Development of quinolone-resistant strains of Escherichia coli in stools of patients with cirrhosis undergoing norfloxacin prophylaxis: clinical consequences

Treatment of Hospital-Acquired Infections in Patients with Cirrhosis - New Challenges

Background

Hospital acquired infections (HAI) in the cirrhotic patients contribute to hepatic decompensation. With emergence of bacterial drug resistance, designing the treatment protocol of HA infection has become the foremost challenge.

Purpose

To analyze the resistance pattern of organisms isolated from hospital-acquired (HA) infections and determine appropriate antibiotics treatment protocols for these infections.

Study Design

A prospective hospital based observational study was undertaken.

Patients and Methods

The present study was conducted over 18 months at Kasturba Medical College, Mangalore, Karnataka, India. Patients with suspected HA infections were subjected to clinical, hematological and microbiological evaluation. Antibiotic sensitivity evaluation was undertaken for the bacteria isolated from these patients.

Results

During the study period, 398 patients with cirrhosis were 472 times admitted to the hospital for treatment. Out of these patients, 40 patients were diagnosed with 50 HA infections. Fifty five different organisms were isolated from these infections. It was found that these 55 bacteria isolates comprised 30 (54.54%) gram-negative (GN) and 25 (45.45%) gram-positive (GP) bacteria. Quite seriously, extended-spectrum beta-lactamase (ESBL) producers and methicillin-resistant Staphylococcus aureus (MRSA) were detected in 40% and 58% of GN and GP infections respectively. A total of 36 (65.4%) and (14.5%) 8 out of 55 isolated organisms exhibited multi–drug resistance (MDR) and extensive drug resistance (XDR) behavior, respectively.

Conclusion

Cirrhosis patients with HA infection possess higher prevalence of MDR and XDR infections. In such sick patients, cephalosporin and quinolones are not the appropriate empirical antibiotics. Herein, we propose a tigecycline with carbapenem like meropenem and vancomycin based empirical antibiotics protocol to be prescribed for such patients. De-escalation is advised after the culture sensitivity report is obtained.

Comparative efficacy of long-term antibiotic treatments in the primary prophylaxis of spontaneous bacterial peritonitis

BACKGROUND & AIMS

Several antibiotic treatments aiming to prevent spontaneous bacterial peritonitis (SBP) in cirrhotic patients with low-protein content in ascitic fluid have been tested; however, there are limited data on the comparative efficacy of these regimens. We assessed their comparative efficacy through a network meta-analysis and using GRADE criteria to appraise quality of evidence.

METHODS

Through literature review through October 2018, we identified 10 randomized controlled trials comparing antibiotic treatments (norfloxacin, ciprofloxacin, trimethoprim/sulfamethoxazole and rifaximin) with each other or placebo. Primary outcome was SBP occurrence, with mortality rate and rate of other infections as secondary outcomes.

RESULTS

In comparison with placebo, moderate quality evidence supports the use of norfloxacin and ciprofloxacin in primary prophylaxis of SBP (risk ratio 0.23; 95% CI, 0.09-0.56; P = 0.001 and 0.23; 0.07-0.79; P = 0.02 respectively) while only low quality evidence suggests superiority of rifaximin (risk ratio 0.15; 0.05-0.42). When antimicrobial agents were compared to each other, no significant difference was found. With regard to mortality, moderate quality supports the superiority of norfloxacin over placebo (risk ratio, 0.68; 95% CI, 0.47-0.99; P = 0.04), while ciprofloxacin and rifaximin showed only a non-significant benefit and no significant difference was found in the other comparisons. None of the tested antibiotics proved to significantly decrease the rate of other infections.

CONCLUSIONS

Norfloxacin appears to have significant benefit both in terms of SBP prevention and mortality; ciprofloxacin represents a valuable option although without a clear survival benefit. Rifaximin shows interesting results but needs to be tested in further trials.

Daily Norfloxacin vs. Weekly Ciprofloxacin to Prevent Spontaneous Bacterial Peritonitis: A Randomized Controlled Trial

OBJECTIVES

For the prevention of spontaneous bacterial peritonitis (SBP) in cirrhotic patients with ascites, norfloxacin 400 mg per day is recommended as a standard regimen. This study aims to investigate whether ciprofloxacin once weekly administration is not inferior to norfloxacin once daily administration for the prevention of SBP.

METHODS

This is an investigator-initiated open-label randomized controlled trial conducted at seven tertiary hospitals in South Korea. Liver cirrhosis patients with ascites were screened, and enrolled in this randomized controlled trial if ascitic protein ≤1.5 g/dL or the presence of history of SBP. Ascitic polymorphonucleated cell count needed to be <250/mm³. Patients were randomly assigned into norfloxacin daily or ciprofloxacin weekly group, and followed-up for 12 months. Primary endpoint was the prevention of SBP.

RESULTS

One hundred twenty-four patients met enrollment criteria and were assigned into each group by 1:1 ratio (62:62). Seven patients in the norfloxacin group and five patients in the ciprofloxacin group were lost to follow-up. SBP developed in four patients (4/55) and in three patients (3/57) in each group, respectively (7.3% vs. 5.3%, P = 0.712). The transplant-free survival rates at 1 year were comparable between the groups (72.7% vs. 73.7%, P = 0.970). Incidence of infectious complication, hepatorenal syndrome, hepatic encephalopathy, and variceal bleeding rates were not significantly different (all P = ns). The factors related to survival were models representing underlying liver function.

CONCLUSION

Once weekly ciprofloxacin was as effective as daily norfloxacin for the prevention of SBP in cirrhotic patients with ascites.

Management of Infectious Complications Associated with Acute-on-Chronic Liver Failure

Introduction

Acute-on-chronic liver failure (ACLF) is associated with a high susceptibility to infections leading to complications and poor prognosis. The sensitized immune system overwhelmingly responds to invading bacteria leading to organ damage. After resolution of infection or prolonged disease duration, the phagocytic system becomes irresponsive with a reduced bacterial clearance capacity promoting secondary infection.

Methods

This review focuses on the best management strategies for patients with ACLF and infections. Using the following terms, an extensive literature research on the Medline database was performed: 'acute-on-chronic liver failure', 'infection', 'ACLF', 'bacteria', 'multi-resistance'.

Results

Analysis of the literature confirmed that delayed diagnosis and treatment of infections in patients with ACLF results in a poor prognosis. Patients with ACLF should be considered as having a potential infection and should undergo a complete screening for sepsis. Once biochemical analysis indicates a potential infection, such as abnormal levels of C-reactive protein and procalcitonin, antibiotic treatment should be initiated immediately without microbiological culture results. For community-acquired infections third-generation cephalosporins are still the first choice, whereas in the nosocomial setting antibiotics with broader spectrum, such as piperacillin/combactam or carbapenems ± glycopeptides, are preferred. The patient should be re-assessed 48 h after treatment initiation in order to tailor the treatment. Non-response is suspicious, likely due to bacterial resistance or fungal infection, which should be considered when choosing further treatment strategies. Albumin substitution to prevent hepatorenal syndrome and to improve patients' outcome is mandatory in patients with spontaneous bacterial peritonitis. Prophylactic antibiotic therapy is suitable to prevent infections in high-risk patients.

Conclusion

The screening for infections and its treatment is an essential part of managing patients with ACLF. In order to improve patients' prognosis, antibiotic treatment should be initiated once an infection is suspected. However, preventive strategies are already established and should be applied according to the guidelines.

Norfloxacin is more effective than Rifaximin in avoiding bacterial translocation in an animal model of cirrhosis

BACKGROUND & AIMS

Norfloxacin administration is useful in preventing bacterial infections in cirrhosis but associated to the generation of resistant species. Rifaximin is known to reach high concentrations in the intestinal lumen without generating relevant resistance in the intestinal flora. Our aim was to compare the effect of Norfloxacin and Rifaximin on intestinal flora composition, bacterial translocation and survival in cirrhotic rats.

METHODS

Cirrhosis was induced in rats by oral administration of CCl₄ . Animals were divided into three groups: only CCl₄ (group I, n = 10); CCl₄ + Norfloxacin (group II, n = 17) and CCl₄ + Rifaximin (group III, n = 14). Gut bacterial composition, bacterial translocation and cytokine levels were measured.

RESULTS

Forty-one rats were finally included. The incidence of viable and non-viable bacterial translocation was significantly reduced in animals receiving Norfloxacin; Rifaximin also decreased the incidence of viable and non-viable bacterial translocation, but did not reach statistical significance. Serum TNF-α levels were significantly lower in antibiotic groups. Norfloxacin modified intestinal microbiota, depleting significantly more pathobionts than Rifaximin.

CONCLUSION

Norfloxacin is more effective than Rifaximin in preventing bacterial translocation in rats with cirrhosis probably because of its capacity to reduce pathobionts from intestinal microbiota.

[Surveillance of Antimicrobial Resistant Esherichia coli by Rectal Swab Method--Annual Change of Prevalence of Quinolone-resistant and ESBL Producing Strains from 2009 to 2013]

Although most of commonly used antimicrobial agents had been susceptible to Esherichia coli, recently there are a lot of reports concerning about community-acquired infection caused by resistant E. coli. The aim of this study is to define the prevalence of resistant E. coli in normal flora colonization by the rectal swab method. From June 2009 to December 2013, 251 male patients (50-85 year-old, median 68) planned to transrectal prostate biopsy participated in this study. Stools stuck on the glove at the digital examination were provided for culture specimen. Identification of E. coli and determination of MIC was performed by MicroScan WalkAway40plus (Siemens). Isolated E. coli were deemed quinolone-resistant strains when their MIC of levofloxacine was 4 μg/mL or above according to the breakpoint MIC by the CLSI criteria. ESBL producing ability was determined by the double disk method used by CVA contained ESBL definition disc (Eikenkagaku). Of the 251 study patients, 224 patients had positive cultures of E. coli. Twenty-four patients had quinolone-resistant strains and 9 patients had ESBL producing strains. The prevalence of quinolone-resistant strains in 2009, 2010, 2011, 2012 and 2013 were 5.9% (2 out of 34 strains), 13.5% (5 out of 37 strains), 12.5% (4 out of 32 strains), 9.0% (6 out of 67) and 13.0% (7 out of 54 strains), respectively. The prevalence of ESBL producing strains in 2009, 2010, 2011, 2012 and 2013 were 0% (0 out of 34 strains), 5.4% (2 out of 37 strains), 3.1% (1 out of 32 strains), 3.0% (2 out of 67 strains) and 7.4% (4 out of 54 strains), respectively. In 2013, the prevalence of antimicrobial resistant E. coli, both quinolone-resistant and ESBL producing strains, were increasing. We have to pay a close attention to the increase of resistant E. coli.

Impact of fluoroquinolones on human microbiota. Focus on the emergence of antibiotic resistance

The aggregate of microorganisms residing on the surface of the skin, in the oropharynx and in the GI tract, known as the human microbiota, play a major role as natural reservoirs for bacterial resistance to antibiotics. Fluoroquinolones (FQ) are among the most prescribed antibiotics and a major increase in FQ resistance is occurring worldwide. High concentrations of FQ are found in microbial ecosystems explaining their profound effect on the clinically relevant bacteria that compose them. Yet, because of different local pharmacokinetics, distinct selective pressures occur in the different microbiota. Here we review the qualitative and quantitative impact of FQ on the three main human microbiota and their consequences, particularly in terms of emergence of antibiotic resistance. Finally, we review potential actions that could decrease the impact of FQs on microbiota.

Risk factor of community-onset spontaneous bacterial peritonitis caused by fluoroquinolone-resistant Escherichia coli in patients with cirrhosis

BACKGROUND & AIMS

Despite the high prevalence of antimicrobial-resistant Escherichia coli in hospital-acquired infections, the clinical epidemiology of fluoroquinolone (FQ) resistance in community-onset spontaneous bacterial peritonitis (SBP) in patients with cirrhosis is not well understood. This study was performed to evaluate clinical features and risk factors for community-onset SBP caused by FQ-resistant E. coli.

METHODS

A case-control control study was performed using cases of community-onset SBP from June 2000 to August 2011 at Samsung Medical Center (Seoul, Korea). Patients with FQ-resistant E. coli were designated as case patients. A control group I (CG I) patient was defined as a person whose clinical sample yielded FQ-susceptible E. coli, and a control group II (CG II) patient was defined as a person with a negative culture result.

RESULTS

A total of 82 subjects with community-onset SBP caused by E. coli were identified, of which 26 (31.7%) were FQ-resistant E. coli infection. Fifty-seven matched subjects were randomly selected for CG II. Compared with CG I, previous SBP episodes (OR, 4.91; 95% CI, 1.50-16.53; P = 0.010), prior use of FQ within 30 days (OR, 7.05; 95% CI, 1.17-42.38; P = 0.033), and third-generation cephalosporin resistance (OR, 17.68; 95% CI, 1.67-187.26; P = 0.017) were significantly associated with FQ-resistant E. coli. Compared with CG II, a previous SBP episode was significantly associated with FQ-resistant E. coli (OR, 4.20; 95% CI, 1.50-11.80; P = 0.006).

CONCLUSION

FQ-resistant E. coli is a significant cause of community-onset SBP, with relation to previous SBP episodes, recent FQ use and third-generation cephalosporin resistance.

Effects of the adjunctive probiotic VSL#3 on portal haemodynamics in patients with cirrhosis and large varices: a randomized trial

BACKGROUND

Probiotics, by altering gut flora, may favourably alter portal haemodynamics in patients with cirrhosis.

AIM

To investigate the effect of probiotics on portal pressure in patients with cirrhosis.

METHODS

Randomized double-blind placebo-controlled trial conducted in G.B. Pant Hospital, New Delhi. A total of 94 cirrhotic patients having large oesophageal varices without history of variceal bleeding were randomized to three treatment groups and given 2 months' treatment with propranolol plus placebo, propranolol plus antibiotics (norfloxacin 400 mg BD) or propranolol plus probiotic (VSL#3, 900 billion/day) randomly assigned in 1:1:1 ratio. Outcome measures were change in Hepatic venous pressure gradient (HVPG): Response rate (Percentage of patients having a decrease from baseline of ≥20% or to ≤12 mm Hg) and changes from baseline; biochemical markers of inflammation: changes from baseline.

RESULTS

Adjunctive probiotics increased the response rate compared with propranolol alone (58% vs. 31%, P = 0.046), similar to adjunctive antibiotics (54%). The mean fall in HVPG was greater with either adjunctive probiotics (3.7 mm Hg vs. 2.1 mm Hg, P = 0.061) or adjunctive antibiotics (3.4 mm Hg) than with propranolol alone. Both adjunctive therapies were associated with greater decreases in TNF-α levels (in both peripheral and hepatic venous blood) that resulted from propranolol-only treatment. No clinically relevant between-group differences were observed in the type or frequency of adverse events.

CONCLUSIONS

Adjunctive probiotic (VSL#3) improved the response rate to propranolol therapy and was safe and well tolerated in patients with cirrhosis. Adjunctive probiotic therapy merits further study for reduction in portal pressure.

Targeting the gut-liver axis in cirrhosis: antibiotics and non-selective β-blockers

The gut-liver axis in cirrhosis and portal hypertension is gaining increasing attention as a key pathophysiological mechanism responsible for progression of liver failure and development of complications such as spontaneous infections and hepatocellular carcinoma. Antibiotics and non-selective β-blockers (NSBB) intercept this axis and each drug has proven efficacy in clinical trials. A synergistic effect is a hitherto unproven possibility. There is an increasing body of evidence supporting improved outcome with expanded use of NSBB and antibiotic therapy beyond current indications. This review addresses the issue of pharmacological treatment of cirrhosis and portal hypertension with antibiotics and NSBB. We discuss their mechanism of action and suggest that combining the two treatment modalities could potentially reduce the risk of complications.

Microbiological characteristics of acute prostatitis after transrectal prostate biopsy

Purpose

We aimed to identify microbiological characteristics in patients with acute prostatitis after transrectal prostate biopsy to provide guidance in the review of prevention and treatment protocols.

Materials and Methods

A retrospective analysis of medical records was performed in 1,814 cases who underwent prostate biopsy at Seoul St. Mary's Hospital and St. Vincent's Hospital over a 5 year period from 2006 to 2011. Cases in which acute prostatitis occurred within 7 days after the biopsy were investigated. Before starting treatment with antibiotics, sample collections were done for culture of urine and blood. Culture and drug susceptibility was identified by use of a method established by the Clinical and Laboratory Standards Institute.

Results

A total of 1,814 biopsy procedures were performed in 1,541 patients. For 1,246 patients, the procedure was the first biopsy, whereas for 295 patients it was a repeat biopsy. Twenty-one patients (1.36%) were identified as having acute bacterial prostatitis after the biopsy. Fifteen patients (1.2%) had acute prostatitis after the first biopsy, and 6 patients (2.03%) experienced acute prostatitis after a repeat biopsy. Even though the incidence of acute bacterial prostatitis was higher after repeat biopsy than that after the first biopsy, there was no statistically significant intergroup difference in terms of incidence (χ²=1.223, p=0.269). When the collected urine and blood samples were cultured, Escherichia coli was found in samples from 15 patients (71.4%), Klebsiella pneumoniae in 3 patients (14.3%), Enterobacter intermedius in 1 patient (4.8%), E. aerogenes in 1 patient (4.8%), and Pseudomonas aeruginosa in 1 patient (4.8%). A fluoroquinolone-resistant strain was confirmed in 5 cases (23.8%) in total. Three cases of E. coli and 1 case of Klebsiella had extended-spectrum β-lactamase activity.

Conclusions

Empirical treatment of acute prostatitis should be done with consideration of geographical prevalence and drug resistance. This study will provide meaningful information for the management of acute prostatitis after transrectal prostate biopsy.

Management of bacterial infections in cirrhosis

Bacterial infections are very frequent in advanced cirrhosis and become the first cause of death of these patients. Despite numerous experimental data and significant advances in the understanding of the pathogenesis of sepsis in cirrhosis, the outcome remains poor. Classical diagnostic parameters such as C-reactive protein and SIRS criteria have less diagnostic capacity in the cirrhotic population, often delaying the diagnosis and the management of bacterial infection. Prompt and appropriate empirical antibiotic treatment of infection and early resuscitation of patients with severe sepsis or septic shock are essential in determining patient's outcome. A strategy of careful restriction of prophylactic antibiotics to the high-risk populations could reduce the spread of multidrug resistant bacteria. This review is focused on the currently recommended diagnostic, therapeutic and prophylactic strategies for bacterial infections in the cirrhotic population.

Prevalence and risk factors of infections by multiresistant bacteria in cirrhosis: a prospective study

Epidemiology, risk factors, and clinical effect of infections by multiresistant bacteria in cirrhosis are poorly known. This work was a prospective evaluation in two series of cirrhotic patients admitted with infection or developing infection during hospitalization. The first series was studied between 2005 and 2007 (507 bacterial infections in 223 patients) and the second between 2010 and 2011 (162 bacterial infections in 110 patients). In the first series, 32% of infections were community acquired (CA), 32% healthcare associated (HCA), and 36% nosocomial. Multiresistant bacteria (92 infections; 18%) were isolated in 4%, 14%, and 35% of these infections, respectively (P < 0.001). Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E; n = 43) was the main multiresistant organism identified, followed by Pseudomonas aeruginosa (n = 17), methicillin-resistant Staphylococcus aureus (n = 14), and Enterococcus faecium (n = 14). The efficacy of currently recommended empirical antibiotic therapy was very low in nosocomial infections (40%), compared to HCA and CA episodes (73% and 83%, respectively; P < 0.0001), particularly in spontaneous bacterial peritonitis, urinary tract infection, and pneumonia (26%, 29%, and 44%, respectively). Septic shock (26% versus 10%; P < 0.0001) and mortality rate (25% versus 12%; P = 0.001) were significantly higher in infections caused by multiresistant strains. Nosocomial origin of infection (hazard ratio [HR], 4.43), long-term norfloxacin prophylaxis (HR, 2.69), recent infection by multiresistant bacteria (HR, 2.45), and recent use of β-lactams (HR, 2.39) were independently associated with the development of multiresistant infections. Results in the second series were similar to those observed in the first series.

CONCLUSIONS

Multiresistant bacteria, especially ESBL-producing Enterobacteriaceae, are frequently isolated in nosocomial and, to a lesser extent, HCA infections in cirrhosis, rendering third-generation cephalosporins clinically ineffective. New antibiotic strategies tailored according to the local epidemiological patterns are needed for the empirical treatment of nosocomial infections in cirrhosis.

Emergence and spread of antibiotic resistance following exposure to antibiotics

Within a susceptible wild-type population, a small fraction of cells, even <10(-9) , is not affected when challenged by an antimicrobial agent. This subpopulation has mutations that impede antimicrobial action, allowing their selection during clinical treatment. Emergence of resistance occurs in the frame of a selective compartment termed a mutant selection window (MSW). The lower margin corresponds to the minimum inhibitory concentration of the susceptible cells, whereas the upper boundary, named the mutant prevention concentration (MPC), restricts the growth of the entire population, including that of the resistant mutants. By combining pharmacokinetic/pharmacodynamic concepts and an MPC strategy, the selection of resistant mutants can be limited. Early treatment avoiding an increase of the inoculum size as well as a regimen restricting the time within the MSW can reduce the probability of emergence of the resistant mutants. Physiological and, possibly, genetic adaptation in biofilms and a high proportion of mutator clones that may arise during chronic infections influence the emergence of resistant mutants. Moreover, a resistant population can emerge in a specific selective compartment after acquiring a resistance trait by horizontal gene transfer, but this may also be avoided to some extent when the MPC is reached. Known linkage between antimicrobial use and resistance should encourage actions for the design of antimicrobial treatment regimens that minimize the emergence of resistance. Emergence of a resistant bacterial subpopulation within a susceptible wild-type population can be restricted with a regimen using an antibiotic dose that is sufficiently high to inhibit both susceptible and resistant bacteria.

Increased intestinal permeability as a predictor of bacterial infections in patients with decompensated liver cirrhosis and hemorrhage

BACKGROUND AND AIM

There have been no trials comparing the prophylactic effect of oral quinolone and intravenous cephalosporin antibiotics and elucidating the predictive factors for the occurrence of bacterial infections in cirrhotic patients with gastrointestinal bleeding in Asian-Pacific region.

METHODS

One hundred and thirteen patients with advanced liver cirrhosis and active gastrointestinal hemorrhage were enrolled in our study. The patients were randomly allocated into either the oral ciprofloxacin group (n = 50, 500 mg every 12 h) or the intravenous ceftriaxone group (n = 63, 2.0 g per day for 7 days).

RESULTS

Proven or possible infections were significantly more frequent in the patients in the oral ciprofloxacin group (34.0%) than the intravenous ceftriaxone group (14.3%, P = 0.002). The intestinal permeability index (IPI, mean [SD]) measured the day after admission was significantly higher in the patients with proven or possible infections (1.45 [0.96]) compared with the no infection group (0.46 [0.48], P <0.01). By multivariate analysis, oral ciprofloxacin prophylaxis and higher IPI at the time of inclusion were independent and significant predictors for proven or possible infections. By receiver operating characteristic curve analysis, the best cutoff value of IPI for the prediction of the occurrence of bacterial infection was 0.62%.

CONCLUSIONS

The frequency of proven or possible infections was significantly lower in the intravenous ceftriaxone group compared with the oral ciprofloxacin group. The IPI measured the day after admission is a good clinical parameter predicting the occurrence of infection in these patients.

Independent behavior of commensal flora for carriage of fluoroquinolone-resistant bacteria in patients at admission

The important role of commensal flora as a natural reservoir of bacterial resistance is now well established. However, whether the behavior of each commensal flora is similar to that of other floras in terms of rates of carriage and risk factors for bacterial resistance is unknown. During a 6-month period, we prospectively investigated colonization with fluoroquinolone-resistant bacteria in the three main commensal floras from hospitalized patients at admission, targeting Escherichia coli in the fecal flora, coagulase-negative Staphylococcus (CNS) in the nasal flora, and α-hemolytic streptococci in the pharyngeal flora. Resistant strains were detected on quinolone-containing selective agar. Clinical and epidemiological data were collected. A total of 555 patients were included. Carriage rates of resistance were 8.0% in E. coli, 30.3% in CNS for ciprofloxacin, and 27.2% in streptococci for levofloxacin; 56% of the patients carried resistance in at least one flora but only 0.9% simultaneously in all floras, which is no more than random. Risk factors associated with the carriage of fluoroquinolone-resistant strains differed between fecal E. coli (i.e., colonization by multidrug-resistant bacteria) and nasal CNS (i.e., age, coming from a health care facility, and previous antibiotic treatment with a fluoroquinolone) while no risk factors were identified for pharyngeal streptococci. Despite high rates of colonization with fluoroquinolone-resistant bacteria, each commensal flora behaved independently since simultaneous carriage of resistance in the three distinct floras was uncommon, and risk factors differed. Consequences of environmental selective pressures vary in each commensal flora according to its local specificities (clinical trial NCT00520715 [http://clinicaltrials.gov/ct2/show/NCT00520715]).

[Current problems in the prevention and treatment of infections in patients with cirrhosis]

Infections in patients with cirrhosis are a common complication causing substantial morbidity and mortality. Bacterial translocation plays an important role in the pathogenesis of many infections in cirrhosis. In turn, infections are involved in the pathogenesis of many episodes of decompensated cirrhosis, such as esophageal variceal bleeding, renal insufficiency, the hemodynamic alterations of cirrhosis, and hepatic encephalopathy. Spontaneous bacterial peritonitis is currently the most frequent infection in cirrhosis. Mortality from this entity has recently decreased due to early diagnosis, the use of appropriate antibiotic therapy, and albumin administration. However, infections due to multiresistant microorganisms have recently increased, leading to greater mortality. Primary prophylaxis with quinolones is effective in preventing infections and is associated with lower mortality in a selected population of patients with liver cirrhosis.

Norfloxacin modulates the inflammatory response and directly affects neutrophils in patients with decompensated cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis undergoing selective intestinal decontamination with norfloxacin show a reduction in serum cytokine levels, probably because of a combined effect of norfloxacin on bowel flora and neutrophils.

METHODS

Thirty-one patients with cirrhosis receiving norfloxacin (400 mg/day) were included. Blood samples were collected at 0.5-4 hours (peak samples group, n = 47) and at 22-24 hours (trough samples group, n = 84) after dose. Fifty-nine ascitic fluid samples were obtained. Single doses of norfloxacin and trimethoprim/sulfamethoxazole were administered to 13 and 5 patients, respectively, (temporal profile group) and samples were collected at 0, 0.5, 1, 1.5, 2, 4, and 24 hours. Norfloxacin, trimethoprim/sulfamethoxazole, cytokines, nitric oxide, expression levels of nuclear factor (NF)-kappaB and inhibitor of NF-kappaB (IkB-alpha), neutrophil oxidative burst, and rate of apoptotic events were determined.

RESULTS

All samples were bacterial DNA negative and had no significant levels of lipopolysaccharide. Serum and ascitic levels of tumor necrosis factor-alpha, interferon-gamma, interleukin-12, and nitric oxide were significantly lower in peak than in trough samples. A correlation was present between serum norfloxacins concentrations and tumor necrosis factor-alpha (r = -0.68; P < .001), interferon-gamma (r = -0.66; P < .001), interleukin-12 (r = -0.66; P < .001), and nitric oxide (r = -0.68; P < .001). Serum norfloxacin's highest concentrations (1 +/- 0.5 microg/mL) were achieved at 1-2 hours and concurred in time with the lower levels of cytokines and nitric oxide. Intracellular norfloxacin's highest levels (2 +/- 1 microg/mL/10(7) cells) were observed at 2 hours and concurred with a lower NF-kappaB expression, a reduced anion superoxide generation, and apoptotic rate in response to phorbol myristate acetate. Trimethoprim/sulfamethoxazole did not significantly modulate cytokine expression.

CONCLUSIONS

Norfloxacin but not trimethoprim/sulfamethoxazole modulates inflammatory response and directly affects neutrophils in patients with cirrhosis.

Clinical features and prognosis of spontaneous bacterial peritonitis in korean patients with liver cirrhosis: a multicenter retrospective study

Background/Aims

Although early recognition and treatment with effective antibiotics have lead to improvements in the prognosis of patients with spontaneous bacterial peritonitis (SBP), it remains to be a serious complication in cirrhotic patients. This study was designed to evaluate the clinical manifestations and prognosis of patients with liver cirrhosis and SBP in Korea.

Methods

This was a multicenter retrospective study examining 157 episodes of SBP in 145 patients with cirrhosis. SBP was diagnosed based on a polymorphonuclear cell count in ascitic fluid of >250 cells/mm³ in the absence of data compatible with secondary peritonitis.

Results

The mean age of the cohort was 56 years, and 121 (77%) of the 157 episodes of SBP occurred in men. Microorganisms were isolated in 66 episodes (42%): Gram-negative bacteria in 54 (81.8%), Gram-positive in 11 (16.7%), and Candida in 1. Isolated Gram-negative organisms were resistant to third-generation cephalosporin in 6 cases (17%), to ciprofloxacin in 11 (20.8%), and to penicillin in 33 (62.3%). The treatment failure and in-hospital mortality rates were 12.1% and 21%, respectively. A high Model of End-Stage Liver Disease (MELD) score, SBP caused by extended-spectrum β-lactamase-producing organisms, and hepatocellular carcinoma were independent prognostic factors of high in-hospital mortality.

Conclusions

SBP remains to be a serious complication with high in-hospital mortality, especially in patients with a high MELD score.

Gastrointestinal tract colonization with fluoroquinolone-resistant Escherichia coli in hospitalized patients: changes over time in risk factors for resistance

OBJECTIVE

The prevalence of fluoroquinolone (FQ) resistance in Escherichia coli has increased markedly in recent years. Despite the important role of gastrointestinal tract colonization with FQ-resistant E. coli (FQREC), the prevalence of and risk factors for FQREC colonization among the general hospitalized patient population have not been described, to our knowledge. The objective of this study was to identify the prevalence of and risk factors for FQREC colonization among hospitalized patients.

DESIGN

Three-year case-control study. Case patients (ie, all subjects with FQREC colonization) were compared with control patients (ie, all subjects without FQREC colonization).

SETTING

Two large medical centers within an academic health system.

PARTICIPANTS

All patients hospitalized at the 2 study hospitals.

MAIN OUTCOME MEASURE

Three annual fecal surveillance surveys were conducted. All patients colonized with FQREC (levofloxacin minimum inhibitory concentration, >or=8 microg/mL) were identified.

RESULTS

Of the 774 subjects, 89 (11.5%) were colonized with FQREC. Although there was a significant association between prior FQ use and FQREC colonization on bivariable analysis (odds ratio [OR], 2.02 [95% confidence interval {CI}, 1.14-3.46]; P=.01), there was statistically significant effect modification by year of study (P=.005). In multivariable analyses, after controlling for the hospital and for the duration of hospitalization prior to sampling, the association between FQ use and FQREC colonization was as follows: adjusted OR (aOR), 0.97 (95% CI, 0.29-3.23) in 2002; aOR, 1.41 (95% CI, 0.57-3.50) in 2003; and aOR, 9.87 (95% CI, 3.67-26.55) in 2004.

CONCLUSIONS

The association between prior FQ use and FQREC colonization varied significantly by study year, suggesting that the clinical epidemiology of resistant organisms may change over time. Furthermore, in the context of recent work showing significant changes in FQREC prevalence as well as changes in FQ resistance mechanisms (specifically, efflux overexpression) over the same time period, these results suggest a previously unrecognized complexity in the relationship between the clinical and molecular epidemiology of FQ resistance.

Genetic background of Escherichia coli isolates from patients with spontaneous bacterial peritonitis: relationship with host factors and prognosis

Spontaneous bacterial peritonitis (SBP) is a severe complication in patients with cirrhosis and ascites. It is predominantly caused by Escherichia coli. The phylogenetic group and virulence genotype of E. coli isolates causing SBP were investigated, and the association of these characteristics with host factors and prognosis was examined. Seventy-six episodes of E. coli SBP that occurred over a 9-year period were studied. The phylogenetic group of the isolates and the presence of 36 virulence factor genes were investigated. The influence of bacterial and host factors on in-hospital mortality was assessed by multiple logistic regression. Phylogenetic groups A, B1, B2 and D were found in 26%, 4%, 46% and 24% of the isolates, respectively. Virulence factor genes were more frequent in B2 isolates than in non-B2 isolates (mean virulence score 15.4 vs. 7.3, p <10(-4)). Ciprofloxacin resistance was significantly associated with non-B2 groups and a low virulence score. Host factors independently associated with a shift from B2 to non-B2 isolates were norfloxacin prophylaxis (OR 13.01, p 0.0213) and prothrombin ratio (OR 1.04 for a 10% decrease, p 0.0211). The model for end-stage liver disease (MELD) score (OR 1.83, p 0.0007) and hospital-acquired SBP (OR 4.13, p 0.0247) were independent predictors of in-hospital mortality. In contrast, outcome was not influenced by the phylogenetic group or the virulence profile. These findings indicate that the characteristics of E. coli isolates causing SBP vary with the severity of liver disease and with fluoroquinolone prophylaxis. Host factors are more important than bacterial factors in predicting in-hospital mortality.

Role of host and bacterial virulence factors in Escherichia coli spontaneous bacterial peritonitis

OBJECTIVES

Host factors and bacterial virulence determinants may play a role in Escherichia coli (E. coli) spontaneous bacterial peritonitis. We evaluated the importance of these factors in the emergence of fluoroquinolone-resistant strains and outcome in cirrhotic patients with E. coli spontaneous bacterial peritonitis.

METHODS

E. coli spontaneous bacterial peritonitis was detected in a 2-year period in three tertiary hospitals. Clinical and bacteriological data were obtained. Phylogenetic group and 15 virulence genes of E. coli strains were analyzed by polymerase gene reaction and compared with 50 isolates from pyelonephritis patients.

RESULTS

Forty-seven E. coli spontaneous bacterial peritonitis patients were identified, 18 (38%) were fluoroquinolone-resistant, a 12% increase compared with our earlier series from 1997 to 2002. Fluoroquinolone resistance was associated with norfloxacin prophylaxis, increased resistance to trimethoprim-sulfamethoxazole and cefotaxime, and less bacterial virulence, as demonstrated by a higher prevalence of 'nonpathogenic' phylogenetic groups A+B1 (56 vs. 28%; P=0.04) and lower virulence scores in fluoroquinolone-resistant E. coli compared with fluoroquinolone-susceptible E. coli. E. coli strains from cirrhotic patients belonged more frequently to 'nonpathogenic' phylogenetic groups A+B1, had fewer virulence factors and higher rates of fluoroquinolone resistance than isolates from pyelonephytis patients. Immunosuppression was independently associated with in-hospital and 3-month mortality. Bacterial virulence factors were unrelated to mortality.

CONCLUSION

Fluoroquinolone-resistant E. coli spontaneous bacterial peritonitis prevalence is increasing because of norfloxacin prophylaxis. Strains from peritonitis are less virulent than strains from pyelonephritis because of a higher prevalence of A+B1 phylogeny and quinolone resistance. Mortality is related to immunosuppression, but not to bacterial virulence factors.

Bacterial DNA in patients with cirrhosis and noninfected ascites mimics the soluble immune response established in patients with spontaneous bacterial peritonitis

Bacterial infections and severity of associated inflammatory reaction influence prognosis in patients with advanced cirrhosis. We compared the innate immune response to bacterial DNA (bactDNA) translocation with that caused by viable bacteria translocation in patients with spontaneous bacterial peritonitis and the relationship between the cytokine response and serum levels of bactDNA. The bactDNA translocation was investigated in 226 patients with cirrhosis and noninfected ascites, 22 patients with spontaneous bacterial peritonitis, and 10 patients with ascites receiving continuous norfloxacin. Serum and ascitic fluid tumor necrosis factor alpha, interferon-gamma, interleukin-12, and nitric oxide metabolites were measured via enzyme-linked immunosorbent assay. Bacterial genomic identifications were made via amplification and sequencing of the 16S ribosomal RNA gene and digital quantization with DNA Lab-on-chips. The bactDNA was present in 77 noninfected patients (34%) and in all cases of spontaneous bacterial peritonitis, even in those with culture-negative ascitic fluid. No patient receiving norfloxacin showed bactDNA translocation. Levels of all cytokines were similar in patients with bactDNA translocation or spontaneous bacterial peritonitis and significantly higher than in patients without bactDNA or in those receiving norfloxacin. Serum bactDNA concentration paralleled levels of all cytokines and nitric oxide in a series of patients with bactDNA translocation or spontaneous bacterial peritonitis followed during 72 hours. Antibiotic treatment in the series of patients with spontaneous bacterial peritonitis did not abrogate bactDNA translocation in the short term.

CONCLUSION

bactDNA translocation-associated cytokine response is indistinguishable from that in patients with spontaneous bacterial peritonitis and is dependent on bactDNA concentration. Norfloxacin abrogates bactDNA translocation and cytokine response.

Primary prophylaxis of spontaneous bacterial peritonitis delays hepatorenal syndrome and improves survival in cirrhosis

BACKGROUND & AIMS

Norfloxacin is highly effective in preventing spontaneous bacterial peritonitis recurrence in cirrhosis, but its role in the primary prevention of this complication is uncertain.

METHODS

Patients with cirrhosis and low protein ascitic levels (<15 g/L) with advanced liver failure (Child-Pugh score > or = 9 points with serum bilirubin level > or = 3 mg/dL) or impaired renal function (serum creatinine level > or = 1.2 mg/dL, blood urea nitrogen level > or = 25 mg/dL, or serum sodium level < or = 130 mEq/L) were included in a randomized controlled trial aimed at comparing norfloxacin (35 patients) vs placebo (33 patients) in the primary prophylaxis of spontaneous bacterial peritonitis. The main end points of the trial were 3-month and 1-year probability of survival. Secondary end points were 1-year probability of development of spontaneous bacterial peritonitis and hepatorenal syndrome.

RESULTS

Norfloxacin administration reduced the 1-year probability of developing spontaneous bacterial peritonitis (7% vs 61%, P < .001) and hepatorenal syndrome (28% vs 41%, P = .02), and improved the 3-month (94% vs 62%, P = .003) and the 1-year (60% vs 48%, P = .05) probability of survival compared with placebo.

CONCLUSIONS

Primary prophylaxis with norfloxacin has a great impact in the clinical course of patients with advanced cirrhosis. It reduces the incidence of spontaneous bacterial peritonitis, delays the development of hepatorenal syndrome, and improves survival.

[Spontaneous bacterial peritonitis due to methicillin-resistant Staphylococcus aureus in patients with cirrhosis]

A substantial epidemiologic change in the etiology of spontaneous bacterial peritonitis (SBP) has been observed in recent years. Gram-positive, as well as multiresistant bacteria, have emerged as an important cause of SBP mainly among hospitalized patients. In this setting, SBP caused by methicillin-resistant Staphylococcus aureus (MRSA) could become a major clinical problem in the near future. We present two cases of SBP due to MRSA without clinical response to vancomycin, even though in vitro sensitivity was observed in both cases. We review the current literature on the incidence and clinical significance of SBP due to MRSA infection in cirrhotic patients, as well as its prevention and treatment.

Determination of norfloxacin in pharmaceuticals, human serum, and urine using a luminol—dissolved oxygen chemiluminescence system

A sensitive chemiluminescence method, based on the enhancive effect of norfloxacin on the reaction between luminol and dissolved oxygen in a flow injection system, was proposed for the determination of norfloxacin. The increment of the chemiluminiscence intensity was proportional to the concentration of norfloxacin, giving a calibration graph linear over the concentration from 0.4 ng mL−1 to 400.0 ng mL−1 (r 2 = 0.9988) with the detection limit of 0.1 ng mL−1 (3 × σ noise). At the flow rate of 2.0 mL min−1, a complete determination of norfloxacin, including sampling and washing, could be accomplished in 30 s with the relative standard deviation lower than 3.0 %. The proposed method was applied successfully to determine norfloxacin in pharmaceuticals, human urine, and serum. Possible mechanism of the reaction was also discussed.

Changes in the Profiles of Causative Agents and Antibiotic Resistance Rate for Spontaneous Bacterial Peritonitis: an Analysis of Cultured Microorganisms in Recent 12 Years

BACKGROUNDS/AIMS

The causative agents for spontaneous bacterial peritonitis (SBP) and antibiotic resistance rate vary according to the regions and time. This study evaluated the recent changes in the profiles of microorganisms and antibiotic resistance rate for the choice of effective antibiotics in treating SBP.

METHODS

The clinical records of 1,018 episodes of SBP from November, 1994 to December, 2005, were analyzed retrospectively. The profiles of the causative agents for SBP and the rate of antibiotic resistance were compared in every 4-year-term.

RESULTS

The microorganisms were isolated in 394 out of 1018 episodes (38.7%). Gram negative and positive organisms constituted 71.6% and 21.3%, respectively. The five most commonly isolated organisms were E. coli (35.8%), K. pneumoniae (15.5%), viridans Streptococci (10.4%), S. pneumoniae (4.8%) and Aeromonas group (4.6%). The rate of E. coli resistant to cefotaxime (0%, 5.4%, 7.4%) and ciprofloxacin (4.3%, 21.6%, 28.4%) were increased in recent years. In the gram positive organisms, all isolates of viridans Streptococci and Pneumococci were sensitive to cefotaxime and ciprofloxacin. Recently, methicillin-resistant Staphylococcus aureus (MRSA) (28%) and vancomycin-resistant Enterococci (VRE) (31%) have been isolated. In each period, the overall antibiotic resistance rates to cefotaxime were 12.5%, 14.0%, 14.8%, to ciprofloxacin were 3.1%, 16.7%, 18.0%, and to imipenem were 4.7%, 7.0%, 4.2%.

CONCLUSIONS

Cefotaxime may still be the choice of primary empirical antibiotics for the treatment of SBP in Korea because the rate of resistance is acceptable. However, it is important to be aware of the recent increase in ciprofloxacin-resistant E. coli, extended spectrum beta-lactamase (ESBL)-producing gram negative bacilli, MRSA and VRE.

Norfloxacin vs ceftriaxone in the prophylaxis of infections in patients with advanced cirrhosis and hemorrhage

BACKGROUND & AIMS

Oral norfloxacin is the standard of therapy in the prophylaxis of bacterial infections in cirrhotic patients with gastrointestinal hemorrhage. However, during the last years, the epidemiology of bacterial infections in cirrhosis has changed, with a higher incidence of infections caused by quinolone-resistant bacteria. This randomized controlled trial was aimed to compare oral norfloxacin vs intravenous ceftriaxone in the prophylaxis of bacterial infection in cirrhotic patients with gastrointestinal bleeding.

METHODS

One hundred eleven patients with advanced cirrhosis (at least 2 of the following: ascites, severe malnutrition, encephalopathy, or bilirubin >3 mg/dL) and gastrointestinal hemorrhage were randomly treated with oral norfloxacin (400 mg twice daily; n = 57) or intravenous ceftriaxone (1 g/day; n = 54) for 7 days. The end point of the trial was the prevention of bacterial infections within 10 days after inclusion.

RESULTS

Clinical data were comparable between groups. The probability of developing proved or possible infections, proved infections, and spontaneous bacteremia or spontaneous bacterial peritonitis was significantly higher in patients receiving norfloxacin (33% vs 11%, P = .003; 26% vs 11%, P = .03; and 12% vs 2%, P = .03, respectively). The type of antibiotic used (norfloxacin), transfusion requirements at inclusion, and failure to control bleeding were independent predictors of infection. Seven gram-negative bacilli were isolated in the norfloxacin group, and 6 were quinolone resistant. Non-enterococcal streptococci were only isolated in the norfloxacin group. No difference in hospital mortality was observed between groups.

CONCLUSIONS

Intravenous ceftriaxone is more effective than oral norfloxacin in the prophylaxis of bacterial infections in patients with advanced cirrhosis and hemorrhage.

Norfloxacin decreases bacterial adherence of quinolone-resistant strains of Escherichia coli isolated from patients with cirrhosis

BACKGROUND

Long-term administration of norfloxacin is recommended for secondary prophylaxis of spontaneous bacterial peritonitis in cirrhosis, but it may be associated with the development of quinolone-resistant bacteria in stools. However, these bacteria rarely cause infections.

AIM

To assess bacterial adherence of either quinolone-sensitive or -resistant Escherichia coli obtained from stools of cirrhotic patients, as one of the main virulence factors, and its variations when sub-minimum inhibitory concentration of norfloxacin were added to the medium.

METHODS

E. coli strains were co-cultured with oral epithelial cells obtained from patients in presence/absence of norfloxacin. Bacterial adherence was measured as percentage of cells exhibiting positive adherence and the number of bacteria attached to epithelial cells.

RESULTS

37 sensitive and 22 resistant E. coli strains were studied. Bacterial adherence was similar in both series (78% vs. 81%, P = N.S.), and these percentages were similarly and significantly reduced when subminimum inhibitory concentration of norfloxacin was added to the culture medium (P < 0.001).

CONCLUSIONS

Bacterial adherence of E. coli obtained from patients with cirrhosis is unrelated to the sensitivity/resistance to quinolones, and is similarly reduced in both cases when subminimum inhibitory concentration of norfloxacin is added to the medium.

Fluoroquinolone consumption and resistance in haematology–oncology patients: ecological analysis in two university hospitals 1999–2002

OBJECTIVES

To compare rates of in vitro fluoroquinolone resistance of bacterial isolates obtained from inpatients of two haematology-oncology services with high and low fluoroquinolone consumption.

METHODS

Two hospitals with consistently high (A) and low (B) fluoroquinolone use in their haematology-oncology services between the years 1999 and 2002 were identified in a hospital antibiotic use surveillance project. Rates of in vitro resistance to fluoroquinolones in inpatients of the services were determined for Escherichia coli and coagulase-negative staphylococcal bloodstream isolates, and also for Pseudomonas aeruginosa and Staphylococcus aureus isolates from any site.

RESULTS

Fluoroquinolone resistance of E. coli was significantly higher in hospital A than in hospital B, but there was no such correlation between fluoroquinolone use and resistance rates for P. aeruginosa and staphylococci.

CONCLUSION

The impact of antibiotic consumption on the prevalence of resistance may differ widely between different pathogens. Interventions using ecological analyses of the relationship between hospital antibiotic use and resistance need to consider pathogen-specific dynamics in the emergence and control of bacterial resistance.

Recent increase in antibiotic-resistant microorganisms in patients with spontaneous bacterial peritonitis adversely affects the clinical outcome in Korea

BACKGROUND AND AIM

Recently, antibiotic-resistant microorganisms have been increasingly noted in Korean patients with spontaneous bacterial peritonitis (SBP). The present study investigated the changing pattern of antibiotic resistance and its effects on the clinical outcome in treating SBP.

METHODS

The present study retrospectively analyzed 87 episodes of SBP in 1995, 222 in 1998, and 271 in 1999. The isolated microorganisms and their antibiotic susceptibility were compared, and prognostic factors for survival were analyzed.

RESULTS

Microorganisms were isolated in 41% of total episodes. The three most frequently isolated organisms were Escherichia coli (48%), Klebsiella pneumoniae (15%), and Aeromonas (8%). Strains that were resistant to cefotaxime in Gram-negative bacilli significantly increased from 7% in 1995 to 28% in 1999, and those to ciprofloxacin increased from 10% to 32%. Treatment failure also increased from 6% to 23%. Combined hepatocellular carcinoma and SBP caused by extended-spectrum beta-lactamase-producing strains were two independent prognostic factors for survival.

CONCLUSION

Considering the increase in antibiotic-resistant microorganisms related to SBP, measures to prevent the in-hospital spread of resistant strains and the indiscriminate use of antibiotics should be instituted more stringently.

Oral bile acids reduce bacterial overgrowth, bacterial translocation, and endotoxemia in cirrhotic rats

Experiments were performed to test whether conjugated bile acid administration would decrease bacterial overgrowth, bacterial translocation, and endotoxemia in ascitic cirrhotic rats. Cholylsarcosine, a deconjugation-dehydroxylation resistant and cholylglycine, a deconjugation-dehydroxylation susceptible bile acid were used. Rats with CCl(4)-induced cirrhosis and ascites were fed cholylsarcosine, cholylglycine (both at 70 mg/kg/d), or placebo for 2 weeks. Healthy rats, as controls, were treated similarly. In cirrhotic rats receiving placebo, bile secretion from an acute biliary fistula was lower than in healthy rats (27.2 +/- 6.5 vs. 53.0 +/- 3.1 microL/kg/min; mean +/- SE, P<.05). The administration of conjugated bile acids to cirrhotic rats normalized bile secretion (cholylsarcosine, 51.8 +/- 6.29; cholylglycine, 52.72 +/- 8.9 microL/kg/min). Total ileal bacterial content was 6-fold higher in ascitic cirrhotic rats than in healthy rats. Conjugated bile acid administration reduced bacterial content to normal levels. Bacterial translocation was less in cirrhotic animals receiving conjugated bile acids (cholylsarcosine, 33%; cholylglycine, 26%) than in animals receiving placebo (66%). Endotoxemia was decreased in cirrhotic rats by conjugated bile acid feeding (cholylsarcosine, 0.098 +/- 0.002; cholylglycine 0.101 +/- 0.007 EU/mL) compared with placebo (0.282 +/- 0.124, P <.001). Survival was greater in animals receiving conjugated bile acids (cholylsarcosine, 10/15; cholylglycine, 11/15; placebo, 5/15). In conclusion, the administration of conjugated bile acids to ascitic cirrhotic rats increased bile acid secretion, eliminated intestinal bacterial overgrowth, decreased bacterial translocation, decreased endotoxemia, and increased survival. Oral conjugated bile acids may be useful in preventing bacterial translocation, endotoxemia, and spontaneous bacterial perotonitis in cirrhotic patients.

Role of immunosuppression in the development of quinolone-resistant Escherichia coli spontaneous bacterial peritonitis and in the mortality of E. coli spontaneous bacterial peritonitis

BACKGROUND

Norfloxacin decreases the incidence of spontaneous bacterial peritonitis in cirrhotics, but promotes the appearance of quinolone-resistant Escherichia coli.

AIM

: To define the characteristics of quinolone-resistant E. coli spontaneous bacterial peritonitis.

METHODS

E. coli-positive ascitic fluid cultures were identified during a 6-year period. Data on quinolone-sensitive and quinolone-resistant E. coli spontaneous bacterial peritonitis were compared.

RESULTS

One hundred and two E. coli-positive ascitic fluid cultures were detected. Cirrhotics accounted for 67 cases. Spontaneous bacterial peritonitis was found in 47 of the 67 (70%) cases [35 (74%) caused by quinolone-sensitive and 12 (26%) caused by quinolone-resistant E. coli]. Norfloxacin prophylaxis was higher in the quinolone-resistant group (92% vs. 6%, P < 0.001). Compared with patients with quinolone-sensitive E. coli spontaneous bacterial peritonitis, those with quinolone-resistant E. coli spontaneous bacterial peritonitis showed a higher prevalence of associated immunosuppressive factors (immunosuppressive drugs, human immunodeficiency virus infection or cancer) (92% vs. 20%, P < 0.001). Steroid therapy was independently associated with quinolone-resistant E. coli spontaneous bacterial peritonitis (odds ratio, 49; 95% confidence interval, 3.4-699; P = 0.004). The Child-Pugh score (P = 0.03), immunosuppression (P = 0.02) and renal failure (P = 0.01) were independent predictors of E. coli spontaneous bacterial peritonitis-related mortality.

CONCLUSIONS

Associated immunosuppression is an important co-factor for the development of quinolone-resistant E. coli spontaneous bacterial peritonitis and for E. coli spontaneous bacterial peritonitis-related mortality.

Spontaneous bacterial peritonitis caused by quinolone-resistant Escherichia coli: could steroid therapy play a role?

Prophylaxis with norfloxacin has been shown to be effective in preventing spontaneous bacterial peritonitis (SBP) in liver cirrhosis. This therapy is associated with the appearance of quinolone-resistant Escherichia coli. However, only four cases of SBP caused by quinolone-resistant E. coli have been reported so far. We present four cases of quinolone-resistant E. coli SBP in three patients receiving oral quinolones, and who were on corticosteroid therapy to treat associated disorders.

Bacterial infections in cirrhosis: epidemiological changes with invasive procedures and norfloxacin prophylaxis

The extensive use of invasive procedures and of long-term norfloxacin prophylaxis in the management of cirrhotic patients may have influenced the epidemiology of bacterial infections in cirrhosis. We conducted a prospective evaluation of all bacterial infections diagnosed in patients with cirrhosis in a Liver Unit between April 1998 and April 2000. A total of 405 patients presented 572 bacterial infections in 507 admissions. Spontaneous bacterial peritonitis was the most frequent infection (138 cases). Gram-positive cocci were responsible for 53% of total bacterial infections in the study, being the main bacteria isolated in nosocomial infections (59%). Patients requiring treatment in an intensive care unit and those submitted to invasive procedures presented a higher rate of infections caused by gram-positive cocci (77% vs. 48%, P <.001 and 58% vs. 40%, P <.02, respectively). Fifty percent of culture-positive spontaneous bacterial peritonitis in patients on long-term norfloxacin administration (n = 93) and 16% in patients not receiving this therapy (n = 414) were caused by quinolone-resistant gram-negative bacilli, P =.01. The rate of culture-positive spontaneous bacterial peritonitis caused by trimethoprim-sulfamethoxazole-resistant gram-negative bacilli was also very high in patients on long-term norfloxacin administration (44% vs. 18%, P =.09). In conclusion, infections caused by gram-positive cocci have markedly increased in cirrhosis. This phenomenon may be related to the current high degree of instrumentation of cirrhotic patients. Quinolone-resistant spontaneous bacterial peritonitis constitutes an emergent problem in patients on long-term norfloxacin prophylaxis, with trimethoprim-sulfamethoxazole not being a valid alternative.

Carriage of Staphylococcus aureus and of gram-negative bacilli resistant to third-generation cephalosporins in cirrhotic patients: a prospective assessment of hospital-acquired infections

OBJECTIVE

To study the relation between Staphylococcus aureus nasal and stool colonization, stool carriage of gram-negative bacilli resistant to third-generation cephalosporins (CephR), and subsequent infections during hospitalization.

DESIGN

Prospective study.

PATIENTS

551 cirrhotic patients with 589 consecutive hospital stays. All patients were screened within 48 hours of admission; 589 nasal swabs, 417 stool specimens, and 589 urine samples were analyzed.

RESULTS

Carriage rates were 18.8% for methicillin-sensitive S aureus (MSSA), 16.3% for methicillin-resistant S aureus (MRSA), and 13.7% for CephR. We observed 87 episodes of spontaneous bacterial peritonitis, 63 cases of bacteremia, and 167 urinary tract infections occurred. Only 1 case of bacteremia and 4 urinary tract infections due to CephR occurred in patients carrying the same organism in their stools. The risk of MRSA ascitic fluid infections, bacteremia, and urinary tract infections was 3.1% versus 1% (not significant), 8.3% versus 0.8% (P<.001), and 11.4% versus 0.6% (P<.001) in carriers and noncarriers, respectively. Pulsed-field gel electrophoresis (PFGE) of isolates from 16 patients infected by MSSA (3 cases) and MRSA (13 cases) demonstrated that the colonizing strains matched the invasive strains in the 3 MSSA cases and in 8 of 13 MRSA cases.

CONCLUSION

Carriage of CephR strains is not associated with subsequent infection by these organisms in hospitalized cirrhotic patients. In contrast, MRSA carriage was an important risk factor for MRSA bacteremia and urinary tract infection.