embB Gene association with Ethambutol drug Resistance in Mycobacterium Tuberculosis Patients

Background: Tuberculosis (TB) is fatal and life threatening infectious disease. The transmission rate of tuberculosis is very high. Various drugs are used as treatment for TB. Recently it has been observed that one of the most important factor for fast TB spread is development of anti-TB drug resistant mycobacterium tuberculosis (MTB). Various combination of drugs like isoniazid (INH), rifampicin (RIF), Streptomycin(SM), pyrazinamide (PZA) or ethambutol (EMB) are in global use for TB treatment. Improper usage of these drugs makes the person prone to develop anti-TB drug resistant tuberculosis. Aim: To evaluate association of embB gene with ethambutol resistance in Mycobacterium Tuberculosis. Methods: 104 Specimens of sputum from suspected tuberculosis patients were processed for inoculation in Lowenstein J Medium after it has been decontaminated properly. Kit method by using QIAamp DNA Mini kit was utilized for extraction of DNA. Then region from base 6953 to 10249 of embB gene was amplified through PCR and then followed by sequencing with the aid of softwares blast2seq and ClustalW2. Three primer sets were utilized to amplify embB gene. Ethambutol (EMB) Resistant MTB specimens were processed to study mutation in embB gene. Results: Out of the total 104 sputum specimens, 14 samples were found to have ethambutol resistance. These 14 samples were then processed for mutational analysis. DNA sequence analysis of these 14 samples confirmed embB gene mutation in 10 samples. Mutational analysis revealed that 08 samples showed mutation at codon 306 and two samples showed mutation at 319 codon. The reported mutation Methionine →Isoleucine was seen in 07 samples with ATG codon replaced by ATA codon at codon position 306. One sample showed mutation as Methionine →Isoleucine with ATG codon replaced by ATC codon at codon position 306. Two samples showed mutation as Tyrosine →Serine with TAT codon replaced by TCT at 319 codon position in embB gene. Conclusion: This study concludes that mutation of certain genes particularly point mutation of embB gene at codon 306 and 319 is associated with drug resistance of ethambutol in ethambutol resistant mycobacterium tuberculosis patients. Keywords: Ethambutol, embB gene, Mycobacterium tuberculosis.

Prevalence and molecular identification of Mycobacteria isolated from animals slaughtered at Sokoto modern abattoir, Sokoto State, Nigeria

This study investigated the molecular epidemiology of Mycobacteria isolated from animals slaughtered at Sokoto modern abattoir. During meat inspection, 104 suspected tuberculosis lesions were sampled from a total of 102,681 animals slaughtered between November 2016 and January 2018. These samples were subjected to Ziehl Neelsen staining, followed by culture on Lowenstein-Jensen media. Subsequently, polymerase chain reaction (PCR) and sequencing of the 65KDa heat shock protein (hsp65) gene were performed to identify and phylogenetically characterize the cultured organisms. Because sequencing of the hsp65 gene was unable to distinguish between Mycobacterium bovis (M. bovis) and M. tuberculosis, PCR was performed to amplify a genomic region-specific to M. bovis in order to differentiate them from M. tuberculosis. Results showed that, 14 samples yielded growth after culture. Furthermore, hsp65 was detected in 9 out of the 14 isolates screened, 5 of the amplicons were successfully sequenced. Similarity search using NCBI BLAST tool showed the five sequences to share highest identities with Mycobacterium novocastrense (95.99%), M. canettii (94.54%), and M. tuberculosis/M. bovis (100%). Two out of the 5 isolates were confirmed to be M. bovis after PCR amplification using M. bovis specific primers. Phylogenetic tree further confirmed the identity of these isolates by placing them close to species of their kind. Further studies should be conducted to establish the transmission dynamics of the zoonotic Mycobacteria between animals and their owners, to facilitate control and eradication of tuberculosis.

A Rare Case of Cardiac Hydatid Disease without Liver and Lungs Involvement

Hydatid disease is a parasitic infection caused by Echinococcus granulosus. Cardiac involvement is rare especially without liver and lungs tissue involvement. We describe a 12-year-old male patient referred to Mofid Children's Hospital, Tehran, Iran in Jul 2020 due to chronic pericardial effusion and suspected tuberculosis infection from Afghanistan. Echocardiography revealed a cystic lesion in the interventricular septum. Thoracic and abdominal computed tomography showed no similar cystic lesion in the lungs and liver. The patient underwent open-heart surgery for cystectomy and medical treatment with albendazole. Histological examination confirmed hydatid cyst diagnosis. The patient was discharged in good condition and oral albendazole was continued.

Tuberculosis/HIV Co-infection among Internally Displaced Persons (IDP) in Gombe State, Nigeria

Background: Tuberculosis is a global health problem associated with high morbidity and mortality. Rapid diagnosis of tuberculosis is essential for early disease management. Human Immunodeficiency Virus (HIV) is a virus that gradually attacks the immune system and the immune system is our body’s natural defence against illness. Co-infection of TB and HIV is when someone has both HIV and TB infections. This study determined the TB/HIV Co-infection among IDP’s. Methodology: A total of 130 sputum samples from suspected tuberculosis patients were examined from August 2020 to September 2020. Result: Fifty-nine patients 59(45.4%) were males and seventy-one 71 patients (54.6%) were females. Seventeen patients (13.07%) had tuberculosis. Ten (10) cases of the TB patients were found to be co-infected with HIV. The CD4+ cell count of the TB/HIV co-infected patients falls below 250 cells/mm3 compared to the mono-infected patients who had CD4+ above 250 cells/mm3. Conclusion: This study showed that TB/HIV coinfection was associated with age group 21-40 years was high.

Evaluation of GeneXpert MTB/Rif Assay and the Conventional Methods for Detection of Pulmonary Tuberculosis in Internally Displaced Persons (IDP) Camps in Gombe State

Background: Tuberculosis is a global health problem associated with high morbidity and mortality. Rapid diagnosis of tuberculosis is essential for early disease management. Aim: This study evaluated the performance of gene expert MTB/ RIF assay for the diagnosis of pulmonary tuberculosis and rifampin (RIF) resistance with conventional methods. Methods: A total of 130 sputum samples from suspected tuberculosis patients were examined from July 2019 to August 2019. Results: Fifty-nine patients 59(45.4%) were males and seventy-one 71 patients (54.6%) were females. Seventeen patients (13.07%) had tuberculosis. Of the 17 Confirmed tuberculosis patients, 6(35.2%) were ZN positive, 11(64.7%) were GeneXpert positive and 17(100%) were positive to TB Culture. One sample showed false-positive GeneXpert result. The GeneXpert assay achieved 47.1% sensitivity, 97.3% specificity, 72.7% Positive Predictive Value (PPV) and 92.4% Negative Predictive Value (NPV) while ZN Staining method had 35.3% Sensitivity, 97.27% Specificity, 100% PPV and 91.1% NPV. GeneXpert detected 5(29.41%) Rifampicin resistant TB. The risk factors associated with tuberculosis in this study had HIV (17.6%), Malnutrition (13.8%) and Overcrowding (15.3%). Conclusion: GeneXpert MTB/RIF assay is a helpful tool for rapid diagnosis and prompt treatment of TB. However, the use of Genexpert does not eliminate the need of conventional microscopy, culture and anti-tubercular sensitivity that are required to monitor the progression of treatment.

Safety and diagnostic yield of endobronchial ultrasound-guided lymph node biopsy in children and adolescents with suspected tuberculosis

Referring to a literature review published recently in this Journal, we report a single-center case series of 45 children and adolescents (age 2-17 years) with suspected tuberculosis (TB) and negative microscopy on repeated sputum or gastric aspirate samples. All subjects underwent flexible airway endoscopy including bronchoalveolar lavage (BAL) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) without adverse events. Among 41 subjects with a final TB diagnosis, Mycobacterium tuberculosis was detected by PCR and/or culture in 20 (49% bacteriological confirmation) with 11 cases relying exclusively on results from TBNA samples. Only 7 of 17 positive culture results related to sputum (17% confirmation rate), and 9 of 17 on the combination of sputum and BAL (22%) respectively. The sampling site of a person’s first positive culture was TBNA in 13 of 17 cases (76%). Bacteriological confirmation was essential for diagnostic accuracy and tailored treatment based on individual drug susceptibility testing. We therefore recommend the inclusion of bronchoscopy and EBUS-TBNA in a comprehensive diagnostic protocol for smear-negative pediatric TB suspects.