Mycobacterium tuberculosis resistance to rifampicin is mainly mediated through mutations in the rpoB gene. The effects of rpoB mutations are relieved by secondary mutations in rpoA or rpoC genes. This study aims to identify mutations in rpoB, rpoA, and rpoC genes of Mycobacterium tuberculosis isolates and clarify their contribution to rifampicin resistance. Seventy isolates were identified by acid-fast bacilli smear, Genexpert assay, and growth on Lowenstein Jensen medium. Drug susceptibility, testing was performed by the proportional method. DNA extraction, PCR, and sequencing were accomplished for the entire rpoA, rpoB, and rpoC genes. Twenty-three isolates (32.85%) showed resistance to rifampicin by either proportion method or Genexpert assay. Sequence analysis of the rpoB gene revealed fourteen different mutation patterns. Inside the rifampicin resistance determining region (RRDR), codons: S531L, D516V were highly mutated with frequencies of (21.73%, 17.39%) respectively. Outside the RRDR, there were nine different types of mutations, and M479L was the most prevalent one. Out of 23 RIF resistant isolates, seven isolates (30.43%) carried mutations in the rpoA gene, and twelve isolates (52.17%) harbored a mutation in rpoC. Most of the mutations were identified for the first time in this study. The current study demonstrated that mutations in rpoB, rpoA, and rpoC contributed to RIF resistance in Mycobacterium tuberculosis and this new finding may be relevant to realize how compensatory mutations in the rpoA and rpoC genes restore the fitness cost caused by rifampin resistance-conferring mutations in rpoB.
Background: Tuberculosis (TB) is still a major global public health problem worldwide. The global prevalence of Mycobacterium (M tuberculosis) infection has been estimated in 32% of the world population with more than 8 million new cases diagnosed each year.
Materials and Methods: A total of 192 M tuberculosis complex isolates were collected from patients with positive sputum smear who had been treated previously with the four main anti- tuberculosis drugs for more than two months. The isolates were identified by their colonial morphology, pigmentation, shapes on Ziehl-Neelsen smears, growth on Löwenstein-Jenson medium and biochemical tests as niacin and nitrate tests. A propor
... Show MoreBackground: Tuberculosis (TB) is a major public health issue and a main cause of global morbidity and mortality. TB is the world's ninth leading cause of death despite the numerous treatment strategies for managing the disease.
Objective: To assess the traditional method (direct smear examination and culture) against real-time PCR as pulmonary and extrapulmonary tuberculosis laboratory diagnostic techniques.
Cases and methods: Samples were collected from (612) TB cases, (409) of whom were pulmonary tuberculosis (PTB) and (203) were extrapolmonary tuberculosis (EPTB). The cases were seeking care at the Specialized Chest and Respiratory Disease Center/ National Reference Laboratory for Tuberculosis (NRL) in Baghdad, during the period
57 isolates of Mycobacterium tuberculosis and Mycobacterium bovis were identified; they were isolated from different clinical sources which included sputum, bronchial wash, abscess, pleural fluid, gastric fluid, eye fluid, and CSF, also urine and ear swab. This investigation was carried out on 198 patient attended National Reference Laboratory for T.B during September 2009. Also the study declared that the ratio of separation of this bacterium from male was (67.6%) and it’s higher than the ratio of separation this bacterium from females which was (32.3%). The susceptibility of Mycobacterium tuberculosis to melatonin was evaluated. Many concentrati
... Show MoreCystic fibrosis (CF) is an autosomal recessive multisystem disease that results from mutation(s) of the cystic fibrosis transmembrane conductance regulator (
Congenital adrenal hyperplasia is a group of autosomal recessive disorders. The most frequent one is 21-hydroxylase deficiency. Analyzing
Tuberculosis status as the second leading causes of significant morbidity and mortality from an infectious disease worldwide, after human immunodeficiency virus (HIV). Sample collection was conducted at the Institute of Chest and Respiratory Diseases/Baghdad Medical City in Baghdad. The collection interval was from August to October 2014, 629 suspected TB patients were examined during this period. The results revealed among total 629 specimens, 56 (8.9%) of the specimens were positive by direct examination and 573 (91.1%) negative specimens by smear microscopy. Fifty six DNA samples were extracted from positive ZN smears of sputum specimens and 40 samples from healthy persons (as control) were subjected to molecular diagnosis by real tim
... Show MoreMohammed Hassan Salman is one of the Iraqi national figures who put a clear mark to promote the health institution and to improve the Iraqi people, even it was written about him as "The man who struggled to fight the tuberculosis", He began to struggle against this social courage that has been killing hundreds of Iraqis since his joining of Association for combating tuberculosis in 1999 and his big role in the application of (B-C-G) for the first in Iraq.
In this search, a new bioluminescent technique was proved for pyrophosphate which was employed to single- nucleotide polymorphism (SNP) diagnosis using one-base extension reaction. Four Mycobacterium tuberculosis genes were chosen (Rpob, InhA, KatG, GyrA) genes. Fifty-four specimens were used in this study fifty-three proved as drug-resistant specimens by The Iraqi Institute of Chest and Respiratory Diseases in Baghdad., also one specimen was used as a negative control. The procedure of this assay was as follows. A specific primer within each aliquot owning a short 3-OH end of the base of the target gene was hybridized to the single-stranded DNA template. Then, (exo-) Klenow DNA polymerase and one of either ?-thio-dATP, dTTP, dGTP, or dCTP
... Show More Background: The resistance to antimicrobial factors is an increasingly global problem worldwide, especially among nosocomial bacteria. Staphylococci have become one of the common causes of nosocomialinfections. Multi drug-resistant staphylococci pose a growing problem for human health.
ObjectiveThis study was carried out to evaluate the association between the antibiotic susceptibility patterns and the msrA Erythromycin-Resistant gene in staphylococci isolates obtained from various clinical samples of patients.
Methods: A total of 25 staphylococci clinical isolates were collected from the central Health Lab. DNA from each sample was extracted and The gene implicated in resistance to erythromycin (msrA) was amplified using PCR