Immunodiagnosis of Fascioliasis in Ruminants by ELISA Method: A Mini-Review.

Fascioliasis is an important zoonotic disease prevalent in domestic animals and it leads to socioeconomic impact in rural farming communities of the developing world. The gold standard diagnosis of ruminant fascioliasis involves coprological detection of Fasciola spp. eggs or recovery of flukes in infected livers. Coprological analysis is unreliable in the patent period of chronic infection, and even then, its sensitivity is relatively low. Robust diagnostic tools that can promptly and accurately detect an active infection are crucial to avoid complications and further losses in ruminant livestock productivity, as well as to preserve the livelihood of communities at risk. Immunodiagnosis determined by antibody and antigen detection in the sera and faeces of infected ruminants provides a valuable alternative to the parasitological diagnostic approach. This review discusses current developments in immunological techniques by enzyme-linked immunosorbent assay (ELISA) in the detection of ruminant fascioliasis and summarises the performance of various ELISAs in studies conducted to date. Indirect ELISAs demonstrated effective immunodiagnostic performance with high sensitivities and specificities. Cathepsin L ELISA is the most favourable antigen in serodiagnosis, among other recombinant and native proteins evaluated. Sandwich ELISA provides excellent sensitivity and specificity, which correlates well with the fluke burden. Utilising monoclonal antibodies in sandwich ELISA reduces the detection time and performance variations that commonly occur in polyclonal antibody ELISA.

Seasonal Occurrence of Cattle Fascioliasis in Kelantan, Malaysia.

A longitudinal study was conducted in five randomly selected farms in Kelantan, Malaysia to determine the seasonal occurrence of cattle fascioliasis and its association with climatic factors. A total of 480 faecal samples were collected by a random purposive sampling method from July 2018 to June 2019. The faecal samples were examined for the presence of Fasciola eggs using a formalin ether sedimentation technique. Meteorological data including temperature, humidity, rainfall, and pan evaporation were obtained from a local meteorological station. The overall prevalence of cattle fascioliasis in Kelantan was 45.8%. The prevalence was observed to be slightly higher during the wet season from August to December (50-58%) than during the dry season from January to June (30-45%). Meanwhile, the mean eggs per gram (EPG) were highest in June (191.1 ± 0.48) and lowest in October (77.62 ± 95.5). However, there were no significant differences in the mean of EPG between the monthly prevalence, tested using one-way ANOVA (p = 0.1828). A statistically significant association (p = 0.014) was observed between the disease and cattle breeds, with Charolais and Brahman showing lower odds of having the disease. There were significant moderate-to-strong positive correlations between cattle fascioliasis and rainfall (r = 0.666; p = 0.018) and humidity (r = 0.808; p = 0.001), as well as strong negative correlations with evaporation (r = -0.829; p = 0.001). The results indicated that the higher prevalence of cattle fascioliasis in Kelantan was correlated with the climatic factors, which include higher rainfall and humidity and lower evaporation.

Aptamer-Based Electrochemical Biosensors for the Detection of Salmonella: A Scoping Review.

The development of rapid, accurate, and efficient detection methods for Salmonella can significantly control the outbreak of salmonellosis that threatens global public health. Despite the high sensitivity and specificity of the microbiological, nucleic-acid, and immunological-based methods, they are impractical for detecting samples outside of the laboratory due to the requirement for skilled individuals and sophisticated bench-top equipment. Ideally, an electrochemical biosensor could overcome the limitations of these detection methods since it offers simplicity for the detection process, on-site quantitative analysis, rapid detection time, high sensitivity, and portability. The present scoping review aims to assess the current trends in electrochemical aptasensors to detect and quantify Salmonella. This review was conducted according to the latest Preferred Reporting Items for Systematic review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. A literature search was performed using aptamer and Salmonella keywords in three databases: PubMed, Scopus, and Springer. Studies on electrochemical aptasensors for detecting Salmonella published between January 2014 and January 2022 were retrieved. Of the 787 studies recorded in the search, 29 studies were screened for eligibility, and 15 studies that met the inclusion criteria were retrieved for this review. Information on the Salmonella serovars, targets, samples, sensor specification, platform technologies for fabrication, electrochemical detection methods, limit of detection (LoD), and detection time was discussed to evaluate the effectiveness and limitations of the developed electrochemical aptasensor platform for the detection of Salmonella. The reported electrochemical aptasensors were mainly developed to detect Salmonella enterica Typhimurium in chicken meat samples. Most of the developed electrochemical aptasensors were fabricated using conventional electrodes (13 studies) rather than screen-printed electrodes (SPEs) (two studies). The developed aptasensors showed LoD ranges from 550 CFU/mL to as low as 1 CFU/mL within 5 min to 240 min of detection time. The promising detection performance of the electrochemical aptasensor highlights its potential as an excellent alternative to the existing detection methods. Nonetheless, more research is required to determine the sensitivity and specificity of the electrochemical sensing platform for Salmonella detection, particularly in human clinical samples, to enable their future use in clinical practice.

Colorimetric Approach for Nucleic Acid Salmonella spp. Detection: A Systematic Review.

Water- and food-related health issues have received a lot of attention recently because food-poisoning bacteria, in particular, are becoming serious threats to human health. Currently, techniques used to detect these bacteria are time-consuming and laborious. To overcome these challenges, the colorimetric strategy is attractive because it provides simple, rapid and accurate sensing for the detection of Salmonella spp. bacteria. The aim of this study is to review the progress regarding the colorimetric method of nucleic acid for Salmonella detection. A literature search was conducted using three databases (PubMed, Scopus and ScienceDirect). Of the 88 studies identified in our search, 15 were included for further analysis. Salmonella bacteria from different species, such as S. Typhimurium, S. Enteritidis, S. Typhi and S. Paratyphi A, were identified using the colorimetric method. The limit of detection (LoD) was evaluated in two types of concentrations, which were colony-forming unit (CFU) and CFU per mL. The majority of the studies used spiked samples (53%) rather than real samples (33%) to determine the LoDs. More research is needed to assess the sensitivity and specificity of colorimetric nucleic acid in bacterial detection, as well as its potential use in routine diagnosis.

Quantum Dot-Based Lateral Flow Immunoassay as Point-of-Care Testing for Infectious Diseases: A Narrative Review of Its Principle and Performance.

Infectious diseases are the world's greatest killers, accounting for millions of deaths worldwide annually, especially in low-income countries. As the risk of emerging infectious diseases is increasing, it is critical to rapidly diagnose infections in the early stages and prevent further transmission. However, current detection strategies are time-consuming and have exhibited low sensitivity. Numerous studies revealed the advantages of point-of-care testing, such as those which are rapid, user-friendly and have high sensitivity and specificity, and can be performed at a patient's bedside. The Lateral Flow Immunoassay (LFIA) is the most popular diagnostic assay that fulfills the POCT standards. However, conventional AuNPs-LFIAs are moderately sensitive, meaning that rapid detection remains a challenge. Here, we review quantum dot (QDs)-based LFIA for highly sensitive rapid diagnosis of infectious diseases. We briefly describe the principles of LFIA, strategies for applying QDs to enhance sensitivity, and the published performance of the QD-LFIA tested against several infectious diseases.

CRISPR-Cas Systems-Based Bacterial Detection: A Scoping Review.

Recently, CRISPR-Cas system-based assays for bacterial detection have been developed. The aim of this scoping review is to map existing evidence on the utilization of CRISPR-Cas systems in the development of bacterial detection assays. A literature search was conducted using three databases (PubMed, Scopus, and Cochrane Library) and manual searches through the references of identified full texts based on a PROSPERO-registered protocol (CRD42021289140). Studies on bacterial detection using CRISPR-Cas systems that were published before October 2021 were retrieved. The Critical Appraisal Skills Programme (CASP) qualitative checklist was used to assess the risk of bias for all the included studies. Of the 420 studies identified throughout the search, 46 studies that met the inclusion criteria were included in the final analysis. Bacteria from 17 genera were identified utilising CRISPR-Cas systems. Most of the bacteria came from genera such as Staphylococcus, Escherichia, Salmonella, Listeria, Mycobacterium and Streptococcus. Cas12a (64%) is the most often used Cas enzyme in bacterial detection, followed by Cas13a (13%), and Cas9 (11%). To improve the signal of detection, 83% of the research exploited Cas enzymes' trans-cleavage capabilities to cut tagged reporter probes non-specifically. Most studies used the extraction procedure, whereas only 17% did not. In terms of amplification methods, isothermal reactions were employed in 66% of the studies, followed by PCR (23%). Fluorescence detection (67%) was discovered to be the most commonly used method, while lateral flow biosensors (13%), electrochemical biosensors (11%), and others (9%) were found to be less commonly used. Most of the studies (39) used specific bacterial nucleic acid sequences as a target, while seven used non-nucleic acid targets, including aptamers and antibodies particular to the bacteria under investigation. The turnaround time of the 46 studies was 30 min to 4 h. The limit of detection (LoD) was evaluated in three types of concentration, which include copies per mL, CFU per mL and molarity. Most of the studies used spiked samples (78%) rather than clinical samples (22%) to determine LoD. This review identified the gap in clinical accuracy evaluation of the CRISPR-Cas system in bacterial detection. More research is needed to assess the diagnostic sensitivity and specificity of amplification-free CRISPR-Cas systems in bacterial detection for nucleic acid-based tests.

Prevalence and Risk Factors of Bovine Fascioliasis in Kelantan, Malaysia: A Cross-Sectional Study.

Bovine fascioliasis is an important zoonotic parasitic disease that causes significant economic losses to the livestock industry. The aim of this study was to determine the prevalence and risk factors of bovine fascioliasis in Kelantan. In this cross-sectional study, a total of 308 stool and blood samples of farmed cattle were collected from December 2017 to June 2018. The stool samples were examined microscopically for the presence of Fasciola spp. eggs following a formalin-ether sedimentation process. The blood samples were subjected to a commercial ELISA kit (Bio-X-Diagnostic, Rochefort, Belgium) for the detection of anti-Fasciola IgG antibody. The association between coprological findings and risk factors was determined using Pearson's chi-square (χ2). The coproprevalence and seroprevalence of bovine fascioliasis was 14.6% and 37.3%, respectively. There were significant (P < 0.05) associations between the risk of infections and the sex, type of feedings, anthelmintic treatment and farm hygiene. Female cattle (OR: 3.104; 95% CI: 1.265, 7.615), feeding by grazing (OR: 4.458; 95% CI: 1.823, 10.90), untreated cattle (OR: 3.833; 95% CI: 1.620, 9.071), non-schedule anthelminthic treatment (OR: 3.927; 95% CI: 1.685, 9.152) and farm that have never been cleaned (OR: 2.829; 95% CI: 1.428, 5.608) showed higher odds of Fasciola spp. infection. These findings suggested bovine fascioliasis is a serious veterinary disease in Kelantan. Thus, appropriate control, prevention and monitoring strategies of this parasitic infection are urgently needed to reduce the burden of the disease.

Fascioliasis pada lembu adalah penyakit parasit zoonotik penting yang menyebabkan kerugian ekonomi yang signifikan pada industri ternakan. Tujuan kajian ini adalah untuk menentukan prevalens dan faktor risiko fascioliasis pada lembu ternak di Kelantan. Dalam kajian keratan rentas ini, sejumlah 308 sampel tinja dan sampel darah daripada lembu ternak telah diambil dari Disember 2017 hingga Jun 2018. Sampel tinja telah diperiksa secara mikroskopik bagi mengesan kehadiran telur Fasciola spp. melalui proses sedimentasi formalin-eter. Sampel darah telah disaring menggunakan kit ELISA komersial (Bio-X-diagnostics) untuk pengesanan antibodi anti-Fasciola IgG. Hubungan antara penemuan koprologi dan faktor risiko telah ditentukan dengan menggunakan ujian Chi-ganda dua (χ2). Koproprevalens dan seroprevalens fascioliasis pada lembu masingmasing adalah 14.6% dan 37.3%. Terdapat perbezaan signifikan (P < 0.05) antara risiko jangkitan dan jantina, kaedah pemakanan, penggunaan ubat cacing dan kebersihan ladang. Lembu betina (OR: 3.104; 95% CI: 1.265, 7.615), kaedah pemakanan melalui teknik ragut (OR: 4.458; 95% CI: 1.823, 10.90), lembu yang tidak dirawat (OR: 3.833; 95% CI: 1.620, 9.071), rawatan secara tidak berkala (OR: 3.927; 95% CI: 1.685, 9.152) dan ladang yang tidak pernah dibersih (OR: 2.829; 95% CI: 1.428, 5.608) merupakan antara risiko lebih tinggi untuk dijangkiti Fasciola spp.. Penemuan ini mencadangkan bahawa fascioliasis pada lembu adalah penyakit veterinar yang serius di Kelantan. Oleh itu, strategi kawalan, pencegahan dan pengawasan yang sesuai bagi jangkitan parasit ini amat diperlukan untuk mengurangkan beban penyakit ini.

Nucleic Acid-Based Lateral Flow Biosensor for Salmonella Typhi and Salmonella Paratyphi: A Detection in Stool Samples of Suspected Carriers.

A multiplex rapid detection system, based on a PCR-lateral flow biosensor (mPCR-LFB) was developed to identify Salmonella Typhi and Salmonella Paratyphi A from suspected carriers. The lower detection limit for S. Typhi and S. Paratyphi A was 0.16 and 0.08 ng DNA equivalent to 10 and 102 CFU/mL, respectively. Lateral flow biosensor was used for visual detection of mPCR amplicons (stgA, SPAint, ompC, internal amplification control) by labeling forward primers with fluorescein-isothiocyanate (FITC), Texas Red, dinitrophenol (DNP) and digoxigenin (DIG) and reverse primers with biotin. Binding of streptavidin-colloidal gold conjugate with the amplicons resulted in formation of a red color dots on the strip after 15-20 min of sample exposure. The nucleic acid lateral flow analysis of the mPCR-LFB was better in sensitivity and more rapid than the conventional agarose gel electrophoresis. Moreover, the mPCR-LFB showed 100% sensitivity and specificity when evaluated with stools spiked with 100 isolates of Salmonella genus and other bacteria. A prospective cohort study on stool samples of 1176 food handlers in outbreak areas (suspected carriers) resulted in 23 (2%) positive for S. Typhi. The developed assay has potential to be used for rapid detection of typhoid carriers in surveillance program.

In vitro anti-Candida activity of Quercus infectoria gall extract-based vaginal cream and its local tissue effects in vivo

Aims@#Aqueous extract of Quercus infectoria (QI) galls has been reported to possess anti-fungal and anti-inflammatory activities. Hence, this study aimed to determine in vitro antimicrobial activity of formulated QI gall extract-based vaginal cream against Candida albicans and to evaluate the possible side effects on the cervicovaginal epithelium of healthy rats. @*Methodology and results@#Three different cream formulations containing 10%, 20%, and 30% of QI gall extract respectively were tested for their antimicrobial activity against C. albicans (ATCC 10231) by using disc diffusion test. Microbroth serial dilution method was performed in determining the minimum inhibitory concentration (MIC) and fungicidal concentration (MFC). The 30% formulated extract cream (FEC) was applied topically on the cervicovaginal surface of healthy Sprague Dawley (SD) rats and examined for local tissue effects histologically. The mean scores of inhibition zone diameter were compared by one-way ANOVA and post-hoc test using PRISM software. All extract cream formulations displayed a relatively good anti-Candida activity. The MIC values exhibited by 10%, 20%, and 30% FEC against C. albicans were 1.094 mg/mL, 0.547 mg/mL, and 0.068 mg/mL, respectively. The 10% and 20% FECs showed a significant difference (P=0.0254) in the mean of inhibition zone diameter. The lowest MFC value (0.068 mg/mL) was shown by 30% FEC. There were no abnormal changes seen at the vagina and cervical mucosa after 2 weeks application of 30% FEC. @*Conclusion, significance and impact of study@#QI gall extract formulated in the cream base has an anti-Candida activity in vitro and the present finding suggests that this herbal cream formulation is potentially useful in preventing vaginal candidiasis without causing any unwanted local side effects.