bacterial contamination Dotaz Zobrazit nápovědu
Public transport represents a potential site for the transmission of resistant pathogens due to the rapid movement of large numbers of people. This study aimed to investigate the bacterial contamination of frequently touched surfaces in the public transport system operating in the proximity of the biggest Czech hospital during the coronavirus pandemic despite extensive cleaning and disinfection efforts. In June and September 2020, samples from the metro trains, ground transport and stationary objects were collected, enriched and cultured. The antimicrobial susceptibility was tested by broth microdilution. Staphylococcus aureus isolates exhibiting inconclusive results of vancomycin susceptibility testing were retested by broth macrodilution and subjected to whole genome sequencing. All S. aureus isolates were tested for vancomycin heteroresistance (hVISA). A total of 513/542 (94.6 %) samples were culture-positive with higher frequency in September (p = 0.004). S. aureus was the most frequent opportunistic bacterial pathogen found (3.7 %, 20/542) followed by Enterobacterales spp. (1.8 %, 10/542). No methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamase producers (ESBL) or carbapenemase-producing bacteria were detected. Resistance to clinically relevant drugs was rare except for resistance to ampicillin (67 %, 8/12), cefuroxime (42 %, 5/12) in Enterobacterales and chloramphenicol (90 %, 18/20), penicillin (45 %, 9/20), and erythromycin (20 %, 4/20) in S. aureus. One S. aureus isolate was shown to be resistant to vancomycin (8 mg/L) by forming large visible cell aggregates. Population analysis profile-area under the curve ratio (PAP-AUC) testing did not confirm the hVISA phenotype, but mutations in the hVISA phenotype-related gene vraR and other genes related to cell wall synthesis (fmtB) and intercellular adhesion (sasC) were found. Our study shows that in the COVID-19 pandemic, despite the intensive use of disinfectants, public transport was a source of opportunistic bacterial pathogens including S. aureus with unusual vancomycin resistance phenotype that could be easily missed by standard susceptibility testing.
- Klíčová slova
- Antimicrobial resistance, Environmental contamination, Public transport, Staphylococcus aureus, Vancomycin resistance, Whole genome sequencing,
- MeSH
- antibakteriální látky * farmakologie MeSH
- COVID-19 * MeSH
- doprava MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- pandemie MeSH
- rezistence na vankomycin MeSH
- SARS-CoV-2 * MeSH
- Staphylococcus aureus * účinky léků genetika MeSH
- vankomycin * farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
- Názvy látek
- antibakteriální látky * MeSH
- vankomycin * MeSH
Two methods for detection of mycoplasma contamination in cell cultures, sera, and live-virus vaccines were compared: the direct culture test and the DNA staining method employing bisBenzimide (Hoechst No. 33258). Contamination by different species of mycoplasma was found in 39% samples tested. It is recommended to use both techniques for a reliable detection of mycoplasma contamination.
- MeSH
- atenuované vakcíny MeSH
- DNA bakterií analýza MeSH
- kontaminace léku * MeSH
- krev mikrobiologie MeSH
- kultivační techniky metody MeSH
- kultivované buňky MeSH
- Mycoplasma izolace a purifikace MeSH
- reprodukovatelnost výsledků MeSH
- virové vakcíny * MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- atenuované vakcíny MeSH
- DNA bakterií MeSH
- virové vakcíny * MeSH
Healthy fish populations lead to healthy aquatic ecosystems and it is our responsibility to be a part of the solution. Fish is one of the most favored foods and is suitable for people of all ages. Fish is an essential source of protein, vitamins, and minerals and a source of income for millions of people. Human population growth and climate change are putting a strain on our food system, demanding the development of sustainable services to enhance global food production and its security. Food safety is an intricate problem in both developed and developing countries. Fresh fish is a highly perishable food with a limited life span; as a result, it must be delivered and kept carefully to minimize deterioration and assure safety. Fish spoilage is linked to biochemical changes that occur post-harvest, such as storage and transportation. These modifications can account for fish spoilage by altering the taste, texture, and appearance. Fish harvesting, distribution, and post-harvest handling are all unhygienic, resulting in poor and unpredictable fish quality in the market. Many innovative and effective control measurements of various bacteria in fish have been proposed and evaluated. This review is a systematic approach to investigating post-harvest fish spoilage, its assessment, and control strategies.
In this study we investigated the microbial contamination of 126 samples of photographic and cinematographic materials from 10 archival funds in the Czech Republic. Microorganisms were isolated from the light-sensitive layer by swabbing it with a polyurethane sponge. Microbial isolates were identified by MALDI-TOF MS (bacteria) or by phenotype testing and microscopy (fungi). Bacterial contamination was more abundant and more diverse than fungal contamination, and both were significantly associated with archives. The most frequently isolated fungal genera were Cladosporium, Eurotium, Penicillium, Aspergillus and Alternaria. The most frequently isolated bacteria were Gram-positive genera such as Staphylococcus, Micrococcus, Kocuria, Streptococcus and Bacillus. This bacterial and fungal diversity suggests that air is the main vehicle of contamination. We also analysed the impact of the type of material used for the carrier (paper, baryta paper, cellulose acetate and nitrate or glass) or the light-sensitive layer (albumen, gelatine, collodion and other) on the level and diversity of microbial contamination. Carriers such as polyester and cellulose nitrate may have a negative impact on bacterial contamination, while paper and baryta paper may have a partially positive impact on both fungal and bacterial contamination.
The special issue "New Insight into Mycotoxins and Bacterial Toxins: Toxicity Assessment, Molecular Mechanism and Food Safety" in Food and Chemical Toxicology contains 19 articles on current hot topics in mycotoxins and bacterial toxins. Dietary exposure to mycotoxins and risk assessments are reported in this issue. Molecular mechanisms of multiple mycotoxins and emerging mechanisms of toxicity are especially concerned by researchers. Moreover, mycotoxin-detoxifying substances and antimicrobial agents are also fully investigated in the context. This special issue will help to further understand the mycotoxins and bacterial toxins, casting new light for the control of food safety.
- Klíčová slova
- Bacterial toxins, Food safety, Molecular mechanism, Mycotoxin-detoxifying, Mycotoxins,
- MeSH
- bakteriální toxiny * toxicita MeSH
- bezpečnost potravin * MeSH
- hodnocení rizik MeSH
- kontaminace potravin analýza MeSH
- lidé MeSH
- mykotoxiny * toxicita analýza MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- úvodní články MeSH
- úvodníky MeSH
- Názvy látek
- bakteriální toxiny * MeSH
- mykotoxiny * MeSH
Microbial contamination in cultural heritage storage facilities is undoubtedly still a huge problem and leads to the biodeterioration of historical objects and thus the loss of information for future generations. Most studies focus on fungi that colonize materials, which are the primary agents of biodeterioration. However, bacteria also play crucial roles in this process. Therefore, this study focuses on identifying bacteria that colonize audio-visual materials and those present in the air in the archives of the Czech Republic. For our purposes, the Illumina MiSeq amplicon sequencing method was used. Using this method, 18 bacterial genera with an abundance of higher than 1% were identified on audio-visual materials and in the air. We also evaluated some factors that were assumed to possibly influence the composition of bacterial communities on audio-visual materials, of which locality was shown to be significant. Locality also explained most of the variability in bacterial community structure. Furthermore, an association between genera colonizing materials and genera present in the air was demonstrated, and indicator genera were evaluated for each locality. IMPORTANCE The existing literature on microbial contamination of audio-visual materials has predominantly used culture-based methods to evaluate contamination and has overlooked the potential impact of environmental factors and material composition on microbial communities. Furthermore, previous studies have mainly focused on contamination by microscopic fungi, neglecting other potentially harmful microorganisms. To address these gaps in knowledge, our study is the first to provide a comprehensive analysis of bacterial communities present on historical audio-visual materials. Our statistical analyses demonstrate the critical importance of including air analysis in such studies, as airborne microorganisms can significantly contribute to the contamination of these materials. The insights gained from this study are not only valuable in developing effective preventive measures to mitigate contamination but also valuable in identifying targeted disinfection methods for specific types of microorganisms. Overall, our findings highlight the need for a more holistic approach to understanding microbial contamination in cultural heritage materials.
- Klíčová slova
- Illumina MiSeq, air contamination, audio-visual materials, bacterial contamination, cultural heritage,
- MeSH
- atmosféra MeSH
- Bacteria * genetika MeSH
- houby genetika MeSH
- mikrobiota * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Thallium (Tl) is a highly toxic trace metal, included in the US EPA list of priority pollutants. Even though its toxicity is potentially higher or comparable to Cd or Hg, its environmental impact is largely unknown. Despite its toxicity, only a few recent studies are mapping the impact of recently introduced Tl on soil microbial communities, namely in agricultural systems but no studies focus on its long term effect. To complement the understanding of the impact of Tl on soil, this study aims to describe the influence of extremely high naturally occurring Tl concentration (50 mg/kg of potentially bioavailable Tl) on soil microbial communities. Our investigation concentrated on samples collected at Buus (Erzmatt, Swiss Jura, Switzerland), encompassing forest and meadow soil profiles of the local soil formed on hydrothermally mineralized dolomite rock, which is naturally rich in Tl. The soil profiles showed a significant proportion of potentially bioavailable Tl. Yet, even this high concentration of Tl has a limited impact on the richness of the soil bacterial community. Only the meadow soil samples show a reduced richness compared to control samples. Furthermore, our analysis of geogenic Tl contamination in the region unveiled a surprising finding: compared to other soils of Switzerland and in stark contrast to soils affected by recent mining activities, the structure of the bacterial community in Buus remained relatively unaffected. This observation highlights the unique ability of soil microbial communities to withstand extreme Tl contamination. Our study advances the understanding of Tl's environmental impact and underscores the resilience of soil microbes in the face of severe long-term contamination.
- Klíčová slova
- Bacterial community, Bacterial ecology, Contamination, Diversity, Heavy metals, Thallium,
- MeSH
- Bacteria MeSH
- látky znečišťující půdu * analýza MeSH
- monitorování životního prostředí MeSH
- půda chemie MeSH
- rtuť * analýza MeSH
- stopové prvky * analýza MeSH
- thallium analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
- Názvy látek
- látky znečišťující půdu * MeSH
- půda MeSH
- rtuť * MeSH
- stopové prvky * MeSH
- thallium MeSH
Bacterial contamination of semen has become an important contributor to the reduced shelf life of insemination doses in the poultry industry, which is why antibiotics (ATBs) are an important component of semen extenders. Due to a global rise in antimicrobial resistance, the aim of this study was to assess the efficiency of selected commercially available semen extenders to prevent possible bacterial contamination of rooster ejaculates. Two selected extenders free from or containing 31.2 µg/mL kanamycin (KAN) were used to process semen samples from 63 healthy Lohmann Brown roosters. Phosphate-buffered saline without ATBs was used as a control. The extended samples were stored at 4 °C for 24 h. Sperm motility, viability, mitochondrial activity, DNA integrity and the oxidative profile of each extended sample were assessed following 2 h and 24 h of storage. Furthermore, selective media were used to quantify the bacterial load and specific bacterial species were identified with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The results indicate that semen extenders enriched with KAN ensured a significantly higher preservation of sperm quality in comparison to their KAN-free counterparts. Bacterial load was significantly decreased in diluents supplemented with ATBs (p ≤ 0.001); however, KAN alone was not effective enough to eradicate all bacteria since several Escherichia coli, Enterococcus faecalis, Enterococcus faecium and Micrococcus luteus were retrieved from samples extended in KAN-supplemented commercial extenders. As such, we may suggest that more focus should be devoted to the selection of an optimal combination and dose of antibiotics for poultry extenders, which should be accompanied by a more frequent bacteriological screening of native as well as extended poultry semen.
- Klíčová slova
- MALDI-TOF, bacterial contamination, bacterial resistance, kanamycin, roosters, semen extender,
- Publikační typ
- časopisecké články MeSH
External fixators of serious fractures could be an attractive substrate on which microorganisms can accumulate. Therefore, this study aimed to develop a suitable method for enabling the simulation of a real situation when osteosynthetic fixation material is open for the potential threat of bacterial attack. Agar-based media represented human tissue, and the metallic pin characterized the screw in the fixation. Various types of agar, supplements, and contamination strategy by Staphylococcus aureus were tested. The influence of the initial bacterial concentration was also examined. Surfaces were observed by scanning electron microscopy (SEM), and all results were compared. Brain Heart Infusion Agar with the Egg Yolk Tellurite Emulsion was established in a transparent test tube as a suitable system for enabling the good interpretability of bacterial contamination in the pin's surroundings. Pin contamination has been found to be an appropriate approach for testing microbial growth, rather than agar surface contamination, which distorted obtained results. A lower initial colony forming units (CFU) provided better clarity of the test. SEM observation of the pin surface was comparable with the visual evaluations in the test tubes. Results were assembled for positive and negative control samples as well. Screening method for the most common bacteria S. aureus has been standardized and developed. This experimental setup could also be a useful tool for surface modification with antibacterial properties testing.
- Klíčová slova
- Antibacterial test, Biofilm, External fixation, Silver, Staphylococcus aureus, Titanium,
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy účinky léků růst a vývoj MeSH
- externí fixátory mikrobiologie MeSH
- kontaminace zdravotnického vybavení * MeSH
- kultivační média MeSH
- lidé MeSH
- mikroskopie elektronová rastrovací MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus účinky léků růst a vývoj ultrastruktura MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- kultivační média MeSH
- Klíčová slova
- ANTIBIOTICS *, BACTERIA *, DRUG RESISTANCE, MICROBIAL *, EXPERIMENTAL LAB STUDY *,
- MeSH
- antibakteriální látky * MeSH
- antibiotická rezistence * MeSH
- antituberkulózní antibiotika * MeSH
- Bacteria * MeSH
- kontaminace léku * MeSH
- výzkum * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky * MeSH
- antituberkulózní antibiotika * MeSH
