Determination of Dominant Serovars and Molecular Analysis of hly and iap Genes Related to Listeria monocytogenes Strains Isolated from Spontaneous Human Abortions in Tehran

Abstract

Article Subject: Molecular Microbiology DOI: Background and Aims: Listeria monocytogenes, a gram positive, facultative, intracellular bacterium is the causative agent of listeriosis that is transmitted to human through raw and ready-to-eat foods. The aim of the present study was to determine dominant serovars of L. monocytogenes isolated from spontaneous abortion using phenotypic and genotypic methods. Materials and Methods: In present study, 258 clinical specimens including placental secretions, vaginal swabs and blood samples from 123 patients with abortion were selected in sterile condition then bacteriological, serological and molecular tests were conducted; dominant serotypes were identified by Multiplex PCR. Results: Out of 28 (%18.8) isolates of L. monocytogenes 21 (%17.7), 5 (%5.7) and 2 (%3.37) were isolated from placental secretions, vaginal swabs and blood respectively. Maximum and minimum isolated of bacteria related to placental secretions and vaginal swabs with 21 and 2 isolates respectively, of which 14 (%50) 1/2a, 10 (%35.7) 4b and 4 (%14.6) 2c serovars were reported for the first time. All of serovars played a key role in the spontaneous abortion as dominant and common serotypes in Iran. All of the isolates 28 (%22.76) showed hlyA gene and 24 isolates (%19.57) were positive for iap gene and compaired with control group there was significant different between the two groups (P<0.0002). Conclusion: The present study showed the isolation dominant and common serotypes of L. monocytogenes from spontaneous abortion and demonstrated that the presence of hlyA and iap were effective genes in increasing aggressive and pathogenicity. Serotypes that lacked the iap gene have less pathogenicity and influenced the pathogenesis in mice. It was also concluded that in the absence of access to molecular tests, performing PI-PLC, Congored and in vivo pathogenicity can be effective in detecting pathogenic serotypes from non-pathogenic L. monocytogenes.

Comparison of genetic variations between high- and low-risk Listeria monocytogenes isolates using whole-genome de novo sequencing

“…Act A in L. monocytogenes encodes the surface protein act A, which is responsible for actin-based motility and cell-to-cell spread ( Vàzquez-Boland et al, 2001 ). Rezaei et al (2019) showed that the presence of hly A and iap in L. monocytogenes is effective in increasing its aggressiveness and pathogenicity. Cellular invasion requires the presence of bacterial surface proteins internalin A ( inl A) and/or inl B and their interaction with the cellular receptors E-cadherin and/or Met, respectively ( Kühbacher et al, 2018 ).…”

Prevalence of Chlamydia trachomatis and Listeria monocytogenes in Infertile Men and the Effect on Semen Parameters

“…Listeriamonocytogenes, an intracellular and opportunistic pathogen, enter the body through contaminated water and food and cause a systemic infection called listeriosis, which in turn causes meningoencephalitis in pregnant women, the elderly, and those with immunodeficiency (13). The clinical spectrum of listeriosis contains two specific targets; the placental-maternal unit and the central nervous system (15). Listeriosis in pregnant women is asymptomatic or has mild flu-like symptoms.…”

“…These problems can affect especially those patients with a background disease or severe conditions, and other high-risk individuals such as pregnant women, and unborn or newborn babies and immunocompromised persons. The incidence of listeriosis among pregnant females with a history of spontaneous abortion is 12 per 100,000, while its prevalence is reported as 0.7 per 100,000 in healthy individuals, and about one-third of reported human listeriosis cases are associated with recurrent abortion (15). L. monocytogenes can cause inflammation in the placenta or amniotic sac, fetal infection, and even abortion or stillbirth as the bacteria can cross the placenta barrier (16).…”

Comparison of genetic variations between high- and low-risk Listeria monocytogenes isolates using whole-genome de novo sequencing

“…2018). ActA in L. monocytogenes encodes the surface protein actA, which is responsible for actin-based motility and cellto-cell spread (Vàzquez-Boland et al 2001) Rezaei et al (2019). showed that the presence of hlyA and iap in L. monocytogenes is effective in increasing its aggressiveness and pathogenicity.…”