Antimicrobial resistance in E. coli from Swedish calves and the surrounding environment

The discovery of the first antibiotic by Alexander Fleming was a major milestone in the history of modern medicine. However, with each new antibiotic class introduced to the market, antimicrobial resistance (AMR) rapidly occurred. AMR is a zoonotic problem and even though many countries worldwide banned the use of antibiotics for animal growth promotion, the amount of antimicrobial use for livestock is still high.In this project the situation of antimicrobial resistance was evaluated at 55 Swedish dairy farms. The MICs for 14 antibiotic classes were analyzed for 481 E.coli isolates from different sample types (calves, manure drainages, manure wells, birds, rodents, flies). 40.7% of all isolates were resistant to at least one of the antibiotic drugs, among which 63.3% were multi-resistant. The antibiotic to which the highest number of strains was resistant to was Streptomycin, an antibiotic that is commonly used for infected cows. Interestingly, strains from one type of host were more resistant to certain antibiotic classes than others. Transmission between all sample types is therefore less likely. However, results from whole-genome-sequencing showed the same MLST types of strains from the same and neighboring farms, demonstrating close relatedness and a possible transmission. Furthermore, high colistin-resistance prevalence occurred (4.1-27.8%), which was not expected as no colistin-resistant strain has been isolated from animals in Sweden so far. Only one ESBL-producing E.coli was found, which goes along with previous studies. Taken together, these findings highlight the importance of understanding the situation of antimicrobial resistance at Swedish dairy farm and give an insight into transmission routes

Antimicrobial resistance in E. coli from Swedish calves and the surrounding environment

The discovery of the first antibiotic by Alexander Fleming was a major milestone in the history of modern medicine. However, with each new antibiotic class introduced to the market, antimicrobial resistance (AMR) rapidly occurred. AMR is a zoonotic problem and even though many countries worldwide banned the use of antibiotics for animal growth promotion, the amount of antimicrobial use for livestock is still high.In this project the situation of antimicrobial resistance was evaluated at 55 Swedish dairy farms. The MICs for 14 antibiotic classes were analyzed for 481 E.coli isolates from different sample types (calves, manure drainages, manure wells, birds, rodents, flies). 40.7% of all isolates were resistant to at least one of the antibiotic drugs, among which 63.3% were multi-resistant. The antibiotic to which the highest number of strains was resistant to was Streptomycin, an antibiotic that is commonly used for infected cows. Interestingly, strains from one type of host were more resistant to certain antibiotic classes than others. Transmission between all sample types is therefore less likely. However, results from whole-genome-sequencing showed the same MLST types of strains from the same and neighboring farms, demonstrating close relatedness and a possible transmission. Furthermore, high colistin-resistance prevalence occurred (4.1-27.8%), which was not expected as no colistin-resistant strain has been isolated from animals in Sweden so far. Only one ESBL-producing E.coli was found, which goes along with previous studies. Taken together, these findings highlight the importance of understanding the situation of antimicrobial resistance at Swedish dairy farm and give an insight into transmission routes

Antimicrobial Resistance Patterns in Organic and Conventional Dairy Herds in Sweden

Monitoring antimicrobial resistance (AMR) and use (AMU) is important for control. We used Escherichia coli from healthy young calves as an indicator to evaluate whether AMR patterns differ between Swedish organic and conventional dairy herds and whether the patterns could be related to AMU data. Samples were taken twice, in 30 organic and 30 conventional dairy herds. Selective culturing for Escherichia coli, without antibiotics and with nalidixic acid or tetracycline, was used to estimate the proportions of resistant isolates. Microdilution was used to determine the minimum inhibitory concentrations (MICs) for thirteen antimicrobial substances. AMU data were based on collection of empty drug packages. Less than 8% of the bacterial growth on non-selective plates was also found on selective plates with tetracycline, and 1% on plates with nalidixic acid. Despite some MIC variations, resistance patterns were largely similar in both periods, and between organic and conventional herds. For most substances, only a few isolates were classified as resistant. The most common resistances were against ampicillin, streptomycin, sulfamethoxazole, and tetracycline. No clear association with AMU could be found. The lack of difference between organic and conventional herds is likely due to a generally good animal health status and consequent low AMU in both categories

Measuring Airborne Antibiotic Resistance Genes in Swiss Cities via a DNA-Enabled Electrochemical Chip-Based Sensor

Antibiotic resistance genes (ARGs) as an emerging airborne pollutants are a significant and growing concern for public and environmental health. Accurate surveillance and quantitation of low-dose ARGs in the air have become critical in providing evidence-based public risk assessment for population health management. With this work, we introduced a portable and sensitive electrochemical (EC) bioanalytical platform for detecting airborne ARGs, which relied on the EC current response of surface-initiated ARGs hybridization. These low-cost chips for EC ARGs sensing exhibited good thermal (25∼60 °C) and long-term stability (6 days). The prototype of the biosensor system demonstrated an ultralow limit of detection (7.4 fM) and excellent anti-interference performance. For the first time, an EC sensor was applied successfully to identify and quantitate two types of ARGs (floR and bla-TEM genes) from real-world PM2.5 (particulate matter with aerodynamic diameters less than 2.5 μm) samples. Results for PM2.5 collected from Bern (urban area), Basel (suburban area), Zürich (urban area), Sion (airport highway area), and Rigi (rural and high-altitude area) in Switzerland were obtained, in favorable agreement with gel electrophoresis analysis. The results indicated that our EC biosensor offered a reliable and attractive alternative to the current methods for airborne ARG detection.ISSN:2690-064

Carriage of carbapenemase- and extended-spectrum cephalosporinase-producing Escherichia coli and Klebsiella pneumoniae in humans and livestock in rural Cambodia; gender and age differences and detection of bla(OXA-48 )in humans

Objectives This study investigates the frequency and characteristics of carbapenemase-producing Escherichia coli/Klebsiella pneumoniae (CPE/K) and extended-spectrum cephalosporinase-producing E. coli/K. pneumoniae (ESCE/K) in healthy humans and livestock in rural Cambodia. Additionally, household practices as risk factors for faecal carriage of ESCE/K are identified. Methods Faecal samples were obtained from 307 humans and 285 livestock including large ruminants, pigs and poultry living in 100 households in rural Cambodia in 2011. Each household was interviewed, and multilevel logistic model determined associations between household practices/meat consumption and faecal carriage of ESCE/K. CPE and ESCE/K were detected and further screened for colistin resistance genes. Results CPE/K isolates harbouring bla(OXA-48 )were identified in two humans. The community carriage of ESCE/K was 20% in humans and 23% in livestock. The same ESBL genes: bla(CTX-M-15), bla(CTX-M-14), bla(CTX-M-27), bla(CTX-M-55), bla(SHV-2), bla(SHV-12), bla(SHV-28); AmpC genes: bla(CMY-2), bla(CMY-42,) bla(DHA-1); and colistin resistance genes: mcr-1-like and mcr-3-like were detected in humans and livestock. ESCE/K was frequently detected in women, young children, pigs and poultry, which are groups in close contact. The practice of burning or burying meat waste and not collecting animal manure indoors and outdoors daily were identified as risk factors for faecal carriage of ESCE/K. Conclusions Faecal carriage of E. coli and K. pneumoniae harbouring extended-spectrum cephalosporinase genes are common in the Cambodian community, especially in women and young children. Exposure to animal manure and slaughter products are risk factors for intestinal colonization of ESCE/K in humans.Funding Agencies|Swedish Civil Contingencies Agency; Swedish International Development Cooperation Agency [2010-7876]; Swedish Research Council VR [2016-02606]</p