Glycerol amendment enhances biosulfidogenesis in acid mine drainage-affected areas: An incubation column experiment.

Microbial sulfate (SO4 2-) reduction in Acid Mine Drainage (AMD) environments can ameliorate the acidity and extreme metal concentrations by consumption of protons via the reduction of SO4 2- to hydrogen sulfide (H2S) and the concomitant precipitation of metals as metal sulfides. The activity of sulfate-reducing bacteria can be stimulated by the amendment of suitable organic carbon sources in these generally oligotrophic environments. Here, we used incubation columns (IC) as model systems to investigate the effect of glycerol amendment on the microbial community composition and its effect on the geochemistry of sediment and waters in AMD environments. The ICs were built with natural water and sediments from four distinct AMD-affected sites with different nutrient regimes: the oligotrophic Filón Centro and Guadiana acidic pit lakes, the Tintillo river (Huelva, Spain) and the eutrophic Brunita pit lake (Murcia, Spain). Physicochemical parameters were monitored during 18 months, and the microbial community composition was determined at the end of incubation through 16S rRNA gene amplicon sequencing. SEM-EDX analysis of sediments and suspended particulate matter was performed to investigate the microbially-induced mineral (neo)formation. Glycerol amendment strongly triggered biosulfidogenesis in all ICs, with pH increase and metal sulfide formation, but the effect was much more pronounced in the ICs from oligotrophic systems. Analysis of the microbial community composition at the end of the incubations showed that the SRB Desulfosporosinus was among the dominant taxa observed in all sulfidogenic columns, whereas the SRB Desulfurispora, Desulfovibrio and Acididesulfobacillus appeared to be more site-specific. Formation of Fe3+ and Al3+ (oxy)hydroxysulfates was observed during the initial phase of incubation together with increasing pH while formation of metal sulfides (predominantly, Zn, Fe and Cu sulfides) was observed after 1-5 months of incubation. Chemical analysis of the aqueous phase at the end of incubation showed almost complete removal of dissolved metals (Cu, Zn, Cd) in the amended ICs, while Fe and SO4 2- increased towards the water-sediment interface, likely as a result of the reductive dissolution of Fe(III) minerals enhanced by Fe-reducing bacteria. The combined geochemical and microbiological analyses further establish the link between biosulfidogenesis and natural attenuation through metal sulfide formation and proton consumption.

Bilateral enucleation due to multi-bacterial fulminant endogenous panophthalmitis. / Enucleación bilateral por panoftalmitis endógena polimicrobiana fulminante.

The case is presented of a 62 year-old woman with a rapid, progressive bilateral decrease in visual acuity and panuveitis with orbital cellulitis. She was also in poor general condition, with emesis and fever. Septicaemia due to Klebsiella pneumoniae and bilateral endogenous panophthalmitis were diagnosed. The ocular infection quickly progressed to sclerokeratitis and bilateral perforation despite broad spectrum systemic antibiotic management, and eventually the patient required bilateral enucleation. Microbiological cultures of the surgical pieces identified Klebsiella pneumoniae and Candida magnoliae. To our knowledge, this is the third published case that required bilateral enucleation or evisceration due to endogenous panophthalmitis, and the first case of endogenous ocular infection caused by Candida magnoliae.

Malignant transformation of a conjunctival keratoacanthoma requiring enucleation.

PURPOSE: We report a rare case of rapid transformation of a conjunctival keratoacanthoma (KA) into a highly aggressive squamous cell carcinoma requiring enucleation. To our knowledge, this is the second such case reported in the literature. METHODS: Case report. RESULTS: A 73-year-old man presented with a recurrent conjunctival lesion in the right eye. A slit lamp examination revealed a hyperkeratotic lesion in the limbar conjunctiva adhered to deep planes but with no ocular involvement. An incisional biopsy was performed because an area of scleromalacia was observed underlying the lesion. Histological findings were consistent with conjunctival KA. One week later, a raised lesion was observed invading the anterior chamber. Histological examination of another excisional biopsy specimen indicated conjunctival squamous cell carcinoma. The right eye was enucleated. Histological analysis confirmed intraocular tumor invasion. Complete clinical remission was observed over one year of follow up. CONCLUSIONS: Although conjunctival keratoacanthoma is normally benign, it is important to correctly differentiate between KA and squamous cell carcinoma, and closely monitor the eye after surgery because of the rare possibility of recurrence or conversion to squamous cell carcinoma. Immunohistochemistry could help in the diagnosis and management of dubious cases.

Resolution of conjunctival melanoma with topical interferon alpha 2b in a patient with mitomycin C intolerance. / Resolución de un melanoma conjuntival con interferón tópico alfa 2b en un paciente con intolerancia a la mitomicina C.

OBJECTIVE: To describe the clinical and histological resolution of a case of an inexcisable conjunctival melanoma using topical interferon alpha 2b (INFα2b) in a patient with mitomycin C (MMC) intolerance. CASE REPORT: Conjunctival melanoma is a rare, but potentially sight- and life-threatening, tumour. In cases of multiple lesions, or when surgical excision is not possible, topical combination chemotherapy with MMC and INFα2b has been described as first line therapy. The case is presented of a 77 year-old woman with a multifocal conjunctival in situ melanoma, who was intolerant to initial treatment with MMC and was switched to long-term INFα2b therapy, with a good outcome. CONCLUSIONS: When topical MMC is given as chemotherapy treatment for primary acquired melanosis with atypia or in situ melanoma is not well tolerated, switching to INFα2b seems to be a good option. This approach could replace surgical management of pigmented tumours, especially the larger ones, with potential benefits that include less dependence on surgical margins. This report prompts a need for prospective studies designed to examine the role of INFα2b as primary treatment for heavily pigmented conjunctival tumours avoiding the ocular surface toxicity caused by MMC.

Microbially mediated aluminosilicate formation in acidic anaerobic environments: A cell-scale chemical perspective.

Through the use of scanning transmission electron microscopy (STEM) combined with other complementary techniques (SEM, cryo-TEM, HRTEM, and EELS), we have studied the interaction of microorganisms inhabiting deep anoxic waters of acidic pit lakes with dissolved aluminum, silica, sulfate, and ferrous iron. These elements were close to saturation (Al, SiO2 ) or present at very high concentrations (0.12 m Fe(II), 0.12-0.22 m SO42- ) in the studied systems. The anaerobic conditions of these environments allowed investigation of geomicrobial interactions that are difficult to see in oxidized, Fe(III)-rich environments. Detailed chemical maps and through-cell line scans suggest both extra- and intracellular accumulation of Al, Si, S, and Fe(II) in rod-like cells and other structures (e.g., spherical particles and bacteriomorphs) of probable microbial origin. The bacterial rods showed external nanometric coatings of adsorbed Fe(II) and Al on the cell surface and cell interiors with significant presence of Al, Si, and S. These microbial cells coexist with spherical particles showing similar configuration (Fe(II) external coatings and [Al, Si, S]-rich cores). The Al:Si and Al:S ratios and the good Al-Si correlation in the cell interiors suggest the concurrent formation of two amorphous phases, namely a proto-aluminosilicate with imogolite-like composition and proto-hydrobasaluminite. In both cases, the mineralization appears to comprise two stages: a first stage of aluminosilicate and Al-hydroxysulfate precipitation within the cell or around cellular exudates, and a second stage of SO42- and Fe(II) adsorption on surface sites existing on the mineral phases in the case of (SO42- ) or on presumed organic molecules [in the case of Fe(II)]. These microbially related solids could have been formed by permineralization and mineral replacement of senescent microbial cells. However, these features could also denote biomineralization by active bacterial cells as a detoxification mechanism, a possibility which should be further explored. We discuss the significance of the observed Al/microbe and Si/microbe interactions and the implications for clay mineral formation at low pH.

Keratitis secondary to Fusarium spp. in Spain 2012-2014. / Queratitis secundaria a Fusarium spp. en España 2012-2014.

OBJECTIVE: To describe the clinical-epidemiological characteristics of a case series of fungal keratitis associated with Fusarium spp.., in Spain during the years 2012 to 2014. METHODS: A retrospective study of a case series was conducted on a systematic random sample of 10% of patients identified in Health Centres of provincial capitals (n=250). The centres were asked whether they had been presented with cases of Fusarium spp. keratitis characterised by microbiological methods. Of the 23 centres that responded, 14 had detected cases, with 13 of them accepting to participate, and 11 of them completing the study. The latter being sent a previously validated questionnaire. The variables analysed were: age, gender, habitual residence, profession, disease and medical history (previous systemic and ocular diseases, previous eye surgeries), and their outcomes. RESULTS: The response rate was 92%, identifying 23 cases of Fusarium spp.. of which 21 (91.3%) of them lived in urban areas. The professions most affected by the disease included chefs, administrative, and technical, with 13 cases (56.5%). The treatment guidelines established to confirm the infection showed the combined use of topical antibiotics associated with antiviral and/or antifungal agents. The use of contact lenses (86.9%) was the main risk factor. DISCUSSION: This study showed that this is a rare disease in Spain, but that a large percentage of people who present with the disease are resident in urban areas, and they work in closed environments, focusing attention on microtraumas caused by use of contact lenses.

[Development of a PCR for the detection and quantification of parasitism by Demodex folliculorum infestation in biopsies of skin neoplasms periocular area]. / Desarrollo de una PCR para la detección y cuantificación de la parasitación por Demodex folliculorum en biopsias de neoplasias cutáneas del área periocula.

OBJECTIVE: To standardize the relative quantification by mass of tissue parasitism by Demodex folliculorum infestation from neoplastic skin biopsies periocular using molecular amplification to study the possible relationship of the appearance of eyelid basal cell carcinoma with the presence and density of the mite in later works. METHODS: A quantitative PCR was developed real-time probes TaqMan. PCR was tested in a pilot 46 actual biopsy samples nodular basal cell carcinoma series. RESULTS: The sensitivity was placed with a detection limit of between 1 and 10 copies / µl. 50% (23/46) of the biopsies were positive for D. folliculorum. The specificity was 100% confirmed by sequencing. CONCLUSIONS: The technique shows good results for sensitivity and specificity that can make it useful as a tool for studies of cause and effect D. folliculorum and basal cell carcinoma.