, and positive control was effective in inhibiting and killing bacterial growth of Porphyromonas gingivalis. Keywords: Antibacterial, Kecapi leaf extract, Porphyromonas gingivalis

Artificial aging of rice using a sterilization box equipped with infrared heating and ultraviolet‐C radiation

AbstractAging of rice starts from the time of its harvest and continues until it is consumed. It positively impacts the cooking and eating qualities of rice, but natural aging takes years. In this study, artificial aging of rice was carried out at 70°C using simultaneous infrared (IR) radiation heating (3.18 × 104 W/m2) for 1, 3, 5, and 7 h and ultraviolet‐C (UV‐C) irradiation (49.24 J/cm2‐h) in a designed box. IR heating at 70°C combined with UV‐C irradiation for 5 h was the optimized condition for artificial aging. At optimized conditions, the proportionate change of rice was the highest as 0.21, followed by that for naturally aged (0.15) and non‐aged (0.08). The values of elongation ratio and actual elongation after cooking were the highest in artificial aging, followed by those for naturally aged and non‐aged rice. Water uptake (%) value was also the highest for artificial aging (89.62%), followed by that for naturally aged (68.45%) and non‐aged (59.93%) rice. Furthermore, nutritional values, microstructure, and antibacterial studies were carried out at optimized conditions. No significant changes in nutritional values viz., starch, protein, and fat were observed in artificially aged rice in comparison to one‐year‐old naturally aged rice. Electron microscopy analysis showed no changes in the structure of starch granules, which further revealed no adverse effect of IR radiation heating on the microstructure of rice. Results from the spread plate assay showed no growth of bacterial colony indicating the antibacterial effectiveness of artificial aging. Thus, simultaneous artificial aging as well as surface disinfection of rice can be carried out by combining IR radiation heating and UV‐C irradiation. These observations endorsed the effectiveness of the designed box for the artificial aging of rice without compromising the cooking and nutritional qualities. A preliminary sensory test was conducted. Overall, an efficient, inexpensive, and easy‐to‐handle artificial aging combined with surface disinfection was accomplished.

Voltage, power, and energy production of a Shewanella oneidensis biofilm microbial fuel cell in microgravity

Future long-term space travel requires both efficient waste management and renewable energy production to be feasible. One such option in addressing these issues is a microbial fuel cell (MFC) that converts chemical energy in organic matter to electrical energy through biological processes of microbes. Electroactive biofilms are special colonies of microbes that utilize an extracellular matrix to increase the endurance and growth of bacterial colonies through the sharing of resources and the depositing of electrons. We studied the power production of a biofilm MFC by testing the fuel cell in microgravity over time on the International Space Station (ISS). We utilized Shewanella oneidensis, an established electroactive biofilm, to break down a nutrient solution and release electrons and protons, producing a voltage difference across the cell. The S. onedensis biofilm grew more prolifically under low-pressure conditions, making it well suited for microgravity; consequently, the consumption of sodium lactate in a larger biofilm caused an increase in anaerobic respiration of the bacteria. This increased the voltage difference recorded across the cell and the corresponding power of the MFC. Our results are consistent with our hypothesis that there would be an increase in voltage and power production over time; however, an insufficient amount of growth medium eventually led to a decrease in voltage and power production as the biofilm died out. Power output during microgravity testing increased over time, coinciding with nutrient solution pump cycles. This experiment established that an MFC is a promising avenue for the development of renewable energy in microgravity.

Bioactivities of Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg) leaves from forest medicinal plants of Kutai Ethnic

The utilization of traditional medicine and treatment within the community of Kutai Kartanegara, East Kalimantan, Indonesia is characterized by a wide range of practices. Medicinal plant extracts containing secondary metabolites, possessing diverse molecular structures and biological activities, exhibit promising potential for the development of medicines targeting various diseases. Phenolic compounds, present in plants, exhibit numerous biological effects, including antioxidant and antimicrobial properties. These secondary metabolite compounds play a crucial role in safeguarding against disease-induced damage. Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg), a forest plant, has been traditionally employed by the local population for the treatment of diabetes. The objective of this study is to investigate the biological activities of the ethanol extract derived from Nek Kara leaves. The analysis encompasses the examination of phytochemical content, toxicity, as well as antioxidant and antimicrobial activities of the extract. The antioxidant activity is assessed through DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity using a spectrophotometer, while toxicity is determined via the BSLT (Brine Shrimp Lethality Test). The antimicrobial activity is evaluated using the diffusion method. The findings reveal the presence of phytochemical content, such as alkaloids, flavonoids, tannins, and steroids, within the ethanol extract derived from Nek Kara leaves. The BSLT results indicate the absence of toxic bioactivities in the ethanol extract. Furthermore, the Nek Kara leaf extract demonstrates potent antioxidant activity and exhibits inhibitory effects on the growth of bacterial and fungal colonies.

Qualitative Chemical Plant Characterization and Evaluation of the Antioxidant and Antimicrobial potential of Rhododendron, a high Attitudinal Medicinal Plant in Uttarakhand, India

The objective of our study was to analyze and screen the antioxidant and antimicrobial activity of Rhododendron species (especially rawatii and arboreum using methanol as solvent system) in order to display potent antioxidant and antimicrobial activity. These Rhododendron species may be considered them as one of the immunobiological sources for future novel antioxidants (food and pharmaceutical formulations) and antimicrobial agent. In this study, we performed the antioxidant activity in methanolic leaves and flower extract of Rhododendron rawatii and Rhododendron arboretum using parameters i.e. DPPH scavenging activity, total phenolic and flavonoid content. In addition, antimicrobial activity was also performed against bacterial strains. The results of these studies showed that leaves of Rhododendron rawatii (10 mg/ml; 100 µl) showed higher antioxidant and antimicrobial activity followed by Rhododendron arboreum and flowers of both species of Rhododendron. In short, these studies may have revealed that Rhododendron rawatii act as an antioxidant and antimicrobial agent due to its free radical scavenging and inhibition in the growth of bacterial colonies.

Photodynamic inactivation of methicillin-resistant Staphylococcus aureus by using Giemsa dye as a photosensitizer

The rise of antibiotic-resistant bacteria calls for innovative approaches to combat multidrug-resistant strains. Here, the potential of the standard histological stain, Giemsa, to act as a photosensitizer (PS) for antimicrobial photodynamic inactivation (aPDI) against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains is reported. Bioassays were performed using various Giemsa concentrations (ranging from 0.0 to 20.0 µM) under 625 nm illumination at a light dose of 30 J cm−2. Remarkably, Giemsa completely inhibited the growth of MSSA and MRSA bacterial colonies for concentrations at 10 µM and higher but exhibited no inhibitory effect without light exposure. Partition coefficient analysis revealed Giemsa's affinity for membranes. Furthermore, we quantified the production of reactive oxygen species (ROS) and singlet oxygen (1O2) to elucidate the aPDI mechanisms underlying bacterial inactivation mediated by Giemsa. These findings highlight Giemsa stain's potential as a PS in aPDI for targeting multidrug-resistant bacteria.

Development, Characterization, and Antibacterial Analysis of the Selenium-Doped Bio-Glass-Collagen-Gelatin Composite Scaffold for Guided Bone Regeneration.

Background Guided bone regeneration (GBR) is an often-used technique to aid the successful placement of dental implants in sites with deficient bone. The search for the ideal GBR membrane with bioactive components improving the regenerative outcomes is still on. In this study, a novel composite GBR membrane was developed using selenium-doped bio-glass, collagen, and gelatin. It was further characterized for surface, chemical, biocompatibility, and antibacterial properties. Methodology Selenium-doped bio-glass was prepared using the sol-gel method. The membrane was fabricated using an equal ratio of collagen and gelatin mixed with 1% selenium-doped bio-glass. The solution was poured to obtain a thin layer of the material which was lyophilized to obtain the final GBR membrane. The membrane was analyzed with scanning electron microscopy, energy dispersive X-ray (EDX) analysis, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), zebrafish cytotoxicity test, and antibacterial assay. Results The membrane revealed good surface roughness with lamellar and fibrillar arrangement with a minute granular surface ideal for cell attachment and proliferation. The EDX analysis revealed the presence of carbon, oxygen, and nitrogen as predominant components with trace amounts of calcium, phosphorus, silica, and selenium. Fourier transform infrared spectroscopy analysis also proved the presence of collagen, gelatin, and bio-glass. The membrane revealed excellent biocompatibility with zebrafish growth at a normal rate with 90% viability maintained at 48, 72, and 96 hours and 95% viability at 120 hours. It also exhibited excellent antibacterial activity against Staphylococcus aureus and Escherichia coli with minimal growth of bacterial colonies. Conclusion The developed novel selenium bio-glass collagen and gelatin composite scaffold has a good surface and antibacterial properties along with excellent biocompatibility. Further cell line and in vivo studies should be conducted to explore its role in bone regeneration.

Bacterial colony size growth estimation by deep learning

The bacterial growth rate is important for pathogenicity and food safety. Therefore, the study of bacterial growth rate over time can provide important data from a medical and veterinary point of view. We trained convolutional neural networks (CNNs) on manually annotated solid medium cultures to detect bacterial colonies as accurately as possible. Predictions of bacterial colony size and growth rate were estimated from image sequences of independent Staphylococcus aureus cultures using trained CNNs. A simple linear model for control cultures with less than 150 colonies estimated that the mean growth rate was 60.3 mu m/h for the first 24 h. Analyzing with a mixed effect model that also takes into account the effect of culture, smaller values of change in colony size were obtained (control: 51.0 mu m/h, rifampicin pretreated: 36.5mu m/h). An increase in the number of neighboring colonies clearly reduces the colony growth rate in the control group but less typically in the rifampicin-pretreated group. Based on our results, CNN-based bacterial colony detection and the subsequent analysis of bacterial colony growth dynamics might become an accurate and efficient tool for bacteriological work and research.

Rapid and automated screening of carbapenemase- and ESBL-producing Gram-negative bacteria from rectal swabs using chromogenic agar media and the ScanStation device.

The ScanSation 100 device (Interscience, France) is an incubator allowing real-time detection of bacterial colony growth by frequently imaging agar plates over time, counting CFU, and detecting colony color. This study evaluated its performance for the early detection of carbapenemase-producing bacteria (CPB) and extended-spectrum β-Lactamase-producing bacteria (ESBL-PB) from rectal swabs inoculated on CHROMagar mSuperCARBA and ESBL media, respectively. Rectal screening ESwabs collected from patients admitted to Grenoble University Hospital between January and June 2021 were analyzed. After inoculation, chromogenic media were incubated for 24 h in the automaton, with image acquisition every 30 min. ScanStation results were compared to visual observations of the plates after 24 h of incubation. In total, 501 rectal swabs were tested. ScanStation showed 100% positive percent agreement (PPA) for the detection of CPB and ESBL-PB, whereas the PPA of color categorization ranged between 45% and 100%. Negative percent agreement (NPA) ranged between 70% and 98%. Negative predictive values (NPVs) were 100% for both bacterial groups, whereas positive predictive values (PPVs) were 70.3% for CPB and 81.0% for ESBL-PB. Importantly, real-time screening allowed detection of the first suspected colony within 10-14 h of growth, on average, whereas visual observation is usually only performed once a day after 18-24 h of incubation. Our study demonstrates the potential use of early images to accelerate the detection of CPB and ESBL-PB and implement effective and timely infection control measures. IMPORTANCE The ScanStation 100 device is an incubator able to follow the real-time growth of bacterial colonies on agar plates through digital imaging, allowing users to sort plates according to the presence or absence of colonies, and to distinguish their color using four numeric color filters. Real-time screening shows that first colony detection is possible much earlier (after 10-14 h of growth, on average), whereas visual observation is usually performed only once a day after 18-24 h of incubation. The ScanStation device, combined with chromogenic agar media, is an efficient automated screening method to accelerate the detection of Gram-negative multidrug-resistant bacteria in laboratories that do not have access to larger laboratory automation systems. Our study shows that setting the image acquisition to one or two early images may allow for the detection of positive samples that were inoculated in the morning, by the end of the working day.

Optimasi Produksi Kitosan Dari Kitin Limbah Cangkang Bekicot Dan Pengaplikasiannya Untuk Pembuatan Handsanitizer

The Since the outbreak of the Corona Virus Disease 2019 (COVID-19) in Indonesia starting in March 2020, the government has urged the public to bemore aware of maintaining cleanliness and health in an effort to break the chain of transmission and spread of the disease. One of the clean living patterns that later became a habit for the community is to maintain hand hygiene. It is recommended to wash the hands diligently. However, if it is difficult to wash hands, then a hand sanitizer could be an option. The widely available hand sanitizer is an alcohol-based hand sanitizer. Ethanol, an alcohol compound, in a certain concentration is known as an effective antibacterial and antiviral. The use of alcohol (ethanol) in hand sanitizer is considered less safe for health because alcohol can irritate the skin. Alcohol is also a flammable compound. In addition, for the Indonesian people, who are predominantly Muslim, the presence of alcohol (ethanol) in the hand sanitizer makes people doubt the halal status of the hand sanitizer. One of compounds that has potential to replace the use of alcohol in hand sanitizer is chitosan. Chitosan can be used as an antibacterial agent because of the positive charge that can interact with the negatively charged of the bacterial cell surface. The existence of these interactions can interfere with the growth of bacterial colonies. Chitosan can naturally be found in the shells of mollusca. One type of mollusca shell with a high content of chitosan is the snail. The application of chitosan from snail shell waste to produce hand sanitizersvprovides a solution in overcoming environmental problems from the negativevimpact of snail shells if disposed carelessly and is a solution in producing halalvand safe hand sanitizers for the skin.

Synthesis of an Azo-Cyanine Dye as an RNA Probe for Distinguishing Gram-Positive Bacteria from Gram-Negative Bacteria

AbstractWe have developed a new cyanine fluorescent probe, Azo-ETO3, that shows better RNA selectivity than commercial dyes in solution. Azo-ETO3 can image the RNA of mitochondria in living cells and the RNA of the nucleolus and cytoplasm in fixed cells. As a practical application, Azo-ETO3 emits strong fluorescence when interacting with Gram-positive bacteria, and it can be used to selectively label G+ bacteria in the presence of other bacteria. In addition, Azo-ETO3 exhibits low toxicity and has essentially no major impact on bacterial colony growth. These properties could make it useful as a tool for distinguishing bacterial species.