Insight into the dynamics of drinking water resistome in China.

Antibiotic resistance (AR) is a serious environmental hazard of the current age. Antibiotic resistance genes (ARGs) are the fundamental entities that spread AR in the environment. ARGs are likely to be transferred from the non-pathogenic to pathogenic microbes that might ultimately be responsible for the AR in humans and other organisms. Drinking water (DW) is the primary interaction route between ARGs and humans. Being the highest producer and consumer of antibiotics China poses a potential threat to developing superbugs and ARGs dissemination. Herein, we comprehensively seek to review the ARGs from dominant DW sources in China. Furthermore, the origin and influencing factors of the ARGs to the DW in China have been evaluated. Commonly used methods, both classical and modern, are being compiled. In addition, the risk posed and mitigation strategies of DW ARGs in China have been outlined. Overall, we believe this review would contribute to the assessment of ARGs in DW of China and their dissemination to humans and other animals and ultimately help the policymakers and scientists in the field to counteract this problem on an emergency basis.

Reduction of metronidazole in municipal wastewater and protection of activated sludge system using a novel immobilized Aspergillus tabacinus LZ-M.

Metronidazole (MNZ) accumulation inhibits municipal wastewater treatment bio-systems, and an effective solution to augment anaerobic activated sludge (AAS) is required. This research discovered that Aspergillus tabacinus LZ-M could degrade 77.39% of MNZ at 5 mg/L. MNZ was metabolized into urea, and the enzymes involved in its degradation were aminotransferase, methyltransferase, monooxygenase, and CN cleavage hydrolase. The strain was immobilized in polyurethane foam and used in AAS for the treatment of MNZ-containing municipal wastewater. The results showed that, using immobilized LZ-M, MNZ was completely removed, and the degradation efficiency of wastewater's chemical oxygen demand (COD) was increased from 11.7% to 83.31%. The extracellular polymer and ROS levels indicated that MNZ's toxicity on AAS was reduced. Furthermore, bioaugmentation stabilized its microbial community, and decreased MNZ resistance genes. These observations confirm that the immobilized fungi are effective in protecting AAS against antibiotic contamination in the treatment process of municipal wastewater.

The source, fate and prospect of antibiotic resistance genes in soil: A review.

Antibiotic resistance genes (ARGs), environmental pollutants of emerging concern, have posed a potential threat to the public health. Soil is one of the huge reservoirs and propagation hotspot of ARGs. To alleviate the potential risk of ARGs, it is necessary to figure out the source and fate of ARGs in the soil. This paper mainly reviewed recent studies on the association of ARGs with the microbiome and the transmission mechanism of ARGs in soil. The compositions and abundance of ARGs can be changed by modulating microbiome, soil physicochemical properties, such as pH and moisture. The relationships of ARGs with antibiotics, heavy metals, polycyclic aromatic hydrocarbons and pesticides were discussed in this review. Among the various factors mentioned above, microbial community structure, mobile genetic elements, pH and heavy metals have a relatively more important impact on ARGs profiles. Moreover, human health could be impacted by soil ARGs through plants and animals. Understanding the dynamic changes of ARGs with influencing factors promotes us to develop strategies for mitigating the occurrence and dissemination of ARGs to reduce health risks.

Exploring blood microbial communities and their influence on human cardiovascular disease.

BACKGROUND: Cardiovascular disease (CVD) is the single biggest contributor to global mortality. CVD encompasses multiple disorders, including atherosclerosis, hypertension, platelet hyperactivity, stroke, hyperlipidemia, and heart failure. In addition to traditional risk factors, the circulating microbiome or the blood microbiome has been analyzed recently in chronic inflammatory diseases, including CVD in humans. METHODS: For this review, all relevant original research studies were assessed by searching in electronic databases, including PubMed, Google Scholar, and Web of Science, by using relevant keywords. RESULTS: This review demonstrated that elevated markers of systemic bacterial exposure are associated with noncommunicable diseases, including CVD. Studies have shown that the bacterial DNA sequence found in healthy blood belongs mainly to the Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria phyla. In cardiac events, such as stroke, coronary heart disease, and myocardial infarction, the increased proportion of Proteobacteria and Actinobacteria phyla was found. Lipopolysaccharides are a major component of Proteobacteria, which play a key role in the onset of CVD. Moreover, recently, a study reported the lower cholesterol-degrading bacteria, including Caulobacterales order and Caulobacteraceae family were both considerably reduced in myocardial infarction. CONCLUSION: Proteobacteria and Actinobacteria were shown to be independent markers of the risk of CVD. This finding is evidence for the new concept of the role played by blood microbiota dysbiosis in CVD. However, the association between blood microbiota and CVD is still inconsistent. Thus, more deep investigations are required in future to fully understand the role of the bacteria community in causing and preventing CVD.

Nationality and body location alter human skin microbiome.

Skin microbiomes function directly in human health and are affected by various external and internal factors. However, few studies have showed the variation of human skin microbiota at multiple body sites in individuals of different national origin living in the same environment. Here, using 16S rRNA sequencing, we investigated the diversity and function of skin microbiomes in different body locations of Chinese and Pakistani individuals from a single college in China. Body location and nationality significantly affected community structures, while season and gender only impacted community member. Due to different lifestyles and likely genetic characteristics of the hosts, Proteobacteria was more abundant in Pakistanis than in Chinese individuals. There were significant differences in the Shannon diversity of skin microorganisms among different skin sites of Chinese individuals, but not in Pakistanis. PICRUSt prediction indicated that gene functions involved in carbohydrate metabolism, lipid metabolism, and xenobiotics biodegradation and metabolism were higher in bacteria collected from Pakistanis than those from Chinese individuals, but the amino acid metabolism of skin microorganisms in Chinese people was higher. The relative abundances of potential pathogenic bacteria also differed in different body locations, providing a foundation for studying skin-associated bacterial diseases. Through a meta-analysis of 233 human skin samples from eight elevational sites in western China, we found that skin microbial diversity first decreased and then increased with increasing altitude. Network analysis showed positive correlation between altitude and Lactobacillus, Chryseobacterium, or Acinetobacter. Our results uncover the variation of human skin microbiota allowing future explorations of potential significance for human health. KEY POINTS: • Body location and nationality affect skin microbiota diversity and function. • Proteobacteria was more abundant in Pakistanis than in Chinese. • Skin microbial diversity first decreased and then increased with elevated altitude.

Differences in Gut Microbiome Composition and Antibiotic Resistance Gene Distribution between Chinese and Pakistani University Students from a Common Peer Group.

Gut microbiomes play important functional roles in human health and are also affected by many factors. However, few studies concentrate on gut microbiomes under exercise intervention. Additionally, antibiotic resistance genes (ARGs) carried by gut microbiomes may constantly pose a threat to human health. Here, ARGs and microbiomes of Chinese and Pakistanis participants were investigated using 16S rRNA gene sequencing and high-throughput quantitative PCR techniques. The exercise had no impact on gut microbiomes in the 12 individuals investigated during the observation period, while the different distribution of gut microbiomes was found in distinct nationalities. Overall, the dominant microbial phyla in the participants' gut were Bacteroidota, Firmicutes and Proteobacteria. Some genera such as Prevotella and Dialister were more abundant in Pakistani participants and some other genera such as Bacteroides and Faecalibacterium were more abundant in Chinese participants. The microbial diversity in Chinese was higher than that in Pakistanis. Furthermore, microbial community structures were also different between Chinese and Pakistanis. For ARGs, the distribution of all detected ARGs is not distinct at each time point. Among these ARGs, floR was distributed differently in Chinese and Pakistani participants, and some ARGs such as tetQ and sul2 are positively correlated with several dominant microbiomes, particularly Bacteroidota and Firmicutes bacteria that did not fluctuate over time.

Exploring microbial communities, assessment methodologies and applications of animal's carcass decomposition: a review.

Animals are an essential part of the ecosystem, and their carcasses are the nutrient patches or hotspots where nutrients accumulate for a long time. After death, the physical and chemical properties undergo alterations inside the carcass. The animal carcass is decomposed by many decomposers such as bacteria, fungi, microeukaryotes and insects. The role of microbial symbionts in living organisms is well explored and studied, but there is a scarcity of knowledge and research related to their role in decomposing animal carcasses. Microbes play an important role in carcass decomposition. The origins of microbial communities associated with a carcass, including the internal and external microbiome, are discussed in this review. The succession and methods used for the detection and exploration of decomposition-associated microbial communities have been briefly described. Also, the applications of carcass-associated microbial taxa have been outlined. This review is intended to understand the dynamics of microbial communities associated with the carcass and pave the way to estimate postmortem interval and its role in recycling nutrients.

Ramadan Fasting Leads to Shifts in Human Gut Microbiota Structured by Dietary Composition.

The structure and diversity of human gut microbiota are directly related to diet, though less is known about the influences of ethnicity and diet-related behaviors, such as fasting (intermittent caloric restriction). In this study, we investigated whether fasting for Ramadan altered the microbiota in Chinese and Pakistani individuals. Using high-throughput 16S rRNA gene sequencing and self-reported dietary intake surveys, we determined that both the microbiota and dietary composition were significantly different with little overlap between ethnic groups. Principal Coordinate Analyses (PCoA) comparison of samples collected from both groups before and after fasting showed partial separation of microbiota related to fasting in the Pakistani group, but not in the Chinese group. Measurement of alpha diversity showed that Ramadan fasting significantly altered the coverage and ACE indices among Chinese subjects, but otherwise incurred no changes among either group. Specifically, Prevotella and Faecalibacterium drove predominance of Bacteroidetes and Firmicutes in the Pakistani group, while Bacteroides (phylum Bacteroidetes) were the most prevalent among Chinese participants both before and after fasting. We observed significant enrichment of some specific taxa and depletion of others in individuals of both populations, suggesting that fasting could affect beta diversity. Notably, Dorea, Klebsiella, and Faecalibacterium were more abundant in the Chinese group after fasting, while Sutterella, Parabacteroides, and Alistipes were significantly enriched after fasting in the Pakistani group. Evaluation of the combined groups showed that genera Coprococcus, Clostridium_XlV, and Lachnospiracea were all significantly decreased after fasting. Analysis of food intake and macronutrient energy sources showed that fat-derived energy was positively associated with Oscillibacter and Prevotella, but negatively associated with Bacteroides. In addition, the consumption of sweets was significantly positively correlated with the prevalence of Akkermansia. Our study indicated that diet was the most significant influence on microbiota, and correlated with ethnic groups, while fasting led to enrichment of specific bacterial taxa in some individuals. Given the dearth of understanding about the impacts of fasting on microbiota, our results provide valuable inroads for future study aimed at novel, personalized, behavior-based treatments targeting specific gut microbes for prevention or treatment of digestive disorders.

Temporal succession of water microbiomes and resistomes during carcass decomposition in a fish model.

Carcass decomposition in water may cause serious environmental pollution, which poses a great threat to water quality and public health. However, water microbial community succession and antibiotic resistance genes (ARGs) during carcass decomposition process are less explored. Using high-throughput sequencing and high-throughput quantitative PCR techniques, the temporal succession of water bacterial communities and ARGs profiles in experimental groups (fish carcasses) and control groups (no carcasses) containing two different types of water (the Yellow River water and tap water) in different successional stages were studied. Our results showed that NH3-N concentration in the corpse groups has greatly risen and exceeded more than 28 times on average over the safety thresholds of water quality. Some potential pathogenic genera Comamonas, Bacteroides and Pseudomonas significantly increased during carcass decomposition process. The bacterial communities of the Yellow River water and tap water in the experimental groups exhibited similar succession patterns, and community dissimilarities between the two groups decreased and smaller over time, indicating that bacterial community convergence. NH3-N, NO3-N and time were three most important factors in determining bacteria community structures. The influence of water type on corpse bacterial community structures was significant but weak. The gene copy number of seven detected ARGs (cmlA1-01, floR, sul1, sul2, tetG-01, tetM-01 and tetQ) in the experimental groups was more abundant than that in the control groups. The ARGs concentrations in the corpse groups were even enriched 19-fold (minimum) to 148-fold (maximum) compared to the gene tetQ of the Yellow River water in the control groups on the initial stage. Redundancy analysis (RDA) indicated that Bacteroidetes and Firmicutes were significantly correlated with all detected ARGs. This study emphasizes that cadaver degradation leads to the deterioration of nitrogen pollution, the abundance increase of potential pathogens, and the transfer of ARGs from dead animals to water environment, thereby uncovering the harmful effects of related water pollution for human health.