Metagenomic insight into the acidophilic functional communities driving elemental geochemical cycles in an acid mine drainage lake.

Acidophiles play a key role in the generation, evolution and attenuation of acid mine drainage (AMD), which is characterized by strong acidity (pH<3.5) and high metal concentrations. In this study, the seasonal changes of acidophilic communities and their roles in elemental cycling in an AMD lake (pH∼3.0) in China were analyzed through metagenomics. The results showed eukaryotic algae thrived in the lake, and Coccomyxa was dominant in January (38.1%) and May (33.9%), while Chlorella in July (9.5%). The extensive growth of Chlamydomonas in December (22.7%) resulted in an ultrahigh chlorophyll a concentration (587 µg/L), providing abundant organic carbon for the ecosystem. In addition, the iron-oxidizing and nitrogen-fixing bacterium Ferrovum contributed to carbon fixation. Ammonia oxidation likely occurred in the acidic lake, as was revealed by archaea Ca. Nitrosotalea. To gain a competitive advantage in the nutrient-poor environment, some acidophiles exhibited facultative characteristics, e.g. the most abundant bacterium Acidiphilium utilized both organic and inorganic carbon, and obtained energy from organic matter, inorganic sulfur, and sunlight simultaneously. It was suggested that sunlight, rather than chemical energy of reduced iron-sulfur was the major driver of elemental cycling in the AMD lake. The results are beneficial to the development of bioremediation strategies for AMD.

Succession of Microbial Communities in Waste Soils of an Iron Mine in Eastern China.

The reclamation of mine dump is largely centered on the role played by microorganisms. However, the succession of microbial community structure and function in ecological restoration of the mine soils is still poorly understood. In this study, soil samples with different stacking time were collected from the dump of an iron mine in China and the physicochemical characteristics and microbial communities of these samples were comparatively investigated. The results showed that the fresh bare samples had the lowest pH, highest ion concentration, and were the most deficient in nutrients while the acidity and ion concentration of old bare samples decreased significantly, and the nutritional conditions improved remarkably. Vegetated samples had the weakest acidity, lowest ion concentration, and the highest nutrient concentration. In the fresh mine soils, the iron/sulfur-oxidizers such as Acidiferrobacter and Sulfobacillus were dominant, resulting in the strongest acidity. Bacteria from genera Acidibacter, Metallibacterium, and phyla Cyanobacteria, WPS-2 were abundant in the old bare samples, which contributed to the pH increase and TOC accumulation respectively. Acidobacteriota predominated in the vegetated samples and promoted nutrient enrichment and plant growth significantly. The microbial diversity and evenness of the three types of soils increased gradually, with more complex microbial networks, suggesting that the microbial community became more mature with time and microorganisms co-evolved with the mine soils.

Both pH and salinity shape the microbial communities of the lakes in Badain Jaran Desert, NW China.

Badain Jaran Desert (BJD), characterized by extremely arid climate and tallest sand dunes in the world, is the second largest desert in China. Surprisingly, there are a large number of permanent lakes in this desert. At present, little is known about the composition and distribution of microbial communities in these desert lakes, which are an important bioresource and play a fundamental role in the elemental cycles of the lakes. In this study, the physicochemical characteristics and microbial communities of water samples from 15 lakes in BJD were comparatively investigated. The results showed that the lakes were rich in Na+, Cl-, CO32- and HCO3- while Ca2+ and Mg2+ were scarce, with pH 8.52-10.27 and salinity 1.05-478.70 g/L. Bacteria dominated exclusively in low saline lakes (salinity < 50 g/L) while archaea were predominant in hypersaline lakes (salinity > 250 g/L), which abundance increased along salinity gradient linearly. Genera Flavobacterium, Synechocystis and Roseobacter from phyla Bacteroidetes, Cyanobacteria, Alphaproteobacteria were the major members in low saline lakes whereas Halomonas, Aliidiomarina and Halopelagius from Gammaproteobacteria and Euryarchaeota were abundant in moderately saline lakes (salinity 50-250 g/L). The hypersaline lakes were predominated by extreme halophiles such as Halorubrum, Halohasta and Natronomonas from Euryarchaeota. The correlation among the microbes in the lakes was mainly positive, suggesting they can survive in the harsh environments through synergistic interactions. Statistical analyses indicated that physicochemical characteristics rather than spatial factors shaped the microbial communities in the desert lakes. The pH was the most important environmental factor controlling alpha diversity, while salinity was the major driver determining microbial community structure in BJD lakes. In contrast, geographic factors had no significant impact on the microbial community compositions.

Contrasting seasonal variations of geochemistry and microbial community in two adjacent acid mine drainage lakes in Anhui Province, China.

Acid mine drainage (AMD) is generated by the bio-oxidation of sulfide minerals. To understand the AMD formation and evolution, it is necessary to determine the composition and variation of acidophilic community, and their role in AMD ecosystem. In this study, we compared seasonal variations of geochemistry and microbial composition of two adjacent AMD lakes with different formation histories in Anhui Province, China. Lake Paitu (PT) formed in 1970s near a mine dump and the pH was in the range of 3.01-3.16, with the lowest in spring and summer while the highest in winter. The main ions in PT were Al and SO42-, whereas Fe concentration was relatively low. The concentrations of these ions were the lowest in summer and the highest in winter. Lake Tafang (TF) formed in around 2013 in a pit was more acidic (pH 2.43-2.75), but the seasonal variation of pH was the same as PT. Compared with Lake PT, TF had higher Fe, lower Al and SO42- concentrations, and showed no significant seasonal changes. Despite salient seasonal variations of prokaryotic composition in Lake PT, Ferrovum was the major iron-oxidizing bacterium in most seasons. Furthermore, Lake PT was also rich in heterotrophic bacteria (48.6 ± 15.9%). Both prokaryotic diversity and evenness of Lake TF were lower than PT, and chemolithotrophic iron-oxidizing bacteria (71.7 ± 25.4%) were dominant in almost all samples. Besides Ferrovum, more acid tolerant iron-oxidizer Leptospirillum and Acidithiobacillus were also abundant in Lake TF. Chlamydomonas was the major eukaryote in Lake PT and it flourished repeatedly at the end of December, causing an extremely high chlorophyll a concentration (587 µg/L) at one sampling site in 2016, which provided rich nutrients for heterotrophic bacteria. The main alga in Lake TF was Chrysonebula, but its concentration was low, apparently because of the strong acidity and dark red color of lake water.

Patient Dissatisfaction Following Total Knee Arthroplasty: A Systematic Review of the Literature.

BACKGROUND: Dissatisfaction following total knee arthroplasty (TKA) is common. Approximately 20% of patients report dissatisfaction following primary TKA. This systematic literature review explores key factors affecting patient dissatisfaction following TKA. METHODS: Six literature databases published between 2005 and 1 January 2016 were searched using 3 key search phrases. Papers were included if the study investigated patient dissatisfaction in primary unilateral or bilateral TKA. Information from each article was categorized to the domains of socioeconomic, preoperative, intraoperative, and postoperative factors affecting patient dissatisfaction. RESULTS: This review found that patient dissatisfaction pertains to several key factors. Patient expectations prior to surgery, the degree of improvement in knee function, and pain relief following surgery were commonly cited in the literature. Fewer associations were found in the socioeconomic and surgical domains. CONCLUSION: Identifying who may be dissatisfied after their TKA is mystifying; however, we note several strategies that target factors whereby an association exists. Further research is needed to better quantify dissatisfaction, so that the causal links underpinning dissatisfaction can be more fully appreciated and strategies employed to target them.

A standards-based approach to quality improvement for HIV services at Zambia Defence Force facilities: results and lessons learned.

INTRODUCTION: The Zambia Defence Force adopted the Standards-Based Management and Recognition approach to improve the quality of the HIV-related services at its health facilities. This quality improvement intervention relies on comprehensive, detailed assessment tools to communicate and verify adherence to national standards of care, and to test and implement changes to improve performance. METHODS: A quasi-experimental evaluation of the intervention was conducted at eight Zambia Defence Force primary health facilities (four facilities implemented the intervention and four did not). Data from three previous analyses are combined to assess the effect of Standards-Based Management and Recognition on three domains: facility readiness to provide services; observed provider performance during antiretroviral therapy (ART) and antenatal care consultations; and provider perceptions of the work environment. RESULTS: Facility readiness scores for ART improved on four of the eight standards at intervention sites, and one standard at comparison sites. Facility readiness scores for prevention of mother-to-child transmission (PMTCT) of HIV increased by 15 percentage points at intervention sites and 7 percentage points at comparison sites. Provider performance improved significantly at intervention sites for both ART services (from 58 to 84%; P < 0.01) and PMTCT services (from 58 to 73%; P = 0.003); there was no significant change at comparison sites. Providers' perceptions of the work environment generally improved at intervention sites and declined at comparison sites; differences in trends between study groups were significant for eight items. CONCLUSIONS: A standards-based approach to quality improvement proved effective in supporting healthcare managers and providers to deliver ART and PMTCT services in accordance with evidence-based standards in a health system suffering from staff shortages.

Effects of a performance and quality improvement intervention on the work environment in HIV-related care: a quasi-experimental evaluation in Zambia.

BACKGROUND: Human resource shortages and reforms in HIV-related care make it challenging for frontline health care providers in southern Africa to deliver high-quality services. At health facilities of the Zambian Defence Forces, a performance and quality improvement approach was implemented to improve HIV-related care and was evaluated in 2010/2011. Changes in providers' work environment and perceived quality of HIV-related care were assessed to complement data of provider performance. METHODS: The intervention involved on-site training, supportive supervision, and action planning focusing on detailed service delivery standards. The quasi-experimental evaluation collected pre- and post-intervention data from eight intervention and comparison facilities matched on defence force branch and baseline client volume. Overall, 101 providers responded to a 24-item questionnaire on the work environment, covering topics of drugs, supplies, and equipment; training, feedback, and supervision; compensation; staffing; safety; fulfilment; and HIV services quality. In bivariate analysis and multivariate analyses, we assessed changes within each study group and between the two groups. RESULTS: In the bivariate analysis, the intervention group providers reported improvements in the work environment on adequacy of equipment, feeling safe from harm, confidence in clinical skills, and reduced isolation, while the comparison group reported worsening of the work environment on supplies, training, safety, and departmental morale.In the multivariate analysis, the intervention group's improvement and the comparison group's decline were significant on perceived adequacy of drugs, supplies, and equipment; constructive feedback received from supervisor and co-workers; and feeling safe from physical harm (all P <0.01, except P <0.04 for equipment). Further, the item "provider lacks confidence in some clinical skills" declined in the intervention group but increased in the comparison group (P = -0.005). In multivariate analysis, changes in perceived quality of HIV care did not differ between study groups. Provider perceptions were congruent with observations of preparing drugs, supplies, equipment, and in service delivery of prevention of mother-to-child transmission of HIV and antiretroviral therapy follow-up care. CONCLUSIONS: The performance and quality improvement intervention implemented at Zambian Defence Forces' health facilities was associated with improvements in providers' perceptions of work environment consistent with the intervention's focus on commodities, skills acquisition, and receipt of constructive feedback.

Evaluation of a quality improvement intervention to prevent mother-to-child transmission of HIV (PMTCT) at Zambia defence force facilities.

BACKGROUND: The Zambian Defence Force (ZDF) is working to improve the quality of services to prevent mother-to-child transmission of HIV (PMTCT) at its health facilities. This study evaluates the impact of an intervention that included provider training, supportive supervision, detailed performance standards, repeated assessments of service quality, and task shifting of group education to lay workers. METHODS: Four ZDF facilities implementing the intervention were matched with four comparison sites. Assessors visited the sites before and after the intervention and completed checklists while observing 387 antenatal care (ANC) consultations and 41 group education sessions. A checklist was used to observe facilities' infrastructure and support systems. Bivariate and multivariate analyses were conducted of findings on provider performance during consultations. RESULTS: Among 137 women observed during their initial ANC visit, 52% came during the first 20 weeks of pregnancy, but 19% waited until the 28th week or later. Overall scores for providers' PMTCT skills rose from 58% at baseline to 73% at endline (p=0.003) at intervention sites, but remained stable at 52% at comparison sites. Especially large gains were seen at intervention sites in family planning counseling (34% to 75%, p=0.026), HIV testing during return visits (13% to 48%, p=0.034), and HIV/AIDS management during visits that did not include an HIV test (1% to 34%, p=0.004). Overall scores for providers' ANC skills rose from 67% to 74% at intervention sites, but declined from 65% to 59% at comparison sites; neither change was significant in the multivariate analysis. Overall scores for group education rose from 87% to 91% at intervention sites and declined from 78% to 57% at comparison sites. The overall facility readiness score rose from 73% to 88% at intervention sites and from 75% to 82% at comparison sites. CONCLUSIONS: These findings are relevant to civilian as well as military health systems in Zambia because the two are closely coordinated. Lessons learned include: the ability of detailed performance standards to draw attention to and strengthen areas of weakness; the benefits of training lay workers to take over non-clinical PMTCT tasks; and the need to encourage pregnant women to seek ANC early.

Improving performance of Zambia Defence Force antiretroviral therapy providers: evaluation of a standards-based approach.

BACKGROUND: The Zambia Defence Force (ZDF) has applied the Standards-Based Management and Recognition (SBM-R®) approach, which uses detailed performance standards, at some health facilities to improve HIV-related services offered to military personnel and surrounding civilian communities. This study examines the effectiveness of the SBM-R approach in improving facility readiness and provider performance at ZDF facilities. METHODS: We collected data on facility readiness and provider performance before and after the 2010-2012 intervention at 4 intervention sites selected for their relatively poor performance and 4 comparison sites. Assessors observed whether each facility met 16 readiness standards and whether providers met 9 performance standards during consultations with 354 returning antiretroviral therapy (ART) clients. We then calculated the percentages of criteria achieved for each readiness and performance standard and conducted bivariate and multivariate analyses of provider performance data. RESULTS: Facilities' ART readiness scores exceeded 80% before the intervention at both intervention and comparison sites. At endline, scores improved on 4 facility readiness standards in the intervention group but on only 1 standard in the comparison group. Multivariate analysis found that the overall provider performance score increased significantly in the intervention group (from 58% to 84%; P<.01) but not in the comparison group (from 62% to 70%). The before-and-after improvement in scores was significantly greater among intervention sites than among comparison sites for 2 standards-initial assessment of the client's condition and nutrition counseling. CONCLUSION: The standards-based approach, which involved intensive and mutually reinforcing intervention activities, showed modest improvements in some aspects of providers' performance during ART consultations. Further research is needed to determine whether improvements in provider performance affect client outcomes such as adherence to ART.

The effects of HIV on the sensitivity of a whole blood IFN-gamma release assay in Zambian adults with active tuberculosis.

BACKGROUND: Interferon gamma release assays (IGRA) are replacing the tuberculin skin test (TST) as a diagnostic tool for Mycobacterium tuberculosis infection. However research into the test's performance in the high HIV-TB burden setting is scarce. This study aimed to define the sensitivity of an IGRA, QuantiFERON-TB Gold In-Tube (QGIT), in adult Zambian patients with active smear-positive tuberculosis. Secondary outcomes focussed on the effect of HIV on the test's performance. PRINCIPAL FINDINGS: Patients attending government health clinics were recruited within 1 month of starting treatment for TB. Subjects were tested with QGIT and TST. T lymphocyte counts were estimated (CD3(+), CD4(+), CD8(+)). QGIT was performed for 112 subjects. 83/112 were QGIT positive giving an overall sensitivity of 74% [95%CI: 66,82]. A marked decrease in sensitivity was observed in HIV positive patients with 37/59 (63%) being QGIT positive compared to 31/37 (84%) HIV negative patients [chi(2) p = 0.033]. Low CD4(+) count was associated with increases in both indeterminate and false-negative results. Low CD4(+) count in combination with high/normal CD8(+) count was associated with false-negative results. TST was recorded for 92 patients, 62/92 were positive, giving a sensitivity of 67% [95%CI: 58,77]. Although there was little difference in the overall sensitivities, agreement between TST and QGIT was poor. CONCLUSIONS: QGIT was technically feasible with results in HIV negative subjects comparable to those achieved elsewhere. However, where under-treated HIV is prevalent, an increased proportion of both indeterminate and false-negative QGIT results can be expected in patients with active TB. The implications of this for the diagnosis of LTBI by QGIT is unclear. The diagnostic and prognostic relevance of IGRAs in high burden settings needs to be better characterised.