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Volume 13, Number 9—September 2007


Reduced Sensitivity of Influenza A (H5N1) to Oseltamivir

Jennifer L. McKimm-Breschkin*Comments to Author , Paul W. Selleck†, Tri Bhakti Usman‡, and Michael A. Johnson†
Author affiliations: *CSIRO Molecular and Health Technologies, Parkville, Victoria, Australia; †CSIRO Livestock Industries, Geelong, Victoria, Australia; ‡Disease Investigation Centre Region IV, Yogyakarta, Indonesia;

Main Article

Table 2

Mean IC50s of isolates from each group against alternative source of oseltamivir*†

Virus Oseltamivir, IC50, nmol/L
A/Mississippi/3/2001 wt 3.2 (2.1)
A/Chicken/Vietnam/008/2004 0.7 (0.4)
A/Chicken/Cambodia/Kandal/23/2004 0.4 (0.2)
A/Goose/Cambodia/Kandal/2005 4.2 (0.5)
A/Chicken/Cambodia/Kandal/3/2005 4.8 (0.5)
A/Chicken/Indonesia/Wates/77/2005 25.6 (2.5)
A/Chicken/Indonesia/Wates/126/2005 14.7 (2.3)

*IC50, drug concentration for 50% inhibition of enzyme activity; wt, wild type.
†Isolates were tested in duplicate in 2 separate assays. IC50s and standard errors (in parentheses) were calculated by using the nonlinear curve-fitting function in Sigmaplot (Systat Software Inc., London, UK).

Main Article

1Isolates tested were the following: A/Mississippi/3/2001 wt, A/Mississippi/3/2001 H274Y; A/quail/Kelantan/6309/2004, A/chicken/Kelantan/5858/2004, A/quail/Vietnam/007B/2004, A/duck/Vietnam/007A/2004, A/chicken/Vietnam/0024/2004, A/chicken/Vietnam/0023/2004 A/chicken/Vietnam/0018/2004, A/chicken/Vietnam/0015/2004, A/chicken/Vietnam/0010/2004, A/chicken/Vietnam/008/2004; A/chicken/Cambodia/Siem Reap/77B/2004, A/chicken/Cambodia/Siem Reap/76/2004, A/chicken/Cambodia/Takeo/45/2004, A/chicken/Cambodia/Kandal/23/2004, A/chicken/Cambodia/Pong Peay/1B/2004, A/chicken/Cambodia/Pong Peay/1A/2004, A/goose/Cambodia/Kandal/2005, A/chicken/Cambodia/Kandal/3/2005, A/chicken/Cambodia/Kandal/2/2005, A/chicken/Cambodia/Kandal/1/2005, A/chicken/Indonesia/Wates/130/2005, A/chicken/Indonesia/Wates/126/2005, A/chicken/Indonesia/Wates/83/2005, A/chicken/Indonesia/Wates/80/2005, A/chicken/Indonesia/Wates/77/2005, A/chicken/Indonesia/Wates/1/2005.

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