Relative Productivity of Five Selective Plating Agars for the Recovery of Salmonella from Selected Food Types

1979 ◽  
Vol 62 (2) ◽  
pp. 320-326
Author(s):  
Wallace H Andrews ◽  
Clyde R Wilson ◽  
Paul L Poelma ◽  
Aida Romero
Keyword(s):  
Brilliant Green ◽  
Food Samples ◽  
Food Category ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Selective Plating ◽  
Relative Productivity ◽  
Selective Enrichment Broth

Abstract During a 3-year period, the relative productivity of brilliant green (BG), bismuth sulfite (BS), Salmonella-Shigella (SS), Hektoen enteric (HE), and xylose lysine desoxycholate (XLD) agars for recovering Salmonella from 9 food types was determined. Following preenrichment, selective enrichment of food samples in tetrathionate broth followed by streaking to BS agar was the single most productive selective enrichment broth-agar combination for recovery of Salmonella in 5 of these food types. A study of the performance of these 5 agars used individually and in various combinations, showed that none of the 5 agars used individually nor any of the possible paired combinations of these agars could be used to satisfactorily detect Salmonella in the 9 food types. The use of all 5 agars was not necessary because one combination of 4 agars (BG, BS, HE, and XLD) recovered 100% of the Salmonella isolates, as compared with the number of Salmonella isolates recovered by the 5-agar combination, in each food category. This particular 4-agar combination, along with two 3-agar combinations (BG, BS, and XLD agars, and BS, HE, and XLD agars), were each able to recover more Salmonella isolates than the combination of BG, BS, and SS agars, the combination currently recommended by the AOAC. Finally, the relative costs of using these agars, singly and in various combinations, were determined.

A New Method for Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii Detection using a Novel Chromogenic Agar

2020 ◽  
Author(s):  
Paul Nguyen ◽  
Oscar Juárez ◽  
Lawrence Restaino
Keyword(s):  
Detection System ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Food Samples ◽  
Test Method ◽  
Good Growth ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Arcobacter Butzleri ◽  
Selective Enrichment Broth

Arcobacter species are Gram-negative rods that have been implicated in food- and waterborne illness. Although various cultural isolation methods have been proposed, the current procedures are unable to fully suppress growth of background microbiota present in food samples which inhibits Arcobacter isolation. The purpose of this study was to develop a selective enrichment broth and chromogenic plating medium to detect three Arcobacter species that have been recognized as emerging foodborne pathogens: Arcobacter butzleri , Arcobacter cryaerophilus and Arcobacter skirrowii . The developed Nguyen-Restaino-Juárez Arcobacter detection system consists of a selective enrichment broth (NRJ-B) and a selective/differential plating media (NRJ-M). The protocol of the detection method was determined by evaluating growth of A. butzleri , A. cryaerophilus and A. skirrowii under various temperature (30, 35 and 42ᴼC) and incubation (aerobic, microaerophilic and anaerobic) conditions. Additionally, 47 Arcobacter strains and 39 non- Arcobacter strains were tested in the inclusivity and exclusivity evaluations of NRJ-B and NRJ-M. Overall, the study determined the optimal growth conditions of Arcobacter species using the NRJ- Arcobacter detection system was aerobic incubation at 30ᴼC. NRJ-B supported good growth of A. butzleri , A. cryaerophilus , and A. skirrowii while effectively suppressing growth of non- Arcobacter strains after 48 h. Furthermore, NRJ-M yielded 97.8% inclusivity and 100.0% exclusivity using the tested strains and resulted in salmon-pigmented Arcobacter colonies (1.0 to 1.5 mm in diameter) after 72 h. The novel protocol is the first to develop a chromogenic plating media for the isolation of Arcobacter species. This simple and reliable test method would greatly contribute to understanding the distribution of pathogenic Arcobacter species in food samples.

Evaluation of Methods for Recovery of Salmonella from Dairy Cattle, Poultry, and Swine Farms

2003 ◽  
Vol 66 (11) ◽  
pp. 1987-1995 ◽  
Author(s):  
PHILIPUS PANGLOLI ◽  
YOBOUET DJE ◽  
S. P. OLIVER ◽  
A. MATHEW ◽  
D. A. GOLDEN ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Recovery Time ◽  
Brilliant Green ◽  
Enrichment Broth ◽  
Ph Adjustment ◽  
Selective Enrichment ◽  
Swine Farms ◽  
Effects Of Ph ◽  
Selective Plating ◽  
Evaluation Of Methods

Current official methods for detection and isolation of Salmonella are mostly designed for foods. The objective of this study was to determine optimal methods for detection and isolation of Salmonella from animal and environmental samples of dairy, poultry, and swine farms. Preenrichment in lactose broth versus direct enrichment (no preenrichment) prior to selective enrichment in Rappaport-Vassiliadis, selenite cystine, and tetrathionate incubated at 35 and 42°C and in four differential/selective plating media (brilliant green, bismuth sulfite, Hektoen enteric, and xylose-lysine-tergitol 4 agar base) were evaluated for their ability to recover Salmonella from artificially contaminated samples. The effects of pH adjustments to samples on Salmonella recovery were determined. A pH adjustment of the enrichment broth to 6.8 ± 0.2 after addition of samples significantly improved recovery of Salmonella. The most effective medium combinations for isolation of Salmonella from farm samples depended on the type of samples. Generalizations of protocols for recovery of Salmonella from farm samples might result in poor recovery, increased recovery time, and increased sample processing costs.

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.

scholarly journals Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown’s Medium at Kampong Cham Provincial Hospital, Cambodia

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 302 ◽  
Author(s):  
Somary Nhem ◽  
Joanne Letchford ◽  
Chea Meas ◽  
Sovanndeth Thann ◽  
James C. McLaughlin ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Low Frequency ◽  
Culture Methods ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Provincial Hospital ◽  
Testing Protocol ◽  
Standard Culture ◽  
Diagnostic Microbiology ◽  
Selective Enrichment Broth

Melioidosis infection, caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown’s medium to standard culture methods. Two specimens (0.8%) were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4%) was positive using standard methods. These findings demonstrate that B. pseudomallei is rarely detected in sputum at this hospital. The low frequency of B. pseudomallei in sputum specimens precludes drawing any conclusions about the relative benefits of an enhanced sputum testing protocol at this site. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are likely to be important factors in facilitating identification of melioidosis.

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