Morphometric analysis of the corneal endothelium of Yacare caiman (Caiman yacare) using scanning electron microscopy

The objective of this study was to examine the endothelial surface morphology and to perform morphometric analysis of the corneal endothelial cells of Yacare caiman (Caiman yacare) using scanning electron microscopy. Morphometric analysis with regard to polygonality, mean cell area, cell density and coefficient of variation of mean cell area was performed. Cell areas were measured using image analysis software. The normal corneal endothelium of Yacare caiman consisted of polygonal cells of uniform size and shape with interdigitations of the cell borders. Microvilli appeared as protrusions on the cellular surface. The average cell area was 270 +/- 24 microm(2) and the endothelial cell density was 3704 +/- 324 cells/mm(2). The coefficient of variation of cell area was 0.22. This study demonstrates that the Yacare caiman corneal endothelium is similar to those described in other vertebrates.     

SHORT COMMUNICATION: Normal aerobic bacterial conjunctival flora in the Crab‐eating raccoon (Procyon cancrivorus) and Coati (Nasua nasua) housed in captivity in pernambuco and paraiba (Northeast,Brazil)

Objective To determine the normal aerobic bacterial conjunctival population of the Coatis and the Crab‐eating raccoons housed in captivity in the Pernambuco and Paraiba states of Brazil. Animals studied Ten healthy Coatis and 10 healthy Crab‐eating raccoons were selected for this study. Animals are from three zoos situated at the Pernambuco and Paraiba States in the north‐east of Brazil. Procedures After ophthalmologic examination, swabs from healthy animals were carefully collected in order to avoid contamination. Samples were identified and submitted to the laboratory. Swabs were plated for culture on ovine blood agar (8%) and agar Levine and incubated at 37 °C and observed 24 and 48 h. Results Staphylococcus spp. was the most common microorganism isolated from conjunctival sac. Shigella spp. comprised the Gram‐negative genera isolated. Escherichia coli were isolated from the right eye of one Coati that had no growth at contralateral eye. Nine eyes from coatis and 10 from Crab‐eating raccoons had no microorganisms isolated. Conclusion Our results were in accordance with previous studies indicating Staphylococcus sp., followed by Corynebacterium spp. as the most common inhabitant of the eyes of most mammalian species.     

Molecular phylogenetic analysis of Onchocerca lupi and its Wolbachia endosymbiont

The morphology of Onchocerca lupi, responsible for canine ocular onchocercosis, is unique within the genus. Earlier analyses of the 5S ribosomal RNA gene spacer region sequence of the parasite and the 16S ribosomal RNA gene sequence of its Wolbachia endosymbiotic bacteria (Rickettsiales) supported the morphological and biological arguments that O. lupi is a distinct species. However, the exact phylogenetic position of O. lupi and its endosymbiont could not be unambiguously determined. Herein we report analyses based on the mitochondrial cytochrome oxidase I (COI) gene of the filarial species and the Wolbachia surface protein (wsp) and the bacterial cell-cycle ftsZ genes of their wolbachiae. Our results indicate that O. lupi separated from other Onchocerca spp. early in evolution. This is in line with the previous morphological analysis demonstrating that O. lupi is an atypical Onchocerca species showing both primitive and evolved characters. The phylogenetic trees generated for the COI sequences of filariae and the wsp and ftsZ sequences of their wolbachiae were congruent with each other, which supports the hypothesis that nematodes and their Wolbachia endobacteria share a long co-evolutionary history.     

Study on the inductive factors of hypobiosis of Ostertagia ostertagi in cattle

Two experiments were carried out to determine the causes producing the Ostertagia ostertagi hypobiosis phenomenon in cattle. In the first experiment, the effect of time on third-stage larvae in the environment was studied during a 2-year period. Three experimental paddocks contaminated with O. ostertagi eggs at different times of the year were used, and the levels of hypobiosis were recorded by using 'indicator' and 'tracer' calves. The results suggest that time as such is not a hypobiosis-inductive factor. The second experiment was conducted under laboratory conditions, where the effects of temperature and light on infective larvae were studied. Infective larvae were subjected to different conditions of temperature and light during 6 weeks, and then inoculated to parasite-naive calves, which were slaughtered after 4 weeks. Percentages of hypobiotic larvae in these calves varied from 3.5 to 94.8%, depending on the different storage conditions the larvae underwent before inoculation. Results suggest that increasing temperature and increasing time of light exposure simulating spring conditions would be the factors which act upon third-stage larvae inducing them to a later hypobiotic stage in the host.     

Model field study of Sumithion 50 EC and Fusilade S on pheasants.

Toxicological studies on wild animals play an important role in the ecotoxicological examination of pesticides. The applied model tests enable the assessment of toxicological consequences with particular regard to the life and nutrition of wild animals in the ploughed field among plants treated with pesticides. The application of different pesticide formulations on plough-land may pose a simultaneous chemical burden to wild birds. In this model study, manifestations of the interaction between an insecticide and a herbicide were studied in pheasants. The birds were placed on lucerne in cages (48 m2) and sprayed once. The applied doses were: Sumithion 50 EC 1 litre/ha + Fusilade S 6 litres/ha (practical doses) and Sumithion 50 EC 5 litres/ha + Fusilade S 30 litres/ha. The analytically determined pesticide concentration of the lucerne was taken as a basis in the further treatment of fodder. The fodder of pheasants contained the following chemicals: 85 mg/kg Sumithion 50 EC + 510 mg/kg Fusilade S and 425 mg/kg Sumithion 50 EC + 2250 mg/kg Fusilade S. Sporadic deaths observed among the pheasants were of traumatic origin and not due to a toxic effect. The decrease of body weight was significant only at the higher dose levels. Acetylcholinesterase (AChE) activity of the blood decreased significantly in both dose groups. On the basis of the results obtained it can be established that at the dose level used in the practice the pesticides studied do not give rise to a toxic interaction in pheasants.     

Ochratoxin a content of urine samples of healthy humans in Hungary

The ochratoxin A (OTA) content of urine samples from 88 healthy humans living at five settlements in three counties of Hungary was determined by immunoaffinity column cleanup and high-performance liquid chromatography (HPLC). OTA was detected in 61% of the samples in an average concentration of 0.013 ng/ml (range: 0.006-0.065 ng/ml). OTA concentrations measured in urine samples from men and women were not significantly different. The OTA concentration of samples from Heves county was significantly (t-test; p < 0.003) higher than that of samples from Hajdú-Bihar and Somogy counties. The regional differences in OTA concentration of urine samples indicate regional differences in the OTA exposure of the human population. Further studies are necessary to determine the cause of the regional differences in the OTA intake. The studies allow us to conclude that the OTA intake of the majority of the Hungarian population is low (< 1 ng/kg of body weight per day) but a certain part of the rural population may take up higher levels of OTA.     

Fluctuation in the concentration of sex steroids and aflatoxin B1 in the seminal plasma of boars and its relation to sperm production

The concentration of testosterone, 17-beta oestradiol and aflatoxin B1 were studied in the semen plasma of 21 boars of four breeds for the period of twelve months. The following spermiological parameters were investigated: semen volume, sperm concentration, percentage of abnormal spermatozoa, and survival of spermatozoa. The fertilizing capacity of ejaculates was evaluated according to the conception rate of sows and gilts after the first insemination, according to the average number of piglets per litter and average number of live-born piglets per litter. The highest aflatoxin B1 residues in sperm were recorded in March to May and were related with aflatoxin concentration in feed ration. The group of boars with fertility disorders had more aflatoxin in their sperm (up to 100 pmol . l-1), lower sperm concentration, lower survival of spermatozoa, and a larger proportion of abnormal spermatozoa. The year season had a significant influence on the concentration of the hormones. The highest average value of testosterone (10.2 +/- 1.28 nmol) was obtained in autumn and lower values were recorded in winter. The changes in 17-beta estradiol concentration were similar to the changes in testosterone content, with the maximum value in November (0.249 nmol X 1(-1]. The boars with reproduction disorders had a significantly lower concentration of 17-beta oestradiol. Significant correlations were found between the concentration of the hormones, semen volume, and sperm concentration. 17-beta oestradiol also had a significant positive correlation to abnormal spermatozoa and to the activity of aspartate aminotransferase.