Browsing by Subject "persistenssi"

The life cycle of Chlamydia pneumoniae is a biphasic developmental cycle, as a obligate intracellular bacterium, it forms various morphological forms, including elementary bodies, reticulate bodies and aberrant bodies belonging to a persistent form. Due to the bacterial life cycle and the fact that chronication of C. pneumoniae infection and formation of persistent infection as well as pathogenesis is a complex problem involving multiple signaling pathways and affecting several different cells, it is useful to seek medication to influence infection from different stages of the bacterial life cycle. There are several different factors that induce persistence and thus models of persistence. Although the detection of aberrant RBs and thus aberrant bodies in C. pneumoniae infected tissues does not provide complete certainty about chronic infection, the bacterium has been linked to chronic health problems such as atherosclerotic cardiovascular disease and asthma. The aim of the study was to develop a persistence model induced by beta-lactam antibiotics, amoxicillin and penicillin G, in A549 cells by monitoring the size, shape, and number of inclusions using the IPA method and the immunofluorescence staining method for infection. In addition, the antibiotic sensitizing effect of three compounds on pulmonary chlamydial infection was studied. This effect was monitored by examining the recovery of persistent infection and by monitoring the protective effect of the compounds on beta-lactam-induced persistence. The work succeeded in finding an infection model that is well suited for studying beta-lactam persistence. Due to treatment recommendations, pulmonary chlamydial infections are practically treated with beta-lactam antibiotics. Based on the methods used, it was found that amoxicillin concentrations of 10 and 25 µg/ml and penicillin G concentrations of 100 U/ml and 250 U/ml were sufficiently effective to transfer bacteria to a state of persistence. It was found that the amoxicillin persistence model is reversible based on the increase in the size of the inclusions, especially at 25 µg/ml and quantitatively at 10 µg/ml. It was concluded that amoxicillin at a concentration of 10 µg/ml is sufficient to induce persistence in a beta-lactam antibiotic-induced persistence model. Further quantitative studies on the persistence model are needed, such as quantitative PCR based on the OmpA gene to determine more accurate dose-response relationships. Glutathione levels should also be monitored in the persistence model.

Chlamydia pneumoniae is an intracellular human pathogen that causes respiratory infections such as pneumonia. Antibodies have been found in serological samples worldwide and most likely every person gets an infection at least once in lifetime. In particular, persistent C.pneumoniae-infection has been associated with multiple chronic diseases such as atherosclerosis, asthma and neurological diseases. C.pneumoniae has a unique two-stage life cycle with two morphological forms; elementary body and reticulate body. In addition, the bacterium has a chronic persistent form. Persistent infection is very typical. Persistent infection can be produced in many ways in vitro, but it has been also found that C.pneumoniae is spontaneously transformed into persistent form in macrophages and monocytes. The aim of this study was to investigate the effect of anti-chlamydial compounds previously identified in the research group on the persistent infektion of C.pneumoniae. For the study, the growth of the bacteria was monitored by qPCR in different cell lines and the compatibility of the compounds with the used persistence model was studied. Four different cell lines were used in the study; HL epithelial cells, Raw264.7 macrophages, THP1 monocytes and macrophages. The effect of compounds on the used cell line was first examined by viability assays. For further studies, C.pneumoniae growth was studied in different cell lines. An qPCR method was set up and used to monitor C.pneumoniae genome copy numbers in infected samples. Based on the growth curves, the measurement points were determined for further studies. Finally, the effect of suitable compounds on C.pneumoniae infection was investigated in epithelial, monocyte and macrophage cell lines. From the investigated compounds, Schisandra chinensis-lingnans were selected for further studies with Raw264.7 cells. The genome number wa not found to decrease compared to the after schisandrin or schisandrin B treatment. In the experiment of the growth of the bacterium, schisandrin-treated samples showed that the genome number of bacterium would be re-grown. This may potentially mean the persistent infection change back to the active form, whereby the bacterium resumed proliferate in the host cell. Based on the results of this study, schisandrin may be considered a potential compound for further studies and a possible model compound for the development of compound against C.pneumoniae infection. However, further studies on the effect of the compounds on persistent infection are needed.