Control Indicators for the Examination of Pork for Trichinella spiralis by the Acid-Pepsin Digestion Method

1994 ◽  
Vol 57 (2) ◽  
pp. 173-175
Author(s):  
CONNIE D. ANDREWS ◽  
DONALD W. WEBERT
Keyword(s):  
Trichinella Spiralis ◽  
Digestion Method ◽  
Pepsin Digestion ◽  
Artificial Digestion ◽  
Collagen Membranes ◽  
Negative Controls

Artificial digestion using an acidified pepsin solution is one of several methods of examination of meat for the presence of Trichinella spiralis larvae. Indicator devices, which serve as visible ‘positive’ and ‘negative’ Controls, have been developed for use in this digestion method. The indicators are color-coded, red and blue, modified-collagen membranes. One each of the red and blue colored membranes are added to the solution along with the sample. The digestion of the blue indicator and the retention of the red indicator are established as criteria that the process is within acceptable limits.

Sensitivity of Artificial Digestion and Enzyme Immunoassay Methods of Inspection for Trichinae in Pigs

1998 ◽  
Vol 61 (3) ◽  
pp. 339-343 ◽  
Author(s):  
H. R. GAMBLE
Keyword(s):  
Sample Size ◽  
Enzyme Immunoassay ◽  
Trichinella Spiralis ◽  
Serological Testing ◽  
Digestion Method ◽  
Artificial Digestion ◽  
Eu Directives ◽  
Digestion Methods ◽  
Pooled Sample ◽  
The Eu

Forty-seven pigs were infected with varying doses of Trichinella spiralis and tested for evidence of infection by serology, using an enzyme immunoassay (EIA), and by artificial digestion methods. Using a 1-g sample, as prescribed in accordance with European Union (EU) directives, the sensitivity of the pooled-sample artificial digestion method was between three and five larvae per gram (LPG) of tissue. Using a 5-g sample size, in accordance with methods described in the U.S. Code of Federal Regulations, and as required for the inspection of horses exported to the EU, the sensitivity of the test was increased to approximately 1 LPG. Serological testing by EIA detected pigs with as few as 0.02 LPG, but detection times varied from 4 to 8 weeks after infection. Mean postinoculation times for detection by serology were 32 to 42 days. On the basis of these results, it is clear that digestion testing using a 5-g sample size is the only method of those tested here that is completely reliable for detection of trichinae infection at a level that will protect public health. Both digestion testing using a 1-g sample and EIA have drawbacks. However, EIA remains a highly effective tool for epidemiological purposes and for monitoring trichinae infection on the farm.

Detection of Trichinellosis in Pigs by Artificial Digestion and Enzyme Immunoassay

1996 ◽  
Vol 59 (3) ◽  
pp. 295-298 ◽  
Author(s):  
H. R. GAMBLE
Keyword(s):  
Enzyme Immunoassay ◽  
Trichinella Spiralis ◽  
Federal Regulations ◽  
Testing Methods ◽  
Digestion Method ◽  
Inspection Method ◽  
Sample Digestion ◽  
Artificial Digestion ◽  
Digestion Methods ◽  
Pooled Sample

The objective of this study was to demonstrate the reliability of current and proposed methods for the inspection of swine and other species for infection with the parasite Trichinella spiralis. Five groups of pigs were infected with doses of 2500, 500, 100, 50, and 20 T. spiralis larvae to establish moderate and low-level infections. Pigs were bled periodically during the study for samples to be tested by enzyme immunoassay (EIA). At the conclusion of the study, pigs were slaughtered and tissues collected for analyses of worm burdens and for comparison of digestion testing methods. Comparisons of pooled sample digestion methods were made using inspection methods prescribed by European Union Directives and the USDA, Code of Federal Regulations. Pooled sample digestion testing using 1-g samples was effective for detecting pigs with larval densities of >10 larvae per gram (LPG) of tissue but only partially effective for pigs with infections of <3 LPG. Pooled sample digestion testing using 5-g samples detected all pigs with infection levels >1 LPG. The EIA detected all T. spiralis-infected pigs, but did not detect infections in some pigs until 49 days after inoculation. These results demonstrate that the pooled sample digestion method using a 5-g sample size is the most effective inspection method for reducing the risk of human exposure to T. spiralis in pork.

scholarly journals Larval Gnathostomes and Spargana in Chinese Edible Frogs, Hoplobatrachus rugulosus, from Myanmar: Potential Risk of Human Infection

2020 ◽  
Vol 58 (4) ◽  
pp. 467-473
Author(s):  
Jong-Yil Chai ◽  
Bong-Kwang Jung ◽  
Jin-Youp Ryu ◽  
Hyun-Seung Kim ◽  
Sung-Jong Hong ◽  
...  
Keyword(s):  
Potential Risk ◽  
Human Infection ◽  
Local Market ◽  
Digestion Method ◽  
Artificial Digestion ◽  
Potential Risks ◽  
The Mean

Chinese edible frogs, Hoplobatrachus rugulosus, were examined to estimate the potential risks of human gnathostomiasis and sparganosis in Myanmar. A total of 20 frogs were purchased in a local market of Yangon and examined with naked eyes and the artificial digestion method after skin peeling in June 2018 and June 2019. Larvae of gnathostomes and Spirometra (=spargana) were detected in 15 (75.0%) and 15 (75.0%) frogs with average intensities of 10.5 and 6.3 larvae per infected frog, respectively. Gnathostome larvae were 2.75-3.80 (av. 3.30) mm long and 0.29-0.36 (0.33) mm wide. They had a characteristic head bulb with 4 rows of hooklets, a muscular long esophagus, and 2 pairs of cervical sac. The mean number of hooklets were 41, 44, 47, and 50 on the 1st, 2nd, 3rd, and 4th row, respectively. Collected spargana were actively moving, particularly with the scolex part, and have ivory-white color and variable in size. Conclusively, it has been first confirmed that Chinese edible frogs, H. rugulosus, are highly infected with larval gnathostomes and spargana in this study. Consuming these frogs is considered a potential risk of human gnathostomiasis and sparganosis in Myanmar.

Molecular cloning of enolase from Trichinella spiralis and the protective immunity in mice

2018 ◽  
Vol 63 (2) ◽  
pp. 252-260 ◽  
Author(s):  
Xuliang Zhang ◽  
Lixin Xu ◽  
Xiaokai Song ◽  
Xiangrui Li ◽  
Ruofeng Yan
Keyword(s):  
Recombinant Protein ◽  
Trichinella Spiralis ◽  
Flow Cytometric Analysis ◽  
Recombinant Plasmids ◽  
Flow Cytometric ◽  
Th2 Immune Response ◽  
Wide Range ◽  
Muscle Larvae ◽  
Ifn Γ ◽  
Negative Controls

Abstract Trichinella spiralis, the main pathogen of trichinosis, infects a wide range of mammalian hosts and is one of the most widespread parasites worldwide. For parasites, glycolysis is the most important way to generate energy. Previous studies showed that some enzymes involved in the glycolytic pathway play roles in regulation the host immunity. In this paper, enolase from T. spiralis was cloned and the protective potentials were studied. One hundred and sixty ICR mice were divided into four groups and vaccinated with recombinant enolase (pET-ENO), eukaryotic recombinant plasmid encoding enolase (pVAX1-ENO) and negative controls (pVAXl and PBS), respectively. Two weeks after the second immunization, each mouse was challenged orally with 200 muscle larvae (MLs) of T. spiralis. Results showed that mice vaccinated with pET-ENO and pVAX1-ENO induced specific antibodies of IgG, IgA, IgM, but no IgE. Subclasses of IgG antibodies showed that mice immunized with recombinant protein and recombinant plasmids induced a Th1/Th2 immune response. Concentrations of serum cytokines were detected and showed significant increase of IFN-γ, IL-4 and TGFβ1, while IL-17 in each group was not significantly different. Flow cytometric analysis showed significant increase of CD4+ and CD8+ T lymphocytes in the groups immunized with recombinant protein and recombinant plasmids. Challenge infection demonstrated that immunized groups had a reduced number of worm burdens. The reductions of larvae per gram muscle (LPG) in pET-ENO and pVAX1-ENO group were 17.7% and 15.8% when compared with PBS control.

Methods for the Detection of Trichinellosis in Horses

1996 ◽  
Vol 59 (4) ◽  
pp. 420-425 ◽  
Author(s):  
H. RAY GAMBLE ◽  
ALVIN A. GAJADHAR ◽  
MORSE B. SOLOMON
Keyword(s):  
Enzyme Immunoassay ◽  
Trichinella Spiralis ◽  
Larval Density ◽  
Human Health Risk ◽  
Dependent Manner ◽  
Sample Sizes ◽  
Tissue Samples ◽  
Artificial Digestion ◽  
Dose Dependent ◽  
Digestion Methods

Twelve horses were infected with various doses of Trichinella spiralis and then tested for infection using direct (artificial digestion) and indirect (enzyme immunoassay) methods. Horses became infected in a dose-dependent manner. Larvae accumulated preferentially in the tongue, followed by the masseter, neck, supraspinatus, trapezius, and diaphragm. At lower infection levels, the tongue harbored several times more parasites than were found in other tissues. The sensitivity of artificial digestion methods for detecting infections was directly related to sample size. One-gram samples were not reliable for detecting infection levels of <3 larvae per g (LPG). In sample sizes of 5 or 10 g the technique allowed infections as low as 1 LPG to be detected. The enzyme immunoassay (EIA) detected all infected horses; the times following infection at which horses became seropositive varied in a dose-dependent manner, but 11 of 12 horses were positive in the EIA by 4 weeks postinoculation. One horse, with a larval density in the tongue of 0.39 LPG, did not become seropositive until 7 weeks postinoculation. The results suggest that artificial digestion of horse carcasses for trichinae should concentrate on tissue samples from the tongue or masseter muscles. Sample sizes should be a minimum of 5 g using pooled-sample digestion methods to assure detection of all infections which might pose a human health risk. The EIA is a potential substitute for artificial digestion methods and could also be useful for antemortem testing and for epidemiological studies.

Use of Proficiency Samples To Assess Diagnostic Laboratories in France Performing a Trichinella Digestion Assay

2007 ◽  
Vol 70 (7) ◽  
pp. 1685-1690 ◽  
Author(s):  
ISABELLE VALLÉE ◽  
PAULINE MACÉ ◽  
LORRY FORBES ◽  
BRAD SCANDRETT ◽  
BENOIT DURAND ◽  
...  
Keyword(s):  
Trichinella Spiralis ◽  
Reference Laboratory ◽  
Test Sensitivity ◽  
National Reference ◽  
Large Samples ◽  
Routine Diagnosis ◽  
Muscle Larvae ◽  
Artificial Digestion ◽  
Meat Samples ◽  
Subsequent Identification

Routine diagnosis of animal trichinellosis for food safety and trade relies on a method of artificial digestion to free Trichinella muscle larvae from meat for subsequent identification by microscopy. As part of a quality control system, the French National Reference Laboratory (NRL) initiated ring trials to determine the sensitivity of the test performed in the 72 routine diagnostic laboratories in France. A method was devised to obtain calibrated meat samples containing known numbers of capsules with Trichinella spiralis muscle larvae. This method was based on an incomplete artificial digestion of Trichinella-infected mice carcasses to allow the collection of intact Trichinella capsules. Capsules were placed into a meatball of 100 ± 2 g of pork and horsemeat to produce proficiency samples. Three categories of samples were prepared: small (3 to 5 capsules), medium (7 to 10), and large (12 to 15). The sensitivity was expressed as the percentage of muscle larvae recovered from each proficiency sample. Reproducibility was tested with ring trials organized between two NRLs (France and Canada), and a reference sensitivity of 84.9% was established. National ring trials were then organized in France, with the 72 routine diagnostic laboratories each receiving four proficiency samples per session. After five sessions, an improvement in the digest test sensitivity was observed. Results at the fifth session indicated sensitivities of 78.60% ± 23.70%, 81.19% ± 19.59%, and 80.52% ± 14.71% muscle larvae for small, medium, and large samples, respectively. This study supports the use of proficiency samples to accurately evaluate the performance of routine diagnostic laboratories that conduct digestion tests for animal trichinellosis diagnosis.

scholarly journals Optimization of the pepsin digestion method for anisakids inspection in the fishing industry

2013 ◽  
Vol 191 (3-4) ◽  
pp. 276-283 ◽  
Author(s):  
María Llarena-Reino ◽  
Carmen Piñeiro ◽  
José Antonio ◽  
Luis Outeriño ◽  
Carlos Vello ◽  
...  
Keyword(s):  
Fishing Industry ◽  
Digestion Method ◽  
Pepsin Digestion

scholarly journals Echinostoma macrorchis Metacercariae in Cipangopaludina chinensis malleata from Xiengkhuang Province, Lao PDR and Morphologies of Adults from Experimental Animals

2019 ◽  
Vol 57 (6) ◽  
pp. 657-664
Author(s):  
Woon-Mok Sohn ◽  
Byoung-Kuk Na ◽  
Dongmin Lee ◽  
Keeseon S. Eom ◽  
Tai-Soon Yong ◽  
...  
Keyword(s):  
Ventral Sucker ◽  
Lao Pdr ◽  
Morphological Characteristics ◽  
The Body ◽  
Digestion Method ◽  
Experimental Animals ◽  
Artificial Digestion ◽  
Average Size ◽  
Large Ovary ◽  
End Group

We identified the echinostome metacercariae in Chinese mystery snails, <i>Cipangopaludina</i> <i>chinensis</i> <i>malleata</i>, from Xiengkhuang Province, Lao PDR with morphologies of adult worms recovered. Total 20 snails were examined with artificial digestion method and then the collected metacercariae were orally infected to a mouse and a rat. Adult worms recovered from experimental animals were observed with a light microscope and a SEM. The metacercariae were round, 125×123 µm in average size, with a moderately thick cyst wall, collar spines distributed in the head collar and excretory granules in 2 canals of excretory tube. Adult flukes (3-week-old in a rat) were elongated, ventrally curved and 5.310×1.023 mm in average size. Head collar distinct, bearing 43 collar spines with 5 end group ones on each side. Oral sucker subterminal, prepharynx very short, pharynx well developed, and esophagus relatively short. Cirrus sac well developed, with a saccular seminal vesicle, and ventral sucker very large. Ovary round and on the median line of the body. Testes tandom and elongated. Eggs operculated, elliptical and 90×57 µm in average size. In the SEM observation, the head crown prominent, with 43 collar spines resembled with horns of younger stag. Scale-like tegumental spines were densely distributed on the surface between the head collar and ventral sucker, and their densities were decreased posteriorly. Conclusively, the metacercariae detected in <i>C</i>. <i>chinensis</i> <i>malleata</i> from Lao PDR were identified as those of <i>Echinostoma</i> <i>macrorchis</i> based on the morphological characteristics of adult worms.

Sign in / Sign up

Export Citation Format

Share Document