1. Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, *Hospital Umum Sarawak, Jalan Tun Abang Haji Openg, 93590 Kuching, Sarawak, †Hospital Queen Elizabeth, Jalan Mat Salleh, 88590 Kota Kinabalu, Sabah, ‡Hospital Alor Setar, Jalan Sultan Badlishah, 05590 Alor Setar, Kedah and §Faculty of Allied Health Sciences, National University of Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia