Impact of short-term storage on the quantity of extended-spectrum beta-lactamase–producing Escherichia coli in broiler litter under practical conditions

Abstract

Applying broiler litter containing extended-spectrum beta-lactamase ( ESBL )–producing Escherichia coli ( E. coli ) to arable land poses a potential risk for humans to get colonized by contact with contaminated soil or vegetables. Therefore, an inactivation of these bacteria before land application of litter is crucial. We performed 2 short-term litter storage trials (one in summer and winter, respectively), each covering a time span of 5 D to investigate the effectiveness of this method for inactivation of ESBL-producing E. coli in chicken litter. Surface and deep litter samples were taken from a stacked, ESBL-positive chicken litter heap in triplicates in close sampling intervals at the beginning and daily for the last 3 D of the experiments. Samples were analyzed quantitatively and qualitatively for ESBL-producing E. coli , total E. coli , and enterococci. Selected isolates were further characterized by whole-genome sequencing ( WGS ). In the depth of the heap ESBL-producing E. coli were detected quantitatively until 72 h and qualitatively until the end of the trial in winter. In summer detection was possible quantitatively up to 36 h and qualitatively until 72 h. For surface litter samples a qualitative detection of ESBL-producing E. coli was possible in all samples taken in both trials. In the deep samples a significant decrease in the bacterial counts of over 2 Log 10 was observed for total E. coli in the winter and for total E. coli and enterococci in the summer. Genetic differences of the isolates analyzed by WGS did not correlate with survival advantage. In conclusion, short-term storage of chicken litter stacked in heaps is a useful tool for the reduction of bacterial counts including ESBL-producing E. coli . However, incomplete inactivation was observed at the surface of the heap and at low ambient temperatures. Therefore, an extension of the storage period in winter as well as turning of the heap to provide aerobic composting conditions should be considered if working and storage capacities are available on the farms.

Low airborne tenacity and spread of ESBL‐/AmpC‐producing Escherichia coli from fertilized soil by wind erosion

“…ESBL-producing E. coli are rapidly inactivated in chicken litter. In a study recently published by Siller et al (2020), ESBL-producing E. coli concentrations decreased from an average of 3.4 × 10 5 cfu g −1 in fresh chicken litter below the detection limit after storage periods of 36 h in the summer and 72 h in the winter. To limit this inactivation in the litter used in the wind tunnel trials, the timespan between litter collection and aerosolization was minimized.…”

Detection of ESBL/AmpC-Producing and Fosfomycin-Resistant Escherichia coli From Different Sources in Poultry Production in Southern Brazil

“… Gazal et al (2015) analyzed poultry litter after the composting process, observing that few isolates (6.3%) contained virulence genes from extra-intestinal pathogenic E. coli and were susceptible to a large number of antimicrobials. Siller et al (2020) demonstrated that short-term storage reduces the amount of ESBL-producing E. coli in poultry litter. Therefore, the practice of composting or storage is a good alternative for eliminating possible pathogens and multiresistant strains.…”

Agricultural fertilization with poultry manure results in persistent environmental contamination with the pathogenClostridioides difficile

“…We previously reported that chicken manure carried additional pathogens, including Enterococcus faecium and extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (Thiel et al ., 2020). However, ESBL E. coli died off within a few days during manure storage (Siller et al ., 2020) and enterococci rapidly declined in soil within weeks after fertilization (Thiel et al ., 2020). In the present study, in contrast, we demonstrate that viable C. difficile remained detectable in fertilized soil for several years and hence represented a long-lasting pollution.…”