ABSTRACT
Veillonella parvula is a non-motile gram-negative coccus that forms part of the normal microbiota in several body sites and which has been rarely isolated as cause of infections in human population, particularly in bacteremias. Here we give the overview of characteristics of genus Veillonella and the summary of its role in infections, particularly in bacteremia. We additionally report two patients with bacteremia due to V. parvula. Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as V. parvula by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. The two patients were male and one of them had risk factors for anaerobic bacteremia. The isolates were susceptible to most antibiotics and the outcome was successful in both patients. Bacteremia due to V. parvula is still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification of these species.
Subject(s)
Anti-Bacterial Agents , Bacteremia , Gram-Negative Bacterial Infections , RNA, Ribosomal, 16S , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Veillonella , Humans , Bacteremia/microbiology , Bacteremia/diagnosis , Male , RNA, Ribosomal, 16S/genetics , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Veillonella/genetics , Veillonella/isolation & purification , Veillonella/classification , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/diagnosis , Middle Aged , Sequence Analysis, DNA , Aged , Microbial Sensitivity Tests , DNA, Bacterial/genetics , Treatment Outcome , AdultABSTRACT
The composition and functioning of soil bacterial communities, as well as their responses to multiple perturbations, are not well understood in the terrestrial ecosystems. Our study focuses on the bacterial community of erosive and poorly developed soils (Haplic Leptosols) in Mediterranean rangelands of Extremadura (W Spain) with different grazing intensities. Leptosols from similar natural conditions were selected and sampled at two depths to determine the soil properties as well as the structure and activity of bacterial communities. As grazing intensified, the soil C and N content increased, as did the number and diversity of bacteria, mainly of fast-growing lineages. Aridibacter, Acidobacteria Gp6 and Gp10, Gemmatimonas, and Segetibacter increased their abundance along the grazing-intensity gradient. Firmicutes such as Romboutsia and Turicibacter from livestock microbiome also increased. In functional terms, the KEGG pathways enriched in the soils with moderate and high grazing intensity were ABC transporters, DNA repair and recombination proteins, the two-component system, and the degradation of xenobiotics. All of these proved to be related to stronger cell division and response mechanisms to environmental stressors such as drought, warming, toxic substances, and nutrient deprivation. Consequently, the bacterial community was affected by grazing, but appeared to adapt and counteract the effects of a high grazing intensity. Therefore, a clearly detrimental effect of grazing was not detected in the bacterial community of the soils studied.
Subject(s)
Ecosystem , Microbiota , Animals , Livestock , Soil Microbiology , Bacteria/genetics , Acidobacteria , Soil/chemistryABSTRACT
BACKGROUND: Iron deficiency is the top leading cause of anaemia, whose treatment has been shown to deteriorate gut health. However, a comprehensive analysis of the intestinal barrier and the gut microbiome during IDA have not been performed to date. This study aims to delve further into the analysis of these two aspects, which will mean a step forward minimising the negative impact of iron supplements on intestinal health. METHODS: IDA was experimentally induced in an animal model. Shotgun sequencing was used to analyse the gut microbiome in the colonic region, while the intestinal barrier was studied through histological analyses, mRNA sequencing (RNA-Seq), qPCR and immunofluorescence. Determinations of lipopolysaccharide (LPS) and bacteria-specific immunoglobulins were performed to assess microbial translocation. RESULTS: Microbial metabolism in the colon shifted towards an increased production of certain amino acids, short chain fatty acids and nucleotides, with Clostridium species being enriched during IDA. Structural alterations of the colonic epithelium were shown by histological analysis. RNA-Seq revealed a downregulation of extracellular matrix-associated genes and proteins and an overall underdeveloped epithelium. Increased levels of serum LPS and an increased immune response against dysbiotic bacteria support an impairment in the integrity of the gut barrier during IDA. CONCLUSIONS: IDA negatively impacts the gut microbiome and the intestinal barrier, triggering an increased microbial translocation. This study emphasizes the deterioration of gut health during IDA and the fact that it should be addressed when treating the disease.
ABSTRACT
Iron deficiency anemia (IDA) is a global public health concern affecting 1.6 billion people worldwide. The administration of iron supplements during the treatment of IDA adversely affects the intestinal barrier function and the composition and functionality of the intestinal microbiome, both of which are already altered during IDA. For this reason, it is of great interest to develop nutritional strategies aimed at alleviating these gut alterations associated with IDA and its treatment. In this sense, fermented goat's milk (FGM) was studied due to its nutritional quality. Our findings showed that in anemic animals the consumption of a FGM-based diet, compared to a standard diet, had positive modulatory effects on the intestinal microbiome. FGM-based diet restored intestinal dysbiosis, the intestinal barrier functionality, and bacterial translocation, contributing to a more efficient recovery of IDA. Therefore, FGM is a useful nutritional tool to ease intestinal alterations occurring during IDA and during its treatment.
Subject(s)
Anemia, Iron-Deficiency , Gastrointestinal Microbiome , Animals , Humans , Milk/microbiology , Anemia, Iron-Deficiency/drug therapy , Iron , GoatsABSTRACT
Clostridium innocuum is a Gram-positive anaerobic spore-forming bacillus that has been identified as part of the normal intestinal microbiota. This bacterium has been rarely associated with human infections, and only few severe infections have been reported until now. In this work, we report on four patients with bacteremia due to C. innocuum, which were well identified by MALDI-TOF MS. Moreover, a review of the previous published cases of bacteremia due to this anaerobic bacterium has been performed.
Subject(s)
Bacteremia , Clostridium Infections , Humans , Clostridium Infections/drug therapy , Anti-Bacterial Agents/therapeutic use , Base Composition , Sequence Analysis, DNA , RNA, Ribosomal, 16S , Phylogeny , Clostridium , Bacteremia/drug therapy , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Murdochiella asaccharolytica is a Gram-positive anaerobic coccus firstly isolated from wound specimens, since then, it was very rarely isolated from human infections. We report the first case of bloodstream infection due to this bacterium in a 90 years-old-man. The patient had a history of B-cell lymphoma and presented with pain and induration of the base of penis along with fever. A blood culture was obtained yielding M. asaccharolytica in pure culture. Only resistance to clindamycin was demonstrated. Treatment with metronidazole was started and the clinical evolution improved with antimicrobial treatment, being discharged after 6 days.
Subject(s)
Bacteremia , Bacterial Infections , Gram-Positive Cocci , Male , Humans , Aged, 80 and over , Bacteria, Anaerobic , Bacterial Infections/drug therapy , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteremia/microbiology , Metronidazole/therapeutic use , Bacteria , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
We report an uncommon case of bacteremia due to Lancefieldella parvula isolated in pure culture. We present a 72 year-old-man affected with cancer admitted with abdominal pain due to a parietal rupture of the urinary bladder. After surgical treatment, the patient developed fever and two sets of blood cultures yielded a pure culture of an anaerobic microorganism identified as L. parvula (formerly Atopobium parvulum) by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. The isolate was susceptible to all antibiotics and the outcome was finally successful. Bacteremia due to L. parvula is an uncommon disease and, in that case, MALDI-TOF MS was an useful tool for the initial identification.
Subject(s)
Actinobacteria , Bacteremia , Humans , Aged , RNA, Ribosomal, 16S/genetics , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteremia/etiology , Actinobacteria/genetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationSubject(s)
Humans , Male , Female , Middle Aged , Aged , Prevotella , Mediastinitis , Pleural Effusion , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: To report a series of four uncommon cases of bacteremia due to Parabacteroides distasonis. METHODS: We have analyzed the epidemiological characteristics, clinical features, diagnostic methods, treatment and outcome of these patients. RESULTS: Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as P. distasonis by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. All patients were male and they had risk factors for anaerobic bacteremia. All isolates were susceptible to metronidazole and the outcome was successful in three patients. CONCLUSIONS: Bloodstream infections due to P. distasonis are still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification.
Subject(s)
Bacteremia , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteroidetes/genetics , Female , Humans , Male , RNA, Ribosomal, 16S/genetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methodsABSTRACT
Sleeping sickness or African trypanosomiasis is a serious health concern with an added socio-economic impact in sub-Saharan Africa due to direct infection in both humans and their domestic livestock. There is no vaccine available against African trypanosomes and its treatment relies only on chemotherapy. Although the current drugs are effective, most of them are far from the modern concept of a drug in terms of toxicity, specificity and therapeutic regime. In a search for new molecules with trypanocidal activity, a high throughput screening of 2000 microbial extracts was performed. Fractionation of one of these extracts, belonging to a culture of the fungus Amesia sp., yielded a new member of the curvicollide family that has been designated as curvicollide D. The new compound showed an inhibitory concentration 50 (IC50) 16-fold lower in Trypanosoma brucei than in human cells. Moreover, it induced cell cycle arrest and disruption of the nucleolar structure. Finally, we showed that curvicollide D binds to DNA and inhibits transcription in African trypanosomes, resulting in cell death. These results constitute the first report on the activity and mode of action of a member of the curvicollide family in T. brucei.
Subject(s)
Trypanocidal Agents , Trypanosoma brucei brucei , Trypanosomiasis, African , Animals , Fungi , Humans , Trypanocidal Agents/chemistry , Trypanocidal Agents/pharmacology , Trypanosomiasis, African/drug therapyABSTRACT
Prevotella species are Gram-negative anaerobic bacilli mainly involved in oral cavity infections. We report a rare case of bacteremia due to P. oris of probable hepatic origin. A 70-year-old man with a history of diabetes mellitus was admitted for general malaise, fever and dyspnea. The patient was admitted to the ICU due to septic shock. Two sets of blood cultures yielded a pure culture of an anaerobic microorganism identified as P. oris by MALDI-TOF MS. The same microorganism was isolated from a hepatic abscess drainage. Only resistance to penicillin was documented. Treatment with piperacillin-tazobactam and levofloxacin was administered, and the patient was discharged following his recovery.
Subject(s)
Bacteremia , Prevotella , Aged , Bacteremia/diagnosis , Bacteremia/drug therapy , Humans , Male , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationSubject(s)
Humans , Female , Adult , Pantoea , Bacteremia , Gram-Negative Facultatively Anaerobic Rods , Intensive Care Units , Case-Control Studies , Communicable Diseases , MicrobiologyABSTRACT
Phocaeicola (Bacteroides) dorei is a Gram-negative anaerobic bacillus that is rarely isolated from human specimens. Its accurate identification can be hampered by its close taxonomic relationship with Bacteroides vulgatus. We report on two patients with bacteremia due to P. (B.) dorei, which was initially identified as B. vulgatus by MALDI-TOF MS.
Subject(s)
Bacteremia , Bacteroides , Bacteremia/diagnosis , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Porphyromonas species are Gram-negative anaerobic bacilli mainly involved in human periodontal diseases. We report an uncommon case of bacteremia due to P. asaccharolytica in a patient with necrotizing fasciitis. A 52-year-old woman with a history of diabetes mellitus was admitted for an extensive necrotizing lesion on the left lower limb. After she developed septic shock, two sets of blood cultures were taken. Anaerobic bottles yielded a pure culture of a microorganism initially identified as P. uenonis by MALDI-TOF MS but with a low log score, and a gene sequencing technique was therefore applied, identifying the isolate as P. asaccharolytica. Only resistance to penicillin and clindamycin was documented. Treatment with meropenem was administered, and the patient was discharged following her recovery.
Subject(s)
Bacteremia/microbiology , Fasciitis, Necrotizing/microbiology , Porphyromonas/physiology , Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Fasciitis, Necrotizing/drug therapy , Female , Humans , Middle Aged , Porphyromonas/drug effects , Porphyromonas/genetics , Porphyromonas/isolation & purificationABSTRACT
Guanine quadruplexes (G4s) are non-canonical nucleic acid structures commonly found in regulatory genomic regions. G4 targeting has emerged as a therapeutic approach in cancer. We have screened naphthalene-diimides (NDIs), a class of G4 ligands, in a cellular model of colorectal cancer (CRC). Here, we identify the leading compound T5 with a potent and selective inhibition of cell growth by high-affinity binding to G4s in ribosomal DNA, impairing RNA polymerase I (Pol I) elongation. Consequently, T5 induces a rapid inhibition of Pol I transcription, nucleolus disruption, proteasome-dependent Pol I catalytic subunit A degradation and autophagy. Moreover, we attribute the higher selectivity of carbohydrate-conjugated T5 for tumoral cells to its preferential uptake through the overexpressed glucose transporter 1. Finally, we succinctly demonstrate that T5 could be explored as a therapeutic agent in a patient cohort with CRC. Therefore, we report a mode of action for these NDIs involving ribosomal G4 targeting.
Subject(s)
Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Enzyme Inhibitors/pharmacology , Imides/pharmacology , Naphthalenes/pharmacology , RNA Polymerase I/antagonists & inhibitors , Ribosomes/drug effects , Aged , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Cycle/drug effects , Cell Proliferation/drug effects , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Female , G-Quadruplexes/drug effects , Humans , Imides/chemistry , Male , Middle Aged , Naphthalenes/chemistry , RNA Polymerase I/metabolism , Ribosomes/metabolismABSTRACT
The application of next generation sequencing techniques has allowed the characterization of the urinary tract microbiome and has led to the rejection of the pre-established concept of sterility in the urinary bladder. Not only have microbial communities in the urinary tract been implicated in the maintenance of health but alterations in their composition have also been associated with different urinary pathologies, such as urinary tract infections (UTI). Therefore, the study of the urinary microbiome in healthy individuals, as well as its involvement in disease through the proliferation of opportunistic pathogens, could open a potential field of study, leading to new insights into prevention, diagnosis and treatment strategies for urinary pathologies. In this review we present an overview of the current state of knowledge about the urinary microbiome in health and disease, as well as its involvement in the development of new therapeutic strategies.