The Swedish model for prioritising research on the use of antibiotics: Aligning public funding with research gaps.

Due to the meagre development of new antibiotics, optimising the use of currently available antibiotics is important to reduce resistance pressures and to safeguard existing treatment options. The Public Health Agency of Sweden (PHAS) was tasked in 2014 to (1) develop a model for identifying and prioritising research gaps and (2) initiate studies to improve knowledge on how to optimise the use of existing antibiotics. A survey addressing knowledge-gaps and suggesting studies needed was distributed to a broad network of Swedish and European clinicians and experts. An independent reference group prioritised the proposals, applying predefined criteria focusing on public health relevance. The PHAS sponsored and led two multi-centre RCTs in cooperation with clinical researchers and took part in additional studies. A second survey and prioritization exercise following the same model was performed in 2019. The Swedish case study described in this paper provides an example of the role that the public sector can play in order to support the improved use of existing antibiotics. National and international institutions are well suited to perform systematic reviews of research priorities with a focus on public health concerns. The ultimate success of the model depends on political engagement, a close dialogue with healthcare professionals, collaboration between international sister-authorities responsible for public health in other countries, the availability of research funding, harmonisation of regulatory issues and regular revisions of clinical guidelines. The experience from the Swedish model illustrates opportunities for meeting clinical needs and filling knowledge gaps on existing off-patent antibiotics.

Antibiotic consumption among a Swedish cohort of children born in 2006.

AIM: It is important to measure antibiotic consumption because it contributes to antimicrobial resistance. Our objective was to follow all children born in 2006 in Sweden and to analyse antibiotic consumption during each month of life for the first two years and thereafter for every year during their third to fifth years of life. METHODS: This was a register-based, open-cohort study where we used the Swedish Prescribed Drug Register, which covers the whole population, to identify the type and date of purchase of antibiotics for the children in the cohort. RESULTS: During the first one-year follow-up period, 101 555 children up to one year of age were living in Sweden, of which 50 135 were boys and 49 420 were girls. Children consumed the largest amount of antibiotics during their second year of life. In our cohort, 51% received antibiotics at some point during the second year and 24% received multiple treatments. The consumption then dropped with every year of life during the follow-up. CONCLUSION: This study suggests that actions against overprescribing of antibiotics to children should be targeted towards the second year of life in order to have the greatest effect on consumption.

Overuse of antibiotics for the common cold - attitudes and behaviors among doctors in rural areas of Shandong Province, China.

BACKGROUND: Irrational antibiotic use is common in rural areas of China, despite the growing recognition of the importance of appropriate prescribing to contain antibiotic resistance. The aim of this study was to analyze doctors' attitudes and prescribing practices related to antibiotics in rural areas of Shandong province, focusing on patients with the common cold. METHODS: A survey was conducted with doctors working at thirty health facilities (village clinics, township health centers and county general hospitals) in three counties within Shandong province. Questions were included on knowledge and attitudes towards antibiotic prescribing. Separately, a random selection of prescriptions for patients with the common cold was collected from the healthcare institutions at which the doctors worked, to investigate actual prescribing behaviors. RESULTS: A total of 188 doctors completed the survey. Most doctors (83%, 149/180) had attended training on antibiotic use since the beginning of their medical practice as a doctor, irrespective of the academic level of their undergraduate training. Of those that had training, most had attended it within the past three years (97%, 112/116). Very few doctors (2%, 3/187) said they would give antibiotics to a patient with symptoms of a common cold, and the majority (87%, 156/179) would refuse to prescribe an antibiotic even if patients were insistent on getting them. Doctors who had attended training were less likely to give antibiotics in this circumstance (29% vs. 14%, p < 0.001). A diagnosis of common cold was the only diagnosis reported on 1590 out of 8400 prescriptions. Over half (55%, 869/1590) of them included an antibiotic. Prescriptions from village clinics were more likely to contain an antibiotic than those from other healthcare institutions (71% vs. 44% [township] vs. 47% [county], p < 0.001). CONCLUSIONS: Most doctors have recently attended training on antibiotic use and report they would not prescribe antibiotics for patients with a common cold, even when placed under pressure by patients. However, more than half of the prescriptions from these healthcare institutions for patients with the common cold included an antibiotic. Exploring and addressing gaps between knowledge and practice is critical to improving antibiotic use in rural China.

Changes in patterns of antibiotic use in Chinese public hospitals (2005-2012) and a benchmark comparison with Sweden in 2012.

Changes in patterns of antibiotic use in Chinese hospitals before and after intensive nationwide interventions are reported and compared with Chinese national targets and antibiotic use in Swedish hospitals. Chinese data were collected quarterly and yearly from selected patient prescriptions/medical records and medicines inventory control systems from 15 hospitals (2005-2012). Swedish data were extracted from a 2010-point prevalence survey and 2009-2012 sales data from seven university hospitals. An interrupted time series with segmented regression analysis was used to measure changes in patterns of antibiotic use in Chinese hospitals before and after the interventions. Following the 2011 interventions, significant reductions in antibiotic use in Chinese hospitals were seen: the proportion of prescriptions with antibiotics decreased 4.7% (P=0.03) and the proportion of medical records with antibiotic prescription decreased 7.3% (P=0.04). The proportions of prescriptions and medical records with antibiotics in Chinese hospitals in 2012 were 10% and 50%, respectively, and remained much higher than Swedish hospitals (1.1% in DDD for outpatients and 34% in number of patients for inpatients). Inpatient consumption in Chinese hospitals dropped significantly from 910 DDD/1000 inpatient days in 2008 to 473 in 2012 (588 in Swedish hospitals). Antibiotics are being used less frequently in Chinese hospitals, broad-spectrum antibiotics are still preferred, and overall usage is higher than Sweden. A significant reduction in overall inpatient antibiotic consumption was observed after the interventions. It is not possible to identify whether the changes have resulted in less inappropriate antibiotic use. Further studies are needed.

Varying high levels of faecal carriage of extended-spectrum beta-lactamase producing Enterobacteriaceae in rural villages in Shandong, China: implications for global health.

Antibiotic resistance is considered a major threat to global health and is affected by many factors, of which antibiotic use is probably one of the more important. Other factors include hygiene, crowding and travel. The rapid resistance spread in Gram-negative bacteria, in particular extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E), is a global challenge, leading to increased mortality, morbidity and health systems costs worldwide. Knowledge about resistance in commensal flora is limited, including in China. Our aim was to establish the faecal carriage rates of ESBL-E and find its association with known and suspected risk factors in rural residents of all ages in three socio-economically different counties in the Shandong Province, China. Faecal samples and risk-factor information (questionnaire) were collected in 2012. ESBL-E carriage was screened using ChromID ESBL agar. Risk factors were analysed using standard statistical methods. Data from 1000 individuals from three counties and in total 18 villages showed a high and varying level of ESBL-E carriage. Overall, 42% were ESBL-E carriers. At county level the carriage rates were 49%, 45% and 31%, respectively, and when comparing individual villages (n = 18) the rate varied from 22% to 64%. The high level of ESBL-E carriage among rural residents in China is an indication of an exploding global challenge in the years to come as resistance spreads among bacteria and travels around the world with the movement of people and freight. A high carriage rate of ESBL-E increases the risk of infection with multi-resistant bacteria, and thus the need for usage of last resort antibiotics, such as carbapenems and colistin, in the treatment of common infections.

Molecular characterisation of trimethoprim resistance in Escherichia coli and Klebsiella pneumoniae during a two year intervention on trimethoprim use.

BACKGROUND: Trimethoprim resistance is increasing in Enterobacteriaceae. In 2004-2006 an intervention on trimethoprim use was conducted in Kronoberg County, Sweden, resulting in 85% reduction in trimethoprim prescriptions. We investigated the distribution of dihydrofolate reductase (dfr)-genes and integrons in Escherichia coli and Klebsiella pneumoniae and the effect of the intervention on this distribution. METHODOLOGY/PRINCIPAL FINDINGS: Consecutively isolated E. coli (n = 320) and K. pneumoniae (n = 54) isolates phenotypically resistant to trimethoprim were studied. All were investigated for the presence of dfrA1, dfrA5, dfrA7, dfrA8, dfrA12, dfrA14, dfrA17 and integrons class I and II. Isolates negative for the seven dfr-genes (n = 12) were also screened for dfr2d, dfrA3, dfrA9, dfrA10, dfrA24 and dfrA26. These genes accounted for 96% of trimethoprim resistance in E. coli and 69% in K. pneumoniae. The most prevalent was dfrA1 in both species. This was followed by dfrA17 in E. coli which was only found in one K. pneumoniae isolate. Class I and II Integrons were more common in E. coli (85%) than in K. pneumoniae (57%). The distribution of dfr-genes did not change during the course of the 2-year intervention. CONCLUSIONS/SIGNIFICANCE: The differences observed between the studied species in terms of dfr-gene and integron prevalence indicated a low rate of dfr-gene transfer between these two species and highlighted the possible role of narrow host range plasmids in the spread of trimethoprim resistance. The stability of dfr-genes, despite large changes in the selective pressure, indirectly suggests a low fitness cost of dfr-gene carriage.

Extended antimicrobial resistance screening of the dominant faecal Escherichia coli and of rare resistant clones.

Fifty faecal samples from healthy adults were grown on MacConkey agar and three pink colonies were subcultured, identified to species level and their antimicrobial susceptibility determined. Forty-seven samples yielded 141 isolates of Escherichia coli that were susceptible to most antimicrobials. Resistance was noted for ampicillin (30.5%), chloramphenicol (12.1%), tetracycline (23.4%), trimethoprim (24.8%) and co-trimoxazole (22.7%). A direct faecal plating method was used for extended resistance screening with E. coli as the indicator organism. Zone breakpoints were determined using normalised resistance interpretation and gave similar susceptibility results. Eighty-eight isolates of E. coli from within the zones of inhibition revealed four times more antimicrobial resistance. Extended antimicrobial resistance screening both provides the susceptibility profile of the dominant E. coli isolate and detects greater resistance in rare isolates.

Acquired sulphonamide resistance genes in faecal Escherichia coli from healthy children in Bolivia and Peru.

Antimicrobial resistance and sulphonamide resistance determinants were studied in 20 co-trimoxazole resistant Escherichia coli in faecal samples from healthy children in Bolivia and Peru. Methods used were disc diffusion susceptibility tests, PCR, sequence analysis and plasmid conjugation assays. All isolates but one were resistant to at least two different classes of antimicrobials; 19 isolates also carried at least one sul-gene. The most frequent gene was sul2 followed by sul1 and sul3, which was detected in one isolate. This is the first observation of sul3 on the American continent. In conclusion, the high prevalence of sul-genes in this material of faecal commensal E. coli isolates points to a potential role of the faecal flora in the emergence and spread of antimicrobial resistance.

Integrons and multidrug resistance among Escherichia coli causing community-acquired urinary tract infection in southern India.

Antimicrobial resistance genes are often clustered in integrons, genetic elements capable of recombination. There is a paucity of data on the prevalence and role of integrons from community-acquired infections in developing countries where resistance to co-trimoxazole is high. We determined the prevalence of integrons among Escherichia coli causing community-acquired urinary tract infection (UTI). Consecutive isolates of E. coli obtained from UTI of pregnant women at the Christian Medical College Hospital, Vellore, India, during 2002 were included. All isolates were tested for susceptibility to 16 antimicrobials using the disc diffusion method and for integrons of classes 1 and 2 by PCR. Of the 58 isolates tested, 28 (48.3%) were resistant to co-trimoxazole and trimethoprim. All these isolates carried integrons. Three additional isolates were sulfonamide resistant but integron negative. Class 1 integrons were present in 21 (36.2%) isolates. Resistance to ampicillin (p=0.000), nalidixic acid (p=0.001), chloramphenicol (p=0.02), tetracycline (p=0.004) and gentamicin (p=0.02) was significantly more common in isolates with integrons. DNA sequencing of two isolates with integrons showed the presence of aadA, dfr1 and dfr7 genes. This study demonstrated that integrons are widely prevalent in India and that they might play a role in multidrug resistance in E. coli from community-acquired UTI.

Sulphonamide resistance gene sul3 found in Escherichia coli isolates from human sources.

OBJECTIVES: The aim of this study was to investigate the molecular basis of an observed increasing resistance to trimethoprim and sulphonamides despite a simultaneous decline in co-trimoxazole consumption. The distribution of sulphonamide resistance genes sul1, sul2 and the recently discovered sul3 was studied in a collection of clinical isolates of Enterobacteriaceae. METHODS: PCR with primers specific for sul1, sul2 and sul3 was used to detect the three known sulphonamide resistance genes in the isolate collection. Sequence analysis was used for confirmation of results. Restriction endonuclease digestion and conjugational transfer assays were used for plasmid analysis. RESULTS: In 64 sulphonamide-resistant isolates, 39 sul1 genes and 48 sul2 genes were detected. Twenty-five isolates carried both sul1 and sul2 and two were negative for both genes. With PCR and sequence analysis these two were shown to harbour the new sulphonamide resistance gene sul3, which was carried by different plasmids. CONCLUSIONS: Sulphonamide resistance gene sul3, which is widespread among pigs in Switzerland, has now also been identified in two different clinical isolates of Escherichia coli, located in urinary tract infections in patients in Sweden.

New dfr2 gene as a single-gene cassette in a class 1 integron from a trimethoprim-resistant Escherichia coli isolate.

Resistance to trimethoprim among Enterobacteriaceae is increasing in spite of a stable or decreasing use of the drug. Integrons are common among these bacteria and many of them contain dfr gene cassettes. A clinical isolate of Escherichia coli from a urine specimen obtained at the Karolinska Hospital in Stockholm was resistant to trimethoprim, ampicillin, sulfonamides, chloramphenicol, streptomycin, and norfloxacin. PCR analysis with primers specific for the 5' and 3' sequences flanking the cassettes in class 1 integrons, detected a very short cassette region of no more than approximately 400 bp. Sequence analysis of the entire integron was performed, revealing a single-gene cassette of 411 bp encoding a new dihydrofolate reductase. The gene cassette comprised all sequences between the flanking conserved sequences and encoded only 78 amino acids. By homology it belongs to the unique group of dfr2 gene cassettes and being the fourth described gene in this group the new gene is called dfr2d. The enzymes encoded by the dfr2 genes are 67% identical and are not related to any other known dfr gene products.