Comparative Efficiency of Brilliant Green, Bismuth Sulfite, Salmonella-Shigella, Hektoen Enteric, and Xylose Lysine Desoxycholate Agars for the Recovery of Salmonella from Foods: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 899-928
Author(s):  
Wallace H Andrews ◽  
Paul L Poelma ◽  
Clyde R Wilson ◽  
◽  
C Abeyta ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
False Positive ◽  
Relative Efficiency ◽  
Brilliant Green ◽  
Collaborative Study ◽  
False Negative ◽  
Reaction Rates ◽  
Negative Reaction ◽  
Comparative Efficiency ◽  
False Positive Reactions

Abstract The relative efficiency of brilliant green (BG), bismuth sulfite (BS), Salmonella-Shigella (SS), xylose lysine desoxycholate (XLD), and Hektoen enteric (HE) agars for the recovery of Salmonella from 5 foods was collaboratively studied in 11 laboratories. The analytical efficiency of various paired combinations of the 5 agars was statistically compared according to 3 parameters: (1) productivity or recovery of Salmonella, (2) rate of enumeration of cultures that were false positive for Salmonella, and (3) rate of enumeration of false-negative reactions. In descending order of productivity, the sequential rankingwasBS, XLD, HE, BG, and SS agars. In ascending order, the rates of false-positive reactions based on a statistical analysis of paired agar combinations was HE, BS, BG and XLD (tie), and SS agars. Analogously, in ascending order, the sequence of false-negative reaction rates was BS, XLD, HE, BG, and SS agars. The combination of BS, XLD, and HE agars is more efficient for recovery of Salmonella from foods than is the present official combination of BG, BS, and SS agars. The revision of official final action method 46.054 to replace the combination of BG, BS, and SS agars with a combination of BS, XLD, and HE agars has been adopted official first action.

Histochemical Diagnosis of Hirschsprung Disease

PEDIATRICS ◽  
1982 ◽  
Vol 69 (6) ◽  
pp. 755-761
Author(s):  
Carolyn Coker Huntley ◽  
Louis deS. Shaffner ◽  
Venkata R. Challa ◽  
Anne D. Lyerly
Keyword(s):  
Lamina Propria ◽  
False Positive ◽  
Ganglion Cells ◽  
False Negative ◽  
Hirschsprung Disease ◽  
Nerve Fibers ◽  
Infants And Children ◽  
Muscularis Mucosa ◽  
False Positive Reactions ◽  
In Infants And Children

A histochemical staining technique for detection of acetylcholinesterase (AChE) in rectal suction biopsies was compared with the presence or absence of ganglion cells in full-thickness or suction biopsies for the diagnosis of Hirschsprung disease (HD) in infants and children. Biopsies from 55 of 58 children were adequate for both the AChE assay and routine pathologic examination for ganglion cells. Two patterns of AChE staining were noted. With pattern A, prominent nerve fibers staining for AChE were seen throughout the muscularis mucosa and the lamina propria. With pattern B, similar fibers were seen only in the muscularis mucosa and the areas of lamina propria that were immediately adjacent. No "false-negative" AChE staining reactions were found in patients with HD. No "false-positive" reactions showing pattern A were found. This pattern was diagnostic for HD. Three false-positive reactions were found showing pattern B in patients with conditions other than HD. Among 22 patients with HD, 19 were males and three were females. Pattern A occurred in all age groups and in both sexes. Pattern B in patients with HD was seen exclusively in male infants 1 month of age or less. Experience suggests that the AChE staining of rectal suction biopsies is an excellent screening test for HD in infants and children. If pattern B is encountered, however, the specimen should be examined by routine pathologic techniques for the presence of submucosal ganglion cells.

Recovery of Salmonella Species from Nonfat Dry Milk Rehydrated Under Rapid and Reduced Pre-enrichment Conditions: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 807-810
Author(s):  
Paul L Poelma ◽  
Wallace H Andrews ◽  
Clyde R Wilson ◽  
◽  
B Bennett ◽  
...  
Keyword(s):  
Relative Efficiency ◽  
Room Temperature ◽  
Brilliant Green ◽  
Collaborative Study ◽  
Significant Difference ◽  
Dry Milk ◽  
Aoac Method ◽  
Sample Water ◽  
Nonfat Dry Milk ◽  
Water Ratio

Abstract A collaborative study was conducted to compare the relative efficiency of the AOAC rapid rehydration method with the reduced rehydration soak method for the recovery of Salmonella species from nonfat dry milk (NFDM). In the AOAC method, a 25 g sample of NFDM is rapidly rehydrated at a 1:9 sample/water ratio and mixed by swirling. After 60 min, the flask contents are adjusted to a pH of 6.8, and 0.45 mL of 1% aqueous brilliant green dye solution is added. The flasks are then incubated at 35°C. In the soak method, a 25 g sample of NFDM is gently added to the sterile brilliant green (BG) water at a 1:9 sample/ BG water ratio and allowed to soak undisturbed for 60 min at room temperature before incubation. Twelve collaborators analyzed 3 shipments of samples with the following results for the AOAC and soak methods: shipment 1—31 and 46 positive samples, respectively, with a 48% increase in detection by the soak method; shipment 3-45 and 66 positive samples, respectively, with a 47% increase in detection by the soak method; shipment 2—no significant difference in recovery of Salmonella species by the 2 methods. It is recommended that the official final action method for the detection of Salmonella species, 46.054- 46.067, be revised to use the soak method for the analysis of nonfat dry milk.

Pre-enrichment Broths for Recovery of Salmonella from Milk Chocolate and Edible Casein: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 893-898
Author(s):  
Paul L Poelma ◽  
Wallace H Andrews ◽  
Clyde R Wilson ◽  
◽  
C M Coles ◽  
...  
Keyword(s):  
Relative Efficiency ◽  
Brilliant Green ◽  
Collaborative Study ◽  
Control Laboratory ◽  
Milk Chocolate ◽  
Dry Milk ◽  
Peptone Water ◽  
Nonfat Dry Milk

Abstract A collaborative study was conducted to compare the relative efficiency of nonfat dry milk with brilliant green dye (NFDM-BG) and buffered peptone water (BPVV) as pre-enrichment broths for recovery of Salmonella from milk chocolate. Lactose broth and modified lactose broth with added 1% NaHCO3 and brilliant green dye were compared as pre-enrichment broths for recovery of Salmonella from edible casein. Two sets of 8 samples each of milk chocolate, containing initial levels of Salmonella ranging from <0.03 to 43 organisms/g, were examined by 13 collaborators. Of 104 determinations, 102 (98.1%) and 100(96.2%) using NFDM-BG and BPW, respectively, were in agreement with sample results of the control laboratory. Two sets of 7 samples each of edible casein, containing initial levels of Salmonella ranging from <0.03 to 93 organisms/g, were also examined by the 13 collaborators. Of 91 determinations, 87 (95.6%) and 88 (96.7%) using lactose broth and modified lactose broth, respectively, were in agreement with sample results of the control laboratory. For recovery of Salmonella, therefore, NFDM-BG pre-enrichment is recommended for milk chocolate, and lactose broth is recommended for casein. The proposed revision of official final action method 46.054-46.067 has been adopted official first action

Multilaboratory Validation of a Luminex Microbead-Based Suspension Array for the Identification of the 11 Most Clinically Relevant Shiga Toxin–Producing Escherichia coli O Serogroups†

2013 ◽  
Vol 76 (5) ◽  
pp. 867-870 ◽  
Author(s):  
ANDREW LIN ◽  
JULIE A. KASE ◽  
MICHELLE M. MOORE ◽  
INSOOK SON ◽  
NELLY TRAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
Shiga Toxin ◽  
False Positive ◽  
Collaborative Study ◽  
False Negative ◽  
Robust Method ◽  
Suspension Array ◽  
Negative Results ◽  
False Negative Results

Rapid and high-throughput identification and serotyping of Shiga toxin–producing Escherichia coli (STEC) O serogroups is important for detecting, investigating, and controlling STEC infection outbreaks and removing hazardous products from commerce. A Luminex microbead-based suspension array has been developed to identify the 11 most clinically relevant STEC serogroups: O26, O45, O91, O103, O104, O111, O113, O121, O128, O145, and O157. Here we present results of a blinded multilaboratory collaborative study involving 10 participants from nine laboratories using 55 unknown strains. From the total 495 analyses, two false-positive and three false-negative results were obtained, indicating the assay to be a rapid, high-throughput, and robust method for identifying clinically relevant STEC serogroups.

A Collaborative Study on the Detection of Staphylococcal Enterotoxins in Foods with an Enzyme Immunoassay Kit (TECRA)

1996 ◽  
Vol 59 (4) ◽  
pp. 390-397 ◽  
Author(s):  
C. E. PARK ◽  
D. WARBURTON ◽  
P. J. LAFFEY ◽  
Keyword(s):  
Enzyme Immunoassay ◽  
False Positive ◽  
Collaborative Study ◽  
False Negative ◽  
Negative Control ◽  
Rabbit Serum ◽  
Staphylococcal Enterotoxins ◽  
Repeatability And Reproducibility ◽  
Positive Results ◽  
Control Samples

One of the commercially available enzyme immunoassay kits for the detection of staphylococcal enterotoxins (SEs) in foods, the TECRA screening kit (Bioenterprises Pty. Ltd., Roseville, New South Wales, Australia), has microtiter plates coated with a mixture of antibodies to all of the SEs. A collaborative study was conducted to ascertain whether specificity, sensitivity, repeatability, and reproducibility of the results obtained using this kit would meet food-safety criteria. Thirteen Canadian collaborators participated in this study to analyze both various foods to which 1.0 to 3.0 ng of SE/g of food had been added and negative control samples. In addition, the effect of animal serum in these analyses was examined. The results indicate that all collaborators (100%) were able to detect the minimum toxin levels of 1.0 ng of SEA/g of ham and 1.0 ng of SEB/g of salami and SE or SEs in other samples (chicken, turkey, and cheese) containing 2.0 to 3.0 ng/g, without any false-negative results. With regard to negative control samples, all collaborators obtained correct results except when analyzing two types of food: two collaborators (15%) showed weak false-positive results with salami and all analysts found strong false-positive results with mussels. The problem regarding specificity could be largely corrected by treating the sample with rabbit serum (0.1 volume in 1.0 volume food extract). The repeatability and reproducibility of results from the kit were acceptable.

scholarly journals Intercurrence of Paratuberculosis in Intradermal Tuberculin Test Reactive Cattle

2020 ◽  
Vol 48 ◽  
Author(s):  
Mariana Assunção De Souza ◽  
Nicolle Pereira Soares ◽  
Alessandra Aparecida Medeiros-Ronchi ◽  
Brendhal Almeida Silva ◽  
Pedro Paulo Feitosa De Albuquerque ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
False Positive ◽  
False Negative ◽  
Complex Mixture ◽  
Pathological Finding ◽  
Intradermal Test ◽  
Mesenteric Lymph Nodes ◽  
Serological Tests ◽  
Mesenteric Lymph ◽  
False Positive Reactions

Background: Bovine tuberculosis control programs are based on a standard diagnostic method, the intradermal test with purified protein derivatives, which is used to identify and eliminate diseased animals. Currently none of the tests available allow complete differentiation between infected and uninfected animals. The main limitations of the tests available are related to diagnostic sensitivity and specificity, which results in false positive reactions due to the existence of cross infections, and also false negative, inherent to the state of energy of some animals. The aim of this work was to study the intercurrence of paratuberculosis in tuberculosis reactive cattle by the comparative cervical test.Materials, Methods & Results: Three hundred and thirty four cattle were evaluated using the comparative cervical test (CCT) and serology for tuberculosis (TB) and paratuberculosis (PTB) ELISA IDEXX®. All of the animals testing positive by CCT were euthanized and necropsied. Fragments of lymph node, lung and intestine were collected and analyzed using histopathological techniques, with staining by Hematoxylin-Eosin (HE). Samples of lung and lymph nodes (retropharyngeal, submandibular, cervical and mediastinal) of the animals testing positive by CCT were evaluated using qPRC for M. bovis, and intestinal and mesenteric lymph nodes using PCR for PTB. Of the 334 cattle evaluated using the comparative cervical test, 16 were considered positive. No lesions suggestive of tuberculosis were found in the macroscopic inspection of the carcasses. The most evident anatomical and pathological finding was a thickening of intestinal mucosa, found in 12 of the 16 cattle submitted to necropsy. No microscopic lesions suggestive of TB were identified nor was the presence of M. bovis detected by qPCR. The main histopathological findings were observed in the small intestine and mesenteric lymph nodes and identified as enteritis, lymphangitis, lymphangiectasia and granulomatous lymphadenitis. In the intestine the changes are characterized by dilated and inflamed lymphatic vessels and intense inflammatory infiltrate on the mucosa and submucosa. Of the 334 serum samples evaluated, the M. bovis ELISA Antibody Test (IDEXX®) identified 17 positive animals. All the cattle considered positive by M. bovis ELISA were considered negative by CCT. In the samples from nine animals (9/16), DNA from M. avium subsp. paratuberculosis (MAP) was identified and in twelve carcasses (12/16) lesions characteristic of PTB were found, which were subsequently confirmed by histopathological techniques. In another nine animals of the herd anti-MAP antibodies were detected. None of those that tested positive by PTB ELISA were reactive by CCT.Discussion: Animals considered positive by TB ELISA that were not positive in the intradermal test does not mischaracterize the clinical picture of the disease. Considering the inverse relationship between cell-mediated and humoral responses to M. bovis, the intradermal test and the serological tests are designed to measure different immunological responses, which develop during different stages of infection. The progress of the cellular immunological response to humoral immunity occurs in the most advanced stages of tuberculosis. Of the 16 cattle considered positive by CCT, 12 animals presented macroscopic and histological lesions suggestive of PTB and DNA from MAP was detected in nine. Although it is the official test for the control of TB in different countries, the intradermal test with PPD has presented limitations, primarily related to specificity. M. avium subsp. Paratuberculosis is considered the main cause of false positive reactions in the intradermal test. The PPD bacterial extract is a complex mixture of proteins, lipids, sugars and nucleic acids, and many of these components are also shared by numerous species of mycobacteria (tuberculous or not). 

Performance of the Microplate BacTrace™ ELISA Technique for Detection of Foodborne Salmonella

1990 ◽  
Vol 53 (10) ◽  
pp. 841-845 ◽  
Author(s):  
J.-Y. D'AOUST ◽  
E. DALEY ◽  
A. M. SEWELL
Keyword(s):  
False Positive ◽  
Brilliant Green ◽  
Test System ◽  
Citrobacter Freundii ◽  
High Moisture ◽  
Elisa System ◽  
False Positive Reactions ◽  
Pure Cultures ◽  
Elisa Technique ◽  
Structural Antigen

The developmental BacTrace™ ELISA system which recognizes a common structural antigen (CSA-1) in the cell wall of target microorganisms was tested with pure cultures and naturally contaminated foods. The system readily detected all of the 104 Salmonella test strains but produced 38 (52.1%) false-positive reactions upon examination of 73 nonsalmonellae cultures. Citrobacter freundii, Escherichia coli, and Proteus mirabilis were primarily responsible for erroneous results. Of 119 foods tested, 37 (31.1%) were found to contain Salmonella by a standard cultural procedure. Parallel BacTrace™ testing of the nutrient broth (NB), tetrathionate brilliant green (TBG43), and selenite cystine (SC35) broth cultures arising from standard cultural analyses identified 24 (64.9%), 25 (67.6%), and 31 (83.8%) Salmonella contaminated foods, respectively. Maximum sensitivity of the test system (89.2%) could be attained through combination of ELISA results from both TBG43 and SC35. False-positive reactions were particularly prominent with high moisture foods.

Sign in / Sign up

Export Citation Format

Share Document