Rossanna Rodríguez-Canul

Presence of Panulirus argus Virus 1 (PaV1) in juvenile spiny lobsters Panulirus argus from the Caribbean coast of Mexico

Macroscopic evidence, histological sections, transmission electron microscopy (TEM) evaluation, and PCR analyses of 25 apparently diseased juvenile spiny lobsters Panulirus argus from the reef lagoon of Puerto Morelos, Mexico, showed the presence of Panulirus argus Virus 1 (PaV1). Cowdry Type A intranuclear viral inclusions were observed in histological analyses, icosahedral viral particles were observed by TEM, and PCR using specific primers for PaV1 amplified a fragment of 499 bp. This is the first report of PaV1 infecting P. argus outside the Florida Keys, USA.

Chemotherapy of porcine cysticercosis with albendazole sulphoxide.

Cysticercosis is a zoonotic disease of humans produced by the larval stage of swine parasite, Taenia solium. Chemotherapy of infected pigs is a possible strategy for avoiding disease transmission and improving health programs in endemic areas of cysticercosis. In this preliminary study, seven naturally infected pigs from 6 to 12 months of age were allotted to treated (n = 4) and control groups (n = 3). The treated animals received a subcutaneous injection in their forelegs and thighs of 15 mg/kg per body weight of albendazole sulphoxide (ABZSO; Pisa, Mexico) once per day for 8 days. At the same time, the control group received a subcutaneous injection of saline solution (9% NaCl). After 12 weeks, all the animals were slaughtered and at least 200 metacestodes were isolated from the muscles and brain of each animal. Using histology and the metacestode viability criteria described in this study, treated animals had no viable cysts in their muscle (0/200), while 7 of 17 (41.1%) viable cysts were observed in those isolated from their brains. In the control group, 183/200 (91.5%) muscle metacestodes were viable and from brain, 22/29 (75.8%) metacestodes were viable. The 15 mg/kg per body weight dosage of ABZSO was 100% effective against muscular cysticercosis as shown by the lack of viable cysts and the micro-calcifications in meat from the treated pigs.

Detection of Panulirus argus Virus 1 (PaV1) in exported frozen tails of subadult-adult Caribbean spiny lobsters Panulirus argus

The Caribbean spiny lobster Panulirus argus is a valuable fishing resource and the trade in frozen lobster tails is an important industry. However, the presence of the pathogenic virus Panulirus argus Virus 1 (PaV1), which causes systemic infection in P. argus and is particularly lethal to juvenile individuals, has not been previously examined in imported/exported lobster products. We used PCR assays to determine the presence of PaV1 in abdominal muscle tissue of 22 frozen P. argus tails exported from Belize to Mexico. Based on their size, the tails belonged to subadult-adult lobsters. Using specific primers targeted for PaV1 resulted in 11 tails showing a specific 499 bp band. The sequence of positive amplified fragments showed a high similarity to PaV1 (95% identity with GenBank accession no. EF206313.1). Although the pathogenicity of PaV1 was not evaluated in the present study, our results provide the first evidence of PaV1 in frozen lobster tails exported in the seafood industry as well as the first molecular evidence of PaV1 in adult lobsters.

Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

Sea cucumber is widely consumed as a putative functional food. It contains many biologically-active substances, but only limited research on its properties in vivo has been done. The effects of different meals containing Isostichopus badionotus, a sea cucumber from southeast Mexico, on growth performance and body lipid profile in young rats were analyzed. Sea cucumber body wall was either lyophilized, cooked (100 °C, 1 h in water) and lyophilized, or oven-dried (70 °C for 12 h). It was then ground and incorporated into cholesterol-containing diets. I. badionotus meals supported growth and improved lipid profile in rats. In particular, serum cholesterol, low density lipoproteins, triglycerides concentration and atherogenic index values were greatly reduced by some I. badionotus containing diets. Liver total lipids, triglycerides and cholesterol were also reduced. Cooking or heat-treatment of the meals lowered but did not abolish their hypolipidemic potency. Gene expression analysis of several key genes involved in cholesterol and lipid metabolism in liver showed that diets containing I. badionotus repressed the induction of key genes associated with dyslipidemia exerted by cholesterol supplementation. Consumption of I. badionotus from the Yucatan Peninsula is beneficial for dyslipidemia, although biological effect is clearly dependent on preparation method.

Humoral Antibody Response of the Tilapia Oreochromis niloticus Against Cichlidogyrus spp. (Monogenea)

The humoral immune response of the tilapia Oreochromis niloticus was evaluated using a direct ELISA. Serum was tested from fish infected with Cichlidogyrus spp. (Monogenea) and from fish injected intraperitoneally with the Cichlidogyrus spp. antigenic extract, i.e., 150 μl of the Cichlidogyrus spp. saline extract diluted in Freunds complete adjuvant (FCA) (1:1) were inoculated intraperitoneally at day 0, followed by 2 dosages of 50 μl of the same Cichlidogyrus spp. saline extract diluted in Freunds incomplete adjuvant (FIA) (1:1) at weeks 2 and 4, respectively. The humoral response was also evaluated by the double immunodiffusion test (DID) and by serum protein and total immunoglobulin (Ig) determinations. The IgM OD values in the hyperimmune fish were significantly higher than in the infected and uninfected fish groups. In the DID test, a precipitation (antigen–antibody) band was observed between the Cichlidogyrus spp. saline extract and hyperimmune sera, but not with the other groups. Increases in serum protein concentration and total Igs were observed in the immunized fish at weeks 2 and 10 postinjection. Results from this study suggest that tilapia is capable of producing an induced humoral immune response against an antigenic extract of Cichlidogyrus spp.

Physiological and immunological characterization of Caribbean spiny lobsters Panulirus argus naturally infected with Panulirus argus Virus 1 (PaV1)

The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten of the 13 variables differed significantly between the 2 groups. Using these variables, a principal component analysis yielded 2 separate clusters: one corresponding to the healthy group and the other corresponding to the infected group. In particular, infected lobsters exhibited significantly lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxidase (PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglycerides. These features are consistent with metabolic wasting, hyperlipidemia, and presumed immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the healthy group. Infected lobsters also showed significantly higher levels of total PO activity in degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune response by the PO system during the systemic infection with PaV1.

Panulirus argus virus 1 (PaV1) infection prevalence and risk factors in a Mexican lobster fishery employing casitas

In Bahía de la Ascensión in Mexico, the Caribbean spiny lobster Panulirus argus fishery is based on extensive use of artificial shelters (casitas) that can harbor both juveniles and adults of this highly gregarious species. There is concern that the use of casitas might increase contact transmission of Panulirus argus virus 1 (PaV1). However, a previous study found no evidence for lobster crowding within casitas influencing the prevalence of clinical PaV1 disease, although differences in clinical prevalence were noted between different bay environments. To investigate this more closely, 683 lobsters were sampled from casitas in 2 zones in this bay (Vigía Chico, a shallow low-vegetation zone, and Punta Allen, a deeper dense-vegetation zone) previously found to have the lowest and highest prevalence, respectively, of observed clinical signs. When hemolymph collected from these lobsters was tested by PCR, the prevalence of PaV1 infection was found to be significantly lower in Vigía Chico relative to Punta Allen irrespective of season or the size, sex, or presence of shell injuries on lobsters. Among 714 large commercial-catch lobsters collected throughout the bay, the prevalence of infection was low irrespective of year or sex. For all lobsters tested, the sensitivity (0.510) at which PaV1 infection was detected by observed clinical signs was about half that determined by PCR, but the specificity of clinical signs was absolute (1), indicating that a simple 2× correction factor can be used to accurately estimate PaV1 infection prevalence based on more easily conducted visual assessments of lobsters.

Non-lethal detection of DNA from Cichlidogyrus spp. (Monogenea, Ancyrocephalinae) in gill mucus of the Nile tilapia Oreochromis niloticus.

Infection of Nile tilapia Oreochromis niloticus by monogeneans of the genus Cichlidogyrus is harmful. Currently, diagnosis of this infection is based on invasive techniques and the identification of isolated parasites by their morphology. To facilitate diagnosis, we have developed a non-lethal polymerase chain reaction (PCR) test for detection of Cichlidogyrus spp. DNA in the gill mucus of O. niloticus, using 5 pairs of specific primers based on Cichlidogyrus sclerosus 28S rRNA (Cicly 1 to Cicly 5) which generate fragments of approximately 188, 180, 150, 159 and 189 bp, respectively. PCR specificity was tested using genomic DNA extracted individually from 175 isolated Cichlidogyrus spp., 75 Gyrodactylus cichlidarum and 75 endopararasitic Enterogyrus spp., as well as from 75 protozoans Trichodina spp. The Cicly primers were used to detect Cichlidogyrus spp. DNA in mucus from the gills of 23 Nile tilapia confirmed to be infected with the parasite. Negative controls consisted of 45 uninfected Nile tilapia. The limit of sensitivity of the assay was 1.2 ng of purified parasite DNA. The Cicly primers did not amplify DNA from the mucus of non-infected Nile tilapia, G. cichlidarum, Trichodina spp. or Enterogyrus spp. In all cases, the sensitivity and specificity of the test were 100%. The sequences of all the amplified fragments showed a high similarity to that of the 28S rRNA region of C. sclerosus (93 to 100% identical to GenBank Accession No. DQ157660.1). We provide evidence for a safe and non-invasive DNA-based diagnostic method for the presence of Cichlidogyrus in the gill mucus of O. niloticus.

High serotonin levels due to the presence of the acanthocephalan Hexaglandula corynosoma could promote changes in behavior of the fiddler crab Uca spinicarpa.

Between February and June 2010, 113 fiddler crabs Uca spinicarpa were collected from the Chuburna lagoon system on the northern coast of the Yucatan Peninsula, México. Of the 68 crabs gathered outside their burrows, 13 were infected with 25 cystacanths of Hexaglandula corynosoma (intensity of infection from 1 to 5) and the remaining 55 crabs were uninfected. The other 45 crabs were found inside their burrows and only one was found infected with 1 cystacanth of H. corynosoma. Serotonin (5-HT) levels were higher in the group of crabs infected with H. corynosoma in contrast to the group of uninfected crabs and the group of those infected with other parasites. A redundancy analysis corroborated a positive relationship between 5-HT and the intensity of infection with H. corynosoma. In contrast, dopamine levels remained similar among different groups of crabs.

Correction: Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats.

Fig 1 is incorrect in both the original article and the correction published on March 6, 2015. The CNC data points and CC data points are erroneously switched. The authors have provided a corrected version here. Fig 1 Weight gain in rats during dietary supplementation period.