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Chandrashekhar KM, Isloor S, Veeresh BH, Hegde R, Rathnamma D, Murag S, Veeregowda BM, Upendra HA, Hegde NR. Limit of detection of genomic DNA by conventional PCR for estimating the load of Staphylococcus aureus and Escherichia coli associated with bovine mastitis. Folia Microbiol (Praha) 2015; 60:465-72. [PMID: 25773783 DOI: 10.1007/s12223-015-0384-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 03/02/2015] [Indexed: 01/15/2023]
Abstract
Detection of mastitis-associated bacteria can be accomplished by culturing or by molecular techniques. On the other hand, rapid and inexpensive methods to enumerate bacterial load without culturing can be better achieved by molecular methods. Staphylococcus aureus and Escherichia coli are the predominant bacterial pathogens associated with bovine mastitis. Here, we describe the application of conventional PCR for the limit of detection (LOD) of genomic DNA of S. aureus and E. coli based on single-copy genes. The selected genes were thermonuclease (nuc), aureolysin (aur), and staphopain A (scpA) for S. aureus and β-D-glucuronidase A (uidA), cytochrome d oxidase (cyd), and rodA (a gene affecting cell shape and methicillin sensitivity) for E. coli. The LOD was 5.3, 15.9, and 143 pg for aur, nuc, and scpA genes, corresponding to S. aureus genomic copies of 1.75 × 10(3), 5.16 × 10(3), and 4.71 × 10(4), respectively. The LOD was 0.45, 12.3 and 109 pg for uidA, rodA and cyd genes, corresponding to E. coli genome copies of 8.91 × 10(1), 2.43 × 10(3), and 2.16 × 10(4), respectively. Application of uidA and aur PCRs to field strains revealed that as low as approximately 100 genome copies of E. coli and 1000-10,000 copies of S. aureus could be detected. This study is the first to report LOD of genomic DNA using conventional PCR for aur and scpA genes of S. aureus, and rodA and cyd genes of E. coli. The results should be useful for developing assays to assess bacterial load in milk and to determine the load that contributes to subclinical or clinical mastitis.
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Affiliation(s)
- K M Chandrashekhar
- Department of Microbiology, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - Shrikrishna Isloor
- Department of Microbiology, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - B H Veeresh
- Department of Microbiology, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - Raveendra Hegde
- Institute of Animal Health and Veterinary Biologicals, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - D Rathnamma
- Department of Microbiology, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - Shivaraj Murag
- Institute of Animal Health and Veterinary Biologicals, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - B M Veeregowda
- Department of Microbiology, Karnataka Veterinary Animal and Fisheries Sciences University, Hebbal, Bengaluru, 560024, India
| | - H A Upendra
- Institute of Wildlife Veterinary Research, Kudige, Kodagu, 571232, India
| | - Nagendra R Hegde
- Ella Foundation, Genome Valley, Turkapally, Shameerpet Mandal, Hyderabad, 500078, India.
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Antiabong JF, Boardman W, Smith I, Brown MH, Ball AS, Goodman AE. “Cycliplex PCR” confirmation of Fusobacterium necrophorum isolates from captive wallabies: A rapid and accurate approach. Anaerobe 2013; 19:44-9. [DOI: 10.1016/j.anaerobe.2012.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 07/16/2012] [Accepted: 12/05/2012] [Indexed: 11/30/2022]
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Wang S, Levin RE. Interference of Real-Time PCR Quantification ofVibrio vulnificusby a Novel DNase from the Eastern Oyster (Crassostrea virginica). FOOD BIOTECHNOL 2010. [DOI: 10.1080/08905431003784721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Molecular Analysis of Bacterial Community DNA in Sludge Undergoing Autothermal Thermophilic Aerobic Digestion (ATAD): Pitfalls and Improved Methodology to Enhance Diversity Recovery. DIVERSITY-BASEL 2010. [DOI: 10.3390/d2040505] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ahmadi M, Rohani SMR, Ayremlou N. Detection of Staphylococcus aureus in milk by PCR. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s00580-009-0901-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nájera-Sánchez G, Maldonado-Rodríguez R, Ruíz Olvera P, de la Garza LM. Development of two multiplex polymerase chain reactions for the detection of enterotoxigenic strains of Staphylococcus aureus isolated from foods. J Food Prot 2003; 66:1055-62. [PMID: 12801009 DOI: 10.4315/0362-028x-66.6.1055] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Two multiplex polymerase chain reactions were developed for the detection of enterotoxigenic strains of Staphylococcus aureus: one multiplex reaction for the simultaneous detection of enterotoxigenic strains type A (entA), type B (entB), and type E (entE) and another for the simultaneous detection of enterotoxigenic strains type C (entC) and type D (entD). Both reactions were standardized with the use of the reference enterotoxigenic strains of S. aureus: FRI 722, producer of staphylococcal enterotoxin (SE) type A (SEA); FRI 1007, producer of SEB; FRI 137, producer of SEC1; FRI 472, producer of SED; and FRI 326, producer of SEE. Optimized methods were used to determine the presence of enterotoxigenic types for 51 S. aureus strains isolated from meat (sausage, ham, and chorizo) and dairy (powdered milk and cheese) products by the Baird-Parker technique. The enterotoxigenic capacities of the strains were determined by the indirect enzyme-linked immunosorbent assay (ELISA) with the use of reference staphylococcal toxins and antitoxins. Fifty of the 51 strains isolated were enterotoxigenic and produced one to four enterotoxin types, with the most frequently produced types being SEA and SED. Levels of correlation between the presence of genes that code for the production of SE (as determined by polymerase chain reaction) and the expression of these genes (as determined by the indirect ELISA) were 100% for SEA and SEE, 86% for SEC, 89% for SED, and 47% for SEB.
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Affiliation(s)
- Gabriela Nájera-Sánchez
- Microbiology Department, Escuela Nacional de Ciencias Biológicas, Instituto Politècnico Nacional, Prolongación de Carpio y Plan de Ayala, Casco de Santo Tomás, C.P. 11340, México, DF.
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Mäntynen V, Niemelä S, Kaijalainen S, Pirhonen T, Lindström K. MPN-PCR-quantification method for staphylococcal enterotoxin c1 gene from fresh cheese. Int J Food Microbiol 1997; 36:135-43. [PMID: 9217102 DOI: 10.1016/s0168-1605(97)01243-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PCR detection methods have been extensively used in diagnostic microbiology. However, a lack of a simple and reliable method for quantification of the PCR products has partly hindered the use of PCR in routine food laboratories. The quantification of PCR products can be done by combining the principles of MPN statistics and PCR technique. We have developed a simple and sensitive MPN-PCR assay for detection and enumeration of enterotoxin C producing Staphylococcus aureus NCTC 10655 from fresh cheese. By amplifying single copy chromosomal enterotoxin C gene fragment, we could detect as little as 20 cfu/g. By Moran's test, most of the DNA dilution series appeared to fulfill the basic mathematical assumptions of ordinary MPN methods. The analysis with MPN-PCR took one day to perform compared with three days analysis time with plate counting. This MPN-PCR method can be readily applied with different primer systems without extensive development work.
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Affiliation(s)
- V Mäntynen
- Department of Applied Chemistry and Microbiology, University of Helsinki BIOCENTER, Finland.
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