Polymerase Chain Reaction targeting insertion sequence IS6110 for the diagnosis of pulmonary tuberculosis among Sudanese children and young adults

Int J Mycobacteriol. 2014 Dec;3(4):252-8. doi: 10.1016/j.ijmyco.2014.09.014. Epub 2014 Oct 28.

Abstract

This study was carried out in Khartoum State during the period from January 2011 to December 2013 to improve the rate of detection of Mycobacterium tuberculosis (MTB) in children with symptoms of tuberculosis (TB) infection using different conventional and advanced diagnostic techniques. One hundred and ninety-seven specimens of gastric lavage and sputum were collected from different hospitals in Khartoum State, including Elbolok Hospital, Jafar Ibn Owf Hospital, Elasha'ab Teaching Hospital, Soba University Hospital and Academy Charity Hospital. All children participating in the study were subjected to the Mantoux test after obtaining appropriate consent injected by 5 tuberculin units of tuberculin purified protein derivative, and the results were recorded after three days. Specimens were decontaminated and inoculated on Lowenstein-Jensen media according to the modified Petroff's method. Two smears were prepared and stained by Ziehl-Neelsen stain and Auramine fluorescent dye; bacterial DNA was extracted from each specimen by using phenol chloroform method, and then the Polymerase Chain Reaction technique was adopted to detect Insertion Sequence IS6110 gene of MTB in these specimens. This study showed that the positive results for TST, ZN, Auramine, Culture and PCR were 86 (43.7%), 16 (8.1%), 22 (11.2%), 32 (16.2%) and 35(17.8%), respectively. The study concluded that the PCR technique is the most sensitive and specific technique for a quick identification of MTB in gastric lavage and sputum from children who are unable to expectorate a good quality sputum sample or who are diagnosed as negative using conventional diagnostic methods.

Keywords: Gastric lavage; Löwenstein–Jensen medium; Pediatric tuberculosis; Polymerase chain reaction.