Co-existence of physiologically similar sulfate-reducing bacteria in a full-scale sulfidogenic bioreactor fed with a single organic electron donor

A combination of culture-dependent and independent methods was used to study the co-existence of different sulfate-reducing bacteria (SRB) in an upflow anaerobic sludge bed reactor treating sulfate-rich wastewater. The wastewater was fed with ethanol as an external electron donor. Twenty six strains of SRB were randomly picked and isolated from the highest serial dilution that showed growth (i.e. 108). Repetitive enterobacterial palindromic polymerase chain reaction and whole cell protein profiling revealed a low genetic diversity, with only two genotypes among the 26 strains obtained in the pure culture. The low genetic diversity suggests the absence of micro-niches within the reactor, which might be due to a low spatial and temporal micro-heterogeneity. The total 16S rDNA sequencing of two representative strains L3 and L7 indicated a close relatedness to the genus Desulfovibrio. The two strains differed in as many as five physiological traits, which might allow them to occupy distinct niches and thus co-exist within the same habitat. Whole cell hybridisation with fluorescently labeled oligonucleotide probes was performed to characterise the SRB community in the reactor. The isolated strains Desulfovibrio L3 and Desulfovibrio L7 were the most dominant SRB, representing 30–35% and 25–35%, respectively, of the total SRB community. Desulfobulbus-like bacteria contributed for 20–25%, and the Desulfobacca acetoxidans-specific probe targeted approximately 15–20% of the total SRB. The whole cell hybridisation results thus revealed a consortium of four different species of SRB that can be enriched and maintained on a single energy source in a full-scale sulfidogenic reactor

Linezolid Compared with Eperezolid, Vancomycin, and Gentamicin in an In Vitro Model of Antimicrobial Lock Therapy for Staphylococcus epidermidis Central Venous Catheter-Related Biofilm Infections

Central venous catheter (CVC)-related infection (CVC-RI) is a common complication of CVC use. The most common etiological agents of CVC-RI are gram-positive organisms, in particular, staphylococci. An in vitro model for the formation of biofilms by Staphylococcus epidermidis ATCC 35984 on polyurethane coupons in a modified Robbins device was established. Biofilm formation was confirmed by electron microscopy and was quantified by determination of viable counts. Mueller-Hinton broth was replaced with sterile physiological saline (control) or a solution of vancomycin (10 mg/ml), gentamicin (10 mg/ml), linezolid (2 mg/ml), or eperezolid (4 mg/ml). Viable counts were performed with the coupons after exposure to antimicrobials for periods of 24, 72, 168, and 240 h. The mean viable count per coupon following establishment of the biofilm was 4.6 × 10(8) CFU/coupon, and that after 14 days of exposure to physiological saline was 2.5 × 10(7) CFU/coupon. On exposure to vancomycin (10 mg/ml), the mean counts were 2.5 × 10(7) CFU/coupon at 24 h, 4.3 × 10(6) CFU/coupon at 72 h, 1.4 × 10(5) CFU/coupon at 168 h, and undetectable at 240 h. With gentamicin (10 mg/ml) the mean counts were 2.7 × 10(7) CFU/coupon at 24 h, 3.7 × 10(6) CFU/coupon at 72 h, 8.4 × 10(6) CFU/coupon at 168 h, and 6.5 × 10(6) CFU/coupon at 240 h. With linezolid at 2 mg/ml the mean counts were 7.1 × 10(5) CFU/coupon at 24 h and not detectable at 72, 168, and 240 h. With eperezolid (4 mg/ml) no viable cells were recovered after 168 h. These data suggest that linezolid (2 mg/ml) and eperezolid (4 mg/ml) achieve eradication of S. epidermidis biofilms more rapidly than vancomycin (10 mg/ml) and gentamicin (10 mg/ml)

Divergence of intracellular and extracellular HSP72 in type 2 diabetes: does fat matter?

Mammalian cells have developed a range of adaptations to survive against acute and prolonged (but not lethal) stresses (Beckmann et al. 1992). Among these adaptations, the heat shock response is the most conserved, being found in all prokaryotes and eukaryotes (Locke and Noble 1995). Heat shock proteins (HSPs) are considered part of a family of proteins known as "stress proteins" since their expression is induced by a wide range of stressors, such as oxidative stress (Krause et al. 2007), thermal stress (Yang et al. 1996), ischaemia (Richard et al. 1996), exercise (Krause et al. 2007), metabolic stress (Beckmann et al. 1992) and many others. The genes encoding Hsps are highly conserved, and many of these genes and their protein products can be assigned to different families on the basis of their typical molecular weight (kDa): HSP110 (or officially named HSPH), HSP90 (or HSPC), HSP70 (or HSPA), HSP60 (or HSPD1), HSP40 (or DNAJ) and small hsp families (HSPB) (Kampinga et al. 2009). In eukaryotes, many families comprise multiple members that differ in inducibility, intracellular localization and function (Feder and Hofmann 1999)

Vagus nerve stimulation in refractory idiopathic generalised epilepsy: an Irish retrospective observational study

Objective: Refractory idiopathic generalised epilepsy (IGE; also known as genetic generalised epilepsy) is a clinical challenge due to limited available therapeutic options. While vagus nerve stimulation (VNS) is approved as an adjunctive treatment for drug-resistant focal epilepsy, there is limited evidence supporting its efficacy for refractory IGE. Methods: We conducted a single-centre retrospective analysis of adult IGE patients treated with VNS between January 2003 and January 2022. We analysed the efficacy, safety, tolerability, stimulation parameters and potential clinical features of VNS response in this IGE cohort. Results: Twenty-three IGE patients were implanted with VNS between January 2003 and January 2022. Twenty-two patients (95.65%) were female. The median baseline seizure frequency was 30 per month (interquartile range [IQR]= 140), including generalised tonic-clonic seizures (GTCS), absences, myoclonus, and eyelid myoclonia with/without absences. The median number of baseline anti-seizure medications (ASM) was three (IQR= 2). Patients had previously failed a median of six ASM (IQR= 5). At the end of the study period, VNS therapy remained active in 17 patients (73.9%). amongst patients who continued VNS, thirteen (56.5% of the overall cohort) were considered responders (≥50% seizure frequency reduction). Amongst the clinical variables analysed, only psychiatric comorbidity correlated with poorer seizure outcomes, but was non-significant after applying the Bonferroni correction. Although 16 patients reported side-effects, none resulted in the discontinuation of VNS therapy. Significance: Over half of the patients with refractory IGE experienced a positive response to VNS therapy. VNS represents a viable treatment option for patients with refractory IGE, particularly for females, when other therapeutic options have been exhausted.</p