Klebsiella pneumoniae causes a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically, K. pneumoniae has caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore, K. pneumoniae strains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity in K. pneumoniae strains, and not every factor plays the same critical role in all virulent Klebsiella strains. Recent studies have identified additional K. pneumoniae virulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections.

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

Introduction A Why POC Diagnostics? B Time B Patient Responsibility and Compliance B Cost B Diagnostic Targets C Proteins C Metabolites and Other Small Molecules C Nucleic Acids C Human Cells D Microbes/Pathogens D Drugs and Food Safety D Current Context of POC Assays E POC Glucose Assays E Lateral Flow Assays E Limitations of “Traditional” POC Approaches F Enabling Technologies G Printing and Laminating G Microfluidic Technologies and Approaches: “Unit Operations” for POC Devices G Pumping and Valving H Mixing I Separation I Reagent Storage J Sample Preparation K Surface Chemistry and Device Substrates L Physical Adsorption L Bioaffinity Attachment L Covalent Attachment M Substrate Materials M Detection M Electrochemical Detection N Optical Detection N Magnetic Detection N Label-Free Methods O Enabling Multiplexed Assays O Recent Innovation O Lateral Flow Assay Technologies O Proteins P Antibodies P Protein Expression and Purification Q Nucleic Acids Q Aptamers R Infectious Diseases and Food/Water Safety R Blood Chemistry S Coagulation Markers S Whole Cells S Trends, Unmet Needs, Perspectives T Glucose T Global Health and the Developing World T Personalized Medicine and Home Testing U Technology Trends U Multiplexing V Author Information V Biographies V Acknowledgment W References W

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Point of care diagnostics: Status and future

Contrary to common belief, the association between diabetes mellitus and increased susceptibility to infection in general is not supported by strong evidence.1,2 However, many specific infections are more common in diabetic patients, and some occur almost exclusively in them. Other infections occur with increased severity and are associated with an increased risk of complications in patients with diabetes. Several aspects of immunity are altered in patients with diabetes. Polymorphonuclear leukocyte function is depressed, particularly when acidosis is also present. Leukocyte adherence, chemotaxis, and phagocytosis may be affected.3–5 Antioxidant systems involved in bactericidal activity may also be impaired.6 The . . .

Infections in patients with diabetes mellitus.

142 Summary of Recommendation Statements 143 Chapter 1: Introduction 154 Chapter 2: General principles in the management of glomerular disease 156 Chapter 3: Steroid-sensitive nephrotic syndrome in children 163 Chapter 4: Steroid-resistant nephrotic syndrome in children 172 Chapter 5: Minimal-change disease in adults 177 Chapter 6: Idiopathic focal segmental glomerulosclerosis in adults 181 Chapter 7: Idiopathic membranous nephropathy 186 Chapter 8: Idiopathic membranoproliferative glomerulonephritis 198 Chapter 9: Infection-related glomerulonephritis 200 Chapter 10: Immunoglobulin A nephropathy 209 Chapter 11: Henoch-Schönlein purpura nephritis 218 Chapter 12: Lupus nephritis 221 Chapter 13: Pauci-immune focal and segmental necrotizing glomerulonephritis 233 Chapter 14: Anti-glomerular basement membrane antibody glomerulonephritis 240 Methods for guideline development 243 Biographic and Disclosure Information 252

KDIGO Clinical Practice Guideline for Glomerulonephritis

Hosts and bacteria have coevolved over millions of years, during which pathogenic bacteria have modified their virulence mechanisms to adapt to host defense systems. Although the spread of pathogens has been hindered by the discovery and widespread use of antimicrobial agents, antimicrobial resistance has increased globally. The emergence of resistant bacteria has accelerated in recent years, mainly as a result of increased selective pressure. However, although antimicrobial resistance and bacterial virulence have developed on different timescales, they share some common characteristics. This review considers how bacterial virulence and fitness are affected by antibiotic resistance and also how the relationship between virulence and resistance is affected by different genetic mechanisms (e.g., coselection and compensatory mutations) and by the most prevalent global responses. The interplay between these factors and the associated biological costs depend on four main factors: the bacterial species involved, virulence and resistance mechanisms, the ecological niche, and the host. The development of new strategies involving new antimicrobials or nonantimicrobial compounds and of novel diagnostic methods that focus on high-risk clones and rapid tests to detect virulence markers may help to resolve the increasing problem of the association between virulence and resistance, which is becoming more beneficial for pathogenic bacteria.

Antimicrobial Resistance and Virulence: a Successful or Deleterious Association in the Bacterial World?

Background Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas. The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain. Objectives To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings. Patients and Methods Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997. According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN. The clinical manifestations, management, and outcome were compared. The gas contents of specimens from 6 patients were analyzed. The pathological findings from 8 patients who received nephrectomy were reviewed. The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis. Results Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit. The other 2 nondiabetic patients (4%) had severe hydronephrosis. Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A 1c level higher than 0.08. Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens. The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients). The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients). In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived. In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P Conclusions Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN. Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation. For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome. For extensive EPN (classes 3 and 4) with a more benign manifestation (ie,

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/485260/ioi81340.pdf

Emphysematous Pyelonephritis: Clinicoradiological Classification, Management, Prognosis, and Pathogenesis

Background. In dialysis patients, protein-energy wasting (PEW) is associated with high mortality, and some indicators of PEW, such as serum albumin value, subjective global assessment (SGA) score and handgrip strength (HGS), may predict mortality. However, whether PEW is associated with poor renal outcomes and whether the indicators of PEW can predict renal outcomes in patients with non-dialysis-dependent chronic kidney disease (CKD-ND) is still unclear.Methods. We enrolled 128 clinically stable patients with CKD-ND and followed up for 33.8 +/- 9.2 months. Baseline characteristics, echocardiographic information, laboratory data, HGS, SGA scores, anthropometric parameters, bio-impedance analyses and other indicators of PEW were examined in relation to the risk of reaching renal composite end points of pre-dialysis mortality or dialysis-dependent end-stage renal disease.Results. Twenty-six patients reached composite renal end points. Multivariate Cox regression analyses showed that HGS was an independent predictor of renal outcome in patients with CKD-ND of Stages 1-5 [CKD(1-5), hazard ratio (HR) = 0.90, P = 0.004] or advanced CKD-ND of Stages 3b [defined as estimated glomerular filtration rate (eGFR) of 30-44 mL/min/1.73m(2)] to 5 (CKD(3b-5), HR 0.91, P = 0.031), but not serum albumin, SGA score or other indicators of PEW. When the cutoffs were set at 24.65 kg in men with CKD(1-5), 20.15 kg in men with CKD(3b-5) and 10.15 kg in women with CKD(1-5) or CKD(3b-5), which were deduced from receiver-operating characteristics analyses, patients with lower HGS had significantly poor renal outcomes in Kaplan-Meier survival analyses in all subgroups and higher HR for reaching renal end points in multivariate Cox regression analyses in all subgroups except for women with CKD(3b-5), whose HR had marginal significance (HR = 3.78, P = 0.068) after adjusting for age and eGFR.Conclusions. This is the first study demonstrating that HGS is an independent predictor of composite renal outcomes in CKD-ND patients. HGS can be incorporated to clinical practice for assessing nutrition status and renal prognosis in patients with CKD-ND.

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Handgrip strength is an independent predictor of renal outcomes in patients with chronic kidney diseases

Outer membrane proteins (OMPs) serve as the permeability channels for nutrients, toxins, and antibiotics. In Escherichia coli, OmpA has been shown to be involved in bacterial virulence, and OmpC is related to multidrug resistance. However, it is unclear whether OmpC also has a role in the virulence of E. coli. The aims of this study were to characterize the role of OmpC in antimicrobial resistance and bacterial virulence in E. coli. The ompC deletion mutant showed significantly decreased susceptibility to carbapenems and cefepime. To investigate the survival of E. coli exposed to the innate immune system, a human blood bactericidal assay showed that the ompC mutant increased survival in blood and serum but not in complement-inactivated serum. These effects were also demonstrated in the natural selection of OmpC mutants. Also, C1q interacted with E. coli through a complex of antibodies bound to OmpC as a major target. Bacterial survival was increased in the wild-type strain in a dose-dependent manner by adding free recombinant OmpC protein or anti-C1q antibody to human serum. These results demonstrated that the interaction of OmpC-specific antibody and C1q was the key step in initiating the antibody-dependent classical pathway for the clearance of OmpC-expressing E. coli. Anti-OmpC antibody was detected in human sera, indicating that OmpC is an immunogen. These data indicate that the loss of OmpC in E. coli is resistant to not only antibiotics, but also the serum bactericidal effect, which is mediated from the C1q and anti-OmpC antibody-dependent classical pathway.

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Loss of Outer Membrane Protein C in Escherichia coli Contributes to Both Antibiotic Resistance and Escaping Antibody-Dependent Bactericidal Activity

Microfluidic paper-based platform for whole blood creatinine detection

https://www.ajkd.org/article/S0272-6386(05)00740-7/pdf

Chin Chung Tseng

Papers

Emphysematous Pyelonephritis: Clinicoradiological Classification, Management, Prognosis, and Pathogenesis

Handgrip strength is an independent predictor of renal outcomes in patients with chronic kidney diseases

Loss of Outer Membrane Protein C in Escherichia coli Contributes to Both Antibiotic Resistance and Escaping Antibody-Dependent Bactericidal Activity

Microfluidic paper-based platform for whole blood creatinine detection

Host and bacterial virulence factors predisposing to emphysematous pyelonephritis.