Project description:Two main articles have used this data. The small bacterium Mycoplasma pneumoniae with its annotated 689 protein-coding genes and 44 RNAs constitutes an ideal system for global and conditional transcription analysis in bacteria. We have combined spotted arrays under more than 120 conditions with several strand-specific, high resolution tiling arrays to obtain an unprecedented level of detail of bacterial gene expression. We have found 68 new non-annotated transcripts, of which the vast majority are potential regulatory RNAs, 53 of them in antisense to known genes. Integration of all data confirmed a dynamic and complex view of bacterial transcription: Under reference conditions in a rich medium, 138 polycistronic and 212 monocistronic transcripts could be identified, with almost half of the polycistronic operons showing a ‘staircase’-like expression pattern, i.e. the expression level within each gene is constant, but succeeding genes have lower expression. Furthermore, under different conditions, operons can divide into smaller transcriptional units, possibly by utilization of internal promoters resulting in many alternative transcripts. More complex bacteria show similar responses to external stresses, although M. pneumoniae lacks the respective transcription regulators, indicating the existence of yet uncharacterized common response mechanisms. This is supported by the concerted expression of genes, some of which with common upstream DNA motifs, form distinct operons under different conditions indicating additional factors regulating their expression. Frequent antisense transcripts, alternative transcripts and multiple regulators per gene thus cannot longer be seen as indicators of eukaryote-specific regulatory complexity. Keywords: stress response, time series
Project description:Two main articles have used this data. The small bacterium Mycoplasma pneumoniae with its annotated 689 protein-coding genes and 44 RNAs constitutes an ideal system for global and conditional transcription analysis in bacteria. We have combined spotted arrays under more than 120 conditions with several strand-specific, high resolution tiling arrays to obtain an unprecedented level of detail of bacterial gene expression. We have found 68 new non-annotated transcripts, of which the vast majority are potential regulatory RNAs, 53 of them in antisense to known genes. Integration of all data confirmed a dynamic and complex view of bacterial transcription: Under reference conditions in a rich medium, 138 polycistronic and 212 monocistronic transcripts could be identified, with almost half of the polycistronic operons showing a ‘staircase’-like expression pattern, i.e. the expression level within each gene is constant, but succeeding genes have lower expression. Furthermore, under different conditions, operons can divide into smaller transcriptional units, possibly by utilization of internal promoters resulting in many alternative transcripts. More complex bacteria show similar responses to external stresses, although M. pneumoniae lacks the respective transcription regulators, indicating the existence of yet uncharacterized common response mechanisms. This is supported by the concerted expression of genes, some of which with common upstream DNA motifs, form distinct operons under different conditions indicating additional factors regulating their expression. Frequent antisense transcripts, alternative transcripts and multiple regulators per gene thus cannot longer be seen as indicators of eukaryote-specific regulatory complexity. Keywords: Stress, genetic modification, time series, drug treatment
Project description:BackgroundMycoplasma pneumoniae (MP) is a common pathogen of community-acquired respiratory infections. The clinical characteristics hospital-acquired MP infections are rarely reported in the literature. Our ward is mainly responsible for the management of patients during the perioperative period of cardiac surgery. Several patients had fever during the improvement of their condition after cardiac surgery, and the effect of upgrading antibiotics and increasing the antibacterial spectrum was not good.MethodsUsing inpatient data of Guangdong Provincial People's Hospital, we conducted a retrospective case series study of hospital-acquired MP infection after cardiac surgery from January 2015 to December 2020 to investigate the clinical characteristics. Clinical data was extracted from patients with a confirmed diagnosis of MP infection after >48 hours of hospitalization. All analyses for this study were descriptive. Data were expressed as mean ± standard deviation (SD), median with range or number with percentage as appropriate.ResultsWe totally included 22 patients. The time of onset of hospital-acquired MP infection after surgery was 23.32±12.57 days, and the duration of antibiotic use before the onset of infection was 4-40 days. Both fever and sore throat were the main symptoms of nosocomial MP infection, and the rash was the most common physical sign. Laboratory tests were normal for peripheral blood leukocyte count and procalcitonin in most patients (17 cases), while the lymphocyte count was decreased in 10 cases. A single serum anti-MP antibody titer ≥1:160 combined with clinical manifestations and imaging helped confirm nosocomial MP infection, although a double serum anti-MP antibody (four-fold change in titer) wasn't seen. With quinolone therapy, such as levofloxacin, all the patients' temperature gradually returned to normal and were discharged uneventfully.ConclusionsPatients after cardiac surgery should be aware of the presence of hospital-acquired MP infection when they develop new fever accompanied by atypical bacterial infection signs such as sore throat and rash during treatment. In such cases, changes in MP antibody titers need to be monitored and anti-MP therapy is required.
Project description:We have found that early corticosteroid therapy was effective for reducing morbidity during five Korea-wide epidemics. We evaluated the clinical and laboratory parameters of 56 children who received early corticosteroid treatment for pneumonia that was caused by macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae) or macrolide-sensitive M. pneumoniae between July 2019 and February 2020. All subjects had dual positive results from a PCR assay and serological test, and received corticosteroids within 24–36 h after admission. Point mutation of residues 2063, 2064, and 2067 was identified in domain V of 23S rRNA. The mean age was 6.8 years and the male:female ratio was 1.2:1 (31:25 patients). Most of the subjects had macrolide-resistant M. pneumoniae (73%), and all mutated strains had the A2063G transition. No significant differences in clinical and laboratory parameters were observed between macrolide-resistant and macrolide-sensitive M. pneumoniae groups that were treated with early dose-adjusted corticosteroids. Higher-dose steroid treatment may be needed for patients who have fever that persists for >48 h or increased biomarkers such as lactate dehydrogenase concentration at follow-up despite a usual dose of steroid therapy.