| division of single host cells after infection with chlamydiae. | mouse fibroblasts (l cells) were infected in suspension with chlamydia psittaci (6bc) and then plated out on a solid substrate at a density of 80 cells per cm2 so that the effect of chlamydial infection on the division of single host cells and their progeny could be determined. uninfected l cells multiplied with a mean generation time of 15 h. the generation time of single l cells infected with 1.5 50% infectious units (id50) of c. psittaci was over twice as long. half of the infected l cells ha ... | 1978 | 624590 |
| ultrastructural studies of the nucleoids of the pleomorphic forms of chlamydia psittaci 6bc: a comparison with bacteria. | the nucleoids of the various pleomorphic forms of chlamydia psittaci have been examined by direct observation of infected cells and by observations on isolated particles. the fixation and staining methods used were the same as those routinely used for the examination of bacteria to facilitate the comparison of chlamydial fine structure with that of bacteria. the nucleoids of reticulate bodies were composed of fine fibrils which extended throughout these particles. the nucleoids of intermediate b ... | 1976 | 56212 |
| wheat germ agglutinin blockage of chlamydial attachment sites: antagonism by n-acetyl-d-glucosamine. | addition of 2 to 10 micrograms of wheat germ agglutinin (wga), a lectin from triticum vulgaris specific for n-acetyl-d-glucosamine, per ml to suspensions of mouse fibroblasts (l cells) blocked the attachment of 14c-labeled chlamydia psittaci 6bc to the l-cell surface. wga and strain 6bc competed for similar sites on l cells, but once bound, one was not replaced by the other. n-acetyl-d-glucosamine, but not other monosaccharides of related structure, antagonized the blocking action of wga. lectin ... | 1979 | 500195 |
| sucrose density differences of chlamydia psittaci 6bc in relation to its host. | previous studies on chlamydia psittaci 6bc propagated in different hosts have shown differences in cytotoxicity but no differences in the ultrastructure of the individual particles. it is shown here that the 6bc strain derived from yolk sac of infected chick embryo sedimented in sucrose gradients at lower densities than the 6bc strain derived from l-cells. host-related modifications of lipid concentrations of the 6bc strains have been previously documented by others. it is thought that the pheno ... | 1977 | 559537 |
| toxicity of low and moderate multiplicities of chlamydia psittaci for mouse fibroblasts (l cells). | when mouse fibroblasts (l cells) were infected in suspension or in monolayer with 10 to 100 50% infectious doses (id(50)) of chlamydia psittaci (6bc) per host cell, they showed signs of damage 24 to 48 h later. host-cell injuries were termed multiplication dependent when both the ingestion and subsequent reproduction of c. psittaci were required; when only ingestion but not replication was needed, the injuries were considered to be multiplication independent. the time that the injury was first a ... | 1977 | 924681 |
| kinetics of phagocytosis of chlamydia psittaci by mouse fibroblasts (l cells): separation of the attachment and ingestion stages. | the kinetics of phagocytosis of chlamydia psittaci (6bc) by monolayers of mouse fibroblasts (l cells) was studied with an assay that distinguished between the attachment and ingestion phases of phagocytosis. at multiplicities of 10 and 100 50% infectious doses (id50) per l cell, virtually all of the inoculated c. psittaci had been attached and ingested after 60 min at 37 degrees c. at multiplicities of 500 to 5,000 id50 per l cell, the initial rates of attachment and ingestion of c. psittaci to ... | 1978 | 631892 |
| alterations in the ultrastructure of chlamydia psittaci 6bc harvested from the allantoic fluid of chick embryos. | the allantoic fluid of chick embryos infected with chlamydia psittaci is routinely used as a source of material for the study of the chemical and biological properties of the chlamydiae. we have examined pellets recovered from this allantoic fluid by low- and high-speed centrifugation, as well as high-speed pellets which had been stored at -70 degrees c, and we find that all of the pleomorphic forms of the chlamydiae are present in these materials. the reticulate bodies and large intermediate bo ... | 1976 | 943217 |
| phagocytic and chlamydiae-inhibiting activities of stimulated and nonstimulated periotneal mouse macrophages. | phagocytic and chamydiacidal properties of nonstimulated and stimulated mouse mononuclear cells for two chlamydia psittaci 6bc strains were investigated. it was determined that macrophages kept in monolayer culture (i.e. stimulated phagocytes) developed much more efficient chlamydiacidal ability than did cells kept in suspension directly after harvest (i.e. nonstimulated phagocytes). a thousandfold decrease of chlamydial infectivity was observed 60 min after induction of phagocytosis in stimulat ... | 1976 | 986871 |
| autoradiography of [3h]thymidine-labeled chlamydia psittaci 6bc in mononuclear phagocytes. | incorporation of tritiated [3h]thymidine by chlamydia psittaci 6bc was achieved by growing the parasites in chick embryo yolk sac explants which were exposed to exogenous labeled thymidine. these labeled, purified chlamydiae were next observed by autoradiography within mouse peritoneal macrophages. the number of silver grains remained constant in the cytoplasm of macrophages throughout the developmental cycle of the parasite. the proliferation of labeled chlamydiae in macrophages was confirmed b ... | 1976 | 943214 |
| immunofluorescence of peritoneal phagocytes after infection of mice with l-cell-attenuated chlamydia psittaci 6bc. | large amounts of particulate antigen of chlamydia psittaci 6bc attenuated by growth in l cells were phagocytized by peritoneal mononuclear phagocytes during the 1st h after intraperitoneal inoculation. the phagocytes subsequently destroyed the immunofluorescent (if) properties of the chlamydial antigens. it is suggested that the early damage of phagocytes by lysosomal enzymes activation induced by chlamydiae contributed to the relatively early disappearance of if antigens from the peritoneal flu ... | 1975 | 1097065 |
| immediate toxicity of high multiplicities of chlamydia psittaci for mouse fibroblasts (l cells). | one hour after suspensions of mouse fibroblasts (l cells) were exposed to 500 to 1,000 l-cell 50% infectious doses of chlamydia psittaci (6bc), the l cells failed to attach to and spread out on solid substrates, phagocytosed polystyrene latex spheres at reduced rates, incorporated less [14c]isoleucine into protein, and had smaller soluble pools of nucleoside triphosphates. the infected l cells began to die at 8 h and were all dead by 20 h. lower multiplicities of infection took correspondingly l ... | 1976 | 985806 |
| lysosomes and the "toxicity" of rickettsias. vi. in vivo response of mouse peritoneal phagocytes to l-cell-grown chlamydia psittaci 6bc strain. | the l-cell-grown 6bc strain of c. psittaci inoculated intraperitoneally in mice induced an injurious effect on mononuclear phagocytes and their lysosomes; the influx of polymorphonuclear phagocytes (pmn's) increased markedly and the pmn's showed karyorrhexis and lysis. cytochemical methods failed to detect chlamydial forms in peritoneal fluids from day 1 and up to 6 days after inoculation of mice. chlamydial infectivity was not detected in either the cell-bound or the cell-free fractions of peri ... | 1975 | 1090349 |
| requirements for ingestion of chlamydia psittaci by mouse fibroblasts (l cells). | ingestion of 14c-amino acid-labeled chlamydia psittaci (6bc) by mouse fibroblasts (l cells) was inhibited when the host cells were incubated for 30 min at 37 degrees c in earle salts containing 10 mug of crystalline trypsin per ml. tryptic digestion also inhibited the ingestion of 1-mum polystrene latex beads. trypsin-treated l cells almost completely recovered their ability to ingest chlamydiae after 4 h at 37 degrees c in medium 199 with 5% fetal calf serum. cycloheximide (10 mug/ml) blocked t ... | 1976 | 965090 |
| electron microscopy of the in vivo internalization of virulent chlamydia psittaci 6bc strain. | the internalization of virulent chlamydia psittaci 6bc particles by wandering mononuclear phagocytes in the peritoneal cavity of intraperitoneally inoculated mice occurred asynchronously, i.e., fragile reticulate bodies (rb) appeared to be more readily phagocytized than the rigid elementary bodies (eb). early damage of mononuclear phagocytes occurred after internalization of chlamydiae. this was followed by a decreased uptake of particles, and may explain the relatively long persistence (up to ... | 1975 | 1148946 |
| developmental cycle-specific host-free rna synthesis in chlamydia spp. | the incorporation of radiolabeled gtp into rna in host-free chlamydia trachomatis serovar l2 organisms was investigated. the incorporation was partially inhibited by rifampin and dactinomycin and hydrolyzed by rnase. rna made by host-free chlamydiae consisted mainly of species of fewer than 800 bases in size, although 16s and 23s species were noted by agarose-gel electrophoresis. the hybridization of radiolabeled host-free rna to restriction fragments of the gene encoding the major outer membran ... | 1990 | 1698176 |
| cloning and sequence analysis of the major outer membrane protein gene of chlamydia psittaci 6bc. | the gene encoding the major outer membrane protein (momp) of the psittacine chlamydia psittaci strain 6bc was cloned and sequenced. n-terminal protein sequencing of the mature momp indicated that it is posttranslationally processed at a site identical to the site previously identified in the momp of chlamydia trachomatis l2. the nucleotide sequence of the c. psittaci 6bc momp gene was found to be 67 to 68% identical to those of human c. trachomatis strains, 73% identical to that of chlamydia pne ... | 1991 | 1856001 |
| ultrastructural studies of chlamydia psittaci 6bc in situ in yolk sac explants and l cells: a comparison with gram-negative bacteria. | chlamydia psittaci (6bc) was grown in yolk sac explants and in l cells and fixed by perfusion in situ to provide undamaged material for comparison with gram-negative bacteria. reticulate, intermediate, and elementary bodies were all seen to lack a well-defined periplasmic space; intermediate and elementary bodies showed condensations of the nucleoid which differ from common bacterial configurations; and the cytoplasm of highly condensed elementary bodies was much more electron dense than that of ... | 1975 | 1238156 |
| the effect of purification on the ultrastructure and infectivity of egg-attenuated chlamydia psittaci (6bc). | a procedure is described for the purification of mixed populations of the three different morphological forms of chlamydia psittaci (6bc) from infected yolk sac membranes. elementary bodies and small intermediate bodies are not perceptibly damaged during purification which involves homogenization of the host cells, differential centrifugation, sedimentation through 20% sucrose, and treatment with trypsin. the observation that elementary bodies undergo plasmolysis in 20% sucrose is interpreted as ... | 1975 | 1238157 |
| protein synthesis early in the developmental cycle of chlamydia psittaci. | the incorporation of [35s]methionine into protein by intracellular and host-free chlamydia psittaci 6bc was analyzed at intervals between 15 min and 28 h postinfection by autoradiography of sodium dodecyl sulfate-polyacrylamide gels. the profiles of proteins synthesized in the two systems were similar at all times, indicating that the host-free system can be used to monitor the temporal expression of genes in chlamydiae. the host-free system permitted detection of synthesis of chlamydial protein ... | 1988 | 3182069 |
| synthesis of protein in host-free reticulate bodies of chlamydia psittaci and chlamydia trachomatis. | synthesis of protein by the obligate intracellular parasitic bacteria chlamydia psittaci (6bc) and chlamydia trachomatis (serovar l2) isolated from host cells (host-free chlamydiae) was demonstrated for the first time. incorporation of [35s]methionine and [35s]cysteine into trichloroacetic acid-precipitable material by reticulate bodies of chlamydiae persisted for 2 h and was dependent upon a exogenous source of atp, an atp-regenerating system, and potassium or sodium ions. magnesium ions and am ... | 1985 | 3997784 |
| acquisition and synthesis of folates by obligate intracellular bacteria of the genus chlamydia. | we undertook studies focused on folate acquisition by chlamydia trachomatis l2, chlamydia psittaci 6bc, and c. psittaci francis. results from in situ studies, using wild-type host cells, confirmed that c. trachomatis l2 and c. psittaci 6bc are sensitive to sulfonamides whereas c. psittaci francis is resistant. in addition c. trachomatis l2 and c. psittaci francis were inhibited by methotrexate in situ whereas c. psittaci 6bc was not. in contrast to c. trachomatis, neither c. psittaci strain was ... | 1992 | 1430206 |
| ultrastructural studies of chlamydia psittaci 6bc variant strains. i. ultrastructure of the surface layers of egg-passaged 6bc strain. | | 1973 | 4127533 |
| in vivo-activated mononuclear phagocytes and protective immunity to chlamydiae in mice. | peritoneal macrophages (m phi s) collected from chlamydia psittaci 6bc-immune mice after intraperitoneal challenge with 10(6) 6bc (immune-boosted [ib] m phi s) were compared by various functional criteria with other in vivo- and in vitro-activated m phi populations. while casein-, protease peptone-, and thioglycolate (thio)-elicited m phi s were equally susceptible to in vitro infection with 6bc, ib m phi s did not support chlamydial growth and m phi s from mycobacterium tuberculosis bcg- or lis ... | 1988 | 3131246 |
| sequence analysis and lipid modification of the cysteine-rich envelope proteins of chlamydia psittaci 6bc. | the envelopes of elementary bodies of chlamydia spp. consist largely of disulfide-cross-linked major outer membrane protein (momp) and two cysteine-rich proteins (crps). the momp gene of chlamydia psittaci 6bc has been sequenced previously, and the genes encoding the small and large crps from this strain were cloned and sequenced in this study. the crp genes were found to be tandemly arranged on the chlamydial chromosome but could be independently expressed in escherichia coli. the deduced 87-am ... | 1991 | 2050637 |
| lysosomes in l cells infected with chlamydia psittaci 6bc strain. | | 1971 | 4106184 |
| immunofluorescence of peritoneal phagocytes after infection in vivo with egg-attenuated chlamydia psittaci 6bc. | | 1973 | 4358601 |
| chlamydia psittaci: inclusion vacuole ultrastructure. | the inclusion ultrastructure of fibroblasts infected with chlamydia psittaci (6bc) was studied. electron microscopic techniques were used which permitted the observation of whole infected host cells and 1.0-micron sectioned preparations. it was shown that the cytoplasmic inclusion vacuoles of infected cells contained interconnecting structures within which chlamydiae reproduce. | 1980 | 6250694 |
| lymphokine-mediated inhibition of chlamydia replication in mouse fibroblasts is neutralized by anti-gamma interferon immunoglobulin. | experiments were carried out to characterize immunologically mediated chlamydial persistence in cell culture. mouse fibroblasts were activated to restrict chlamydia psittaci 6bc replication by including mitogen (concanavalin a)-induced spleen cell supernatant fluids from immunized animals in the growth medium. when mouse fibroblasts were incubated with lymphokine for 24 h before infection and then with growth medium after infection (preinfection treatment), chlamydial replication was delayed but ... | 1983 | 6417024 |
| structural and polypeptide differences between envelopes of infective and reproductive life cycle forms of chlamydia spp. | significant differences in cysteine-containing proteins and detergent-related solubility properties were observed between outer membrane protein complexes of reproductive (reticulate body) and infective (elementary body) forms of chlamydia psittaci (6bc). elementary bodies harvested at 48 h postinfection possessed a 40-kilodalton major outer membrane protein and three extraordinarily cysteine-rich outer membrane proteins of 62, 59, and 12 kilodaltons, all of which were not solubilized by sodium ... | 1984 | 6690419 |
| the genus-specific lipopolysaccharide epitope of chlamydia is assembled in c. psittaci and c. trachomatis by glycosyltransferases of low homology. | chlamydiae possess a genus-specific epitope that is located on the lipopolysaccharide (lps) and is composed of a 3-deoxy-d-manno-octulosonic acid (kdo) trisaccharide of the sequence alpha kdo-(2-->8)--alpha kdo-(2-->4)-alpha kdo. in chlamydia trachomatis, this trisaccharide is biosynthetically generated through the action of a multi-functional kdo-transferase encoded by the gene gsea. gsea of chlamydia psittaci 6bc was cloned and expressed in a rough mutant (re chemotype) of escherichia coli (st ... | 1993 | 7523826 |
| architecture of the cell envelope of chlamydia psittaci 6bc. | the cysteine-rich envelope proteins of the elementary body form of chlamydiae are thought to be located in the outer membrane on the basis of their insolubility in the weak anionic detergent n-lauryl sarcosinate (sarkosyl). we found, however, that the insolubility of the small (enva) and the large (envb) cysteine-rich proteins of chlamydia psittaci 6bc in sarkosyl is dependent on the maintenance of a supramolecular disulfide-cross-linked complex and is unlikely to be a valid indicator of outer m ... | 1995 | 7532170 |
| the structures of oligosaccharide bisphosphates isolated from the lipopolysaccharide of a recombinant escherichia coli strain expressing the gene gsea [3-deoxy-d-manno-octulopyranosonic acid (kdo) transferase] of chlamydia psittaci 6bc. | the lipopolysaccharide from the recombinant strain escherichia coli f515-140 containing the cloned gene gsea [3-deoxy-d-manno-octulopyranosonic acid (kdo) transferase] from chlamydia psittaci 6bc was isolated and sequentially de-o-acylated and de-n-acylated. the products were separated by high-performance anion-exchange chromatography into three fractions, two of which contained a single compound. their structures were elucidated by high-field nmr spectroscopy as alpha-kdo-(2-->4)-alpha-kdo-(2-- ... | 1995 | 7744029 |
| enhancement of in vitro transcription by addition of cloned, overexpressed major sigma factor of chlamydia psittaci 6bc. | obligate parasitic bacteria of the genus chlamydia possess a developmental cycle that takes place entirely within eucaryotic host cells. because standard methods of genetic analysis are not available for chlamydiae, an in vitro transcription system has been developed to elucidate the mechanisms by which chlamydiae regulate gene expression. the in vitro system is specific for chlamydial promoters but is inefficient, presumably because the rna polymerase is not saturated with sigma factor. therefo ... | 1994 | 8188604 |
| characterization of lipoprotein enva in chlamydia psittaci 6bc. | the primary sequence of the small cysteine-rich protein (enva) of chlamydia psittaci 6bc has been shown to possess a potential lipid modification/signal peptidase ii-processing site, and the mature protein was labeled by a [3h]palmitic acid precursor. we further characterized the mature enva, showing that it lacks the n-terminal methionine of the primary peptide, is hydrophobic despite a peptide sequence that is predicted to be hydrophilic, and appears to be lipid modified at an n-terminal cyste ... | 1994 | 7928970 |
| enhancement of in vitro transcription by addition of cloned, overexpressed major sigma factor of chlamydia psittaci 6bc. | | 1994 | 8021204 |
| molecular cloning, sequence analysis and functional characterization of the gene kdsa, encoding 3-deoxy-d-manno-2-octulosonate-8-phosphate synthase of chlamydia psittaci 6bc. | the kdsa gene encoding 3-deoxy-d-manno-2-octulosonate-8-phosphate (kdo-8-p) synthase of chlamydia psittaci 6bc was cloned by complementing the temperature-sensitive kdsa mutant salmonella enterica serovar typhimurium ag701i50. the sequence analysis of a recombinant dna fragment revealed an open reading frame of 807 nucleotides which codes for a polypeptide of 269 amino acids with a high degree of similarity to known kdsa proteins. in addition, alignments of kdo-8-p synthases with bacterial and f ... | 1997 | 9063447 |
| structural analysis of the lipopolysaccharide from chlamydophila psittaci strain 6bc. | the lipopolysaccaride of chlamydophila psittaci 6bc was isolated from tissue culture-grown elementary bodies using a modified phenol/water procedure followed by extraction with phenol/chloroform/light petroleum. compositional analyses indicated the presence of 3-deoxy-dmanno-oct-2-ulosonic acid, glcn, organic bound phosphate and fatty acids in a molar ratio of approximately 3. 3 : 2 : 1.8 : 4.6. deacylated lipopolysaccharide was obtained after successive microscale treatment with hydrazine and p ... | 2000 | 10971582 |
| identification of polymorphic outer membrane proteins of chlamydia psittaci 6bc. | the genomes of chlamydia spp. encode a family of putative outer membrane proteins, referred to as polymorphic outer membrane proteins (pomps), which may play a role in the avoidance of host immune defenses. we analyzed avian strain 6bc of chlamydia psittaci by polyacrylamide gel electrophoresis for the expression of pomps. at least six putative pomps were identified on the basis of their size (90 to 110 kda) and labeling with an outer membrane-specific probe, 3-(trifluoromethyl)-3-(m-[125i]iodop ... | 2001 | 11254603 |
| identification of an early-stage gene of chlamydia psittaci 6bc. | chlamydiae are parasitic bacteria characterized by a temporally regulated developmental cycle. in the early stage of the cycle, metabolically inert elementary bodies reorganize to dividing reticulate bodies, a process about which little is known. the purpose of this investigation was to identify and clone chlamydial genes that are expressed preferentially during the early stage of the developmental cycle of chlamydia psittaci 6bc. several potential early genes were cloned with highly radioactive ... | 1993 | 8491714 |
| human mannose-binding protein inhibits infection of hela cells by chlamydia trachomatis. | the role that collectin (mannose-binding protein) may play in the host's defense against chlamydial infection was investigated. recombinant human mannose-binding protein was used in the inhibition of cell culture infection by chlamydia trachomatis (c/tw-3/ot, e/uw-5/cx, and l2/434/bu), chlamydia pneumoniae (ar-39), and chlamydia psittaci (6bc). mannose-binding protein (mbp) inhibited infection of all chlamydial strains by at least 50% at 0.098 microg/ml for tw-3 and uw-5, and at 6.25 microg/ml f ... | 1998 | 9529088 |
| induction of apoptosis by chlamydia psittaci and chlamydia trachomatis infection in tissue culture cells. | the role of programmed cell death (apoptosis) in llc-mk2 cells infected with chlamydia trachomatis lgv2 serotype and chlamydia psittaci 6bc strain was investigated using flow cytometry and tunel procedures. the number of apoptotic cells was significantly higher at 72 and 96 hours post infection in the chlamydia infected cell cultures in comparison with mock-infected cells. we postulate the apoptotic process to be a mechanism induced by c. trachomatis and c. psittaci infection in llc-mk2 cells. | 1998 | 9728403 |
| frequency of spontaneous mutations that confer antibiotic resistance in chlamydia spp. | mutations in rrna genes (rrn) that confer resistance to ribosomal inhibitors are typically recessive or weakly codominant and have been mostly reported for clinical strains of pathogens possessing only one or two rrn operons, such as helicobacter pylori and mycobacterium spp. an analysis of the genome sequences of several members of the chlamydiaceae revealed that these obligate intracellular bacteria harbor only one or two sets of rrna genes. to study the contribution of rrna mutations to the e ... | 2005 | 15980362 |
| a monoclonal antibody recognizing the 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) trisaccharide alphakdo(2-->4)alphakdo(2-->4)alphakdo of chlamydophila psittaci 6bc lipopolysaccharide. | a monoclonal antibody (mab) s45-18 was generated against a synthetic neoglycoconjugate containing the trisaccharide alphakdo(2-->4)alphakdo(2-->4)alphakdo (kdo, 3-deoxy-d-manno-oct-2-ulopyranosonic acid) which represents a structure of the lipopolysaccharide (lps) from chlamydophila psittaci 6bc. the antibody was characterized by binding and inhibition assays in elisa using: (i) the immunizing antigen and chemically synthesized derivatives thereof; (ii) chlamydial elementary bodies (eb); and (ii ... | 2000 | 11521056 |
| lipid composition of the hemagglutinating active fraction obtained from chick embryos infected with chlamydia psittaci 6bc. | the lipid composition of the concentrated hemagglutininating active fraction (hf) of allantoic fluid from infected eggs, but free from chlamydia psittaci 6bc, was compared to concentrated normal allantoic fluid (naf). phosphatidyl-choline (pc) and phosphatidylethanolamine were the major lipid classes of the total phospholipid fraction. some quantitative differences were found in the amount of pc and phosphatidylserine present in hf and naf. lysophosphatidylcholine was present in hf but absent in ... | 1970 | 16557838 |
| structural analyses of the lipopolysaccharides from chlamydophila psittaci strain 6bc and chlamydophila pneumoniae strain kajaani 6. | lipopolysaccharides (lpss) of chlamydophila psittaci 6bc and chlamydophila pneumoniae kajaani 6 contain 3-deoxy-d-manno-oct-2-ulosonic acid (kdo), glcn, organic bound phosphate, and fatty acids in the molar ratios of approximately 3:2:2.2:4.8 and approximately 2.9:2:2.1:4.9, respectively. the lpss were immunoreactive with a monoclonal antibody against a family-specific epitope of chlamydial lps. this finding, together with methylation analyses of both lpss and maldi-tof ms experiments on de-o-, ... | 2001 | 11705470 |
| endotoxic activity and chemical structure of lipopolysaccharides from chlamydia trachomatis serotypes e and l2 and chlamydophila psittaci 6bc. | the lipopolysaccharide (lps) of chlamydia trachomatis serotype e was isolated from tissue culture-grown elementary bodies and analyzed structurally by mass spectrometry and 1h, 13c and 31p nuclear magnetic resonance. the lps is composed of the same pentasaccharide bisphosphate alphakdo-(2-8)-alphakdo-(2-4)-alphakdo-(2-6)-betaglcn-4p-(1-6)-alphaglcn-1p (kdo is 3-deoxy-alpha-d-manno-oct-2-ulosonic acid) as reported for c. trachomatis serotype l2[rund, s., lindner, b., brade, h. and holst, o. (1999 ... | 2003 | 12542694 |
| fitness cost due to mutations in the 16s rrna associated with spectinomycin resistance in chlamydia psittaci 6bc. | the fitness cost of a resistance determinant is the primary parameter that determines its frequency in vivo. as a model for analysis of the impact of drug resistance mutations on the intracellular life cycle of chlamydia spp., we studied the growth of four genetically defined spectinomycin-resistant (spc(r)) clonal variants of chlamydia psittaci 6bc isolated in the plaque assay. the development of each variant was monitored over 46 h postinfection in the absence of drug, either in pure culture o ... | 2005 | 16251283 |
| frequency of development and associated physiological cost of azithromycin resistance in chlamydia psittaci 6bc and c. trachomatis l2. | azithromycin is a major drug used in the treatment and prophylaxis of chlamydial infections. spontaneous azithromycin-resistant mutants of chlamydia psittaci 6bc were isolated in vitro in the plaque assay at a frequency of about 10(-8). isogenic clonal variants with a(2058)c, a(2059)g, or a(2059)c mutations in the unique 23s rrna gene (escherichia coli numbering system) displayed mics for multiple macrolides (i.e., azithromycin, erythromycin, josamycin, and spiramycin) at least 100 times higher ... | 2007 | 17908942 |
| genome sequences of the zoonotic pathogens chlamydia psittaci 6bc and cal10. | chlamydia psittaci is a highly prevalent avian pathogen and a potentially lethal zoonosis, causing life-threatening pneumonia in humans. we report the genome sequences of c.psittaci 6bc, the prototype strain for the species, and c. psittaci cal10, a widely used laboratory strain. | 2011 | 21622741 |