Drug Susceptibility Testing Of Mycobacterium Tuberculosis And Peripheral Blood Cytokine Detection Of MDR-TB Patients

Objective: To study the sensitivity of Mtb to the three commonly usedfluoroquinolones ofloxacin (OFX), levofloxacin (LFX), and moxifloxacin(MFX), and analyze the drug resistance, to provide the basis for the clinicalusage of drugs for Mtb therapy. To explore the serum level of tumor necrosisfactor alpha (TNF-alpha) and gamma interferon (IFN-gamma) in MDR TBpatients.Methods: The drug susceptibility testing was done using the proportionmethod, with analysis of moxifloxacin and isoniazid (INH), streptomycin (SM),rifampicin (RFP), ethambutol (EMB), ofloxacin (OFL), levofloxacin (LVF),prothionamide (TH1321), parasal (PAS), ciprofloxacin (CIP), and amikacin(Am). The serum TNF-alpha and IFN-γ level were determined by indirectELISA in MDR TB patients.Results:1) Totally376Mtb positive cases were detected in750Mtbpatients with sputum culture. The drug resistant rate for different drugs are:17.0%with Moxifloxacin (64cases),60.6%with Isoniazid,44.1withStreptomycin,51.5%with Rifampicin,42.0%with Ethambutol,37.6%withOfloxacin,25.0%with Levofloxacin,52.1%with Prothionamide,56.9%withPara-aminosalicylic acid,66.5%with Ciprofloxacin,44.1%with Amikacin.2) Serum TNF-α analysis in MDR TB patient showed that thelevel of TNF-α decreased with progression of the lesions range. Lung field1~2 group had significantly higher TNF-α level than the lung field5~6group(P<0.01). Patients without tuberculous cavity had higher TNF-α than thepatients with tuberculous cavity (P<0.05). Serum IFN-γ analysis showed thatlung field group5~6was statistically higher than group3~4(P<0.05).Conclusion:1) MDR-TB induce intensively inflammatory reaction with TNF-α andIFN-γ level increasing. These cytokine play a role in TB and associate withpatient’s condition.2) Mtb has already showed high resistance rate to OFX and LFX in thedrug susceptibility testing, which should be paid attention in clinic.Moxifloxacin showed good antibacterial effects, and it is an effective anti-TBdrug. Drug susceptibility testing should be done before drugs are used foranti-TB therapy, to provide information for specific therapy in clinic.