Penicillium and Talaromyces spp. emerging pathogens in dogs since 1990s.

Penicillium and Talaromyces spp. are environmental saprophytic molds rarely encountered as infectious agents in humans and animals. This article summarizes the clinical features, treatment, and outcomes of proven infections caused by Penicillium or Talaromyces in four dogs in France. Two dogs had disseminated infections, while the other two had a localized form. All dogs had positive histopathological results showing the presence of hyaline septate hyphae and a positive fungal culture with typical Penicillium conidiophores. Talaromyces georgiensis (n = 1), Penicillium labradorum (n = 2), and Penicillium from section Ramosa series Raistrickiorum (n = 1), were identified based on Internal Transcribed Spacer (ITS) Sanger sequencing. The dogs were initially treated with ketoconazole or itraconazole. Second-line treatment was initiated in three dogs, but after several relapses, the prognosis remained poor. Since the 1990s, 18 cases of Penicillium or Talaromyces infections in dogs have been described worldwide. This series of four reports brings new cases to those already reported in the literature, which are probably underestimated in the world.

Penicillium and Talaromyces spp. are molds found in the environment that rarely cause infections in humans and animals. This article summarizes the clinical features and treatment of proven infections caused by Penicillium or Talaromyces species in four dogs in France.

Aggregatibacter aphrophilus chronic lacrimal canaliculitis: a case report.

BACKGROUND: Chronic canaliculitis is often misdiagnosed as conjunctivitis, delaying proper documentation and management. Aggregatibacter aphrophillus has not been implicated in chronic canaliculitis. CASE PRESENTATION: We report a case of unilateral chronic epiphora associated with chronic lacrimal canaliculitis resistant to prolonged topical antibiotic treatment in a 65-year-old woman without notable medical history. Canaculotomy, curettage with removal of concretions and tubing with silicone stent for six weeks resolved this chronic infection. Culturing lacrimal secretions and concretions yielded Aggregatibacter aphrophilus in pure culture. Histological analyses showed elongated seed clusters surrounded by neutrophils. Fluorescence in Situ Hybridization confirmed the presence of bacteria in two distinctive concretions. CONCLUSION: This first documented case of A. aphrophilus chronic lacrimal canaliculitis illustrates that optimal surgical management of chronic lacrimal canaliculitis allows for both accurate microbiological diagnosis and treatment.

Ultrasound-assisted synthesis of mesoporous zirconia-hydroxyapatite nanocomposites and their dual surface affinity for Cr3+/Cr2O7(2-) ions.

Zirconia-hydroxyapatite nanocomposites were prepared by sol-gel deposition of zirconium oxide from a zirconium alkoxide in the presence of apatite colloidal suspension under ultrasonication. The material porosity evolves from mainly microporous zirconia to mesoporous hydroxyapatite, with decreasing surface area and increasing pore volume. XRD studies indicate that the apatite phase is well-preserved within the composite materials. The homogeneous dispersion of apatite colloids within the zirconia network was supported by TEM observations and nitrogen sorption measurements. (31)P solid-state NMR studies suggest that partial dissolution of apatite may have occurred during the preparation, leading to the adsorption of phosphate species on zirconia particles. This is confirmed by XRD studies of nanocomposites after thermal treatment that demonstrate the preferred formation of tetragonal over monoclinic ZrO(2) in the presence of hydroxyapatite. In order to investigate the surface properties of these novel materials, the adsorption of Pb(2+), Cr(3+), and Cr(2)O(7)(2-) was evaluated. Metal cations were preferentially adsorbed on apatite-rich composites, whereas Cr(2)O(7)(2-) shows a good affinity for the zirconia-rich phases. Zirconia-apatite materials showed the most promising performance in terms of recyclability. These nanocomposites that combine microporosity, mesoporosity and dual sorption properties for these species appear as interesting materials for metal ion remediation and may also find applications as biomaterials.

How to design cell-based biosensors using the sol-gel process.

Inorganic gels formed using the sol-gel process are promising hosts for the encapsulation of living organisms and the design of cell-based biosensors. However, the possibility to use the biological activity of entrapped cells as a biological signal requires a good understanding and careful control of the chemical and physical conditions in which the organisms are placed before, during, and after gel formation, and their impact on cell viability. Moreover, it is important to examine the possible transduction methods that are compatible with sol-gel encapsulated cells. Through an updated presentation of the current knowledge in this field and based on selected examples, this review shows how it has been possible to convert a chemical technology initially developed for the glass industry into a biotechnological tool, with current limitations and promising specificities.

Risk of Chlamydia abortus transmission via embryo transfer using in vitro produced early bovine embryos.

The objectives of this study were to determine (i) whether Chlamydia (C.) abortus would adhere to the intact zona pellucida (ZP-intact) of early in vitro produced bovine embryos; (ii) whether the bacteria would adhere to the embryos (ZP-free) after in vitro infection; and (iii) the efficacy of the International Embryo Transfer Society (IETS) washing protocol. The experimentation was made twice. For each replicate 100 (8-16-cell) bovine embryos produced in vitro were randomly divided into 10 batches. Height batches (4 ZP-intact and 4 ZP-free) of 10 embryos were incubated in a medium containing 4 × 107Chlamydia/ml of AB7 strain. After incubation for 18 h at 37 °C in an atmosphere of 5% CO2, the embryos were washed in accordance with the IETS guidelines. In parallel, two batches (1 ZP-intact and 1 ZP-free) of 10 embryos were subjected to similar procedures but without exposure to C. abortus as a control group. The 10 washing fluids from each batch were collected and centrifuged for 1 h at 13,000×g. Each batch of washed embryos and each wash pellets were tested using PCR. C. abortus DNA was found in all ZP-intact and ZP-free batches of 10 embryos after 10 successive washes. For ZP-intact infected embryos, Chlamydia-DNA was also detected in all 10 wash baths for two batches (2/8) of embryos, whereas for ZP-free infected embryos, Chlamydia-DNA was detected in all 10 wash baths for 6/8 batches of embryos. In contrast, none of the embryos or their washing fluids in the control batches was DNA positive. The bacterial load for batches of 10 embryos after the 10 wash baths was significantly higher for batches of ZP-free embryos (20.7 ±â€¯9 × 103 bacteria/mL) than for batches of ZP-intact embryos (0.47 ±â€¯0.19 × 103 bacteria/mL). These results demonstrate that C. abortus adheres to the ZP as well as the early embryonic cells of in vitro produced bovine embryos after in vitro infection, and that the standard washing protocol recommended by the IETS fails to remove it.

Biomimetic dual templating of silica by polysaccharide/protein assemblies.

The control of silica growth by living organisms such as diatoms is known to involve the templating effect of several biomolecules working concomitantly. However, until now, biomimetic studies involving model molecules have mainly been performed with single templates. We show here that the addition of two biopolymers, gelatin and alginic acid, to silicate solutions allows the formation of complex structures resulting from the combined templating effect of both components at different scales. Gelatin is able to activate silica formation resulting in hybrid aggregates at the nanoscale. Alginic acid does not interfere with silica condensation but is able to control silica morphology through the assembly of these gelatin-silica aggregates at the microscale. For all materials, calcination up to 700 degrees C degrades the polymer component of the hybrid material and opens macroporosity in the silica network. In parallel, the high thermal stability of gelatin allows a good preservation of initial silica nanoparticle size upon heating whereas a coarsening process is observed in the sole presence of alginate. These results correlate well with previous models of biosilicification and suggest that the use of multiple templates is a suitable approach to elaborate more complex silica architectures.

Sol-gel encapsulation of cells is not limited to silica: long-term viability of bacteria in alumina matrices.

A colloidal route to aqueous alumina gels is described, allowing the long-term viability of encapsulated bacteria.

Assembly of a polyoxometalate into an anisotropic gel.

The self-assembly of the polyoxomolybdate [MnMo6O18[(OCH2)3CNHCO(4-C5H4N)]2]3- and [PdCl2(PhCN)2] yields a transparent and birefringent gel.

Ligand-Driven Light-Induced Spin Change in Transition-Metal Complexes: Selection of an Appropriate System and First Evidence of the Effect, in Fe(II)(4-styrylpyridine)(4)(NCBPh(3))(2).

The first observation of a ligand-driven light-induced spin-state change (LD-LISC effect) in a transition-metal complex is reported. The compounds under investigation are of the type Fe(II)L(4)X(2), where L is a cis/trans photoisomerizable ligand. For an iron(II) spin-state change to result from ligand cis <--> trans conversion, the Fe(II)(trans-L)(4)X(2) species had to exhibit a thermally-induced high-spin state <--> low-spin state crossover. This property was checked by variable-temperature magnetic susceptibility measurements, for compounds with X(-) = NCBPh(3)(-) or NCBH(3)(-) and L = 1-phenyl-2-(4-pyridyl)ethene (or 4-styrylpyridine, abbreviated as Stpy), 1-(4-R-phenyl)-2-(4-pyridyl)ethene (R = CH(3), COOCH(3)), or 1-(1-naphthyl)-2-(4-pyridyl)ethene. The results are comparatively discussed. The best candidate for the LD-LISC effect to be observed is found to be Fe(Stpy)(4)(NCBPh(3))(2): the complex (C(t)) formed with trans-Stpy undergoes a thermally-induced spin crossover centered around 190 K; the one (C(c)) formed with cis-Stpy retains the high-spin state at any temperature. Photoisomerization of the Stpy ligand, at 140 K, in the complex embedded within a cellulose acetate matrix, is effectively shown, on the basis of UV-vis absorption measurements, to trigger the spin-state change of the iron(II) ions.

Living bacteria in silica gels.

The encapsulation of enzymes within silica gels has been extensively studied during the past decade for the design of biosensors and bioreactors. Yeast spores and bacteria have also been recently immobilized within silica gels where they retain their enzymatic activity, but the problem of the long-term viability of whole cells in an inorganic matrix has never been fully addressed. It is a real challenge for the development of sol-gel processes. Generic tests have been performed to check the viability of Escherichia coli bacteria in silica gels. Surprisingly, more bacteria remain culturable in the gel than in an aqueous suspension. The metabolic activity of the bacteria towards glycolysis decreases slowly, but half of the bacteria are still viable after one month. When confined within a mineral environment, bacteria do not form colonies. The exchange of chemical signals between isolated bacteria rather than aggregates can then be studied, a point that could be very important for 'quorum sensing'.