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We assessed the efficacy of oversampling techniques to enhance machine learning model performance in predicting Escherichia coli MG1655 presence in spinach wash water. Three oversampling methods were applied to balance two datasets, forming the basis for training random forest (RF), support vector machines (SVMs), and binomial logistic regression (BLR) models. Data underwent method‐specific centering and standardization, with outliers replaced by feature‐specific means in training datasets. Testing occurred without these preprocessing steps. Model hyperparameters were optimized using a subset of testing data via 10‐fold cross‐validation. Models were trained on full datasets and tested on newly acquired spinach wash water samples. Synthetic Minority Oversampling Technique (SMOTE) and Adaptive Synthetic Sampling approach (ADASYN) achieved strong results, with SMOTE RF reaching an accuracy of 90.0%, sensitivity of 93.8%, specificity of 87.5%, and an area under the curve (AUC) of 98.2% (without data preprocessing) and ADASYN achieving 86.55% accuracy, 87.5% sensitivity, 83.3% specificity, and a 92.4% AUC. SMOTE and ADASYN significantly improved (p < 0.05) SVM and RF models, compared to their non‐oversampled counterparts without preprocessing. Data preprocessing had a mixed impact, improving (p < 0.05) the accuracy and specificity of the BLR model but decreasing the accuracy and specificity (p < 0.05) of the SVM and RF models. The most influential physiochemical feature for E. coli detection in wash water was water conductivity, ranging from 7.9 to 196.2 µS. Following closely was water turbidity, ranging from 2.97 to 72.35 NTU within this study. [ABSTRACT FROM AUTHOR]

The release of airborne pathogens with antimicrobial resistance is a growing global public health threat. The potential spread of antimicrobial resistant bacteria and antimicrobial resistance genes (ARB/ARGs) from wastewater effluents through aerosolization is not fully understood. Septic tanks are on-site wastewater treatment systems (OWTS) used in about 25% of households in the United States (US). The system in this study consists of four tanks connected by two different treatment types, with wastewater moving from the most contaminated, Tank 1, to the most purified holding, Tank 4. Aerosol samples at each tank were collected in the summer and winter with open and closed lids to observe their effect on bioaerosol emissions. The water inside each tank was also sampled to compare the bacteria concentration and composition. Results from microbial and molecular analysis indicate lower concentrations of bacteria in the aerosols compared to the water samples. The antibiotic testing indicates that aerosolized bacteria from the winter were more resistant to the antibiotics used compared to the aerosolized bacteria from the summer. The occurrence of aerosolized bacteria likely depends on operational conditions and discharge methods, on changes in humidity, temperature, and air velocity, while the effluent resistance can be influenced by quorum sensing. Further assessment of the water and bioaerosol microbiome should include the genomic analysis of antimicrobial resistance of bacterial isolates from both sources and thus provide an important link regarding human exposure to ARBs/ARGs near wastewater treatment systems. Copyright © 2023 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

We have determined the genomic sequences of four virulent myophages, Bcepl, Bcep43, BcepB1A, and Bcep781, whose hosts are soil isolates of the Burkholderia cepacia complex. Despite temporal and spatial separations between initial isolations, three of the phages (Bcep1, Bcep43, and Bcep781, designated the Bcep781 group) exhibit 87% to 99% sequence identity to one another and most coding region differences are due to synonymous nucleotide substitutions, a hallmark of neutral genetic drift. Phage BcepB1A has a very different genome organization but is clearly a mosaic with respect to many of the genes of the Bcep781 group, as is a defective prophage element in Photorhabdus luminescens. Functions were assigned to 27 out of 71 predicted genes of Bcep1 despite extreme sequence divergence. Using a lambda repressor fusion technique, 10 Bcep781-encoded proteins were identified for their ability to support homotypic interactions. While head and tail morphogenesis genes have retained canonical gene order despite extreme sequence divergence, genes involved in DNA metabolism and host lysis are not organized as in other phages. This unusual genome arrangement may contribute to the ability of the Bcep781-1ike phages to maintain a unified genomic type. However, the Bcep781 group phages can also engage in lateral gene transfer events with otherwise unrelated phages, a process that contributes to the broader-scale genomic mosaicism prevalent among the tailed phages.

Nanotechnology plays a big part in our modern daily lives, ranging from the biomedical sector to the energy sector. There are different physicochemical and biological methods to synthesise nanoparticles towards multiple applications. Biogenic production of nanoparticles through the utilisation of microorganisms provides great advantages over other techniques and is increasingly being explored. This review examines the process of the biogenic synthesis of nanoparticles mediated by microorganisms such as bacteria, fungi and algae, and their applications. Microorganisms offer a disparate environment for nanoparticle synthesis. Optimum production and minimum time to obtain the desired size and shape, to improve the stability of nanoparticles and to optimise specific microorganisms for specific applications are the challenges to address, however. Numerous applications of biogenic nanoparticles in medicine, environment, drug delivery and biochemical sensors are discussed. [ABSTRACT FROM AUTHOR]

We have developed a simple way to generate binary patterns based on spectral slopes in different frequency ranges at fluctuation-enhanced sensing. Such patterns can be considered as binary "fingerprints" of odors. The method has experimentally been demonstrated with a commercial semiconducting metal oxide (Taguchi) sensor exposed to bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) and processing their stochastic signals. With a single Taguchi sensor, the situations of empty chamber, tryptic soy agar (TSA) medium, or TSA with bacteria could be distinguished with 100% reproducibility. The bacterium numbers were in the range of 2.5 × 104-106. To illustrate the relevance for ultra-low power consumption, we show that this new type of signal processing and pattern recognition task can be implemented by a simple analog circuitry and a few logic gates with total power consumption in the microWatts range. [ABSTRACT FROM AUTHOR]

We have determined the genomic sequences of four virulent myophages, Bcep1, Bcep43, BcepB1A, and Bcep781, whose hosts are soil isolates of the Burkholderia cepacia complex. Despite temporal and spatial separations between initial isolations, three of the phages (Bcep1, Bcep43, and Bcep781, designated the Bcep781 group) exhibit 87% to 99% sequence identity to one another and most coding region differences are due to synonymous nucleotide substitutions, a hallmark of neutral genetic drift. Phage BcepB1A has a very different genome organization but is clearly a mosaic with respect to many of the genes of the Bcep781 group, as is a defective prophage element in Photorhabdus luminescens. Functions were assigned to 27 out of 71 predicted genes of Bcep1 despite extreme sequence divergence. Using a lambda repressor fusion technique, 10 Bcep781-encoded proteins were identified for their ability to support homotypic interactions. While head and tail morphogenesis genes have retained canonical gene order despite extreme sequence divergence, genes involved in DNA metabolism and host lysis are not organized as in other phages. This unusual genome arrangement may contribute to the ability of the Bcep781-like phages to maintain a unified genomic type. However, the Bcep781 group phages can also engage in lateral gene transfer events with otherwise unrelated phages, a process that contributes to the broader-scale genomic mosaicism prevalent among the tailed phages. [ABSTRACT FROM AUTHOR]

We have developed a simple way to generate binary patterns based on spectral slopes in different frequency ranges at fluctuation-enhanced sensing. Such patterns can be considered as binary "fingerprints" of odors. The method has experimentally been demonstrated with a commercial semiconducting metal oxide (Taguchi) sensor exposed to bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) and processing their stochastic signals. With a single Taguchi sensor, the situations of empty chamber, tryptic soy agar (TSA) medium, or TSA with bacteria could be distinguished with 100% reproducibility. The bacterium numbers were in the range of 2.5 × 10(4)-10(6). To illustrate the relevance for ultra-low power consumption, we show that this new type of signal processing and pattern recognition task can be implemented by a simple analog circuitry and a few logic gates with total power consumption in the microWatts range.