Genetic transformation of a clinical (genital tract), plasmid-free isolate of Chlamydia trachomatis: engineering the plasmid as a cloning vector.

Our study had three objectives: to extend the plasmid-based transformation protocol to a clinical isolate of C. trachomatis belonging to the trachoma biovar, to provide "proof of principle" that it is possible to "knock out" selected plasmid genes (retaining a replication competent plasmid) and to investigate the plasticity of the plasmid. A recently developed, plasmid-based transformation protocol for LGV isolates of C.

Development of a transformation system for Chlamydia trachomatis: restoration of glycogen biosynthesis by acquisition of a plasmid shuttle vector.

Chlamydia trachomatis remains one of the few major human pathogens for which there is no transformation system. C. trachomatis has a unique obligate intracellular developmental cycle.

Unity in variety--the pan-genome of the Chlamydiae.

Chlamydiae are evolutionarily well-separated bacteria that live exclusively within eukaryotic host cells. They include important human pathogens such as Chlamydia trachomatis as well as symbionts of protozoa. As these bacteria are experimentally challenging and genetically intractable, our knowledge about them is still limited.

The role of monocyte/macrophages as vehicles of dissemination of Simkania negevensis: an in vitro simulation model.

Exposure to Simkania negevensis (Sn), an intracellular microorganism that has been associated with respiratory tract infections in infants and adults, is prevalent. Sn can multiply within free-living amoebae and has been detected in domestic water supplies, which may constitute a source of infection with the organism. Its path of transport from its portal of entry to the body to its target organs is unknown.

Versatility of Simkania negevensis infection in vitro and induction of host cell inflammatory cytokine response.

Objective: Simkania negevensis (Sn) is an intracellular microorganism belonging to the family Simkaniaceae in the order Chlamydiales and has been associated with respiratory tract infections in infants and adults. The aim of this study was to analyze the outcome of Sn infection in different cell types.

Methods: The results of Sn infection were examined by infectivity assays, PCR and EM.

Simkania negevensis in bronchoalveolar lavage of lung transplant recipients: a possible association with acute rejection.

Background: Simkania negevensis is a novel organism closely related to chlamydiae. The organism has been associated with community acquired pneumonia and acute exacerbation of chronic obstructive pulmonary disease. The prevalence and pathogenic potential of S.

Domestic water supplies as a possible source of infection with Simkania.

Objectives: Simkania negevensis, a Chlamydia-like microorganism that has been associated with respiratory infections in children and adults, can multiply within free-living amoebae; moreover, it has been detected in domestic water supplies. The aim of this study was to determine whether there is similarity between Simkania organisms found in water and those detected in clinical samples.

Methods: PCR, membrane immunoassay for the detection of Simkania antigen, and isolation in cell culture were used for the detection of S.

Infection with Simkania negevensis in Brooklyn, New York.

Background: Simkania negevensis is a Chlamydia-like intracellular organism that is prevalent in populations from a wide range of geographic areas. The role of the organism in respiratory disease in the United States is unknown.

Objective: To study the association between infection with S.

Evidence for the presence of Simkania negevensis in drinking water and in reclaimed wastewater in Israel.

Simkania negevensis is a recently discovered chlamydia-like intracellular microorganism which has been associated with bronchiolitis in infants and with community-acquired pneumonia in adults; a high seroprevalence of antibodies to the microorganism has been found in various population groups. S. negevensis can be grown in various cell lines as well as in free-living amoebae such as Acanthamoeba polyphaga.

High rate of Simkania negevensis among Canadian inuit infants hospitalized with lower respiratory tract infections.

To determine the prevalence of Simkania negevensis in causing pulmonary infections in children, nasopharyngeal washes were obtained from 22 infants hospitalized with acute bronchiolitis in the Baffin Island, Canada. 14 (63.6%) were positive for S.

Infections with the chlamydia-like microorganism Simkania negevensis, a possible emerging pathogen.

Although evidence for the existence of numerous chlamydia-like microorganisms has been discovered in both environmental samples and clinical specimens, very few have been grown in vitro, and little is known of their pathogenic potential. Of all such organisms, Simkania negevensis is probably the most extensively studied. This review summarizes current knowledge about this intracellular bacterium, focusing especially on human infections.

The growth cycle of Simkania negevensis.

Simkania negevensis, a bacterium formerly referred to as 'the micro-organism Z' or 'Simkania Z', belongs to the order Chlamydiales, assigned to the family Simkaniaceae: The purpose of this study was to investigate the production of Simkania negevensis progeny in infected cells in comparison with the well-documented Chlamydiaceae developmental cycle. It was found that replicating Simkania negevensis in Vero cells resembled the reticulate bodies of all known chlamydial species: in electron micrographs they were reticulated, homogeneously staining, and often caught in the process of binary division. These replicative forms were found in low abundance shortly after infection, but by 3 days post-infection they were the most prevalent particles in host cells.