The Water Distribution Of Mycobacterium Tuberculosis Research In Shanghai

Although members of the Mycobacterium tuberculosis complex (MTC) are responsible for the majority of mycobacterial infections worldwide, environmental opportunistic infections due to non-tuberculous mycobacteria (NTM) are increasingly becoming more of a public health challenge. Mycobacteria other than Mycobacterium tuberculosis complex and Mycobacterium leprae are called nontuberculous mycobacterial (NTM). More than 100 species of NTM have been characterized. Human disease caused by NTM infection presents as at least one of four distinct clinical syndromes:pulmonary disease, lymphadenitis, cutaneous disease and disseminated disease, of which pulmonary disease is the most common manifestation. NTM can be found throughout the environment and can be isolated from soil, water (including tap water), dust, milk, and various animals and birds. Unlike M. tuberculosis, airborne human-to-human transmission of NTM is considered a rare event, although airborne NTM may be a major source of respiratory infections. It is reported that incidence of NTM is increasing, particularly in developed countries. The increase is mainly due to increases in HIV prevalence, iatrogenic immune depression, and frequent contact with environmental NTM. Improvements in detection and culture methods available for NTM also contribute to the increase. However, the relative difficulties in the diagnosis of NTM, together with high rates of resistance to the most commonly used anti-mycobacterial drugs, hinder successful treatment and cure, making NTM disease a challenge for microbiologists and physicians alike.In China, there have been few epidemiologic reports of NTM. Traditionally, identification of mycobacteria to the species level is performed by studying phenotypic traits. However, such methods are time-consuming and produce equivocal results. More recently.16S rRNA sequencing-based identification has been explored as a more accurate method to identify many organisms, including mycobacterial. We identified NTM with this method and conducted a series of study concerning epidemiology of NTM.In this study, we identified one hundred and seven NTM isolates identified from respiratory specimens in Shanghai from Jan 2008 to Dec 2008 by using traditional biochemical method and 16S rRNA sequencing. Compared the results of traditional biochemical method and 16S rRNA sequencing and analyzed the advantage and disadvantage of traditional biochemical method and 16S rRNA sequencing. At the same time, a retrospective analysis was performed on these ntm isolates to determine the prevalence, trends and risk factors of ntm. We analyzed the distribution of ntm from shanghai environmental water and tap water system to determine the possible sources of ntm infection in shanghai. Furthermore, we investigated molecular epidemiology of M. tuberculosis in Changning area of Shanghai by VNTR typing method of Mycobacterium tuberculosis.The traditional biochemical method of NTM species identification relies upon the phenotypic characteristics of biochemical testing, pigment production, growth characteristics, and colonial morphology. The traditional biochemical method is the national standard method of NTM species identification in china. However, they are time-consuming and with almost 100 currently established species, a number that continues to rise, biochemical algorithms become too complex, which results in misidentification. The most well-known, the 16S rRNA gene, is considered a gold standard for identification for all bacteria and is widely recognized as a rapid and accurate method of identifying known and novel mycobacteria. In this study, we identified one hundred and seven NTM isolates identified from respiratory specimens in Shanghai from Jan 2008 to Dec 2008 by using traditional biochemical method and 16S rRNA sequencing. The result suggested that the coincidence rate of the results which come from two methods were 93.5%. 16S rRNA sequencing identification is the only approach that can provide useful information in the case of a new species with the use of phylogenetic software. Combining the available data of first-line antituberculosis drug resistance and Epidemiology, We conducted a retrospective analysis of nontuberculous mycobacteria isolated from respiratory specimens in Shanghai from Jan 2008 to Dec 2008 to determine the prevalence trends and first-line antituberculosis drug resistance of NTM. Eight different NTM species were identified, including M. kansasii, M. intracellulare, M. avium, M. gordonae, and M. fortuitum. M. kansasii was the most commonly identified NTM(42.1%). Our data suggest that some sputum smear-positive patients may have NTM and may require different treatment regimens than pulmonary tuberculosis patients.To determine the possible sources of ntm infection in shanghai. We analyzed the distribution of ntm from shanghai environmental water and tap water system. A total of 229 samples (environmental water and tap water) were examined for mycobacteria. Isolates were identified by 16S rDNA sequencing. The grand positive rates of water in shanghai was 18.34%. The positive rates of environmental water and tap water were 13.79% and 26.19%, respectively. Environmental water were more contaminated with NTM(p=0.0195). M. gordonae, M. fortuitum, M. peregrinum, M. szulgai, M. kansasii were identified. M. gordonae was the most frequently identified species in environmental water. M. gordonae and M. kansasii were the most frequently identified species in tap water. Our results suggest that M. kansasii disease in the shanghai may be contracted from tap water. But still need molecular epidemiology investigation followed.Previous studies showed that pulmonary TB patients might belong to the newly developed cases in shanghai. M. tuberculosis isolates from newly diagnosed culture positive lung tuberculosis patients in Changning area of Shanghai were subjected to 7 loci VNTR typing to explore the molecular-epidemiology of Mycobacterium tuberculosis in Changning area of Shanghai. In Changning area of Shanghai,91 strains were identified into 79 unique isolates and 9 clusters. The estimated rate of recent transmission was 13.18% in Changning area of Shanghai. In this study, a retrospective analysis was performed to determine the prevalence of TB patients, some TB patients with the same cluter lived in the same Community. We think the transmission of TB in Changning District is serious. These findings highlight the urgency of increasing efforts to interrupt the transmission of tuberculosis in communities and facilities.