An Hcp100 gene fragment reveals Histoplasma capsulatum presence in lungs of Tadarida brasiliensis migratory bats.

Histoplasma capsulatum was sampled in lungs from 87 migratory Tadarida brasiliensis bats captured in Mexico (n=66) and Argentina (n=21). The fungus was screened by nested-PCR using a sensitive and specific Hcp100 gene fragment. This molecular marker was detected in 81·6% [95% confidence interval (CI) 73·4-89·7] of all bats, representing 71 amplified bat lung DNA samples. Data showed a T. brasiliensis infection rate of 78·8% (95% CI 68·9-88·7) in bats captured in Mexico and of 90·4% (95% CI 75·2-100) in those captured in Argentina. Similarity with the H. capsulatum sequence of a reference strain (G-217B) was observed in 71 Hcp100 sequences, which supports the fungal findings. Based on the neighbour-joining and maximum parsimony Hcp100 sequence analyses, a high level of similarity was found in most Mexican and all Argentinean bat lung samples. Despite the fact that 81·6% of the infections were molecularly evidenced, only three H. capsulatum isolates were cultured from all samples tested, suggesting a low fungal burden in lung tissues that did not favour fungal isolation. This study also highlighted the importance of using different tools for the understanding of histoplasmosis epidemiology, since it supports the presence of H. capsulatum in T. brasiliensis migratory bats from Mexico and Argentina, thus contributing new evidence to the knowledge of the environmental distribution of this fungus in the Americas.

Pneumocystis diversity as a phylogeographic tool.

Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.

Synthesis of ethyl phenylacetate by lyophilized mycelium of Aspergillus oryzae.

Lyophilized mycelia of Aspergillus oryzae CBS 102.07, Aspergillus oryzae MIM, Rhizopus oryzae CBS 112.07, Rhizopus oryzae CBS 391.34, Rhizopus oryzae CBS 260.28 and Rhizopus oryzae CBS 328.47 were tested in this study to select the best biocatalysts for ethanol acylation with phenylacetic acid. The mycelium-bound carboxylesterase activity of A. oryzae MIM, which exhibited the best performances, was initially investigated at 50 degrees C, either in 0.1 M phosphate buffer or in n-heptane to catalyse the hydrolysis or the synthesis, respectively, of ethyl phenylacetate. The results in terms of product and substrate concentrations versus time were used to estimate the maximum molar conversions at equilibrium, the equilibrium constants, and the times needed to reach half maximum conversions, thus providing sufficient information about this biotransformation. The values of the apparent equilibrium constants, estimated at 20 degrees C

Microarchitecture and innervation of the human latissimus dorsi muscle.

Re-investigation of the adult human latissimus dorsi muscle (HLD) by microdissection of acetylcholinesterase (AChE)-stained material revealed a complicated microstructure of this muscle. Motor endplates distribute over the entire muscle; numerous AChE-stained myomyonal and myotendinous junctions are interspersed. After teasing muscle fascicles from selected representative areas, the following results were obtained. Most of the single muscle fibers constituting the fascicles are shorter than the length of the fascicles. They are linked together by myomyonal junctions or by myotendinous intersections end-to-end, end-to-side, or via muscular crossbridges side-to-side, thus forming chains and nets of varying appearance and length. Additionally, many fiber furcations were found. These observations throw light on the microarchitectural basis of local mass changes of the triangular HLD occurring during its convergence from its wide lumbar and thoracic attachment line to its narrow tendon attached to the humeral crista tuberculi minoris. The microstructural observations also explain why motor endplates spread over the whole muscle, instead of being restricted to a single central endplate-band, as is found in the majority of other muscles. To clarify postnatal development, the topography of endplates in adult muscles was compared with fetal and infantile muscles. Primarily, the endplate bands were clearly demarcated; their width then broadened, and they gradually scattered into groups of single endplates. Simultaneous with these developmental changes, a corresponding branching of the thoracodorsal nerve occurs.

Nitrate and phosphate removal by Spirulina platensis.

The cyanobacterium Spirulina platensis was used to verify the possibility of employing microalgal biomass to reduce the contents of nitrate and phosphate in wastewaters. Batch tests were carried out in 0.5 dm3 Erlenmeyer flasks under conditions of light limitation (40 micromol quanta m(-2) s(-1)) at a starting biomass level of 0.50 g/dm3 and varying temperature in the range 23-40 degrees C. In this way, the best temperature for the growth of this microalga (30 degrees C) was determined and the related thermodynamic parameters were estimated. All removed nitrate was used for biomass growth (biotic removal), whereas phosphate appeared to be removed mainly by chemical precipitation (abiotic removal). The best results in terms of specific and volumetric growth rates (mu=0.044 day(-1), Qx=33.2 mg dm(-3) day(-1)) as well as volumetric rate and final yield of nitrogen removal (Q(N-NO3-)=3.26 mg dm(-3) day(-1), Y(N-NO3-)=0.739) were obtained at 30 degrees C, whereas phosphorus was more effectively removed at a lower temperature. In order to simulate full-scale studies, batch tests of nitrate and phosphate removal were also performed in 5.0 dm3 vessels (mini-ponds) at the optimum temperature (30 degrees C) but increasing the photon fluence rate to 80 micromol quanta m(-2) s(-1) and varying the initial biomass concentration from 0.25 to 0.86 g/dm3. These additional tests demonstrated that an increase in the inoculum level up to 0.75 g/dm3 enhanced both NO3- and PO4(3-) removal, confirming a strict dependence of these processes on biomass activity. In addition, the larger surface area of the ponds and the higher light intensity improved removal yields and kinetics compared to the flasks, particularly concerning phosphorus removal (mu=0.032-0.050 day(-1), Qx=34.7-42.4 mg dm(-3) day(-1), Q(N-NO3-)=3.24-4.06 mg dm(-3) day(-1), Y(N-NO3-)=0.750-0.879, Q(P-PO4(3-))=0.312-0.623 mg dm(-3) day(-1), and Y(P-PO4(3-))=0.224-0.440).

Pneumocystis diversity as a phylogeographic tool

Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.