Potential impact on kidney infection: a whole-genome analysis of Leptospira santarosai

Leptospira santarosai serovar Shermani is the most frequently encountered serovar, and it causes leptospirosis and tubulointerstitial nephritis in Taiwan. This study aims to complete the genome sequence of L. santarosai serovar Shermani and analyze the transcriptional responses of L. santarosai serovar Shermani to renal tubular cells. To assemble this highly repetitive genome, we combined reads that were generated from four next-generation sequencing platforms by using hybrid assembly approaches to finish two-chromosome contiguous sequences without gaps by validating the data with optical restriction maps and Sanger sequencing. Whole-genome comparison studies revealed a 28-kb region containing genes that encode transposases and hypothetical proteins in L. santarosai serovar Shermani, but this region is absent in other pathogenic Leptospira spp. We found that lipoprotein gene expression in both L. santarosai serovar Shermani and L. interrogans serovar Copenhageni were upregulated upon interaction with renal tubular cells, and LSS19962, a L. santarosai serovar Shermani-specific gene within a 28-kb region that encodes hypothetical proteins, was upregulated in L. santarosai serovar Shermani-infected renal tubular cells. Lipoprotein expression during leptospiral infection might facilitate the interactions of leptospires within kidneys. The availability of the whole-genome sequence of L. santarosai serovar Shermani would make it the first completed sequence of this species, and its comparison with that of other Leptospira spp. may provide invaluable information for further studies in leptospiral pathogenesis

Acute kidney injury in the tropics

Acute kidney injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. AKI in the tropics is strikingly different from that in the developed world in terms of etiology and presentation. In addition, there is a stark contrast between well-developed and poor areas in the tropics. The true epidemiological picture of AKI in the tropics is not well understood due to the late presentation of patients to tertiary centers. Infections remain the major culprit in most cases of AKI, with high mortality rates in the tropics. Human immunodeficiency virus–related AKI, related to nephrotoxicity due to antiretroviral therapy, is on the rise. Acute tubular necrosis and thrombotic microangiopathy are the most common mechanisms of AKI. A notable problem in the tropics is the scarcity of resources in health centers to support patients who require critical care due to AKI. This article reviews the unique and contrasting nature of AKI in the tropics and describes its management in each situation