Molecular Differentiation and Analysis of Drug Resistant Genes and Virulence Factors of Pathogens in Patients with Infectious Spondylitis

Infectious spondyltis is not uncommon clinically. It accounts for 2-7% of all cases of osteomyelitis. The predisposing factors include other site infections, DM, urinary tract infection, drug abuse, and an immune compromise. A delay in the diagnosis of it is usually owing to its insidious and nonspecific clinical presentations; and minimal radiological changes occurred at the initial stage. Literature noted that, even in medical center hospitals, a delay in diagnosis of infectious spondylitis can be 4-6 weeks. The most common organisms causing pyogenic spondylitis include staphylococcus aureus and streptococcus species. However, TB infection can not be overlooked in the differential diagnosis of spine infection. Currently, a trend of reemerged TB infection has drawed much attentions in Taiwan. The diagnosis of spine infection is usually a long and tedious process. In pyogenic cases, a positive blood culture rate is only seen in 2/3 of the patients. In TB spine, the specificity of acid-fast stain was less than 30%. Furthermore, TB culture and drug susceptibility test were very time-consuming, a period of 6-8 weeks was usually required before a definite report available. In addition, the sensitivity of TB culture was reported as low as 50%. The treatment of pyogenic or TB spondylitis mainly rely on antibiotic treatments. However, the optimal period of antibiotic administration is still an issue of debate. The recommended treatment period for pyogenic spondylitis is 4-6 weeks; and in TB spine, 1 to 1.5 years. Increasing drug resistance emerged in these patients is partly due to its prolonged and empirical antibiotic usage. The specific aims of this proposal are (1) to establish a new Multiplex PCR method to detect and differentiate pathogens from formalin-fixed, paraffin-embedded tissue of patients with infectious spondylitis; and an association of drug resistance with the mutations, such as rpoB and katG drug resistant genes. (2) to apply the Multiplex PCR and real-time PCR method to differentiate and to detect drug resistance genes of the pathogens of clinical samples from patients with infectious spondylitis; and to establish a method to detect the alive pathogens for validation of end point to stop drug use. (3) to analyze the molecular characterization of genotypes and virulence factors of pathogens; and an association of genotypes with virulence factors to cause tuberculous spondylitis. The health-relatedness and long-term goals of this proposal are to offer a more rapid and reliable method in diagnosing either pyogenic or TB spondylitis. An early detection of drug resistance of pathogens can be achieved; and an early chemotherapy can be effectively administrated. Furthermore, the study of genotypes and virulence factors of the pathogens can help to elucidate the pathogenesis of infectious spondylitis.

Project ID:PC9902-1691 
External Project ID:NSC98-2314-B182-011-MY3