ABSTRACT
Sulfonamide antibiotics (SAs) are serious pollutants to ecosystems and environments. Previous studies showed that microbial degradation of SAs such as sulfamethoxazole (SMX) proceeds via a sad-encoded oxidative pathway, while the sulfonamide-resistant dihydropteroate synthase gene, sul, is responsible for SA resistance. However, the co-occurrence of sad and sul genes, as well as how the sul gene affects SMX degradation, was not explored. In this study, two SMX-degrading bacterial strains, SD-1 and SD-2, were cultivated from an SMX-degrading enrichment. Both strains were Paenarthrobacter species and were phylogenetically identical; however, they showed different SMX degradation activities. Specifically, strain SD-1 utilized SMX as the sole carbon and energy source for growth and was a highly efficient SMX degrader, while SD-2 did could not use SMX as a sole carbon or energy source and showed limited SMX degradation when an additional carbon source was supplied. Genome annotation, growth, enzymatic activity tests, and metabolite detection revealed that strains SD-1 and SD-2 shared a sad-encoded oxidative pathway for SMX degradation and a pathway of protocatechuate degradation. A new sulfonamide-resistant dihydropteroate synthase gene, sul918, was identified in strain SD-1, but not in SD-2. Moreover, the lack of sul918 resulted in low SMX degradation activity in strain SD-2. Genome data mining revealed the co-occurrence of sad and sul genes in efficient SMX-degrading Paenarthrobacter strains. We propose that the co-occurrence of sulfonamide-resistant dihydropteroate synthase and sad genes is crucial for efficient SMX biodegradation. KEY POINTS: ⢠Two sulfamethoxazole-degrading strains with distinct degrading activity, Paenarthrobacter sp. SD-1 and Paenarthrobacter sp. SD-2, were isolated and identified. ⢠Strains SD-1 and SD-2 shared a sad-encoded oxidative pathway for SMX degradation. ⢠A new plasmid-borne SMX resistance gene (sul918) of strain SD-1 plays a crucial role in SMX degradation efficiency.
Subject(s)
Dihydropteroate Synthase , Sulfamethoxazole , Sulfamethoxazole/metabolism , Dihydropteroate Synthase/genetics , Ecosystem , Anti-Bacterial Agents/metabolism , Sulfonamides/metabolism , Sulfanilamide , Biodegradation, Environmental , CarbonABSTRACT
Co-occurrence networks inferred from the abundance data of microbial communities are widely applied to predict microbial interactions. However, the high workloads of bacterial isolation and the complexity of the networks themselves constrained experimental demonstrations of the predicted microbial associations and interactions. Here, we integrate droplet microfluidics and bar-coding logistics for high-throughput bacterial isolation and cultivation from environmental samples, and experimentally investigate the relationships between taxon pairs inferred from microbial co-occurrence networks. We collected Potamogeton perfoliatus plants (including roots) and associated sediments from Beijing Olympic Park wetland. Droplets of series diluted homogenates of wetland samples were inoculated into 126 96-well plates containing R2A and TSB media. After 10 days of cultivation, 65 plates with > 30% wells showed microbial growth were selected for the inference of microbial co-occurrence networks. We cultivated 129 bacterial isolates belonging to 15 species that could represent the zero-level OTUs (Zotus) in the inferred co-occurrence networks. The co-cultivations of bacterial isolates corresponding to the prevalent Zotus pairs in networks were performed on agar plates and in broth. Results suggested that positively associated Zotu pairs in the co-occurrence network implied complicated relations including neutralism, competition, and mutualism, depending on bacterial isolate combination and cultivation time.
Subject(s)
Microbiota , Microfluidics , Microfluidics/methods , Microbial Consortia/genetics , Bacteria/genetics , Microbiota/genetics , Microbial InteractionsABSTRACT
Among fundamental research questions in subterranean biology, the role of subterranean microbiomes playing in key elements cycling is a top-priority one. Karst caves are widely distributed subsurface ecosystems, and cave microbes get more and more attention as they could drive cave evolution and biogeochemical cycling. Research have demonstrated the existence of diverse microbes and their participance in biogeochemical cycling of elements in cave environments. However, there are still gaps in how these microbes sustain in caves with limited nutrients and interact with cave environment. Cultivation of novel cave bacteria with certain functions is still a challenging assignment. This review summarized the role of microbes in cave evolution and mineral deposition, and intended to inspire further exploration of microbial performances on C/N/S biogeocycles.
ABSTRACT
Nitrogen (N2) gas in the atmosphere is partially replenished by microbial denitrification of ammonia. Recent study has shown that Alcaligenes ammonioxydans oxidizes ammonia to dinitrogen via a process featuring the intermediate hydroxylamine, termed "Dirammox" (direct ammonia oxidation). However, the unique biochemistry of this process remains unknown. Here, we report an enzyme involved in Dirammox that catalyzes the conversion of hydroxylamine to N2. We tested previously annotated proteins involved in redox reactions, DnfA, DnfB, and DnfC, to determine their ability to catalyze the oxidation of ammonia or hydroxylamine. Our results showed that none of these proteins bound to ammonia or catalyzed its oxidation; however, we did find DnfA bound to hydroxylamine. Further experiments demonstrated that, in the presence of NADH and FAD, DnfA catalyzed the conversion of 15N-labeled hydroxylamine to 15N2. This conversion did not happen under oxygen (O2)-free conditions. Thus, we concluded that DnfA encodes a hydroxylamine oxidase. We demonstrate that DnfA is not homologous to any known hydroxylamine oxidoreductases and contains a diiron center, which was shown to be involved in catalysis via electron paramagnetic resonance experiments. Furthermore, enzyme kinetics of DnfA were assayed, revealing a Km of 92.9 ± 3.0 µM for hydroxylamine and a kcat of 0.028 ± 0.001 s-1. Finally, we show that DnfA was localized in the cytoplasm and periplasm as well as in tubular membrane invaginations in HO-1 cells. To the best of our knowledge, we conclude that DnfA is the first enzyme discovered that catalyzes oxidation of hydroxylamine to N2.
Subject(s)
Alcaligenes , Ammonia , Hydroxylamines , Oxidoreductases , Alcaligenes/enzymology , Ammonia/metabolism , Bacterial Proteins/metabolism , Flavin-Adenine Dinucleotide/metabolism , Hydroxylamines/metabolism , NAD/metabolism , Nitrogen/metabolism , Oxidation-Reduction , Oxidoreductases/metabolism , OxygenABSTRACT
INTRODUCTION: Chronic myeloid leukaemia (CML) is a myeloproliferative neoplasm characterized by constitutive activity of the tyrosine kinase BCR-ABL1. Drug resistance remains one of the major challenges in CML therapy. MicroRNA (miR)-199a-3p plays an important role in many tumours but has rarely been investigated in CML. We aimed to analyse the role and mechanism of miR-199a-3p in regulating imatinib resistance in CML. METHODS: The expression of miR-199a-3p and mammalian target of rapamycin (mTOR) in the serum of CML patients and CML cells was examined by quantitative real-time polymerase chain reaction. The levels of apoptosis-related proteins were determined using western blot. The relative cell survival rate and cell proliferation were determined using a CCK-8 assay and a bromodeoxyuridine (BrdU) assay, respectively. Cell cycle and apoptosis were analysed using flow cytometry. Moreover, a dual-luciferase reporter assay was performed to verify the correlation between miR-199a-3p and mTOR. RESULTS: MiR-199a-3p was downregulated in the serum of CML patients and in CML cells, while mTOR was upregulated. Both miR-199a-3p overexpression and mTOR silencing inhibited CML cell proliferation, promoted CML cell apoptosis, and sensitized these cells to imatinib. mTOR silencing reversed the promoting effect of miR-199a-3p inhibition on the proliferation of CML cells and the inhibitory effects on cell apoptosis and sensitivity to imatinib. MiR-199a-3p directly targeted mTOR. CONCLUSION: MiR-199a-3p suppressed cell propagation, facilitated apoptosis of CML cells, and sensitized CML cells to imatinib by downregulating mTOR signalling.
Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive , MicroRNAs , Apoptosis , Bromodeoxyuridine/pharmacology , Bromodeoxyuridine/therapeutic use , Cell Line, Tumor , Cell Proliferation , Humans , Imatinib Mesylate/pharmacology , Imatinib Mesylate/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Luciferases/pharmacology , Luciferases/therapeutic use , MicroRNAs/genetics , MicroRNAs/metabolism , Protein-Tyrosine Kinases , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , TOR Serine-Threonine Kinases/pharmacologyABSTRACT
Non-human primates harbour diverse microbiomes in their guts. As a part of the China Microbiome Initiatives, we cultivated and characterized the gut microbiome of cynomolgus monkeys (Macaca fascicularis). In this report, we communicate the characterization and taxonomy of eight bacterial strains that were obtained from faecal samples of captive cynomolgus monkeys. The results revealed that they represented eight novel bacterial species. The proposed names of the eight novel species are Alkaliphilus flagellatus (type strain MSJ-5T=CGMCC 1.45007T=KCTC 15974T), Butyricicoccus intestinisimiae MSJd-7T (MSJd-7T=CGMCC 1.45013T=KCTC 25112T), Clostridium mobile (MSJ-11T=CGMCC 1.45009T=KCTC 25065T), Clostridium simiarum (MSJ-4T=CGMCC 1.45006T=KCTC 15975T), Dysosmobacter acutus (MSJ-2T=CGMCC 1.32896T=KCTC 15976T), Paenibacillus brevis MSJ-6T (MSJ-6T=CGMCC 1.45008T=KCTC 15973T), Peptoniphilus ovalis (MSJ-1T=CGMCC 1.31770T=KCTC 15977T) and Tissierella simiarum (MSJ-40T=CGMCC 1.45012T=KCTC 25071T).
Subject(s)
Paenibacillus , Animals , Bacterial Typing Techniques , Base Composition , Clostridium , DNA, Bacterial/genetics , Fatty Acids/chemistry , Feces , Haplorhini , Phospholipids , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Heterotrophic nitrifiers are able to oxidize and remove ammonia from nitrogen-rich wastewaters but the genetic elements of heterotrophic ammonia oxidation are poorly understood. Here, we isolated and identified a novel heterotrophic nitrifier, Alcaligenes ammonioxydans sp. nov. strain HO-1, oxidizing ammonia to hydroxylamine and ending in the production of N2 gas. Genome analysis revealed that strain HO-1 encoded a complete denitrification pathway but lacks any genes coding for homologous to known ammonia monooxygenases or hydroxylamine oxidoreductases. Our results demonstrated strain HO-1 denitrified nitrite (not nitrate) to N2 and N2 O at anaerobic and aerobic conditions respectively. Further experiments demonstrated that inhibition of aerobic denitrification did not stop ammonia oxidation and N2 production. A gene cluster (dnfT1RT2ABCD) was cloned from strain HO-1 and enabled E. coli accumulated hydroxylamine. Sub-cloning showed that genetic cluster dnfAB or dnfABC already enabled E. coli cells to produce hydroxylamine and further to 15 N2 from (15 NH4 )2 SO4 . Transcriptome analysis revealed these three genes dnfA, dnfB and dnfC were significantly upregulated in response to ammonia stimulation. Taken together, we concluded that strain HO-1 has a novel dnf genetic cluster for ammonia oxidation and this dnf genetic cluster encoded a previously unknown pathway of direct ammonia oxidation (Dirammox) to N2 .
Subject(s)
Ammonia , Water Purification , Aerobiosis , Alcaligenes/genetics , Alcaligenes/metabolism , Ammonia/metabolism , Denitrification , Escherichia coli/metabolism , Nitrification , Nitrites/metabolism , Nitrogen/metabolism , Oxidation-Reduction , Sewage , Water Purification/methodsABSTRACT
Biological foaming (or biofoaming) is a frequently occurring problem in wastewater treatment plants (WWTPs) and is attributed to the overwhelming growth of filamentous bulking and foaming bacteria (BFB). Biological foaming has been intensively investigated, with BFB like Microthrix and Skermania having been identified from WWTPs and implicated in foaming. Nevertheless, studies are still needed to improve our understanding of the microbial diversity of WWTP biofoams and how microbial activities contribute to foaming. In this study, sludge foaming at the Qinghe WWTP of China was monitored, and sludge foams were investigated using culture-dependent and culture-independent microbiological methods. The foam microbiomes exhibited high abundances of Skermania, Mycobacterium, Flavobacteriales, and Kaistella. A previously unknown bacterium, Candidatus Kaistella beijingensis, was cultivated from foams, its genome was sequenced, and it was phenotypically characterized. Ca. K. beijingensis exhibits hydrophobic cell surfaces, produces extracellular polymeric substances (EPS), and metabolizes lipids. Ca. K. beijingensis abundances were proportional to EPS levels in foams. Several proteins encoded by the Ca. K. beijingensis genome were identified from EPS that was extracted from sludge foams. Ca. K. beijingensis populations accounted for 4 to 6% of the total bacterial populations in sludge foam samples within the Qinghe WWTP, although their abundances were higher in spring than in other seasons. Cooccurrence analysis indicated that Ca. K. beijingensis was not a core node among the WWTP community network, but its abundances were negatively correlated with those of the well-studied BFB Skermania piniformis among cross-season Qinghe WWTP communities. IMPORTANCE Biological foaming, also known as scumming, is a sludge separation problem that has become the subject of major concern for long-term stable activated sludge operation in decades. Biological foaming was considered induced by foaming bacteria. However, the occurrence and deterioration of foaming in many WWTPs are still not completely understood. Cultivation and characterization of the enriched bacteria in foaming are critical to understand their genetic, physiological, phylogenetic, and ecological traits, as well as to improve the understanding of their relationships with foaming and performance of WWTPs.
Subject(s)
Flavobacteriaceae , Sewage , Water Purification , China , Flavobacteriaceae/classification , Flavobacteriaceae/isolation & purification , Phylogeny , Sewage/microbiologyABSTRACT
Aquatic and wetland systems are widely used for landscapes and water regeneration. Microbiomes and submerged macrophytes (hydrophytes) play essential roles in conversions of organic and inorganic compounds in those ecosystems. The systems were extensively investigated for microbial diversities and compositions. However, little is known about how hydrophytes recruited diverse microbiota and affected functional zonation in aquatic systems. To address this issue, epiphytic leaf and root, sediment, and surrounding water samples were collected from the dragon-shape aquatic system in Beijing Olympic Park. Metagenomic DNAs were extracted and subjected to sequencing. Results showed that epiphytic leaf and root microbiomes and metabolic marker genes were remarkably different from that of surrounding environment. Twenty indicator bacterial genera for epiphytic microbiomes were identified and 50 metabolic marker genes were applied to evaluate the function of epiphytic leaf and root, water, and sediment microbiomes. Co-occurrence analysis revealed highly modularized pattern of metabolic marker genes and indicator bacterial genera related to metabolic functions. These results suggested that hydrophytes shaped microbiomes and drove functional zonation in aquatic systems. KEY POINTS: ⢠Microbiomes of hydrophytes and their surrounding environments were investigated. ⢠Twenty indicator bacterial genera highly specific to epiphytic biofilms were identified. ⢠Epiphytes recruited unique microbiomes and drove functional zonation in aquatic systems.
Subject(s)
Metagenomics , Microbiota , BeijingABSTRACT
Karst caves are widely distributed subsurface systems, and the microbiomes therein are proposed to be the driving force for cave evolution and biogeochemical cycling. In past years, culture-independent studies on the microbiomes of cave systems have been conducted, yet intensive microbial cultivation is still needed to validate the sequence-derived hypothesis and to disclose the microbial functions in cave ecosystems. In this study, the microbiomes of two karst caves in Guizhou Province in southwest China were examined. A total of 3,562 bacterial strains were cultivated from rock, water, and sediment samples, and 329 species (including 14 newly described species) of 102 genera were found. We created a cave bacterial genome collection of 218 bacterial genomes from a karst cave microbiome through the extraction of 204 database-derived genomes and de novo sequencing of 14 new bacterial genomes. The cultivated genome collection obtained in this study and the metagenome data from previous studies were used to investigate the bacterial metabolism and potential involvement in the carbon, nitrogen, and sulfur biogeochemical cycles in the cave ecosystem. New N2-fixing Azospirillum and alkane-oxidizing Oleomonas species were documented in the karst cave microbiome. Two pcaIJ clusters of the ß-ketoadipate pathway that were abundant in both the cultivated microbiomes and the metagenomic data were identified, and their representatives from the cultivated bacterial genomes were functionally demonstrated. This large-scale cultivation of a cave microbiome represents the most intensive collection of cave bacterial resources to date and provides valuable information and diverse microbial resources for future cave biogeochemical research.IMPORTANCE Karst caves are oligotrophic environments that are dark and humid and have a relatively stable annual temperature. The diversity of bacteria and their metabolisms are crucial for understanding the biogeochemical cycling in cave ecosystems. We integrated large-scale bacterial cultivation with metagenomic data mining to explore the compositions and metabolisms of the microbiomes in two karst cave systems. Our results reveal the presence of a highly diversified cave bacterial community, and 14 new bacterial species were described and their genomes sequenced. In this study, we obtained the most intensive collection of cultivated microbial resources from karst caves to date and predicted the various important routes for the biogeochemical cycling of elements in cave ecosystems.
Subject(s)
Caves/microbiology , Genome, Bacterial , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Biodiversity , Coenzyme A-Transferases/genetics , Coenzyme A-Transferases/metabolism , Metagenome , Metagenomics , Microbiota , Nitrogen/metabolism , Phylogeny , RNA, Ribosomal, 16S/genetics , Sulfur/metabolismABSTRACT
PURPOSE: Currently, the routine screening program has insufficient capacity for the early diagnosis of lung cancer. Therefore, a type of chitosan-molecular beacon (CS-MB) probe was developed to recognize the miR-155-5p and image the lung cancer cells for the early diagnosis. METHODS: Based on the molecular beacon (MB) technology and nanotechnology, the CS-MB probe was synthesized self-assembly. There are four types of cells-three kinds of animal models and one type of histopathological sections of human lung cancer were utilized as models, including A549, SPC-A1, H446 lung cancer cells, tumor-initiating cells (TICs), subcutaneous and lung xenografts mice, and lox-stop-lox(LSL) K-ras G12D transgenic mice. The transgenic mice dynamically displayed the process from normal lung tissues to atypical hyperplasia, adenoma, carcinoma in situ, and adenocarcinoma. The different miR-155-5p expression levels in these cells and models were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The CS-MB probe was used to recognize the miR-155-5p and image the lung cancer cells by confocal microscopy in vitro and by living imaging system in vivo. RESULTS: The CS-MB probe could be used to recognize the miR-155-5p and image the lung cancer cells significantly in these cells and models. The fluorescence intensity trends detected by the CS-MB probe were similar to the expression levels trends of miR-155 tested by qRT-PCR. Moreover, the fluorescence intensity showed an increasing trend with the tumor progression in the transgenic mice model, and the occurrence and development of lung cancer were dynamically monitored by the differen fluorescence intensity. In addition, the miR-155-5p in human lung cancer tissues could be detected by the miR-155-5p MB. CONCLUSION: Both in vivo and in vitro experiments demonstrated that the CS-MB probe could be utilized to recognize the miR-155-5p and image the lung cancer cells. It provided a novel experimental and theoretical basis for the early diagnosis of the disease. Also, the histopathological sections of human lung cancer research laid the foundation for subsequent preclinical studies. In addition, different MBs could be designed to detect other miRNAs for the early diagnosis of other tumors.
Subject(s)
Lung Neoplasms/diagnostic imaging , Lung Neoplasms/genetics , MicroRNAs/analysis , A549 Cells , Animals , Chitosan/chemistry , Early Detection of Cancer/methods , Heterografts , Humans , Mice , Mice, Nude , Mice, Transgenic , MicroRNAs/biosynthesis , MicroRNAs/genetics , Molecular Imaging/methods , Molecular Probes/chemistry , NanotechnologyABSTRACT
Microorganisms in wastewater treatment plants (WWTPs) play a key role in the removal of pollutants from municipal and industrial wastewaters. A recent study estimated that activated sludge from global municipal WWTPs harbors 1 × 109 to 2 × 109 microbial species, the majority of which have not yet been cultivated, and 28 core taxa were identified as "most-wanted" ones (L. Wu, D. Ning, B. Zhang, Y. Li, et al., Nat Microbiol 4:1183-1195, 2019, https://doi.org/10.1038/s41564-019-0426-5). Cultivation and characterization of the "most-wanted" core bacteria are critical to understand their genetic, physiological, phylogenetic, and ecological traits, as well as to improve the performance of WWTPs. In this study, we isolated a bacterial strain, designated SJ-1, that represents a novel cluster within Betaproteobacteria and corresponds to OTU_16 within the 28 core taxa in the "most-wanted" list. Strain SJ-1 was identified and nominated as Casimicrobium huifangae gen. nov., sp. nov., of a novel family, Casimicrobiaceae. C. huifangae is ubiquitously distributed and is metabolically versatile. In addition to mineralizing various carbon sources (including carbohydrates, aromatic compounds, and short-chain fatty acids), C. huifangae is capable of nitrate reduction and phosphorus accumulation. The population of C. huifangae accounted for more than 1% of the bacterial population of the activated sludge microbiome from the Qinghe WWTP, which showed seasonal dynamic changes. Cooccurrence analysis suggested that C. huifangae was an important module hub in the bacterial network of Qinghe WWTP.IMPORTANCE The activated sludge process is the most widely applied biotechnology and is one of the best ecosystems to address microbial ecological principles. Yet, the cultivation of core bacteria and the exploration of their physiology and ecology are limited. In this study, the core and novel bacterial taxon C. huifangae was cultivated and characterized. This study revealed that C. huifangae functioned as an important module hub in the activated sludge microbiome, and it potentially plays an important role in municipal wastewater treatment plants.
Subject(s)
Betaproteobacteria/classification , Betaproteobacteria/physiology , Sewage/microbiology , Betaproteobacteria/genetics , Microbiota , Phylogeny , RNA, Bacterial/analysis , RNA, Ribosomal, 16S/analysisABSTRACT
Caves are typified by their permanent darkness and a shortage of nutrients. Consequently, bacteria play an important role in sustaining such subsurface ecosystems by dominating primary production and fueling biogeochemical cycles. China has one of the world's largest areas of karst topography in the Yunnan-Guizhou Plateau, yet the bacteriomes in these karst caves remain unexplored. In this study, bacteriomes of eight karst caves in southwest China were examined, and co-occurrence networks of cave bacterial communities were constructed. Results revealed abundant and diversified bacterial communities in karst caves, with Proteobacteria, Actinobacteria, and Firmicutes being the most abundant phyla. Statistical analysis revealed no significant difference in bacteriomes among the eight caves. However, a PCoA plot did show that the bacterial communities of 128 cave samples clustered into groups corresponding to sampling types (air, water, rock, and sediment). These results suggest that the distribution of bacterial communities is driven more by sample types than the separate caves from which samples were collected. Further community-level composition analysis indicated that Proteobacteria were most dominant in water and air samples, while Actinobacteria dominated the sediment and rock samples. Co-occurrence analysis revealed highly modularized assembly patterns of the cave bacterial community, with Nitrosococcaceae wb1-P19, an uncultured group in Rokubacteriales, and an uncultured group in Gaiellales, being the top-three keystone members. These results not only expand our understanding of cave bacteriomes but also inspires functional exploration of bacterial strains in karst caves.
ABSTRACT
Complex chemosensory systems control multiple biological functions in bacteria, such as chemotaxis, gene regulation, and cell cycle progression. Many species contain more than one chemosensory system per genome, but little is known about their potential interplay. In this study, we reveal cross talk between two chemosensory pathways that modulate chemotaxis and biofilm formation in Comamonas testosteroni We demonstrate that some chemoreceptors that govern chemotaxis also contribute to biofilm formation and these chemoreceptors can physically interact with components of both pathways. Finally, we show that the chemotaxis histidine kinase CheA can phosphorylate not only its cognate response regulator CheY2 but also one of the response regulators from the pathway mediating biofilm formation, FlmD. The phosphoryl group transfer from CheA to CheY2 is much faster than that from CheA to FlmD, which is consistent with chemotaxis being a fast response and biofilm formation being a much slower developmental process. We propose that cross talk between chemosensory pathways may play a role in coordination of complex behaviors in bacteria.IMPORTANCE In many bacteria, two or more homologous chemosensory pathways control several cellular functions, such as motility and gene regulation, in response to changes in the cell's microenvironment. Cross talk between signal transduction systems is poorly understood; while generally it is considered to be undesired, in some instances it might be beneficial for coregulation of complex behaviors. We demonstrate that several receptors from the pathway controlling motility can physically interact with downstream components of the pathway controlling biofilm formation. We further show that a kinase from the pathway controlling motility can also phosphorylate a response regulator from the pathway controlling biofilm formation. We propose that cross talk between two chemosensory pathways might be involved in coordination of two types of cell behavior-chemotaxis and biofilm formation.
Subject(s)
Biofilms/growth & development , Chemotaxis , Comamonas testosteroni/physiology , Gene Expression Regulation, Bacterial , Gene Regulatory Networks , Comamonas testosteroni/genetics , Histidine Kinase/metabolism , Phosphorylation , Protein Processing, Post-Translational , Signal TransductionABSTRACT
A Gram-stain-positive, rod-shaped, endospore-forming, motile and aerobic bacterial isolate, designated strain K2E09-144T, was obtained from animal faeces that were collected from a karst cave in Guizhou province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain K2E09-144T represents a novel member of the genus Cohnella within the family Paenibacillaceae of the phylum Firmicutes. Strain K2E09-144T was phylogenetically closely related to Cohnella nanjingensis D45T (16S rRNA gene sequence similarity 97.0â%). The major cellular fatty acids were anteiso-C15:0, iso-C16:0 and C16â:â0. The major isoprenoid quinone was menaqinone 7 (MK-7). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified phospholipid, four unidentified aminophospholipids, one glycolipid and one unidentified lipid. The isomer type of diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The genome of strain K2E09-144T comprised 6.43 Mb, and encoded 6029 genes in total. The DNA G+C content of the genomic DNA was 53.3 mol%. Based on its phylogenetic, phenotypic and chemotaxonomic characteristics, strain K2E09-144T is considered to represent a novel species of the genus Cohnella, for which the name Cohnella faecalis sp. nov. is proposed. The type strain is K2E09-144T (=CGMCC 1.13587T=NBRC 113454T).
Subject(s)
Bacillales/classification , Caves/microbiology , Feces/microbiology , Phylogeny , Animals , Bacillales/isolation & purification , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry , Glycolipids/chemistry , Naphthols/chemistry , Peptidoglycan/chemistry , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Terpenes/chemistryABSTRACT
A Gram-stain-negative, rod-shaped, motile and strictly aerobic novel bacterial isolate, designated strain K1W11S-77T, was obtained from a water sample that was collected from a karst cave in Guizhou province, PR China. The results of a phylogenetic analysis based on 16S rRNA gene sequences indicated that K1W11S-77T represented a member of the genus Crenobacter within the family Neisseriaceae of the phylum Proteobacteria. K1W11S-77T was phylogenetically closely related to Crenobacter luteusYIM 78141T (Their 16S rRNA gene sequence similarity is 95.02â%). Growth of K1W11S-77T occurred at 10-30 °C, at pH 7-9, and in the presence of 0-1â% (w/v) NaCl. The major cellular fatty acids were C12â:â0, C16â:â0, C18:1ω7c and summed feature 3. The major isoprenoid quinone was Q-8. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and one unidentified phospholipid. The genome of K1W11S-77T was 3.27 Mb long and encoded 3167 annotated genes. The DNA G+C content of the genomic DNA was 65.3 mol%. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, K1W11S-77T is considered to represent a novel species of the genus Crenobacter, for which the name Crenobactercavernae sp. nov. is proposed. The type strain is K1W11S-77T (=CGMCC 1.13527T=NBRC 113452T).
Subject(s)
Caves/microbiology , Neisseriaceae/classification , Phylogeny , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Neisseriaceae/isolation & purification , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistryABSTRACT
OBJECTIVE: To evaluate the effects of treatment with risperidone and aripiprazole on serum prolactin, testosterone and estradiol levels in female patients with schizophrenia in China. METHODS: In the retrospective study, Data were collected and included prolactin, testosterone and estradiol levels of 30 female patients with risperidone monotherapy. In the prospective study, Another 30 female schizophrenic patients were randomized to receive risperidone or adjunctive aripiprazole for six weeks. Serum prolactin, testosterone and estradiol levels were measured. RESULTS: Serum prolactin, testosterone and estradiol levels in both studies were significantly decreased after risperidone treatment compared with baseline (P<0.05), and prolactin levels remained at a high level. Serum prolactin levels in the adjunctive aripiprazole group were significantly decreased after treatment compared with baseline in the prospective study (P<0.05). Doses of 5 mg and 10 mg of adjunctive aripiprazole achieved the same efficacy at the end of treatment. CONCLUSIONS: Risperidone treatment decreased serum testosterone and estradiol levels. Adjunctive aripiprazole relieved hyperprolactinemia, but had no effect on testosterone or estradiol levels. Adjunctive aripiprazole at a dose of 5 mg is recommended for clinical use.
Subject(s)
Aripiprazole/therapeutic use , Estradiol/blood , Prolactin/blood , Risperidone/therapeutic use , Schizophrenia/blood , Schizophrenia/drug therapy , Antipsychotic Agents/therapeutic use , Female , Humans , Middle Aged , Prospective Studies , Retrospective Studies , Testosterone/bloodABSTRACT
Lung cancer is still the most common cancer globally. Early screening remains the key to improve the prognosis of patients. There is currently a lack of specific and sensitive methods for early screening of lung cancer. In recent years, studies have found that microRNA plays an important role in the occurrence and development of lung cancer and become a biological target in the early diagnosis of lung cancer. In this study, lung cancer cells, subcutaneous xenografts of lung cancer in nude mice, and Lox-Stop-lox K-ras G12D transgenic mice were used as models. The transgenic mice displayed the dynamic processes from normal lung tissue to atypical hyperplasia, adenomas, carcinoma in situ and lung adenocarcinoma. It was found that miR-155 and somatostatin receptor 2 (SSTR2) were expressed in all the disease stages of transgenic mice. Through molecular beacon (MB) technology and nanotechnology, chitosan-molecular beacon (CS-MB) nanoparticles and targeted octreotide (OCT) were conjugated and synthesized. The octreotide-conjugated chitosan-molecular beacon nanoparticles (CS-MB-OCT) can specifically bind to SSTR2 expressed by the lung cancer cells to achieve the goal of identification of lung cancer cells and imaging miR-155 in vivo and in vitro. Fluorescence imaging at different disease stages of lung cancer in Lox-Stop-lox K-ras G12D transgenic mice was performed, and could dynamically monitor the occurrence and development of lung cancer by different fluorescence intensity ranges. The current research, in turn, provides new idea, new method, and new technology for the early screening of lung cancer.