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Enrichment Broth (enrichment + broth)
Selected AbstractsA STUDY ON SUITABILITY OF FOUR ENRICHMENT BROTHS FOR PCR-BASED DETECTION OF LISTERIA MONOCYTOGENES FROM RAW MEATJOURNAL OF FOOD SAFETY, Issue 1 2006J. BALAMURUGAN ABSTRACT Four enrichment broths were evaluated for their compatibility with the polymerase chain reaction (PCR) for detection of Listeria monocytogenes from raw meat after single-step enrichment. Standardized PCR protocols for listeriolysin O (hlyA) gene were used for the species-specific identification of L. monocytogenes. Four broths, namely, modified University of Vermont broth (MUVM), Listeria enrichment broth (LEB), Fraser broth (FB) and polymyxin, acriflavin, lithium chloride, ceftazidime, aesculin, mannitol, egg yolk broth (PALCAM) , were inoculated with L. monocytogenes. The enriched cultures were subjected for PCR. Similarly, meat samples were artificially spiked with various concentrations of L. monocytogenes, these spiked samples were enriched in the above-mentioned four broths and subjected to PCR to determine the medium that was most compatible for PCR-based detection of L. monocytogenes. The aliquots taken during different incubation periods were subjected to three different procedures for the concentration of the target organism for use in PCR. Results revealed that MUVM was better than other broths for the detection of L. monocytogenes by both PCR and cultural method; moreover, it was able to support the growth of as low as 10 cfu/g of meat. Concentration of the target organisms by centrifugation and washing with PCR buffer was the most suitable method for improving PCR performance for detection of L. monocytogenes. Goat (n = 67) and buffalo (n = 45) meat samples from local markets were also screened by both PCR and cultural method to validate the results obtained from the spiking studies. Both results were in agreement in spiking studies as well as screening of market meat samples. [source] Comparison of three enrichment media for the isolation of Campylobacter spp. from foodsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2000C.L. Baylis Aim: This study compared the performance of three Campylobacter enrichment broths: Bolton broth (BB), Campylobacter Enrichment broth (CEB) and Preston broth (PB). Methods and Results: Pure cultures of target and competitor organisms, and naturally-contaminated food samples, were used to establish the performance of these media. In pure culture the PB supported the growth of the greatest number of strains of Campylobacter spp. but failed to inhibit some competitor organisms. The CEB showed the opposite result, inhibiting all 15 competitor organisms used but failing to support the growth of five Campylobacter strains. By comparison, BB showed the best compromise between inhibition of competitors and growth of Campylobacter. Conclusions: Plates inoculated with BB and CEB food enrichments resulted in more Campylobacter growth than those inoculated with PB, which supported significantly less typical growth (P , 0·001). The most common competitor organism isolated from PB was Escherichia coli, and Pseudomonas spp. were frequently isolated from BB and CEB. Both BB and CEB were better than PB for the isolation of Campylobacter from naturally-contaminated foods, although BB yielded more confirmed Campylobacter growth than CEB. Significance and Impact of the Study: This study highlighted differences in performance of media used to isolate Campylobacter spp. from foods. [source] A STUDY ON SUITABILITY OF FOUR ENRICHMENT BROTHS FOR PCR-BASED DETECTION OF LISTERIA MONOCYTOGENES FROM RAW MEATJOURNAL OF FOOD SAFETY, Issue 1 2006J. BALAMURUGAN ABSTRACT Four enrichment broths were evaluated for their compatibility with the polymerase chain reaction (PCR) for detection of Listeria monocytogenes from raw meat after single-step enrichment. Standardized PCR protocols for listeriolysin O (hlyA) gene were used for the species-specific identification of L. monocytogenes. Four broths, namely, modified University of Vermont broth (MUVM), Listeria enrichment broth (LEB), Fraser broth (FB) and polymyxin, acriflavin, lithium chloride, ceftazidime, aesculin, mannitol, egg yolk broth (PALCAM) , were inoculated with L. monocytogenes. The enriched cultures were subjected for PCR. Similarly, meat samples were artificially spiked with various concentrations of L. monocytogenes, these spiked samples were enriched in the above-mentioned four broths and subjected to PCR to determine the medium that was most compatible for PCR-based detection of L. monocytogenes. The aliquots taken during different incubation periods were subjected to three different procedures for the concentration of the target organism for use in PCR. Results revealed that MUVM was better than other broths for the detection of L. monocytogenes by both PCR and cultural method; moreover, it was able to support the growth of as low as 10 cfu/g of meat. Concentration of the target organisms by centrifugation and washing with PCR buffer was the most suitable method for improving PCR performance for detection of L. monocytogenes. Goat (n = 67) and buffalo (n = 45) meat samples from local markets were also screened by both PCR and cultural method to validate the results obtained from the spiking studies. Both results were in agreement in spiking studies as well as screening of market meat samples. [source] Effect of heat treatment on Cronobacter spp. in reconstituted, dried infant formula: preparation guidelines for manufacturersLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2009P.-C. Chen Abstract Aim:, To explore safe guidelines for manufacturers and consumers to prepare, handle and store dry infant formula (DIF) to protect infants against Cronobacter spp. Methods and Results:, Selected strains (2.45, FSM 293, ATCC-12868, FSM-271) screened from 68 strains of Cronobacter spp. were used to study growth and survival in commercial DIF. Prototype growth patterns in Enterobacteriaceae enrichment broth (EEB) containing a cocktail comprised of ATCC 12868, ATCC 29004, ATCC 29544 and ATCC 51329 showed a rapid increase in cell count (2·0 log10 to 6·2 log10 CFU ml,1). Infant formula provided a better protective environment for the cells of Cronobacter strains than did buffered peptone water. Experiments on survival in inoculated (104,106 CFU ml,1) reconstituted infant formula (RIF), preparation temperature, the effect of preparation volume (one-serving or two-serving) and effect of storage at room temperature for up to 10 h provided information to develop consumer guidelines for DIF preparation and handling. Conclusions:, Reconstituted DIF in water at >70°C in larger volumes, minimizing storage time before feeding and storing unused reconstituted formulate at <4°C, may reduce the risk of Cronobacter infection in infants. Significance and Impact of the Study:, Meningitis, necrotizing enterocolitis and bacteremia in premature babies has been linked to contaminated milk powder and DIF; better handling practices may improve the safety of these foods for neonates. [source] A selective broth enrichment combined with real-time nuc-mecA -PCR in the exclusion of MRSAAPMIS, Issue 1 2010TANJA PASANEN Pasanen T, Korkeila M, Mero S, Tarkka E, Piiparinen H, Vuopio-Varkila J, Vaara M, Tissari P. A selective broth enrichment combined with real-time nuc-mecA -PCR in the exclusion of MRSA. APMIS 2010; 118: 74,80. We analyzed the performance of a selective enrichment broth combined with Taqman-based real-time duplex nuc-mecA -PCR to expedite the screening of methicillin-resistant Staphylococcus aureus (MRSA). We found the broth to be able to select MRSA strains (oxacillin MIC range 4,256 ,g/ml) from MSSA strains. A total of 31 MRSA strains were found from 1250 clinical samples screened. The nuc-mecA -PCR was positive from all enrichment broths containing MRSA. From the remaining 1219 samples negative for MRSA on culture/subculture, 138 samples were nuc+/mecA+ in PCR. The sensitivity of the test was 93.5%, specificity 88.6%, positive predictive value 17.3%, and negative predictive value 99.8% as compared to culture. Thus, with this method, the negative MRSA results can be reliably reported within 24,48 h from sampling. The method is a practical additional alternative to those already described for the same purpose. [source] Comparison of three enrichment media for the isolation of Campylobacter spp. from foodsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2000C.L. Baylis Aim: This study compared the performance of three Campylobacter enrichment broths: Bolton broth (BB), Campylobacter Enrichment broth (CEB) and Preston broth (PB). Methods and Results: Pure cultures of target and competitor organisms, and naturally-contaminated food samples, were used to establish the performance of these media. In pure culture the PB supported the growth of the greatest number of strains of Campylobacter spp. but failed to inhibit some competitor organisms. The CEB showed the opposite result, inhibiting all 15 competitor organisms used but failing to support the growth of five Campylobacter strains. By comparison, BB showed the best compromise between inhibition of competitors and growth of Campylobacter. Conclusions: Plates inoculated with BB and CEB food enrichments resulted in more Campylobacter growth than those inoculated with PB, which supported significantly less typical growth (P , 0·001). The most common competitor organism isolated from PB was Escherichia coli, and Pseudomonas spp. were frequently isolated from BB and CEB. Both BB and CEB were better than PB for the isolation of Campylobacter from naturally-contaminated foods, although BB yielded more confirmed Campylobacter growth than CEB. Significance and Impact of the Study: This study highlighted differences in performance of media used to isolate Campylobacter spp. from foods. [source] A STUDY ON SUITABILITY OF FOUR ENRICHMENT BROTHS FOR PCR-BASED DETECTION OF LISTERIA MONOCYTOGENES FROM RAW MEATJOURNAL OF FOOD SAFETY, Issue 1 2006J. BALAMURUGAN ABSTRACT Four enrichment broths were evaluated for their compatibility with the polymerase chain reaction (PCR) for detection of Listeria monocytogenes from raw meat after single-step enrichment. Standardized PCR protocols for listeriolysin O (hlyA) gene were used for the species-specific identification of L. monocytogenes. Four broths, namely, modified University of Vermont broth (MUVM), Listeria enrichment broth (LEB), Fraser broth (FB) and polymyxin, acriflavin, lithium chloride, ceftazidime, aesculin, mannitol, egg yolk broth (PALCAM) , were inoculated with L. monocytogenes. The enriched cultures were subjected for PCR. Similarly, meat samples were artificially spiked with various concentrations of L. monocytogenes, these spiked samples were enriched in the above-mentioned four broths and subjected to PCR to determine the medium that was most compatible for PCR-based detection of L. monocytogenes. The aliquots taken during different incubation periods were subjected to three different procedures for the concentration of the target organism for use in PCR. Results revealed that MUVM was better than other broths for the detection of L. monocytogenes by both PCR and cultural method; moreover, it was able to support the growth of as low as 10 cfu/g of meat. Concentration of the target organisms by centrifugation and washing with PCR buffer was the most suitable method for improving PCR performance for detection of L. monocytogenes. Goat (n = 67) and buffalo (n = 45) meat samples from local markets were also screened by both PCR and cultural method to validate the results obtained from the spiking studies. Both results were in agreement in spiking studies as well as screening of market meat samples. [source] | ||||||||||