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Rapid on-site detection of pathogenic bacteria with high sensitivity and specificity is becoming an urgent need in public health assurance, medical diagnostics, environmental monitoring, and food safety fields. Despite being reliable and widely used, the existing methods of bacteria detection are cumbersome and time-consuming, which is not conducive to field detection. Microfluidic lab-on-a-chip technology has provided a detective tool for various analytes, due to its miniaturization, portability and low reagent consumption. Within this progress report, advances in the bacteria detection using microfluidic biosensors were discussed. Typical methods for pathogenic bacteria capture, separation and detection were introduced respectively in the first part. Then key applications of microfluidic biosensor-based rapid bacteria detection were presented. Finally, we made a conclusion and discussed possible research prospects in aspects of microfluidic biosensors for rapid detection of pathogenic bacteria.

Illegal drugs are among the multitude of goods examined by customs officers at the border. With the emergence of fentanyl and fentanyl analogues, the goal of field detection of drugs becomes two-fold: to interdict illegal drug movement and to assist in the protection of the health and safety of frontline officers. This work reports a study of nine fentanyl-related substances (acetylfentanyl, benzoylfentanyl, beta-hydroxythiofentanyl, butyrylfentanyl, carfentanil, despropionylfentanyl, fentanyl, furanylfentanyl and parafluoroisobutyrylfentanyl) using a commercial off-the-shelf ion mobility spectrometer (COTS IMS) and the results from analyzing 84 seized samples containing fentanyl-related substances. The results showed that the COTS IMS was capable of detecting the presence of programmed fentanyl-related substances. Unprogrammed fentanyl-related substances were detected, however no alarm was generated and the information was accessible via the advanced user mode only. The COTS IMS was not able to distinguish between several pairs of substances with similar reduced mobility values. During this study, six fentanyl analogues were intercepted by our laboratory for the first time (2-isopropylfuranylfentanyl, 2-methoxyfuranylfentanyl, 2-methfuranylfentanyl, 4-chlorofuranylfentanyl, cyclopropylfentanyl and methoxyacetylfentanyl) and their reduced mobility values are presented herein.

Shellfish toxins, as one kind of marine toxin, have attracted worldwide attention due to their severe threat to food safety and human health. Therefore, it is highly essential and urgent to develop a low-cost and convenient method to detect these toxins. With the rapid advance in microfabrication processes, micro/nano biosensors provide novel approaches to address this issue. In addition to their features of low cost, portability, easy operation, high efficiency and high bioactivity, micro/nano biosensors have great potential to realize on-the-spot, rapid detection of shellfish toxins. This review focuses on the most recent advances in the development of micro/nano biosensors for shellfish toxin detection. These biosensors are mainly classified into five categories according to their transducer detection principles, which include optical devices, electrochemical sensors, electrochemiluminescence, field-effect transistors, and acoustic devices. Sensor strategies, toxin analytes, biosensitive elements, coupling methods and field detection performance are highlighted to discuss the applications of shellfish toxin detection. With advances in sensor technology, biomaterials, microfabrication and miniaturized electronics, micro/nano biosensors applied to in-field fast detection of shellfish toxins are expected to play a critical role in food safety, environmental monitoring, and foreign trade in the foreseeable future. Finally, the current challenges and future development trends of micro/nano biosensors for shellfish toxin detection are discussed.

African Swine Fever (ASF) is a highly infectious viral disease with high mortality. The most recent ASF outbreak in Vietnam occurred in 2019, posing a threat to spread to the neighboring Asian countries. Without a commercial vaccine or efficient chemotherapeutics successfully developed, rapid diagnosis and necessary biosecurity procedures are required to control the disease. While the diagnosis method of ASF recommended by the World Organization of Animal Health is real-time PCR, it is not suitable for in-field detection of the disease. In this study, a colorimetric Loop-Mediated Isothermal Amplification (LAMP) assay was developed and evaluated for ASF virus detection using crude serum samples collected from domestic pigs in Vietnam during the 2019 outbreak. The LAMP results can be readily visualized to naked eyes within 30 minutes without the requirement of DNA extraction and sophisticated equipment. The sensitivity, specificity, and limit of detection of colorimetric LAMP assay were comparable to a commercial diagnostic real-time PCR kit. Results strongly indicate that the developed colorimetric LAMP assay is highly recommended for the in-field diagnosis of ASF.

Xanthomonas campestris pv. musacearum (Xcm) is the causal agent of banana xanthomonas wilt, a major threat to banana production in eastern and central Africa. The pathogen is present in very high levels within infected plants and can be transmitted by a broad range of mechanisms; therefore early specific detection is vital for effective disease management. In this study, a polyclonal antibody (pAb) was developed and deployed in a lateral flow device (LFD) format to allow rapid in-field detection of Xcm. Published Xcm PCR assays were also independently assessed: only two assays gave specific amplification of Xcm, whilst others cross-reacted with non-target Xanthomonas species. Pure cultures of Xcm were used to immunize a rabbit, the IgG antibodies purified from the serum and the resulting polyclonal antibodies tested using ELISA and LFD. Testing against a wide range of bacterial species showed the pAb detected all strains of Xcm, representing isolates from seven countries and the known genetic diversity of Xcm. The pAb also detected the closely related Xanthomonas axonopodis pv. vasculorum (Xav), primarily a sugarcane pathogen. Detection was successful in both naturally and experimentally infected banana plants, and the LFD limit of detection was 105 cells mL−1. Whilst the pAb is not fully specific for Xcm, Xav has never been found in banana. Therefore the LFD can be used as a first-line screening tool to detect Xcm in the field. Testing by LFD requires no equipment, can be performed by non-scientists and is cost-effective. Therefore this LFD provides a vital tool to aid in the management and control of Xcm.

The remote, timely and in-field detection of sulfured additives in natural gas pipelines is a challenge for environmental, commercial and safety reasons. Moreover, the constant control of the level of odorants in a pipeline is required by law to prevent explosions and accidents. Currently, the detection of the most common odorants (THT = tetrahydrothiophane; TBM = tertiary butyl mercaptan) added to natural gas streams in pipelines is made in situ by using portable gas chromatography apparatuses. In this study, we report the analysis of the ultraviolet spectra obtained by a customized ultraviolet spectrophotometer, named Spectra, for the in-field detection of thiophane and tertiary butyl mercaptan. Spectra were conceived to accomplish the remote analysis of odorants in the pipelines of the natural gas stream through the adoption of technical solutions aimed to adapt a basic bench ultraviolet spectrophotometer to the in-field analysis of gases. The remotely controlled system acquires spectra continuously, performing the quantitative determination of odorants and catching systemic or accidental variations of the gaseous mixture in different sites of the pipeline. The analysis of the experimental spectra was carried out also through theoretical quantum mechanical approaches aimed to detect and to correctly assign the nature of the intrinsic electronic transitions of the two odorants, thiophane and tertiary butyl mercaptan, that cause the ultraviolet absorptions. So far, these theoretical aspects have never been studied before. The absorption maxima of thiophane and tertiary butyl mercaptan spectra were computationally simulated through the usage of selected molecular models with satisfactory results. The good matches between the experimental and theoretical datasets corroborate the reliability of the collected data. During the tests, unexpected pollutants and accidental malfunctions have been detected and also identified by Spectra, making this instrument suitable for many purposes.

Globally, mushroom poisoning is becoming one of the most serious food safety-related problems. To investigate the source of mushroom poisoning, a rapid method for identifying toxic mushrooms is urgently required. This study aimed to establish a colorimetric method based on loop-mediated isothermal amplification (LAMP) for rapid detection of Amanita sepiacea based on the analysis of the beta-tubulin gene. Specific LAMP primers for species specificity identification were designed. The primers designed by the colorimetric method did not cross-react with 41 non-target species mushrooms, and 1 ng of A. sepiacea DNA was detected. The detection method established herein can be used to identify A. sepiacea when present at concentrations as low as 1% in mixed fresh, cooked, or fried mushroom samples. The whole detection process only takes 30 min and requires heating and no complex instrumental help. Therefore, this method can be used in the field detection of poisonous mushrooms.

A study was conducted on the Brigham Young University campus during January and February 2015 to identify winter-time sources of fine particulate material in Utah Valley, Utah. Fine particulate mass and components and related gas-phase species were all measured on an hourly averaged basis. Light scattering was also measured during the study. Included in the sampling was the first-time source apportionment application of a new monitoring instrument for the measurement of fine particulate organic marker compounds on an hourly averaged basis. Organic marker compounds measured included levoglucosan, dehydroabietic acid, stearic acid, pyrene, and anthracene. A total of 248 hourly averaged data sets were available for a positive matrix factorization (PMF) analysis of sources of both primary and secondary fine particulate material. A total of nine factors were identified. The presence of wood smoke emissions was associated with levoglucosan, dehydroabietic acid, and pyrene markers. Fine particulate secondary nitrate, secondary organic material, and wood smoke accounted for 90% of the fine particulate material. Fine particle light scattering was dominated by sources associated with wood smoke and secondary ammonium nitrate with associated modeled fine particulate water.The identification of sources and secondary formation pathways leading to observed levels of PM

Ciguatera fish poisoning is a food-borne illness caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the Gambierdiscus genus. Since most surveillance programs currently rely on the survey of Gambierdiscus cell densities and species composition, supplementary toxin-based methods allowing the time- and spatially integrated sampling of toxins in ciguateric environments are needed for a more reliable assessment and management of the risks associated with Gambierdiscus proliferation. Solid Phase Adsorption Toxin Tracking (SPATT) filters use porous synthetic resins capable of adsorbing toxins directly from the water column. To assess the ability of these passive monitoring devices to retain Gambierdiscus toxins, SPATT bags filled with 10 g of HP20 resin were deployed for 48 h in two French Polynesian locations at high (Nuku Hiva Island) vs. low to moderate (Kaulcura Atoll) risk of ciguatera. CTXs could be detected in SPATT bags extracts from Nuku Hiva Island, as assessed by the mouse neuroblastoma cell-based assay (CBA-N2a) and liquid chromatography - tandem mass spectrometry (LC-MS/MS) analyses. Results of in vitro experiments suggest that the saturation limit of CTXs on HP20 resin, for a deployment time of 48 h, is similar or equal to 55 ng P-CTX-3C equiv. g(-1), resin. Despite the non detection of maitotoxin (MTX), LC-MS/MS analyses showed that two other compounds also produced by Gambierdiscus species were retained on SPATT bags, i.e. iso-P-CTX-3B/C and a putative MTX analogue, known as MTX-3. This study, the first to demonstrate the suitability of SPATT technology for the in situ monitoring of Gambierdiscus toxins, highlights the potential application of this tool for routine ciguatera risk assessment and management programs.

The collection and analysis of drugs in oral fluid (OF) at the roadside has become more feasible with the introduction of portable testing devices such as the Alere™ DDS®2 Mobile Test System (DDS®2). The objective of this study was to compare the on-site results for the DDS®2 to laboratory-based confirmatory assays with respect to detection of drugs of abuse in human subjects. As part of a larger Institutional Review Board approved study, two OF samples were collected from each participant at a music festival in Miami, FL, USA. One OF sample was field screened using the DDS®2, and a confirmatory OF sample was collected using the Quantisal™ OF collection device and submitted to the laboratory for testing. In total, 124 subjects participated in this study providing two contemporaneous OF samples. DDS®2 field screening yielded positive results for delta-9-tetrahydrocannabinol (THC) (n = 27), cocaine (n = 12), amphetamine (n = 3), methamphetamine (n = 3) and benzodiazepine (n = 1). No opiate-positive OF samples were detected. For cocaine, amphetamine, methamphetamine and benzodiazepines, the DDS®2 displayed sensitivity, specificity and accuracy of 100%. For THC, the DDS®2 displayed sensitivity of 90%, specificity of 100% and accuracy of 97.5%, when the threshold for confirmation matched that of the manufacturers advertised cut-off. When this confirmatory threshold was lowered to the analytical limit of detection (i.e., 1 ng/mL), apparent device performance for THC was poorer due to additional samples testing positive by confirmatory assay that had tested negative on the DDS®2, demonstrating a need for correlation between manufacturer cut-off and analytical reporting limit. These results from drug-using subjects demonstrate the value of field-based OF testing, and illustrate the significance of selecting an appropriate confirmation cut-off concentration with respect to performance evaluation and detection of drug use.

Early detection of Banana Xanthomonas Wilt (BXW) in the field and immediate destruction of infected plants or plant tissue are key control methods to prevent the introduction and spread of BXW. This requires rapid, cost-effective and an on- site diagnostic tool to detect the bacterium, Xanthomonas campestris pv musacearum (Xcm). Polymerase chain reaction (PCR) detection technique for BXW is efficient but requires expensive equipment and knowledgeable expertise; this limits PCR application to the laboratory. This study therefore was carried out to evaluate the enzyme-linked immunosorbent assay (ELISA) tool configured as a lateral flow device (LFD) for detection of Xcm. Studies on the systemicity of Xcm in banana were carried out using the BXW-LFD in a field trial of 300 banana plants of Pisang Awak inoculated with the Xcm at Kiifu Forest, Mukono District, Uganda. Pseudo-stem samples from symptomatic and asymptomatic suckers were collected and tested with the LFD and the results compared with conventional PCR using the GspDm BXW primers. The LFD was able to detect Xcm 3 days post inoculation (dpi), 2 cm above and below inoculation site, 15 to 35 days in the pseudo-stem, 35 to 42 days to reach the corm and 81 days in the lateral roots. The rate of Xcm movement in banana was found to be sigmoid in nature, leveling off as the bacteria moved down the pseudo-stem towards the corm. Conventional PCR was only 24% more sensitive than the LFD. The use of the BXW LFD can therefore boost BXW control measures through improved surveillance and quarantine services to arrest the introduction and spread of the disease within and between national borders. Key words: Banana Xanthomonas Wilt lateral flow device (BXW LFD), Banana Xanthomonas wilt, Xanthomonas campestris pv musacearum, complete systemicity, incomplete systemicity, lateral flow device.

Ion mobility spectrometry (IMS) is a well known field technique for the detection of various materials such as explosives and narcotics. IMS has been used for the detection and identification of nicotine, and this paper describes a simple preparation method and analysis using an Ionscan 500DT which could be used in a field environment for the detection of nicotine in e-liquids. E-liquids containing nicotine are presently a topic of much debate in many countries and their shipment across the Canadian border is prohibited. The method described here would allow border officers or any other operators of IMS instruments to use this technique to correctly determine the presence or absence of nicotine in the e-liquid; this would allow the timely importation of the e-liquids with no nicotine and restrict the laboratory analysis only to those liquids containing nicotine. The IMS method has been used on a number of samples received from manufacturers of e-liquids as well as samples seized at the border. The results of the IMS analysis correspond well with those obtained using a Gas Chromatograph – Mass Spectrometer (GC-MS) method of analysis for nicotine.

Bacterial spot of tomato is caused by Xanthomonas gardneri, X. euvesicatoria, X. perforans, and X. vesicatoria. Current diagnostic methods for the pathogens are not in-field assays. Recombinase polymerase amplification (RPA) is ideal for in-field detection assays, because it is an isothermal technique that is rapid and more tolerant to inhibitors compared with polymerase chain reaction. Hence, novel RPA probes and primers were designed to amplify regions of the hrcN gene of X. gardneri, X. euvesicatoria, and X. perforans. The X. gardneri RPA is specific to X. gardneri with a detection limit of 106 CFU/ml and detected X. gardneri in lesions from naturally (n = 6) or artificially (n = 18) infected plants. The X. euvesicatoria RPA detects both X. euvesicatoria and X. perforans with a detection limit of 106 CFU/ml and detected both pathogens in plants artificially infected (n = 36) or naturally infected (n = 85) with either X. euvesicatoria or X. perforans. The X. perforans RPA is specific to X. perforans with a detection limit of 107 CFU/ml. Although the X. perforans RPA assay was unable to detect X. perforans from lesions, the X. euvesicatoria RPA was successfully used in field to detect X. perforans from symptomatic field samples (n = 31). The X. perforans RPA was then used to confirm the pathogen in the laboratory. The X. euvesicatoria and X. gardneri RPA is promising for rapid, real-time in-field detection of bacterial spot and one of the first developed among plant pathogenic bacteria.

The purpose of this study is to apply the visual qualitative (LFD-LAMP) and advanced quantitative loop-mediated isothermal amplification (EVA-LAMP) methods to detect Listeria monocytogenes, which is an important pathogenic foodborne bacterium. This research designed a new set of primers to amplify the hlyA gene of L. monocytogenes. The LFD-LAMP products were detected by lateral flow device (LFD) with the naked eyes, and the test results were consistent with agarose gel electrophoresis. Meanwhile, an advanced quantitative LAMP assay was established which depended on the EVA Green. The detection limit of the EVA-LAMP method was 10 pg/μL, and a good linear relationship was obtained. The subsequent analysis of contaminated raw food samples showed that the primers were able to identify L. monocytogenes in food. The LFD-LAMP and EVA-LAMP reactions can be used as sensitive, rapid and simple methods for the detection of L. monocytogenes, especially on field detection. Practical Applications This work suggests a specific, sensitive, cost-effective and nonpollution LAMP assay for the detection of Listeria monocytogenes. A new set of hlyA-based primers was designed and successfully used to detect L. monocytogenes in raw food samples. Amplicon detection by visual LFD method proved to be as useful as the gel, but more convenient and clean. The LFD-LAMP detection method in this study testifies as a significant advancement toward making LAMP a potential on-site detection. Otherwise, in contrast to the traditional real-time LAMP approach, this is a novel study to describe a real-time quantitative LAMP assay based on EVA Green to detect L. monocytogenes in the fields of food safety.

La Crosse virus (LACV), a leading cause of arboviral pediatric encephalitis in the United States, is emerging in Appalachia. Here, we report field and laboratory evidence that suggest LACV may be using Culex mosquitoes as additional vectors in this region. This bunyavirus was detected by reverse-transcriptase polymerase chain reaction in two pools of Culex mosquitoes in southwestern Virginia and in six pools in West Virginia. To assess vector competence, we offered LACV blood meals to field-collected Culex restuans Theobald, Cx. pipiens L., and Aedes triseriatus (Say). Both Culex species were susceptible to infection. LACV-positive salivary expectorate, indicative of the ability to transmit, was detected in a small proportion of Cx. restuans (9%) and Cx. pipiens (4%) compared with Ae. triseriatus (40%). In a companion study of Cx. restuans only, we found that adults derived from nutritionally stressed larvae were significantly more likely to disseminate and transmit LACV. Our results indicate a potential role of Culex spp. in LACV dynamics that should be explored further in endemic areas.

Self-propelled micromotor-based fluorescent "On-Off" detection of nerve agents is described. The motion-based assay utilizes Si/Pt Janus micromotors coated with fluoresceinamine toward real-time "on-the-fly" field detection of sarin and soman simulants.

Anthracnose crown rot (ACR) is one of the major diseases affecting strawberry crops grown in warm climates and causes huge yield losses each year. ACR is caused by the fungus Colletotrichum. Since this airborne disease spreads rapidly, detection at the early stage of infection is critical. The objective of this study was to investigate the feasibility of detecting ACR in strawberry at its early stage under field conditions using spectroscopy technology. Hyperspectral data were collected in-field using a mobile platform on three categories of strawberry plants: infected but asymptomatic, infected and symptomatic, and healthy. As a comparison, indoor data were also collected from the same three categories of strawberry plants under a controlled laboratory setup. Three classification models, stepwise discriminant analysis (SDA), Fisher discriminant analysis (FDA), and the k-Nearest Neighbor (kNN) algorithms, were investigated for their potential to differentiate the three infestation categories. Thirty-three spectral vegetation indices (SVIs) were calculated as inputs using selected spectral bands in the visible (VIS) and near infrared (NIR) regions to train classification models. The mean classification accuracies of in-field tests for the three infestation categories were 71.3%, 70.5%, and 73.6% for SDA, FDA, and kNN, respectively. These accuracies were approximately 15–20% lower than those of the indoor tests. The low accuracy (15.4%) of classifying healthy leaves in-field using the kNN model was possibly due to the training datasets being unbalanced. After the adjustment of sample sizes of each category, the accuracies of kNN improved greatly, especially for the healthy and symptomatic categories. Overall, SDA was the optimal classifier for both indoor and in-field tests for detection strawberry ACR. However, kNN performed better for asymptomatic leaves in the field in the case of balanced sample sizes of each category., The authors would like to thank the United States Department of Agriculture - National Institute of Food and Agriculture for their financial support (#2013-67021-20934). Also, the first author was supported by the China Scholarship Council and the National High Technology Research and Development Program (863) of China (2012AA10A504).

First responders need a cost-effective method to detect fentanyl, a potent synthetic opioid, in the field. A new electrochemical sensor takes as little as 1 min to identify the drug (Anal. Chem. 20...

The fluorogenic probe o-OH is able to detect and quantify organophosphorus nerve agent mimics in solution and in the vapor phase following immobilization on a solid substrate, making the system a suitable candidate for the field detection of chemical warfare agents. Detection is achieved by the suppression of internal rotation upon phosphorylation of a reactive phenolate, resulting in a large fluorescence “turn-on” response.

Near‐Infrared Spectroscopy (NIRS) is an emerging medical countermeasure for rapid, field detection of hematomas caused by traumatic brain injury (TBI). Bench and animal tests to determine NIRS sensitivity and specificity are needed. However, current animal models involving non-invasively induced, localized neural damage are limited. We investigated an in vivo murine hematoma model in which cerebral hemorrhage was induced noninvasively by high-intensity focused ultrasound (HIFU) with calibrated positioning and parameters. To characterize the morphology of induced hematomas, we used skull-intact histological evaluation. A multi-wavelength fiber-optic NIRS system with three source-detector separation distances was used to detect hematoma A 1.1 MHz transducer produced consistent small-to-medium hematoma localized to a single hemisphere, along with bruising of the scalp, with a low mortality rate. A 220 kHz transducer produced larger, more diffuse hematomas, with higher variability in size and a correspondingly higher mortality rate. No skin bruising or blood accumulation between the skin and skull was observed following injury application with the 220 kHz transducer. Histological analysis showed higher sensitivity for larger hematomas (>4x4 mm2). NIRS optical density change after HIFU was able to detect all hematomas, with sensitivity dependent on wavelength and separation distance. While improvements in methods for validating cerebral blood distribution are needed, the HIFU hematoma model provided useful insights that will inform development of biologically relevant, performance test methods for cerebral NIRS systems.

The capability to collect timely information about the substances employed on-site at a crime scene is of fundamental importance during scientific investigations in crimes involving the use of explosives. TNT (2,4,6-trinitrotoluene) is one of the most employed explosives in the 20th century. Despite the growing use of improvised explosives, criminal use and access to TNT is not expected to decrease. Immunoassays are simple and selective analytical tests able to detect molecules and their immunoreactions can occur in portable formats for use on-site. This work demonstrates the application of three immunochemical assays capable of detecting TNT to typical forensic samples from experimental tests: an indirect competitive ELISA with chemiluminescent detection (CL-ELISA), a colorimetric lateral flow immunoassay (LFIA) based on colloidal gold nanoparticles label, and a chemiluminescent-LFIA (CL-LFIA). Under optimised working conditions, the LOD of the colorimetric LFIA and CL-LFIA were 1 μg mL−1 and 0.05 μg mL−1, respectively. The total analysis time for LFIAs was 15 min. ELISA proved to be a very effective laboratory approach, showing very good sensitivity (LOD of 0.4 ng mL−1) and good reproducibility (CV value about 7%). Samples tested included various materials involved in controlled explosions of improvised explosive devices (IEDs), as well as hand swabs collected after TNT handling tests. In the first group of tests, targets covered with six different materials (metal, plastic, cardboard, carpet fabric, wood and adhesive tape) were fixed on top of wooden poles (180 cm high). Samples of soil from the explosion area and different materials covering the targets were collected after each explosion and analysed. In the second group of tests, hand swabs were collected with and without hand washing after volunteers simulated the manipulation of small charges of TNT. The small amount of solution required for each assay allows for several analyses. Results of immunoassays confirmed that they were suitable to detect post-blast residues in soil and target materials and post transfer residues on hands, allowing further confirmation by more selective techniques. ELISA and LFIAs results obtained from the same solution were consistently in good agreement, and were confirmed by gas chromatography coupled to mass spectrometry (GC–MS). The reported immunoassays data demonstrates the suitability of LFIAs as on-site rapid and effective assays to detect TNT traces. The CL-ELISA proved useful in obtaining very sensitive detection in forensic investigations and testing, while CL-LFIA had performances in between LFIA and CL-ELISA.

Mastitis is an important disease of dairy cattle. There are two forms of mastitis. One is clinical and another is sub clinical. Clinical Mastitis is easily detected by its clinical signs and milk quality but sub clinical mastitis shows no lesions. Other hand subclinical mastitis cause most economic losses compared to clinical form. Thus rapid field detection technique is a strong tool to reduce this form. California Mastitis Test (CMT) is the most quick and reliable field test to detect this form of mastitis.

Salmonella is an important human enteropathogen associated with poultry. Poultry is routinely analyzed for Salmonella by industry, regulatory, and research laboratories. Effectiveness of selective plating media is critical to Salmonella laboratory analysis. Many media routinely used in the food microbiology laboratory were developed for all Gram-negative human enteric pathogens encountered in a clinical laboratory, rather than for Salmonella alone. The presence of extraneous, non-Salmonella bacteria make the recognition of Salmonella on these plates very difficult. This, more than any other factor, contributes to poor performance of a medium. Primarily because of the poor performance of many selective agars in detecting Salmonella from non-clinical samples, food microbiology laboratories usually use two or more plating media to reduce false negative results.

A field investigation was undertaken following an outbreak of water-borne tularemia in Northern Norway. Francisella tularensis bacterial cellular components were analysed by rapid immunochromatography (RI)-testing, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Water from 1 reservoir, fed from a rapid stream, tested negative. From another reservoir, 2 of a chain of 3 wells tested negative. The third well, at the end of the chain, contained lemming (Lemmus lemmus) carcasses and gave ample proof of F. tularensis contamination. We concluded that the origin of the outbreak was dead, infective lemming carcasses in the water sources. For the various sampling materials, the RI-test proved itself particularly handy and versatile, compared with the ELISA and the PCR.

A new, field-adapted, colorimetric method for detecting sulfonamide drugs in urine is described. The method uses the color reagent, p-dimethylaminocinnamaldehyde, and has a detection limit of about 1 microgram/ml. Analysis of 35 samples collected in the field, comparing results obtained with the colorimetric field test with those obtained using high-performance liquid chromatography, indicated a calculated sensitivity value of 94% and a specificity value of 94% for the test to detect the presence of sulfonamides. The field test can be modified to allow quantitation of sulfonamides in urine in field situations, using a hand-held, portable photometer for measuring the absorbance of test solutions. For this test, calculated coefficients of variation for day to day reproducibility wereor = 5% at sulfonamide concentrationsor = 3 micrograms/ml. This new test for detecting the presence of sulfonamides in urine is more sensitive and reliable than the presently used Bratton-Marshall test.

A simple and easy method of concentrating white spot syndrome virus by employing aluminium sulphate, alum as a flocculant was developed and evaluated for field detection. The concentrated virus was detected by a monoclonal antibody based flow-through assay, RapiDot and compared its performance with polymerase chain reaction. The semi-purified virus that was flocculated by 15 and 30 ppm alum in a 50 ml cylinder can be detected successfully by both RapiDot and I step PCR. In addition, alum could also flocculate the virus that is detectable by II step PCR and the concentration of virus was similar to the one observed in water from an infected pond. Furthermore, experimental infection studies validated the successful concentration of virus by alum flocculation followed by rapid detection of virus using monoclonal antibody based RapiDot. Overall, the results obtained in this study indicate that the white spot syndrome virus in water could be easily flocculated by alum for sensitive field detection by monoclonal antibody based RapiDot.

Early breast cancer detection is an emerging field of research as it can save the women infected by malignant tumors. Microwave imaging has recently been proposed for detecting small malignant breast tumors at early stages. Microwave imaging for medical application has been of interest for many years, recently it proposed for detecting small malignant breast tumors. Microwave images are maps of the electrical property distributions in the dielectric properties between cancerous tissues and healthy tissues; it is possible to use it as a diagnosis tool. In this research contribution, the authors have over viewed the research status of microwave imaging for malignant tumor detection. The tomography imaging system for detecting small malignant breast lesions have been explored.

This study investigates the viability of using common bivalve mollusks as bioaccumulators of marker compounds that can be used to verify the production or use of chemical warfare agents (CWAs). The bioaccumulation of synthetic contaminants in bivalve mollusks and other aquatic organisms is a widespread phenomenon, and the analysis of resident biota is an effective means of detecting and verifying the presence of contaminants and possibly identifying their anthropogenic source. The study reported in this paper demonstrates that detection and verification of the presence of CWAs (specifically, nerve agents VX and GB/Sarin) may be accomplished by a technique that measures the bioaccumulation of marker compounds in brackish-water clams

Wild birds have been implicated in the spread of highly pathogenic avian influenza (HPAIV) of the H5N1 subtype, prompting surveillance along migratory flyways. Sampling of wild birds is often conducted in remote regions, but results are often delayed because of limited local analytical capabilities, difficulties with sample transportation and permitting, or problems keeping samples cold in the field. In response to these challenges, the performance of a portable real-time, reverse transcriptase-polymerase chain reaction (rRT-PCR) unit (RAPID((R)), Idaho Technologies, Salt Lake City, UT) that employed lyophilized reagents (Influenza A Target 1 Taqman; ASAY-ASY-0109, Idaho Technologies) was compared to virus isolation combined with real-time RT-PCR conducted in a laboratory. This study included both field- and experimental-based sampling. Field samples were collected from migratory shorebirds captured in northern California, while experimental samples were prepared by spiking fecal material with an H6N2 AIV isolate. Results indicated that the portable rRT-PCR unit had equivalent specificity to virus isolation with no false positives, but sensitivity was compromised at low viral titers. Use of portable rRT-PCR with lyophilized reagents may expedite surveillance results, paving the way to a better understanding of wild bird involvement in HPAIV H5N1 transmission.

The adaptation and use of a Bloodhound® ST214 electronic nose to rapidly detect TB in sputum samples has been discussed in the past, with some promising results being obtained in 2007. Some of the specific VOC’s associated with Mycobacteria tuberculosis organisms are now being discovered and a paper was published in 2008, but the method of predicting the presence of TB in sputum samples using the VOC biomarkers has yet to be fully optimised. Nevertheless, with emphasis on the sampling techniques and with new data processing techniques to obtain consistent results progress is being made Sensitivity and specificity levels for field detection of TB have been set by WHO at a minimum level of 85% and 95% respectively, and the e‐nose technique is working towards these figures. In a series of experiments carried out in Mbeya, Tanzania, Africa, data from a full 5 days of sampling was combined giving a total of 248 sputum samples analysed. From the data obtained we can report results that show specificities and sensitivities in the 70–80% region when actually predicting the presence of TB in unknown sputum samples. The results are a further step forward in the rapid detection of TB in the clinics in developing countries and show continued promise for future development of an optimised instrument for TB prediction.

Elastic scattering is a cheap and simple-to-use tool that holds the promise of rapid and accurate diagnosis in many applications,including dysplasia arising in Barrett's esophagus. It is being developed as an optical biopsy technique, but preliminary work shows that it may be possible to use this approach as a field detection device. Even as a point measurement technique or optical biopsy, the technique may become an invaluable tool to endoscopists. This article focuses on elastic scattering spectroscopy (also known as diffuse reflectance spectroscopy).

Flow cytometry can be used for the detection and identification of microorganism [1]. However traditional instrumentation is bulky and complicated to operate and align. These factors combine to make flow cytometry less than ideal for the field detection of biological agents.

RAPID and accurate diagnosis is necessary for the effective control of foot-and-mouth disease (FMD). Some laboratorybased methods are rapid, generating a result within a few hours, but the time taken to transport suspect clinical material to the laboratory can be lengthy, and this delay can preclude laboratory confirmation of disease. Notably, the implementation of the control strategy adopted by the UK government in the 2001 FMD epizootic – to slaughter animals on infected premises within 24 hours – meant that in the majority of cases, diagnosis based on clinical signs was not substantiated by laboratory investigation. Retrospective analyses have indicated that the reliance upon clinical diagnosis alone resulted in over-reporting of FMD, since the presence of FMD virus (FMDV) on 23 per cent of farms designated as infected premises was not confirmed by laboratory methods (Ferris and others 2006). These factors have given rise to the idea that the reliability of diagnosis may be improved by using rapid and sensitive tests that can be used in situ or close to a suspect premises, without transferring the samples to a central laboratory. The use of rapid diagnostic assays was recommended in two major reports considering the 2001 FMD outbreak (Anderson 2002, Royal Society 2002). Previous studies (Callahan and others 2002, Hearps and others 2002), have developed rapid reverse transcriptase-PCR (RT-PCR) assays for detecting FMDV; however, limitations in the hardware and some aspects of the protocols used have restricted the adoption of these assays for field detection of FMDV. In light of the general interest in this issue, this short communication describes recent progress that has been made towards the development of a mobile RT-PCR assay for FMDV detection. This study describes the evaluation of a portable real-time

A novel nucleic acid amplification method, loop-mediated isothermal amplification, was developed and recently demonstrated detection of Newcastle disease virus (NDV) in tissue samples. But slaughter of poultry for test samples is often faced with resentment by low-income farmers. This study was undertaken to determine the test properties of reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) in detection of NDV in clinical cases using cloacal and oropharyngeal swabs. Samples included 46 tracheal tissues, 94 cloacal and 107 oro-pharyngeal swabs from on-station and 30 spleens, 74 cloacal and 74 oro-pharyngeal swabs from the field. Analysis was done using specific RT-LAMP targeting the fusion (F) protein. While the method detected NDV from swab samples, no RNA of other poultry disease viruses was amplified, indicating analytical specificity of 100%. RT-LAMP took ≤36 minutes in 83% (n=329) of positive reactions with all samples amplified in

Extract There are many ways in which a milking machine can transmit infection from cow to cow. The immediate transfer of infection by the, teat-cups is obvious and the reduction of the effectiveness of this vector has been shown to reduce the incidence of mastitis (Wilkinson, 1965). The change from bucket to pipeline milkers has been associated with an increase in the incidence of mastitis arid this has been attributed to the vacuum instability of the latter system. Fell and Richards (1970) have studied the relation-ship between machine stability and the level of somatic cells in milk, and Whittlestone and Fell (1969) have suggested that milk line vacuum instability could be associated with flow conditions that could give rise to the movement of potentially infected milk from the pipeline back into the clusters. This potential vector has been overlooked in the past but its presence, would clearly negate the beneficial effects of “back flushing”. A field study was therefore undertaken to estimate ...