Comparison of the in vitro susceptibility of rifaximin versus norfloxacin against multidrug resistant bacteria in a hospital setting. A proof-of-concept study for use in advanced cirrhosis

Microbiome therapeutics for hepatic encephalopathy

Hepatic encephalopathy (HE) is a complication of cirrhosis characterised by neuropsychiatric and motor dysfunction. Microbiota-host interactions play an important role in HE pathogenesis. Therapies targeting microbial community composition and function have been explored for the treatment of HE. Prebiotics, probiotics and faecal microbiota transplant (FMT) have been used with the aim of increasing the abundance of potentially beneficial taxa, while antibiotics have been used to decrease the abundance of potentially harmful taxa. Other microbiome therapeutics, including postbiotics and absorbents, have been used to target microbial products. Microbiome-targeted therapies for HE have had some success, notably lactulose and rifaximin, with probiotics and FMT also showing promise. However, there remain several challenges to the effective application of microbiome therapeutics in HE, including the resilience of the microbiome to sustainable change and unpredictable clinical outcomes from microbiota alterations. Future work in this space should focus on rigorous trial design, microbiome therapy selection, and a personalised approach to HE.

Microbial Infections as a Trigger for Acute-on-Chronic Liver Failure: A Review

Microbial infection is an important cause of acute-on-chronic liver failure (ACLF), which is a syndrome that results in multiple organ dysfunction or failure and is accompanied by an increased short-term risk of mortality. Early detection and treatment of microbial infection can effectively reduce the mortality of patients with ACLF. However, antimicrobial resistance has recently increased due to the increased use of antimicrobial agents. Therefore, it is important to choose appropriate antibiotics and antifungal agents for early prevention or treatment of patients with microbial infection and ACLF to reduce the occurrence of drug resistance and to reduce patient mortality. This review summarizes the current status in the understanding of the epidemiology, pathogenesis, early diagnosis, treatment, and strategies for prevention of microbial infection in patients with ACLF.

Role of Rifaximin in Spontaneous Bacterial Peritonitis Prevention

Cirrhosis affects millions of people around the world and is associated with increased morbidity and mortality. Spontaneous bacterial peritonitis (SBP) is a common complication of liver disease with cirrhosis and accounts for up to 30% of infections in patients with cirrhosis. Patients with a history of SBP and those deemed to be at high risk often are prescribed antibiotics to reduce the incidence of SBP. Fluoroquinolones and sulfamethoxazole-trimethoprim are commonly used antibiotics for long-term prevention for these specified populations; however, these antibiotics are associated with several adverse effects and interactions that may be harmful to patients. In addition, resistance development may decrease the efficacy of SBP treatment and prophylaxis. Given these limitations, rifaximin, a nonabsorbable, broad-spectrum antibiotic that is used for hepatic encephalopathy, may serve as a prophylactic alternative to conventional therapy. This review discusses guideline-recommended therapy and the evidence for using rifaximin for SBP prophylaxis.

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.

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.

Prevalence of current patterns and predictive trends of multidrug-resistant Salmonella Typhi in Sudan

Background

Enteric fever has persistence of great impact in Sudanese public health especially during rainy season when the causative agent Salmonella enterica serovar Typhi possesses pan endemic patterns in most regions of Sudan - Khartoum.

Objectives

The present study aims to assess the recent state of antibiotics susceptibility of Salmonella Typhi with special concern to multidrug resistance strains and predict the emergence of new resistant patterns and outbreaks.

Methods

Salmonella Typhi strains were isolated and identified according to the guidelines of the International Standardization Organization and the World Health Organization. The antibiotics susceptibilities were tested using the recommendations of the Clinical Laboratories Standards Institute. Predictions of emerging resistant bacteria patterns and outbreaks in Sudan were done using logistic regression, forecasting linear equations and in silico simulations models.

Results

A total of 124 antibiotics resistant Salmonella Typhi strains categorized in 12 average groups were isolated, different patterns of resistance statistically calculated by (y = ax − b). Minimum bactericidal concentration’s predication of resistance was given the exponential trend (y = n e^x) and the predictive coefficient R² > 0 < 1 are approximately alike. It was assumed that resistant bacteria occurred with a constant rate of antibiotic doses during the whole experimental period. Thus, the number of sensitive bacteria decreases at the same rate as resistant occur following term to the modified predictive model which solved computationally.

Conclusion

This study assesses the prediction of multi-drug resistance among S. Typhi isolates by applying low cost materials and simple statistical methods suitable for the most frequently used antibiotics as typhoid empirical therapy. Therefore, bacterial surveillance systems should be implemented to present data on the aetiology and current antimicrobial drug resistance patterns of community-acquired agents causing outbreaks.

Electronic supplementary material

The online version of this article (10.1186/s12941-017-0247-4) contains supplementary material, which is available to authorized users.