1
|
Comparative study of Pd@Pt nanozyme improved colorimetric N-ELISA for the paper-output portable detection of Staphylococcus aureus. Talanta 2022; 247:123503. [DOI: 10.1016/j.talanta.2022.123503] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 11/20/2022]
|
2
|
Assessment of Quality and Safety of Farm Level Produced Cheeses from Sheep and Goat Milk. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11073196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Consumption of sheep’s and goat’s milk and cheese is currently increasing. The production process of these types of cheese is being carried out by traditional domestic production at farm level. However, knowledge in the field of hygiene, technology and health safety of cheeses are still insufficient. This study aimed to examine the physical and chemical quality and microbiological safety of sheep’s and goat’s milk and cheeses made from them. The month of milking influenced the content of milk components (p < 0.001) in sheep’s milk and goat’s milk, but no changes in SCC content during the examined period were found (p > 0.05). Level of contamination by Enterobacteriaceae sp. and coagulase-positive staphylococci was lower than 5 log CFU/mL in sheep’s and goat’s milk. During the ripening time, the number of lactic acid bacteria significantly raised (p < 0.001). Ripening time statistically changed (p < 0.001) not just the microbial safety of cheeses but also the color (p < 0.01). Under the applicable regulations, the analyzed samples were evaluated as suitable for human consumption.
Collapse
|
3
|
Kingsbury JM, Soboleva TK. Evaluation of culture-based and molecular detection methods for Campylobacter in New Zealand raw cows' milk. J Appl Microbiol 2020; 130:478-492. [PMID: 32725959 DOI: 10.1111/jam.14798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 01/23/2023]
Abstract
AIMS This study evaluated the performance of a commercial molecular detection method (mericon Campylobacter triple kit real-time/quantitative (q)PCR) and a selective plating medium (R&F Campylobacter jejuni/Campylobacter coli Chromogenic Plating Medium (CCPM)) against a culture-based reference method (ISO 10272-1:2017 detection procedure B) for the detection of Campylobacter from raw milk enrichment broths. METHODS AND RESULTS New Zealand raw cows' milk and Ultra-High Temperature-processed milk samples were inoculated with 50, 125 and 500 colony forming units of C. jejuni and C. coli cocktail per analytical unit. Samples were tested for Campylobacter after 0, 24- and 48 h refrigeration. ISO 10272-1:2017 proved to be a sensitive detection method (77/80 positive samples); detection only failed for some milk samples tested 48 h postinoculation. CCPM was as effective as Cefoperazone Charcoal Deoxycholate Agar for selective plating of Campylobacter raw milk enrichments (78/80 positive samples). However, the qPCR detected Campylobacter in only 42/80 samples and qPCR reaction inhibition was observed. CONCLUSIONS The ISO 10272-1:2017 method was a more sensitive method for Campylobacter detection from raw milk than the mericon Campylobacter triple kit qPCR, and CCPM was a useful complementary medium to mCCDA where one of these media is required by the standard. SIGNIFICANCE AND IMPACT OF THE STUDY In regions where testing is required or recommended, optimized methods for Campylobacter detection from raw milk will reduce risk to the raw milk consumer. Although molecular methods are generally touted as a rapid alternative to culture, issues with inhibition due to matrix components mean that culture-based methods might provide the most sensitive option for Campylobacter detection in raw milk. Findings also emphasize the importance of minimizing the time between milk collection and testing for Campylobacter.
Collapse
Affiliation(s)
- J M Kingsbury
- Institute of Environmental Science and Research, Christchurch, New Zealand
| | - T K Soboleva
- New Zealand Food Safety, Ministry for Primary Industries, Wellington, New Zealand
| |
Collapse
|
4
|
Gao X, Yao X, Zhong Z, Jia L. Rapid and sensitive detection of Staphylococcus aureus assisted by polydopamine modified magnetic nanoparticles. Talanta 2018; 186:147-153. [PMID: 29784342 DOI: 10.1016/j.talanta.2018.04.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/08/2018] [Accepted: 04/15/2018] [Indexed: 10/17/2022]
Abstract
Pathogens cause significant morbidity and mortality to humans. Thus, development of fast and reliable methods for detection and identification of pathogens is urgently needed to increase protection level of public health and ensure the safety of consumers. Herein, a rapid and sensitive method has been developed for Staphylococcus aureus (S. aureus) detection based on the dual role of polydopamine modified magnetic nanoparticles (PDA@Fe3O4 NPs) combined with polymerase chain reaction (PCR) and capillary electrophoresis (CE). The core-shell type structure PDA@Fe3O4 NPs were prepared, which are spherical, about 152 ± 20 nm in diameter and the PDA shell is about 17.5 ± 1.6 nm. PDA@Fe3O4 NPs play a dual role including efficient capture of bacteria and extraction of DNA. In the pH range of 3.0-7.0, the capture efficiency of S. aureus by PDA@Fe3O4 NPs was more than 95% in 5 min. The adsorption capacity of the PDA@Fe3O4 NPs for S. aureus is 1.2 × 108 cfu mg-1. The efficient capture and concentration of bacteria from large volumes of samples by PDA@Fe3O4 NPs avoids the time-consuming culture-enrichment prior to PCR. Interestingly, PDA@Fe3O4 NPs were also found to be efficient adsorbents for extraction of genomic DNA from pathogens based on the electrostatic interaction. The process can be finished in 25 min. The PDA@Fe3O4 NPs based solid phase extraction combined with PCR and CE allows for detecting the order of 102 cfu mL-1S. aureus in tap water and orange juice samples. The whole process takes < 5.5 h. The developed method would provide a promising platform for rapid and sensitive detection of pathogens.
Collapse
Affiliation(s)
- Xiaomei Gao
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Xin Yao
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Zitao Zhong
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Li Jia
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| |
Collapse
|
5
|
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Hassani S, Hosseini Doust R, Mohebati Mobarez A. Enterotoxin A Gene Barrier Staphylococcus aureus Within Traditionally Dairy Products of Tehran. INTERNATIONAL JOURNAL OF ENTERIC PATHOGENS 2014. [DOI: 10.17795/ijep20906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
8
|
Kadiroğlu P, Korel F, Ceylan C. Quantification of Staphylococcus aureus in white cheese by the improved DNA extraction strategy combined with TaqMan and LNA probe-based qPCR. J Microbiol Methods 2014; 105:92-7. [PMID: 25016130 DOI: 10.1016/j.mimet.2014.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 10/25/2022]
Abstract
Four different bacterial DNA extraction strategies and two different qPCR probe chemistries were studied for detection of Stapylococcus aureus from white cheeses. Method employing trypsin treatment followed by a commercial kit application and TaqMan probe-based qPCR was the most sensitive one detecting higher counts than standards in naturally contaminated samples.
Collapse
Affiliation(s)
- Pınar Kadiroğlu
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
| | - Figen Korel
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
| | - Cagatay Ceylan
- Department of Food Engineering, İzmir Institute of Technology, Urla, İzmir, Turkey.
| |
Collapse
|
9
|
Fusco V, Quero GM. Culture-Dependent and Culture-Independent Nucleic-Acid-Based Methods Used in the Microbial Safety Assessment of Milk and Dairy Products. Compr Rev Food Sci Food Saf 2014; 13:493-537. [DOI: 10.1111/1541-4337.12074] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/08/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Vincenzina Fusco
- Nal. Research Council of Italy; Inst. of Sciences of Food Production (CNR-ISPA); Bari Italy
| | - Grazia Marina Quero
- Nal. Research Council of Italy; Inst. of Sciences of Food Production (CNR-ISPA); Bari Italy
| |
Collapse
|
10
|
Nagaraj S, Ramlal S, Sripathy MH, Batra HV. Development and evaluation of a novel combinatorial selective enrichment and multiplex PCR technique for molecular detection of major virulence-associated genes of enterotoxigenic Staphylococcus aureus in food samples. J Appl Microbiol 2013; 116:435-46. [PMID: 24119042 DOI: 10.1111/jam.12364] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/29/2013] [Accepted: 10/01/2013] [Indexed: 11/28/2022]
Abstract
AIMS To develop a multiplex PCR assay coupled with selective enrichment step to detect major virulence-associated genes of enterotoxigenic Staphylococcus aureus and evaluate the same directly on contaminated food samples. METHODS AND RESULTS The most important virulence-associated genes of Staph. aureus, which are commonly related to food safety issues, are targeted in this study. They include five major enterotoxigenic genes-sea, seb, sec, seg and sei, tst-which encodes TSST-1, mecA-which confer methicillin resistance and coa-for the enzyme coagulase along with an internal amplification control (IAC) to rule out false-negative result. A modified mannitol salt broth (MSB) supplemented with sodium pyruvate was used for selective enrichment of Staph. aureus from food samples prior to PCR. Evaluation of efficiency of different media revealed that enrichment of samples in modified MSB followed by PCR resulted in specific, sensitive and effective amplification of the targeted genes in comparison with other enrichment media. Incorporation of bovine serum albumin (BSA) as PCR enhancer improved the intensity of amplicons. The standardized multiplex PCR (mPCR) format was able to detect all the target genes at a bacterial load of 10(6) CFU ml(-1) in any sample. The PCR results were unequivocally correlated with the conventional methods when the mPCR format was assessed on a total of 91 Staph. aureus isolates. The entire assay was found to be effectual when evaluated on naturally contaminated food samples. CONCLUSIONS The combinatorial approach involving selective enrichment followed by mPCR developed in this study was found to be effective for the detection of toxigenic Staph. aureus directly from various food sources. SIGNIFICANCE AND IMPACT OF THE STUDY The developed format would find a promising application in early detection of food contaminations as well as in the diagnosis of food poisoning due to Staph. aureus.
Collapse
Affiliation(s)
- S Nagaraj
- Microbiology Division, Defence Food Research Laboratory, Mysore, India
| | - S Ramlal
- Microbiology Division, Defence Food Research Laboratory, Mysore, India
| | - M H Sripathy
- Microbiology Division, Defence Food Research Laboratory, Mysore, India
| | - H V Batra
- Microbiology Division, Defence Food Research Laboratory, Mysore, India
| |
Collapse
|
11
|
Janštová B, Necidová L, Janštová B, Vorlová L. Staphylococcus aureus growth and enterotoxin production in different types of milk. ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS 2013. [DOI: 10.11118/actaun201260050103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
12
|
Cupáková Š, Pospíšilová M, Karpíšková R, Janštová B, Vorlová L. Microbiological quality and safety of goat's milk from one farm. ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS 2013. [DOI: 10.11118/actaun201260060033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
13
|
|
14
|
Cretenet M, Even S, Le Loir Y. Unveiling Staphylococcus aureus enterotoxin production in dairy products: a review of recent advances to face new challenges. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s13594-011-0014-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
15
|
Aprodu I, Walcher G, Schelin J, Hein I, Norling B, Rådström P, Nicolau A, Wagner M. Advanced sample preparation for the molecular quantification of Staphylococcus aureus in artificially and naturally contaminated milk. Int J Food Microbiol 2011; 145 Suppl 1:S61-5. [DOI: 10.1016/j.ijfoodmicro.2010.09.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 08/06/2010] [Accepted: 09/20/2010] [Indexed: 10/19/2022]
|
16
|
Fusco V, Quero GM, Morea M, Blaiotta G, Visconti A. Rapid and reliable identification of Staphylococcus aureus harbouring the enterotoxin gene cluster (egc) and quantitative detection in raw milk by real time PCR. Int J Food Microbiol 2011; 144:528-37. [DOI: 10.1016/j.ijfoodmicro.2010.11.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 09/10/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
|
17
|
COMUNIAN ROBERTA, PABA ANTONIO, DAGA ELISABETTAS, DUPRE’ ILARIA, FRANCESCA SCINTU MARIA. Traditional and innovative production methods of Fiore Sardo cheese: a comparison of microflora with a PCR-culture technique. INT J DAIRY TECHNOL 2010. [DOI: 10.1111/j.1471-0307.2010.00581.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Ifesan BOT, Voravuthikunchai SP. Effect of Eleutherine americana Merr. extract on enzymatic activity and enterotoxin production of Staphylococcus aureus in broth and cooked pork. Foodborne Pathog Dis 2009; 6:699-704. [PMID: 19580455 DOI: 10.1089/fpd.2009.0279] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Crude ethanolic extract from the bulb of Eleutherine americana was investigated for its inhibitory activities against lipase and protease enzymes and enterotoxin production by Staphylococcus aureus. Eleven isolates that demonstrated high enzyme activity with three reference strains were selected to study the effect of extract on enzyme production. Exposure of the isolates to subminimal inhibitory concentrations, (1/2) minimum inhibitory concentration (MIC) (125 microg/mL), and (1/4)MIC (62.5 microg/mL) of the crude extract resulted in both partial and total inhibition of lipase and protease enzymes. About 15% of the 106 isolates were positive for enterotoxin production with staphylococcal enterotoxin A (11.3%), enterotoxin B (3.7%), and enterotoxin C (10.3%), and no enterotoxin D was produced. The production of staphylococcal enterotoxins A-D in the presence or absence of the crude extract was carried out. In the broth system, the extract reduced enterotoxin production at subminimal inhibitory concentrations compared with the control. At MIC, total enterotoxin inhibition was observed for enterotoxin C production, whereas synthesis of enterotoxins A, B, and D was totally eliminated at 2MIC. The food system study revealed that the extract could delay production of enterotoxins A, B, and C compared with the control. The extract at 2 mg/mL delayed production of toxins A and C for 8 and 4 h, while toxin B was not detected in the pork at 48 h. The ability of E. americana extract to inhibit lipase and protease enzymes and to delay enterotoxin production in food could present it as a novel food additive to combat the growth of S. aureus in food.
Collapse
Affiliation(s)
- Beatrice O T Ifesan
- Department of Microbiology, Natural Products Research Centre, Prince of Songkla University, Thailand
| | | |
Collapse
|
19
|
Pelisser MR, Klein CS, Ascoli KR, Zotti TR, Arisi ACM. Ocurrence of Staphylococcus aureus and multiplex pcr detection of classic enterotoxin genes in cheese and meat products. Braz J Microbiol 2009; 40:145-8. [PMID: 24031334 PMCID: PMC3768504 DOI: 10.1590/s1517-838220090001000025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 06/29/2008] [Accepted: 11/02/2008] [Indexed: 11/22/2022] Open
Abstract
Multiplex PCR was used to investigate the presence of enterotoxins genes (sea, seb, sec, sed and see) and femA gene (specific for Staphylococcus aureus) in coagulase-positive staphylococci (CPS) isolated from cheese and meat products. From 102 CPS isolates, 91 were positive for femA, 10 for sea, 12 for sed and four for see.
Collapse
Affiliation(s)
- Marcia Regina Pelisser
- Departamento de Ciência e Tecnologia de Alimentos, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina , Florianópolis, SC , Brasil ; Universidade do Contestado , Concórdia, SC , Brasil
| | | | | | | | | |
Collapse
|
20
|
Freitas MFD, Luz IDS, Silveira-Filho VDM, W.P. Júnior J, Stamford TL, Mota RA, Sena MJD, Almeida AMD, Balbino VDQ, Leal-Balbino TC. Staphylococcal toxin genes in strains isolated from cows with subclinical mastitis. PESQUISA VETERINARIA BRASILEIRA 2008. [DOI: 10.1590/s0100-736x2008001200010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study was carried out in 11 dairy herds in four municipal districts of the rural area of the State of Pernambuco, Brazil. Out of 984 quarter milk (246 cows), 10 (1.0%) were positive for clinical mastitis, 562 (57.1%) for subclinical mastitis and 412 (41.9%) were negative. A total of 81 Staphylococcus spp. isolates were obtained from milk samples from the cows diagnosed with subclinical mastitis. From these, 53 (65.0%) were S. aureus, 16 (20.0%) coagulase-positive staphylococci (CPS) and 12 (15.0%) coagulase-negative staphylococci (CNS). The isolates were further investigated for the presence of toxin genes by multiplex and uniplex PCR. The main gene observed was seg followed by seh, sei and sej. The distribution of these observed genes among the isolates obtained from different areas showed a regional pattern for the SEs. The presence of toxin genes in the strains isolated from bovine milk demonstrates a potential problem for public health.
Collapse
|
21
|
Rapid and Sensitive Detection of Staphylococcus aureus in Food Using Selective Enrichment and Real-Time PCR Targeting a New Gene Marker. FOOD ANAL METHOD 2008. [DOI: 10.1007/s12161-008-9056-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
22
|
Lee KH, Lee JW, Wang SW, Liu LY, Lee MF, Chuang ST, Shy YM, Chang CL, Wu MC, Chi CH. Development of a Novel Biochip for Rapid Multiplex Detection of Seven Mastitis-Causing Pathogens in Bovine Milk Samples. J Vet Diagn Invest 2008; 20:463-71. [DOI: 10.1177/104063870802000408] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
To efficiently prevent and treat bovine mastitis and minimize its effect on the dairy industry, a sensitive, rapid, and specific test is required for identifying the mastitis-causing pathogens. In this study, a biochip capable of detecting 7 common species of mastitis-causing pathogens, including Corynebacterium bovis, Mycoplasma bovis, Staphylococcus aureus, and the Streptococcus spp. S. agalactiae, S. bovis, S. dysgalactiae, and S. uberis, within 6 hr was developed. The technique is based on DNA amplification of genes specific to the target pathogens and consists of 4 basic steps: DNA extraction of bacteria, polymerase chain reaction, DNA hybridization, and colorimetric reaction. To examine the accuracy and specificity of this biochip, a preliminary test with 82 random quarter milk samples were analyzed and compared with results from conventional microbiological methods conducted simultaneously. Results from all but 1 sample analyzed by the biochip were in agreement with those analyzed by bacteriology. The biochip could be a feasible tool for rapidly diagnosing mastitis-causing pathogens in milk and providing information for a more effective treatment to cure mastitis.
Collapse
Affiliation(s)
| | - Jai-Wei Lee
- Council of Agriculture, Taiwan Livestock Research Institute, Taiwan; the Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Taiwan
| | - Shih-Wen Wang
- Dr. Chip Biotechnology Inc., Chu-Nan, Miao-Li, Taiwan
| | - Lu-Yuan Liu
- Dr. Chip Biotechnology Inc., Chu-Nan, Miao-Li, Taiwan
| | - Mei-Fen Lee
- Dr. Chip Biotechnology Inc., Chu-Nan, Miao-Li, Taiwan
| | - Shih-Te Chuang
- the Department of Veterinary Medicine, National Chunghsin University, Taiwan
| | | | | | | | - Chau-Hwa Chi
- The Department of Veterinary Medicine, National Taiwan University, Taiwan
| |
Collapse
|
23
|
Cremonesi P, Perez G, Pisoni G, Moroni P, Morandi S, Luzzana M, Brasca M, Castiglioni B. Detection of enterotoxigenic Staphylococcus aureus isolates in raw milk cheese. Lett Appl Microbiol 2007; 45:586-91. [DOI: 10.1111/j.1472-765x.2007.02231.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Kubota M, Hayashi T, Iwasaki K, Ohtsuka H, Kohiruimaki M, Kawamura S, Sakaguchi K, Abe R. Rapid and effective method for separation of Staphylococcus aureus from somatic cells in mastitis milk. J Dairy Sci 2007; 90:4100-7. [PMID: 17699027 DOI: 10.3168/jds.2006-671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Quantitative PCR can be an effective method for identifying the bacteria causing mastitis. However, PCR detection is hampered by the presence of inflammatory somatic cells. To eliminate this problem, we attempted to establish methods that allow the effective separation of bacterial cells from somatic cells in mastitis milk with amino-silica. Somatic cells and Staphylococcus aureus cells have different sizes, surface structures, and overall electrical charges; therefore, their adsorption and desorption behavior on amino-silica was also different. We found that although amino-silica could efficiently adsorb both somatic cells and Staph. aureus, somatic cells were adsorbed much more strongly than bacterial cells. We identified conditions under which most of the somatic cells adsorbed and only Staph. aureus desorbed from amino-silica upon addition of a desorption solution. We demonstrated that this procedure effectively eliminated somatic cells in heavily contaminated milk samples, which resulted in improved clarity of the PCR band. These results indicate that pretreatment of the samples with amino-silica made the PCR-based strategy for identifying and quantifying disease-causing bacteria applicable for all milk samples.
Collapse
Affiliation(s)
- M Kubota
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Cremonesi P, Castiglioni B, Malferrari G, Biunno I, Vimercati C, Moroni P, Morandi S, Luzzana M. Technical Note: Improved Method for Rapid DNA Extraction of Mastitis Pathogens Directly from Milk. J Dairy Sci 2006; 89:163-9. [PMID: 16357279 DOI: 10.3168/jds.s0022-0302(06)72080-x] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Efficient control against bovine mastitis requires sensitive, rapid, and specific tests to detect and identify the main bacteria that cause heavy losses to the dairy industry. Molecular detection of pathogenic microorganisms is based on DNA amplification of the target pathogen. Therefore, efficient extraction of DNA from pathogenic bacteria is a major step. In this study, we aimed to develop a specific, sensitive, and rapid method to extract DNA directly from the main gram-positive bacteria known to cause bovine mastitis (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis) found in milk samples. The DNA extraction method is based on the lysing and nuclease-inactivating properties of the chaotropic agent, guanidinium thiocyanate, together with the nucleic acid-binding properties of the silica particles. An efficient protocol consisting of 6 basic steps (3 of which were done twice) was developed and applied directly to milk samples. Absence of PCR inhibitors and DNA quality were evaluated by PCR amplification of the species-specific DNA sequences of the target bacteria. The level of sensitivity achieved in our experiments is applicable to milk sample analysis without sample enrichment.
Collapse
Affiliation(s)
- P Cremonesi
- Department of Biomedical Sciences and Technologies, University of Milan, Segrate, Milan, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Ercolini D, Fusco V, Blaiotta G, Sarghini F, Coppola S. Response of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Staphylococcus aureus to the Thermal Stress Occurring in Model Manufactures of Grana Padano Cheese. J Dairy Sci 2005; 88:3818-25. [PMID: 16230687 DOI: 10.3168/jds.s0022-0302(05)73067-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The purpose of this research was to investigate the effect of temperature in the technology of production of Grana cheese against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Staphylococcus aureus. According to the technology of production, the cheese curds are cooked at 55 degrees C and then cooled at room temperature (25 degrees C). A curd-cooling model was developed to estimate the temperature variation across the curd during cooling, and the thermal stress was applied to the pathogens according to the model in model-scale productions of Grana cheese artificially contaminated with approximately 10(4) cfu/mL of the selected pathogens. According to the numerical results, the initial temperature inside the cheese is kept at almost the initial value (above 50 degrees C) for at least 4 h during cooling, whereas the crust of the curd cools rapidly to 30 degrees C in the first hour. The best case was that of the core of the cheese where the high temperature was able to efficiently eliminate the contaminating pathogens. Moreover, the worst case was where the external ring of the curd in which a more rapid cooling allowed bacterial survival. Therefore, the thermal stress in the technology of production of Grana cheese can be only partially effective in the control of the selected pathogens. However, the whole technology of production includes other hurdles that can affect the survival of the pathogens and that need to be taken into account as a whole to evaluate the safety of Grana Padano cheese.
Collapse
Affiliation(s)
- D Ercolini
- Dipartimento di Scienza degli Alimenti, Sezione di Microbiologia Agraria, Alimentare e Ambientale e di Igiene, Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Italy.
| | | | | | | | | |
Collapse
|
27
|
BARUZZI FEDERICO, MATARANTE ALESSANDRA, CAPUTO LEONARDO, MOREA MARIA. DEVELOPMENT OF A CULTURE-INDEPENDENT POLYMERASE CHAIN REACTION-BASED ASSAY FOR THE DETECTION OF LACTOBACILLI IN STRETCHED CHEESE. ACTA ACUST UNITED AC 2005. [DOI: 10.1111/j.1745-4581.2005.00018.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
28
|
Blaiotta G, Ercolini D, Pennacchia C, Fusco V, Casaburi A, Pepe O, Villani F. PCR detection of staphylococcal enterotoxin genes in Staphylococcus spp. strains isolated from meat and dairy products. Evidence for new variants of seG and seI in S. aureus AB-8802. J Appl Microbiol 2004; 97:719-30. [PMID: 15357721 DOI: 10.1111/j.1365-2672.2004.02349.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS Evaluation of the occurrence of most known staphylococcal enterotoxin (SE) genes, egc (enterotoxin gene cluster) and TSST1 (toxic shock syndrome toxin 1) gene in both coagulase-positive (CPS) and coagulase-negative (CNS) staphylococcal strains isolated from meat and dairy products. METHODS AND RESULTS Specificity and reliability of the PCR detection methods used were ascertained by using nine reference strains of Staphylococcus (S. aureus) harbouring SE genes (seA to seE; seG, seH, seI, seM, seJ, seN and seO) and egc (containing the following sequence of genes: seO, seM, seI, phient1, phient2, seN and seG). Of 109 wild Staphylococcus spp. strains analysed, only 11 S. aureus strains were SE and/or TSST1 PCR-positive. The last 11 strains also appeared to harbour the egc. Restriction endonuclease analysis of part of the egc of both reference and wild strains showed that different variants of the egc exist. Moreover, nucleotide sequences of seG and seI indicate that the egc of the strain AB-8802 is characterized by the presence of variants of these enterotoxins (seGv and seIv). CONCLUSIONS The occurrence of SE genes in CNS and other non-S. aureus species isolated from Napoli-type salami, raw water buffalo milk and natural whey cultures used for mozzarella cheese manufacturing is very rare. SIGNIFICANCE AND IMPACT OF THE STUDY During this study it was shown that at least five different egc may exist in S. aureus. A thorough study of egc polymorphism should provide further insight into the phylogenetics of the egc.
Collapse
Affiliation(s)
- G Blaiotta
- Dipartimento di Scienza degli Alimenti, Sezione di Microbiologia Agraria, Alimentare, Ambientale e di Igiene, Stazione di Microbiologia Industriale, Università degli Studi di Napoli Federico II, Via Università, Portici, Italy
| | | | | | | | | | | | | |
Collapse
|