Mutations Associated with Rifampicin Resistance in Mycobacterium tuberculosis Isolates from Moroccan Patients: Systematic Review.

BACKGROUND: In recent years, the treatment of tuberculosis has been threatened by the increasing number of patients with drug resistance, especially rifampicin resistance, which is the most effective first-line antibiotic against Mycobacterium tuberculosis. METHODS: We performed a systematic review of the literature by searching the PubMed database for studies of rifampicin-resistant Mycobacterium tuberculosis (MTB) isolates from Moroccan patients, published between 2010 and 2020. The aim of this review was to quantify the frequency of the most common mutations associated with rifampicin resistance, to describe the frequency at which these mutations co-occur. Identified studies were critically appraised according to the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. RESULTS: 6 studies met our inclusion criteria. Results show that 99.36% of MTB isolates had a single-point mutation, and the most commonly mutated codon of rpoB gene is 531 with 70.33% of phenotypically resistant strains. However, 10.38% of MTB strains phenotypically resistant to RIF did not exhibit any mutation in the rpoB gene. CONCLUSION: Identification of a resistance-associated mutation to rifampicin can be a good marker of drug-resistant TB, but lack of a mutation in the target sequence must be interpreted with caution.

Epidemiological profile among pulmonary and extrapulmonary tuberculosis patients in Laayoune, Morocco.

INTRODUCTION: despite major strides in the prevention, diagnosis and management of tuberculosis, the disease continues to be one of the most pressing global health problems, particularly in developing countries. The purpose of the present study was to describe the epidemiological profile among tuberculosis patients in Laayoune, Morocco. METHODS: a retrospective study was conducted among tuberculosis patients (having extrapulmonary tuberculosis and pulmonary tuberculosis), registered in the diagnosis of tuberculosis and respiratory diseases reference center of Laayoune, between January 2017 and May 2018. Demographic characteristics, clinical presentation of TB and apparent risk factors of the disease were obtained from the medical case records of all patients. RESULTS: during the study period, a total of 211 patients (125 males and 86 females) with tuberculosis were enrolled. The majority of cases (93.40%) were newly diagnosed and the segment with the pulmonary tuberculosis was 63.50%. The highest disease burden was found in the ≥15 year age group (92.40%; p=0.022). Men were more frequently affected by pulmonary tuberculosis (70.90%), while extrapulmonary tuberculosis was more commonly detected in women (61%) (p<0.0001). The most common sites of extrapulmonary disease were lymphatic (32.47%), pleural (16.88%) and spinal tuberculosis (15.58%). HIV infection and smoking seem to be the most important risk factors that affect host defense against TB infection. CONCLUSION: the results obtained in tuberculosis patients in Laayoune, Morocco, showed that active tuberculosis was associated with risk factors such as sex, age and smoking.

Rapid molecular assays for detection of tuberculosis.

Tuberculosis (TB) is an infectious disease that remains an important public health problem at the global level. It is one of the main causes of morbidity and mortality, due to the emergence of antibiotic resistant Mycobacterium strains and HIV co-infection. Over the past decade, important progress has been made for better control of the disease. While microscopy and culture continue to be indispensible for laboratory diagnosis of tuberculosis, the range of several molecular diagnostic tests, including the nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have expanded tremendously. They are becoming more accessible not only for detection and identification of Mycobacterium tuberculosis complex in clinical specimens, but now extend to diagnosing multi-drug resistant strains. Molecular diagnostic tests provide timely results useful for high-quality patient care, low contamination risk, and ease of performance and speed. This review focuses on the current diagnostic tests in use, including emerging technologies used for detection of tuberculosis in clinical specimens. The sensitivity and specificity of these tests have also been taken into consideration.

Rapid discrimination of environmental Vibrio by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

The aim of this study was to discriminate 30 Vibrio strains isolated from two wastewater treatment plants from Agadir, Morocco by two molecular typing methods, pulsed-field gel electrophoresis (PFGE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Out of the 30 strains of Vibrio examined in this study, 5 isolates could not be typed by PFGE and consistently appeared as a smear on the gel. In general, high genetic biodiversity among the Vibrio strains was found regardless to the isolation source. The results of MALDI TOF analysis show a high congruence of strain grouping demonstrating the accuracy and reliability of MALDI-TOF MS.