title: Molecular typing and drug sensitivity testing of Mycobacterium tuberculosis isolated by a community-based survey in Ethiopia.
abstract: BACKGROUND
  The identification of circulating TB strains in the community and drug sensitivity patterns is essential for the tuberculosis control program. This study was undertaken to identify M. tuberculosis strains circulating in selected communities in Ethiopia as well as to evaluate the drug sensitivity pattern of these strains.
  
  
  METHODS
  This study was a continuation of the Ethiopian National TB Prevalence Survey that was conducted between 2010 and 2011. Culture-positive isolates of M. tuberculosis from previous study were typed using region of difference (RD) 9-based polymerase chain reaction (PCR) and spoligotyping. Drug sensitivity testing was conducted using the indirect proportion method on Lowenstein-Jensen media.
  
  
  RESULTS
  All 92 isolates were confirmed as M. tuberculosis by RD9-based PCR and spoligotyping of 91 of these isolates leds to the identification of 41 spoligotype patterns. Spoligotype revealed higher diversity (45 %) and among this 65.8 % (27/41) were not previously reported. The strains were grouped into 14 clusters consisting of 2-15 isolates. The dominant strains were SIT53, SIT149 and SIT37 consisting of 15, 11, and 9 isolates, respectively. Our study reveals 70 % (64/91) clustered strains and only 39.1 % (25/64) occurred within the same Kebele. Further assignment of the strains to the lineages showed that 74.7 % (68/91) belonged to Euro-American lineage, 18.6 % (17/91) to East Africa Indian lineage and the remaining 6.5 % (6/91) belonged to Indo-oceanic lineage. Valid drug susceptibility test results were available for 90 of the 92 isolates. Mono-resistance was observed in 27.7 % (25/90) and poly-resistance in 5.5 % (5/90) of the isolates. Moreover, multi-drug resistance (MDR-TB) was detected in 4.4 % of the isolates whilst the rest (60/90) were susceptible to all drugs. The highest level of mono-resistance, 26.6 % (24/90), was observed for streptomycin with majority (91.1 %) of streptomycin mono-resistant strains belonging to the Euro-American lineage.
  
  
  CONCLUSIONS
  In this study, the strains of M. tuberculosis circulating in selected sites of Ethiopia were identified along with the drug sensitivity patterns. Thus, these findings are useful for the TB Control Program of the country.
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. mimishaget@yahoo.com.
authors.forename: Muluwork
authors.initials: M
authors.lastname: Getahun
authors.affiliation: Aklilu Lema Institute of Pathobiology, Addis Ababa, Ethiopia. gobenachimdi2009@yahoo.co.uk.
authors.forename: Gobena
authors.initials: G
authors.lastname: Ameni
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. abesh_K@yahoo.com.
authors.forename: Abebaw
authors.initials: A
authors.lastname: Kebede
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. zollazede@gmail.com.
authors.forename: Zelalem
authors.initials: Z
authors.lastname: Yaregal
authors.affiliation: Armauer Hansen Research Institute, Addis Ababa, Ethiopia. elenahailu@yahoo.com.
authors.forename: Elena
authors.initials: E
authors.lastname: Hailu
authors.affiliation: Aklilu Lema Institute of Pathobiology, Addis Ababa, Ethiopia. gtmedhin@yahoo.com.
authors.forename: Grimay
authors.initials: G
authors.lastname: Medihn
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. daniel978et@yahoo.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Demssie
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. fevtiz@yahoo.com.
authors.forename: Feven
authors.initials: F
authors.lastname: Girmachew
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. yetimlt@gmail.com.
authors.forename: Yetnebersh
authors.initials: Y
authors.lastname: Fiseha
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. abimeaza@gmail.com.
authors.forename: Abyot
authors.initials: A
authors.lastname: Meaza
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. natidires@yahoo.com.
authors.forename: Nathneal
authors.initials: N
authors.lastname: Dirse
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. macagonafir@gmail.com.
authors.forename: Mulualem
authors.initials: M
authors.lastname: Agonafir
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. fdtanga@gmail.com.
authors.forename: Feleke
authors.initials: F
authors.lastname: Dana
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. t_fasil05@yahoo.com.
authors.forename: Fasil
authors.initials: F
authors.lastname: Tsegaye
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. zalebachew@gmail.com.
authors.forename: Zeleke
authors.initials: Z
authors.lastname: Alebachew
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. almaz_abe1@yahoo.com.
authors.forename: Almaz
authors.initials: A
authors.lastname: Abebe
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. amhak@ehnri.gov.et.
authors.forename: Amha
authors.initials: A
authors.lastname: Kebede
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia. eshetuu@yahoo.com.
authors.forename: Eshetu
authors.initials: E
authors.lastname: Lemma
mesh_terms: D005002:Ethiopia / Q000453:epidemiology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D058889:Molecular Typing; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D062486:Public Health Surveillance; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology*