The aim of this work was the validation of a rapid, real-time PCR assay based on TaqMan technology for the unequivocal identification of Salmonella spp. to be used directly on an agar-grown colony. A real-time PCR system targeting at the Salmonella spp. invA gene was optimized and validated through a four times repeated blind experiment performed in two different laboratories including 50 Salmonella spp. with representative strains from each of the 5 different Salmonella subgenera and 30 non-Salmonella strains. Both parameters DeltaR(n) (fluorescence intensity of template through a normalized reporter value) and C(T) (cycle at which the fluorescence intensity achieved a pre-established threshold) were analyzed. Overall mean DeltaR(n) and C(T) values for Salmonella strains (2.14+/-0.87 and 15.30+/-0.90, respectively) were statistically different from values for non-Salmonella strains, allowing the establishment of cut-off DeltaR(n) and C(T) values based on 95% confidence intervals that allowed the correct identification of all strains tested in each independent experiment. The accuracy of this assay in terms of inclusivity and exclusivity was 100%. Moreover, the PCR system proved to be especially convenient because the pre-mix containing all PCR reagents except for the bacterial cells could be kept at -20 degrees C for at least 1 month before its use. The optimized TaqMan real-time PCR assay is a useful, simple and rapid method for routine identification of Salmonella spp., irrespective of the particular subgenus.
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http://dx.doi.org/10.1016/s0167-7012(03)00071-x | DOI Listing |
Vet Med Int
December 2024
Department of Biology, Aksum University, Axum, Ethiopia.
Safety and quality of milk and milk products are an increasing concern worldwide. Milk and milk products are major causes of milk-borne diseases due to contamination with microorganisms resulting from a lack of standard milk handling procedures and hygienic practices. Thus, the study aims to investigate the microbial quality and safety of cow milk and milk products and isolate some bacteria in Tigray.
View Article and Find Full Text PDFJ Infect Public Health
December 2024
Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address:
Background: Currently, antimicrobial agents are widely used in both animals and agriculture, causing the crisis of multidrug-resistant (MDR) bacteria. In this study we surveyed for 4 important antimicrobial-resistant bacteria: extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Salmonella spp., and methicillin-resistant Staphylococcus aureus (MRSA) from the environment around chicken and pig farms.
View Article and Find Full Text PDFJ Infect Dis
December 2024
Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
Background: Enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi A in addition to gastroenteritis and invasive disease, predominantly attributable to nontyphoidal Salmonella serovars Typhimurium and Enteritidis, are major causes of death and disability across the globe. A broad-spectrum vaccine that protects against disease caused by typhoidal and nontyphoidal serovars of Salmonella is not available for humans but would prevent a considerable burden of disease worldwide.
Methods: We previously developed a broad-spectrum vaccine for Gram-negative bacteria that is based on the inner core domain of detoxified Escherichia coli O111, Rc (J5) mutant lipooligosaccharide, a highly conserved antigen across Gram-negative bacteria, complexed with an outer membrane protein of group B Neisseria meningitidis.
Iran J Microbiol
December 2024
Departments of Biostatistics and Epidemiology, Research Center for Healthcare Data Modeling, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Background And Objectives: Salmonellosis is among the most common food-born infections, caused by spp. bacteria. Present study has investigated the frequency and antibiotic resistance pattern of spp.
View Article and Find Full Text PDFPol J Vet Sci
September 2024
National Diagnostic and Research Veterinary Medical Institute, National Food Safety Center, 15 Pencho Slaveykov blvd, 1606, Sofia, Bulgaria.
Salmonella spp. is an important zoonotic and foodborne pathogen. It is spread worldwide and represents a public health risk.
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