BACKGROUND: Despite widespread use of acyclovir, infection with acyclovir-resistant herpes simplex virus type 2 (HSV-2) remains uncommon. To understand the frequency and clinical significance of acyclovir-resistant isolates, we evaluated the in vitro acyclovir sensitivities of sequential isolates from 34 immunocompetent women. METHODS: HSV-2-seropositive women collected daily samples of genital secretions while receiving acyclovir or placebo, each for 10 weeks. In vitro acyclovir sensitivity testing was performed using the dye uptake assay; isolates for which the concentration of acyclovir that inhibited cytopathic effect by 50% (EC50) was > or = 3 microg/mL were defined as resistant. RESULTS: A total of 351 isolates from 26 women were tested (median, 10 isolates/woman [range, 3-45 isolates/woman]). The median EC50 was 0.91 microg/mL. Overall, 7 isolates (1.7%) from 6 women had EC50 values > or = 3 microg/mL. None of the women was receiving acyclovir when the acyclovir-resistant isolates were detected. Acyclovir-sensitive and acyclovir-resistant isolates were detected in samples collected on the same day from separate anatomic sites in 3 women. The acyclovir-resistant isolates were transient, because acyclovir-sensitive isolates were obtained before and after the acyclovir-resistant isolates from 5 women were detected. CONCLUSIONS: Among immunocompetent women, the finding of acyclovir-resistant HSV-2 isolates likely represents transient mucosal variants and does not predict treatment failure.
BACKGROUND: Despite widespread use of acyclovir, infection with acyclovir-resistant herpes simplex virus type 2 (HSV-2) remains uncommon. To understand the frequency and clinical significance of acyclovir-resistant isolates, we evaluated the in vitro acyclovir sensitivities of sequential isolates from 34 immunocompetent women. METHODS:HSV-2-seropositive women collected daily samples of genital secretions while receiving acyclovir or placebo, each for 10 weeks. In vitro acyclovir sensitivity testing was performed using the dye uptake assay; isolates for which the concentration of acyclovir that inhibited cytopathic effect by 50% (EC50) was > or = 3 microg/mL were defined as resistant. RESULTS: A total of 351 isolates from 26 women were tested (median, 10 isolates/woman [range, 3-45 isolates/woman]). The median EC50 was 0.91 microg/mL. Overall, 7 isolates (1.7%) from 6 women had EC50 values > or = 3 microg/mL. None of the women was receiving acyclovir when the acyclovir-resistant isolates were detected. Acyclovir-sensitive and acyclovir-resistant isolates were detected in samples collected on the same day from separate anatomic sites in 3 women. The acyclovir-resistant isolates were transient, because acyclovir-sensitive isolates were obtained before and after the acyclovir-resistant isolates from 5 women were detected. CONCLUSIONS: Among immunocompetent women, the finding of acyclovir-resistant HSV-2 isolates likely represents transient mucosal variants and does not predict treatment failure.
Authors: Peter J Ireland; John E Tavis; Michael P D'Erasmo; Danielle R Hirsch; Ryan P Murelli; Mark M Cadiz; Bindi S Patel; Ankit K Gupta; Tiffany C Edwards; Maria Korom; Eileen A Moran; Lynda A Morrison Journal: Antimicrob Agents Chemother Date: 2016-03-25 Impact factor: 5.191
Authors: Miguel A Minaya; Travis L Jensen; Johannes B Goll; Maria Korom; Sree H Datla; Robert B Belshe; Lynda A Morrison Journal: J Virol Date: 2017-11-14 Impact factor: 5.103
Authors: Kening Wang; Gowtham Mahalingam; Susan E Hoover; Erik K Mont; Steven M Holland; Jeffrey I Cohen; Stephen E Straus Journal: J Virol Date: 2007-04-25 Impact factor: 5.103
Authors: Eva Marie Quijano Cardé; Zeinab Yazdi; Susan Yun; Ruixue Hu; Heather Knych; Denise M Imai; Esteban Soto Journal: Front Vet Sci Date: 2020-10-22