Tepidamorphus gemmatus gen. nov., sp. nov., a slightly thermophilic member of the Alphaproteobacteria

Two isolates, with an optimum growth temperature of about 45–50 °C and an optimum pH for growth between 7.5 and 8.5, were recovered from a hot spring in the Furnas area on the Island of São Miguel in the Azores. Strains form irregular rod-shaped cells are motile and stain Gram negative. The cells multiply by budding. These strains are non-pigmented, strictly aerobic, catalase and oxidase positive. These organisms assimilated carbohydrates, organic acids and amino acids. The major fatty acids are 19:0_{cyclo ω8c} and 18:0. Ubiquinone 10 is the major respiratory quinone. The major polar lipids are diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine in addition to one unidentified aminolipid and one unidentified glycolipid. Bacteriochlorophyll a, puf genes and RuBisCo genes were not detected. Analysis of the 16S rRNA gene shows the strains to cluster with species of the genera Afifella, Rhodobium, Anderseniella and Amorphus to which they have sequence similarity in the range 93–94%. Based on 16S rRNA gene sequence analysis, physiological and biochemical characteristics we describe a new species of a novel genus represented by strain CB-27A^T (=DSM 19345^T=LMG 24113^T) for which we propose the name Tepidamorphus gemmatus.     

Caffeine and CSC,adenosine A2A antagonists,offer neuroprotection against 6-OHDA-induced neurotoxicity in rat mesencephalic cells

In this study, the cytoprotective effects of caffeine (CAF) and 8-(3-chlorostyryl)-caffeine (CSC), A_2A receptor antagonists, were tested against 6-OHDA-induced cytotoxicity, in rat mesencephalic cells. Both drugs significantly increased the number of viable cells, after their exposure to 6-OHDA, as measured by the MTT assay. While nitrite levels in the cells were drastically increased by 6-OHDA, their concentrations were brought toward normality after CAF or CSC, indicating that both drugs block 6-OHDA-induced oxidative stress which leads to free radicals generation. A complete blockade of 6-OHDA-induced lipid peroxidation, considered as a major source of DNA damage, was observed after cells treatment with CAF or CSC. 6-OHDA decreased the number of normal cells while increasing the number of apoptotic cells. In the CAF plus 6-OHDA group, a significant recover in the number of viable cells and a decrease in the number of apoptotic cells were seen, as compared to the group treated with 6-OHDA alone. A similar effect was observed after cells exposure to CSC in the presence of 6-OHDA. Unexpectedly, while a significant lower number of activated microglia was observed after cells exposure to CAF plus 6-OHDA, this was not the case after cells exposure to CSC under the same conditions. While CAF lowered the percentage of reactive astrocytes increased by 6-OHDA, CSC presented no effect. The effects of these drugs were also examined on the releases of myeloperoxidase (MPO), an inflammatory marker, and lactate dehydrogenase (LDH), a marker for cytotoxicity, in human neutrophils, in vitro. CSC and CAF (0.1, 1 and 10 μg/ml) produced inhibitions of the MPO release from PMA-stimulated cells, ranging from 45 to 83%. In addition, CSC and CAF (5, 50 and 100 μg/ml) did not show any cytotoxicity in the range of concentrations used, as determined by the LDH assay. All together, our results showed a strong neuroptrotection afforded by caffeine or CSC, on rat mesencephalic cells exposed to 6-OHDA. Furthermore, CSC and caffeine actions, inhibiting MPO as well as LDH releases, would contribute to their possible benefit in the treatment of neurodegenerative diseases, including DP. These effects are partially due to the ability of these A_2A antagonists to decrease the cells free radicals production and oxidative stress, that are major components of 6-OHDA-induced cytotoxicity.     

Transitional cell carcinoma of the ovary: A rare case and review of literature

Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm.     

Binding of Azole Antibiotics to Staphylococcus aureus Flavohemoglobin Increases Intracellular Oxidative Stress

In this work, we report that flavohemoglobin contributes to the azole susceptibility of Staphylococcus aureus. We first observed that deletion of the flavohemoglobin gene leads to an increase in the viability of imidazole-treated S. aureus cells and that reversion to the wild-type phenotype occurs upon expression of flavohemoglobin from a multicopy plasmid. Further spectroscopic analyses showed that miconazole, the most efficient azole antibiotic against S. aureus, ligates to heme of both oxidized and reduced flavohemoglobin. The binding of miconazole to oxidized flavohemoglobin, with an association constant of 1.7 × 10⁶ M⁻¹, typical of a tight, specific binding equilibrium, results in augmentation of the superoxide production by the enzyme. These results are corroborated by in vivo studies showing that imidazole-treated S. aureus cells expressing flavohemoglobin contain a larger amount of reactive oxygen species. Moreover, it was observed that the survival of miconazole-treated S. aureus internalized by murine macrophages is higher for cells lacking flavohemoglobin. Altogether, the present data revealed that in S. aureus, flavohemoglobin enhances the antimicrobial activity of imidazoles via an increase of intracellular oxidative stress.Staphylococcus aureus is an opportunistic pathogen responsible for a large number of human infections that cause systemic diseases from a mild to life-threatening character. The increasing incidence of methicillin-resistant S. aureus (MRSA) strains observed in the past few years makes S. aureus infections a leading threat to public health, causing more deaths in the United States and Europe than human immunodeficiency virus (AIDS) (11). Like other Gram-positive bacteria, staphylococci are sensitive to imidazoles (27). Imidazoles (such as clotrimazole, miconazole, ketoconazole, and sulconazole) (Fig. ​(Fig.1)1) represent one of the major classes of azole antifungal that are useful in the treatment of infections, including cutaneous and vaginal candidiasis (8). The activity of these antifungal drugs derives primarily from inhibition of the biosynthesis of ergosterol, an essential component of the fungal plasma membrane, at the level of lanosterol 14-alpha demethylase. Furthermore, in fungi and yeast, azole treatment leads to an increase in the endogenous production of reactive oxygen species (ROS) (12, 25). For example, in Candida albicans and Saccharomyces cerevisiae, the miconazole inhibition of cytochrome c oxidase, peroxidase, and catalase has been reported to be responsible for a high level of ROS production (3, 4). It has also been reported that clotrimazole inhibition of Plasmodium falciparum hemoperoxidase leads to ROS accumulation in this protozoan pathogen (26). For S. cerevisiae, C. albicans, and Escherichia coli, the action of imidazoles was also correlated with the inhibition of the nitric oxide (NO) scavenger activity of flavohemoglobin (7).Open in a separate windowFIG. 1.Structures of the azole (imidazole; 1,2,4-triazole) antibiotics investigated.Flavohemoglobins (Hmp) are widespread among bacteria and yeast and contain three domains: C-terminal NAD- and flavin adenine dinucleotide (FAD)-binding domains, which together constitute a ferredoxin-NADP⁺ oxidoreductase-like domain, and an N-terminal globin domain, which harbors a single B-type heme. The high-spin heme contains one axial histidine and binds small molecules like NO, carbon monoxide (CO), and dioxygen (O₂). The heme can also bind bulky aromatic bases, since it is inserted in a large hydrophobic pocket (7). We observed that the binding of imidazoles to S. aureus flavohemoglobin results in an increase in the amount of deleterious reactive oxygen species produced by flavohemoglobin that contributes to the bactericidal effect of azole antibiotics toward S. aureus.     

Salinicoccus salsiraiae sp. nov.: a new moderately halophilic gram-positive bacterium isolated from salted skate

Two moderately halophilic low G + C Gram-positive bacteria were isolated from a sample of salted skate (Class Chondrychthyes, Genus Raja). Phylogenetic analysis of the 16S rRNA gene sequence of strains RH1^T and RH4 showed that these organisms represented a novel species of the genus Salinicoccus. The new isolates formed pink–red colonies and flocculated in liquid media, with optimum growth in media containing 4% NaCl and pH of about 8.0. These organisms are aerobic but reduce nitrate to nitrite under anaerobic conditions. Acid is produced from several carbohydrates. Oxidase and catalase were detected. Menaquinone 6 was the major respiratory quinone. The major fatty acids of strains RH1^T and RH4 were 15:0 anteiso and 15:0 iso. The G + C contents of DNA were 46.2 and 46.0 mol%, respectively. The peptidoglycan was of A3alpha L-Lys-Gly_5–6 type. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we suggest that strain RH1^T (=LMG 22840 = CIP 108576) represents a new species of the genus Salinicoccus, for which we propose the name Salinicoccus salsiraiae.     

Role of melanin in the pathogenesis of cutaneous sporotrichosis

In this study, we evaluate the clinical, histopathological and ultra structural aspects of the infection by field strain (MEL⁺) and mutated strain (MEL^?) of Sporothrix schenckii. The development of sporotrichosis at the inoculation sites was similar for both groups of animals after the second week of the experimental period. Statistical differences appeared only at weeks 3 and 5. The pigmented isolate had greater tissue invasive capacity, promoting the formation of multifocal granulomas, whereas the albino isolate induced an enhanced inflammatory response, restraining the agent to the core of the granulomas.     

Effects of predation pressure on the feeding behaviour of the serpa tetra Hyphessobrycon eques (Ostariophysi, Characidae)

The indirect, non-lethal results of predation, such as reduction in feeding time or restraint in seeking sexual partners and/or natural resources, have a drastic effect on prey populations. In this study, we investigated the behaviour of two serpa tetras Hyphessobrycon eques groups, one wild and the other born and raised in captivity, to evaluate how their feeding behaviour is affected by the avian predator, the rufescent tiger-heron Trigrisoma lineatum (using a taxidermy specimen). For a total of 133 observation hours, the feeding behaviour of each fish group was observed according to the absence (control) or presence (treatments) of a predator near the aquarium surface. The results showed that the presence of a predator on the surface inhibits the feeding behaviour of H. eques. The differences observed between the groups are probably due to the fishes experiences with predators. Our results suggest that fish-eating birds may affect prey populations in streams and ponds perhaps more through non-lethal effects, on feeding behaviour for example, than directly through death rates.     

Phylogenetic analysis of the alpha-globin pseudogene-4 (Hba-ps4) locus in the house mouse species complex reveals a stepwise evolution of t haplotypes [published erratum appears in Mol Biol Evol 1994 Jan;11(1):158]

A parsimony analysis was performed on restriction sites at the Hba-ps4 pseudogene locus within one of four inversions associated with mouse t haplotypes. The results suggest that all t haplotypes form a monophyletic group and that the in (17)4 inversion originated before the radiation of the Mus musculus species complex but after the divergence of the lineages leading to M. spretus, M. abbotti, and M. hortulanus. A time frame based on the evolutionary rate of mouse pseudogenes places the origin of this t haplotype inversion at 1.5 Mya, or approximately 1.5 Myr after the origin of the more proximal t complex inversion, in (17)2. The accumulated evidence indicates that complete t haplotypes have been assembled in a stepwise manner, with each of these inversions occurring on separate chromosomal lineages and at different evolutionary times. In addition, the evolutionary relationships of pseudogene sequences resulting from genetic exchange between wild-type and t haplotype alleles were examined. Analysis of sequences from the 5' and 3' sides of a putative site of recombination resulted in cladograms with different topologies. The implications for hypotheses concerning the evolutionary forces acting on t haplotypes and their rapid propagation throughout worldwide populations of mice are discussed.      

In vitro susceptibility to 5-fluorocytosine and nystatin of common clinical yeast isolates

The sensitivity to nystatin, 5-fluorocytosine (5-FC) or both was studied for 131 clinical isolates of Candida albicans, 47 of Candida parapsilosis, 34 of Candida tropicalis, 7 of Candida guilliermondii, 28 of Torulopsis glabrata and 1 of Torulopsis Candida.All strains were inhibited by concentrations of nystatin within the usual range of sensitivity except one strain of T. glabrata and another of T. Candida whose minima inhibitory concentrations (MICs) were respectively 250 U/ml and > 20000 U/ml.In respect to 5-FC it was found, after 7 days of incubation at 37 °C, the following frequencies of resistance: C. albicans 28/106 (26%), C. parapsilosis 11/47 (23%), C. tropicalis 24/34 (71%), C. guilliermondii 1/7, T. glabrata 1/28 (4%) and T. candida 0/1. It was particularly striking the activity of 5-FC against T. glabrata.