title: Mycobacterium tuberculosis of the RDRio genotype is the predominant cause of tuberculosis and associated with multidrug resistance in Porto Alegre City, South Brazil.
abstract: Spoligotyping has shown Mycobacterium tuberculosis strains to be composed of different lineages, and some of them are not just geographically restricted but also affect specific ethnic populations and are associated with outbreaks and drug resistance. We recently described a particular subtype within the Latin American-Mediterranean (LAM) family, called RD(Rio), widespread in Brazil. Moreover, recent data also indicate that RD(Rio) is present in many countries on all continents and is associated with cavitary disease and multidrug resistance (MDR). To further explore the relationship between RD(Rio) and MDR, we conducted a study in a tuberculosis (TB) reference center responsible for the care of MDR patients in Rio Grande do Sul, the southernmost Brazilian state. From a collection of 237 clinical isolates, RD(Rio) alone was responsible for one-half of all MDR cases, including one large group composed of strains with identical IS6110-restriction fragment length polymorphism (RFLP) and having the LAM5 signature. We additionally had complete data records for 96 patients and could make comparisons between the presence and absence of RD(Rio). No difference in clinical, radiological or laboratory features was observed, but a significantly greater number of cases with MDR were described in patients infected with an RD(Rio) strain (P = 0.0015). Altogether, RD(Rio) was responsible for 38% of all TB cases. These data support and confirmed previous findings that RD(Rio) is the main agent responsible for TB in Brazil and is associated with drug resistance. Considering that RD(Rio) is a globally distributed genotype, such findings raise concern about the increase in MDR in certain human populations.
authors: Fundação Estadual de Produção e Pesquisa em Saúde, Porto Alegre, Brazil.
authors: Elis Regina
authors: ER
authors: Dalla Costa
authors: Luiz Claudio Oliveira
authors: LC
authors: Lazzarini
authors: Paulo Fernado
authors: PF
authors: Perizzolo
authors: Chyntia Acosta
authors: CA
authors: Díaz
authors: Fernanda S
authors: FS
authors: Spies
authors: Lucas Laux
authors: LL
authors: Costa
authors: Andrezza W
authors: AW
authors: Ribeiro
authors: Caroline
authors: C
authors: Barroco
authors: Sandra Jungblut
authors: SJ
authors: Schuh
authors: Marcia Aparecida
authors: MA
authors: da Silva Pereira
authors: Claudia F
authors: CF
authors: Dias
authors: Harrison M
authors: HM
authors: Gomes
authors: Gisela
authors: G
authors: Unis
authors: Arnaldo
authors: A
authors: Zaha
authors: Pedro E
authors: PE
authors: Almeida da Silva
authors: Philip N
authors: PN
authors: Suffys
authors: Maria L R
authors: ML
authors: Rossetti
mesh_terms: D001938:Brazil / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D058889:Molecular Typing; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000382:microbiology*