Evaluation of a Colorimetric DNA Hybridization Test for Detection of Salmonellae in Meat and Poultry Products

1991 ◽  
Vol 54 (2) ◽  
pp. 127-130 ◽  
Author(s):  
BONNIE E. ROSE ◽  
CARLOS M. LLABRÉS ◽  
BARBARA BENNETT
Keyword(s):  
Dna Hybridization ◽  
False Positive ◽  
False Negative ◽  
Culture Method ◽  
Poultry Products ◽  
Conventional Culture ◽  
Hybridization Test ◽  
Probe Assay ◽  
Positive Results ◽  
Conventional Culture Method

A commercially available colorimetric DNA hybridization test was compared with the USDA/FSIS conventional culture method for detection of salmonellae in naturally contaminated meat and poultry products and inoculated ground beef samples. All samples which were Salmonella-positive by the culture method were also positive by the DNA probe assay. There were no false-negative or false-positive results by the colorimetric DNA hybridization test, which was slightly more sensitive than the culture method.

scholarly journals Evaluation of consensus method for the culture of Burkholderia pseudomallei in soil samples from Laos

2018 ◽  
Vol 3 ◽  
pp. 132 ◽  
Author(s):  
David A.B. Dance ◽  
Michael Knappik ◽  
Sabine Dittrich ◽  
Viengmon Davong ◽  
Joy Silisouk ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Burkholderia Pseudomallei ◽  
Enrichment Culture ◽  
False Negative ◽  
Culture Method ◽  
Soil Samples ◽  
Consensus Method ◽  
Conventional Culture ◽  
Two Samples ◽  
Conventional Culture Method

Background: We have previously shown that PCR following enrichment culture is the most sensitive method to detect Burkholderia pseudomallei in environmental samples. Here we report an evaluation of the published consensus method for the culture of B. pseudomallei from Lao soil in comparison with our conventional culture method and with PCR with or without prior broth enrichment. Methods: One hundred soil samples were collected from a field known to contain B. pseudomallei and processed by: (i) the conventional method, (ii-iii) the consensus method using media prepared in either Laos or Thailand, and (iv) the consensus method performed in Thailand, as well as by (v) PCR following direct extraction of DNA from soil and (vi) PCR following broth pre-enrichment. Results: The numbers of samples in which B. pseudomallei was detected were 42, 10, 7, 6, 6 and 84, respectively. However, two samples were positive by the consensus method but negative by conventional culture, and one sample was negative by PCR following enrichment although B. pseudomallei was isolated by the conventional culture method. Conclusions/Discussion: The results show that no single method will detect all environmental samples that contain B. pseudomallei. People conducting environmental surveys for this organism should be aware of the possibility of false-negative results using the consensus culture method. An approach that entails screening using PCR after enrichment, followed by the evaluation of a range of different culture methods on PCR-positive samples to determine which works best in each setting, is recommended.

Comparative Study of Colorimetric DNA Hybridization Method and Conventional Culture Procedure for Detection of Salmonella in Foods

1990 ◽  
Vol 73 (3) ◽  
pp. 419-424 ◽  
Author(s):  
Samuel W Chan ◽  
Stephen G Wilson ◽  
Marcela Vera-Garcia ◽  
Kevan Whippie ◽  
Margaret Ottaviani ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Culture Method ◽  
Nucleic Acid Hybridization ◽  
Hybridization Method ◽  
Conventional Culture ◽  
End Point Detection ◽  
Salmonella Serotypes ◽  
Point Detection ◽  
Conventional Culture Method ◽  
Culture Procedure

Abstract A second generation nucleic acid hybridization assay has been developed and evaluated against the conventional culture method for detection of salmonellae In foods. The assay Involves a liquid hybridization with Sa/mone/fo-speclflc oligonucleotide probes, capture of probe:target hybrids onto a solid support (plastic dipstick), and a colorimetric end point detection. The assay can be completed In 2.5 h, following approximately 44 h of culture enrichment. One thousand samples representing 20 food types were analyzed in parallel by both methods. Samples Included unlnoculated test product, and product Inoculated with Salmonella at 2 levels. Eighteen Salmonella serotypes were used as Inocula. The data demonstrate that the colorlmetric hybridization method and the conventional culture method are equivalent In their ability to detect Salmonella contamination of foods.

scholarly journals Evaluation of consensus method for the culture of Burkholderia pseudomallei in soil samples from Laos

2018 ◽  
Vol 3 ◽  
pp. 132
Author(s):  
David A.B. Dance ◽  
Michael Knappik ◽  
Sabine Dittrich ◽  
Viengmon Davong ◽  
Joy Silisouk ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Burkholderia Pseudomallei ◽  
Enrichment Culture ◽  
False Negative ◽  
Culture Method ◽  
Soil Samples ◽  
Consensus Method ◽  
Conventional Culture ◽  
Two Samples ◽  
Conventional Culture Method

Background: We have previously shown that PCR following enrichment culture is the most sensitive method to detect Burkholderia pseudomallei in environmental samples. Here we report an evaluation of the published consensus method for the culture of B. pseudomallei from Lao soil in comparison with our conventional culture method and with PCR with or without prior broth enrichment. Methods: One hundred soil samples were collected from a field known to contain B. pseudomallei and processed by: (i) the conventional method, (ii-iii) the consensus method using media prepared in either Laos or Thailand, and (iv) the consensus method performed in Thailand, as well as by (v) PCR following direct extraction of DNA from soil and (vi) PCR following broth pre-enrichment. Results: The numbers of samples in which B. pseudomallei was detected were 42, 10, 7, 6, 6 and 84, respectively. However, two samples were positive by the consensus method but negative by conventional culture, and one sample was negative by PCR following enrichment although B. pseudomallei was isolated by the conventional culture method. Conclusions/Discussion: The results show that no single method will detect all environmental samples that contain B. pseudomallei. People conducting environmental surveys for this organism should be aware of the possibility of false-negative results using the consensus culture method. An approach that entails screening using PCR after enrichment, followed by the evaluation of a range of different culture methods on PCR-positive samples to determine which works best in each setting, is recommended.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Prevalence and Antimicrobial Susceptibility of Salmonella Isolated from a Variety of Raw Meat Sausages in Gaborone (Botswana) Retail Stores

2012 ◽  
Vol 75 (4) ◽  
pp. 637-642 ◽  
Author(s):  
RONALD GAELEKOLWE SAMAXA ◽  
MAITSHWARELO IGNATIUS MATSHEKA ◽  
SUNUNGUKO WATA MPOLOKA ◽  
BERHANU ABEGAZ GASHE
Keyword(s):  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
Culture Method ◽  
Multidrug Resistant ◽  
Pcr Assay ◽  
Raw Meat ◽  
Conventional Culture ◽  
The Difference ◽  
Conventional Culture Method

The objective of the study was to provide baseline data on the prevalence and antimicrobial susceptibility of Salmonella in different types of raw meat sausages directly accessible to the consumers in Gaborone, Botswana. A total of 300 raw sausages comprising 79 beef, 78 pork, 72 chicken, and 71 mutton samples were concurrently analyzed for the presence of Salmonella using a conventional culture method and a validated PCR method. The PCR assay results were in full concordance with those of the conventional culture method for the detection of Salmonella. Sixty-five (21.7%) of 300 samples were positive for Salmonella by both the conventional culture method and PCR assay. Even though more chicken samples contained Salmonella than did any other sausage type, the difference in the presence of Salmonella among the four sausages types was not significant. Eleven serotypes were identified, and Salmonella enterica subsp. salamae II was most prevalent in all the sausage types. Beef sausages generally had higher mesophilic bacterial counts than did the other three sausage types. However, higher microbial counts were not reflective of the presence of salmonellae. Susceptibility of the Salmonella enterica serotypes to 20 antimicrobial agents was determined, and Salmonella Muenchen was resistant to the widest array of agents and was mostly isolated from chicken sausages. Regardless of the meat of origin, all 65 Salmonella isolates were resistant to at least four antimicrobial agents: amikacin, gentamicin, cefuroxime, and tombramycin. This resistance profile group was the most common in all four sausage types, comprising 90% of all Salmonella isolates from beef, 71% from pork, 63% from mutton, and 35% from chicken. These results suggest that raw sausages pose a risk of transmitting multidrug-resistant Salmonella isolates to consumers.

Three Years of Experience With Random Urinary Homovanillic and Vanillylmandelic Acid Levels in the Diagnosis of Neuroblastoma

PEDIATRICS ◽  
1987 ◽  
Vol 79 (2) ◽  
pp. 203-205
Author(s):  
Mendel Tuchman ◽  
Margaret L. R. Ramnaraine ◽  
William G. Woods ◽  
William Krivit
Keyword(s):  
False Positive ◽  
Homovanillic Acid ◽  
False Negative ◽  
False Negative Rate ◽  
Urine Samples ◽  
Vanillylmandelic Acid ◽  
Test Results ◽  
Upper Limit ◽  
Positive Results ◽  
Rule Out

During the last 3 years, random urine samples from 408 patients were tested for elevated homovanillic acid (HVA) and vanillylmandelic acid (VMA) levels to rule out the diagnosis of neuroblastoma. Thirty-seven of these patients had elevated HVA and/or VMA levels, and neuroblastoma was subsequently diagnosed. In three additional patients with negative test results (normal HVA and VMA levels), tumors were subsequently diagnosed (false-negative rate of 7.5%). Ten percent of the patients with neuroblastoma had normal HVA and 27.5% had normal VMA levels at the time of diagnosis. Only one patient (2.5%) with neuroblastoma had elevated VMA levels in the presence of normal HVA levels. More than 60% of the patients with neuroblastoma had urinary HVA and/or VMA levels higher than twice the upper limit of normal. No false-positive results were encountered. Age and stage distributions of the patients are shown, and the significance of the results is discussed.

N.B.T. TEST—FALSE-NEGATIVE AND FALSE-POSITIVE RESULTS

The Lancet ◽  
1972 ◽  
Vol 299 (7764) ◽  
pp. 1341-1342 ◽  
Author(s):  
RonaldP. Ng ◽  
T.K. Chan ◽  
D. Todd
Keyword(s):  
False Positive ◽  
False Negative ◽  
Positive Results

scholarly journals High Prevalence of yadA-Positive Yersinia enterocolitica in Pig Tongues and Minced Meat at the Retail Level in Finland

1999 ◽  
Vol 62 (2) ◽  
pp. 123-127 ◽  
Author(s):  
MARIA FREDRIKSSON-AHOMAA ◽  
SEBASTIAN HIELM ◽  
HANNU KORKEALA
Keyword(s):  
Yersinia Enterocolitica ◽  
Culture Method ◽  
Selective Enrichment ◽  
Conventional Culture ◽  
High Prevalence ◽  
Retail Outlets ◽  
Polymerase Chain ◽  
Meat Samples ◽  
Minced Meat ◽  
Conventional Culture Method

Polymerase chain reaction (PCR) was used to determine the prevalence of yadA-positive Yersinia enterocolitica in pig tongues and minced meat at the retail level in Finland and to confirm the yadA-positive Y. enterocolitica isolates recovered from the same samples using the conventional culture method. A total of 51 pig tongues purchased at 12 retail outlets and 255 minced meat samples purchased at 40 retail outlets in the Helsinki area were studied. The prevalence of Y. enterocolitica carrying the yadA gene was 92% in pig tongues and 25% in minced meat using PCR and 78% in tongues and 2% in minced meat with the culture method. The prevalence of yadA-positive tongues was higher (98%) when both PCR- and culture-positive results were included because Y. enterocolitica carrying the yadA gene could also be isolated in three PCR-negative tongue samples. In the minced meat samples, all PCR-negative samples were also culture-negative. With the culture method, 66 of 80 yadA-positive isolates in 38 tongues and all yadA-positive isolates (4) in four minced meat samples were recovered after selective enrichment. A total of 92 isolates of Y. enterocolitica bioserotype 4/O:3 in tongues and 5 isolates in minced meat were found, of which 13% in tongues and 20% in minced meat did not carry the yadA gene.

Thyroid Screening for Early Discharged Infants

PEDIATRICS ◽  
1996 ◽  
Vol 98 (1) ◽  
pp. 41-44
Author(s):  
Judy G. Saslow ◽  
Ernest M. Post ◽  
Carol A. Southard
Keyword(s):  
New Jersey ◽  
Congenital Hypothyroidism ◽  
False Positive ◽  
False Negative ◽  
Negative Results ◽  
Thyroid Screening ◽  
False Negative Results ◽  
Positive Results

Objective. As neonatal discharge before 24 hours of life becomes commonplace, the rejection of congenital hypothyroidism (CH) screening specimens obtained too early has created the need for numerous additional tests. We sought to determine whether the specimens obtained before 24 hours could be used safely. Methods. During a 31-day period we measured thyrotropin in all thyroid-screening specimens that had been obtained before 24 hours. We also examined the early specimens from every infant diagnosed in New Jersey with CH during 1993 or 1994. Results. Among the 663 specimens, those obtained at or before 12 hours and those from infants with birth weights less than 2500 g had too many low thyroxine results to be useful. Among the 515 specimens obtained at more than 12 to 24 hours from newborns weighing 2500 g or more, 37 (7%) had low thyroxine levels and 12 (2.3%) had thyrotropin levels of 20 µIU/mL (mU/L) or higher. Four hundred seventy-one of the 515 infants had subsequent specimens obtained at more than 24 hours, and none of the results were abnormal. There was no child weighing more than or equal to 2500 g who was diagnosed with CH in 1993 and 1994 whose specimen obtained at 24 hours or less was normal. Conclusions. Accepting specimens obtained at more than 12 to 24 hours from infants weighing 2500 g or more would have resulted in more than the usual number of false-positive results but no false-negative results. This would have decreased the requests for additional specimens by more than 90%.

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