S. Déniz

Digestive pathology of sea turtles stranded in the Canary Islands between 1993 and 2001

Digestive lesions were observed in 84 of 136 sea turtles (128 Caretta caretta, four Chelonia mydas and four Dermochelys coriacea) stranded in the Canary Islands between January 1993 and December 2001. In the oral cavity ulcerative and necropurulent stomatitis were the most frequently observed lesions, and in the oesophagus ulcerative and fibrinous oesophagitis, and traumatic oesophageal perforation were most frequently observed; all these lesions were mainly associated with the ingestion of fishing hooks. Different histological types of gastritis were observed in 35 of the turtles; necropurulent and fibrinous gastritis were associated with bacterial infections caused mainly by Proteus species, Vibrio alginolyticus, and Staphylococcus species, and larval nematodes of the genus Anisakis were responsible for a form of parasitic gastritis observed in 16 of the turtles. Different histological types of enteritis, including catarrhal, fibrinous, necropurulent and necrotising enteritis, affected 36 turtles; a wide range of Gram-negative and Grampositive bacteria, including Bacillus species, Escherichia coli, Pasteurella species, Proteus species, Staphylococcus species, Streptococcus species and V alginolyticus, were isolated from these lesions. All the cases of necrotising enteritis were associated with intestinal intussusception caused by the ingestion of monofilament fishing lines. Necrotising and/or multifocal granulomatous hepatitis were the lesions most commonly observed in the liver; they affected 29 of the turtles and were associated with Aeromonas hydrophila, Citrobacter species, E coli, Proteus species, Staphylococcus species and V alginolyticus infections. According to the stranding reports and the gross and histological lesions observed, 33 of the turtles had digestive lesions associated with the ingestion of hooks and monofilament lines, and two had lesions associated with the ingestion of crude oil.

Isolation of Cryptococcus species including C. neoformans from cloaca of pigeons

Upper digestive tract of the pigeon (Columba livia) is well known as a reservoir for different species of Cryptococcus, but lower portions are not so frequently studied. In the present study, we tested on selective media a total of 331 pigeon cloacal swabs; Cryptococcus spp. were recovered from 26 (7.85%). Cryptococcus uniguttulatus was isolated from 11 samples (3.32%), C. laurentii from six (1.81%), C. neoformans var. neoformans from six (1.81%) and C. albidus from three of them (0.91%). The results show the importance of pigeon in the cryptococcosis epidemiology as reservoir and carrier for C. neoformans var. neoformans, but also for other Cryptococcus species of increasing clinical interest.

Presence of C. albidus , C. laurentii and C. uniguttulatus in Crop and Droppings of Pigeon Lofts ( Columba livia )

Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this disease.

The in vitro immunomodulatory effect of extracellular products (ECPs) of Vagococcus fluvialis L21 on European sea bass (Dicentrarchus labrax) leucocytes.

The immune associated genes, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-α (TNF-α), ciclo-oxigenase-2 (COX-2), and Mx gene were studied by real-time PCR in head-kidney leucocytes of sea bass after incubation with the extracellular products (ECPs) of the probiotic strain Vagococcus fluvialis L21 and polyinosinic:polycytidylic acid (POLY I:C), at different times (T1.5, T6, T12, T24, T48 and T72). In general, we can observe how pro-inflammatory cytokines IL-1β, TNF-α, IL-6 and COX-2 studied displayed a strong peak after stimulation with 1.5 h of ECPs of V. fluvialis L21, significant differences (P < 0.05) exist with other periods and with the POLY I: C at the same time. Similarly to the case of IL-10 also produced a statistically significant (P < 0.05) peak of expression on leukocytes that were stimulated with the ECPs of V. fluvialis L21. In the case of Mx gene expression, we note that in almost all sampling times there is an up-regulation of the Mx gene in leucocytes incubated with ECPs and POLY I:C compared to the control and Mx expression was higher in leucocytes that were stimulated with the ECPs of V. fluvialis for all times, except in T24. With these results we can consider that the ECPs of V. fluvialis L21 have a great power of stimulating the in vitro expression of immune-related genes and may even be useful as adjuvants for vaccine in aquaculture.

Differential innate immune response of European seabass (Dicentrarchus labrax) against Streptococcus iniae.

Streptococcus iniae is a Gram-positive bacteria that causes invasive infections with severe septicemia and meningitis, producing high economic losses in marine and continental aquaculture. Head kidney leukocytes of European sea bass (Dicentrarchus labrax) were used to measure the differential innate immune response upon infection with S. iniae. The complete inhibition in the production of intracellular superoxide radicals and total peroxidase content was observed in infected cells. This study also elucidates changes in the relative expression of some immune-related genes. Interleukin 1β, tumor necrosis factor-α and interleukin-6 reached a peak of expression at 4-8 h post-infection, subsequently decreasing significantly up to 48 h post-infection. However, interleukin-10 and Mx protein increased over time, reaching the pick of expression at 48 h post-infection, whereas caspase-3 showed down regulation until 48 h post-infection. The in vivo study of immune related genes show the same kinetics of mRNAs expression as in vitro experience. The proinflammatory cytokines mRNA transcription levels peaked at an earlier time in vivo than in vitro system. Our findings indicate that there is a direct relationship between the dissemination of bacteria and the resulting infection-associated inhibition of respiratory burst, apoptosis, and the pro- and anti-inflammatory gene expression profiles.

Streptococcus iniae in Gilthead Seabream (Sparus aurata, L.) and Red Porgy (Pagrus pagrus, L.) Ultrastructural Analysis

Streptococcosis caused by Streptococcus iniae has become one of the most serious marine and freshwater aquatic diseases in the past decade, causing large losses in farmed and wild fish worldwide. In this study, we performed an ultrastructural study of major lesions in gilthead seabream Sparus aurata and red porgy Pagrus pagrus experimentally infected with the S. iniae IUSA-1 strain, isolated in a natural outbreak in Spain in the mentioned species. The transmission electron micrographs revealed the resistance of this pathogen inside the phagosome, indicating that the macrophage may provide a significant bacterial reservoir for continuing infection, disease dissemination, and tissue injury by crossing the blood-brain barrier.

The effect of probiotic Enterococcus gallinarum L-1 on the innate immune parameters of outstanding species to marine aquaculture

In this work, we evaluated the effect of the probiotic Enterococcus gallinarum L-1 on the cellular immune system of four different fish species of great interest in aquaculture such as gilthead sea bream (Sparus aurata), European sea bass (Dicentrarchus labrax), meagre (Argyrosomus regius) and red porgy (Pagrus pagrus). Phagocytic activity, respiratory burst and peroxidase content of leucocytes were observed 30 minutes after incubation with the probiotic E. gallinarum strain L-1, alive or inactivated with heat shock or ultraviolet (UV) light at different concentrations of 107, 108 and 109 cfu mL−1 (final concentration 106, 107 and 108 cfu mL−1). E. gallinarum produced dose-dependent increments in respiratory burst in red porgy, sea bream and sea bass leucocytes. About 106 and 107 cfu mL−1 of live and inactivated bacteria with no stimulation of the respiratory burst activity of sea bream and red porgy head kidney leucocytes was shown. The highest values of peroxidase content were observed in red porgy cells with stimulation indexes higher than 1 in each treatment. Statistical analysis revealed that differences were only significant in sea bream where UV light-inactivated bacteria denote statistically significant differences (P < 0.05) with respect to other treatments. Highest values of phagocytic activity were obtained in sea bream leucocytes incubated with live bacteria (26% ± 1.88), where significant differences (P < 0.05) with other species were detected. Our results suggest that the in vitro assays may be useful in optimising their effective dose and viability for the immunomodulatory effects of probiotic bacteria, although in vivo studies are necessary to confirm the immunomodulatory effect of this strain.

ISOLATION OF MYCOBACTERIUM KANSASII FROM A TUBERCULIN-POSITIVE GOAT

a comparison between means technique (Carrasco 1986). The effects of treatment on seasonality are shown in Figs 1 and 2. and the results of this study appear to indicate that administration of PGF2a at the time of insemination breaks the seasonality of swine reproduction. Seasonal infertility is associated with impaired secretion of lutenising hormone and thus an increased embryonic mortality, resulting in lower fertility and decreased litter size (reviewed by Love and others 1993). Ovulation is known to be associated with intrafollicular synthesis of PGF2a. Transcervical infusion of PGF2a has been shown to produce an intrafollicular increase of PGF2a concentration, and also to advance ovulation by approximately 12 hours (Weiler and Claus 1991). The results of the present study support this observation and indicate the beneficial effects of ovulation-inducing substances such as PGF2a in the improvement of the success rate of swine artificial insemination, especially during the low fertility season.

Mortality Caused by Staphylococcus xylosus in Red Porgy (Pagrus pagrus) Fish

Abstract Padilla, D., Acosta, F., Rodríguez, F., Gómez. V., Déniz. S. and Real. F. 2001. Mortality caused by Staphylococcus xylosus in red porgy (Pagrus pagrus) fish. J. Appl. Anim. Res., 19: 203–208. In a group of experimental red porgy breeders from the Instituto Canario de Ciencias Marinas de Taliarte (Las Palmas, Spain), displaying haemorrhages and sudden death, Staphylococcus xylosus was isolated in pure culture from internal organs showing most prominent lesions of hepatitis and nephritis. Two trials were carried out to show the virulence of this isolated strain by two fish species, gilthead sea-bream (Sparus aurata) and red porgy (Pagrus pagrus). Similar clinicopathologic effects resulted from these trials and the red porgies used were the most affected fishes.

In vitro susceptibility testing of Malassezia pachydermatis to gentamicin

BACKGROUND Two studies have observed that growth media containing gentamicin can inhibit the growth of the yeast organism Malassezia pachydermatis. The minimum inhibitory concentration (MIC) of this bactericidal antibiotic for this organism has not been previously determined. OBJECTIVE To evaluate the susceptibility of M. pachydermatis isolates to gentamicin. METHODS The MIC of gentamicin was determined using a modified version of the M27-A3 microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. A modified Christensens urea broth was used to enhance the growth of the M. pachydermatis isolates. Visual and spectrophotometric end-point readings were performed to detect the presence or absence of yeast growth. RESULTS The MIC50 and MIC90 of gentamicin were 8.12 μg/mL and 32.5 μg/mL, respectively; M. pachydermatis strains were classified as susceptible (S), intermediate (I) and resistant (R). The susceptibility of these isolates to gentamicin in vitro, by visual and spectrophotometric end-point reading, was: S, 54-56%; I, 40-41%; and R, 3-6%. CONCLUSION Prospective MICs for M. pachydermatis have been established for gentamicin.