Kaur S, Malik S V S, Vaidya V M, Barbuddhe S B
Division of Veterinary Public Health, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India.
J Appl Microbiol. 2007 Nov;103(5):1889-96. doi: 10.1111/j.1365-2672.2007.03414.x.
To assess the extent of Listeria monocytogenes in causation of human spontaneous abortions by isolation methods and PCR analysis for the presence of virulence-associated genes.
A total of 305 samples comprising blood, urine, placental bits, faecal and vaginal swabs were collected from 61 patients with spontaneous abortions. Listeria spp. were isolated from 10 samples collected from nine (14.8%) patients. Confirmation of these isolates was based on biochemical tests, haemolysis on blood agar, CAMP test, phosphatidylinositol-specific phospholipase C (PI-PLC) assay followed by in vivo pathogenicity tests and multiplex PCR to detect virulence-associated genes (prfA, plcA, hlyA, actA and iap). Three isolates were confirmed as L. monocytogenes. Of these, two isolates turned out to be pathogenic and found to posses all five genes. However, the remaining two haemolytic L. monocytogenes isolates lacking the plcA gene and activity in the PI-PLC assay were found to be nonpathogenic by in vivo tests.
The occurrence of pathogenic L. monocytogenes in cases of spontaneous abortions was 3.3%. It seems that the plcA gene and its expression have an important role as essential virulence determinants in pathogenic Listeria spp.
The recovery of pathogenic L. monocytogenes isolates from cases of spontaneous abortion indicates the significance of listeric infection in pregnant women.
通过分离方法及对毒力相关基因存在情况的聚合酶链反应（PCR）分析，评估单核细胞增生李斯特菌在人类自然流产病因中的作用程度。
从61例自然流产患者中采集了总共305份样本，包括血液、尿液、胎盘组织、粪便及阴道拭子。从9例（14.8%）患者的10份样本中分离出李斯特菌属。这些分离株的鉴定基于生化试验、血平板上的溶血试验、CAMP试验、磷脂酰肌醇特异性磷脂酶C（PI-PLC）测定，随后进行体内致病性试验及多重PCR以检测毒力相关基因（prfA、plcA、hlyA、actA和iap）。3株分离株被确认为单核细胞增生李斯特菌。其中，2株分离株被证明具有致病性且发现拥有所有5个基因。然而，通过体内试验发现，其余2株溶血的单核细胞增生李斯特菌分离株缺乏plcA基因且PI-PLC测定无活性，为非致病性。
自然流产病例中致病性单核细胞增生李斯特菌的发生率为3.3%。plcA基因及其表达似乎作为致病性李斯特菌属重要的毒力决定因素发挥着重要作用。
从自然流产病例中分离出致病性单核细胞增生李斯特菌表明李斯特菌感染对孕妇具有重要意义。
