Safety of food products is assessed by hygiene standards, which include biological, chemical and physical risk factors. Biological risk factors include viruses, bacteria, mold and yeast fungi, protozoa, helminths and their toxins. Their presence in food products is either completely unacceptable, or should not exceed the acceptable ranges of concentrations in a certain volume of the test products. The original scoring technique was used for a quantitative assessment of biological risks. The persistence of microorganisms and helminthes was evaluated in meat, dairy and vegetable products, culinary products, eggs, canned food, pickles and marinades. Among the studied biological risk factors, the following have very low persistence in food products: adolescari of Fasciola spp.; eggs of Trichocephalus trichiuris, Enterobius vermicularis, Hymenolepis nana, Echinococcus spp., Ascaris lumbricoides, Strongyloides stercoralis larvae, cysts of Lamblia intestinalis, Entamoeba histolytica. Low persistence was demonstrated by Rotavirus, hepatitis A virus, the genus Norovirus, bacteria of the Leptospira spp. and Vibrio spp., Escherichia coli, Toxoplasma gondii and Cryptosporidium parvum. Medium persistence was demonstrated by plerocercoids of Diphyllobothrium spp, cysticercuses of Taeniarhynchus saginatus and Taenia solium, bacteria Shigella spp. and Francisella tularensis. High persistence was shown by larvae of the genus Trichinella, metacercaria Opisthorchidae, bacteria Mycobacterium spp., Proteus spp., Campylobacter spp., Yersinia spp., Brucella spp., Bacillus cereus, Clostridium perfringens, Staphylococcus aureus and Clostridium botulinum. Aphthovirus, Salmonella spp. and Listeria monocytogenes have very high persistence.

The most widely used feed ingredients in the world are fishmeal and soybean, which, despite having high-quality digestible protein and good fat content, are considered environmentally unsustainable and increasingly expensive. This issue also involves the guinea pig, a very important animal protein source for people in Andean regions in South America. Here we investigate the substitution of soybean meal with 50% and 100% black soldier fly larvae meal in the guinea pig diet and its effects on meat quality (fatty acid profile, amino acid profile, water-holding capacity, pH, proximal composition, and color). The results showed no differences in the protein content and amino acid profile of meat nor in the n-6:n-3 and P/S ratios, but did show an increment in the desirable fats (mono- and polyunsaturated fatty acids) in the guinea pigs fed with black soldier fly larvae meal. All the other analyzed parameters showed no differences among the diets tested. These results suggest that total replacement of soybean meal with black soldier fly larvae meal in guinea pig nutrition is feasible since meat quality was maintained or improved.

The regulation of river flow in the Volga basin has caused irreversible changes to aquatic ecosystems. The transformation of the Volga into a cascade of hydraulic structures with a non-flow regime has resulted in a decrease in depth and flow, and an increase in the temperature and concentration of chemical elements, which has induced the process of eutrophication. The change in the species diversity of aquatic organisms under conditions of intense eutrophication was studied on models of water bodies from the Volga basin; the Kostroma section of the Gorky reservoir (Kostroma spill and the middle river section), and lakes Galichskoe and Chukhlomskoe were studied. Rheophilic biocenosis was replaced by a limnophilic one, the migration paths of fish were disrupted, and population characteristics were changed. In accordance with environmental conditions, the level of primary production and the calculated Carlson trophic index (TSI) and Broth-proposed index (ITS) (1987), the water bodies of the northern part of the upper Volga region are classified as follows: the middle river section of the Gorky reservoir is mesotrophic-eutrophic (TSI = 55.2, ITS = 16.2); the Kostroma spill is eutrophic with a tendency to hypertrophy (TSI = 67.4, ITS = 6.8); Lake Galichskoe is eutrophic with a tendency to dystrophy (TSI = 63.2, ITS = 8.4), and Lake Chukhlomskoe is hypertrophic with a tendency to dystrophy (TSI = 77.4, ITS = 8.0). In addition, frequent fluctuations in water level, reaching 1 m, have had an adverse effect on inhabitants of the littoral zone including the spawning fish, which may lead to disappearance of some of the region’s most sensitive species.

No abstract

Planta Med. 57, Supplement Issue 2 1991 A45 drugs for treating the disease. The limitations of, and problems associated with, the treatment of human and animal trypanosomiasis have been extensively reviewed (1). However, in Africa, the debilitating effects of the disease, and its devastating toll on livestock as well as humans, is very real. As part of our general screening of naturally occurring compounds with biological activity, we have examined a number of compounds for possible anti-trypanosomal activity, using mice infected with the drug-sensitive stabilates of 7'rypanosoma brucei and Trypanosoma evans/i developed at the Kenya Trypanosomiasis Research Institute. Five pure compounds isolated from various plants were tested. These were crotepoxide from Cro ton macrostachyus, 9methoxychelerythrine from Zoo thoxylum c/zolybeum and its chloride derivative, rutin from Bricleliaferruginea, and dihydrowisaoine from Piper guineeose. Preliminary tests were carried out using 80mg/kg body weight of the substances. Suramin (20 mg/kg) and berenil (3.5 mg/kg) were used as standards. 70 mice weighing between 20-25g were divided into 7 groups of 10 and inoculated with the known drug-sensitive stabilates of the trypanosomes (KETRI-2401-Tb T. brocei and KETRI 2449 Tb T. eeansii). When parasitaemia was established, 5 out often mice in each group were treated ip. with suramin, berenil, and each of the test compounds. The remaining five were left untreated as controls. The treated mice were then observed for an average of up to 30 days. The test compounds showing signs of activity were then used for further investigation. At 80mg/kg, 9-methoxychelerythrine chloride proved lethal to the mice, while its free base had no significant effect on parasitaemia. Crotepoxide, rutin, and dihydrowisanine suppressed parasitaemia to some extent, but did not clear the parasites. The suppression lasted 3 days for dihydrowisanine, 4 days or crotepoxide, and 15 days for rutin. These compounds were then tested again at 100 mg/kg. At this dose, rutin suppressed parasitemia for 10-15 days, while the number of days by crotepoxide rose from 4 to 9 days. Subsequent death after single dose treatment was found not to be due to drug toxicity, but due to a relapse in the parasitaemia. These preliminary results indicate that both rutin and crotepoxide have some trypanosidal activity when administered as a single dose, and need to be further investigated. Divided doses over a short period, or at shorter intervals, as well as tests at lower doses of the compounds which proved lethal to the animals at higher doses, need to be carried out. Work in this regard is still continuing.