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Background The application of disinfectants on dental instruments is one way to prevent cross-infection. Cross infection can occur due to microorganisms found in blood, saliva and dental plaque which can contaminate the instruments used by dental health workers. Thus, indirect contact transmission of pathogenic microorganisms occurs from instruments that have been contaminated by dental health workers. Ozone water and 4.8% chloroxylenol are disinfecting agents used to disinfect medical instruments. This study aimed to determine the effectiveness of disinfection of ozone water and 4.8% chloroxylenol in reducing the number of bacterial colonies on dental extraction instruments at the USU Dental and Oral Hospital between October-December 2022. Methods The samples used were mandibular molar pliers that have been used in tooth extraction procedures. This study was experimental and used three sample groups, where each group consisted of 10 tooth extraction instruments. The treatment group used ozone water and 4.8% chloroxylenol and the negative control group was cleaned with distilled water. The test effectiveness in this study used bacteria colony counter using the scatter cup method. Data were analyzed using the Kruskal Wallis and Mann-Whitney U tests. Results The results of the data analysis showed a p-value ≤0.001, which means that there was a significant difference in the disinfection using ozone water and 4.8% chloroxylenol on the number of bacterial colonies on dental extraction instruments. The results of this study show that the average number of bacterial colonies formed in the ozone water treatment group was 4.00 ± 4.32, 16.00 ± 6.65 in the 4.8% chloroxylenol treatment group, and 217.50 ± 39.24 in the negative control group (Aquadest). Conclusions From this study it can be said that ozone water is more effective in disinfecting dental extraction instruments than 4.8% chloroxylenol.

In this paper, we introduce a new and advanced multi-feature selection method for bacterial classification that uses the salp swarm algorithm (SSA). We improve the SSA's performance by using opposition-based learning (OBL) and a local search algorithm (LSA). The proposed method has three main stages, which automate the categorization of bacteria based on their unique characteristics. The method uses a multi-feature selection approach augmented by an enhanced version of the SSA. The enhancements include using OBL to increase population diversity during the search process and LSA to address local optimization problems. The improved salp swarm algorithm (ISSA) is designed to optimize multi-feature selection by increasing the number of selected features and improving classification accuracy. We compare the ISSA's performance to that of several other algorithms on ten different test datasets. The results show that the ISSA outperforms the other algorithms in terms of classification accuracy on three datasets with 19 features, achieving an accuracy of 73.75%. Additionally, the ISSA excels at determining the optimal number of features and producing a better fit value, with a classification error rate of 0.249. Therefore, the ISSA method is expected to make a significant contribution to solving feature selection problems in bacterial analysis. [ABSTRACT FROM AUTHOR]

In the field of microbiology, the counting of bacterial colonies is fundamental and mandatory. This is done to estimate the number of bacterial cells in every 1 milliliter or gram of sample. The counting takes a long time and is tedious, so it requires an accurate and fast counting method. The image quality used is very low and contains noise. Therefore, a preprocessing method is needed to reduce the noise. The Perona-Malik filter method is known to be able to remove noise well. However, it is difficult to determine the appropriate gradient threshold parameter ( ) for each different image. To find the appropriate value of , the original Sobel Mask method and Sobel Mask Fractional-Order are used to estimate the value of . The experimental results show the results of noise reduction using PMD with a value of from the original Sobel Mask and Sobel Mask Fractional-Order. The results of the accuracy of determining the value of k with the Sobel Mask Fractional-Order (α=1.0) show higher results based on the F-Measure values for samples 1, 2, and 3 respectively 97%, 98%, and 90%.

The Chavy–Waddy–Kolokolnikov model for the description of bacterial colonies is considered. In order to establish if the mathematical model is integrable, the Painlevé test is conducted for the nonlinear ordinary differential equation which corresponds to the fourth-order partial differential equation. The restrictions on the mathematical model parameters for ordinary differential equations to pass the Painlevé test are obtained. It is determined that the method of the inverse scattering transform does not solve the Cauchy problem for the original mathematical model, since the corresponding nonlinear ordinary differential equation passes the Painlevé test only when its solution is stationary. In the case of the stationary solution, the first integral of the equation is obtained, which makes it possible to represent the general solution in the quadrature form. The stability of the stationary points of the investigated mathematical model is carried out and their classification is proposed. Periodic and solitary stationary solutions of the Chavy–Waddy–Kolokolnikov model are constructed for various parameter values. To build analytical solutions, the method of the simplest equations is also used. The solutions, obtained in the form of a truncated expansion in powers of the logistic function, are represented as a closed formula using the formula for the Newton binomial. [ABSTRACT FROM AUTHOR]

The bacterial colony is a powerful experimental platform for broad biological research, and reaction–diffusion models are widely used to study the mechanisms of its formation process. However, there are still some crucial factors that drastically affect the colony growth but are not considered in the current models, such as the non-homogeneously distributed nutrient within the colony and the substantially decreasing expansion rate caused by agar dehydration. In our study, we propose two plausible reaction–diffusion models (the VN and MVN models) based on the above two factors and validate them against experimental data. Both models provide a plausible description of the non-homogeneously distributed nutrient within the colony and outperform the classical Fisher–Kolmogorov equation and its variation in better describing experimental data. Moreover, by accounting for agar dehydration, the MVN model captures how a colony’s expansion slows down and the change of a colony’s height profile over time. Furthermore, we demonstrate the existence of a traveling wave solution for the VN model. [ABSTRACT FROM AUTHOR]

Objectives: To assess the proportion of children, symptomatic for urinary tract infection (UTI), with urine culture showing single bacterial species >104 CFU/mL, and to compare patient and disease characteristics between children having low counts (from >104-105 CFU/mL) and those with counts >105 CFU/mL. Methods: Prospective observational study, enrolling symptomatic children aged 1 month to 12 years. Mid-stream clean-void or catheter collected urine were cultured. Children with single species >104 CFU/mL were scheduled for imaging studies, following age criteria of Indian Society of Pediatric Nephrology guidelines. The main outcome was proportion with single bacterial species >104 CFU/mL in urine culture. Results: Of 216 children (132 males) with median (IQR) age of 24 (12, 48) months, 38 (17.6%) showed single species growth >104 CFU/mL. Of these, 29 (13.4%) were diagnosed as UTI at cutoff >105 CFU/mL, and an additional 9 (4.2%) were found to have 'probable low-count UTI' (from >104 to 105 CFU/mL). One child in the latter group had bilateral hydroureteronephrosis, vesico-ureteral reflux and renal scarring. There was largely no difference in parameters between children with low counts and those with counts >105 CFU/mL. Conclusion: An additional proportion of symptomatic children with probable urinary tract infection and possible underlying urological abnormalities may be identified by lowering bacterial colony count cutoff to >104 CFU/mL, in clean-voided and catheter-based urine samples. [ABSTRACT FROM AUTHOR]

Background: The application of disinfectants on dental instruments is one way to prevent cross-infection. Cross infection can occur due to microorganisms found in blood, saliva and dental plaque which can contaminate the instruments used by dental health workers. Thus, indirect contact transmission of pathogenic microorganisms occurs from instruments that have been contaminated by dental health workers. Ozone water and 4.8% chloroxylenol are disinfecting agents used to disinfect medical instruments . This study aimed to determine the effectiveness of disinfection of ozone water and 4.8% chloroxylenol in reducing the number of bacterial colonies on dental extraction instruments at the USU Dental and Oral Hospital between October-December 2022. Methods: The samples used were mandibular molar pliers that have been used in tooth extraction procedures. This study was experimental and used three sample groups, where each group consisted of 10 tooth extraction instruments. The treatment group used ozone water and 4.8% chloroxylenol and the negative control group was cleaned with distilled water. The test effectiveness in this study used bacteria colony counter using the scatter cup method. Data were analyzed using the Kruskal Wallis and Mann-Whitney U tests. Results: The results of the data analysis showed a p-value ≤0.001, which means that there was a significant difference in the disinfection using ozone water and 4.8% chloroxylenol on the number of bacterial colonies on dental extraction instruments. The results of this study show that the average number of bacterial colonies formed in the ozone water treatment group was 4.00 ± 4.32, 16.00 ± 6.65 in the 4.8% chloroxylenol treatment group, and 217.50 ± 39.24 in the negative control group (Aquadest). Conclusions: From this study it can be said that ozone water is more effective in disinfecting dental extraction instruments than 4.8% chloroxylenol.

In this paper, we introduce a new and advanced multi-feature selection method for bacterial classification that uses the salp swarm algorithm (SSA). We improve the SSA’s performance by using opposition-based learning (OBL) and a local search algorithm (LSA). The proposed method has three main stages, which automate the categorization of bacteria based on their unique characteristics. The method uses a multi-feature selection approach augmented by an enhanced version of the SSA. The enhancements include using OBL to increase population diversity during the search process and LSA to address local optimization problems. The improved salp swarm algorithm (ISSA) is designed to optimize multi-feature selection by increasing the number of selected features and improving classification accuracy. We compare the ISSA’s performance to that of several other algorithms on ten different test datasets. The results show that the ISSA outperforms the other algorithms in terms of classification accuracy on three datasets with 19 features, achieving an accuracy of 73.75%. Additionally, the ISSA excels at determining the optimal number of features and producing a better fit value, with a classification error rate of 0.249. Therefore, the ISSA method is expected to make a significant contribution to solving feature selection problems in bacterial analysis.

The physical interactions of growing bacterial cells with each other and with their surroundings significantly affect the structure and dynamics of biofilms. Here a 3D agent-based model is formulated to describe the establishment of simple bacterial colonies expanding by the physical force of their growth. With a single set of parameters, the model captures key dynamical features of colony growth by non-motile, non EPS-producing E. coli cells on hard agar. The model, supported by experiment on colony growth in different types and concentrations of nutrients, suggests that radial colony expansion is not limited by nutrients as commonly believed, but by mechanical forces. Nutrient penetration instead governs vertical colony growth, through thin layers of vertically oriented cells lifting up their ancestors from the bottom. Overall, the model provides a versatile platform to investigate the influences of metabolic and environmental factors on the growth and morphology of bacterial colonies.

Classical microbiology has paved the path forward for the development of modern biotechnology and microbial biosensing platforms. Microbial culturing and isolation using the Petri plate revolutionized the field of microbiology. In 1887, Julius Richard Petri invented possibly the most important tool in microbiology, the Petri plate, which continues to have a profound impact not only on reliably isolating, identifying, and studying microorganisms but also manipulating a microbe to study gene expression, virulence properties, antibiotic resistance, and production of drugs, enzymes, and foods. Before the recent advances in gene sequencing, microbial identification for diagnosis relied upon the hierarchal testing of a pure culture isolate. Direct detection and identification of isolated bacterial colonies on a Petri plate with a sensing device has the potential for revolutionizing further development in microbiology including gene sequencing, pathogenicity study, antibiotic susceptibility testing, and for characterizing industrially beneficial traits. An optical scattering sensor designated BARDOT (bacterial rapid detection using optical scattering technology) that uses a red-diode laser, developed at the beginning of the 21st century at Purdue University, some 220 years after the Petri-plate discovery can identify and study bacteria directly on the plate as a diagnostic tool akin to Raman scattering and hyperspectral imaging systems for application in clinical and food microbiology laboratories. [ABSTRACT FROM AUTHOR]

Classical microbiology has paved the path forward for the development of modern biotechnology and microbial biosensing platforms. Microbial culturing and isolation using the Petri plate revolutionized the field of microbiology. In 1887, Julius Richard Petri invented possibly the most important tool in microbiology, the Petri plate, which continues to have a profound impact not only on reliably isolating, identifying, and studying microorganisms but also manipulating a microbe to study gene expression, virulence properties, antibiotic resistance, and production of drugs, enzymes, and foods. Before the recent advances in gene sequencing, microbial identification for diagnosis relied upon the hierarchal testing of a pure culture isolate. Direct detection and identification of isolated bacterial colonies on a Petri plate with a sensing device has the potential for revolutionizing further development in microbiology including gene sequencing, pathogenicity study, antibiotic susceptibility testing , and for characterizing industrially beneficial traits. An optical scattering sensor designated BARDOT (bacterial rapid detection using optical scattering technology) that uses a red-diode laser, developed at the beginning of the 21st century at Purdue University, some 220 years after the Petri-plate discovery can identify and study bacteria directly on the plate as a diagnostic tool akin to Raman scattering and hyperspectral imaging systems for application in clinical and food microbiology laboratories.

Bacillus mycoides Ko01 strain grows rapidly and forms extensive rhizoidal colonies on hard agar despite limited surface water availability. The agar concentrations affect the handedness of the colonies as well as other colony architectures. In this study, we found that the local curvature of cell chains in the developing colonies did not vary based on the agar concentration, while concentration does affect the handedness of chirality at the macroscale. This result suggests independence between the microscale filament curvature and macroscale colony chirality. In addition, we discovered a novel microscopic property of cells that has not been observed before: T-shaped budding under extremely low surface water availability conditions. We propose that this feature gives rise to chaotic colony morphology. Together with bundling of chains, cells form a unique set of spatial arrangements under different surface water availability. These properties appear to impact the structural features of thick tendrils, and thereby the overall morphology of colonies. Our study provides additional insights as to how bacteria proliferate, spread, and develop macroscale colony architecture under water-limited conditions. [ABSTRACT FROM AUTHOR]

The Chavy–Waddy–Kolokolnikov model for the description of bacterial colonies is considered. In order to establish if the mathematical model is integrable, the Painlevé test is conducted for the nonlinear ordinary differential equation which corresponds to the fourth-order partial differential equation. The restrictions on the mathematical model parameters for ordinary differential equations to pass the Painlevé test are obtained. It is determined that the method of the inverse scattering transform does not solve the Cauchy problem for the original mathematical model, since the corresponding nonlinear ordinary differential equation passes the Painlevé test only when its solution is stationary. In the case of the stationary solution, the first integral of the equation is obtained, which makes it possible to represent the general solution in the quadrature form. The stability of the stationary points of the investigated mathematical model is carried out and their classification is proposed. Periodic and solitary stationary solutions of the Chavy–Waddy–Kolokolnikov model are constructed for various parameter values. To build analytical solutions, the method of the simplest equations is also used. The solutions, obtained in the form of a truncated expansion in powers of the logistic function, are represented as a closed formula using the formula for the Newton binomial.

In this study, we addressed the challenge of excessive fluorescence background in bacterial colony Raman detection and aimed to achieve rapid identification of colonies. To overcome this issue, we employed a combination of droplet microcavity and label-free Surface Enhanced Raman Spectroscopy (SERS) technologies for spectroscopic analysis of five species of lactic acid bacteria (LAB) colonies during fermentation. This approach, coupled with Supported Vector Machine (SVM) and K-Nearest Neighbors (KNN) machine learning algorithms, facilitated the identification and analysis of spectral data. Comparing the results with conventional bacterial colony Raman spectra, the SERS spectra exhibited clear peaks, a higher and more stable signal-to-noise ratio, and noticeable spectral differences between various colonies, overcoming the limitations of insufficient fluorescence background. Moreover, the detection speed was notably enhanced, each SERS spectrum requires only 0.5 s, and the acquisition of the 100 spectral data points necessary for one bacterial colony is accomplished in less than 1 min. The SVM algorithm demonstrated a bacterial colony identification rate exceeding 95%, while the KNN algorithm achieved a rate surpassing 90%. These findings highlight the practical importance of using droplet microcavity combined with label-free SERS technology for quick and robust identification of the bacterial colonies. • Droplet optical microcavity combined with label-free SERS technology for direct ultra-fast identification of colonies. • The process does not require additional processing of the colonies and can complete data collection within 1 min. • Excellent results for the identification of lactic acid bacteria colonies for yogurt fermentation. [ABSTRACT FROM AUTHOR]

During the development of vaccines, bacterial colony forming units (CFUs) are counted in order to quantify the yield in the fermentation process. This manual task is long, tedious, and subject to errors. In this work, multiple segmentation algorithms based on the U-Net CNN architecture are tested and proven to offer robust, automated CFU counting. It is also shown that the multiclass generalisation with a bespoke loss function allows virulent and avirulent colonies to be distinguished with acceptable accuracy. While many possibilities are left to explore, our results show the potential of deep learning for separating and classifying bacterial colonies. [ABSTRACT FROM AUTHOR]

Background As mobile phones act as a potential source of microbial contamination, particularly in a hospital environment, the effectiveness of two most debated interventions namely ultraviolet radiation and disinfectant wipes in reducing the microbial contamination of mobile phones is compared. Objective To screen the mobile phones of healthcare personnel for the presence of microorganisms and to compare the effectiveness of ultraviolet radiation and disinfectant wipes in reducing microbial contamination. Methods and materials Pre-intervention and post-intervention swabs were collected before and after the use of each intervention respectively using 56 samples and cultured for growth in nutrient agar. Agar plates are subjected to quantitative analysis using bacterial colony count to reflect the efficacy of the specific intervention used. The data collected was entered in Microsoft Excel (Microsoft ® Corp., Redmond, WA, USA) and analysis was done using standard statistical packages. Results While comparing the pre-intervention bacterial load with the post-intervention load, post-intervention bacterial contamination in terms of colony-forming units/CFU has drastically reduced after both interventions, which is validated by statistical significance. However, it was observed participants using disinfectant wipes as intervention had 2.07 times higher chance of having a low bacterial load which wasn't statistically significant. Conclusion Our study shows that with the use of any intervention from the above-mentioned interventions, bacterial load or bacterial contamination can be reduced significantly, thus pointing out that both ultraviolet radiation and disinfectant wipes are effective in reducing contamination of mobile phones. It was also found that male doctors have more bacterial load than females, which can be minimized by effectively changing behavioral habits., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: The research study was selected by ICMR for a short-term studentship program (ICMR STS 2020) and got approved for the ICMR Research grant. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, De et al.)

The manual selection of transformed bacterial colonies from non-transformed ones grown on agar plate post-blue-white screening -- despite chromogenic difference -- is cumbersome, owing to their small size and large cell number. The present study offers a lucrative solution to this problem by the design of an automated system that is not only fast and less laborious but also low priced and user-friendly. The image masking technique was used to distinguish plated transformed colonies. This method uses computer vision techniques to detect the number of blue and white colonies post bacterial transformation on agar plates and calculate the transformation efficiency. To assess the proposed model with the manual counting method, we have validated the model by comparing the manual counting of colonies with the automated system count. Hence, a model was developed that would be an added advantage to biotechnologists as it would minimize the time required for counting and help in productive research. [ABSTRACT FROM AUTHOR]

The aim of the current study was to evaluate the effect of dietary Lactococcus lactis subsp. lactis and chitin on blood and serum biochemical parameters and intestine bacteria of common carp. To do the experiment, 360 juvenile carp with mean initial weight of 12±1.5 g were randomly distributed in the fiberglass tanks designed based on different levels of chitin 0, 1 and 2% and probiotic 0 and 2% (1 ×107CFU/g) in diet and the experiment lasted for eight weeks. The experimental treatments were including control (treatment 1), probiotic 2% (treatment 2), chitin 1% (treatment 3), chitin 2% (treatment 4), probiotic 2% + chitin 1% (treatment 5) and probiotic 2% + chitin 1% (treatment 6). On the end of the experiment, blood parameters including red blood cell (RBC), Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), hematocrit (HCT), white blood cell (WBC), lymphocyte, eosinophil and monocyte, serum biochemical parameters including total protein, albumin, glucose, cholesterol, triglyceride and intestinal bacterial colony were determined. The results showed that RBC, MCV, MCH, MCHC, Hb, HCT, thrombocyte, monocyte had no significant difference among treatments (p>0.05), But, maximum level of WBC in treatments 5 and 3 (18.03±1.66, 16.86±1.49 103 mm3, respectively), lymphocyte in treatments 5 and 2 (70.40±4.58, 65.00±2.65, respectively) and eosinophil in treatments 3 and 6 (2.67±1.16, 1.67±0.58, respectively) were observed. Biochemical parameters showed no significant difference among experimental treatments and control, but, there were significant difference among the diets containing probiotic and chitin or/and a mixture of probiotic and chitin (p

Abstract Branching pattern formation is common in many microbes. Extensive studies have focused on addressing how such patterns emerge from local cell–cell and cell–environment interactions. However, little is known about whether and to what extent these patterns play a physiological role. Here, we consider the colonization of bacteria as an optimization problem to find the colony patterns that maximize colony growth efficiency under different environmental conditions. We demonstrate that Pseudomonas aeruginosa colonies develop branching patterns with characteristics comparable to the prediction of modeling; for example, colonies form thin branches in a nutrient‐poor environment. Hence, the formation of branching patterns represents an optimal strategy for the growth of Pseudomonas aeruginosa colonies. The quantitative relationship between colony patterns and growth conditions enables us to develop a coarse‐grained model to predict diverse colony patterns under more complex conditions, which we validated experimentally. Our results offer new insights into branching pattern formation as a problem‐solving social behavior in microbes and enable fast and accurate predictions of complex spatial patterns in branching colonies.

Branching pattern formation is common in many microbes. Extensive studies have focused on addressing how such patterns emerge from local cell–cell and cell–environment interactions. However, little is known about whether and to what extent these patterns play a physiological role. Here, we consider the colonization of bacteria as an optimization problem to find the colony patterns that maximize colony growth efficiency under different environmental conditions. We demonstrate that Pseudomonas aeruginosa colonies develop branching patterns with characteristics comparable to the prediction of modeling; for example, colonies form thin branches in a nutrient‐poor environment. Hence, the formation of branching patterns represents an optimal strategy for the growth of Pseudomonas aeruginosa colonies. The quantitative relationship between colony patterns and growth conditions enables us to develop a coarse‐grained model to predict diverse colony patterns under more complex conditions, which we validated experimentally. Our results offer new insights into branching pattern formation as a problem‐solving social behavior in microbes and enable fast and accurate predictions of complex spatial patterns in branching colonies. SYNOPSIS: Optimization modeling demonstrates that branching patterns maximize the growth efficiency of Pseudomonas colonies in adverse environments. An optimization rule of pattern formation provides a new way of predicting complex colony patterns. Branching patterns optimize the growth of bacterial colonies when resources are limited.Optimal branching patterns vary under different conditions.Branching patterns under complex conditions can be predicted by a coarse‐grained model based on the optimization rule of pattern formation. [ABSTRACT FROM AUTHOR]

Bacteria utilize electron conduction in their communities to drive their metabolism, which has led to the development of various environmental technologies, such as electrochemical microbial systems and anaerobic digestion. It is challenging to measure the conductivity among bacterial cells when they hardly form stable biofilms on electrodes. This makes it difficult to identify the biomolecules involved in electron conduction. In the present study, we aimed to identify c -type cytochromes involved in electron conduction in Shewanella oneidensis MR-1 and examine the molecular mechanisms. We established a colony-based bioelectronic system that quantifies bacterial electrical conductivity, without the need for biofilm formation on electrodes. This system enabled the quantification of the conductivity of gene deletion mutants that scarcely form biofilms on electrodes, demonstrating that c -type cytochromes, MtrC and OmcA, are involved in electron conduction. Furthermore, the use of colonies of gene deletion mutants demonstrated that flavins participate in electron conduction by binding to OmcA, providing insight into the electron conduction pathways at the molecular level. Furthermore, phenazine-based electron transfer in Pseudomonas aeruginosa PAO1 and flavin-based electron transfer in Bacillus subtilis 3610 were confirmed, indicating that this colony-based system can be used for various bacteria, including weak electricigens.

Classification of bacteria is essential in the medical diagnosis of infectious agents, their phylogenetic study, and their biotechnological exploitation for healthcare, food, industry, and agricultural sectors. Nevertheless, skilled experts and professional human-effort are necessary to identify and classify the bacteria manually. With the advancement of technology, now the task of recognizing details from digital stereomicroscopes is being performed by computers based on machine learning and computer vision technologies. Besides, machine learning methods include Deep Neural Networks (NN) has attained remarkable outcomes in the field of image classification recently. Furthermore, other machine learning methods except for NN methods already have acceptable performance. In this paper, we review the publications, which investigate the discrimination between bacteria genera and suborders based on macroscopic images via image processing and machine learning methods. The published research works in this regard are summarized, and the pros and cons of them are discussed. Moreover, the related databases and resources for this purpose are surveyed, and the lack of such data points in the global catalogue of microorganisms is criticized. In addition, in this paper, we have investigated an approach to automate the process of bacteria recognition and classification with the use of the Gabor transform and XGBoost classification method. We have used a dataset that includes microscopic images of three different Myxobacterial suborders. The trained model was able to recognize and classify all members of three different categories of bacteria, while the experimental results of prediction achieved an accuracy of around 91%, which has enhancement about 2% in term of accuracy. [ABSTRACT FROM AUTHOR]

Ventilator-associated pneumonia (VAP) remains a problem with the highest cos, morbidity and mortalityt in the Intensive Care Unit (ICU). The correlation between mechanical ventilation and pneumonia is considered as common sense, yet scientific evidence to support this statement is still needed. This research aims to analyze the bacterial colony grows in mechanical ventilation circuit and those grew in the patient’s sputum culture. We performed an observational study. Samples for bacterial culture were taken from ventilator circuit and patient sputum on Day-0, Day-3 and Day-7. Sputum samplings are collected using double catheter tracheal aspiration technique; Results are then analyzed with Chi-square test. While the similarity of bacteria species in ventilator circuit to patient’s sputum is analyzed with Binomial test. Two samples are dropped out immediately due to the rate of bacterial growth on Day-0. Bacterial colony growth in ventilator circuit shows a significant difference on Day-3 and Day-7 at 50% and 92% respectively (p = 0.05). A comparison for the bacterial similarity of the ventilator circuit and patient’s sputum shows that the bacterial growth on Day-3 is 7 out of 14 (50%) and 3 with more than 105 CFU/ml colony; while on Day-7, there are 13 out of 14 positive bacterial growth, both in the circuit and the patient’s sputum. Among them, 5 out of 14 (35%) of the bacterial colony which grow in the circuit have the same species as those grow in patient’s sputum. The recent study shows that there is bacteria colony growth in the ventilator circuit after Day-3 and a significant increase on Day-7. Almost half of the colony illustrates similar species from both ventilator circuit and patient’s sputum. This suggests that the bacterial growth on Day-7 in the ventilator circuit might be related to those growth in patient’s sputum.

The physical interactions of growing bacterial cells with each other and with their surroundings significantly affect the structure and dynamics of biofilms. Here a 3D agent-based model is formulated to describe the establishment of simple bacterial colonies expanding by the physical force of their growth. With a single set of parameters, the model captures key dynamical features of colony growth by non-motile, non EPS-producing E. coli cells on hard agar. The model, supported by experiment on colony growth in different types and concentrations of nutrients, suggests that radial colony expansion is not limited by nutrients as commonly believed, but by mechanical forces. Nutrient penetration instead governs vertical colony growth, through thin layers of vertically oriented cells lifting up their ancestors from the bottom. Overall, the model provides a versatile platform to investigate the influences of metabolic and environmental factors on the growth and morphology of bacterial colonies.

Objective: Dental procedures create aerosols and splatters that are ejected from the operating site in a ballistic trajectory contaminating the operator and the dental cubicle. They transmit various pathogens, leading to cross-contamination in the dental clinics. The aim of the study was to determine the aerosol and splatter contamination during minor oral surgical procedures and to assess the risk of spread of nosocomial infection in our dental institution. Materials and Methods: This evaluation study was done during various dental procedures including extraction and minor oral surgical procedures such as impaction, transalveolar extractions, and alveoloplasty in the department of oral and maxillofacial surgery. A total of 30 participants who were treated in the department of oral and maxillofacial surgery were included in the study. Several samples were collected from different regions of dental cubicle and sent for microbiological analysis. The colony-forming units (cfu) for each procedure from different regions were counted. Data obtained were statistically analyzed and results obtained. Results: Bacterial colony counts were greater in cultures obtained from the left middle cubicle compared with the right middle cubicle and the results were statistically significant (P < 0.05). Bacterial colony counts cultured following alveoloplasty procedure were greater in number when compared to transalveolar extraction procedure. Conclusion: From our study, it is concluded that aerosol and splatter contamination analyzed by number of bacterial cfu during different minor oral surgical procedures exceeded the permissible limits. Thus, strictly following appropriate universal barrier precautions, infection control measures, and the usage of high-volume evacuation plays a valuable role in the reduction of aerosol and splatter propagation. The operator and patient position, the type of procedure, and the type of rotary instrument used to determine the trajectory of aerosol and splatter contamination during various minor oral surgical procedures. [ABSTRACT FROM AUTHOR]

The present work explores bacterial colonies and their individual and social behaviours under the lens of complex adaptive systems. We initially provide a background on the biology of bacteria to describe important phenomena, such as quorum-sensing, individual and collective behaviours, adaptation, evolution and self-organization over the influence of mechanical effects on bacterial systems and connecting scales. We then explore some associations between bacterial colonies and complex adaptive systems by considering components and ownerships of self-organization. The main contribution of this paper places emphasis on individual decision-making and behaviour as a cause of bacterial colonies’ actions, i.e., how self-organization and collective behaviours impact the ability of a bacterial colony to address an environmental stimulus and maintain itself as an open biological and fault-tolerant system. Finally, we conclude the work and provide some comments regarding future research. [ABSTRACT FROM AUTHOR]

Objective: Scrubs and white coats are worn by health-care professionals in clinical environment as a part of personal protective equipment. Scrubs, white coats, and uniforms of dental personnel are spattered by saliva, aerosols, and blood, and there is definite risk of infection through various transmissible pathogens. The main aim of this study was to determine the level of bacterial contamination presents on disposable surgical dental care clothing worn over scrubs of dental students to assess the risk of spread of nosocomial infection in our dental institution. Materials and Methods: This study was conducted among postgraduate dental students who performed various dental procedures including extraction and minor oral surgical procedures such as impaction, transalveolar extractions, and alveoloplasty in the department of oral and maxillofacial surgery. A total of 45 participants who were treated in the department of oral and maxillofacial surgery were included in the study. Several samples were collected from different regions of disposable surgical dental care clothing of the students and sent for microbiological analysis. Results: Bacterial colony counts were greater in cultures obtained from the sleeve cuffs of the surgical dental care clothing compared with the neck region (collar region). Bacterial colony counts cultured following alveoloplasty procedure were greater in number when compared to transalveolar extraction procedure. Conclusion: From our study, it is concluded that disposable dental care clothing is highly contaminated with pathogenic bacteria and the results of the study strictly mandate the use of personal protective surgical dental care clothing before minor surgical procedures to prevent cross infection in the dental clinic. [ABSTRACT FROM AUTHOR]

The swarm behaviour can be controlled by different localizations of attractants (food pieces) and repellents (dangerous places), which, respectively, attract and repel the swarm propagation. If we assume that at each time step, the swarm can find out not more than p−1 attractants ( [ABSTRACT FROM AUTHOR]

Colonies are an abundant form of bacterial multicellularity; however, relatively little is known about the initial stages of their construction. We have previously described that colony development of the soil bacterium Bacillus subtilis is a highly ordered process, typically initiating with the formation of extending cell chains arranged in a Y shape structure. Furthermore, we demonstrated that Y arm extension is a key for defining the size of the future colony. Here we conducted a genetic screen surveying for mutants deficient in these early developmental stages, and revealed LtaS, the major lipoteichoic acid (LTA) synthase, to be crucial for execution of these events. We found that the ltaS mutant fails to produce proper Y shape structures, forming extremely elongated chains of cells with no evidence of chain breakage, necessary for Y shape formation. Furthermore, we show that frequent cell death at the tips of the cell chains is a major cause in limiting arm extension. Collectively, these perturbations lead to the production of a small sized colony by the mutant. Thus, deficiency in LTA synthesis causes a mechanical failure in executing the colony developmental program.

Colonies are an abundant form of bacterial multicellularity; however, relatively little is known about the initial stages of their construction. We have previously described that colony development of the soil bacterium Bacillus subtilis is a highly ordered process, typically initiating with the formation of extending cell chains arranged in a Y shape structure. Furthermore, we demonstrated that Y arm extension is a key for defining the size of the future colony. Here we conducted a genetic screen surveying for mutants deficient in these early developmental stages, and revealed LtaS, the major lipoteichoic acid (LTA) synthase, to be crucial for execution of these events. We found that the ltaS mutant fails to produce proper Y shape structures, forming extremely elongated chains of cells with no evidence of chain breakage, necessary for Y shape formation. Furthermore, we show that frequent cell death at the tips of the cell chains is a major cause in limiting arm extension. Collectively, these perturbations lead to the production of a small sized colony by the mutant. Thus, deficiency in LTA synthesis causes a mechanical failure in executing the colony developmental program. [ABSTRACT FROM AUTHOR]