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Aim and Background. spoilgotyping is a method based on 36bp DR(Direct Repeat) chromosomal loci polymorphism which is connected to one or two 35- 41 spacersequences. There have been 94 differet intra DR spacer sequences identified and only 43 of them are used as usual. Mycobacterium tuberculosis complex strains can be identified in order to lacking or having these sequences.

Materials and methods. spoilgotyping test was done on 149 TB smear positive patients.Primary separation of mycobacterium strains was done through petrof 4% method and by Lowenstein Jensen(LJ) media. Biochemical tests such as Niacin test / Catalase activity / Nitrate reduction were done due to strains identifying. Drug sensitivity to INH(2Mg/ml) / RIF(40Mg/ml) / STM(10Mg/ml) and ETBI(2Mg/ml) was accomplished proportional and strains were distributed to three groups: sensitive, MDR, non MDR. DNA was extracted by CTAB method on positive clonies. Sequences were amplified by PCR and after denaturating amplified sequences, hybridation with Streptavidine peroxidase enzyme through line reverse blot method was accomplished. Luminoscense was added and the membrane was put onto the X-ray film. Then we did radiology step.

Results: Serotypes were divided into 9 groups (Beijine/CAS23/Haarlem/U/T2/T1/EAI3/EAI2/CAS2). The majority group was Haarlem (27%) and minority one was T2 (0.4%). There were also identified 2 strains belonging to Mycobacterium bovis.

Conclusion: Used method in this study is easy/precipitate and has high sensitivity. In every time using this method there could be 43 samples distinguished.

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Aim and Background: Bacterial arthritis is one of the arthritis diseases known that can rapidly cause joint damage. Among the bacteria causing septic arthritis, Mycobacterium tuberculosis (MTB) is one of those that rarely produce arthritis. The aim of this study is to examine the presence of MTB in synovial fluid of patients with arthritis using Polymerase Chain Reaction (PCR)
Materials and Methods: This study was carried out on 70 synovial fluid samples gathered from Shariati Hospital. DNA was extracted using Phenol-Chloroform standard extraction technique. PCR test optimized on the basis of IS6110 target gene. Samples were analyzed by PCR test after evaluation of specificity and sensitivity of PCR.
RESULT: PCR test was optimized and the 317-bp amplicon detected by 1.5% agarose gel electrophoresis. Limit of detection (LOD) was estimated as 100 copy/Reaction. MTB DNA was detected in 4 (5.7%) synovial fluid samples of patients with arthritis.
CONLUSION: First step in treatment is rapid and accurate diagnosis. MTB have some characteristics including slow generation making the identification difficult and exhausting through culturing and biochemical tests that sometimes leads to ambiguous results. Results of this study confirm that MTB could play a role in bacterial arthritis and rapid diagnosis using PCR provides us with accurate treatment.

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Aim and Background: Diagnosis of drug-resistant tuberculosis is of high value considering the importance of controlling tuberculosis. Identifying and introducing a rapid and specific diagnostic method for the causative agent of tuberculosis, Mycobacterium tuberculosis, is of great importance. The aim of this study is molecular characterization the presence of drug-resistant Mycobacterium tuberculosis to first- and second-line drugs in suspected tuberculosis patients.
Materials and methods: This study was conducted on 2895 patients referred to different laboratory centers who were suspected to tuberculosis. The samples that were positive on the culture medium were examined by the drug resistance evaluation method and also the sequencing was performed on drug resistant genes including katG, rpoB, rrsL and gyrA to identify the corresponding mutations.
Findings: During the study period from October 2018 to March 2022, 2895 people, a total of 283 positive samples and 60 resistant samples were isolated, and the relevant mutations in each gene were determined based on nucleotide changes on the relevant genes.
Conclusion: Due to the fact that the diagnosis of tuberculosis, especially in the case of Mycobacterium tuberculosis, is time consuming especially when samples are positive and it takes a long time to perform the resistance evaluation test. So molecular identification and identification of the relevant mutations on the related drug-resistance genes, provides the possibility of accurate diagnosis and timely treatment