Ultrastructural analysis of the effects of erythromycin on the morphology and developmental cycle of Chlamydia trachomatis HAR-13

Clark, Richard B.; Schatzki, Peter F.; Dalton, Harry P.

doi:10.1007/bf00521290

Cited by 21 publications

(15 citation statements)

References 12 publications

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“…In general, agents that target bacterial protein or RNA synthesis can inhibit chlamydial differentiation either from EB to RB or from RB to EB, depending on when they are added to an in vitro infection, whereas those that target DNA or peptidoglycan synthesis specifically inhibit RB-to-EB differentiation (78). For example, 10 g of erythromycin/ml, which reduces ribosome activity, inhibited C. trachomatis serovar A EB-to-RB differentiation in McCoy cells when added within 12 h PI (24). When the erythromycin was applied at later times PI, infections were established featuring enlarged RB that could not differentiate to EB (24).…”

Section: Chlamydial Persistence In Vitromentioning

confidence: 99%

Chlamydial Persistence: beyond the Biphasic Paradigm

et al. 2004

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Section: Chlamydial Persistence In Vitromentioning

confidence: 99%

Chlamydial Persistence: beyond the Biphasic Paradigm

et al. 2004

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“…Other antibiotics have also been reported to induce abnormal chlamydial development. Erythromycin, when used in subinhibitory concentrations, produced small inclusions of C. trachomatis, with RBs twice the size of typical RBs (6). Treatment of C. trachomatis with sulfonamides induced development of small inclusions containing irregular RBs with ruffled membranes, mini-RB-like forms, and numerous ghost particles (10,12).…”

mentioning

confidence: 98%

“…Persistent chlamydial infections can be established in vitro using several methods, including treatment with cytokines (2,4,16,18) or antibiotics (5,6) or by deprivation of certain nutrients (13). In all cases they have been described as having morphologically abnormal reticulate bodies (RBs), which suggests that they are somehow altered during their otherwise normal development.…”

mentioning

confidence: 99%

Ultrastructural Study ofChlamydia pneumoniaeIn a Continuous-Infection Model

et al. 2001

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We have established an in vitro model of long-term continuous Chlamydia pneumoniae infection in HEp-2 cells. Using transmission electron microscopy, we demonstrated the presence of spontaneous abnormal chlamydial inclusions similar in appearance to the persistent chlamydial forms induced in vitro by treatment with cytokines or antibiotics or by nutrient deprivation.Chlamydia pneumoniae is a frequent cause of communityacquired pneumonia and bronchitis in adults and children. Like other chlamydial species, it can cause prolonged or chronic infections which may persist for months or years (11). These persistent infections have been implicated in the development of a number of chronic diseases, including chronic obstructive pulmonary disease, atherosclerosis, and asthma (20). However, whether persistent C. pneumoniae is a cause, a triggering cofactor, or an innocent bystander remains controversial.Persistent chlamydial infections can be established in vitro using several methods, including treatment with cytokines (2, 4, 16, 18) or antibiotics (5, 6) or by deprivation of certain nutrients (13). In all cases they have been described as having morphologically abnormal reticulate bodies (RBs), which suggests that they are somehow altered during their otherwise normal development.In the present study we describe the ultrastructural findings determined using an in vitro model of long-term continuous C. pneumoniae infection in HEp-2 cells, a respiratory epithelial cell line (14,17).Briefly, confluent HEp-2 cells were inoculated once with C. pneumoniae isolate TW-183 (ATCC VR2282) or CM-1 (ATCC VR1360) to achieve 100% infection. After 3 to 5 days, when lysis of most of the infected host cells was seen, the culture medium was replaced with fresh medium but without added cycloheximide. After 1 week of further incubation, growth of colonies of new host cells was observed. Since then, continuous C. pneumoniae cultures have been maintained for over 4 years by reseeding the infected host cells into new flasks to prevent overgrowth. No new cells or chlamydiae were added. C. pneumoniae remained viable and cultivable in this model.Two days prior to sampling, the continuously infected cells were seeded onto six-well plates. Cell monolayers were trypsinized, and infected cells were collected into 1.5-ml centrifuge tubes and fixed with 3% glutaraldehyde in 0.1 M cacodylate buffer overnight at 4°C. Samples were prepared for transmission electron microscopy by standard procedures (9). Samples were postfixed in osmium tetroxide, followed by uranyl acetate. The cells were then dehydrated in increasing concentrations of ethanol (50, 70, and 90%) and acetone (90 and 100%) and subsequently embedded in Spurr's epoxy resin. Ultrathin sections (50 to 100 nm in thickness) were prepared and collected onto 200-mesh copper grids, contrasted with 1% uranyl acetate and Reynolds lead citrate before being examined, and photographed using a JEOL 1200EX transmission electron microscope.Three types of chlamydial inclusions were observed by transmission el...

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“…To induce persistence, we added penicillin as described elsewhere (Clark et al, 1982). The persistent state of C. trachomatis upon penicillin exposure at 24 h p.i.…”

Section: Cl-55 Lyses Aberrant Chlamydial Forms Induced By Penicillinmentioning

confidence: 99%

“…Research from multiple teams has demonstrated that an encounter with specific stimuli can transform Chlamydia into a third state called 'persistence' (Clark et al, 1982;Harper et al, 2000), which has been defined as a reversible interruption of productive intracellular chlamydial growth mediated by environmental factors (Beatty et al, 1994). Persistence is an alternative outcome of a productive bacterial infection where a subpopulation of the bacteria becomes 'invisible' in response to prolonged antibiotic treatment, warding off innate and adaptive immune responses, causing little or no symptoms in the infected host, and possibly unnoticed by the diagnostician (Bavoil et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones inhibits intracellular growth and persistence of Chlamydia trachomatis

Zigangirova

Kost

Didenko

et al. 2016

Journal of Medical Microbiology

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A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones inhibits intracellular growth and persistence of Chlamydia trachomatis Chlamydia trachomatis is one of the most common sexually transmitted pathogens in the world and often causes chronic inflammatory diseases that are insensitive to antibiotics. The type 3 secretion system (T3SS) of pathogenic bacteria is a promising target for therapeutic intervention aimed at bacterial virulence and can be an attractive alternative for the treatment of chronic infections. Recently, we have shown that a small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones produced through the chemical modification of the thiohydrazides of oxamic acids, designated CL-55, inhibited the intracellular growth of C. trachomatis in a T3SS-dependent manner. To assess the feasibility of CL-55 as a therapeutic agent, our aim was to determine which point(s) in the developmental cycle CL-55 affects. We found that CL-55 had no effect on the adhesion of elementary bodies (EBs) to host cells but significantly suppressed EB internalization. We further found that CL-55 inhibited the intracellular division of reticulate bodies (RBs). An ultrastructural analysis revealed loss of contact between the RBs and the inclusion membrane in the presence of CL-55. Finally, we found that our T3SS inhibitor prevented the persistence of Chlamydia in cell culture and its reversion to the infectious state. Our findings indicate that our T3SS inhibitor may be effective in the treatment of both productive and persistent infections.

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Ultrastructural analysis of the effects of erythromycin on the morphology and developmental cycle of Chlamydia trachomatis HAR-13

Cited by 21 publications

References 12 publications

Chlamydial Persistence: beyond the Biphasic Paradigm

Chlamydial Persistence: beyond the Biphasic Paradigm

Ultrastructural Study ofChlamydia pneumoniaeIn a Continuous-Infection Model

A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones inhibits intracellular growth and persistence of Chlamydia trachomatis

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