Bacterial epidemiology and antimicrobial resistance in ascitic fluid: a 2-year retrospective study

Use of Bacterial DNA Concentration in Ascites as a Marker for Spontaneous Bacterial Peritonitis

Background and aims

Spontaneous bacterial peritonitis (SBP) is a common and serious complication in patients with decompensated cirrhosis. Precise quantification of bacterial DNA (bactDNA) and the related inflammatory response might add further information on the course of disease. The aim of the study was to evaluate the association between bactDNA, cytokine levels and clinical outcome.

Methods

Ascites and serum samples of 98 patients with decompensated liver cirrhosis (42 with SBP and 56 without SBP) as well as serum samples of 21 healthy controls were collected. BactDNA in ascites and serum was detected and quantified by 16S rRNA PCR. Concentrations of IL-1β, TNF-α, IL-6, IL-8 and IL-10 were measured by a LEGENDplexTM multi-analyte flow assay. Clinical data were collected and analyzed retrospectively.

Results

BactDNA was detected more frequently in ascites of patients with SBP (n = 24/42; 57.1%) than in ascites of patients without SBP (n = 5/56; 8.9%; P < 0.001). Additionally, IL-6 levels in both ascites and serum were significantly higher in patients with SBP (ascites P < 0.001, serum P = 0.036). The quantity of bactDNA in ascites was strongly correlated with polymorphonuclear neutrophil count in ascites (r = 0.755; P < 0.001) as well as ascites IL-6 levels (r = 0.399; P < 0.001). Receiver operating characteristic (ROC) curve analysis to diagnose SBP provided an AUC of 0.764 (95% CI: 0.661-0.867) for serum IL-6 levels, an AUC of 0.810 (95% CI: 0.714-0.905) for ascites IL-6 levels, and an AUC of 0.755 (95% CI: 0.651-0.858) for bactDNA levels in ascites.

Conclusions

The correlation between the amount of bactDNA and IL-6 confirms the pathophysiological relevance of bactDNA and IL-6 as potential biomarkers for the diagnosis of SBP.

Prevalence of Spontaneous Bacterial Peritonitis (SBP) in Hepatitis B (HBV), and Hepatitis C (HCV) Liver Cirrhosis: A Systematic Review and Meta-Analysis

Background and Aim: Spontaneous bacterial peritonitis (SBP) is a common infection in liver cirrhosis. This systematic review and meta-analysis provide detailed information on the prevalence of SBP among hepatitis B virus (HBV) and hepatitis C virus (HCV)-related liver cirrhosis globally. Methods: A systematic search for articles describing the prevalence of SBP in HBV and HCV-related cirrhosis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Our search returned ten (10) eligible articles involving 1713 viral cirrhosis cases representing eight (8) countries. A meta-analysis was performed on our eligible studies using the random effect model. A protocol was registered with PROSPERO (CRD42022321790). Results: The pooled prevalence of SBP in HBV-associated cirrhosis had the highest estimate [8.0% (95% CI, 2.7−21.0%; I2 = 96.13%; p < 0.001)], followed by SBP in HCV-associated liver cirrhosis [4.0% (95% CI, 1.3%−11.5%; I2 = 88.99%; p < 0.001)]. China (61.8%, CI: 57.1−66.3%), the USA (50.0%, CI: 34.6−65.4%), and Holland (31.1%, CI: 21.6−42.5%) had the highest estimate for SBP in HBV associated liver cirrhosis, SBP in HCV associated liver cirrhosis and SBP in HBV + HCV associated liver cirrhosis respectively. There was a significant difference in the prevalence of SBP in viral hepatitis-associated liver cirrhosis with the year of sampling and method of SBP detection at P < 0.001. There was an increase in SBP incidence at the beginning of 2016 across the liver cirrhosis in this study. Conclusion: The findings of this review revealed a rise in the incidence of SBP in viral hepatitis over the last decade. The latter indicates a possible future rise in the global prevalence of SBP among HBV and HCV-related liver cirrhosis.

An Epidemiological Meta-Analysis on the Worldwide Prevalence, Resistance, and Outcomes of Spontaneous Bacterial Peritonitis in Cirrhosis

Background and Aims: Spontaneous bacterial peritonitis (SBP) is a common and potentially fatal complication of liver cirrhosis. This study aims to analyze the prevalence of SBP among liver cirrhotic patients according to geographical location and income level, and risk factors and outcomes of SBP. Methods: A systematic search for articles describing prevalence, risk factors and outcomes of SBP was conducted. A single-arm meta-analysis was performed using generalized linear mix model (GLMM) with Clopper-Pearson intervals. Results: Ninety-Nine articles, comprising a total of 5,861,142 individuals with cirrhosis were included. Pooled prevalence of SBP was found to be 17.12% globally (CI: 13.63-21.30%), highest in Africa (68.20%; CI: 12.17-97.08%), and lowest in North America (10.81%; CI: 5.32-20.73%). Prevalence of community-acquired SBP was 6.05% (CI: 4.32-8.40%), and 11.11% (CI: 5.84-20.11%,) for healthcare-associated SBP. Antibiotic-resistant microorganisms were found in 11.77% (CI: 7.63-17.73%) of SBP patients. Of which, methicillin-resistant Staphylococcus aureus was most common (6.23%; CI: 3.83-9.97%), followed by extended-spectrum beta-lactamase producing organisms (6.19%; CI: 3.32-11.26%), and lastly vancomycin-resistant enterococci (1.91%; CI: 0.41-8.46%). Subgroup analysis comparing prevalence, antibiotic resistance, and outcomes between income groups was conducted to explore a link between socioeconomic status and SBP, which revealed decreased risk of SBP and negative outcomes in high-income countries. Conclusion: SBP remains a frequent complication of liver cirrhosis worldwide. The drawn link between income level and SBP in liver cirrhosis may enable further insight on actions necessary to tackle the disease on a global scale.

Current Status and Prospects of Spontaneous Peritonitis in Patients with Cirrhosis

Spontaneous bacterial peritonitis (SBP) is a common cirrhotic ascites complication which exacerbates the patient's condition. SBP is caused by gram-negative bacilli and, to a lesser extent, gram-positive cocci. Hospital-acquired infections show higher levels of drug-resistant bacteria. Geographical location influences pathogenic bacteria distribution; therefore, different hospitals in the same country record different bacteria strains. Intestinal changes and a weak immune system in patients with liver cirrhosis lead to bacterial translocation thus causing SBP. Early diagnosis and timely treatment are important in SBP management. When the treatment effect is not effective, other rare pathogens should be explored.

Factors that predict recurrent spontaneous bacterial peritonitis in cirrhotic patients

BACKGROUND

The recurrence rate of spontaneous bacterial peritonitis (SBP) is increasing in cirrhotic patients. Antibiotic prophylaxis should be prescribed in all cirrhotic patients after the first episode of SBP. However, antibiotics promote the development of antibiotic-resistant bacteria.

OBJECTIVE

To identify the factors that predict the recurrence of SBP after the first episode in cirrhotic patients to optimise the stratification for secondary antibiotic prophylaxis.

METHODS

This retrospective study included 145 cirrhotic patients who had their first SBP episode during 2011-2015. The 86 patients who survived were divided into either the SBP recurrence or non-recurrence group according to patient SBP outcome during the 2-year follow-up. Demographical, clinical and laboratory parameters were recorded at SBP diagnosis and before hospital discharge. SBP recurrence rate, recurrence-free survival and in-hospital mortality were also analysed.

RESULTS

The recurrence rate of SBP after the first episode was 69.8% (60/86), and the median recurrence-free survival time was 142 days. The in-hospital mortality rate was 40.7% (59/145). The significant predictive factors for recurrence of SBP were serum potassium ≥4 mEq/L (HR: 1.89; P = .028), serum albumin ≤2 g/dL (HR: 2.5; P = .003) at diagnosis of SBP and platelet count before discharge ≤100 000/microliter (HR: 1.93; P = .029).

CONCLUSION

SBP frequently recurs in cirrhotic patients. Serum potassium ≥4 mEq/L, serum albumin ≤2g/dL at SBP diagnosis and platelet count ≤100 000/microliter before discharge were identified as factors that may predict the recurrence of SBP after the first episode.

Recognition of Antibiotic Resistance in Spontaneous Bacterial Peritonitis Caused by Escherichia coli in Liver Cirrhotic Patients in Civil Hospital Karachi

Introduction

Spontaneous bacterial peritonitis (SBP) is the most common life-threatening infection in patients with ascites due to liver cirrhosis. The infection is most commonly caused by the bacterium Escherichia coli, commonly referred to as E. coli. Over the past few years, the incidence of antimicrobial resistance against E. coli has risen drastically, leading to increased morbidity and mortality.

Methods

This cross-sectional study was conducted to determine the pattern of resistance using variations of antibiotics against E. coli, to prevent its empirical usage and initiate an appropriate target antibiotic therapy. The data were collected from May 2017 to October 2017 and included a total of 184 patients. The patients had previously been diagnosed with chronic liver disease and had presented with E. coli-induced SBP in the medicine wards at Civil Hospital, Karachi, which is the largest tertiary care hospital in the city. All participants underwent diagnostic paracentesis, and the ascitic fluid samples were sent to labs for culture and sensitivity to antibiotics.

Results

The sample population consisted of 184 participants, of which two-thirds (63.6%; n=117/184) of the population consisted of males. The mean age of the participants was 47.6±10.7 years. More than half of the patients had hepatitis C (54.9%; n=101/184) while the remaining were diagnosed with hepatitis B (45.1%; n=83/184). The ascitic fluid showed varying percentages of resistance for drugs, with no resistance to imipenem and meropenem while ciprofloxacin showed the highest resistance in eradicating the bacterium, E. coli. Additionally, a statistical correlation was tested between drug resistance and factors like age, gender, duration of liver disease, and duration of ascites. Ciprofloxacin and tetracycline showed a positive correlation between the resistance of these drugs and the age, gender, and duration of chronic liver disease in the participants while trimethoprim/sulfamethoxazole, amoxicillin/clavulanic acid, and piperacillin/tazobactam showed a positive association with the duration of ascites.

Conclusion

A rapid diligent intervention of cirrhotic patients with complicated ascites is crucial to alleviate patient mortality. Due to the rising bacterial resistance, primarily, epidemiological patterns should be assessed and analyzed in our regional hospitals, and then, antibiotics should be prescribed meticulously.

Causative agents and outcome of spontaneous bacterial peritonitis in cirrhotic patients: community-acquired versus nosocomial infections

Background

Spontaneous bacterial peritonitis (SBP) is a serious complication and common cause of death in patients with liver cirrhosis. This study was conducted to compare the microbiological characteristics, drug resistance, and treatment outcomes for nosocomial SBP and community-acquired SBP.

Methods

A retrospective study was performed on 334 patients with culture-positive SBP at Beijing Youan Hospital, China, between January 2012 and December 2016. The medical records for these patients were reviewed, and their clinical and laboratory data were analyzed.

Results

A total of 155 (46.4%) patients with nosocomial SBP and 179 (53.6%) with community-acquired SBP were included in this study. From the patients’ ascitic fluids, 334 pathogenic strains, including 178 Gram-negative bacterial strains, 138 Gram-positive bacterial strains and 18 other microbial strains were isolated. E. coli was the major pathogen (24.3%), followed by Klebsiella pneumoniae (12.0%) and Enterococcus faecium (10.5%). The proportion of Enterococcus was significantly higher in the patients with nosocomial SBP (6.1% vs. 27.7%, P < 0.001) than in the patients with community-acquired SBP. The main pathogens isolated from the nosocomial infections were significantly more resistant to the first-line recommended drug. Compared with community-acquired SBP, nosocomial SBP had a poorer outcome (36.8% vs. 24.6%; P = 0.016). The independent predictors for 30-day mortality included nosocomial infection, Child-Pugh classification, hepatocellular carcinoma, renal failure and hepatic encephalopathy.

Conclusion

Gram-negative bacteria were the major pathogens involved in SBP in the cirrhotic patients. The strains isolated from the patients with nosocomial SBP displayed higher drug resistance than those isolated from patients with community-acquired SBP. Compared with community-acquired SBP, nosocomial SBP had a poorer outcome. When choosing drug treatments, the acquisition site of infection and the local epidemiological situation should be taken into account.

Multidrug-resistant bacterial infections in cirrhotic patients: an epidemiological study

BACKGROUND

The purpose of this study is to describe the epidemiological features of bacterial infections caused by multidrug-resistant (MDR) bacteria in cirrhotic patients and their impact on mortality.

METHODS

A retrospective study of cirrhotic patients with culture-confirmed bacterial infections was performed between 2011 and 2017.

RESULTS

A total of 635 episodes in 563 patients with cirrhosis were included. Bacterial infections caused by MDR isolates accounted for 44.1% (280/635) of the episodes, nearly half of which were hospital acquired (48.4%). The most common MDR isolation site was the respiratory tract (36.4%, 102 episodes), followed by the abdominal cavity (35.4%, 99 episodes). Of the MDR isolates, carbapenem-resistant Enterobacteriaceae (CRE) (91 episodes) were the most common. Patients infected with MDR bacteria had significantly higher mortality than those not infected (25.1% vs 17.4%, p = 0.025). However, this increased mortality could be largely attributed to methicillin-resistant Staphylococcus aureus (MRSA). After adjustment for age, sex, and the model for end-stage liver disease (MELD) score, only MRSA infection was an independent risk factor for 28-day mortality in the multivariable Cox proportional hazard regression model analysis (HR, 2.964, 95% CI (1.175-7.478), p = 0.021).

CONCLUSIONS

MDR bacterial infections, especially CRE, have become frequent in patients with cirrhosis in recent years, with MRSA infections significantly increasing short-term mortality.

Mortality from Spontaneous Bacterial Peritonitis Among Hospitalized Patients in the USA

BACKGROUND AND AIM

Spontaneous bacterial peritonitis (SBP) is a serious complication of cirrhosis and is associated with significant morbidity and mortality. In this study, we examined the clinical characteristics and risk factors associated with mortality in hospitalized patients presenting with SBP.

METHODS

The Nationwide Inpatient Sample was queried for all hospitalizations involving SBP from 2006 to 2014 using the International Classification of Disease-9-CM Code. Logistic regression was performed to evaluate the association between SBP mortality and factors such as age, gender, race/ethnicity, and concomitant medical conditions at presentation (e.g., variceal hemorrhage, hepatic encephalopathy, acute renal failure, coagulopathy, and other infections including pneumonia). The lengths of stay (LOS) and total charges were also examined.

RESULTS

From 2006 to 2014, there were 88,167 SBP hospitalizations with 29,963 deaths (17.6% in-hospital mortality). The mean age of patients who died in the hospital was higher (58.2 years vs. 55.8, p < 0.01) than those who survived the admission. Acute alcoholic hepatitis was noted among a higher proportion of patients who died (7.0 vs. 5.9%, p < 0.01), who were also likely to have more medical comorbidities. In multivariable analysis, older age, female gender, hepatic encephalopathy, coagulopathy, variceal hemorrhage, sepsis, pneumonia, and acute kidney injury were associated with increased in-hospital mortality. This group also had longer LOS (11.6 days vs. 9.1, p < 0.01) and higher total charges ($138,273 vs. $73,533, p < 0.01).

CONCLUSION

SBP is associated with significant in-hospital mortality, especially in patients with concurrent risk factors. SBP remains a significant burden to the healthcare system.

Low ascitic fluid total protein levels is not associated to the development of spontaneous bacterial peritonitis in a cohort of 274 patients with cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a complication to decompensated cirrhosis. Fluoroquinolones may prevent SBP. However, predictive markers for SBP are wanted. Guidelines suggest that patients with ascitic fluid protein below 15 g/l receive fluoroquinolones to prevent SBP. This study aimed to assess the clinical utility of low ascitic fluid protein in predicting SBP in patients with cirrhosis and ascites.

METHODS

A total of 274 patients with cirrhosis and ascites underwent paracentesis between January 2010 and June 2015. Patients were followed until two years, development of SBP, initiation of ciprofloxacin, death or liver transplantation. Data were compared between groups of patients with 'high' or 'low' ascitic protein.

RESULTS

SBP developed in 31 patients (11.3%). No difference in mean ascitic fluid protein levels were found (SBP, mean: 8.5 g/l and no SBP 8.2 g/l, p = .825). SBP developed at equal rates in patients with 'high' or 'low' ascitic protein (10.8% (≤15 g/l) and 14.0% (>15 g/l), p = .599). The same trend was observed when adjusting the threshold below 10 g/l (11.9% (≤10 g/l) and 10.2% (>10 g/l), p = .697).

CONCLUSIONS

Low ascitic fluid protein does not predict SBP in patients with cirrhosis and ascites. Better markers are needed.

Nosocomial and Community-Acquired Spontaneous Bacterial Peritonitis in patients with liver cirrhosis in China: Comparative Microbiology and Therapeutic Implications

Spontaneous bacterial peritonitis (SBP) is a common complication of liver cirrhosis. This study was performed to compare the microbiological characteristics of nosocomial and community-acquired episodes of bacterial peritonitis in China. Five hundred and seventy-five strains were isolated from the ascitic fluid of cirrhotic patients from the Beijing 302 Hospital from January 2014 to December 2014. The patients in the community-acquired SBP (n = 311) and the nosocomial SBP (n = 264) groups exhibited significant differences in clinical symptoms (P < 0.01). In both groups, most of the bacteria were Escherichia coli, Klebsiella pneumoniae, coagulase-negative staphylococcus and Enterococcus. There were more frequent gram-positive cocci (G⁺ C) in the nosocomial group (n = 170). Compared with the community-acquired group, the proportion of Enterococcus was significantly increased in the nosocomial group (9.0% vs. 16.6%, P < 0.05). The resistance rate of the main pathogenic bacteria to the recommended first-line drug in the guideline was very high. Community-acquired and nosocomial SBP groups exhibited differences in clinical symptoms and antibiotic susceptibility tests. Optimal treatments should be provided for these patients. We recommend that cefoperazone/sulbactam or piperacillin/tazobactam should be used for the empirical treatment of SBP.

A Real-World Evaluation of Repeat Paracentesis-guided Management of Spontaneous Bacterial Peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a common infection in cirrhosis associated with high mortality. More than 20% of patients with SBP do not respond to initial antibiotics. Guidelines differ in recommendations to repeat paracentesis (retap) to confirm antibiotic efficacy. We aim to evaluate the effect of retap-guided management of SBP on antibiotic escalation and 30-day transplant-free survival.

MATERIALS AND METHODS

Retrospective cohort study of cirrhotic patients with SBP admitted to a single transplant center from 2010 to 2014. Patients were divided into 2 groups: retap-guided management versus no retap. Prevalence of initial antibiotic treatment failure, defined as <25% decrease in ascitic polymorphonuclear cells, and factors associated with treatment failure, antibiotic escalation and 30-day transplant-free survival were evaluated.

RESULTS

Out of 210 patients, 146 (age 58, 74% male, mean model for end-stage liver disease score, 25) had retap and treatment failure was noted in 28 (22%). Gram-positive bacteria accounted for 44% of all positive cultures and third-generation cepahalosporin resistance was noted in 23%. Thirty-day transplant-free survival was 72% and 62% in retap and control groups, respectively (P=0.07). Treatment failure independently doubled the 30-day mortality rate (hazard ratio: 2.15, 1.03 to 4.50, P=0.04). After adjusting for age, model for end-stage liver disease and nosocomial infection, retap-guided management was not associated with improved survival (P=0.34).

CONCLUSIONS

The prevalence of initial treatment failure is high (22%) in patients with SBP and doubles the 30-day mortality risk, supporting recommendations to retap all patients with SBP.

PREVALENCE OF BACTERIAL RESISTANCE IN HOSPITALIZED CIRRHOTIC PATIENTS IN SOUTHERN BRAZIL: A NEW CHALLENGE

BACKGROUND & AIMS

An increased frequency of infections by multiresistant bacteria has been described in hospitalized patients. The aim of this study was to evaluate the bacterial resistance profile in cirrhotic patients.

METHODS

This is a retrospective observational study. We assessed the antimicrobial susceptibility of 5,839 bacterial isolates from patients with and without cirrhosis. Regarding the multidrug resistance, we evaluated 4,505 bacterial isolates from 2,180 patients.

RESULTS

Two hundred and fifty-one patients had cirrhosis (mean age 57.6 ± 11 years; 61.8% were male, 47.8% of cases associated with hepatitis C virus). Of the isolates of patients with and without cirrhosis, 174/464 (37.5%) and 1,783/4,041 (44.1%) were multiresistant, respectively (p = 0.007). E. coli was the most common multiresistant bacteria in both groups. Approximately 20% of E. coli and Klebsiella sp. isolates were ESBL-producers and 44% of S. aureus isolates were methicillin-resistant in cirrhotic patients. In cirrhotic patients admitted to the emergency department, hospital ward, and intensive care unit, 28.3%, 50% and 40% had multiresistant isolates, respectively. In patients with and without cirrhosis, 36.2% and 33.5% of isolates were resistant to third-generation cephalosporins, respectively.

CONCLUSIONS

The empirical treatment of infections in hospitalized patients using broad-spectrum antibiotics should consider the observed pattern of bacterial resistance.

Extensively drug-resistant bacteria are an independent predictive factor of mortality in 130 patients with spontaneous bacterial peritonitis or spontaneous bacteremia

AIM: To evaluate the epidemiology and outcomes of culture-positive spontaneous bacterial peritonitis (SBP) and spontaneous bacteremia (SB) in decompensated cirrhosis.

METHODS: We prospectively collected clinical, laboratory characteristics, type of administered antibiotic, susceptibility and resistance of bacteria to antibiotics in one hundred thirty cases (68.5% males) with positive ascitic fluid and/or blood cultures during the period from January 1, 2012 to May 30, 2014. All patients with SBP had polymorphonuclear cell count in ascitic fluid > 250/mm³. In patients with SB a thorough study did not reveal any other cause of bacteremia. The patients were followed-up for a 30-d period following diagnosis of the infection. The final outcome of the patients was recorded in the end of follow-up and comparison among 3 groups of patients according to the pattern of drug resistance was performed.

RESULTS: Gram-positive-cocci (GPC) were found in half of the cases. The most prevalent organisms in a descending order were Escherichia coli (33), Enterococcus spp (30), Streptococcus spp (25), Klebsiella pneumonia (16), S. aureus (8), Pseudomanas aeruginosa (5), other Gram-negative-bacteria (GNB) (11) and anaerobes (2). Overall, 20.8% of isolates were multidrug-resistant (MDR) and 10% extensively drug-resistant (XDR). Health-care-associated (HCA) and/or nosocomial infections were present in 100% of MDR/XDR and in 65.5% of non-DR cases. Meropenem was the empirically prescribed antibiotic in HCA/nosocomial infections showing a drug-resistance rate of 30.7% while third generation cephalosporins of 43.8%. Meropenem was ineffective on both XDR bacteria and Enterococcus faecium (E. faecium). All but one XDR were susceptible to colistin while all GPC (including E. faecium) and the 86% of GNB to tigecycline. Overall 30-d mortality was 37.7% (69.2% for XDR and 34.2% for the rest of the patients) (log rank, P = 0.015). In multivariate analysis, factors adversely affecting outcome included XDR infection (HR = 2.263, 95%CI: 1.005-5.095, P = 0.049), creatinine (HR = 1.125, 95%CI: 1.024-1.236, P = 0.015) and INR (HR =1.553, 95%CI: 1.106-2.180, P = 0.011).

CONCLUSION: XDR bacteria are an independent life-threatening factor in SBP/SB. Strategies aiming at restricting antibiotic overuse and rapid identification of the responsible bacteria could help improve survival.

[Spontaneous bacterial peritonitis in patients with cirrhosis]

Spontaneous bacterial peritonitis (SBP) is a severe complication occurring in patients with cirrhosis, and is associated with high mortality. Liver transplantation should be considered after a first episode of SBP. Gram-negative bacilli are the major cause of SBP, however there is an increasing trend of Gram-positive cocci related SBP. Management includes empirical antibiotic treatment and albumin infusion. The choice of antibiotics depends on the site of acquisition (community-acquired vs nosocomial or health-care associated infection) and local resistance profile, due to the emergence of drug-resistant bacteria. Secondary prophylaxis is recommended after resolution of SBP and reduces recurrence and mortality. Primary prophylaxis in patients with low protein ascites (<15 g/L) should be restricted to patients with severe cirrhosis awaiting for liver transplantation.

Review article: spontaneous bacterial peritonitis--bacteriology, diagnosis, treatment, risk factors and prevention

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with cirrhosis and ascites.

AIM

To review the known and changing bacteriology, risk factors, ascitic fluid interpretation, steps in performing paracentesis, treatment, prophylaxis and evolving perspectives related to SBP.

METHODS

Information was obtained from reviewing medical literature accessible on PubMed Central. The search term 'spontaneous bacterial peritonitis' was cross-referenced with 'bacteria', 'risk factors', 'ascites', 'paracentesis', 'ascitic fluid analysis', 'diagnosis', 'treatment', 'antibiotics', 'prophylaxis', 'liver transplantation' and 'nutrition'.

RESULTS

Gram-positive cocci (GPC) such as Staphylococcus, Enterococcus as well as multi-resistant bacteria have become common pathogens and have changed the conventional approach to treatment of SBP. Health care-associated and nosocomial SBP infections should prompt greater vigilance and consideration for alternative antibiotic coverage. Acid suppressive and beta-adrenergic antagonist therapies are strongly associated with SBP in at-risk individuals.

CONCLUSIONS

Third-generation, broad-spectrum cephalosporins remain a good initial choice for SBP treatment. Levofloxacin is an acceptable alternative for patients not receiving long-term flouroquinolone prophylaxis or for those with a penicillin allergy. For uncomplicated SBP, early oral switch therapy is reasonable. Alternative antibiotics such as pipercillin-tazobactam should be considered for patients with nosocomial SBP or for patients who fail to improve on traditional antibiotic regimens. Selective albumin supplementation remains an important adjunct in SBP treatment. Withholding acid suppressive medication deserves strong consideration, and discontinuing beta-adrenergic antagonist therapy in patients with end-stage liver disease and resistant ascites is standard care. Liver transplant evaluation should be undertaken for patients who develop SBP barring contraindications.

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

Recently, important changes have been reported regarding the epidemiology of bacterial infections in liver cirrhosis. There is an emergence of multiresistant bacteria in many European countries and also worldwide, including the United States and South Korea. The classic empirical antibiotic treatment (third-generation cephalosporins, e.g., ceftriaxone, cefotaxime or amoxicillin-clavulanic acid) is still effective in infections acquired in the community, but its failure rate in hospital acquired infections and in some health-care associated infections is high enough to ban its use in these settings. The current editorial focuses on the different epidemiology of bacterial infections in cirrhosis across countries and on its therapeutic implications.

Spontaneous bacterial peritonitis: The clinical challenge of a leaky gut and a cirrhotic liver

Spontaneous bacterial peritonitis (SBP) is a frequent, life-threatening bacterial infection in patients with liver cirrhosis and ascites. Portal hypertension leads to increased bacterial translocation from the intestine. Failure to eliminate invading pathogens due to immune defects associated with advanced liver disease on the background of genetic predisposition may result in SBP. The efficacy of antibiotic treatment and prophylaxis has declined due to the spread of multi-resistant bacteria. Patients with nosocomial SBP and with prior antibiotic treatment are at a particularly high risk for infection with resistant bacteria. Therefore, it is important to adapt empirical treatment to these risk factors and to the local resistance profile. Rifaximin, an oral, non-absorbable antibiotic, has been proposed to prevent SBP, but may be useful only in a subset of patients. Since novel antibiotic classes are lacking, we have to develop prophylactic strategies which do not induce bacterial resistance. Farnesoid X receptor agonists may be a candidate, but so far, clinical studies are not available. New diagnostic tests which can be carried out quickly at the patient’s site and provide additional prognostic information would be helpful. Furthermore, we need tools to predict antibiotic resistance in order to tailor first-line antibiotic treatment of spontaneous bacterial peritonitis to the individual patient and to reduce mortality.

Prevalence of methicillin resistant Staphylococcus aureus among Egyptian patients after surgical interventions

BACKGROUND

Staphylococcus aureus (S. aureus) is isolated frequently from surgical site infections and other soft tissue infections. There are limited data examining the prevalence of methicillin resistant S. aureus (MRSA) among Egyptian patients after surgery. The current study determined the prevalence of MRSA isolated from surgical site and soft tissue infections at Minia University Hospital (MUH), determined their susceptibility to β-lactams and other antimicrobials, and examined their mecA gene expression.

METHODS

A total of 208 hospitalized patients attending the General Surgery Department at MUH were enrolled and all had skin and soft tissue infections (SSTIs) of different causes. These 208 patients (143 males and 65 females) were suffering from surgical site infection (SSI; n=82), diabetic foot (n=52), abscess (n=45), or burn (n=29) infections. Samples were cultured on different media for isolation and identification of S. aureus and the isolates were screened for antibiotic susceptibility. All MRSA isolates were tested by polymerase chain reaction to detect the mecA gene responsible for methicllin resistance.

RESULTS

241 Staphylococcal species represented the most common isolates (64.8%) among 371 collected isolates from the 208 patients. Out of the 241 staphylococcal isolates, 127 were S. aureus (61% of the total patients). The prevalence of S. aureus among SSI, diabetic foot, abscess, and burn patients were 59%, 75%, 56%, and 52%, whereas that of MRSA was 16%, 17%, 13%, and 10%, respectively. MRSA isolates (n=31; 15% of patients) showed multiple resistance to at least one member of the antimicrobial groups tested with an average resistance to 6.6±1.9 antimicrobial groups. Polymerase chain reaction data showed that only 29 isolates of the MRSA isolates (94%) were positive for mecA gene.

CONCLUSIONS

Staphylococcus aureus isolates are the major pathogens responsible for wound and surgical site infections at MUH and MRSA are a potential threat for wound patients in Egypt.

New determinants of prognosis in bacterial infections in cirrhosis

Despite major advances in the knowledge and management of liver diseases achieved in recent decades, decompensation of cirrhosis still carries a high burden of morbidity and mortality. Bacterial infections are one of the main causes of decompensation. It is very important for clinical management to be aware of the population with the highest risk of poor outcome. This review deals with the new determinants of prognosis in patients with cirrhosis and bacterial infections reported recently. Emergence of multiresistant bacteria has led to an increasing failure rate of the standard empirical antibiotic therapy recommended by international guidelines. Moreover, it has been recently reported that endothelial dysfunction is associated with the degree of liver dysfunction and, in infected patients, with the degree of sepsis. It has also been reported that relative adrenal insufficiency is frequent in the non-critically ill cirrhotic population and it is associated with a higher risk of developing infection, severe sepsis, hepatorenal syndrome and death. We advise a change in the standard empirical antibiotic therapy in patients with high risk for multiresistant infections and also to take into account endothelial and adrenal dysfunction in prognostic models in hospitalized patients with decompensated cirrhosis.

Evolving epidemiology and antimicrobial resistance in spontaneous bacterial peritonitis: a two-year observational study

BACKGROUND

Current recommendations for empirical antimicrobial therapy in spontaneous bacterial peritonitis (SBP) are based on quite old trials. Since microbial epidemiology and the management of patients have changed, whether these recommendations are still appropriate must be confirmed.

METHODS

An observational study that exhaustively collected the clinical and biological data associated with positive ascitic fluid cultures was conducted in four French university hospitals in 2010-2011.

RESULTS

Two hundred and sixty-eight documented positive cultures were observed in 190 cirrhotic patients (median age 61.5 years, 58.5% Child score C). Of these, 57 were classified as confirmed SBP and 140 as confirmed bacterascites. The predominant flora was Gram-positive cocci, whatever the situation (SBP, bacterascites, nosocomial/health-care related or not). Enteroccocci (27.7% E. faecium) were isolated in 24% of the episodes, and in 48% from patients receiving quinolone prophylaxis. E. coli were susceptible to amoxicillin-clavulanate and to third-generation cephalosporins in 62.5% and 89.5% of cases, respectively. No single antibiotic allowed antimicrobial coverage of more than 60%. Only combinations such as amoxicillin + third-generation cephalosporin or cotrimoxazole allowed coverage close to 75-80% in non-nosocomial episodes. Combinations based on broader spectrum antibiotics should be considered for empirical therapy of nosocomial infections.

CONCLUSIONS

Our study confirmed the changing spectrum of pathogens in SBP and bacterascites, and the need for more complex antibiotic strategies than those previously recommended. Our findings also underline the need for new clinical trials conducted in the current epidemiological context.

Patterns of antimicrobial resistance in the causative organisms of spontaneous bacterial peritonitis: a single centre, six-year experience of 1981 samples

Background/Aims. Spontaneous bacterial peritonitis (SBP) is one of the leading causes of morbidity and mortality in patients with cirrhosis. This study aims to determine the microbial agents of SBP and the pattern of antibiotic resistance, in a large number of ascitic samples. Methodology. In a cross-sectional, single center, hospital based study, 1981 consecutive ascitic fluid samples were recruited from 2005 to 2011. Samples were dichotomized into three-year periods, in order to assess the trend of resistance to the first-line empirical antibiotics. Results. SBP was found in 482 (24.33%) of samples, of which 314 (65.15%) were culture positive. The most prevalent isolated pathogen was E. coli (33.8%), followed by staphylococcus aureus (8.9%) and Enterococcus (8.6%). No significant changes in the proportion of gram-negative/gram-positive infections occurred during this period. A percentage of resistant strains to cefotaxime (62.5%, 85.7%), ceftazidim (73%, 82.1%), ciprofloxacin (30, 59.8%), ofloxacin (36.8%, 50%), and oxacilin (35%, 51.6%) were significantly increased. E. coli was most sensitive to imipenem, piperacillin-tazobactam, amikacin, ceftizoxime, and gentamicin. Conclusions. The microbial aetiology of SBP remains relatively constant. However, the resistance rate especially to the first-line recommended antibiotics was significantly increased. This pattern must be watched closely and taken into account in empirical antibiotic treatment.

Increasing frequency of gram-positive cocci and gram-negative multidrug-resistant bacteria in spontaneous bacterial peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is historically caused by Gram-negative bacteria (GNB) almost exclusively Enterobacteriaceae. Recently, an increasing rate of infections with Gram-positive cocci (GPC) and multidrug-resistant (MDR) microorganisms was demonstrated.

AIMS

To assess possible recent changes of the bacteria causing SBP in cirrhotic patients.

METHODS

We retrospectively recorded 47 cases (66% males) during a 4-year-period (2008-2011).

RESULTS

Twenty-eight (60%) patients had healthcare-associated infections while 15 (32%) received prophylactic quinolone treatment. GPC were found to be the most frequent cause (55%). The most prevalent organisms in a descending order were Streptococcus spp (n = 10), Enterococcus spp (n = 9), Escherichia coli (n = 8), Klebsiella pneumonia (n = 5), methicillin-sensitive Staphylococcus aureus (n = 4) and coagulase-negative Staphylococcus spp (n = 3). Nine of the isolated bacteria (19%) were MDR, including carbapenemase-producing K. pneumonia (n = 4), followed by extended-spectrum beta-lactamase-producing E. coli (n = 3) and Pseudomonas aeruginosa (n = 2). MDR bacteria were more frequently isolated in healthcare-associated than in community-acquired infections (100% vs 50%, P = 0.006), in patients receiving long-term quinolone prophylaxis (67% vs 24%, P = 0.013) and in those with advanced liver disease as suggested by higher MELD score (28 vs 19, P = 0.012). More infections with GNB than GPC were healthcare-associated (81% vs 42%, P = 0.007). Third-generation cephalosporin resistance was observed in 49% and quinolone resistance in 47%.

CONCLUSIONS

GPC were the most frequent bacteria in culture-positive SBP and a variety of drug-resistant microorganisms have emerged. As a result of high rates of resistance in currently recommended therapy and prophylaxis, the choice of optimal antibiotic therapy is vital in the individual patient.

Diagnosis and management of bacterial infections in decompensated cirrhosis

Bacterial infections are one of the most frequent complications in cirrhosis and result in high mortality rates. Patients with cirrhosis have altered and impaired immunity, which favours bacterial translocation. Episodes of infections are more frequent in patients with decompensated cirrhosis than those with compensated liver disease. The most common and life-threatening infection in cirrhosis is spontaneous bacterial peritonitis followed by urinary tract infections, pneumonia, endocarditis and skin and soft-tissue infections. Patients with decompensated cirrhosis have increased risk of developing sepsis, multiple organ failure and death. Risk factors associated with the development of infections are severe liver failure, variceal bleeding, low ascitic protein level and prior episodes of spontaneous bacterial peritonitis (SBP). The prognosis of these patients is closely related to a prompt and accurate diagnosis. An appropriate treatment decreases the mortality rates. Preventive strategies are the mainstay of the management of these patients. Empirical antibiotics should be started immediately following the diagnosis of SBP and the first-line antibiotic treatment is third-generation cephalosporins. However, the efficacy of currently recommended empirical antibiotic therapy is very low in nosocomial infections including SBP, compared to community-acquired episodes. This may be associated with the emergence of infections caused by Enterococcus faecium and extended-spectrum β-lactamase-producing Enterobacteriaceae, which are resistant to the first line antimicrobial agents used for treatment. The emergence of resistant bacteria, underlines the need to restrict the use of prophylactic antibiotics to patients with the greatest risk of infections. Nosocomial infections should be treated with wide spectrum antibiotics. Further studies of early diagnosis, prevention and treatment are needed to improve the outcomes in patients with decompensated cirrhosis.

Changing bacteriology of abdominal and surgical sepsis

PURPOSE OF REVIEW

This review focuses on recent changes in epidemiological aspects of bacteria-induced intra-abdominal infections (IAIs), including the dominant pathogens, antimicrobial susceptibility profiles, and emerging resistance phenotypes.

RECENT FINDINGS

Enterobacteriaceae species, including Escherichia coli and Klebsiella pneumoniae, remain the major pathogens contributing to abdominal sepsis, although Pseudomonas aeruginosa and Acinetobacter baumannii have recently become common causes of hospital-acquired IAIs. The prevalence of multidrug-resistant Gram-negative bacilli, especially those that produce extended-spectrum β-lactamases (ESBLs), has increased worldwide, although the distribution of those organisms varies from region to region. Furthermore, recent changes in interpretive breakpoints for antimicrobial susceptibility testing recommended by the Clinical Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) have resulted in a marked increase in the reported rates of resistance among Gram-negative bacilli to carbapenems, extended-spectrum cephalosporins, and fluoroquinolones. Besides, routine detection and reporting of ESBL phenotypes for clinical isolates have not been recommended after following new interpretive breakpoints. More studies are needed to investigate the impacts of these changes on therapeutic strategies and epidemiological surveillance. In addition, pathogens carrying New Delhi metallo-β-lactamases (NDMs), K. pneumoniae carbapenemases (KPCs), and other carbapenemases show extended resistance to currently available antibiotics and rapid transfer between species and countries. Although some of these pathogens are still susceptible to tigecycline and colistin, rates of resistance to these two agents are rising.

SUMMARY

Abdominal sepsis due to multidrug-resistant bacteria, especially ESBL producers, and international and interspecies spreading of metallo-β-lactamase raise key therapeutic problems.

The new epidemiology of nosocomial bacterial infections in cirrhosis: therapeutical implications

Cirrhotic patients are at increased risk of developing infection, sepsis and death. Enterobacteriaceae and nonenterococcal streptococci are the main bacteria responsible for spontaneous and urinary infections in this population. Prompt and appropriate treatment is basic in the management of cirrhotic patients with infection. Third-generation cephalosporins continue to be the gold-standard antibiotic treatment of the majority of infections acquired in the community because responsible strains are usually susceptible to β-lactams. By contrary, nosocomial infections are nowadays frequently caused by multiresistant bacteria (extended-spectrum β-lactamase-producing Enterobacteriaceae, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci among others) that are nonsusceptible to the main antibiotics. Treatment of these infections requires the use of broader spectrum antibiotics (carbapenems) or of antibiotics that are active against specific resistant bacteria (glycopeptides, linezolid, daptomycin, amikacin and colistin). Empirical antibiotic schedules must be adapted to the local epidemiological pattern of antibiotic resistance. Careful restriction of antibiotic prophylaxis to the high-risk population is also mandatory to reduce the spread of multiresistant bacteria in cirrhosis.

Identification of bacterial pathogens in ascitic fluids from patients with suspected spontaneous bacterial peritonitis by use of broad-range PCR (16S PCR) coupled with high-resolution melt analysis

Spontaneous bacterial peritonitis (SBP) can be a severe complication occurring in patients with cirrhosis and ascites, with associated mortality often as high as 40%. Traditional diagnostics for SBP rely on culture techniques for proper diagnosis, although recent reports suggest that the presence of bacterial DNA in peritoneal fluid in patients with cirrhosis and ascites is an indicator of SBP. A previously published broad-range PCR (16S PCR) coupled with high-resolution melt analysis (HRMA) was compared with standard culture techniques for diagnosis of SBP in 106 peritoneal fluid samples from patients with suspected SBP. The sensitivity and specificity for 16S PCR for detecting eubacterial DNA compared with those of standard culture techniques were 100% (17/17) and 91.5% (85/89), respectively. Overall, HRMA concordance with species identification was 70.6% (12/17), although the 5 samples that were discordant at the species level were SBP resulting from a polymicrobial infection, and species-level identification for polymicrobial infections is outside the capability of HRMA. Both the broad-range 16S PCR and HRMA analysis provide useful diagnostic adjunctive assays for clinicians in detecting and identifying pathogens responsible for SBP.