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New Microbes and New Infections Mar 2018is an aerobic, Gram-positive and nonmotile bacterium. It was first isolated in 1941 from the mycetoma and ovaries of the bedbug. The primary strains were named and... (Review)
Review
is an aerobic, Gram-positive and nonmotile bacterium. It was first isolated in 1941 from the mycetoma and ovaries of the bedbug. The primary strains were named and and are different from the Collins , 1988 classification of the new genus. Human infections with species are rare because the species is a kind of saprophyte bacterium; however, most information regarding this species comes from case reports. Molecular markers for the identification include sequencing of 16S rRNA, and genes. Given the lack of information on the treatment of infections, a combination of various antibiotic agents is recommended.
PubMed: 29556401
DOI: 10.1016/j.nmni.2017.10.002 -
World Journal of Clinical Cases Aug 2022species are obligate aerobic, gram-positive, weak acid-fast, nonmotile bacilli. They are found in various environments, such as soil, water, sludge, and petroleum... (Review)
Review
species are obligate aerobic, gram-positive, weak acid-fast, nonmotile bacilli. They are found in various environments, such as soil, water, sludge, and petroleum reservoir wastewater, and belong to the order . In 2016, there was a reclassification of species within the genus , merging the species () and . species are clinically considered to be a rare opportunistic pathogen, because most reported cases have been related to bacteremia and intravascular prosthetic devices and immunosuppression. To date, it has been isolated only from human specimens, and has always been associated with clinical disease; human infections are very rare. Reported infections have included pneumonia, brain abscesses, catheter-related bloodstream infections, ocular infections, bacteremia, and sepsis presenting with septic pulmonary emboli in patients who are immunocompromised. To date, there is no commercially available test for identification. On the other hand, sequence-based identification, including matrix-assisted laser desorption ionization time-of-flight mass spectrometry, is an alternative method for identifying clinical isolates that are either slow growers or difficult to identify through biochemical profiling. The golden standards for diagnosis and optimal management still remain to be determined. However, newer molecular biological techniques can provide accurate identification, and contribute to the appropriate selection of definitive therapy for infections caused by this organism. Combinations of several antimicrobial agents have been proposed for treatment, though the length of treatment for infections has yet to be determined, and should be individualized according to clinical response. Immunocompromised patients often experience severe cases due to infection, and life-threatening events associated with dissemination and/or failure of source control have occurred. Favorable prognoses can be achieved through earlier identification of the cause of infection, as well as successful management, including appropriate antibiotic therapy together with source control. Further analyses of similar cases are required to establish the most adequate diagnostic methods and treatment regimens for infections.
PubMed: 36157836
DOI: 10.12998/wjcc.v10.i24.8443 -
Frontiers in Microbiology 2022Weizhou Island and Xieyang Island are two large and young volcanic sea islands in the northern part of the South China Sea. In this study, high-throughput sequencing...
Weizhou Island and Xieyang Island are two large and young volcanic sea islands in the northern part of the South China Sea. In this study, high-throughput sequencing (HTS) of 16S rRNA genes was used to explore the diversity of Actinobacteria in the Weizhou and Xieyang Islands. Moreover, a traditional culture-dependent method was utilized to isolate Actinobacteria, and their antibacterial and cytotoxic activities were detected. The alpha diversity indices (ACE metric) of the overall bacterial communities for the larger island (Weizhou) were higher than those for the smaller island (Xieyang). A beta diversity analysis showed a more dispersive pattern of overall bacterial and actinobacterial communities on a larger island (Weizhou). At the order level, Frankiales, Propionibacteriales, Streptomycetales, Micrococcales, Pseudonocardiales, Micromonosporales, Glycomycetales, Corynebacteriales, and Streptosporangiales were the predominant Actinobacteria. A total of 22.7% of the OTUs shared 88%-95% similarity with some known groups. More interestingly, 15 OTUs formed a distinct and most predominant clade, and shared identities of less than 95% with any known families. This is the first report about this unknown group and their 16S rRNA sequences obtained from volcanic soils. A total of 268 actinobacterial strains were isolated by the culture-dependent method. Among them, 55 species were isolated, representing that 76.6% of the total and were the most abundant. Moreover, some rare Actinobacteria were isolated. These included spp., spp., spp., spp., spp., and spp. Among them, eight spp. exhibited antibacterial activity against . Only three strains inhibited the growth of . Four strains showed good activity against aquatic pathogenic bacterial strains of . The cytotoxicity assay results showed that 27 strains (10.07%) exhibited cytotoxic activity against HeLa and A549 cell lines. Many actinobacterial strains with cytotoxic activity were identified as rare Actinobacteria, which illustrated that volcanic islands are vast reservoirs for Actinobacteria with promising antibacterial and cytotoxic activity. This study may significantly improve our understanding of actinobacterial communities on volcanic islands. The isolated Actinobacteria showed promising prospects for future use.
PubMed: 35903476
DOI: 10.3389/fmicb.2022.911408 -
Frontiers in Immunology 2021The intestinal mucosa is lined by epithelial cells, which are key cells to sustain gut homeostasis. Food allergy is an immune-mediated adverse reaction to food, likely...
The intestinal mucosa is lined by epithelial cells, which are key cells to sustain gut homeostasis. Food allergy is an immune-mediated adverse reaction to food, likely due to defective regulatory circuits. is a non-pathogenic bacterium with immunomodulatory properties. We hypothesize that the anti-inflammatory effect of dead . on activated epithelial cells modulates milk allergy through the restoration of tolerance in a mouse model. Epithelial cells (Caco-2 and enterocytes from mouse gut) and macrophages were stimulated with . and induction of luciferase under the NF-κB promoter, ROS and cytokines production were studied. Balb/c mice were mucosally sensitized with cow´s milk proteins plus cholera toxin and orally challenged with the allergen to evidence hypersensitivity symptoms. After that, mice were orally administered with heat-killed . as treatment and then challenged with the allergen. The therapeutic efficacy was (clinical score and cutaneous test) and (serum specific antibodies and cytokines-ELISA, and cell analysis-flow cytometry) evaluated. Heat-killed . modulated the induction of pro-inflammatory chemokines, with an increase in anti-inflammatory cytokines by intestinal epithelial cells and by macrophages with decreased OX40L expression. , oral administration of . increased the frequency of lamina propria CD4CD25FoxP3 T cells, and clinical signs were lower in . -treated mice compared with milk-sensitized animals. depletion of Tregs (anti-CD25) abrogated . immunomodulation. In conclusion, these bacteria suppressed the intestinal inflammatory immune response to reverse food allergy.
Topics: Actinobacteria; Animals; Caco-2 Cells; Humans; Immune Tolerance; Interleukin-10; Intestinal Mucosa; Mice; Mice, Inbred BALB C; Milk Hypersensitivity; T-Lymphocytes, Regulatory; Th2 Cells
PubMed: 33995359
DOI: 10.3389/fimmu.2021.641597 -
Microbiology Spectrum Dec 2023species have been clinically regarded as rare but emerging opportunistic pathogens causing various infections in humans. pneumonia has often been misdiagnosed as...
species have been clinically regarded as rare but emerging opportunistic pathogens causing various infections in humans. pneumonia has often been misdiagnosed as pulmonary tuberculosis due to its clinical presentation resembling tuberculosis-like syndromes. species have also been confused in the laboratory with other phylogenetic bacteria, such as . This study aimed to investigate the clinical, microbiological, and molecular characteristics; species distribution; and antimicrobial susceptibility of species. Immunodeficiency and chronic pulmonary disease appeared to be risk factors for pneumonia, and the presence of bronchiectasis and pulmonary nodules on imaging was highly correlated with this infection. The study confirmed that (heat shock protein 60) and (the secretion ATPase) genes are reliable for identifying species. Additionally, the (stable small RNA) gene showed promise as a tool for discriminating between different species with the shortest sequence length. In terms of antimicrobial susceptibility, quinolones, trimethoprim/sulfamethoxazole, amikacin, minocycline, linezolid, and tigecycline demonstrated potent activity against isolates in our study. The study also proposed a resistance mechanism involving a substitution (S91R) within the quinolone-resistance-determining region of the gene, which confers resistance to levofloxacin and ciprofloxacin. Furthermore, we found that disk diffusion testing is not suitable for testing the susceptibilities of isolates to ciprofloxacin, imipenem, and minocycline. In conclusion, our systematic investigation may contribute to a better understanding of this rare pathogen. species are rare but emerging human pathogens that share remarkable similarities with other mycolic acid-containing genera of the order Actinomycetales, especially . Consequently, misdiagnosis and therapeutic failures can occur in clinical settings. Despite the significance of accurate identification, antimicrobial susceptibility, and understanding the resistance mechanism of this important genus, our knowledge in these areas remains fragmentary and incomplete. In this study, we aimed to address these gaps by investigating promising identification methods, the antimicrobial susceptibility patterns, and a novel quinolone resistance mechanism in species, utilizing a collection of clinical isolates. The findings of our study will contribute to improve diagnosis and successful management of infections caused by species, as well as establishing well-defined performance and interpretive criteria for antimicrobial susceptibility testing.
Topics: Humans; Minocycline; Phylogeny; Microbial Sensitivity Tests; Actinomycetales; Quinolones; Ciprofloxacin; Hospitals, Teaching; Anti-Infective Agents; China; Pneumonia; Anti-Bacterial Agents
PubMed: 37874148
DOI: 10.1128/spectrum.01644-23 -
Microbes and Infection May 2012The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic organisms, exhibiting filamentous branching structures... (Review)
Review
The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic organisms, exhibiting filamentous branching structures which fragment into rods or coccoid forms. Lung pathogens of the order comprise Mycobacterium, Nocardia, Corynebacterium, Actinomyces, Kytococcus, Rothia, Williamsia, as well as Gordonia, Tsukamurella and Rhodococcus. Particularly, members of the last three genera are uncommon aerobic agents of lung cavitations and tuberculosis(TB)-like syndromes, that should be carefully considered in the aetiology of parenchymal lesions. Correct identification of such organisms is hard to obtain, but is crucial to provide patients with adequate diagnose and treatment. Then, this review aims to unearth their airway tropism, as well as their clinical impact as agents of lung disease.
Topics: Actinomycetales; Actinomycetales Infections; Humans; Pneumonia, Bacterial
PubMed: 22192786
DOI: 10.1016/j.micinf.2011.11.014 -
Marine Drugs Jul 2022Three new glycosylated secondary metabolites, including a new indole alkaloid, pityriacitrin D (), and two new trehalose lipids ( and ), together with three known...
Three new glycosylated secondary metabolites, including a new indole alkaloid, pityriacitrin D (), and two new trehalose lipids ( and ), together with three known compounds (-) were isolated from two marine-derived bacterial strains, 168CLC-66.1 and IV19-045. The structures of - were determined by extensive analysis and comparison of their spectroscopic data with literature values. The absolute configurations of sugar moieties were determined by chemical derivatization followed by LC-MS analysis. Cytotoxicity of - against six cancer cell lines was evaluated by SRB assay, and showed moderate activity against all the tested cell lines with GI values ranging from 8.0 to 10.9 µM.
Topics: Actinomycetales; Bacteria; Molecular Structure
PubMed: 35877757
DOI: 10.3390/md20070464 -
Emerging Infectious Diseases Jul 2022Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP...
Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP 111916), Tsukamurella toyonakaense, from a patient given a misdiagnosis of nontuberculous mycobacterial pulmonary disease caused by unidentified mycobacteria. Genomic identification of this Tsukamurella species helped clarify its clinical characteristics and epidemiology.
Topics: Humans; Lung Diseases; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 35731181
DOI: 10.3201/eid2807.212320 -
Scientific Reports May 2022Co-culture is an efficient strategy for natural product discovery. We have used mycolic acid-containing bacteria (MACB) Tsukamurella pumonis TP-B0596 to induce secondary...
Co-culture is an efficient strategy for natural product discovery. We have used mycolic acid-containing bacteria (MACB) Tsukamurella pumonis TP-B0596 to induce secondary metabolism by actinomycetes and have found several natural products. We also observed that MACB attached to the mycelium of Streptomyces lividans forming coaggregates during combined-culture. This stimulated interest in the interactions among actinomycetes and MACB, and we found that soil isolated cultures contained a mixture of actinomycetes and MACB. Our previously observed interactions were the result of selective screening and combination of bacteria in the lab, which warranted investigation of the existence of these interactions in the natural soil environment. Therefore, in this paper, we report the interaction between a co-isolated natural pair of actinomycetes and MACB in terms of morphology and metabolic changes. A natural pair of actinomycetes and MACB co-aggregated in liquid culture and showed metabolic changes. Interestingly, co-aggregated actinomycetes and MACB were re-isolated from soil with no obvious morphological colony differences from the colony of a single strain. The results demonstrate that there is a stochastic chance of picking colonies containing co-aggregated actinomycetes and MACB, which suggests that the pair can exist in co-aggregate form in the soil environment and interact with each other.
Topics: Actinobacteria; Actinomyces; Bacteria; Biological Products; Mycolic Acids; Soil
PubMed: 35508597
DOI: 10.1038/s41598-022-11406-2 -
Scientific Reports Aug 2020Although many advances have been achieved to treat aggressive tumours, cancer remains a leading cause of death and a public health problem worldwide. Among the main...
Although many advances have been achieved to treat aggressive tumours, cancer remains a leading cause of death and a public health problem worldwide. Among the main approaches for the discovery of new bioactive agents, the prospect of microbial secondary metabolites represents an effective source for the development of drug leads. In this study, we investigated the actinobacterial diversity associated with an endemic Antarctic species, Deschampsia antarctica, by integrated culture-dependent and culture-independent methods and acknowledged this niche as a reservoir of bioactive strains for the production of antitumour compounds. The 16S rRNA-based analysis showed the predominance of the Actinomycetales order, a well-known group of bioactive metabolite producers belonging to the Actinobacteria phylum. Cultivation techniques were applied, and 72 psychrotolerant Actinobacteria strains belonging to the genera Actinoplanes, Arthrobacter, Kribbella, Mycobacterium, Nocardia, Pilimelia, Pseudarthrobacter, Rhodococcus, Streptacidiphilus, Streptomyces and Tsukamurella were identified. The secondary metabolites were screened, and 17 isolates were identified as promising antitumour compound producers. However, the bio-guided assay showed a pronounced antiproliferative activity for the crude extracts of Streptomyces sp. CMAA 1527 and Streptomyces sp. CMAA 1653. The TGI and LC values revealed the potential of these natural products to control the proliferation of breast (MCF-7), glioblastoma (U251), lung/non-small (NCI-H460) and kidney (786-0) human cancer cell lines. Cinerubin B and actinomycin V were the predominant compounds identified in Streptomyces sp. CMAA 1527 and Streptomyces sp. CMAA 1653, respectively. Our results suggest that the rhizosphere of D. antarctica represents a prominent reservoir of bioactive actinobacteria strains and reveals it as an important environment for potential antitumour agents.
Topics: Actinobacteria; Actinomycetales; Antarctic Regions; Anthracyclines; Antineoplastic Agents; Biological Factors; Cell Line, Tumor; Cell Proliferation; Culture Techniques; Dactinomycin; Drug Discovery; Humans; Neoplasms; Streptomyces
PubMed: 32807803
DOI: 10.1038/s41598-020-69786-2