Bacteriological and epidemiological studies of campylobacter spp. in Swedish broilers

Campylobacter jejuni is the most frequently reported cause of bacterial gastrointestinal illness in humans in Sweden. Chicken products are considered an important risk factor for human infection. This thesis analyses and identifies sources and risk factors for colonisation of Campylobacter spp. in broilers at both farm level and slaughter. Slaughter groups with a low within-group prevalence were identified, split slaughter was confirmed as a risk factor and contamination of carcasses was shown to occur both during transport and during the slaughter process. Environmental campylobacter load was comparable on high and low incidence farms, indicating that hygiene regime is of greater importance than environmental load. Slaughter groups with a high within-flock prevalence had significantly higher campylobacter load in carcasses at slaughter than slaughter groups with a low degree of colonisation Campylobacter jejuni is the Campylobacter sp. predominantly found in broilers. Strain characterisation below species level, so-called subtyping, is a helpful tool in epidemiological studies, e.g. in determination of transmission routes. Certain subtypes were shown to be common in Sweden and may have a higher ability to survive in the environment around broiler houses. The results from phylogenetic analysis indicated that typing based on 16S rRNA sequencing is not always sufficient for differentiating between C. jejuni and C. coli. However, nine different 16S rRNA types were identified among 47 Swedish campylobacter isolates from broilers. About one-third of Swedish broiler producers seldom deliver any campylobacter-positive broilers to slaughter, demonstrating that it is possible to produce campylobacter-free chickens in Sweden. The factors identified as carrying the highest risk of producing campylobacter-positive broilers in Sweden were (i) insufficient general tidiness on the farm, (ii) split slaughter, (iii) an in-line position of the doors between the outside and access into broiler houses instead of an angled position. Furthermore, (iv) high risk farms often had other livestock such as cattle and pigs, and (v) high risk farms were more frequently situated in groves than in forest. Reducing the proportion of campylobacter-infected broiler flocks and the numbers of campylobacter on broiler carcasses would considerably lower the risk for consumers

Prevalence and genomic characteristics of zoonotic gastro-intestinal pathogens and ESBL/pAmpC producing Enterobacteriaceae among Swedish corvid birds

Introduction: Wild birds pose a potential threat to animal and human health by spreading infectious diseases. In the present study, we studied the occurrence of bacterial zoonotic pathogens as well as enterobacteria with transferrable antimicrobial resistance genes among Swedish corvids. Materials and methods: Intestines from 66 jackdaws, crows, rooks and magpies from the vicinity of livestock farms at 14 locations in 7 counties were analysed by direct culture or PCR screening followed by culture. Isolates were investigated by whole-genome sequencing. Results and discussion: Campylobacter jejuni were detected in 82% and Yersinia in 3% of the birds. ESBL-producing E. coli were found in one sample (2%) and carried blaCTX-M-55. No Enterobacteriaceae with transferable carbapenem resistance were identified. No Salmonella or E. coli O157:H7 were found, but PCR analysis for enterohaemorrhagic E. coli virulence genes revealed 35% positive samples for intimin, 9% for verotoxin 1 and 17% for verotoxin 2. C. jejuni isolates from corvids were compared to previously published isolates from Swedish sources by multi-locus sequence typing based on genome sequences. All corvid C. jejuni isolates formed a cluster, intermingled with human and chicken isolates. Our results indicate that C. jejuni is ubiquitous among Swedish corvid birds, with sporadic transmission to poultry and humans

Skördemetoder av industrihampa

Hemp is an old agricultural plant and has been used for hundreds of years for making textiles, ropes and other fibre products. In the middle of the last century the Swedish government prohibited all growing of hemp. Natural fibres were replaced by syntetic fibres instead. Today there is a newly awakened interest for using natural fibres from renewable materials. Growing of industrial hemp for fiber is allowed in Sweden again. I want in my Paper give Swedish growers an insight of which harvesting methods that have been tried in Sweden and how they worked. In Germany, where hemp cultivation have been allowed since the middle of the 1990´s, they have developed specialbuilt harvesting machines that been adapted to German conditions. In Sweden its mainly on Gotland new machines manufactures and experiments has been carried out. It's very interesting to compare the growers experiences. I've been talking to five Swedish growers and there are simularities but also differences how they harvest. How the individual farmer harvest from a year to another is often also different. There are many factors that affects the conditions of harvest that you can't help. For example precipitation, when the first frost is coming etc. Things that also matters is the final use of the hemp. If it's for energy production you don't have to take notice about the strength of the fibres. Growers I'd talked to prefer to harvest their hemp in late autumn, in winter or even spring, because the hemp in this season are more or less retted, and you don't have to dry it further. The hemp used for fibers or energy need a frost to stop growing and drop the foliage. It´s a benefit if the leafs stay at the field, it means that the nutrition not leaves the field and it's a great advantage for the ecological cultivators. I will not be surprised if the hemp will be a more extensive crop in Sweden in the future. Hemp is a comprehensive crop that also fit very well in the ecologic cultivation. I think that the farmers in Sweden mainly should grow hemp for extract energy or fibres when our climate is most suitable to this type of cultivation.Hampa är en gammal kulturväxt som använts i många århundraden för tillverkning av bl.a. textilier och rep. I mitten av 1900-talet förbjöds all odling av hampa och dessa naturliga fibrer ersattes med syntetiska. Idag finns det dock ett nyvaknat intresse för odling av förnybar energi och naturliga fibrer. Odling av industrihampa för fiberändamål är därför åter tillåtet i Sverige. Jag vill med mitt examensarbete framförallt ge svenska odlare en inblick i vilka skördemetoder som prövats i Sverige samt hur dessa fungerat. I Tyskland där hampodlingen varit tillåten sedan mitten på 1990-talet har man utvecklat speciella skördemaskiner som anpassats efter deras förhållanden. I Sverige är det främst på Gotland som framställning och experimenterande med olika maskintyper gjorts. Det är intressant att jämföra odlarnas erfarenheter av skörd. I mitt arbete har jag intervjuat fem svenska odlare och det finns både likheter och skillnader på hur man går till väga vid skörden. Men skillnaderna är inte bara mellan odlarna. Hur den enskilde odlaren skördar är olika också från år till år. Detta beror naturligtvis på hur de yttre opåverkbara faktorerna är, t ex nederbörd av regn och snö, när den första frosten kommer o.s.v. Det skiljer sig även åt vad den slutliga användningen av hampan ska vara till. Går all hampa åt till energiproduktion bryr man sig givetvis inte så mycket om hur fibrernas styrka är. De odlare jag pratat med föredrar att skörda sin hampa på senhösten, på vintern eller till och med senare, beroende på att hampan då är mer eller mindre rötad. I och med detta är hampan relativt torr och ingen eftertorkning behöver ske. Hampan behöver en frostknäpp för att sluta växa och tappa bladen. Det är en fördel att bladen blir kvar på fältet då det mesta av näringen sitter där. På så vis bortför man mindre näring från åkern vilket är viktigt framförallt vid ekologisk odling. Jag kommer inte att bli förvånad om hampodlingen blir mer omfattande i Sverige framöver. Det är en mycket allsidig gröda som dessutom passar väl in i den ekologiska odlingen. Jag anser att man i Sverige först och främst ska inrikta sig på att odla hampa för att utvinna energi eller framställning av fibrer, då vårt klimat passar bäst för denna typ av odling

Reducing Campylobacter jejuni, Enterobacteriaceae and total aerobic bacteria on transport crates for chickens by irradiation with 265-nm ultraviolet light (UV-C LED)

It is critical to maintain low levels of microbes in the whole food production chain. Due to high speed of slaughter, lack of time, and structural characteristics of crates, sufficient cleaning and disinfection of crates used for transporting chickens to abattoirs is a challenge. Inadequately cleaned transport crates for broiler chickens caused a major outbreak of campylobacteriosis in Sweden in 2016-2017, when the contaminated crates in-troduced Campylobacter to the chickens during thinning. This study evaluated the antibacterial efficacy of 265nm ultraviolet (UV-C) LED light on artificially contaminated chicken transport crates. In a laboratory study, a transport crate artificially contaminated with Campylobacter and cecum contents was irradiated with 265-nm UV-C light by a continuous LED array in a treatment cabinet. The transport crate was sampled 52 times by cotton swabs before and after UV-C treatment for 1 min (20.4 mJ/cm2) and 3 min (61.2 mJ/cm2). The swab samples were analysed for Campylobacter jejuni (C. jejuni), bacteria belonging to the family Enterobacteriaceae, and total aerobic bacteria. After irradiation with UV-C LED light for 1 min, a mean reduction in C. jejuni of log 2.0 +/- 0.5 CFU/mL was observed, while after irradiation for 3 min the reduction was log 3.1 +/- 1.0 CFU/mL. The mean reduction in Enterobacteriaceae was log 1.5 +/- 0.3 CFU/mL after 1 min of irradiation and log 1.8 +/- 0.8 CFU/mL after 3 min. The mean reduction in total aerobic bacteria was log 1.4 +/- 0.4 CFU/mL after 1 min of irradiation and log 1.6 +/- 0.5 CFU/mL after 3 min. Significant reductions in bacterial load were observed in all samples after UV-C treatment and extending the treatment time from 1 to 3 min significantly increased the reduction in C. jejuni. However, before implementation of UV-C LED treatment in commercial chicken abattoirs, the irradiation unit would need to be extended and/or the washing procedure before UV-C treatment, to reduce the amount of organic matter on transport crates, would need to be improved

Effect of Some Plant-Based Substances on Microbial Content and Sperm Quality Parameters of Bull Semen

The rapid emergence of antibacterial resistance requires alternatives to antibiotics to be found, including for semen preservation. One of the possible alternatives would be to use plant-based substances with known antimicrobial effects. The objective of this study was to test the antimicrobial effect of pomegranate powder, ginger, and curcumin extract in two concentrations on bull semen microbiota after exposure for <2 h and 24 h. An additional aim was to evaluate the effect of these substances on sperm quality parameters. The bacterial count in semen was low from the beginning; however, a reduction was present for all tested substances compared with control. A reduction in bacterial count in control samples was also observed with time. Curcumin at a concentration of 5%, reduced bacterial count by 32% and was the only substance that had a slight positive effect on sperm kinematics. The other substances were associated with a decline in sperm kinematics and viability. Neither concentration of curcumin had a deleterious effect on sperm viability parameters measured by flow cytometry. The results of this study indicate that curcumin extract at a concentration of 5% can reduce the bacterial count and does not have a negative influence on bull sperm quality

Presence of pathogenic bacteria in faeces from dogs fed raw meat-based diets or dry kibble

Background Feeding dogs with raw meat-based diets (RMBD) has increased in popularity in recent years. Proponents claim that RMBD is more natural for dogs, because it is what their ancestors (wolves) eat. Opponents claim that RMBD is a health hazard to both humans and animals, with a risk of spreading zoonotic bacteria and resistant bacterial strains.Methods This cross-sectional study investigated differences in bacteria shedding in faeces between dogs fed RMBD and dogs fed dry kibble. Faeces samples from 50 dogs from the same municipality were analysed for the presence of extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli, Campylobacter and Salmonella.Results For the 25 dogs fed RMBD, ESBL E coli was isolated from 13 faeces samples, Campylobacter from 12 and Salmonella from 1. For the 25 dogs fed dry kibble, ESBL-producing E coli was isolated from one faeces sample and Campylobacter from four, while Salmonella was not detected.Conclusion There was thus a significant difference in excretion of zoonotic and resistant bacteria in faeces between dogs fed RMBD and dogs fed dry kibble. These results confirm that RMBD can pose a microbiological risk not only for dogs, but also for people handling RMBD and faeces from dogs

Antimicrobial Resistance in Vaginal Bacteria in Inseminated Mares

Antimicrobials are added to semen extenders to inhibit the growth of bacteria that are transferred to the semen during collection. However, this non-therapeutic use of antimicrobials could contribute to the development of antimicrobial resistance. The objective of this study was to determine changes in the antibiotic susceptibility of vaginal microbiota after artificial insemination. Swabs were taken from the vagina of 26 mares immediately before artificial insemination and again 3 days later. Bacteria isolated from the vagina at both time points were subjected to antibiotic susceptibility testing and whole-genome sequencing. In total, 32 bacterial species were identified. There were increases in the resistance of Escherichia coli to trimethoprim (p = 0.0006), chloramphenicol and (p = 0.012) tetracycline (p = 0.03) between day 0 and day 3. However, there was no significant effect of exposure to antibiotics in semen extenders with respect to the resistance of Staphylococcus simulans and Streptococcus equisimilis (p > 0.05). Whole-genome sequencing indicated that most phenotypic resistance was associated with genes for resistance. These results indicate that the resistance patterns of vaginal bacteria may be affected by exposure to antibiotics; therefore, it would be prudent to minimize, or preferably, avoid using antibiotics in semen extenders

Antibiotic resistance patterns in cervical microbes of gilts and sows

Extenders for boar semen contain antibiotics, which may induce antimicrobial resistance (AMR) in inseminated females. The objective was to investigate AMR of bacteria isolated from the cervix of sows and gilts in standing heat, representing females previously exposed to antibiotics in the semen extender and non-exposed females, respectively. Cervical swabs were taken from 30 multiparous sows and 30 gilts prior to their first insemination. After culturing on agar plates, bacterial isolates were identified by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry and antimicrobial minimum inhibitory concentrations (MIC) were determined. Differences in antibiotic resistance between sows and gilts were analyzed by Chi-squared or Fisher’s exact test. Bacteria isolated were mostly Staphylococcus spp., Streptococcus spp. and Corynebacterium spp. Higher MICs were observed for isolates from sows than from gilts. Most (>80%) Corynebacterium spp. were resistant to clindamycin; small numbers (<20%) were resistant to gentamicin, penicillin, vancomycin, ciprofloxacin and rifampicin, with no differences between gilts and sows. Corynebacterium from gilts were more often resistant to tetracycline than those from sows (25% vs. 4.17%; p = 0.04). In conclusion, bacteria from the porcine cervix showed low resistance to most antibiotics except for clindamycin, but antibacterial resistance may increase with increasing parity

Identification of Transmission Routes of Campylobacter and On-Farm Measures to Reduce Campylobacter in Chicken

An in-depth analysis was performed on Swedish broiler producers that had delivered chickens with Campylobacter to slaughter over several years, in order to identify possible transmission routes and formulate effective measures to prevent chickens being colonized with Campylobacter. Between 2017 and 2019, 626 samples were collected at farm level and Campylobacter was isolated from 133 (21.2%). All C. jejuni and C. coli isolated from these samples were whole-genome sequenced, together with isolates from the corresponding cecum samples at slaughter (n = 256). Core genome multi-locus sequence typing (cgMLST) analysis, using schemes consisting of 1140 and 529 genes for C. jejuni and C. coli, respectively, revealed that nearby cattle, contaminated drinking water, water ponds, transport crates, and parent flocks were potential reservoirs of Campylobacter. A novel feature compared with previous studies is that measures were implemented and tested during the work. These contributed to a nationwide decrease in Campylobacter-positive flocks from 15.4% in 2016 to 4.6% in 2019, which is the lowest ever rate in Sweden. To conclude, there are different sources and routes of Campylobacter transmission to chickens from different broiler producers, and individual measures must be taken by each producer to prevent Campylobacter colonization of chickens

Environmental benefits of circular food systems: The case of upcycled protein recovered using genome edited potato

Although essential in the human diet, large quantities of available protein are currently lost or under-utilized within the food system, including protein rich side streams from conventional potato starch production. By using the genome editing technique CRISPR-Cas9, conventional starch potato cultivars can be upgraded to facilitate high-value recovery of potato protein fit for human consumption. In turn, this could support the nessecary transition towards more circular food systems. The aim of this study was to assess what environmental benefits could be gained by shifting from conventional protein recovery practice to a novel approach using genome edited potato. Our results, using consequential life cycle assessment, showed that the novel protein recovery scenario provided substantial environmental savings for every ton potato starch produced, with a reduction in global warming impact, terrestrial acidification, land use and ecosystem damage of −720 kgCO2eq, −13 kgSO2eq, −760 m2a crop eq, and −1.1 × 10−5 species.yr respectively. The potential environmental benefits of using genome edited potato were maintained even when simulating reduced tuber yield, increased production inputs, and substitution of various protein sources. Although currently limited by EU legislation and technical maturity, high-value protein recovery from food side streams holds a promising potential to support sustainable production and circularity within the food system