Detection Of Bacterial Contamination Research Articles

A spectroscopy-based proof-of-concept (POC) for developing loading of pathogen analyzer (LOPA) for dairy products

Detection of bacterial contamination in dairy products of daily use is a challenge worldwide. We have utilized Methylene Blue Reduction Test (MBRT) for quantification of the microbial count in dairy products (milk) and developed a proof-of-concept (POC) based on this for in-filed applications. In this study, we have used pasteurized milk contaminated with model bacteria Escherichia coli, and Staphylococcus aureus for the calibration and validation of the developed POC. The conversion of MB to Leuco-MB i.e., the colorimetric change due to the reduction of MB to Leuco-MB in presence of microbes has been utilized as the tool to detect presence of microbes in milk. The absorbance peak for methylene blue (MB) at 664 nm decreases significantly in presence of microbes and the blue color becomes faded. In our study, we have employed methylene blue (MB) discolouration phenomenon to estimate the microbial count in milk samples using our developed spectroscopy based POC. The limit of detection (LOD) and the limit of quantitation (LOQ) of the POC were found to be 0.32 CFU/mL and 0.97 CFU/mL. The end users of the developed POC are primarily those involved in the production, processing, testing, regulation, and research of dairy products to ensure they meet safety standards and protect public health. These include retailers, dairy farmers, dairy processors, quality control laboratories, regulatory agencies and research institutions. In our experiment, we have observed a significant change in MB absorption in the milk contaminated with microbes. The indigenously developed sensor strips designed for the working of the POC turn to colorless Leuco-MB compared to milk without the microbes. The analysis of the strips has been measured in the developed device.

Application of miniaturized most probable number method for bacterial detection in water samples: detection of multi-drug-resistant Ralstonia insidiosa in drinking water.

The detection of bacterial contamination in drinking water is essential for monitoring the spread of foodborne diseases. We developed a simple, portable, and low-cost method of mini most probable number (mini MPN) to semi-enumerate bacterial suspension in water as a drinking water analogue. In this study, there is no significant difference between mini MPN and the standard method, technique plate count (TPC), at 10 and 100 CFU/ml Klebsiella pneumoniae suspension with a P-value of 0.28. For the ease-of-use aspect of this method, we tested several variables to prove it can be mass-applied in society. The usage of a sterile-plastic pipette, sample inoculation conducted in a biosafety cabinet (BSC), the usage of a 3-month storage medium, and incubation temperature conducted at room temperature compared to aseptic standard laboratory technique showed P-value > 0.05. In a trial for this method, we used commercialized drinking water for bacterial enumeration and characterization. We found multi-drug resistant (MDR) Ralstonia insidiosa which was resistant to at least four antimicrobial classes, including aminoglycosides, penicillins, cephalosporin, and carbapenem. Vitek 2 Compact was used for bacterial identification and antimicrobial susceptibility testing. A virulence test in Omphisa fuscidentalis larvae showed R. insidiosa strain D had a low virulence.

Au-Pt Coating Improved Catalytic Stability of Au@AuPt Nanoparticles for Pressure-Based Point-of-Care Detection of Escherichia coli O157:H7.

Point-of-care testing (POCT) technologies facilitate onsite detection of pathogens in minutes to hours. Among various POCT approaches, pressure-based sensors that utilize gas-generating reactions, particularly those catalyzed by nanozymes (e.g., platinum nanoparticles, PtNPs, or platinum-coated gold nanoparticles, and Au@PtNPs) have been shown to provide rapid and sensitive detection capabilities. The current study introduces Au-Pt alloy-coated gold nanoparticles (Au@AuPtNPs), an innovative nanozyme with enhanced catalytic activity and relatively high stability. For pathogen detection, Au@AuPtNPs are modified with H1 or H2 hairpin DNAs that can be triggered to undergo a hybridization chain reaction (HCR) that leads to their aggregation upon recognition by an initiator strand (Ini) with H1-/H2-complementary aptamers tethered to magnetic beads (MBs). Pathogen binding to the aptamer exposes Ini, which then binds Au@AuPtNPs and initiates a HCR, resulting in Au@AuPtNP aggregation on MBs. These Au@AuPtNP aggregates exhibit strong catalysis of O2 from the H2O2 substrate, which is measured by a pressure meter, enabling detection of Escherichia coli (E. coli) O157:H7 at concentrations as low as 3 CFU/mL with high specificity. Additionally, E. coli O157:H7 could also be detected in simulated water and tea samples. This method eliminates the need for costly, labor- and training-intensive instruments, supporting its further testing and validation for deployment as a rapid-response POCT application in the detection of bacterial contaminants.

Detection of Bacterial Contaminants and Identification of Salmonella Sp. in Cilok Snack in Selaparang District, Mataram

Cilok is a boiled snack made from starch with or without a mixture of minced meat, has a savory and chewy taste. Cilok is one of the favorite snacks in Indonesia. Most cilok sellers sell their cilok right on the side of the main road for hours. This allows cilok that are sold to be contaminated with various bacteria. This study aims to calculate the Total Plate Count (TPC) of bacteria and to identify Salmonella sp. in cilok and its sauce in Selaparang District, Mataram City. This study used quantitative method in the form of calculating the TPC of the bacteria and qualitative method in the form of sample isolation on selective media, sugar, and biochemical tests. The results of this study showed that the TPC of the bacteria from the cilok sellers samples number 1 to 8 were 1,2x102, 1x101, 1x101, 2x101, 1,2x102, 1,5x102, 3,9x101, and 3,5x102 cfu/g respectively. Meanwhile, the TPC of the bacteria from sellers' sauce samples number 1 to 8 were 2x102, 1,8x103, 1x101, 1x101, 1,5x101, 7,9x103, 1,7x105 and 1,7x103 cfu/mL, and there was no contamination of Salmonella sp. on cilok nor its sauce samples. All the cilok samples that has been examined had TPC bacterial value that did not exceed the standards set by SNI 7388-2009, so they were still safe for consumption. Meanwhile, one out of eight sauce samples had a bacterial TPC value that exceeded the standard, making it not safe for consumption.

High performance 3-methyl-1-butanol gas sensor based on olfactory receptor derived peptide on pyramidal-structure substrates

Detection of bacterial contamination in food is a critical issue for ensuring public health and safety. In response, we present a high-performing olfactory receptor-derived peptide (ORP) sensor for the detection of 3-methyl-1-butanol, a by-product produced by common meat-borne bacteria. Our approach involved the covalent attachment of ORPs to carbon nanotubes (CNTs) using a combination of pyramidal silicon substrate modification, thioester modification of CNTs, and chemical ligation of n-terminus cysteine-modified ORPs. The resulting sensor showed remarkable sensitivity with a detection limit of 0.0001 ppt—three orders of magnitude lower than previous reports. Moreover, our results demonstrate the sensor's selectivity and stability, making it a promising tool for a variety of applications, including food safety, medical detection, and environmental protection.

Detection of Bacterial Contaminants from Operating Theatres at Hospitals in Shendi City, Sudan

Background: Operating room contamination is recognized as one of the most common life-threatening microbial contaminations in hospital environments, especially operating rooms and other specialty units, and is an ever- increasing cause of nosocomial infections. Objective: The purpose of this study was to isolate and identify bacterial contaminants in Shendi hospital operating room. Between July-September 2021. Materials and Methods: Sixty samples were collected from various locations in the operating room and all isolated bacteria were identified. The study isolated five types of bacteria from the Shendi Hospital operating room. Results: The results showed that Micrococcus was the most common bacterial contaminant isolated from the operating room. Leteus 21 (32.3%) Staphylococci. Epidermis 16 (24.6%), Staphylococci aureus 11 (16.9%), Bacillus sp. 9 (13.8%), Bacillus cereus 8 (12.3%)) and the lowest contaminants were isolated from soil 15 (23%), and focus lamp 5 (7.7%). This study may point to the fact that the Shendi Hospital operating room had bacterial contamination that could lead to postoperative wound infections (SSI). Reasons for contamination may be due to excessive attendance, personnel movement, and ineffective sterilization and disinfection procedures. Conclusions: Bacterial contamination was highest in operating room beds, followed by carts, floors, and focused lambs. Micrococcus spp, S. epidermidis, S. aureus, and Bacillus species have proven to be the most serious contaminants in the operating room, and are a dangerous cause of hospital-acquired infections, killing patients and hospital staff threatening. This may indicate that the sterilization method is not efficient enough, putting the patient at risk for postoperative infection. Some organisms were resistant to Gentamicin and highly sensitive to Imipenem, Ciprofloxacin, and Ceftriaxone.

Detection of Bacterial Contaminants on Gate Passes Issued to Motorists in Federal University Dutse, Northwest Nigeria

The study was conducted to isolate and identify possible bacterial contaminants on the gate passes issued to motorists in the three (3) major gates leading to Federal University Dutse. Swab stick method was employed to sample possible bacterial contaminants from seventy (70) gate passes. Sampling was done at the end of the daily activities to maximize the chances of isolating bacteria that might be present thereon. The swab sticks labelled S1 to S70, were instantaneously taken to the Microbiology laboratory with a view to conducting bacteriological analysis by means of customary microbiological methods. Plate colony count method was adopted to compute the number of bacteria present on the sampled gate passes. 'Results generated on the total viable count show that S31 sampled from gate two had the highest load (1.68 × 10-2 CFU/mL) while S43 sampled from the same gate recorded the lowest load (0.34 × 10-3 CFU/mL). Four (4) bacteria; Escherichia coli, Staphylococcus aureus, Klebsiella sp. and Salmonella sp. were detected on the sampled gate passes. All the gate passes issued to motorists coming in and out of the Federal University Dutse were contaminated with different bacteria most of which are known to be pathogenic. Due to the results derived from this study, it is therefore suggested that the University authority should make available hand antiseptics for motorists and security staff handling the gate passes in order to minimize and prevent the spread of pathogenic bacteria.

Detection of bacterial contaminants via frequency manipulation of amino-groups functionalized Fe3O4 nanoparticles based resonant sensor

Bacterial infections have a large impact on public health. Through this study, we report on the development of complementary split-ring resonators (CSRR) supplemented by functionalized nanoparticles to detect bacteria in the aqueous medium. Iron oxide (Fe3O4) nanoparticles were functionalized with amino groups using (3-aminopropyl) triethoxysilane (APTES) to form (APTES@Fe3O4) nanoparticles, which have a specific affinity towards the bacterial species. This affinity was evaluated using the Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacterial species. The resonant sensor was tuned at 430 MHz and the CSRR sensor bed was further activated using APTES@Fe3O4 nanoparticles. Bacterial detection was studied over a range of concentrations from 2.66 × 109 cells to 2.66 × 108 cells. The sensor actively responded to small changes in bacterial concentration, showing an overall shift in resonance frequency of ∼44 MHz (∼40 MHz/cell count) for E. coli and ∼55 MHz (50.43 MHz/cell count) for S. aureus. Dextran sulphate and Chitosan were used as the references. The magnetic character of the conjugated system exhibited strong interaction of the bacterial species with APTES@Fe3O4, justifying the high selectivity towards these species. This demonstrates the feasibility of a sensitive, fast, portable device, against the traditionally used time-consuming bio-assays.

Rapid detection of bacterial contaminants in platelet concentrates using the next generation BACT/ALERT® VIRTUO® Microbial Detection System: improved safety and operational efficiency

Rapid detection of bacterial contaminants in platelet concentrates using the next generation BACT/ALERT® VIRTUO® Microbial Detection System: improved safety and operational efficiency

The PGDprime immunoassay for detection of bacterial contamination in platelet concentrates: sensitivity and specificity

The PGDprime immunoassay for detection of bacterial contamination in platelet concentrates: sensitivity and specificity

Detection of Bacterial Contamination in Dental Unit Water Lines and Testing the Effectiveness of Disinfectants against these Contaminants

Aim: Contaminated dental unit water lines (DUWLs) are a possible source for spreading microorganisms in dental practices. The aim of this study was to detect the bacterial contamination of dental unit water and investigate the effectiveness of the disinfectants.
 Methodology: Bacterial contamination was detected by a) using bacterial culture of heterotrophic bacteria, total coliforms and Pseudomonas aeruginosa and b) Scanning electron microscopy (SEM) of DUWLs tube. Subsequently, dentists were suggested to treat the DUWLs with disinfectants to eradicate bacterial contaminants and its effectiveness was tested after three months.
 Results: Bacterial contamination of the water samples ranged from not detected to 2.38×106 CFU/mL. Out of 34 DUWLs water samples tested, 30 (88.24%) samples exceeded the Centers for Disease Control and Prevention (CDC) and Environmental Protection Agency (EPA) recommended threshold of ≤500 CFU /mL, whereas only 4 (11.76%) samples met the standards. Contamination by total coliforms and P. aeruginosa was detected in 52.94% and 64.7% of samples respectively. SEM displayed a dense biofilm on DUWLs tubing confirming the bacterial contamination. The intervention for disinfection of DUWLs resulted more than 50% samples with acceptable bacterial count in test performed after three months.
 Conclusion: The high rate of bacterial contamination of dental unit water highlights the need to disinfect and monitor the quality of DUWLs periodically.

Detection of Bacterial Contamination and Antibiotic Resistance at Neonate Intensive Care Units in Ibn Al-Atheer Teaching Hospital for Children

The study included the isolation and diagnosis of some gram positive and negative bacterial species from (NICU ) in Ibn Al-Atheer Teaching hospital for children from from August 2019 to February 2020 .A total of 90 swabs were obtained from various sites of Intensive Care Unit from Ibn Al-Atheer hospital environment and inoculated on culture media. The obtained growth revealed different bacterial colonies which had been tested for their morphological and biochemical characteristics. Eighty pure isolates were obtained including (76 ) Gram positive, and (4 ) Gram negative bacterial isolates. The highest rate of bacterial contamination had been found in the couh and incubator. The most prevalent bacteria isolated from inanimate surfaces were Staphylococcus aureus, Coagulase negative staphylococci, Bacillus, in addition to Diphtheroids, Lactobacillus, Streptococcus pneumoniae, Klebsiella pneumoniae, and E, coli. Antibiotic susceptibility testing for all isolates was performed using (8) types of commonly used antibiotics in Iraq. Taken all together, gram positive and negaive bacteria showed high resistance against streptomycin, erythromycin, and ampicillin respectively. Notably, resistance to ampicillin and gentamicin were demonstrated which are commonly given as the first line of treatment in NICUs.

Colorimetric and electrochemical detection of pathogens in water using silver ions as a unique probe

The manuscript highlights the efficacy of silver ions to act as a unique probe for the detection of bacterial contamination in water samples. The bacterial cell membrane adherence property of the silver ions was employed to develop two different bacterial detection assays employing colorimetric and electrochemical techniques. In one of the schemes, silver ion was used directly as a detector of bacteria in a colorimetric assay format, and in the other scheme surface-functionalized antibodies were used as a primary capture for specific detection of Salmonella enterica serovar Typhi. The colorimetric detection is based on silver-induced inhibition of urease activity and silver ion utilization by bacteria for the rapid screening of enteric pathogens in water. The specific detection of bacteria uses an antibody-based electrochemical method that employs silver as an electrochemical probe. The ability of silver to act as an electrochemical probe was investigated by employing Anodic Stripping Voltammetry (ASV) for targeted detection of Salmonella Typhi. For further insights into the developed assays, inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM) studies were performed. The sensitivity of the developed assay was found to be 100 cfu mL−1 for colorimetric and 10 cfu mL−1 for electrochemical assay respectively.

How to speed up the detection of aerobic microbial contaminations by using isothermal microcalorimetry

Isothermal microcalorimetry (IMC) is regarded as a promising diagnostic tool for fast detection of bacterial contaminations in various matrices. Based on a reference detection time determined by visual inspection of bacterial growth on solid medium, we investigated the strict aerobically growing Pseudomonas putida mt-2 KT2440 in a static 4-mL ampoule system on solid and liquid media by IMC to evaluate the three main options to reduce the detection time of bacterial contamination. Firstly, the sample preparation (e.g. membrane filtration) leads to an elevated number of bacteria in the measuring ampoule and thus to a reduced detection time. Secondly, the amount of substrate and oxygen has been investigated by varying the filling volume of medium in the calorimetric ampoule. Here, we were able to show how biophysical characteristics like the substrate and oxygen diffusion determined the shape of heat flow signals and thus the detection time. Finally, the technical framework determines the sensitivity of the IMC instrument. We examined the impact of four different detection threshold values (2, 10, 50 and 100 µW) on the detection time as a function of the initial number of bacteria presented in the ampoule and the filling volume.

Detection of Bacterial Contamination in Imported Live Poultry Vaccines to Egypt in 2018

Detection of Bacterial Contamination in Imported Live Poultry Vaccines to Egypt in 2018

Detection of bacterial contamination in imported and local red and white meat in Tikrit city, Iraq

Detection of bacterial contamination in imported and local red and white meat in Tikrit city, Iraq

Detection of bacterial contamination in filled and dried biscuit products of young children

Detection of bacterial contamination in filled and dried biscuit products of young children

Hybrid plasmonic/photonic crystals for optical detection of bacterial contaminants

Here, we show that a hybrid plasmonic/photonic crystal consisting of a thin layer of bioactive plasmonic material (i.e. silver) deposited on top a 1D PhC can detect one of the most common bacterial contaminant, namely Escherichia coli. We speculate that the change in the plasmon charge density brought about by metal/bacterium interaction results in a variation of the plasmon resonance that, in turns, translates in a shift of the photonic structural color.

Detection of Bacterial Contamination and Ph Quantity Using Digitalization Strategy

Food is essential for all the human being. In the food we are gained the more number of energy to our body. But now days, Lot of chemical substances that are added in the food. That makes human being to be unhealthy person. Children are also affected due to unhealthy food. In our proposal, we used to find the quality of food using the pH sensor. The pH sensors are used to find the pH value of the food and also find the bacterial contamination of the food. This project is used for the government to find the quality of food in the restaurant and display their result in the server and also check the quality of food and display the output pH value in the message using GSM. In additional, we can also share the location of the restaurant.

Multimodal Magneto-Fluorescent Nanosensor for Rapid and Specific Detection of Blood-Borne Pathogens.

Detection of bacterial contaminants in blood and platelet concentrates (PCs) continues to be challenging in clinical settings despite available current testing methods. At the same time, it is important to detect the low bacterial contaminants present at the time of transfusion. Herein, we report the design and synthesis of a dual-modal magneto-fluorescent nanosensor (MFnS) by integrating magnetic relaxation and fluorescence modalities for the wide-range detection of blood-borne pathogens. In this study, functional MFnS are designed to specifically detect Staphylococcus epidermidis and Escherichia coli, two of the predominant bacterial contaminants of PCs. Specific interaction between the target pathogen and functional MFnS resulted in the change of water proton's magnetic relaxation time (T2 MR), indicative of sensitive detection of the target bacteria from low to high colony forming unit (CFU). In addition, the acquired MR signal of MFnS further facilitated the quantitative assessment of the slow and fast growth kinetics of target pathogens. Moreover, the presence of fluorescence modality in MFnS allowed for the detection of multi-contaminants. The bacterial detection was also performed in complex media including whole blood and platelet concentrates, which further demonstrated for it's robust detection sensitivity. Overall, our study indicated that the designer MFnS will have potential for the wide-range detection of blood-borne pathogens, and features desirable qualities including timeliness, sensitivity and, specificity.