Dietzia Dotaz Zobrazit nápovědu
Častými „kontaminantami" zachycenými při mykobakteriologické kultivaci dekontaminovaných vzorků jsou bakterie řádu Actinomycetales. Jsou to obvykle bakterie klasifikované v čeledi Corynehacterineae rodů Corynebacteríum, Dietzia, Gordonia, Nocardia, Rhodococcus a Tsukamurella. Tyto bakterie často kolonizují dýchací cesty a za určitých podmínek mohou vyvolat život ohrožující onemocnění. U pacientů s těžkou imunodeficiencí jsou pravidelným vyvolavatelem život ohrožujících infekcí bakterie rodu Nocardia. Jsou to vláknité bakterie, vytvářející v kultuře vzdušné mycelium, jsou částečně acidorezistentní a jsou rezistentní na lysozym. Vyvolávají nokardiózu, tj. vzácné ale závažné onemocnění pacientů s různými typy imunodeficience. Diferenciálně diagnosticky je třeba odlišit rody Streptomyces, Actinomadura, Nocardiopsis a další půdní saprofyty, které nejsou acidorezistentní, jsou citlivé na lysozym a rychleji rostou. Často kolonizují dýchací cesty u pacientů s postižením plic, onemocnění vyvolávají velmi vzácně. Diagnostika aerobních aktinomycet a vyšetření citlivosti na antibiotika mají svá úskalí vyplývající z delší růstové doby, obtížné barvitelnosti a necharakteristických biochemických reakcí. K přesné identifikaci do rodu a species je nutná polyfázová identifikace izolatu s využitím metod molekulární mikrobiologie. Při včasné diagnóze bývají infekce vyvolané aerobními aktinomycetami dobře léčitelné cílenou terapií antibiotiky.
Frequent "contaminants" detected during mycobacterial culture of decontaminated samples are bacteria of the order Actinomycetales. These are usually bacteria classified as the family Corynebacterineae, genera Corynebacterium, Dietzia, Gordonia, Nocardia, Rhodococcus and Tsukamurella. These bacteria frequently colonize the airways and, under certain circumstances, they may cause life-threatening diseases. In severely immunocompromised patients, they regularly cause life-threatening infections with bacteria of the genus Nocardia. These filamentous bacteria, developing aerial mycelium in the culture, are partly acid-resistant and resistant to lysozyme. They cause nocardiosis, a rare but serious disease in patients with various types of immune deficiency. Differential diagnosis must distinguish between the genera Streptomyces, Actinomadura and Nocardiopsis and other soil saprophytes that are not acid-resistant, sensitive to lysozyme and faster growing. They frequently colonize the airways of patients with lung disease but very rarely cause diseases. The diagnosis of aerobic actinomycetes and determination of their sensitivity to antibiotics are problematic since they grow longer, are difficult to stain and are involved in atypical biochemical reactions. Precise identification of the genera and species requires polyphasic identification of isolates using molecular microbiology methods. If diagnosed early, infections caused by aerobic actinomycetes are easy to treat with targeted antibiotic therapy.
- Klíčová slova
- léčba, vyšetření citlivosti, identifikace, diagnostika, Tsukamurella, Gordonia, Dietzia, dekontaminované vzorky,
- MeSH
- Actinomycetales klasifikace růst a vývoj MeSH
- bakteriologické techniky MeSH
- Corynebacterium MeSH
- epidemiologie MeSH
- infekce bakteriemi řádu Actinomycetales diagnóza MeSH
- lidé MeSH
- Mycobacterium růst a vývoj MeSH
- Nocardia MeSH
- nokardióza MeSH
- Rhodococcus MeSH
- Streptomyces MeSH
- tuberkulóza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Subseafloor sediments present an untapped source of novel bacterial species with industrially important bioactivities. Subseafloor core samples collected during the Integrated Ocean Drilling Program Expeditions 315, 316, and 331 and stored in Kochi Core Center at -80 °C for 1 to 4 years were used for cultivation-based study of viable actinomycetes. In total, more than 100 actinomycete-like colonies were isolated from two deep-frozen subseafloor sediment samples. Isolated actinomycetes showed close similarity to known Actinotalea, Dietzia, Gordonia, Isoptericola, Microbacterium, Nocardia, Rhodococcus, Pseudonocardia, Streptomyces, and Tsukamurella species and were halotolerant. Bioactivity assays revealed that two of the isolates were producing potent antibacterial compound(s) and one isolate was having antifungal activity. Our study demonstrated that deep-frozen subseafloor core samples could be a potential source of viable actinomycetes, which may be used in drug discovery.
Pre-separation and pre-concentration of bacteria is an important step especially when they are uncultured and bacterial concentration in the matrix is low. This study describes a preparative method based on isoelectric focusing of colored microorganisms in a cellulose-based separation medium from a high conductivity matrix. The isoelectric points found for the examined cells were 1.8 for Micrococcus luteus, 3.5 for Dietzia sp., and 4.7 for Rhodotorula mucilaginosa using capillary isoelectric focusing. The final positions of the zones of colored microbial cells in the cellulose-bed are indicated by colored pI markers. Segments of the separation medium with cells were harvested by a spatula, simply purified using centrifugation and analyzed by capillary isoelectric focusing and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The determined recovery ranged from 78% to 93%. The viability of the harvested cells was verified by their cultivation.
BACKGROUND: Kissing bugs (Triatominae) are blood-feeding insects best known as the vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. Considering the high epidemiological relevance of these vectors, their biology and bacterial symbiosis remains surprisingly understudied. While previous investigations revealed generally low individual complexity but high among-individual variability of the triatomine microbiomes, any consistent microbiome determinants have not yet been identified across multiple Triatominae species. METHODS: To obtain a more comprehensive view of triatomine microbiomes, we investigated the host-microbiome relationship of five Triatoma species sampled from white-throated woodrat (Neotoma albigula) nests in multiple locations across the USA. We applied optimised 16S rRNA gene metabarcoding with a novel 18S rRNA gene blocking primer to a set of 170 T. cruzi-negative individuals across all six instars. RESULTS: Triatomine gut microbiome composition is strongly influenced by three principal factors: ontogeny, species identity, and the environment. The microbiomes are characterised by significant loss in bacterial diversity throughout ontogenetic development. First instars possess the highest bacterial diversity while adult microbiomes are routinely dominated by a single taxon. Primarily, the bacterial genus Dietzia dominates late-stage nymphs and adults of T. rubida, T. protracta, and T. lecticularia but is not present in the phylogenetically more distant T. gerstaeckeri and T. sanguisuga. Species-specific microbiome composition, particularly pronounced in early instars, is further modulated by locality-specific effects. In addition, pathogenic bacteria of the genus Bartonella, acquired from the vertebrate hosts, are an abundant component of Triatoma microbiomes. CONCLUSION: Our study is the first to demonstrate deterministic patterns in microbiome composition among all life stages and multiple Triatoma species. We hypothesise that triatomine microbiome assemblages are produced by species- and life stage-dependent uptake of environmental bacteria and multiple indirect transmission strategies that promote bacterial transfer between individuals. Altogether, our study highlights the complexity of Triatominae symbiosis with bacteria and warrant further investigation to understand microbiome function in these important vectors. Video abstract.
- MeSH
- Chagasova nemoc parazitologie MeSH
- divoká zvířata klasifikace mikrobiologie MeSH
- mikrobiota genetika fyziologie MeSH
- RNA ribozomální 16S genetika MeSH
- Triatominae klasifikace mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- audiovizuální média MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
