Enumeration of micro-organisms in processed soy products with an automated most probable number method compared with standard plate method

Katase, Mitsuru; Tsumura, Kyosuke

doi:10.1111/j.1472-765x.2011.03143.x

Cited by 20 publications

(10 citation statements)

References 16 publications

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“…The TEMPO system is an automated most probable number (MPN), which is based on the measurements of fluorescence method for enumerating aerobic bacteria and specific pathogens in foods [48][49][50]. Further, our results are in accordance with those observed by Katase and Tsumura [51], Blagoeva et al [52], and Łobacz et al [53], who compared the results of the TEMPO system with the corresponding methods to enumerate total aerobic bacteria, coliforms, Enterobacteriaceae, yeast and mold, S. aureus, and lactic acid bacteria. Moreover, comparisons of different methods for quantifying L. monocytogenes biofilms have shown that among the indirect counting methodologies, the one that gives the best results is the TEMPO system [54].…”

Section: Bacterial Enumeration On Polymer Surfacessupporting

confidence: 90%

Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Fontecha‐Umaña

Ríos-Castillo

Ripolles‐Avila

et al. 2020

Foods

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Food contact surfaces are primary sources of bacterial contamination in food industry processes. With the objective of preventing bacterial adhesion and biofilm formation on surfaces, this study evaluated the antimicrobial activity of silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticle-containing polyester surfaces (concentration range from 400 ppm to 850 ppm) using two kinds of bacteria, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli), and the prevention of bacterial biofilm formation using the pathogen Listeria monocytogenes. The results of antimicrobial efficacy (reductions ≥ 2 log CFU/cm 2 ) showed that at a concentration of 850 ppm, ZnO-NPs were effective against only E. coli (2.07 log CFU/cm 2 ). However, a concentration of 400 ppm of Ag-NPs was effective against E. coli (4.90 log CFU/cm 2 ) and S. aureus (3.84 log CFU/cm 2 ). Furthermore, a combined concentration of 850 ppm Ag-NPs and 400 ppm ZnO-NPs showed high antimicrobial efficacy against E. coli (5.80 log CFU/cm 2 ) and S. aureus (4.11 log CFU/cm 2 ). The results also showed a high correlation between concentration levels and the bacterial activity of Ag-ZnO-NPs (R 2 = 0.97 for S. aureus, and R 2 = 0.99 for E. coli). They also showed that unlike individual action, the joint action of Ag-NPs and ZnO-NPs has high antimicrobial efficacy for both types of microorganisms. Moreover, Ag-NPs prevent the biofilm formation of L. monocytogenes in humid conditions of growth at concentrations of 500 ppm. Additional studies under different conditions are needed to test the durability of nanoparticle containing polyester surfaces with antimicrobial properties to optimize their use.Foods 2020, 9, 442 2 of 15 studies include the development of antimicrobial surfaces capable of preventing and/or inhibiting bacterial adhesion [8][9][10][11].Metal agents such as silver, copper, zinc, titanium, and cobalt have antimicrobial properties. When these agents remain on surfaces, their biocidal properties are gradually released onto the surface through a process of ion exchange, providing continuous, lasting antimicrobial activity [12][13][14]. The biocidal properties of metal agents depend on the characteristics of their nanoparticles, such as size, distribution, morphology, and the release of very small quantities of their cations on the substrates on which they are acting [15,16]. The antimicrobial activity of these agents is also affected by extrinsic factors, such as the pH of the medium, time of exposure, concentration, UV radiation, and the presence of other substances or microorganisms [17][18][19].Two of the most extended nanocomposites for antibacterial purposes are silver and zinc oxides embedded in polymeric matrices [20][21][22]. The antimicrobial activity of silver (Ag) and zinc (Zn) repels or inhibits the initial attachment of bacteria by either exhibiting an anti-biofouling effect or by inactivating cells in contact with surfaces, causing their death [23,24]. Additionally, the antibacterial properties of these agents reduce the risk o...

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Section: Bacterial Enumeration On Polymer Surfacessupporting

confidence: 90%

Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Fontecha‐Umaña

Ríos-Castillo

Ripolles‐Avila

et al. 2020

Foods

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“…These values can be ranked as good in method comparison studies according to correlation ranking index described by Ferrati et al (2005). Similarly in the study of Katase and Tsumura (2011), a remarkable correlation (r = 0.96) was determined between TEMPO STA and mannitol salt agar in artificially contaminated processed soy products.…”

Section: Discussionmentioning

confidence: 98%

Evaluation of TEMPO STA for the Enumeration of Coagulase-positive Staphylococci in Cheese

Torlak¹,

Akan

2012

FSTR

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TEMPO STA is based on traditional most probable number technique and is a test for use with the TEMPO system for an automated enumeration of coagulase-positive staphylococci in 24 h in food products. In this study, TEMPO STA was compared with Baird-Parker (BP) agar which is the most cited medium in reference methods for the enumeration of coagulase-positive staphylococci in cheese. A method comparisons study was conducted both artificially and naturally contaminated cheese samples. Pearson correlation coefficients were determined as 0.875 and 0.897 between the two methods for naturally and artificially contaminated samples, respectively. In general, absolute differences did not exceed one log between results obtained by the two methods. According to intra-laboratory reproducibility standard deviation of two methods, TEMPO STA was more precise than BP agar. The results of this study showed that TEMPO STA is an efficient alternative method for the enumeration of coagulase-positive staphylococci in cheese.Keywords: coagulase-positive staphylococci, TEMPO STA, Baird-Parker agar, method comparison, cheese *To whom correspondence should be addressed. E-mail: torlakemrah@yahoo.com IntroductionSeveral mass outbreaks of food-borne diseases especially related to dairy products showed that food-borne disease outbreaks have become an important risk for public health (Greig and Ravel 2009;Tauxe et al., 2010). The burden of foodborne diseases on the economy is also substantial (Scharff et al., 2009). In spite of the increase in the number of food companies that implemented the HACCP system, the incidence of food-borne diseases in many development countries is increasing especially due to the increase in production and distribution capabilities of the food industry (WHO, 2003).Staphylococcal food poisoning is one of the most common food-borne diseases throughout the world resulting from the consumption of foods containing sufficient amounts of preformed staphylococcal enterotoxins by enterotoxigenic strains of coagulase-positive staphylococci (CPS). It is mainly concerned with Staphylococcus aureus, but also with S. intermedius and certain strains of S. hyicus (Balaban and Rasooly, 2000;Le Loir et al., 2003;Argudin et al., 2010). For S. aureus strains, there is a high correlation (93% to 100%) between coagulase production and the production of enterotoxins (Martin and Myers, 1994).Although the Baird-Parker (BP) agar was first introduced in 1962 by Baird-Parker (Baird-Parker, 1962), this medium is still widely used by food microbiology laboratories, especially official laboratories, for enumeration of CPS. First part of the current ISO standard (ISO, 1999) describes the use of BP agar for enumeration of CPS in foods with the plate count technique. A further confirmation step is necessary to detect coagulase activity in BP agar method. The selectivity of the BP agar is due to lithium chloride and potassium tellurite solution, suppressing growth of organisms other than staphylococci. The differentiation of CPS is performed by pot...

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“…Thus, rapid identification of bacteria is as important as enumeration of bacteria (Katase and Tsumura, 2011;Tsumura and Tsuboi, 2012;Katase et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

High-Throughput Identification of Coliforms in Processed Soybean Products Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

Katase

Tsumura

2014

FSTR

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Enumeration of micro-organisms in processed soy products with an automated most probable number method compared with standard plate method

Cited by 20 publications

References 16 publications

Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Evaluation of TEMPO STA for the Enumeration of Coagulase-positive Staphylococci in Cheese

High-Throughput Identification of Coliforms in Processed Soybean Products Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

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