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Evaluation of 2D ion chamber arrays for patient specific quality assurance using a static phantom at a 0.35 T MR-Linac. Z Med Phys 2024:S0939-3889(23)00150-2. [PMID: 38184375 DOI: 10.1016/j.zemedi.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/31/2023] [Accepted: 12/18/2023] [Indexed: 01/08/2024]
Abstract
INTRODUCTION Patient specific quality assurance (QA) in MR-Linacs can be performed with MR-compatible ion chamber arrays. However, the presence of a static magnetic field can alter the angular response of such arrays substantially. This works investigates the suitability of two ion chamber arrays, an air-filled and a liquid-filled array, for patient specific QA at a 0.35 T MR-Linac using a static phantom. METHODS In order to study the angular response, the two arrays were placed in a static, solid phantom and irradiated with 9.96 × 9.96 cm2 fields every 10° beam angle at a 0.35 T MR-Linac. Measurements were compared to the TPS calculated dose in terms of gamma passing rate and relative dose to the central chamber. 20 patient specific quality assurance plans were measured using the liquid-filled array. RESULTS The air-filled array showed asymmetric angular response changes of central chamber dose of up to 18% and down to local 3 mm / 3% gamma rates of 20%, while only minor differences within 3% (excluding parallel irradiation and beams through the couch edges) were found for the liquid-filled ion chamber array without rotating the phantom. Patient plan QA using the liquid-filled array yielded a median local 3 mm / 3% 3D gamma passing rate of 99.8% (range 96.9%-100%). CONCLUSION A liquid-filled ionization chamber array in combination with a static phantom can be used for efficient patient specific plan QA in a single measurement set-up in a 0.35 T MR-Linac, while the air-filled ion chamber array phantom shows large angular response changes and has its limitations regarding patient specific QA measurements.
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Abstract
As a biochemist, Louis Pasteur focused on fermentation, demonstrating that it was a vital process. In 1860, he discovered anaerobic life and the strict anaerobes, particularly those responsible for butyric fermentation. Then, in spite of his lack of medical background, Pasteur turned to investigating the role of bacteria in human and animal diseases. In 1877, Pasteur and Joubert described for the first time a pathogenic anaerobe, the 'septic vibrio' (now Clostridium septicum). Not only was the bacterium cultivated, but the disease symptoms described and the disease experimentally reproduced. Pasteur also described what are now known as mixed anaerobic infections. A historical review of Pasteur's work is made in the light of our present knowledge of this field.
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244 RISK OF NEED FOR EXTRACORPOREAL MEMBRANE OXYGENATION SUPPORT IN NEONATES WITH CONGENITAL DIAPHRAGMATIC HERNIA TREATED WITH INHALED NITRIC OXIDE. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Use of high-frequency jet ventilation in neonates with hypoxemia refractory to high-frequency oscillatory ventilation. J Matern Fetal Neonatal Med 2003; 13:398-402. [PMID: 12962265 DOI: 10.1080/jmf.13.6.398.402] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To describe the response to high-frequency jet ventilation in infants with hypoxemic respiratory failure unresponsive to high-frequency oscillatory ventilation. METHODS This was a retrospective analysis of chart records on demographics, ventilator settings, blood gas analysis and calculated oxygenation index prior to and during the first 7 days of high-frequency jet ventilation in ten consecutive infants. RESULTS Before the initiation of high-frequency jet ventilation, the ventilatory mean airway pressure (MAP; cmH2O), fraction of inspired oxygen (FiO2) and oxygenation index on high-frequency oscillatory ventilation were 14.3 +/- 1.3, 0.97 +/- 0.02 and 29 +/- 5, respectively. Three hours after the initiation of high-frequency jet ventilation, the oxygenation index improved to 18 +/- 4 (p < 0.001) and the improvement was sustained during the study period. By 6 h of high-frequency jet ventilation, the FiO2 decreased to 0.62 +/- 0.09 (p < 0.01) and, by 1-3 h of ventilation, the MAP decreased to 10.9 +/- 1.3 (p < 0.01). The improvement in FiO2 persisted for 7 days while, although the MAP remained lower throughout the study, the improvement in MAP failed to reach statistical significance after 72 h. No significant changes in pH, pCO2, or pO2 before or during high-frequency jet ventilation were noted. CONCLUSION High-frequency jet ventilation improves hypoxemic respiratory failure unresponsive to high-frequency oscillatory ventilation in infants. These findings suggest that not all high-frequency ventilatory devices yield the same clinical results.
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The mechanism of radiotherapy responsible for the prevention of heterotopic ossification: a cellular and subcellular analyze of an in vitro model using the mesenchymal C2C12 cell line of the mouse. Int J Radiat Oncol Biol Phys 2001. [DOI: 10.1016/s0360-3016(01)01903-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Novel Diffusion Analysis in Advanced Chemically Amplified DUV Resists Using Photometric Methods. J PHOTOPOLYM SCI TEC 1999. [DOI: 10.2494/photopolymer.12.695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
An enterotoxigenic strain of Bacteroides fragilis was the sole organism isolated from the cerebrospinal fluid of a two-and-a-half-month neonate who had a medullary-colonic fistula as part of a complex congenital malformation, but no brain abscess. A rapid latex particle agglutination test for detection of bacterial antigen was positive for Haemophilus influenzae type b, suggesting that Bacteroides fragilis and Haemophilus influenzae type b might share some capsular antigens. In order to determine the role of the enterotoxin with respect to virulence of the strain, antibodies to a 20 kDa protein were sought in the patient's serum, but Western blot of the culture supernatant revealed only antibodies to a 45 kDa bacterial protein. The patient was successfully treated with metronidazole and imipenem.
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Plasmids pIP419 and pIP421 from Bacteroides: 5-nitroimidazole resistance genes and their upstream insertion sequence elements. MICROBIOLOGY (READING, ENGLAND) 1995; 141 ( Pt 4):927-35. [PMID: 7773395 DOI: 10.1099/13500872-141-4-927] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The genetic organization of two different 5-nitroimidazole (5-Ni) resistance genes was investigated: nimC and nimD from Bacteroides plasmids pIP419 and pIP421, respectively. The nimC gene (492 bp) and the nimD gene (495 bp) directed the synthesis of polypeptides with deduced molecular masses of 18.37 kDa and 18.48 kDa, respectively. The predicted proteins showed 67-83% identity and 78-91% similarity with the products of two other nimA and nimB genes previously described and could be derived from a common ancestral gene. An insertion sequence element (IS1170) was identified upstream of the nimC gene. IS1170 is 1604 bp in length and is flanked by imperfect inverted repeats (15 bp). IS1170 is similar to the Bacteroides insertion sequence element IS942 with an identity of 70% at the nucleotide level. The single copy of IS1170 present on plasmid pIP419 is integrated 24 bp upstream of the initiation codon of nimC. Similar genetic organization was found on plasmid pIP421. One copy of another insertion sequence (IS1169) was found 4 bp upstream of the first ATG codon of the nimD gene. This element (1325 bp) shows a strong homology at the nucleotide level (70% identity) with IS1186 and IS1168 found to be associated with the Bacteroides carbapenem resistance gene cfiA, and the 5-Nirgenes nimA and nimB, respectively. There is strong evidence that, as in the case of the cfiA gene, the transcription of the four nim genes so far studied is directed by outward-oriented promoters, carried on the right ends of the different insertion sequence elements.
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Abstract
This review focuses on genetic and molecular data regarding antibiotic resistance in anaerobes, particularly Clostridium perfringens, Clostridium difficile, Bacteroides species, and Prevotella species. The determinants of resistance are frequently transferable through a conjugation-like process; plasmid self-transfer, plasmid mobilization, or (in Bacteroides species) chromosomal conjugative elements can be involved. The determinants can be localized on transposons. At the genetic level, resistance determinants can be highly specific for one or several anaerobes or may exhibit homology with genes from aerobes. The latter observation suggests that anaerobes are able to exchange genetic material from a "gene pool" shared with aerobic organisms.
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Nucleotide sequence analysis of two 5-nitroimidazole resistance determinants from Bacteroides strains and of a new insertion sequence upstream of the two genes. Antimicrob Agents Chemother 1994; 38:1047-51. [PMID: 8067736 PMCID: PMC188148 DOI: 10.1128/aac.38.5.1047] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
DNA sequence analysis of regions from plasmid pIP417 and chromosome BF8 which encode 5-nitroimidazole resistance in Bacteroides strains allowed the identification of two open reading frames corresponding to new genes, nimA (528 bp) and nimB (492 bp). Either gene may confer 5-nitroimidazole resistance to susceptible strains of Bacteroides. The encoded polypeptides have deduced molecular masses of 20.1 and 18.6 kDa, respectively, and share about 73% identity and 85% similarity. A new insertion sequence (IS) element named IS1168 lies 14 bases upstream of the nimA gene. The complete sequence of IS1168 was determined. A similar IS exists 12 bp upstream of the nimB gene. About 60% of the BF8 IS element was also sequenced and shown to be almost identical to IS1168.
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Abstract
The recent finding that Bacillus stearothermophilus adenylate kinase contains a zinc atom coordinated to four cysteines prompted us to investigate the metal-binding properties of the enzyme from various bacteria. We conclude that zinc was present only in adenylate kinase from gram-positive species and that this property is correlated with the presence of three or four Cys residues in the sequence Cys-X2-Cys-X16-Cys-X2-Cys/Asp, in which X stands for different amino acid residues.
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Botulinum antibodies in dystonic patients treated with type A botulinum toxin: frequency and significance. Neurology 1993; 43:1715-8. [PMID: 8414019 DOI: 10.1212/wnl.43.9.1715] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We measured serum antibodies to botulinum toxin (ABT) in 96 patients with focal dystonia who had been treated with type A botulinum toxin. The frequency of detectable ABT was 3% (three patients). Patients with ABT had received more than 50 ng of botulinum toxin, and the shortest time between two injections was significantly less than in patients without ABT. The clinical evolution of the three patients was heterogeneous: one had decreased effectiveness with repeated injections, another had persistent improvement, and the third never responded to toxin injections.
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Abstract
Thirty-three clinical isolates of Bacteroides strains with a moderate-to-high level of resistance to 5-nitroimidazole were compared with three strains previously studied by Southern blotting of their DNA. Whether plasmid-borne or chromosomally determined, all genetic determinants that are resistant to 5-nitroimidazole belong to two hybridization groups.
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Characterization of restriction endonuclease BfrBI from Bacteroides fragilis strains BE3 and AIP 10006. FEMS Microbiol Lett 1992; 74:133-6. [PMID: 1526445 DOI: 10.1016/0378-1097(92)90418-n] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A new type II restriction endonuclease, named BfrBI, was detected in two strains of Bacteroides fragilis, BE3 and AIP 10006 (NCTC 9343T). The enzyme BfrBI, an isoschizomer of NsiI and AvaIII, recognized the hexanucleotide sequence [5'-ATG decreases CAT-3'], with a cleavage site generating blunt ends.
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Cloning of aBacteroides fragilischromosomal determinant coding for 5-nitroimidazole resistance. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05334.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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17
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Cloning of a Bacteroides fragilis chromosomal determinant coding for 5-nitroimidazole resistance. FEMS Microbiol Lett 1992; 74:1-5. [PMID: 1516803 DOI: 10.1016/0378-1097(92)90728-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Strain BF8 is a plasmid-free Bacteroides fragilis, resistant to 5-nitroimidazole (5-Ni) antibiotics (metronidazole, ornidazole and tinidazole). The resistance was transferable by conjugation into Bacteroides fragilis BF638R. The total DNA of a Nir transconjugant was used for the construction of a Sau3A genomic library in a B. fragilis cloning vector pFK707 delta H1 (4.2 kb). By electrotransformation of strain BF638R, a recombinant plasmid containing an insert of 5.4 kb was obtained which conferred to the host strain the resistance to 5-Ni. The physical map of the insert was established. After deletion analysis of the insert, the Nir determinant was localized on a HpaII-HincII fragment of 1.6 kb in size. This Nir determinant has been compared by Southern-blot analysis with other Bacteroides Nir determinants of plasmid origin.
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Characterization of restriction endonucleaseBfrBI fromBacteroides fragilisstrains BE3 and AIP 10006. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05355.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Genetic and molecular analysis of pIP417 and pIP419: Bacteroides plasmids encoding 5-nitroimidazole resistance. Plasmid 1992; 27:181-90. [PMID: 1513876 DOI: 10.1016/0147-619x(92)90020-b] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This report describes a genetic and molecular analysis of two transferable Bacteroides plasmids, pIP417 and pIP419, which carry genetic determinants conferring low-level resistance to 5-nitroimidazoles. The restriction endonuclease cleavage sites for each plasmid were localized. The NiR genetic determinants of pIP417 and pIP419 plasmids have been cloned into the Bacteroides cloning vector pBI191 (C.J. Smith, J. Bacteriol. 164, 294-301, 1985) as PvuII and Sau3A fragments, respectively. Both inserts had different restriction sites and did not cross-hybridize by Southern blot analysis. Genetic data obtained by cloning into pBI191 clearly show that the PvuII-generated fragments A (Rep) and B (Mob) of pIP417 are involved in plasmid replication and transfer, respectively. Although encoding resistance to the same antibiotic, both plasmids appeared different with regard to the 5-nitroimidazole resistance and replication genetic determinants. However, they share a homology in a region involved, at least in one case, in plasmid transfer. Considering the spontaneous high level of resistance to 5-nitroimidazole in Escherichia coli, this work, based on direct gene cloning into Bacteroides, demonstrates the value of such an approach.
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[Abscess of the penis caused by Plevotella biviae (Bacteroides bivius)]. Presse Med 1991; 20:1947-8. [PMID: 1837094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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[Capnocytophaga meningitis in a non immunocompromised patient]. Presse Med 1991; 20:709-10. [PMID: 1828587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Pathogenicite des bacteries anaerobies. Med Mal Infect 1990. [DOI: 10.1016/s0399-077x(05)80049-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Clostridium bifermentans serovar malaysia: sporulation, biogenesis of inclusion bodies and larvicidal effect on mosquito. Res Microbiol 1990; 141:721-33. [PMID: 1980958 DOI: 10.1016/0923-2508(90)90066-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sporulation of Clostridium bifermentans serovar malaysia, which has a larvicidal activity towards mosquitoes, was examined by electron microscopy. Parasporal inclusion bodies lacking a crystalline structure were first detected at t5 (5 h after the end of exponentional growth). Also, the presence of "brush-bottle"-like appendages appearing first at t5 was noted; these remained attached to the spores when released after sporangium lysis. Larvicidal activity assayed on Anopheles stephensi larvae appeared at t0 and increased rapidly to a maximum between t5 and t8. However, a decrease in bacterial toxicity occurred with sporangium lysis.
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[Bacteriologic diagnosis of Clostridium perfringens infection]. LA REVUE DU PRATICIEN 1990; 40:689-90. [PMID: 2183343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
We report the characterization of a strain of Bacteroides vulgatus, BV17, that exhibits a moderate resistance to 5-nitroimidazoles and carries plasmids of 4.5, 5, 7.7, and 56 kb. A genetic determinant involved in this resistance is carried by the 7.7 +/- 0.2-kb plasmid (pIP417). This plasmid can be introduced and replicated in a sensitive strain of B. fragilis 638R by transformation or by conjugation. In the latter case, the transfer may involve mobilization by the 56-kb conjugative plasmid (pIP418) regularly found in transconjugants but not in transformants.
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Presence of Choline in Teichoic acid of Clostridium acetobutylicum N1-4 and Choline Inhibition of Autolytic Functions. Microbiology (Reading) 1988. [DOI: 10.1099/00221287-134-6-1603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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29
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Transfection and transformation ofClostridium acetobutylicum strain N1-4081 protoplasts. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01875765] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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30
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[Isolation of Propionibacterium acnes from a cervical lymph node in Whipple's disease]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 1987; 11:524-6. [PMID: 2440756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Sporomusa paucivorans sp. nov., a Methylotrophic Bacterium That Forms Acetic Acid from Hydrogen and Carbon Dioxide. ACTA ACUST UNITED AC 1987. [DOI: 10.1099/00207713-37-2-93] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Place des bactéries anaérobies à Gram positif non sporulées dans les suppurations survenant en chirurgie orthopédique. A propos de 49 cas. Med Mal Infect 1986. [DOI: 10.1016/s0399-077x(86)80062-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Conjugal transfer of plasmid-mediated antibiotic resistance from streptococci to Clostridium acetobutylicum. ANNALES DE L'INSTITUT PASTEUR. MICROBIOLOGIE 1985; 136B:275-82. [PMID: 3938632 DOI: 10.1016/s0769-2609(85)80073-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Three broad host-range MLS plasmids, pAM beta 1 (Em), pIP501 (Em, Cm) and pJH4 (Em, Sm, Km), were transferred by a conjugation-like process from Streptococcus faecalis to Clostridium acetobutylicum. The plasmids were stably maintained and antibiotic resistances were fully expressed in C. acetobutylicum, except for chloramphenicol resistance, which was poorly expressed, if at all. The C. acetobutylicum strains harbouring every plasmid could be used as donors in intraspecific matings with frequencies of approximately 1 X 10(-5) to 1 X 10(-6).
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Isolation and characterization of butanol-resistant mutants of Clostridium acetobutylicum. Appl Environ Microbiol 1985; 50:1238-43. [PMID: 4091556 PMCID: PMC238732 DOI: 10.1128/aem.50.5.1238-1243.1985] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In a wild-type strain of Clostridium acetobutylicum isolated from soil, solvent production appeared limited by butanol toxicity. Butanol-resistant mutants have been obtained which produced significantly higher solvent concentrations (about 30%) than the wild-type strain. Some other physiological differences were observed between a selected resistant mutant and the wild-type strain at the level of solvent resistance and sporulation.
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Plasmid detection and isolation in strains of Clostridium acetobutylicum and related species. MOLECULAR & GENERAL GENETICS : MGG 1983; 189:178-80. [PMID: 6574306 DOI: 10.1007/bf00326075] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Twenty-one strains of Clostridium acetobutylicum, C. butylicum and Clostridium saccharoperbutylacetonicum were examined. Seven of them contained extrachromosomal DNA molecules, with a size ranging from 2.6 to more than 50 megadaltons. Strain M1 carries a small plasmid of 2.6 megadaltons, AB10 at least one plasmid of 2.6 megadaltons, AB12 one plasmid of 5.2 megadaltons, AB14 and AB16 a plasmid of about 7 megadaltons and a large one of more than 50 megadaltons, AB17 carries at least one plasmid of 6.7 megadaltons and AB18 two plasmids (4-6 megadaltons and 10-12 megadaltons). All of them are cryptic as at present no function can be correlated with their presence in a bacterial strain.
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Macrolide, lincosamide, streptogramin and tetracycline transferable resistance in the Bacteroides fragilis group. J Antimicrob Chemother 1981; 8 Suppl D:87-94. [PMID: 6802794 DOI: 10.1093/jac/8.suppl_d.87] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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Resistance to tetracycline, erythromycin, and clindamycin in the Bacteroides fragilis group: inducible versus constitutive tetracycline resistance. Antimicrob Agents Chemother 1981; 20:314-20. [PMID: 7305321 PMCID: PMC181693 DOI: 10.1128/aac.20.3.314] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The transferability of plasmid-mediated tetracycline, erythromycin, and clindamycin resistance was studied in 63 clinical isolates of the Bacteroides fragilis group. Of 48 strains which were tetracycline resistant (Tcr), the regulation of both the expression of Tcr and its transferability was shown to be under inducible control by tetracycline. In 29 of the strains, Tcr was transferable; in the majority of these (26 strains), transferability was inducible (Trai) and it was constitutive (Trac) in only 3 strains. All four possible phenotypes were found (Tci Trai, Tci Trac, Tcc Trai, and Tcc Trac), which indicates independent control of both Tcr expression and its transferability. Resistance to erythromycin and clindamycin was cotransferred with Tcr in 14 of the 48 Tcr strains and transferred independently of Tcr in only 1 strain.
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Transposon-like structures in the Bacteroides fragilis MLS plasmid plP 410. MOLECULAR & GENERAL GENETICS : MGG 1981; 181:559-61. [PMID: 6267427 DOI: 10.1007/bf00428754] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Homoduplexes of plasmid plP 410 encoding MLS resistance in Bacteroides fragilis strain 92 revealed two "transposon-like" structures: a 17.4 kb loop flanked by 0.75 inverted repeats, and a 4.5 kb loop flanked by 0.2 kb inverted repeats. The large structure is deleted in a derivative plasmid harboured by a MLS susceptible strain. We have also showed that the long and short inverted repeats are structurally related.
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[Thermostable factor in Clostridium butyricum responsible for experimental pathogenesis]. COMPTES RENDUS DES SEANCES DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 1981; 292:763-6. [PMID: 6788394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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41
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[Detection of "Clostridium difficile" on minimal and selective medium and by immunofluorescence antibody staining (author's transl)]. ANNALES DE MICROBIOLOGIE 1981; 132:149-57. [PMID: 7015956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A minimal and selective medium containing 5 aminoacids, 3 vitamins, a low sugar concentration and 2 antibiotics (cefoxitin at 16 microgram/ml and streptomycin at 500 microgram/ml) is described for isolation of Clostridium difficile from the gut. Comparable results were obtained with this medium and using spore isolation by the sodium thioglycolate-lysozyme technique. An antiserum specific to C. difficile was prepared and used for detection by immunofluorescent antibody staining. This is a very sensitive technique which leads to a quick and early identification of this bacterial species.
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Abstract
In susceptible strain of Bacteroides fragilis, tetracycline uptake is biphasic. The initial phase is independent of adenosine 5'-triphosphate synthesis, which is coupled to fumarate reduction; this phase is not altered by expression of tetracycline resistance genes in a resistant strain. The second phase appears to occur by active transport, since it is largely reduced by rotenone, an inhibitor of electron transport to fumarate; moreover, this phase is under negative control of the tetracycline resistance gene.
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Common regulatory mechanism of expression and conjugative ability of a tetracycline resistance plasmid in Bacteroides fragilis. Nature 1979; 278:657-9. [PMID: 450069 DOI: 10.1038/278657a0] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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44
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Abstract
Resistance to clindamycin, erythromycin, streptogramins, and tetracycline was shown to be transferable from a clinical isolate of Bacteroides fragilis subspecies distasonis to a sensitive strain of B. fragilis subspecies fragilis. Resistance to clindamycin, erythromycin, and streptogramins was transferable from a clinical isolate of B. fragilis subspecies fragilis to the sensitive strain of B. fragilis subspecies fragilis. Except for tetracycline, resistance to all of these antibiotics was spontaneously curable en bloc at a frequency of approximately 10(-2). These results suggest that resistance to these antibiotics is determined by a plasmid.
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45
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46
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[Saprophytic and pathogenic anaerobes]. LA REVUE DU PRATICIEN 1977; 27:97-102. [PMID: 834951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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47
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[Current aspects of botulism]. LA REVUE DU PRATICIEN 1977; 27:173-6. [PMID: 834949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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48
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[Gynecologic infections due to anaerobes]. LA REVUE DU PRATICIEN 1977; 27:149-54. [PMID: 834946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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49
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[Research and identification of anaerobes in current bacteriology]. LA REVUE DU PRATICIEN 1977; 27:107-18. [PMID: 319518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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50
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[Transfer of the tetracycline-chloramphenicol plasmid in Clostridium perfringens]. COMPTES RENDUS HEBDOMADAIRES DES SEANCES DE L'ACADEMIE DES SCIENCES. SERIE D: SCIENCES NATURELLES 1975; 281:317-9. [PMID: 172257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two plasmids which confer resistance to Tetracycline-Chloramphenicol and Erythromycine-Clindamycine were found in a strain of Clostridium perfringens. The plasmid (Tet-Chl) was shown to be transferable to sensitive strains of C. perfringens. The transfer experiments were made with the wild type strain or strains cured by one plasmid or the other as donor strains.
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