Nematodes of zoonotic importance in Cynoscion guatucupa (Pisces) in the state of Rio de Janeiro / Nematóides de importância zoonótica em Cynoscion guatucupa (Pisces) no estado do Rio de Janeiro

Between January and August 2012, thirty specimens of Cynoscion guatucupa (Cuvier, 1830) caught off coast of the municipality of Itajaí, state of Santa Catarina, Brazil (26° 54' 28″ S and 48° 39' 43″ W) and commercialized in the state of Rio de Janeiro were investigated for the presence of zoonotic nematodes. In total 853 larvae of four nematode parasite species were found. There were three species of Anisakidae: three larvae of Anisakis sp., with prevalence (P) of 10%, mean intensity (MI) of 1.0, mean abundance (MA) of 0.1 and infection site (IS) in the mesentery; five of Terranova sp. with P = 13.3%, MI = 1.25, MA = 0.17, range of infection (RI) from 1 to 2 and IS = mesentery; and seven of Contracaecum sp. with P = 6.6%, MI = 3.5, MA = 0.23, RI = 1 to 4 and IS = mesentery and abdominal cavity. There was one species of Raphidascarididae: 838 larvae of Hysterothylacium deardorffoverstreetorum with P = 83.3%, MI = 33.52, MA = 27.93, RI = 1 to 219 and IS = mesentery, liver serosa and abdominal cavity. This is the first report of larvae of Anisakis sp. and Contracaecum sp in C. guatucupa in Brazil.

Entre janeiro e agosto de 2012, 30 espécimes de Cynoscion guatucupa (Cuvier, 1830) pescados no litoral do município de Itajaí, estado de Santa Catarina, Brasil (26° 54' 28″ S e 48° 39' 43″ W) e comercializados no estado do Rio de Janeiro, foram investigados quanto á presença de nematóides zoonóticos. Foram encontradas 853 larvas de quatro espécies de nematóides parasitos. Três espécies pertencem á Anisakidae, sendo três larvas de Anisakis sp., com prevalência (P) de 10%, intensidade média (IM) de 1, abundância média (AM) de 0,1 e sítio de infecção (SI) o mesentério; cinco de Terranova sp., com P = 13,3%, IM = 1,25, AM = 0,17, amplitude de variação da intensidade de infecção (AI) de 1 a 2 e SI = mesentério; e sete de Contracaecum sp., com P = 6,6%, IM = 3,5, AM = 0,23, AI = 1 a 4 e SI = mesentério e cavidade abdominal. Uma espécie pertence á Raphidascarididae, sendo 838 larvas de Hysterothylacium deardorffoverstreetorum com P = 83,3%, IM = 33,52, AM = 27,93, AI = 1 a 219 e SI = mesentério, serosa do fígado e cavidade abdominal. Este é o primeiro registro de larvas de Anisakis sp. e Contracaecum sp. em C. guatucupa no Brasil.

In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae)

Human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the Anisakidae family. The present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against Contracaecum sp (Nematoda: Anisakidae). Four hundred live larvae of Contracaecum sp obtained from "traíra" fish (Hoplias malabaricus, Bloch, 1974) were analyzed on 40 Petri dishes (10 larvae each) with the compounds to be tested. The final concentrations tested for each compound were 250, 125, 62.5, and 31.2 µg/mL and the evaluation was carried out at five different times (2, 4, 8, 24, and 48 h). The larvicidal action of geraniol and citronellal was statistically superior (P < 0.005) to the control (1 percent ethanol) at concentrations of 250 and 31.2 µg/mL (geraniol) and 250, 125, and 62.5 μg/mL (citronellal). However, no larvicidal activity was observed at concentrations of 125 and 62.5 µg/mL for geraniol and 31.2 µg/mL for citronellal. When the larvicidal action of geraniol was compared to that of citronellal, the former was found to be statistically superior (P < 0.05) to the latter at concentrations of 250 and 31.2 μg/mL. On the other hand, citronellal was statistically superior (P < 0.005) to geraniol at concentrations of 125 and 62.5 μg/mL. The larval mortality rate in terms of time (hours) was higher for geraniol with the passing of time at the 250 μg/mL concentration. At this concentration (in 48 h) the best larvicidal effect was observed with 90 percent lethality. The larvae were considered to be dead using no motility and loss of structural integrity as parameters. The data indicate that natural terpene compounds should be more explored for antihelminthic activity and can be useful for other studies about anisakiasis treatment.

Avaliação da resistência de larvas de Contracaecum sp. (nematoda: anisakidae) à ação da citronela, Cymbopogon sp., in natura, administrada como tratamento da anisakiose em coelhos infectados experimentalmente / Evaluation of the resistence of the Contracaecum sp. larvae, (nematoda: anisakidae), to the action of the citronella, Cymbopogon sp., in natura, administered as treatment of anisakiosis in experimentally infected rabbits

A avaliação da ação larvicida da citronela, Cymbopogon sp., in natura foi feita através da administração da planta ad libitum a coelhos, Oryctolagus cuniculi, experimentalmente infectados com larvas de Contracaecum sp. Com intervalos regulares de 24 horas após o início da administração da planta, foram realizadas eutanásias e necropsias dos animais infectados, analisando-se a eficácia através de parâmetros como número e viabilidade de larvas recuperadas. A citronela in natura apresentou baixa ação larvicida sobre Contracaecum sp Federal

The evaluation of the larvicide action of the citronella, Cymbopogon sp., in natura was done through the feeding of the citronella grass ad libitum to rabbits, Oryctolagus cuniculi, experimentally infected by Contracaecum sp. larvae. By regular intervals of 24 hours after the beginning of the experiment, the infected animals went submitted to eutanasy and necropsy exams to analyse the action of the plant, using parameters as the number and viability of the recovered larvae. The citronella in natura produced low larvicide action over Contracaecum sp. experimentally.

Análise do parasitismo por Contracaecum sp. e Eustrongylides sp. em cacharas, Pseudoplatystoma fasciatum (Linnaeus, 1766) (Pisces: Pimelodidae) provenientes do rio Cuiabá, Mato Grosso, Brasil / Analisys of the parasitism by Contracaecum sp. and Eustrongylides sp. in cacharas, Pseudoplatystoma fasciatum (Linnaeus, 1766) (Pisces: Pimelodidae) from Cuiabá river, Mato Grosso, Brazil

Cento e quarenta e nove espécimes de cacharas (Pseudoplatystoma fasciatum) foram capturados do rio Cuiabá, estado de Mato Grosso, durante o período de outubro de 2004 a abril de 2006, para análise do parasitismo por larvas de nematóides. Encontrou-se prevalência de 100% destes peixes parasitados por larvas de Contracaecum sp. e/ou Eustrongylides sp. A análise do parasitismo foi feita por registro da prevalência e localização das larvas encontradas. Cinco cacharas (3,35%) apresentaram parasitismo por larvas de Contracaecum sp. na musculatura esquelética e 147 (98,65%) no mesentério. Cinquenta cacharas (33,55 %) apresentaram larvas de Eustrongylides sp. na musculatura esquelética e 117 (78,52%) no mesentério. A intensidade média de infecção foi de 15,42 larvas/peixe para Contracaecum sp. e de 6,37 larvas/peixe para Eustrongylides sp. O peso médio dos peixes examinados foi de 5,59 kg (1,9-10,5 kg) e o comprimento total médio de 82,39 cm (63,5-105 cm). Não foi observada correlação entre parâmetros biométricos como comprimento total e peso dos hospedeiros e a intensidade de infecção.

One hundred and forty-nine cacharas (Pseudoplatystoma fasciatum) specimens were captured from Cuiabá river, Mato Grosso State, between october of 2004 to april of 2006, intending to analyse the parasitism by nematode larvae. The prevalence was 100% to parasitism by Contracaecum sp. and/or Eustrongylides sp. larvae. The analysis of the parasitism were done by prevalence record and the localization of the larvae founded. Five cacharas (3,35 %) presented parasitism by Contracaecum larvae in the skeletal muscle and one hundred and forty-seven (98,65 %) on the mesenterium. Fifty cacharas (33,55%) presented Eustrongylides sp. larvae in the skeletal muscle and one hundred seventeen (78,52%) on the mesenterium. The mean intensity of infection was 15,42 larvae/fish for Contracaecum sp. and 6,37 larvae/fish for Eustrongylides sp. The average of weight to the examined fishes was 5,59 kg (1,9-10,5 kg) and the average of the total length was 82,39 cm (63,5-105 cm). Correlation between biomethric parameters as host´s total length and weight and the intensity of infection was not observed.