[1] Univ Putra Malaysia, Fac Med & Hlth Sci, Dept Biomed Sci, Serdang 43400, Malaysia
[2] Univ Putra Malaysia, Fac Med & Hlth Sci, Dept Pathol, Serdang 43400, Malaysia
[3] Univ Putra Malaysia, Fac Med & Hlth Sci, Dept Human Anat, Serdang 43400, Malaysia
[4] Univ Putra Malaysia, Fac Med, Dept Microbiol, Serdang 43400, Malaysia
[5] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Microbiol, Singapore 117595, Singapore