Identification Of Pathogenic Bacteria Research Articles

Specific discrimination of pathogenic bacteria causing septic arthritis using Raman spectroscopy: In-vitro study

In this study we performed preliminary experiments using Raman spectroscopy as an evolving technology in biofluid and microbial characterization, to explore its potential for rapid diagnosis of pathogenic bacteria in an in-vitro synovial fluid infection model. Normal human synovial fluids samples were collected from patients undergoing knee surgery and the three most common pathogenic bacteria introduced in-vitro into the samples. The bacterial growth was systematically monitored using a Raman spectroscopy. Multivariate regression analysis of acquired spectra showed bacterial characteristic Raman bands related to bacterial cell membranes and DNA structures to increase continuously as the incubation period was increased. Spectra signature recorded from cultured synovial fluid samples showed a significant loss in synovial quality and protein morphology over time compared to control samples. In this study, Raman spectroscopy shows promise for rapid pathogenic bacteria identification in synovial fluid. Marker peaks distinguished inoculated bacteria, while chemical changes reveal infection dynamics.

Rapid Detection of Broad-Spectrum Pathogenic Bacteria Based on Highly Sensitive Proton Response of the Nucleic Acid Amplification SPQC Platform.

Pathogenic bacteria significantly contribute to elevated morbidity and mortality rates, highlighting the urgent need for early and precise detection. Currently, there is a paucity of effective broad-spectrum methods for detecting pathogenic bacteria. We have developed an innovative proton-responsive series piezoelectric quartz crystal (PR-SPQC) platform for the broad-spectrum identification of pathogenic bacteria. This was achieved by retrieving and aligning sequences from the NCBI GenBank database to identify and validate 16S rRNA oligonucleotide sequences that are signatures of pathogenic bacteria but absent in humans or fungi. The hyperbranched rolling circle amplification, activated exclusively by the screened target, exponentially generates protons that are detected by SPQC through a 2D polyaniline (PANI) film. The PR-SPQC platform demonstrates broad-spectrum capabilities in detecting pathogenic bacteria, with a detection limit of 2 CFU/mL within 90 min. Clinical testing of blood samples yielded satisfactory results. With its advantages in miniaturization, cost efficiency, and suitability for point-of-care testing, PR-SPQC has the potential to be extensively used for the rapid identification of diverse pathogenic bacteria within clinical practice and public health sectors.

RamanCluster: A deep clustering-based framework for unsupervised Raman spectral identification of pathogenic bacteria

Raman spectroscopy serves as a powerful and reliable tool for the characterization of pathogenic bacteria. The integration of Raman spectroscopy with artificial intelligence techniques to rapidly identify pathogenic bacteria has become paramount for expediting disease diagnosis. However, the development of prevailing supervised artificial intelligence algorithms is still constrained by costly and limited well-annotated Raman spectroscopy datasets. Furthermore, tackling various high-dimensional and intricate Raman spectra of pathogenic bacteria in the absence of annotations remains a formidable challenge. In this paper, we propose a concise and efficient deep clustering-based framework (RamanCluster) to achieve accurate and robust unsupervised Raman spectral identification of pathogenic bacteria without the need for any annotated data. RamanCluster is composed of a novel representation learning module and a machine learning-based clustering module, systematically enabling the extraction of robust discriminative representations and unsupervised Raman spectral identification of pathogenic bacteria. The extensive experimental results show that RamanCluster has achieved high accuracy on both Bacteria-4 and Bacteria-6, with ACC values of 77 % and 74.1 %, NMI values of 75 % and 73 %, as well as AMI values of 74.6 % and 72.6 %, respectively. Furthermore, compared with other state-of-the-art methods, RamanCluster exhibits the superior accuracy on handling various complicated pathogenic bacterial Raman spectroscopy datasets, including situations with strong noise and a wide variety of pathogenic bacterial species. Additionally, RamanCluster also demonstrates commendable robustness in these challenging scenarios. In short, RamanCluster has a promising prospect in accelerating the development of low-cost and widely applicable disease diagnosis in clinical medicine.

Exonuclease-III Assisted the Target Recycling Coupling with Hybridization Chain Reaction for Sensitive mecAGene Analysis by Using PGM.

In the field of neonatal infections nursing, methicillin-resistant Staphylococcus aureus (MRSA) is a major bacterial pathogen. Here, we present a portable biosensor for MRSA detection that is both highly sensitive and portable, owing to its implementation on the personal glucose meter (PGM) platform. The H probe was fixed on the magnetic bead for mecA gene analysis. A blunt 3' terminus appeared in the MBs-H probe when the mecA gene was present. Exonuclease-III (Exo-III) recognized the blunt terminus and cleaved it, freeing the mecA gene and so facilitating target recycling. In the meantime, the remaining H probe-initiated hybridization chain reaction (HCR) led to the desired signal amplification. Portable quantitative detection of mecA gene is possible because PGM can read the quantity of invertase tagged on HCR product. After optimizing several experimental parameters, such as the concentration of Exo-III and incubation time, the constructed sensor is extremely sensitive, with a detection limit of 2 CFU/mL. The results from this sensitive PGM-based sensor are in agreement with those obtained from plate counting methods, suggesting that it can be used to accurately assess the MRSA content in artificial clinical samples. In addition, the PGM sensor can significantly cut down on time spent compared to plate counting techniques. The manufactured sensor provides a promising option for accurate identification of pathogenic bacteria.

Isolation and Identification of Pathogenic Bacteria from Hospital Door Handles/knobs

Background and objectives. Contracting infectious diseases from microbial contaminated door handles is a potential threat to health and safety. Therefore, we performed microbiological screening of door handles at the door handles of Zawia Education Hospital, Zawia, Libya, to estimate the presence of potentially pathogenic organisms. Methodology. A total of 125 samples were collected aseptically by using a moistened sterile bacteriologic swab on different days by scrubbing the selected handles and immersing them in the sterile broth to be transported to the microbiology laboratory, within no more than 30 minutes after collection. All the bacterial isolates were characterized and identified by standard diagnostic microbiological procedures and criteria, according to the Clinical and Laboratory Standards Institute. Data were presented as counts and percentages using Excel spread data sheath. Results: There was a total of 147 isolates obtained from the 12 sampled departments. The frequency of isolation of these organisms from these samples was as follows: coagulase-negative staphylococcus (16.80%) in 21 samples, Staphylococcus aureus (10.40%) in 13 samples, Diphtheroid (76.00%) in 95 samples, non-lactose fermenting gram negative bacilli (12.80%) in 16 samples, streptococcus pyogenes (0.80%) in one sample, and Klebsiella pneumoniae (0.80%) in one sample. Conclusion. Staphylococcus aureus, coagulase negative staphylococcus, streptococcus pyogenes, klebsiella pneumonae, Diphtheroid, and non-lactose fermenting gram-negative bacilli were the main bacteria isolated in this research study. The results of the present study demonstrated that contact surfaces such as door handles are often colonized by several bacteria and serve as a potential source of infections.

Line image sensor-based colony fingerprinting system for rapid pathogenic bacteria identification

The rapid identification of pathogenic bacteria is crucial across various industries, including food or beverage manufacturing. Bacterial microcolony image-based classification has emerged as a promising approach to expedite identification, automate inspections, and reduce costs. However, conventional imaging methods have significant practical limitations, namely low throughput caused by the limited imaging range and slow imaging speed. To address these challenges, we developed an imaging system based on a line image sensor for rapid and wide-field imaging compared to existing colony imaging methods. This system can image a standard Petri dish (92 mm in diameter) completely within 22 s, successfully acquiring bacterial microcolony images. This process yielded a set of discrimination parameters termed as colony fingerprints, which were employed for machine learning. We demonstrated the performance of our system by identifying Staphylococcus aureus in food products using a machine learning model trained on a colony fingerprint dataset of 15 species from 9 genera, including foodborne pathogens. While conventional mass spectrometry-based methods require 24 h of incubation, our colony fingerprinting approach achieved 96% accuracy in just 10 h of incubation. Line image sensor offer high imaging speeds and scalability, allowing for swift and straightforward microbiological testing, eliminating the need for specialized expertise and overcoming the limitations of conventional methods. This innovation marks a transformative shift in industrial applications.

Cas-based bacterial detection: recent advances and perspectives.

Persistent bacterial infections pose a formidable threat to global health, contributing to widespread challenges in areas such as food safety, medical hygiene, and animal husbandry. Addressing this peril demands the urgent implementation of swift and highly sensitive detection methodologies suitable for point-of-care testing and large-scale screening. These methodologies play a pivotal role in the identification of pathogenic bacteria, discerning drug-resistant strains, and managing and treating diseases. Fortunately, new technology, the CRISPR/Cas system, has emerged. The clustered regularly interspaced short joint repeats (CRISPR) system, which is part of bacterial adaptive immunity, has already played a huge role in the field of gene editing. It has been employed as a diagnostic tool for virus detection, featuring high sensitivity, specificity, and single-nucleotide resolution. When applied to bacterial detection, it also surpasses expectations. In this review, we summarise recent advances in the detection of bacteria such as Mycobacterium tuberculosis (MTB), methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (E. coli), Salmonella and Acinetobacter baumannii (A. baumannii) using the CRISPR/Cas system. We emphasize the significance and benefits of this methodology, showcasing the capability of diverse effector proteins to swiftly and precisely recognize bacterial pathogens. Furthermore, the CRISPR/Cas system exhibits promise in the identification of antibiotic-resistant strains. Nevertheless, this technology is not without challenges that need to be resolved. For example, CRISPR/Cas systems must overcome natural off-target effects and require high-quality nucleic acid samples to improve sensitivity and specificity. In addition, limited applicability due to the protospacer adjacent motif (PAM) needs to be addressed to increase its versatility. Despite the challenges, we are optimistic about the future of bacterial detection using CRISPR/Cas. We have already highlighted its potential in medical microbiology. As research progresses, this technology will revolutionize the detection of bacterial infections.

Identification of pathogenic bacteria (Vibrio sp) in the waters of the industrial area of north aceh regency and lhokseumawe city

North Aceh Regency and Lhokseumawe City’s waters are mangrove ecosystems, estuaries, fisheries management activities, and industrialization activities. Activities in the industrial areas of North Aceh Regency and Lhokseumawe City have the ability to contaminate waters and affect the chemical and physical composition of the water, which has a direct impact on the abundance of harmful bacteria (Vibrio sp). The study looked at the distribution of harmful bacteria (Vibrio sp) in water near industrial areas in North Aceh Regency and Lhokseumawe City. The purpose of this study is to investigate the abundance of pathogenic bacteria (Vibrio sp.) in the waterways of North Aceh Regency and Lhokseumawe City's industrial areas. This study will also look into the relationship between water quality factors and the abundance of harmful bacteria. The study was carried out in July and August 2023 at four stations placed in marine waters near the industrial area. The research methods used in this research are survey methods and laboratory analysis. Purposive sampling and the ANOVA test were the analysis and sampling techniques employed in this study. The findings demonstrated that there was no discernible variation in Vibrio parahaemolyticus between stations 1, 2, 3, and 4. Station 2 saw a strong Vibrio cholerae effect (p > 0.05), resulting in 87.20 74.36b CFU/ml. Vibrio total from the four research stations that significantly affected station 2 (p > 0.05) were 280.00 167.26b CFU/ml.

Qualitative and quantitative rapid detection of VOCs differentially released by VAP-associated bacteria using PTR-MS and FGC-PTR-MS.

Ventilator-associated pneumonia (VAP) is a prevalent disease caused by microbial infection, resulting in significant morbidity and mortality within the intensive care unit (ICU). The rapid and accurate identification of pathogenic bacteria causing VAP can assist clinicians in formulating timely treatment plans. In this study, we attempted to differentiate bacterial species in VAP by utilizing the volatile organic compounds (VOCs) released by pathogens. We cultured 6 common bacteria in VAP in vitro, including Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Staphylococcus aureus, which covered most cases of VAP infection in clinic. After the VOCs released by bacteria were collected in sampling bags, they were quantitatively detected by a proton transfer reaction-mass spectrometry (PTR-MS), and the characteristic ions were qualitatively analyzed through a fast gas chromatography-proton transfer reaction-mass spectrometry (FGC-PTR-MS). After conducting principal component analysis (PCA) and analysis of similarities (ANOSIM), we discovered that the VOCs released by 6 bacteria exhibited differentiation following 3 h of quantitative cultivation in vitro. Additionally, we further investigated the variations in the types and concentrations of bacterial VOCs. The results showed that by utilizing the differences in types of VOCs, 6 bacteria could be classified into 5 sets, except for A. baumannii and E. cloacae which were indistinguishable. Furthermore, we observed significant variations in the concentration ratio of acetaldehyde and methyl mercaptan released by A. baumannii and E. cloacae. In conclusion, the VOCs released by bacteria could effectively differentiate the 6 pathogens commonly associated with VAP, which was expected to assist doctors in formulating treatment plans in time and improve the survival rate of patients.

Pathogenic microbiota in the oral and nasal cavity of healthy individuals as a potential source of infections

Oral microbiota is personalized and varied among human habitats. Detection and identification of pathogenic bacteria and fungi are considered as a strategy for the prevention and control of infectious diseases. To date, no studies have investigated the prevalence of bacterial pathogens and fungi in healthy individuals in Vietnam, particularly the ethnic minorities.This study aimed to evaluate the presence of aerobic bacteria and fungi in the oral and nasal cavities of Jrai healthy individuals in the Central Highland. Oral and nasal swab samples of 140 healthy Vietnamese were collected. Microbiological procedures were performed using standard techniques. A total of 220 bacterial isolates were identified. Of which, 10% (22/220) were potentially pathogenic species including Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Neisseria meningitidis, and Staphylococcus aureus. The most predominant bacteria family was Moraxellaceae (40%, 88/220), followed by Streptococcaceae (36.82%, 81/220). Fungi were not detected in all samples. The oral and nasal cavity of healthy individuals harbors high frequencies of bacterial pathogens, suggesting its potential role as a source for these species. These pathogenic bacteria constitute the threat of their spread and the development of general infections. Infectious microbiota from the oral and nasal cavity should be examined as a preventive screening to control infectious diseases.

Rapid detection of viable Acinetobacter baumannii and antibiotic susceptibility testing based on a phage amplification-Taqman qPCR assay

BackgroundTimely and accurate identification of pathogenic bacteria and antibiotic susceptibility could decrease misuse and overuse of antibiotics. In this study, we developed a phage amplification-Taqman qPCR assay for simultaneous viable Acinetobacter baumannii (A. baumannii) detection and determination of broad-spectrum antimicrobial susceptibility based on quantification of phage DNA replication in one single tube. ResultsThe two-phage cocktail used in the current phage amplification-Taqman qPCR assay consists of phage p53 and phage pB3074. Once a lytic phage infects its host, phages could specifically recognize the viable cells and replicate themselves within the cells to produce hundreds of progeny phages. With dual phage cocktail concentration (5.00 × 103 PFU/mL to 5.00 × 104PFU/mL) used, down to 50 CFU /mL of viable A. baumannii could be detected within 3 h from bronchoalveolar lavage fluid spiked with A. baumannii in an incubation volume of 2 mL. We further illustrated that antibiotic susceptibility testing results could be obtained within 2 h based on current phage amplification-Taqman qPCR assay to measure the phenotypic response of A. baumannii from spiked bronchoalveolar lavage fluid after only 30 min of antibiotic exposure. Testing of 12 bronchoalveolar lavage fluid samples spiked by different strains showed that the phage amplification-Taqman qPCR assay had 100 % (95 %CI: 74.12 to 100) identification agreement with the initial spiked concentrations of the bacteria. Subsequent antibiotic susceptibility testing results of 9 bronchoalveolar lavage fluid samples spiked by different strains also had shown that the phage amplification-Taqman qPCR assay had good agreements with the standard broth microdilution method, with an overall agreement of 100 % (95 % CI, 70.09 to 100) for ceftazidime and aztreonam. Significance and NoveltyDue to the high rapidity, high sensitivity, good specificity, low cost, and the ability to distinguish between live and dead bacteria, the phage amplification-Taqman qPCR assay provides an effective and promising strategy for the simultaneous detection of viable bacteria and determination of broad-spectrum antimicrobial susceptibility.

Microbial Quality Evaluation of Seafood Samples from the Vishakhapatnam Coast, Andhra Pradesh, India

Consumption of seafood has increased, resulting in the production and productivity of aquaculture in the past few years. Since, seafood is crucial in human nutrition, providing essential nutrients and proteins. However, their perishable nature and vulnerability to microbial contamination make them prone to spoilage and foodborne illnesses. Therefore, the microbiological analysis of fish samples is paramount to ensure their quality and safety for consumption. In this study, microbiology of fish samples, encompassing various aspects such as microbial load assessment, and pathogen detection. Isolation and identification of pathogenic bacteria viz., Total plate count, Escherichia coli, Total coliforms, Vibrio spp, Staphylococcus aureus, and Salmonella spp. These pathogens pose severe health risks to consumers and highlight the necessity of effective monitoring and control measures throughout the seafood supply chain. Proper handling, storage, and processing practices minimise microbial contamination and preserve fish quality. Implementing Hazard Analysis Critical Control Point (HACCP) plans and Good Manufacturing Practices (GMP) helps ensure the safety of fish products and prevent outbreaks of foodborne illnesses.

Isolation and identification of pathogenic bacteria of the genus Escherichia and Salmonella in the water environment tested positive for antibiotic residues in the city of Ndjamena, Cha

Objective: The water environment is facing increasing contamination by antibiotic residues, favoring the development of pathogenic bacteria, in particular Escherichia and Salmonella. This study aims to determine the presence of pathogenic bacteria of the genus Escherichia and Salmonella in the water environment containing antibiotic residues in the city of Ndjamena, Chad. Methodology and results: Information gathered from questionnaires and the results of preliminary positive tests (premiTest) were used to identify the sample. A total of 27 wastewater samples from retention basins, hospital drainage channels, abattoir water and the Chari and Logone rivers were tested positive for antibiotic residues and retained for isolation of Escherichia and Salmonella bacteria. Cultures on specific media (EMB for Escherichiaand SS for Salmonella) were carried out in accordance with reference methods. A total of 36 isolates were obtained, including 15 of the Escherichia genus with a prevalence of 55.6% and 20 of the Salmonella genus with a prevalence of 74%. Analyzing the data by commune, a 100% prevalence of Salmonella was observed in the 2nd, 3rd, 6th and 10th arrondissements, and 80% and 57.1% respectively in the 8th and 7th arrondissements. Escherichia isolates were 100% prevalent in the 8th and 10th arrondissements, and 75% and 66.6% respectively in the 1st and 10th arrondissements. At neighborhood level, 100% Salmonella prevalence was observed in Ardepdjoumal, Diguel, Diguel Est, Gardolet, Clemat, Ndjari and Walia, while 100% E. coli prevalence was found in Dembé, Diguel, Diguel Est, Clemat, Ndjari, Walia, Gueli and Zafaye. These prevalences varied significantly at the 5% level (p-value = 0.004224 for Salmonella and p-value = 0.01921 for Escherichia) between the different districts and neighborhoods of the city of Ndjamena. Conclusion and application of results: This study revealed variability in the presence of Salmonella and E. coli in water samples from the various districts and neighborhoods of N’Djamena, with prevalences ranging from 0 to 100%. These high prevalences are explained by poor waste management in communes, health and veterinary establishments, highlighting for the first time the level of contamination of the water environment by these pathogenic bacteria. It is essential that the Ministries of Public Health and Livestock exert pressure to prohibât the discharge of drug residues into wastewater, in order to prevent drug résistance mechanisms in Chad.

Improving the identification and diagnostic efficiency of Metagenomic Next-Generation Sequencing for mycobacterial granuloma on postoperative formalin-fixed paraffin-embedded specimens

ObjectiveMetagenomic Next-Generation Sequencing (mNGS) has been validated to have an important role in the diagnosis of mycobacterium infection. The study aimed to further explore the mycobacteria identification ability of mNGS on formalin-fixed paraffin-embedded（FFPE）tissues from postoperative specimens. MethodsPatients who underwent surgical biopsy or resection for clarifying the diagnosis and whose initial postoperative pathology indicated granulomatous lesions were included. Fresh tissues were sent for mycobacterium culture and Xpert MTB/RIF (Xpert) to establish the diagnosis. FFPE specimens were sent for mNGS and molecular pathology，the diagnostic values were compared between the two methods. ResultsA total of 65 cases with definite diagnoses were finally included in the study. 31 cases were confirmed as mycobacterium granuloma using the fresh specimen etiology as diagnostic criteria. The overall sensitivity and specificity of mNGS on FFPE specimens in the diagnosis of mycobacterium granuloma were 100% and 88.24%, respectively. In 19 cases diagnosed as tuberculous granulomas, the sensitivity (100% vs47.37%) and negative predictive value (NPV, 100%vs 82.14%) of mNGS were both significantly higher than that of molecular pathology on the FFPE section（both p 0.00）while the positive predictive value (PPV) and specificity were not significantly different. In 12 cases diagnosed as Non-tuberculous mycobacterium (NTM）granuloma, the sensitivity of mNGS was also significantly higher than that of molecular pathology on FFPE section (100% vs 66.67%, p 0.00) while the specificity, PPV and NPV were all not significantly different. ConclusionsThe mNGS could be used for one-time detection of pathogens on FFPE sections with high sensitivity. It could be recommended as a supplementary method for the identification of pathogenic bacteria in the diagnosis of postoperative granuloma lesions.

FPBA-modified magnetic nanoparticles combined with Au@AgNPs for label-free SERS detection of foodborne pathogens in milk

We report a low-cost and highly sensitive label-free SERS biosensor for pathogen detection. Herein, this study prepared 4-formylphenylboric acid (FPBA) functionalized magnetic nanoparticles to adsorb pathogenic bacteria through boric acid affinity principle, and used aptamer modified Au@AgNPs as SERS substrate to specifically combine with pathogenic bacteria to form a sandwich structure. The pathogenic bacteria were detected by portable Raman spectrometer for SERS detection, and the fingerprint signals of pathogenic bacteria were analyzed by principal component analysis (PCA) to achieve the purpose of classification and identification of pathogenic bacteria. Under the optimized conditions, the SERS detection of Staphylococcus aureus (S. aureus) was 102 ∼ 106 CFU/mL (R2 = 0.9925), and the limit of detection (LOD) was 34 CFU/mL. The linear range of Escherichia coli (E. coli) showed a good linear relationship in the range of 102 ∼ 106 CFU/mL (R2 = 0.9993), and the LOD was 18 CFU/mL. The whole detection process was used the portable Raman spectrometer, which makes it suitable for the application of point-of-care testing (POCT).

Identification of pathogenic bacteria using the spectra of native DNA molecules

The purpose of detecting low-frequency (relative to infrared and ultraviolet) resonance absorption of an electromagnetic field in the centimeter wavelength range using DNA molecules at a frequency corresponding to the natural frequency of torsional vibrations of the native DNA helix is to find a relationship between the length of DNA (its spectrum) and the type of a bacterium. Instead of DNA solution, cultures of different bacteria that contained DNA were used and the resonance frequencies of torsional vibrations of the helices in DNA molecules were calculated for them. The cultures were placed in test tubes or in a cuvette and were subjected to microwave irradiation. Theoretical analysis was carried out with respect to the DNA reaction to external centimeter radiation and the resonant DNA frequencies of three types of bacteria such as E. coli M17, M. avium and Mycobacterium tuberculosis were determined. Peak absorption of the ultrahigh-frequency electromagnetic field by bacterial cultures was detected at frequencies close to the calculated natural frequencies of torsional vibrations of DNA helices of the said types of bacteria: 10.271 GHz, 10.317 GHz and 10.356 GHz, respectively.

Identification of Pathogenic Bacteria by Spectra of Native DNA Molecules

Identification of Pathogenic Bacteria by Spectra of Native DNA Molecules

Poly(amino acids) towards sensing pathogenic bacteria: A review

On the planet Earth, the living of numerous species has strongly depended on microorganisms, one of which is bacteria. Among various bacteria, the role of pathogenic bacteria in terms of prevalent diseases, environmental disasters, and even animal life are undeniable. Indeed, in the modern era, diagnosis of the spread of these bacteria in different settings including the human body, food matrix, and environment can able us to control them. Despite the advancement of sensing platforms, there is a huge shortage in the development of sensitive and selective sensing approaches. Hence, fabrication efficient sensing-assay can play an important role. Amino acids (AAs) are part of biocompatible materials that have attracted attention as a promising class in various biosensors as sensing probes. This review focuses on the application of poly(AAs) such as cysteine and poly (Cysteine), lysine and poly (Lysine), glutamic acid and poly (Glutamic acid), glycine and poly (Glycine) and other types of poly(AAs) in terms of pathogenic bacteria detection. In addition, the role of different nanomaterials along with biological factors in increasing the sensitivity and selectivity of these types of assays will be reviewed. To elaborate, the identification of pathogenic bacteria will be investigated using different diagnostic platforms such as electrochemiluminescence (ECL), optical, electrochemical (EC), and photoelectrochemical (PEC) techniques, which will pay special attention to the role of AA and poly AA. Finally, the existing technological and research gaps will be examined and criticized in order to solve them in the future. It should be noted the prepared study is the first comprehensive review of bacterial assay detection by using poly(AAs) in the construction of biosensors.

Simple and rapid co-freezing construction of SERS signal probes for the sensitive detection of pathogens

In this study, we proposed a rapid and sensitive surface-enhanced Raman scattering (SERS)-based biosensor for pathogen detection. The biosensor utilized wheat germ agglutinin (WGA)-modified raspberry-like Fe3O4@Au magnetic nanoparticles (RAuMNPs) as capture elements to enrich the target pathogen and used co-freezing aptamer/5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB)/gold nanoparticles (AuNps) tags as the signal source. Compared to conventional AuNps tags, aptamer/DTNB tags manufactured by co-freezing were easy to prepare, highly stable and had a high affinity for the target bacteria. WGA-coated RAuMNPs captured Escherichia coli (E. coli) O157:H7 from real samples, such as human urine, serum, and skimmed milk, within 20 min under optimized conditions. The combined use of the co-freezing SERS tags and RAuMNPs-WGA significantly improved the analytical sensitivity of the proposed SERS platform, enabling detection as low as 8 cells/mL of target bacteria with a linear range of 10 to 106 cells/mL. Furthermore, the platform successfully detected DNA from difficult-to-culture or slow-growing pathogens, such as Mycobacterium tuberculosis. Overall, this sensitive and fast SERS platform has promising potential for accurate and efficient identification of pathogenic bacteria from cultures and various samples.

Identification Of Pathogenic Bacteria In Fermented Bekamal Using B14A Isolate

The content of protein and nutrients in beef makes microorganisms able to live and breed well, it is easy for pathogenic microorganisms to grow and make beef quickly damaged, so processing technology is needed to extend the shelf life such as fermentation techniques. Bekamal is a fermented beef product from the Banyuwangi district. Bacteria in the bekamal fermentation process are lactic acid bacteria. B14A isolate is assumed as lactic acid bacteria that isolated from bekamal which will be used as a starter for meat fermentation in this study. The purpose of this study is to determine the content of pathogenic microorganisms in fermented bekamal meat using B14A isolate. The samples used in this study were fresh beef and bekamal which was fermented by B14A isolate in 0, 7, 14, and 21 days and the commercial one for 1 month, 2 months, and 3 months. Parameters analyzed include the content of Escherichia coli, Staphylococcus aureus, and Salmonella sp. The method in this study was tested using Qualitative Descriptive Analysis with 8 samples and each consisting of 3 replications. The results showed that all samples of fresh beef were contaminated with three types of pathogens and all samples of bekamal were negative for all three types of pathogens.