Strong correlation between the rates of intrinsically antibiotic-resistant species and the rates of acquired resistance in Gram-negative species causing bacteraemia, EU/EEA, 2016

BackgroundAntibiotic resistance, either intrinsic or acquired, is a major obstacle for treating bacterial infections.AimOur objective was to compare the country-specific species distribution of the four Gram-negative species Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter species and the proportions of selected acquired resistance traits within these species.MethodWe used data reported for 2016 to the European Antimicrobial Resistance Surveillance Network (EARS-Net) by 30 countries in the European Union and European Economic Area.ResultsThe country-specific species distribution varied considerably. While E. coli accounted for 31.9% to 81.0% (median: 69.0%) of all reported isolates, the two most common intrinsically resistant species P. aeruginosa and Acinetobacter spp. combined (PSEACI) accounted for 5.5% to 39.2% of isolates (median: 10.1%). Similarly, large national differences were noted for the percentages of acquired non-susceptibility to third-generation cephalosporins, carbapenems and fluoroquinolones. There was a strong positive rank correlation between the country-specific percentages of PSEACI and the percentages of non-susceptibility to the above antibiotics in all four species (rho > 0.75 for 10 of the 11 pairs of variables tested).ConclusionCountries with the highest proportion of P. aeruginosa and Acinetobacter spp. were also those where the rates of acquired non-susceptibility in all four studied species were highest. The differences are probably related to national differences in antibiotic consumption and infection prevention and control routines.

Impact of livestock-associated MRSA in a hospital setting

OBJECTIVES

The Netherlands is known for a stringent search and destroy policy to prevent spread of MRSA. In the hospital setting, livestock-associated MRSA (LA-MRSA) is frequently found in patients coming from the high density farming area in the south of the Netherlands. The aim of the study was to determine the contribution of LA-MRSA in the epidemiology of MRSA in cases found following the Dutch search and destroy policy.

PATIENTS AND METHODS

From two hospitals serving a population of 550,000 persons all data on MRSA cultures and subsequent control measures from 2008 and 2009 were retrospectively collected and analyzed.

RESULTS

A total of 3856 potential index patients were screened for MRSA, 373 (9.7%) were found to be positive, 292 ( 78%) LA-MRSA and 81 (22%) non-LA-MRSA respectively. No secondary cases were found among contact research in persons exposed to LA-MRSA (0/416), whereas similar contact research for non-LA-MRSA resulted in 83 (2.5%) secondary cases. LA-MRSA were rarely found to cause infections.

CONCLUSIONS

LA-MRSA is more prevalent than non-LA-MRSA in Dutch Hospitals in the South of the Netherlands. However, retrospectively studied cases show that the transmission rate for LA-MRSA was much lower than for non-LA-MRSA. This suggest that infection control practices for LA-MRSA may possibly be less stringent than for non-LA-MRSA.

Antimicrobial drug use and resistance in Europe

Routine surveillance data indicate a relation between use and resistance and support interventions designed to reduce antimicrobial consumption at a national level in Europe.

Our study confronts the use of antimicrobial agents in ambulatory care with the resistance trends of 2 major pathogens, Streptococcus pneumoniae and Escherichia coli, in 21 European countries in 2000–2005 and explores whether the notion that antimicrobial drug use determines resistance can be supported by surveillance data at national aggregation levels. The data obtained from the European Surveillance of Antimicrobial Consumption and the European Antimicrobial Resistance Surveillance System suggest that variation of consumption coincides with the occurrence of resistance at the country level. Linear regression analysis showed that the association between antimicrobial drug use and resistance was specific and robust for 2 of 3 compound pathogen combinations, stable over time, but not sensitive enough to explain all of the observed variations. Ecologic studies based on routine surveillance data indicate a relation between use and resistance and support interventions designed to reduce antimicrobial drug consumption at a national level in Europe.

Emergence of methicillin-resistant Staphylococcus aureus of animal origin in humans

MRSA from an animal reservoir has recently entered the human population and is now responsible for >20% of all MRSA in the Netherlands.

In 2003 in the Netherlands, a new methicillin-resistant Staphylococcus aureus (MRSA) strain emerged that could not be typed with Sma1 pulsed-field gel electrophoresis (NT-MRSA). The association of NT-MRSA in humans with a reservoir in animals was investigated. The frequency of NT-MRSA increased from 0% in 2002 to >21% after intensified surveillance was implemented in July 2006. Geographically, NT-MRSA clustered with pig farming. A case–control study showed that carriers of NT-MRSA were more often pig or cattle farmers (pig farmers odds ratio [OR] 12.2, 95% confidence interval [CI] 3.1–48.6; cattle farmers OR 19.7, 95% CI 2.3–169.5). Molecular typing showed that the NT-MRSA strains belonged to a new clonal complex, ST 398. This study shows that MRSA from an animal reservoir has recently entered the human population and is now responsible for >20% of all MRSA in the Netherlands.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in invasive isolates from southern and eastern Mediterranean countries

OBJECTIVES

Efforts aimed at curtailing the ever increasing spread of methicillin-resistant Staphylococcus aureus (MRSA) require effective information of its epidemiology. However, knowledge about the situation in southern and eastern countries of the Mediterranean is incomplete since reports have been sporadic and difficult to compare.

METHODS

Over a 36 month period from 2003 to 2005, the ARMed project collected more than 5000 susceptibility test results of invasive isolates of S. aureus from blood cultures routinely processed within participating laboratories servicing 62 hospitals situated in Algeria, Cyprus, Egypt, Jordan, Lebanon, Malta, Morocco, Tunisia and Turkey.

RESULTS

Overall, the median MRSA proportion was 39% (interquartile range: 27.1% to 51.1%). The highest proportions of MRSA were reported by Jordan, Egypt and Cyprus, where more than 50% of the invasive isolates were methicillin-resistant. Considerable variation was identified in the proportion of MRSA in hospitals within the same country.

CONCLUSIONS

It appears that most of the countries in the Mediterranean region are experiencing a surge in MRSA infections. This requires a greater focus to identify relevant drivers of resistance and implement effective practices in order to address them, especially improved infection control and antibiotic consumption practices.