Proteomic analyses of urinary exosomes identify novel potential biomarkers for early diagnosis of sickle cell nephropathy, a sex-based study.

Sickle cell nephropathy (SCN) is a leading cause of morbidity and mortality in sickle cell disease (SCD). Early intervention is crucial for mitigating its effects. However, current diagnostic methods rely on generic tests and may not detect SCN until irreversible renal damage occurs. Therefore, specific biomarkers for early diagnosis of SCN are needed. Urinary exosomes, membrane-bound vesicles secreted by renal podocytes and epithelial cells, contain both common and cell type-specific membrane and cytosolic proteins, reflecting the physiologic and pathophysiologic states of the kidney. Using proteomics, we analyzed the proteomes of urinary exosomes from humanized SCD mice at 2 months (without albuminuria) and 4 months (with albuminuria) of age. Excretion of 164 proteins were significantly increased and 176 proteins was significantly decreased in the exosomes when mice developed albuminuria. Based on the relevance to SCD, chronic kidney disease and Western blot confirmation in mice, we analyzed protein abundance of heparanase, cathepsin C, α2-macroglobulin and sarcoplasmic endoplasmic Ca2+ ATPase-3 (SERCA3) in the urinary exosomes and urine of 18 SCD subjects without albuminuria and 12 subjects with albuminuria using Western blot analyses. Both male and female subjects increased or tended to increase the excretion of these proteins in their urinary exosomes upon developing albuminuria, but female subjects demonstrated stronger correlations between the excretion of these proteins and urine albumin creatinine ratio (UACR) compared to male subjects. In contrast, exosomal excretion of Tamm-Horsfall protein, ß-actin and SHP-1 was independent of albuminuria. These findings provide a foundation for a time-course study to determine whether increases in the levels of these proteins precede the onset of albuminuria in patients, which will help determine the potential of these proteins as biomarkers for early detection of SCN.

Climate warming and increasing Vibrio vulnificus infections in North America.

Vibrio vulnificus is an opportunistic bacterial pathogen, occurring in warm low-salinity waters. V. vulnificus wound infections due to seawater exposure are infrequent but mortality rates are high (~ 18%). Seawater bacterial concentrations are increasing but changing disease pattern assessments or climate change projections are rare. Here, using a 30-year database of V. vulnificus cases for the Eastern USA, changing disease distribution was assessed. An ecological niche model was developed, trained and validated to identify links to oceanographic and climate data. This model was used to predict future disease distribution using data simulated by seven Global Climate Models (GCMs) which belong to the newest Coupled Model Intercomparison Project (CMIP6). Risk was estimated by calculating the total population within 200 km of the disease distribution. Predictions were generated for different "pathways" of global socioeconomic development which incorporate projections of greenhouse gas emissions and demographic change. In Eastern USA between 1988 and 2018, V. vulnificus wound infections increased eightfold (10-80 cases p.a.) and the northern case limit shifted northwards 48 km p.a. By 2041-2060, V. vulnificus infections may expand their current range to encompass major population centres around New York (40.7°N). Combined with a growing and increasingly elderly population, annual case numbers may double. By 2081-2100 V. vulnificus infections may be present in every Eastern USA State under medium-to-high future emissions and warming. The projected expansion of V. vulnificus wound infections stresses the need for increased individual and public health awareness in these areas.

Prevalence and Characteristics of CKD in the US Military Health System: A Retrospective Cohort Study.

Rationale & Objective: The US Military Health System (MHS) is a global health care network with a diverse population that is more representative of the US population than other study cohorts and with fewer disparities in health care access. We aimed to examine the prevalence of chronic kidney disease (CKD) in the MHS and within demographic subpopulations. Study Design: Multiple cross-sectional analyses of demographic and claims-based data extracted from the MHS Data Repository, 1 for each fiscal year from 2006-2015. Setting & Population: Multicenter health care network including active-duty military, retirees, and dependents. The average yearly sample size was 3,285,348 individuals. Exposures: Age, sex, race, active-duty status, and active-duty rank (a surrogate for socioeconomic status). Outcome: CKD, defined as the presence of matching International Classification of Diseases, Ninth Revision, codes on either 1 or more inpatient or 2 or more outpatient encounters. Analytical Approach: t test for continuous variables and χ2 test for categorical variables; multivariable logistic regression for odds ratios. Results: For 2015, the mean (standard deviation) age was 38 (16). Crude CKD prevalence was 2.9%. Age-adjusted prevalence was 4.9% overall-1.9% active-duty and 5.4% non-active-duty individuals. ORs for CKD were calculated with multiple imputations to account for missing data on race. After adjustment, the ORs for CKD (all P < 0.001) were 1.63 (95% CI, 1.62-1.64) for an age greater than 40 years, 1.16 (95% CI, 1.15-1.17) for Black race, 1.15 (95% CI, 1.14-1.16) for senior enlisted rank, 0.94 (95% CI, 0.93-0.95) for women, and 0.50 (95% CI, 0.49-0.51) for active-duty status. Limitations: Retrospective study based on International Classification of Diseases, Ninth Revision, coding. Conclusions: Within the MHS, older age, Black race, and senior enlisted rank were associated with a higher risk of CKD, whereas female sex and active-duty status were associated with a lower risk.

Detection and Potential Virulence of Viable but Non-Culturable (VBNC) Listeria monocytogenes: A Review.

The detection, enumeration, and virulence potential of viable but non-culturable (VBNC) pathogens continues to be a topic of discussion. While there is a lack of definitive evidence that VBNC Listeria monocytogenes (Lm) pose a public health risk, recent studies suggest that Lm in its VBNC state remains virulent. VBNC bacteria cannot be enumerated by traditional plating methods, so the results from routine Lm testing may not demonstrate a sample's true hazard to public health. We suggest that supplementing routine Lm testing methods with methods designed to enumerate VBNC cells may more accurately represent the true level of risk. This review summarizes five methods for enumerating VNBC Lm: Live/Dead BacLightTM staining, ethidium monoazide and propidium monoazide-stained real-time polymerase chain reaction (EMA- and PMA-PCR), direct viable count (DVC), 5-cyano-2,3-ditolyl tetrazolium chloride-4',6-diamidino-2-phenylindole (CTC-DAPI) double staining, and carboxy-fluorescein diacetate (CDFA) staining. Of these five supplementary methods, the Live/Dead BacLightTM staining and CFDA-DVC staining currently appear to be the most accurate for VBNC Lm enumeration. In addition, the impact of the VBNC state on the virulence of Lm is reviewed. Widespread use of these supplemental methods would provide supporting data to identify the conditions under which Lm can revert from its VBNC state into an actively multiplying state and help identify the environmental triggers that can cause Lm to become virulent. Highlights: Rationale for testing for all viable Listeria (Lm) is presented. Routine environmental sampling and plating methods may miss viable Lm cells. An overview and comparison of available VBNC testing methods is given. There is a need for resuscitation techniques to recover Lm from VBNC. A review of testing results for post VBNC virulence is compared.

Treatment for Severe Coronavirus Disease 2019 With the Seraph-100 Microbind Affinity Blood Filter.

To determine whether Seraph-100 (Exthera Medical Corporation, Martinez, CA) treatment provides clinical benefit for severe coronavirus disease 2019 cases that require mechanical ventilation and vasopressor support. DATA SOURCES: The first two patients in the United States treated with the novel Seraph-100 device. These cases were reviewed by the Food and Drug Administration prior to granting an emergency use authorization for treatment of coronavirus disease 2019. STUDY SELECTION: Case series. DATA EXTRACTION: Vasopressor dose, mean arterial pressure, temperature, interleukin-6, C-reactive protein, and other biomarker levels were documented both before and after Seraph-100 treatments. DATA SYNTHESIS: Vasopressor dose, temperature, interleukin-6, and C-reactive protein levels declined after Seraph-100 treatments. Severe acute respiratory syndrome coronavirus 2 viremia was confirmed in the one patient tested and cleared by the completion of treatments. CONCLUSIONS: Seraph-100 use may improve hemodynamic stability in coronavirus disease 2019 cases requiring mechanical ventilation and vasopressor support. These findings warrant future study of a larger cohort with the addition of mortality and total hospital day outcomes.

Phylogeography of the marine pathogen, Vibrio vulnificus, revealed the ancestral scenarios of its evolution.

Vibrio vulnificus is the leading cause of seafood-associated deaths worldwide. Despite the growing knowledge about the population structure of V. vulnificus, the evolutionary history and the ancestral relationships of strains isolated from various regions around the world have not been determined. Using the largest collection of sequence and isolate data of V. vulnificus to date, we applied ancestral character reconstruction to study the phylogeography of V. vulnificus. Multilocus sequence typing data from 10 housekeeping genes were used for the inference of ancestral states and reconstruction of the evolutionary history. The findings showed that the common ancestor of all V. vulnificus populations originated from East Asia, and later evolved into two main clusters that spread with time and eventually evolved into distinct populations in different parts of the world. While we found no meaningful insights concerning the evolution of V. vulnificus populations in the Middle East; however, we were able to reconstruct the ancestral scenarios of its evolution in East Asia, North America, and Western Europe.

Corrigendum: Phylogeny of Vibrio vulnificus From the Analysis of the Core-Genome: Implications for Intra-Species Taxonomy.

[This corrects the article DOI: 10.3389/fmicb.2017.02613.].

Survey of non-tunneled temporary hemodialysis catheter clinical practice and training.

BACKGROUND: Nephrologists are placing fewer non-tunneled temporary hemodialysis catheters. Requiring competence for nephrology fellow graduation is controversial. METHODS: Anonymous, online survey of all graduates from a single, military nephrology training program (n = 81; 1985-2017) and all US Nephrology program directors (n = 150). RESULTS: Graduate response and completion rates were 59% and 100%, respectively; 93% agreed they had been adequately trained; 58% (26/45) place non-tunneled temporary hemodialysis catheters, independent of academic practice or time in practice, but 12/26 did ⩽5/year and 23/26 referred some or all. The most common reason for continuing non-tunneled temporary hemodialysis catheter placement was that it is an essential emergency procedure (92%). The single most significant barrier was time to do the procedure (49%). Program director response and completion rates were 50% and 79%, respectively. The single most important barrier to fellow competence was busyness of the service (36%), followed by disinterest (21%); 55% believed that non-tunneled temporary hemodialysis catheter insertion competence should be required, with 81% indicating it was an essential emergency procedure. The majority of graduates and program directors agreed that simulation training was valuable; 76% of programs employ simulation. Graduates who had simulation training and program directors with ⩽20 years of practice were significantly more likely to agree that simulation training was necessary. CONCLUSION: Of the graduate respondents from a single training program, 58% continue to place non-tunneled temporary hemodialysis catheters; 55% of program directors believe non-tunneled temporary hemodialysis catheter procedural competence should be required. Graduates who had non-tunneled temporary hemodialysis catheter simulation training and younger program directors consider simulation training necessary. These findings should be considered in the discussion of non-tunneled temporary hemodialysis catheter curriculum requirements.

Relationship between the Viable but Nonculturable State and Antibiotic Persister Cells.

Bacteria have evolved numerous means of survival in adverse environments with dormancy, as represented by "persistence" and the "viable but nonculturable" (VBNC) state, now recognized to be common modes for such survival. VBNC cells have been defined as cells which, induced by some stress, become nonculturable on media that would normally support their growth but which can be demonstrated by various methods to be alive and capable of returning to a metabolically active and culturable state. Persister cells have been described as a population of cells which, while not being antibiotic resistant, are antibiotic tolerant. This drug-tolerant phenotype is thought to be a result of stress-induced and stochastic physiological changes as opposed to mutational events leading to true resistance. In this review, we describe these two dormancy strategies, characterize the molecular underpinnings of each state, and highlight the similarities and differences between them. We believe these survival modes represent a continuum between actively growing and dead cells, with VBNC cells being in a deeper state of dormancy than persister cells.

Vibrio spp. infections.

Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats; of the >100 described Vibrio spp., ~12 cause infections in humans. Vibrio cholerae can cause cholera, a severe diarrhoeal disease that can be quickly fatal if untreated and is typically transmitted via contaminated water and person-to-person contact. Non-cholera Vibrio spp. (for example, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus) cause vibriosis - infections normally acquired through exposure to sea water or through consumption of raw or undercooked contaminated seafood. Non-cholera bacteria can lead to several clinical manifestations, most commonly mild, self-limiting gastroenteritis, with the exception of V. vulnificus, an opportunistic pathogen with a high mortality that causes wound infections that can rapidly lead to septicaemia. Treatment for Vibrio spp. infection largely depends on the causative pathogen: for example, rehydration therapy for V. cholerae infection and debridement of infected tissues for V. vulnificus-associated wound infections, with antibiotic therapy for severe cholera and systemic infections. Although cholera is preventable and effective oral cholera vaccines are available, outbreaks can be triggered by natural or man-made events that contaminate drinking water or compromise access to safe water and sanitation. The incidence of vibriosis is rising, perhaps owing in part to the spread of Vibrio spp. favoured by climate change and rising sea water temperature.

Survey of Kidney Biopsy Clinical Practice and Training in the United States.

BACKGROUND AND OBJECTIVES: Practicing clinical nephrologists are performing fewer diagnostic kidney biopsies. Requiring biopsy procedural competence for graduating nephrology fellows is controversial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: An anonymous, on-line survey of all Walter Reed training program graduates (n=82; 1985-2017) and all United States nephrology program directors (n=149; August to October of 2017), regarding kidney biopsy practice and training, was undertaken. RESULTS: Walter Reed graduates' response and completion rates were 71% and 98%, respectively. The majority felt adequately trained in native kidney biopsy (83%), transplant biopsy (82%), and tissue interpretation (78%), with no difference for ≤10 versus >10 practice years. Thirty-five percent continued to perform biopsies (13% did ≥10 native biopsies/year); 93% referred at least some biopsies. The most common barriers to performing biopsy were logistics (81%) and time (74%). Program director response and completion rates were 60% and 77%. Seventy-two percent cited ≥1 barrier to fellow competence. The most common barriers were logistics (45%), time (45%), and likelihood that biopsy would not be performed postgraduation (41%). Fifty-one percent indicated that fellows should not be required to demonstrate minimal procedural competence in biopsy, although 97% agreed that fellows should demonstrate competence in knowing/managing indications, contraindications, and complications. Program directors citing ≥1 barrier or whose fellows did <50 native biopsies/year in total were more likely to think that procedural competence should not be required versus those citing no barriers (P=0.02), or whose fellows performed ≥50 biopsies (P<0.01). CONCLUSIONS: Almost two-thirds of graduate respondents from a single military training program no longer perform biopsy, and 51% of responding nephrology program directors indicated that biopsy procedural competence should not be required. These findings should inform discussion of kidney biopsy curriculum requirements.

Vibrio vulnificus: new insights into a deadly opportunistic pathogen.

Vibrio vulnificus is a Gram-negative aquatic bacterium first isolated by the United States (US) Centers for Disease Control and Prevention (CDC) in 1964. This bacterium is part of the normal microbiota of estuarine waters and occurs in high numbers in molluscan shellfish around the world, particularly in warmer months. Infections in humans are derived from consumption of seafood produce and from water exposure. Vibrio vulnificus is a striking and enigmatic human pathogen, yet many aspects related to its biology, genomics, virulence capabilities and epidemiology remain elusive and poorly understood. This pathogen is responsible for over 95% of seafood-related deaths in the United States, and carries the highest fatality rate of any food-borne pathogen. Indeed, infections associated with this pathogen that progress to primary septicaemia have a similar case fatality rate to category BSL 3 and 4 pathogens, such as anthrax, bubonic plague, Ebola and Marburg fever. Interestingly, V. vulnificus infections disproportionately affect males (∼85% of cases) and older patients (> 40 years), especially those with underlying conditions such as liver diseases, diabetes and immune disorders. New insights from molecular studies and comparative genomic approaches have offered tantalising insights into this pathogen. A recent increase and geographical spread in reported infections, in particular wound cases, underlines the growing international importance of V. vulnificus, particularly in the context of coastal warming. We outline and explore here a range of current data gaps regarding this important pathogen, and provide some current thoughts on approaches to elucidate key aspects associated with this bacterium.

Different abundance and correlational patterns exist between total and presumed pathogenic Vibrio vulnificus and V. parahaemolyticus in shellfish and waters along the North Carolina coast.

Monitoring of Vibrio vulnificus and V. parahaemolyticus abundance is pertinent due to the ability of these species to cause disease in humans through aquatic vectors. Previously, we performed a multiyear investigation tracking Vibrio spp. levels in five sites along the southeastern North Carolina coast. From February 2013 to October 2015, total V. vulnificus and V. parahaemolyticus abundance was measured in water, oysters and clams. In the current study, pathogenic subpopulations were identified in these isolates using molecular markers, revealing that 5.3% of V. vulnificus isolates possessed the virulence-correlated gene (vcgC), and 1.9% of V. parahaemolyticus isolates harbored one or both of the virulence-associated hemolysin genes (tdh and trh). Total V. parahaemolyticus abundance was not sufficient to predict the abundance of pathogenic subpopulations. Specifically, pathogenic V. parahaemolyticus isolates were more often isolated in cooler waters and were sometimes isolated when no other V. parahaemolyticus strains were detectable. Vibrio vulnificus clinical (C-) genotypes correlated with total V. vulnificus; however, salinity, water depth and total suspended solids influenced C- and E-genotypes differently. Lastly, we documented individual oysters harboring significantly higher V. vulnificus levels for which there was no ecological explanation, a phenomenon that deserves closer attention due to the potentially elevated health hazard associated with these 'hot' shellfish.

Interinstrumental transfer of a fast short-end injection capillary electrophoresis method: Application to the separation of niobium, tantalum, and their substituted ions.

The interinstrumental transfer of a short-end CE method was studied. A model separation of the hexameric forms of niobium, tantalum, and their substituted ions (Nb6-x Tax with 0 ≤ x ≤ 6) was selected as test case. The method was first optimized on a Beckman instrument and in a second step transferred to an Agilent instrument. The transfer needed updated guidelines that tackled differences in effective capillary length, 8.5 (Agilent) versus 10 cm (Beckman), because of instrumental different capillary cartridges. Differences in effective length lead to migration time and separation efficiency inequalities, illustrated by a decrease in resolution between the substituted ions. The difference in effective length was overcome by adapting the lift offset parameter of the Agilent instrument. The lift offset default setting is 4 mm and by increasing this parameter both the inlet and outlet lifts are lowered and thus the detection window can be displaced and consequently the effective length was increased. The decrease in effective length difference and the effect on the separation efficiency was investigated and led finally to a restored separation of the substituted ions. The adaptation of the lift offset parameter during short-end injection methods was added to earlier developed guidelines to facilitate interinstrumental method transfer of CE methods.

Impact of hypoxia on gene expression patterns by the human pathogen, Vibrio vulnificus, and bacterial community composition in a North Carolina estuary.

Estuarine environments are continuously being shaped by both natural and anthropogenic sources which directly/indirectly influence the organisms that inhabit these important niches on both individual and community levels. Human infections caused by pathogenic Vibrio species are continuing to rise, and factors associated with global climate change have been suggested to be impacting their abundance and geographical range. Along with temperature, hypoxia has also increased dramatically in the last 40 years, which has led to persistent dead zones worldwide in areas where these infections are increasing. Thus, utilizing membrane diffusion chambers, we investigated the impact of in situ hypoxia on the gene expression of one such bacterium, Vibrio vulnificus, which is an inhabitant of these vulnerable areas worldwide. By coupling these data with multiple abiotic factors, we were able to demonstrate that genes involved in numerous functions, including those involved in virulence, environmental persistence, and stressosome production, were negatively correlated with dissolved oxygen. Furthermore, comparing 16S ribosomal RNA, we found similar overall community compositions during both hypoxia and normoxia. However, unweighted beta diversity analyses revealed that although certain classes of bacteria dominate in both low- and high-oxygen environments, there is the potential for quantitative shifts in lower abundant species, which may be important for effective risk assessment in areas that are becoming increasingly more hypoxic. This study emphasizes the importance of investigating hypoxia as a trigger for gene expression changes by marine Vibrio species and highlights the need for more in depth community analyses during estuarine hypoxia.