Pig Tongue Research Articles

Trichinella spp. in Slaughtered Pigs of India: From Neglected Disease to an Emerging Food Safety Threat for Public Health

Background. In India, Trichinella nematode worm remains highly neglected due to the paucity of research. Recent trichinellosis outbreaks in humans associated with pork meal in north India have highlighted an emerging food safety concern due to this neglected parasite. Aim. This study aimed to ascertain the existence of Trichinella species and to identify them in slaughtered pigs intended for human consumption in the Punjab and Uttaranchal regions of North India. Materials and Methods. A total of 1,194 slaughter pig tongue samples were screened in 239 pools using the double separatory funnel method for recovery of Trichinella larvae. The species of recovered larvae were confirmed by multiplex PCR assay and sequencing. A phylogenetic tree was constructed to ascertain the closest lineage. Results. This study reported 3.77% and 1.26% Trichinella positivity in pooled and individual pig samples, respectively. Pigs slaughtered in Punjab reported higher positivity (1.73%) than pigs in Uttaranchal (0.81%). Among all places, Jalandhar recorded highest positivity of 5.66%, followed by 2.22% in Nainital and 0.8% in Patiala, whereas none of the pig samples from Chandigarh, Ludhiana, Bathinda, Tehri Garhwal, Pauri Garhwal, Kashipur, Haridwar was positive. Molecular confirmation by PCR and sequencing confirmed the recovered Trichinella larvae as T. britovi and T. nelsoni. Conclusion. Trichinella parasite remained highly neglected in India; however, the detection of sylvatic Trichinella species in pigs intended for human consumption indicated the emergence of zoonotic foodborne risk at wild animal-domestic pig and human interfaces. To the best of our knowledge, this is the first study reporting T. britovi and T. nelsoni in pigs of North India. Trichinella positivity in slaughtered pigs is an early alarm for the emergence of foodborne risk from this neglected parasitic worm. Considering the importance of pigs as a source of meat and their role as a reservoir for Trichinella raised the food safety concern that warrants strict meat inspection and extensive studies on neglected parasites in India.

Thermal damage and excision time of micro and super pulsed diode lasers: A comparative ex vivo analysis.

The primary aim of this ex vivo study was to evaluate thermal damage and cutting efficiency of micro and super pulsed diode lasers. The secondary aim was to suggest a guideline to perform simple surgical excisions adequate for histopathological evaluation. Ten groups of 10 specimens of pig tongues were excised using a blade (G1), a micro pulsed (G2-G9), and a super pulsed diode (G10) lasers. Different output power, pulse duration, pulse interval, and duty cycle were tested. Quantitative measures of thermal damage and excision times were recorded. Statistical analysis was performed at a significance level of 5%. The control group (G1) presented no thermal damage. Within the laser groups (G2-G10), no statistically significant differences in depth of thermal damage (µm) were noted. G3 showed significantly less area of thermal damage (mm2 ) when compared with G7 and G9 (p < .05). The median excision time of the control group and super pulsed diode laser group were significantly lower (p < .001) than the micro pulsed diode laser groups. The cutting efficiency of the super pulsed diode laser is comparable to traditional blade, and with appropriate parameters, these lasers can produce predictable surgical outcomes with less collateral damage.

A novel experimental set up for in situ oral lubrication measurements

Oral lubrication has attracted a growing research interest in recent years because of its importance in influencing food texture and mouth-feel sensation. A number of tribometers have been developed for oral tribology studies, but all are designed for in vitro applications only. In this work, a new experimental set up has been established for in situ oral lubrication measurements; and further to determine oral lubrication as influenced by food consumption in relation to texture and mouth-feel. The design was based on a mechanical coupling between a texture analyzer and an intra-oral pressure sensor, and on a simultaneous digitizing of signals from both devices. Feasibility and reliability of the set up was firstly tested using hard–hard frosted glass surfaces with varying sliding speeds and two different normal forces; then using pig's tongue – polydimethylsiloxane soft surfaces with artificial saliva and food samples varying fat content at different sliding speeds. Consistent friction coefficients were observed in hard-hard surface lubrication tests and fat content-dependent friction coefficients were seen in soft surface lubrication tests. After these, in situ friction coefficients were measured in 10 healthy subjects, both under unstimulated oral conditions and after consumption of fluid foods. It was found that friction coefficient measured with no food consumption (unstimulated) was correlated to the salivary viscosity as well as salivary flow rate. The oral friction coefficient showed a strong correlation with the sensory intensity perception of astringency and slipperiness. Results from this work demonstrate that this simple experimental set up is feasible and reliable. Our work provides a new experimental technique for oral lubrication studies in relation to the controlling mechanisms of oral sensation of food texture and mouth-feel.

Topographic study of human tongue in relation to oral tribology

Human tongue plays a critical role in food oral processing and in particular to food manipulation and texture sensation. We speculate that different topographic characteristics among human individuals could be a fundamental cause for different food oral behavior and sensory perception. We hypothesize that tongue surface roughness will influence oral lubrication and therefore texture sensation. As the first initiative, this work investigated surface profile of human tongue. Altogether 71 young Chinese subjects participated in this investigation. Double moulding using silicone rubber and followed by gypsum was applied for the replication of the surface microstructure of human tongue. Optical scanning was applied to obtain 3D data of the replicated tongue surfaces. Mountains Map software was used to analyze topographic features. The method was verified by specimen of standard surfaces as well as pig's tongue. Results show that human tongue is generally symmetrical along the central line, but varies across the different area of the tongue. Tongue tip is the roughest part of the tongue. The roughness of the tongue decreases gradually from the front to the back. The calculated arithmetic roughness of the tongue tip varies from 50 μm to 160 μm for the investigated subjects, with an arithmetic average Sa at 89.53 ± 20.48 μm and a square root average Sq at 114.80 ± 25.47 μm. A preliminary analysis showed a possible correlation between tongue surface roughness and oral lubrication.

Microstructure and frictional properties on biological mucosa

Swallowing disorder has been becoming a serious issue with increasing in elderly people. Disorder sometimes appears with an decrease in saliva, because saliva has an important role in lubrication over the oral cavity and throat. Though the structure of biological mucosa has been studied physiologically, there are only few studies that examined the influence of its micro structure on fluid lubrication. Therefore, we investigated the friction characteristics by reproducing the micro structure of oral cavity and pharynx. As an example of the oral cavity mucous membrane, the tongue of a pig was subjected to observation by microscope and laser surface shape and roughness measuring machine. As a result, roughness properties of a pig tongue differed from root part to tip part, and it was confirmed that hemispherical protrusions were observed on the tip part by irregular arrangement. An imitation tongue was produced using a high-precision 3D printer. Furthermore, the concentration of thickener was determined from the measurement of the viscous characteristic by the rotational viscometer to have the same viscosity as that of saliva. We measured friction coefficients on the imitation tongue lubricated by artificial saliva. The friction coefficients were changed depending on the lubrication condition and the moving speed.

Prevalence of pathogenic Yersinia enterocolitica in minced meat, pig tongues and hearts at the retail level in the Czech Republic detected by real time PCR

Yersiniosis is the third most frequently reported zoonosis in the European Union and Yersinia enterocolitica is the most common species causing human infections. Pigs are assumed to be the main reservoir of human pathogenic Y. enterocolitica with the presence of bacteria mainly in the tonsils and intestinal content. Undercooked pork and pork products have been suggested as the primary source of human yersiniosis. Nevertheless, data on the prevalence of pathogenic Y. enterocolitica in foodstuffs including pork products are very limited. A molecular based method (real time PCR) targeting the ompF gene (detection of Yersinia genus) and the ail gene (a chromosomally located virulence marker of Y. enterocolitica) was used to determine the prevalence of pathogenic Y. enterocolitica in minced meat and edible pork offal at the retail level in the Czech Republic. A total of 50 pig tongues, 50 pig hearts, and 93 samples of minced meat containing pork were purchased at nine retail outlets in Brno. High detection rates of Yersinia spp. were found in all types of samples (pig tongues, 80.0%; pig hearts, 40.0%; and minced meat, 55.9%). The highest prevalence of pathogenic Y. enterocolitica was found in pig tongues (40.0%), followed by pig hearts (18.0%) and minced meat samples (17.2%). Although from the point of view of food safety the merely molecular detection of DNA of the pathogenic bacteria could represent a false positive result, our results indicate the presence of pathogenic Y. enterocolitica in raw pork products at the retail level in the Czech Republic, which may pose a risk of consumer infection. Sufficient heat treatment and prevention of cross-contamination during preparation of food in the kitchen should be recommended.

Characteristics of Listeria monocytogenes isolated from tonsils of slaughtered fattening pigs in Switzerland

Of 504 tonsil samples from slaughtered fattening pigs, 5.6 % were positive for Listeria monocytogenes by culture after enrichment. The 28 L. monocytogenes isolates were analyzed to gain insights into genetic relationships and virulence-associated traits. Of the 28 isolates, 57 % belonged to serotype 1/2a (genetic lineage II), 25 % to serotype 4b (genetic lineage I) and 18 % to serotype 1/2b (genetic lineage I). These serotypes are commonly associated with human listeriosis cases. Multilocus sequence typing assigned the 28 isolates to 16 clonal complexes (CCs) and three singletons, including one new sequence type (ST768). Several of these CCs were also found in strains from human infections. Sequence analysis of the whole internalin A gene (inlA) showed that all but one isolate (CC6/serotype 4b) encoded full-length proteins. Clinical strains from human patients commonly harbor full-length inlA. On the other hand, genes for benzalkonium chloride tolerance were not found and all but one isolate lacked genes for the stress survival islet (SSI-1). Thus, tonsils of slaughtered fattening pigs can be colonized with L. monocytogenes of public health impact. To counteract this threat during slaughter, prevention of contamination of carcasses and the environment is of major importance, in particular adherence to good slaughter hygiene practice. With regard to pig tonsils, special attention must be given to the handling and contamination of head meat and pig tongues.

Ex vivo approach to studying bio-adhesive and tribological properties of artificial salivas for oral dryness (xerostomia)

Saliva plays fundamental role in the maintenance of the good mouth health and in the lubrication process during oral functions including speech and mastication. Xerostomia, or dry mouth syndrome, is a disease due to an insufficient saliva secretion, or a total absence of saliva. The effects of xerostomia are very unpleasant in the daily life. They lead to some important inconveniences as the dental caries, the loss of teeth or some difficulties to speak.The causes of xerostomia are various but the most of the times they are often associated to irradiation and radiotherapy used to treat cancers of the head and neck. To try to re-wet the oral cavity, salivary substitutes are generally used. They are supposed to re-lubricate the mouth.In this work, a method for measuring adhesion and lubrication of the salivary substitutes has been tested ex vivo on pig tongue. The results indicated that the bio-adhesive properties of the salivary substitutes were fairly close to those of human saliva, while their lubricate capacity were rather less efficient. The experimental method proposed here seems to be interesting to characterise and improve the salivary substitutes performances.

Physical and sensory characterizations of oral coatings of oil/water emulsions.

The physical and sensory properties of oil coatings on the tongue formed by five oil/water emulsions varying in oil content were investigated. A total of 20 subjects processed orally each emulsion for 30 s in triplicate. In vivo fluorescence measurements at the front and back of the anterior tongue were made to quantify the oil fraction deposited at different time points. Calibration lines relating fluorescence intensity to oil fraction were determined using pig tongues at 37.5 °C to mimic oral conditions. The oil fraction on the tongue increased linearly with an increasing oil content of the emulsions. The oil fraction deposited at the back of the anterior tongue was 1.5-2.0× larger than at the front. The intensity of sensory attributes describing after-feel perception was related to the oil fraction by Weber-Fechner's law. This study uses in vivo fluorescence to study food behavior in the mouth and unravel new insights in after-feel perception of emulsions.

Simulation for training in oral cancer biopsy: A surgical model and feedback from GDPs

Objectives: To describe a new bench model for oral precancer/cancer biopsy training and to assess its effectiveness in terms of trainees’ perception. Study design: Cross-sectional, descriptive, performed on 424 general dental practitioners (GDP) who undertook biopsies on a pig tongue. The participants were assessed by direct observation for 2.5 hours using specific check-lists and by means of a self-applied questionnaire. Results: The workshop was perceived as “very interesting” even by those with previous surgical experience (Xi - Xj = 0.07; 95%CI= -0.20-0.09). Most GDPs considered themselves able to undertake oral biopsies on real patients after the workshop. Those who had previously received theoretical continuous education courses on oral biopsy scored higher values within the group (Xi - Xj = 0.20; 95%CI= 0.04-0.37). Conclusions: There is a need for including clinical abilities workshops when instructing on oral biopsy techniques. More studies are needed to validate the procedure and to address cognitive and communication skills. Key words:Models, animal, education, dental, continuing, biopsy, oral cancer, oral surgical procedures.

CO2 laser oral soft tissue welding: an in vitro study

Although there are some studies reporting the benefits of using laser to improve wound closure, there were a few studies in a model of oral mucosa. The aim of this in vitro study was to compare immediate tensile strength of the wound closure between suture alone and suture combined with CO2 laser welding. The study was conducted in 40 samples of the tissue blocks from ventral sides of pig tongues. A 20 mm-length and 5 mm-depth incision was made in each sample. The samples were randomly allocated into 2 groups namely: the control group and the experimental group. The samples of the control group were sutured with 3- stitch of 4-0 black silk. The samples of the experimental group were irradiated with CO2 laser (ultrapulse mode, 800 Watt peak power, 10 Hz, 0.2 ms pulse duration and 2,262.62 J/cm(2) energy density) before sutured. The immediate tensile strength of the wound was measured by using customized tensiometer under stereomicroscope. The median of tensile strength of the control group and the experimental group were 30.40 g/cm(2) and 40.50 g/cm(2), respectively. There was no statistically significant difference between the groups (P value = 0.58). The proportions of the samples without wound dehiscence at the maximum limit of the tensiometer (120 g/cm(2)) were 0.15 (3/20) in the control group and 0.35 (7/20) in the experimental group. The CO2 laser welding used in this study failed to show a greater immediate tensile strength but had a higher proportion of the wound without dehiscence at the 120 g/cm(2) tensile strength by comparison with the suture alone.

Geographic Correlation between Tapeworm Carriers and Heavily Infected Cysticercotic Pigs

BackgroundNeurocysticercosis is a leading cause of preventable epilepsy in the developing world. Sustainable community-based interventions are urgently needed to control transmission of the causative parasite, Taenia solium. We examined the geospatial relationship between live pigs with visible cysticercotic cysts on their tongues and humans with adult intestinal tapeworm infection (taeniasis) in a rural village in northern Peru. The objective was to determine whether tongue-positive pigs could indicate high-risk geographic foci for taeniasis to guide targeted screening efforts. This approach could offer significant benefit compared to mass intervention.MethodsWe recorded geographic coordinates of all village houses, collected stool samples from all consenting villagers, and collected blood and examined tongues of all village pigs. Stool samples were processed by enzyme-linked immunosorbent assay (ELISA) for presence of Taenia sp. coproantigens indicative of active taeniasis; serum was processed by enzyme-linked immunoelectrotransfer blot for antibodies against T. solium cysticercosis (EITB LLGP) and T. solium taeniasis (EITB rES33).FindingsOf 548 pigs, 256 (46.7%) were positive for antibodies against cysticercosis on EITB LLGP. Of 402 fecal samples, 6 (1.5%) were positive for the presence of Taenia sp. coproantigens. The proportion of coproantigen-positive individuals differed significantly between residents living within 100-meters of a tongue-positive pig (4/79, 5.1%) and residents living >100 meters from a tongue-positive pig (2/323, 0.6%) (p = 0.02). The prevalence of taeniasis was >8 times higher among residents living within 100 meters of a tongue-positive pig compared to residents living outside this range (adjusted PR 8.1, 95% CI 1.4–47.0).ConclusionsTongue-positive pigs in endemic communities can indicate geospatial foci in which the risk for taeniasis is increased. Targeted screening or presumptive treatment for taeniasis within these high-risk foci may be an effective and practical control intervention for rural endemic areas.

Anatomia dos ramos do nervo lingual em suíno

The distribution and ramifications of the lingual nerve of 18 tongues of adult pigs from both genders with no strain specification were studied. The material freshly collected in slaughter routine was cooled (4°C) for transportation, fixed in formaldehyde aqueous solution (7%, 72h), immerse in nitric acid aqueous solution (15%, 72h) and dissected with magnifying glass (RASOR, II-20). Each dissected antimere enabled the recording of primary, secondary and tertiary lingual nervous branches present inside the myofascial structure of the organ, exhibiting different arrangements: left antimere: 4 to 10 primary branches, 4 to 12 secondary antimeres and 0 to 11 tertiary branches; right antimere: 3 to 8 primary branches, 0 to 11 secondary antimeres and 0 to 10 tertiary branches. In 27.6% of analyses, the lingual branches established associations with the fibers of the hypoglossal nerve in the corresponding antimere.

Spatial Distribution of Taenia solium Porcine Cysticercosis within a Rural Area of Mexico

Cysticercosis is caused by Taenia solium, a parasitic disease that affects humans and rurally bred pigs in developing countries. The cysticercus may localize in the central nervous system of the human, causing neurocysticercosis, the most severe and frequent form of the disease. There appears to be an association between the prevalence of porcine cysticercosis and domestic pigs that wander freely and have access to human feces. In order to assess whether the risk of cysticercosis infection is clustered or widely dispersed in a limited rural area, a spatial analysis of rural porcine cysticercosis was applied to 13 villages of the Sierra de Huautla in Central Mexico. Clustering of cases in specific households would indicate tapeworm carriers in the vicinity, whereas their dispersal would suggest that the ambulatory habits of both humans and pigs contribute to the spread of cysticercosis. A total of 562 pigs were included in this study (August–December 2003). A global positioning system was employed in order to plot the geographic distribution of both cysticercotic pigs and risk factors for infection within the villages. Prevalence of pig tongue cysticercosis varied significantly in sampled villages (p = 0.003), ranging from 0% to 33.3% and averaging 13.3%. Pigs were clustered in households, but no differences in the clustering of cysticercotic and healthy pigs were found. In contrast, the presence of pigs roaming freely and drinking stagnant water correlated significantly with porcine cysticercosis (p = 0.07), as did the absence of latrines (p = 0.0008). High prevalence of porcine cysticercosis proves that transmission is still quite common in rural Mexico. The lack of significant differentiation in the geographical clustering of healthy and cysticercotic pigs weakens the argument that focal factors (e.g., household location of putative tapeworm carriers) play an important role in increasing the risk of cysticercosis transmission in pigs. Instead, it would appear that other wide-ranging biological, physical, and cultural factors determine the geographic spread of the disease. Extensive geographic dispersal of the risk of cysticercosis makes it imperative that control measures be applied indiscriminately to all pigs and humans living in this endemic area.

Fat retention at the tongue and the role of saliva: Adhesion and spreading of ‘protein-poor’ versus ‘protein-rich’ emulsions

Fat perception of food emulsions has been found to relate to in-mouth friction. Previously, we have shown that friction under mouth-like conditions strongly depends on the sensitivity of protein-stabilized emulsion droplets to coalescence. Here, we investigated whether this also implies that oral fat retention depends in a similar manner on the stability of the emulsion droplets against coalescence. We investigate the separate contributions of droplet adhesion and droplet spreading to fat retention at the tongue, as well as the role of saliva. We perform e x vivo (Confocal Raman Spectroscopy; Confocal Scanning Laser Microscopy) experiments using pig's tongue surfaces in combination with human in vivo experiments. These reveal that protein-poor (unstable) emulsions are retained more at the tongue than protein-rich (stable) emulsions. Furthermore, the layer formed by adhering protein-poor droplets is more stable against rinsing. Saliva is found to be very efficient in removing fat and emulsion droplets from the oral surface but its role in fat retention needs further research. We relate our results to the colloidal forces governing droplet adhesion and spreading.

Application of oral tissue in tribological measurements in an emulsion perception context

Tribological measurements are indicated to be a tool in predicting the creamy in-mouth sensation of a food product. Tribological measurements relating lubricational behaviour of a food product to perception are often conducted with artificial surfaces. In this work we used pig's tongue to mimic the human tongue, which has the advantage of having surface characteristics similar to a human tongue. Using biological material has also some drawbacks. The most important drawbacks are the limited availability, the individual differences between the tongues, and the relative fast degradation of the tissue. The aim of this study was to identify the characteristics of the tongue in terms of surface roughness, deformability and wetting properties. The knowledge on these characteristics can serve as reference when using modified poly dimethyl siloxane (PDMS) in tribological experiments relating perception to in-mouth friction. Furthermore, we demonstrated that these characteristics are crucial in tribological studies to draw rightful conclusions. Tribological measurements were performed with an experimental set-up combining friction measurement with confocal scanning laser microscope (CSLM) observations. We identified the importance of these characteristics for tribology measurements performed in relation to sensory perception. It is shown that the tongue surface has some very typical characteristics, including the presence of papillae and a hydrophilic mucus layer, and an elastic modulus that is at least two orders of magnitude smaller than that of smooth PDMS surfaces. The different surface characteristics appear to lead to completely different lubricational behaviour of the food emulsions between these surfaces. Furthermore, for food emulsions differences in the occurrence of coalescence were found between shearing with pig's tongue and PDMS surfaces. Therefore, we conclude that for studies relating sensory properties of food systems to lubricational behaviour, a careful choice of representative surfaces is essential and that modification of smooth PDMS can result in surfaces having characteristics closer to tongue tissue.

Lubrication of Oral Surfaces by Food Emulsions: the Importance of Surface Characteristics

ABSTRACT: The friction between surfaces in relative motion lubricated by food emulsions has been measured. Different types of surfaces were tested, including metal, glass, rubber, and mucosal surfaces (pig tongue and pig esophagus). We demonstrate that the load‐dependent behavior of the coefficient of kinetic friction was different for various types of surfaces used; it decreased with increasing load for the mucosal surfaces, but was constant for glass‐metal surfaces. We show that this difference is an effect of the roughness and the deformability of the surfaces. For mucosal surfaces, the friction force did not depend on the oil fraction in the measured range of 10% to 40% (w/w). Furthermore, 3 commercial dairy products were tested between these surfaces. The lubrication properties of the low‐fat (1.5% fat content) and high‐fat (3.5% fat content) milk were comparable to those of the model emulsions. However, the friction force of the commercial cream (35% fat content) was found to be much lower.

Experimental study on characteristic of bioheat transfer and numerical simulation for the temperature fields in transverse and longitudinal sections of pig tongue

The influence factors of the tongue tissue structure on the temperature fields are importantly laid on the diameters and positions of arteries. Then temperature fields of certain sections are simulated by the finite element method (FEM). The results show that temperature gradients of the tongue in length are wider than in depth as a result of the specific vascularity. Thereby the relationship between temperature fields of tongue surface and those in transverse and longitudinal sections can be developed. This work will be further referential to study on the characteristics of heat transfer in human tongue, and will promote the development of bioheat transfer science.

Molecular epidemiology of Yersinia enterocolitica 4/O:3.

ConclusionsThe main source of sporadic human YE 4:O3 infections in Finland is the pig. YE 4:O3 is a common bacterium in slaughtered pigs, especially in tonsils. During evisceration, the tonsils are removed in conjunction with the pluck set (tongue, oesophagus, trachea, heart, lungs, diaphragm, liver and kidneys). The spread of YE 4:O3 from highly contaminated tonsils to the offal can not be avoided, especially when they hang together on a hook. Contaminated pig tongues, hearts, livers and kidneys have shown to be an important transmission vehicle of this bacterium from pigs to man. The only way to prevent the spread of pathogenic YE from pig tonsils to offal, carcasses and the environment is to modify the European Union legislation (64/433/EEC), to mandate that the head, containing the tonsils and tongue, should be removed prior to evisceration and that inspection and handling of the head, tonsils and tongue should occur in a separate room.

Artefacts produced by suture traction during incisional biopsy of oral lesions.

The aim of this study is to compare the artefacts ascribed to the technique of incisional biopsy using a punch or scalpel and the influence of suture use for traction and delivery of the specimen. A total of 160 samples were obtained from 10 fresh pig tongues by four experienced oral surgeons. Handling artefacts (squeeze artefacts): crush, splits, fragmentation and pseudocysts were assessed. No differences were identified in terms of crush, fragmentation or pseudocysts between samples obtained with a punch or scalpel. Splits were more frequent in those biopsies taken with a scalpel (chi2 = 9.26; P= 0.0023). Artefacts in the punch biopsy group were significantly less than in the group that combined punch and suture traction (P < 0.01). The scalpel and suture traction group showed significantly more artefacts than the group without suture. It is concluded the use of a stitch for traction in small incisional biopsies causes squeeze artefacts, so its use should be restricted to specimen orientation.