The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform

Sebastian Guenther - One of the best experts on this subject based on the ideXlab platform.

  • low dose colonization of broiler chickens with esbl AmpC producing escherichia coli in a seeder bird model independent of antimicrobial selection pressure
    Frontiers in Microbiology, 2019
    Co-Authors: Caroline Robe, Anja Blasse, Roswitha Merle, Anika Friese, Uwe Roesler, Sebastian Guenther
    Abstract:

    Extended-spectrum Beta-Lactamase- (ESBL-) and AmpC Beta-Lactamase- (AmpC-) producing Enterobacteriaceae pose a risk for both human and animal health. For livestock, highest prevalences have been reported in broiler chickens, which are therefore considered as a reservoir of multidrug-resistant bacteria. The possibility of transfer to humans either by a close contact to colonized broiler flocks or through contaminated retail meat results in the necessity to develop intervention measures for the entire broiler production chain. In this regard, a basic understanding of the colonization process is mandatory including the determination of the minimal bacterial load leading to a persistent colonization of broiler chickens. Therefore, we conducted a bivalent broiler colonization study close to real farming conditions without applying any antimicrobial selection pressure. ESBL- and AmpC- negative broiler chickens (Ross 308) were co- colonized on their third day of life with two strains: one CTX-M-15-producing Escherichia coli-ST410 and one CMY-2/mcr-1-positive E. coli-ST10. Colonization was assessed by cloacal swabs over the period of the trial, starting 24 h post inoculation. During the final necropsy, the contents of crop, jejunum, cecum and colon were quantified for the occurrence of both bacterial strains. To define the minimal oral colonization dosage 104 to 101 colony forming units (cfu) were orally inoculated to four separately housed broiler groups (each n=19, all animals inoculated) and a dosage of already 101 cfu E. coli led to a persistent colonization of all animals of the group after three days. To assure stable colonization, however, a dosage of 102 cfu E. coli was chosen for the subsequent seeder- bird trial. In the seeder- bird trial one fifth of the animals (seeder, n=4) were orally inoculated and kept together with the non- inoculated animals (sentinel, n=16) to mimic the route of natural infection. After 35 days of trial, all animals were colonized with both E. coli strains. Given the low colonization dosage and the low seeder/sentinel ratio, the rapid spread of ESBL- and AmpC- producing Enterobacteriaceae in conventional broiler farms currently seems inevitably resulting in an urgent need for the development of intervention strategies to reduce colonization of broilers during production.

Uwe Roesler - One of the best experts on this subject based on the ideXlab platform.

  • low dose colonization of broiler chickens with esbl AmpC producing escherichia coli in a seeder bird model independent of antimicrobial selection pressure
    Frontiers in Microbiology, 2019
    Co-Authors: Caroline Robe, Anja Blasse, Roswitha Merle, Anika Friese, Uwe Roesler, Sebastian Guenther
    Abstract:

    Extended-spectrum Beta-Lactamase- (ESBL-) and AmpC Beta-Lactamase- (AmpC-) producing Enterobacteriaceae pose a risk for both human and animal health. For livestock, highest prevalences have been reported in broiler chickens, which are therefore considered as a reservoir of multidrug-resistant bacteria. The possibility of transfer to humans either by a close contact to colonized broiler flocks or through contaminated retail meat results in the necessity to develop intervention measures for the entire broiler production chain. In this regard, a basic understanding of the colonization process is mandatory including the determination of the minimal bacterial load leading to a persistent colonization of broiler chickens. Therefore, we conducted a bivalent broiler colonization study close to real farming conditions without applying any antimicrobial selection pressure. ESBL- and AmpC- negative broiler chickens (Ross 308) were co- colonized on their third day of life with two strains: one CTX-M-15-producing Escherichia coli-ST410 and one CMY-2/mcr-1-positive E. coli-ST10. Colonization was assessed by cloacal swabs over the period of the trial, starting 24 h post inoculation. During the final necropsy, the contents of crop, jejunum, cecum and colon were quantified for the occurrence of both bacterial strains. To define the minimal oral colonization dosage 104 to 101 colony forming units (cfu) were orally inoculated to four separately housed broiler groups (each n=19, all animals inoculated) and a dosage of already 101 cfu E. coli led to a persistent colonization of all animals of the group after three days. To assure stable colonization, however, a dosage of 102 cfu E. coli was chosen for the subsequent seeder- bird trial. In the seeder- bird trial one fifth of the animals (seeder, n=4) were orally inoculated and kept together with the non- inoculated animals (sentinel, n=16) to mimic the route of natural infection. After 35 days of trial, all animals were colonized with both E. coli strains. Given the low colonization dosage and the low seeder/sentinel ratio, the rapid spread of ESBL- and AmpC- producing Enterobacteriaceae in conventional broiler farms currently seems inevitably resulting in an urgent need for the development of intervention strategies to reduce colonization of broilers during production.

  • prevalence and quantitative analysis of esbl and AmpC Beta Lactamase producing enterobacteriaceae in broiler chicken during slaughter in germany
    International Journal of Food Microbiology, 2018
    Co-Authors: Philine Von Tippelskirch, Anika Friese, Uwe Roesler, Katrin Daehre, Michaela Projahn, Greta Golz, Thomas Alter, Stefanie Orquera
    Abstract:

    Abstract Food producing animals are considered a reservoir for Extended-spectrum Beta-Lactamase (ESBL) and AmpC Beta-Lactamase (AmpC) producing Enterobacteriaceae. Therefore, meat is discussed to be a potential source for the transmission of these resistant bacteria to humans. There is only limited information about the quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in different sample matrices during slaughter and their distribution in the slaughterhouse environment. Therefore, the aim of this study was to determine the prevalence as well as quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in caecum, skin and filet samples of different broiler chicken flocks during slaughter in Germany. In addition, environmental samples were taken during slaughter of the respective flocks. To gain insights into possible transmission routes of ESBL-/AmpC-producing Enterobacteriaceae, the corresponding phylogroup and Beta-Lactamase genes were determined for selected isolates. ESBL-/AmpC-producing Enterobacteriaceae were detected during slaughter of all seven investigated flocks. On average, 47% (83/175) of caecum, 55% (96/175) of skin, 28% (49/175) of filet and 28% (25/89) of environmental samples harboured ESBL-/AmpC-producing Enterobacteriaceae. Prevalence varied widely between the flocks as well as between the different sample matrices. In about half of the caecum (23/40) and skin (19/40) samples as well as 85% (17/20) of the filet samples, the number of putative ESBL-/AmpC-producing Enterobacteriaceae (cefotaxime resistant Enterobacteriaceae) was below quantification limit. The median of cefotaxime resistant Enterobacteriaceae was 2.5 × 103 cfu/g in caecum, 1.5 × 103 cfu/g in skin and 1.5 × 102 cfu/g in filet samples. The median of cefotaxime resistant Enterobacteriaceae was, depending on the sample matrix, 1–4 log units below the median of total Enterobacteriaceae. Using real-time PCR, in 82% (629/767) of the cefotaxime resistant Enterobacteriaceae at least one of the investigated Beta-Lactamase genes blaCTX-M, blaSHV, blaTEM, blaAmpC-CIT was detected. The respective resistance genes of 322 isolates were further sequenced. The predominant bla-gene was blaCMY-2 (48%), followed by blaSHV-12 (23%). A contamination from the broiler chicken to the slaughterhouse environment and vice versa seems probable as isolates of the same species and phylogroup, encoding the same resistance genes were detected in all matrices during slaughter of the respective flock as well as in the slaughterhouse environment.

  • extended spectrum Beta Lactamase AmpC Beta Lactamase producing enterobacteriaceae in broiler farms transmission dynamics at farm level
    Microbial Drug Resistance, 2017
    Co-Authors: Katrin Daehre, Uwe Roesler, Michaela Projahn, Torsten Semmler, Anika Friese
    Abstract:

    The occurrence of extended-spectrum Beta-Lactamase- (ESBL) and/or AmpC Beta-Lactamase- (AmpC) producing Enterobacteriaceae in livestock, especially in broiler fattening flocks, has been demonstrated in previous studies. Nevertheless, data on transmission routes of these resistant bacteria into the fattening farms are rare. Therefore, seven broiler fattening flocks were investigated for the occurrence of ESBL-/AmpC-producing Enterobacteriaceae during the course of the fattening period with the special focus on horizontal transmission routes. ESBL-/AmpC-producing Enterobacteriaceae from both individual animals and their housing environment were isolated at different time points and the housing environment was even sampled before the arrival of the chickens. All obtained ESBL-/AmpC-producing Enterobacteriaceae were examined for their bacterial species, Escherichia coli phylogroup, and occurrence of resistance genes. Selected isolates were further analyzed via whole-genome sequencing. All seven investigated f...

  • longitudinal monitoring of extended spectrum Beta Lactamase AmpC producing escherichia coli at german broiler chicken fattening farms
    Applied and Environmental Microbiology, 2013
    Co-Authors: H Laube, Anika Friese, C Von Salviati, Beatriz Guerra, A Kasbohrer, Lothar Kreienbrock, Uwe Roesler
    Abstract:

    Antimicrobial resistance of Escherichia coli to modern Beta-lactam antibiotics due to the production of extended-spectrum Beta-Lactamases (ESBL) and/or plasmid-mediated AmpC Beta-Lactamases (AmpC) represents an emerging and increasing resistance problem that dramatically limits therapeutic options in both human and veterinary medicine. The presence of ESBL/AmpC genes in commensal E. coli from food-producing animals like broilers may pose a human health hazard. However, there are no data available concerning the prevalence of ESBL/AmpC-producing E. coli in German broiler flocks using selective methods. In this longitudinal study, samples were taken from seven conventional broiler fattening farms at three different times within one fattening period. Various samples originating from the animals as well as from their direct environment in the barn were investigated for the occurrence of ESBL/AmpC-producing E. coli. Average detection levels of 51, 75, and 76% in animal samples collected during the three samplings in the course of the fattening period demonstrate a colonization of even 1-day-old chicks, as well as a continuous significant (P < 0.001) increase in prevalence thereafter. The detection frequencies in housing environmental samples were relatively high, with an increase over time, and ranged between 54.2 and 100%. A total of 359 E. coli isolates were characterized by PCR and partly via the disc diffusion method. This study shows that prevalence of ESBL/AmpC-producing E. coli increases during the fattening period of the broiler flocks examined. Both colonized day-old chicks and contaminated farm environments could represent significant sources of ESBL/AmpC-producing E. coli in German broiler fattening farms.

Anika Friese - One of the best experts on this subject based on the ideXlab platform.

  • low dose colonization of broiler chickens with esbl AmpC producing escherichia coli in a seeder bird model independent of antimicrobial selection pressure
    Frontiers in Microbiology, 2019
    Co-Authors: Caroline Robe, Anja Blasse, Roswitha Merle, Anika Friese, Uwe Roesler, Sebastian Guenther
    Abstract:

    Extended-spectrum Beta-Lactamase- (ESBL-) and AmpC Beta-Lactamase- (AmpC-) producing Enterobacteriaceae pose a risk for both human and animal health. For livestock, highest prevalences have been reported in broiler chickens, which are therefore considered as a reservoir of multidrug-resistant bacteria. The possibility of transfer to humans either by a close contact to colonized broiler flocks or through contaminated retail meat results in the necessity to develop intervention measures for the entire broiler production chain. In this regard, a basic understanding of the colonization process is mandatory including the determination of the minimal bacterial load leading to a persistent colonization of broiler chickens. Therefore, we conducted a bivalent broiler colonization study close to real farming conditions without applying any antimicrobial selection pressure. ESBL- and AmpC- negative broiler chickens (Ross 308) were co- colonized on their third day of life with two strains: one CTX-M-15-producing Escherichia coli-ST410 and one CMY-2/mcr-1-positive E. coli-ST10. Colonization was assessed by cloacal swabs over the period of the trial, starting 24 h post inoculation. During the final necropsy, the contents of crop, jejunum, cecum and colon were quantified for the occurrence of both bacterial strains. To define the minimal oral colonization dosage 104 to 101 colony forming units (cfu) were orally inoculated to four separately housed broiler groups (each n=19, all animals inoculated) and a dosage of already 101 cfu E. coli led to a persistent colonization of all animals of the group after three days. To assure stable colonization, however, a dosage of 102 cfu E. coli was chosen for the subsequent seeder- bird trial. In the seeder- bird trial one fifth of the animals (seeder, n=4) were orally inoculated and kept together with the non- inoculated animals (sentinel, n=16) to mimic the route of natural infection. After 35 days of trial, all animals were colonized with both E. coli strains. Given the low colonization dosage and the low seeder/sentinel ratio, the rapid spread of ESBL- and AmpC- producing Enterobacteriaceae in conventional broiler farms currently seems inevitably resulting in an urgent need for the development of intervention strategies to reduce colonization of broilers during production.

  • prevalence and quantitative analysis of esbl and AmpC Beta Lactamase producing enterobacteriaceae in broiler chicken during slaughter in germany
    International Journal of Food Microbiology, 2018
    Co-Authors: Philine Von Tippelskirch, Anika Friese, Uwe Roesler, Katrin Daehre, Michaela Projahn, Greta Golz, Thomas Alter, Stefanie Orquera
    Abstract:

    Abstract Food producing animals are considered a reservoir for Extended-spectrum Beta-Lactamase (ESBL) and AmpC Beta-Lactamase (AmpC) producing Enterobacteriaceae. Therefore, meat is discussed to be a potential source for the transmission of these resistant bacteria to humans. There is only limited information about the quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in different sample matrices during slaughter and their distribution in the slaughterhouse environment. Therefore, the aim of this study was to determine the prevalence as well as quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in caecum, skin and filet samples of different broiler chicken flocks during slaughter in Germany. In addition, environmental samples were taken during slaughter of the respective flocks. To gain insights into possible transmission routes of ESBL-/AmpC-producing Enterobacteriaceae, the corresponding phylogroup and Beta-Lactamase genes were determined for selected isolates. ESBL-/AmpC-producing Enterobacteriaceae were detected during slaughter of all seven investigated flocks. On average, 47% (83/175) of caecum, 55% (96/175) of skin, 28% (49/175) of filet and 28% (25/89) of environmental samples harboured ESBL-/AmpC-producing Enterobacteriaceae. Prevalence varied widely between the flocks as well as between the different sample matrices. In about half of the caecum (23/40) and skin (19/40) samples as well as 85% (17/20) of the filet samples, the number of putative ESBL-/AmpC-producing Enterobacteriaceae (cefotaxime resistant Enterobacteriaceae) was below quantification limit. The median of cefotaxime resistant Enterobacteriaceae was 2.5 × 103 cfu/g in caecum, 1.5 × 103 cfu/g in skin and 1.5 × 102 cfu/g in filet samples. The median of cefotaxime resistant Enterobacteriaceae was, depending on the sample matrix, 1–4 log units below the median of total Enterobacteriaceae. Using real-time PCR, in 82% (629/767) of the cefotaxime resistant Enterobacteriaceae at least one of the investigated Beta-Lactamase genes blaCTX-M, blaSHV, blaTEM, blaAmpC-CIT was detected. The respective resistance genes of 322 isolates were further sequenced. The predominant bla-gene was blaCMY-2 (48%), followed by blaSHV-12 (23%). A contamination from the broiler chicken to the slaughterhouse environment and vice versa seems probable as isolates of the same species and phylogroup, encoding the same resistance genes were detected in all matrices during slaughter of the respective flock as well as in the slaughterhouse environment.

  • extended spectrum Beta Lactamase AmpC Beta Lactamase producing enterobacteriaceae in broiler farms transmission dynamics at farm level
    Microbial Drug Resistance, 2017
    Co-Authors: Katrin Daehre, Uwe Roesler, Michaela Projahn, Torsten Semmler, Anika Friese
    Abstract:

    The occurrence of extended-spectrum Beta-Lactamase- (ESBL) and/or AmpC Beta-Lactamase- (AmpC) producing Enterobacteriaceae in livestock, especially in broiler fattening flocks, has been demonstrated in previous studies. Nevertheless, data on transmission routes of these resistant bacteria into the fattening farms are rare. Therefore, seven broiler fattening flocks were investigated for the occurrence of ESBL-/AmpC-producing Enterobacteriaceae during the course of the fattening period with the special focus on horizontal transmission routes. ESBL-/AmpC-producing Enterobacteriaceae from both individual animals and their housing environment were isolated at different time points and the housing environment was even sampled before the arrival of the chickens. All obtained ESBL-/AmpC-producing Enterobacteriaceae were examined for their bacterial species, Escherichia coli phylogroup, and occurrence of resistance genes. Selected isolates were further analyzed via whole-genome sequencing. All seven investigated f...

  • longitudinal monitoring of extended spectrum Beta Lactamase AmpC producing escherichia coli at german broiler chicken fattening farms
    Applied and Environmental Microbiology, 2013
    Co-Authors: H Laube, Anika Friese, C Von Salviati, Beatriz Guerra, A Kasbohrer, Lothar Kreienbrock, Uwe Roesler
    Abstract:

    Antimicrobial resistance of Escherichia coli to modern Beta-lactam antibiotics due to the production of extended-spectrum Beta-Lactamases (ESBL) and/or plasmid-mediated AmpC Beta-Lactamases (AmpC) represents an emerging and increasing resistance problem that dramatically limits therapeutic options in both human and veterinary medicine. The presence of ESBL/AmpC genes in commensal E. coli from food-producing animals like broilers may pose a human health hazard. However, there are no data available concerning the prevalence of ESBL/AmpC-producing E. coli in German broiler flocks using selective methods. In this longitudinal study, samples were taken from seven conventional broiler fattening farms at three different times within one fattening period. Various samples originating from the animals as well as from their direct environment in the barn were investigated for the occurrence of ESBL/AmpC-producing E. coli. Average detection levels of 51, 75, and 76% in animal samples collected during the three samplings in the course of the fattening period demonstrate a colonization of even 1-day-old chicks, as well as a continuous significant (P < 0.001) increase in prevalence thereafter. The detection frequencies in housing environmental samples were relatively high, with an increase over time, and ranged between 54.2 and 100%. A total of 359 E. coli isolates were characterized by PCR and partly via the disc diffusion method. This study shows that prevalence of ESBL/AmpC-producing E. coli increases during the fattening period of the broiler flocks examined. Both colonized day-old chicks and contaminated farm environments could represent significant sources of ESBL/AmpC-producing E. coli in German broiler fattening farms.

Caroline Robe - One of the best experts on this subject based on the ideXlab platform.

  • low dose colonization of broiler chickens with esbl AmpC producing escherichia coli in a seeder bird model independent of antimicrobial selection pressure
    Frontiers in Microbiology, 2019
    Co-Authors: Caroline Robe, Anja Blasse, Roswitha Merle, Anika Friese, Uwe Roesler, Sebastian Guenther
    Abstract:

    Extended-spectrum Beta-Lactamase- (ESBL-) and AmpC Beta-Lactamase- (AmpC-) producing Enterobacteriaceae pose a risk for both human and animal health. For livestock, highest prevalences have been reported in broiler chickens, which are therefore considered as a reservoir of multidrug-resistant bacteria. The possibility of transfer to humans either by a close contact to colonized broiler flocks or through contaminated retail meat results in the necessity to develop intervention measures for the entire broiler production chain. In this regard, a basic understanding of the colonization process is mandatory including the determination of the minimal bacterial load leading to a persistent colonization of broiler chickens. Therefore, we conducted a bivalent broiler colonization study close to real farming conditions without applying any antimicrobial selection pressure. ESBL- and AmpC- negative broiler chickens (Ross 308) were co- colonized on their third day of life with two strains: one CTX-M-15-producing Escherichia coli-ST410 and one CMY-2/mcr-1-positive E. coli-ST10. Colonization was assessed by cloacal swabs over the period of the trial, starting 24 h post inoculation. During the final necropsy, the contents of crop, jejunum, cecum and colon were quantified for the occurrence of both bacterial strains. To define the minimal oral colonization dosage 104 to 101 colony forming units (cfu) were orally inoculated to four separately housed broiler groups (each n=19, all animals inoculated) and a dosage of already 101 cfu E. coli led to a persistent colonization of all animals of the group after three days. To assure stable colonization, however, a dosage of 102 cfu E. coli was chosen for the subsequent seeder- bird trial. In the seeder- bird trial one fifth of the animals (seeder, n=4) were orally inoculated and kept together with the non- inoculated animals (sentinel, n=16) to mimic the route of natural infection. After 35 days of trial, all animals were colonized with both E. coli strains. Given the low colonization dosage and the low seeder/sentinel ratio, the rapid spread of ESBL- and AmpC- producing Enterobacteriaceae in conventional broiler farms currently seems inevitably resulting in an urgent need for the development of intervention strategies to reduce colonization of broilers during production.

James A Karlowsky - One of the best experts on this subject based on the ideXlab platform.

  • ceftazidime avibactam an evidence based review of its pharmacology and potential use in the treatment of gram negative bacterial infections
    Core Evidence, 2014
    Co-Authors: Philippe Lagacewiens, Andrew Walkty, James A Karlowsky
    Abstract:

    Avibactam (NXL104, AVE1330A) is a semi-synthetic, non-β-lactam, β-Lactamase inhibitor that is active against Ambler class A, class C, and some class D serine β-Lactamases. In this review, we summarize the in vitro data, pharmacology, mechanisms of action and resistance, and clinical trial data relating to the use of this agent combined with ceftazidime for the treat- ment of Gram-negative bacterial infections. The addition of avibactam to ceftazidime improves its in vitro activity against Enterobacteriaceae and Pseudomonas aeruginosa. Avibactam does not improve the activity of ceftazidime against Acinetobacter spp., Burkholderia spp., or most anaerobic Gram-negative rods. Pharmacodynamic data indicate that ceftazidime-avibactam is bactericidal at concentrations achievable in human serum. Animal studies demonstrate that ceftazidime-avibactam is effective in ceftazidime-resistant Gram-negative septicemia, meningitis, pyelonephritis, and pneumonia. Limited clinical trials published to date have reported that ceftazidime-avibactam is as effective as therapy with a carbapenem in complicated urinary tract infection and complicated intra-abdominal infection (combined with metronidazole) includ- ing infection caused by cephalosporin-resistant Gram-negative isolates. Safety and tolerability of ceftazidime-avibactam in clinical trials has been excellent, with few serious drug-related adverse events reported. Given the abundant clinical experience with ceftazidime and the sig- nificant improvement that avibactam provides in its activity against contemporary β-Lactamase- producing Gram-negative pathogens, it is likely this new combination agent will play a role in the empiric treatment of complicated urinary tract infections (monotherapy) and complicated intra-abdominal infections (in combination with metronidazole) caused or suspected to be caused by antimicrobial-resistant pathogens (eg, extended spectrum Beta-Lactamase-, AmpC-, or Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae and multidrug-resistant P. aeruginosa). Potential future uses also include hospital-acquired pneumonia (in combination with antistaphylococcal and antipneumococcal agents) or treatment of skin and soft tissue infec- tions caused by antimicrobial-resistant Gram-negative pathogens (eg, diabetic foot infections), but further clinical trials are required.