First insight into the environmental fate of N-acetylated sulfonamides from wastewater disinfection to solar-irradiated receiving waters.

The worldwide detection of emerging transformation products of organic micropollutants has raised accumulating concerns owing to their unknown environmental fate and undesired toxicity. This work first explored the reaction kinetics and mechanisms of the prevalent N-acetylated sulfonamides (N4-AcSAs, the typical sulfonamide metabolites) from wastewater disinfection to solar-irradiated receiving waters. The transformation scenarios included chlorination/bromination, photodegradation, and solar/chlorine treatment. The halogenations of two N4-AcSAs (N4-acetylated sulfadiazine, N4-AcSDZ; N4-acetylated sulfamethoxazole, N4-AcSMX) were pH-dependent at pH 5.0-8.0, and the reactions between the neutral forms of oxidants and anionic N4-AcSAs dominated the process. Furthermore, solar-based photolysis significantly eliminated N4-AcSAs in small water bodies with low dissolved organic carbon levels, while the indirect photolysis mediated by hydroxyl radicals and carbonate radicals contributed the most. The presence of chlorine residues in solar-irradiated wastewater effluents promoted the decay of N4-AcSAs, in which the generated hydroxyl radicals and ozone played a major role. Product analysis suggested the main transformation patterns of N4-AcSAs during the above scenarios included electrophilic attack, bond cleavage, SO2 extrusion, hydroxylation, and rearrangement. Multiple secondary products maintained higher persistence, mobility, and toxicity to aquatic organisms than N4-AcSAs. Overall, the natural and engineered transformations of such micropollutants underlined the necessity of including their degradation products in future chemical management and risk assessment.

Associations between gut microbiota and osteoporosis or osteopenia in a cohort of Chinese Han youth.

Osteoporosis (OP) is a common metabolic bone disease characterized by low bone mass and microstructural deterioration of bone. Changes in the composition and structure of gut microbiota (GM) are related to changes of bone mass and bone microstructure. However, the relationship between GM and bone mineral density (BMD) is complex, and data are especially scarce for Chinese Han youth. Therefore, 62 Chinese Han youth participants were recruited. Furthermore, according to the T-score evaluation criteria of the World Health Organization (WHO), we divided the BMD levels of participants into three groups: osteoporosis\BDL, osteopenia\BDM, normal bone density\BDH, and the associations between GM community and BMD groups were conducted. According to alpha and beta diversity analysis, significant differences were found in the microbial richness and composition between groups. The dominant phyla of GM in a cohort of Chinese Han youth were Bacteroidota (50.6%) and Firmicutes (41.6%). Anaerobic microorganisms, such as g_Faecalibacterium and g_Megamonas, account for the largest proportion in the gut, which were mainly Firmicutes phylum. The dominant genera and species in the three BMD groups were g_Prevotella, g_Bacteroides, g_Faecalibacterium, g_Megamonas, s_Prevotella copri, s_unclassified_g_Faecalibacterium, s_unclassified_g_Prevotella, s_unclassified_g_Bacteroides and s_Bacteroides plebeius. g_Faecalibacterium, g_Bacteroides and g_Ruminococcus differed between the BDH and BDL groups as well as between the BDH and BDM groups. LEfSe showed three genus communities and eight species communities were enriched in the three BMD groups, respectively. The associations between microbial relative abundance and T-score was not statistically significant by Spearman and regression analysis. In conclusion, the alpha diversity indexes in the BDH group were higher than in the BDL group, and several taxa were identified that may be the targets for diagnosis and therapy of OP.

The novel probiotic preparation based on Lactobacillus spp. mixture on the intestinal bacterial community structure of Cherry Valley duck.

The development and utilization of probiotics have many environmental benefits when they are used to replace antibiotics in animal production. In this study, intestinal lactic acid bacteria were isolated from the intestines of Cherry Valley ducks. Probiotic lactic acid bacterial strains were screened for antibacterial activity and tolerance to produce a Lactobacillus spp. mixture. The effects of the compound on the growth performance and intestinal flora of Cherry Valley ducks were studied. Based on the results of the antibacterial activity and tolerance tests, the highly active strains Lactobacillus casei 1.2435, L. salivarius L621, and L. salivarius L4 from the intestines of Cherry Valley ducks were selected. The optimum ratio of L. casei 1.2435, L. salivarius L621, and L. salivarius L4 was 1:1:2, the amount of inoculum used was 1%, and the fermentation time was 14 h. In vivo experiments showed that compared with the control group, the relative abundances of intestinal Lactobacillus and Blautia were significantly increased in the experimental group fed the lactobacilli compound (P < 0.05); the relative abundances of Parabacteroides, [Ruminococcus]_torques_group, and Enterococcus were significantly reduced (P < 0.05), and the growth and development of the dominant intestinal flora were promoted in the Cherry Valley ducks. This study will provide more opportunities for Cherry Valley ducks to choose microecological agents for green and healthy breeding.

Association of ADRB2 gene polymorphisms and intestinal microbiota in Chinese Han adolescents.

Gut microbiota are closely related to health, and the ß2-adrenergic receptor (ADRB2) gene is associated with gastrointestinal diseases. However, little is known about the relationship between ADRB2 gene polymorphisms and intestinal microbiota. In the present study, we aimed to explore the relationship between ADRB2 gene polymorphisms and gut microbiota in Chinese Han adolescents. Data analysis showed that the relative abundance, PICRUSt function prediction, and Chao1 and ACE indices of gut microbiota were significantly different between males and females (P < 0.05). The rs1042711 was positively associated with the relative abundance of Actinobacteria, Coriobacteriia, Bifidobacteriales, Erysipelotrichi, and Erysipelotrichales. The rs12654778 was negatively associated with Bacilli, Lactobacillales, Bacteroidaceae, and Bacteroides. rs1042713 was positively associated with Lactobacillales and Bifidobacteriales. The rs1042717 was positively associated with Bifidobacteriales and negatively associated with Veillonellaceae. The rs1042719 was negatively associated with Erysipelotrichi and Erysipelotrichales and positively associated with Erysipelotrichi, Erysipelotrichales, Bifidobacteriales, and Ruminococcaceae in females. The rs1801704 was positively associated with Erysipelotrichi, Erysipelotrichales, Bifidobacteriales, Actinobacteria, Coriobacteriia, and Bifidobacteriales. The rs2053044 was positively associated with Ruminococcaceae, Dialister, Firmicutes, Clostridia, Clostridiales, Bifidobacteriales, and Faecalibacterium and negatively associated with Bacilli, Lactobacillales, Lachnospiraceae, and Porphyromonadaceae (P < 0.05). These results suggested that the relative abundance, diversity, and PICRUSt function predictions of male and female gut microbiomes differ significantly and that ADRB2 gene polymorphisms were associated with gut microbiome abundance in Chinese Han adolescents.

Intestinal Microbiota of Anser fabalis Wintering in Two Lakes in the Middle and Lower Yangtze River Floodplain.

The intestinal microbiota of migratory birds participate in the life activities of the host and are affected by external environmental factors. The difference in habitat environment provides diversity in external environmental selection pressure for the same overwintering waterfowl, which may be reflected in their intestinal microbiota. Caizi lake and Shengjin Lake in the Middle and Lower Yangtze River Floodplain are the main habitats for migratory waterfowl in winter, especially the Anser fabalis (A. fabalis). It is important to explore the changes in intestinal microbiota composition and function of A. fabalis in the early overwintering period to clarify the effect of habitat size and protection status on intestinal microbiota. In this study, the composition and structural characteristics of the intestinal microbiota of A. fabalis in Shengjin Lake (SL) and Caizi Lake (CL) were preliminarily explored in order to obtain data for the migratory birds. In both SL and CL groups, 16S rRNA amplicon sequencing analysis showed that Firmicutes was the dominant bacterial phylum, but the relative abundance showed significant differences. Lactobacillus was the most abundant genus in both SL and CL groups. At the species level, the abundance of L. aviaries was the highest, with a relative abundance in both SL and CL groups of more than 34%. When comparing the average relative abundance of the 15 most abundant genera, it was found that Subdoligranulum, Exiguobacterium, and Terrisporobacter had higher abundances in the intestinal microbiota of CL A. fabalis, while Streptococcus and Rothia had higher abundances in the intestinal microbiota of SL A. fabalis. There was only a positive correlation between Bacteroidota and Proteobacteria in the intestinal microbiota flora of SL A. fabalis, and the species were closely related. At the same time, there were positive and negative correlations between Firmicutes and Actinomycetes. However, CL is mainly associated with a positive correlation between Firmicutes and Actinomycetes, and there are also a small number of connections between Firmicutes. PICRUSt1 prediction analysis revealed that the Clusters of Orthologous Groups (COG) functions of SL and CL involve energy production and transformation, amino acid transport and metabolism, carbohydrate transport and metabolism, and transcription. Understanding the changes in intestinal microbiota in Aves during the overwintering period is of great importance to explore the adaptation mechanism of migratory Aves to the overwintering environment. This work provides basic data for an A. fabalis intestinal microbiota study.

Lactobacillus fermentum 1.2133 display probiotic potential in vitro and protect against Salmonella pullorum in chicken of infection.

The efficacy of Lactobacillus as an antibiotic substitute has been investigated as one of the potential strategies to prevent Salmonella infection in poultry. The purpose of this study was to explore the antibacterial activity of Lactobacillus fermentum 1.2133 (Lact. fermentum 1.2133) against Salmonella pullorum CVCC533 (Salm. pullorum CVCC533) and its effect on chickens infected with Salm. pullorum CVCC533. Results showed that Lact. fermentans 1.2133 has antibacterial activity against Salm. pullorum CVCC533 and the cell-free fermentation supernatant of Lact. fermentum 1.2133 had a bactericidal effect on the bacteria in the Salm. pullorum CVCC533 biofilm by significantly reducing the number of Salmonella and aerobic bacteria in the chicken duodenum, ileum, and cecum, including Escherichia shigella (P < 0.05), improved the species abundance of Lactobacilli (P < 0.05). The damage to the chicken intestine by Salm. pullorum CVCC533 was reduced as the expression of avian beta-defensin 2 (AvBD2) mRNA in chicken small intestine was increased (P < 0.05). The results showed that Lact. fermentum 1.2133 had the potential to be a probiotic for poultry due to its regulation of intestinal AvBD2 mRNA as well as its intestinal flora.

Effect of Lactobacillus reuteri S5 Intervention on Intestinal Microbiota Composition of Chickens Challenged with Salmonella enteritidis.

To understand the mechanism of lactic acid bacteria against Salmonella enteritidis infection; we examined how lactic acid bacteria regulated the intestinal microbiota to resist infection by pathogenic bacteria. The probiotic strain Lactobacillus reuteri S5 was used to construct an animal model of S. enteritidis infected broilers. A high-throughput sequencing technology was used to analyze the regulatory effects of L. reuteri S5 on the structure of the intestinal microbiota of broilers infected with S. enteritidis; and to examine the possible defense mechanism they used. Our results showed that the administration of L. reuteri S5 reduced colonization of S. enteritidis (p < 0.05), decreased intestinal permeability (p < 0.05), and reduced the bacterial displacement likely due by S. enteritidis colonization (p < 0.05), suggesting some enhancement of the intestinal barrier function. Furthermore, L. reuteri S5 increased the number of operational taxonomic units (OTUs) in the chicken cecal microflora and the relative abundance of Lactobacillaceae and decreased the relative abundance of Enterobacteriaceae. These results suggest that the lactic acid bacterium L. reuteri S5 protected the intestinal microbiota of chickens against S. enteritidis infection.

Antagonistic activity and mechanism of Lactobacillus rhamnosus SQ511 against Salmonella enteritidis.

Salmonella enteritidis is an important food-borne pathogen. The use of antibiotics is a serious threat to animal and human health, owing to the existence of resistant strains and drug residues. Lactic acid bacteria, as a new alternative to antibiotics, has attracted much attention. In this study, we investigated the antibacterial potential and underlying mechanism of Lactobacillus rhamnosus SQ511 against S. enteritidis ATCC13076. The results revealed that L. rhamnosus SQ511 significantly inhibited S. enteritidis ATCC13076 growth or even caused death. Laser confocal microscopic imaging revealed that the cell-free supernatant (CFS) of L. rhamnosus SQ511 elevated the reactive oxygen species level and bacterial membrane depolarization in S. enteritidis ATCC13076, leading to cell death. Furthermore, L. rhamnosus SQ511 CFS had severely deleterious effects on S. enteritidis ATCC13076, causing membrane destruction and the release of cellular materials. In addition, L. rhamnosus SQ511 CFS significantly reduced the expression of virulence, motility, adhesion, and invasion genes in S. enteritidis ATCC13076 (P < 0.05), and considerably inhibited motility and biofilm formation capacity (P < 0.05). Thus, antimicrobial compounds produced by L. rhamnosus SQ511 strongly inhibited S. enteritidis growth, mobility, biofilm formation, membrane disruption, and reactive oxygen species generation, and regulated virulence-related gene expressions, presenting promising applications as a probiotic agent.

Biological characteristics and whole-genome analysis of the potential probiotic, Lactobacillus reuteri S5.

Lactic acid bacteria are micro-organisms used for probiotic purposes and form major parts of human and mammalian intestinal microbiota, exerting important health-promoting effects on the host. Here, we evaluated Lactobacillus reuteri strain S5 isolated from the intestines of healthy white feather broilers. Lactobacillus reuteri S5 grew best after 20 h of incubation in MRS medium. Lactic acid production was 1·42 mmol l-1 at 24 h, which was well tolerated. Activities of T-AOC, GSH-Px and T-SOD in the cell-free fermentation supernatant of L. reuteri S5 were higher than those in the bacteria, and the strain showed good hydrophobicity in vitro. The dominant carbon and nitrogen sources of L. reuteri S5 were glucose and soybean meal. A high-quality complete genome map of L. reuteri S5 was obtained using a Pacbio nanopore third-generation sequencing platform. The results showed that L. reuteri S5 possesses a complete primary metabolic pathway, encoding the main functional enzymes of the glycolysis pathway and pentose phosphate pathway. The genome contains genes encoding antioxidants and conferring tolerance to inorganic salt ions, acids and bile salts. This study shows that L. reuteri S5 is a probiotic strain with excellent probiotic characteristics and has great potential for the development of feed additives to promote animal health.

The ion-imprinted oyster shell material for targeted removal of Cd(II) from aqueous solution.

In order to realize the sustainable utilization of waste oyster shell and develop a targeted removal technology for cadmium. A novel ion-imprinted oyster shell material (IIOS) was prepared by surface imprinting technique. The prepared samples were characterized by scanning electron microscope, Fourier infrared spectrometer, X-ray diffractometer, thermogravimetric analysis and N2 adsorption-desorption. The adsorption performances of IIOS for Cd(II) from aqueous solution were studied by the single factor sequential batch, kinetics, isotherms, selectivity and recycling experiments. The characterization researches showed that IIOS was successfully prepared. The adsorption experiments indicated that the adsorption process reached equilibrium within 240 min; the maximum adsorption capacity was up to 69.1 mg g-1 with the initial Cd(II) concentration of 75 mg L-1 at pH 5; the adsorption process fitted well to the pseudo-second-order model and the Langmuir isotherm model, which revealed the chemisorption characteristic of Cd(II). Moreover, IIOS exhibited a good targeted adsorption of Cd(II) in several binary competition systems owing to the present of these imprinted cavities. The recycling experiment showed that the targeted removal ratio of IIOS for Cd(II) remained above 80% after used six times. The results of this study indicated that it is a promising prospect for waste oyster shell used as IIOS to dispose heavy metals in wastewater.

Acid-sensitive and L61-crosslinked hyaluronic acid nanogels for overcoming tumor drug-resistance.

Low intracellular drugs concentration is one of the main representations of multidrug resistance (MDR), which often results in a weak or failed chemotherapy on cancer treatment. Herein, an acid-sensitive and pluronic L61-linked hyaluronic acid nanogels (HA-L61OE/NGs) were developed for solving this problem. The nanogels could well hold more drugs under neutral condition, while triggering efficiently drugs release (61.42% within 24 h) in acidic environment. In vitro cells experiments demonstrated that the nanogels greatly increased intracellular drugs concentration by CD44-mediated endocytosis and L61-mediated anti-MDR effect, resulting in the enhanced cell-killing in MDR cells. In vivo studies verified HA-L61OE/NGs could avoid drugs leakage in blood and reduce systemic toxicity. Subsequently, the specific accumulation and penetration of nanogels at tumor regions lead to the highest tumor growth inhibition (TGI, 77.42%). Overall, HA-L61OE/NGs were effective on MDR tumor therapy and expected to be further used in clinical trials.

Effects of probiotics on cecal microbiome profile altered by duck Escherichia coli 17 infection in Cherry Valley ducks.

Avian colibacillosis is one of the most serious infectious bacterial diseases that endanger the modern poultry industry. Lactobacillus is believed to inhibit intestinal pathogens and maintain a healthy gut microbiota. This study aimed to investigate Lactobacillus supplementation in Cherry Valley ducks to prevent the intestinal flora dysbiosis caused by Duck Escherichia coli 17. One hundred and twenty healthy one day old Cherry Valley ducks were randomized to three study groups (Group I = the control group; Group II = duck Escherichia coli 17 challenge group and Group III = DE17 challenge group supplemented with lactic acid bacteria composite preparation). Cherry Valley ducks in Group II and Group III were gavage challenged with DE17 (1 × 105 CFU/mL) on day 14. Pyrosequencing of the V3/V4 variable regions of the genes encoding for 16S rRNA was used for sequence analysis. The results showed that the normal intestinal microecology was affected by DE17, including a relative increase in proteobacteria. At the same time, the Lactobacillales were increased and harmful bacteria were decreased in different intestinal segments of ducks in Group III, compared to those in Group II. Network analysis showed that dietary lactic acid bacteria addition improved the interaction pattern within the cecal microbiota of ducks and the result showed that in Ruminococcus_2 was independently present in the group III and Lachnospiraceae_NK4A136_group species correlation existed between group I and group III. This study proved that oral supplementation with Lactobacillus casei 1.2435, Lactobacillus rhamnosus 621 and Lactobacillus rhamnosus A4 can mitigate DE17 induced intestinal flora dysbiosis.

Analysis of high-throughput sequencing for cecal microbiota diversity and function in hens under different rearing systems.

Rearing systems play an important role in animal welfare, health and the composition of the gut microbiome. Therefore, the purpose of this study was to investigate the effects of different rearing systems on the composition and function of cecal microbiota in chickens. The 120-day-old Lohmann hens of cage rearing systems (CRS) and free-range systems (FRS) were studied. The cecal bacterial populations of hens were surveyed by high-throughput sequencing (HTS) of the bacterial 16S rRNA hypervariable region V3-V4 combined with metagenomic sequencing analysis. The 16S rRNA sequencing analysis showed that the cecal microbiota differed between the FRS and CRS. The three most abundant bacteria phyla in the two systems were the Bacteroidetes (> 48%), Firmicutes (> 37%), and Proteobacteria (> 6%), the Deferribacteres (> 2.4%) were found in FRS and almost absent in CRS (< 0.01%). The three most abundant genera were the Bacteroides, Rikenellaceae_RC9, and Faecalibacterium, and we found relative abundance of the Parabacteroides (P < 0.05), Prevotellaceae_Ga6A1 (P < 0.01), unclassified Proteobacteria (P < 0.05), and unclassified Spirochaetaceae (P < 0.01) was greater in FRS, whereas abundance of Faecalibacterium, Ruminococcaceae, and Helicobacter was greater in CRS (P < 0.05). Functional gene classification of metagenomic sequencing suggested that energy production and conversion, carbohydrate transport and metabolism, as well as amino acid transport and metabolism were significantly more abundant in FRS, and we identified a range of antibiotic resistance categories in gut microbes of hens reared under both systems. We confirmed differences in microbe gut composition and function in hens reared using two contrasting systems, and ARGs were also identified in the microbiota of these hens. This work has produced new data for laying hens in different production systems and increased the understanding of intestinal microorganisms in laying hens.

Antagonistic trait of Lactobacillus reuteri S5 against Salmonella enteritidis and assessment of its potential probiotic characteristics.

Salmonella enteritidis is an important foodborne pathogen that has caused multiple outbreaks of infection associated with poultry and egg consumption. Thus, the prevention and inhibition of Salmonella enteritidis infection are of great concern. Lactic acid bacteria have anti-pathogenic activity; however, their underlying mechanisms and modes of action have not yet been clarified. In this study, the antibacterial mechanism of Lactobacillus reuteri S5 (L. reuteri S5) against Salmonella enteritidis ATCC13076 (S. enteritidis ATCC13076) was studied by different methods. We found that L. reuteri S5 was able to form a stable biofilm formation, colonizing the entire intestinal tract of chickens. In addition, bacterial cultures and the cell-free supernatant (CFS) of L. reuteri S5 inhibited SE ATCC13076 growth, and this growth inhibition was also observed in the co-culture assay. This effect may be predominantly caused by antimicrobial metabolites produced by L. reuteri S5. Furthermore, treatment with the CFS of L. reuteri S5 resulted in a significant reduction in the expression of Salmonella virulence, motility and adhesion genes and a significant reduction in the motility ability and inhibitory effect on biofilm formation. In addition, the damage to the membrane structure and intracellular structure induced by the CFS of L. reuteri S5 could be observed on Transmission electron microscopy images and dodecyl sulfate, sodium salt (SDS)-Polyacrylamide gel electrophoresis confirmed the disruptive action of the CFS of L. reuteri S5 on the cytoplasmic membrane. Our findings demonstrate that L. reuteri S5, an intestinal Lactobacillus species associated with chicken health, is able to form biofilm and stably colonize chicken intestines. It also possesses anti-SE activity, preventing SE growth, inhibits the expression of SE genes involved in adhesion and invasion, virulence and cell membrane integrity, inhibits SE biofilm formation and motility, damages or destroys bacterial structures, and inhibits intracellular protein synthesis. L. reuteri S5 therefore has potential applications as a probiotic agent.

Comparative metagenomic sequencing analysis of cecum microbiotal diversity and function in broilers and layers.

The composition of the gastrointestinal microorganisms in poultry is closely associated with the host and its environment. In this study, using 16S rRNA and metagenomic techniques, we comprehensively analyzed the structure and diversity of the cecal microbiota of broiler chickens (BC) and laying hens (LH). The 16S rRNA sequencing analysis showed Firmicutes, Bacteroidetes, and Proteobacteria were the main cecal bacterial phyla in BC and LH. However, at the genus level, LH had a greater abundance of Bacteroides (P < 0.05), Rikenellaceae_RC9_gut_group (P < 0.01), Phascolarctobacterium (P < 0.05), Desulfovibrio (P < 0.05), Prevotellaceae_UCG-001 (P < 0.05), and unclassified_o_Bacteroidales (P < 0.05), whereas BC had a greater abundance of Alistipes (P < 0.05), Rikenella (P < 0.05), Ruminococcaceae_UCG-005 (P < 0.05), Lachnoclostridium (P < 0.05), and unclassified_f_Ruminococcaceae (P < 0.05). It is particularly noteworthy that the genus Desulfovibrio was significantly more abundant in the LH cecum than in the BC cecum (P < 0.05). A metagenomic analysis showed that the annotations in the LH dataset were significantly more abundant than in the BC dataset, and included replication, recombination and repair, energy production and transformation, cell wall/membrane/envelope biogenesis, and amino acid transport and metabolism-related functions (P < 0.05). This study indicates that microbial genotypic differences in chickens of the same species can cause changes in the abundances of the gut microbiota, but do not alter the structural composition or major functional characteristics of the gut microbiota.