ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.

Prevalence and risk factors of exit-site infection in incident peritoneal dialysis patients

BACKGROUND

Exit-site infection (ESI) is a common complication in peritoneal dialysis (PD) patients. Clearly understanding the risk factors may be useful for the prevention of ESI. This study was to explore the prevalence and risk factors of ESI in incident PD patients.

METHODS

We evaluated ESI in incident PD patients who had catheter insertion in our center between 1 January 2009 and 31 December 2013, with follow-up for 1 year. We collected data on demographics, clinical features, and nursing care methods of the exit site (ES).

RESULTS

We recruited 1133 incident PD patients (687 male (60.6%); mean age 47.0 ± 15.1 years), and 245 (21.6%) had diabetes. Median follow-up was 12.0 months. One hundred and thirty-one patients had 139 episodes of ESI with a rate of 92.8 patient-months per episode (0.13 episodes per year). Coagulase-negative staphylococcus was the main pathogen, accounting for 33.8% of the ESIs. Gram-positive rods, Staphylococcus aureus, Pseudomonas, fungi, and other organisms accounted for 23.0%, 15.8%, 1.4%, 1.4%, and 2.9%, respectively. No bacterial growth was found in 15.1%. There were no differences in demographic and laboratory data (age, gender, primary kidney disease, hemoglobin, white blood cell, serum albumin, blood urea nitrogen, serum creatinine, and C-reactive protein) between the ESI and non-ESI groups. Poor competency of ES care, poor catheter immobilization, history of catheter-pulling injury, and mechanical stress on the ES were significantly associated with increased risk of ESI.

CONCLUSIONS

The prevalence of ESI was 0.13 episodes per year. Poor competency of ES care, catheter mobilization, history of catheter-pulling injury, and mechanical stress by waist belt or the protective bag of PD on ES were risk factors for ESI.

Frog Skin-Derived Peptides Against Corynebacterium jeikeium: Correlation between Antibacterial and Cytotoxic Activities

Corynebacterium jeikeium is a commensal bacterium that colonizes human skin, and it is part of the normal bacterial flora. In non-risk subjects, it can be the cause of bad body smell due to the generation of volatile odorous metabolites, especially in the wet parts of the body that this bacterium often colonizes (i.e., groin and axillary regions). Importantly, in the last few decades, there have been increasing cases of serious infections provoked by this bacterium, especially in immunocompromised or hospitalized patients who have undergone installation of prostheses or catheters. The ease in developing resistance to commonly-used antibiotics (i.e., glycopeptides) has made the search for new antimicrobial compounds of clinical importance. Here, for the first time, we characterize the antimicrobial activity of some selected frog skin-derived antimicrobial peptides (AMPs) against C. jeikeium by determining their minimum inhibitory and bactericidal concentrations (MIC and MBC) by a microdilution method. The results highlight esculentin-1b(1-18) [Esc(1-18)] and esculentin-1a(1-21) [Esc(1-21)] as the most active AMPs with MIC and MBC of 4-8 and 0.125-0.25 µM, respectively, along with a non-toxic profile after a short- and long-term (40 min and 24 h) treatment of mammalian cells. Overall, these findings indicate the high potentiality of Esc(1-18) and Esc(1-21) as (i) alternative antimicrobials against C. jeikeium infections and/or as (ii) additives in cosmetic products (creams, deodorants) to reduce the production of bad body odor.

Peritoneal Dialysis Cuff-Shaving-A Salvage Therapy for Refractory Exit-Site Infections

Introduction:Cuff-shaving has been described as a salvage technique for refractory exit-site infections, with conflicting data regarding infection and catheter outcomes. We describe our experience with cuff-shaving as a rescue therapy for exit-site infections unresponsive to systemic therapy.Methods:We retrospectively reviewed patients who underwent cuff-shaving between January 2012 and June 2017. Refractory exit-site infection was defined as purulent discharge from the exit site with no clinical response after 3 weeks of systemic antibiotic treatment.Results:Fifty-three cuff-shavings were included, mean age was 53.4 ± 13.4 years, 26 patients were male. Median dialysis vintage was 29 months (interquartile range [IQR] 14.3 - 38), and 39 (73.6%) were on continuous ambulatory peritoneal dialysis (CAPD). The exit-site infection rate before cuff-shaving was 1.12 episodes per patient-year and the median time from infection to shaving was 52 days (IQR 35 - 76). The most frequent agents were Staphylococcus aureus (34%), Corynebacterium spp. (17%) and Pseudomonas aeruginosa (15%). Median follow-up was 9 months (IQR 1 - 18.5), during which time 35 catheters were removed, 5 due to non-infectious reasons. Using the Kaplan-Meier survival analysis, median catheter survival was 24 months (95% confidence interval [CI] 4.17 - 43.83). At 12 months, the probability of catheter survival was 54% and was not statistically different between gram-positive and gram-negative agents, although it was significantly shorter for fungal agents.Conclusion:Cuff-shaving is a feasible rescue therapy to treat refractory exit-site infections. In our experience, it allowed resolution of infections in a significant proportion of cases, except for fungal agents, and therefore extended catheter survival time, besides being associated with a small rate of complications.

A corny cause of cerebrospinal fluid ascites: A case report and review of literature

OBJECTIVE

To report a rare cause of cerebrospinal fluid ascites.

METHODS

A 37-year-old female with history of intracranial hypertension and a ventriculo-peritoneal shunt was referred to liver clinic for evaluation of newly developed ascites.

RESULTS

Initially, the cause of ascites was thought to be secondary to a liver etiology. However, this was excluded after a comprehensive evaluation including portal pressure measurements. We determined the ascites to be infected cerebrospinal fluid secondary to a rare commensal organism, Corynebacterium non-Jeikeium, which resolved after removing ventriculo-peritoneal shunt, appropriate antibiotics and conversion to a ventriculo-atrial shunt.

CONCLUSION

Cerebrospinal fluid ascites is a rare complication of VP shunts and since 1976 only 8 cases of Corynebacterium non jk VP shunt infections have been reported in the literature but none associated with ascites. Also this report highlights the beneficial role of transjugular portal pressure measurements in the evaluation of ascites.

Clinical significance of coryneform Gram-positive rods from blood identified by MALDI-TOF mass spectrometry and their susceptibility profiles - a retrospective chart review

With the advent of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), most Gram-positive rods (GPRs) are readily identified; however, their clinical relevance in blood cultures remains unclear. Herein, we assessed the clinical significance of GPRs isolated from blood and identified in the era of MALDI-TOF MS. A retrospective chart review of patients presenting to the Mayo Clinic, Rochester, MN, from January 1, 2013, to October 13, 2015, was performed. Any episode of a positive blood culture for a GPR was included. We assessed the number of bottles positive for a given isolate, time to positivity of blood cultures, patient age, medical history, interpretation of culture results by the healthcare team and whether infectious diseases consultation was obtained. We also evaluated the susceptibility profiles of a larger collection of GPRs tested in the clinical microbiology laboratory of the Mayo Clinic, Rochester, MN from January 1, 2013, to October 31, 2015. There were a total of 246 GPRs isolated from the blood of 181 patients during the study period. 56% (n = 101) were deemed contaminants by the healthcare team and were not treated; 33% (n = 59) were clinically determined to represent true bacteremia and were treated; and 8% (n = 14) were considered of uncertain significance, with patients prescribed treatment regardless. Patient characteristics associated with an isolate being treated on univariate analysis included younger age (P = 0.02), identification to the species level (P = 0.02), higher number of positive blood culture sets (P < 0.0001), lower time to positivity (P < 0.0001), immunosuppression (P = 0.03), and recommendation made by an infectious disease consultant (P = 0.0005). On multivariable analysis, infectious diseases consultation (P = 0.03), higher number of positive blood culture sets (P = 0.0005) and lower time to positivity (P = 0.03) were associated with an isolate being treated. 100, 83, 48 and 34% of GPRs were susceptible to vancomycin, meropenem, penicillin and ceftriaxone, respectively.

Corynebacterium diphtheriae as an emerging pathogen in nephrostomy catheter-related infection: evaluation of traits associated with bacterial virulence

Corynebacterium diphtheriae still represents a global medical challenge, particularly due to the significant number of individuals susceptible to diphtheria and the emergence of non-toxigenic strains as the causative agents of invasive infections. In this study, we characterized the clinical and microbiological features of what we believe to be the first case of C. diphtheriae infection of a percutaneous nephrostomy catheter insertion site in an elderly patient with a fatal bladder cancer. Moreover, we demonstrated the potential role of adherence, biofilm formation and fibrin deposition traits in C. diphtheriae from the catheter-related infection. Non-toxigenic C. diphtheriae isolated from the purulent discharge (named strain BR-CAT5003748) was identified by the API Coryne system (code 1 010 324) and a multiplex PCR for detection of dtxR and tox genes. Strain BR-CAT5003748 showed resistance to oxacillin, ceftazidime and ciprofloxacin. In experiments performed in vitro, the catheter isolate was classified as moderately hydrophobic and as moderately adherent to polystyrene surfaces. Glass provided a more effective surface for biofilm formation than polystyrene. Micro-organisms adhered to (>1.5 x 10(6) c.f.u.) and multiplied on surfaces of polyurethane catheters. Microcolony formation (a hallmark of biofilm formation) and amorphous accretions were observed by scanning electron microscopy on both external and luminal catheter surfaces. Micro-organisms yielded simultaneous expression of localized adherence-like and aggregative-like (LAL/AAL) adherence patterns to HEp-2 cells. Interestingly, the coagulase tube test resulted in the formation of a thin layer of fibrin embedded in rabbit plasma by the non-toxigenic BR-CAT5003748 strain. In conclusion, C. diphtheriae should be recognized as a potential cause of catheter-related infections in at-risk populations such as elderly and cancer patients. LAL/AAL strains may be associated with virulence traits that enable C. diphtheriae to effectively produce biofilms on catheter surfaces. Biofilm formation and fibrin deposition could have contributed to the persistence of C. diphtheriae at the infected insertion site and the obstruction of the nephrostomy catheter.