Standardization and quality assurance for antimicrobial resistance surveillance of Streptococcus pneumoniae and Staphylococcus aureus within the European Antimicrobial Resistance Surveillance System (EARSS)

Surveillance of Resistance to New Antibiotics in an Era of Limited Treatment Options

As with any health threat, our ability to respond to the emergence and spread of antimicrobial resistance depends on our ability to understand the scale of the problem, magnitude, geographical spread, and trends over time. This is especially true for resistance emergence to newer antibiotics coming to the market as last-resort treatments. Yet current antibiotic surveillance systems are limited to monitoring resistance to commonly prescribed drugs that have been on the market for a long time. This qualitative study determined the essential elements and requirements of antimicrobial resistance surveillance for new antibiotics based on literature review, interviews and expert consensus. After an extensive mapping exercise, 10 experts participated in a modified Delphi consultation to identify consensus on all elements required for surveillance of resistance to novel antibiotics. The main findings indicate that there is a need for a two-phase system; an early alert system transitioning to routine surveillance, led by the public sector to gather and share essential data on resistance to newer antibiotics in a transparent manner. The system should be decentralized, run largely from national level, but be coordinated by an arm of an existing international public health institution. Priority should be given to monitoring emergence of resistance among already multi-drug resistant pathogens causing infections, over a broader selection of pathogens to maximize clinical impact. In conclusion, we cannot rely on current AMR surveillance systems to monitor resistance emergence to new antibiotics. A new, public system should be set-up, starting with a focus on detecting resistance emergence, but expanding to a more comprehensive surveillance as soon as there is regional spread of resistance to the new antibiotic. This article provides a framework based on expert agreement, which could guide future initiatives.

15 years of antibiotic stewardship policy in the Nancy Teaching Hospital

OBJECTIVES

The authors report the results of a 15-year antibiotic stewardship policy in the Nancy Teaching Hospital and assess the impact of reinforcing this policy on antibiotic consumption.

METHODS

Antibiotic stewardship policy was initiated in the mid 90s and then reinforced from 2006 onwards. It was completed by prescription guidelines, nominative prescription of antibiotics, and an operational infectious diseases team (OIDT). The objectives were to promote antibiotic stewardship and decrease the use of extended broad spectrum or costly molecules and intravenous administration. Antibiotics consumption, as defined daily dose per 1000 patient days (DDD/1000PD) and in euros, was monitored from 2005 onwards.

RESULTS

Between 2005 and 2008, overall yearly cost of antibiotics dropped by 34% (-€1,308,902) and consumption in DDD/1000PD by 10%. This drop in consumption concerned all antibiotic classes. Teicoplanin prescription dropped by more than 50% and use of fluoroquinolone IV decreased by 15% in 3years. The operational team's interventions were effective since nearly 80% of suggested prescription amendments were accepted by prescribers.

CONCLUSIONS

This experiment shows that it is possible to implement antibiotic stewardship policy. Our results prove a significant decrease in overall consumption of antibiotic, a change in prescribing patterns, with a shift towards the use of cheaper antibiotics.

Ten years of antibiotic consumption in ambulatory care: trends in prescribing practice and antibiotic resistance in Austria

Background

The primary aims of this study were (i) to determine the quantity and pattern of antibiotic use in Austria between 1998 and 2007 and (ii) to analyze antibiotic resistance rates in relation to antibiotic consumption in important clinical situations in order to provide data for empirical therapeutic regimens for key indications.

Methods

Consumption data and resistance data were obtained via the Austrian surveillance networks European Antimicrobial Resistance Surveillance System (EARSS) and European Surveillance on Antimicrobial Consumption (ESAC). The EARSS collects data on isolates from blood and cerebrospinal fluid obtained predominantly in the hospital setting. The Anatomical Therapeutic Chemical (ATC) classification and the Defined Daily Dose (DDD) measurement units were assigned to the data. The number of DDDs and packages per 1,000 inhabitants (PID) were used to calculate the level of antibiotic consumption. Antibiotic resistance was expressed in resistance rates, i.e., the percentage of resistant isolates compared to all isolates of one bacterial species.

Results

The overall antibiotic consumption measured in DIDs increased by 10% between 1998 and 2007, whereas PIDs decreased by 3%. The consumption of substances within the drug utilization 90% segment (measured in PID) increased for ciprofloxacin (+118.9), clindamycin (+76.3), amoxicillin/clavulanic acid (+61.9%), cefpodoxime (+31.6), azithromycin (+24.7); and decreased for erythromycin (-79.5%), trimethoprim (-56,1%), norfloxacin (-48.8%), doxycycline (-44.6), cefaclor (-35.1%), penicillin (-34.0%), amoxicillin (-22.5), minocycline (-21.9%) and clarithromycin (-9.9%). Starting in 2001, an increase in the percentage of invasive E. coli isolates resistant to aminopenicillins (from 35% to 53%), fluoroquinolones (from 7% to 25.5%) and third-generation cephalosporins (from 0% to 8.8%) was observed. The percentage of nonsusceptible or intermediate penicillin-resistant pneumococcal isolates remained stable over this time period at around 5%. For macrolides, the rate of resistant isolates increased from 5% to 12.8%, with a peak in 2005 at 14.7%.

Conclusion

The Austrian resistance data can not explain the fundamental change in prescribing practice. The more frequent use of ciprofloxacin has most likely contributed to rising resistance rates in E. coli in Austria. Penicillin G is still a highly effective substance for the treatment of invasive infections caused by pneumococci.

Vancomycin for treatment of invasive, multi-drug resistant Staphylococcus aureus infections

Staphylococcus aureus is a bacterial pathogen responsible for a variety of serious infections and is a frequent cause of nosocomial disease. During the last 60 years, S. aureus has developed increasing in vitro resistance to virtually all antimicrobials. In contrast, vancomycin has maintained a high degree of activity in vitro against this pathogen, although slight changes with in vitro activity could vastly change clinical activity. As a result, vancomycin has become the mainstay of therapy for invasive infections due to methicillin-resistant strains. However, clinical strains of S. aureus with intermediate resistance to vancomycin were reported in 1996, followed in 2002 with reports of isolates that were fully resistant. Although many authorities believe vancomycin remains the drug of choice for most staphylococcal-resistant infections, important issues surrounding its clinical application remain. These include the need for multiple daily dosing, intravenous administration, requirements for serum concentration monitoring, increasing resistance in vitro, modest efficacy rates and (less frequently) treatment-limiting adverse effects. This review addresses these important topics.

Bedeutung von MRSA in der Patientenversorgung

Methicillin-resistant Staphylococcus aureus (MRSA) has for several years been increasingly spreading at inpatient and outpatient health care facilities. This constitutes a great epidemiological problem. Measures are needed for MRSA management, including screening, hygiene, containment, and sanitation as well as for a stricter control of antibiotic use. In order to be able to monitor and assess the MRSA problem in the future, there are surveillance systems which can provide approaches for continuously improving MRSA management and thus offer a long-term solution. In this context, regional networks for implementing MRSA prevention strategies are of particular importance. Their goal is reducing MRSA-caused infections in an area and stop circulation of MRSA between the various health care facilities. For the management of MRSA infections, interdisciplinary cooperation between the attending orthopedic specialist and the clinical microbiologist is very important for planning an effective treatment regimen to ensure a successful outcome, particularly in view of the growing shortage of resources in the healthcare system.

Methicillin-resistant Staphylococcus aureus in Europe, 1999-2002

European Antimicrobial Resistance Surveillance System shows large variations in methicillin-resistant S. aureus.

We explored the variation in proportions of methicillin-resistant Staphylococcus aureus (MRSA) between and within countries participating in the European Antimicrobial Resistance Surveillance System and temporal trends in its occurrence. This system collects routine antimicrobial susceptibility tests for S. aureus. We examined data collected from January 1999 through December 2002 (50,759 isolates from 495 hospitals in 26 countries). MRSA prevalence varied almost 100-fold, from <1% in northern Europe to >40% in southern and western Europe. MRSA proportions significantly increased in Belgium, Germany, Ireland, the Netherlands, and the United Kingdom, and decreased in Slovenia. Within countries, MRSA proportions varied between hospitals with highest variance in countries with a prevalence of 5% to 20%. The observed trends should stimulate initiatives to control MRSA at national, regional, and hospital levels. The large differences between hospitals indicate that efforts may be most effective at regional and hospital levels.

Trends of penicillin and erythromycin resistance among invasive Streptococcus pneumoniae in Europe

OBJECTIVES

To forecast trends in resistance to penicillin and erythromycin among Streptococcus pneumoniae in Europe.

METHODS

Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has collected routine antimicrobial susceptibility test results of S. pneumoniae. To observe and predict changes of reduced susceptibility over time, we used a multinomial logistic regression model.

RESULTS

Large variations in penicillin and erythromycin non-susceptibility were observed between countries, and reduced susceptibility to erythromycin (17%) has become more frequent than reduced susceptibility to penicillin (10%) in Europe overall. An overall decrease in single penicillin non-susceptibility, but an increase in dual non-susceptibility was observed, indicating a shift of single penicillin to combined non-susceptibility with erythromycin. By 2006, the proportion of single erythromycin and dual non-susceptibility could increase to as much as 20.4% and 8.9%, respectively.

CONCLUSIONS

Our results indicate that appropriately dosed beta-lactams for empirical therapy are still the treatment of choice, and that macrolides should be used with prudence.

Resistance surveillance in Italy: four-year results from the MYSTIC program

The MYSTIC program is an international, multicenter surveillance study that compares the activity of meropenem, in centers that are prescribers, with that of imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin and gentamicin. These Italian data are from 3 centers (neutropenia, cystic fibrosis and intensive care units). A total of 2,072 (238 Gram-positive and 1,834 Gram-negative) aerobic microorganisms were collected during the study. Pseudomonas aeruginosa (33.4%) was the most isolated species followed by Escherichia coli (14.4%). All except one Enterobacteriaceae strain isolated were fully susceptible to meropenem. Moreover, the activity of meropenem against Enterobacteriaceae was about eight-fold greater than that of imipenem and four- to eight-fold more active than that of ceftazidime. Meropenem was highly active against non-fermentative Gram-negative microorganisms, exceeding the activity of most of the other antimicrobial agents tested. Moreover, meropenem showed increasing activity during the 4 years of study (starting from 86.2% in 1997 to 94.0% in 2000). In conclusion, our results indicate that meropenem has excellent potency and spectrum of activity despite being prescribed for the treatment of seriously ill patients, and appears to be a reliable option for the initial empirical treatment of serious nosocomial infections.

A European study on the relationship between antimicrobial use and antimicrobial resistance

In Europe, antimicrobial resistance has been monitored since 1998 by the European Antimicrobial Resistance Surveillance System (EARSS). We examined the relationship between penicillin nonsusceptibility of invasive isolates of Streptococcus pneumoniae and antibiotic sales. Information was collected on 1998-99 resistance data for invasive isolates of S. pneumoniae to penicillin, based on surveillance data from EARSS and on outpatient sales during 1997 for beta-lactam antibiotics and macrolides. Our results show that in Europe antimicrobial resistance of S. pneumoniae to penicillin is correlated with use of beta-lactam antibiotics and macrolides.