ICMSF methods studies. VI. The influence of selective enrichment media and incubation temperatures on the detection of Salmonella in dried foods and feeds

1974 ◽  
Vol 20 (11) ◽  
pp. 1509-1511 ◽  
Author(s):  
D. A. Gabis ◽  
J. H. Silliker
Keyword(s):  
Brilliant Green ◽  
Selective Enrichment ◽  
Significant Difference ◽  
Low Moisture Foods ◽  
Incubation Temperatures ◽  
Red Meats ◽  
Enrichment Condition ◽  
By Products ◽  
Dried Foods

Recovery of Salmonella from low-moisture foods was studied using selective enrichment in tetrathionate brilliant green and selenite-cystine broths at 35C and 43C. A total of 1375 samples of dried dairy, soya, and rendered animal by-products were analyzed. All samples were preenriched before selective enrichment. No significant difference in recovery was detected between tetrathionate brilliant green and selenite cystine at either temperature, which is in contrast to our earlier findings with red meats. Pairing of enrichment conditions resulted in the detection of more positive samples than the use of any single enrichment condition.

ICMSF methods studies. IX. The influence of selective enrichment broths, differential planting media, and incubation temperatures on the detection of Salmonella in dried foods and feed ingredients

1977 ◽  
Vol 23 (9) ◽  
pp. 1225-1231 ◽  
Author(s):  
D. A. Gabis ◽  
J. H. Silliker
Keyword(s):  
Elevated Temperature ◽  
Brilliant Green ◽  
The Other ◽  
Feed Ingredients ◽  
Selective Media ◽  
Selective Enrichment ◽  
Enrichment Cultures ◽  
Incubation Temperatures ◽  
Better Than ◽  
Dried Foods

Ninety-eight dried foods and feed ingredients were analyzed for Salmonella using tetrathionate brilliant green (T) and selenite cystine (S) broths incubated at 35 and 43 °C. The four enrichment cultures for each sample were subcultured in duplicate onto brilliant green (BG), Salmonella–Shigella (SS), and bismuth sulfite (BS) agars, one plate of each being incubated at 35 °C, the other at 43 °C. Salmonellae were isolated from 44 of the 98 samples. Differences in the Salmonella recovery rates from the four selective enrichment conditions were not significant. However, there was a trend toward a higher proportion of Salmonella colonies on the selective media when the enrichment broths were incubated at 43 °C, although the differences were significant only with BG and SS subcultured from T. While the four enrichment systems were not significantly different, the trend toward a higher proportion of Salmonella colonies on the differential media subcultured from 43 °C enrichment broths indicates an advantage to incubation at the elevated temperature. Incubation of selective agars at 35 °C was best because at 43 °C Salmonella recovery was significantly reduced. Detection of salmonellae on BS was significantly better than on BG or SS.

Limited Sensitivity of Short (6 h) Selective Enrichment for Detection of Foodborne Salmonella

1990 ◽  
Vol 53 (7) ◽  
pp. 562-565 ◽  
Author(s):  
J.-Y D'AOUST ◽  
A. SEWELL ◽  
A. JEAN
Keyword(s):  
Brilliant Green ◽  
High Moisture ◽  
Selective Enrichment ◽  
Under Five ◽  
Analytical Protocol ◽  
Quantitative Analyses ◽  
Low Moisture Foods ◽  
Limited Sensitivity

Short (6 h) enrichment under five different selective conditions adversely affected the isolation of Salmonella from pre-enriched samples of naturally contaminated foods. Of the 109 high moisture and 18 low moisture foods found to contain salmonellae following conventional (24 h) enrichment, combined results of the abbreviated enrichment procedures identified only 99 (90.8%) and 13 (72.2%) contaminated samples, respectively. The productivities of tetrathionate brilliant green (TBG43) and Muller-Kauffman tetrathionate (MKTBG43) broths consistently exceeded that obtained with the modified Rappaport (RV43), tetrathionate brilliant green (TBG35), and selenite cystine (SC35) media after 6 and 24 h of incubation. Semi-quantitative analyses of growth under all enrichment conditions indicated that short (6 h) enrichment negatively affected method sensitivity through reduced numbers of Salmonella colonies and heavy growth of nonsalmonellae on bismuth sulfite (BSA) and brilliant green sulfa (BGS) plating media. These findings raise concerns on the dependability of commercial diagnostic schemes that incorporate abbreviated (6 h) enrichment in TBG35 and/or SC35 in their analytical protocol.

scholarly journals Evaluation of Culture Media for Selective Enrichment and Isolation of Salmonella in Seafood

2010 ◽  
Vol 93 (5) ◽  
pp. 1468-1471 ◽  
Author(s):  
Rakesh Kumar ◽  
Poothuvallil K Surendran ◽  
Nirmala Thampuran
Keyword(s):  
Brilliant Green ◽  
Culture Media ◽  
Performance Difference ◽  
Selective Isolation ◽  
Salmonella Spp ◽  
Selective Enrichment ◽  
Significant Difference ◽  
Agar Media ◽  
Isolation Media

Abstract Seafood, including fish, shrimp, clam, crab, mussel, oyster, lobster, squid, octopus, and cuttlefish samples, was used to compare the recovery of Salmonella serovars by different selective enrichment and isolation media. The samples were selectively enriched in Rappaport-Vassiliadis (RV) broth and tetrathionate broth (TT), followed by selective isolation on Hektoen enteric (HE) agar, xylose lysine desoxycholate (XLD) agar, bismuth sulfite (BS) agar, and Brilliant Green (BG) agar media. Of 443 seafood samples analyzed, 108 were found to be contaminated with Salmonella. The role of selective enrichment in Salmonella spp. recovery with RV medium was distinctly high (70%) compared to TT broth (30%). The selective enrichment in RV broth followed by selective isolation on XLD, HE, BS, and BG agar recovered Salmonella at levels of 56, 41, 28, and 16%, respectively. Similarly, after enrichment in TT broth, XLD and HE agars recovered 27 and 23 respectively. The recovery of Salmonella with enrichment in TT followed by isolation on BS and BG was abysmally low at 4.6 and 5, respectively. There was no significant difference (P > 0.05) in the recovery of Salmonella using the combinations of XLD and HE media with selective enrichment in RV broth. However, performance difference (P <0.05) was observed in the recovery when BS and BG with RV, and XLD, HE, BS, and BG agars with TT broth were used. The present study showed that the combination of RV with XLD was the most efficient media for isolation of Salmonella from seafood when compared to other isolation media combinations.

Recovery of Salmonella from Fluid Milk

1988 ◽  
Vol 51 (5) ◽  
pp. 409-411 ◽  
Author(s):  
CLYDE R. WILSON ◽  
WALLACE H. ANDREWS ◽  
PAUL L. POELMA ◽  
VERNEAL R. BRUCE
Keyword(s):  
Brilliant Green ◽  
Incubation Temperature ◽  
Skim Milk ◽  
Selective Enrichment ◽  
Whole Milk ◽  
Peptone Water ◽  
Incubation Temperatures ◽  
Fluid Milk

Methodology was developed for isolation of Salmonella from skim milk, 2% fat milk, whole milk and buttermilk. Lactose broth, lactose broth plus brilliant green dye, buffered peptone water and each milk type plus brilliant green dye were evaluated as preenrichment broths. Incubation temperatures of 35 and 43°C were compared for use at the preenrichment stage. The recovery of Salmonella was determined after selective enrichment in selenite cystine, tetrathionate and Rappaport-Vassiliadis broths. Results indicated that fluid milk should be examined for Salmonella by being preenriched in lactose broth, subcultured to selenite cystine and tetrathionate broths and streaked to selective agars, with 35°C as the incubation temperature throughout the analysis.

ICMSF methods studies. V. The influence of selective enrichment media and incubation temperatures on the detection of salmonellae in raw frozen meats

1974 ◽  
Vol 20 (6) ◽  
pp. 813-816 ◽  
Author(s):  
J. H. Silliker ◽  
D. A. Gabis
Keyword(s):  
Brilliant Green ◽  
Medium Temperature ◽  
Raw Meat ◽  
Selective Media ◽  
Selective Enrichment ◽  
Incubation Temperatures

Sixty lots of frozen raw meat were analyzed for Salmonella using preenrichment in lactose broth followed by selective enrichment in four different selective broths, each incubated at 35C and 43C. Incubation at 43C resulted in detection of more Salmonella-containing samples. The highest recovery was observed with selenite cystine at 43C. However, the data indicated that two selective broths should be used for maximum recovery. Tetrathionate broth without brilliant green was inferior to the three other selective media used, both at 35C and 43C. Using selenite cystine, tetrathionate brilliant green, and selenite brilliant green sulfa broths, a number of medium/temperature pairs gave Salmonella recoveries approaching that obtained from all eight medium/temperature variables combined.

scholarly journals Characterization and optimization of extracellular enzymes production by Aspergillus niger strains isolated from date by-products

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Reda Bellaouchi ◽  
Houssam Abouloifa ◽  
Yahya Rokni ◽  
Amina Hasnaoui ◽  
Nabil Ghabbour ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Enzyme Expression ◽  
Specific Enzyme ◽  
Enzymatic Production ◽  
High Production Rate ◽  
High Production ◽  
Incubation Temperatures ◽  
By Products

Abstract Background This work aims to study the optimal conditions of the fermentation culture medium used for the production of extracellular enzymes (amylase, cellulase, lipase, and protease) from previously isolated Aspergillus niger strains in date by-products. Results The five most powerful isolates selected based on the zone of degradation formed on Petri plates by the substrate were subjected to the quantitative evaluation of their enzymatic production. All five strains showed almost similar API-ZYM profiles, with minor variations observed at the level of some specific enzyme expression. The production of cellulase and amylase was depending on pH and incubation temperatures. ASP2 strain demonstrated the high production rate of amylase (at pH 5 and 30 °C) and cellulase (at pH 6 and 30 °C) for 96 h of incubation. Conclusion The A. niger showed the ability to produce several extracellular enzymes and can be used in the valorization of different agroindustrial residues.

scholarly journals Extraction and Mass Spectrometric Characterization of Terpenes Recovered from Olive Leaves Using a New Adsorbent-Assisted Supercritical CO2 Process

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1301
Author(s):  
Zully J. Suárez Montenegro ◽  
Gerardo Álvarez-Rivera ◽  
Jose A. Mendiola ◽  
Elena Ibáñez ◽  
Alejandro Cifuentes
Keyword(s):  
Aluminum Oxide ◽  
Silica Gel ◽  
Supercritical Co2 ◽  
Olive Leaves ◽  
Fractionation Process ◽  
Selective Enrichment ◽  
Adsorption Desorption ◽  
First Time ◽  
By Products

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO2 fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.

Classification of algogenic organic matter concerning its contribution to the bacterial regrowth potential and by-products formation

1998 ◽  
Vol 37 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Wido Schmidt ◽  
Beate Hambsch ◽  
Heike Petzoldt
Keyword(s):  
Organic Matter ◽  
Chlorine Dioxide ◽  
Relative Increase ◽  
Residual Chlorine ◽  
Additional Increase ◽  
Bacterial Regrowth ◽  
Humic Compounds ◽  
Significant Difference ◽  
The Impact ◽  
By Products

The bacterial regrowth potential (BRP) and the by-products formation potential after the disinfection (DBP) are parameters recognized to be influenced by the origin of organic matter dissolved in water. A significant difference of the impact of humic compounds and algogenic organic matter (AOM), characteristic for raw waters from reservoirs, to both parameters can be assumed. In systematic laboratory experiments the influence of AOM on the BRP as well as DBP was examined. Different fractions of the AOM were chlorinated and treated with chlorine dioxide. In addition to that the influence of the ozonation was investigated. To assess the biodegradable fraction of the organic matter (BDOC) a large spectrum of by-products (aldehydes and keto-acids) was analyzed. The BRP in the water was determined by the measurement of the increase of biomass in the water samples. It could be proved, that the chlorination of intact algae cells containing waters may cause a significant increase of the biodegradability in the water if the residual chlorine is totally required. In the case of the disinfection of the AOM containing waters with chlorine dioxide the relative increase of the BRP was lower in comparison to the chlorinated waters. The preozonation of the algae containing waters indicates an additional increase of the BRP, but only by ozonation of the algae cells. The ozonation of the algae metabolites does not influence the BRP, but it causes a significant decrease of the THM-formation if chlorine is used for disinfection.

Preenrichment Conditions for Effective Recovery of Salmonella in Foods and Feed Ingredients

1979 ◽  
Vol 42 (2) ◽  
pp. 153-157 ◽  
Author(s):  
J. Y. D'AOUST ◽  
C. MAISHMENT
Keyword(s):  
Brilliant Green ◽  
False Negative ◽  
Food Samples ◽  
Contamination Level ◽  
Experimental Conditions ◽  
Feed Ingredients ◽  
Selective Enrichment ◽  
Negative Results ◽  
False Negative Results ◽  
The Cost

The efficacy of Clausen, EE, Eugon, GN, Tergitol 7, lactose and nutrient broths as Salmonella preenrichment media was evaluated using 165 food samples with an incident contamination level ranging from 1.5 to 460 salmonellae/100 g. Replicate food samples (100 g) were preenriched in each of seven media (900 ml) for 6 h and 24 h at 35 C; various amounts (10, 1.0 and 0.1 ml) of preenriched cultures were selectively enriched in tetrathionate brilliant green (43 C) and selenite cystine (35 C) broths and plated on bismuth sulfite and brilliant green sulfa agars. Short (6 h) and 24-h preenrichment conditions resulted in 26 (16%) and 8 (5%) false negative results, respectively. Recovery of Salmonella from 6-h but not 24-h preenrichment cultures also varied directly with the portion of culture inoculated into selective enrichment broths. None of the preenrichment media tested performed satisfactorily at 6 h of incubation where levels of recovery ranged from 32 to 62%; at 24 h, good recovery was obtained with all media (95 to 100%) except EE broth (74%). The incidence of competitive flora was significantly higher on selenite + brilliant green sulfa than on tetrathionate + bismuth sulfite; transfer volumes (10 and 1.0 ml) and preenrichment media did not contribute significantly to the presence of non-salmonellae on plating media. Characteristics of preenrichment media were found to be less critical than preenrichment incubation time for effective recovery of Salmonella in foods and feed ingredients. The use of 1.0- rather than 10-ml preenrichment transfer volume is indicated because it proved to be completely reliable under our experimental conditions and reduced the cost of analyses.

Comparison of EB and Fraser Enrichment Broths for the Detection of Listeria spp. and Listeria monocytogenes in Raw-Milk Dairy Products and Environmental Samples

1996 ◽  
Vol 59 (11) ◽  
pp. 1172-1175 ◽  
Author(s):  
GEERTRUI M. VLAEMYNCK ◽  
RENAAT MOERMANS
Keyword(s):  
Listeria Monocytogenes ◽  
Dairy Products ◽  
Raw Milk ◽  
Chain Reaction ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Isolation Frequency ◽  
Detection And Identification ◽  
Significant Difference ◽  
Polymerase Chain

This study is a comparison of the isolation frequency of Listeria spp. and Listeria monocytogenes from selected naturally contaminated dairy products, especially soft smear-ripened cheeses from raw milk and samples of feces and rinse samples from the udder taken on the farm, by using an enrichment broth (EB) recommended by the International Dairy Federation and the U.S. Food and Drug Administration (IDF and FDA) or Fraser broth as the selective enrichment. Detection and identification were carried out according to the IDF protocols and a polymerase chain reaction technique. Listeria spp. were detected in 39.8% of the 570 samples while 15.3% were positive for L. monocytogenes. For cheese and curd samples, Fraser enrichment broth gave a statistically significant higher recovery for all Listeria spp. (26 to 21 %) as well as for L. monocytogenes in particular (9 to 1.4%). For raw milk and samples taken from feces and the udder rinse no significant difference was found between EB and Fraser broth. A combination of both enrichments resulted in an increase of recovery over all matrices by 15%.

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