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Kompatscher M, Bartosik K, Erharter K, Plangger R, Juen F, Kreutz C, Micura R, Westhof E, Erlacher M. Contribution of tRNA sequence and modifications to the decoding preferences of E. coli and M. mycoides tRNAGlyUCC for synonymous glycine codons. Nucleic Acids Res 2024; 52:1374-1386. [PMID: 38050960 PMCID: PMC10853795 DOI: 10.1093/nar/gkad1136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 12/07/2023] Open
Abstract
tRNA superwobbling, used by certain bacteria and organelles, is an intriguing decoding concept in which a single tRNA isoacceptor is used to decode all synonymous codons of a four-fold degenerate codon box. While Escherichia coli relies on three tRNAGly isoacceptors to decode the four glycine codons (GGN), Mycoplasma mycoides requires only a single tRNAGly. Both organisms express tRNAGly with the anticodon UCC, which are remarkably similar in sequence but different in their decoding ability. By systematically introducing mutations and altering the number and type of tRNA modifications using chemically synthesized tRNAs, we elucidated the contribution of individual nucleotides and chemical groups to decoding by the E. coli and M. mycoides tRNAGly. The tRNA sequence was identified as the key factor for superwobbling, revealing the T-arm sequence as a novel pivotal element. In addition, the presence of tRNA modifications, although not essential for providing superwobbling, was shown to delicately fine-tune and balance the decoding of synonymous codons. This emphasizes that the tRNA sequence and its modifications together form an intricate system of high complexity that is indispensable for accurate and efficient decoding.
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Affiliation(s)
- Maria Kompatscher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Karolina Bartosik
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Kevin Erharter
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Raphael Plangger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Fabian Sebastian Juen
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, CNRS UPR 9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Matthias D Erlacher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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Baby V, Ambroset C, Gaurivaud P, Falquet L, Boury C, Guichoux E, Jores J, Lartigue C, Tardy F, Sirand-Pugnet P. Comparative genomics of Mycoplasma feriruminatoris, a fast-growing pathogen of wild Caprinae. Microb Genom 2023; 9:001112. [PMID: 37823548 PMCID: PMC10634449 DOI: 10.1099/mgen.0.001112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023] Open
Abstract
Mycoplasma feriruminatoris is a fast-growing Mycoplasma species isolated from wild Caprinae and first described in 2013. M. feriruminatoris isolates have been associated with arthritis, kerato conjunctivitis, pneumonia and septicemia, but were also recovered from apparently healthy animals. To better understand what defines this species, we performed a genomic survey on 14 strains collected from free-ranging or zoo-housed animals between 1987 and 2017, mostly in Europe. The average chromosome size of the M. feriruminatoris strains was 1,040±0,024 kbp, with 24 % G+C and 852±31 CDS. The core genome and pan-genome of the M. feriruminatoris species contained 628 and 1312 protein families, respectively. The M. feriruminatoris strains displayed a relatively closed pan-genome, with many features and putative virulence factors shared with species from the M. mycoides cluster, including the MIB-MIP Ig cleavage system, a repertoire of DUF285 surface proteins and a complete biosynthetic pathway for galactan. M. feriruminatoris genomes were found to be mostly syntenic, although repertoires of mobile genetic elements, including Mycoplasma Integrative and Conjugative Elements, insertion sequences, and a single plasmid varied. Phylogenetic- and gene content analyses confirmed that M. feriruminatoris was closer to the M. mycoides cluster than to the ruminant species M. yeatsii and M. putrefaciens. Ancestral genome reconstruction showed that the emergence of the M. feriruminatoris species was associated with the gain of 17 gene families, some of which encode defence enzymes and surface proteins, and the loss of 25 others, some of which are involved in sugar transport and metabolism. This comparative study suggests that the M. mycoides cluster could be extended to include M. feriruminatoris. We also find evidence that the specific organization and structure of the DnaA boxes around the oriC of M. feriruminatoris may contribute to drive the remarkable fast growth of this minimal bacterium.
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Affiliation(s)
- Vincent Baby
- Université de Bordeaux, INRAE, UMR BFP, F-33882, Villenave d’Ornon, France
- Present address: CDVUM, Faculté de médecine vétérinaire, Université de Montréal, 3200 rue Sicotte, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Chloé Ambroset
- Université de Lyon, Anses–Laboratoire de Lyon, VetAgro Sup, UMR Mycoplasmoses animales, 69007 Lyon, France
| | - Patrice Gaurivaud
- Université de Lyon, Anses–Laboratoire de Lyon, VetAgro Sup, UMR Mycoplasmoses animales, 69007 Lyon, France
| | - Laurent Falquet
- Department of Biology, University of Fribourg and Swiss Institute of Bioinformatics, CH-1700 Fribourg, Switzerland
| | | | - Erwan Guichoux
- Université de Bordeaux, INRAE, BIOGECO, 33610 Cestas, France
| | - Joerg Jores
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, CH-3001 Bern, Switzerland
| | - Carole Lartigue
- Université de Bordeaux, INRAE, UMR BFP, F-33882, Villenave d’Ornon, France
| | - Florence Tardy
- Université de Lyon, Anses–Laboratoire de Lyon, VetAgro Sup, UMR Mycoplasmoses animales, 69007 Lyon, France
- Present address: Mycoplasmology, Bacteriology and Antibioresistance Unit, Laboratoire Anses Ploufragan Plouzané Niort, BP 53, 31 rue des fusillés, F-22440 Ploufragan, France
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Janis C, Bischof D, Gourgues G, Frey J, Blanchard A, Sirand-Pugnet P. Unmarked insertional mutagenesis in the bovine pathogen Mycoplasma mycoides subsp. mycoides SC: characterization of a lppQ mutant. Microbiology (Reading) 2008; 154:2427-2436. [PMID: 18667575 PMCID: PMC2628567 DOI: 10.1099/mic.0.2008/017640-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycoplasma mycoides subspecies mycoides small colony (SC) is the aetiologic agent of contagious bovine pleuropneumonia (CBPP), a respiratory disease causing important losses in cattle production. The publication of the genome sequence of M. mycoides subsp. mycoides SC should facilitate the identification of putative virulence factors. However, real progress in the study of molecular mechanisms of pathogenicity also requires efficient molecular tools for gene inactivation. In the present study, we have developed a transposon-based approach for the random mutagenesis of M. mycoides subsp. mycoides SC. A PCR-based screening assay enabled the characterization of several mutants with knockouts of genes potentially involved in pathogenicity. The initial transposon was further improved by combining it with the transposon gammadelta TnpR/res recombination system to allow the production of unmarked mutations. Using this approach, we isolated a mutant free of antibiotic-resistance genes, in which the gene encoding the main lipoprotein LppQ was disrupted. The mutant was found to express only residual amounts of the truncated N-terminal end of LppQ. This approach opens the way to study virulence factors and pathogen-host interactions of M. mycoides subsp. mycoides SC and to develop new, genetically defined vaccine strains.
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Affiliation(s)
- Carole Janis
- INRA, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
- Université Victor Segalen Bordeaux 2, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
| | - Daniela Bischof
- Institute of Veterinary Bacteriology, Universität Bern, Laenggassstrasse 122, CH-3012 Berne, Switzerland
| | - Géraldine Gourgues
- INRA, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
- Université Victor Segalen Bordeaux 2, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
| | - Joachim Frey
- Institute of Veterinary Bacteriology, Universität Bern, Laenggassstrasse 122, CH-3012 Berne, Switzerland
| | - Alain Blanchard
- INRA, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
- Université Victor Segalen Bordeaux 2, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
| | - Pascal Sirand-Pugnet
- INRA, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
- Université Victor Segalen Bordeaux 2, UMR 1090, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
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Bischof DF, Janis C, Vilei EM, Bertoni G, Frey J. Cytotoxicity of Mycoplasma mycoides subsp. mycoides small colony type to bovine epithelial cells. Infect Immun 2008; 76:263-9. [PMID: 17998309 PMCID: PMC2223633 DOI: 10.1128/iai.00938-07] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 09/07/2007] [Accepted: 10/29/2007] [Indexed: 11/20/2022] Open
Abstract
The cytotoxicities of various strains of Mycoplasma mycoides subsp. mycoides small colony type (SC), the agent of contagious bovine pleuropneumonia (CBPP), were measured in vitro using embryonic calf nasal epithelial (ECaNEp) cells. Strains isolated from acute cases of CBPP induced high cytotoxicity in the presence of glycerol, concomitant with the release of large amounts of toxic H2O2 that were found to be translocated into the cytoplasms of the host cells by close contact of the Mycoplasma strains with the host cells. Currently used vaccine strains also showed high cytotoxicity and high H2O2 release, indicating that they are attenuated in another virulence attribute. Strains isolated from recent European outbreaks of CBPP with mild clinical signs, which are characterized by a defect in the glycerol uptake system, released small amounts of H2O2 and showed low cytotoxicity to ECaNEp cells. M. mycoides subsp. mycoides SC strain PG1 released large amounts of H2O2 but was only slightly cytotoxic. PG1 was found to have a reduced capacity to bind to ECaNEp cells and was unable to translocate H2O2 into the bovine cells, in contrast to virulent strains that release large amounts of H2O2. Thus, an efficient translocation of H2O2 into host cells is a prerequisite for the cytotoxic effect and requires an intact adhesion mechanism to ensure a close contact between mycoplasmas and host cells.
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Affiliation(s)
- Daniela F Bischof
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, Universität Bern, Länggass-Strasse 122, Postfach, CH-3001 Bern, Switzerland
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Bonvin-Klotz L, Vilei EM, Kühni-Boghenbor K, Kapp N, Frey J, Stoffel MH. Domain analysis of lipoprotein LppQ in Mycoplasma mycoides subsp. mycoides SC. Antonie Van Leeuwenhoek 2008; 93:175-83. [PMID: 17674137 PMCID: PMC2140093 DOI: 10.1007/s10482-007-9191-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 07/06/2007] [Indexed: 10/26/2022]
Abstract
The lipoprotein LppQ is the most prominent antigen of Mycoplasma mycoides subsp. mycoides small colony type (SC) during infection of cattle. This pathogen causes contagious bovine pleuropneumonia (CBPP), a devastating disease of considerable socio-economic importance in many countries worldwide. The dominant antigenicity and high specificity for M. mycoides subsp. mycoides SC of lipoprotein LppQ have been exploited for serological diagnosis and for epidemiological investigations of CBPP. Scanning electron microscopy and immunogold labelling were used to provide ultrastructural evidence that LppQ is located to the cell membrane at the outer surface of M. mycoides subsp. mycoides SC. The selectivity and specificity of this method were demonstrated through discriminating localization of extracellular (i.e., in the zone of contact with host cells) vs. integral membrane domains of LppQ. Thus, our findings support the suggestion that the accessible N-terminal domain of LppQ is surface exposed and such surface localization may be implicated in the pathogenesis of CBPP.
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Affiliation(s)
- Laetitia Bonvin-Klotz
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
| | - Edy M. Vilei
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
| | - Kathrin Kühni-Boghenbor
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
| | - Nadine Kapp
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
| | - Joachim Frey
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
| | - Michael H. Stoffel
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, Postfach, 3001 Bern, Switzerland
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Vilei EM, Correia I, Ferronha MH, Bischof DF, Frey J. Beta-D-glucoside utilization by Mycoplasma mycoides subsp. mycoides SC: possible involvement in the control of cytotoxicity towards bovine lung cells. BMC Microbiol 2007; 7:31. [PMID: 17439646 PMCID: PMC1855930 DOI: 10.1186/1471-2180-7-31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 04/17/2007] [Indexed: 12/20/2022] Open
Abstract
Background Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides small-colony type (SC) is among the most serious threats for livestock producers in Africa. Glycerol metabolism-associated H2O2 production seems to play a crucial role in virulence of this mycoplasma. A wide number of attenuated strains of M. mycoides subsp. mycoides SC are currently used in Africa as live vaccines. Glycerol metabolism is not affected in these vaccine strains and therefore it does not seem to be the determinant of their attenuation. A non-synonymous single nucleotide polymorphism (SNP) in the bgl gene coding for the 6-phospho-β-glucosidase (Bgl) has been described recently. The SNP differentiates virulent African strains isolated from outbreaks with severe CBPP, which express the Bgl isoform Val204, from strains to be considered less virulent isolated from CBPP outbreaks with low mortality and vaccine strains, which express the Bgl isoform Ala204. Results Strains of M. mycoides subsp. mycoides SC considered virulent and possessing the Bgl isoform Val204, but not strains with the Bgl isoform Ala204, do trigger elevated levels of damage to embryonic bovine lung (EBL) cells upon incubation with the disaccharides (i.e., β-D-glucosides) sucrose and lactose. However, strains expressing the Bgl isoform Val204 show a lower hydrolysing activity on the chromogenic substrate p-nitrophenyl-β-D-glucopyranoside (pNPbG) when compared to strains that possess the Bgl isoform Ala204. Defective activity of Bgl in M. mycoides subsp. mycoides SC does not lead to H2O2 production. Rather, the viability during addition of β-D-glucosides in medium-free buffers is higher for strains harbouring the Bgl isoform Val204 than for those with the isoform Ala204. Conclusion Our results indicate that the studied SNP in the bgl gene is one possible cause of the difference in bacterial virulence among strains of M. mycoides subsp. mycoides SC. Bgl does not act as a direct virulence factor, but strains possessing the Bgl isoform Val204 with low hydrolysing activity are more prone to survive in environments that contain high levels of β-D-glucosides, thus contributing in some extent to mycoplasmaemia.
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Affiliation(s)
- Edy M Vilei
- Institute of Veterinary Bacteriology, University of Bern, Länggass-Strasse 122, Postfach, CH-3001 Bern, Switzerland
| | - Ivone Correia
- Laboratório Nacional de Investigação Veterinária, Departamento de Biologia Celular, Estrada de Benfica 701, P-1549-011 Lisbon, Portugal
| | - M Helena Ferronha
- Laboratório Nacional de Investigação Veterinária, Departamento de Biologia Celular, Estrada de Benfica 701, P-1549-011 Lisbon, Portugal
| | - Daniela F Bischof
- Institute of Veterinary Bacteriology, University of Bern, Länggass-Strasse 122, Postfach, CH-3001 Bern, Switzerland
| | - Joachim Frey
- Institute of Veterinary Bacteriology, University of Bern, Länggass-Strasse 122, Postfach, CH-3001 Bern, Switzerland
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Wise KS, Foecking MF, Röske K, Lee YJ, Lee YM, Madan A, Calcutt MJ. Distinctive repertoire of contingency genes conferring mutation- based phase variation and combinatorial expression of surface lipoproteins in Mycoplasma capricolum subsp. capricolum of the Mycoplasma mycoides phylogenetic cluster. J Bacteriol 2006; 188:4926-41. [PMID: 16788201 PMCID: PMC1483001 DOI: 10.1128/jb.00252-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The generation of surface variation among many divergent species of Mollicutes (mycoplasmas) occurs through stochastic expression patterns of diverse lipoprotein genes. The size and wide distribution of such variable gene sets in minimal (approximately 0.6- to 1.4-Mb) mycoplasmal genomes suggest their key role in the adaptation and survival of these wall-less monoderms. Diversity through variable genes is less clearly established among phylogenetically similar mycoplasmas, such as the Mycoplasma mycoides cluster of ruminant pathogens, which vary widely in host range and pathobiology. Using (i) genome sequences from two members of this clade, Mycoplasma capricolum subsp. capricolum and M. mycoides subsp. mycoides small colony biotype (SC), (ii) antibodies to specific peptide determinants of predicted M. capricolum subsp. capricolum gene products, and (iii) analysis of the membrane-associated proteome of M. capricolum subsp. capricolum, a novel set of six genes (vmcA to vmcF) expressing distinct Vmc (variable M. capricolum subsp. capricolum) lipoproteins is demonstrated. These occur at two separate loci in the M. capricolum subsp. capricolum genome, which shares striking overall similarity and gene synteny with the M. mycoides subsp. mycoides SC genome. Collectively, Vmc expression is noncoordinate and combinatorial, subject to a single-unit insertion/deletion in a 5' flanking dinucleotide repeat that governs expression of each vmc gene. All vmc genes share modular regions affecting expression and membrane translocation. In contrast, vmcA to vmcD genes at one locus express surface proteins with highly structured size-variable repeating domains, whereas vmcE to vmcF genes express products with short repeats devoid of predicted structure. These genes confer a distinctive, dynamic surface architecture that may represent adaptive differences within this important group of pathogens as well as exploitable diagnostic targets.
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Affiliation(s)
- Kim S Wise
- Department of Molecular Microbiology and Immunology, University of Missouri-Columbia, M616 Medical Sciences Building, One Hospital Drive, Columbia, MO 65212, USA.
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Singh VP, Srivastava NC, Kumar M, Sunder MJ, Varshney JP. Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides type LC from a case of caprine arthritis. Comp Immunol Microbiol Infect Dis 2004; 27:273-84. [PMID: 15178001 DOI: 10.1016/j.cimid.2003.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides LC from a case of caprine arthritis is reported in the study. The isolate was identified based on biochemical, digitonin sensitivity and growth inhibition tests. The virulence of the organism was studied by pathogenicity test in mice and goat. The antigenic and genomic profile of the isolate was compared with that of the standard strain (Y-Goat). Using different sets of primers, polymerase chain reaction was employed for rapid detection of the strain.
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Affiliation(s)
- Vijendra P Singh
- National Referral Laboratory on Mycoplasma, Division of Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar, UP, India.
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Gasparich GE, Whitcomb RF, Dodge D, French FE, Glass J, Williamson DL. The genus Spiroplasma and its non-helical descendants: phylogenetic classification, correlation with phenotype and roots of the Mycoplasma mycoides clade. Int J Syst Evol Microbiol 2004; 54:893-918. [PMID: 15143041 DOI: 10.1099/ijs.0.02688-0] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The genus Spiroplasma (helical mollicutes: Bacteria: Firmicutes: Mollicutes: Entomoplasmatales: Spiroplasmataceae) is associated primarily with insects. The Mycoplasma mycoides cluster (sensu Weisburg et al. 1989 and Johansson and Pettersson 2002) is a group of mollicutes that includes the type species - Mycoplasma mycoides - of Mycoplasmatales, Mycoplasmataceae and Mycoplasma. This cluster, associated solely with ruminants, contains five other species and subspecies. Earlier phylogenetic reconstructions based on partial 16S rDNA sequences and a limited sample of Spiroplasma and Mycoplasma sequences suggested that the genus Mycoplasma was polyphyletic, as the M. mycoides cluster and the grouping that consisted of the hominis and pneumoniae groups of Mycoplasma species were widely separated phylogenetically and the M. mycoides cluster was allied with Spiroplasma. It is shown here that the M. mycoides cluster arose from Spiroplasma through an intermediate group of non-helical spiroplasmal descendants - the Entomoplasmataceae. As this conclusion has profound implications in the taxonomy of Mollicutes, a detailed phylogenetic study of Spiroplasma and its non-helical descendants was undertaken. These analyses, done with maximum-parsimony, provide cladistic status; a new nomenclature is introduced here, based on 'bottom-up' rather than 'top-down' clade classification. The order Entomoplasmatales consists of four major clades: (i) the Mycoides-Entomoplasmataceae clade, which contains M. mycoides and its allies and Entomoplasma and Mesoplasma species and is a sister lineage to (ii) the Apis clade of Spiroplasma. Spiroplasma and the Entomoplasmataceae are paraphyletic, but this status does not diminish their phylogenetic usefulness. Five species that were previously unclassified phylogenetically are basal to the Apis clade sensu strictu and to the Mycoides clade. One of these species, Spiroplasma sp. TIUS-1, has very poor helicity and a very small genome (840 kbp); this putative species can be envisioned as a 'missing link' in the evolution of the Mycoides-Entomoplasmataceae clade. The other two Spiroplasma clades are: (iii) the Citri-Chrysopicola-Mirum clade (serogroups I, II, V and VIII) and (iv) the ixodetis clade (serogroup VI). As Mesoplasma lactucae represents a basal divergence within the Mycoides-Entomoplasmataceae clade, and as Entomoplasma freundtii is basal to the Mycoides clade, M. mycoides and its allies must have arisen from an ancestor in the Entomoplasmataceae. The paraphyletic grouping that consists of the Hominis and Pneumoniae groups (sensu Johansson & Pettersson 2002) of Mycoplasma species contains the ancestral roots of Ureaplasma spp. and haemoplasmas. This clade is a sister lineage to the Entomoplasmatales clade. Serological classifications of spiroplasma are very highly supported by the trees presented. Genome size and G+C content of micro-organismal DNA were moderately conserved, but there have been frequent and polyphyletically distributed genome reductions. Sterol requirements were polyphyletic, as was the ability to grow in the presence of polyoxyethylene sorbitan-supplemented, but not serum-supplemented, media. As this character is not phylogenetically distributed, Mesoplasma and Entomoplasma should be combined into a single genus. The phylogenetic trees presented here confirm previous reports of polyphyly of the genus Mycoplasma. As both clades of Mycoplasma contain several species of great practical importance, a change of the genus name for species in either clade would have immense practical implications. In addition, a change of the genus name for M. mycoides would have to be approved by the Judicial Commission. For these reasons, the Linnaean and phylogenetic classifications of Mycoplasma must for now be discrepant.
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Affiliation(s)
- Gail E Gasparich
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA
| | - Robert F Whitcomb
- US Department of Agriculture, Vegetable Laboratory, BARC, Beltsville, MD 20705, USA
| | - Deborah Dodge
- Business Group Diagnostics, Bayer Corporation, Emeryville, CA 94608, USA
| | - Frank E French
- Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA
| | - John Glass
- Institute for Biological Energy Alternatives, 1901 Research Boulevard, Suite 600, Manassas, VA 20850, USA
| | - David L Williamson
- Department of Anatomical Sciences, State University of New York, Stony Brook, NY 11794, USA
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Djordjevic SP, Vilei EM, Frey J. Characterization of a chromosomal region of Mycoplasma sp. bovine group 7 strain PG50 encoding a glycerol transport locus (gtsABC). Microbiology (Reading) 2003; 149:195-204. [PMID: 12576593 DOI: 10.1099/mic.0.25742-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycoplasma species bovine group 7, represented by the type strain PG50, is one of six members of the Mycoplasma mycoides cluster and has been implicated in sporadic and outbreak cases of polyarthritis and mastitis in Australian dairy cattle. This study describes cloning and sequencing a 7.9 kb region of the PG50 chromosome and identification of genes involved in glycerol transport (gtsA, gtsB and gtsC) that are followed by a putative lipoprotein gene lppB and a genomic locus containing two ORFs encoding putative membrane proteins. Long range PCR using primers spanning gtsABC and downstream flanking genes, and Southern hybridization analyses using a suite of probes derived from M. mycoides subsp. mycoides small colony type (SC) strain Afadé for gtsA, gtsB and gtsC, lppB and the two downstream genes confirmed that these genes were conserved among Mycoplasma sp. bovine group 7 isolates and mycoplasmas belonging to the M. mycoides subcluster [M. mycoides subsp. mycoides SC, M. mycoides subsp. mycoides large colony type (LC) and M. mycoides subsp. capri] but were absent in mycoplasmas belonging to the Mycoplasma capricolum subcluster (M. capricolum subsp. capricolum and M. capricolum subsp. capripneumoniae). M. capricolum subsp. capricolum type strain California kid did not hybridize with the probe for gtsA and gave only weak or no hybridization signals with probes derived from the loci downstream of gtsABC, suggesting that this region has diverged in mycoplasmas belonging to subspecies of M. capricolum. It is shown that PG50, after the addition of a physiological concentration of glycerol to the growth medium, generates H(2)O(2) at levels comparable with strain Afadé, implying that the glycerol transport system is functional in Mycoplasma sp. bovine group 7. This suggests that in PG50, as in M. mycoides subsp. mycoides SC, glycerol uptake is followed by phosphorylation to glycerol 3-phosphate and then conversion to dihydroxyacetone phosphate, catalysed by L-alpha-glycerophosphate oxidase, resulting in the production of H(2)O(2). The ability of Mycoplasma sp. bovine group 7 to generate significant amounts of hydrogen peroxide may be important in pathogenesis.
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Affiliation(s)
- Steven P Djordjevic
- NSW Agriculture, Elizabeth Macarthur Agricultural Institute, Private Mail Bag 8, Camden, NSW, Australia 2570.
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Rice P, Houshaymi BM, Abu-Groun EA, Nicholas RA, Miles RJ. Rapid screening of H(2)O(2) production by Mycoplasma mycoides and differentiation of European subsp. mycoides SC (small colony) isolates. Vet Microbiol 2001; 78:343-51. [PMID: 11182500 DOI: 10.1016/s0378-1135(00)00305-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mycoplasma mycoides strains were screened for the ability to produce H(2)O(2) from glucose and glycerol metabolism using rapid and simple colorimetric assays. In quantitative assays, H(2)O(2) production by washed cell suspensions was detected by the oxidation of o-dianisidine in the presence of peroxidase. In qualitative assays, a 3,3'-diaminobenzidine-peroxidase reagent was applied to colonies on agar plates. Both methods enabled differentiation of European subsp. mycoides SC (small colony) isolates from other M. mycoides strains by their inability to produce H(2)O(2) from glycerol metabolism. In addition, two strains of subsp. capri were identified which produced large amounts of H(2)O(2) from glucose oxidation. In lysed cells of these strains, NADH oxidation gave approximately 1 mol H(2)O(2) per mol NADH oxidised whereas in 36 subsp. mycoides and 10 other subsp. capri strains, the quantity produced was 0.01-0.20mol H(2)O(2) per mol NADH oxidised.
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Affiliation(s)
- P Rice
- Division of Life Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, SE1 8WA, London, UK
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12
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Vilei EM, Frey J. Genetic and biochemical characterization of glycerol uptake in mycoplasma mycoides subsp. mycoides SC: its impact on H(2)O(2) production and virulence. Clin Diagn Lab Immunol 2001; 8:85-92. [PMID: 11139200 PMCID: PMC96015 DOI: 10.1128/cdli.8.1.85-92.2001] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Highly virulent strains of Mycoplasma mycoides subsp. mycoides SC belonging to the African cluster contain an operon with the genes gtsA, gtsB, and gtsC, encoding membrane ATP binding cassette transporter proteins GtsA, GtsB, and GtsC, which are involved in glycerol transport. Strain Afadé from the African cluster incorporated [U-(14)C]glycerol with a time-dependent increase. The less virulent strain L2 of the European cluster, which lacks gtsB and gtsC, failed to incorporate glycerol. Antibodies against GtsB noncompetitively inhibited glycerol uptake. L-alpha-Glycerophosphate was not transported by M. mycoides subsp. mycoides SC. It is postulated to be synthesized by phosphorylation of glycerol during transport and subsequently metabolized further to dihydroxyacetone phosphate accompanied by release of H(2)O(2). Peroxide production in glycerol-containing growth medium was high for the African strain Afadé but very low for the European strain L2. Virtually no H(2)O(2) was produced by both strains without glycerol. Hence, the efficient glycerol uptake system found in the virulent strain of the African cluster leads to a strong release of peroxide, a potential virulence factor which is lacking in the less virulent European strains. M. mycoides subsp. mycoides SC might have adopted, as a strategy for virulence, a highly efficient uptake system for glycerol which allows the production of an active metabolic intermediate that damages host cells.
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Affiliation(s)
- E M Vilei
- Institute for Veterinary Bacteriology, University of Berne, CH-3012 Berne, Switzerland
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Rice P, Houshaymi BM, Nicholas RA, Miles RJ. A rapid biochemical test to aid identification of Mycoplasma mycoides subsp. mycoides small colony (SC) strains. Lett Appl Microbiol 2000; 30:70-4. [PMID: 10728565 DOI: 10.1046/j.1472-765x.2000.00674.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability to utilize maltose, as determined by measurement of oxygen uptake, is used to differentiate Mycoplasma mycoides subsp. mycoides small colony (SC) and M. capricolum subsp. capripneumoniae (all strains negative) from other members of the M. mycoides cluster (M. mycoides subsp. capri, M. mycoides subsp. mycoides large colony (LC), M. capricolum subsp. capricolum; and bovine serogroup 7; 94% of strains positive). Rapid tests for maltose utilizing ability were developed, based on hydrolysis of a chromogenic alpha-glucosidase (maltase) substrate (p-nitrophenyl-alpha-D-glucopyranoside, colourless) to give a brightly coloured product (p-nitrophenol, yellow). On agar plates, colonies of maltose-utilizing strains became coloured within 40 min.
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Affiliation(s)
- P Rice
- Division of Life Sciences, King's College London, UK
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Macao B, Luirink J, Samuelsson T. Ffh and FtsY in a Mycoplasma mycoides signal-recognition particle pathway: SRP RNA and M domain of Ffh are not required for stimulation of GTPase activity in vitro. Mol Microbiol 1997; 24:523-34. [PMID: 9179846 DOI: 10.1046/j.1365-2958.1997.3551729.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mycoplasma mycoides contains a signal-recognition particle (SRP) composed of an RNA molecule and an SRP54 homologue (Ffh). We have now identified a mycoplasma homologue to the alpha subunit of the mammalian SRP receptor and Escherichia coli FtsY. The protein (MmFtsY) was expressed in E. coli and purified to homogeneity. MmFtsY has a weak intrinsic GTPase activity but GTP hydrolysis was markedly stimulated when it was combined with mycoplasma Ffh (MmFfh) and SRP RNA. Also, in the absence of SRP RNA GTPase activity was significantly enhanced. Furthermore, GTP hydrolysis was stimulated when MmFtsY was combined with the N-terminal GTPase domain (N+G) of MmFfh. These findings indicate that basic features of the GTPase activation mechanism are independent of the C-terminal M domain of the MmFfh protein. We propose that the activation is mediated to a large extent by contacts between the GTPase domains of the mycoplasma Ffh and FtsY proteins and that the contribution of the M domain and SRP RNA in the activation mechanism is mainly for modifying the conformation of the MmFfh GTPase domain.
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Affiliation(s)
- B Macao
- Department of Medical Biochemistry, Göteborg University, Sweden
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Houshaymi BM, Miles RJ, Nicholas RA. Oxidation of glycerol differentiates African from European isolates of Mycoplasma mycoides subspecies mycoides SC (small colony). Vet Rec 1997; 140:182-3. [PMID: 9055397 DOI: 10.1136/vr.140.7.182] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Jan G, Fontenelle C, Verrier F, Le Hénaff M, Wróblewski H. Selective acylation of plasma membrane proteins of Mycoplasma mycoides subsp. mycoides SC, the contagious bovine pleuropneumonia agent. Curr Microbiol 1996; 32:38-42. [PMID: 8555942 DOI: 10.1007/s002849900007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The plasma membrane of Mycoplasma mycoides subsp. mycoides SC (strain KH3J) contains over 160 polypeptides with apparent molecular masses ranging from 14 to 125 kDa and isoelectric point values (pIs) from 5 to 9. In vivo labeling with [14C]-fatty acids revealed about 35 acylated polypeptides including the two major components p42 and p65 and displaying pIs between 5.5 and 9.0, with a majority between 6.5 and 8. The amphiphilic nature of most of these acyl proteins was confirmed by Triton X-114 phase partitioning. Gas-liquid chromatography analyses showed that the order of preference for protein acylation was 16:0 > 18:2c > 18:1c > 18:0 > 14:0, with 16:0 being the major O-ester-bound fatty acyl chain and 18:2c the major N-linked chain. The presence of S-glycerylcysteine and a ratio of [O-ester-bound acyl chains + N-linked chains]/O-ester bound chains of approximately 1.2 in M. mycoides subsp. mycoides SC membrane proteins are consistent with a lipid modification similar to that occurring in lipoproteins of Gram-negative eubacteria that contain an N-terminal acyl S-glycerylcysteine.
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Affiliation(s)
- G Jan
- Département Membranes et Osmorégulation, CNRS URA n. 256, Université de Rennes, France
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17
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Abstract
A protein homologous to SRP54, a subunit of the mammalian signal recognition particle (SRP), was identified in Mycoplasma mycoides. The mycoplasma protein was expressed in E.coli and purified to near homogeneity. It was shown to bind specifically in vitro to a small mycoplasma RNA with structural features related to the RNA component of SRP. These findings provide evidence of a ribonucleoprotein complex in mycoplasma reminiscent of SRP. A part of the RNA was protected from ribonuclease digestion in the presence of the SRP54 homologue. The protected region contains structural elements that have been highly conserved in SRP RNAs during evolution.
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Affiliation(s)
- T Samuelsson
- Department of Medical Biochemistry, University of Göteborg, Sweden
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Abstract
Oxygen uptake and H2O2 accumulation during the metabolism of glucose and glycerol by whole cells, and of L-alpha-glycerophosphate (GP) and NADH by cells lysed with Triton, was determined for the type strains of six fermentative Mycoplasma species. Oxidation of glucose and of NADH by M. mycoides, M. pneumoniae and M. putrefaciens was accompanied by the accumulation of relatively small quantities of H2O2 (less than 0.05 mol/mol O2), though larger quantities (0.17-0.24 mol/mol O2) were produced by M. dispar. M. fermentans and M. canis were distinguished from the other strains used in that O2 uptake in the presence of glucose could not be demonstrated. However, metabolism of glucose was indicated by a reduction in the pH of the suspending medium and lysed cells oxidised NADH with the production of approximately 1.0 mol H2O2/mol O2 taken up. Glycerol was oxidised by all the strains studied except M. fermentans, and large quantities of H2O2 (0.48-1.07 mol/mol O2) accumulated. Cells of the glycerol-oxidising strains, lysed with Triton, oxidised GP with the production of approximately 1.0 mol H2O2/mol O2 utilised, which indicated the presence of a GP oxidase. The importance of H2O2 production as a factor in the pathogenicity of some mycoplasmas might depend upon the availability of glycerol in vivo.
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Affiliation(s)
- R J Miles
- Microbial Physiology Research Group, King's College, London
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Abstract
To select mutants lacking dAMP uptake, log-phase cells of Mycoplasma mycoides subsp. mycoides Y were incubated with high-specific-activity [32P]dAMP and then stored several weeks at -20 degrees C to allow 32P decay before plating out. Mutants were screened for lack of labeling by [32P]dAMP. Two mutants were studied further by uptake and growth experiments with other nucleotides.
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Affiliation(s)
- R Youil
- Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia
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Skala LZ, Nekhorosheva AG, Shabalova LA, Shanina AG. [Method of determining the antibiotic concentration in biological material]. Antibiot Med Biotekhnol 1987; 32:500-2. [PMID: 3118793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To lower the role of natural antibacterial activity of biological substrates from humans and laboratory animals in microbiological assay of bleomycin (bleomycin) with B. subtilis ATCC 6633 as the test-microbe, it was suggested to increase the procedure sensitivity by using the medium modification. In determining concentrations of aminoglycosides by the agar diffusion method the use of B. pumilus NCTC 8241 as the test-microbe is recommended.
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Iakovlev VP, Skala LZ, Slobodskoĭ RA, Nekhorosheva AG, Lur'e LA. [Ampicillin pharmacokinetics in prostatic adenoma patients]. Antibiot Med Biotekhnol 1987; 32:525-8. [PMID: 2445279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Studies on ampicillin pharmacokinetics in patients with prostate adenoma showed that adenoma did not influence the antibiotic kinetics. The ampicillin maximum concentration in tissues and organs of the urinary corresponded to the peak concentrations in blood. Therefore, development of dosage regimens providing the drug efficient concentrations in tissues and organs of the urinary tract should be based on ampicillin kinetics in the blood.
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22
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Skala LZ, Abramian RG, Shanina AG, Razgarova NK, Nekhorosheva AG. [Pharmacokinetics of benzylpenicillin and gentamycin administered by different routes to patients with acute and chronic nonspecific lung diseases]. Antibiot Med Biotekhnol 1987; 32:520-3. [PMID: 3118796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pharmacokinetic studies showed that endobronchial administration of benzylpenicillin and gentamicin to patients with acute and chronic pneumonia unlike intramuscular administration provided the antibiotic concentrations in bronchial secretions effective against middle sensitive and moderately resistant strains of microorganisms within 1-5 hours. Such concentrations maintained at the levels sufficient for inhibiting sensitive microflora growth for 24-36 hours with the use of benzylpenicillin and for 6 days with the use of gentamicin. This also lowered the risk of toxic complications.
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Iakovlev VP, Skala LZ, Nekhorosheva AG, Shabalova LA, Borisov IN. [Characteristics of intrarenal ampicillin distribution in chronic pyelonephritis in children]. Antibiot Med Biotekhnol 1987; 32:523-5. [PMID: 3314689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Pharmacokinetics and characteristic features of ampicillin kidney distribution were studied in 21 children with chronic pyelonephritis without signs of renal insufficiency who had undergone urological operations. It was found possible to provide the antibiotic concentrations efficient against ampicillin sensitive and partially middle sensitive microorganisms in the renal parenchyma, pelvis wall, ureterocele, megaureter and urinary bladder. Ampicillin concentrations in tissues of the urinary system were shown to correspond to a higher extent to the concentrations attained in blood than those in urine.
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Miles RJ, Beezer AE, Lee DH. Kinetics of utilization of organic substrates by Mycoplasma mycoides subsp. mycoides in a salts solution: a flow-microcalorimetric study. J Gen Microbiol 1985; 131:1845-52. [PMID: 3903037 DOI: 10.1099/00221287-131-8-1845] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The metabolism of various organic substrates by suspensions of Mycoplasma mycoides subsp. mycoides in a salts solution was followed by microcalorimetry. Enthalpy changes associated with metabolism were in good agreement with theoretical values. Substrate utilization showed Michaelis kinetics, allowing saturation constants (Km) and maximum specific rates of substrate utilization (Vmax) to be determined. In cells grown on a complex medium containing glucose, Km values were: glucose, fructose, N-acetylglucosamine, glycerol and pyruvate, less than 5 microM; lactate, 20 microM; glucosamine, 130 microns, and mannose, 1 mM. Values of Vmax for glycerol, pyruvate and lactate were similar and approximately twice those for glucose, mannose, glucosamine and N-acetylglucosamine; Vmax for fructose was one-quarter of that for glucose. In cells grown on complex medium in which glucose was replaced by mannose, glucosamine or N-acetylglucosamine, Vmax and Km for the respective growth sugars and for glucose were not significantly affected. However, in cells grown in the presence of fructose, Vmax for fructose increased to the value observed for glucose. It is suggested that M. mycoides is adapted to, and is constitutive for, the utilization of a single sugar (glucose), and a single amino sugar (N-acetylglucosamine), but that in the presence of fructose a fructose-utilizing pathway is induced.
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Abstract
Mycoplasma mycoides subsp. mycoides has been shown to possess an unusual capacity for the uptake and utilization of exogenous deoxyribonucleoside 5'-monophosphates intact without prior dephosphorylation. In this study, it was found that once inside the cell, deoxyribonucleoside 5'-monophosphates were rapidly phosphorylated to the triphosphate level and incorporated into DNA. Catabolism of deoxyribonucleoside 5'-monophosphates was also observed. Competition studies indicated that a single uptake system with a higher affinity for deoxyribonucleotides mediates the uptake of nucleoside 5'-monophosphates.
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Abstract
By measuring the specific activity of deoxyribonucleotides isolated from DNA after the incorporation of 14C-labeled precursors with and without competition from other nucleotide precursors, we defined the major pathways of pyrimidine deoxyribonucleotide synthesis in Mycoplasma mycoides subsp. mycoides. Uracil, guanine, and thymine are required for the synthesis of nucleotides. Cytidine competed effectively with uracil to provide all of the deoxycytidine nucleotide, as well as most of the deoxyribose-1-phosphate, for the synthesis of thymidylate from thymine via thymidine phosphorylase. Each of dUMP, dCMP, and dTMP competed with cytidine for incorporation into DNA thymidylate. Appreciable incorporation of exogenous deoxyribonucleoside 5'-monophosphates into DNA without prior dephosphorylation was observed. Dephosphorylation also occurred since the added deoxyribonucleotide provided phosphate for the synthesis of the other nucleotides in DNA in competition with the 32Pi in the growth medium. Hydroxyurea inhibited cell growth and decreased the intracellular level of dATP, consistent with the action of a ribonucleoside diphosphate reductase with regulatory properties similar to those of the Escherichia coli enzyme.
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Benyoucef M, Rigaud JL, Leblanc G. Cation transport mechanisms in Mycoplasma mycoides var. Capri cells. Na+-dependent K+ accumulation. Biochem J 1982; 208:529-38. [PMID: 6762210 PMCID: PMC1154001 DOI: 10.1042/bj2080529] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We have studied some features of K+ accumulation by glycolysing Mycoplasma mycoides var. Capri cells. We report that when Na+ is absent from the external medium, K+ accumulates up to the level predicted by the amplitude of the transmembrane electrical potential, delta psi m, measured by Rb+ and methyltriphenylphosphonium cation (TPMP+) distribution. Therefore, under these experimental conditions, the coupling mechanism of K+ uptake consists of a delta psi m-driven uniport. More important, when Na+ is present in the external medium, the level of K+ accumulation by glycolysing Mycoplasma cells is far too steep to be equilibrium with delta psi m (-120 mV for delta muK+ compared with -90mV for delta muRb+ or delta muTPMP+). Our results clearly indicate the presence in Mycoplasma of an active K+-transport system specifically stimulated by Na+. Furthermore, by controlling the amplitude of the energy-dependent delta muH+, we obtain strong evidence that this specific Na+-stimulated K+ transport is modulated by the transmembrane electrical potential. Finally, we show that ATP is consumed when such a transport system is in activity.
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Benyoucef M, Rigaud JL, Leblanc G. Cation transport mechanisms in Mycoplasma mycoides var. Capri cells. The nature of the link between K+ and Na+ transport. Biochem J 1982; 208:539-47. [PMID: 6219666 PMCID: PMC1154002 DOI: 10.1042/bj2080539] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have studied the links between the mechanisms of Na(+), K(+) and H(+) movements in glycolysing Mycoplasma mycoides var. Capri cells. In the light of the results reported in the preceding paper [Benyoucef, Rigaud & Leblanc (1982) Biochem. J.208, 529-538], we investigated certain properties of the membrane-bound ATPase of Mycoplasma cells, with special reference to its ionic requirements and sensitivity to specific inhibitors. Our findings show, first, that, although Na(+) stimulated ATPase activity, K(+) did not affect it, and, secondly, that NN'-dicyclocarboidi-imide and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD) were potent inhibitors of the basal ATPase activity, which was unaffected by vanadate and ouabain. We also investigated the movements of Na(+) and H(+) under the experimental conditions applied to the study of the K(+) uptake reported in the preceding paper, and found that when ;Na(+)-loaded cells' previously equilibrated with (22)Na(+) were diluted in a sodium-free medium, addition of glucose induced a rapid efflux of (22)Na(+). This energy-dependent efflux was independent of the presence of KCl in the medium. Studies of the changes in internal pH by 9-aminoacridine fluorescence or [(14)C]methylamine distribution indicated that the movement of Na(+) was coupled to that of protons moving in the opposite direction, a finding that supports the presence of an Na(+)/H(+) antiport. When Na(+)-loaded cells are diluted in an Na(+)-rich medium the Na(+)/H(+) antiport is still active, but cannot decrease the intracellular Na(+) concentration. Under such conditions, net (22)Na(+) extrusion is specifically dependent on the presence of K(+) in the medium. The present results and those derived from the study of K(+) accumulation (the preceding paper) can be rationalized by assuming that Mycoplasma mycoides var. Capri cells contain two transport systems for Na(+) extrusion: an Na(+)/H(+) antiport and an ATP-consuming Na(+)/K(+)-exchange system.
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Le Grimellec C, Leblanc G. Recent developments in the study of potassium transport in Mycoplasma mycoides subspecies capri. Rev Infect Dis 1982; 4 Suppl:S59-64. [PMID: 6126924 DOI: 10.1093/clinids/4.supplement_1.s59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The effects of modifications in the cholesterol and fatty acid contents of membranes on the transport of potassium have been studied in Mycoplasma mycoides subspecies capri. A decrease in the cholesterol content from 110 micrograms/mg of membrane protein to less than 10 micrograms/mg of membrane protein is associated with a decrease in the level of intracellular potassium from 40 micrograms of K/mg of protein to 23 micrograms of K/mg of cell protein. Replacement of oleate plus palmitate by elaidate alone in the growth medium has only limited effects on the intracellular K content. In metabolizing cells, 42K influxes were 0.42, 0.65, and 0.69 micrograms of K/mg of cell protein per min for cholesterol-rich cells supplemented with elaidate or with oleate plus palmitate and for cells adapted to low cholesterol and supplemented with elaidate, respectively. This increase in influx was associated with an increase in membrane fluidity as determined by fluorescence polarization experiments in which 1,6-diphenyl-1,3,5-hexatriene was used as a probe. For elaidate-supplemented cells, examination of the temperature dependence of 43K influx revealed the existence of a break or a discontinuity at temperatures corresponding to modifications in the physical state of the membrane. The lack of correspondence between the patterns of K+ influx and the Mg++-adenosine triphosphatase (ATPase) activity indicates that the sensitivity of this influx to the physical state of the membrane is not attributable to the Mg++-ATPase but likely reflects an effect of membrane lipids on the K+ carrier itself.
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Abstract
Mycoplasma mycoides subsp. mycoides grows readily but does not formylate methionyl-transfer ribonucleic acid in a defined medium without an added formyl donor. Formylation occurs when the medium is supplemented with N5,N10-methenyltetrahydrofolate or N10-formyltetrahydrofolate, but not with folate.
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31
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Abstract
The results presented show that in Mycoplasma mycoides var. Capri, regulation of glucose uptake by its non-metabolizable analogue methyl alpha-D-glucoside, can be used to control intracellular ATP content. This in turn leads to a control of the rate of proton extrusion catalysed by the Mg2+-dependent ATPase (phi (cHxN)2C H+) and the respective amplitudes of the components of delta mu H+. When Mycoplasma cells are incubated with 10 mM methyl alpha-D-glucoside, the amplitude of phi (cHxN)2C H+, of the electrical potential delta psi and of the chemical gradient delta pH become continuous functions of external glucose concentration within the limits of the non-energized and fully energized states. Analysis of the relationships between graduated amplitudes of delta psi, delta pH and phi (cHxN) 2C H+ show that the primary form of energy stored by a delta mu H+ generator is the electrical potential.
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Abstract
The electrochemical proton gradient, delta mu H+ generated upon glycolysis by Mycoplasma mycoides var. Capri cells has been determined. The components, the transmembrane pH gradient, delta pH, and the membrane potential, delta psi, were measured using several methods. The determination of the delta pH was conducted by measuring the transmembrane distribution of weak acids (acetate and butyrate) and of a weak base (methylamine), using flow dialysis and filtration techniques. The transmembrane electrical potential was determined from the distribution of the lipophilic cation Ph3MeP+ and of Rb+ or K+ in the presence of valinomycin. At extra-cellular pH 7.2, glycolyzing Mycoplasma cells maintain an internal pH more alkaline (0.5 pH unit) than that of the milieu and an electrical potential of - 85 mV, interior negative. The delta mu H+ in M. mycoides var. Capri cells is thus about - 115 mV. When the external pH was altered from 7.7 to 5.7 delta psi decreased from - 90 mV to - 60 mV. On other hand although the internal pH decreased, delta pH was found to increase from 0.2 to 1.0 pH unit. Since the changes in delta psi were largely compensated by the changes in delta pH, delta mu H+ remained practically constant at about - 115 mV throughout the pH range tested. Finally, inhibition of delta pH by N,N'-dicyclohexylcarbodiimide, carbonylcyanide-p-trifluoromethoxyphenylhydrazone or nigericin confirmed that chemiosmotic phenomena contribute to energy transduction across the membranes of M. mycoides var. Capri cells.
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33
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Buttery SH, Cottew GS, Lloyd LC. Effect of soluble factors from Mycoplasma mycoides subsp. mycoides on the collagen content of bovine connective tissue. J Comp Pathol 1980; 90:303-14. [PMID: 7000863 DOI: 10.1016/0021-9975(80)90066-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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34
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Leblanc G, Le Grimellec C. Active K+ transport in Mycoplasma mycoides var. Capri. Net and unidirectional K+ movements. Biochim Biophys Acta 1979; 554:156-67. [PMID: 378256 DOI: 10.1016/0005-2736(79)90015-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Analysis of the cation composition of growing Mycoplasma mycoides var. Capri indicates that these organisms have a high intracellular K+ concentration (Ki: 200--300 mM) which greatly exceeds that of the growth medium, and a low Na+ concentration (Na+i: 20 mM). Unlike Na+i,K+i varies with cell aging. The K+ transport properties studied in washed organisms resuspended in buffered saline solution show that cells maintain a steady and large K+ concentration gradient across their membrane at the expense of metabolic energy mainly derived from glycolysis. In starved cells, K+i decreases and is partially compensated by a gain in Na+. This substitution completely reverses when metabolic substrate is added (K+ reaccumulation process). Kinetic analysis of K+ movement in cells with steady K+ level shows that most of K+ influx is mediated by an autologous K+-K+ exchange mechanism. On the other hand, during K+ reaccumulation by K+-depleted cells, a different mechanism (a K+ uptake mechanism) with higher transport capacity and affinity drives the net K+ influx. Both mechanisms are energy-dependent. Ouabain and anoxia have no effect on K+ transport mechanisms; in contrast, both processes are completely blocked by dicyclohexylcarbodiimide, an inhibitor of the Mg2+ -dependent ATPase activity.
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Leblanc G, Le Grimellec C. Active K+ transport in Mycoplasms mycoides var. Capri. Relationships between K+ distribution, electrical potential and ATPase activity. Biochim Biophys Acta 1979; 554:168-79. [PMID: 36912 DOI: 10.1016/0005-2736(79)90016-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The addition of 5 . 10(-5) M or less of dicyclohexylcarbodiimide to Mycoplasma mycoides var. Capri preferentially influences K+ influx rather than efflux and reduces by 30--40% the activity of the membrane-bound Mg2+- ATPase. Adding valinomycin to metabolizing cells does not markedly affect K+ distribution but induces a rapid and complete loss of intracellular K+ in non-metabolizing cells. Uncoupling agents such as dinitrophenol, carbonylcyanide p-trifluoromethoxyphenylhydrazone, dissipate the K+ concentration gradient only when combined with valinomycin. Variations in the merocyanine fluorescence intensity indicate that a transmembrane electrical potential (delta psi) is generated on cell energization. This delta psi, not affected by valinomycin or uncouplers when used alone, is collapsed by a mixture of both. No change in fluorescence intensity can be detected when glucose is added to dicyclohexylcarbodiimide treated organisms. These experiments suggest that the membrane-bound Mg-ATPase activity control K+ distribution in these organisms through the generation of a transmembrane electrical potential difference.
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36
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Abstract
The major pathways of ribonucleotide biosynthesis in Mycoplasma mycoides subsp. mycoides have been proposed from studies on its use of radioactive purines and pyrimidines. To interpret more fully the observed pattern of pyrimidine usage, cell extracts of this organism have been assayed for several enzymes associated with the salvage synthesis of pyrimidine nucleotides. M. mycoides possessed uracil phosphoribosyltransferase, uridine phosphorylase, uridine (cytidine) kinase, uridine 5'-monophosphate kinase, and cytidine 5'-triphosphate synthetase. No activity for phosphorolysis of cytidine was detected, and no in vitro conditions were found to give measurable deamination of cytidine. Of the two potential pathways for incorporation of uridine, our data suggest that this precursor would largely undergo initial phosphorolysis to uracil and ribose-1-phosphate. Conversely, cytidine is phosphorylated directly to cytidine 5'-monophosphate in its major utilization, although conversion of cytidine to uracil, uridine, and uridine nucleotide has been observed in vivo, at least when uracil is provided in the growth medium. Measurements of intracellular nucleotide contents and their changes on additions of pyrimidine precursors have allowed suggestions as to the operation of regulatory mechanisms on pyrimidine nucleotide biosynthesis in M. mycoides in vivo. With uracil alone or uracil plus uridine as precursors of pyrimidine ribonucleotides, the regulation of uracil phosphoribosyltransferase and cytidine 5'-triphosphate synthetase is probably most important in determining the rate of pyrimidine nucleotide synthesis. When cytidine supplements uracil in the growth medium, control of cytidine kinase activity would also be important in this regard.
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37
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Rodwell AW, Rodwell ES. Relationships between strains of Mycoplasma mycoides subspp. mycoides and capri studied by two-dimensional gel electrophoresis of cell proteins. J Gen Microbiol 1978; 109:259-63. [PMID: 370343 DOI: 10.1099/00221287-109-2-259] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Strains of Mycoplasma mycoides subsp. mycoides have been divided into small colony (SC) and large colony (LC) types (Cottew & Yeats, 1978). The protein patterns of representative strains of these two types and of M. mycoides subsp. capri were compared by a high resolution, two-dimensional gel electrophoretic method. The results suggest that the LC strains are more closely related to M. mycoides subsp. capri than to the SC strains of M. mycoides subsp. mycoides.
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Abstract
The major pathways of ribonucleotide biosynthesis in Mycoplasma mycoides subsp. mycoides were proposed previously from studies of its usage of radioactive purines and pyrimidines. To interpret more fully the pattern of purine usage, we have assayed cell-free extracts of this organism for several enzymes associated with the salvage synthesis of purine nucleotides. M. mycoides possessed phosphoribosyltransferases for adenine, guanine, and hypoxanthine, purine nucleoside phosphorylase, GMP reductase, GMP kinase, adenylosuccinate synthetase, and adenylosuccinate lyase. Purine nucleoside kinase and adenosine deaminase were not detected. Examination of kinetic properties and regulation of some of the above enzymes revealed differences between M. mycoides and Escherichia coli. Most notable of these were the greater susceptibility of the enzymes from M. mycoides to inhibition by nucleotides and the more widespread involvement of GMP as an inhibitor. Observations on enzyme activities in vitro allow an adequate explanation of the capacity of guanine to provide M. mycoides with its full requirement for purine nucleotides.
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Abstract
Some strains of Mycoplasma mycoides subsp. mycoides, mostly isolated from goats, grow to greater turbidity in broth and form larger colonies on solid medium than does the type strain, PG1. These strains also digest casein, liquefy inspissated serum actively and survive longer at 45 degrees C and are referred to as LC (large colony) strains. Strains more closely resembling PG1 have been called SC (small colony) strains. The SC strains comprise those from contagious bovine pleuropneumonia (CBPP) and some from goats. One LC strain was isolated from a steer; all others have come from goats. Differentiation of M. mycoides subsp. mycoides into 2 types on the basis of the characteristics described may be relevant to their role in CBPP.
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Schiefer HG, Gerhardt U, Brunner H. Localization of a phosphoglycolipid in Mycoplasma membranes using specific anti-lipid-antibodies. Zentralbl Bakteriol Orig A 1977; 239:262-9. [PMID: 337735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A phosphoglycolipid, presumably identical to glyceryl-phosphoryldiglycosyl diglyceride, is the main component of the membrane glycolipids of Mycoplasma mycoides subsp. capri. It is immunologically active. Anti-phosphoglycolipid antibodies were induced in rabbits by intravenous injection of the flocculated complexes of methylated bovine serum albumin with a mixture of the phosphoglycolipid and the auxiliary lipids, phosphatidyl-choline and cholesterol. The specificities of the antibodies directed against the phosphoglycolipid, are due to both the phosphate and carbohydrate moieties of the lipid molecule. Anti-phosphoglycolipid antibodies were detected in the sera of rabbits intravenously immunized with intact M. mycoides subsp. capri. The intravenous method of immunization was chosen in order to select for a response to surface antigenic determinants. Anti-phosphoglycolipid antibodies specifically reacted with intact organisms and isolated membranes of M. mycoides subsp. capri, as shown by complement fixation and agglutination tests. The antigenic determinants of the phosphoglycolipid are mainly located on the outer membrane surface. It is concluded that the antigenic determinants of the phosphoglycolipid in intact M. mycoides subsp. capri significantly contribute to the surface architecture of mycoplasma membranes.
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Abstract
Aerobic reduction of tellurite by five Acholeplasma species and two Mycoplasma species was investigated by light and electron microscopy. Among the Acholeplasma species, colonies of A. laidlawii and A. oculi exhibited a heavy, macroscopically visible reduction of tellurite, whereas the reaction of A. axanthum was weaker. A. granularum and A. modicum did not reduce the substrate under the experimental conditions employed. The two subspecies of M. mycoides also reacted with tellurite, as did also the investigated strain of M. bovigenitalium although to a lesser extent. Ultrastructurally, reduction sites were localized to the cytoplasmic membrane in the three tellurite positive Acholeplasma species and apparently to the cytoplasm of M. mycoides subsp. mycoides. Reduction sites could not be demonstrated in M. mycoides subsp. capri and in M. bovigenitalium. The results support previous evidence obtained by biochemical methods which indicates membrane localization of redox enzymes in Acholeplasmas.
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Abstract
By measuring the specific activity of nucleotides isolated from ribonucleic acid after the incorporation of (14)C-labeled precursors under various conditions of growth, we have defined the major pathways of ribonucleotide synthesis in Mycoplasma mycoides subsp. mycoides. M. mycoides did not possess pathways for the de novo synthesis of nucleotides but was capable of interconversion of nucleotides. Thus, uracil provided the requirement for both pyrimidine ribonucleotides. Thymine is also required, suggesting that the methylation step is unavailable. No use was made of cytosine. Uridine was rapidly degraded to uracil. Cytidine competed effectively with uracil to provide most of the cytidine nucleotide and also provided an appreciable proportion of uridine nucleotide. In keeping with these results, there was a slow deamination of cytidine to uridine with further degradation to uracil in cultures of M. mycoides. Guanine was capable of meeting the full requirement of the organism for purine nucleotide, presumably by conversion of guanosine 5'-monophosphate to adenosine 5'-monophosphate via the intermediate inosine 5'-monophosphate. When available with guanine, adenine effectively gave a complete provision of adenine nucleotide, whereas hypoxanthine gave a partial provision. Neither adenine nor hypoxanthine was able to act as a precursor for the synthesis of guanine nucleotide. Exogenous guanosine, inosine, and adenosine underwent rapid cleavage to the corresponding bases and so show a pattern of utilization similar to that of the latter.
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Abstract
The binding of iodinated wheat germ agglutinin, Ricinus communis agglutinin, and concanavalin A to mycoplasma cells and membranes was examined. All mycoplasmas studied specifically bound concanavalin A or R. communis agglutinin and, to a lesser degree, wheat germ agglutinin. The binding of lectins to whole cells was similar to that recorded for membranes, suggesting that significant binding only occurred on the outer surface of the mycoplasma membrane. Proteolysis of the membrane almost always increased the capacity to bind lectins, which indicates that additional carbohydrate groups on the mycoplasma membrane are masked by a protein layer or protein complexes on the membrane. The observation that carbohydrates are apparently exposed on the surface of mycoplasma membranes should stimulate more concentrated study on the isolation and chemical characterization of these substances since it is quite likely that they are responsible for a variety of reactions between mycoplasmas and host cells.
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Ojo MO. Caprine pneumonia. II. Biochemical characterisation and serological identification of mycoplasmas. Trop Anim Health Prod 1976; 8:137-46. [PMID: 788268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Thirty strains Mycoplasma isolated from pneumonic lungs of goats were chracterised biochemically and serologically. On the basis of biochemical characteristics, the strains were divided into three groups. (A) Eighteen strains which fermented glucose and mannose, digested serum and reduced tetrazolium, (B) 10 strains which reduced tetrazolium, formed "film and spots" and possessed phosphatase activity and (C) two strains which catabolised arginine only. Serologically group A strains were identified as M. mycoides subspecies, group B strains could not be fully identified but on the basis of immunofluorescence and biochemical reactions were put in the M. agalactiae subspecies; there are to be further investigated. Group C strains were identified as M. arginini.
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Archer DB. Effect of the lipid composition of Mycoplasma mycoides subspecies capri and phosphatidylcholine vesicles upon the action of polyene antibiotics. Biochim Biophys Acta 1976; 436:68-76. [PMID: 776229 DOI: 10.1016/0005-2736(76)90220-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
(1) The effects of filipin and amphotericin methyl ester upon the K+ efflux from Mycoplasma mycoides subsp. capri and egg lecithin sonicated vesicles were investigated. Both the nature of the sterol and the composition of the membranes affected the sensitivity to each polyene antibiotic. (2) M. mycoides subsp. capri containing ergosterol was much more sensitive to amphotericin methyl ester than cells containing cholesterol. Cholesterol-containing cells were about twice as sensitive to filipin as the ergosterol-containing cells. These results were confirmed with phosphatidylcholine vesicles. (3) At 2 degrees C the filipin sensitivity of M. mycoides subsp. capri was independent of the membrane cholesterol content and the sensitivity towards amphotericin methyl ester decreased when the membrane cholesterol content was increased, in contrast to the results at 20 degrees C. (4) At 2 degrees C, sterol-free egg lecithin vesicles became very sensitive to both filipin and amphotericin methyl ester and the presence of cholesterol in the vesicles did not increase the sensitivity further. At high concentrations of cholesterol (greater than 30 mol%), the polyene antibiotic sensitivity, particularly towards amphotericin methyl ester, was greatly reduced.
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Abstract
The wall-covered bacteria Micrococcus lysodeikticus, Bacillus megaterium, and Proteus mirabilis incorporated exogenous cholesterol into their cytoplasmic membrane in quantities resembling those incorporated by sterol-nonrequiring mycoplasmas. Cholesterol incorporation into the outer membrane of P. mirabilis was much more restricted than into the cytoplasmic membrane.
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47
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Archer DB. The use of a fluorescent sterol to investigate the mode of action of amphotericin methyl ester, a polyene antibiotic. Biochem Biophys Res Commun 1975; 66:195-201. [PMID: 1100049 DOI: 10.1016/s0006-291x(75)80313-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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48
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Archer DB, Gale EF. Antagonism by sterols of the action of amphotericin and filipin on the release of potassium ions from Candida albicans and Mycoplasma mycoides subsp. capri. J Gen Microbiol 1975; 90:187-90. [PMID: 1100776 DOI: 10.1099/00221287-90-1-187] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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49
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Abstract
A technique for measuring glucose utilisation by mycoplasmas, in which the disappearance of glucose is monitored by the glucose-oxidase method, is proposed as an alternative to the pH method. For maximum reliability the number of organisms in the test suspension must exceed a critical minimum value. Differences in efficiency of glucose utilisation were demonstrated between species of Mycoplasma and Acholeplasma.
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50
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Abstract
Mycoplasma mycoides subsp. capri was grown in different media. The amounts of the lipids in these media were varied, resulting in altered lipid compositions of the cells. Lowering the amounts of cholesterol in the media resulted in less cholesterol incorporation into the cell lipid, with a concomitant decrease in the amount of phospholipid. The changes in the phospholipid/cholesterol ratio in the mycoplasmas were very small compared with the large changes in the amounts of cholesterol which occurred when the cholesterol content in the medium was altered. Changes in the amounts of glycolipid and glyceride in the cell lipid also resulted from alterations of the cholesterol concentration in the media. Under these conditions cell with reduced cholesterol contents were more sensitive to lysis by digitonin. No changes were observed in the polyacrylamide gel electrophoretic pattern of cellular or membrane proteins when the cholesterol was replaced by other sterols.
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