Cattle are commonly treated with antibiotics that may survive digestion and promote antibiotic resistance when manure or composted manure is used as a soil amendment for crop production. This study was conducted to determine the effects of antibiotic administration and soil amendment practices on microbial diversity and antibiotic resistance of bacteria recovered from the surfaces of lettuce and radishes grown using recommended application rates. Vegetables were planted in field plots amended with raw manure from antibiotic-treated dairy cows, composted-manure from cows with different histories of antibiotic administration, or a chemical fertilizer control (12 plots, n=3). Culture-based methods, 16SrDNA amplicon sequencing, qPCR and shot-gun metagenomics were utilized to profile bacteria and characterize the different gene markers for antibiotic resistance. Culture-based methodologies revealed that lettuce grown in soils amended with BSAs had significantly larger clindamycin resistant populations compared to control conditions. Growth in BSAs was associated with significant changes to the bacterial community composition of radish and lettuce. Total sul1 copies were 160X more abundant on lettuce grown in manure and total tet(W) copies were 30X more abundant on radishes grown in manure. Analysis of shotgun metagenomic data revealed that lettuce grown in manure-amended soils possessed resistance genes for three additional antibiotic classes compared to other treatments. This study demonstrates that raw, antibiotic-exposed manure may alter microbiota and the antibiotic resistance genes present on vegetables. Proper composting of BSAs as recommended by the U.S. Department of Agriculture and Environmental Protection Agency is recommended to mitigate the spread of resistance to vegetable surfaces. / MSLFS / Antibiotics are drugs responsible for killing infectious diseases in both humans and animals. In cows, antibiotics are frequently used when they get infections in their udders. These drugs can be excreted through manure and urine and end up in the environment. Manure or composted manure is often applied as a soil amendment for crop production. The presence of antibiotics in soil may promote antibiotic resistance, meaning bacteria that carry antibiotic resistance genes (ARGs) are capable of surviving exposure to drugs that would normally kill them. Such bacteria may eventually pass their ARGs to pathogens, which then could no longer be treated effectively by antibiotics when there is an infection. Thus, there is concern that overuse of antibiotics in agriculture can contribute to reduced effectiveness of antibiotics and the growing global antibiotic resistance health crisis. This study sought to determine if prior antibiotic administration affected the antibiotic resistance of bacteria found on the surfaces of vegetables grown in soil amended with manure or compost from dairy cows. Lettuce and radishes were grown in the field in plots amended with raw manure from antibiotic-treated dairy cows, compost from cows with different histories of antibiotic administration, or a chemical fertilizer control. Mature vegetables were harvested and used to enumerate antibiotic-resistant bacterial colonies. Additionally, the 16S rRNA gene, which is a ubiquitous gene found in all bacteria, was sequenced to identify the kinds of microbes that colonized the radish and lettuce surfaces when grown under the different conditions. DNA was extracted from the bacteria collected from the vegetable surfaces to and different methods were used to identify the kinds of ARGs present and to which kinds of antibiotics they encode resistance. The results of the study indicated that raw, antibiotic-exposed manure may increase the bacteria found on vegetables in addition to their ARGs. Proper composting of manure, as recommended by the U.S. Department of Agriculture (USDA) and the Environmental Protection Agency (EPA), is recommended to mitigate resistance and control microbial populations on fresh vegetables.

Raw vegetables can sometimes be the source of outbreaks of human illness; however the potential for fresh vegetables to serve as a vehicle for antibiotic -resistant bacteria is poorly understood. Antibiotics and antibiotic-resistant bacteria have been shown to persist in manure of animals administered antibiotics, and in compost generated from this manure, where there is the potential for their transfer to produce. The purpose of this study was to determine the survival of antibiotic-resistant bacteria on raw, peeled, carrots after washing with commonly used chemical sanitizers. Multi-drug resistant E. coli O157:H7 and Pseudomonas aeruginosa were inoculated into a compost slurry of composted manure from dairy cattle, with and without prior administration of antibiotics, and used to inoculate carrot surfaces prior to the washing studies. This approach provided defined model antibiotic-resistant pathogens present within a background microbial community simulating potential carry over from manure-derived fertilizer. Carrots (n=3, 25g) were air-dried and stored at 4 °C until washing with tap water, XY-12 (sodium hypochlorite, 50 ppm free chlorine) or Tsunami 100 (peroxyacetic acid/hydrogen peroxide, 40 ppm free paracetic acid), according to manufacturer's directions. A second batch of carrots representing each inoculation x wash condition (n=3) were individually packaged for storage at 2 °C for 1,7, and 14 days, or 10 °C for 7 days and enumerated on those day intervals to recover bacteria from the surfaces of washed carrots. The resulting previously washed and stored carrots were subject to serial dilution and plated onto corresponding agar to enumerate total aerobic bacteria (R2A), aerobic bacteria tolerant or resistant to antibiotics (antibiotic-supplemented R2A), E. coli (Eosin Methylene Blue), and Pseudomonas spp. (Pseudomonas Isolation Agar). In addition, the tetA gene was quantified from the carrot samples as a measure of the effect of sanitizers and storage on an antibiotic resistance gene known to be carried by the inoculated bacteria.Inclusion of sanitizer in the wash water significantly reduced the absolute numbers of inoculated bacteria (E.coli and Pseudomonas) as well as populations of bacteria capable of growth on the R2A media containing cefotaxime (10μg/mL), sulfamethoxazole (100μg/mL), or tetracycline (3μg/mL). Comparable reductions in the inoculated P. aeruginosa resistant to tetracycline (PIA T, 4μg/mL), bacteria resistant to cefotaxime (10μg/mL) and tetracycline (3μg/mL) occurred after washing with XY-12 or Tsunami 100. The sanitizer effectiveness may be bacterial dependent, as evident by larger absolute reductions of the inoculated E. coli (EMB) and bacteria grown on sulfamethoxazole (100μg/mL)-amended plates after washing with Tsunami 100 compared to washing with tap water or XY-12. Re-growth of both the inoculated and native compost-associated bacteria was inhibited by storage at 2 °C, as there were no significant differences in the log CFU/g values on the various media (total aerobic bacteria, bacteria on antibiotic-amended plates, E. coli inoculum, P. aeruginosa inoculum) during the 14-day storage period. However, temperature abuse at 10 °C resulted in significant re-growth of native Pseudomonas, compared to storage at 2 °C. A sanitizer-associated interaction between re-growth and temperature was also observed for bacteria resistant to clindamycin (25μg/mL) and cefotaxime (10μg/mL), with substantial re-growth occurring only on carrots washed with Tsunami 100. There was no significant re-growth of the inoculated E. coli O157:H7 at either temperature. Results indicate that some bacterial populations are reduced by post-harvest washes and that temperature abuse of fresh produce may result in increases in antibiotic-resistant bacterial populations. / Master of Science in Life Sciences / Fresh vegetables are frequently washed to remove soil and pests before shipment to suppliers, with the goal of creating a ready-to-eat- product for consumers. The inclusion of a chemical sanitizer in the wash water has the benefit of killing or reducing the number of bacteria in the wash water. Chemical sanitizers also have the potential to reduce spoilage bacteria and human pathogenic bacteria on the vegetable and prevent cross-contamination from one vegetable to another. While the intention of sanitizers is to reduce bacterial numbers in wash water, there can be added benefit of also reducing bacterial numbers on vegetable surfaces. Given the rising problem of antibiotic resistance, in this study we sought to determine the effectiveness of two commonly used wash water sanitizers for reducing antibiotic-resistant bacterial pathogens and other antibiotic-resistant bacteria on carrots. It was not possible to completely eliminate all bacteria on the carrots by washing, a frequent misconception. However, washing in water that included a food-grade sanitizer, Tsunami 100 (peroxyacetic acid/hydrogen peroxide) or XY-12 (sodium hypochlorite), numbers of <i>E.coli</i> and <i>Pseudomonas</i> that had been pre-inoculated on the carrots were reduced. Despite the reduction in numbers after washing, the surviving bacteria on the carrot surfaces grew significantly when stored improperly at warm temperatures (10°C instead of 2 °C). Bacteria that could grow in the presence of antibiotics were reduced by the sanitizer wash and did not re-grow when stored at 2qC. The use of food-grade sanitizers does reduce the numbers of some bacteria on carrots, but it is equally important that consumers store produce at chilled temperatures to prevent re-growth of potentially harmful bacteria.

Due to the recent rise in antibiotic resistant pathogens, and the difficulties surrounding the quest for new antibiotics, many researchers have started revisiting antibiotic interactions in hopes of finding new treatment options. The primary outcome of this project was to examine the efficacy of concomitant antibiotic use under varying nutrient conditions, to identify variations in antibiotic interactions. Antibiotic interactions were studied, utilizing E. coli as a model bacterial system, grown in four different media types. E. coli cultures were treated with streptomycin, tobramycin, erythromycin, and amikacin individually and in a pairwise fashion at varying doses. We found that at least some antibiotic efficacies were dependent on the environmental nutrient conditions E. coli was grown in, as the antibiotics were not equally effective in all media types. E. coli grown in potato dextrose broth, in particular, showed extremely high tolerance to antibiotic inhibition. In addition, we observed several variations in antibiotic interactions, depending on the combination of antibiotics and environmental conditions utilized. It is predicted that differences in available nutrients is the primary cause of the observed discrepancies in antibiotic properties between media. The observation of changes in antibiotic efficacy under different environmental and nutrient conditions has serious implications for use of antibiotic combinations as drug treatments. Not all microenvironments within the human body have identical nutrient make-up. If the interactions antibiotics are reported to have in one environmental condition change under another, reckless prescription of combinations could lead to a serious adverse reaction. Thus, this is an important area for future in vitro and in vivo research.

Introduktion: Antibiotikaresistens är idag ett av de största globala hoten mot folkhälsan. Antibiotikaresistens innebär att bakterier blir resistenta mot läkemedlet antibiotika, vilket leder till att sjukdomar som tidigare varit behandlingsbara med antibiotika blir svårbehandlade eller icke behandlingsbara. Detta leder i sin tur till högre dödlighet, längre sjukhusvistelser samt en högre kostnad för vården. Resistensen sker även naturligt men det är tydligt att överanvändning och missbrukning av antibiotikan skyndar på resistensutvecklingen avsevärt. Syfte: Syftet med den här studien är att undersöka människors beteende gällande antibiotikaanvändning utifrån ett antibiotikaresistent perspektiv. Metod: Det här är en empirisk studie som genomförts i form av en enkätundersökning.Studiedesign är en tvärsnittsdesign. Denna design innebär att data samlas in från mer än ettenda fall vid en viss tidpunkt. Studiepopulationen består av män och kvinnor i åldersgruppen18 år och uppåt utan en övre gräns.Resultat: Resultatet visar att respondenterna är medvetna om antibiotikaresistens och 88,7 %svarar att de är medvetna om att det finns antibiotikaresistens, 87,3 % följer läkarens behandlingsrekommendation. Resultatet visar att 18,3 % skulle kunna tänka sig att köpa antibiotika receptfritt på apotek utomlands utan en läkares ordination om de blir sjuka och 25 % av dem har en högskoleutbildning/universitetsutbildning. Slutsats: Generellt sett visar studien på att det finns en medvetenhet om antibiotikaresistens,vilket också visar sig i respondenternas beteende. Respondenternas beteende följer med vadsom bidrar till att resistensutvecklingen minskar i samhället som handlar om att följa läkarensbehandlingsrekommendation samt att inte köpa receptfria antibiotika. Restriktivt användandeav antibiotika bidrar till minskad resistens. / Introduction: Antibiotic resistance is today one of the biggest global threats to public health. Antibiotic resistance means that bacteria become resistant to the drug antibiotics, which leads to diseases that have previously been treatable with antibiotics becoming difficult to treat or not treatable, which in turn leads to a higher mortality, longer hospital stays and a higher cost of care. The resistance also occurs naturally, but it is clear that overuse and misuse of the antibiotic accelerates the development of resistance considerably. Aim: The aim of this study is to investigate human behavior regarding antibiotic use from an antibiotic-resistant perspective. Method: This is an empirical study conducted in the form of a survey. Study design is a cross-sectional design. This design means that data is collected from more than a single case at a given time. Study populations consists of men and women in the age group 18 years and older without an upper limit. Results: The results show that the respondents are aware of antibiotic resistance and 88.7 % answer that they are aware that there is antibiotic resistance. 87.3% follow the doctor's treatment recommendation. The results show that 18.3% could buy antibiotics without a prescription at pharmacies abroad without a doctor's prescription if they become ill and 25 % of them have a university education. Conclusion: In general, the study shows that there is an awareness of antibiotic resistance, which is also reflected in the respondents' behavior. The respondents' behavior follows what contributes to reducing the development of resistance in society, which is about following the doctor's treatment recommendation and not to buy over-the-counter antibiotics. Restrictive use of antibiotics contributes to reduced resistance.

Rising global antibiotic resistance has caused concerns over sources and pathways for the spread of contributing factors. Majority of the antimicrobials used in the U.S. are involved in veterinary medicine, primarily with livestock rearing. Animal manure land application integrates livestock farming and agroecosystems. This manure contains antibiotic resistant elements (AREs) (resistant bacteria, resistance genes, and veterinary antibiotics) that contribute towards antimicrobial resistance. Altering manure application techniques can reduce surface runoff of other contaminants such as excess N and P, pesticides, and hormones, that can impact water quality. Conventional tillage practices in the U.S. has reduced or stopped, making subsurface injection of manure a promising option when compared to surface application. Our research compared manure application methods, manure application seasons, cropping system, and manure-rainfall time gaps to gauge the impact on AREs in the environment. Two field-scale rainfall simulation studies were conducted along with one laboratory study. Using the injection method lowered concentrations of manure associated AREs entering surface runoff. When manure was surface applied and rainfall occurred 7 d after application, 9-30 times less resistant fecal coliform bacteria (FCB) entered surface runoff when compared to 1 d time gap for that broadcast method. Within a day of manure application, antibiotic resistance gene (ARG) profiles in soil began to differ from each other based on manure application and soil ARG richness in all manure-amended soil increased compared to the background. Runoff from injection plots contained 52 ARGs with higher abundance compared to runoff from surface applied plots. ARGs in the former were more correlated to soil and more correlated to manure in the latter. The highest antibiotic concentrations were in the injection slit soil of those plots. Antibiotic concentrations in samples corresponded positively to concentrations of resistant FCB and ARGs, and there was a positive correlation between resistant FCB and their associated ARGs (Spearman's ρ = 0.43-0.63). A CRIISPR-Cas12a assay for quantification of ARGs in environmental samples was just as precise as conventional methods. There is also potential for in-situ detection. These combined results can hopefully help farmers improve manure management practices that mitigate spread of AREs to surrounding water, crops, and soil. / Doctor of Philosophy / Rising global antibiotic resistance cause concerns over sources and pathways for the spread of contributing factors. Most of the antimicrobials used in the U.S. are involved in veterinary medicine, especially with livestock rearing. Overuse of antibiotics that are medically important to human medicine compromises the effectiveness of our medicines. Animal manure contains antibiotic resistant elements (AREs) such as resistant bacteria, resistance genes, and antibiotics) that contribute towards resistance issues. Once these AREs enter the environment, they can be taken up by crops, runoff into surface water or leached into ground water, or even reside within the animal products we consume. Altering manure application techniques is beneficial for nutrient conservation but also potentially for reducing ARE spread. With our research, we compared manure application methods, manure application seasons, cropping systems, and manure-rainfall time gaps to find ways to balance the need for manure application and the spread of resistance. We used two field-scale rainfall simulation studies along with one laboratory study. Overall, using the injection method resulted in significantly lower concentrations of manure associated AREs entering surface runoff. When manure was surface applied and rainfall occurred 7 d after application, less resistant fecal coliform bacteria (FCB) entered surface runoff when compared to the 1 d time gap for broadcast methods. Within a day of manure application, antibiotic resistance gene (ARG) profiles in soil began to differ from each other and soil ARG totals in all manure applied soil increased compared to the background. Runoff from injection plots contained more soil ARGs and runoff from surface applied plots containing more manure associated ARGs. The subsurface injection method also caused highest antibiotic concentrations in the injection slit soil of those plots. High antibiotic concentrations in samples generally meant high concentrations of resistant FCB and ARGs, and resistant FCB were also found with their associated ARGs as well. A CRISPR-Cas12a assay for quantification of ARGs in environmental samples was just as precise as conventional methods. There is also potential for onsite detection. These combined results can hopefully help farmers improve manure management practices that mitigate spread of AREs to surrounding water, crops, and soil.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Ludek Zurek / Transfer of bacteria, including antibiotic resistant strains between companion animals and people is likely due to close physical contacts. However, surveillance programs on prevalence of antibiotic resistance are focused mainly on food animals and very little is known about the role of companion animals in the development and spread of antibiotic resistant bacteria. For this study, enterococci were chosen as model organism due to intrinsic and acquired antibiotic resistance and several virulence traits that make them the 3rd most important nosocomial pathogens. In addition, increased fecal shedding of antibiotic resistant bacteria from stressed animals has been reported from studies on food animals. To determine whether the gut microbiota of pet animals serves as a reservoir of clinically important enterococci, 360 enterococcal isolates from two groups: healthy group and pyoderma (stressed) group with 9 dogs in each were identified and screened for resistance to 10 antibiotics and 4 virulence traits. The transferability of resistance determinants and clonality of selected isolates were assessed by horizontal gene transfer assays and pulsed-field gel electrophoresis, respectively. In addition, overall diversity of bacteria as well as antibiotic and metal resistance genes in feces of healthy dogs was assessed by tag-encoded parallel pyrosequencing and microarray analysis, respectively. The most prevalent enterococcal species identified was E. faecalis: healthy group (70.5%); pyoderma group (44.0%). In the pyoderma group, antibiotic resistance and virulence traits (esp, gelE) were more frequent than in the healthy group; however, the overall prevalence of antibiotic resistant strains was low (< 37%) in both groups. The most prevalent resistance genes were tet(M)and tet(S). The antibiotic resistance traits were transferable in-vitro in E. faecalis (tetracycline, erythromycin, doxycycline) and E. faecium (tetracycline). Genotyping revealed less diverse E. faecalis community in pyoderma infected dogs. Pyrosequencing (~7,500 sequences per dog) revealed Firmicutes as the dominant phylum and most common genera included Turicibacter, Lactobacillus, Ruminococcus, Clostridium, and Fusobacterium. Two phyla Lentisphaerae (<1%) and Fibrobacteres (<1%) are reported for the first time from healthy dogs. Microarray data revealed the presence of several tetracycline, erythromycin, aminoglycoside, and copper resistance genes; however, most of these originated from one animal with history of chronic skin infection two year prior to our sampling. Higher prevalence of antimicrobial resistance in pyoderma infected dogs may be related to stress; however, this requires further investigation. In conclusion, based on our data, healthy and pyoderma infected dogs do not represent an important reservoir of clinically significant antibiotic resistant microbiota.

The concentration of triclosan in antiseptics, disinfectants and preservatives in products exceeds the minimal lethal levels. Extensive use of triclosan and antibiotics results in bacterial resistance to their active ingredients. The precise relationship between use and resistance, however, has been challenging to define. The aim of the study was to identify and determine antibiotic resistance profiles of triclosan tolerant heterotrophic plate count bacteria isolates from sewage influent and effluent. R2 agar supplemented with triclosan was utilised to isolate the triclosan resistant bacteria. To determine the minimum inhibitory concentration (MIC), organisms were incubated for 24 hours at selected concentrations of triclosan. Polymerase chain reaction (PCR) amplification of the 16S rRNA region was done to identify isolates. An assay for cross resistance to various antibiotics was performed. Determination of enhanced resistance to antibiotics by adding antimicrobials to the medium will be performed by using three antibiotics. High performance liquid chromatography was conducted to quantified levels of triclosan persistent in sewage water. Forty-four isolates were resistant to levels of triclosan ranging from 0.25 mg/l to 0.5 mg/l. Minimum inhibitory concentration values of these isolates ranged from 0.125 mg/l to >1 mg/l of triclosan. 16S rDNA methods were used and five main genera namely, Bacillus, Pseudomonas, Enterococcus, Brevibacillus and Paenibacillus were identified. Cell wall targeting antibiotics showed more pronounced relation with the triclosan concentration. Relation to triclosan concentration is not as apparent with the antibiotic targeting protein synthesis. Combination of antimicrobials indicated that at certain triclosan concentrations synergism or antagonism is observed. The importance of applying the correct concentration and combination of antimicrobials is observed. Levels of triclosan were found throughout the sewage water. HPLC values indicated the presence of triclosan at post-grid removal and effluent of the WWTP. The triclosan concentrations decrease through the WWTP but small concentrations enter our water bodies. The presence of bacterial species that are resistant to high concentrations of triclosan and multiple antibiotics enter our natural water bodies and is cause for concern. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

The concentration of triclosan in antiseptics, disinfectants and preservatives in products exceeds the minimal lethal levels. Extensive use of triclosan and antibiotics results in bacterial resistance to their active ingredients. The precise relationship between use and resistance, however, has been challenging to define. The aim of the study was to identify and determine antibiotic resistance profiles of triclosan tolerant heterotrophic plate count bacteria isolates from sewage influent and effluent. R2 agar supplemented with triclosan was utilised to isolate the triclosan resistant bacteria. To determine the minimum inhibitory concentration (MIC), organisms were incubated for 24 hours at selected concentrations of triclosan. Polymerase chain reaction (PCR) amplification of the 16S rRNA region was done to identify isolates. An assay for cross resistance to various antibiotics was performed. Determination of enhanced resistance to antibiotics by adding antimicrobials to the medium will be performed by using three antibiotics. High performance liquid chromatography was conducted to quantified levels of triclosan persistent in sewage water. Forty-four isolates were resistant to levels of triclosan ranging from 0.25 mg/l to 0.5 mg/l. Minimum inhibitory concentration values of these isolates ranged from 0.125 mg/l to >1 mg/l of triclosan. 16S rDNA methods were used and five main genera namely, Bacillus, Pseudomonas, Enterococcus, Brevibacillus and Paenibacillus were identified. Cell wall targeting antibiotics showed more pronounced relation with the triclosan concentration. Relation to triclosan concentration is not as apparent with the antibiotic targeting protein synthesis. Combination of antimicrobials indicated that at certain triclosan concentrations synergism or antagonism is observed. The importance of applying the correct concentration and combination of antimicrobials is observed. Levels of triclosan were found throughout the sewage water. HPLC values indicated the presence of triclosan at post-grid removal and effluent of the WWTP. The triclosan concentrations decrease through the WWTP but small concentrations enter our water bodies. The presence of bacterial species that are resistant to high concentrations of triclosan and multiple antibiotics enter our natural water bodies and is cause for concern. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Background: Antibiotic treatment of humans was introduced in 1930. The drug improved the living conditions globally due to the fact that bacterial diseases now could be treated. The development of antibiotic resistant bacteria is undeniable and globalization increases the spread of the resistant bacteria. The main reason for the emergence of resistant bacteria are incorrect and excessive use of antibiotics. Aim: The aim of the study is to investigate registered nurses’ experiences when caring for patients that have been subscribed antibiotic treatment. Method: A qualitative study with a semi-structured interview design based on interviews with eight nurses from one private hospital in The Philippines. The interviews were transcribed and analyzed using a qualitative content analysis. Result: Three themes were identified in the study, “To increase compliance”, “Nurses’ knowledge of antibiotic treatment” and “The nurses’ reflections on antibiotic treatment”. The first theme describes how the nurses provide a safe and open-minded environment for the patients, how to support and encourage the patient during treatment and how to give comprehensible information to the patient. The second theme describes the nurses’ knowledge of the emergence of antibiotic resistance, reasons for antibiotic treatment, the manifestation of antibiotic resistance and also the effects of antibiotic resistance. The third theme describes the nurses’ reflections and thoughts concerning antibiotics as well as how they perceive the population’s knowledge of antibiotics. Discussion: All of the nurses highlighted the poverty in The Philippines as the main reason for poor compliance. A large part of the population cannot afford to consult a doctor which results in people treating themselves without the proper knowledge. A majority of the nurses therefore request health education provided from the government.  A private hospital also strives to please the patient which can result in doctors prescribing a lot of antibiotics to please their patients.

The hypotheses of this study are that reduction and rational usage of antibiotics reduces development of antibiotic resistance. In Sweden, the trends do not follow this pattern. Despite a decrease in prescriptions of antibiotics, there is an increase in the number of patients infected with Methicillin-resistant Staphylococcus Aureus (MRSA), Extended Spectrum Beta-Lactamases (ESBL) and ESBL selecting for carbapenem-resistance (ESBLCARBA). This study aims to study factors affecting antibiotic resistance management. An additional aim is to use a multidisciplinary approach for a subject that has mostly been studied with quantitative methods. First, linear regressions investigated any possible significant changes of prescription rates in outpatient care, hospital usage of antibiotic groups and antibiotic resistance. After this, nine interviews were conducted with physicians in outpatient care, hospital care and with representatives from the Swedish Strategic Programme for the Rational Use of Antimicrobial Agents and Surveillance of Resistance (Strama), a network working for Swedish prevention against antibiotics resistance. There was a significant decrease in the number of prescriptions of antibiotics in outpatient care among all Swedish counties and a small, but significant increase of antibiotics used in hospitals. The number of patients infected with multidrug resistant bacteria also show a significant increase. The interviews revealed that health care workers in all counties follow the same guidelines and try to be as specific as possible in choosing antibiotics to hit specific bacteria. The respondents suggested migration and extended travelling as explanations to the growing number of cases of multidrug resistant bacteria. Further, two major factors emerged as important for an efficient antibiotic resistance management; Education/knowledge and Discussion. The results indicate a need for further research on rational usage of antibiotics and the use of broad-spectrum antibiotics in hospital care, rather than the reduction through prescriptions. The results indicate that rational usage has a bigger impact than reduction. Using a multidisciplinary approach gave a broader perspective on the issue and future studies should see the possibilities of mixing quantitative and qualitative studies.