Proximity ligation strategy for the genomic reconstruction of microbial communities associated with the ectoparasite Caligus rogercresseyi.

The sea louse Caligus rogercresseyi has become one of the main constraints for the sustainable development of salmon aquaculture in Chile. Although this parasite's negative impacts are well recognized by the industry, some novel potential threats remain unnoticed. The recent sequencing of the C. rogercresseyi genome revealed a large bacterial community associated with the sea louse, however, it is unknown if these microorganisms should become a new focus of sanitary concern. Herein, chromosome proximity ligation (Hi-C) coupled with long-read sequencing were used for the genomic reconstruction of the C. rogercresseyi microbiota. Through deconvolution analysis, we were able to assemble and characterize 413 bacterial genome clusters, including six bacterial genomes with more than 80% of completeness. The most represented bacterial genome belonged to the fish pathogen Tenacibacullum ovolyticum (97.87% completeness), followed by Dokdonia sp. (96.71% completeness). This completeness allowed identifying 21 virulence factors (VF) within the T. ovolyticum genome and four antibiotic resistance genes (ARG). Notably, genomic pathway reconstruction analysis suggests putative metabolic complementation mechanisms between C. rogercresseyi and its associated microbiota. Taken together, our data highlight the relevance of Hi-C techniques to discover pathogenic bacteria, VF, and ARGs and also suggest novel host-microbiota mutualism in sea lice biology.

Genome-scale comparative analysis for host resistance against sea lice between Atlantic salmon and rainbow trout.

Sea lice (Caligus rogercresseyi) is an ectoparasite which causes major production losses in the salmon aquaculture industry worldwide. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two of the most susceptible salmonid species to sea lice infestation. The objectives of this study were to: (1) identify genomic regions associated with resistance to Caligus rogercresseyi in Atlantic salmon and rainbow trout by performing single-step Genome-Wide Association studies (ssGWAS), and (2) identify candidate genes related to trait variation based on exploring orthologous genes within the associated regions across species. A total of 2626 Atlantic salmon and 2643 rainbow trout were challenged and genotyped with 50 K and 57 K SNP panels, respectively. We ran two independent ssGWAS for sea lice resistance on each species and identified 7 and 13 regions explaining more than 1% of the genetic variance for the trait, with the most important regions explaining 3% and 2.7% for Atlantic salmon and rainbow trout, respectively. We identified genes associated with immune response, cytoskeleton function, and cell migration when focusing on important genomic regions for each species. Moreover, we found 15 common orthogroups which were present in more than one associated genomic region, within- or between-species; however, only one orthogroup showed a clear potential biological relevance in the response against sea lice. For instance, dual-specificity protein phosphatase 10-like (dusp10) and dual-specificity protein phosphatase 8 (dusp8) were found in genomic regions associated with lice density in Atlantic salmon and rainbow trout, respectively. Dusp10 and dusp8 are modulators of the MAPK pathway and might be involved in the differences of the inflammation response between lice resistant and susceptible fish from both species. Our results provide further knowledge on candidate genes related to sea lice resistance and may help establish better control for sea lice in fish populations.

Chromosome-scale genome assembly of the sea louse Caligus rogercresseyi by SMRT sequencing and Hi-C analysis.

Caligus rogercresseyi, commonly known as sea louse, is an ectoparasite copepod that impacts the salmon aquaculture in Chile, causing losses of hundreds of million dollars per year. In this study, we report a chromosome-scale assembly of the sea louse (C. rogercresseyi) genome based on single-molecule real-time sequencing (SMRT) and proximity ligation (Hi-C) analysis. Coding RNAs and non-coding RNAs, and specifically long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) were identified through whole transcriptome sequencing from different life stages. A total of 23,686 protein-coding genes and 12,558 non-coding RNAs were annotated. In addition, 6,308 lncRNAs and 5,774 miRNAs were found to be transcriptionally active from larvae to adult stages. Taken together, this genomic resource for C. rogercresseyi represents a valuable tool to develop sustainable control strategies in the salmon aquaculture industry.

Tackling the Molecular Drug Sensitivity in the Sea Louse Caligus rogercresseyi Based on mRNA and lncRNA Interactions.

Caligus rogercresseyi, commonly known as sea louse, is an ectoparasite copepod that impacts the salmon aquaculture in Chile, causing losses of hundreds of million dollars per year. This pathogen is mainly controlled by immersion baths with delousing drugs, which can lead to resistant traits selection in lice populations. Bioassays are commonly used to assess louse drug sensitivity, but the current procedures may mask relevant molecular responses. This study aimed to discover novel coding genes and non-coding RNAs that could evidence drug sensitivity at the genomic level. Sea lice samples from populations with contrasting sensitivity to delousing drugs were collected. Bioassays using azamethiphos, cypermethrin, and deltamethrin drugs were conducted to evaluate the sensitivity and to collect samples for RNA-sequencing. Transcriptome sequencing was conducted on samples exposed to each drug to evaluate the presence of coding and non-coding RNAs associated with the response of these compounds. The results revealed specific transcriptome patterns in lice exposed to azamethiphos, deltamethrin, and cypermethrin drugs. Enrichment analyses of Gene Ontology terms showed specific biological processes and molecular functions associated with each delousing drug analyzed. Furthermore, novel long non-coding RNAs (lncRNAs) were identified in C. rogercresseyi and tightly linked to differentially expressed coding genes. A significant correlation between gene transcription patterns and phenotypic effects was found in lice collected from different salmon farms with contrasting drug treatment efficacies. The significant correlation among gene transcription patterns with the historical background of drug sensitivity suggests novel molecular mechanisms of pharmacological resistance in lice populations.

Regional climate affects salmon lice dynamics, stage structure and management.

Regional variation in climate can generate differences in population dynamics and stage structure. Where regional differences exist, the best approach to pest management may be region-specific. Salmon lice are a stage-structured marine copepod that parasitizes salmonids at aquaculture sites worldwide, and have fecundity, development and mortality rates that depend on temperature and salinity. We show that in Atlantic Canada and Norway, where the oceans are relatively cold, salmon lice abundance decreases during the winter months, but ultimately increases from year to year, while in Ireland and Chile, where the oceans are warmer, the population size grows monotonically without any seasonal declines. In colder regions, during the winter the stage structure is dominated by the adult stage, which is in contrast to warmer regions where all stages are abundant year round. These differences translate into region-specific recommendations for management: regions with slower population growth have lower critical stocking densities, and regions with cold winters have a seasonal dependence in the timing of follow-up chemotherapeutic treatments. Predictions of our salmon lice model agree with empirical data, and our approach provides a method to understand the effects of regional differences in climate on salmon lice dynamics and management.

Caligus rogercresseyi acetylcholinesterase types and variants: a potential marker for organophosphate resistance.

BACKGROUND: Control of the sea louse Caligus rogercresseyi in the Chilean salmonid industry is reliant on chemical treatments. Azamethiphos was introduced in 2013, although other organophosphates were previously used. In 2014, reduced sensitivity to azamethiphos was detected in the Los Lagos Region using bioassays. The main target of organophosphates is the enzyme acetylcholinesterase (AChE). Mutations in the AChE gene are the main cause of organophosphate resistance in arthropods, including other sea lice. In the present study, we aimed to characterize C. rogercresseyi AChE(s) gene(s) and to study the association between AChE variants and azamethiphos resistance in this sea louse species. METHODS: Samples of adult male and female C. rogercresseyi were collected in the Los Lagos Region in 2014. Twenty-four hour exposure bioassays with azamethiphos were performed to select sensitive and resistant lice. The full-length cDNA coding sequences encoding for two AChEs in C. rogercresseyi were molecularly characterized. One of the AChE genes was screened by direct sequencing in the azamethiphos-selected lice to search for variants. An additional louse sampling was performed before and after an azamethiphos treatment in the field in 2017 to validate the findings. RESULTS: The molecular analysis revealed two putative AChEs in C. rogercresseyi. In silico analysis and 3D modelling of the protein sequences identified both of them as invertebrate AChE type 1; they were named C. rogercresseyi AChE1a and 1b. AChE1a had the characteristics of the main synaptic AChE, while AChE1b lacked some of the important amino acids of a typical AChE. A missense change found in the main synaptic AChE (1a), F318F/V (F290 in Torpedo californica), was associated with survival of C. rogercresseyi at high azamethiphos concentrations (bioassays and field treatment). The amino acid change was located in the acyl pocket of the active-site gorge of the protein. CONCLUSIONS: The present study demonstrates the presence of two types of AChE1 genes in C. rogercresseyi. Although enzymatic assays are needed, AChE1a is most probably the main synaptic AChE. The function of AChE1b is unknown, but evidence points to a scavenger role. The AChE1a F/V318 variant is most probably involved in organophosphate resistance, and can be a good marker for resistance monitoring.

Lethal and sub-lethal effects of commonly used anti-sea lice formulations on non-target crab Metacarcinus edwardsii larvae.

The pesticides used by the salmon industry to treat sea lice, are applied in situ via a bath solution and are subsequently discharged into the surrounding medium. The effects of cypermethrin, deltamethrin, azamethiphos and hydrogen peroxide were assessed on the performance of Metacarcinus edwardsii larvae, an important crab for Chilean fishery. All larvae were dead or dying after 30 min of exposure to cypermethrin and after 40 min to deltamethrin at concentrations 100 and 20 times lower (0.15 and 0.1 µg L-1, respectively) than the concentrations and exposure times recommended by the manufacturers (CRM) to treat sea lice. Azamethiphos affected all larvae at a concentration 10 times lower than CRM. Hydrogen peroxide had the lowest detrimental effects, but at the CRM, 100% of the larvae were affected. Sub-lethal effects, i.e prolonged developmental time, were observed at concentrations lower than CRM. Repeated exposure to azamethiphos (0.0625-0.5 µg L-1) and hydrogen peroxide (188-1500 mg L-1) had effects on survival. In conclusion, the pesticides used against parasitic copepod tested here, negatively affect non-target crustacean larvae. Due to the product's characteristics, the lethal effects of the pyrethroids probably are restricted to the time and area of application, while the action of azamethiphos may extend to a wider area. Current data are insufficient to accurately dimension the effects of these compounds in the field. More research is required to evaluate the consequences of prolonged developmental times and/or reduction in appendage mobility, so as the effects of these compounds on the pelagic and benthic communities.

Next-Generation Transcriptome Profiling of the Salmon Louse Caligus rogercresseyi Exposed to Deltamethrin (AlphaMax™): Discovery of Relevant Genes and Sex-Related Differences.

Sea lice are one of the main parasites affecting the salmon aquaculture industry, causing significant economic losses worldwide. Increased resistance to traditional chemical treatments has created the need to find alternative control methods. Therefore, the objective of this study was to identify the transcriptome response of the salmon louse Caligus rogercresseyi to the delousing drug deltamethrin (AlphaMax™). Through bioassays with different concentrations of deltamethrin, adult salmon lice transcriptomes were sequenced from cDNA libraries in the MiSeq Illumina platform. A total of 78 million reads for females and males were assembled in 30,212 and 38,536 contigs, respectively. De novo assembly yielded 86,878 high-quality contigs and, based on published data, it was possible to annotate and identify relevant genes involved in several biological processes. RNA-seq analysis in conjunction with heatmap hierarchical clustering evidenced that pyrethroids modify the ectoparasitic transcriptome in adults, affecting molecular processes associated with the nervous system, cuticle formation, oxidative stress, reproduction, and metabolism, among others. Furthermore, sex-related transcriptome differences were evidenced. Specifically, 534 and 1033 exclusive transcripts were identified for males and females, respectively, and 154 were shared between sexes. For males, estradiol 17-beta-dehydrogenase, sphingolipid delta4-desaturase DES1, ketosamine-3-kinase, and arylsulfatase A, among others, were discovered, while for females, vitellogenin 1, glycoprotein G, transaldolase, and nitric oxide synthase were among those identified. The shared transcripts included annotations for tropomyosin, γ-crystallin A, glutamate receptor-metabotropic, glutathione S-transferase, and carboxipeptidase B. The present study reveals that deltamethrin generates a complex transcriptome response in C. rogercresseyi, thus providing valuable genomic information for developing new delousing drugs.

Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi.

Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S) as well as in an aspartic protease group (D). Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP) were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi.

Two novel male-associated peroxinectin genes are downregulated by exposure to delousing drugs in Caligus rogercresseyi.

Peroxinectin (PX) is a protein involved in cell adhesion, peroxidase activities, and the encapsulation of invaders in diverse species, including parasitic copepods. Recently, a transcript denoted peroxinectin-like was identified in the salmon louse Lepeophtheirus salmonis, and this was significantly correlated with the immune response of host fish. Thus, the PX gene is a potential candidate to evaluate host-parasite interactions, as well as to analyze responses to delousing drugs used in the salmon aquaculture industry worldwide. The objective of this study was to identify Peroxinectin transcripts in the Chilean salmon louse Caligus rogercresseyi, and to determine expression levels after exposition to the antiparasitics deltamethrin and azamethiphos. Two novel transcript homologs to peroxinectins were identified from a transcriptomic library of C. rogercresseyi. Moreover, in silico gene transcription levels were evaluated through RNA-seq analyses based on unique gene read levels in transcriptomic libraries that were constructed from sea lice exposed to delousing drugs. The identified transcripts were named Peroxinectin-Cr1 and Peroxinectin-Cr2, which, respectively, had lengths of 2543 and 2555 base pairs. Both PX transcripts were highly associated with male adults, and transcription levels were significantly reduced by deltamethrin and azamethiphos. This result suggests a modulation of peroxinectin in response to delousing drugs.

Increasing transcriptome response of serpins during the ontogenetic stages in the salmon louse Caligus rogercresseyi (Copepoda: Caligidae).

Serine protease inhibitors, or serpins, target serine proteases, and are important regulators of intra- and extracellular proteolysis. For parasite survival, parasite-derived protease inhibitors have been suggested to play essential roles in evading the host's immune system and protecting against exogenous host proteases. The aim of this work was to identify serpins via high throughput transcriptome sequencing and elucidate their potential functions during the lifecycle of the salmon louse Caligus rogercresseyi. Eleven putative, partial serpin sequences in the C. rogercresseyi transcriptome were identified and denoted as Cr-serpins 1 to 11. Comparative analysis of the deduced serpin-like amino acid sequences revealed a highly conserved reactive center loop region. Interestingly, P1 residues suggest putative functions involved with the trypsin/subtilisin, elastase, or subtilisin inhibitors, which evidenced increasing gene expression profiles from the copepodid to adult stage in C. rogercresseyi. Concerning this, Cr-serpin 10 was mainly expressed in the copepodid stage, while Cr-serpins 3, 4, 5, and 11 were mostly expressed in chalimus and adult stages. These results suggest that serpins could be involved in evading the immune response of the host fish. The identification of these serpins furthers the understanding of the immune system in this important ectoparasite species.

Epidemiological description of the sea lice (Caligus rogercresseyi) situation in southern Chile in August 2007.

Salmon sea lice represent one of the most important threats to salmon farming throughout the world. Results of private monitoring efforts have shown an increase in the number of positive cages and cage-level abundance of sea lice in southern Chile since 2004. As a consequence, the Chilean Fisheries Service implemented an Official Surveillance Program in the main salmon production area of southern Chile to assess the situation of sea lice in fish farms. Results showed that the prevalence of sea lice in the fish farms was 53.4%, ranging from 3.5% in Puerto Aysén to 100% in the Seno de Reloncaví zone. The average sea lice abundance was 11.8 per fish (Geometrical mean (GM)=8.61, 95% CI (2.1-6.9)). The highest levels were found in Seno de Reloncaví (GM=24.99, 95% CI (15.9-39.2)), Hornopirén (GM=14.7, 95% CI (10.4-20.8)) and Chiloé norte (GM=9.75, 95% CI (1-1.9)), and the lowest loads were observed in Puerto Aysén (GM=1.35, 95%CI (1-1.9)) and Puerto Cisnes (GM=1.67, 95%CI (1.1-2.6)). Salmo salar and Oncorhynchus mykiss had the highest abundance levels (GM=6.93, 95% CI (5.7-8.5), and (GM=5.55, 95% CI (3.6-8.5), respectively). O. kisutch showed lower levels (GM=1.34, 95% CI (1-1.7)), apparently being more resistant to infestation. Sea lice in farmed salmon are widely distributed in different zones of southern Chile, and are becoming a serious threat to this industry. Prevalence and abundance levels were found to be generally high, decreasing in southern zones.

Difilobotríase: atualidades e perspectivas / Diphyllobothriasis: updates and perspectives

A difilobotríase é uma moléstia intestinal provocada por cestódeos do gênero Diphyllobothrium (tênia) que até pouco tempo havia poucos relatos em nosso país. Porém, em decorrência do aumento do consumo de peixes crus, mal cozidos ou defumados e da falta de cuidado nos seus preparos, vêm sendo identificados casos autóctones no Brasil. O número de pessoas parasitadas pelo platelminto difilobotríase, presente em várias regiões do mundo, vem aumentando desde 2003. A doença pode ser assintomática ou causar desconforto abdominal e interferir na absorção da vitamina B12, podendo causar anemia megaloblástica. Abster-se do consumo de pescado cru, defumado em temperaturas inadequadas ou mal cozido é a principal medida para a sua prevenção.

The intestinal diphyllobotriasis is a disease caused by Diphyllobothrium (cestodes of the genus Taenia [tapeworm]) that until recently had a few reports in our country. However, as a result of increased consumption of raw fish, soft-boiled or smoked and lack of care in their staging have been identified indigenous cases in Brazil. The number of people by the flatworm diphyllobotriasis parasitized, present in various regions of the world, comes increasing since 2003. The disease may be asymptomatic or cause abdominal discomfort and interferes in the absorption of vitamin B12, leading to megaloblastic anemia. Avoid from eating raw, smoked or soft-boiled fish is the primaries beware of their prevention.

A comparison of sea lice, Caligus rogercresseyi, fecundity in four areas in southern Chile.

A survey was carried out between March 2006 and February 2007 on the fecundity of Caligus rogercresseyi in four areas of Region X (Lat 42 degrees S) in Chile. An average length of 4.83 +/- 0.4 mm for gravid females and 4.78 +/- 0.56 mm for males was recorded from the four areas, with no significant differences in length between sexes. Although females were largest in spring and summer, egg strings were longer and there were higher number of eggs per string in winter. The lowest salinity values were recorded in the Hornopirén area, which had the largest gravid females and the highest number of eggs per string during the study. The number of lice treatments showed no influence on the fecundity rate in the four areas. Prevalence and abundance of C. rogercresseyi were influenced by salinity and temperature.

Ocorrência de Vibrio parahaemolyticus e Salmonella spp. em “sashimis” comercializados em restaurantes no município do Rio de Janeiro / Occurrence of Vibrio parahaemolyticus and Salmonella spp. in sashimi commercialized in restaurants at the city Rio de Janeiro

Visando conhecer a segurança do produto "sashimi" de salmão fornecido em restaurantes, e dos riscos potenciais ao consumidor, a pesquisa objetivou avaliar a ocorrência de Vibrio parahaemolyticus e de Salmonella spp na matéria-prima, no produto final antes de sua exposição à venda e após sua exposição ao cliente; e de Salmonella spp nas mãos dos manipuladores, em dois restaurantes (RI e RII). Os estabelecimentos foram classificados pelas diferentes condições de higiene e climatização do ambiente de manipulação, sendo RII considerado o melhor. Foi verificada a ausência de Vibrio parahaemolyticus em 100% das amostras; presença de Salmonella spp. em 12,5% do total de amostras analisadas, sendo todas estas pertencentes a RII: 25% estava presente na mão do manipulador e 75%, presente na matéria-prima e produtos finais. Através dos resultados da pesquisa pôde-se concluir que ambos os estabelecimentos estavam em conformidade com a RDC 12 de 2001 da ANVISA para Vibrio parahaemolyticus, mas RII enquadrou-se fora dos padrões estabelecidos quanto à presença de Salmonella spp. O resultado sugere que RII necessita da adoção eficaz de práticas higiênicosanitárias na elaboração de "sashimi" para eliminar a presença de Salmonella spp., que é um risco potencial à saúde do consumidor.(AU)

In order to know the quality and safety of the sashimi salmon comes in restaurants and its potential risks to the consumer, this research aimed evaluated the occurrence of Vibrio parahaemolyticus and Salmonella in raw material, on the final product before its exposure to sales and after exposure to the client and Salmonella spp in the hands of handlers, in two restaurants (RI and RII). The difference between the places was classified by the conditions of environmental air handling and hygiene, and RII was considered the best. It was verified the absence of Vibrio parahaemolyticus in 100% of samples, the presence of Salmonella spp. in 12.5% of total samples analyzed, with absence in all samples of RI and presence in 25% of samples at RII. In this proven contamination, 25% was present in the hands of the handlers and 75% present in the raw material and finished products. Based on the results of research it was concluded that both establishments were in compliance with the legislation for the first microorganism, but RII, although had the best conditions of climate and hygiene, framed outside of the microbiological standards established by the presence of Salmonella spp. The results suggest that the establishment in violation of the law requires the efficient and effective adoption of adequate sanitary practices in preparation of sashimi to avoid the presence of Salmonella spp., which can pose a risk to consumer health.(AU)

Ocorrência de Vibrio parahaemolyticus e Salmonella spp. em “sashimis” comercializados em restaurantes no município do Rio de Janeiro / Occurrence of Vibrio parahaemolyticus and Salmonella spp. in sashimi commercialized in restaurants at the city Rio de Janeiro

Visando conhecer a segurança do produto "sashimi" de salmão fornecido em restaurantes, e dos riscos potenciais ao consumidor, a pesquisa objetivou avaliar a ocorrência de Vibrio parahaemolyticus e de Salmonella spp na matéria-prima, no produto final antes de sua exposição à venda e após sua exposição ao cliente; e de Salmonella spp nas mãos dos manipuladores, em dois restaurantes (RI e RII). Os estabelecimentos foram classificados pelas diferentes condições de higiene e climatização do ambiente de manipulação, sendo RII considerado o melhor. Foi verificada a ausência de Vibrio parahaemolyticus em 100% das amostras; presença de Salmonella spp. em 12,5% do total de amostras analisadas, sendo todas estas pertencentes a RII: 25% estava presente na mão do manipulador e 75%, presente na matéria-prima e produtos finais. Através dos resultados da pesquisa pôde-se concluir que ambos os estabelecimentos estavam em conformidade com a RDC 12 de 2001 da ANVISA para Vibrio parahaemolyticus, mas RII enquadrou-se fora dos padrões estabelecidos quanto à presença de Salmonella spp. O resultado sugere que RII necessita da adoção eficaz de práticas higiênicosanitárias na elaboração de "sashimi" para eliminar a presença de Salmonella spp., que é um risco potencial à saúde do consumidor.

In order to know the quality and safety of the sashimi salmon comes in restaurants and its potential risks to the consumer, this research aimed evaluated the occurrence of Vibrio parahaemolyticus and Salmonella in raw material, on the final product before its exposure to sales and after exposure to the client and Salmonella spp in the hands of handlers, in two restaurants (RI and RII). The difference between the places was classified by the conditions of environmental air handling and hygiene, and RII was considered the best. It was verified the absence of Vibrio parahaemolyticus in 100% of samples, the presence of Salmonella spp. in 12.5% of total samples analyzed, with absence in all samples of RI and presence in 25% of samples at RII. In this proven contamination, 25% was present in the hands of the handlers and 75% present in the raw material and finished products. Based on the results of research it was concluded that both establishments were in compliance with the legislation for the first microorganism, but RII, although had the best conditions of climate and hygiene, framed outside of the microbiological standards established by the presence of Salmonella spp. The results suggest that the establishment in violation of the law requires the efficient and effective adoption of adequate sanitary practices in preparation of sashimi to avoid the presence of Salmonella spp., which can pose a risk to consumer health.

[Aquaculture and public health. The emergence of diphyllobothriasis in Chile and the world]. / Acuicultura y salud pública. La expansión de la difilobotriasis en Chile y el mundo.

Recent clinical and epidemiológical information, an analysis of the literature, and study of the technical aspects of Chilean salmon aquaculture indicate that this activity has the ability to expand the range of diphyllobothriasis caused by the fish tapeworm Diphyllobothrium latum. Evidence for expansion of the range of the fish tapeworm includes the emergences of clinical cases in Brazil related to consumption of salmon produced in Chile. Expansion of the range of this parasite is also suggested by an increase of its geographical range in Chile, beyond its previously endemic foci in the lakes of Regions IX and X. Prevention of further dissemination of this parasitic disease rests on an improvement of sanitation and sewage disposal around the lakes of Regions IX, X and XI in Chile, improvement in aquaculture methods including curtailing the use of fish tapeworm-contaminated lakes to grow juveniles forms of salmonids and more measures to decrease the number of salmonid escapees from marine pens to prevent their return to rivers and lakes carrying the infestation. Moreover, tracking the origin of juveniles in marketed salmon, determining the presence of plerocercoids in them, and increased education of the public regarding the potential dangers of eating raw fish should also be implemented. Only by stimulating the dialogue between the industry, consumers and state regulators will it be possible to implement appropriate measures to prevent further expansion of this parasitic disease by salmon aquaculture.

Acuicultura y salud pública: La expansión de la difilobotriasis en Chile y el mundo / Aquaculture and public health: The emergence of diphyllobothriasis in Chileand the world

Recent clinical and epidemiológica! information, an analysis of the literature, and study of the technical aspects of Chilean salmon aquaculture indicate that this activity has the ability to expand the range of diphyllobothriasis caused by the fish tapeworm Diphyllobothrium latum. Evidence for expansion of the range of the fish tapeworm includes the emergences of clinical cases in Brazil related to consumption of salmon produced in Chile. Expansion of the range of this parasite is also suggested by an increase of its geographical range in Chile, beyond its previously endemic foci in the lakes of Regions IX and X. Prevention of further dissemination of this parasitic disease rests on an improvement of sanitation and sewage disposal around the lakes of Regions IX, X and XI in Chile, improvement in aquaculture methods including curtailing the use offish tapeworm-contaminated lakes to grow juveniles forms ofsalmonids and more measures to decrease the number of salmonid escapees from marine pens to prevent their return to rivers and lakes carrying the infestation. Moreover, tracking the origin ofjuveniies in marketed salmon, determining the presence of plerocercoids in them, and increased education of the public regarding the potential dangers of eating raw fish should also be implemented. Only by stimulating the dialogue between the industry, consumers and state regulators will it be possible to implement appropriate measures to prevent further expansion of this parasitic disease by salmon aquaculture.

Registro de nuevos casos de difilobotriasis humana en Chile (1981-1992), incluído un caso de infección múltiple por diphyllobothrium latum / Record of new cases of human diphyllobothriasis in Chile (1981-1992), including a case of multiple diphyllobotrium latum infection

New records of human diphyllobothriasis in Chile (1981-1992), with a case of multiple diphyllobotrium latum infection