Immunochromatographic Test Research Articles

Nosocomial cluster of patients infected with imipenemase-1-producing Enterobacter ludwigii.

Introduction. Imipenemase (IMI) enzymes are an uncommon class A carbapenemases that have been isolated from aquatic environments and, occasionally, from clinical isolates of Enterobacterales.Aim. We describe a cluster of three patients infected by IMI-1 carbapenemase-producing Enterobacter ludwigii (IMI-1-Elud) in a tertiary university hospital in Gran Canaria, Spain.Methodology. Antimicrobial susceptibility was determined using the Vitek2 AST-N355 card and antibiotic gradient strips. The modified carbapenem inactivation method (CIM) test was performed in cases where the ertapenem MIC value was higher than 0.125 mg l-1. The carbapenemase was identified by PCR and DNA microarray and later characterized by whole-genome next-generation sequencing (NGS) with Illumina.Results. Three patients presented thoracic or abdominal infections caused by IMI-1-Elud ST1677 from 14 June 2022 to 14 July 2022. All patients underwent at least one gastroscopy during their admission, and two of them were located in adjoining rooms. Isolates were resistant to carbapenems, colistin and fosfomycin but susceptible to ciprofloxacin. IMI/NMC-A carbapenemase was detected by PCR and hybridization test and confirmed by NGS as IMI-1. All patients underwent at least one gastroscopy, and two of them were in nearby rooms. Patients showed microbiological and clinical improvement following focus drainage and targeted antibiotic treatment with a fluoroquinolone.Conclusions. This study reports the first documented global outbreak of patients infected with IMI-1-Elud. The source appeared to be related to endoscopes. Contact transmission may also have played a role. A screening method such as the modified CIM test is crucial for detecting less common carbapenemases that might not be identified by rapid molecular or immunochromatographic tests, as these often do not include bla IMI genes, which could lead to the undetected dissemination of carbapenemase-producing Enterobacterales. Effective infection source control and targeted treatment are essential for achieving a favourable clinical outcome.

Accuracy evaluation of diagnostic methods for visceral leishmaniasis in adult patients with and without HIV infection: clinical management implications.

Visceral leishmaniasis (VL) poses a serious health threat, particularly when untreated, necessitating accurate diagnosis. While the gold-standard method involves identifying amastigotes in bone marrow aspirate (BMA), this procedure is invasive and occasionally contraindicated. Additionally, when VL is associated with HIV infection the serologies accuracies could be affected. This study aims to evaluate and compare diagnostic methods for VL in patients with and without HIV coinfection. We enrolled prospectively 127 consecutive adult VL patients, 48 (37.8%) of whom had HIV coinfection, in Brazil's Midwestern region, where VL is endemic. Parasitological examination served as the reference standard for accuracy analysis, with index tests including immunofluorescent antibody test (IFAT), immunochromatographic test with rK39 protein (rK39-ICT), and blood polymerase chain reaction (PCR). Specificity assessment involved 430 healthy blood donors from the same endemic area. Ninety-two patients had parasitologically confirmed VL. Among HIV-uninfected patients, rK39-ICT exhibited sensitivity comparable to PCR (93.6%; 95% CI: 83.6-100 vs. 97.8%; 95% CI: 93.6-99.2, respectively) and superior to IFAT (71.1%; 95% CI: 57.9-84.3). However, in HIV-infected patients, rK39-ICT sensitivity was notably lower than PCR (40.0%; 95% CI: 22.5-57.5 vs. 97.4%; 95% CI: 92.5-98.9) and similar to IFAT (67.5%; 95% CI: 52.9-82.0). Combining two serological tests in parallel identified 82.1% of parasitologically confirmed VL cases, with a negative likelihood ratio significantly lower than either test alone. No test achieved a specificity of 90%, and there were no significant differences in specificity observed among the index tests. The positivity rate of parasitological examination in the 127 VL patients was higher in HIV-infected compared to HIV-uninfected patients, 91.3% (95% CI: 83.2-99.4) versus 67.6% (95% CI: 56.9-78.3), respectively. These findings underscore the necessity of accounting for HIV infection when choosing VL diagnostic methods. Although rK39-ICT provides reliable results in HIV-uninfected patients, BMA examination remains crucial for accurate diagnosis in individuals with HIV/AIDS. In cases where bone marrow aspiration is contraindicated, employing IFAT and rK39-ICT in parallel could be considered, as the occurrence of both positive results is uncommon in healthy individuals from endemic areas.

Fabrication of Core-Shell Quantum Dots Microbeads with high stability, enhanced sensitivity and potential application in C-Reactive Protein (CRP) and Procalcitonin (PCT) Immunochromatography in Vitro Diagnostic Reagents

Cardiovascular and cerebrovascular diseases represent the leading causes of mortality among middle-aged and elderly populations in China, with inflammation identified as a significant contributing factor. Consequently, the early diagnosis and management of inflammation are of paramount importance. C-reactive protein (CRP) and procalcitonin (PCT) serve as biomarkers for myocardial inflammation. In this study, we developed a quantum dot immunochromatographic strip that was capable of simultaneously detecting these two biomarkers with enhanced sensitivity and specificity. The comb amphiphilic poly (octadecyl-alt-polyethylene glycol) was synthesized through an amide reaction, which was employed to coat oil-soluble quantum dots, thereby transforming them into water-soluble quantum dots microbeads suitable for the coupling with biological macromolecules. These quantum dots microbeads were utilized as luminescent materials in the immunochromatographic strip for the concurrent detection of CRP and PCT. The assay required only 100 μL of sample and provided results within 10 minutes, demonstrating commendable precision, stability, sensitivity, and accuracy. Clinical evaluations had confirmed that the developed CRP and PCT quantum dots immunochromatographic test strips were accurate reliable, underscoring their significant potential for practical routine clinical application in the early accurate diagnosis of myocardial inflammation.

Preparation and preliminary application of fluorescent microsphere test strips for feline parvovirus antibodies

This study introduces a novel diagnostic modality for the detection of feline panleukopenia virus (FPV) antibodies in feline serum by using fluorescent microsphere immunochromatographic test strips (FM-ICTS). Leveraging the inherent specificity of antigen-antibody interactions, the FM-ICTS approach demonstrates considerable potential for efficient and accurate FPV antibody detection within a short timeframe. The FM-ICTS method demonstrates strong diagnostic performance, with consistent accuracy and stability over time. PBS buffer dilution enables detection across the range of FPV antibody haemagglutination inhibition (HI) titres in both healthy and immunized or infected cats. A high correlation (R² = 0.9733) between the T/C ratio and FPV antibody titres confirms the method’s effectiveness in quantifying these titres. Clinical validation with 84 samples supports its reliability by matching results with HI assays. Additionally, stability tests show that the test strips maintain performance during storage, with a coefficient of variation (CV) below 12% over three months at 25℃. This innovative FM-ICTS framework emerges as a promising avenue for expedient and dependable disease diagnosis within the realm of veterinary science, offering implications for timely disease management and surveillance.

Development and Epitope Mapping of Seven Mouse Anti-Human Coagulation Factor XIII-B Subunit Monoclonal Antibodies.

Coagulation factor XIII (FXIII) is an enzyme that strengthens hemostatic clots, and its deficiency can cause life-threatening bleeding. We immunized mice with human plasma-derived FXIII to generate monoclonal antibodies (mAbs) against the B subunit (FXIII-B), which stabilizes the A subunit (FXIII-A) of FXIII, and analyzed their properties. The epitopes of the seven mouse antihuman FXIII-B mAbs obtained were found to be the 3rd, 5th, 6th, 9th, and 10th Sushi domains. One of these mAbs, mAb 5-6C, recognized the 10th Sushi domain and inhibited the fibrin cross-linking reaction without affecting the amine incorporation activity of FXIII. We previously reported that the 10th Sushi domain is the site where FXIII-B binds to fibrin and functions to bring FXIII-A closer to the substrate fibrin. Except for mAb 5-6C, mouse mAbs with high yields were used to measure the amount of FXIII-B antigen by an immunochromatography test (ICT), which showed a high correlation with enzyme-linked immunosorbent assay-obtained results. In addition, we developed a prototype ICT to detect anti-FXIII-B autoantibodies using mAb 1-3C, which showed good results in measuring the amount of FXIII-B antigen. Thus, mouse mAbs may be useful for clinical applications. mAb 5-6C targeting the 10th Sushi domain may also be useful for inhibiting thrombosis progression when humanized as antibody medicines.

Intestinal Protozoa, Helminth Infection, and Associated Factors among Tuberculosis Patients and Nontuberculosis Persons in Bobo-Dioulasso City, Burkina Faso.

We report the frequency and associated factors of tuberculosis (TB) and parasite coinfection from newly diagnosed pulmonary TB patients (TB+) and non-TB participants (TB-) from the Regional Tuberculosis Control Center, households, and health facilities in Bobo-Dioulasso from 2019 to 2021. Biological samples were examined for parasite infection using direct microscopy, concentration techniques, and the immunochromatographic rapid test. Data were analyzed using STATA 14. Of a total of 192 participants involved, 95 were TB+ and 97 were non-TB. There was no statistically significant difference in parasitic infections between the two groups, although it was higher in TB+ than TB- (69.5% [66/95] versus 55.7% [54/97]; P = 0.07). Protozoal infection prevalence was significantly higher in patients with TB+ than in those TB- (61.1% versus 37.1%; P = 0.001). Specifically, Entamoeba spp. and Cryptosporidium spp. followed this pattern with 35.8% versus 19.6% (P = 0.01) and 22.1% versus 8.3% (P = 0.007), respectively. Although higher in TB+ patients, helminthiasis frequency was not significantly different between the two groups (23.2% versus 15.5%; P = 0.2). Helminth species were Schistosomia mansoni (17.9% versus 12.4%), Dicrocoelium dendriticum (3.2% versus 1.0%), Enterobius vermicularis (2.1% versus 2.1%), Wuchereria bancrofti (1.1% versus 0.0%), and Hymenolepis nana (1.1% versus 0.0%). Illiteracy (adjusted odds ratio [aOR]: 2.5; 95% CI: 1.0-6.1), smoking (aOR: 2.4; 95% CI: 1.1-5.3), and handwashing after defecation (aOR: 2.4; 95% CI: 1.2-4.7) were associated with parasites. This study reported a high frequency of parasite coinfection in TB patients. These findings suggest the need for adequate health education for behavioral change and systematic diagnosing of parasites in TB patients for better coinfection management.

Dual-color immunochromatographic test strip for simultaneous sensitive detection of malachite green and leucomalachite green residues in fish and shrimp meat samples

A sensitive dual immunochromatographic test strip (dual-ICTS) was developed to detect malachite green (MG) and its metabolite, leucomalachite green (LMG), using two types of gold nanoparticles: round-shaped (red) and star-shaped (blue). The detection limits were determined to be 0.221 μg L−1 for MG and 0.214 μg L−1 for LMG, respectively. The dual-ICTS provided a cut-off value of 1.8 μg L−1 for MG and LMG detection. The dual-ICTS successfully detected MG and LMG in food samples, with recovery rates ranging from 86 % to 116 %. The dual-ICTS was evaluated by correlation analysis between the proposed assay and the well-established enzyme-linked immunosorbent assay in the MG and LMG detection. This is the first report on the development of the ICTS that can detect both MG and LMG at the same time within only 5 min, making it a sensitive and rapid tool for on-site detection.

Exploring Acute Diarrhea in Infants: A Comprehensive Review of Infectious Agents and Laboratory Diagnostic Techniques

Introduction: acute diarrhea is one of the main causes of mortality in children under 5 years of age around the world. They disproportionately affect underdeveloped countries, where access to health services, drinking water and sanitation is limited. Objective: this review identifies the most relevant and recent studies associated with the topic, recognizes the most common infectious agents and determines the laboratory techniques used for their diagnosis. Methods: the literature was reviewed from sources such as Elsevier, PubMed, Scopus, SciELO and Google Scholar during the period March-May 2024, published in the last 5 years and several studies prior to 2019 that contributed relevant information to the topic. Results: previous studies reveal that acute childhood diarrhea is mainly characterized by its fecal-oral transmission, caused by Rotavirus and Adenovirus, and sometimes by Escherichia coli, Salmonella spp., Giardia lamblia and Entamoeba histolytica, among others. Acute diarrhea is characterized by the presence of three or more soft or liquid stools per day, and is classified according to its duration. Fecal increase, dehydration and electrolyte abnormalities are associated complications and constitute clinically useful elements for its diagnosis. For viruses, rapid tests and PCR are used, for bacteria, cultures and antibiograms, and for parasites, coproparasites, ELISA and PCR. Conclusion: These disorders represent a significant health challenge, with a considerable impact on morbidity and mortality, originating from viruses, bacteria and parasites. The diagnosis is made through physical, coprological examinations, immunochromatographic and molecular tests

Seroprevalence of Hepatic Viruses and Associated Risk Factors Among Rehabilitated Patients During the Post-Addictive Phase

Background: Drug addiction poses a major public health risk, particularly in terms of the transmission of blood-borne infections like Hepatitis B (HBV), Hepatitis C (HCV), and Human Immunodeficiency Virus (HIV) among users.Objective: To assess the seroprevalence of HBV, HCV, and HIV and identify associated risk factors among drug users in rehabilitation centers in Islamabad, Pakistan.Methods: A cross-sectional study was conducted on 203 drug users from July to October 2022. Participants were screened for HBV, HCV, and HIV using immunochromatographic tests (ICT) and confirmed by Enzyme-Linked Immunosorbent Assay (ELISA). Demographic and risk factor data were collected through structured forms. Statistical analysis was performed using SPSS version 20.0, including descriptive statistics and chi-square tests for associations.Results: The prevalence rates for HCV, HBV, and HIV were 15.8%, 9.3%, and 3.4%, respectively. Intravenous drug users showed a higher prevalence of HCV (8.4%) compared to non-intravenous users (7.4%). Needle sharing (55.7%) and low socio-economic status (83.2%) were significant risk factors.Conclusion: HCV is highly prevalent among drug users, especially intravenous users, necessitating targeted harm reduction strategies and enhanced rehabilitation facilities.

Modulating of d-band center in Cu single-atom anchored Co3O4 nanozyme for sensitive immunochromatographic test strip

Immunochromatographic test strip (ITS) has been widely employed for point-of-care diagnoses. However, how to significantly enhance the analytical sensitivity of device-free ITS remains a challenge. Here, we synthesized a Cu single-atom anchored Co3O4 (CuSA/Co3O4) nanozyme that possesses ultrahigh peroxidase-mimicking catalytic activity owing to d-band center upshift mediated by Cu single-atom. Molecular orbital analysis demonstrated that d orbitals in CuSA/Co3O4 have stronger orbital hybridization affinity than Co3O4 to H2O2′s π* orbitals. This reinforces hydroxyl radical (OH) production and provides a stronger catalytic colorimetric signal, which is beneficial for improving the sensitivity of ITS. Moreover, we applied the CuSA/Co3O4 to ITS as a signal reporter for monitoring Xanthomonas oryzae pv. oryzicola (Xoc), the pathogen of rice bacterial leaf streak. The visual limit of detection (LOD) of the developed CuSA/Co3O4-based ITS was as low as 6.4 × 102 CFU mL−1, which is 25-fold more sensitive than the traditional Au nanoparticles (AuNP)-based ITS. Taken together, this work demonstrates the great potential of CuSA/Co3O4 nanocomposite as a signal reporter to improve the sensitivity of ITS for on-site Xoc detection.

New Insights into Leishmaniasis in Rabbits Raised in the Northeast Region of Brazil.

This study aimed to investigate the occurrence of leishmaniasis in domestic rabbits (Oryctolagus cuniculus) in the state of Sergipe, Brazil, and to evaluate the associated clinical signs. A total of 31 rabbits from urban and rural areas were clinically examined using cytological, immunological, and serological tests. Blood and cytological samples were collected and analysed for the presence of Leishmania parasites and antibodies. Immunochromatographic tests were used to screen for anti-Leishmania antibodies, and cytological analysis of skin lesions was performed to detect the presence of Leishmania amastigotes. Of the rabbits tested, 19.35% were reactive in the anti-Leishmania antibody screening, and 3.33% tested positive for Leishmania amastigotes in skin lesion cytology. Clinical signs included cachexia, lymphadenomegaly, dehydration, apathy, dermatitis, ophthalmopathy, and alopecia. Cytological analysis revealed pyogranulomatous inflammation with Leishmania amastigotes present. The findings suggest that leishmaniasis is present among domestic rabbits in this region CONCLUSION: This study demonstrates the presence of leishmaniasis in domestic rabbits in the Northeast of Brazil. The findings underline the importance of early diagnosis and intervention in preventing the spread of the disease, and highlight the need for further research into the role of rabbits as potential reservoirs of Leishmania.

A novel peptide pair-based rapid fluorescent diagnostic system for malaria Plasmodium falciparum detection

Advanced diagnostic materials, such as aptamers, are required due to the scarcity of efficient diagnostic antibodies and the low sensitivity of rapid diagnostic kits at detecting the malaria parasite, Plasmodium falciparum. MethodsTwo peptides M2.9 [(KPTAEQTESPELQSAPEN) and M2.17 (KILFNVYSPLGCTCECWV)] were designed using simple epitope prediction tools and modified against the merozoite surface antigen 2 of P. falciparum (Pf.MSP2) by 3-dimensional modeling based on binding affinity. Based on five prediction tools for hydropathy, M2.17 was selected as an appropriate capture peptide. A peptide-based fluorescence-linked immunosorbent assay (FLISA) and a peptide pair-based fluorescent immunochromatographic test strip (FICT) were developed to detect P. falciparum 3D7 (drug-sensitive) and P. falciparum K1 (multi drugs-resistant) strains. ResultsBioinformatic analysis of two peptides demonstrated the potential binding affinity with the merozoite surface protein 2 of P. falciparum (Pf.MSP2) with a positive hydropathy value. The limit of detection (LOD) of FLISA was 10 parasites/μL and of a peptide pair-linked rapid FICT system was 5 and 200 parasites/μL for P. falciparum 3D7 and K1, respectively. Compared to commercial rapid detection systems (RDTs), a peptide pair-linked FICT system exhibited a 20-fold greater efficiency in detecting P. falciparum 3D7 and specifically discriminated another protozoan spp. ConclusionA peptide pair-linked rapid diagnostic strip could be an alternative to conventional RDTs for monitoring wild-type and drug-resistant malaria parasites.

High serological and molecular prevalence of Ehrlichia canis and other vector-borne pathogens in dogs from Boa Vista Island, Cape Verde

Despite the high global impacts of canine vector-borne diseases (CVBD) due to their wide distribution and zoonotic potential, the current epidemiological situation of CVBD in many tropical and subtropical regions remains unknown. This study examines the seroprevalence and molecular prevalence of Ehrlichia canis and other pathogens causing CVBDs (Leishmania infantum, Dirofilaria immitis, Babesia spp., Anaplasma spp. and Hepatozoon canis) in dogs living on the island of Boa Vista (Cape Verde Republic). Blood samples and infesting ticks were taken from 150 dogs across the island (stray, shelter, and pet dogs). Serum samples were tested using a rapid immunochromatographic test (Uranotest® Quattro) that detects antibodies against E. canis, L. infantum, Anaplasma spp. and D. immitis antigen. Levels of serum antibodies against E. canis were measured using the immunofluorescence antibody test (IFAT). In addition, tick-borne pathogens in blood samples (Anaplasma spp., Babesia spp., Hepatozoon spp., and Ehrlichia canis) were detected by microscopy observation and/or PCR plus sequencing. The seroprevalence of E. canis was extremely high at 82% (123/150), as revealed by both immunochromatography and IFAT. Most dogs returning a seropositive test result (82.92%; 102/123) had antibody titres > 1:1280 but showed no clinical signs or notable laboratory abnormalities. Of the 123 animals testing seropositive for E. canis, 67 (54.47%) also presented antibodies against Anaplasma spp., and 13 (10.56%) showed the presence of Hepatozoon spp. gamonts in the blood smear. Ehrlichia canis infection was detected in 17.1% (25/146) of dogs tested by direct sequencing of polymerase chain reaction (PCR) products. Co-infections were detected in seven of these dogs: four dogs tested PCR-positive for both E. canis and A. platys, two dogs tested positive for E. canis and Hepatozoon spp., and one dog tested positive for E. canis, A. platys and Hepatozoon spp. Rhipicephalus sanguineus sensu lato was the only tick species found infesting the canine study population. The high prevalence of tick-borne pathogens detected in dogs from Boa Vista Island highlights a need for improved control measures designed to prevent the transmission of these pathogens.Graphical

Rapid lateral flow test for Mycobacterium tuberculosis complex and non-tuberculous mycobacteria differentiation

The diagnosis of mycobacterial infections, including both the Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM), poses a significant global medical challenge. This study proposes a novel approach using immunochromatographic (IC) strip tests for the simultaneous detection of MTBC and NTM. Traditional methods for identifying mycobacteria, such as culture techniques, are hindered by delays in distinguishing between MTBC and NTM, which can affect patient care and disease control. Molecular methods, while sensitive, are resource-intensive and unable to differentiate between live and dead bacteria. In this research, we developed unique monoclonal antibodies (mAbs) against Ag85B, a mycobacterial secretory protein, and successfully implemented IC strip tests named 8B and 9B. These strips demonstrated high concordance rates with conventional methods for detecting MTBC, with positivity rates of 93.9% and 85.9%, respectively. For NTM detection, the IC strip tests achieved a 63.2% detection rate compared to culture methods, considering variations in growth rates among different NTM species. Furthermore, this study highlights a significant finding regarding the potential of MPT64 and Ag85B proteins as markers for MTBC detection. In conclusion, our breakthrough method enables rapid and accurate detection of both MTBC and NTM bacteria within the BACTEC MGIT system. This approach represents a valuable tool in clinical settings for distinguishing between MTBC and NTM infections, thereby enhancing the management and control of mycobacterial diseases.Key points• Panel of mAbs for differentiating MTB versus NTM• IC strips for diagnosing MTBC and NTM after the BACTEC MGIT• Combined detection of MTP64 and Ag85B enhances diagnostic accuracy

Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to Theileria equi and Babesia caballi in horses and donkeys

Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to <i>Theileria equi</i> and <i>Babesia caballi</i> in horses and donkeys

A method development for sertraline detection in the blood

Aim – to develop a method for isolation and determination of sertraline in biological fluids. Material and methods. For the study we used "Zoloft" drug ("Pfizer", USA). The study equipment and substances: liquid chromatograph Shimadzu LC-20 Prominence (Japan) with detector SPD-M20A, gas chromatograph Agilent Technologies (USA) 7890 A / 5977 MSD, (program MassHunter GC-MS ), waters vacuum unit and cartridges for solid-phase extraction Oasis HLB; papain enzymes (MedFloran, Russia); trypsin, chymotrypsin, hyaluronidase (Lidaza) (Samson-Med LLC, Russia); test strips from different manufacturers under trade names: "Be sure", "NarcoCHEC", "FACTOR-MED". Urine samples were obtained after administration of the drug to laboratory animals – guinea pigs. The base of sertraline from a solution of its salt was isolated by liquid-liquid extraction (LLE) with organic solvents and their mixtures at pH = 10, 11 and 12 (pKa sertraline 9.48). Obtaining data on the effectiveness of blood sample preparation methods (liquid-liquid extraction, solid-phase extraction and enzymatic hydrolysis) for sertraline was carried out on enriched model samples of donor blood according to the method proposed by Cheger. Results. Cross-positive urine test results were obtained with immunochromatographic test strips for derivatives of e 1,4-benzodiazepine and synthetic cannabimimetics ("spice"). The study with 1 mg/ml solution of sertraline gave a negative result. Desmethylsertraline, a major metabolite, was detected in the urine, a peak with a retention time of about 12.75 min, the peak of the original substance during the synthesis of sertraline – sertralinimine and the peak of the native sertraline with a retention time of about 12.65 min. A method for detecting sertraline by HPLC has been developed. Conclusion. The use of the enzymatic blood hydrolysis with trypsin allows for increasing the degree of extraction by 1.5 times when compared with liquid-liquid extraction with chloroform, and by 2 times when compared with solid-phase extraction.

Validation of the Microlab Salmonella for Detection of Salmonella O Group A-E in Selected Foods: AOAC Performance Tested MethodSM 052401.

Microlab Salmonella is an all-in-one solution for detection of Salmonella O Groups A-E that integrates, in a single disposable device, all elements to perform the analysis; a ready-to-use enrichment broth, a lateral flow immunochromatography test and a chemical agent for bacterial inactivation. Microlab Salmonella can be easily used on-site and does not require specific laboratory equipment or technical skills. The device is sealed during the analysis avoiding risks of contamination and is therefore safe to use in food production environments. This report details the method validation study for raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, deli ham and pasteurized liquid egg. Matrix studies and inclusivity/exclusivity, product consistency/stability, and robustness testing were conducted to assess the method's performance. Inclusivity/exclusivity testing showed that the Microlab Salmonella method was able to detect Salmonella O Group A-E isolates while excluding the non-Salmonella strains. In the matrix studies the differences between the candidate and reference methods were not statistically significant. Minor variations in test parameters (enrichment time, time to read results, and enrichment temperature) did not affect the performance of the Microlab assay. There were no statistically significant differences between recently manufactured lots and those that were halfway through their expiration period or between those that were close to expiring. The reported data confirms that Microlab Salmonella is reliable for detecting Salmonella in raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, pasteurized liquid egg and deli ham. Microlab Salmonella is validated to detect Salmonella in select food matrixes. Microlab Salmonella integrates the steps of enrichment, detection, and inactivation in a single device.

Fluorescence immunochromatographic detection of antibodies to the p72 protein of African swine fever virus

The African swine fever virus (ASFV), a highly contagious pathogen responsible for African swine fever (ASF), causes significant economic losses in the global pork industry. Due to its large and complex structure, ASFV remains refractory to commercial vaccine development, necessitating the creation of rapid, sensitive, and specific diagnostic tools for disease control. In this study, quantum dots were conjugated to ASFV p72 protein to establish a fluorescent immunochromatographic assay for detecting ASFV-specific antibodies. The assay test strips contained four adjacent pads arranged sequentially: a sample-application pad, a pad containing mobile antigen-probe conjugate, a nitrocellulose readout pad featuring a test line containing immobilised staphylococcal protein A and a control line containing immobilised monoclonal antibodies against the ASFV p72 protein, and an absorbent pad driving the directional flow of liquid via capillary action. The resulting fluorescence immunochromatographic assay demonstrated highly sensitive and specific ASFV antibody detection in under 15 min. Specificity testing showed no cross-reactivity with serum antibodies against other viruses and sensitivity surpassing that of commercial ASFV antibody colloidal gold immunochromatographic test strips. This novel approach offers rapid detection, excellent specificity, and high sensitivity, and supports the future development of fluorescent immunochromatographic test strips for ASFV antibody detection.

Development of a Sensitive Monoclonal Antibody-Based Colloidal Gold Immunochromatographic Strip for Lomefloxacin Detection in Meat Products.

Lomefloxacin (LOM), an antibiotic crucial for preventing various animal diseases in animal husbandry, can pose serious health risks when found in excessive amounts in meat products. The development of highly specific and sensitive colloidal gold immunochromatographic test strips is essential for the accurate detection of this class of antibiotics. Our study utilized a monoclonal antibody (mAb) assay and immunochromatographic strips to detect lomefloxacin residues in meat products. The results showed minimal cross-reactivity with other structural analogs, with a maximum half inhibitory concentration (IC50) of 0.93 ng/mL and a linear range of 0.38 to 2.3 ng/mL for the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA). The recovery of LOM was 80% to 120%, with an average coefficient of variation below 5%. The immunochromatographic strip test results showed a visual detection limit of 2.5 ng/g, meeting the market requirements for the test. This study highlights the significance of specific and sensitive testing methods for detecting lomefloxacin, ensuring consumers' safety and health.

Rapid detection of OTA and ZEN with dual quantum dots fluorescence immunochromatographic test strip

Rapid detection of OTA and ZEN with dual quantum dots fluorescence immunochromatographic test strip