Ribosomal ribonucleic acid cistron homologies among Hyphomicrobium and various other bacteria

1977 ◽  
Vol 23 (4) ◽  
pp. 478-481 ◽  
Author(s):  
Richard L. Moore

The extent of hybrid formation between the ribosomal ribonucleic acid (r-RNA) of Hyphomicrobium strain B-522 and deoxyribonucleic acid (DNA) from bacteria of 21 different genera was examined. Three generalized groupings were formed. Group I (72–100%) consisted entirely of other strains of Hyphomicrobium. Representatives of the genera Rhodopseudomonas, Chromatium, Caulobacter, Prosthecomicrobium, Rhodomicrobium, Hyphomonas, and Hyphomicrobium made up group II (49–69%). The remaining Gram-negative, Gram-positive, and cell wall – less bacteria fell into group III (12–40%). The taxonomic implications of these results are discussed.

2016 ◽  
Vol 22 (5) ◽  
pp. 232-237
Author(s):  
Nina I. Gabrielyan ◽  
E. M Gorskaya ◽  
O. A Savostyanova ◽  
T. S Spirina ◽  
M. N Kornilov ◽  
...  

The study was carried out to investigate etiology and rate of prevalence of nosocomial strains of microbes in biosubstrates of patients in case of development of infectious complications and level of their resistance to various groups of antibiotics. The retrospective analysis of agents of post-operational infectious complications and their sensitivity to antibiotics in 99 patients after operations of transplantation of liver and kidneys in 2013. The patients were allocated on three groups: group I - patients of department of reanimation and intensive therapy after mentioned operations (17 individuals); group II (42 individuals) - after orthotopic transplantation of liver (19 patients) and orthotopic transplantation of kidneys (23 patients); group III (57 patients) - after kindred transplantation of hepatic lobe from living relative donor. The retrospective analysis of agents of post-operational infectious complications in patients underwent transplantation of liver and kidneys demonstrated that out of 1285 identified strains of microbes, 60.8% were presented by Gram-positive microflora with predominance of coagulase-negative staphylococci and enterococci. Among Gram-negative microflora, enterobacteria comprised the largest percentage (61%). The analysis of antibioticgrams of agents of infectious complications established low level of sensitivity of strains of both Gram-positive and Gram-negative microbes isolated from patients of department of reanimation and intensive therapy and to carbapenems and average level of sensitivity to Tigacil. In overall, poly-resistance of strains was established. The differences in antibiotics resistance for strains of pathogens isolated in department of reanimation and intensive therapy and specialized departments were established. The received data can be used for correction of application of antibiotics in prevention and therapy of post-operational infectious complications.


Author(s):  
B.K. Ghosh

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsukasa Tominari ◽  
Ayumi Sanada ◽  
Ryota Ichimaru ◽  
Chiho Matsumoto ◽  
Michiko Hirata ◽  
...  

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.


2004 ◽  
Vol 23 (6) ◽  
pp. 627-630 ◽  
Author(s):  
Mercedes Berlanga ◽  
M.Teresa Montero ◽  
Jordi Hernández-Borrell ◽  
Miquel Viñas

Author(s):  
Vinoo Subramaniam Ramachandran ◽  
Mensudar Rathakrishnan ◽  
Malathy Balaraman Ravindrran ◽  
Alargarsamy Venkatesh ◽  
Vidhya Shankari Shanmugasundaram ◽  
...  

Bacteria and its by-products are found to be the main cause of pulpal and periapical infection of tooth. Infected root canals of tooth harbours a wide variation of microbial flora that includes both Gram-positive and Gram-negative microorganisms. Bacterial components such as Lipopolysaccharide (LPS) of gram negative bacteria and Lipoteichoic Acid (LTA) of gram positive bacteria have the potential to enter the peri-apical tissue of tooth and initiate the inflammatory process. After microbial death that occurs either due to body’s defence cells or by antibiotic action, bacterial cell wall components such as LTA are released which can persist inside macrophages for prolonged periods causing chronic inflammation. Once these cell-wall components are recognized by the body immune surveillance cells, numerous inflammatory mediators are released leading to inflammation and subsequent pathological consequences. The purpose of this review is intend to summarize the role of gram positive bacterial component LTA in causing endodontic infection and use of potential therapeutic agents against LTA.


1999 ◽  
Vol 181 (20) ◽  
pp. 6347-6353 ◽  
Author(s):  
Richard van Kranenburg ◽  
Harmjan R. Vos ◽  
Iris I. van Swam ◽  
Michiel Kleerebezem ◽  
Willem M. de Vos

ABSTRACT Sixteen exopolysaccharide (EPS)-producing Lactococcus lactis strains were analyzed for the chemical compositions of their EPSs and the locations, sequences, and organization of theeps genes involved in EPS biosynthesis. This allowed the grouping of these strains into three major groups, representatives of which were studied in detail. Previously, we have characterized theeps gene cluster of strain NIZO B40 (group I) and determined the function of three of its glycosyltransferase (GTF) genes. Fragments of the eps gene clusters of strains NIZO B35 (group II) and NIZO B891 (group III) were cloned, and these encoded the NIZO B35 priming galactosyltransferase, the NIZO B891 priming glucosyltransferase, and the NIZO B891 galactosyltransferase involved in the second step of repeating-unit synthesis. The NIZO B40 priming glucosyltransferase gene epsD was replaced with an erythromycin resistance gene, and this resulted in loss of EPS production. This epsD deletion was complemented with priming GTF genes from gram-positive organisms with known function and substrate specificity. Although no EPS production was found with priming galactosyltransferase genes from L. lactis orStreptococcus thermophilus, complementation with priming glucosyltransferase genes involved in L. lactis EPS andStreptococcus pneumoniae capsule biosynthesis could completely restore or even increase EPS production in L. lactis.


1979 ◽  
Vol 57 (6) ◽  
pp. 879-888 ◽  
Author(s):  
L. Bonen ◽  
W. F. Doolittle ◽  
G. E. Fox

We report here the sequences of oligonucleotides released by T1-ribonuclease digestion of the 16S ribosomal RNA's (rRNA's) of the unicellular cyanobacteria Agmenellum quadruplicatum (strain BG-1) and Synechococcus 7502. We compare them with sequences previously obtained for the 16S rRNA's of six other cyanobacteria and two chloroplasts, and conclude that: (i) Synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes Agmenellum quadruplicatum, usually considered to be a Synechococcus; (ii) filamentous cyanobacteria of the genera Nostoc and Fischerella arose from within the Synechocystis group; (iii) phylogenetic diversity (and hence presumably evolutionary antiquity) within the Synechococcus group is very great; and (iv) red algal chloroplasts are of definite cyanobacterial origin, while Euglena chloroplasts are of separate and quite possibly noncyanobacterial origin. We also present the results of a computer-aided search among the 10 oligonucleotide 'catalogues' for families of related but nonidentical sequences. Examination of these families reinforces the above conclusions.


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