Volume 15, Number 12—December 2009
Molecular Epidemiology of Glanders, Pakistan
|Epidemiologic group and subgroup designation (isolate names)†||Description||Clade(s)‡||Total VNTR differences between subgroups|
Group 1a (PRL2)
Group 1b (PRL11, PRL13)
||Strains were collected from an outbreak among Faisalabad Mounted Police Horses (n = 18) in June 1999. Biochemical test results (based on Analytical Profile Index 20E strips; BioMériux, Marcy l’Etoile, France) differed nonsubstantially (data not shown). Therefore, only 3 isolates were evaluated by using VNTR. Strains PRL11 and PRL13 were isolated from horses that were kept at 2 stables ≈8 km away from each other, but the 2 stables had a history of mixing.
Group 2a (PRL42)
Group 2b (PRL45)
||Samples came from 2 sporadic cases of glanders in draught mules from the Faisalabad district in 2007. Reports indicate that these animals drank from communal water troughs available in different zones of Faisalabad.
Group 3a (PRL1)
Group 3b (PRL41)
Group 3c (PRL7)
||Samples came from 3 sporadic cases of glanders in draught equids from the Faisalabad district during different years (2002, 2006, and 2000, respective to subgroup listing). Reports indicate that these animals drank from communal water troughs available in different zones of Faisalabad.
B, no clade¶
Group 4a (PRL33)
Group 4b (PRL34)
||Samples were obtained from 2 donkeys that worked and were housed together in a brick factory in the district of Faisalabad. Samples were collected 3 weeks apart in 2007, and the strains were passaged 3× in guinea pigs before DNA was extracted for VNTR evaluation.
Group 5a (PRL19)
Group 5b (PRL20)
||In September 2005, an outbreak of glanders occurred at the Lahore Polo Club. Two isolates were obtained from separate horses in this group, and each isolate had a different biochemical profile (data not shown).
|Group 6 Group 6a (PRL3, PRL4) Group 6b (PRL44)||From November 2004 to March 2005, two horses from a farm in Sargodha (PRL3, PRL4) participated in matches at the Lahore Polo Club. Horses were returned to their farm in late spring 2005. In the fall of 2005, there was a glanders outbreak at the Lahore Polo Club (see Group 5 above). In December 2005, the 2 horses on the Sargodha farm tested positive for glanders after being housed together during the winter. A mule (PRL44) that was also present at the Sargodha farm tested negative for glanders at this time. Approximately 2 years later, the same mule tested positive for glanders after reports of 6 months’ standing nasal discharge. Records indicate the mule was brought to the farm at a young age from the city of Multan and never left the farm before onset of symptoms.||A||4/15 loci|
*VNTR, variable number tandem repeats.
†Samples from equines with similar histories were assigned to the same epidemiologic group (e.g., Group 1, Group 2). Subgroups were defined based on VNTR data; samples with identical VNTR genotypes were assigned to the same subgroup (e.g., PRL11 and PRL13 in Group 1b).
‡See Figure 2.
§Data are comparing subgroups 3a and 3b to each other (PRL1 and PRL41) and excluding subgroup 3c (PRL7).
¶Data are comparing subgroups 3a and 3b combined (PRL1 with PRL41) to subgroup 3c (PRL7).