Varghese Bright, Enani Mushira, Shoukri Mohammed, AlThawadi Sahar, AlJohani Sameera, Al-Hajoj Sahal
Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
Medical Specialties Department, King Fahad Medical City, Riyadh, Saudi Arabia.
PLoS Negl Trop Dis. 2017 Jan 11;11(1):e0005288. doi: 10.1371/journal.pntd.0005288. eCollection 2017 Jan.
Clinical relevance of nontuberculous mycobacteria (NTM) is increasing worldwide including in Saudi Arabia. A high species diversity of NTM's has been noticed in a recent study. However, the identification in diagnostic laboratories is mostly limited to common species. The impact of NTM species diversity on clinical outcome is so far neglected in most of the clinical settings.
METHODOLOGY/PRINCIPAL FINDINGS: During April 2014 to September 2015, a nationwide collection of suspected NTM clinical isolates with clinical and demographical data were carried out. Primary identification was performed by commercial line probe assays. Isolates identified up to Mycobacterium species level by line probe assays only were included and subjected to sequencing of 16S rRNA, rpoB, hsp65 and 16S-23S ITS region genes. The sequence data were subjected to BLAST analysis in GenBank and Ez-Taxon databases. Male Saudi nationals were dominated in the study population and falling majorly into the 46-59 years age group. Pulmonary cases were 59.3% with a surprising clinical relevance of 75% based on American Thoracic Society guidelines. Among the 40.7% extra-pulmonary cases, 50% of them were skin infections. The identification revealed 16 species and all of them are reporting for the first time in Saudi Arabia. The major species obtained were Mycobacterium monascence (18.5%), M. cosmeticum (11.1%), M. kubicae (11.1%), M. duvalli (7.4%), M.terrae (7.4%) and M. triplex (7.4%). This is the first report on clinical relevance of M. kubicae, M. tusciae, M.yongonense, M. arupense and M.iranicum causing pulmonary disease and M. monascence, M. duvalli, M. perigrinum, M. insubricum, M. holsaticum and M. kyorinense causing various extra-pulmonary diseases in Saudi Arabia. Ascites caused by M. monascence and cecum infection by M. holsaticum were the rarest incidents.
CONCLUSIONS/SIGNIFICANCE: To the first time in the country, clinical significance of various rare NTM's are well explored and the finding warrants a new threat to the Saudi Arabian clinical settings.
非结核分枝杆菌（NTM）在全球范围内（包括沙特阿拉伯）的临床相关性正在增加。最近的一项研究发现NTM具有高度的物种多样性。然而，诊断实验室中的鉴定大多限于常见物种。在大多数临床环境中，NTM物种多样性对临床结果的影响至今仍被忽视。
方法/主要发现：在2014年4月至2015年9月期间，在全国范围内收集了疑似NTM临床分离株以及临床和人口统计学数据。通过商业线性探针检测进行初步鉴定。仅通过线性探针检测鉴定到分枝杆菌属水平的分离株被纳入，并对其16S rRNA、rpoB、hsp65和16S - 23S ITS区域基因进行测序。序列数据在GenBank和Ez - Taxon数据库中进行BLAST分析。研究人群中沙特男性国民占主导，主要集中在46 - 59岁年龄组。肺部病例占59.3%，根据美国胸科学会指南，其临床相关性令人惊讶地达到75%。在40.7%的肺外病例中，50%为皮肤感染。鉴定出16个物种，所有这些物种均为首次在沙特阿拉伯报道。主要的物种有嗜热栖热放线菌（18.5%）、美容分枝杆菌（11.1%）、库氏分枝杆菌（11.1%）、杜氏分枝杆菌（7.4%）、土分枝杆菌（7.4%）和三联分枝杆菌（7.4%）。这是关于库氏分枝杆菌、托斯卡纳分枝杆菌、永贡分枝杆菌、阿鲁彭斯分枝杆菌和伊朗分枝杆菌引起肺部疾病以及嗜热栖热放线菌、杜氏分枝杆菌、奇异分枝杆菌、因苏布里分枝杆菌、霍尔萨蒂分枝杆菌和京都分枝杆菌在沙特阿拉伯引起各种肺外疾病的临床相关性的首次报告。由嗜热栖热放线菌引起的腹水和由霍尔萨蒂分枝杆菌引起的盲肠感染是最罕见的病例。
结论/意义：该国首次对各种罕见NTM的临床意义进行了充分探索，这一发现对沙特阿拉伯的临床环境构成了新的威胁。
