Efficacy of Norfloxacin Prophylaxis to Prevent Spontaneous Bacterial Peritonitis: A Systematic Review and Meta-Analysis

Infections in cirrhosis

Cirrhosis is an immune dysfunction state, and as such, patients with cirrhosis are susceptible to bacterial, fungal, and viral infections. Because of infection, these patients have a propensity to develop multiorgan failure, which is associated with high mortality. Bacterial infections are the most prevalent type of infection in patients with cirrhosis, with the prevalence of bacterial infections in patients admitted for an acute decompensating event ranging from 24% to 29%. Together with invasive fungal infections, bacterial infections are the most severe. Multidrug-resistant organisms have been evolving at a rapid and alarming rate around the world, which presents enormous challenges. The development of effective measures for the prevention, early detection, and treatment of infections in patients with cirrhosis is challenging, given the rising incidence of infections in this patient population.

Bacterial Infections in Acute-on-chronic Liver Failure: Epidemiology, Diagnosis, Pathogenesis, and Management

Acute-on-chronic liver failure (ACLF) is a distinct condition characterized by the abrupt exacerbation of pre-existing chronic liver disease, often leading to multi-organ failures and significant short-term mortalities. Bacterial infection is one of the most frequent triggers for ACLF and a common complication following its onset. The impact of bacterial infections on the clinical course and outcome of ACLF underscores their critical role in the pathogenesis of systemic inflammation and organ failures. In addition, the evolving epidemiology and increasing prevalence of multidrug-resistant bacteria in cirrhosis and ACLF highlight the importance of appropriate empirical antibiotic use, as well as accurate and prompt microbiological diagnosis. This review provided an update on recent advances in the epidemiology, diagnosis, pathogenesis, and management of bacterial infections in ACLF.

Position paper on perioperative management and surgical risk in the patient with cirrhosis

INTRODUCTION

Management of the patient with cirrhosis of the liver that requires surgical treatment has been relatively unexplored. In Mexico, there is currently no formal stance or expert recommendations to guide clinical decision-making in this context.

AIMS

The present position paper reviews the existing evidence on risks, prognoses, precautions, special care, and specific management or procedures for patients with cirrhosis that require surgical interventions or invasive procedures. Our aim is to provide recommendations by an expert panel, based on the best published evidence, and consequently ensure timely, quality, efficient, and low-risk care for this specific group of patients.

RESULTS

Twenty-seven recommendations were developed that address preoperative considerations, intraoperative settings, and postoperative follow-up and care.

CONCLUSIONS

The assessment and care of patients with cirrhosis that require major surgical or invasive procedures should be overseen by a multidisciplinary team that includes the anesthesiologist, hepatologist, gastroenterologist, and clinical nutritionist. With respect to decompensated patients, a nephrology specialist may be required, given that kidney function is also a parameter involved in the prognosis of these patients.

Multidrug-resistant bacterial infections in the liver transplant setting

Bacterial infections pose a life-threatening complication in patients with decompensated liver cirrhosis and acute-on-chronic liver failure. An increasing prevalence of infections caused by multidrug-resistant organisms (MDROs) has been observed in these patients, significantly impacting prognosis. A growing body of evidence has identified the most common risk factors for such infections, enabling the development of preventive strategies and therapeutic interventions. MDRO infections may also occur after liver transplantation (most commonly in the early post-operative phase), affecting both graft and patient survival. This review provides an overview of MDRO infections before and after liver transplantation, discussing epidemiological aspects, risk factors, prevention strategies, and novel therapeutic approaches. Furthermore, it examines the implications of MDRO infections in the context of prioritizing liver transplantation for the most severe patients, such as those with acute-on-chronic liver failure.

A Machine Learning Algorithm Avoids Unnecessary Paracentesis for Exclusion of SBP in Cirrhosis in Resource-limited Settings

BACKGROUND & AIMS

Despite the poor prognosis associated with missed or delayed spontaneous bacterial peritonitis (SBP) diagnosis, <15% get timely paracentesis, which persists despite guidelines/education in the United States. Measures to exclude SBP non-invasively where timely paracentesis cannot be performed could streamline this burden.

METHODS

Using Veterans Health Administration Corporate Data Warehouse (VHA-CDW) we included patients with cirrhosis between 2009 and 2019 who underwent timely paracentesis and collected relevant clinical information (demographics, cirrhosis severity, medications, vitals, and comorbidities). XGBoost-models were trained on 75% of the primary cohort, with 25% reserved for testing. The final model was further validated in 2 cohorts: Validation cohort #1: In VHA-CDW, those without prior SBP who received 2nd early paracentesis, and Validation cohort #2: Prospective data from 276 non-electively admitted University hospital patients.

RESULTS

Negative predictive values (NPVs) at 5%,10%, and 15% probability cutoffs were examined. Primary cohort: n = 9643 (mean age, 63.1 ± 8.7 years; 97.2% men; SBP, 15.0%) received first early paracentesis. Testing-set NPVs for SBP were 96.5%, 93.0%, and 91.6% at the 5%, 10%, and 15% probability thresholds, respectively. In Validation cohort #1: n = 2844 (mean age, 63.14 ± 8.37 years; 97.1% male; SBP, 9.7%) with NPVs were 98.8%, 95.3%, and 94.5%. In Validation cohort #2: n = 276 (mean age, 56.08 ± 9.09; 59.6% male; SBP, 7.6%) with NPVs were 100%, 98.9%, and 98.0% The final machine learning model showed the greatest net benefit on decision-curve analyses.

CONCLUSIONS

A machine learning model generated using routinely collected variables excluded SBP with high NPV. Applying this model could ease the need to provide paracentesis in resource-limited settings by excluding those unlikely to have SBP.

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

Terlipressin therapy is associated with increased risk of colonisation with multidrug-resistant bacteria in patients with decompensated cirrhosis

BACKGROUND

Patients with cirrhosis are susceptible to develop bacterial infections that trigger acute decompensation (AD) and acute-on-chronic liver failure (ACLF). Infections with multidrug-resistant organisms (MDRO) are associated with deleterious outcome. MDRO colonisation frequently proceeds MDRO infections and antibiotic therapy has been associated with MDRO colonisation.

AIM

The aim of the study was to assess the influence of non-antibiotic medication contributing to MDRO colonisation.

METHODS

Three hundred twenty-four patients with AD and ACLF admitted to the ICU of Frankfurt University Hospital with MDRO screening were included. Regression models were performed to identify drugs associated with MDRO colonisation. Another cohort (n = 129) from Barcelona was included to validate. A third multi-centre cohort (n = 203) with metagenomic sequencing data of stool was included to detect antibiotic resistance genes.

RESULTS

A total of 97 patients (30%) were identified to have MDRO colonisation and 35 of them (11%) developed MDRO infection. Patients with MDRO colonisation had significantly higher risk of MDRO infection than those without (p = 0.0098). Apart from antibiotic therapy (odds ratio (OR) 2.91, 95%-confidence interval (CI) 1.82-4.93, p < 0.0001), terlipressin therapy in the previous 14 days was the only independent covariate associated with MDRO colonisation in both cohorts, the overall (OR 9.47, 95%-CI 2.96-30.23, p < 0.0001) and after propensity score matching (OR 5.30, 95%-CI 1.22-23.03, p = 0.011). In the second cohort, prior terlipressin therapy was a risk factor for MDRO colonisation (OR 2.49, 95% CI 0.911-6.823, p = 0.075) and associated with risk of MDRO infection during follow-up (p = 0.017). The validation cohort demonstrated that antibiotic inactivation genes were significantly associated with terlipressin administration (p = 0.001).

CONCLUSIONS

Our study reports an increased risk of MDRO colonisation in patients with AD or ACLF, who recently received terlipressin therapy, while other commonly prescribed non-antibiotic co-medications had negligible influence. Future prospective trials are needed to confirm these results.

Outcomes in patients with spontaneous bacterial peritonitis utilizing first-line or alternative agents for secondary prophylaxis

PURPOSE

The American Association for the Study of Liver Diseases guidelines recommend ciprofloxacin as a first-line option for spontaneous bacterial peritonitis (SBP) prophylaxis, citing literature that is over 30 years old. There is insufficient data and guidance for prophylaxis in cases of fluoroquinolone treatment failure or intolerance. This study aimed to evaluate outcomes in patients whose antimicrobial prophylaxis was switched from first-line therapies to an alternative agent versus those who were not switched following recurrent SBP.

METHODS

This study was an institutional review board-approved retrospective chart review of patients admitted to University of Kentucky HealthCare from 2014 through 2020. Patients included were 18 years of age or older with a diagnosis of recurrent SBP. The primary outcome examined was SBP recurrence rate following initial prophylaxis failure. Additional analyses targeted secondary outcomes, including 6-month mortality, development of SBP complications, development of an adverse drug reaction, and development of multidrug-resistant pathogens.

RESULTS

Fifty-three patients were identified with recurrent SBP and divided into 2 cohorts: 25 patients were switched from their original prophylactic agent while 28 patients continued on the same agent after SBP recurrence. Patients in the switch group had lower rates of recurrence (52% vs 100%). Additionally, these patients had lower 6-month mortality rates (24% vs 57.1%; P = 0.015). Thirteen patients in the no-switch group and 3 patients in the switch group required intensive care on a subsequent admission (46.4% vs 12%; P = 0.008). There were no significant differences between the groups in rates of other SBP complications.

CONCLUSION

Patients switched from their original prophylactic agent had lower rates of SBP recurrence with significantly lower 6-month mortality rates.

Antibiotics in Chronic Liver Disease and Their Effects on Gut Microbiota

Impairments in liver function lead to different complications. As chronic liver disease progresses (CLD), hypoalbuminemia and alterations in bile acid compositions lead to changes in gut microbiota and, therefore, in the host-microbiome interaction, leading to a proinflammatory state. Alterations in gut microbiota composition and permeability, known as gut dysbiosis, have important implications in CLD; alterations in the gut-liver axis are a consequence of liver disease, but also a cause of CLD. Furthermore, gut dysbiosis plays an important role in the progression of liver cirrhosis and decompensation, particularly with complications such as hepatic encephalopathy and spontaneous bacterial peritonitis. In relation to this, antibiotics play an important role in treating CLD. While certain antibiotics have specific indications, others have been subjected to continued study to determine whether or not they have a modulatory effect on gut microbiota. In contrast, the rational use of antibiotics is important, not only because of their disrupting effects on gut microbiota, but also in the context of multidrug-resistant organisms. The aim of this review is to illustrate the role of gut microbiota alterations in CLD, the use and impact of antibiotics in liver cirrhosis, and their harmful and beneficial effects.

Norfloxacin versus alternative antibiotics for prophylaxis of spontaneous bacteria peritonitis in cirrhosis: a systematic review and meta-analysis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a life-threatening complication in patients with advanced cirrhosis. Prophylactic Norfloxacin used to be considered effective in SBP prevention, but in recent years its efficacy has been partially compromised by increasing quinolone-resistant bacteria. However, whether the effects of alternative prophylactic regimens are superior to norfloxacin remains controversial. The goal of this study is to compare the effects of norfloxacin with other antibiotics in SBP prophylaxis for cirrhotic patients.

METHODS

We systematically searched Pubmed, Embase, and Cochrane Library Databases. Two reviewers independently identified relevant random control trials (RCTs) comparing the role of norfloxacin and other antibiotics in SBP prevention.

RESULTS

Eight studies comprising 1043 cirrhotic patients were included in this study. Norfloxacin and alternative antibiotics displayed comparable effects in SBP prophylaxis, survival benefit, overall infection prevention, and safety. Subgroup analyses revealed that rifaximin prophylaxis could reduce the recurrence of SBP with fewer adverse events but failed to improve overall survival compared with norfloxacin.

CONCLUSIONS

Other antibiotics are a reasonable alternative to norfloxacin in the prophylaxis of SBP. Rifaximin prophylaxis could be an alternative choose of antibiotic for SBP prevention because of its better protective effect and safety.

Primary prophylaxis for spontaneous bacterial peritonitis is linked to antibiotic resistance in the Veterans Health Administration

Spontaneous bacterial peritonitis (SBP) is a major cause of mortality. Although SBP primary prophylaxis (SBPPr) with fluoroquinolones and trimethoprim-sulfamethoxazole (TMP-SMX) is often used, resistance could reduce its benefit.

AIM

Analyze peritoneal fluid resistance patterns in patients with a first SBP episode with/without SBPPr using the Veterans Health Administration corporate data warehouse and to evaluate national antibiograms. Corporate data warehouse data were extracted using validated International Classification of Disease-9/10 codes, culture, resistance data, and outcomes of 7553 patients who developed their first inpatient SBP between 2009 and 2019 and compared between those with/without SBPPr. Escherichia coli ( E. coli ) and Klebsiella pneumoniae ( K. pneumoniae ) sensitivity to ciprofloxacin and TMP-SMX was calculated using 2021 Veterans Health Administration antibiogram data from all states. The most common isolates were E. coli , K. pneumoniae , and Staphylococcus species. Veterans taking ciprofloxacin SBBPr had higher fluoroquinolone resistance (34% vs 14% no SBPPr, p <0.0001); those taking TMP-SMX had higher TMP-SMX resistance (40% vs 14%, p <0.0001). SBPPr patients showed higher culture positivity, greater length of stay, higher second SBP, and higher probability of liver transplant rates versus no SBPPr. Multivariable models showed SBBPr to be the only variable associated with gram-negative resistance, and SBPPr was associated with a trend toward longer length of stay. E. coli ciprofloxacin sensitivity rates were 50%-87% and 43%-92% for TMP-SMX. K. pneumoniae ciprofloxacin sensitivity was 76%-100% and 72%-100% for TMP-SMX.

CONCLUSION

Among patients who developed their first SBP episode, there was a higher prevalence of antibiotic resistance in those on SBPPr, with a high rate of fluoroquinolone resistance across the Veterans Health Administration sites.

Gut-liver axis: barriers and functional circuits

The gut and the liver are characterized by mutual interactions between both organs, the microbiome, diet and other environmental factors. The sum of these interactions is conceptualized as the gut-liver axis. In this Review we discuss the gut-liver axis, concentrating on the barriers formed by the enterohepatic tissues to restrict gut-derived microorganisms, microbial stimuli and dietary constituents. In addition, we discuss the establishment of barriers in the gut and liver during development and their cooperative function in the adult host. We detail the interplay between microbial and dietary metabolites, the intestinal epithelium, vascular endothelium, the immune system and the various host soluble factors, and how this interplay establishes a homeostatic balance in the healthy gut and liver. Finally, we highlight how this balance is disrupted in diseases of the gut and liver, outline the existing therapeutics and describe the cutting-edge discoveries that could lead to the development of novel treatment approaches.

Mastering Core Recommendations during HEPAtology ROUNDS in Patients with Advanced Chronic Liver Disease

Efficient and thorough care of hospitalized patients with advanced chronic liver disease is of utter importance to improve outcomes and optimize quality of life. This requires understanding current evidence and best practices. To facilitate focus on up-to-date knowledge and a practical approach, we have created the HEPA-ROUNDS mnemonic while outlining a practical review of the literature with critical appraisal for the busy clinician. The HEPA-ROUNDS mnemonic provides a structured approach that incorporates critical concepts in terms of prevention, management, and prognostication of the most common complications frequently encountered in patients with advanced chronic liver disease. In addition, implementing the HEPA-ROUNDS mnemonic can facilitate education for trainees and staff caring for patients with advanced chronic liver disease.

Early Diagnosis and Prevention of Infections in Cirrhosis

Strategies to prevent infection and improve outcomes in patients with cirrhosis. HAV, hepatitis A virus; HBV, hepatitis B virus; COVID-19, novel coronavirus disease 2019; NSBB, nonselective β-blocker; PPI, proton pump inhibitors.Cirrhosis is a risk factor for infections. Majority of hospital admissions in patients with cirrhosis are due to infections. Sepsis is an immunological response to an infectious process that leads to end-organ dysfunction and death. Preventing infections may avoid the downstream complications, and early diagnosis of infections may improve the outcomes. In this review, we discuss the pathogenesis, diagnosis, and biomarkers of infection; the incremental preventive strategies for infections and sepsi; and the consequent organ failures in cirrhosis. Strategies for primary prevention include reducing gut translocation by selective intestinal decontamination, avoiding unnecessary proton pump inhibitors' use, appropriate use of β-blockers, and vaccinations for viral diseases including novel coronavirus disease 2019. Secondary prevention includes early diagnosis and a timely and judicious use of antibiotics to prevent organ dysfunction. Organ failure support constitutes tertiary intervention in cirrhosis. In conclusion, infections in cirrhosis are potentially preventable with appropriate care strategies to then enable improved outcomes.

Synthesis of New Norfloxacin-Tin Complexes to Mitigate the Effect of Ultraviolet-Visible Irradiation in Polyvinyl Chloride Films

Polyvinyl chloride is used in the manufacturing of a wide range of products, but it is susceptible to degradation if exposed to high temperatures and sunlight. There is therefore a need to continuously explore the design, synthesis, and application of new and improved additives to reduce the photodegradation of polyvinyl chloride in harsh environments and for outdoor applications. This research investigates the use of new norfloxacin–tin complexes as additives to inhibit the photodegradation of polyvinyl chloride to make it last longer. Reactions between norfloxacin and substituted tin chlorides, in different molar ratios and in methanol under reflux conditions, gave the corresponding organotin complexes in high yields. The chemical structures of the synthesized complexes were established, and their effect on the photodegradation of polyvinyl chloride due to ultraviolet-visible irradiation was investigated. Norfloxacin–tin complexes were added to polyvinyl chloride at very low concentrations and homogenous thin films were made. The films were irradiated for a period of up to 300 h, and the damage that occurred was assessed using infrared spectroscopy, polymeric materials weight loss, depression in molecular weight, and surface inspection. The degree of photodegradation in the polymeric materials was much less in the blends containing norfloxacin–tin complexes compared to the case where no additives were used. The use of the additives leads to a reduction in photodegradation (e.g., a reduction in the formation of short-chain polymeric fragments, weight loss, average molecular weight depletion, and roughness factor) of irradiated polyvinyl chloride. The norfloxacin–tin complexes contain aromatic moieties (aryl and heterocycle), heteroatoms (nitrogen, oxygen, and fluorine), and an acidic center (tin atom). Therefore, they act as efficient photostabilizers by absorbing the ultraviolet radiation and scavenging hydrogen chloride, peroxides, and radical species, thereby slowing the photodegradation of polyvinyl chloride.

Impact of colonization with multidrug-resistant organisms on antibiotic prophylaxis in patients with cirrhosis and variceal bleeding

Background

The efficacy of antibiotic prophylaxis to prevent rebleeding or infection after variceal bleeding in patients with liver cirrhosis colonized with multidrug-resistant organisms (MDROs) is unknown.

Methods

In this retrospective study, patients with liver cirrhosis and endoscopically confirmed variceal bleeding who were treated at a tertiary care center in Germany and were screened for MDROs at the time of bleeding were eligible for inclusion. Efficacy of antibiotic prophylaxis was evaluated in patients stratified according to microbiological susceptibility testing.

Results

From 97 patients, the majority had decompensated liver cirrhosis (median MELD Score 17) and ACLF was present in half of the patients (47.4%). One third of patients were colonized with MDRO at baseline. De-novo infection until day 10 or the combination of de-novo infection or rebleeding were comparable among both groups (p = 0.696 and p = 0.928, log-rank-test). Risk of de-novo infection or rebleeding was not significantly increased in patients who received antibiotic prophylaxis that did not cover the MDRO found upon baseline screening. Acute-on-chronic liver failure at baseline was the strongest and only independent risk factor that was associated with both outcomes (OR 5.52, 95%-CI 1.48–20.61, p = 0.011 and OR 11.5, 95%-CI 2.70–48.62, p<0.001). Neither MDRO colonization at baseline nor covering all detected MDRO with antibiotic prophylaxis (i.e. “adequate” prophylaxis) impacted transplant-free survival. Again, the presence of ACLF was the strongest independent risk factor associated with mortality (OR 9.85, 95%-CI 3.58–27.12, p<0.0001).

Conclusion

In this study, MDRO colonization did not increase the risk of rebleeding, infections nor death, even if antibiotic prophylaxis administered did not cover all MDRO detected at MDRO screening. Patients with ACLF had an increased risk of bleeding, infections and death.

Indications for medical antibiotic prophylaxis and potential targets for antimicrobial stewardship intervention: a narrative review

BACKGROUND

Most of the antimicrobial stewardship (AMS) literature has focused on antimicrobial consumption for the treatment of infections, for the prophylaxis of surgical site infection and for the prevention of endocarditis. The role of AMS for medical antibiotic prophylaxis (AP) has not been adequately addressed.

AIMS

To identify targets for AMS interventions for medical AP in adult patients.

SOURCES

Targeted searches were conducted in PubMed.

CONTENT

The various indications for medical AP and relevant evidence from practice guidelines are outlined. The following were identified as potential targets for AMS interventions: (a) addressing under-utilization of antibiotic-sparing strategies (e.g. for recurrent urinary tract infections, recurrent soft-tissue infections, recurrent exacerbations associated with bronchiectasis or chronic obstructive pulmonary disease), (b) reducing unnecessary AP beyond recommended indications (e.g. for acute pancreatitis, bite wounds, or urinary catheter manipulations), (c) reducing the use of AP with a broader spectrum than necessary, (d) reducing the use of AP for longer than the recommended duration (e.g. AP for prevention of osteomyelitis in open fractures or AP in high-risk neutropenia), (e) evaluating the role of antibiotic cycling to prevent the emergence of resistance during prolonged AP (e.g. in recurrent urinary tract infections or prophylaxis for spontaneous bacterial peritonitis), and (f) addressing research gaps regarding appropriate indications or antibiotic regimens for medical prophylaxis.

IMPLICATIONS

This review summarizes current trends in AP and proposes targets for AMS interventions.

Liver cirrhosis

Cirrhosis is widely prevalent worldwide and can be a consequence of different causes, such as obesity, non-alcoholic fatty liver disease, high alcohol consumption, hepatitis B or C infection, autoimmune diseases, cholestatic diseases, and iron or copper overload. Cirrhosis develops after a long period of inflammation that results in replacement of the healthy liver parenchyma with fibrotic tissue and regenerative nodules, leading to portal hypertension. The disease evolves from an asymptomatic phase (compensated cirrhosis) to a symptomatic phase (decompensated cirrhosis), the complications of which often result in hospitalisation, impaired quality of life, and high mortality. Progressive portal hypertension, systemic inflammation, and liver failure drive disease outcomes. The management of liver cirrhosis is centred on the treatment of the causes and complications, and liver transplantation can be required in some cases. In this Seminar, we discuss the disease burden, pathophysiology, and recommendations for the diagnosis and management of cirrhosis and its complications. Future challenges include better screening for early fibrosis or cirrhosis, early identification and reversal of causative factors, and prevention of complications.

Prevention of Cirrhosis Complications: Looking for Potential Disease Modifying Agents

The current therapeutic strategies for the management of patients with cirrhosis rely on the prevention or treatment of specific complications. The removal of the causative agents (i.e., viruses or alcohol) prevents decompensation in the vast majority of patients with compensated cirrhosis. In contrast, even when etiological treatment has been effective, a significant proportion of patients with decompensated cirrhosis remains at risk of further disease progression. Therefore, therapies targeting specific key points in the complex pathophysiological cascade of decompensated cirrhosis could represent a new approach for the management of these severely ill patients. Some of the interventions currently employed for treating or preventing specific complications of cirrhosis or used in other diseases (i.e., poorly absorbable oral antibiotics, statins, albumin) have been proposed as potential disease-modifying agents in cirrhosis (DMAC) since clinical studies have shown their capacity of improving survival. Additional multicenter, large randomized clinical trials are awaited to confirm these promising results. Finally, new drugs able to antagonize key pathophysiological mechanisms are under pre-clinical development or at the initial stages of clinical assessment.

Obeticholic Acid Decreases Intestinal Content of Enterococcus in Rats With Cirrhosis and Ascites

The intestinal microbiome and bacterial translocation (BT), the passage of microorganisms from the gut lumen to mesenteric lymph nodes and other extra-intestinal sites, are main mechanisms implicated in liver injury and further decompensation in patients with cirrhosis. We hypothesized that obeticholic acid (OCA), a semisynthetic bile acid, would change the microbiome composition and reduce bacterial translocation in experimental cirrhosis. Rats with cirrhosis induced by carbon tetrachloride inhalation (a nonseptic model) with ascites present for at least 7 days were randomized to receive a 14-day course of OCA at a dose of 5 mg/kg/day (n = 34) or placebo (n = 34). Stool was collected at days 1 (randomization), 8, and 14 (sacrifice) for analysis of intestinal microbiome using the V4 hypervariable region of the bacterial 16S gene amplified by polymerase chain reaction. Bacteriological cultures of mesenteric lymph nodes, blood, and ascites were performed at end of study. Twenty-four animals in each group reached the end of study. Compared with placebo, rats treated with OCA had decreased relative abundance of Enterococcus in both ileum content (P = 0.02) and in stool (P < 0.001). BT from pathogenic bacteria was not different between groups. At end of treatment, rats on OCA had a significantly lower aspartate aminotransferase (AST) (266 vs. 369 IU/L; P < 0.01) and higher serum albumin (0.9 vs. 0.7 g/dL; P < 0.01) than rats on placebo. Conclusion: Although OCA did not appear to reduce BT by pathogenic bacteria, the reduction in intestinal content of Enterococcus, which has been associated with hepatocyte death, in OCA-treated animals is consistent with our observed improvements in AST and in liver function, as evidenced by higher serum albumin.

Antibiotic prophylaxis in patients with cirrhosis: Current evidence for clinical practice

Patients with cirrhosis show an increased susceptibility to infection due to disease-related immune-dysfunction. Bacterial infection therefore represents a common, often detrimental event in patients with advanced liver disease, since it can worsen portal hypertension and impair the function of hepatic and extra-hepatic organs. Among pharmacological strategies to prevent infection, antibiotic prophylaxis remains the first-choice, especially in high-risk groups, such as patients with acute variceal bleeding, low ascitic fluid proteins, and prior episodes of spontaneous bacterial peritonitis. Nevertheless, antibiotic prophylaxis has to deal with the changing bacterial epidemiology in cirrhosis, with increased rates of gram-positive bacteria and multidrug resistant rods, warnings about quinolones-related side effects, and low prescription adherence. Short-term antibiotic prophylaxis is applied in many other settings during hospitalization, such as before interventional or surgical procedures, but often without knowledge of local bacterial epidemiology and without strict adherence to antimicrobial stewardship. This paper offers a detailed overview on the application of antibiotic prophylaxis in cirrhosis, according to the current evidence.

Stool and sputum microbiome during quinolone prophylaxis of spontaneous bacterial peritonitis: an exploratory study

INTRODUCTION

Quinolone prophylaxis is recommended for patients with advanced cirrhosis at high risk of spontaneous bacterial peritonitis (SBP) or with prior SBP. Yet, the impact of long-term antibiotic prophylaxis on the microbiome of these patients is poorly characterized.

METHODS

Patients with liver cirrhosis receiving long-term quinolone prophylaxis to prevent SBP were prospectively included and sputum and stool samples were obtained at baseline, 1, 4 and 12 weeks thereafter. Both bacterial DNA and RNA were assessed with 16S rRNA sequencing. Relative abundance, alpha and beta diversity were calculated and correlated with clinical outcome.

RESULTS

Overall, 35 stool and 19 sputum samples were obtained from 11 patients. Two patients died (day 9 and 12) all others were followed for 180 days. Reduction of Shannon diversity and bacterial richness was insignificant after initiation of quinolone prophylaxis (p > 0.05). Gut microbiota were significantly different between patients (p < 0.001) but non-significantly altered between the different time points before and after initiation of antibiotic prophylaxis (p > 0.05). A high relative abundance of Enterobacteriaceae > 20% during quinolone prophylaxis was found in three patients. Specific clinical scenarios (development of secondary infections during antibiotic prophylaxis or the detection of multidrug-resistant Enterobacteriaceae) characterized these patients. Sputum microbiota were not significantly altered in individuals during prophylaxis.

CONCLUSION

The present exploratory study with small sample size showed that inter-individual differences in diversity of gut microbiota were high at baseline, yet quinolone prophylaxis had only a moderate impact. High relative abundances of Enterobacteriaceae during follow-up might indicate failure of or non-adherence to quinolone prophylaxis. However, our results may not be clinically significant given the limitations of the study and therefore future studies are needed to further investigate this phenomenon.