ABSTRACT
PURPOSE: Mycoplasma pneumoniae is an extracellular pathogen that attaches to and destroys the ciliated epithelial cells of the respiratory tract. The vascular endothelial growth factor (VEGF) is a critical angiogenic factor that manages the formation and function of vascular networks. Thus, we examined whether M. pneumoniae lysate (MPL) induces VEGF and MPL-induced VEGF expression is regulated by the activation of mitogen-activated protein kinase (MAPK) pathways in airway epithelial cells. METHODS: Cells were treated with MPL in dose and time dependent manners or pretreated with chemical inhibitors of MAPK signaling molecules before the addition of MPL. The supernatants were measured by a specific human VEGF enzyme-linked immunosorbent assay (ELISA). The RNAs were extracted and synthesized into cDNAs for VEGF gene expression by polymerase chain reaction. RESULTS: MPL considerably increased VEGF mRNA 2 hours after treatment, which was gradually reduced thereafter. On the other hand, VEGF protein was continuously amplified for 12 hours after both 5 and 10 microg/mL MPL treatment. Pretreatment with U0126 (a specific extracellular signal-regulated kinase inhibitor) and SB202190 (a specific p38 inhibitor) abolished MPL-stimulated VEGF protein close to basal level (-85%), whereas JNK inhibitor II (a specific c-Jun N-terminal kinase inhibitor) partially decreased VEGF protein (57%). CONCLUSION: We concluded that MPL induces VEGF expression through the activation of MAPK signaling molecules (ERK, p38 and JNK) in airway epithelial cells.
Subject(s)
Humans , Angiogenesis Inducing Agents , Butadienes , DNA, Complementary , Enzyme-Linked Immunosorbent Assay , Epithelial Cells , Gene Expression , Hand , Imidazoles , JNK Mitogen-Activated Protein Kinases , Mycoplasma , Mycoplasma pneumoniae , Nitriles , Phosphotransferases , Pneumonia , Pneumonia, Mycoplasma , Polymerase Chain Reaction , Protein Kinases , Pyridines , Respiratory System , RNA , RNA, Messenger , Vascular Endothelial Growth Factor AABSTRACT
Forty-four strains of Helicobacter pylori were isolated from Kosin Medical Center were tested of resistance to antimicrobial agents, and the mechanism of resistance to clarithromycin was investigated. We determined the MICs of amoxicillin, amoxicillin/clavulanic acid, clarithromycin, and metronidazole by agar and broth dilution method. To detect the mutations of 23S rRNA which is associated with clarithromycin resistance, a 3'-mismatched polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis with restriction enzymes BbsI and BsaI were performed. The nucleotide sequence of 23S rRNA was determined. All H. pylori strains appeared to be susceptible to amoxicillin/clavulinic acid, but 2.3% of strains (1 strain) are resistant to amoxicillin, 13.6% (6 strains) to clarithromycin, and 15.9% (7 strains) to metronidazole. No PCR products was observed by the 3'-mismatched PCR. A 291 bp of PCR product was not digested by BbsI, but was digested by BsaI, which was a characteristic of the A2143G point mutation in the 23S rRNA gene. The nucleotide sequencing analysis revealed that all resistant strains had A2143G, T2182C, and T2244C mutations in 23S rRNA gene.
Subject(s)
Agar , Amoxicillin , Anti-Infective Agents , Base Sequence , Clarithromycin , Genes, rRNA , Helicobacter pylori , Helicobacter , Korea , Metronidazole , Point Mutation , Polymerase Chain Reaction , Polymorphism, Restriction Fragment LengthABSTRACT
The throat swabs obtained from 1,098 adults and 432 children patients with respiratory diseases were examined for Mycoplasma pneumoniae infection detected by culture and polymerase chain reaction (PCR). Antimicrobial susceptibilities of the resulting 60 M. pneumoniae isolates were evaluated by testing minimum inhibitory concentrations (MICs) of erythromycin, minocycline, tetracycline, josamycin, sparfloxacin, ofloxacin, and ciprofloxacin by a broth micro-dilution method. In a preliminary screening, the detection rate of M. pneumoniae by PCR was 29.2% (277/948) for the adults and 28.3% (90/318) for the children. In the second survey, the isolation rate of M. pneumoniae by culture was 29.3% (44/150) for the adults, and 14.0% (16/114) for the children. The PCR detection rate was 36.7% (55/150) for the adults and 23.7% (27/114) for the children. The MIC90s of the M. pneumoniae isolates were 0.015 mg/ml for erythromycin, lower than 0.03 mg/ml for josamycin, 0.06 mg/ml for sparfloxacin and minocycline, 0.12 mg/ml for tetracycline, 0.5 mg/ml for ofloxacin and CFC-222, and 1.0 mg/ml for ciprofloxacin. The isolates were susceptible to erythromycin, josamycin, sparfloxacin, minocycline, tetracycline, and ofloxacin, but the 63.3% of them was resistant to ciprofloxacin. These results indicate that the PCR method has a significant potential as a rapid and sensitive method for early detection of M. pneumoniae infection in clinical specimens as compared with the culture method, but the PCR method could not provide any information concerning the biological chracteristics of M. pneumoniae strains. Erythromycin, josamycin, sparfloxacin, minocycline, and tetracycline could be recommended as the antimicrobial agents of choice in Korea.
Subject(s)
Adult , Child , Humans , Anti-Infective Agents , Ciprofloxacin , Erythromycin , Josamycin , Korea , Mass Screening , Microbial Sensitivity Tests , Minocycline , Mycoplasma pneumoniae , Mycoplasma , Ofloxacin , Pharynx , Pneumonia , Pneumonia, Mycoplasma , Polymerase Chain Reaction , TetracyclineABSTRACT
No Abstract Available.