Al-Ethafa Luma F M, Almialy Ahmed Jassim, Gharban Hasanain A J, Essa Isra'a M, Al-Eqabi Sattar R S
Department of Environmental Health, College of Environmental Sciences, Al-Qasim Green University, Babylon 51013, Iraq.
Department of Veterinary Clinical Sciences, Faculty of Veterinary Medicine, University of Kufa, Najaf 54001, Iraq.
Vet World. 2025 Jul;18(7):1899-1910. doi: 10.14202/vetworld.2025.1899-1910. Epub 2025 Jul 17.
is a significant zoonotic pathogen linked to reproductive losses in livestock and serious health risks in humans. In Iraq, listeriosis remains underreported in sheep, with limited data on its molecular and epidemiological characteristics. This study aimed to (1) estimate the seroprevalence of in recently aborted ewes, (2) evaluate the association between seropositivity and clinical indicators, and (3) perform molecular detection and phylogenetic analysis of polymerase chain reaction (PCR)-confirmed isolates.
From November 2023 to August 2024, 168 aborted ewes in Wasit Province, Iraq, were sampled for vaginal swabs and blood. Enzyme-linked immunosorbent assay (ELISA) was used for serological screening, while DNA extracted from swabs underwent PCR amplification targeting the gene. PCR-positive samples were sequenced and phylogenetically analyzed using MEGA-11 software. Clinical data were statistically correlated with seropositivity using odds ratios (OR) and relative risk (RR).
ELISA revealed a seroprevalence of 23.21%, with the majority of infections classified as mild. PCR confirmed in 3.57% of swabs. Seropositivity significantly correlated with vaginal discharge (30.08%, p = 0.0121), retained placenta, and recent abortion history. Higher infection risk was observed in ewes with no or single previous abortions (OR = 2.464; RR = 2.207) and in flocks with ≤10% abortion rates (OR = 3.729; RR = 2.731). Phylogenetic analysis of six local isolates (GenBank IDs PQ865989.1-PQ865994.1) revealed 96.43%-97.62% sequence identity with an Iranian reference strain (MT071644.1), suggesting regional transmission links.
This study is the first to molecularly characterize ovine in Iraq, revealing both the prevalence of subclinical infection and cross-border phylogenetic relationships. The integration of serological and molecular diagnostics highlighted underrecognized infections and provided novel insights into the epidemiology of strains. Findings emphasize the need for broader regional surveillance, improved diagnostic protocols, and biosecurity measures in ovine reproductive health management.
是一种重要的人畜共患病原体，与家畜繁殖损失及人类严重健康风险相关。在伊拉克，绵羊李斯特菌病的报告仍然不足，其分子和流行病学特征的数据有限。本研究旨在：（1）估计近期流产母羊中的血清阳性率；（2）评估血清阳性与临床指标之间的关联；（3）对聚合酶链反应（PCR）确诊的分离株进行分子检测和系统发育分析。
2023年11月至2024年8月，对伊拉克瓦西特省的168只流产母羊采集阴道拭子和血液样本。采用酶联免疫吸附测定（ELISA）进行血清学筛查，从拭子中提取的DNA进行靶向基因的PCR扩增。对PCR阳性样本进行测序，并使用MEGA-11软件进行系统发育分析。临床数据使用优势比（OR）和相对风险（RR）与血清阳性进行统计学关联分析。
ELISA显示血清阳性率为23.21%，大多数感染被归类为轻度。PCR在3.57%的拭子中检测到。血清阳性与阴道分泌物（30.08%，p = 0.0121）、胎盘滞留和近期流产史显著相关。在没有或仅有一次先前流产的母羊中（OR = 2.464；RR = 2.207）以及流产率≤10%的羊群中（OR = 3.729；RR = 2.731）观察到更高的感染风险。对六个本地分离株（GenBank编号PQ865989.1 - PQ865994.1）的系统发育分析显示，与伊朗参考菌株（MT071644.1）的序列同一性为96.
