Due to the advancement of 16S rRNA sequencing technology, the lower respiratory tract microbiota, which was considered non-existent, has been revealed. The correlation between these microorganisms and diseases such as tumor has been a hot topic in recent years. As the bacteria in the surrounding can infiltrate the tumors, researchers have also begun to pay attention to the biological behavior of tumor bacteria and their interaction with tumors. In this review, we present the characteristic of the lower respiratory tract bacteria and summarize recent research findings on the relationship between these microbiota and lung cancer. On top of that, we also summarize the basic feature of bacteria in tumors and focus on the characteristic of the bacteria in lung cancer. The relationship between bacteria in lung cancer and tumor development is also been discussed. Finally, we review the potential clinical applications of bacterial communities in the lower respiratory tract and lung cancer, and summarize key points of sample collection, sequencing, and contamination control, hoping to provide new ideas for the screening and treatment of tumors.
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Humans ; Lung Neoplasms ; RNA, Ribosomal, 16S/genetics* ; Bacteria/genetics* ; Microbiota ; Respiratory System ; Lung/microbiology*

Pneumocystis, an important opportunistic fungal pathogen that parasitizes in multiple mammalian lungs, may cause life-threatening Pneumocystis pneumonia (PCP) and even death among immunocompromised individuals. With the rapid development of high-throughput sequencing and multi-omics technologies, systematic comparative analyses of genome, transcriptome, and whole-genome sequencing results demonstrate that Pneumocystis is a type of obligate biotrophic fungi, and requires obtaining nutrition from hosts. In addition, sexual reproduction is an essential process for Pneumocystis survival, production and transmission, and asexual reproduction facilitates Pneumocystis survival, which provides new insights into understanding of the whole developmental process of Pneumocystis in the host lung and inter-host transmission of Pneumocystis. This review summarizes the advances in the reproduction mode of Pneumocystis and underlying mechanisms, which provides insights into prevention and treatment of PCP, notably for the prophylaxis against nosocomial transmission of PCP.
Humans ; Lung/microbiology* ; Pneumocystis/genetics* ; Pneumonia, Pneumocystis/microbiology*

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R² = 0.033; P = 0.018), followed by acute kidney injury (AKI; R² = 0.032; P = 0.011) and plasma MIP-1β level (R² = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.
Acute Kidney Injury/complications* ; Bacteria/classification* ; Chemokine CCL4/blood* ; Community-Acquired Infections/microbiology* ; Humans ; Lung ; Microbiota/genetics* ; Pneumonia, Bacterial/diagnosis* ; Prognosis ; RNA, Ribosomal, 16S/genetics*

This paper was mainly to discuss the potential role and mechanism of Lianhua Qingwen Capsules(LHQW) in inhibiting pathological inflammation in the model of acute lung injury caused by bacterial infection. For in vitro study, the mRNA expression of MCP-1 in RAW264.7 cells and THP-1 cells, the content of MCP-1 in cell supernatant, as well as the effect of LHQW on chemotaxis of macrophages were detected. For in vivo study, mice were randomly divided into 7 groups, including normal group, model group(LPS 5 mg·kg~(-1)), LHQW 300, 600 and 1 200 mg·kg~(-1)(low, middle and high dose) groups, dexamethasone 5 mg·kg~(-1) group and penicillin-streptomycin group. Then, the anal temperature was detected two hours later. Dry weight and wet weight of lung tissues in mice were determined; TNF-α and MCP-1 levels in alveolar lavage fluid and MCP-1 in serum were detected. In addition, the infiltration of alveolar macrophages was also observed and the infiltration count of alveolar macrophages was measured by CCK-8 method. HE staining was also used to observe the inflammatory infiltration of lung tissues in mice. Both of the in vitro and in vivo data consistently have confirmed that: by down-regulating the expression of MCP-1, LHWQ could efficiently decrease the chemotaxis of monocytes toward the pulmonary infection foci, thus blocking the disease development in ALI animal model.
Acute Lung Injury ; microbiology ; Animals ; Bacterial Infections ; drug therapy ; Bronchoalveolar Lavage Fluid ; Capsules ; Chemokine CCL2 ; metabolism ; Chemotaxis ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Lipopolysaccharides ; Lung ; Macrophages ; drug effects ; Mice ; RAW 264.7 Cells ; Random Allocation ; THP-1 Cells ; Tumor Necrosis Factor-alpha ; metabolism

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg(d. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1β in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.
Animals ; Cytokines ; metabolism ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; therapeutic use ; Gastrointestinal Microbiome ; drug effects ; Houttuynia ; chemistry ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Inflammation ; drug therapy ; pathology ; Influenza A Virus, H1N1 Subtype ; pathogenicity ; Intestinal Mucosa ; drug effects ; metabolism ; microbiology ; pathology ; Lung ; drug effects ; metabolism ; pathology ; Male ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; drug therapy ; pathology ; physiopathology ; Plant Extracts ; chemistry ; Polysaccharides ; chemistry ; pharmacology ; therapeutic use ; Toll-Like Receptors ; metabolism ; Zonula Occludens-1 Protein ; metabolism

Helicobacter pylori (H. pylori) is the causative agent of chronic gastritis and peptic ulcer diseases and is an important risk factor for the development functional dyspepsia, peptic ulceration, gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. H. pylori has very high rates of infection in human populations, and it is estimated that over 50% of the world population is infected. Recently, certain extra-gastric manifestations, linked to H. pylori infection, have been widely investigated. Noteworthy, a growing body of evidences supports an association between H. pylori infection with lung cancer. The present review intend to highlight not only the most recent evidences supporting this association, but also some missed points, which must be considered to validate this emerging association.
Helicobacter Infections ; complications ; Helicobacter pylori ; physiology ; Humans ; Lung Neoplasms ; complications ; microbiology

OBJECTIVESTo investigate the mechanism of the Chinese medicine theory that Fei (Lung) and Dachang (Large Intestine) are exteriorly and interiorly related via synchronous observation on the dynamic changes of the respiratory and intestinal microflora.

METHODSForty specific pathogen free Sprague-Dawley rats were selected and randomly divided into blank (10 rats) and chronic bronchitis model groups (30 rats). The blank group rats were put into the smoke-free environment and the model group rats were put into the smoke environment in order to establish pulmonary disease (chronic bronchitis) model. Then the corresponding changes of the respiratory and intestinal microflflora of the model on 20th, 50th and 70th days were synchronously observed.

RESULTSThe respiratory tract microflflora showed an increase in the total aerobic and Staphylococcus aureus and reduced anaerobic amount signifificantly on 20th day in the respiratory tract microflflora (P<0.05 or 0.01). On 50th day, total aerobic, total anaerobic amount and bififidobacterium signifificantly increased (P<0.05). On 70th day, Staphylococcus aureus reduced and lactobacillus increased signifificantly (P<0.01). The intestinal microflflora showed an increase in the total aerobic, Clostridium perfringens, enterobacter and enterococcus significantly increased on 20th day (P<0.05 or 0.01). Staphylococcus aureus on 50th day increased significantly (P<0.05). Total aerobic and enterococcus increased, total anaerobic and Clostridium perfringens reduced signifificantly on 70th day (P<0.05 or 0.01).

CONCLUSIONThe microecosystem of respiratory tract and intestine of rat model during the pathological process showed a dynamic disorder, indicating an interaction between the lung and large intestine which may be one of the connotations as they exteriorly and interiorly related.

Animals ; Bronchitis, Chronic ; microbiology ; pathology ; Disease Models, Animal ; Gastrointestinal Microbiome ; Intestines ; microbiology ; Lung ; microbiology ; Male ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo investigate the prokaryotic expression of proteins pneumococcal endopeptidase O (PepO) and pneumococcal surface adhesin A (PsaA) in Streptococcus pneumoniae and their immunoprotective effect as vaccine candidate proteins.

METHODSSpecific primers of target gene fragments were designed, and then PCR amplification was performed to establish recombinant plasmids pET28a(+)-pepO and pET28a(+)-psaA, which were transformed into host cells, Escherichia coli BL21 and DE3, respectively, to induce expression. Highly purified target proteins PepO and PsaA were obtained after purification. Mucosal immunization was performed for BALB/c mice and specific antiserum was prepared. ELISA was used to measure the antibody titer, and Western blot was used to analyze the specificity of the antiserum of target proteins. The mice were randomly divided into negative control group, PepO group, PsaA group, and PepO+PsaA combined immunization group, with 18 mice in each group. The models of different serotypes of Streptococcus pneumoniae infection were established to evaluate the immunoprotective effect of target proteins used alone or in combination.

RESULTSThe target proteins PepO and PsaA were successfully obtained and Western blot demonstrated that the antiserum of these proteins had good specificity. There was no significant difference in the titers of IgA in saliva and IgG in serum between the PepO group and the combined immunization group (P>0.05); however, these two groups had significantly higher antibody titers than the PsaA group (P<0.05). The PepO, PsaA, and combined immunization groups had significantly higher protection rates for mice infected with Streptococcus pneumoniae D39 and CMCC31436 in the nasal cavity than the negative control group (P<0.05). The PepO and combined immunization groups had a significantly higher protection rate for mice infected with Streptococcus pneumoniae D39 than the PsaA group (P<0.05). The results of colonization experiment showed that compared with the control group, the PepO, PsaA, and combined immunization groups showed a significant reduction in the colonization of Streptococcus pneumoniae (CMCC31693 and CMCC31207) in the nasopharynx and lung (P<0.05). The combined immunization group showed a better effect on reducing the colonization of CMCC31207 in the lung than the PepO and PsaA alone groups.

CONCLUSIONSCombined PepO/PsaA vaccines may produce a better protective effect by mucosal immunization compared with the vaccine used alone in mice. The combined vaccines can effectively reduce the colonization of Streptococcus pneumoniae in the nasopharynx and lung. Therefore, such protein vaccines may have a great potential for research and development.

Adhesins, Bacterial ; immunology ; Animals ; Antibodies, Bacterial ; analysis ; Bacterial Proteins ; immunology ; Female ; Immunization ; Lipoproteins ; immunology ; Lung ; microbiology ; Metalloendopeptidases ; immunology ; Mice ; Mice, Inbred BALB C ; Pneumococcal Infections ; prevention & control ; Pneumococcal Vaccines ; immunology ; Saliva ; immunology

A worsening scenario of drug-resistant tuberculosis has increased the need for new treatment strategies to tackle this worldwide emergency. There is a pressing need to simplify and shorten the current 6-month treatment regimen for drug-susceptible tuberculosis. Rifamycins and fluoroquinolones, as well as several new drugs, are potential candidates under evaluation. At the same time, treatment outcomes of patients with drug-resistant tuberculosis should be improved through optimizing the use of fluoroquinolones, repurposed agents and newly developed drugs. In this context, the safety and tolerance of new therapeutic approaches must be addressed.
Animals ; Antitubercular Agents/adverse effects/*therapeutic use ; *Drug Discovery ; *Drug Repositioning ; Drug Resistance, Bacterial ; Drug Therapy, Combination ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Humans ; Lung/*drug effects/microbiology ; Mycobacterium tuberculosis/*drug effects/pathogenicity ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/microbiology

Antifungal Agents ; therapeutic use ; Female ; Humans ; Lung ; microbiology ; pathology ; Lung Diseases, Fungal ; drug therapy ; etiology ; Middle Aged ; Schizophyllum ; drug effects ; pathogenicity ; Voriconazole ; therapeutic use