Effect of high dose vitamin D3 on the HIV-1 reservoir: A pilot randomised controlled trial.

Introduction: Antiretroviral therapy for people living with HIV-1 must be taken lifelong due to the persistence of latent virus in long-lived and proliferating CD4+ T cells. Vitamin D3 is a steroidal gene transcription regulator which exerts diverse effects on immune and epithelial cells including reductions in CD4+ T cell proliferation and improvement in gut barrier integrity. We hypothesised that a high dose of vitamin D3 would reduce the size of the HIV-1 reservoir by reducing CD4+ T cell proliferation. Methods: We performed a randomised placebo-controlled trial evaluating the effect of 24 weeks of vitamin D3 (10,000 international units per day) on the HIV-1 reservoir and immunologic parameters in 30 adults on antiretroviral therapy; participants were followed for 12 weeks post-treatment. The primary endpoint was the effect on total HIV-1 DNA at week 24. Parameters were assessed using mixed-effects models. Results: We found no effect of vitamin D3 on the change in total HIV-1 DNA from week 0 to week 24 relative to placebo. There were also no changes in integrated HIV-1 DNA, 2-long-terminal repeat (2-LTR) circles or cell-associated HIV-1 RNA. Vitamin D3 induced a significant increase in the proportion of central memory CD4+ and CD8+ T cells, a reduction in the proportion of senescent CD8+ T cells and a reduction in the natural killer cell frequency at all time points including week 36, 12 weeks after the study drug cessation. At week 36, there was a significant reduction in total HIV-1 DNA relative to placebo and persistently elevated 25-hydroxyvitamin D levels. No significant safety issues were identified. Conclusions: Vitamin D3 administration had a significant impact on the T cell differentiation but overall effects on the HIV-1 reservoir were limited and a reduction in HIV-1 DNA was only seen following cessation of the study drug. Additional studies are required to determine whether the dose and duration of vitamin D3 can be optimised to promote a continued depletion of the HIV-1 reservoir over time. Trial registration: ClinicalTrials.gov NCT03426592.

Human Immunodeficiency Virus (HIV)-Infected CCR6+ Rectal CD4+ T Cells and HIV Persistence On Antiretroviral Therapy.

BACKGROUND: Identifying where human immunodeficiency virus (HIV) persists in people living with HIV and receiving antiretroviral therapy is critical to develop cure strategies. We assessed the relationship of HIV persistence to expression of chemokine receptors and their chemokines in blood (n = 48) and in rectal (n = 20) and lymph node (LN; n = 8) tissue collected from people living with HIV who were receiving suppressive antiretroviral therapy. METHODS: Cell-associated integrated HIV DNA, unspliced HIV RNA, and chemokine messenger RNA were quantified by quantitative polymerase chain reaction. Chemokine receptor expression on CD4+ T cells was determined using flow cytometry. RESULTS: Integrated HIV DNA levels in CD4+ T cells, CCR6+CXCR3+ memory CD4+ T-cell frequency, and CCL20 expression (ligand for CCR6) were highest in rectal tissue, where HIV-infected CCR6+ T cells accounted for nearly all infected cells (median, 89.7%). Conversely in LN tissue, CCR6+ T cells were infrequent, and there was a statistically significant association of cell-associated HIV DNA and RNA with CCL19, CCL21, and CXCL13 chemokines. CONCLUSIONS: HIV-infected CCR6+ CD4+ T cells accounted for the majority of infected cells in rectal tissue. The different relationships between HIV persistence and T-cell subsets and chemokines in rectal and LN tissue suggest that different tissue-specific strategies may be required to eliminate HIV persistence and that assessment of biomarkers for HIV persistence may not be generalizable between blood and other tissues.

Barriers and strategies to achieve a cure for HIV.

9 years since the report of a cure for HIV after C-C chemokine receptor type 5 Δ32 stem cell transplantation, no other case of HIV cure has been reported, despite much research. However, substantial progress has been made in understanding the biology of the latent HIV reservoir, and in measuring the amount of virus that persists after antiretroviral therapy (ART) with increasingly sophisticated approaches. This knowledge is being translated into a long pipeline of clinical trials seeking to reduce viral persistence in participants on suppressive treatment and ultimately to allow safe cessation of ART. In this Review, we discuss the main barriers preventing the development of an HIV cure, methods used to measure HIV persistence in individuals on ART, clinical strategies that aim to cure HIV, and future directions for studies in the field of HIV cure research.

Raising the Stakes: Loss of Efflux Pump Regulation Decreases Meropenem Susceptibility in Burkholderia pseudomallei.

Background: Burkholderia pseudomallei, the causative agent of the high-mortality disease melioidosis, is a gram-negative bacterium that is naturally resistant to many antibiotics. There is no vaccine for melioidosis, and effective eradication is reliant on biphasic and prolonged antibiotic administration. The carbapenem drug meropenem is the current gold standard option for treating severe melioidosis. Intrinsic B. pseudomallei resistance toward meropenem has not yet been documented; however, resistance could conceivably develop over the course of infection, leading to prolonged sepsis and treatment failure. Methods: We examined our 30-year clinical collection of melioidosis cases to identify B. pseudomallei isolates with reduced meropenem susceptibility. Isolates were subjected to minimum inhibitory concentration (MIC) testing toward meropenem. Paired isolates from patients who had evolved decreased susceptibility were subjected to whole-genome sequencing. Select agent-compliant genetic manipulation was carried out to confirm the molecular mechanisms conferring resistance. Results: We identified 11 melioidosis cases where B. pseudomallei isolates developed decreased susceptibility toward meropenem during treatment, including 2 cases not treated with this antibiotic. Meropenem MICs increased from 0.5-0.75 µg/mL to 3-8 µg/mL. Comparative genomics identified multiple mutations affecting multidrug resistance-nodulation-division (RND) efflux pump regulators, with concomitant overexpression of their corresponding pumps. All cases were refractory to treatment despite aggressive, targeted therapy, and 2 were associated with a fatal outcome. Conclusions: This study confirms the role of RND efflux pumps in decreased meropenem susceptibility in B. pseudomallei. These findings have important ramifications for the diagnosis, treatment, and management of life-threatening melioidosis cases.

Herpes simplex virus-2 transmission following solid organ transplantation: Donor-derived infection and transplantation from prior organ recipients.

BACKGROUND: Owing to limited availability of donor organs, previous solid organ transplant (SOT) recipients are increasingly considered as potential organ donors. We report donor-derived transmission of herpes simplex virus type-2 (HSV-2) to two clusters of SOT recipients with transmission from the original donor and an HSV-2-infected recipient who subsequently became a donor. METHODS: We reviewed medical records of the donors and recipients in both clusters. Pre-transplant serology and virological features of HSV-2 were characterized. Genotyping of HSV-2 isolates to determine potential for donor transmission of HSV-2 through transplantation of organs from prior organ recipients was performed. RESULTS: A kidney-pancreas recipient died day 9 post transplant. Following confirmation of brain death, the lungs and recently transplanted kidney were donated to two further recipients. The liver was not retrieved, but biopsy confirmed HSV-2 infection. Testing on the original donor showed negative HSV-2 polymerase chain reaction and HSV immunoglobulin (Ig)M, but positive HSV-2 IgG. The liver recipient from the original donor developed HSV-2 hepatitis and cutaneous infection that responded to treatment with intravenous acyclovir. In the second cluster, lung and kidney recipients both developed HSV-2 viremia that was successfully treated with antiviral therapy. Genotyping of all HSV-2-positive samples showed 100% sequence homology for three recipients. CONCLUSIONS: Donor-derived HSV infection affected two clusters of recipients because of transplantation of organs from a prior organ recipient. HSV should be considered as a possible cause of illness in febrile SOT recipients in the immediate post-transplant period and may cause disseminated disease and re-infection in HSV-2-seropositive recipients. Testing of HSV serology and prophylaxis may be considered in SOT recipients not receiving cytomegalovirus prophylaxis.

Intravenous therapy duration and outcomes in melioidosis: a new treatment paradigm.

BACKGROUND: International melioidosis treatment guidelines recommend a minimum 10 to 14 days' intravenous antibiotic therapy (intensive phase), followed by 3 to 6 months' oral therapy (eradication phase). This approach is associated with rates of relapse, defined as recurrence following the eradication phase, that can exceed 5%. Rates of recrudescence, defined as recurrence during the eradication phase, have not previously been reported. In response to low eradication phase completion rates in Australia, a local guideline has evolved over the last ten years recommending a longer minimum intensive phase duration for many cases of melioidosis. METHODOLOGY/ PRINCIPAL FINDINGS: This retrospective cohort study reviews antibiotic duration for the first episode of care for all patients diagnosed with melioidosis and surviving the intensive phase during a recent three year period in the tropical north of Australia's Northern Territory; we also review adherence to the current local guideline and treatment outcomes. Of 215 first episodes of melioidosis surviving the intensive phase, the median (interquartile range) intensive phase duration was 26 (14-34) days. One hundred and eight (50.2%) patients completed eradication therapy; 58 (27.0%) patients took no eradication therapy. At 28 months' follow-up, one (0.5%) relapse and eleven (5.1%) recrudescences had occurred. On exact logistic regression analysis, the only independent risk factors for recrudescence were self-discharge during the intensive phase (odds ratio 6.2 [95% confidence interval 1.2-30.0]) and septic shock (odds ratio 5.3 [95% confidence interval 1.1-25.7]). CONCLUSIONS/ SIGNIFICANCE: Relapsed melioidosis is rare in patients who receive a minimum intensive phase duration specified by our guideline and extended according to clinical progress. Recrudescence rates may improve with reductions in rates of self-discharge. Given the low relapse rate despite a high rate of eradication therapy non-adherence, the duration and necessity of eradication therapy for different patients after guideline-concordant intensive therapy should be evaluated further.

Sequence type 131 fimH30 and fimH41 subclones amongst Escherichia coli isolates in Australia and New Zealand.

The clonal composition of Escherichia coli causing extra-intestinal infections includes ST131 and other common uropathogenic clones. Drivers for the spread of these clones and risks for their acquisition have been difficult to define. In this study, molecular epidemiology was combined with clinical data from 182 patients enrolled in a case-control study of community-onset expanded-spectrum cephalosporin-resistant E. coli (ESC-R-EC) in Australia and New Zealand. Genetic analysis included antimicrobial resistance mechanisms, clonality by DiversiLab (rep-PCR) and multilocus sequence typing (MLST), and subtyping of ST131 by identification of polymorphisms in the fimH gene. The clonal composition of expanded-spectrum cephalosporin-susceptible E. coli and ESC-R-EC isolates differed, with six MLST clusters amongst susceptible isolates (median 7 isolates/cluster) and three clusters amongst resistant isolates, including 40 (45%) ST131 isolates. Population estimates indicate that ST131 comprises 8% of all E. coli within our population; the fluoroquinolone-susceptible H41 subclone comprised 4.5% and the H30 subclone comprised 3.5%. The H30 subclone comprised 39% of all ESC-R-EC and 41% of all fluoroquinolone-resistant E. coli within our population. Patients with ST131 were also more likely than those with non-ST131 isolates to present with an upper than lower urinary tract infection (RR=1.8, 95% CI 1.01-3.1). ST131 and the H30 subclone were predominant amongst ESC-R-EC but were infrequent amongst susceptible isolates where the H41 subclone was more prevalent. Within our population, the proportional contribution of ST131 to fluoroquinolone resistance is comparable with that of other regions. In contrast, the overall burden of ST131 is low by global standards.

Recurrent melioidosis in the Darwin Prospective Melioidosis Study: improving therapies mean that relapse cases are now rare.

The Darwin Prospective Melioidosis Study has documented 785 melioidosis cases over 23 years. Recurrent melioidosis occurred in 39/679 (5.7%) patients surviving initial infection; 29 patients suffered relapse of the original infection, and 10 presented with a new Burkholderia pseudomallei infection. With improved therapy, relapse has become rare in recent years.

Community-onset Escherichia coli infection resistant to expanded-spectrum cephalosporins in low-prevalence countries.

By global standards, the prevalence of community-onset expanded-spectrum-cephalosporin-resistant (ESC-R) Escherichia coli remains low in Australia and New Zealand. Of concern, our countries are in a unique position, with high extramural resistance pressure from close population and trade links to Asia-Pacific neighbors with high ESC-R E. coli rates. We aimed to characterize the risks and dynamics of community-onset ESC-R E. coli infection in our low-prevalence region. A case-control methodology was used. Patients with ESC-R E. coli or ESC-susceptible E. coli isolated from blood or urine were recruited at six geographically dispersed tertiary care hospitals in Australia and New Zealand. Epidemiological data were prospectively collected, and bacteria were retained for analysis. In total, 182 patients (91 cases and 91 controls) were recruited. Multivariate logistic regression identified risk factors for ESC-R among E. coli strains, including birth on the Indian subcontinent (odds ratio [OR]=11.13, 95% confidence interval [95% CI]=2.17 to 56.98, P=0.003), urinary tract infection in the past year (per-infection OR=1.430, 95% CI=1.13 to 1.82, P=0.003), travel to southeast Asia, China, the Indian subcontinent, Africa, and the Middle East (OR=3.089, 95% CI=1.29 to 7.38, P=0.011), prior exposure to trimethoprim with or without sulfamethoxazole and with or without an expanded-spectrum cephalosporin (OR=3.665, 95% CI=1.30 to 10.35, P=0.014), and health care exposure in the previous 6 months (OR=3.16, 95% CI=1.54 to 6.46, P=0.02). Among our ESC-R E. coli strains, the blaCTX-M ESBLs were dominant (83% of ESC-R E. coli strains), and the worldwide pandemic ST-131 clone was frequent (45% of ESC-R E. coli strains). In our low-prevalence setting, ESC-R among community-onset E. coli strains may be associated with both "export" from health care facilities into the community and direct "import" into the community from high-prevalence regions.

Eosinophils in severe sepsis in northern australia: do the usual rules apply in the tropics?

OBJECTIVES: Eosinophilia is rare in severe sepsis in temperate areas. We present a case of suspected severe sepsis with eosinophilia that proved fatal and was subsequently diagnosed as drug rash with eosinophilia and systemic symptoms. We aim to determine how common eosinophilia in severe sepsis is in the tropics, where there is a higher background rate of eosinophilia due to parasitic infection. DESIGN: Retrospective analysis of prospective cohort study. SETTING: Tertiary hospital in tropical northern Australia. PATIENTS: Prospectively recruited cohort including all patients at least 15 years old admitted to a 350-bed teaching hospital in northern Australia between May 6, 2007, and May 5, 2008, with community-onset severe sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Peripheral eosinophil counts on days 1 and 3 of admission and at the time of discharge were recorded for each patient. Eosinopenia was defined as less than 0.1×10 9/L and eosinophilia as greater than 0.6×10 9/L. The median eosinophil count on day 1 was 0.0 (interquartile range, 0.0-0.1; range, 0.0-0.7×10 9/L). Out of 245 patients, 243 patients (99.1%) had a normal or low eosinophil count at admission. Lower counts correlated with higher Acute Physiology and Chronic Health Evaluation II score and 28-day mortality (p=0.02 for both correlations). The median count rose during the course of admission to 0.2 (interquartile range, 0.1-0.4) at the time of discharge (p<0.001 compared with day 1 count). Patients with eosinophilia at discharge were more likely to be Indigneous or remote-dwelling than those without eosinophilia, suggesting an unmasking of preexisting eosinophilia as sepsis resolves. CONCLUSIONS: Eosinophilia is rare in severe sepsis, even in the tropics. Patients with suspected severe sepsis and eosinophilia should have diagnoses other than sepsis excluded. One such diagnosis is drug rash with eosinophilia and systemic symptoms.