Epidemiology of selected Mycobacterium tuberculosis complex members in the Czech Republic in 2000-2016.

The paper concerns the epidemiology of Mycobacterium tuberculosis complex (MTBC) members except for M. tuberculosis in the Czech Republic in 2000 to 2016. M. bovis was confirmed in 18 patients. M. caprae was diagnosed in two patients in 2001 and 2016 and M. microti in one patient in 2007. M. africanum was detected in one HIV infected woman from Nigeria in 2011. As regards animals, M. pinnipedii was isolated in 2009 from one Southern sea lion (Otaria flavescens) imported from Germany. In 2002, M. caprae was isolated from two Bactrian camels (Camelus ferus) kept in a zoological garden. M. tuberculosis was isolated from one dog in 2004 and from two domestic pigs in 2007. In both cases, the source of M. tuberculosis was an infected patient. Upon examination of 3 727 environmental samples of water and sediments, none of the MTBC members was detected in the stu-died period. Infected persons coming from M. africanum endemic countries (especially West African countries) and infected animals can be considered as the current risk factors for transmission of MTBC species. If the epidemiological situation remains as it is now, there is no risk of transmission of MTBC species via milk or unpasteurised dairy products. Keywords: mycobacterial ecology - domestic and wild animals - food safety.

Factors Affecting Antioxidant Response in Fish from a Long-term Mercury-Contaminated Reservoir.

The objective of this work was to evaluate antioxidant defence and oxidative damage in organs (liver, gills, kidney, and brain) of five fish species (Aspius aspius, Esox lucius, Sander lucioperca, Abramis brama, Rutilus rutilus) from the long-term mercury-contaminated Skalka Reservoir in the Czech Republic. Special emphasis was placed on a comprehensive assessment of the factors that may affect the antioxidant response to mercury in fish. Antioxidant enzymes (glutathione reductase, glutathione peroxidase, and glutathione-S-transferase) did not significantly respond to mercury contamination. Levels of the analysed enzymes and oxidative damage to lipids were predominantly determined by a separate organ factor or species factor, or by the combination of both (p < 0.001). Levels of total glutathione and the reduced/oxidized glutathione ratio were influenced by mercury contamination in combination with their specific organ distribution (p < 0.001). Our results suggest that species and type of organ alone or in combination are more important factors than chronic exposure to mercury contamination with respect to effects on antioxidant defence in fish under field conditions. Our findings suggest that the main antioxidant defensive mechanism in fish from the studied long-term mercury contaminated site was the inter-tissue distribution of glutathione.

Recovery ability of common carp (Cyprinus carpio) after a short-term exposure to terbuthylazine.

Effects of a high terbuthylazine concentration (3.3 mg/1) on Cyprinus carpio were studied using a commercial herbicide formulation Click 500 SC (terbuthylazine 500 g/l). The fish were exposed to the pesticide for 24 h and allowed to recover for 6 days. Biometric parameters, plasma biochemical parameters and biomarkers of oxidative stress as well as histopathological changes in selected tissues were assessed on day 1 and 7. After a 24-h exposure, there were significant alterations found in the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as in the plasma concentrations of glucose, natrium, chlorides, calcium and phosphorus. Hepatosomatic index, plasma albumin and lactate reflected the treatment with a delay. Ion levels and ALT were found to be restored after a 6-day recovery period, which was too short for AST activity and glucose to diminish to the control levels. The histopathological examination revealed disorders in the gills of the exposed fish, however, the changes were not detected after a 6-day recovery period. The study shows high regeneration potential of the fish.