Fig 11 - uploaded by Sanya Kudan
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TEM of ‘‘Type III’mitochondria in a male gametocyte. An apicoplast is observed with a multi-membranous organelle containing electron-dense matrix and absence of internal cristae. The bar represents 1 μM. M, mitochondria; P, crystalline pigment. A, apicoplast.
Source publication
Mitochondria of the human malarial parasite Plasmodium falciparum in sexual blood stages (or gametocytes) had been structurally different from those of asexual blood stages of their life cycle in human host. We report here the existence of mitochondrial heterogeneity based on their characteristics of ultrastructural morphology in the asexual and se...
Citations
... Antibiogram profiles of the bacterial isolates suggest that all of them belong to MDR strains. The presence of these bacteria in hospital wards indicated that they could constitute a major health risk to humans and associated animals like cats and rodents because urinary tract, biliary tract and peritoneal infections, wound infections, sepsis, gastroenteritis, and pneumonia are all possible illnesses caused by these microbes [32,33]. ...
German cockroaches, Blattella germanica L. are the most dangerous pests in hospital environments which cause diseases like food poisoning, dysentery, and diarrhea. Antibiogram and multidrug resistance (MDR) patterns of the bacterial isolates from the cockroaches inhabiting three Wards of Rajshahi Medical College Hospital, Rajshahi, Bangladesh, were determined. A total of 52 bacterial isolates, 26 from the cuticle and 26 from the gut, comprising 20 (38.5 %) from the Neuromedicine ward, 18 (34.6 %) from the Orthopaedic ward, and 14 (26.9 %) from the Surgery ward, were used for biochemical assays and diagnostic characteristics, where seven Gram-negative rod species were identified. E. coli (n=8 or 40 %), Klebsiella spp. (n=5 or 28 %) and Klebsiella spp. (5 or 35 %) constituted the most dominant bacteria from the three wards respectively. Antibiogram of the bacterial isolates against 18 commonly used antibiotics revealed that Serratia, Klebsiella, Escherichia, and Pseudomonas were resistant to Ceftazidime, whereas Salmonella, Enterobacter, and Proteus were sensitive to the drug. Results of the present study suggest that the German cockroaches might serve as reservoirs for pathogenic and MDR bacteria, which in turn could be responsible for the spread of common food-borne diseases in hospital patients, their attendants, and health professionals.
Nine of the 20 most utilized freshwater aquaculture fish species around the world have been genetically modified (GM), and another five species of aquaculture interest and two species for research are being extensively worked on. Modifications are focused on production-related traits, with growth enhancement by far in the most advanced state with respect to commercial application currently awaiting regulatory decision. Other aspects more or less developed are phenotypic modifications of ornamental fishes and, for disease resistance, biomonitoring, biocontrol and pharmaceutical production and xenotransplantation of tissue to humans. While GM technology may hold potential benefits for the fresh water ecosystem, they are not viewed scientifically as universally positive, and a number of critical issues have been identified, including ecological risks, food safety and ethics. More specifically, GM fishes may pose problems in making use of limited fresh water, pollution and disrupting the ecological balance. Such issues will need to be resolved before commercial application will become widely accepted. Assessing ecological risk is complicated by pleiotropic effects from the transgene acting on the animals, the sensitivity to rearing conditions and the complexity of natural freshwater ecosystems.
Sporozoites of the apicomplexan Cryptosporidium parvum possess a small, membranous organelle sandwiched between the nucleus and crystalloid body. Based upon immunolabelling data, this organelle was identified as a relict mitochondrion. Transmission electron microscopy and tomographic reconstruction reveal the complex arrangement of membranes in the vicinity of this organelle, as well as its internal organization. The mitochondrion is enveloped by multiple segments of rough endoplasmic reticulum that extend from the outer nuclear envelope. In tomographic reconstructions of the mitochondrion, there is either a single, highly-folded inner membrane or multiple internal subcompartments (which might merge outside the reconstructed volume). The infoldings of the inner membrane lack the tubular "crista junctions" found in typical metazoan, fungal, and protist mitochondria. The absence of this highly conserved structural feature is congruent with the loss, through reductive evolution, of the normal oxidative phosphorylation machinery in C. parvum. It is proposed that the retention of a relict mitochondrion in C. parvum is a strategy for compartmentalizing away from the cytosol toxic ferrous iron and sulfide, which are needed for iron sulfur cluster biosynthesis, an essential function of mitochondria in all eukaryotes.
The mitochondrial electron transport system is necessary for growth and survival of malarial parasites in mammalian host cells. NADH dehydrogenase of respiratory complex I was demonstrated in isolated mitochondrial organelles of the human parasite Plasmodium falciparum and the mouse parasite Plasmodium berghei by using the specific inhibitor rotenone on oxygen consumption and enzyme activity. It was partially purified by two sequential steps of fast protein liquid chromatographic techniques from n-octyl glucoside solubilization of the isolated mitochondria of both parasites. In addition, physical and kinetic properties of the malarial enzymes were compared to the host mouse liver mitochondrial respiratory complex I either as intact or as partially purified forms. The malarial enzyme required both NADH and ubiquinone for maximal catalysis. Furthermore, rotenone and plumbagin (ubiquinone analog) showed strong inhibitory effect against the purified malarial enzymes and had antimalarial activity against in vitro growth of P. falciparum. Some unique properties suggest that the enzyme could be exploited as chemotherapeutic target for drug development, and it may have physiological significance in the mitochondrial metabolism of the parasite.
