Molecular Epidemiology of Rhodococcus equi of Intermediate Virulence Isolated from Patients with and Without Acquired Immune Deficiency Syndrome in Chiang Mai, Thailand

• Main Authors: Takai S., Tharavichitkul P., Takarn P., Khantawa B., Tamura M., Tsukamoto A., Takayama S., Yamatoda N., Kimura A., Sasaki Y., Kakuda T., Tsubaki S., Maneekarn N., Sirisanthana T., Kirikae T.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-0346256760&partnerID=40&md5=e7633ce5f577a882ea02a5c0b7617955; http://cmuir.cmu.ac.th/handle/6653943832/2692
• Institution: Chiang Mai University

We investigated the prevalence of virulent Rhodococcus equi in clinical isolates from 69 sporadic cases (60 men, 8 women, and 1 patient of unknown sex) in Chiang Mai, Thailand, between 1993 and 2001. Fifty were human immunodeficiency virus (HIV) positive, 3 were HIV negative, and HIV status was unknown for 16. Fifty-two (75%) of 69 isolates were strains of intermediate virulence that contained the virulence-associated 20-kDa antigen, and 17 isolates (25%) were avirulent. No virulent strains with the virulence- associated 15-17-kDa antigens were identified. R. equi was isolated from HIV-positive patients' houses and those of their neighbors: avirulent strains were widespread, but only 1 strain of intermediate virulence was isolated. R. equi strains of intermediate virulence were isolated from 4 (0.8%) of 500 submaxillary lymph nodes from apparently healthy pigs in Chiang Mai. The routes of R. equi acquisition should be investigated from the viewpoint of zoonosis and public health.