-
UCL Open. Environment 2023The aim of this study is to obtain knowledge about which cultivable bacterial species are present in indoor air in homes, and whether the concentration and diversity of...
The aim of this study is to obtain knowledge about which cultivable bacterial species are present in indoor air in homes, and whether the concentration and diversity of airborne bacteria are associated with different factors. Measurements have been performed for one whole year inside different rooms in five homes and once in 52 homes. Within homes, a room-to-room variation for concentrations of airborne bacteria was found, but an overlap in bacterial species was found across rooms. Eleven species were found very commonly and included: , , , , , and . The concentrations of Gram-negative bacteria in general and the species were significantly associated with the season with the highest concentrations in spring. The concentrations of , and were associated positively with relative humidity (RH), and concentrations of were associated negatively with temperature and air change rate (ACR). concentrations were associated negatively with ACR. Overall, this study identified species which are commonly present in indoor air in homes, and that the concentrations of some species were associated with the factors: season, ACR and RH.
PubMed: 37229345
DOI: 10.14324/111.444/ucloe.000056 -
Journal of Clinical Microbiology Jan 2010A 68-year-old man who had undergone two penetrating keratoplasties of his left eye was admitted with early corneal graft failure. Culture of the anterior chamber fluid...
A 68-year-old man who had undergone two penetrating keratoplasties of his left eye was admitted with early corneal graft failure. Culture of the anterior chamber fluid yielded Paracoccus yeei, a nonfermentative gram-negative bacillus which thus far had only been implicated in ocular disease by means of PCR and 16S rRNA gene sequencing directly on patient material.
Topics: Aged; Bacterial Typing Techniques; DNA, Bacterial; DNA, Ribosomal; Graft Rejection; Gram-Negative Bacterial Infections; Humans; Keratitis; Keratoplasty, Penetrating; Male; Molecular Sequence Data; Paracoccus; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 19889897
DOI: 10.1128/JCM.01798-09 -
Sensors (Basel, Switzerland) Nov 2022Microbial mediator biosensors for surface water toxicity determination make it possible to carry out an early assessment of the environmental object’s quality without...
Microbial mediator biosensors for surface water toxicity determination make it possible to carry out an early assessment of the environmental object’s quality without time-consuming standard procedures based on standard test-organisms, and provide broad opportunities for receptor element modifying depending on the required operational parameters analyzer. Four microorganisms with broad substrate specificity and nine electron acceptors were used to form a receptor system for toxicity assessment. Ferrocene was the most effective mediator according to its high rate constant of interaction with the microorganisms (0.33 ± 0.01 dm3/(g × s) for yeast Saccharomyces cerevisiae). Biosensors were tested on samples containing four heavy metal ions (Cu2+, Zn2+, Pb2+, Cd2+), two phenols (phenol and p-nitrophenol), and three natural water samples. The «ferrocene- Escherichia coli» and «ferrocene-Paracoccus yeei, E. coli association» systems showed good operational stability with a relative standard deviation of 6.9 and 7.3% (14 measurements) and a reproducibility of 7 and 5.2% using copper (II) ions as a reference toxicant. Biosensor analysis with these systems was shown to highly correlate with the results of the standard method using Chlorella algae as a test object. Developed biosensors allow for a valuation of the polluted natural water’s impact on the ecosystem via an assessment of the influence on bacteria and yeast in the receptor system. The systems could be used in toxicological monitoring of natural waters.
Topics: Metallocenes; Water; Escherichia coli; Saccharomyces cerevisiae; Reproducibility of Results; Chlorella; Ecosystem; Biosensing Techniques; Metals, Heavy; Water Pollutants, Chemical
PubMed: 36366221
DOI: 10.3390/s22218522 -
Journal of Global Infectious Diseases May 2010Ibuprofen and acetaminophen are common chemical agents that have anti-inflammatory, antipyretic, and analgesic activity.
BACKGROUND
Ibuprofen and acetaminophen are common chemical agents that have anti-inflammatory, antipyretic, and analgesic activity.
AIMS
To detect any potential antibacterial effects of ibuprofen and acetaminophen on pathogenic bacteria.
MATERIALS AND METHODS
Ibuprofen and acetaminophen were tested for antibacterial activity against seven isolates of bacteria including gram positive bacteria (Staphylococci aureus and Bacillus subtilis) and gram negative bacteria (E. coli, Enterobacter aerogenes, Enterobacter cloacae, Salmonella typhi and Paracoccus yeei). Spectrophotometer assay was applied to determine the antibacterial activities of ibuprofen and acetaminophen. Three controls were included in this study: Ampicilline sodium (20 mug/ml); cefotaxime sodium (20 mug/ml) and chemical free medium.
RESULTS
Staphylococcus aureus and Paracoccus yeei were susceptible to lower concentrations of ibuprofen and acetaminophen (MIC=1.25 mg/ml), while two strains of Enterobacter exhibited resistance to these agents.
CONCLUSIONS
Ibuprofen and acetaminophen showed a potential antibacterial effect on isolated strains of bacteria. They had the same ability to inhibit bacterial growth.
PubMed: 20606962
DOI: 10.4103/0974-777X.62880 -
Membranes Oct 2022Biomembranes based on an organosilica sol-gel matrix were used to immobilize bacteria VKM B-3302 as part of a biochemical oxygen demand (BOD) biosensor....
Biomembranes based on an organosilica sol-gel matrix were used to immobilize bacteria VKM B-3302 as part of a biochemical oxygen demand (BOD) biosensor. Diethoxydimethylsilane (DEDMS) and tetraethoxysilane (TEOS) were used as precursors to create the matrix in a 1:1 volume ratio. The use of scanning electron microscopy (SEM) and the low-temperature nitrogen adsorption method (BET) showed that the sol-gel matrix forms a capsule around microorganisms that does not prevent the exchange of substrates and waste products of bacteria to the cells. The use of DEDMS as part of the matrix made it possible to increase the sensitivity coefficient of the biosensor for determining BOD by two orders of magnitude compared to a biosensor based on methyltriethoxysilane (MTES). Additionally, the long-term stability of the bioreceptor increased to 68 days. The use of such a matrix neutralized the effect of heavy metal ions on the microorganisms' catalytic activity in the biosensor. The developed biosensor was used to analyze water samples from water sources in the Tula region (Russia).
PubMed: 36295743
DOI: 10.3390/membranes12100983 -
Enzyme and Microbial Technology Feb 2021This work investigated the use of redox-active polymers based on bovine serum albumin and chitosan, covalently bound to mediators neutral red and ferrocene and...
This work investigated the use of redox-active polymers based on bovine serum albumin and chitosan, covalently bound to mediators neutral red and ferrocene and containing carbon nanotubes, for immobilization of Paracoccus yeei VKM B-3302 bacteria. The structures of produced polymers were studied by IR spectroscopy and scanning electron microscopy. Cyclic voltammetry and impedance spectroscopy found the electrochemical characteristics of the investigated systems: the heterogeneous electron transfer rate constant, the constant of the rate of interaction with P. yeei bacteria and the impedance. The systems containing carbon nanotubes and ferrocene-based redox-active polymer proved to be the most promising. Biosensors formed using the hybrid polymers had a high sensitivity with the lower boundary of 0.1 mg/dm of the detected BOD concentrations and a high correlation (R = 0.9916) with the standard BOD assay of surface water samples.
Topics: Biosensing Techniques; Electrochemical Techniques; Electrodes; Nanotubes, Carbon; Oxidation-Reduction; Paracoccus; Polymers
PubMed: 33375974
DOI: 10.1016/j.enzmictec.2020.109706 -
Enzyme and Microbial Technology Jan 2022In this publication an alternative approach to investigations of bacterial growth is proposed. Contrary to the conventional physical methods it is based on enzyme...
In this publication an alternative approach to investigations of bacterial growth is proposed. Contrary to the conventional physical methods it is based on enzyme activity detection. The procedure for real-time and on-line monitoring of microbial ureolytic activity (applied as a model experimental biosystem) in the flow analysis format is presented. The developed fully-mechanized bioanalytical flow system is composed of solenoid micropumps and microvalves actuated by Arduino microcontroller. The photometric detection based on Nessler reaction is performed using dedicated flow-through optoelectronic detector made of paired light emitting diodes. The developed bioanalytical system allows discrete assaying of microbial urease in the wide range of activity up to 5.4 U mL with detection limit below 0.44 U mL, a high sensitivity in the linear range of response (up to 200 mV U mL and relatively high throughput (9 detection per hour). The proposed differential procedure of measurements (i.e. a difference between peaks register for sample with and without external addition of urea is treated as an analytical signal) allows elimination of interfering effects from substrate and products of biocatalysed reaction as well as other components of medium used for microbial growth. The developed bioanalytical system was successfully applied for the control of growth of urease-positive bacteria strains (Proteus vulgaris, Klebsiella pneumoniae and Paracoccus yeei) including examination of effects from various microbial cultivation conditions like temperature, composition of culture medium and amount of substrate required for induction of bacterial enzymatic activity. The developed bioanalytical flow system can be applied for metabolic activity-based estimation of parameters of lag and log phases of microbial growth as well as for detection of decline phase.
Topics: Bacteria; Culture Media; Klebsiella pneumoniae; Urea; Urease
PubMed: 34670184
DOI: 10.1016/j.enzmictec.2021.109899 -
Biofilm Dec 2022In patients with acute respiratory failure, mechanical ventilation through an endotracheal tube (ET) may be required to correct hypoxemia and hypercarbia. However,...
In patients with acute respiratory failure, mechanical ventilation through an endotracheal tube (ET) may be required to correct hypoxemia and hypercarbia. However, biofilm formation on these ETs is a risk factor for infections in intubated patients, as the ET can act as a reservoir of microorganisms that can cause infections in the lungs. As severely ill COVID-19 patients often need to be intubated, a better knowledge of the composition of ET biofilms in this population is important. In Spring 2020, during the first wave of the COVID-19 pandemic in Europe, 31 ETs were obtained from COVID-19 patients at Ghent University Hospital (Ghent, Belgium). Biofilms were collected from the ET and the biofilm composition was determined using culture-dependent (MALDI-TOF mass spectrometry and biochemical tests) and culture-independent (16S and ITS1 rRNA amplicon sequencing) approaches. In addition, antimicrobial resistance was assessed for isolates collected via the culture-dependent approach using disc diffusion for 11 antimicrobials commonly used to treat lower respiratory tract infections. The most common microorganisms identified by the culture-dependent approach were those typically found during lung infections and included both presumed commensal and potentially pathogenic microorganisms like , , and . More unusual organisms, such as , were also identified, but each only in a few patients. The culture-independent approach revealed a wide variety of microbes present in the ET biofilms and showed large variation in biofilm composition between patients. Some biofilms contained a diverse set of bacteria of which many are generally considered as non-pathogenic commensals, whereas others were dominated by a single or a few pathogens. Antimicrobial resistance was widespread in the isolates, e.g. 68% and 53% of all isolates tested were resistant against meropenem and gentamicin, respectively. Different isolates from the same species recovered from the same ET biofilm often showed differences in antibiotic susceptibility. Our data suggest that ET biofilms are a potential risk factor for secondary infections in intubated COVID-19 patients, as is the case in mechanically-ventilated non-COVID-19 patients.
PubMed: 35720435
DOI: 10.1016/j.bioflm.2022.100079 -
Microorganisms Dec 2020Mobile phones (MPs) of healthcare workers (HCWs) may represent an important source of transmission of infectious agents. This longitudinal study documents the...
Mobile phones (MPs) of healthcare workers (HCWs) may represent an important source of transmission of infectious agents. This longitudinal study documents the contamination of these tools. Ten MPs handled by senior pediatricians were sampled once a week during 23 weeks in three pediatric wards of the University Hospital of Saint-Etienne, France. Cultures were performed for bacteria and multiplex PCR assays for a panel of respiratory and enteric viruses. A questionnaire on hygiene habits regarding phoning and care was filled-in by pediatricians before and after the study. From a total of 230 samples, 145 (63%) were contaminated by at least one pathogen. The MPs from emergency departments were the most impacted. Viruses were detected in 179 samples; bacteria were isolated in 59 samples. Contamination increased during the winter epidemic peak. A cross-contamination by between hands and MPs of different HCWs was demonstrated. The communication of the study results influenced the hygiene behaviors. This study highlights the contamination of MPs by pathogens that are resistant in the environment, and its sustainability along the winter season. The role of MPs as vectors of nosocomial infection needs to be better investigated.
PubMed: 33339327
DOI: 10.3390/microorganisms8122011 -
Journal of Biotechnology Aug 2020The CO fixation by autotrophic microbes has an important significance for improving carbon sequestration in composting. In this work, the succession of autotrophic...
The CO fixation by autotrophic microbes has an important significance for improving carbon sequestration in composting. In this work, the succession of autotrophic CO-fixing bacterial communities was investigated using quantitative PCR and high-throughput sequencing of the ribulose-1,5-bisphosphate carboxylase/oxygenase genes (cbbL and cbbM). The results presented that the number of autotrophic CO-fixing bacteria was comparable to that in the soil, and most species have not been classified into known bacterial groups, only part of them was assigned into Proteobacteria and Actinobacteria. Phylogenetic analysis displayed that the dominant known cbbL-containing bacteria were Allochromatium vinosum, Rhodobacter sphaeroides, Nitrobacter winogradskyi, Paracoccus yeei and Porphyrobacter sp. CACIAM 03H1, while the dominant known cbbM-containing bacteria were Sulfuritalea hydrogenivorans, Pseudomonas resinovorans, Achromobacter xylosoxidans, Sphingopyxis macrogoltabida and Thermomonospora curvata. In addition, canonical correspondence analysis showed that the evolution of autotrophic CO-fixing bacterial communities was greatly affected by physico-chemical parameters such as temperature, C/N and pH.
Topics: Autotrophic Processes; Bacteria; Bacterial Proteins; Carbon Dioxide; Composting; High-Throughput Nucleotide Sequencing; Microbial Consortia; Ribulose-Bisphosphate Carboxylase
PubMed: 32553532
DOI: 10.1016/j.jbiotec.2020.06.010