ABSTRACT
UNLABELLED: Tuberculosis is explicitly recognized as a major global public health problem. In Côte d'Ivoire, relapse cases represent 66.5% of patients eligible for retreatment according to the National Tuberculosis Control Program. This study objective was to detect multidrug-resistance tuberculosis among relapse cases. Patients were recruited in tuberculosis centers in routine. A standardized questioning was administrated. Two sputum samples were collected and transported at Institut Pasteur. Sputum samples were decontaminated by NALC method. The DNA extraction was realized with 500µl of decontaminated sputum sample with smear-positive. MTBDRplus assay version 2.0 was performed according to the manufacturer's instruction. An internal quality control program with positive and negative controls was implemented for interpretation of results. In total 146 relapse cases with smear positive were studied. Out of selected patients, 130 had received the 2RHZE/4RH regimen and 16, the 2RHZES/1RHZE/5HRE. In group of relapse cases previously treated with 2RHZE/4RH regimen, 40 (31.3%, IC95%: [0.23; 0.39]) had punctual mutations at codon 526 in rpoB gene. Although, in patients under treated with 2RHZES/1RHZE/5HRE, a mutation in rpoB gene was identified in 12 of 16 sputum samples. Thirteen mutations conferring a resistance to Isoniazid were observed of which 9 in katG gene and 4 in katG and promoter region of inhA gene. The comparison (Chi-square with Yates correction) of resistance rates to Rifampin estimated showed a statistically significant difference. CONCLUSION: Use of a rapid method to detect drug-resistance in recurrent TB cases has permitted to identify patients eligible for first-line drugs or not.
ABSTRACT
Mycobacterium ulcerans infections are a public health problem in Céte d'Ivoire. The etiological diagnosis of this disease made by culture remains a big concern due to the slowness and difficulties encountered. This detection by culture of M. ulcerans represents a big interest as it allows obtaining the circulating strains for research. The purpose of this study was to determine on a routine basis in a poorly equipped laboratory, in vitro culture of M. ulcerans from exudates of skin ulcerations and from biopsy of patients with suspected Buruli ulcer. A particular attention was paid to the conditioning of the sample forwarded to the laboratory and inoculation in Lowenstein-Jensen medium supplemented with glycerol. The results of the three methods for the analysis showed 26.7, 57.4 and 17.8% positive rate respectively in the microscopy examination by nested PCR and by culture. In all the analysis, the positive rate from biopsy is higher than that obtained from exudates. The overall contamination rate by invasion of the three tubes of culture by fungi is 15.8 with 14.3 and 19.4% respectively,from exudates and biopsies. All positive samples in Ziehl-Neelsen staining and in culture were also positive by nested PCR. The nested PCR confirmed the positive strains found in culture, which were responsible for skin ulcerations. After culture, only one strain was nPCR negative. This strain was identified as Mycobacterium Gordonae. Our culture conditions showed that M. ulcerans was not the only strain identified and that other strains were present in the culture. We can conclude that the culture of M. ulcerans, in spite of the growth difficulties of the bacterium can be performed in laboratory in developing countries despite the lack of reagent and consumables. The implementation of this culture is the only way to determine sensitivity tests in vitro and in vivo in order to treat patients with Buruli ulcer.
