Psychrobacter raelei sp. nov., isolated from a dog with peritonitis.

A strain belonging to the genus Psychrobacter, named PraFG1T, was isolated from the peritoneal effusion of a stray dog during necropsy procedures. The strain was characterized by the phylogenetic analyses based on the nucleotide sequences of 16S and 23S rRNA genes and of gyrB, which placed the strain in the genus Psychrobacter. The nucleotide sequence of the chromosome confirmed the placement, showing an average nucleotide identity of 72.1, 77.7, and 77.5 % with the closest related species, namely Psychrobacter sanguinis, Psychrobacter piechaudii, and Psychrobacter phenylpyruvicus, respectively, thus indicating a novel species. The polyphasic characterization by biochemical and fatty acid profiling as well as MALDI-TOF supported those findings. The strain was halotolerant, capable of growing within a temperature range between 4 and 37 °C, it was positive for catalase and oxidase, indole producing, nitrate reducing, and not able to use 5-keto-d-gluconic acid as a carbon source. Taken together, the data suggest that strain PraFG1T could be considered as representing a novel species, with the name Psychrobacter raelei sp. nov. (type strain PraFG1T=CIP 111873T=LMG 32233T).

Antibiotic Treatment in Complicated Appendicitis: Can It Be Optimized?

BACKGROUND: The management of complicated appendicitis is inconclusive. Guidelines have not been established for the use of personalized antibiotic treatment. OBJECTIVES: To investigate specific risk factors to consider during the initial first-choice antibiotic therapy in children with complicated appendicitis. METHODS: This study included all pediatric patients younger than 18 years of age who underwent a laparoscopic appendectomy during 2012-2022 at a single tertiary medical center. RESULTS: In total, 300 pediatric patients underwent laparoscopic appendectomy due to complicated appendicitis. The patients were treated with ceftriaxone + metronidazole (CM). For 57 (19%) patients, the empirical treatment was changed to tazobactam/piperacillin (TP) due to resistant bacteria or clinical deterioration. The presence of generalized peritonitis during surgery and C-reactive protein (CRP) levels above 20 mg/L at admission were identified as risk factors for changing the antibiotic regimen from CM to TP. CONCLUSIONS: Generalized peritonitis and CRP > 20 gr/L were highly correlated with changing the antibiotic regimen to TP. For such patients, initial treatment with TP may result in clinical improvement and shorter hospitalization.

Prognosis of spontaneous bacterial peritonitis in patients with hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fourth leading cause of death from cancer worldwide. Spontaneous bacterial peritonitis (SBP) is associated with poor prognosis. This study aimed to evaluate risk factors, differences in clinical characteristics and prognosis of SBP in patients with HCC in comparison with non-HCC patients. METHODS: This study was conducted on patients with cirrhosis who were admitted to hospital with SBP. The patients were divided into two groups: SBP group with HCC (n = 150) and SBP group without HCC (n = 250). RESULTS: Men and women accounted for 72% and 28% (n = 108 and 42, respectively) of the population in SBP group with HCC with mean age 55.8 ± 13.1 years. They accounted for 68.4% and 31.6% (n = 171 and 79, respectively) in the SBP group without HCC with mean age 56.8 ± 10.5 years. In-hospital mortality was 25.3% in the SBP group with HCC and 18.8% in SBP group without HCC. Gastrointestinal bleeding was the most common cause of death in both groups. No significant difference was observed in patient outcomes between the two studied groups. The deceased patients had significantly higher levels of leukocytes and neutrophils in ascitic fluid as well as a higher frequency of positive culture results than in patients who survived (p < 0.001). However, there was no significant difference in protein level in ascitic fluid or causative organism between patients who survived and those who died (p = 0.63 and 0.19, respectively). CONCLUSIONS: Prognosis of SBP in patients with HCC seemed similar to that in patients without HCC.

Risks of Proton Pump Inhibitors in Patients with Cirrhosis: Please Peruse the Indications.

The use of proton pump inhibitor (PPI) in cirrhotic patients can be associated with increased risks of long-term mortality, decompensation, hepatic encephalopathy, spontaneous bacterial peritonitis, and infection, but not with short-term mortality. Ensure clear indications at lowest effective dose of is mandatory for the use of PPI among cirrhotic patients.

Systematically analysis of decompensated cirrhotic patients with spontaneous bacterial peritonitis to identify diagnostic and prognostic indexes.

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a common complication in patients with cirrhosis. The diagnosis of SBP is still mostly based on ascites cultures and absolute ascites polymorphonuclear (PMN) cell count, which restricts the widely application in clinical settings. This study aimed to identify reliable and easy-to-use biomarkers for both diagnosis and prognosis of cirrhotic patients with SBP. METHODS: We conducted a retrospective study including 413 cirrhotic patients from March 2013 to July 2022 in the First Affiliated Hospital of Guangxi Medical University. Patients' clinical characteristics and laboratory indices were collected and analyzed. Two machine learning methods (Xgboost and LASSO algorithms) and a logistic regression analysis were adopted to screen and validate the indices associated with the risk of SBP. A predictive model was constructed and validated using the estimated area under curve (AUC). The indices related to the survival of cirrhotic patients were also analyzed. RESULTS: A total of 413 cirrhotic patients were enrolled in the study, of whom 329 were decompensated and 84 were compensated. 52 patients complicated and patients with SBP had a poorer Child-Pugh score (P < 0.05). Patients with SBP had a greater proportion of malignancies than those without SBP(P < 0.05). The majority of laboratory test indicators differed significantly between patients with and without SBP (P < 0.05). Albumin, neutrophil-to-lymphocyte ratio (NLR), and ferritin-to-neutrophil ratio (FNR) were found to be independently associated with SBP in decompensated cirrhotic patients using LASSO algorithms, and logistic regression analysis. The model established by the three indices showed a high predictive value with an AUC of 0.808. Furthermore, increased neutrophils, ALP, and C-reactive protein-to-albumin ratio (CAR) were associated with the shorter survival time of patients with decompensated cirrhosis, and the combination of these indices showed a greater predictive value for cirrhotic patients. CONCLUSIONS: The present study identified FNR as a novel index in the diagnosis of SBP in decompensated patients with cirrhosis. A model based on neutrophils, ALP and CAR showed high performance in predicting the prognosis of patients with decompensated cirrhosis.

Significance of Serum Procalcitonin and C-Reactive Protein in the Diagnosis and Prediction of Spontaneous Bacterial Peritonitis in Decompensated Chronic Liver Disease.

The role of serum procalcitonin (PCT) and C-reactive protein (CRP) levels in the diagnosis of spontaneous bacterial peritonitis (SBP) with decompensated chronic liver disease (CLD) has been a subject of debate. The purpose of this cross-sectional, observational study was to evaluate the significance of CRP and PCT for the diagnosis and prediction of SBP in decompensated CLD patients. Fifty patients with ascites due to decompensated CLD were enrolled conveniently from the department of Gastrointestinal, Hepatobiliary and Pancreatic disorders (GHPD), BIRDEM General Hospital, Bangladesh from July 2019 to July 2020. Of these decompensated CLD patients with SBP were enrolled as the case group and without SBP as control group. Diagnostic and predictive value of PCT and CRP were calculated using the different statistical analysis. Among 50 patients, SBP was diagnosed in 9 patients (18.0%). The ROC analysis results yielded that the optimum cut off value for PCT was 0.67ng/ml and sensitivity, specificity, positive predictive value, negative predictive value, accuracy, AUC were 88.9%, 90.2%, 66.6%, 97.3, 90%, 0.947 respectively. On the contrary the optimum cut off value for CRP was 57.4mg/L and sensitivity, specificity, positive predictive value, negative predictive value, accuracy, AUC were 77.8%, 85.4%, 53.8%, 94.5%, 84%, 0.859 respectively. Our results indicate that the value of serum PCT and CRP were reliable to diagnose SBP in ascites due to decompensated CLD. Serum PCT and CRP level measurements may provide an early good diagnostic test for SBP in decompensated CLD patients.

Bacterial peritonitis in paediatric appendicitis; microbial epidemiology and antimicrobial management.

BACKGROUND: Appendicitis remains a common surgical emergency in children. Empirical antibacterial treatment is indicated to reduce infective complications. We investigate the bacterial pathogens identified intra-operatively during appendectomies in children to guide empirical surgical antimicrobial prophylaxis options. METHODS: A retrospective analysis of patients (< 18 years old) undergoing an appendectomy across a multisite London hospital (Nov 2019-March 2022) was undertaken. Patient-related outcomes including length of hospital stay (LOS), days of antibacterial therapy (DOT), intra-operative microbiology and post-operative radiology reports were interrogated. RESULTS: 304 patients underwent an appendectomy during this period; 39.1% of patients had intraoperative samples cultured. Bacterial pathogens were found in 73/119 (61.3%) cases; the most common isolates being Escherichia coli (42.0%), Pseudomonas aeruginosa (21.0%), milleri Streptococcus spp. (14.3%) and Bacteroides fragilis (5.9%). Polymicrobial infection was common (32/73). Isolation of Pseudomonas spp. from intra-operative sampling was associated with a greater LOS (7.0 vs. 5.0 days; p = 0.011) but nil effect on the incidence of postoperative collections. Presence of milleri Streptococcus spp. was associated with longer LOS (7.0 vs. 5.0 day; p = 0.007), DOT (12.0 vs. 8.5 day; p = 0.007) but had no observed outcome on postoperative collections (29.4% vs. 18.6%; p = 0.330). 48% of E. coli positive cultures were co-amoxiclav resistant and prolonged LOS compared to the non-resistant group (7.0 vs. 5.0 days; p = 0.040) but had no difference in post-operative collections (29.2% vs. 17.9%; p = 0.260). CONCLUSION: A high proportion of children with appendicitis have Pseudomonas spp. isolated, leading to a prolonged LOS. Evolving Enterobacterales resistance and the presence of Pseudomonas spp. necessitate extended antibacterial coverage for paediatric appendectomies with evidence of peritonitis.

Impact of Prophylactic Norfloxacin in Multidrug Resistant Bacterial Infections in the Early Liver Posttransplant Period.

OBJECTIVES: Norfloxacin is indicated as primary or secondary prophylaxis for spontaneous bacterial peritonitis in patients with cirrhosis. A history of spontaneous bacterial peritonitis favors colonization by multidrug-resistant bacteria. Infections caused by these bacteria increase morbidity and mortality after transplant. We investigated prophylactic norfloxacin as a risk factor for multidrug-resistant bacterial infections in the early posttransplant period. MATERIALS AND METHODS: This prospective cohort study included all adult liver recipients in 2 centers between 2015 and 2016. Recipients were classified into 2 groups according to whether or not they received prophylactic norfloxacin pretransplant. Data collection from liver recipients included pretransplant and first month after transplant clinical and microbiological data. Demographic and clinical data of corresponding donors were also collected. RESULTS: We included 157 liver recipients: 54 (34.6%) received norfloxacin and 103 (65.6%) did not received norfloxacin. There were 63 postoperative infections in 47 recipients (29.9%); 17/63 (27%) were multidrug- resistant bacterial infections. The urinary tract was the most commonly affected site (10/17 episodes, 58.8%), and Klebsiella pneumoniae was the microorganism most often isolated (8/17, 47.1%). Incidence of multidrug-resistant bacterial infection was higher in the norfloxacin group (22.2% vs 4.9%; relative risk = 5.6, 95% CI, 1.85-16.89; P = .001).This association was significant after controlling for most confounding factors, including pretransplant vasoactive support (P = .03), Model for End-Stage Liver Disease score (P = .01), previous spontaneous bacterial peritonitis (P = .02), chronic renal impairment (P = .005), number of packed red blood cells (P = .004), use of antilymphocyte globulin as induction (P = .006), and hepatocellular carcinoma (P = .02), but not pre- transplant antibiotic treatment (P = .06). CONCLUSIONS: For recipients who have received prophylactic norfloxacin, clinicians should be aware of the high risk of multidrug-resistant bacterial infections during the first month after liver transplant.

A case report: Infection-related glomerulonephritis and mantle cell lymphoma due to mycobacterium avium complex infection.

RATIONALE: Mycobacterium avium complex (MAC) infection is common in lung, liver and skin. However, MAC presenting with peritonitis is uncommon and is particularly rare in immunocompetent patients. We report a case of infection-associated glomerulonephritis and mantle cell lymphoma caused by peritonitis due to MAC. PATIENT CONCERNS: We report a case of a 73-year-old elderly man with fever and abdominal pain for 2 days and gradually developed anuria, ascites, and abdominal lymphadenopathy. DIAGNOSES: The initial diagnosis was peritonitis and acute renal failure. There was no significant relief of symptoms after empirical anti-infective therapy and hemodialysis. infection-associated glomerulonephritis, mantle cell lymphoma, and peritonitis due to MAC were diagnosed by renal biopsy, abdominal lymph node biopsy, and metagenomics next-generation sequencing. INTERVENTIONS: The patient received empirical antibiotic therapy, hemodialysis, and anti-MAC therapy. OUTCOMES: Unfortunately, the patient eventually died of septic shock after the 21st day of admissiom. LESSONS: Early diagnosis of MAC infection is essential. When the cause of fever is unknown, metagenomics next-generation sequencing can be considered.

[Intra-abdominal infections in adults caused by Streptococcus pneumoniae: report of 18 cases] / Infecciones intraabdominales en adultos causadas por Streptococcus pneumoniae: reporte de 18 casos.

Introduction: Streptococcus pneumoniae (Spn) is occasionally implicated as a cause of intra-abdominal infection (IIASpn) that can be 1) spontaneous bacterial peritonitis (SBP) in elderly patients with previous peritoneal disease, associated with cirrhosis, in most of the cases 2) associated or adjacent to an intra-abdominal organ or postsurgical. (IIAbq) 3) peritonitis in previously healthy young women (PHYW). Our objective is report 18 cases of IIASpn describing: clinical presentation, comorbidities, need for surgery, microbiological findings, sensitivity of Spn to antimicrobials, therapeutic behavior, and evolution. Methods: study of 18 adult patients with IIASpn. Clinical and microbiological characteristics and evolution of infections were analyzed. Results: IIASpn occurred in 9 PHYW, 6 men and 1 woman with SBP, and 2 men with appendicitis. The PHYW were operated on (4 pelviperitonitis, 3 salpingitis, 2 and tubo ovarian abscess) and had a favorable evolution. In the intraoperative samples, pure culture of Spn sensitive to penicillin was isolated. Three of four patients had positive blood culture. Five of seven patients with SBP died and in the peritoneal fluid developed Spn in pure culture. A large percentage of strains presented decreased sensitivity to penicillin. Four of five had a positive blood culture. Patients with appendicitis had favorable evolution. Conclusions: IIASpn in PHYW was the most frequent presentation, surgery played a significant role in treatment and the clinical response was excellent. The second presentation occurred in elderly patients with cirrhosis, most of whom died. Appendicitis was the third presentation in patients who evolved favorably.

Introducción: Streptococcus pneumoniae (Spn) ocasionalmente causa infección intraabdominal (IIASpn) que puede ser: 1) peritonitis bacteriana espontánea (PBE) en paciente añosos con enfermedad peritoneal previa, asociada con cirrosis, en la mayoría de los casos; 2) asociada o adyacente a un órgano intraabdominal o postquirúrgica (IIAbq); 3) peritonitis en mujeres jóvenes previamente sanas (MJPS). Nuestro objetivo es reportar 18 casos de IIASpn describiendo: presentación clínica, comorbilidades, necesidad de cirugía, microbiología y sensibilidad a los antimicrobianos, conducta terapéutica y evolución. Métodos: estudio de 18 pacientes adultos con IIASpn en un período de 23 años. Análisis de las características clínicas, microbiología y evolución de los pacientes. Resultados: las IIASpn ocurrieron en 9 MJPS, 6 varones y una mujer con PBE, y 2 varones con apendicitis. Las MJPS fueron intervenidas quirúrgicamente (4 pelviperitonitis, 3 salpingitis y 2 abscesos tubo ovárico) y evolucionaron favorablemente. En las muestras intraoperatorias se aisló Spn cultivo puro sensible a penicilina. Tres de cuatro pacientes tuvieron hemocultivo positivo. Cinco de siete pacientes con PBE fallecieron y en las muestras de líquido peritoneal desarrolló Spn cultivo puro. Gran porcentaje de cepas presentó sensibilidad disminuida a penicilina. Cuatro de cinco, tuvieron hemocultivo positivo. Los pacientes con apendicitis evolucionaron favorablemente. Conclusiones: La IIASpn en MJPS fue la presentación más frecuente, la cirugía jugó un rol significativo en el tratamiento y la respuesta clínica fue excelente. La segunda presentación ocurrió en pacientes añosos con cirrosis y en su mayoría, fallecieron. La apendicitis fue la tercera presentación en pacientes que evolucionaron favorablemente.

Tubo-ovarian mass with raised CA-125 in a 21-year-old female.

INTRODUCTION: Peritonitis associated with fungal species Curvularia lunata seldom occurs with only five cases reported in the literature, all in middle-age patients with comorbidities undergoing dialysis. CASE REPORT: A 21-year-old female who was referred to surgical oncology OPD with a diagnosis of ovarian malignancy, based on raised cancer antigen 125 (CA 125) and suspected tubo-ovarian mass (TOM) on magnetic resonance imaging (MRI). A review of the MRI showed a pelvic collection with TOM, suggestive of infective pathology. Fungal culture and mass spectroscopy of the cystic collection identified the presence of Curvularia lunata. She was treated with oral itraconazole which showed symptomatic improvement and radiological response. In the follow-up period, the patient developed chest wall swelling, aspiration and geneXpert® revealed multidrug-resistant (MDR) tuberculosis, and treatment was started. CONCLUSIONS: Unusual causes of TOM and raised CA 125 should be kept in mind when dealing with young patients, as the possibility of epithelial ovarian cancer in this age is very low.

Human Amnion-Derived Mesenchymal Stromal Cells: A New Potential Treatment for Carbapenem-Resistant Enterobacterales in Decompensated Cirrhosis.

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with decompensated cirrhosis and ascites. The only cure for SBP is antibiotic therapy, but the emerging problem of bacterial resistance requires novel therapeutic strategies. Human amniotic mesenchymal stromal cells (hA-MSCs) possess immunomodulatory and anti-inflammatory properties that can be harnessed as a therapy in such a context. METHODS: An in vitro applications of hA-MSCs in ascitic fluid (AF) of cirrhotic patients, subsequently infected with carbapenem-resistant Enterobacterales, was performed. We evaluated the effects of hA-MSCs on bacterial load, innate immunity factors, and macrophage phenotypic expression. RESULTS: hA-MSCs added to AF significantly reduce the proliferation of both bacterial strains at 24 h and diversely affect M1 and M2 polarization, C3a complement protein, and ficolin 3 concentrations during the course of infection, in a bacterial strain-dependent fashion. CONCLUSION: This study shows the potential usefulness of hA-MSC in treating ascites infected with carbapenem-resistant bacteria and lays the foundation to further investigate antibacterial and anti-inflammatory roles of hA-MSC in in vivo models.

Identification of structurally diverse menaquinone-binding antibiotics with in vivo activity against multidrug-resistant pathogens.

The emergence of multidrug-resistant bacteria poses a threat to global health and necessitates the development of additional in vivo active antibiotics with diverse modes of action. Directly targeting menaquinone (MK), which plays an important role in bacterial electron transport, is an appealing, yet underexplored, mode of action due to a dearth of MK-binding molecules. Here we combine sequence-based metagenomic mining with a motif search of bioinformatically predicted natural product structures to identify six biosynthetic gene clusters that we predicted encode MK-binding antibiotics (MBAs). Their predicted products (MBA1-6) were rapidly accessed using a synthetic bioinformatic natural product approach, which relies on bioinformatic structure prediction followed by chemical synthesis. Among these six structurally diverse MBAs, four make up two new MBA structural families. The most potent member of each new family (MBA3, MBA6) proved effective at treating methicillin-resistant Staphylococcus aureus infection in a murine peritonitis-sepsis model. The only conserved feature present in all MBAs is the sequence 'GXLXXXW', which we propose represents a minimum MK-binding motif. Notably, we found that a subset of MBAs were active against Mycobacterium tuberculosis both in vitro and in macrophages. Our findings suggest that naturally occurring MBAs are a structurally diverse and untapped class of mechanistically interesting, in vivo active antibiotics.

Identifying early indicators of secondary peritonitis in critically ill patients with cirrhosis.

Ascitic fluid infection (AFI) is a life-threatening complication of cirrhosis. We aimed to identify early indicators of secondary peritonitis (SP), which requires emergency surgery, and to describe the outcomes of SP and spontaneous bacterial/fungal peritonitis (SBFP). Adults with cirrhosis and AFI admitted to 16 university or university-affiliated ICUs in France between 2002 and 2017 were studied retrospectively. Cases were identified by searching the hospital databases for relevant ICD-10 codes and hospital charts for AFI. Logistic multivariate regression was performed to identify factors associated with SP. Secondary outcomes were short- and long-term mortality and survivors' functional outcomes. Of 178 included patients (137 men and 41 women; mean age, 58 ± 11 years), 21 (11.8%) had SP, confirmed by surgery in 16 cases and by abdominal computed tomography in 5 cases. Time to diagnosis exceeded 24 h in 7/21 patients with SP. By multivariate analysis, factors independently associated with SP were ascitic leukocyte count > 10,000/mm3 (OR 3.70; 95%CI 1.38-9.85; P = 0.009) and absence of laboratory signs of decompensated cirrhosis (OR 4.53; 95%CI 1.30-15.68; P = 0.017). The 1-year mortality rates in patients with SBFP and SP were 81.0% and 77.5%, respectively (Log-rank test, P = 0.92). Patients with SP vs. SBFP had no differences in 1-year functional outcomes. This multicenter retrospective study identified two indicators of SP as opposed to SBFP in patients with cirrhosis. Using these indicators may help to provide early surgical treatment.

Are Pattern Recognition Receptors Associated with Hepatocellular Carcinoma?

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the important causes of mortality due to malignancy. Toll-like receptors (TLRs) are very important in liver pathophysiology in terms of their roles in the innate immune system, such as the regulation of inflammation, wound healing, stimulation of adaptive immune responses, promotion of epithelial regeneration, and carcinogenesis. In this study, we planned to examine the role of TLR1 (rs4833095, rs5743551) and nucleotide-binding oligomerization domain (NOD2) (rs2066844, rs2066845, rs2066847) polymorphisms in the development of HCC and their effects on the clinical presentation of HCC patients. METHODS: Our study was designed prospectively. Cirrhotic and HCC patients who were followed up in our clinic between January 2015 and September 2018 were included in the study. Sex, age, cirrhosis etiology, Child-Pugh class, and MELD scores were recorded. TLR1 and NOD2 polymorphisms were studied by the PCR method. RESULTS: HCC developed in 88 (31.4%) of the 280 patients who were followed up, either during the recruitment phase of our study or during the follow-up. The mean follow-up time of our patient group was 17.04 ± 11.72 months, and the mean follow-up time of HCC patients was 12.09 ± 10.26 months. TLR1 (rs5743551) polymorphism was associated with HCC development (P = .003). TLR1 (rs5743551) and NOD2 (rs2066844) polymorphisms were associated with the development of spontaneous bacterial peritonitis (SBP) in the HCC patient group (P = .013 and P = .021, respectively). CONCLUSION: We think that increased bacterial translocation in cirrhotic patients may contribute to HCC development by causing chronic inflammation, especially in patients with TLR 1 (rs5743551) polymorphism.

Safety of Endoscopy in Peritoneal Dialysis Patients.

INTRODUCTION: Endoscopic procedures can provoke peritonitis in patients receiving peritoneal dialysis (PD). The aim of this study was to assess the development of peritonitis after endoscopic procedures in PD patients. METHODS: We retrospectively reviewed the data from PD patients who underwent endoscopies in 3 tertiary hospitals between 2008 and 2018. The patients were grouped into nonprophylactic, prophylactic, and prior antibiotic therapy groups. The incidence of peritonitis within 7 days of endoscopy was assessed. We also examined the factors associated with peritonitis. RESULTS: There were 1,316 endoscopies performed in 570 PD patients. The peritonitis rate after endoscopy was 3.0%. Specifically, the peritonitis rate was 1.8% for esophagogastroduodenoscopies, 4.2% for the colonoscopy group, and 5.3% for the sigmoidoscopy group. The prior antibiotic therapy group showed a significantly higher risk of peritonitis (odds ratio = 4.6; 95% confidence interval: 2.2-9.6; P < 0.01). Prophylactic antibiotics were not associated with reducing peritonitis. Therapeutic colonoscopies such as polypectomy were associated with an increased risk of developing peritonitis (odds ratio = 6.5; 95% confidence interval: 1.6-25.9). However, biopsies were not associated with an increased risk of peritonitis. DISCUSSION: Prophylactic antibiotics did not reduce the risk of peritonitis after endoscopy in PD patients. Therapeutic colonoscopies such as polypectomy and prior antibiotic therapy before endoscopy were associated with an increased risk of peritonitis.

Factors Contributing to Peritonitis in Peritoneal Dialysis: Comparing Triple Cuff Saudi Catheter to Double Cuff Tenckhoff Catheter: A 12-Year Observational Study.

Very few detailed descriptive studies focusing on peritonitis in patients on peritoneal dialysis (PD) have been published. Most of the current information is available through from either study with the limited number of patients or isolated case reports. We conducted an observational study of our PD-peritonitis database over the past 12 years to study the clinical profile and the outcomes of peritonitis episodes in our PD center. A total of 1123 patients (male: 59.5%) with 319 episodes of peritonitis were identified. Of the patients, 130 (11.6%) were considered immunocompromised (steroid use, failed renal transplant, systemic lupus erythematosus, malignancy) and 468 (41.7%) had diabetes mellitus. The total number of bacterial peritonitis episodes was 319; of these 226 (70.8%) were seen with double cuff Tenckhoff PD catheter and 93 (29.2%) occurred with triple-cuff Saudi PD catheter (P = 0.0001). Of all peritonitis episodes 170 (53.3%) episodes were caused by a single Gram-positive organism, 124 (38.9%) episodes by a single Gram-negative organism, and 25 (7.8%) were polymicrobial. Coagulase-negative staphylococci were responsible for most cases of Gram-positive peritonitis (n = 110, 64.7%), while Escherichia coli was the causative organism in 67 (54.0%) of the single Gram-negative episodes. Peritonitis episodes due to Gram-positive organisms had a better outcome than those caused by Gram-negative bacteria. Fifteen (4.7%) of the 319 episodes resulted in death in 13 patients. In 79 (24.8%) episodes, the patients had to be transferred to hemodialysis because of unresolved peritonitis. Resolution rate was 75.2% (240 episodes) which was influenced by PD catheter type, PD duration and the number of days peritoneal fluid effluent remained above 100 cells/µL. Other modifiable and non-modifiable factors had no effect on the resolution rate. Peritonitis episodes due to Gram-positive organisms had a better outcome than those with Gram-negative or polymicrobial etiology. Peritonitis resolution rates were worse with Staphylococcus aureus and Pseudomonas aeruginosa infections. Diabetes, current steroid use, and exit-site/tunnel infections seemed to have limited influence on the peritonitis outcome. Type of PD catheter (double Tenckhoff vs triple-cuff Saudi catheter), duration of PD and the number of days peritoneal fluid effluent remained >100 cells/µL were the only factors with significant effects on the outcome.

Dietary Fiber Drives IL-1ß-Dependent Peritonitis Induced by Bacteroides fragilis via Activation of the NLRP3 Inflammasome.

Intestinal barrier is essential for dietary products and microbiota compartmentalization and therefore gut homeostasis. When this barrier is broken, cecal content overflows into the peritoneal cavity, leading to local and systemic robust inflammatory response, characterizing peritonitis and sepsis. It has been shown that IL-1ß contributes with inflammatory storm during peritonitis and sepsis and its inhibition has beneficial effects to the host. Therefore, we investigated the mechanisms underlying IL-1ß secretion using a widely adopted murine model of experimental peritonitis. The combined injection of sterile cecal content (SCC) and the gut commensal bacteria Bacteroides fragilis leads to IL-1ß-dependent peritonitis, which was mitigated in mice deficient in NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome components. Typically acting as a damage signal, SCC, but not B. fragilis, activates canonical pathway of NLRP3 promoting IL-1ß secretion in vitro and in vivo. Strikingly, absence of fiber in the SCC drastically reduces IL-1ß production, whereas high-fiber SCC conversely increases this response in an NLRP3-dependent manner. In addition, NLRP3 was also required for IL-1ß production induced by purified dietary fiber in primed macrophages. Extending to the in vivo context, IL-1ß-dependent peritonitis was worsened in mice injected with B. fragilis and high-fiber SCC, whereas zero-fiber SCC ameliorates the pathology. Corroborating with the proinflammatory role of dietary fiber, IL-1R-deficient mice were protected from peritonitis induced by B. fragilis and particulate bran. Overall, our study highlights a function, previously unknown, for dietary fibers in fueling peritonitis through NLRP3 activation and IL-1ß secretion outside the gut.

Erythropoietin Promotes Infection Resolution and Lowers Antibiotic Requirements in E. coli- and S. aureus-Initiated Infections.

Endogenous mechanisms underlying bacterial infection resolution are essential for the development of novel therapies for the treatment of inflammation caused by infection without unwanted side effects. Herein, we found that erythropoietin (EPO) promoted the resolution and enhanced antibiotic actions in Escherichia coli (E. coli)- and Staphylococcus aureus (S. aureus)-initiated infections. Levels of peritoneal EPO and macrophage erythropoietin receptor (EPOR) were elevated in self-limited E. coli-initiated peritonitis. Myeloid-specific EPOR-deficient mice exhibited an impaired inflammatory resolution and exogenous EPO enhanced this resolution in self-limited infections. Mechanistically, EPO increased macrophage clearance of bacteria via peroxisome proliferator-activated receptor γ (PPARγ)-induced CD36. Moreover, EPO ameliorated inflammation and increased the actions of ciprofloxacin and vancomycin in resolution-delayed E. coli- and S. aureus-initiated infections. Collectively, macrophage EPO signaling is temporally induced during infections. EPO is anti-phlogistic, increases engulfment, promotes infection resolution, and lowers antibiotic requirements.