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

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

Effectiveness of Cleaning and Sanitation of Stable Environment and Riding Equipment Following Contamination With Streptococcus equi Subsp. equi

Streptococcus equi subsp. equi ( S. equi) is transmitted via contact with infected horses or fomites such as equipment or surfaces of the stable environment. Effective cleaning and sanitation is essential to mini-mize risk of fomite-associated infections. This study assessed the effectiveness of cleaning and sanitation of experimentally S. equi contaminated materials and equipment found in stables. Wood, concrete, plas-tic, leather halters, leather gloves and polyester webbing halters were inoculated with a 24-hour culture S. equi laboratory strain. In addition, selected materials were inoculated with a clinical strain of S. equi. Three days post inoculation all materials were sampled for retention of viable S. equi and a subset of each material was cleaned and sanitized. After an additional 2 days all treated and untreated materials were sampled for continued retention of viable S. equi. Separate subsets of contaminated polyester halter material were washed at 40 degrees C with or without drying at 70 degrees C, or washed at 60 degrees C. After cleaning and sanitation, all samples except polyester halters were culture negative. Even before cleaning and sanita-tion leather appears to poorly support survival of S. equi. After washing at 40 degrees C and tumble drying, 14 of 16 halters were culture positive, however culture negative when washed at 60 degrees C. Routine cleaning and sanitation of fomites contaminated with S. equi was generally effective to eliminate viable bacteria. How-ever, survival between materials and strains differed, with leather poorly permissive to S. equi survival even without cleaning, whereas polyester webbing halters retained viable S. equi even after washing at temperatures of 40 degrees C.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/

Escherichia coli O157:H7 reduction in hamburgers with regard to premature browning of minced beef, colour score and method for determining doneness

This study investigated the effect of premature browning (PMB) on the survival of Escherichia coli O157:H7 in beef hamburgers after cooking with respect to interior colour of the hamburger and recommendations to cook hamburgers to a core temperature of 71 degrees C. Assessment of doneness by visual inspection or measurement of internal temperature was compared in terms of survival and the increased relative risk of illness due to PMB was estimated. At the last consume-by-day, hamburgers made from minced meat packaged in 80/20 O-2/CO2 (MAP hamburger) and from meat minced at retail packaged in atmospheric condition (control hamburger) were inoculated with a gfp-tagged strain of E. coli O157:H7 (E. coli O157:H7gfp+). Hamburgers were cooked for different times during assessment of the core temperature every 30 s and cut in halves after cooking. Doneness was evaluated based on visual judgement of the internal colour using a score chart (C-score) from 'uncooked' (score 1) to 'tan with no evidence of pink' (score 5). An alternative five point score chart (TCC-score) including texture of the meat, clarity of meat juice and internal colour was also developed. Enumeration of viable E. coli O157:H7gfp+ in cooked hamburgers was based on fluorescent colonies recovered from plates. Results showed that MAP hamburgers developed PMB when compared with controls (P = 0.0003) and that the shortest cooking time for the highest C-score was 6 and 11 min for MAP and control hamburgers, respectively. The mean temperature in the MAP hamburger was then 60.3 degrees C. The TCC-score reduced the difference between MAP and control hamburgers. It was also shown that the survival of E. coli O157:H7gfp+ was highest in MAP hamburgers. The predicted absolute risks for illness were highest for MAP hamburgers for all C-scores and the relative risk associated with PMB increased with doneness. For a C-score of 4 (slightly pink) the predicted relative risk for illness was 300 times higher for MAP hamburger than for controls. A variable pathogen reduction was observed when cooking hamburgers to temperatures of 70-76 degrees C (the 5th and 95th percentile range was around 33 log CFU). The lower reductions, at the 5th percentile, may, depending on initial contamination levels, not be enough to ensure sufficient and safe inactivation of E. coli O157:H7. Efforts to inform consumers about PMB in minced meat packaged in high oxygen packages (>= 60% O-2) are needed with the aim to make consumers use thermometers correctly or at least not determine doneness based only on meat colour

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

Potential for residual contamination by Streptococcus equi subspp equi of endoscopes and twitches used in diagnosis of carriers of strangles

Background Endoscopic examinations are essential for diagnosis and treatment of strangles (S equi infection) in horses. However, even after disinfection, endoscopes may retain viable bacteria or bacterial DNA. Twitches are commonly used during endoscopic examinations and can thus also potentially transmit the organism to other horses.Objectives To evaluate the efficacy of different disinfectant methods to eliminate S equi from experimentally contaminated endoscopes and twitches and the effectiveness of field disinfection of endoscopes used in sampling carriers of S equi.Study design Experimental contamination and observational field study.Methods One endoscope and 30 twitches were contaminated with standardised S equi broth solutions. The endoscope was disinfected following three protocols using various disinfectants for manual disinfection. A fourth protocol used an automated endoscope reprocessor (AER). The twitches (n = 30) were disinfected following eight different disinfecting protocols. Three endoscopes used in sampling for silent carriers were disinfected following a field-based protocol. After each protocol the endoscopes and twitches were sampled for S equi by culture and qPCR.Results Following experimental contamination all endoscope disinfection protocols, apart from 1/6 of the ethanol protocol were S equi culture negative. However, no endoscope disinfection protocol completely eliminated retention of S equi DNA. Field disinfection of endoscopes after sampling carriers yielded no culture positives and all but one (13/14) were qPCR negative. All twitches disinfected following experimental contamination were culture negative but sodium hypochlorite was the only disinfectant that completely eliminated detection of S equi DNA.Main limitations Experimental contamination may not reflect the numbers of S equi transferred to endoscopes or twitches during use on silent carriers and purulent secretions from infected horses may influence survival of S equi.Conclusions While most disinfection methods appear to ensure removal of cultivable S equi, residual DNA can remain on both endoscopes and twitches

Extended Spectrum Beta-Lactamase/AmpC-Producing E Coli in Dogs Treated with Antimicrobials in Surgical Wards

The aim of this study is to investigate the prevalence and carriage of Extended Spec - trum Beta-Lactamase (ESBL) and AmpC- producing strains of E. coli and Klebsi - ella spp in hospitalized dogs treated with antimicrobials. Tissue and fecal samples from 66 dogs were analyzed for presence of AmpC or ESBL producing bacteria. The dogs had to have been admitted to the surgical ward for at least 24 hours and have received antimicrobial treatment. Samples were plated onto bovine blood agar and after incubation for 24 + 24 h, five colonies morphologically consistent with E.coli and Klebsiella spp , were selected and recultured onto media containing antimicrobials. Dogs carrying ESBL/AmpC- producing bacteria were retested for rectal colonisation at 3-6 months intervals for up to 16 months. Five (7.6%) dogs carried bacterial strains posi - tive for ESBL/AmpC- producing- genes in feces. All tissue samples were negative. One dog, previously positive for bla CMY-2 , carried ESBL genotype bla TEM-52 , in the second sample. Four dogs remained posi - tive throughout the testing. None of the dogs had signs of infection or symptoms associ - ated with the carriage of ESBL or plasmid mediated-AmpC- producing bacteria. Seven unique MLVA-types were identified. The results from this study show fecal car - riage for as long as 16 months of ESBL/ AmpC- producing E.coli in dogs treated with antimicrobials. Although clonal spread could not be verified in this study, the risk of dissemination of multiresistant bacteria in animal hospitals and in the community must be considered

Occurrence of Campylobacter spp. in Swedish calves, common sequence types and antibiotic resistance patterns

Aims Cattle are the second most important cause of human campylobacteriosis, after poultry, but there are knowledge gaps regarding Campylobacter in cattle. This study examined the occurrence of Campylobacter, the species present, sequence types and antibiotic resistance in Swedish cattle.Methods and Results Faeces samples collected from 154 calves on seven Swedish farms, and 69 follow-up samples from a second collection occasion, were analysed. Campylobacter were isolated from 77% of calves at the first sampling, with Campylobacter jejuni as the most frequently isolated species. Animals kept on deep straw bedding were less likely to be colonized with Campylobacter. Whole-genome sequencing of 90 C. jejuni samples resulted in 11 sequence types, among which ST-19 and ST-21 were most frequent. Antimicrobial resistance analyses showed that 46% of 142 isolates analysed were resistant to quinolones, while all isolates belonging to ST-19, ST-22 and ST-441 were resistant to ciprofloxacin and nalidixic acid.Conclusions Campylobacter jejuni was the species most frequently isolated in calves and a strong association was found between sequence type and antimicrobial resistance pattern.Significance and Impact of the Study The high proportion of calves with quinolone-resistant Campylobacter jejuni should be considered in a One Health perspective

Differences in Genotype and Antimicrobial Resistance between Campylobacter spp. Isolated from Organic and Conventionally Produced Chickens in Sweden

Antibiotic resistance is a major challenge worldwide and increased resistance to quinolones in Campylobacter is being reported. Analysis of antibiotic resistance was performed on 157 Campylobacter strains (123 C. jejuni and 34 C. coli) from conventional and organic chickens produced in Sweden. Susceptibility for tetracycline, ciprofloxacin, erythromycin, nalidixic acid, streptomycin, and gentamycin was determined by microdilution. All 77 isolates from organic chickens were sensitive to all antibiotics, except two C. jejuni that were resistant to tetracycline. Of the 80 isolates from conventional chickens, 22.5% of C. jejuni and 11.1% of C. coli were resistant to quinolones and 5.6% of C. jejuni were resistant to tetracycline. Whole-genome sequencing resulted in 50 different sequence types of C. jejuni and six of C. coli. Nine sequence types were found in both organic and conventional chickens. Two of these (ST-19 and ST-257) included isolates from conventional broilers with different resistance phenotypes to the remaining isolates from conventional and organic broilers. There are management differences between the production systems, such as feed, breed, use of coccidiostats, and access to outdoor area. It is unlikely that quinolone resistance has arisen due to use of antimicrobials, since fluoroquinolones are not permitted in Swedish broiler production

Survival of Campylobacter jejuni in frozen chicken meat and risks associated with handling contaminated chicken in the kitchen

Most Campylobacter infections in humans are sporadic cases, often connected to private households. Chicken meat is believed to be the main source of human exposure to Campylobacter and there are significant risks of cross-contamination when handling Campylobacter-contaminated chicken in the kitchen. One post-harvest pre-ventive measure to reduce Campylobacter concentrations on chicken meat is freezing. This study examined survival of different sequence types of C. jejuni during freezing and risk factors during handling of C. jejuni-contaminated chicken meat in the kitchen. Chicken fillets were artificially contaminated before freezing with two different sequence types of C. jejuni (ST-257 and ST-918), at concentrations in the meat of 4.1 log10 CFU/g (low) and 5.3 log10 CFU/g (high). Risk factors in the kitchen were assessed by swabbing gloves before and after washing, to simulate hands before and after washing. Utensils such as scissors and forceps used for cutting were also sampled, while a cutting board was sampled twice to simulate before and after wiping.The greatest decrease in Campylobacter concentrations in the freezer occurred in the first four days and the decrease then flattened off. After 49 days in the freezer, concentrations on meat contaminated with high and low levels of ST-257 decreased by 2.0 log10 CFU/g and 1.5 log10 CFU/g, respectively, while concentrations on chicken meat contaminated with a high and low level of ST-918 decreased by 1.0 log10 CFU/g and 0.7 log10 CFU/ g, respectively. Campylobacter was isolated from all simulated environmental samples. The highest load in the environment of both sequence types was unwashed gloves and the first sampling of the unwiped cutting board. Transfer from gloves and the cutting board was lower after washing/wiping, but high concentrations (>= 2 log10 CFU/mL rinse fluid) of Campylobacter persisted for all samples contaminated with ST-918 and for 18 of 20 samples contaminated with ST-257.In conclusion, there are differences between Campylobacter sequence types in their ability to withstand freezing stress and Campylobacter remaining on hands after washing and on cutting boards after wiping is a likely source of cross-contamination in the kitchen