The Antibacterial Properties and Safety of a Nanoparticle-Coated Parquet Floor

Floor antibacterial technology prevents the human body from cross-infection with bacterial diseases. The most commonly used approach to endow daily-used floors with antibacterial properties is to apply a thin film of antibacterial agents on the parquet floor surface. In the present study, five commercial antibacterial nanoparticles were first dispersed in melamine resin solution, and then applied on a floor. Afterwards, the antibacterial properties of the nanoparticle-coated floor were investigated, in which Escherichia coli was used as the target bacteria. The impact of the nanoparticle dispersing agents on the ultimate antibacterial properties of the floor were also investigated. The results showed that silver nanoparticle-loaded hydroxyl zirconium sodium phosphate (Ag-HZDP) was most suitable as the antibacterial agent of a melamine coating for parquet flooring. With the help of sodium hexametaphosphate, the antibacterial agent was able to disperse well in the melamine resin solution and was also able to disperse well on the floor surface. When the loading amount of Ag-HZDP was 1 wt % or higher, the prepared antibacterial floor was able kill almost all the bacteria cultivated on its surface. Moreover, the prepared antibacterial floor had a lower toxicity compared with a pristine cedar substrate. The present study provides an effective way to provide daily-used parquet floors with excellent antibacterial properties

Changes of the Microbiota Composition on the Surface of Pig Carcasses during Chilling and Its Associations with Alterations in Chiller’s Temperature and Air Humidity

In this study, we investigated changes of microbiota composition on the surface of pig carcasses during chilling and their associations with temporal and spatial changes of wind speed, air temperature, and air humidity. The composition of microbiota on a carcass surface varied greatly with sampling sites; in particular, the surfaces of forelegs and neck had higher load of microorganisms and different microbiota composition compared to in the air and other carcass parts. However, such a difference in the microbiota composition decreased as chilling time extended. The positive detection ratios of microbial genes resistant to sulfonamides, quinolones, tetracyclines, and β-lactams were found different greatly with chilling time and sampling sites. The β-lactam and tetracycline resistant genes were observed in higher ratios in airborne microorganisms in the chiller, while the sulfa and tetracycline resistant genes had higher ratios in the microbiota on pig carcasses. Actual measurements and dynamic simulation showed that air temperature and humidity varied greatly among different places in a chiller within the first 8 h of chilling, with higher values close to the door, but the differences became smaller afterwards. The micro-environmental differences and changes in the chiller may cause the different composition of microbiota on pig carcasses

Microbiota changes on the surface of pig carcasses during refrigerated transportation and marketing

We investigated changes in the microbiota composition on the surface of pig carcasses during refrigerated transportation of different distances (200, 300, 400, 500 km) and further transferring to the market place. Microbial samples were obtained by sterile swabs at the starting point, the end points of transportation and the market points. Core temperature of pig carcasses, temperature and air humidity in refrigerated vehicles were also tracked. The air temperature and humidity in the refrigerated vehicles remained relatively constant during transportation. However, the air temperature and carcass temperature at the end points of transportation were the highest for the 500 km group and the lowest for the 400 km group (P < 0.05), while the air humidity was the highest for the 200 km group and the lowest for the 400 km group (P < 0.05). Microbial colony counts showed a slight increase during transportation and differed among five sampling points on the surface of pork carcasses with the highest for the outside of the shoulder and the lowest for the inside of the belly (P < 0.05). Microbiota composition changed greatly and Acinetobacter, Pseudomonas, Psychrobacter, Chryseobacterium, Staphylococcus, Brochothrix, Morexella, and Flavobacterium were the predominant genera. Pseudomonas was the most predominant during transportation

Mapping of Powdery Mildew Resistance Gene pmCH89 in a Putative Wheat-Thinopyrum intermedium Introgression Line

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a globally serious disease adversely affecting wheat production. The Bgt-resistant wheat breeding line CH09W89 was derived after backcrossing a Bgt resistant wheat-Thinopyrum intermedium partial amphiploid TAI7045 with susceptible wheat cultivars. At the seedling stage, CH09W89 exhibited immunity or high resistance to Bgt pathotypes E09, E20, E21, E23, E26, Bg1, and Bg2, similar to its donor line TAI7045 and Th. intermedium. No Th. intermedium chromatin was detected based on genomic in situ hybridization of mitotic chromosomes. To determine the mode of inheritance of the Bgt resistance and the chromosomal location of the resistance gene, CH09W89 was crossed with two susceptible wheat cultivars. The results of the genetic analysis showed that the adult resistance to Bgt E09 in CH09W89 was controlled by a single recessive gene, which was tentatively designated as pmCH89. Two polymorphic SSR markers, Xwmc310 and Xwmc125, were linked to the resistance gene with genetic distances 3.1 and 2.7 cM, respectively. Using the Chinese Spring aneuploid and deletion lines, the resistance gene and its linked markers were assigned to chromosome arm 4BL in the bin 0.68–0.78. Due to its unique position on chromosome 4BL, pmCH89 appears to be a new locus for resistance to powdery mildew. These results will be of benefit for improving powdery mildew resistance in wheat breeding programs

Molecular Characterization of a New Wheat-Thinopyrum intermedium Translocation Line with Resistance to Powdery Mildew and Stripe Rust

A new wheat-Thinopyrum translocation line CH13-21 was selected from the progenies derived from a cross between wheat-Th. intermedium partial amphiploid TAI7047 and wheat line Mianyang11. CH13-21 was characterized by using genomic in situ hybridization (GISH), multicolor-GISH (mc-GISH), multicolor-fluorescence in situ hybridization (mc-FISH) and chromosome-specific molecular markers. When inoculated with stripe rust and powdery mildew isolates, CH13-21 displayed novel resistance to powdery mildew and stripe rust which inherited from its Thinopyrum parent. The chromosomal counting analyses indicated that CH13-21 has 42 chromosomes, with normal bivalent pairing at metaphase I of meiosis. GISH probed by Th. intermedium genomic DNA showed that CH13-21 contained a pair of wheat-Th. intermedium translocated chromosomes. Sequential mc-FISH analyses probed by pSc119.2 and pAs1 clearly revealed that chromosome arm 6BS of CH13-21 was replaced by Thinopyrum chromatin in the translocation chromosome. The molecular markers analysis further confirmed that the introduced Th. intermedium chromatin in CH13-21 belonged to the long arm of homoeologous group 6 chromosome. Therefore, CH13-21 was a new T6BS.6Ai#1L compensating Robertsonian translocation line. It concludes that CH13-21 is a new genetic resource for wheat breeding programs providing novel variation for disease resistances

Cytogenetic analysis of CH7086.

<p>A) GISH patterns of CH7086 using <i>Th. ponticum</i> genomic DNA (labeled with fluorescein-12-dUTP) as probe. Cell was counterstained with DAPI and fluoresces blue. No GISH signal was observed in CH7086. B) Giemsa-C banding of CH7086.</p

Chromosomal Location and Comparative Genomics Analysis of Powdery Mildew Resistance Gene <i>Pm51</i> in a Putative Wheat-<i>Thinopyrum ponticum</i> Introgression Line

<div><p>Powdery mildew (PM) is a very destructive disease of wheat (<i>Triticum aestivum</i> L.). Wheat-<i>Thinopyrum ponticum</i> introgression line CH7086 was shown to possess powdery mildew resistance possibly originating from <i>Th. ponticum</i>. Genomic <i>in situ</i> hybridization and molecular characterization of the alien introgression failed to identify alien chromatin. To study the genetics of resistance, CH7086 was crossed with susceptible genotypes. Segregation in F₂ populations and F_2:3 lines tested with Chinese <i>Bgt</i> race E09 under controlled conditions indicated that CH7086 carries a single dominant gene for powdery mildew resistance. Fourteen SSR and EST-PCR markers linked with the locus were identified. The genetic distances between the locus and the two flanking markers were 1.5 and 3.2 cM, respectively. Based on the locations of the markers by nullisomic-tetrasomic and deletion lines of ‘Chinese Spring’, the resistance gene was located in deletion bin 2BL-0.89-1.00. Conserved orthologous marker analysis indicated that the genomic region flanking the resistance gene has a high level of collinearity to that of rice chromosome 4 and <i>Brachypodium</i> chromosome 5. Both resistance specificities and tests of allelism suggested the resistance gene in CH7086 was different from previously reported powdery mildew resistance genes on 2BL, and the gene was provisionally designated <i>PmCH86</i>. Molecular analysis of <i>PmCH86</i> compared with other genes for resistance to <i>Bgt</i> in the 2BL-0.89-1.00 region suggested that <i>PmCH86</i> may be a new PM resistance gene, and it was therefore designated as <i>Pm51</i>. The closely linked flanking markers could be useful in exploiting this putative wheat-<i>Thinopyrum</i> translocation line for rapid transfer of <i>Pm51</i> to wheat breeding programs.</p></div

A profile of amplification with marker BQ246670 in F₂ population from cross of CH7086/Taichung 29.

<p>M: DNA ladder; P_R: CH7086; P_S: Taichung 29; B_R: resistant bulk; B_S: susceptible bulk; R: homozygous resistant F₂ plants, S: homozygous susceptible F₂ plants. Asterisk indicates the critical band linked with <i>PmCH86</i>.</p