Metagenomic Analysis of Microbial Composition Revealed Cross-Contamination Pathway of Bacteria at a Foodservice Facility

Bacterial contamination of food-contact surfaces can be a potential risk factor for food quality and safety. To evaluate the spatial and temporal variations of the potential cross-contamination routes, we conducted a biogeographical assessment of bacteria in a foodservice facility based on the diversity of microflora on each surface. To this end, we performed high-throughput amplicon sequencing of 13 food-contact and non-food contact surfaces in a foodservice facility throughout a year. The results showed that Bacillus, Acinetobacter, Streptophyta, Enterobacter, Pseudomonas, Serratia, Enhydrobacter, Staphylococcus, Paracoccus, and Lysinibacillus were the dominant genera found on the kitchen surfaces of the foodservice facility. Depending on the season, changes in Firmicute/Proteobacteria ratios were observed, and the fan becomes the main source of outdoor air contamination. The microbial flow associated with spoilage was also observed throughout food preparation. Taken together, our results would be a powerful reference to hygiene managers for improvement of food processes.

Practical approach to prevent COVID-19 infection at breast cancer screening

Background The novel coronavirus disease 2019 (COVID-19) undermines the benefits of cancer screening. To date, no study has identified specific infection control methods. We aimed to provide practical methods for COVID-19 risk reduction during breast cancer screening mammography (MMG) by examining an overview of potential contamination routes of aerosols and possible risks for patients and health care providers. Methods Computational fluid dynamics (CFD) simulations were conducted for airflow and aerosol dispersion in a 3D virtual model of a mobile MMG laboratory room. This model was constructed based on the actual mobile screening MMG bus ‘Cosmos’ in the Chiba Foundation for Health Promotion & Disease Prevention. Examiner and patient geometries were obtained by scanning an actual human using a 3D Scanner. Contamination of the room was evaluated by counting the numbers of suspended and deposited aerosols. Results We applied the CFD simulation model to the exhalation of small or large aerosols from a patient and examiner in the MMG laboratory. Only 14.5% and 54.5% of large and small aerosols, respectively, were discharged out of the room with two doors open. In contrast, the proportion of large and small aerosols discharged out of the room increased to 96.6% and 97.9%, respectively, with the addition of forced gentle wind by the blower fan. This simulation was verified by a mist aerosol experiment conducted in the mobile MMG laboratory. Conclusion Adding forced ventilation to a MMG laboratory with two doors open may enable risk reduction dramatically. This could be applied to other clinical situations.

Phylogeography of Human and Animal Coxiella burnetii Strains: Genetic Fingerprinting of Q Fever in Belgium

Q fever is a zoonotic disease caused by the bacteria Coxiella burnetii. Domestic ruminants are the primary source for human infection, and the identification of likely contamination routes from the reservoir animals the critical point to implement control programs. This study shows that Q fever is detected in Belgium in abortion of cattle, goat and sheep at a different degree of apparent prevalence (1.93%, 9.19%, and 5.50%, respectively). In addition, and for the first time, it is detected in abortion of alpaca (Vicugna pacos), raising questions on the role of these animals as reservoirs. To determine the relationship between animal and human strains, Multiple Locus Variable-number Tandem Repeat Analysis (MLVA) (n=146), Single-Nucleotide Polymorphism (SNP) (n=92) and Whole Genome Sequencing (WGS) (n=4) methods were used to characterize samples/strains during 2009-2019. Three MLVA clusters (A, B, C) subdivided in 23 subclusters (A1-A12, B1-B8, C1-C3) and 3 SNP types (SNP1, SNP2, SNP6) were identified. The SNP2 type/MLVA cluster A was the most abundant and dispersed genotype over the entire territory, but it seemed not responsible for human cases, as it was only present in animal samples. The SNP1/MLVA B and SNP6/MLVA C clusters were mostly found in small ruminant and human samples, with the rare possibility of spillovers in cattle. SNP1/MLVA B cluster was present in all Belgian areas, while the SNP6/MLVA C cluster appeared more concentrated in the Western provinces. A broad analysis of European MLVA profiles confirmed the host-species distribution described for Belgian samples. In silico genotyping (WGS) further identified the spacer types and the genomic groups of C. burnetii Belgian strains: cattle and goat SNP2/MLVA A isolates belonged to ST61 and genomic group III, while the goat SNP1/MLVA B strain was classified as ST33 and genomic group II. In conclusion, Q fever is widespread in all Belgian domestic ruminants and in alpaca. We determined that the public health risk in Belgium is likely linked to specific genomic groups (SNP1/MLVA B and SNP6/MLVA C) mostly found in small ruminant strains. Considering the concordance between Belgian and European results, these considerations could be extended to other European countries.

Novel coronavirus disease 2019 (COVID-19) and challenges in dental practices

The Covid-19 virus appearing in Wuhan in December, 2019 and acting by binding to ACE-2 receptors in the respiratory system has caused many people to die by spreading to the whole world. The virus, which has been detected to spread faster than SARS-CoV and MERS-CoV viruses, spreads from person to person rapidly. People should not be together because it is transmitted from person to person through the respiratory tract. For this reason, it is recommended not to go to health institutions, provided that it is not urgent. However, many emergency patients go to dental clinics and hospitals for treatment. In this review; with possible contamination routes of Covid-19 such as airborne spread, contact spread and contaminated surface spread during patient diagnosis and treatment to prevent Covid-19 contamination, methods preventing spread such as hand hygiene, personal protective measures for dentists, intraoral rubber dam before dental procedures were indicated. It was also mentioned that the fast rotating tool with valves having negative pressure should be used and most importantly, the materials used in the dental clinic should be disposed in accordance with medical waste protocol. How to cite this article: Novel coronavirus disease 2019 (COVID-19) and challenges in dental practices. Int Dent Res 2020;10(3):100-15. https://doi.org/10.5577/intdentres.2020.vol10.n3.5 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Persistent Organic Pollutants in Polar Ecosystems: Current Situation and Future Challenges Under Climate Change

The polar regions had long been regarded as healthy ecosystems free of any hazardous traces left by human activity. Unfortunately, since the intensification of industrial activities leading to huge releases into environment, anthropogenic pollutants through global atmospheric and ocean currents were found with more or less high concentrations in all polar ecosystem compartments. Among these pollutants, one of the most dangerous categories is persistent organic pollutants (POPs). Since polar ecosystems are fragile and have a limited capacity for resilience, their contamination can generate unforeseeable consequences that can affect global cycles. Our work aims to compile data collected through a review of studies carried out within the framework of POPs evolution in polar regions, and then to compare them in order to identify future improvements to be made within the framework of POPs monitoring in the Arctic and Antarctic. According to our observations, POPs concentrations in all ecosystem compartments in Arctic are much higher than in Antarctica. Moreover, global warming influencing the abiotic factors of diffusion and mobility of POPs has led to a massive revolatization of POPs in the Arctic as well as an increase in their concentrations in large mammals. We also noted a lack of availability of consistent and continuous long-term data in Antarctic, which is why an ambiguity persists in the understanding of the POPs contamination routes, their evolution as well as the application of projection models.

Determination of veterinary pharmaceutical runoffs from a swine manure pile using LC–MS/MS

The mass usage of veterinary pharmaceuticals in farms has contributed to environmental pollution in vicinity waters, soils, and sediments from farms and composting facilities. In the present study, we investigated the usage of four antibiotics (viz., lincomycin, sulfamethazine, sulfamethoxazole, and trimethoprim) to understand their contamination routes from livestock manure piles. Residual levels of these antibiotics in a nearby reservoir were set as a positive control (Site 1), and a swine manure pile in a farm (Site 2) and a soil sample around the manure pile (Site 3) were selected for this study. Artificial rainwater was flowed into the manure sample (Site 2), the soil sample around the manure pile (Site 3), and a soil sample around the vicinity river (Site 4). A stream sample (Site 5) around the manure pile and river water near the manure pile (Site 6) were also collected. For qualitative and quantitative analyses, analytical validation was performed, and all the four antibiotics were detected at Site 1 in the concentration range of 0.03–1.6 µg/L. Lincomycin was the antibiotic with the highest detection level. At Site 2, the detection level of all antibiotics remained at 0.3–17.3 µg/L, and their residual amounts were continuously detected in subsequent samples with approximately 30-fold decrease. The migration of antibiotics was confirmed to be independent of pH value. Therefore, this study indicates that farm manure pile should be thoroughly managed for antibiotic contamination in vicinity areas with periodical monitoring, especially waterways.

Dominant Yeast Community in Raw Sheep’s Milk and Potential Transfers of Yeast Species in Relation to Farming Practices

Yeasts are always present in any type of cheese, as well as in the factories where it is produced. However, the role of the yeast community in the cheese making process, as well as the routes of contamination used by yeast species to contaminate milk from the dairy farm environment, are not well known. The objectives of this study were to broaden the knowledge of the dominant yeast community in Manchega sheep’s milk and to assess the contamination routes of the yeast species depending on the farm practices. Milk, teat surface (collected from ten ewes per farm), feed, and air (collected in milking parlours and livestock housing) samples were collected from 12 typical farms in Castilla-La Mancha, Spain with differences in farming practices, and the yeast species were identified using DNA sequencing methods. To evaluate whether certain farming practices have an effect on the distribution of species of yeast in the milk samples, a mixed model was used. The results showed that most of the dominant yeast species (mainly belonging to the genus Candida) found in milk were also found in the other samples, indicating a microbial transfer from the farm environment to the milk. Furthermore, the statistical model showed that factors influencing yeast counts in milk were the presence of yeasts in the milking parlour, the use of silage, and the frequency of acid treatment for cleaning the milking machines. In conclusion, milk contamination from the yeast species present in the dairy farm environment is related to certain farming practices such as the use of silage and the daily use of acid in the cleaning of the milking machines, which favours the presence of desirable microbiota in milk.

The risk mitigation indices associated with some risk mitigation protocols performed on contaminated aqua-cultured catfish (Clarias gariepinus)

The present research quantified the risk mitigation indices associated with some risk mitigation protocols practiced by humans in Nigeria to mitigate the baseline risk of illness that were associated with Clarias gariepinus contaminated with multidrug-resistant AmpC beta-lactamase-producing Enterobacter cloacae pathogen. Identification of the multidrug-resistant AmpC beta-lactamase-producing E. cloacae pathogen was performed with phenotypic and molecular methods. The United States FDA-iRisk stochastic software quantified the baseline and residual risk of illness associated with the contamination and cross-contamination routes of the C. gariepinus chain. The fresh adult C. gariepinus was contaminated with the multidrug-resistant E. cloacae pathogen (median concentration = 4.49 CFU g-1), but this was significantly reduced by the risk mitigation protocols practiced by the human consumers. The risk mitigation practices of human consumers resulted in a risk mitigation index of 0.92, which was equivalent to a 92% reduction in the baseline risk of illness (baseline risk of illness = 7.58 × 10-4; residual risk of illness = 5.9 × 10-5). In spite of the significant risk mitigation, inducible AmpC beta-lactamase resistance genes was still found in the residual multidrug-resistant Enterobacter cloacae pathogen, which survived the inadequate risk mitigation protocols that accounted for 8% residual risk of illness.