title: Molecular epidemiology and genetic diversity of Mycobacterium tuberculosis complex in the Cross River State, Nigeria.
abstract: This study provides with a first insight on Mycobacterium tuberculosis complex epidemiology and genetic diversity in the Cross River State, Nigeria. Starting with 137 smear positive patients recruited over a period of 12months (June 2008 to May 2009), we obtained 97 pure mycobacterial isolates out of which 81 (83.5%) were identified as M. tuberculosis complex. Genotyping revealed a total of 27 spoligotypes patterns with 10 clusters (n=64% or 79% of clustered isolates, 2-32 isolates/cluster), with patients in the age group range 25-34 years being significantly associated with shared-type pattern SIT61 (p=0.019). Comparison with SITVIT2 database showed that with the exception of a single cluster (SIT727/H1), all other clusters observed were representative of West Africa; the two main lineages involved were LAM10-CAM (n=42/81% or 51.8%) of M. tuberculosis and AFRI_2 sublineage of Mycobacterium africanum (n=27/81% or 33.3%). Subsequent 12-loci MIRU typing resulted in a total of 13 SIT/MIT clusters (n=52 isolates, 2-9 isolates per cluster), with a resulting recent n-1 transmission rate of 48.1%. Available drug-susceptibility testing (DST) results for 58/81 clinical isolates revealed 6/58% or 10.4% cases of multiple drug-resistance (MDR); 5/6 MDR cases were caused by strains belonging to LAM10-CAM lineage (a specific cluster SIT61/MIT266 in 4/6 cases, and an orphan spoligotype pattern in 1/6 case). Additionally, MIT266 was associated with streptomycin resistance (p=0.016). All the six MDRTB isolates were concomitantly resistance to streptomycin and ethambutol; however, 4/6 MDR strains with identical MIRU patterns were characterized by consecutive strain numbers hence the possibility of laboratory cross contamination could not be excluded in 3/4 serial cases. The present preliminary study underlines the usefulness of spoligotyping and 12-loci MIRU-VNTRs to establish a baseline of circulating genotypic lineages of M. tuberculosis complex in Nigeria.
authors: Department of Medical Laboratory Science, University of Calabar, Calabar, Nigeria.
authors: Benjamin P
authors: BP
authors: Thumamo
authors: Anne E
authors: AE
authors: Asuquo
authors: Lydia N
authors: LN
authors: Abia-Bassey
authors: Lovett
authors: L
authors: Lawson
authors: Véronique
authors: V
authors: Hill
authors: Thierry
authors: T
authors: Zozio
authors: Nnamdi
authors: N
authors: Emenyonu
authors: Francis O
authors: FO
authors: Eko
authors: Nalin
authors: N
authors: Rastogi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D004269:DNA, Bacterial; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D006801:Humans; D008875:Middle Aged; D018598:Minisatellite Repeats; D058889:Molecular Typing; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D009549:Nigeria / Q000453:epidemiology; D010802:Phylogeny; D014376:Tuberculosis / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial