Effects of environmental disinfection on microbial population and resistance genes: A case study of the microecology within a panda enclosure.

Widespread use of disinfectants raises concerns over their involvement in altering microbial communities and promoting antimicrobial resistance. This study explores the influence of disinfection protocols on microbial populations and resistance genes within an isolated enclosure environment and in the gut of giant pandas (GPs) held within. Samples of panda feces, air conditioning ducts, soil and bamboo were collected before and after disinfection. High-throughput sequencing characterized the microbial flora of GP gut and environmental microbes inside the artificial habitat. Microbial cultures showed that Escherichia coli (34.6%), Enterococcus (15.4%) and other pathogenic bacteria deposited in feces and the enclosure. Isolates exhibit a consistent resistance to disinfectant, with the greatest resistance shown to cyanuric acid, and the lowest to glutaraldehyde-dodecyl dimethyl ammonium bromide (GD-DDAB) and dodecyl dimethyl ammonium bromide (DDAB). The total number of the culturable bacteria in soil and bamboo were significantly diminished after disinfection but increased in the gut. After disinfection, the richness (Chao1 index) of environment samples increased significantly (P < 0.05), while the richness in gut decreased significantly (P < 0.05). Ten genera showed significant change in feces after disinfection. Metagenome sequencing showed that 126 types of virulence genes were present in feces before disinfection and 37 in soil. After disinfection, 110 virulence genes localized in feces and 53 in soil. Eleven virulence genes including ECP and T2SS increased in feces. A total of 182 antibiotic resistance genes (ARGs) subtypes, potentially conferring resistance to 20 classes of drugs, were detected in the soils and feces, with most belonging to efflux pump protein pathways. After disinfection, the number of resistance genes increased both in gut and soil, which suggests disinfection protocols increase the number of resistance pathways. Our study shows that the use of disinfectants helps to shape the microbial community of GPs and their habitat, and increases populations of resistant strain bacteria.

The gut microbiota of gibbons across host genus and captive site in China.

Gut microbiota influences nutrient metabolism and immunity of animal hosts. Better understanding of the composition and diversity of gut microbiota contributes to conservation and management of threatened animals both in situ and ex situ. In this study, we applied 16S rRNA gene amplicon sequencing to evaluate the composition and diversity of the fecal bacterial community of four gibbon genera (Family Hylobatidae) at four Chinese zoos. The results showed that the dominant bacterial phyla were Bacteroidetes, Firmicutes, and Proteobacteria and dominant families were Prevotellaceae (Bacteroidetes), Spirochaetaceae (Spirochaetes) and Ruminococcaceae (Firmicutes) in the gut of all gibbons. Both captive site and host genus had significant effects on the relative abundance of dominant bacteria and structure of gut bacterial community. We found that captive site and host genus did not solely impact gut bacterial diversity, but the interaction between them did. This study provides basic knowledge for gut microbiota of all four gibbon genera and contributes to management and conservation of captive gibbons.

Genomic evolution of island birds from the view of the Swinhoe's pheasant (Lophura swinhoii).

Island endemic birds account for the majority of extinct vertebrates in the past few centuries. To date, the evolutionary characteristics of island endemic bird's is poorly known. In this research, we de novo assembled a high-quality chromosome-level reference genome for the Swinhoe's pheasant, which is a typical endemic island bird. Results of collinearity tests suggest rapid ancient chromosome rearrangement that may have contributed to the initial species radiation within Phasianidae, and a role for the insertions of CR1 transposable elements in rearranging chromosomes in Phasianidae. During the evolution of the Swinhoe's pheasant, natural selection positively selected genes involved in fecundity and body size functions, at both the species and population levels, which reflect genetic variation associated with island adaptation. We further tested for variation in population genomic traits between the Swinhoe's pheasant and its phylogenetically closely related mainland relative the silver pheasant, and found higher levels of genetic drift and inbreeding in the Swinhoe's pheasant genome. Divergent demographic histories of insular and mainland bird species during the last glacial period may reflect the differing impact of insular and continental climates on the evolution of species. Our research interprets the natural history and population genetic characteristics of the insular endemic bird the Swinhoe's pheasant, at a genome-wide scale, provides a broader perspective on insular speciation, and adaptive evolution and contributes to the genetic conservation of island endemic birds.

Adaptations to a cold climate promoted social evolution in Asian colobine primates.

The biological mechanisms that underpin primate social evolution remain poorly understood. Asian colobines display a range of social organizations, which makes them good models for investigating social evolution. By integrating ecological, geological, fossil, behavioral, and genomic analyses, we found that colobine primates that inhabit colder environments tend to live in larger, more complex groups. Specifically, glacial periods during the past 6 million years promoted the selection of genes involved in cold-related energy metabolism and neurohormonal regulation. More-efficient dopamine and oxytocin pathways developed in odd-nosed monkeys, which may have favored the prolongation of maternal care and lactation, increasing infant survival in cold environments. These adaptive changes appear to have strengthened interindividual affiliation, increased male-male tolerance, and facilitated the stepwise aggregation from independent one-male groups to large multilevel societies.

Corrigendum: Wildlife is a potential source of human infections of Enterocytozoon bieneusi and Giardia duodenalis in southeastern China.

[This corrects the article DOI: 10.3389/fmicb.2021.692837.].

Wildlife Is a Potential Source of Human Infections of Enterocytozoon bieneusi and Giardia duodenalis in Southeastern China.

Wildlife is known to be a source of high-impact pathogens affecting people. However, the distribution, genetic diversity, and zoonotic potential of Cryptosporidium, Enterocytozoon bieneusi, and Giardia duodenalis in wildlife are poorly understood. Here, we conducted the first molecular epidemiological investigation of these three pathogens in wildlife in Zhejiang and Shanghai, China. Genomic DNAs were derived from 182 individual fecal samples from wildlife and then subjected to a nested polymerase chain reaction-based sequencing approach for detection and characterization. Altogether, 3 (1.6%), 21 (11.5%), and 48 (26.4%) specimens tested positive for Cryptosporidium species, E. bieneusi, and G. duodenalis, respectively. Sequence analyses revealed five known (BEB6, D, MJ13, SC02, and type IV) and two novel (designated SH_ch1 and SH_deer1) genotypes of E. bieneusi. Phylogenetically, novel E. bieneusi genotype SH_deer1 fell into group 6, and the other genotypes were assigned to group 1 with zoonotic potential. Three novel Cryptosporidium genotypes (Cryptosporidium avian genotype V-like and C. galli-like 1 and 2) were identified, C. galli-like 1 and 2 formed a clade that was distinct from Cryptosporidium species. The genetic distinctiveness of these two novel genotypes suggests that they represent a new species of Cryptosporidium. Zoonotic assemblage A (n = 36) and host-adapted assemblages C (n = 1) and E (n = 7) of G. duodenalis were characterized. The overall results suggest that wildlife act as host reservoirs carrying zoonotic E. bieneusi and G. duodenalis, potentially enabling transmission from wildlife to humans and other animals.

An activatable liposomal fluorescence probe based on fluorescence resonance energy transfer and aggregation induced emission effect for sensitive tumor imaging.

Liposomes are of great interest and importance in tumor imaging, since they can greatly improve the imaging sensitivity and specificity by increasing the accumulation of contrast agents. Still, most liposome-based probes have high background signals during blood circulation, which limits enhancement of S/B ratio and tumor imaging sensitivity. To enhance the S/B ratio of tumor imaging, we construct a fluorescence resonance energy transfer (FRET) and aggregation induced emission (AIE) based liposomal fluorescence probe TPE/BHQ-lipo with excellent FRET effect (99 %) and great fluorescence enhancement upon liposome rupture (120-fold) as well as efficient fluorescence recovery in tumor cell imaging. Finally, we used the TPE/BHQ-lipo to image 4T1 tumor upon intravenous injection of liposomes and the group showed enhanced signal to background ratio of 4.1, compared to 1.8 from control AIE-based liposomal group (TPE-lipo). Our work offers an excellent FRET and AIE-based liposomal probe for high-sensitive tumor imaging.

Succession of Gut Microbial Structure in Twin Giant Pandas During the Dietary Change Stage and Its Role in Polysaccharide Metabolism.

Adaptation to a bamboo diet is an essential process for giant panda growth, and gut microbes play an important role in the digestion of the polysaccharides in bamboo. The dietary transition in giant panda cubs is particularly complex, but it is an ideal period in which to study the effects of gut microbes on polysaccharide use because their main food changes from milk to bamboo (together with some bamboo shoot and coarse pastry). Here, we used 16S rDNA and internal transcribed spacer 1 (ITS1) DNA sequencing and metagenomic sequencing analysis to investigate the succession of the gut microbial structure in feces sampled from twin giant panda cubs during the completely dietary transition and determine the abundances of polysaccharide-metabolizing genes and their corresponding microbes to better understand the degradation of bamboo polysaccharides. Successive changes in the gut microbial diversity and structure were apparent in the growth of pandas during dietary shift process. Microbial diversity increased after the introduction of supplementary foods and then varied in a complex way for 1.5-2 years as bamboo and complex food components were introduced. They then stabilized after 2 years, when the cubs consumed a specialized bamboo diet. The microbes had more potential to metabolize the cellulose in bamboo than the hemicellulose, providing genes encoding cellulase systems corresponding to glycoside hydrolases (GHs; such as GH1, GH3, GH5, GH8, GH9, GH74, and GH94). The cellulose-metabolizing species (or genes) of gut bacteria was more abundant than that of gut fungi. Although cellulose-metabolizing species did not predominate in the gut bacterial community, microbial interactions allowed the giant pandas to achieve the necessary dietary shift and ultimately adapt to a bamboo diet.

Liposome-based probes for molecular imaging: from basic research to the bedside.

Molecular imaging is very important in disease diagnosis and prognosis. Liposomes are excellent carriers for different types of molecular imaging probes. In this work, we summarize current developments in liposome-based probes used for molecular imaging and their applications in image-guided drug delivery and tumour surgery, including computed tomography (CT), ultrasound imaging (USI), magnetic resonance imaging (MRI), positron emission tomography (PET), fluorescence imaging (FLI) and photoacoustic imaging (PAI). We also summarized liposome-based multimodal imaging probes and new targeting strategies for liposomes. This work will offer guidance for the design of liposome-based imaging probes for future clinical applications.

pH sensitive liposomes delivering tariquidar and doxorubicin to overcome multidrug resistance of resistant ovarian cancer cells.

Multidrug resistance of tumour cells is one of the most important hurdles in tumour chemotherapy. To overcome the multidrug resistance, we constructed a pH-sensitive liposome formulation (pHSL) by loading tariquidar (TQR) and DOX simultaneously in this work. The formulation showed high stability at pH 7.4 and excellent sensitivity at acidic pH, which facilitated the delivery of TQR and DOX into cells. Cellular experiments demonstrated that the pHSL/TQR/DOX 0.05 could almost restore the drug sensitivity of OVCAR8/ADR cells. Therefore, the pH sensitive liposome formulation pHSL/TQR/DOX 0.05 was very promising in treating resistant tumours.

Studies on the rheological and gelatinization characteristics of waxy wheat flour.

The chemical composition, rheological and gelatinization characteristics of waxy wheat flour were investigated. Compared with wheat flour, waxy wheat flour has lower protein (9.52%), amylase (1.02%) and higher crude starch (73.19%) contents. Because of its different chemical composition, waxy wheat flour exhibited some better processing characteristics (water-holding capacity, dough development time, extensibility, swelling power and setback) than normal wheat flour. It also exhibited some defects in rheological characteristics, including a higher degree of softening, a lower Farinograph quality number and smaller resistance to extensibility ratio. Differential scanning calorimetry results showed that waxy wheat flour gelatinized at higher onset (To=60.9 °C), peak (Tp=64.9 °C), conclusion (Tc=73.6 °C) temperatures and required more energy (ΔH=7.6J/g) to melt gelatinized starch gels. The results of this investigation indicated that blending waxy wheat flour with normal flour is a promising way to improve product quality in baked foods and to prolong the shelf-life of these products.

Morphological features and physicochemical properties of waxy wheat starch.

Morphological features, granule composition, and physicochemical properties of waxy wheat starch were compared with those of normal wheat starch. The morphologies and granule populations were found to be similar for the two starches. However, waxy wheat starch contained a smaller proportion of B-type granules, had a larger average granule diameter, and a higher degree of crystallinity than normal wheat starch, as measured by particle size analysis and differential scanning calorimetry. These differences resulted in a higher gelatinization temperature, transition enthalpy, peak viscosity, breakdown, swelling power, lower peak viscosity temperature and final viscosity in waxy wheat starch. These points suggest that waxy wheat starch should have greater resistance to retrogradation during cooling and higher water-holding capacity under dry conditions. Highlighting the differences in physicochemical properties of waxy and normal wheat starches should help point toward effective applications of waxy wheat starch in the food industry.