Detection Of Microbial Pathogens Research Articles

Detection of microbial pathogens colonizing foot ulcers of diabetic patients in Enugu, Nigeria

Background: Diabetic foot ulcer (DFU) is a major complication of diabetes mellitus (DM) which is associated with high morbidity and mortality. There is high rate of bacteria colonization especially in those with tendencies for poor wound dressing. This is accompanied by high rate of inappropriate antibiotic usage. The aim of this study is to characterize microbial pathogens colonizing foot ulcers of diabetic patients in Enugu, Nigeria, and to determine the antibiotic susceptibility of these isolates.Methodology: This was a descriptive cross-sectional study of consecutively enrolled diabetic patients with foot ulcers in two tertiary healthcare facilities in Enugu, Nigeria, between May 2021 and February 2022. A structured questionnaire was used to obtain socio-demographic and clinical data of the patients. Pus samples and/or tissues were collected from the ulcer lesion of each patient for aerobic and anaerobic microbial cultures and biochemical identification using standard conventional techniques.Results: A total of 310 diabetic patients with foot ulcers were recruited into the study, with 62.3% (193/310) males and 37.7% (117/310) females, and mean age of 56.0±13.9 years. Bacteria and yeast were isolated from samples of 280 (90.3%) patients while samples of 30 (9.7%) patients had no microbial growth. Males had higher frequency of microbial isolates (90.7%, 175/193) than females (89.7%, 105/117), while the age group ≤ 40 years had higher frequency of microbial isolates (100%, 43/43) compared to other age groups, although the differences are not statistically significant (p>0.05). The distribution of the isolates showed that 15.7% (44/280) were monomicrobial while 84.3% (236/280) were polymicrobial. The highest single isolate was Bacteroides fragilis with 5.0% (14/280), followed by Staphylococcus aureus with 3.2% (9/280). Bacteroides fragilis and S. aureus occurred as the highest combined bacteria isolates with 5.7% (16/280). Most of the patients were colonized by combination of bacterial isolates. The susceptibility indicates that most of the anaerobic bacteria were sensitive to metronidazole while S. aureus isolates were resistant to ofloxacin at a rate of 65.0%. Conclusion: The findings in this study showed that there is high bacteria and fungi colonization of foot ulcers of diabetic patients in Enugu, Nigeria. Routine care of wounds especially frequent changes of dressing materials and the use of potent antiseptics, are recommended.
 Contexte: L'ulcère du pied diabétique (UPD) est une complication majeure du diabète sucré (DM) associée à une morbidité et une mortalité élevées. Il existe un taux élevé de colonisation bactérienne, en particulier chez les personnes ayant tendance à mal panser les plaies. Cela s’accompagne d’un taux élevé d’utilisation inappropriée d’antibiotiques. Le but de cette étude est de caractériser les agents pathogènes microbiens colonisant les ulcères du pied des patients diabétiques à Enugu, au Nigeria, et de déterminer la sensibilité aux antibiotiques de ces isolats.
 Méthodologie: Il s'agissait d'une étude transversale descriptive portant sur des patients diabétiques recrutés consécutivement et souffrant d'ulcères du pied dans deux établissements de soins de santé tertiaires à Enugu, au Nigeria, entre mai 2021 et février 2022. Un questionnaire structuré a été utilisé pour obtenir des données sociodémographiques et cliniques du les patients. Des échantillons de pus et/ou des tissus ont été prélevés sur la lésion ulcéreuse de chaque patient pour des cultures microbiennes aérobies et anaérobies et une identification biochimique à l'aide de techniques conventionnelles standard.
 Résultats: Au total, 310 patients diabétiques souffrant d'ulcères du pied ont été recrutés dans l'étude, avec 62,3% (193/310) d'hommes et 37,7% (117/310) de femmes, et un âge moyen de 56,0±13,9 ans. Des bactéries et des levures ont été isolées à partir d'échantillons de 280 (90,3%) patients, tandis que des échantillons de 30 (9,7%) patients ne présentaient aucune croissance microbienne. Les hommes présentaient une fréquence plus élevée d'isolats microbiens (90,7%, 175/193) que les femmes (89,7%, 105/117), tandis que le groupe d'âge ≤ 40 ans présentait une fréquence plus élevée d'isolats microbiens (100.0%, 43/43) par rapport aux autres groupes d’âge, bien que les différences ne soient pas statistiquement significatives (p>0,05). La répartition des isolats a montré que 15,7% (44/280) étaient monomicrobiens tandis que 84,3% (236/280) étaient polymicrobiens. L'isolat le plus élevé était Bacteroides fragilis avec 5,0% (14/280), suivi de Staphylococcus aureus avec 3,2% (9/280). Bacteroides fragilis et S. aureus étaient les isolats bactériens combinés les plus élevés avec 5,7% (16/280). La plupart des patients étaient colonisés par une combinaison d’isolats bactériens. La sensibilité indique que la plupart des bactéries anaérobies étaient sensibles au métronidazole tandis que les isolats de S. aureus étaient résistants à l'ofloxacine à un taux de 65,0%.
 Conclusion: Les résultats de cette étude ont montré qu'il existe une forte colonisation bactérienne et fongique des ulcères du pied des patients diabétiques à Enugu, au Nigeria. Des soins de routine des plaies, des changements particulièrement fréquents des matériaux de pansement et l'utilisation d'antiseptiques puissants sont recommandés.

Development of Molecular-Based Screening Test for Hepatitis B Virus in Human Plasma Samples.

Despite regular administration of hepatitis B virus (HBV) vaccine in several countries, the mortality rate associated with HBV remains significant. The antiviral medications available for the treatment of HBV infection do not suffice for the serious complications related to chronic HBV infection. Additionally, the serological tests fail to detect early viral replication preventing early treatment response. Recently, many studies have demonstrated the significant advantages of loop-mediated isothermal amplification (LAMP) over serological testing and polymerase chain reaction (PCR), for the rapid detection of microbial pathogens. Here we developed a rapid, sensitive, and portable system-integrative LAMP assay for the detection of HBV DNA in plasma samples. The final optimized assay was achieved with an amplification time of less than 45 min at 62°C. The assay showed 100% specificity, 92.20% sensitivity, and a detection limit of 10 copies/µL in 77 HBV-positive plasma samples with known Cq values. Our results showed that the colorimetric LAMP assay is sensitive, efficient, and supremely reliable for rapid detection of HBV, and may be potentially used as a screening test in areas with poor laboratory facilities and limited resource availability.

On-chip bioluminescence biosensor for the detection of microbial surface contamination

Detection of microbial pathogens is important for food safety reasons, and for monitoring sanitation in laboratory environments and health care settings. Traditional detection methods such as culture-based and nucleic acid-based methods are time-consuming, laborious, and require expensive laboratory equipment. Recently, ATP-based bioluminescence methods were developed to assess surface contamination, with commercial products available. In this study, we introduce a biosensor based on a CMOS image sensor for ATP-mediated chemiluminescence detection. The original lens and IR filter were removed from the CMOS sensor revealing a 12 MP periodic microlens/pixel array on an area of 6.5 mm × 3.6 mm. UltraSnap swabs are used to collect samples from solid surfaces including personal electronic devices, and office and laboratory equipment. Samples mixed with chemiluminescence reagents were placed directly on the surface of the image sensor. Close proximity of the sample to the photodiode array leads to high photon collection efficiency. The population of microorganisms can be assessed and quantified by analyzing the intensity of measured chemiluminescence. We report a linear range and limit of detection for measuring ATP in UltraSnap buffer of 10–1000 nM and 225 fmol, respectively. The performance of the CMOS-based device was compared to a commercial luminometer, and a high correlation with a Pearson's correlation coefficient of 0.98589 was obtained. The Bland-Altman plot showed no significant bias between the results of the two methods. Finally, microbial contamination of different surfaces was analyzed with both methods, and the CMOS biosensor exhibited the same trend as the commercial luminometer.

Quantum dots (QDs) attached magnetic beads (MBs) for on-chip efficient capture and detection of bacteria in ready-to-eat (RTE) foods

In this study, we established a versatile and simple magnetic-assisted microfluidic method for fast bacterial detection. Quantum dots (QDs) were loaded onto magnetic beads (MBs) to construct performance enhanced on-chip capture of bacteria. Escherichia coli (E. coli), as a model bacterium was studied. CdSe QDs were deposited onto the surface of Fe3O4 MBs through layer-by-layer self-assembly to enhance the loading of antibodies (Abs). MBs functionalized with anti-E. coli antibody molecules in a micropillar-based microfluidic chip were utilized to capture E. coli, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for characterization of captured bacteria. This method was found capable of specifically isolating E. coli within the range of 1.0 to 1.0 × 109 CFU/mL, having a detection limit (LOD) of 10 CFU/mL. The average similarity score among mass spectra for the bacterial capture obtained in independent experiments is calculated as 0.97 ± 0.01 (n = 3), which shows this work's excellent reproducibility for bacterial capture. Bacterial growth on ready-to-eat (RTE) foods during its time of storage was successfully monitored. The present protocol has promising potential for microbial control and pathogen detection in the food industry.

Label‐free surface‐enhanced Raman spectroscopy coupled with machine learning algorithms in pathogenic microbial identification: Current trends, challenges, and perspectives

AbstractInfectious diseases caused by microbial pathogens remain a primary contributor to global health burdens. Prompt control and effective prevention of these pathogens are critical for public health and medical diagnostics. Conventional microbial detection methods suffer from high complexity, low sensitivity, and poor selectivity. Therefore, developing rapid and reliable methods for microbial pathogen detection has become imperative. Surface‐enhanced Raman Spectroscopy (SERS), as an innovative non‐invasive diagnostic technique, holds significant promise in pathogenic microorganism detection due to its rapid, reliable, and cost‐effective advantages. This review comprehensively outlines the fundamental theories of Raman Spectroscopy (RS) with a focus on label‐free SERS strategy, reporting on the latest advancements of SERS technique in detecting bacteria, viruses, and fungi in clinical settings. Furthermore, we emphasize the application of machine learning algorithms in SERS spectral analysis. Finally, challenges faced by SERS application are probed, and the prospective development is discussed.

Versatility of reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) from diagnosis of early pathological infection to mutation detection in organisms.

Loop-mediated isothermal amplification (LAMP) is a rapid, state-of-the-art DNA amplification technology, used primarily for the quick diagnosis and early identification of microbial infection, caused by pathogens such as virus, bacteria and malaria. A target DNA can be amplified within 30min using the LAMP reaction, taking place at a steady temperature. The LAMP method uses four or six primers to bind eight regions of a target DNA and has a very high specificity. The devices used for conducting LAMP are usually simple since the LAMP method is an isothermal process. When LAMP is coupled with Reverse Transcription (RT), it allows direct detection of RNA in a sample. This greatly enhances the efficiency of diagnosis of RNA viruses in a sample. Recently, the rampant spread of COVID-19 demanded such a rapid, simple, and cost-effective Point of Care Test (PoCT) for the accurate diagnosis of this pandemic. Loop-mediated isothermal amplification(LAMP) assays are not only used for the detection of microbial pathogens, but there are various other applications such as detection of genetic mutations in food and various organisms. In this review, various implementations of RT-LAMP techniques would be discussed.

Nanotechnology: Current trends in detections of microbial pathogens

The circulation of pathogens in developing countries is one of the major causes of infectious disease outbreaks. Currently, there are limitations to already existing methods for microbial pathogen detection. A significant number of pathogens are left undetected via of conventional methods. The detection methods that are innovative, rapid with high sensitivity and specificity are required to target pathogens. This will aid to overcome present drawbacks in disease management. Nanotechnology is a recent advancements leading to the development of nanoparticle-based assay for detection of specific pathogens. Gold nanoparticles are known to have unique and high surface area. This makes them an ideal candidate for pathogen specific detection. The gold nanoparticles have unique physicochemical properties which are more advantageous over existing conventional detection methods. This review focused on the application of nanotechnology in microbial pathogen detection. With an insight on the exploration of nanotechnology to overcome the limitation of existing detection methods.

Recent advances of the biosensor in microbial sensing

In this review, we discussed the design and manufacture of point-of-care test (POST) devices for the detection of microbial pathogens, including bacteria, viruses, fungi, and parasites. Electrochemical methods and current advances in the field were highlighted in terms of integrated electrochemical platforms, which include mainly microfluidic based approaches and integrated smartphone and Internet of things (IoM) and internet of medical things (IoMT) systems. In addition, the availability of commercial biosensors for the detection of microbial pathogens will be reported. At the end, challenges in point-of-care (POC) biosensor fabrication and expected future advances in biosensor technology were discussed. Integrated biosensor-based platforms with IoM/IoMT typically collect data to track the spread of infectious diseases in the community, which would be useful in terms of better preparedness for current and future pandemics and is expected to prevent social and economic losses.In the last decade, the science of biosensors has made tremendous progress in diagnosing diseases. Drug-resistant bacteria are outperforming drug discovery efforts, jeopardizing modern antibiotics and threatening many inevitable medical procedures that are taken for granted. Combating this worldwide threat will require the invention and application of ever-wider diagnostics of infectious diseases.

Rapid Evolution of Glycan Recognition Receptors Reveals an Axis of Host-Microbe Arms Races beyond Canonical Protein-Protein Interfaces.

Detection of microbial pathogens is a primary function of many mammalian immune proteins. This is accomplished through the recognition of diverse microbial-produced macromolecules including proteins, nucleic acids, and carbohydrates. Pathogens subvert host defenses by rapidly changing these structures to avoid detection, placing strong selective pressures on host immune proteins that repeatedly adapt to remain effective. Signatures of rapid evolution have been identified in numerous immunity proteins involved in the detection of pathogenic protein substrates, but whether similar signals can be observed in host proteins engaged in interactions with other types of pathogen-derived molecules has received less attention. This focus on protein-protein interfaces has largely obscured the study of fungi as contributors to host-pathogen conflicts, despite their importance as a formidable class of vertebrate pathogens. Here, we provide evidence that mammalian immune receptors involved in the detection of microbial glycans have been subject to recurrent positive selection. We find that rapidly evolving sites in these genes cluster in key functional domains involved in carbohydrate recognition. Further, we identify convergent patterns of substitution and evidence for balancing selection in one particular gene, MelLec, which plays a critical role in controlling invasive fungal disease. Our results also highlight the power of evolutionary analyses to reveal uncharacterized interfaces of host-pathogen conflict by identifying genes, like CLEC12A, with strong signals of positive selection across mammalian lineages. These results suggest that the realm of interfaces shaped by host-microbe conflicts extends beyond the world of host-viral protein-protein interactions and into the world of microbial glycans and fungi.

Spectroscopic Methods for the Detection of Microbial Pathogens and Diagnostics of Infectious Diseases—An Updated Overview

Microbial pathogens cause a quarter of all deaths worldwide annually due to deadly infectious diseases. Nevertheless, the fast and precise identification of pathogens remains one of the most challenging tasks in the medical sector. Early identification and characterization of microbes through medical diagnosis could pave the way for specific treatment strategies that could dramatically improve infection management, reduce healthcare costs, mitigate increasing antimicrobial resistance, and save numerous lives. To date, numerous traditional and molecular methods have been employed to diagnose illnesses with proven accuracy, reliability, and efficiency. Here, we have reviewed the most reliable tools that are prerequisites for the rapid detection of microbes. In particular, the remarkable roles of surface-enhanced Raman scattering, Fourier-transform infrared, electrochemical impedance, near-infrared, and MALDI-TOF/TOF in the identification and characterization of pathogenic microbes are discussed in detail. The approaches described herein cover broad ranges of biomedical applications, including the diagnosis of clinical infectious diseases, epidemiology, detection of vector-borne diseases, food security, phytosanitary monitoring, biosensing, and food- and waterborne pathogen detection. Considering the current pandemic outbreak, this review briefly emphasizes the importance of rapid detection and upgraded tools for early diagnosis to prevent the loss of lives.

The selection of software and database for metagenomics sequence analysis impacts the outcome of microbial profiling and pathogen detection.

Shotgun metagenomic sequencing analysis is widely used for microbial profiling of biological specimens and pathogen detection. However, very little is known about the technical biases caused by the choice of analysis software and databases on the biological specimen. In this study, we evaluated different direct read shotgun metagenomics taxonomic profiling software to characterize the microbial compositions of simulated mice gut microbiome samples and of biological samples collected from wild rodents across multiple taxonomic levels. Using ten of the most widely used metagenomics software and four different databases, we demonstrated that obtaining an accurate species-level microbial profile using the current direct read metagenomics profiling software is still a challenging task. We also showed that the discrepancies in results when different databases and software were used could lead to significant variations in the distinct microbial taxa classified, in the characterizations of the microbial communities, and in the differentially abundant taxa identified. Differences in database contents and read profiling algorithms are the main contributors for these discrepancies. The inclusion of host genomes and of genomes of the interested taxa in the databases is important for increasing the accuracy of profiling. Our analysis also showed that software included in this study differed in their ability to detect the presence of Leptospira, a major zoonotic pathogen of one health importance, especially at the species level resolution. We concluded that using different databases and software combinations can result in confounding biological conclusions in microbial profiling. Our study warrants that software and database selection must be based on the purpose of the study.

Enhancing detection of Listeria monocytogenes in food products using an enzyme

There is a need to identify the presence of microorganisms, in particular human pathogens, in food processing facilities and products. Adhesion of pathogens to surfaces poses a detection challenge with biofilms greatly hindering detection by precluding the transfer of specific material to downstream sensors. Enzymes that disrupt biofilms can therefore enhance detection of foodborne pathogens through facilitating their release from abiotic and biotic surfaces. In this study, a recombinant enzyme, CAase, was applied to improve detection of biofilm-embedded Listeria monocytogenes on food and food contact surfaces. Microbiological and molecular detection methods demonstrated that biofilms treated with enzyme for longer than 4 h resulted in a significant increase in the number of cells released into the media compared to untreated controls. This work demonstrates the benefits of inclusion of enzymes and biosurfactants within sample processing and detection protocols because of their ability to contribute to a more rapid, accurate, reliable, and repeatable microbial detection assay when biofilm embedded pathogens are present. •Sample preparation for detecting microbial pathogen in foods. • Enzymatic treatment of biofilms to facilitate microbial pathogen detection. • Method to detect microbial pathogens in foods and on food contact surfaces.

Internet-of-medical-things integrated point-of-care biosensing devices for infectious diseases: Toward better preparedness for futuristic pandemics.

Microbial pathogens have threatened the world due to their pathogenicity and ability to spread in communities. The conventional laboratory-based diagnostics of microbes such as bacteria and viruses need bulky expensive experimental instruments and skilled personnel which limits their usage in resource-limited settings. The biosensors-based point-of-care (POC) diagnostics have shown huge potential to detect microbial pathogens in a faster, cost-effective, and user-friendly manner. The use of various transducers such as electrochemical and optical along with microfluidic integrated biosensors further enhances the sensitivity and selectivity of detection. Additionally, microfluidic-based biosensors offer the advantages of multiplexed detection of analyte and the ability to deal with nanoliters volume of fluid in an integrated portable platform. In the present review, we discussed the design and fabrication of POCT devices for the detection of microbial pathogens which include bacteria, viruses, fungi, and parasites. The electrochemical techniques and current advances in this field in terms of integrated electrochemical platforms that include mainly microfluidic- based approaches and smartphone and Internet-of-things (IoT) and Internet-of-Medical-Things (IoMT) integrated systems have been highlighted. Further, the availability of commercial biosensors for the detection of microbial pathogens will be briefed. In the end, the challenges while fabrication of POC biosensors and expected future advances in the field of biosensing have been discussed. The integrated biosensor-based platforms with the IoT/IoMT usually collect the data to track the community spread of infectious diseases which would be beneficial in terms of better preparedness for current and futuristic pandemics and is expected to prevent social and economic losses.

A systematic assessment of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) application for rapid identification of pathogenic microbes that affect food crops: delivered and future deliverables.

MALDI-TOF MS has decades of experience in the detection and identification of microbial pathogens. This has now become a valuable analytical tool when it comes to the identification and detection of clinical microbial pathogens. This review gives a brief synopsis of what has been achieved using MALDI-TOF MS in clinical microbiology. The major focus, however, is on summarizing and highlighting the effectiveness of MALDI-TOF MS as a novel tool for rapid identification of food crop microbial pathogens. The methods used and the sample preparation methodologies reported thus far have been highlighted and the challenges and gaps and recommendations for fine tuning the technique have been put forth. In an era where anything close to the health and welfare of humanity has been considered as the top priority, this review pitches on one such relevant research topics.

LAMP-Based Point-of-Care Biosensors for Rapid Pathogen Detection

Seeking optimized infectious pathogen detection tools is of primary importance to lessen the spread of infections, allowing prompt medical attention for the infected. Among nucleic-acid-based sensing techniques, loop-mediated isothermal amplification is a promising method, as it provides rapid, sensitive, and specific detection of microbial and viral pathogens and has enormous potential to transform current point-of-care molecular diagnostics. In this review, the advances in LAMP-based point-of-care diagnostics assays developed during the past few years for rapid and sensitive detection of infectious pathogens are outlined. The numerous detection methods of LAMP-based biosensors are discussed in an end-point and real-time manner with ideal examples. We also summarize the trends in LAMP-on-a-chip modalities, such as classical microfluidic, paper-based, and digital LAMP, with their merits and limitations. Finally, we provide our opinion on the future improvement of on-chip LAMP methods. This review serves as an overview of recent breakthroughs in the LAMP approach and their potential for use in the diagnosis of existing and emerging diseases.

Metagenomic next-generation sequencing for the diagnosis of oral and maxillofacial space infections

Background/purposeMetagenomic next-generation sequencing (mNGS) has been widely used for the detection of pathogens causing infectious diseases. This study aimed to evaluate the potential ability of mNGS to detect pathogens causing oral and maxillofacial space infection (OMSI) and compare the results with those of the traditional diagnostic microbial culture method. Materials and methodsWe retrospectively reviewed the data of 218 patients diagnosed with OMSI who underwent microbial culture and mNGS at the Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, from July 2020 to January 2022. ResultsThe positivity rate of mNGS (216 cases) was significantly higher than that of microbial culture (123 cases). The most frequently detected bacteria were different between these two detection methods. Streptococcus constellatus (16.05%, 35), Streptococcus anginosus (15.69%, 34) and Klebsiella pneumoniae (6.88%, 15) were the most commonly isolated bacteria by culture. However, Peptostreptococcus stomatis (61.47%, 134), Parvimonas micra (68.35%, 149) and Streptococcus constellatus (57.34%, 125) were the most commonly detected bacteria by mNGS. mNGS also has advantages in diagnosing viral infections. The optimal numbers of diagnostic reads were 1162 and 588 for the diagnosis of Streptococcus anginosus and Streptococcus constellatus infections, respectively. Read numbers were significantly correlated with C-reactive protein (CRP), procalcitonin (PCT), and blood glucose levels and neutrophil percentage (NEUT%). ConclusionFor pathogens causing OMSI, mNGS had a higher rate of microbial pathogen detection and remarkable advantages in identifying coinfections involving viruses and fungi. The read numbers for mNGS are important for diagnostic accuracy and disease severity evaluation.

Versatility of a Salmonella Loop-Mediated Isothermal Amplification Assay Using Multiple Platforms and Master Mixes in Animal Food Matrices.

Improvement in Salmonella detection methods greatly enhances the efficiency of various food testing programs. A Salmonella loop-mediated isothermal amplification (LAMP) assay has been validated in animal food through multi-laboratory validation. The study aimed to demonstrate the versatility of this molecular assay while expanding it to multiple platforms and various reagent choices for use in animal food testing. Following the U.S. Food and Drug Administration (FDA)'s Guidelines for the Validation of Analytical Methods for the Detection of Microbial Pathogens in Foods and Feeds, we examined the inclusivity, exclusivity, and LOD of the assay using two platforms (7500 Fast and Genie II) and three LAMP master mixes (GspSSD, GspSSD2.0, and WarmStart) in seven animal food matrixes (dry cat food, dry dog food, cattle feed, dairy feed, horse feed, poultry feed, and swine feed). The FDA's Bacteriological Analytical Manual (BAM) Salmonella culture method was the reference method. Inclusivity and exclusivity data were consistent among all six platform and master mix combinations with a few exceptions. Comparable LODs were observed down to the single-cell level (WarmStart was 10-fold less sensitive). Performance was similar to the BAM method for detecting fractional positive results in seven animal food matrixes. Nonetheless, LAMP time to positive results and annealing/melting temperature differed among master mixes and platforms. The Salmonella LAMP assay was successfully validated in two platforms and three master mixes, making it a flexible tool for use by the FDA's field laboratories in regulatory testing of animal food and for adoption by other food testing programs. We demonstrated the LAMP assay's versatility on two platforms and three master mixes for the rapid and reliable screening of Salmonella in seven animal food matrixes. GspSSD2.0 was the fastest master mix (time to positive results as early as 3.5 min) while Genie II had several attractive features from a user perspective.

Microfluidic System for Microbial Pathogen Detection

Conventional microbiological methods for pathogen detection are time consuming methods and require tedious protocol, expensive instruments, and expert personnel, which delays diagnosis time and treatment. To overcome these limitations, a miniature microfluidic system has been introduced for rapid, sensitive, specific, and easy to handle system for microbial pathogen detection. This miniaturized system uses the dynamics of fluid in microchannels for the collection and detection of pathogen. Microfluidics coupled with a different analytical detection system allow the identification and quantification of whole cells, metabolites, and genetic materials, for accurate diagnosis with all details about microbial pathogen. The high throughput efficiency of a microfluidic system is suitable for point-of-care testing of a broad range of pathogens in even resource-limited facilities/areas. Herein, fundamentals of designing and advances in microfluidic chip integrated with analytical system for pathogen detection are discussed. This review will establish microfluidic as a rapid and accurate point-of-care detection system for microbial pathogens.

Enteric Pathogens Risk Factors Associated with Household Drinking Water: A Case Study in Ugu District Kwa-Zulu Natal Province, South Africa.

The occurrence of diarrheal infections depends on the level of water and sanitation services available to households of immunocompromised individuals and children of less than five years old. It is therefore of paramount importance for immunocompromised individuals to be supplied with safe drinking water for better health outcomes. The current study aimed at ascertaining the probability of infection that Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Vibrio cholerae, and rotavirus might cause to rural dwellers as compared to urban dwellers. Both culture-based and molecular-based methods were used to confirm the presence of target microorganisms in drinking water samples, while Beta-Poisson and exponential models were used to determine the health risk assessment. Results revealed the presence of all targeted organisms in drinking water. The estimated health risks for single ingestion of water for the test pathogens were as follows: 1.6 × 10−7 for S. typhimurium, 1.79 × 10−4 for S. dysenteriae, 1.03 × 10−3 for V. cholerae, 2.2 × 10−4 for E. coli O157:H7, and 3.73 × 10−2 for rotavirus. The general quantitative risk assessment undertaken in this study suggests that constant monitoring of household container-stored water supplies is vital as it would assist in early detection of microbial pathogens. Moreover, it will also allow the prompt action to be taken for the protection of public health, particularly for immunocompromised individuals and children who are prone to higher risk of infections.

Case report: Vascular graft infection due to Aspergillus species presenting with recurrent vascular occlusion

BackgroundAn aortic graft implantation is an effective therapeutic method for various aortic diseases. However, it is known that sometimes these implanted grafts can be the foci of infections. Here we report a rare case of graft infection that presented multiple embolisms of aortic branches and peripheral organs.Case presentationA 63-year-old Japanese woman with a history of aortic graft implantation presented with occlusions of large arteries in different loci and time points, with elevation of non-specific inflammatory markers. Thoracic contrast-computed tomography (CT) captured vegetation in the descending aortic graft and the [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) showed accumulation of FDG in the same site, suggesting a graft infection. Despite all these suspicious findings, repeated blood culture examinations never detected any microorganisms. A diagnosis of Aspergillus graft infection was made based on an elevated serum β-D glucan (βDG) and a positive Aspergillus galactomannan (GM) antigen test. The patient subsequently had surgery with replacement of the descending aortic graft and anti-fungal drugs were instituted with significant improvement noted.ConclusionIn the present case, the patient’s specific feature in the anatomical vascular construction, past operation, and basal fundamental diseases collaboratively contributed to the pathogenesis of the present infection. It is important to recognize the risk of graft infection and conduct imaging studies when indicative symptoms emerge. The negativity in blood culture studies often makes detection of pathogenic microbes extremely difficult. This case suggests that non-cultural tests such as bDG and GM can be useful for diagnosis and starting appropriate anti-fungal drugs in the early stages.