Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
World Economic Forum report assesses global risk of antibiotic resistance
The World Economic Forum's 2018 Global Risks Report, released this week, includes a section on antimicrobial resistance (AMR), noting that while initiatives to address antibiotic overuse and the lack of new antibiotics have been launched, concrete successes "remain elusive."
In its 2013 Global Risks Report, the forum devoted a chapter to AMR that highlighted overuse of antibiotics in human and animal health and the fact that no new class of antibiotics had been invented since the 1980s. Revisiting this issue in a section of the 2018 report titled Hindsight, the forum suggests that the risks posed by AMR continue to intensify, both in terms of human health and the global economy.
In the years since 2013, for example, a report commissioned by the UK government ("The Review on Antimicrobial Resistance") estimated that 700,000 deaths a year can be attributed to AMR—a figure significantly higher than presented in the forum's 2013 report. In addition, while the forum estimated in 2013 that the potential economic impact of AMR was 0.4% to 1.6% of global GDP, a study published by the World Bank in 2017 estimated that AMR could have an impact of between 1.1 and 3.8 percentage points by 2050. Resistance to the strongest antibiotics has also continued to spread since 2013, highlighted by rising resistance to carbapenems and emerging resistance to the last-resort antibiotic colistin.
The authors acknowledge that global efforts to address AMR, including the World Health Organization's 2015 Global Action Plan on Antimicrobial Resistance, are encouraging, as are initiatives to encourage the discovery and development of new antibiotics. However, they write, "We still face two trends that spell potential disaster: new classes of drugs are not being invented and resistance to existing drugs continues to spread inexorably."
Jan 17 World Economic Forum 2018 Global Risks Report, section on AMR
Study identifies antibiotic-resistant bacteria, genes in space station
A team led by researchers with the California Institute of Technology's Jet Propulsion Laboratory has identified strains of drug-resistant bacteria and more than a hundred antibiotic resistance genes in microbes collected from the International Space Station (ISS), according to a new study in Scientific Reports.
In the study, researchers collected 24 samples from eight locations aboard the ISS over the span of a year. The samples were cultured to obtain isolates for phenotypic antibiotic susceptibility testing and whole-genome sequencing (WGS) and then subjected to DNA extraction to allow for molecular analysis with Ion AmpliSeq—a next-generation sequencing tool—and metagenomics. The purpose of the study was to analyze the resistome of the ISS, where human-associated opportunistic pathogens have previously been found, in order to better understand the threat of antibiotic-resistant bacteria to astronauts and develop mitigation procedures for future space flights.
In total, 57 biosafety level 2 (BSL 2) microorganisms were tested for resistance to nine antibiotics. Most of the strains (92%) were resistant to penicillin, followed by oxacillin (68%), rifampin (66%), erythromycin (64%), cefoxitin (49%), cefazolin (29%), tobramycin (19%), and gentamicin and ciprofloxacin (14%). A novel species isolated from ISS, Enterobacter bugandensis, was resistant to all 9 antibiotics; Staphylococcus haemolyticus was not resistant to any of the antibiotics. Testing of 12 S aureus isolates, conducted because of the serious health concerns associated with methicillin-resistant S aureus, showed that most strains were susceptible, except four that were resistant to clindamycin.
While WGS showed a collection of 51 genes conferring resistance to 18 antibiotics, AmpliSeq analysis of DNA from the 24 samples detected a total of 123 known antibiotic resistance genes, with those responsible for beta-lactam and trimethoprim resistance being the most abundant and widespread. The metagenomics approach showed that genes conferring resistance to metals (like zinc and copper) and those involved in multidrug efflux pumps were the most abundant. Metagenomic analysis also found widespread fluoroquinolone resistance.
"The results from this study highlight the importance of using a variety of analytical methods to get a comprehensive picture of the resistome on the ISS and to utilize this information to develop concrete antibiotic resistance mitigation strategies," the authors write.
Jan 16 Sci Rep study
Spanish clinicians report successful ICU stewardship program
Originally published by CIDRAP News Jan 18
An antimicrobial stewardship program (ASP) in an intensive care unit (ICU) in a Spanish hospital was associated with a 22% drop in antimicrobial doses, according to a new study in Antimicrobial Agents and Chemotherapy.
Investigators evaluated defined daily doses (DDDs) of antimicrobials per 1,000 patient-days and days of therapy (DOT) per 100 occupied bed-days in a Barcelona ICU before and after ASP implementation (2007-2010 vs. 2011-2015). They also measured associated costs. Data were compiled on 1,971 patients in the pre-ASP period and on 3,031 patients after ASP implementation.
The researchers reported that the percentage of patients treated with one or more antimicrobials dropped from 88.6% to 77.2%, DDDs decreased from 246.8 to 192.3, or 22.1%, and DOT were reduced from 66.7 to 54.6 (an 18.1% drop). The mean cost per trimester decreased from €115,543 ($141,302) to €73,477 ($89,858), a €42,065 ($51,443) savings, and the percentage of the total cost of hospital antimicrobials attributed to ICU antimicrobials decreased from 28.5% to 22.8%.
The cost savings over the 5 years that the program was implemented amounted to almost €1 million ($1.2 million).
Jan 16 Antimicrob Agents Chemother study
German study finds varying antibiotic resistance levels in gonorrhea
Originally published by CIDRAP News Jan 18
A German study published yesterday in BMC Infectious Diseases found low levels of cephalosporin resistance in gonorrhea cases, but resistance was moderate to high against other antibiotics.
Researchers with the country's Gonococcal Resistance Network surveillance system analyzed susceptibility data on samples collected from patients from April 2014 to December 2015. All told, 90% of the 537 Neisseria gonorrhoeae isolates were from men, with a median age of 32 for men and 25 for women.
None of the isolates were resistant to ceftriaxone, and 1.9% (in 2014) and 1.4% (in 2015) of the isolates were resistant to cefixime. But 11.9% and 9.8% of samples showed resistance against azithromycin in 2014 and 2015, respectively, compared with 72.0% and 58.3% for ciprofloxacin and 29.1% and 18.8% for penicillin.
The authors concluded, "Continued surveillance of antimicrobial drug susceptibilities for N. gonorrhoeae remains highly important to ensure efficient disease management."
Jan 17 BMC Infect Dis study
Survey: Most infection specialists don't recommend short antibiotic course
Originally published by CIDRAP News Jan 17
Most infection specialists currently do not advise the shortest possible duration of antibiotic therapy to prescribers, but nearly half are willing to shorten the duration most of the time, a French-led team of researchers reported yesterday in the Journal of Antimicrobial Chemotherapy.
The findings are from a cross-sectional international survey conducted by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Antimicrobial Stewardship and the French Infectious Diseases Society. Infection specialists who gave at least weekly advice on antibiotic prescriptions were invited to participate in the online survey, which included 15 vignettes corresponding to common clinical cases with favorable outcomes. In the first part of the survey (A), the respondents were asked the usual recommendation they would make regarding antibiotic duration for each vignette, and in the second part (B) they were asked the shortest recommendation they would be willing to make for the same cases.
Overall, 866 participants from 58 countries responded to the survey, mostly members of an antibiotic stewardship team (73%), infectious disease specialists (58.7%), or clinical microbiologists (22.8%). Of the 86.5% of respondents (749/866) who were eligible for part A, 36.2% (217/749) recommended a short duration of antibiotic therapy (compared with the literature) in more than 50% of the vignettes, and 4.1% (31/749) recommended a short duration in more than 75% of the cases. Among all answers, short durations of antibiotic therapy were recommended in 42.7% of cases. In multivariable analysis, having fixed durations of antibiotic treatment in regional/national guidelines was independently associated with recommending a short duration (adjusted odds ratio, 1.5).
Of the 76.4% (622/866) of participants eligible for part B, 47.1% (316/622) were willing to shorten treatment duration for at least 50% of the vignettes.
"It is encouraging that almost half of the participants were ready to shorten durations of treatment, as it suggests that these infection specialists, who are frequently antibiotic stewards, are ready to promote strategies aimed at reducing duration of antibiotic therapy," the authors write. "Nevertheless, our results also show that the rest of the participants, who represent the majority, should be the target of specific educational and awareness initiatives, if they are to act as leaders and role models to promote such a strategy."
Jan 16 J Antimicrob Chemother study
UK study finds surfers more likely to be colonized with resistant bacteria
Originally published by CIDRAP News Jan 17
A first-of-its-kind study combining surveillance of antibiotic-resistant bacteria in bathing waters and human exposure estimates has found that surfers are more likely to be colonized by drug-resistant bacteria than non-surfers, UK scientists report in the journal Environment International.
The study, conducted by researchers from the University of Exeter Medical School, aimed to estimate the prevalence of Escherichia coli harboring the extended-spectrum beta-lactamase (ESBL) gene blaCTX-M in waters along the UK coastline. CTX-M genes represent nearly 80% of ESBLs in clinical isolates and can encode resistance to multiple antibiotics. Previous research has indicated that ingesting seawater containing antibiotic-resistant E coli is associated with gut colonization by these bacteria, and that swimming is a risk factor for urinary tract infections caused by ESBL-producing bacteria.
In the first section of the study, the researchers conducted an environmental assessment, collecting 97 coastal water samples to analyze for the proportion of E coli harboring blaCTX-M. The results indicated that, on average, 0.07% of E coli in the coastal waters of England and Wales carry blaCTX-M. They then estimated the risk of exposure to these bacteria among coastal water users, based on the likely number of exposure events, E coli density data in English and Welsh coastal waters, and estimates of the volume of water that water users ingest. They calculated that more than 2.5 million water sport sessions occurred in England and Wales in 2015 that resulted in people ingesting blaCTX-M-harboring E coli, and that surfers were at particularly high risk.
In the third section of the study, rectal swabs were collected from 143 surfers (defined as frequent surfers, body boarders, and body surfers) and a control group of 130 people with very little exposure to seawater. Analysis of the swabs showed that 13 of 143 surfers (9.1%) were fecal carriers of E colithat were phenotypically resistant to cefotaxime, compared with 4 of 130 non-surfers (3.1%), for a risk ratio (RR) of 2.95. Nine of 143 surfers (6.3%) were found to be carriers of blaCTX-M-harboring E coli, compared with 2 of 130 controls (1.5%)—an RR of 4.09.
"While surfers colonised by potentially pathogenic [antibiotic-resistant bacteria] may by asymptomatic, gut bacteria are a major source of infection, and these bacteria may cause problems if colonised individuals develop a health condition in the future that makes them more susceptible to infections," the authors write. They add that further research is needed to investigate the role of coastal waters and other natural environments in the transmission of antibiotic-resistant bacteria.
Jan 14 Environ Int study