Performance of a chromogenic medium for the isolation of Listeria monocytogenes in food

Aragón-Alegro, Lina Casale; Aragon, Davi Casale; Martinez, Edson Zangiacomi; Landgraf, Mariza; Franco, Bernadette Dora Gombossy de Melo; Destro, Maria Teresa

doi:10.1016/j.foodcont.2007.05.013

Cited by 17 publications

(9 citation statements)

References 7 publications

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“…For example, the sensitivity and specificity differed among six ALOA-type media and PALCAM used to detect L. monocytogenes in fish, meat products, and other foodstuffs (18); sensitivities and specificities ranged from 83.3 to 96.7% and from 50.0 to 94.4%, respectively. The same phenomenon occurred when CHROMagar used to detect L. monocytogenes in sliced cooked ham (sensitivity of 56.2%, specificity of 73.6%), ground beef meat (sensitivity of 92.7%, specificity of 76.8%), and frankfurters (sensitivity of 91.2%, specificity of 84.2%) (2).…”

Section: Resultsmentioning

confidence: 64%

Retraction

Mataragas²,

Karaberi³

et al. 2012

j food prot

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Listeria monocytogenes poses a serious threat to public health, and the majority of cases of human listeriosis are associated with contaminated food. Reliable microbiological testing is needed for effective control of this pathogen by the food industry and competent authorities. The aim of this study was to determine the performance of three culture media commonly used for detecting L. monocytogenes in foods. Minced pork meat samples (n = 100) were subjected to microbiological testing for L. monocytogenes according to International Organization for Standardization methods 11290-1:1996 and 11290-2:1998 using PALCAM, ALOA, and RAPID'L. mono culture media in parallel. Presence of the pathogen was confirmed by conducting biochemical and molecular tests on the presumptive L. monocytogenes colonies. Performance attributes of sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, diagnostic odds ratios, error odds ratios, receiving operating characteristic (ROC) curve, and area under this curve were calculated from the presence-absence microbiological test results by combining the results obtained from the culture media and confirmative tests. PALCAM had the best performance in terms of positive predictive value (i.e., a positive result indicates high probability of L. monocytogenes presence) but not in terms of sensitivity (i.e., the ability of the medium to detect the pathogen when present). RAPID'L. mono was the most sensitive medium. None of the culture media were perfect for detecting L. monocytogenes in minced pork meat alone. The pathogen was detected in 16, 19, and 26% (apparent prevalence) of the samples by PALCAM, ALOA, and RAPID'L. mono, respectively, although the true prevalence of the pathogen was 22%. These findings indicate that the use of a single culture medium may lead to erroneous determination of the prevalence of L. monocytogenes.

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Section: Resultsmentioning

confidence: 64%

Retraction

Mataragas²,

Karaberi³

et al. 2012

j food prot

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“…The beta distributions of the se parameter of each medium are displayed in Table 5. The beta distributions for the combination of media were the following: beta(28, 1) and beta (17,1) for ALOA plus RAPID'L.wono and Fluorocult plus CT-SMAC, respectively, in rocket samples and beta (25,3) and beta(19, 1) for ALOA plus RAPID 'L.mono and Fluorocult plus CT-SMAC, respectively, in cucumber samples. Based on these data, pathogen levels were estimated ( Table 5).…”

Section: Resultsmentioning

confidence: 99%

“…For instance, the sensitivity of ALOA used with rocket samples was modeled by a prior where a 95% prior probability interval was (0.780, 0.998), with a prior best guess of 0.938. Such a probability corresponded to the following distribu tion: beta (15,1). In the same way, the beta distributions for the sensitivity and specificity of all media in both food products were calculated (Table 4).…”

Section: Resultsmentioning

confidence: 99%

Estimation of Listeria monocytogenes and Escherichia coli O157:H7 Prevalence and Levels in Naturally Contaminated Rocket and Cucumber Samples by Deterministic and Stochastic Approaches

Hadjilouka

Mantzourani

Katsarou

et al. 2015

Journal of Food Protection

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The aims of the present study were to determine the prevalence and levels of Listeria monocytogenes and Escherichia coli O157:H7 in rocket and cucumber samples by deterministic (estimation of a single value) and stochastic (estimation of a range of values) approaches. In parallel, the chromogenic media commonly used for the recovery of these microorganisms were evaluated and compared, and the efficiency of an enzyme-linked immunosorbent assay (ELISA)-based protocol was validated. L. monocytogenes and E. coli O157:H7 were detected and enumerated using agar Listeria according to Ottaviani and Agosti plus RAPID' L. mono medium and Fluorocult plus sorbitol MacConkey medium with cefixime and tellurite in parallel, respectively. Identity was confirmed with biochemical and molecular tests and the ELISA. Performance indices of the media and the prevalence of both pathogens were estimated using Bayesian inference. In rocket, prevalence of both L. monocytogenes and E. coli O157:H7 was estimated at 7% (7 of 100 samples). In cucumber, prevalence was 6% (6 of 100 samples) and 3% (3 of 100 samples) for L. monocytogenes and E. coli O157:H7, respectively. The levels derived from the presence-absence data using Bayesian modeling were estimated at 0.12 CFU/25 g (0.06 to 0.20) and 0.09 CFU/25 g (0.04 to 0.170) for L. monocytogenes in rocket and cucumber samples, respectively. The corresponding values for E. coli O157:H7 were 0.59 CFU/25 g (0.43 to 0.78) and 1.78 CFU/25 g (1.38 to 2.24), respectively. The sensitivity and specificity of the culture media differed for rocket and cucumber samples. The ELISA technique had a high level of cross-reactivity. Parallel testing with at least two culture media was required to achieve a reliable result for L. monocytogenes or E. coli O157:H7 prevalence in rocket and cucumber samples.

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“…136 (4th edition, revised 2007) 12e25 cfu/25 g soft white mould Brie cheese, hot smoked salmon vacuum-packed, cooked ham vacuum-packed, wheat grain (Loncarevic et al, 2008) substrate for PI-PLC, 5-bromo-4-chloro-3-indolyl-myo-inositol-1-phosphat (X-IP), which results in blue colonies (Janzten et al, 2006). Aragon-Alegro et al (2008) have tested the performance of CHROMagarÔ in the examination of meat products. Hegde et al (2007) have investigated BBL CHROMagarÔ Listeria in various food products and environmental samples and confirmed the results with a visual immunoassay (TECRA) and the USDA-FSIS method.…”

Section: <0mentioning

confidence: 99%