Multiresistant bacterial infections in liver cirrhosis: Clinical impact and new empirical antibiotic treatment policies

Angel or devil: the dual roles of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside in the development of liver injury based on integrating pharmacological techniques: a systematic review

Background and purpose

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) exhibits a dualistic pharmacological profile, acting as both a hepatoprotective and hepatotoxic agent, which is intricately linked to its interaction with multiple signaling pathways and its stereoisomeric forms, namely, cis-SG and trans-SG. The purpose of this study is to evaluate both the hepatoprotective and hepatotoxic effects of TSG and give therapeutic guidance.

Methods

This study performed a systematic search of eight databases to identify preclinical literature up until March 2024. The CAMARADES system evaluated evidence quality and bias. STATA and Python were used for statistical analysis, including dose-effect maps, 3D maps and radar charts to show the dose-time-effect relationship of TSG on hepatoprotection and hepatotoxicity.

Results

After a rigorous screening process, a total of 24 studies encompassing 564 rodents were selected for inclusion in this study. The findings revealed that TSG exhibited bidirectional effects on the levels of ALT and AST, while also regulating the levels of ALT, AST, TNF-α, IL-6, serum TG, serum TC, SOD, MDA, IFN-γ, and apoptosis rate. The histological analysis of liver tissue confirmed the regulatory effects of TSG, and a comprehensive analysis revealed the optimal protective dosage range was 27.27-38.81 mg/kg/d and the optimal toxic dosage range was 51.93-76.07 mg/kg/d. TSG exerts the dual effects on liver injury (LI) through the network of Keap1/Nrf2/HO-1/NQO1, NF-κB, PPAR, PI3K/Akt, JAK/STAT and TGF-β pathways.

Conclusion

TSG could mediate the pathways of oxidation, inflammation, and metabolism to result in hepatoprotection (27.27-38.81 mg/kg/d) and hepatotoxicity (51.93-76.07 mg/kg/d).

Limitations of current techniques in clinical antimicrobial resistance diagnosis: examples and future prospects

Antimicrobial resistance is a global threat to public health. Without proactive intervention, common infections may become untreatable, restricting the types of clinical intervention that can be undertaken and reversing improvements in mortality rates. Effective antimicrobial stewardship represents one approach to restrict the spread of antimicrobial resistance but relies on rapid and accurate diagnostics that minimise the unnecessary use of antibiotics. This is increasingly a key unmet clinical need. In this paper, we describe existing techniques for the detection of antimicrobial resistance, while examining their drawbacks and limitations. We also discuss emerging diagnostic technologies in the field, and the need for standardisation to allow for swifter and more widespread clinical adoption.

Risk factors for pre-transplantation bacteremia in adults with end-stage liver disease: Effects on outcomes of liver transplantation

BACKGROUND AND AIM

Limited data are available regarding pre-liver transplantation (LT) bacteremia in adults with end-stage liver disease. In this study, we investigated the risk factors independently associated with pre-LT bacteremia and their effects on clinical outcomes of LT.

METHODS

This retrospective study performed between 2010 and 2021 included 1287 LT recipients. The study population was categorized into patients with pre-LT bacteremia and those without pre-LT infection. Pre-LT bacteremia was defined as bacteremia detected within 90 days before LT.

RESULTS

Among 1287 LT recipients, 92 (7.1%) developed pre-LT bacteremia. The mean interval between bacteremia and LT was 28.3 ± 19.5 days. Of these 92 patients, seven (7.6%) patients died after LT. Of the 99 microorganisms isolated in this study, gram-negative bacteria were the most common microbes (72.7%). Bacteremia was mainly attributed to spontaneous bacterial peritonitis. The most common pathogen isolated was Escherichia coli (25.2%), followed by Klebsiella pneumoniae (18.2%), and Staphylococcus aureus (15.1%). Multivariate analysis showed that massive ascites (adjusted odds ratio [OR] 1.67, 95% confidence Interval [CI] 1.048-2.687) and a prolonged international normalized ratio for prothrombin time (adjusted OR 1.13, 95% CI 1.074-1.257) were independent risk factors for pre-LT bacteremia in patients with end-stage liver disease. Intensive care unit and in-hospital stay were significantly longer, and in-hospital mortality was significantly higher among LT recipients with pre-LT bacteremia than among those without pre-LT infection.

CONCLUSIONS

This study highlights predictors of pre-LT bacteremia in patients with end-stage liver disease. Pre-LT bacteremia increases the post-transplantation mortality risk.

Nosocomial spontaneous bacterial peritonitis is associated with high mortality - a systematic review and meta-analysis

INTRODUCTION

It is unclear if Nosocomial Spontaneous Bacteria Peritonitis (NSBP) is associated with higher mortality compared with community acquired spontaneous bacterial peritonitis.

METHODS

Database search from inception to May 2022 was conducted. The databases included MEDLINE, EMBASE, Cochrane registry of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus. Inclusion criteria were as follows: adult patients, age >18 years, with a diagnosis of NSBP. Pooled estimates of mortality were calculated following the restricted maximum likelihood method. The mortality rate between NSBP and CA-SBP was reported as odds ratio (OR) and 95% confidence interval (CI). Data synthesis was obtained using random effects meta-analysis. Heterogeneity was reported as I2.

RESULTS

A total of 482 unique titles were screened. Twenty-two articles were included. A total of 2,145 patients with NSBP were included. Patients were followed for a median of 90 days. The pooled mortality rate of NSBP was 52.51% (95% CI 42.77-62.06%; I2 83.72%). Seven studies compared the mortality outcome of patients with NSBP and CA-SBP. NSBP was significantly associated with a higher rate of mortality (OR 2.78, 95% CI 1.87-4.11; I2 36.00%).

CONCLUSION

NSBP was associated with higher mortality rate compared to CA-SBP, which could be due to a higher rate of resistance organisms.

Protective role of resveratrol against VCM-induced hepatotoxicity in male wistar rats

Background: Vancomycin is a glycopeptide antibiotic with a high risk of acute liver injury. Resveratrol is believed to protect the liver against toxicity. Aim: To investigate the ability of resveratrol to attenuate vancomycin-induced liver toxicity in rats injected with vancomycin. Method: Twenty-four adult male Wistar rats were distributed into three groups. The control group received only a vehicle, while the treated group received either vancomycin 200 (mg/kg, i. p.) only or vancomycin (200 mg/kg, i. p.) with resveratrol (20 mg/kg, oral gavage). All groups received their dose once daily for 7 days. Hepatic damage was assessed by measuring biochemical parameter levels in serum, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). Also, antioxidants and inflammation biomarkers such as Interleukin-6 (IL-6), malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH) were measured. Furthermore, the vancomycin-induced pathological changes in the liver were evaluated by histopathological studies. Results: In the vancomycin-treated group, hepatic serum biomarkers such as AST, ALT, ALP, IL-6, and MDA were elevated, while NO and GSH were depleted. However, resveratrol co-treatment with vancomycin prevented the elevation of AST, ALT, ALP, IL-6, and MDA and it protected the liver from NO and GSH depletion. Also, regarding vancomycin-induced degeneration of hepatocytes, resveratrol co-treatment with vancomycin prevented such degeneration and improved mononuclear cells in the liver. Conclusion: The results showed that oral administration of resveratrol has a significant hepatoprotective effect against vancomycin-induced hepatotoxicity.

Korean Guidelines for Use of Antibiotics for Intra-abdominal Infections in Adults

The guidelines are intended to provide practical information for the correct use of antibiotics for intra-abdominal infections in Korea. With the aim of realizing evidence-based treatment, these guidelines for the use of antibiotics were written to help clinicians find answers to key clinical questions that arise in the course of patient care, using the latest research results based on systematic literature review. The guidelines were prepared in consideration of the data on the causative pathogens of intra-abdominal infections in Korea, the antibiotic susceptibility of the causative pathogens, and the antibiotics available in Korea.

Clinical, Laboratory and Bacterial Profile of Spontaneous Bacterial Peritonitis in Vietnamese Patients with Liver Cirrhosis

Aim

Methods

Results

Conclusion

Epidemiology of ascites fluid infections in patients with cirrhosis in Queensland, Australia from 2008 to 2017: A population-based study

Spontaneous bacterial peritonitis (SBP), a common infection in patients with cirrhosis and ascites, is associated with high morbidity and mortality. The aim of this study was to investigate changes in the epidemiology of ascites fluid infections over time in an Australian population, including patient demographics, trends in mortality, length of hospital stay and the nature and antibiotic resistance profile of causative organisms.An observational descriptive population-based epidemiological study of patients with cirrhosis admitted to public hospitals in Queensland during 2008-2017 was performed, linking demographic/clinical and microbiology data.Among 103,165 hospital admissions of patients with cirrhosis, ascites was present in 16,550 and in 60% (9977) a sample of ascitic fluid was tested. SBP was diagnosed in 770 admissions (neutrophil count >250/ml) and bacterascites in 552 (neutrophil count <250/ml with positive culture). The number of admissions with an ascites fluid infection increased by 76% from 2008 to 2017, paralleling an 84% increase in cirrhosis admissions over the same timeframe. Patients with SBP had a longer hospital stay (median 15.7 vs 8.3 days for patients without SBP, P < .001) and higher in-hospital mortality, although this decreased from 39.5% in 2008 to 2010 to 24.8% in 2015 to 2017 (P < .001). Common Gram-positive isolates included coagulase negative staphylococci (37.9%), viridans group streptococci (12.1%), and Staphylococcus aureus (7.2%). Common Gram-negative isolates included Escherichia coli (13.0%), Klebsiella pneumoniae (3.1%) and Enterobacter cloacae (2.6%). The prevalence of resistance to any tested antibiotic was <10%.SBP remains associated with high in-hospital mortality and long hospital stay. Typical skin and bowel pathogens were common, therefore, empirical antibiotic therapy should target these pathogens. This study provides valuable evidence informing infection management strategies in this vulnerable patient population.

Monocyte dysfunction in decompensated cirrhosis is mediated by the prostaglandin E2-EP4 pathway

BACKGROUND & AIMS

Infection is a major problem in advanced liver disease secondary to monocyte dysfunction. Elevated prostaglandin (PG)E₂ is a mediator of monocyte dysfunction in cirrhosis; thus, we examined PGE₂ signalling in outpatients with ascites and in patients hospitalised with acute decompensation to identify potential therapeutic targets aimed at improving monocyte dysfunction.

METHODS

Using samples from 11 outpatients with ascites and 28 patients hospitalised with decompensated cirrhosis, we assayed plasma levels of PGE₂ and lipopolysaccharide (LPS); performed quantitative real-time PCR on monocytes; and examined peripheral blood monocyte function. We performed western blotting and immunohistochemistry for PG biosynthetic machinery expression in liver tissue. Finally, we investigated the effect of PGE₂ antagonists in whole blood using polychromatic flow cytometry and cytokine production.

RESULTS

We show that hepatic production of PGE₂ via the cyclo-oxygenase 1-microsomal PGE synthase 1 pathway, and circulating monocytes contributes to increased plasma PGE₂ in decompensated cirrhosis. Transjugular intrahepatic sampling did not reveal whether hepatic or monocytic production was larger. Blood monocyte numbers increased, whereas individual monocyte function decreased as patients progressed from outpatients with ascites to patients hospitalised with acute decompensation, as assessed by Human Leukocyte Antigen (HLA)-DR isotype expression and tumour necrosis factor alpha and IL6 production. PGE₂ mediated this dysfunction via its EP₄ receptor.

CONCLUSIONS

PGE₂ mediates monocyte dysfunction in decompensated cirrhosis via its EP₄ receptor and dysfunction was worse in hospitalised patients compared with outpatients with ascites. Our study identifies a potential drug target and therapeutic opportunity in these outpatients with ascites to reverse this process to prevent infection and hospital admission.

LAY SUMMARY

Patients with decompensated cirrhosis (jaundice, fluid build-up, confusion, and vomiting blood) have high infection rates that lead to high mortality rates. A white blood cell subset, monocytes, function poorly in these patients, which is a key factor underlying their sensitivity to infection. We show that monocyte dysfunction in decompensated cirrhosis is mediated by a lipid hormone in the blood, prostaglandin E₂, which is present at elevated levels, via its EP₄ pathway. This dysfunction worsens when patients are hospitalised with complications of cirrhosis compared with those in the outpatients setting, which supports the EP₄ pathway as a potential therapeutic target for patients to prevent infection and hospitalisation.

Bacterial Pathogens, Drug-Resistance Profile and Its Associated Factors from Patients with Suspected Peritonitis in Southern Ethiopia

Background

Ascitic fluid plays a critical role in the microbiological diagnosis of peritonitis. Drug-resistant bacterial infection of the peritoneal cavity is becoming a public health threat. However, data on bacterial profile and antimicrobial-resistant pattern of isolates from the ascitic fluid are scarce. Thus, this study was aimed to assess drug-resistant bacteriological profiles and factors associated with peritonitis in southern Ethiopia.

Methods

An institutional-based cross-sectional study was conducted from March 2019 to December 2019. A semi-structured questionnaire was used to collect socio-demographic and clinical data. A total of 147 ascitic fluid samples were aseptically collected and inoculated onto blood agar, MacConkey agar, and chocolate agar. The inoculated culture media were incubated aerobically and micro-aerobically at 37°C for 48 hrs. Bacterial identification was done by standard protocols and the antimicrobial susceptibility testing by Kirby Bauer’s disk diffusion method. Logistic regression was used to identify the associated factors with bacterial peritonitis.

Results

Of the total study participants, the overall magnitude of bacterial peritonitis was 19.05% with a total of 30 bacterial isolates. Majority of the isolates were Gram negative bacteria with predominant species E. coli 36.67% followed by Gram positive S. aureus 13.33%. The multidrug resistant isolates accounts about 43.3% while a quarter of isolated S. aureus were methicillin resistant. The bacterial peritonitis was associated with recent history of surgery [AOR = 8.724, 95% CI: (2.688–28.314)], hospitalization more than seven days [AOR = 8.990, 95% CI: (2.755–29.342)], cirrhosis [AOR = 2.751, 95% CI: (1.109–6.822)] and alcoholism [AOR = 5.802, 95% CI: (1.948–17.285)].

Conclusion

Nearly half of the isolated bacteria were observed to be MDR, and this may alarm all healthcare workers and policymakers. Thus, continuous surveillance of antimicrobial resistance patterns along with associated factors is essential for regular monitoring of transmission of drug-resistant bacteria and the emergence of antibiotic resistance.

Bloodstream Infections Caused by Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Patients with Liver Cirrhosis

Background: This study aimed to investigate the frequency of sequence type (ST) 131 strains and outcome of cirrhotic patients with bloodstream infections (BSIs) caused by extended-spectrum beta-lactamase-producing Escherichiacoli (ESBLEC) and non-extended-spectrum beta-lactamase-producing Escherichiacoli (NESBLEC). Methods: The incidence of ST 131 strains, hospital stay, and 30-day re-admission/mortality were compared between 51 ESBLEC and 51 NESBLEC bacteremic patients with cirrhosis. Results: ST 131 strains were found in 35.3% of the ESBLEC group and 0% of the NESBLEC group (p < 0.001). Mean hospital stay was 26.5 days in the ESBLEC group and 17.1 days in the NESBLEC group (p = 0.006). Thirty-day re-admission rates were 11.8% in the ESBLEC group and 5.9% in the NESBLEC group (p = 0.5). ST 131 strains were associated with 30-day re-admission (odds ratio: 4.5, 95% confidence interval: 1.1–18.9). Thirty-day mortality rate was 31.4% in the ESBLEC group and 23.5% in the NESBLEC group (p = 0.4). Conclusion: In patients with cirrhosis, the ESBLEC BSIs group had a higher frequency of ST 131 strains and longer hospital stay than the NESBLEC BSIs group with similar 30-day re-admission/mortality. ST 131 strains were associated with 30-day re-admission.

Management of infections in patients with cirrhosis in the context of increasing therapeutic resistance: A systematic review

Patients with cirrhosis are prone to develop bacterial infections, which consist in one of the major precursors of Acute-on-Chronic Liver Failure (ACLF) and are responsible for a high mortality rate. In recent years, the management of bacterial infections in patients with cirrhosis has become increasingly complicated due to a change in bacterial ecology associated with a higher rate of cocci gram positive bacteria in Europe and America along with the emergence of a multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacteria leading to a decrease in the efficacy of empirical strategies based on the administration of third-generation cephalosporins. MDR and XDR now account for about 40% of the infections worldwide, and up to 70% in India. Among them, the most common ones are extended-spectrum beta-lactamase producing (ESBL-P) bacteria, carbapenem-resistant enterobacteriaceae (CRE), Methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). An early diagnosis associated to an empirical antibiotic adapted to the site of infection and potential bacterial resistance is now crucial in order to improve the chances of survival and contain the resistance phenomenon. Moreover, a fungal infection must always be discussed in these high-risks patients, especially in the absence of clinical improvement under appropriate antibiotic treatment. In this review, we will focus on the emerging threat of MDR and XDR organisms, as well as fungal infections, in order to better adapt the therapeutic management of cirrhotic patients with infections.

Primary and secondary prophylaxis of spontaneous bacterial peritonitis: current state of the art

Introduction: Spontaneous bacterial peritonitis represents a frequent and severe complication in cirrhotic patients with ascites. In daily practice, the diagnosis of spontaneous bacterial peritonitis might be challenging in the absence of the typical signs and symptoms of infection such as fever or leukocytosis. Areas covered: Aim of this review is to revise the current state of the art on primary and secondary spontaneous bacterial peritonitis. Literature search in Medline/Pubmed was performed. Expert opinion: Historically, gram-negative bacteria were the most frequent etiologic agents of spontaneous bacterial peritonitis, with Escherichia coli and Klebsiella spp. being the most frequently isolated bacteria. However, major changes in this regard occurred over the last few decades with an increasing prevalence of gram-positive, quinolone-resistant, and multidrug-resistant bacteria. In particular, the increasing prevalence of quinolone-resistant bacteria challenged the prominent role of norfloxacin in spontaneous bacterial peritonitis prevention. Given the high mortality rate and the risk of developing the hepatorenal syndrome, prophylaxis of spontaneous bacterial peritonitis is indicated in three high-risk populations: patients with acute gastrointestinal hemorrhage, patients with low total protein content in ascitic fluid and advanced cirrhosis, and patients with a previous history of spontaneous bacterial peritonitis (secondary prophylaxis).

Spontaneous bacterial peritonitis caused by Gram-negative bacteria: an update of epidemiology and antimicrobial treatments

Introduction: Spontaneous bacterial peritonitis (SBP) is a main infectious complication in end-stage liver disease (ESLD) patients. The increasing trend of bacterial resistance in ESLD patients with SBP has been associated with low treatment efficacy of traditional therapy. Cephalosporin use has been restricted to community-acquired infections and in areas/health care settings with low rates of multidrug-resistant (MDR) bacteria. To date, several changes are necessary with regard to empiric therapy recommendations in areas/health care settings with high rates of MDR bacteria. Areas covered: An overview of the epidemiology and antimicrobial treatments of SBP caused by Gram-negative bacteria. Expert opinion: Broad-spectrum antibiotics have been recommended as empiric therapy for suspected SBP in areas/health care settings with high rates of MDR bacteria and secondary treatment, with newer antibiotics, for SBP caused by MDR-Gram-negative bacteria (i.e. new beta-lactam/beta-lactamase inhibitor combinations, cefiderocol, plazomicin, and eravacycline) either alone or in combination.

Emerging Gram-positive bacteria and drug resistance in cirrhosis patients with spontaneous bacterial peritonitis: A retrospective study

Spontaneous bacterial peritonitis (SBP) is one of the most severe complications in liver cirrhosis (LC) patients with ascites. The aim of the present study was to retrospectively analyze the bacterial spectrum and drug resistance in ascites culture of patients with SBP. A total of 3, 189 patients with ascites were enrolled in the present study, including 912 LC patients, of which 247 had SBP. It was revealed that in the 3, 189 patients, the ratio of SBP exhibited annual increases, especially in 2015, and this trend remained when cases were divided into two groups: Group A (admission, 2011-2013) and Group B (admission, 2014-2016). The 247 SBP patients were then stratified into two groups: Group 1 (admission, 2011-2013) and Group 2 (admission, 2014-2016). The rate of infection with gram-positive bacteria (GPB) was markedly higher in Group 2 compared with Group 1. Over time, GPB and gram-negative bacteria (GNB) were increased, while the increase of GPB was greater than that of GNB. Direct bilirubin and C-reactive protein levels, and the positive rate of ascites culture in Group 2 were greater than in Group 1. Furthermore, marked differences in serological and ascitic indexes or pathogeny, as well as complications between the patients with GPB and GNB infection were observed. The results regarding drug sensitivity revealed that the resistance rate of GPB and GNB to penicillin (ampicillin) was 100%, while the resistance rate to amikacin, imipenem, meropenem and piperacillin/tazobactam was 0% for GNB, and similarly, the resistance rate to vancomycin, teicoplanin, amikacin and linezolid was 0% for GPB. The results suggested that combined use of ampicillin/sulbactam or piperacillin/tazobactam should be selected forempirical therapy. In cases of nosocomial infection, these drugs should be combined with vancomycin, linezolid or teicoplanin when required.

Epidemiology and risk factors for multi-drug resistant hospital-acquired urinary tract infection in patients with liver cirrhosis: single center experience in Serbia

BACKGROUND

Cirrhosis-associated immune dysfunction syndrome (CAIDS) has been identified in patients with liver cirrhosis (LC), predisposing them to a wide variety of infections. In patients with LC, healthcare-associated infections involving multi-drug resistant (MDR) bacteria have increased significantly over the last decades. Among them, hospital-acquired urinary tract infections (HA-UTI) are the most common. This study aimed to investigate the rates of antimicrobial resistance among patients with LC and HA-UTI and to determine risk factors associated with their development among patients hospitalized in tertiary care facility in Serbia.

METHODS

This retrospective study included 65 hospitalized patients with LC who had developed HA-UTI. We examined the epidemiology of these infections concerning resistance to the most commonly used antimicrobials and patient-specific risk factors associated with HA-UTI development by MDR pathogens.

RESULTS

The most frequently isolated organisms were Enterococcus spp. (n = 34, 52.3%), Klebsiella spp. (n = 10, 15.4%), and E.coli (n = 6, 9.2%). Thirty-five isolates (53.8%) were identified as MDR, and 30 (46.2%) were non-MDR.We found a statistically significant difference in the distribution of MDR and non-MDR strains, based on Gram staining, with the majority of Gram-negative pathogens being MDR (p = 0.005). We identified age ≥ 65 years (p = 0.007), previous use of cephalosporins as empiric therapy (p = 0.042), and the presence of hepatic encephalopathy (p = 0.011) as independent risk factors for the development of MDR UTIs.

CONCLUSION

This is the first study from Serbia and the Balkans concerning the changing epidemiology of MDR UTI in patients with LC. Our study showed that more than half of HA-UTI was caused by MDR and the most common pathogen was Enterococcus spp. The overall resistance to ceftriaxone was 92%. Our findings underscore the need for institutions to individualize protocols for treatment of hospital-acquired infections, particularly in immunocompromised populations.

Spontaneous bacterial peritonitis in patients with cirrhosis: incidence, outcomes, and treatment strategies

Spontaneous bacterial peritonitis is the most frequent bacterial infection in patients with cirrhosis. The reported incidence varies between 7% and 30% in hospitalized patients with cirrhosis and ascites, representing one of their main complications. Outcomes in patients with spontaneous bacterial peritonitis are poor since acute kidney injury, acute-on-chronic liver failure, and death occur in as much as 54%, 60%, and 40% of the patients, respectively, at midterm. Early antibiotic treatment of spontaneous bacterial peritonitis is crucial. However, the landscape of microbiological resistance is continuously changing, with an increasing spread of multidrug-resistant organisms that make its current management more challenging. Thus, the selection of the empirical antibiotic treatment should be guided by the severity and location where the infection was acquired, the risk factors for multidrug-resistant organisms, and the available information on the local expected bacteriology. The use of albumin as a complementary therapy for selected high-risk patients with spontaneous bacterial peritonitis is recommended in addition to antibiotics. Even though antibiotic prophylaxis has proven to be effective to prevent spontaneous bacterial peritonitis, a careful selection of high-risk candidates is crucial to avoid antibiotic overuse. In this article we review the pathogenesis, risk factors, and prognosis of spontaneous bacterial peritonitis, as well as the current evidence regarding its treatment and prophylaxis.

Bloodstream infection due to Escherichia coli in liver cirrhosis patients: clinical features and outcomes

OBJECTIVES

The study aimed to investigate the clinical characteristics and antibiotic management, as well as independent indicators for survival within 30 days for Escherichia coli bloodstream infection (BSI) in liver cirrhosis.

RESULTS

Hospital-acquired BSI accounted for 60.07%, with prolonged hospital stay (P = 0.000). The prevalence of Extended Spectrum Beta-Lactamases (ESBL) producing bacteria was 48.26%, which correlated with ICU admission (P = 0.015) and high model for end-stage liver disease (MELD) score at onset of BSI (P = 0.035). Moreover, ESBL producing pathogens showed a high resistant to the common antibiotic families and 27.5% pathogens were confirmed as multidrug-resistant (MDR). MDR infection was significantly correlated with ESBL production, ICU admission, inappropriate empiric therapy, resistance to firstly selected antibiotic, and infection duration (P < 0.05 for all). In addition, appropriate empiric therapy within 48 h (HR = 2.581, 95% CI = 1.166-5.715), ICU admission (HR = 4.434, 95% CI = 2.130-8.823), HE (HR = 2.379, 95% CI = 1.115-5.073) and final MELD (HR = 1.074, 95% CI = 1.044-1.106) were independent indicators for 30-day mortality.

MATERIALS AND METHODS

The clinical data were collected from 288 eligible patients, and compared according to survival status and sites of infection acquisition. Drug resistance was recorded according to ESBL. In addition, cox regression analysis model was applied to evaluate the risk factors for 30-day mortality.

CONCLUSIONS

ESBL production can promote resistance to antibiotics in Escherichia coli. Antibiotic regimens, ICU admission, HE and MELD score can help identify the risk individuals who will benefit from the improved therapeutic regimens.

Current and emerging pharmacotherapy for the treatment of bacterial peritonitis

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is the quintessential model of bacterial infection in cirrhotic patients. In these particularly frail subjects, infections clearly worsen prognosis increasing substantially mortality. Furthermore, treatment of SBP has become more challenging because of the growing impact of multidrug-resistant (MDR) bacteria.

AREAS COVERED

This review addresses the reasons behind the change in therapeutic recommendations for SBP that have occurred in the past few years, by focusing on the following aspects: the importance of an early appropriate empirical treatment, the difference between nosocomial and non-nosocomial forms and the overall microbiological shift (rise of Gram-positive bacteria and MDR strains) that have affected SBP.

EXPERT OPINION

Until recently, third-generation cephalosporins have represented the cornerstone of SBP treatment, a safe choice covering the most important causative agents, namely Enterobacteriaceae. Unfortunately, massive exposure to health systems makes cirrhotic patients prone to MDR infections, which poses significant challenges, all the while not forgetting to strike a balance between effective antimicrobial activity and the risk of toxicity in these fragile subjects. Moreover, there is sparse information about new antibiotics in cirrhotic patients and about drugs levels in ascitic fluid. Therefore, further research is needed to optimize the treatment of SBP.

Are third-generation cephalosporins still the empirical antibiotic treatment of community-acquired spontaneous bacterial peritonitis? A systematic review and meta-analysis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a common complication among cirrhotic patients. Guidelines recommend third-generation cephalosporins (3GCs) as empiric antibiotic therapy (EAT) of SBP. Recently, a broad-spectrum EAT was shown to be more effective than cephalosporins in the treatment of nosocomial spontaneous bacterial peritonitis (N-SBP); however, the prevalence of 3GCs-resistant bacteria is high in the nosocomial setting and broad-spectrum EAT cannot be used in all cases of SBP.

AIM

The aim of this study was to evaluate the 3GCs resistance distribution between N-SBP and community-acquired spontaneous bacterial peritonitis (CA-SBP) to clarify whether 3GCs are still an effective therapeutic intervention for CA-SBP.

METHODS

We searched for studies that reported the aetiology of SBP and the resistance profile of both gram-positive and gram-negative bacteria in MEDLINE and Google Scholar databases (since 1 January 2000 to 30 April 2017). A meta-analysis was carried out to estimate the risk difference [relative risk (RR) and 95% confidence intervals (CIs)] for 3GCs resistance in N-SBP and CA-SBP. Heterogeneity was assessed using the I-test.

RESULTS

A total of eight studies were included, including 1074 positive cultures of ascitic fluid in cirrhotic patients; 462 positive cultures were from N-SBP and, among these, 251 (54.3%) were 3GCs resistant. Six hundred and twelve positive cultures were from CA-SBP and, among these, 207 (33.8%) were 3GCs-resistant SBP. A pooled RR of 3GCs resistance in N-SBP compared with CA-SBP showed a significant difference (RR=1.67, 95% CI: 1.14-2.44; P=0.008). We carried out two subgroup analyses: the first according to the median year of study observation (before vs. since 2008) and the second according to the country of the study (China vs. others). The studies carried out before 2008 (327 SBP-positive culture) showed a significantly higher risk for 3GCs-resistant strains in N-SBP compared with CA-SBP (RR=2.36, 95% CI: 1.39-3.99; P=0.001), whereas this was not found in SBP acquired after 2008 (RR=1.24, 95% CI: 0.83-1.84; P=0.29). N-SBP occurring in China had no significantly higher risk for 3GCs-resistant strains compared with CA-SBP (RR=1.44, 95% CI: 0.87-2.37; P=0.16).

CONCLUSION

Our findings suggest that although the pooled RR of 3GCs resistance in N-SBP compared with CA-SBP show that 3GCs are still an effective option for the treatment of CA-SBP, the subanalysis of studies that enroled patients in the last decade did not show a significant higher RR of 3GCs resistance in N-SBP compared with CA-SBP. Therefore, in centres where local patterns of antimicrobial susceptibility (with low rates of 3GCs resistance) are not available, 3GCs should not be used initially for CA-SBP treatment. Future studies are needed to confirm this trend of 3GCs resistance.

Spontaneous bacterial and fungal peritonitis in patients with liver cirrhosis: A literature review

Spontaneous bacterial (SBP) and spontaneous fungal peritonitis (SFP) can be a life-threatening infection in patients with liver cirrhosis (LC) and ascites. One of the possible mechanisms of developing SBP is bacterial translocation. Although the number of polymorphonuclear cells in the culture of ascitic fluid is diagnostic for SBP, secondary bacterial peritonitis is necessary to exclude. The severity of underlying liver dysfunction is predictive of developing SBP; moreover, renal impairment and infections caused by multidrug-resistant (MDR) organism are associated with a fatal prognosis of SBP. SBP is treated by antimicrobials, but initial empirical treatment may not succeed because of the presence of MDR organisms, particularly in nosocomial infections. Antibiotic prophylaxis is recommended for patients with LC at a high risk of developing SBP, gastrointestinal bleeding, or a previous episode of SBP, but the increase in the risk of developing an infection caused by MDR organisms is a serious concern globally. Less is known about SFP in patients with LC, but the severity of underlying liver dysfunction may increase the hospital mortality. SFP mortality has been reported to be higher than that of SBP partially because the difficulty of early differentiation between SFP and SBP induces delayed antifungal therapy for SFP.

Investigation on outcomes and bacterial distributions of liver cirrhosis patients with gram-negative bacterial bloodstream infection

Objective

The study aimed at analyzing the epidemiology and outcomes of liver cirrhosis patients undergoing gram-negative bacterial bloodstream infection.

Results

Totally 508 eligible patients were collected, with 25.79% 30-day mortality, and 58.86% patients were confirmed as nosocomial infection. The most common isolates were Escherichia coli (48.29%) and Klebsiella pneumoniae (19.29%), and multidrug-resistant isolates accounted for 36.61%. The bacterial distributions were similar between survivors and non-survivors (P>0.05), but showed close association with acquisition sites of infection (P<0.05). Nosocomial infection (HR=1.589, 95% CI=1.004-2.517), Child-Pugh grade (HR=2.471, 95% CI=1.279-4.772), septic shock (HR=1.966, 95% CI=1.228-3.146), complications (HR=3.529, 95% CI=2.140-5.818), and WBC (HR=1.065, 95% CI=1.018-1.114) were independent indicators for 30-day mortality. β-lactamase inhibitor antibiotics exerted a high antibacterial activity.

Methods

The inpatients with liver cirrhosis developed gram-negative bacterial bloodstream infection were collected. The clinical characteristics, bacterial distribution and drug sensitivity results of patients were compared according to their 30-day survival status and acquisition sites of infections. Cox regression model was applied to evaluate the risk factors for 30-day mortality.

Conclusion

Escherichia coli and Klebsiella pneumoniae are frequently isolated from gram-negative bacterial bloodstream infection episodes in cirrhosis patients. Acquisition site of infection can influence clinical characteristics and etiological distribution. β-lactamase inhibitor antibiotics may be the first choice for empirical treatments.

Current concepts and future strategies in the antimicrobial therapy of emerging Gram-positive spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is the most common infection in end-stage liver disease patients. SBP is defined as an ascitic fluid infection with a polymorphonuclear leucocyte count ≥ 250/mm3 without an evident intra-abdominal surgically treatable source. Several mechanisms contribute to SBP occurrence, including translocation of gut bacteria and their products, reduced intestinal motility provoking bacterial overgrowth, alteration of the gut's barrier function and local immune responses. Historically, Gram-negative enteric bacteria have been the main causative agents of SBP, thereby guiding the empirical therapeutic choice. However, over the last decade, a worryingly increasing prevalence of Gram-positive and multi-drug resistant (MDR) SBP has been seen. Recently, the microbiological spectrum of SBP seems to have changed in Europe due to a high prevalence of Gram-positive bacteria (48%-62%). The overall proportion of MDR bacteria is up to 22%-73% of cases. Consequently, empirical therapy based on third-generation cephalosporins or amoxicillin/clavulanic acid, can no longer be considered the standard of care, as these drugs are associated with poor outcomes. The aim of this review is to describe, with an epidemiological focus, the evidence behind this rise in Gram-positive and MDR SBP from 2000 to present, and illustrate potential targeted therapeutic strategies. An appropriate treatment protocol should include daptomycin plus ceftaroline and meropenem, with prompt stepdown to a narrower spectrum when cultures and sensitivity data are available in order to reduce both cost and potential antibiotic resistance development.

Nosocomial spontaneous bacterial peritonitis antibiotic treatment in the era of multi-drug resistance pathogens: A systematic review

AIM

To systematically review literature upon aetiology of nosocomial spontaneous bacterial peritonitis (N-SBP) given the rising importance of multidrug-resistant (MDR) bacteria.

METHODS

A literature search was performed on MEDLINE and Google Scholar databases from 2000 to 15th of November 2016, using the following search strategy: "spontaneous" AND "peritonitis".

RESULTS

The initial search through electronic databases retrieved 2556 records. After removing duplicates, 1958 records remained. One thousand seven hundred and thirty-five of them were excluded on the basis of the screening of titles and abstract, and the ensuing number of remaining articles was 223. Of these records, after careful evaluation, only 9 were included in the qualitative analysis. The overall proportion of MDR bacteria turned out to be from 22% to 73% of cases across the studies.

CONCLUSION

N-SBP is caused, in a remarkable proportion, by MDR pathogens. This should prompt a careful re-assessment of guidelines addressing the treatment of this clinical entity.

Antibiotic stewardship and empirical antibiotic treatment: How can they get along?

The aim of this review is to focus on the recent knowledge on antibiotic stewardship and empiric antibiotic treatment in cirrhotic patients. The application of antimicrobial stewardship (AMS) rules appears to be the most appropriate strategy to globally manage cirrhotic patients with infectious complications: indeed they represent a unique way to provide both early diagnosis and appropriate therapy in order to avoid not only antibiotic over-prescription but, more importantly, selection and spread of antimicrobial resistance. Moreover, cirrhotic patients must be considered "frail" and susceptible to healthcare associated infections: applying AMS policies would assure a cost reduction and thus contribute to the improvement of public health strategies.