Although particulate matter (PM) is strongly associated with allergic reactions, the potential risk of the ability of PM derived from poultry houses to induce allergic reactions remains unclear. This study investigated the effects of duck housing PM on allergic reactions in mice. PM samples and fungi were collected from a duck farm. Ovalbumin (OVA) was used as a positive control, with ambient-level concentrations of PM, high-concentration PM (HPM), and fungal experimental groups. Aerosol exposure was performed on the mice. Serum IgE, allergic mediators (histamines and leukotrienes), cytokines, and pulmonary histopathology were analyzed. Furthermore, HPM-induced metabolic profiles in bronchoalveolar lavage fluid were measured. The results revealed that all the treatment groups of mice presented allergic symptoms, including sneezing and coughing; higher concentrations of IgE, His, and LTs in the serum; upregulation of allergic reaction-related cytokines, such as IL4, IL5, and IL33; and microscopic lesions of the lungs characterized by inflammatory cell infiltration were observed in all the treatment groups, indicating that PM and fungi can cause allergic reactions. Notably, allergic reactions were more pronounced in the HPM and fungal groups than in the PM group. In addition, metabolomics analyses revealed that HPM exposure caused metabolic disorders in mouse lungs. The key pathway with the highest correlation to metabolite differences was pyrimidine metabolism, which is associated with allergic reactions. In conclusion, this study demonstrated that exposure to PM in duck houses can cause allergic reactions in mice and significant metabolomic changes in the lungs, especially HPM. Moreover, the contribution of fungal components in the PM cannot be ignored. These findings highlight the potential health risks associated with PM from the poultry industry.

The particulate matter (PM) generated during poultry farming is characterized by its complex composition and substantial emission levels. However, researches on the respiratory damage caused by poultry house PM and the underlying mechanisms remain limited. In this study, inhalable PM collected from duck houses was administered to experimental mice through inhalation exposure. After 10 days of short-term exposure and 30 days of long-term exposure, mice samples were collected for lung histopathological analysis and inflammatory cytokines detection. The results showed that inhalation of duck house PM induced pulmonary and systemic inflammatory responses in both groups of mice, with significant upregulation of IL-6 and CXCL2. Compared to short-term exposure, long-term exposure resulted in more severe microscopic lesions in the lungs. In addition, the concentrations of malondialdehyde (MDA) and glutathione (GSH) increased in mice, indicating that duck house PM could trigger oxidative stress in lungs, we also found duck house PM induced ferroptosis in mice. Furthermore, it was confirmed that duck house PM caused cell damage and increased intracellular iron levels in MLE-12 cells, and PM reduced GSH in a dose-dependent manner. Notably, ferroptosis inhibitor treatment effectively alleviated PM-induced cell damage. These findings indicated that duck house PM can induce ferroptosis in both mice and cells, and ferroptosis plays a critical role in duck house PM-induced lung damage. These results laid a solid foundation for further exploring the mechanism of PM-induced lung injury, and providing a new insight for targeting ferroptosis to treat such damage.

Fine particulate matter (PM2.5) in poultry houses is the main component of air pollution. Long-term exposure to high concentrations of PM2.5 could easily damage the respiratory system of animals. In this study, we first investigated the changes in lung tissue morphology and serum cytokines in SPF chickens after exposure to poultry house PM2.5 and further conduct a combined analysis of its lung transcriptome and metabolome. The results showed that chicken exposed to PM2.5 led to decrease in body weight and cause inflammatory damage such as pulmonary fibrosis in chickens. It also significantly upregulated the expression levels of serum cytokines IL-1β, IL-6, TLR-2, TLR-4, IFN-α, TGF-β and CCL2. Additionally, it affected Arachidonic acid metabolism, Ferroptosis, and mTOR signaling pathways, disrupting metabolic processes and the expression of genes related to pulmonary inflammation. In addition, we validated the results of the multi-omics combined analysis and found that the interaction between the differential metabolite Arachidonic acid and the three differentially expressed genes LTA4H, FTL and PLA2G4A led to pulmonary inflammatory damage and metabolic disorders. The above results indicate that the interaction between pulmonary inflammation-related genes and lung metabolites may play a crucial role in the process of PM2.5-induced lung injury in chickens.

Particulate matter (PM) and the microorganisms of duck houses may have negative impacts on animal and human health. During 2021-2022, PM2.5 and PM10 inside and outside the duck house were sampled with a built-in air sampler in Tai'an City, Shandong Province, and the diversity and abundance of microorganisms within the PM were analyzed by macrogenomic and absolute sequence analysis. The results showed that PM2.5 and PM10 concentrations in the house and at downwind points exceeded the short-term (24 h) guideline of the global air quality guidelines (AQG). Macrogenome sequencing showed that the microbial composition of the PM2.5 samples was dominated by bacteria (exceed 85%); a total of 1316 bacterial genera and 110 fungal genera were identified in PM2.5 samples from duck house 1 in winter, which were much higher than the results of amplicon sequencing method reported before, and relatively high levels of the pathogenic bacteria (Coccidioides immitis, etc.) and the conditionally pathogenic bacterium (Rothia nasimurium) were identified at the species level. Absolute quantitative sequencing detected conditionally pathogenic bacteria and allergens at high levels in PM10 samples: Corynebacterium (5.6x107 copies/g), Aerococcus (9.9x106 copies/g), Alternaria (3.3x106 copies/g), and Aspergillus (8.3x105 copies/g). Moreover, Corynebacterium was the highest content of PM10 in summer and PM2.5 samples in winter, and its pathogenicity and potential threat should be noted. The diversity and relative abundance of microorganisms were similar in the duck house and at the downwind point. The results showed that the microorganisms in the house environment have a greater influence on the air environment around the downwind point and may pose a public health risk to the staff and the surrounding area.

The threat of antimicrobial resistance (AMR) is on the rise globally, especially with the development of animal husbandry and the increased demand for antibiotics. Livestock and poultry farms, as key sites for prevalence of antibiotic-resistant bacteria (ARB), can spread antimicrobial resistance genes (ARGs) through microbial aerosols and affect public health. In this study, total suspended particulate matter (TSP) and airborne culturable microorganisms were collected from duck houses in Tai'an, Shandong Province, and the bacterial communities and airborne ARGs were analyzed using metagenomics and PCR methods. The results showed that the bacterial communities in the air of duck houses were mainly Actinobacteria, Firmicutes, Proteobactria, Chlamydia, and Bcateroidetes at the phylum level. At the genus level, the air was dominated by Corynebacterium, Jeotgalicoccus, Staphylococcus, Brevibacterium, and Megacoccus, and contained some pathogenic bacteria such as Staphylococcus aureus, Corynebacterium diphtheriae, Klebsiella oxytoca, Acinetobacter baumannii, and Pseudomonas aeruginosa, which were also potential hosts for ARGs. The airborne ARGs were mainly macrolides (10.97%), penicillins (10.73%), cephalosporins (8.91%), streptozotocin (8.91%), and aminoglycosides (8.02%). PCR detected 27 ARGs in airborne culturable microorganisms, and comparative analysis between PCR and the metagenomic data revealed that a total of 9 ARGs were found to the same, including macrolides ErmA, ErmF, tetracyclines tetG, tetX, methicarbamazepines dfrA12, dfrA15, aminoglycosides APH3-VI, ANT2-Ⅰ, and sulfonamides sul2. Moreover, inhalation exposure modeling showed that the workers in duck houses inhaled higher concentrations of ARB, human pathogenic bacteria (HPB) and human pathogenic antibiotic-resistant bacteria (HPARB) than hospital workers. These results provide new insights into airborne microorganisms and ARGs in animal farms and lay the foundation for further study.

The environmental conditions of chicken houses play an important role in the growth and development of these animals. The chicken house is an essential place for the formation of microbial aerosols. Microbial aerosol pollution and transmission can affect human and animal health. In this work, we continuously monitored fine particulate matter (PM2.5) in the chicken house environment for four weeks and studied the microbial community structure in the aerosols of the chicken house environment through metagenomic sequencing. Our results found that bacteria, fungi, viruses, and archaea were the main components of PM2.5 in the chicken house environment, accounting for 89.80%, 1.08%, 2.06%, and 0.49%, respectively. Conditional pathogens are a type of bacteria that poses significant harm to animals themselves and to farm workers. We screened ten common conditional pathogens and found that Staphylococcus had the highest relative abundance, while Clostridium contained the most microbial species, up to 456. Basidiomycetes and Ascomycota in fungi showed dramatic changes in relative abundance, and other indexes showed no significant difference. Virulence factors (VF) are also a class of molecules produced by pathogenic microbes that can cause host diseases. The top five virulence factors were found in four groups: FbpABC, HitABC, colibactin, acinetobactin, and capsule, many of which are used for the iron uptake system. In the PM2.5 samples, eight avian viruses were the most significant discoveries, namely Fowl aviadovirus E, Fowl aviadovirus D, Avian leukosis virus, Avian endogenous retrovirus EAV-HP, Avian dependent parvovirus 1, Fowl adenovus, Fowl aviadovirus B, and Avian sarcoma virus. The above results significantly improve our understanding of the microbial composition of PM2.5 in chicken houses, filling a gap on virus composition; they also indicate a potential threat to poultry and to human health. This work provides an important theoretical basis for animal house environmental monitoring and protection.

In recent years, a series of public health issues caused by the spread of antibiotic resistance have been widely concerned. The indoor air of livestock and poultry houses is considered to be one of the main sources of environmental contamination of ARGs. This study characterized the microorganisms and ARGs in the air particulate matter of chicken houses using metagenomics. The study successfully detected 761 different subtypes of resistance genes including aminoglycosides, tetracyclines, MLSB etc., 4 types of mobile genetic elements, and various pathogenic microorganisms from the aerosols in the chicken coop environment. The results showed that the abundance of ARGs in the air of the chicken coop was at a relatively high level, correlation network analysis showed that multiple types of ARGs could promote the emergence of antibiotic-resistant bacteria.

The composition of particulate matter (PM) in poultry farms differs significantly from that of atmospheric PM as there is a higher concentration of microbes on farms. To assess the health effects of PM from poultry farms on pregnant animals, we collected PM from duck houses using a particulate sampler, processed it via centrifugation and vacuum concentration, and subsequently exposed the mice to airborne PM at 0.48 mg/m3 (i.e., low concentration group) and 1.92 mg/m3 (i.e., high concentration group) on the fifth day of pregnancy. After exposure until the twentieth day of pregnancy or spontaneous delivery, mice were euthanized for sampling. The effects of PM from duck houses on the pregnancy toxicity of mice were analyzed using histopathological analysis, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction (qPCR). The results showed that exposure to PM had adverse effects on pregnant mice that reduced their feed intake in both groups. Microscopic lesions were observed in the lungs and placentas of pregnant mice, and the lesions worsened with increased PM concentrations, as shown by alveolar wall thickening, the infiltration of inflammatory cells in pulmonary interstitium, congestion, edema, and cellular degeneration of placenta. In pregnant mice in the high concentration group, exposure to PM significantly increased the expression of inflammatory cytokines in the lungs and placentas, caused oxidative stress, and decreased estrogen level in the blood. Exposure to PM also resulted in the reduced litter sizes of pregnant mice and shorter body and tail lengths in the fetuses delivered. Beyond that, exposure to PM significantly downregulated the levels of antioxidant factor superoxide dismutase and neurotrophic factor Ngf in the brains of fetuses. Collectively, exposure to a high concentration of PM by inhalation among pregnant mice caused significant pregnancy toxicity that led to abnormal fetal development due to inflammatory damage and oxidative stress. These findings established a foundation for future studies on the underlying mechanisms of pregnancy toxicity induced by exposure to PM.

Time series anomaly detection is a binary classification problem with unbalanced data, which aims to identify data that fall outside of the normal behaviors. Since the proportion of the abnormal data is very small, the cost of labeling all data is prohibitively high. Therefore, unsupervised methods are more suitable than supervised methods. With the rapid development of deep learning, various multivariate time series anomaly detection methods based on deep learning have been proposed. However, existing methods do not fully capture the spatial-temporal correlations and are not robust to noise. To address these issues, we propose an unsupervised anomaly detection method called Orthogonal Self-Attention Variational Autoencoder Generative Adversarial Networks (OSVAE-GAN). To fully extract the spatial-temporal correlations, we use an orthogonal self-attention (OS) mechanism. Moreover, to increase the capability to deal with complex multivariate data, we integrate two generative adversarial networks (GANs) with the variational autoencoder (VAE). Finally, to reduce the influence of noise, we introduce the maximum mean discrepancy (MMD) loss. Experiments are conducted on five public datasets, which show that the proposed method is superior to the existing methods.

The outbreak of COVID-19 reminds people that aerosols have an important impact on health. The concentration and composition of microbial aerosol in livestock and poultry houses are closely related to the environmental conditions of livestock and poultry houses, and also related to the healthy growth of livestock and poultry. In our study, 16S and ITS sequencing techniques were used to analyze the relation and difference of bacteria and fungi in the air samples of a chicken house. At the age of 7 to 42 d, the operation classification unit (OTU) numbers of bacteria and fungi identified in our results were 2,398 and 986, respectively, of which the shared OTU numbers were 410 and 141, respectively. At the phylum level, Firmicutes, Proteobacteria, and Actinomycetes were the 3 most abundant bacterial phyla, and Ascomycetes and Basidiomycetes were the top 2 phyla in fungi. At the genus level, 7 differential fungal genera were identified, including Debaryomyces, Trichosporon, Wallemia, Aspergillus, Nigrospora, Fusarium, and Vishniacozyma. Compared with other bacterial genera, Lactobacillus, Cetobacterium, and Romboutsia had the highest abundance (more than 5%). The result showed that the Alpha diversity and Beta diversity of fungi were significantly different in different growing periods. However, only Beta diversity showed significant differences among bacteria. In general, the bacterial and fungal diversity of microbial aerosols in the chicken house increased significantly at the age of 7 to 42 d. And the evenness and richness of airborne fungal communities also increased obviously. In a word, we must pay attention to the complex community composition in the chicken house, this is closely related to animal health and the health of surrounding residents. The cooperation and communication between bacteria and fungi in PM2.5 samples provides a new reference to analyze the influence of microbial aerosol.

In this study, we investigated the effects of probiotics on growth performance, immunity, intestinal flora, and antioxidant capacity of rabbits. Three hundred New Zealand white rabbits were randomly divided into four groups. Groups A, B, C, and D were the lactobacillus group, compound probiotic group, control group, and antibiotic group, respectively. The results showed compared with the control group, the average weight of groups A, B, and D increased by 14.88%, 12.33%, and 11.97%, respectively. Moreover, the index of immune organs and the IgG and IgM in serum of group B were significantly increased (P < 0.05). Meanwhile, the activities of superoxide dismutase (SOD) in group B and catalase (CAT) in group A were significantly increased (P < 0.05). At week 5, the contents of rabbit cecum were taken for metagenome sequencing, and the results showed probiotics increased the relative abundance of Akkermansia, and decreased the relative abundance of Bacteroides. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, we found probiotics could enrich metabolic pathways such as carbohydrates, amino acids, and lipids. According to the Comprehensive Antibiotic Resistance Database (CARD), we found antibiotic resistance ontology (ARO) in cecum mainly included β-lactamases, macrolide 2′-phosphotransferase II, and plasmid-mediated quinolone resistance protein. Among them, there were 1964, 2105, and 1982 types of ARO in group B, group D, and groups A and C, respectively. These results showed probiotics played a beneficial role in maintaining or enhancing the health and growth of rabbits and could replace antibiotics under certain feeding conditions.

Environmental aerosols in animal houses are closely related to the productive performance and health level of animals living in the houses. Preferable housing environments can improve animal welfare and production efficiency, so it is necessary to monitor and study these environments. In recent years, there have been many large-scale outbreaks of respiratory diseases related to biological aerosols, especially the novel coronavirus that has been sweeping the world. This has attracted much attention to the mode of aerosol transmission. With the rapid development of large-scale and intensive breeding, microbial aerosols have gradually become the main factor of environmental pollution in animal houses. They not only lead to a large-scale outbreak of infectious diseases, but they also have a certain impact on the health of animals and employees in the houses and increase the difficulty of prevention and control of animal-borne diseases. This paper reviews the distribution, harm, and control measures of microbial aerosols in animal house environments in order to improve people's understanding of them.

羊肠毒血症、羊快疫发病急死亡快,一般采用免疫接种疫苗的方式才可以有效防控.本研究将C型产气荚膜梭菌的外毒素、D型产气荚膜梭菌外毒素和重组腐败梭菌 α 毒素按一定比例混合,经甲醛灭活乳化后制成二价二联类毒素疫苗.参照《中华人民共和国兽用生物制品质量标准》分别对疫苗进行了安全性检验、无菌检验和免疫效力检验等.6～7月龄的绵羊接种本疫苗21 d后,通过间接ELISA和毒素中和试验检测绵羊血清中抗体效价.免疫效果显示,绵羊血清中抗C型产气荚膜梭菌毒素的抗体效价为1:3200,抗D型产气荚膜梭菌毒素的抗体效价为1:6400,抗腐败梭菌毒素的抗体效价为1:6400;而中和效价分别为1:400,1:800和1:800.说明本实验所制备的疫苗效价较高,且安全可靠,能够为绵羊提供可靠的抗感染保护.该二价二联复合类毒素疫苗是国内首创,使疫苗的抗原成分由菌体上升为毒素蛋白,具有鲜明的创新.

诺维氏梭菌是羊黑疫的致病菌,该菌可使1岁以上的绵羊发病,山羊也可以患此病.由诺维氏梭菌引起的羊黑疫发病急,死亡快,家畜往往还没有表现出明显症状就死亡,给畜牧业带来了巨大损失.本研究利用重组诺维氏梭菌 ɑ 毒素制备单克隆抗体,研究过程中成功制备了2株针对诺维氏梭菌 α 毒素重组蛋白的杂交瘤细胞,分别命名为1978CT716.15.65和1978CT142.38.7.对所得2株杂交瘤细胞分泌的抗体进行间接ELISA测抗体效价,最高可达到1:512000.对所获得的2株杂交瘤细胞进行Western Blot分析发现,2种单克隆抗体均能与重组蛋白发生特异性结合.鉴于单克隆抗体具有生物活性单一、纯度相对比较高且与抗原结合特异性强等优势,可以利用单克隆抗体达到快速检测疾病及治疗疾病的目的,为构建快速检测诺维氏梭菌的检测技术和检测方法奠定了基础.

[目的]研究H9N2亚型禽流感病毒(Avian influenza virus,AIV)对哺乳动物的传染性和致病性.[方法]采集样品进行病毒的分离鉴定,将分离到的病毒以300 μL/只(107 EID50)的剂量通过滴鼻和肺递送方式感染豚鼠,每组各15只,对2组感染效果进行比较,然后通过分离株在豚鼠中的传播能力试验验证其气溶胶传播能力,通过间接免疫荧光试验检测分离株在人支气管上皮细胞上的复制能力.[结果]试验分离到1株H9N2亚型AIV,命名为SD18,病毒通过肺递送和滴鼻2种攻毒方式感染豚鼠后,肺递送组的排毒量显著高于滴鼻组(P＜0.05).通过对豚鼠肺脏相关模式识别受体和抗病毒蛋白的表达检测发现,2种攻毒方式都能诱导相关的免疫因子Toll样受体3(TLR3)、TLR7、抗黏病毒蛋白(MX)和2',5'-腺苷酸激酶(OAS)表达量极显著上调(P＜0.01);2组在攻毒后第6天产生抗体,并呈上升趋势.对SD18株在豚鼠中的传播能力验证发现,SD18株具有通过直接接触和飞沫传播感染豚鼠的能力,但并未证实气溶胶的产生和传播.对SD18株感染人支气管上皮细胞BEAS-2B后发现,在感染后12 h可检测到病毒,24 h时病毒在细胞内复制能力最强,TLR3、TLR7、MX、OAS、白介素6(IL-6)、IL-8、干扰素-β(IFN-β)相关的免疫因子表达量极显著上调(P＜0.01).[结论]H9N2亚型AIV SD18株的跨种传播能力变强,具有不经提前适应便可直接感染豚鼠的能力;SD18株具有通过飞沫传播感染豚鼠并使其产生抗体的能力且SD18株可在人支气管上皮细胞BEAS-2B上进行复制.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused great harm to global public health, resulting in a large number of infections among the population. However, the epidemiology of coronavirus has not been fully understood, especially the mechanism of aerosol transmission. Many respiratory viruses can spread via contact and droplet transmission, but increasing epidemiological data have shown that viral aerosol is an essential transmission route of coronavirus and influenza virus due to its ability to spread rapidly and high infectiousness. Aerosols have the characteristics of small particle size, long-time suspension and long-distance transmission, and easy access to the deep respiratory tract, leading to a high infection risk and posing a great threat to public health. In this review, the characteristics of viral aerosol generation, transmission, and infection as well as the current advances in the aerosol transmission of zoonotic coronavirus and influenza virus are summarized. The aim of the review is to strengthen the understanding of viral aerosol transmission and provide a scientific basis for the prevention and control of these diseases.

Bacillus subtilis BYS2 is a strain with a broad inhibitory spectrum against pathogenic bacteria. In the current study, we report the complete genome sequence of Bacillus subtilis BYS2. The chromosome of BYS2 (4,030,791 bp; G+C content, 43.88%) contained 3,914 protein-encoding genes, with 86 tRNAs, 30 rRNAs, and 5 noncoding RNAs (ncRNAs).

Antibiotic-resistant bacteria (ARB) present a global public health problem. Microorganisms are the main cause of hospital-acquired infections, and the biological contamination of hospital environments can cause the outbreak of a series of infectious diseases. Therefore, it is very important to understand the spread of antibiotic-resistant bacteria in hospital environments. This study examines the concentrations of aerobic bacteria and E. coli in ward environments and the airborne transmission of bacterial drug resistance. The results show that the three wards examined have an average aerobic bacterial concentration of 132 CFU.m(-3) and an average inhalable aerobic bacterial concentration of 73 CFU.m(-3), with no significant difference (P > 0.05) among the three wards. All isolated E. coli showed multi-drug resistance to not only third-generation cephalosporin antibiotics, but also quinolones, aminoglycosides, and sulfonamides. Furthermore, 51 airborne E. coli strains isolated from the air in the three wards and the corridor were screened for ESBLs, and 12 (23.53%) were ESBL-positive. The drug-resistance gene of the 12 ESBL-positive strains was mainly TEM gene, and the detection rate was 66.67% (8/12). According to a homology analysis with PFGE, 100% homologous E. coli from the ward at 5 m and 10 m outside the ward in the corridor shared the same drug-resistance spectrum, which further proves that airborne E. coli carrying a drug-resistance gene spreads out of the ward through gas exchange. This leads to biological pollution inside, outside, and around the ward, which poses a direct threat to the health of patients, healthcare workers, and surrounding residents. It is also the main reason for the antibiotic resistance in the hospital environment. More attention should be paid to comprehensive hygiene management in the surrounding environment of hospitals.

Aspergillus fumigatus is a ubiquitous pathogen in poultry farms, causing aspergillosis in chickens. To study the pathogenicity of A. fumigatus, 14-days-old chickens were infected with fungal conidia (2 × 107 CFU/mL) via thoracic intra-air sacs inoculation. The clinical symptoms, gross and histopathological lesions, and fungal load in the lungs were examined. Additionally, the mRNAs of Toll like receptors (TLR) and pro-inflammatory cytokines were evaluated by quantitative PCR to explore the immune responses induced by A. fumigatus. The results showed that overt depression, ruffled feathers, and dyspnea were observed in the infected chickens as early as 3 days post infection (dpi). Eleven out of 25 infected chickens died from 5 to 9 dpi, and A. fumigatus could also be reisolated from the infected lung. Histopathological examination revealed obvious airsacculitis and pneumonia, characterized by inflammatory cell infiltration (heterophils and macrophages), and granulomatous lesions in the lung. The mRNA expressions of TLR1 and TLR2 were upregulated in the lung and spleen, and most pro-inflammatory cytokines including IL-1β, Cxcl-8, TNF-α, IL-12, and IFN-γ were increased in both the lung and spleen during the tested period, suggesting that the innate immune responses were triggered by A. fumigatus infection, and these cytokines participated in the inflammatory responses against A. fumigatus. These results indicate that A. fumigatus infection by thoracic intra-air sacs inoculation can cause severe respiratory damage in chickens, activate TLR1 and TLR2 mediated immune responses, and elicit large expression of pro-inflammatory cytokines such as IL-1β, Cxcl-8, and IFN-γ. These data will help further understanding of the pathogenesis and immune responses of A. fumigatus infection in the chicken.

Particulate matter (PM) pollution poses a huge public health threat, and exposure to haze pollution for short or long periods of time cause health problems. In this study, 16S rDNA and ITS high-throughput sequencing were used to analyze the microbial components of fine particulate matter (PM2.5) collected between December 20th and December 27th of 2016 during a severe haze in Tai'an, China. Although most inhalable microorganisms are not pathogenic to humans, we detected the presence of some types of bacteria that cause respiratory inflammation (such as Pseudomonas and Corynebacterium), allergic reactions (such as Alternaria), and lung inflammation (such as Nesterenkonia). Acute and chronic haze PM2.5 exposure experiments were conducted using BALB/c mice to gain insight about the harm these microbes may have on human health. Results indicate that acute exposure to haze PM2.5 can cause pathological lung damage, decrease the expressions of oxidative stress indicators T-AOC, SOD, and GSH-PX, increase the expression of MDA, and induce apoptosis. Furthermore, chronic exposure was found to cause more damage. Toll-like receptors can be used identify molecular patterns associated with microbial pathogens. The expression of TLR2 and TLR4 were increased in both single- and repeated-exposure groups, but they were significantly increased in the repeated-exposure group (P < 0.05). The role of biological components in PM in mediating inflammation and pathological damage should not be neglected.