Rapid and specific identification of Brucella spp. using the loop-mediated isothermal amplification lateral flow (Lamp-LFT) assay

Abstract

Brucellosis is a notifiable zoonotic disease that remains endemic in many regions and poses significant risks to both animal and human health. In the livestock industry, it causes substantial economic losses due to abortions, reduced fertility, mandatory culling, and vaccination costs. This study evaluated loop-mediated isothermal amplification combined with a lateral flow test (LAMP-LFT) as a rapid diagnostic tool for detecting Brucella in the abomasal contents of aborted small ruminant fetuses, comparing its performance with conventional polymerase chain reaction (PCR). A total of 145 abomasal content samples from aborted fetuses (90 sheep, 55 goats) were analyzed. After targeting the bcsp31 gene and using Brucella reference strains as positive controls, Brucella was detected in 55 samples (36 sheep, 19 goats) by LAMP, while 50 samples (32 sheep, 18 goats) tested positive by conventional PCR. Five PCR-negative samples were identified as positive using LAMP and LAMP-LFT. The minimum detectable DNA concentrations were 12.0 pg/µL for PCR and 120 fg/µL for LAMP, indicating higher analytical sensitivity for the LAMP-based methods. In conclusion the Brucella LAMP-LFT assay demonstrated consistent detection in both positive controls and field isolates under laboratory conditions, and it is potentially adaptable for field use with standard laboratory procedures for DNA extraction and sample preparation. Its ability to detect Brucella DNA at very low concentrations may facilitate early diagnosis, supporting epidemiological surveillance and disease control.