COMPARISON OF LABORATORY AND INDUSTRIAL SACCHAROMYCES CEREVISIAE STRAINS FOR THEIR INHIBITOR RESISTANCE AND XYLOSE UTILIZATION

There are various kinds of stresses during the process of ethanol fermentation and more inhibitory factors are produced when lignocelluloses hydrolysate is used as the substrate. The pretreatment of lignocelluloses biomass before fermentation causes the increase in the amount of acids and thus the decrease in pH. Low-molecular weight aliphatic acids, furaldehydes and a broad range of aromatic compounds are produced during the pretreatment process. They are the inhibitors for the ethanol producers, such as Saccharomyces cerevisiae. Furthermore, besides glucose, lignocellulose hydrolysate contains other sugars, such as xylose, arabinose, galactose and mannose etc., among which xylose is taking the major proportion. Stress tolerance and xylose utilization are therefore essential for Saccharomyces cerevisiae strains to get high-efficiency fermentation and high-yield ethanol production. In this study, a few laboratory and industrial Saccharomyces cerevisiae strains were selected for the evaluation of their potentials in pH tolerance, inhibitor resistance and xylose utilization. Industrial strains such as TJU (an industrial strain used in some of the bioethanol plants in China), ATCC 4126, and ATCC 96581, an isolate from spent sulfite liquor were compared with some laboratory strains such as ATCC 44771, ATCC 24860 and CBS 8066. The difference of these strains in their pH tolerance was insignificant despite the fact that almost all the strains had less growth when pH was below 4. Among all the yeast strains tested, the haploid laboratory strain ATCC 44771 showed the lowest tolerance to the decrease of pH. As to the inhibitor resistance studies almost all the industrial strains tested had higher inhibitor resistance than the laboratory strains, with ATCC 44771 being the least resistant to the increase in the inhibitor concentrations. The laboratory strain ATCC 24860 showed almost equivalent inhibitor resistance compared with these industrial strains. Further analysis of these strains on their xylose utilization was carried out. Random mutagenesis followed by xylose adaptation was applied. Almost all the laboratory strains died after mutation and all the industrial strains survived with their xylose unitization capabilities increased. In addition, the presence of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural had enhanced their xylsoe assimilation. The above analysis indicated that industrial Saccharomyces cerevisiae strains could be trained for biomass hydrolysate fermentation as they have high pH tolerance, high inhibitor resistance and potentials in xylose utilization. As such, the potential xylose-utilizing mutants are being evaluated for their potentials in biomass hydrolysate fermentation

Ongoing evolution of Chlamydia trachomatis lymphogranuloma venereum: exploring the genomic diversity of circulating strains

Epidemiología molecular; Presión selectiva; Infecciones de transmisión sexualMolecular epidemiology; Selective pressure; Sexually transmitted infectionsEpidemiologia molecular; Pressió selectiva; Infeccions de transmissió sexualLymphogranuloma venereum (LGV), the invasive infection of the sexually transmissible infection (STI) Chlamydia trachomatis , is caused by strains from the LGV biovar, most commonly represented by ompA-genotypes L2b and L2. We investigated the diversity in LGV samples across an international collection over seven years using typing and genome sequencing. LGV-positive samples (n=321) from eight countries collected between 2011 and 2017 (Spain n=97, Netherlands n=67, Switzerland n=64, Australia n=53, Sweden n=37, Hungary n=31, Czechia n=30, Slovenia n=10) were genotyped for pmpH and ompA variants. All were found to contain the 9 bp insertion in the pmpH gene, previously associated with ompA-genotype L2b. However, analysis of the ompA gene shows ompA-genotype L2b (n=83), ompA-genotype L2 (n=180) and several variants of these (n=52; 12 variant types), as well as other/mixed ompA-genotypes (n=6). To elucidate the genomic diversity, whole genome sequencing (WGS) was performed from selected samples using SureSelect target enrichment, resulting in 42 genomes, covering a diversity of ompA-genotypes and representing most of the countries sampled. A phylogeny of these data clearly shows that these ompA-genotypes derive from an ompA-genotype L2b ancestor, carrying up to eight SNPs per isolate. SNPs within ompA are overrepresented among genomic changes in these samples, each of which results in an amino acid change in the variable domains of OmpA (major outer membrane protein, MOMP). A reversion to ompA-genotype L2 with the L2b genomic backbone is commonly seen. The wide diversity of ompA-genotypes found in these recent LGV samples indicates that this gene is under immunological selection. Our results suggest that the ompA-genotype L2b genomic backbone is the dominant strain circulating and evolving particularly in men who have sex with men (MSM) populations.J.C.G. was supported by the Instituto de Salud Carlos III (Plan Estatal de I+D+ i 2013–2016), Grant PI16-01242

Tests for latent tuberculosis in people with end stage kidney disease: a systematic review

BACKGROUND: The relative diagnostic accuracy of interferon γ release assays (IGRAs; based on ELISA [enzyme-linked immunosorbent assay] or ELISPOT [enzyme-linked immunosorbent spot], ie, the QuantiFERON and T-SPOT.TB tests, respectively) and the tuberculin skin test (TST) for latent tuberculosis (TB) infection in people with end-stage kidney disease is uncertain and national guidelines for their use are inconsistent. STUDY DESIGN: Systematic review. SELECTION CRITERIA FOR STUDIES: Evaluated performance of tests for latent TB with clinical risk-factor assessment. SETTING & POPULATION: People with end-stage kidney disease (chronic kidney disease stage 5 [eGFR <15] or kidney transplant recipients). No limits on setting. INDEX TESTS: ELISA- or ELISPOT-based IGRAs, TST, assays to detect antimycobacterial antibodies, and flow cytometry-based tests. OUTCOMES: Odds of test positivity with clinical risk factor for latent TB, expressed as ORs and relative ORs (RORs). RESULTS: 47 studies (6,828 participants) were included, but only 30 studies (4,546 participants) contained sufficient data to contribute to meta-analysis. Studies were predominately in the dialysis population (23/30; 3,700 participants) in countries with low to moderate TB prevalence (0.0-50.0 cases/10(5) persons). BCG vaccination rate was variable (2.7%-100.0%). 9 studies compared IGRAs with the TST directly, 17 studies evaluated the TST only, and the other 4 studies evaluated other tests. Compared to a positive TST result, a positive ELISA-based IGRA result was associated more strongly with radiologic evidence of past TB (ROR, 4.29; 95% CI, 1.83-10.3; P = 0.001) and contact with active TB (ROR, 3.36; 95% CI, 1.61-7.01; P = 0.001). Compared to a negative TST result, a negative ELISA-based IGRA result was associated more strongly with BCG vaccination (ROR, 0.30; 95% CI, 0.14-0.63; P = 0.002). There were insufficient data to compare performance of the ELISPOT-based IGRA with the TST or ELISA-based IGRA. LIMITATIONS: 17 of 47 included studies (36.2%) did not contain sufficient data to contribute to meta-analysis. CONCLUSIONS: Compared to the TST, the ELISA-based IGRA was associated more strongly with risk factors for latent TB in end-stage kidney disease

Preventative and therapeutic potential of tocotrienols on musculoskeletal diseases in ageing

Musculoskeletal health is paramount in an ageing population susceptible to conditions such as osteoporosis, arthritis and fractures. Age-related changes in bone, muscle, and joint function result in declining musculoskeletal health, reduced mobility, increased risk of falls, and persistent discomfort. Preserving musculoskeletal wellbeing is essential for maintaining independence and enhancing the overall quality of life for the elderly. The global burden of musculoskeletal disorders is significant, impacting 1.71 billion individuals worldwide, with age-related muscle atrophy being a well-established phenomenon. Tocotrienols, a unique type of vitamin E found in various sources, demonstrate exceptional antioxidant capabilities compared to tocopherols. This characteristic positions them as promising candidates for addressing musculoskeletal challenges, particularly in mitigating inflammation and oxidative stress underlying musculoskeletal disorders. This review paper comprehensively examines existing research into the preventive and therapeutic potential of tocotrienols in addressing age-related musculoskeletal issues. It sheds light on the promising role of tocotrienols in enhancing musculoskeletal health and overall wellbeing, emphasizing their significance within the broader context of age-related health concerns

First reported outbreak of locally acquired hepatitis E virus infection in Australia

Objective: To determine the source and extent of a locally acquired hepatitis E virus (HEV) infection outbreak. Design, setting and participants: A cluster of notified cases of HEV infection linked to a single restaurant (X) was identified in May 2014. People with laboratory-confirmed HEV infection in New South Wales between January 2013 and December 2014 were interviewed about potential risk factors for HEV infection. Co-diners at restaurant X and patients with suspected but unexplained viral hepatitis were retrospectively tested. Foods eaten by the infected persons were compared with those of seronegative co-diners. HEV RNA detected in sera from infected persons was sequenced and genotyped. Implicated foods were traced back to their sources. Main outcome measures: Potential sources of infection, including overseas travel and foods eaten, and origin of implicated food products. Results: In 55 serologically confirmed cases of HEV infection, 24 people had not travelled overseas during their incubation periods. Of the 24, 17 reported having eaten at restaurant X, 15 of whom could be interviewed. All reported consuming pork liver pâté, compared with only four of seven uninfected co-diners (P < 0.05). The other seven people with locally acquired infections each reported consuming a pork product during their incubation periods. HEV RNA was detected in 16 of the 24 cases; all were of genotype 3. Sequencing indicated greater than 99% homology among restaurant X isolates. HEV RNA was isolated from pork sausages from a batch implicated in one of the locally acquired infections not linked with restaurant X. The pork livers used for pâté preparation by restaurant X were traced to a single Australian farm. Conclusions: This is the first reported HEV outbreak in Australia. HEV should be considered in patients presenting with a compatible illness, even without a history of overseas travel. Pork products should be thoroughly cooked before consumption

Seeking Clarity within Cloudy Effluents: Differentiating Fungal from Bacterial Peritonitis in Peritoneal Dialysis Patients

Fungal peritonitis is a serious complication of peritoneal dialysis (PD) therapy with the majority of patients ceasing PD permanently. The aims of this study were to identify risk factors and clinical associations that may discriminate between fungal from bacterial peritonitis.We retrospectively identified episodes of fungal peritonitis from 2001-2010 in PD patients at Liverpool and Westmead Hospitals (Australia). Fungal peritonitis cases were matched in a 1:2 ratio with patients with bacterial peritonitis from each institution's dialysis registry, occurring closest in time to the fungal episode. Patient demographic, clinical and outcome data were obtained from the medical records.Thirty-nine episodes of fungal peritonitis (rate of 0.02 episodes per patient-year of dialysis) were matched with 78 episodes of bacterial peritonitis. Candida species were the commonest pathogens (35/39; 90% episodes) with Candida albicans (37%), Candida parapsilosis (32%) and Candida glabrata (13%) the most frequently isolated species. Compared to bacterial peritonitis, fungal peritonitis patients had received PD for significantly longer (1133 vs. 775 catheter-days; p = 0.016), were more likely to have had previous episodes of bacterial peritonitis (51% vs. 10%; p = 0.01), and to have received prior antibacterial therapy (51% vs. 10%; p = 0.01). Patients with fungal peritonitis were less likely to have fever and abdominal pain on presentation, but had higher rates of PD catheter removal (79% vs. 22%; p<0.005), and permanent transfer to haemodialysis (87% vs. 24%; p<0.005). Hospital length of stay was significantly longer in patients with fungal peritonitis (26.1 days vs. 12.6 days; p = 0.017), but the all-cause 30-day mortality rate was similar in both groups. Fluconazole was a suitable empiric antifungal agent; with no Candida resistance detected.Prompt recognition of clinical risk factors, initiation of antifungal therapy and removal of PD catheters are key considerations in optimising outcomes