Bacterial resistance in cirrhotic patients: an emerging reality

Spontaneous bacterial peritonitis: update on diagnosis and treatment

Spontaneous bacterial peritonitis (SBP) is a common complication in patients with liver cirrhosis, with an increased risk of mortality. For this reason, a diagnostic paracentesis should be performed in all patients with ascites and clinical features with high diagnostic suspicion. Although literature data abound in identifying new diagnostic markers in serum or ascites, they have not yet been validated. The final diagnosis requires the analysis of ascites and the presence of > 250 mm³ neutrophil polymorphonuclear (PMN) in ascites. If previous data showed that the most common microorganisms identified were represented by gram-negative bacteria, we are currently facing an increase in gram-positive bacteria and multi-drug resistant bacteria. Although prompt and effective treatment is required to prevent outcomes, this becomes challenging as first-line therapies may become ineffective leading to worsening prognosis and increased inhospital mortality. In this paper we will make a brief review of existing data on the diagnosis and treatment of SBP.

Bloodstream infections caused by multidrug-resistant gram-negative bacteria: epidemiological, clinical and microbiological features

Background

Bloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB).

Methods

We conducted a laboratory-based surveillance for gram-negative bacteremia over a 1-year period. The bacterial isolates were identified by MALDI-TOF/MS and the antimicrobial susceptibility testing was performed by VITEK®2. Resistance genes were identified through PCR assays.

Results

Of the 143 patients, 28.7% had infections caused by MDR-GNB. The risk factors for MDR bacteremia were male sex, age ≥ 60, previous antimicrobial use, liver disease and bacteremia caused by K. pneumoniae. K. pneumoniae was the most frequently observed causative agent and had the highest resistance level. Regarding the resistance determinants, SHV, TEM, OXA-1-like and CTX-M-gp1 were predominant enzymatic variants, whereas CTX-M-gp9, CTX-M-gp2, KPC, VIM, GES, OXA-48-like, NDM and OXA-23-like were considered emerging enzymes.

Conclusions

Here we demonstrate that clinically relevant antibiotic resistance genes are prevalent in this setting. We hope our findings support the development of intervention measures by policy makers and healthcare professionals to face antibiotic resistance.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4265-z) contains supplementary material, which is available to authorized users.

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.

A low muscle mass increases mortality in compensated cirrhotic patients with sepsis

BACKGROUND & AIMS

Severe infections and muscle wasting are both associated to poor outcome in cirrhosis. A possible synergic effect of these two entities in cirrhotic patients has not been previously investigated. We aimed at analysing if a low muscle mass may deteriorate the outcome of cirrhotic patients with sepsis.

METHODS

Consecutive cirrhotic patients hospitalized for sepsis were enrolled in the study. Patients were classified for the severity of liver impairment (Child-Pugh class) and for the presence of "low muscle mass" (mid-arm muscle circumference<5th percentile). The development of complication during hospitalization and survival was analysed.

RESULTS

There were 74 consecutive cirrhotics with sepsis. Forty-three of these patients showed low muscle mass. In patients with and without low muscle mass, severity of liver disease and characteristics of infections were similar. Mortality tended to be higher in patients with low muscle mass (47% vs 26%, P = .06). A multivariate analysis selected low muscle mass (P < .01, HR: 3.2, IC: 1.4-4.8) and Child-Pugh C (P < .01, HR: 3.3, 95% IC: 1.5-4.9) as independent predictors of in-hospital mortality. In Child-Pugh A-B patients, mortality was higher in patients with low muscle mass compared with those without (50% vs 16%; P = .01). The mortality rate and the incidence of complications in malnourished patients classified in Child-Pugh A-B were similar to those Child-Pugh C.

CONCLUSIONS

Low muscle mass worsen prognosis in cirrhotic patients with severe infections. This is particularly evident in patients with Child A-B cirrhosis in whom the coexistence of low muscle mass and sepsis caused a negative impact on mortality similar to that observable in all Child C patients with sepsis.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Antibiotic resistance in healthcare-related and nosocomial spontaneous bacterial peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) can be life threatening in patients with liver cirrhosis. In contrast to community-acquired SBP, no standard treatment has been established for healthcare-related and nosocomial SBP.

MATERIALS AND METHODS

We prospectively collected healthcare-related and nosocomial SBP cases from March 2012 till February 2016 at the Department of Internal Medicine I of the University of Bonn and analysed the prevalence of antibiotic resistance among the isolated bacteria. SBP was diagnosed according to international guidelines. Ciprofloxacin, ceftriaxone and meropenem were used as reference substance for resistance to quinolones, third-generation cephalosporins and carbapenems, respectively.

RESULTS

Ninety-two SBP episodes in 86 patients were identified: 63 episodes (69%) were nosocomial. Escherichia coli, Klebsiella species, enterococci and streptococci were most frequently isolated. Frequencies of these microorganisms were comparable for healthcare-related and nosocomial SBP (14% vs. 11%, 14% vs. 8%, 14% vs. 5% and 10% vs. 6%, respectively). In general, antibiotic resistance was higher in isolates from nosocomial than from healthcare-related SBP (50% vs. 18% for quinolones, 30% vs. 11% for piperacillin-tazobactam; P > 0·05), but comparable concerning third-generation cephalosporins (30% vs. 33%). All microorganisms were sensitive to carbapenems apart from nosocomial infections with Enterococcus faecium (n = 3) and Candida albicans (n = 1) due to intrinsic resistance or lack of microbiological efficacy, respectively. No multidrug-resistant microorganisms were detected. Resistance to initial antibiotic treatment affected 30-day survival negatively (18% vs. 68%; P = 0·002).

CONCLUSION

Resistance to initial antibiotic treatment was associated with increased mortality. With resistance to cephalosporins being frequent, piperacillin-tazobactam or carbapenems might be preferred as treatment of SBP.

An empirical broad spectrum antibiotic therapy in health-care-associated infections improves survival in patients with cirrhosis: A randomized trial

Early diagnosis and appropriate treatment of infections in cirrhosis are crucial because of their high morbidity and mortality. Multidrug-resistant (MDR) infections are on the increase in health care settings. Health-care-associated (HCA) infections are still frequently treated as community-acquired with a detrimental effect on survival. We aimed to prospectively evaluate in a randomized trial the effectiveness of a broad spectrum antibiotic treatment in patients with cirrhosis with HCA infections. Consecutive patients with cirrhosis hospitalized with HCA infections were enrolled. After culture sampling, patients were promptly randomized to receive a standard or a broad spectrum antibiotic treatment (NCT01820026). The primary endpoint was in-hospital mortality. Efficacy, side effects, and the length of hospitalization were considered. Treatment failure was followed by a change in antibiotic therapy. Ninety-six patients were randomized and 94 were included. The two groups were similar for demographic, clinical, and microbiological characteristics. The prevalence of MDR pathogens was 40% in the standard versus 46% in the broad spectrum group. In-hospital mortality showed a substantial reduction in the broad spectrum versus standard group (6% vs. 25%; P = 0.01). In a post-hoc analysis, reduction of mortality was more evident in patients with sepsis. The broad spectrum showed a lower rate of treatment failure than the standard therapy (18% vs. 51%; P = 0.001). Length of hospitalization was shorter in the broad spectrum (12.3 ± 7 days) versus standard group (18 ± 15 days; P = 0.03). Five patients in each group developed a second infection during hospitalization with a similar prevalence of MDR (50% broad spectrum vs. 60% standard).

CONCLUSIONS

A broad spectrum antibiotic therapy as empirical treatment in HCA infections improves survival in cirrhosis. This treatment was significantly effective, safe, and cost saving.

The spread of multi drug resistant infections is leading to an increase in the empirical antibiotic treatment failure in cirrhosis: a prospective survey

Background

The spread of multi-resistant infections represents a continuously growing problem in cirrhosis, particularly in patients in contact with the healthcare environment.

Aim

Our prospective study aimed to analyze epidemiology, prevalence and risk factors of multi-resistant infections, as well as the rate of failure of empirical antibiotic therapy in cirrhotic patients.

Methods

All consecutive cirrhotic patients hospitalized between 2008 and 2013 with a microbiologically-documented infection (MDI) were enrolled. Infections were classified as Community-Acquired (CA), Hospital-Acquired (HA) and Healthcare-Associated (HCA). Bacteria were classified as Multidrug-Resistant (MDR) if resistant to at least three antimicrobial classes, Extensively-Drug-Resistant (XDR) if only sensitive to one/two classes and Pandrug-Resistant (PDR) if resistant to all classes.

Results

One-hundred-twenty-four infections (15% CA, 52% HA, 33% HCA) were observed in 111 patients. Urinary tract infections, pneumonia and spontaneous bacterial peritonitis were the more frequent. Forty-seven percent of infections were caused by Gram-negative bacteria. Fifty-one percent of the isolates were multi-resistant to antibiotic therapy (76% MDR, 21% XDR, 3% PDR): the use of antibiotic prophylaxis (OR = 8.4; 95%CI = 1.03-76; P = 0,05) and current/recent contact with the healthcare-system (OR = 3.7; 95%CI = 1.05-13; P = 0.04) were selected as independent predictors. The failure of the empirical antibiotic therapy was progressively more frequent according to the degree of resistance. The therapy was inappropriate in the majority of HA and HCA infections.

Conclusions

Multi-resistant infections are increasing in hospitalized cirrhotic patients. A better knowledge of the epidemiological characteristics is important to improve the efficacy of empirical antibiotic therapy. The use of preventive measures aimed at reducing the spread of multi-resistant bacteria is also essential.

Multi-resistant bacteria in spontaneous bacterial peritonitis: A new step in management?

Spontaneous bacterial peritonitis (SBP) is the most typical infection observed in cirrhosis patients. SBP is responsible for an in-hospital mortality rate of approximately 32%. Recently, pattern changes in the bacterial flora of cirrhosis patients have been observed, and an increase in the prevalence of infections caused by multi-resistant bacteria has been noted. The wide-scale use of quinolones in the prophylaxis of SBP has promoted flora modifications and resulted in the development of bacterial resistance. The efficacy of traditionally recommended therapy has been low in nosocomial infections (up to 40%), and multi-resistance has been observed in up to 22% of isolated germs in nosocomial SBP. For this reason, the use of a broad empirical spectrum antibiotic has been suggested in these situations. The distinction between community-acquired infectious episodes, healthcare-associated infections, or nosocomial infections, and the identification of risk factors for multi-resistant germs can aid in the decision-making process regarding the empirical choice of antibiotic therapy. Broad-spectrum antimicrobial agents, such as carbapenems with or without glycopeptides or piperacillin-tazobactam, should be considered for the initial treatment not only of nosocomial infections but also of healthcare-associated infections when the risk factors or severity signs for multi-resistant bacteria are apparent. The use of cephalosporins should be restricted to community-acquired infections.