Morphological study and molecular epidemiology of Anisakis larvae in mackerel fish

Objective:To examine and study the morphology,epidemiology,and molecular phylogeny of Anisakis larvae in blue mackerel[Scomber australasicus(Cuvier,1832)]and Indian mackerel[Rastrelliger kanagurta(Cuvier,1816)]using light microscope,scanning electron microscope,molecular phylogeny,and species delimitation methods for confirmation and investigation of Anisakis species and their evolutionary relationship.Methods:A total of 90 fish(45 per species)were purchased from a department store in Chiang Mai,Thailand.Anisakis samples were investigated for morphological characteristics using light and scanning electron microscopes.Molecular phylogeny and species delimitation methods based on the cox2 gene were performed.Results:The prevalence,mean intensity(Mean±SEM),and mean abundance of Anisakis larvae(Mean±SEM)in blue mackerel were 77.78%,6.74±1.320,and 5.24±1.107,respectively,and in Indian mackerel,these values were 13.33%,2.50±0.764,and 0.33±0.159,respectively.Scanning electron microscopy showed the detail of morphological characteristics and provided the different shapes of mucron and excretory pores in Anisakis larvae congruent with the phylogenetic tree.The species tree was congruent with the phylogenetic tree.Conclusions:The prevalence,mean intensity,and mean abundance of Anisakis larvae were higher in blue mackerel.To the best of our knowledge,this is the first time that Anisakis pegreffii was found in blue mackerel in Thailand.The phylogenetic tree also supported the morphological data of Anisakis larvae.However,species delimitation based on cox2 revealed 1-3 possible cryptic species in this genus.Anisakis spp.contamination of fish products is unpleasant and a health concern considering human infection with larvae(anisakiasis)arises.

Activity of Tagetes minuta Linnaeus(Asteraceae)essential oil against L3 Anisakis larvae type 1

Objective:To evaluate in vitro effects of Tagetes minuta L. essential oil(TEO) on L3 Anisakis larvae type 1. Methods:In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae three different media were tested:1) a saline solution(SS); 2) an industrial marinating solution; 3) sunflower seeds oil(SO). For each media and concentrations of TEO(0.1%,0.5%,1.0% and 5.0% v/v),20 parasites were introduced into plastic Petri dishes(diameter 90 mm) and maintained at room temperature. As controls,larvae were maintained without TEO under identical experimental conditions in SS,MS and SO. A total of 900 larvae were tested. The normalized mean viability,LT100,LT50 and the percentage of inactivation at 24 hours were calculated. Results:In vitro tests revealed a complete inactivation of parasites in saline solution after 2 hours with 5% and 1% of TEO. In marinating solution,a complete inactivation of parasites was observed after 4 hours at all concentrations used. A slower activity for all TEO concentration was reported in SO. Conclusions:The results obtained,showing a strong activity against Anisakis larvae,confirm TEO as a larvicidal agent in the treatment of human anisakidosis and in the industrial marinating process.

Adult intussusception caused by colonic anisakis: A case report

BACKGROUND Colo-colonic intussusception is an uncommon phenomenon in an adult.Adult intussusception accounts for < 5% of total cases,and the colo-colonic type is < 30% of cases.Although surgical management has been the treatment of choice for intestinal intussusception in adults,because most frequent causes for adult intussusception are malignant in origin,the importance of the roles of preoperative colonoscopic evaluation has recently been emerging.CASE SUMMARY We report an extremely rare case of adult colo-colonic intussusception caused by colonic anisakiasis and successfully treated by endoscopic removal of the Anisakis body.A 59-year-old man visited the emergency department due to 1 day of lower abdominal colicky pain.Abdominopelvic computed tomography (APCT) revealed the presence of mid-transverse colon intussusception without definite necrosis,which was possibly related with colorectal cancer.Because there was no evidence of necrosis at the intussusception site,a colonoscopy was performed to target the colonic lesion and obtain tissue for a histopathological diagnosis.An Anisakis body was found when inspecting the suspicious colonic lesion recorded by APCT.The Anisakis body was removed with forceps assisted by colonoscopy.The patient’s symptoms improved dramatically after removing the Anisakis.A reduced colon without any pathological findings was seen on the follow-up APCT.Without any further treatment,the patient was discharged 5 d after the endoscopy.CONCLUSION When colonic intussusception without necrosis occurs in an adult,physician should consider a colonoscopy to exclude causes cured by endoscopy.

Intestinal anisakiasis can cause intussusception in adults:An extremely rare condition

We report an extremely rare case of adult intussusception caused by anisakiasis. A 41-year-old man was admitted into our hospital for right lower abdominal colicky pain. Ultrasonography and computed tomography revealed the presence of intussusception. As pneumodynamic resolution by colonoscopy failed, surgery was performed. The anisakis body was found in the submucosal layer of the resection specimen. The patient was discharged 9 d after the operation. Anisakiasis may cause intussusception in any country where sushi or sashimi now exists as a popular food. If suspicious, detailed clinical interview as to food intake prior to symptom development is crucial.

Natural products:Perspectives in the pharmacological treatment of gastrointestinal anisakiasis

Objective: To evaluate the activity of different natural products against L3 larvae of Anisakis type I. Methods: Information on investigations into the activity of natural products against the L3 larvae of Anisakis simplex was collected from scientific journals, books, theses and reports via a library and electronic search(using Pubmed, Scopus, Medline, Web of Science and Science Direct). The search terms included: natural products, medicinal plants, essential oils, terpenic derivatives, Anisakis, antinematodal activity. Results: In the literature reviewed numerous papers were found concerning the in vitro and in vivo activity against Anisakis type I of various natural products(plant extracts, essential oils and their major components). Analysis of the results showed that in vitro tests the Melaleuca alternifolia essential oil and the ar-turmerone isolated from Curcuma longa displayed the greatest activity. In vivo, the most active compound was perillaldehyde, the main component of Perilla frutescens essential oil. Conclusions: This study shows that some natural products exhibited promising antianisakis properties.

Endoscopic removal of foreign bodies:A retrospective study in Japan

BACKGROUND The ingestion of foreign bodies(FBs)and food bolus impaction(FBI)in the digestive tract are commonly encountered clinical problems.Methods to handle such problems continue to evolve offering advantages,such as the avoidance of surgery,reduced cost,improved visualization,reduced morbidity,and high removal success rate.However,to date,no studies have evaluated the endoscopic management of FBs in Japan.AIM To elucidate level of safety and efficacy in the endoscopic management of FBs and FBI.METHODS A total of 215 procedures were performed at Keio University Hospital between November 2007 and August 2018.Data were collected from medical charts,and endoscopic details were collected from an endoscopic reporting system.Procedures performed with a flexible gastrointestinal endoscope were only taken into account.Patients who underwent a technique involving FB or FBI from the digestive tract were only included.Data on patient sex,patient age,outpatient,inpatient,FB type,FB location,procedure time,procedure type,removal device type,success,and technical complications were reviewed and analyzed retrospectively.RESULTS Among the 215 procedures,136(63.3%)were performed in old adults(≥60 years),180(83.7%)procedures were performed in outpatients.The most common type of FBs were press-through-pack(PTP)medications[72(33.5%)cases],FBI[47(21.9%)],Anisakis parasite(AP)[41(19.1%)cases].Most FBs were located in the esophagus[130(60.5%)cases]followed by the stomach[68(31.6%)cases].AP was commonly found in the stomach[39(57.4%)cases],and it was removed using biopsy forceps in 97.5%of the cases.The most common FBs according to anatomical location were PTP medications(40%)and dental prostheses(DP)(40%)in the laryngopharynx,PTP(48.5%)in the esophagus,AP(57.4%)in the stomach,DP(37.5%)in the small intestine and video capsule endoscopy device(75%)in the colon.A transparent cap with grasping forceps was the most commonly used device[82(38.1%)cases].The success rate of the procedure was 100%,and complication were observed in only one case(0.5%).CONCLUSION Endoscopic management of FBs and FBI in our Hospital is extremely safe and effective.

Gastric and enteric anisakiasis successfully treated with Gastrografin therapy: A case report

We report a case of a 59-year-old woman who was diagnosed with gastric and small intestinal anisakiasis, which was successfully treated with endoscopic extraction and Gastrografin therapy. She was admitted to our hospital with epigastric pain and vomiting one day after eating raw fish. She exhibited tenderness in the epigastrium without obvious rebound tenderness or guarding. Computed tomography (CT) demonstrated segmental edema of the intestinal wall with proximal dilatation and a small number of ascites. Because enteric anisakiasis was suspected based on the patient's history of recent raw fish consumption and abdominal CT, we performed gastroscopy and confirmed that nine Anisakis larvae were attached to the gastric mucosa. All of the Anisakis larvae were extracted via endoscopy, and the patient was diagnosed with gastric and enteric anisakiasis. Additionally, in the hospital, we performed ileography twice using Gastrografin, which led to shortened hospital stay. Based on the clinical results of this case, we suggest that Gastrografin therapy is a safe, convenient, and useful method to extract enteric Anisakis larvae.

Parasites of Anisakidae Family--Geographical Distribution and Threat to Human Health

Nematodes of the Anisakidae family are important parasites that can cause anisakiasis--human parasitic infection of gastrointestinal tract. Allergic symptoms can arise as secondary immune response after infection by living parasite. In the life cycle of these parasites, intermediate, definitive and paratenic hosts （fish） might occur. In most cases, human anisakiasis is caused by consumption of fish which are infected with the larvae of the Anisakidae family. The purpose of the article was to assess the definitive host, the geographical spread of the parasites and the risk associated with consumption of raw fish and fishery products. Furthermore, this article describes symptoms and treatment of anisakiasis and kinds of preventive measures that can be taken to prevent anisakiasis.

Feeding on clean food?Potential effects of electric organ discharges by Torpedo spp.(Torpediniformes:Torpedinidae)on their trophically transmitted parasites

Members of the Torpedinidae(torpedoes)and Hypnidae(coffin ray)use electric organ discharges(EOD)to stun or kill their prey before consumption.We investigated whether EOD could also negatively affect the helminth larvae infecting these preys through a surrogate model:we applied electric discharges to individuals of blue whiting,Micromesistius poutassou,that harbored live larvae of Anisakis.Larval mortality throughout a 6-h period was significantly higher in the treatment group,suggesting that EODs could significantly hamper helminth recruitment.We then tested whether torpedinids and hypnids(“strong-EOD”families)harbored species-poor helminth(cestode)assemblages compared with“weak-EOD”Torpediniformes(Narcidae and Narkidae)and other Batoidea.Based on comparisons on estimated species diversity and mean species richness of tapeworms at host individual level we found that(i)Torpediniformes had the lowest tapeworm diversity of all Batoidea orders;(ii)Torpedo spp.consistently had the lowest mean cestode richness at host individual level,and this could not be related to other host factors influencing cestode diversity in chondrichthyans,that is body size,trophic level or dietary breath.However,a preliminary comparison between“strong-EOD”and“weak-EOD”Torpediniformes did not detect clear differences of cestode richness.Thus,evidence supporting an unambiguous contribution of EODs to depauperate cestode assemblages requires further research.