Characterization of VIM-1-Producing E. coli Isolated From a German Fattening Pig Farm by an Improved Isolation Procedure

The European Union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2021-2022

This report by the European Food Safety Authority and the European Centre for Disease prevention and Control, provides an overview of the main findings of the 2021-2022 harmonised Antimicrobial Resistance (AMR) monitoring in Salmonella spp., Campylobacter jejuni and C. coli from humans and food-producing animals (broilers, laying hens and fattening turkeys, fattening pigs and cattle under one year of age) and relevant meat thereof. For animals and meat thereof, AMR data on indicator commensal Escherichia coli, presumptive extended-spectrum beta-lactamases (ESBL)-/AmpC beta-lactamases (AmpC)-/carbapenemase (CP)-producing E. coli, and the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) are also analysed. Generally, resistance levels differed greatly between reporting countries and antimicrobials. Resistance to commonly used antimicrobials was frequently found in Salmonella and Campylobacter isolates from humans and animals. In humans, increasing trends in resistance to one of two critically antimicrobials (CIA) for treatment was observed in poultry-associated Salmonella serovars and Campylobacter, in at least half of the reporting countries. Combined resistance to CIA was however observed at low levels except in some Salmonella serovars and in C. coli from humans and animals in some countries. While CP-producing Salmonella isolates were not detected in animals in 2021-2022, nor in 2021 for human cases, in 2022 five human cases of CP-producing Salmonella were reported (four harbouring bla OXA-48 or bla OXA-48-like genes). The reporting of a number of CP-producing E. coli isolates (harbouring bla OXA-48, bla OXA-181, bla NDM-5 and bla VIM-1 genes) in fattening pigs, cattle under 1 year of age, poultry and meat thereof by a limited number of MSs (5) in 2021 and 2022, requires a thorough follow-up. The temporal trend analyses in both key outcome indicators (rate of complete susceptibility and prevalence of ESBL-/AmpC-producers in E. coli) showed an encouraging progress in reducing AMR in food-producing animals in several EU MSs over the last 7 years.

Impact and Diversity of ESBL-Producing Klebsiella pneumoniae Recovered from Raw Chicken Meat Samples in Türkiye

The interrelationship between human, animal and environmental sectors leads to the spread of antibiotic resistance due to selective pressures, evolutionary traits and genomic evolution. In particular, the frequent use of antibiotics in livestock inevitably influences the emergence of specific resistance determinants in human strains, associated with reduced treatment options in clinical therapy. In this study, ESBL-producing Klebsiella pneumoniae strains isolated from chicken meat samples were evaluated for public health implications in Türkiye. Whole-genome sequencing was used for genetic dissection and phylogenetic comparison of their genomes. The isolates were assigned to four MLST types (ST147, ST37, ST2747 and ST219); two of them were found to represent the ST147 clone associated with severe human infections worldwide. In addition to cephalosporins, high resistance levels to quinolones/fluoroquinolones were identified phenotypically, caused by acquired resistance genes and chromosomal point variations. One isolate was also found to carry the qacE∆1 efflux transporter gene, which confers tolerance to quaternary ammonium compounds. The detection of virulence genes (i.e., that coding for enterobactin) associated with the pathogenicity of K. pneumoniae suggests a public health impact. Thus, comprehensive information on the occurrence and impact of K. pneumoniae from livestock is needed to derive appropriate management strategies for consumer protection. In this study, it was shown that poultry meat serves as a reservoir of clinically emerging multidrug-resistant high-risk clones.

Evaluation and validation of laboratory procedures for the surveillance of ESBL-, AmpC-, and carbapenemase-producing Escherichia coli from fresh meat and caecal samples

Introduction

Extended-spectrum β-lactamase- (ESBL) and AmpC- β-lactamase-producing Enterobacterales are widely distributed and emerging in both human and animal reservoirs worldwide. A growing concern has emerged in Europe following the appearance of carbapenemase-producing Escherichia coli (E. coli) in the primary production of food animals. In 2013, the European Commission (EC) issued the Implementing Decision on the monitoring and reporting of antimicrobial resistance in zoonotic and commensal bacteria. The European Union Reference Laboratory for Antimicrobial Resistance (EURL-AR) was tasked with providing two laboratory protocols for samples derived from meat and caecal content, respectively, for the isolation of ESBL- and AmpC-producing E. coli (part 1) and carbapenemase-producing (CP) E. coli (part 2). In this study, we describe the current protocols, including the preparatory work for the development.

Methods

Up to nine laboratory procedures were tested using minced meat as the matrix from beef, pork, and chicken as well as six procedures for the caecal content of cattle, pigs, and chicken. Variables included sample volume, pre-enrichment volume, pre-enrichment broth with and without antimicrobial supplementation, and incubation time/temperature. The procedures were evaluated against up to nine E. coli strains harboring different AMR genes and belonging to the three β-lactamase groups.

Results and discussion

The laboratory procedures tested revealed that the most sensitive and specific methodologies were based on a Buffered Peptone Water pre-enrichment of 225 ml to 25 g or 9 ml to 1 g for minced meat and caecal content, respectively, incubated at 37°C overnight, followed by inoculation onto MacConkey agar supplemented with 1 mg/L cefotaxime for detecting ESBL- and AmpC-producing E. coli and Chrom ID SMART (Chrom ID CARBA and OXA) for CP E. coli, incubated overnight at 37 and 44°C, respectively. We provided two isolation protocols for the EU-specific monitoring of ESBL- and AmpC- producing E. coli (part 1) and CP E. coli (part 2) from fresh meat (protocol 1) and caecal (protocol 2) samples, which have been successfully implemented by all EU Member States for the monitoring period 2014-2027 (EU 2020/1729).

Epidemiology and zoonotic transmission of mcr-positive and carbapenemase-producing Enterobacterales on German turkey farms

Introduction

The emergence of carbapenem-resistant bacteria causing serious infections may lead to more frequent use of previously abandoned antibiotics like colistin. However, mobile colistin resistance genes (mcr) can jeopardise its effectiveness in both human and veterinary medicine. In Germany, turkeys have been identified as the food-producing animal most likely to harbour mcr-positive colistin-resistant Enterobacterales (mcr-Col-E). Therefore, the aim of the present study was to assess the prevalence of both mcr-Col-E and carbapenemase-producing Enterobacterales (CPE) in German turkey herds and humans in contact with these herds.

Methods

In 2018 and 2019, 175 environmental (boot swabs of turkey faeces) and 46 human stool samples were analysed using a combination of enrichment-based culture, PCR, core genome multilocus sequence typing (cgMLST) and plasmid typing.

Results

mcr-Col-E were detected in 123 of the 175 turkey farms in this study (70.3%). mcr-Col-E isolates were Escherichia coli (98.4%) and Klebsiella spp. (1.6%). Herds that had been treated with colistin were more likely to harbour mcr-Col-E, with 82.2% compared to 66.2% in untreated herds (p = 0.0298). Prevalence also depended on husbandry, with 7.1% mcr-Col-E in organic farms compared to 74.5% in conventional ones (p < 0.001). In addition, four of the 46 (8.7%) human participants were colonised with mcr-Col-E. mcr-Col-E isolates from stables had minimum inhibitory concentrations (MICs) from 4 to ≥ 32 mg/l, human isolates ranged from 4 to 8 mg/l. cgMLST showed no clonal transmission of isolates. For one farm, plasmid typing revealed great similarities between plasmids from an environmental and a human sample. No CPE were found in turkey herds or humans.

Discussion

These findings confirm that mcr-Col-E-prevalence is high in turkey farms, but no evidence of direct zoonotic transmission of clonal mcr-Col-E strains was found. However, the results indicate that plasmids may be transmitted between E. coli isolates from animals and humans.

Multidrug resistance, biofilm formation and detection of bla CTX-M and bla VIM genes in E. coli and Salmonella isolates from chutney served at the street-food stalls of Bharatpur, Nepal

Antimicrobial resistance (AMR) amid the bacteria found in ready-to-eat foods is a grave concern today warranting an immediate intervention. The current study was undertaken to explore the status of AMR in E. coli and Salmonella species in ready-to-eat Chutney samples (n = 150) served at the street food stalls in Bharatpur, Nepal, with a major focus on detecting extended-spectrum β-lactamase (ESBL) and metallo β-lactamase (MBL) genes along with biofilm formation. Average viable counts, coliform counts, and Salmonella Shigella counts were 1.33 × 10⁶±141481.4, 1.83 × 10⁵±91303.6, and 1.24 × 10⁵±63933.19 respectively. Out of 150 samples, 41 (27.33%) harbored E. coli, of which 7 were E. coli O157:H7; whereas Salmonella spp. were found in 31 (20.67%) samples. Bacterial contamination of Chutney by E. coli and Salmonella and ESBL-production were both found significantly affected by different sources of water used, personal hygiene and literacy rate of the vendors as well as by the type of cleaning materials used to wash knives and chopping boards (P < 0.05). Antibiotic susceptibility testing revealed that imipenem was the most effective drug against both types of bacterial isolates. Additionally, 14 (45.16%) Salmonella isolates and 27 (65.85%) E. coli isolates were found to be multi-drug resistant (MDR). Total ESBL (bla _CTX-M) producers reported were 4 (12.90%) Salmonella spp. and 9 (21.95%) E. coli. Only 1 (3.23%) Salmonella spp. and 2 (4.88%) E. coli isolates were bla _VIM gene carriers. Dissemination of knowledge of personal hygiene amongst the street vendors and consumer awareness regarding ready-to-eat foods are crucial factors that can be suggested to curtail the emergence and transmission of food-borne pathogens.

The European Union Summary Report on Antimicrobial Resistance in zoonotic and indicator bacteria from humans, animals and food in 2020/2021

Antimicrobial resistance (AMR) data on zoonotic and indicator bacteria from humans, animals and food are collected annually by the EU Member States (MSs) and reporting countries, jointly analysed by EFSA and ECDC and presented in a yearly EU Summary Report. This report provides an overview of the main findings of the 2020-2021 harmonised AMR monitoring in Salmonella spp., Campylobacter jejuni and C. coli in humans and food-producing animals (broilers, laying hens and turkeys, fattening pigs and bovines under 1 year of age) and relevant meat thereof. For animals and meat thereof, indicator E. coli data on the occurrence of AMR and presumptive Extended spectrum β-lactamases (ESBL)-/AmpC β-lactamases (AmpC)-/carbapenemases (CP)-producers, as well as the occurrence of methicillin-resistant Staphylococcus aureus are also analysed. In 2021, MSs submitted for the first time AMR data on E. coli isolates from meat sampled at border control posts. Where available, monitoring data from humans, food-producing animals and meat thereof were combined and compared at the EU level, with emphasis on multidrug resistance, complete susceptibility and combined resistance patterns to selected and critically important antimicrobials, as well as Salmonella and E. coli isolates exhibiting ESBL-/AmpC-/carbapenemase phenotypes. Resistance was frequently found to commonly used antimicrobials in Salmonella spp. and Campylobacter isolates from humans and animals. Combined resistance to critically important antimicrobials was mainly observed at low levels except in some Salmonella serotypes and in C. coli in some countries. The reporting of a number of CP-producing E. coli isolates (harbouring bla _OXA-48, bla _OXA-181, and bla _NDM-5 genes) in pigs, bovines and meat thereof by a limited number of MSs (4) in 2021, requests a thorough follow-up. The temporal trend analyses in both key outcome indicators (rate of complete susceptibility and prevalence of ESBL-/AmpC- producers) showed that encouraging progress have been registered in reducing AMR in food-producing animals in several EU MSs over the last years.

Bacterial genome sequencing tracks the housefly-associated dispersal of fluoroquinolone- and cephalosporin-resistant Escherichia coli from a pig farm

The regular use of antimicrobials in livestock production selects for antimicrobial resistance. The potential impact of this practice on human health needs to be studied in more detail, including the role of the environment for the persistence and transmission of antimicrobial-resistant bacteria. During an investigation of a pig farm and its surroundings in Brandenburg, Germany, we detected abundant cephalosporin- and fluoroquinolone-resistant Escherichia coli in pig faeces, sedimented dust, and house flies (Musca domestica). Genome sequencing of E. coli isolates revealed large phylogenetic diversity and plasmid-borne extended-spectrum beta lactamase (ESBL) genes CTX-M-1 in multiple strains. [Correction added on 28 February 2023, after first online publication: In the preceding sentence, 'and TEM-1' was previously included but has been deleted in this version.] Close genomic relationships indicated frequent transmission of antimicrobial-resistant E. coli between pigs from different herds and across buildings of the farm and suggested dust and flies as vectors for dissemination of faecal pathogens. Strikingly, we repeatedly recovered E. coli from flies collected up to 2 km away from the source, whose genome sequences were identical or closely related to those from pig faeces isolates, indicating the fly-associated transport of diverse ESBL-producing E. coli from the pig farm into urban habitation areas. The observed proximity of contaminated flies to human households poses a risk of transmission of antimicrobial-resistant enteric pathogens from livestock to man.

The hazard of carbapenemase (OXA-181)-producing Escherichia coli spreading in pig and veal calf holdings in Italy in the genomics era: Risk of spill over and spill back between humans and animals

Carbapenemase-producing Enterobacterales (CPE) are considered a major public health issue. In the frame of the EU Harmonized AMR Monitoring program conducted in Italy in 2021, 21 epidemiological units of fattening pigs (6.98%; 95% CI 4.37-10.47%; 21/301) and four epidemiological units of bovines <12 months (1.29%; 95% CI 0.35-3.27%, 4/310) resulted positive to OXA-48-like-producing E. coli (n = 24 OXA-181, n = 1 OXA-48). Whole Genome Sequencing (WGS) for in-depth characterization, genomics and cluster analysis of OXA-181-(and one OXA-48) producing E. coli isolated, was performed. Tracing-back activities at: (a) the fattening holding of origin of one positive slaughter batch, (b) the breeding holding, and (c) one epidemiologically related dairy cattle holding, allowed detection of OXA-48-like-producing E. coli in different units and comparison of further human isolates from fecal samples of farm workers. The OXA-181-producing isolates were multidrug resistant (MDR), belonged to different Sequence Types (STs), harbored the IncX and IncF plasmid replicons and multiple virulence genes. Bioinformatics analysis of combined Oxford Nanopore Technologies (ONT) long reads and Illumina short reads identified bla OXA-181 as part of a transposon in IncX1, IncX3, and IncFII fully resolved plasmids from 16 selected E. coli, mostly belonging to ST5229, isolated during the survey at slaughter and tracing-back activities. Although human source could be the most likely cause for the introduction of the bla OXA-181-carrying IncX1 plasmid in the breeding holding, concerns arise from carbapenemase OXA-48-like-producing E. coli spreading in 2021 in Italian fattening pigs and, to a lesser extent, in veal calf holdings.

Carbapenemase producing Enterobacteriaceae: Environmental reservoirs as primary targets for control and prevention strategies

Carbapenemase-producing Enterobacteriaceae (CPE) have become one of the greatest public health challenges globally. In the past decade, antimicrobial resistance (AMR) was viewed as a clinical problem in many parts of the world; hence, the role and magnitude of the contribution of the environment were not well appreciated. This review article was done with online published articles extracted from different databases using search terms related to the work. Evidence has shown that there exists the presence of carbapenemase genes in the environment, consequently fuelling the dissemination with alarming consequences. CPE when acquired causes life-threatening infections in humans. The health and economic impact of these infections are numerous, including treatment failure due to limited therapeutic options which hamper the containment of infectious diseases, further contaminating the environment and worsening the public health challenge. It is a well-known fact that the rate of emergence of resistant genes has outpaced the production of new antimicrobial agents, so it is pertinent to institute effective environmental measures to combat the spread of AMR organisms before it will completely gain a foothold and take us back to 'the pre-antibiotic era'. Environmental sources and reservoirs of resistant genes should therefore be amongst the primary targets for the control and prevention of the spread of resistant genes in the environment. This calls for the effective implementation of the 'one health' strategy with stakeholders committed to the design and enforcement of environmental mitigation policies and guidelines.

The European Union Summary Report on Antimicrobial Resistance in zoonotic and indicator bacteria from humans, animals and food in 2019–2020

Data on antimicrobial resistance (AMR) in zoonotic and indicator bacteria from humans, animals and food are collected annually by the EU Member States (MSs), jointly analysed by the EFSA and the ECDC and reported in a yearly EU Summary Report. The annual monitoring of AMR in animals and food within the EU is targeted at selected animal species corresponding to the reporting year. The 2020 monitoring specifically focussed on poultry and their derived carcases/meat, while the monitoring performed in 2019 specifically focused on fattening pigs and calves under 1 year of age, as well as their derived carcases/meat. Monitoring and reporting of AMR in 2019–2020 included data regarding Salmonella, Campylobacter and indicator E. coli isolates, as well as data obtained from the specific monitoring of presumptive ESBL‐/AmpC‐/carbapenemase‐producing E. coli isolates. Additionally, some MSs reported voluntary data on the occurrence of methicillin‐resistant Staphylococcus aureus in animals and food, with some countries also providing data on antimicrobial susceptibility. This report provides an overview of the main findings of the 2019–2020 harmonised AMR monitoring in the main food‐producing animal populations monitored, in carcase/meat samples and in humans. Where available, monitoring data obtained from pigs, calves, broilers, laying hens and turkeys, as well as from carcase/meat samples and humans were combined and compared at the EU level, with particular emphasis on multidrug resistance, complete susceptibility and combined resistance patterns to critically important antimicrobials, as well as Salmonella and E. coli isolates possessing ESBL‐/AmpC‐/carbapenemase phenotypes. The key outcome indicators for AMR in food‐producing animals, such as complete susceptibility to the harmonised panel of antimicrobials in E. coli and the prevalence of ESBL‐/AmpC‐producing E. coli have been specifically analysed over the period 2014–2020.

Critically important antimicrobial resistant Enterobacteriaceae in Irish farm effluent and their removal in integrated constructed wetlands

This study investigated the ability of Integrated Constructed Wetlands (ICWs) to remove critically important antimicrobial resistant organisms (AROs) from farm wastewater. Influent samples from the untreated farm waste and effluent samples taken at the end of the ICW system were collected monthly from four ICWs, serving four different farm types (suckler, dairy, dairy & poultry and pig). Using selective media to screen for the presence of carbapenemase resistant organisms, plasmid mediated and AmpC β-Lactamase producing organisms (ESBL/pAmpC) and fluoroquinolone resistant organisms, a total of 82 AROs were obtained with the majority being E. coli (n = 79). Statistically significant were the differences on the number of AROs isolated from influent (higher) compared to effluent, as well as a seasonal effect, with less AROs recovered during winter in comparison to other seasons (P < 0.05). On the other hand, there was no significant differences in the recovery of AROs on different farms. The majority of isolates from each of the farms (99%) were multi drug resistant, with 65% resistant to seven or more antimicrobials. A high incidence of tetracycline, trimethoprim/sulfamethoxazole, and ampicillin resistance was common to the isolates from all four farms but there were differences in ESBL levels with 63% of the isolates recovered from Farm 4 (piggery) being ESBLs compared to 18%, 36% and 4.5% recovered from Farms 1 (suckler), 2 (dairy) and 3 (dairy & poultry), respectively. No carbapenemase producing organisms were isolated. Our results showed that ICWs are effective in removing critically important AROs from farm wastewater on all four farm types.

Slaughterhouse wastewater as a reservoir for extended-spectrum β-lactamase (ESBL)-producing, and colistin-resistant Klebsiella spp. and their impact in a "One Health" perspective

Klebsiella spp. are ubiquitous bacteria capable of colonizing humans and animals, and sometimes leading to severe infections in both. Due to their high adaptability against environmental/synthetic conditions as well as their potential in aquiring antimicrobial/metal/biocide resistance determinants, Klebsiella spp. are recognized as an emerging threat to public health, worldwide. Currently, scarce information on the impact of livestock for the spread of pathogenic Klebsiella spp. is available. Thus, the phenotypic and genotypic properties of extended-spectrum β-lactamase-producing, and colistin-resistant Klebsiella strains (n = 185) from process- and wastewater of two poultry and pig slaughterhouses as well as their receiving municipal wastewater treatment plants (mWWTPs) were studied to determine the diversity of isolates that might be introduced into the food-production chain or that are released into the environment by surviving the wastewater treatment. Selectively-isolated Klebsiella spp. from slaughterhouses including effluents and receiving waterbodies of mWWTPs were assigned to various lineages, including high-risk clones involved in human outbreaks, and exhibited highly heterogeneous antibiotic-resistance patterns. While isolates originating from poultry slaughterhouses showed the highest rate of colistin resistance (32.4%, 23/71), carbapenem-resistant Klebsiella spp. were only detected in mWWTP samples (n = 76). The highest diversity of resistance genes (n = 77) was detected in Klebsiella spp. from mWWTPs, followed by isolates from pig (n = 56) and poultry slaughterhouses (n = 52). Interestingly, no carbapenemase-encoding genes were detected and mobile colistin resistance genes were only obeserved in isolates from poultry and pig slaughterhouses. Our study provides in-depth information into the clonality of livestock-associated Klebsiella spp. and their determinants involved in antimicrobial resistance and virulence development. On the basis of their pathogenic potential and clinical importance there is a potential risk of colonization and/or infection of wildlife, livestock and humans exposed to contaminated food and/or surface waters.

A European multicenter evaluation study to investigate the performance on commercially available selective agar plates for the detection of carbapenemase producing Enterobacteriaceae

The European Food Safety Authority (EFSA) advised to prioritize monitoring carbapenemase producing Enterobacteriaceae (CPE) in food producing animals. Therefore, this study evaluated the performance of different commercially available selective agars for the detection of CPE using spiked pig caecal and turkey meat samples and the proposed EFSA cultivation protocol. Eleven laboratories from nine countries received eight samples (four caecal and four meat samples). For each matrix, three samples contained approximately 100 CFU/g CPE, and one sample lacked CPE. After overnight enrichment in buffered peptone water, broths were spread upon Brilliance™ CRE Agar (1), CHROMID® CARBA (2), CHROMagar™ mSuperCARBA™ (3), Chromatic™ CRE (4), CHROMID® OXA-48 (5) and Chromatic™ OXA-48 (6). From plates with suspected growth, one to three colonies were selected for species identification, confirmation of carbapenem resistance and detection of carbapenemase encoding genes, by methods available at participating laboratories. Of the eleven participating laboratories, seven reported species identification, susceptibility tests and genotyping on isolates from all selective agar plates. Agars 2, 4 and 5 performed best, with 100% sensitivity. For agar 3, a sensitivity of 96% was recorded, while agar 1 and 6 performed with 75% and 43% sensitivity, respectively. More background flora was noticed for turkey meat samples than pig caecal samples. Based on this limited set of samples, most commercially available agars performed adequately. The results indicate, however, that OXA-48-like and non-OXA-48-like producers perform very differently, and one should consider which CPE strains are of interest to culture when choosing agar type.

Comparison of Consumption Data and Phenotypical Antimicrobial Resistance in E. coli Isolates of Human Urinary Samples and of Weaning and Fattening Pigs from Surveillance and Monitoring Systems in Germany

Antimicrobial resistance (AMR) data from humans are mostly collected from clinical isolates, whereas from livestock data also exist from colonizing pathogens. In Germany, livestock data are collected from clinical and nonclinical isolates. We compared resistance levels of clinical and nonclinical isolates of Escherichia coli from weaning and fattening pigs with clinical outpatient isolates of humans from urban and rural areas. We also studied the association of AMR with available antimicrobial use (AMU) data from humans and pigs. Differences between rural and urban isolates were minor and did not affect the comparison between human and pig isolates. We found higher resistance levels to most antimicrobials in human isolates compared to nonclinical isolates of fattening pigs. Resistance to ampicillin, however, was significantly more frequent in clinical isolates of fattening pigs and in clinical and nonclinical isolates of weaning pigs compared to isolates from humans. The opposite was observed for ciprofloxacin. Co-trimoxazole resistance proportions were higher in clinical isolates of weaning and fattening pigs as compared to isolates from humans. Resistance proportions were higher in clinical isolates than in nonclinical isolates from pigs of the same age group and were also higher in weaner than in fattening pigs. Significant associations of AMU and AMR were found for gentamicin resistance and aminoglycoside use in humans (borderline) and for ampicillin resistance in clinical isolates and penicillin use in fattening pigs. In summary, we found significant differences between isolates from all populations, requiring more detailed analyses supported by molecular data and better harmonized data on AMU and AMR.

Characterization of E. coli Isolates Producing Extended Spectrum Beta-Lactamase SHV-Variants from the Food Chain in Germany

Resistance of bacteria to 3^rd generation cephalosporins mediated by beta-lactamases (ESBL, pAmpC) is a public health concern. In this study, 1517 phenotypically cephalosporin-resistant E. coli were screened for the presence of bla_SHV genes. Respective genes were detected in 161 isolates. Majority (91%) were obtained from poultry production and meat. The SHV-12 beta-lactamase was the predominant variant (n = 155), while the remaining isolates exhibited SHV-2 (n = 4) or SHV-2a (n = 2). A subset of the isolates (n = 51) was further characterized by PCR, PFGE, or whole-genome sequencing and bioinformatics analysis. The SHV-12-producing isolates showed low phylogenetic relationships, and dissemination of the bla_SHV-12 genes seemed to be mainly driven by horizontal gene transfer. In most of the isolates, bla_SHV-12 was located on transferable IncX3 (~43 kb) or IncI1 (~100 kb) plasmids. On IncX3, bla_SHV-12 was part of a Tn6 composite transposon located next to a Tn3 transposon, which harbored the fluoroquinolone resistance gene qnrS1. On IncI1 plasmids, bla_SHV-12 was located on an incomplete class 1 integron as part of a Tn21 transposon. In conclusion, SHV-12 is widely distributed in German poultry production and spreads via horizontal gene transfer. Consumers are at risk by handling raw poultry meat and should take care in appropriate kitchen hygiene.

Exploring the Global Spread of Klebsiella grimontii Isolates Possessing blaVIM-1 and mcr-9

The spread of plasmid-mediated carbapenemases within Klebsiella oxytoca is well-documented. In contrast, data concerning the closely related species Klebsiella grimontii are scarce. In fact, despite the recent report of the first bla_KPC-2-producing K. grimontii, nothing is known about its clonality and antibiotic resistance patterns. In a retrospective search in our collection, we identified 2 bla_VIM-positive K. oxytoca strains. Whole-genome sequencing with both Illumina and Nanopore indicated that our strains actually belonged to K. grimontii and were of sequence type 172 (ST172) and ST189. Moreover, the two strains were associated with 297-kb IncHI2/HI2A-pST1 and 90.6-kb IncFII(Yp) plasmids carrying bla_VIM-1 together with mcr-9 and bla_VIM-1, respectively. In the IncHI2/HI2A plasmid, bla_VIM-1 was located in a class 1 integron (In110), while mcr-9 was associated with the qseC-qseB-like regulatory elements. Overall, this plasmid was shown to be very similar to those carried by other Enterobacterales isolated from food and animal sources (e.g., Salmonella and Enterobacter spp. detected in Germany and Egypt). The IncFII(Yp) plasmid was unique, and its bla_VIM-1 region was associated with a rare integron (In1373). Mapping of In1373 indicated a possible origin in Austria from an Enterobacter hormaechei carrying a highly similar plasmid. Core-genome phylogenies indicated that the ST172 K. grimontii belonged to a clone of identical Swedish and Swiss strains (≤15 single nucleotide variants [SNVs] to each other), whereas the ST189 strain was sporadic. Surveillance of carbapenemase-producing K. oxytoca strains should be reinforced to detect and prevent the dissemination of new species belonging to the Klebsiella genus.

Nearly Identical Plasmids Encoding VIM-1 and Mercury Resistance in Enterobacteriaceae from North-Eastern Germany

The emergence of carbapenemase-producing Enterobacteriaceae limits therapeutic options and presents a major public health problem. Resistances to carbapenems are mostly conveyed by metallo-beta-lactamases (MBL) including VIM, which are often encoded on resistance plasmids. We characterized four VIM-positive isolates that were obtained as part of a routine diagnostic screening from two laboratories in north-eastern Germany between June and August 2020. Whole-genome sequencing was performed to address (a) phylogenetic properties, (b) plasmid content, and (c) resistance gene carriage. In addition, we performed phenotypic antibiotic and mercury resistance analyses. The genomic analysis revealed three different bacterial species including C. freundii, E. coli and K. oxytoca with four different sequence types. All isolates were geno- and phenotypically multidrug-resistant (MDR) and the phenotypic profile was explained by the underlying resistance gene content. Three isolates of four carried nearly identical VIM-1-resistance plasmids, which in addition encoded a mercury resistance operon and showed some similarity to two publicly available plasmid sequences from sources other than the two laboratories above. Our results highlight the circulation of a nearly identical IncN-type VIM-1-resistance plasmid in different Enterobacteriaceae in north-eastern Germany.

Isolation Procedure for CP E. coli from Caeca Samples under Review towards an Increased Sensitivity

Due to the increasing reports of carbapenemase-producing Enterobacteriaceae (CPE) from livestock in recent years, the European Reference Laboratory for Antimicrobial Resistances (EURL-AR) provided a protocol for their recovery from caecum and meat samples. This procedure exhibited limitations for the detection of CPE with low carbapenem MIC values. Therefore, it was modified by a second, selective enrichment in lysogeny broth with cefotaxime (CTX 1 mg/L) and with meropenem (MEM 0.125 mg/L) at 37 °C under microaerophilic conditions. By Real-time PCR, these enrichments are pre-screened for the most common carbapenemase genes. Another adaptation was the use of in-house prepared MacConkey agar with MEM and MEM+CTX instead of commercial selective agar. According to the EURL-method, we achieved 100% sensitivity and specificity using the in-house media instead of commercial agar, which decreased the sensitivity to ~75%. Comparing the method with and without the second enrichment, no substantial influence on sensitivity and specificity was detected. Nevertheless, this enrichment has simplified the CPE-isolation regarding the accompanying microbiota and the separation of putative colonies. In conclusion, the sensitivity of the method can be increased with slight modifications.

The European Union Summary Report on Antimicrobial Resistance in zoonotic and indicator bacteria from humans, animals and food in 2018/2019

Data on antimicrobial resistance (AMR) in zoonotic and indicator bacteria from humans, animals and food are collected annually by the EU Member States (MSs), jointly analysed by the EFSA and the ECDC and reported in a yearly EU Summary Report. The annual monitoring of AMR in animals and food within the EU is targeted at selected animal species corresponding to the reporting year. The 2018 monitoring specifically focussed on poultry and their derived carcases/meat, while the monitoring performed in 2019 specifically focused on pigs and calves under 1 year of age, as well as their derived carcases/meat. Monitoring and reporting of AMR in 2018/2019 included data regarding Salmonella, Campylobacter and indicator Escherichia coli isolates, as well as data obtained from the specific monitoring of presumptive ESBL-/AmpC-/carbapenemase-producing E. coli isolates. Additionally, some MSs reported voluntary data on the occurrence of meticillin-resistant Staphylococcus aureus in animals and food, with some countries also providing data on antimicrobial susceptibility. This report provides an overview of the main findings of the 2018/2019 harmonised AMR monitoring in the main food-producing animal populations monitored, in related carcase/meat samples and in humans. Where available, data monitoring obtained from pigs, calves, broilers, laying hens and turkeys, as well as from carcase/meat samples and humans were combined and compared at the EU level, with particular emphasis on multidrug resistance, complete susceptibility and combined resistance patterns to critically important antimicrobials, as well as Salmonella and E. coli isolates possessing ESBL-/AmpC-/carbapenemase phenotypes. The outcome indicators for AMR in food-producing animals such as complete susceptibility to the harmonised panel of antimicrobials in E. coli and the prevalence of ESBL-/AmpC-producing E. coli have been also specifically analysed over the period 2015-2019.

Cluster analysis of resistance combinations in Escherichia coli from different human and animal populations in Germany 2014-2017

Recent findings on Antibiotic Resistance (AR) have brought renewed attention to the comparison of data on AR from human and animal sectors. This is however a major challenge since the data is not harmonized. This study performs a comparative analysis of data on resistance combinations in Escherichia coli (E. coli) from different routine surveillance and monitoring systems for human and different animal populations in Germany. Data on E. coli isolates were collected between 2014 and 2017 from human clinical isolates, non-clinical animal isolates from food-producing animals and food, and clinical animal isolates from food-producing and companion animals from national routine surveillance and monitoring for AR in Germany. Sixteen possible resistance combinations to four antibiotics—ampicillin, cefotaxime, ciprofloxacin and gentamicin–for these populations were used for hierarchical clustering (Euclidian and average distance). All analyses were performed with the software R 3.5.1 (Rstudio 1.1.442). Data of 333,496 E. coli isolates and forty-one different human and animal populations were included in the cluster analysis. Three main clusters were detected. Within these three clusters, all human populations (intensive care unit (ICU), general ward and outpatient care) showed similar relative frequencies of the resistance combinations and clustered together. They demonstrated similarities with clinical isolates from different animal populations and most isolates from pigs from both non-clinical and clinical isolates. Isolates from healthy poultry demonstrated similarities in relative frequencies of resistance combinations and clustered together. However, they clustered separately from the human isolates. All isolates from different animal populations with low relative frequencies of resistance combinations clustered together. They also clustered separately from the human populations. Cluster analysis has been able to demonstrate the linkage among human isolates and isolates from various animal populations based on the resistance combinations. Further analyses based on these findings might support a better one-health approach for AR in Germany.

Identification of a blaVIM-1-Carrying IncA/C2 Multiresistance Plasmid in an Escherichia coli Isolate Recovered from the German Food Chain

Within the German national monitoring of zoonotic agents, antimicrobial resistance determination also targets carbapenemase-producing (CP) Escherichia coli by selective isolation from food and livestock. In this monitoring in 2019, the CP E. coli 19-AB01133 was recovered from pork shoulder. The isolate was assigned to the phylogenetic group B1 and exhibited the multi-locus sequence-type ST5869. Molecular investigations, including whole genome sequencing, of 19-AB01133 revealed that the isolate carried the resistance genes bla_VIM-1, bla_SHV-5 and bla_CMY-13 on a self-transmissible IncA/C₂ plasmid. The plasmid was closely related to the previously described VIM-1-encoding plasmid S15FP06257_p from E. coli of pork origin in Belgium. Our results indicate an occasional spread of the bla_VIM-1 gene in Enterobacteriaceae of the European pig population. Moreover, the bla_VIM-1 located on an IncA/C₂ plasmid supports the presumption of a new, probably human source of carbapenemase-producing Enterobacteriaceae (CPE) entering the livestock and food chain sector.

Phenotypical antimicrobial resistance data of clinical and non-clinical Escherichia coli from poultry in Germany between 2014 and 2017

Antimicrobial resistance (AMR) is a global threat in humans and animals, and antimicrobial usage (AMU) has been identified as a main trigger of AMR. The purpose of this work was to compare data on AMR in clinical and non-clinical isolates of Escherichia coli in German broilers and turkeys between 2014 and 2017. Furthermore, we investigated AMR changes over time and the association of changes in AMU with changes in AMR. Data on clinical and non-clinical isolates together with data on therapy frequency of broilers and turkeys were collected from German monitoring systems. Logistic regression analyses were performed to assess the association between the explanatory factors (AMU, year and isolate type) and the dependent variable (AMR). In broilers, the analysis showed lower resistance proportions of clinical isolates of E. coli to ampicillin and colistin (ampicillin: Odds ratio (OR) and 95% confidence interval (CI) = 0.44 (0.3-0.64), p<0.001; colistin: OR and 95% CI = 0.75 (0.73-0.76), p<0.001) but higher proportions for cefotaxime (OR and 95% CI = 4.58 (1.56-15.1), p = 0.007). Resistance to ampicillin, gentamicin and tetracycline was less frequent in clinical isolates in turkeys (ampicillin: OR and 95% CI = 0.4 (0.29-0.53), p<0.001; gentamicin: OR and 95% CI = 0.5 (0.26-0.94), p = 0.035; tetracycline: OR and 95% CI = 0.4 (0.29-0.55), p<0.001). The analysis found decreasing associations of AMU with resistance to tetracycline in turkeys and to colistin in broilers. Year was associated with a decrease in resistance to colistin in broilers and to tetracycline in turkeys. Differences in resistance found in this study between clinical and non-clinical isolates might play an important role in resistance prevalence. This study indicated that further data analyses over longer time intervals are required to clarify the differences found between clinical and non-clinical isolates and to assess the long-term effects of changes in AMU on the prevalence of AMR.

Bacteria isolated from hospital, municipal and slaughterhouse wastewaters show characteristic, different resistance profiles

Multidrug-resistant bacteria cause difficult-to-treat infections and pose a risk for modern medicine. Sources of multidrug-resistant bacteria include hospital, municipal and slaughterhouse wastewaters. In this study, bacteria with resistance to 3rd generation cephalosporins were isolated from all three wastewater biotopes, including a maximum care hospital, municipal wastewaters collected separately from a city and small rural towns and the wastewaters of two pig and two poultry slaughterhouses. The resistance profiles of all isolates against clinically relevant antibiotics (including β-lactams like carbapenems, the quinolone ciprofloxacin, colistin, and trimethoprim/sulfamethoxazole) were determined at the same laboratory. The bacteria were classified according to their risk to human health using clinical criteria, with an emphasis on producers of carbapenemases, since carbapenems are prescribed for hospitalized patients with infections with multi-drug resistant bacteria. The results showed that bacteria that pose the highest risk, i. e., bacteria resistant to all β-lactams including carbapenems and ciprofloxacin, were mainly disseminated by hospitals and were present only in low amounts in municipal wastewater. The isolates from hospital wastewater also showed the highest rates of resistance against antibiotics used for treatment of carbapenemase producers and some isolates were susceptible to only one antibiotic substance. In accordance with these results, qPCR of resistance genes showed that 90% of the daily load of carbapenemase genes entering the municipal wastewater treatment plant was supplied by the clinically influenced wastewater, which constituted approximately 6% of the wastewater at this sampling point. Likewise, the signature of the clinical wastewater was still visible in the resistance profiles of the bacteria isolated at the entry into the wastewater treatment plant. Carbapenemase producers were not detected in slaughterhouse wastewater, but strains harboring the colistin resistance gene mcr-1 could be isolated. Resistances against orally available antibiotics like ciprofloxacin and trimethoprim/sulfamethoxazole were widespread in strains from all three wastewaters.

First Detection of GES-5-Producing Escherichia coli from Livestock-An Increasing Diversity of Carbapenemases Recognized from German Pig Production

Resistance to carbapenems due to carbapenemase-producing Enterobacteriaceae (CPE) is an increasing threat to human health worldwide. In recent years, CPE could be found only sporadically from livestock, but concern rose that livestock might become a reservoir for CPE. In 2019, the first GES carbapenemase-producing Escherichia coli from livestock was detected within the German national monitoring on antimicrobial resistance. The isolate was obtained from pig feces and was phenotypically resistant to meropenem and ertapenem. The isolate harbored three successive bla_GES genes encoding for GES-1, GES-5 and GES-5B in an incomplete class-I integron on a 12 kb plasmid (pEC19-AB02908; Acc. No. MT955355). The strain further encoded for virulence-associated genes typical for uropathogenic E. coli, which might hint at an increased pathogenic potential. The isolate produced the third carbapenemase detected from German livestock. The finding underlines the importance CPE monitoring and detailed characterization of new isolates.

Molecular Serotyping and Antibiotic Resistance Patterns of Escherichia coli Isolated in Hospital Catering Service in Morocco

Escherichia coli is related to foodborne disease and outbreaks worldwide. It mainly affects persons at high risk as newborns, infants, and individuals with impaired immune system in hospitals. Multidrug-resistant E. coli is currently spreading both in community and hospital settings. Our study aims to evaluate the presence of E. coli and the incidence of its antibiotic resistance in samples obtained from various cooked and raw foods (N = 300), food contact surfaces (N = 238), and food handlers (N = 40) in Moroccan hospital catering service. E. coli was identified using API 20E, and the antibiotic resistance patterns were obtained using the agar disk diffusion methods. However, PCR method was used for O157 and H7 typing. The samples analysis showed that 14.33%, 24.16%, and 45% of food, surfaces, and food handlers harbored E. coli, respectively, with the highest rates obtained in raw meats (34.88%) and salads (34.88%). Molecular amplification shows that 14 E. coli isolates carried the flagellar antigen H7, while there are no isolates showing amplification for O157. The high rate of resistance was noted against ampicillin (100%), amoxicillin-clavulanate acid (100%), nalidixic acid (61.62%), and cefotaxime (59.49%), and isolates obtained from food handler's hands showed the highest rates of resistance. None of the isolates are extended-spectrum beta-lactamases producing, while 27.7% of the isolates were metallo-beta-lactams producing. This first study conducted on Moroccan hospital catering services may draw the authorities' attention to the necessity of setting up a surveillance system to monitor the food preparation process and the safety of prepared food in healthcare settings.

ChromID® CARBA Agar Fails to Detect Carbapenem-Resistant Enterobacteriaceae With Slightly Reduced Susceptibility to Carbapenems

After first detections of carbapenemase-producing Enterobacteriaceae (CPE) in animals, the European Union Reference Laboratory for Antimicrobial Resistance has provided a protocol for the isolation of carbapenemase-producing Escherichia (E.) coli from cecum content and meat. Up to now, only few isolates were recovered using this procedure. In our experience, the choice of the selective agar is important for the efficacy of the method. Currently, the use of the prevailing method fails to detect CPE that exhibit a low resistance against carbapenems. Thus, this study aims to evaluate the suitability of selective media with antibiotic supplements and commercial ChromID^® CARBA agar for a reliable CPE detection. For comparative investigations, detection of freeze-dried carbapenemase-resistant bacteria was studied on different batches of the ChromID^® CARBA agar as well as on MacConkey agar supplemented with 1 mg/L cefotaxime and 0.125 mg/L meropenem (McC+CTX+MEM). The suitability of the different media was assessed within a time of 25 weeks, starting at least six weeks before expiration of the media. Carbapenem-resistant isolates exhibiting a serine-based hydrolytic resistance mechanism (e.g., bla _KPC genes) were consistently detected over 25 weeks on the different media. In contrast, carbapenemase producers with only slightly reduced susceptibility and exhibiting a zinc-catalyzed activity (e.g., bla _VIM, bla _NDM, and bla _IMP) could only be cultivated on long-time expired ChromID^® CARBA, but within the whole test period on McC+CTX+MEM. Thus, ChromID^® CARBA agar appears to be not suitable for the detection of CPE with slightly increased minimum inhibitory concentrations (MIC) against carbapenems, which have been detected in German livestock and thus, are of main interest in the national monitoring programs. Our data are in concordance with the results of eleven state laboratories that had participated in this study with their ChromID^® CARBA batches routinely used for the German CPE monitoring. Based on the determined CPE detection rate, we recommend the use of McC+CTX+MEM for monitoring purposes. This study indicates that the use of ChromID^® CARBA agar might lead to an underestimation of the current CPE occurrence in food and livestock samples.

Rapid spread of OXA-244-producing Escherichia coli ST38 in Germany: insights from an integrated molecular surveillance approach; 2017 to January 2020

Annually, increasing numbers of OXA-244-producing Escherichia coli in 13 German federal states prompted us to initiate an outbreak investigation. Whole genome sequencing revealed that among 148 isolates analysed, most belonged to sequence type 38 with 62 isolates forming a genetically distinct cluster. Although no epidemiological link could be identified between cases, ongoing investigations suggest non-healthcare associated transmission. A screening-PCR was developed facilitating early detection of ST38 cluster isolates to identify the source and transmission route.

Spill-Over from Public Health? First Detection of an OXA-48-Producing Escherichia coli in a German Pig Farm

Resistance to carbapenems is a severe threat to human health. These last resort antimicrobials are indispensable for the treatment of severe human infections with multidrug-resistant Gram-negative bacteria. In accordance with their increasing medical impact, carbapenemase-producing Enterobacteriaceae (CPE) might be disseminated from colonized humans to non-human reservoirs (i.e., environment, animals, food). In Germany, the occurrence of CPE in livestock and food has been systematically monitored since 2016. In the 2019 monitoring, an OXA-48-producing E. coli (19-AB01443) was recovered from a fecal sample of a fattening pig. Phenotypic resistance was confirmed by broth microdilution and further characterized by PFGE, conjugation, and combined short-/long-read whole genome sequencing. This is the first detection of this resistance determinant in samples from German meat production. Molecular characterization and whole-genome sequencing revealed that the bla_OXA-48 gene was located on a common pOXA-48 plasmid-prototype. This plasmid-type seems to be globally distributed among various bacterial species, but it was frequently associated with clinical Klebsiella spp. isolates. Currently, the route of introduction of this plasmid/isolate combination into the German pig production is unknown. We speculate that due to its strong correlation with human isolates a transmission from humans to livestock has occurred.

The European Union Summary Report on Antimicrobial Resistance in zoonotic and indicator bacteria from humans, animals and food in 2017/2018

Data on antimicrobial resistance (AMR) in zoonotic and indicator bacteria from humans, animals and food are collected annually by the EU Member States (MSs), jointly analysed by EFSA and ECDC and reported in a yearly EU Summary Report. The annual monitoring of AMR in animals and food within the EU is targeted at selected animal species corresponding to the reporting year. The 2017 monitoring specifically focussed on pigs and calves under 1 year of age, as well as their derived carcases/meat, while the monitoring performed in 2018 specifically focussed on poultry and their derived carcases/meat. Monitoring and reporting of AMR in 2017/2018 included data regarding Salmonella, Campylobacter and indicator Escherichia coli isolates, as well as data obtained from the specific monitoring of ESBL-/AmpC-/carbapenemase-producing E. coli isolates. Additionally, some MSs reported voluntary data on the occurrence of meticillin-resistant Staphylococcus aureus in animals and food, with some countries also providing data on antimicrobial susceptibility. This report provides, for the first time, an overview of the main findings of the 2017/2018 harmonised AMR monitoring in the main food-producing animal populations monitored, in related carcase/meat samples and in humans. Where available, data monitoring obtained from pigs, calves/cattle, broilers, laying hens and turkeys, as well as from carcase/meat samples and humans were combined and compared at the EU level, with particular emphasis on multiple drug resistance, complete susceptibility and combined resistance patterns to critically important antimicrobials, as well as Salmonella and E. coli isolates exhibiting presumptive ESBL-/AmpC-/carbapenemase-producing phenotypes. The outcome indicators for AMR in food-producing animals, such as complete susceptibility to the harmonised panel of antimicrobials in E. coli and the prevalence of ESBL-/AmpC-producing E. coli have been also specifically analysed over the period 2014-2018.