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Ultrastructural changes induced by Rickettsia slovaca standard type (ST) and wild type (WT) were examined during their life cycle in L929 and Vero cells. R. slovaca invaded the cytoplasm of the host cell by phagocytosis on the 1st d p.i. Rickettsiae adhering to the cytoplasmic membrane were engulfed by cellular extensions and occurred in phagocytic vacuoles. Binary fission of rickettsia was observed. The nuclear chromatin of eukaryotic cells was rearranged and condensed during 3rd and 6th d p.i. Finally, loss of the plasma membrane integrity, destruction of cytoplasm and nucleus resulted in cell lysis. Degeneration of the host cell caused by WT and ST was observed after 4 and 5 d p.i. in L929 cells and after 3 and 6 d p.i. in Vero cells, respectively. WT type was able to penetrate into the nucleus of the host cell and was responsible for dilatation of the perinuclear space and endoplasmic reticulum, causing more pronounced and different cytopathological changes than the ST. [ABSTRACT FROM AUTHOR]

Anaerobic bacteria from Porcellio scaber hindgut were identified and, subsequently, isolated using molecular approach. Phylogenetic affiliation of bacteria associated with the hindgut wall was determined by analysis of bacterial 16S rRNA gene sequences which were retrieved directly from washed hindguts of P. scaber. Sequences from bacteria related to obligate anaerobic bacteria from genera Bacteroides and Enterococcus were retrieved, as well as sequences from ‘A1 subcluster’ of the wall-less mollicutes. Bacteria from the genus Desulfotomaculum were isolated from gut wall and cultivated under anaerobic conditions. In contrast to previous reports which suggested the absence of anaerobic bacteria in the isopod digestive system due to short retention time of the food in the tube-like hindgut, frequent renewal of the gut cuticle during the moulting process, and unsuccessful attempts to isolate anaerobic bacteria from this environment our results indicate the presence of resident anaerobic bacteria in the gut of P. scaber, in spite of apparently unsuitable, i.e. predominately oxic, conditions. [ABSTRACT FROM AUTHOR]

The article reports on intake and assimilation of zinc, copper, and cadmium in the terrestrial isopod "Porceilo scaber Latr. (Crustacea, Isopoda). Terrestrial isopods are organisms of choice in metal and pesticide toxicity studies. Laboratory experiments have shown that elevated concentrations of metals in their diet increase mortality, decrease growth, reproduction, feeding rate and moult frequency, and cause changes at tissue and cellular levels in different isopod species. The aim of our work was to study changes in the food consumption rate as a mechanism of metal intake regulation.

The article discusses a study which investigates the Zinc (Zn) assimilation by Portellio scaber (isopods) exposed to leaves contaminated with Zn at five different concentrations, 300, 1500, and 3000 μg Zn g-1. The objectives of the study was to determine if the amount of assimilated Zn followed the range of Zn concentrations in the food and to examine if assimilation of Zn was influenced by the food consumption rate. The researchers found that isopods assimilated higher amount of Zn when exposed to 1500 μg Zn g-1 contaminated leaves than exposed to 2100 and 3000 μg Zn g-1 contaminated leaves.