• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1481-1489
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• 2021

Early and accurate detection of pathogens is important to improve clinical outcomes of bloodstream infections (BSI), especially in the case of drug-resistant pathogens. In this study, we aimed to develop a culture-independent digital PCR (dPCR) system for multiplex detection of major sepsis-causing gram-negative pathogens and antimicrobial resistance genes using plasma DNA from BSI patients. Our duplex dPCR system successfully detected nine targets (five bacteria-specific targets and four antimicrobial resistance genes) through five reactions within 3 hours. The minimum detection limit was 50 ag of bacterial DNA, suggesting that 1 CFU/ml of bacteria in the blood can be detected. To validate the clinical applicability, cell-free DNA samples from febrile patients were tested with our system and confirmed high consistency with conventional blood culture. This system can support early identification of some drug-resistant gram-negative pathogens, which can help improving treatment outcomes of BSI.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.32-32
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• 2003

Intestinal infections are common in growing pigs and can be caused by multiple pathogens, environmental and management factors [1]. Among the most important viruses in swine enteritis are porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine enteric calicivirus (PECV), porcine group A rotavirus (PRV gp A) and bacteria are Escherichia coli and Salmonella spp. and protozoa is Isospora suis [1]. The DNA chip system can serve as a powerful tool that can be utilized for simultaneous detection of specific pathogenic bacteria strains and viruses [2,3]. The combination of PCR and DNA chip technology will provide a novel method for the detection of porcine enteric pathogens thus revolutionize the diagnosis and management of the disease. The aim of this study is to develop DNA chip system for the rapid and reliable detection of five major porcine enteric pathogens based on oligonucleotide DNA chip hybridization. (omitted)

• Korean Journal of Veterinary Research
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• v.52 no.2
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• pp.75-82
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• 2012

We have developed and optimized a multiplex polymerase chain reaction (mPCR) for simultaneous detection of Brucella, Salmonella and Leptospira with high sensitivity and specificity. Three pairs of oligonucleotide primers were designed to specifically amplify the targeted genes of Salmonella, Leptospira and Brucella species with sizes of 521, 408 and 223 bp, respectively. The mPCR did not produce any nonspecific amplification products when tested against 15 related species of bacteria. The sensitivity of the mPCR was 100 fg for Brucella and 1 pg for both Salmonella and Leptospira species. In the field application, kidney, liver and spleen were collected from wild rats and stray cats and examined by mPCR. The high specificity and sensitivity of this mPCR assay provide a valuable tool for diagnosis and for the simultaneous and rapid detection of three zoonotic bacteria that cause disease in both humans and animals. Therefore, this assay could be a useful alternative to the conventional method of culture and single PCR for the detection of each pathogen.

• Safe Food
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• v.2 no.4
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• pp.11-12
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• 2007

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.740-747
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• 2006

Amplification by universal consensus sequences in pathogenic bacterial DNA would allow rapid identification of pathogenic bacteria, and amplification of genus-specific and species-specific sequences of pathogenic bacterial DNA might be used for genotyping at the genus and species levels. For design of probes for molecular diagnostics, several tools are available as stand-alone programs or as Web application. However, since most programs can design only a few probe sets at one time, they are not suitable for large-scale and automatic probes design. Therefore, for high-throughput design of specific probes in diagnostic array development, an automated design tool is necessary. Thus, we developed a Web-based automatic system for design of genus-specific and species-specific probes for pathogen detection. The system is available at http://www.miprobe.com.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.314-317
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• 2006

A phage technique for detection of Xanthomonas axonopodis pv. citri, a causal bacterium of canker on Sastuma mandarin fruits was developed. Phage and ELISA techniques were compared for their sensitivity for detection of Xanthomonas axonopodis pv. citri on orange fruits. Both of techniques revealed a similar efficiency for the bacterial detection; the pathogenic bacteria were observed in pellet from the fruits with over one canker spot with below 2 mm in diameter. In field assays, the increase of phage population(120%) on surface of the fruits related to the disease development one month later indicated that the bacterial pathogens inhabit on the surface. The procedure will be effectively used for detection of only living bacterial pathogen on fruit surfaces of Satsuma mandarin and for the disease forecasting.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.135-135
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• 2008

Various biosensors were evaluated for identifying and detecting foodborne pathogens in a rapid and effective manner. First, five strains of Escherichia coli and six strains of Salmonella were identified using Fourier transform infrared spectroscopy and a statistical program. For doing this, lipopolysaccharides (LPSs) and outer membrane proteins (OMPs) were extracted from a cell wall of each bacterial strain. As a result, each strain was identifed at the level of 97% for E. coli and 100% for Salmonella. Second, E. coli O157:H7, S. Enteritidis, and Listeria monocytogenes were identified by multiplex PCR products from four specific genes of each bacteria using a capillary electrophoresis (CE). Also, ground beef for E. coli O157:H7, lettuce for S. Enteritidis, and hot dog for L. monocytogenes were used to determine the possibility of detecting pathogens in foods. Foods inoculated with respective pathogen were cultivated for six hours and multiplex PCR products were obtained and assessed. The minimum detection levels of tested bacteria were <10 cells/g, <10 cells/g, and $10^4$ cells/g for E. coli O157:H7, S. Enteritidis, and L. monocytogenes, respectively. Third, it was possible to detect S. Typhimurium in a pure culture and lettuce by a bioluminescence-based detection assay using both recombinant bacteriophage P22::luxI and a bioluminescent bioreporter. In addition, bacteriophage T4 was quantitatively monitored using E. coli including luxCDABE genes.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.3
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• pp.153-162
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• 2011

Objectives : This study has aimed to monitor microbial detection on pill types of herbal medicine which are circulating in markets including Oriental Medical Clinics(O.M.C.s) and Pharmacy in Korea. Methods : 10 different samples of O.M.Cs and 10 different samples of Pharmacy were investigated by culture method and non-culture method based on the 9th edition of microbial examination released by Korea Food & Drug Administration. Results : The total microbial count among each 10 samples were detected within the limit suggested by WHO. 2 samples of O.M.C.s and 1 samples of Pharmacy exceeded WHO's limit in fungi count. No samples exceeded WHO's limit in bacteria count. Most bacteria founded in samples were the phylum of Firmicutes and Proteobacteria which are common in soil by non-culture method. Conclusion : Further study should be followed to set up proper microbial limit of herbal materials including pill types.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.557-561
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• 2019

This study investigated the efficacy of DNA extraction methods for real-time PCR detection of foodborne pathogenic bacteria in livestock manure composts. Livestock manure composts were inoculated with Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Bacillus cereus and incubated in enrichment broth. For DNA extraction, enriched samples were treated following boiling method, by chloroform, C₁₈ powder, and proteinase K. As a result, 4 species of bacteria were detected by real-time PCR when subjected to boiling for 30 min and treated with proteinase K. These results suggest that detection of foodborne pathogens by real-time PCR from livestock manure composts could be applicable using effective DNA extraction methodology such as the boiling method or proteinase K.