Akaba Yuka, Kudo Yoshiko, Ket Vansith, Ket Vansen, Rin En, Masuzawa Toshiyuki
Department of Clinical Laboratory, International University of Health and Welfare Narita Hospital, Chiba Prefecture, Japan.
International Exchange Center, Showa University, Tokyo, Japan.
Vector Borne Zoonotic Dis. 2023 May;23(5):291-297. doi: 10.1089/vbz.2022.0052. Epub 2023 Mar 16.
Leptospirosis represents a major public health threat in Cambodia. To help establish preventive strategies for leptospirosis, we isolated and identified from soil collected in Phnom Penh and its neighboring province during the dry and rainy seasons. Soil samples were collected from 15 sites in the Phnom Penh metropolitan area and Kandal Province in 2019 and 2020. A total of 120 soil samples were collected and analyzed after culturing. Cultured isolates were identified at the species level using 16S rRNA and B gene sequencing analysis. The positive culture rate for was significantly higher for samples collected during the rainy season (31 out of 60 samples, 51.7%) than during the dry season (19 out of 60 samples; < 0.05, chi-squared test). In terms of sampling area, 10 (35.7%) and 13 (46.9%) soil samples from Phnom Penh and 9 (28.1%) and 18 (56.3%) soil samples from Kandal Province were culture-positive when collected during the dry and rainy seasons, respectively. Three isolates from the Kandal samples collected during the dry season were categorized as pathogenic clade type P1 according to 16S rRNA and B sequence analyses. In addition, samples collected during the rainy season from Phnom Penh and Kandal Province (three each) were categorized as clade type P1. The samples with isolates in clade type P1 were collected from riverbanks during both the dry and rainy seasons and from a hospital garden during the rainy season. This is the first report on the isolation of clade P1 species in environmental soil samples from Cambodia. Environmental soil appears to be a reservoir for in the capital city and surrounding areas of Cambodia. This study contributes to the understanding of species distribution in Asian countries.
钩端螺旋体病是柬埔寨主要的公共卫生威胁。为了帮助制定钩端螺旋体病的预防策略，我们在旱季和雨季从金边及其周边省份采集的土壤中进行了分离和鉴定。2019年和2020年从金边大都市区和干丹省的15个地点采集了土壤样本。共采集了120份土壤样本，培养后进行分析。使用16S rRNA和B基因测序分析在物种水平上鉴定培养的分离株。雨季采集的样本（60份样本中的31份，51.7%）的阳性培养率显著高于旱季（60份样本中的19份；P<0.05，卡方检验）。在采样区域方面，旱季和雨季分别从金边采集的10份（35.7%）和13份（46.9%）土壤样本以及从干丹省采集的9份（28.1%）和18份（56.3%）土壤样本培养呈阳性。根据16S rRNA和B序列分析，旱季从干丹样本中分离出的三株菌株被归类为致病进化枝类型P1。此外，雨季从金边和干丹省采集的样本（各三份）也被归类为进化枝类型P1。进化枝类型P1中有分离株的样本在旱季和雨季均采集自河岸，雨季还采集自医院花园。这是关于在柬埔寨环境土壤样本中分离出进化枝P1型钩端螺旋体的首次报告。环境土壤似乎是柬埔寨首都及其周边地区钩端螺旋体的储存库。本研究有助于了解亚洲国家钩端螺旋体的物种分布。
