Table 2.

Available LFA tests for the detection of animal pathogens.

Targeted Analyte	Materials and Methods	Equipment	Samples and Handling	Performance	Reference
PRV	Fluorescent immunochromatographic strip, anti-PRV gB monoclonal antibodies, 3D-printed customized pocket fluorescence observation instrument	None	Homogenized pig tissues	LOD of 0.13 ng/mL. Detection within 13 min	[147]
Porcine epidemic diarrhea virus (PEDV)	LFA test, antibody-functionalized gold nanoparticles, 3D-printed transmittance reader, image analysis	Smartphone	PEDV solution	LOD of 55 ng/mL. Linear detection range: 78–20 × 103 ng/mL	[148]
Bovine ephemeral fever virus (BEFV)	RPA 1, FAM 2, and biotin labeled amplicons, LFA	TwistAmp NFO kit for RPA amplification, heat block	RNA isolation from clinical samples and reverse transcription	LOD of eight copies per reaction. Coincidence rate with real-time PCR of 96.09%. Detection in 25 min	[149]
BVDV	Immunochromato-graphic test strip, anti-NS3 monoclonal antibody 46/1-conjugated gold nanoparticles	None	Leukocyte extracts	Sensitivity and specificity of 100% and 97.2%, respectively. Detection in 15 min	[150]
FMDV	LFA test, gold nanoparticles, monoclonal anti-FMDV antibody 1F10 or 2H6	None	Homogenized epithelial suspensions	Sensitivity of 84% for 1F10 and 88% for 2H6. Specificity of 99% for both antibodies	[151,152]
FMDV viral RNA	RT-LAMP, FIP 3 and BIP 4 labeling at the 5′ terminus with fluorescein and biotin, LFA test	Water bath	RNA, epithelial suspensions spiked with FMD virus, epithelial samples, air samples, RNA isolation	LOD of 10 viral copies	[153]
FMDV viral RNA	RT-RPA-, FAM-, and biotin-labeled amplicons, LFA	TwistAmp NFO kit for RPA amplification, water bath	cDNA, reverse transcription, RNA isolation	LOD of 10 copies (plasmid DNA), 98.6% concordance with real-time PCR	[154]
ASFV DNA	RPA, FITC 5, and biotin labeled amplicons, LFA	TwistAmp NFO kit for RPA amplification, thermocycler	DNA isolated with a magnetic bead-based kit	Positive agreement of 100% with PCR. Detection in 15 min	[155]
Classical Swine Fever (CSFV)	Fluorescent microsphere (FM)-based LFA, monoclonal-antibody-functionalized FMs	Fluorescent immunochromatographic strip reader, fluorescent camera	Tissue extracts	LOD of 5.28 ng/mL, positive coincidence rate, negative coincidence rate, and total coincidence rate of 95.8%, 100%, and 98%, respectively. Detection within 15 min	[156]
CSFV RNA	RT-LAMP-, DIG 6-, and FITC-labeled amplicons, LFA	Thermocycler	Cell-culture supernatants, serum, RNA isolation	LOD of 100 copies per reaction. Detection in 70 min	[157]
PCV-2 antibodies	Immunochromatographic test strip, recombinant-Cap-protein-labeled colloidal gold	None	Serum samples	Agreement of 94% with commercial ELISA. Sensitivity and specificity of 93.14% and 98.70%, respectively. Detection in 5 min	[158]
PRRSV antibodies	Immunochromatographic test strip, PRRSV recombinant membrane and nucleocapsid proteins, Protein-G-conjugated gold nanoparticles	None	Serum samples	Sensitivity of 98.6%, specificity of 97.8%, accuracy of 98.3%	[159]
Salmonella hilA gene	LAMP-, FITC-, and biotin-labeled amplicons, LFA test	Heating block	DNA isolated with commercial kit	LOD values of 13.5 × 10−3 ng/mL of genomic DNA and 6.7 CFU/mL. Detection in 40 min	[160]
Salmonella Typhimurium DNA	RPA-, DIG-, and FAM-labeled amplicons, LFA	TwistAmp RPA reaction kit. Thermostatic water bath	DNA isolated with commercial kit	LOD of 10−6 ng (genomic DNA) and 1.95 CFU/mL in milk samples. Detection in less than 20 min	[161]
Brucella spp.	Multiple cross-displacement amplification, FITC- and biotin-labeling of amplicons, LFA utilizing dye streptavidin-coated polymer nanoparticles	Water bath or heat block	Human- and goat-serum samples, DNA extraction	LOD of 10−5 ng of templates (pure cultures). Detection in 70 min	[162]
Campylobacter jejuni and Campylobacter coli	LFA test, gold nanoparticles, monoclonal mouse anti–Campylobacter A and/or B	None	Chicken feces, dilution with saline, filtration, sedimentation for 10 min	LOD of 6.7 log CFU/g for Campylobacter jejuni or 7.1 log CFU/g for Campylobacter coli. Detection in 20 min	[163]
Mycobacterium avium subsp. paratuberculosis	RPA, labeled amplicons, LFA	TwistAmp RPA reaction kit, thermostatic water tank	DNA extracted with commercial kit	LOD of eight copies per reaction. Sensitivity and specificity of 100% and 97.63%, respectively. Detection in 35 min	[164]
Mycoplasma ovipneumoniae DNA	LAMP-, DIG-, and biotin-labeled amplicons, LFA	Water bath	Lung tissue sample, DNA extraction	LOD of 100 CFU/mL. Sensitivity of 86% in clinical samples, Detection in 70 min	[165]

¹ RPA: recombinase polymerase amplification, ² FAM: fluorescein amidite, ³ FIP: forward inner primer, ⁴ BIP: backward inner primer, ⁵ FITC: fluorescein isothiocyanate, ⁶ DIG: digoxigenin.