Blood transcriptomics to characterize key biological pathways and identify biomarkers for predicting mortality in melioidosis.

Melioidosis is an often lethal tropical disease caused by the Gram-negative bacillus, Burkholderia pseudomallei. The study objective was to characterize transcriptomes in melioidosis patients and identify genes associated with outcome. Whole blood RNA-seq was performed in a discovery set of 29 melioidosis patients and 3 healthy controls. Transcriptomic profiles of patients who did not survive to 28 days were compared with patients who survived and healthy controls, showing 65 genes were significantly up-regulated and 218 were down-regulated in non-survivors compared to survivors. Up-regulated genes were involved in myeloid leukocyte activation, Toll-like receptor cascades and reactive oxygen species metabolic processes. Down-regulated genes were hematopoietic cell lineage, adaptive immune system and lymphocyte activation pathways. RT-qPCR was performed for 28 genes in a validation set of 60 melioidosis patients and 20 healthy controls, confirming differential expression. IL1R2, GAS7, S100A9, IRAK3, and NFKBIA were significantly higher in non-survivors compared with survivors (P < 0.005) and healthy controls (P < 0.0001). The AUROCC of these genes for mortality discrimination ranged from 0.80-0.88. In survivors, expression of IL1R2, S100A9 and IRAK3 genes decreased significantly over 28 days (P < 0.05). These findings augment our understanding of this severe infection, showing expression levels of specific genes are potential biomarkers to predict melioidosis outcomes.

Evolution of the Staphylococcus argenteus ST2250 Clone in Northeastern Thailand Is Linked with the Acquisition of Livestock-Associated Staphylococcal Genes.

Staphylococcus argenteus is a newly named species previously described as a divergent lineage of Staphylococcus aureus that has recently been shown to have a global distribution. Despite growing evidence of the clinical importance of this species, knowledge about its population epidemiology and genomic architecture is limited. We used whole-genome sequencing to evaluate and compare S. aureus (n = 251) and S. argenteus (n = 68) isolates from adults with staphylococcal sepsis at several hospitals in northeastern Thailand between 2006 and 2013. The majority (82%) of the S. argenteus isolates were of multilocus sequence type 2250 (ST2250). S. aureus was more diverse, although 43% of the isolates belonged to ST121. Bayesian analysis suggested an S. argenteus ST2250 substitution rate of 4.66 (95% confidence interval [CI], 3.12 to 6.38) mutations per genome per year, which was comparable to the S. aureus ST121 substitution rate of 4.07 (95% CI, 2.61 to 5.55). S. argenteus ST2250 emerged in Thailand an estimated 15 years ago, which contrasts with the S. aureus ST1, ST88, and ST121 clades that emerged around 100 to 150 years ago. Comparison of S. argenteus ST2250 genomes from Thailand and a global collection indicated a single introduction into Thailand, followed by transmission to local and more distant countries in Southeast Asia and further afield. S. argenteus and S. aureus shared around half of their core gene repertoire, indicating a high level of divergence and providing strong support for their classification as separate species. Several gene clusters were present in ST2250 isolates but absent from the other S. argenteus and S. aureus study isolates. These included multiple exotoxins and antibiotic resistance genes that have been linked previously with livestock-associated S. aureus, consistent with a livestock reservoir for S. argenteus These genes appeared to be associated with plasmids and mobile genetic elements and may have contributed to the biological success of ST2250.IMPORTANCE In this study, we used whole-genome sequencing to understand the genome evolution and population structure of a systematic collection of ST2250 S. argenteus isolates. A newly identified ancestral species of S. aureus, S. argenteus has become increasingly known as a clinically important species that has been reported recently across various countries. Our results indicate that S. argenteus has spread at a relatively rapid pace over the past 2 decades across northeastern Thailand and acquired multiple exotoxin and antibiotic resistance genes that have been linked previously with livestock-associated S. aureus Our findings highlight the clinical importance and potential pathogenicity of S. argenteus as a recently emerging pathogen.

Treatment outcomes after implementation of an adapted WHO protocol for severe sepsis and septic shock in Haiti.

PURPOSE: The World Health Organization (WHO) has developed a simplified algorithm specific to resource-limited settings for the treatment of severe sepsis emphasizing early fluids and antibiotics. However, this protocol's clinical effectiveness is unknown. We describe patient outcomes before and after implementation of an adapted WHO severe sepsis protocol at a community hospital in Haiti. MATERIALS AND METHODS: Using a before-and-after study design, we retrospectively enrolled 99 adult Emergency Department patients with severe sepsis from January through March 2012. After protocol implementation in January 2014, we compared outcomes to 67 patients with severe sepsis retrospectively enrolled from February to April 2014. We defined sepsis according to the WHO's Integrated Management of Adult Illness guidelines and severe sepsis as sepsis plus organ dysfunction. RESULTS: After protocol implementation, quantity of fluid administered increased and the physician's differential diagnoses more often included sepsis. Patients were more likely to have follow-up vital signs taken sooner, a radiograph performed, and a lactic acid tested. There were no improvements in mortality, time to fluids or antimicrobials. CONCLUSIONS: Use of a simplified sepsis protocol based primarily on physiologic parameters allows for substantial improvements in process measures in the care of severely septic patients in a resource-constrained setting.

Clinical care for severe influenza and other severe illness in resource-limited settings: the need for evidence and guidelines.

The 2009 influenza A (H1N1) pandemic highlighted the importance of quality hospital care of the severely ill, yet there is evidence that the impact of the 2009 pandemic was highest in low- and middle-income countries with fewer resources. Recent data indicate that death and suffering from seasonal influenza and severe illness in general are increased in resource-limited settings. However, there are limited clinical data and guidelines for the management of influenza and other severe illness in these settings. Life-saving supportive care through syndromic case management is used successfully in high-resource intensive care units and in global programs such as the Integrated Management of Childhood Illness (IMCI). While there are a variety of challenges to the management of the severely ill in resource-limited settings, several new international initiatives have begun to develop syndromic management strategies for these environments, including the World Health Organization's Integrated Management of Adult and Adolescent Illness Program. These standardized clinical guidelines emphasize syndromic case management and do not require high-resource intensive care units. These efforts must be enhanced by quality clinical research to provide missing evidence and to refine recommendations, which must be carefully integrated into existing healthcare systems. Realizing a sustainable, global impact on death and suffering due to severe influenza and other severe illness necessitates an ongoing and concerted international effort to iteratively generate, implement, and evaluate best-practice management guidelines for use in resource-limited settings.