AEGiS-15IAC: Molecular characterization and antibiotic susceptibility of Mycobacterium tuberculosis strains isolated from patients at an urban hospital in Guatemala.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Molecular characterization and antibiotic susceptibility of Mycobacterium tuberculosis strains isolated from patients at an urban hospital in Guatemala.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. MoOrB1016)

Samayoa-Herrera B, Xet-Mull AM, Velasquez-Porta T, Lau-Bonilla D, Jimenez T, Paz-Garcia L, Arathoon E
Universidad de San Carlos, Escuela de Quimica Biologica, Guatemala City, Guatemala

Introduction: The increase in tuberculosis cases has necessitated a more thorough understanding of infection dynamics. Important factors to address include frequency of new infections versus the rate of reactivation of the disease, rates of antibiotic resistance, and epidemiologic identification of heavily affected groups. Objectives: This study aims to characterize genetic fingerprints, antibiotic susceptibility profiles and epidemiologic factors associated with M. tuberculosis infections at an urban hospital in Guatemala.

METHODS: This was an observational descriptive study using 182 strains isolated at the Hospital General San Juan de Dios (HGSJD) between 2000 and 2002. Molecular characterization was performed using DRE-PCR and antibiotic susceptibility by the modified Cannetti method. Available medical records were reviewed. Statistical analysis was carried out using EPI Info 6.0.

RESULTS: Clustered genetic fingerprints made up 73.6% (134/182) of the strains, while the remaining 26.4% (48/182) had unique genetic patterns. 5.3% (4/75) of the strains were resistant to only one drug, 6.7% (5/75) were resistant to two drugs, while 6.7% (5/75), were multi-drug resistant (MDR) strains. 81% (61/75) of the strains were susceptible to rifampicin, isoniazid, ethambutol and streptomycin. Some drug-resistant strains isolated from pulmonary samples fell into genetic clusters.

CONCLUSIONS: 73.6% (134/182) of the M. tuberculosis strains studied fell into genetic clusters, suggesting that the majority of cases diagnosed at HGSJD between 2000 and 2003 were due to primary recent infection, while only 26.4% (48/182) were due to reactivation of disease. 6.7% of the strains analyzed were MDR, and 12% were resistant to 1-2 anti-tuberculosis drugs. Three strains of MDR M. tuberculosis were isolated from HIV positive patients. Our results highlight the need for drastic changes in the diagnosis, management, treatment and follow-up of tuberculosis in patients treated at urban hospitals.

Keywords: AEGIS, Mycobacterium tuberculosis, Tuberculosis, Multidrug-Resistant, Tuberculosis, Isoniazid, Ethambutol, Rifampin, Streptomycin, Hospitals, Urban, Cluster Analysis, Hospitals, Guatemala, Humans

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