Mycological flora of cigarettes

Hundred strains of fungi were isolated from 48 packets of Greek cigarettes. They were:Aspergillus (28 strains),Penicillium (22),Mucor (18),Alternaria (14),Cladosporium (1),Streptomyces (4),Candida (11) andGeotrichum (2). From 55 packets of cigarettes manufactured outside of Greece other 100 strains of fungi were isolated and identified asAspergillus (35),Penicillium (23),Mucor (10),Alternaria (13),Cladosporium (5),Streptomyces (4),Candida (3),Geotrichum (1),Cephalosporium (2) andScopulariopsis (4).Results of the present study are discussed in relation to the mycological flora of the air in Athens and to the coli-aerogenes bacteria of cigarettes.

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Résumé Les auteurs ont isolé 100 souches de champignons à partir de 48 paquets de cigarettes préparées en Grèce. Ces souches étaient identifiées commeAspergillus (28 souches),Penicillium (22),Mucor (18),Alternaria (14),Cladosporium (1),Streptomyces (4),Candida (11) etGeotrichum (2). D'autre part on a isolé 100 souches de champignons à partir de 55 paquets de cigarettes préparées à l'étranger (surtout aux Etats-Unis et en Angleterre). Ces souches étaientAspergillus (35),Penicillium (23),Mucor (10),Alternaria (13),Cladosporium (5),Streptomyces (4),Candida (3),Geotrichum (1),Cephalosporium (2) etScopulariopsis (4).Les résultats sont discutés en relation avec la flore mycosique de l'air à Athènes et les bactéries coliformes rétrouvées dans les cigarettes préparées en Grèce.

     

Evaluation of double formalin--Lugol's fixation in assessing number and biomass of ciliates: an example of estimations at mesoscale in NE Atlantic

Ciliated protozoa are potential grazers of primary and bacterial production and act as intermediaries between picoplankton and copepods and other large suspension feeders. Accurate determination of ciliate abundance and feeding mode is crucial in oceanic carbon budget estimations. However, the impact of different fixatives on the abundance and cell volume of ciliates has been investigated in only a few studies using either laboratory cultures or natural populations. Lugol's solution and formalin are the most commonly used fixatives for the preservation of ciliates samples. In the present study, the aim was to compare 0.4% Lugol's solution and 2% borated-formalin fixation and evaluate the need of counting duplicate samples each using a different fixative. For this, a large number of samples (n = 110) from the NE Atlantic was analyzed in the frame of POMME program (Multidisciplinary Mesoscale Ocean Program). We established a statistically significant relationship (p < 0.0001) between Lugol's and formalin fixed samples for both abundance (r2 = 0.50) and biomass (r2 = 0.76) of aloricate ciliates which showed that counts were higher in Lugol's solution by a factor of 2 and a non-taxon specific cell-loss in formalin. However, loricate ciliate abundance in our samples which were represented primarily by Tintinnus spp. did not show any difference between the two treatments. Abundance and biomass of mixotrophic ciliates (chloroplast-bearing cells) were for various reasons underestimated in both treatments. Our results show that unique fixation by formalin may severely underestimate ciliates abundance and biomass although their population may not alter. For this reason, Lugol's solution is best for the estimation of their abundance and biomass. However, for counts of mixotrophs and the evaluation of the ecological role of ciliates in carbon flux, double fixation is essential. Compromises regarding the fixatives have lead to severe underestimations of mixotrophs in studies conducted by now.     

Performance of rabbits and oxidative stability of muscle tissues as affected by dietary supplementation with oregano essential oil

The effect of dietary supplementation with oregano essential oil on the performance of rabbits, and the susceptibility of the produced raw and thermally treated muscle tissue to lipid oxidation during refrigerated storage, were investigated. A total of 96 weaned rabbits were separated into four equal groups with three subgroups each. One group was given the basal diet and served as control, two groups were administered diets supplemented with oregano essential oil at levels of 100 and 200 mg/kg diet, whereas the remaining group was given a diet supplemented with alpha-tocopheryl acetate at 200 mg/kg. During the 42-day experimental period, body weight and feed intake were recorded weekly and the feed conversion ratio was calculated. Feeding the experimental diets to rabbits, performance parameters were not affected. Therefore, dietary oregano essential oil exerted no growth-promoting effect on rabbits. With increased supplementation of oregano essential oil, malondialdehyde values decreased in both raw and thermally treated muscles during refrigerated storage. This finding suggests that dietary oregano essential oil exerted a significant antioxidant effect. Dietary supplementation of oregano essential oil at the level of 200 mg/kg was more effective in delaying lipid oxidation compared with the level of 100 mg/kg, but inferior to dietary supplementation of 200 mg alpha-tocopheryl acetate per kg. This study indirectly provides evidence that antioxidant compounds occurring in oregano essential oil were absorbed by the rabbit and increased the antioxidative capacity of tissues.     

The importance of small-sized copepods in a frontal area of the Aegean Sea

Distribution, production and grazing of the copepod communitywere investigated in the northern Aegean Sea, which is characterizedby a permanent thermohaline front. Cruises were conducted alonga transect crossing the frontal area during spring and latesummer. Biomass and production of autotrophs were measured bysize fractionation and heterotrophic nanoflagellates and ciliateswere also studied. Copepod biomass, production and grazing impacton the phytoplankton and ciliate populations were estimated.The copepod community was sampled with a 45 µm net toinclude the smallest species and their developmental stages.The size, structure and distribution of the phytoplankton implythat most carbon was fixed by picoplankton during both seasonsand throughout the study area. The partitioning of carbon amongthe different plankton compartments was not a broad-based pyramidand the biomass of heterotrophs was higher than that of autotrophs,except in the non-frontal region during spring. Copepod biomasswas substantially higher in the frontal area. Our results showedthat the small-sized copepods (calanoids and cyclopoids) dominatedin terms of biomass and production, but also had a greater influenceon the efficiency of the trophic coupling between the primaryproducers and the protozooplankton than the larger species,stressing their importance in the northern Aegean Sea and theEastern Mediterranean in general.     

The effect of inorganic particle concentration on bacteria-virus-nanoflagellate dynamics

The effect of inorganic particle concentrations on bacteria-virus-nanoflagellate dynamics in an oligotrophic coastal system was investigated using a model aluminosilicate, kaolinite, with a modal size of 2.1 μm. Virus-only, bacteria-only and bacteria-virus-nanoflagellate incubations were carried out at increasing kaolinite concentrations to elucidate the microbial response. The sorption of bacteria and viruses to kaolinite particles was negligible over a concentration range of 1-50 mg l(-1). In contrast, the abundance of heterotrophic nanoflagellates was negatively correlated with kaolinite concentrations following both 48 and 96 h incubations. Calculated nanoflagellate bacterial ingestion rates were reduced by 5-35% depending on kaolinite particle concentration. In the bacteria-virus-nanoflagellate incubations viral production increased by 56 × 10(3) to 104 × 10(3) VLPs ml(-1) h(-1) as a function of kaolinite particle concentration. Our results demonstrate for the first time that the interaction of microbial populations with inorganic particles can shift the balance between protist and virally mediated mortality of marine heterotrophic prokaryotes.     

Synonymous mutations in the core gene are linked to unusual serological profile in hepatitis C virus infection

The biological role of the protein encoded by the alternative open reading frame (core+1/ARF) of the Hepatitis C virus (HCV) genome remains elusive, as does the significance of the production of corresponding antibodies in HCV infection. We investigated the prevalence of anti-core and anti-core+1/ARFP antibodies in HCV-positive blood donors from Cambodia, using peptide and recombinant protein-based ELISAs. We detected unusual serological profiles in 3 out of 58 HCV positive plasma of genotype 1a. These patients were negative for anti-core antibodies by commercial and peptide-based assays using C-terminal fragments of core but reacted by Western Blot with full-length core protein. All three patients had high levels of anti-core+1/ARFP antibodies. Cloning of the cDNA that corresponds to the core-coding region from these sera resulted in the expression of both core and core+1/ARFP in mammalian cells. The core protein exhibited high amino-acid homology with a consensus HCV1a sequence. However, 10 identical synonymous mutations were found, and 7 were located in the aa(99-124) region of core. All mutations concerned the third base of a codon, and 5/10 represented a T>C mutation. Prediction analyses of the RNA secondary structure revealed conformational changes within the stem-loop region that contains the core+1/ARFP internal AUG initiator at position 85/87. Using the luciferase tagging approach, we showed that core+1/ARFP expression is more efficient from such a sequence than from the prototype HCV1a RNA. We provide additional evidence of the existence of core+1/ARFP in vivo and new data concerning expression of HCV core protein. We show that HCV patients who do not produce normal anti-core antibodies have unusually high levels of anti-core+1/ARFP and harbour several identical synonymous mutations in the core and core+1/ARFP coding region that result in major changes in predicted RNA structure. Such HCV variants may favour core+1/ARFP production during HCV infection.     

Shifts in bacterial community composition associated with increased carbon cycling in a mosaic of phytoplankton blooms

Marine microbes have a pivotal role in the marine biogeochemical cycle of carbon, because they regulate the turnover of dissolved organic matter (DOM), one of the largest carbon reservoirs on Earth. Microbial communities and DOM are both highly diverse components of the ocean system, yet the role of microbial diversity for carbon processing remains thus far poorly understood. We report here results from an exploration of a mosaic of phytoplankton blooms induced by large-scale natural iron fertilization in the Southern Ocean. We show that in this unique ecosystem where concentrations of DOM are lowest in the global ocean, a patchwork of blooms is associated with diverse and distinct bacterial communities. By using on-board continuous cultures, we identify preferences in the degradation of DOM of different reactivity for taxa associated with contrasting blooms. We used the spatial and temporal variability provided by this natural laboratory to demonstrate that the magnitude of bacterial production is linked to the extent of compositional changes. Our results suggest that partitioning of the DOM resource could be a mechanism that structures bacterial communities with a positive feedback on carbon cycling. Our study, focused on bacterial carbon processing, highlights the potential role of diversity as a driving force for the cycling of biogeochemical elements.     

Frequent genes in rare diseases: panel‐based next generation sequencing to disclose causal mutations in hereditary neuropathies

Hereditary neuropathies comprise a wide variety of chronic diseases associated to more than 80 genes identified to date. We herein examined 612 index patients with either a Charcot‐Marie‐Tooth phenotype, hereditary sensory neuropathy, familial amyloid neuropathy, or small fiber neuropathy using a customized multigene panel based on the next generation sequencing technique. In 121 cases (19.8%), we identified at least one putative pathogenic mutation. Of these, 54.4% showed an autosomal dominant, 33.9% an autosomal recessive, and 11.6% an X‐linked inheritance. The most frequently affected genes were PMP22 (16.4%), GJB1 (10.7%), MPZ, and SH3TC2 (both 9.9%), and MFN2 (8.3%). We further detected likely or known pathogenic variants in HINT1, HSPB1, NEFL, PRX, IGHMBP2, NDRG1, TTR, EGR2, FIG4, GDAP1, LMNA, LRSAM1, POLG, TRPV4, AARS, BIC2, DHTKD1, FGD4, HK1, INF2, KIF5A, PDK3, REEP1, SBF1, SBF2, SCN9A, and SPTLC2 with a declining frequency. Thirty‐four novel variants were considered likely pathogenic not having previously been described in association with any disorder in the literature. In one patient, two homozygous mutations in HK1 were detected in the multigene panel, but not by whole exome sequencing. A novel missense mutation in KIF5A was considered pathogenic because of the highly compatible phenotype. In one patient, the plasma sphingolipid profile could functionally prove the pathogenicity of a mutation in SPTLC2. One pathogenic mutation in MPZ was identified after being previously missed by Sanger sequencing. We conclude that panel based next generation sequencing is a useful, time‐ and cost‐effective approach to assist clinicians in identifying the correct diagnosis and enable causative treatment considerations.

     

Do Botanical Pesticides Alter the Structure of the Soil Microbial Community?

The effects of synthetic pesticides on the soil microbial community have been thoroughly investigated in the past mostly by culture-dependent methods and only few recent studies have used culture-independent approaches for this purpose. However, it should be noted that most of these studies have been conducted in microcosms where the soil microbial community is exposed to unrealistic concentrations of the pesticides, providing an unrealistic exposure scheme for soil microorganism. On the other hand, little is known regarding the potential impact of botanical pesticides on the soil microbial community. Therefore, a laboratory study and a field study were conducted to investigate the effects of synthetic (metham sodium [MS], sodium tetrathiocarbonate [SoTe], and fosthiazate) and botanical pesticides (azadirachtin, quillaja, and pulverized Melia azedarach fruits [PMF]) on the soil microbial community using phospholipid fatty acids (PLFA) analysis. Principal component analysis (PCA) on the results of the laboratory study indicated that the application of PMF resulted in significant changes in the soil microbial community. This was obvious by the proportional increase in the abundance of fatty acids 18:1ω9cis, 18:1ω9trans, which are common in gram-negative bacteria and saprotrophic fungi, and 18:2ω6,9, which is a fungal indicator. This response was attributed to the release of copious amounts of organic carbon and nutrients in the soil by the PMF. On the other hand, MS inhibited fungi and gram-negative bacteria, while fosthiazate and the botanical pesticides quillaja and azadirachtin did not impose significant changes in the soil microbial community. Similar results were obtained by the field study where application of the fumigants MS and SoTe significantly altered the structure of the soil microbial community with the former having a more prominent effect. Fosthiazate imposed mild changes in the soil microbial community, whereas quillaja and azadirachtin again did not show a significant effect. Overall, botanical pesticides, at their recommended dose, did not alter the structure of the soil microbial community compared to synthetic nonfumigant and fumigant pesticides which induced significant changes.