Antimicrobial Resistance in the Food Chain in the European Union

Pilot market surveillance of GMM contaminations in alpha-amylase food enzyme products: A detection strategy strengthened by a newly developed qPCR method targeting a GM Bacillus licheniformis producing alpha-amylase

Using high-throughput metagenomics on commercial microbial fermentation products, DNA from a new unauthorized genetically modified microorganism (GMM), namely the GM B. licheniformis strain producing alpha-amylase (GMM alpha-amylase2), was recently discovered and characterized. On this basis, a new qPCR method targeting an unnatural association of sequences specific to the GMM alpha-amylase2 strain was designed and developed in this study, allowing to strengthen the current GMM detection strategy. The performance of the newly developed qPCR method was assessed for its specificity and sensitivity to comply with the minimum performance requirements established by the European Network of GMO Laboratories for GMO analysis. Moreover, the transferability of the in house validated qPCR method was demonstrated. Finally, its applicability was confirmed by a pilot market surveillance of GMM contaminations conducted for the first time on 40 alpha-amylase food enzyme products labelled as containing alpha-amylase. This pilot market surveillance allowed also to highlight numerous contaminations with GMM alpha-amylase2, including frequent cross-contaminations with other GMM strains previously characterized. In addition, the presence of full-length AMR genes, raising health concerns, was also reported.

The use of new antibacterial drugs against infections caused by multidrug-resistant Gram-negative bacteria: an Italian real-world evidence study in a Lombardy hospital

Infections caused by multidrug-resistant (MDR) bacteria are typically associated with high morbidity and mortality, especially in vulnerable individuals such as patients with prolonged hospitalizations, immunocompromised individuals, and the elderly. This study aimed to provide post-marketing surveillance results concerning the prevalence of antibiotic resistance against Gram-negative bacteria through the collaboration of a multidisciplinary team. Patients involved have been treated with new antibacterial drugs, in particular ceftazidime/avibactam (C/A), meropenem/vaborbactam (M/V), cefiderocol, and ceftolozane/tazobactam (C/T). The most resistant bacterial species were Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter baumannii. Italian Drug Agency (AIFA) monitoring records for inpatients have been collected and analyzed, assessing the characteristics of the patients involved. Adverse drug reactions (ADRs) and drugs involved have been reported using a descriptive analytical approach. All data have been collected retrospectively from patient's medical records and entered into an electronic case report form (CRF). Among the 104 treated patients, Klebsiella spp. accounted for 50.1% of infections, Pseudomonas aeruginosa for 32.7%, Acinetobacter baumannii for 3%, and other bacterial species for 1.92% configuring polymicrobial infections. Regarding treatment outcomes, healing was achieved in 61 (58.6%) patients, 23 (22.1%) patients died, 8 (7.7%) patients discontinued empirical therapy, and 3 (2.9%) patients were lost to follow-up. Despite the introduction of new antibacterial drugs active against Gram-negative bacteria is improving the clinical scenario, it is crucial that the use of new antibacterial drugs be implemented by appropriate antimicrobial stewardship, surveillance programs, and monitoring efforts to prevent further spread of resistance. This study showed that the new antibiotics have good efficacy against MDR bacteria and cause negligible side effects.

Screening of antibiotic residues in raw bovine milk in Lombardy, Italy: Microbial growth inhibition assay and LC-HRMS technique integration for an accurate monitoring

Antibiotic residues in food of animal origin is a great concern for public health worldwide in terms of antibiotic resistance development, potential allergic reactions and disruption of intestinal flora equilibrium. In this study the presence of antibiotic residues in raw bovine milk samples collected from farms located in Lombardy region in Italy from 2018 to 2022 was assessed in the context of the national milk quality payment system. Samples were screened with microbiological growth inhibition test Delvotest ® SP NT and a very low positivity rate ranging from 0.1% to 0.07% over the four years was determined. A total of 79 positive samples were further analysed by LC-HRMS screening technique to confirm positivity and detect the specific antibiotic compound contaminating the sample. The β-lactam antibiotics resulted to be the most frequently detected, with the penicillin G being the most abundant compound. The data suggested that low levels of antibiotic contamination are consistently maintained over the last four years and the integration of the techniques used in this study is a valuable tool for a deep and precise monitoring of antibiotic residues in milk.

Prevalence and Characterization of Salmonella Isolated from Chickens in Anhui, China

Salmonella is one of the most important zoonotic pathogens that can cause both acute and chronic illnesses in poultry flocks, and can also be transmitted to humans from infected poultry. The purpose of this study was to investigate the prevalence, antimicrobial resistance, and molecular characteristics of Salmonella isolated from diseased and clinically healthy chickens in Anhui, China. In total, 108 Salmonella isolates (5.66%) were successfully recovered from chicken samples (n = 1908), including pathological tissue (57/408, 13.97%) and cloacal swabs (51/1500, 3.40%), and S. Enteritidis (43.52%), S. Typhimurium (23.15%), and S. Pullorum (10.19%) were the three most prevalent isolates. Salmonella isolates showed high rates of resistance to penicillin (61.11%), tetracyclines (47.22% to tetracycline and 45.37% to doxycycline), and sulfonamides (48.89%), and all isolates were susceptible to imipenem and polymyxin B. In total, 43.52% isolates were multidrug-resistant and had complex antimicrobial resistance patterns. The majority of isolates harbored cat1 (77.78%), blaTEM (61.11%), and blaCMY-2 (63.89%) genes, and the antimicrobial resistance genes in the isolates were significantly positively correlated with their corresponding resistance phenotype. Salmonella isolates carry high rates of virulence genes, with some of these reaching 100% (invA, mgtC, and stn). Fifty-seven isolates (52.78%) were biofilm-producing. The 108 isolates were classified into 12 sequence types (STs), whereby ST11 (43.51%) was the most prevalent, followed by ST19 (20.37%) and ST92 (13.89%). In conclusion, Salmonella infection in chicken flocks is still serious in Anhui Province, and not only causes disease in chickens but might also pose a threat to public health security.

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.

Chemical Composition, Antioxidant, and Antibiofilm Properties of Essential Oil from Thymus capitatus Plants Organically Cultured on the Greek Island of Lemnos

Essential oils (EOs) are mixtures of volatile plant secondary metabolites and have been exploited by humans for thousands of years for various purposes because of their many bioactivities. In this study, the EO from Thymus capitatus, a thyme species organically cultured on the Greek Island of Lemnos, was analyzed for its chemical composition (through GC-FID and GC-MS), antioxidant activity (AA), and total phenolic content (TPC), as well as its antimicrobial and antibiofilm actions against three important foodborne bacterial pathogens (Salmonella enterica ser. Typhimurium, Listeria monocytogenes, and Yersinia enterocolitica). For the latter investigations, the minimum inhibitory concentrations (MICs) and minimum biofilm inhibitory concentrations (MBICs) of the EO against the planktonic and biofilm growth of each pathogen were determined, together with the minimum biofilm eradication concentrations (MBECs). Results revealed that T. capitatus EO was rich in thymol, p-cymene, and carvacrol, presenting high AA and TPC (144.66 μmol Trolox^TM equivalents and 231.32 mg gallic acid equivalents per g of EO, respectively), while its MICs and MBICs ranged from 0.03% to 0.06% v/v and 0.03% to 0.13% v/v, respectively, depending on the target pathogen. The EO was able to fully destroy preformed (mature) biofilms of all three pathogenic species upon application for 15 min, with MBECs ranging from 2.00 to 6.25% v/v. Overall, the results demonstrate that the EO of organically cultured T. capitatus presents strong antioxidant, antibacterial, and antibiofilm properties and could, therefore, be further exploited as a functional and antimicrobial natural formulation for food and health applications.

Prevalence and Phenotypic Antimicrobial Resistance among ESKAPE Bacteria and Enterobacterales Strains in Wild Birds

Antimicrobial resistance (AMR) is a current public health issue globally. To counter this phenomenon and prioritize AMR in the health sector, the World Health Organization (WHO) published a list of bacterial pathogens against which the development of new antimicrobial agents is urgently needed, designating the ESKAPE pathogens (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) with a 'priority status'. Moreover, the One Health High Level Expert Panel (OHHLEP) states that human health is closely linked to animal and environmental health, thus promoting a holistic One Health approach in order to be prepared to address possible emerging health threats from the human-animal-environment interface. Wild birds may host and spread pathogens, integrating the epidemiology of infectious diseases. The aim of this study was to examine the role of wild birds as a source of ESKAPE bacteria and other antibiotic-resistant enterobacterales. A total of fifty strains within the ESKAPE group were detected in 40/163 cloacal samples of examined birds (24.5%). Additionally, different strains of enterobacterales were detected in 88/163 cloacal samples (53.9%). Isolated strains exhibited antimicrobial resistance, including towards critically important antibiotics (e.g., third, fourth, fifth generation cephalosporins, fluoroquinolones) for human medicine. Our results confirm that wild birds are potential reservoirs of several pathogens and antimicrobial-resistant bacteria and that they could be involved in the dissemination of those bacteria across different environments, with resulting public health concerns.

Antimicrobial Resistance of Salmonella Strains Isolated from Human, Wild Boar, and Environmental Samples in 2018-2020 in the Northwest of Italy

Antimicrobial resistance is one of the most challenging public health problems worldwide, and integrated surveillance is a key aspect in a One Health control strategy. Additionally, Salmonella is the second most common zoonosis in Europe. We aimed to investigate the circulation of Salmonella strains and their related antimicrobial resistance in human, environmental, and wild boar samples from the northwest of Italy, from 2018 to 2020, to obtain a more comprehensive epidemiological picture. Salmonella Typhimurium 1,4,[5],12:i:-, S. Veneziana and S. Newport were the most common serotypes occurring in humans, the environment, and wild boar, respectively. Antimicrobial resistance was rather common in Salmonella isolates, with those from human displaying the highest degree of resistance against sulfadiazine−sulfamerazine−sulfamethazine (>90% of resistance). Moreover, resistance against azithromycin were exclusively observed in environmental samples, while only 7.7% (95% CI = 1.6−20.8) of wild boar isolates experienced resistance against trimethoprim−sulfamethoxazole. Multidrug resistance concurrently involved up to seven antimicrobial classes in human isolates, including third-generation cephalosporins and fluoroquinolones. Salmonella Typhimurium in humans and serotypes Goldcoast and Rissen from environmental sources showed the highest levels of resistance. This study shows diverse antimicrobial resistance patterns in Salmonella strains isolated from different sources and gives a broad picture of antimicrobial resistance spread in wild animals, humans, and the environment.

Multidrug-Resistant Biofilms (MDR): Main Mechanisms of Tolerance and Resistance in the Food Supply Chain

Biofilms are mono- or multispecies microbial communities enclosed in an extracellular matrix (EPS). They have high potential for dissemination and are difficult to remove. In addition, biofilms formed by multidrug-resistant strains (MDRs) are even more aggravated if we consider antimicrobial resistance (AMR) as an important public health issue. Quorum sensing (QS) and horizontal gene transfer (HGT) are mechanisms that significantly contribute to the recalcitrance (resistance and tolerance) of biofilms, making them more robust and resistant to conventional sanitation methods. These mechanisms coordinate different strategies involved in AMR, such as activation of a quiescent state of the cells, moderate increase in the expression of the efflux pump, decrease in the membrane potential, antimicrobial inactivation, and modification of the antimicrobial target and the architecture of the EPS matrix itself. There are few studies investigating the impact of the use of inhibitors on the mechanisms of recalcitrance and its impact on the microbiome. Therefore, more studies to elucidate the effect and applications of these methods in the food production chain and the possible combination with antimicrobials to establish new strategies to control MDR biofilms are needed.

Characterization of Antibiotic Resistant Coliform Bacteria and Resistance Genes Isolated from Samples of Smoothie Drinks and Raw Milk

Raw foodstuffs have been marked as a healthier alternative in the context of nutrient content and are becoming more popular with consumers. Thermally untreated foods may represent a microbiological risk connected with the possible presence of antimicrobial resistance. The aim of this study was to prove that popular raw food beverages such as smoothies and raw milk may be a source of antibiotic-resistant coliform bacteria and resistant genes. The majority of antibiotic-resistant isolates (110) were identified as Enterobacter spp., Escherichia coli, and species of Klebsiella spp., predominantly β-lactam and chloramphenicol resistant. Multidrug resistance has been registered in one-third of resistants. Overproduction of efflux pumps was clarified in 8 different bacteria. The majority of resistant isolates were strong biofilm producers. Antibiotic resistance gene blaOXA was detected in 25% of isolates, especially in E. coli. Resistance genes blaTEM and blaSHV were detected in 19% and 14%, respectively. This is the first study to point out that popular raw drinks such as smoothies or raw milk, besides their nutrient benefits, could represent a reservoir of antibiotic-resistant bacteria as well as antibiotic resistance genes. According to this, raw drinks could contribute to the dissemination of antibiotic resistance in the human gastrointestinal tract and environment.

Current perspective on veterinary drug and chemical residues in food of animal origin

The marked increase in the demand for animal protein of high quality necessitates protecting animals from infectious diseases. This requires increasing the use of veterinary therapeutics. The overuse and misuse of veterinary products can cause a risk to human health either as short-term or long-term health problems. However, the biggest problem is the emergence of resistant strains of bacteria or parasites. This is in addition to economic losses due to the discarding of polluted milk or condemnation of affected carcasses. This paper discusses three key points: possible sources of drug and chemical residues, human health problems, and the possible method of control and prevention of veterinary drug residues in animal products.

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.

Comparative analysis of antimicrobial resistance and genetic characteristics of Escherichia coli from broiler breeder farms in Korea

Broiler breeder farms could be a reservoir of Escherichia coli, disseminating antimicrobial resistance and virulence factors. We investigated the antimicrobial resistance of E. coli from nine broiler breeder farms and characterised their resistance and virulence genes. A total of 256 E. coli showed a high level of resistance to tetracycline, nalidixic acid, ampicillin, and cephalothin, followed by trimethoprim-sulfamethoxazole and chloramphenicol. The resistance to nalidixic acid, ampicillin, trimethoprim–sulfamethoxazole, and chloramphenicol showed significant differences among the farms. Among 202 β-lactam-resistant E. coli, 138 carried β-lactamase genes. The most prevalent β-lactamase gene was blaTEM-1, of which the presence differed significantly across the farms. Out of 197 tetracycline-resistant E. coli isolates, tetA and tetB were detected in 164 and 50, with significant differences among the farms. Also, 45 of 196 nalidixic acid-resistant E. coli carried qnrS while 67 of 149 trimethoprim–sulfamethoxazole-resistant E. coli carried sul2. Among the five virulence genes tested, ompT was the most prevalent, and all genes except for iutA distributed significantly different among the farms. The phenotypic and genotypic characteristics of E. coli were significantly different among the farms; therefore, management at the breeder level is required to control the vertical transmission of E. coli.

Development of a Taxon-Specific Real-Time PCR Method Targeting the Bacillus subtilis Group to Strengthen the Control of Genetically Modified Bacteria in Fermentation Products

Most of the bacteria that are used to produce fermentation products, such as enzymes, additives and flavorings, belong to the Bacillus subtilis group. Recently, unexpected contaminations with unauthorized genetically modified (GM) bacteria (viable cells and associated DNA) that were carrying antimicrobial resistance (AMR) genes was noticed in several microbial fermentation products that have been commercialized on the food and feed market. These contaminations consisted of GM Bacillus species belonging to the B. subtilis group. In order to screen for the potential presence of such contaminations, in this study we have developed a new real-time PCR method targeting the B. subtilis group, including B. subtilis, B. licheniformis, B. amyloliquefaciens and B. velezensis. The method’s performance was successfully assessed as specific and sensitive, complying with the Minimum Performance Requirements for Analytical Methods of GMO Testing that is used as a standard by the GMO enforcement laboratories. The method’s applicability was also tested on 25 commercial microbial fermentation products. In addition, this method was developed to be compatible with the PCR-based strategy that was recently developed for the detection of unauthorized GM bacteria. This taxon-specific method allows the strengthening of the set of screening markers that are targeting key sequences that are frequently found in GM bacteria (AMR genes and shuttle vector), reinforcing control over the food and feed chain in order to guarantee its safety and traceability.

Assessing antimicrobial resistance occurrence in the Portuguese food system: Poultry, pigs and derived food, 2014-2018

Antimicrobial resistance (AMR) spread in the food system is a major threat to public and animal health. We describe AMR trends in zoonotic bacteria and identify risk factors associated with AMR occurrence in animals and derived food in Portugal. Data from the Portuguese AMR surveillance programme on food-producing animals, 2014-2018, were used. AMR frequencies were calculated for Escherichia coli, Campylobacter and Salmonella in broilers, turkeys, pig populations and their derived food products. AMR-associated factors were studied for Salmonella isolates: population, sampling stage (farm, slaughterhouse and processing plant), sample type (environmental, carcase and food), sampler (HACCP, industry, official and official and industry), sample context (control and eradication programmes and monitoring), year (2014-2018) and season. Logistic regression was applied to estimate crude odds ratio and adjusted odds ratio (aOR) with 95% confidence intervals (95% CI). The final models were obtained using a backward stepwise method. This study included 2,157 Escherichia coli, 561 Campylobacter and 1,071 Salmonella isolates. The highest prevalence estimates amongst tested antimicrobials for each bacterial species in 2014-2018 had the following ranges: (i) (fluoro)quinolones: E. coli: 84%-93%, Campylobacter: 94%-98%; (ii) tetracyclines: E. coli: 68%-91%, Campylobacter: 87%-91%, Salmonella: 72%; (iii) penicillins: E. coli: 82%-100%; (iv) sulphonamides: E. coli: 68%-82%. Compared with the reference categories for host (broiler), year (2014), season (winter) and sampler (HACCP own checks), resistance to at least one antimicrobial in Salmonella was significantly less likely in laying hens (aOR 0.28; 95% CI: 0.18-0.42), 2016 (aOR 0.56; 95% CI: 0.33-0.93), 2017 (aOR 0.29; 95% CI: 0.17-0.51) and 2018 (aOR 0.35; 95% CI: 0.20-0.61), autumn (aOR 0.63; 95% CI: 0.40-0.97) and more likely to occur in broiler products (aOR 5.14; 95% CI: 2.61-10.54), pork products (aOR 6.84; 95% CI: 3.74-12.98) and official and industry combined sampling (aOR 2.16; 95% CI: 1.06-4.47). This study reveals a high prevalence of Salmonella resistance, especially during the summer and in post-farm stages of the Portuguese food system to nearly all antimicrobials and in the summer in farms to (fluoro)quinolones. Measures to tackle resistance are required.

In-vitro antibiotic resistance phenotypes of respiratory and enteric bacterial isolates from weaned dairy heifers in California

Antimicrobial drug (AMD) use for bovine respiratory disease (BRD) continues to be concerning for development of antimicrobial resistance (AMR) in respiratory and enteric bacteria of cattle. This study aimed to provide data regarding AMR in respiratory isolates, and identify relationships between respiratory and enteric AMD susceptibility, in weaned dairy heifers. A cross-sectional study was performed between June of 2019 and February 2020, on 6 calf rearing facilities in California. Deep nasopharyngeal and rectal swabs were collected from 341 weaned heifers and submitted for selective bacterial culture and AMR testing. Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni were selectively isolated from respiratory samples; Escherichia coli and Enterococcus spp. were selectively isolated from rectal swabs. Minimum inhibitory concentrations (MIC) were determined for selected isolates against 19 AMD. The proportion of resistant isolates was calculated using Clinical Laboratory Standards Institute (respiratory) or USDA NARMS (enteric) breakpoints; when no applicable breakpoint was available, the distribution of MIC was described and compared. Association between AMR in a calf’s respiratory isolate and a higher or lower MIC of the matched enteric isolates was determined. More than 50% of P. multocida isolates were resistant to each of 7 AMD commonly used to treat BRD (florfenicol, gamithromycin, tildipirosin, tilmicosin, danofloxacin, enrofloxacin and tetracycline). Resistance in respiratory isolates was only associated with higher matched enteric MIC for gamithromycin and tulathromycin. Multidrug resistance was reported in >70% of P. multocida and M. haemolytica isolates. Antimicrobial resistance, including multidrug resistance, in respiratory isolates appears to be widespread in weaned dairy heifers; this finding has not previously been reported and raises concern for the future efficacy of AMD used to treat respiratory diseases in weaned dairy heifers. Enteric bacterial MIC appear to have limited direct association with respiratory isolate AMR classification.

Directed Recovery and Molecular Characterization of Antibiotic Resistance Plasmids from Cheese Bacteria

Resistance to antimicrobials is a growing problem of worldwide concern. Plasmids are thought to be major drivers of antibiotic resistance spread. The present work reports a simple way to recover replicative plasmids conferring antibiotic resistance from the bacteria in cheese. Purified plasmid DNA from colonies grown in the presence of tetracycline and erythromycin was introduced into plasmid-free strains of Lactococcus lactis, Lactiplantibacillus plantarum and Lacticaseibacillus casei. Following antibiotic selection, the plasmids from resistant transformants were isolated, analyzed by restriction enzyme digestion, and sequenced. Seven patterns were obtained for the tetracycline-resistant colonies, five from L. lactis, and one each from the lactobacilli strains, as well as a single digestion profile for the erythromycin-resistant transformants obtained in L. lactis. Sequence analysis respectively identified tet(S) and ermB in the tetracycline- and erythromycin-resistance plasmids from L. lactis. No dedicated resistance genes were detected in plasmids conferring tetracycline resistance to L. casei and L. plantarum. The present results highlight the usefulness of the proposed methodology for isolating functional plasmids that confer antibiotic resistance to LAB species, widen our knowledge of antibiotic resistance in the bacteria that inhabit cheese, and emphasize the leading role of plasmids in the spread of resistance genes via the food chain.

Development of a real-time PCR marker targeting a new unauthorized genetically modified microorganism producing protease identified by DNA walking

A PCR-based DNA walking analysis was performed on a protease product suspected to contain a new unauthorized genetically modified microorganism (GMM). Though the characterization of unnatural associations of sequences between the pUB110 shuttle vector and a Bacillus amyloliquefaciens gene coding for a protease, the presence of the GMM was shown. Based on these sequences of interest, a real-time PCR marker was developed to target specifically the newly discovered GMM, namely GMM protease2. The performance of the real-time PCR marker was assessed in terms of specificity and sensitivity. The applicability of the real-time PCR GMM protease2 marker was also demonstrated on microbial fermentation products. To confirm its use by other GMO enforcement laboratories, the transferability of the in-house validated real-time PCR marker was demonstrated by assays performed by an external laboratory.

Mobile Genetic Elements of Vibrio cholerae and the Evolution of Its Antimicrobial Resistance

Vibrio cholerae (VC) is the causative agent of the severe dehydrating diarrheal disease cholera. The primary treatment for cholera is oral rehydration therapy (ORT). However, in case of moderate to severe dehydration, antibiotics are administered to reduce morbidity. Due to the emergence of multidrug resistant (MDR) strains of VC routinely used antibiotics fail to be effective in cholera patients. Antimicrobial resistance (AMR) is encoded in the genome of bacteria and is usually acquired from other organisms cohabiting in the environment or in the gut with which it interacts in the gut or environmental niche. The antimicrobial resistance genes (ARGs) are usually borne on mobile genetic elements (MGEs) like plasmids, transposons, integrons and SXT constin. Horizontal gene transfer (HGT) helps in the exchange of ARGs among bacteria leading to dissemination of AMR. In VC the acquisition and loss of AMR to many antibiotics have been found to be a dynamic process. This review describes the different AMR determinants and mechanisms of resistance that have been discovered in VC. These ARGs borne usually on MGEs have been recovered from isolates associated with past and present epidemics worldwide. These are responsible for resistance of VC to common antibiotics and are periodically lost and gained contributing to its genetic evolution. These resistance markers can be routinely used for AMR surveillance in VC. The review also presents a precise perspective on the importance of the gut microbiome in the emergence of MDR VC and concludes that the gut microbiome is a potential source of molecular markers and networks which can be manipulated for the interception of AMR in the future.

Characterization of Proteus vulgaris Strain P3M, a Foodborne Multidrug-Resistant Bacterium Isolated from Penaeus vannamei in China

Proteus vulgaris is an important foodborne opportunistic pathogen, both environmentally and clinically. The use of appropriate antibiotics has significant therapeutic effects, but has led to the emergence and spread of drug-resistant strains. In this study, a P. vulgaris strain, designated "P3M," was isolated from Penaeus vannamei in Tianjin, China. The whole genome of P3M was sequenced, generating detailed information, including the key genes involved in important metabolic pathways and their physiological functions. A total of 218 antibiotic resistance genes (ARGs) were predicted in the genome. The determination of various minimum inhibitory concentrations indicated that P3M is a multidrug-resistant (MDR) bacterium, with significant resistance to 16 antibiotics in seven categories. Determination of fractional inhibitory concentration index showed that the combination of ciprofloxacin plus tetracycline exhibited synergistic antimicrobial activity. Bioinformatics and phylogenetic analyses detected the presence of two two-component systems that mediate multidrug resistance and several mobile genetic elements involved in the horizontal transfer of ARGs in P3M. P. vulgaris strains represent a serious challenge to clinicians and infection control teams for its ubiquity worldwide and close relevance with human life. To the best of our knowledge, we report the first isolation and characterization of an important foodborne MDR P. vulgaris strain, and this study will provide necessary theoretical basis for the selection and clinical use of the appropriate antibiotics.

Extensive microbial diversity within the chicken gut microbiome revealed by metagenomics and culture

BACKGROUND

The chicken is the most abundant food animal in the world. However, despite its importance, the chicken gut microbiome remains largely undefined. Here, we exploit culture-independent and culture-dependent approaches to reveal extensive taxonomic diversity within this complex microbial community.

RESULTS

We performed metagenomic sequencing of fifty chicken faecal samples from two breeds and analysed these, alongside all (n = 582) relevant publicly available chicken metagenomes, to cluster over 20 million non-redundant genes and to construct over 5,500 metagenome-assembled bacterial genomes. In addition, we recovered nearly 600 bacteriophage genomes. This represents the most comprehensive view of taxonomic diversity within the chicken gut microbiome to date, encompassing hundreds of novel candidate bacterial genera and species. To provide a stable, clear and memorable nomenclature for novel species, we devised a scalable combinatorial system for the creation of hundreds of well-formed Latin binomials. We cultured and genome-sequenced bacterial isolates from chicken faeces, documenting over forty novel species, together with three species from the genus Escherichia, including the newly named species Escherichia whittamii.

CONCLUSIONS

Our metagenomic and culture-based analyses provide new insights into the bacterial, archaeal and bacteriophage components of the chicken gut microbiome. The resulting datasets expand the known diversity of the chicken gut microbiome and provide a key resource for future high-resolution taxonomic and functional studies on the chicken gut microbiome.

Antimicrobial Resistance Profile and ExPEC Virulence Potential in Commensal Escherichia coli of Multiple Sources

We recently described the genetic antimicrobial resistance and virulence profile of a collection of 279 commensal E. coli of food-producing animal (FPA), pet, wildlife and human origin. Phenotypic antimicrobial resistance (AMR) and the role of commensal E. coli as reservoir of extra-intestinal pathogenic Escherichia coli (ExPEC) virulence-associated genes (VAGs) or as potential ExPEC pathogens were evaluated. The most common phenotypic resistance was to tetracycline (76/279, 27.24%), sulfamethoxazole/trimethoprim (73/279, 26.16%), streptomycin and sulfisoxazole (71/279, 25.45% both) among the overall collection. Poultry and rabbit were the sources mostly associated to AMR, with a significant resistance rate (p > 0.01) to quinolones, streptomycin, sulphonamides, tetracycline and, only for poultry, to ampicillin and chloramphenicol. Finally, rabbit was the source mostly associated to colistin resistance. Different pandemic (ST69/69*, ST95, ST131) and emerging (ST10/ST10*, ST23, ST58, ST117, ST405, ST648) ExPEC sequence types (STs) were identified among the collection, especially in poultry source. Both ST groups carried high number of ExPEC VAGs (pandemic ExPEC STs, mean = 8.92; emerging ExPEC STs, mean = 6.43) and showed phenotypic resistance to different antimicrobials (pandemic ExPEC STs, mean = 2.23; emerging ExPEC STs, mean = 2.43), suggesting their role as potential ExPEC pathogens. Variable phenotypic resistance and ExPEC VAG distribution was also observed in uncommon ExPEC lineages, suggesting commensal flora as a potential reservoir of virulence (mean = 3.80) and antimicrobial resistance (mean = 1.69) determinants.

Outcome of Different Sequencing and Assembly Approaches on the Detection of Plasmids and Localization of Antimicrobial Resistance Genes in Commensal Escherichia coli

Antimicrobial resistance (AMR) is a major threat to public health worldwide. Currently, AMR typing changes from phenotypic testing to whole-genome sequence (WGS)-based detection of resistance determinants for a better understanding of the isolate diversity and elements involved in gene transmission (e.g., plasmids, bacteriophages, transposons). However, the use of WGS data in monitoring purposes requires suitable techniques, standardized parameters and approved guidelines for reliable AMR gene detection and prediction of their association with mobile genetic elements (plasmids). In this study, different sequencing and assembly strategies were tested for their suitability in AMR monitoring in Escherichia coli in the routines of the German National Reference Laboratory for Antimicrobial Resistances. To assess the outcomes of the different approaches, results from in silico predictions were compared with conventional phenotypic- and genotypic-typing data. With the focus on (fluoro)quinolone-resistant E.coli, five qnrS-positive isolates with multiple extrachromosomal elements were subjected to WGS with NextSeq (Illumina), PacBio (Pacific BioSciences) and ONT (Oxford Nanopore) for in depth characterization of the qnrS1-carrying plasmids. Raw reads from short- and long-read sequencing were assembled individually by Unicycler or Flye or a combination of both (hybrid assembly). The generated contigs were subjected to bioinformatics analysis. Based on the generated data, assembly of long-read sequences are error prone and can yield in a loss of small plasmid genomes. In contrast, short-read sequencing was shown to be insufficient for the prediction of a linkage of AMR genes (e.g., qnrS1) to specific plasmid sequences. Furthermore, short-read sequencing failed to detect certain duplications and was unsuitable for genome finishing. Overall, the hybrid assembly led to the most comprehensive typing results, especially in predicting associations of AMR genes and mobile genetic elements. Thus, the use of different sequencing technologies and hybrid assemblies currently represents the best approach for reliable AMR typing and risk assessment.

Microbial Safety of Smoothie Drinks from Fresh Bars Collected in Slovakia

Among the many consumers in Slovakia, smoothies are nowadays gaining popularity. Smoothie drinks are prepared from raw fruits and vegetables. Therefore, their microbiological safety depends on hygiene standards. The aim of this work was to monitor and quantify selected sensitive and antibiotic-resistant microorganisms present in collected smoothies. Twenty analyzed smoothie samples were collected from six food service establishments (fresh bars) in the capital city of Slovakia, Bratislava. Antibiotic-resistant bacteria were found in at least one of each fresh bar. Antibiotic-resistant coliform bacteria prevailed, especially in green smoothies or juices containing more vegetable ingredients. Resistance to ampicillin, ciprofloxacin, tetracycline, chloramphenicol, and gentamicin was observed in the case of coliform bacteria. More than half of the smoothie drink samples did not contain resistant enterococci. On the other hand, vancomycin-resistant enterococci were detected in 20% of samples. The most frequently isolated antibiotic-resistant strains belonged to the Enterobacter spp. or Klebsiella spp. genus. In the last part of the work, the pretreatment effect of smoothie components on the selected microorganisms' counts in the final product was investigated. Washing ingredients with an aqueous solution of a biocide agent containing silver and hydrogen peroxide proved to be the most effective way to decrease bacterial counts.

Potentially Pathogenic Multidrug-Resistant Escherichia coli in Lamb Meat

Extended-spectrum cephalosporin (ESC) resistance remains a threat since ESC are important antimicrobials used to treat infections in humans and animals. Escherichia coli is an important source of ESC-resistance genes, such as those encoding extended-spectrum β-lactamases (ESBLs). E. coli is a common commensal of lambs. Reports that contaminated food can be a source of ESC-resistant bacteria in humans and that ESBL-producing E. coli are found in sheep in Brazil led us to survey their presence in retail lamb meat. Twenty-five samples intended for human consumption were screened for ESC-resistant E. coli, and the isolates were characterized. IncI1-bla_CTX-M-8 and IncHI2-bla_CTX-M-2 were the main plasmids responsible for ESC resistance. The plasmids harbored common ESBL genes in Enterobacteriaceae from food-producing animals in Brazil. IncI1-bla_CTX-M-14 and IncF-bla_CTX-M-55 plasmids, associated with human infections, were also detected. Few CTX-M-producing E. coli have been clustered by typing methods, and some may be genetically pathogenic. The findings indicate the presence of diverse strains of E. coli, harboring important ESBL genes, in lamb meat in Brazil. Surveillance of ESC-resistant bacteria could reduce the spread of antimicrobial resistance through the food chain.

WGS-Based Prediction and Analysis of Antimicrobial Resistance in Campylobacter jejuni Isolates From Israel

Rapid developments in the field of whole genome sequencing (WGS) make in silico antimicrobial resistance (AMR) a target within reach. Campylobacter jejuni is a leading cause of foodborne infections in Israel with increasing rates of resistance. We applied WGS analysis to study the prevalence and genetic basis of AMR in 263 C. jejuni human and veterinary representative isolates retrieved from a national collection during 2003–2012. We evaluated the prediction of phenotypic AMR from genomic data. Genomes were screened by the NCBI AMRFinderPlus and the BioNumerics tools for acquired AMR genes and point mutations. The results were compared to phenotypic resistance determined by broth microdilution. The most prevalent resistant determinants were the multi-drug efflux transporter gene cmeABC (100%), the tetracycline resistance tet(O) gene (82.1%), the quinolone resistance gyrA T861 point mutation (75.7%), and the aadE streptomycin resistance gene. A variety of 12 known β lactam resistance genes (bla_OXA variants) were detected in 241 (92%) isolates, the most prevalent being bla_OXA−193, bla_OXA−461, and bla_OXA−580 (56, 16, and 7%, respectively). Other aminoglycoside resistance genes and the macrolide resistance point mutation were rare (<1%). The overall correlation rate between WGS-based genotypic prediction and phenotypic resistance was 98.8%, sensitivity, specificity, positive, and negative predictive values being 98.0, 99.3, 99.1, and 98.5%, respectively. wgMLST-based phylogeny indicated a high level of clonality and clustering among the studied isolates. Closely related isolates that were part of a genetic cluster (single linkage distance ≤ 15 alleles) based on wgMLST phylogeny mostly shared a homogenous AMR determinant profile. This was observed in 18 of 20 (90.0%) clusters within clonal complex-21, suggesting clonal expansion of resistant isolates. Strong association to lineage was noted for the aadE gene and the various bla_OXA genes. High resistance rates to tetracycline and quinolones and a low resistance rate to macrolides were detected among the Israeli C. jejuni isolates. While a high genotypic-phenotypic correlation was found, some resistance phenotypes could not be predicted by the presence of AMR determinants, and particularly not the level of resistance. WGS-based prediction of antimicrobial resistance in C. jejuni requires further optimization in order to integrate this approach in the routine workflow of public health laboratories for foodborne surveillance.

Country Income Is Only One of the Tiles: The Global Journey of Antimicrobial Resistance among Humans, Animals, and Environment

Antimicrobial resistance (AMR) is one of the most complex global health challenges today: decades of overuse and misuse in human medicine, animal health, agriculture, and dispersion into the environment have produced the dire consequence of infections to become progressively untreatable. Infection control and prevention (IPC) procedures, the reduction of overuse, and the misuse of antimicrobials in human and veterinary medicine are the cornerstones required to prevent the spreading of resistant bacteria. Purified drinking water and strongly improved sanitation even in remote areas would prevent the pollution from inadequate treatment of industrial, residential, and farm waste, as all these situations are expanding the resistome in the environment. The One Health concept addresses the interconnected relationships between human, animal, and environmental health as a whole: several countries and international agencies have now included a One Health Approach within their action plans to address AMR. Improved antimicrobial usage, coupled with regulation and policy, as well as integrated surveillance, infection control and prevention, along with antimicrobial stewardship, sanitation, and animal husbandry should all be integrated parts of any new action plan targeted to tackle AMR on the Earth. Since AMR is found in bacteria from humans, animals, and in the environment, we briefly summarize herein the current concepts of One Health as a global challenge to enable the continued use of antibiotics.

Characterization of Salmonella enterica Isolates from Diseased Poultry in Northern China between 2014 and 2018

Salmonella infection not only causes acute and chronic diseases in poultry flocks, but the infected poultry are among the most important reservoirs for a variety of Salmonella serovars frequently transmitted to humans. This study aimed to investigate the occurrence of Salmonella spp. in local poultry farms in China. Samples (n = 4255), including dead-in-shell embryos, culled day-old-hatchings and 1- to 4-week-old diseased birds, were collected for Salmonella culture from broiler chicken, meat-type duck and pigeon farms in northern China between 2014 and 2018. A total of 103 Salmonella were isolated. S. enterica serovar Enteritidis and S. Typhimurium were the most prevalent serovars, representing 53.4% and 34.9% of the isolates, respectively. Serovar diversity was the highest in ducks, with the S. Apeyeme being isolated for the first time from duck tissues. All isolates were characterized by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). MLST showed that all S. Enteritidis isolates shared the same sequence type (ST11), and Typhimurium showed several rare STs in addition to ST19. In comparison, PFGE showed better discrimination for S. Enteritidis and S. Typhimurium isolates, with nine distinct pulsotypes being observed. The isolates exhibited varying degrees of resistance to 15 tested antimicrobials and identified S. Enteritidis isolates (98.18%) with multiple antimicrobial resistance were a cause for concern. Our data on invasive Salmonella infection in meat-type poultry in local farms can be used to identify sources and factors associated with Salmonella spread in poultry and the associated food chain.

Gene pool transmission of multidrug resistance among Campylobacter from livestock, sewage and human disease

The use of antimicrobials in human and veterinary medicine has coincided with a rise in antimicrobial resistance (AMR) in the food-borne pathogens Campylobacter jejuni and Campylobacter coli. Faecal contamination from the main reservoir hosts (livestock, especially poultry) is the principal route of human infection but little is known about the spread of AMR among source and sink populations. In particular, questions remain about how Campylobacter resistomes interact between species and hosts, and the potential role of sewage as a conduit for the spread of AMR. Here, we investigate the genomic variation associated with AMR in 168 C. jejuni and 92 C. coli strains isolated from humans, livestock and urban effluents in Spain. AMR was tested in vitro and isolate genomes were sequenced and screened for putative AMR genes and alleles. Genes associated with resistance to multiple drug classes were observed in both species and were commonly present in multidrug-resistant genomic islands (GIs), often located on plasmids or mobile elements. In many cases, these loci had alleles that were shared among C. jejuni and C. coli consistent with horizontal transfer. Our results suggest that specific antibiotic resistance genes have spread among Campylobacter isolated from humans, animals and the environment.

A Novel Single Domain Antibody Targeting FliC Flagellin of Salmonella enterica for Effective Inhibition of Host Cell Invasion

The enteric pathogen, Salmonella enterica is a major cause of human gastroenteritis globally and with increasing bacterial resistance to antibiotics, alternative solutions are urgently needed. Single domain antibodies (sdAbs), the smallest antibody fragments that retain antigen binding specificity and affinity, are derived from variable heavy-chain only fragments (VHH) of camelid heavy-chain-only immunoglobulins. SdAbs typically contain a single disulfide bond simplifying recombinant protein production in microbial systems. These factors make sdAbs ideally suited for the development of effective anti-bacterial therapeutics. To this end, we generated an anti-Salmonella VHH library from which we screened for high affinity sdAbs. We present a novel sdAb (Abi-Se07) that targets the Salmonella virulence factor, FliC, required for bacterial motility and invasion of host cells. We demonstrate that Abi-Se07 bound FliC with a K_D of 16.2 ± 0.1 nM. In addition, Abi-Se07 exhibited cross-serovar binding to whole cells of S. enterica serovar Typhimurium, Heidelberg, and Hadar. Abi-Se07 significantly inhibited bacterial motility and significantly reduced S. enterica colonization in a more native environment of chicken jejunum epithelium. Taken together, we have identified a novel anti-Salmonella sdAb and discuss future efforts toward therapeutic development.

Marine Macrolides with Antibacterial and/or Antifungal Activity

Currently, the increasing resistance of microorganisms to antibiotics is a serious problem. Marine organisms are the source of thousands of substances, which also have antibacterial and antifungal effects. Among them, marine macrolides are significant. In this review, the antibacterial and/or antifungal activities of 34 groups of marine macrolides are presented. Exemplary groups are chalcomycins, curvulides, halichondramides, lobophorins, macrolactins, modiolides, scytophycins, spongistatins, or zearalanones. In the paper, 74 antibiotics or their analog sets, among which 29 with antifungal activity, 25 that are antibacterial, and 20 that are both antifungal and antibacterial are summarized. Also, 36 macrolides or their sets are produced by bacteria, 18 by fungi, ten by sponges, seven by algae, two by porifera, and one by nudibranch. Moreover, the chemical structures of representatives from each of the 34 groups of these antibiotics are presented. To summarize, marine organisms are rich in natural macrolides. Some of these may be used in the future in the treatment of bacterial and fungal infections. Marine macrolides can also be potential drugs applicable against pathogens resistant to currently known antibiotics.

Salmonella control in poultry flocks and its public health impact

An increase in confirmed human salmonellosis cases in the EU after 2014 triggered investigation of contributory factors and control options in poultry production. Reconsideration of the five current target serovars for breeding hens showed that there is justification for retaining Salmonella Enteritidis, Salmonella Typhimurium (including monophasic variants) and Salmonella Infantis, while Salmonella Virchow and Salmonella Hadar could be replaced by Salmonella Kentucky and either Salmonella Heidelberg, Salmonella Thompson or a variable serovar in national prevalence targets. However, a target that incorporates all serovars is expected to be more effective as the most relevant serovars in breeding flocks vary between Member State (MS) and over time. Achievement of a 1% target for the current target serovars in laying hen flocks is estimated to be reduced by 254,400 CrI95[98,540; 602,700] compared to the situation in 2016. This translates to a reduction of 53.4% CrI95[39.1; 65.7] considering the layer-associated human salmonellosis true cases and 6.2% considering the overall human salmonellosis true cases in the 23 MSs included in attribution modelling. A review of risk factors for Salmonella in laying hens revealed that overall evidence points to a lower occurrence in non-cage compared to cage systems. A conclusion on the effect of outdoor access or impact of the shift from conventional to enriched cages could not be reached. A similar review for broiler chickens concluded that the evidence that outdoor access affects the occurrence of Salmonella is inconclusive. There is conclusive evidence that an increased stocking density, larger farms and stress result in increased occurrence, persistence and spread of Salmonella in laying hen flocks. Based on scientific evidence, an impact of Salmonella control programmes, apart from general hygiene procedures, on the prevalence of Campylobacter in broiler flocks at the holding and on broiler meat at the end of the slaughter process is not expected.

Prevalence, Serotyping, Molecular Typing, and Antimicrobial Resistance of Salmonella Isolated From Conventional and Organic Retail Ground Poultry

Ground poultry is marketed as a healthier alternative to ground beef despite the fact that poultry is a major source of foodborne Salmonella. The objectives of this study were to determine the prevalence of Salmonella in Oklahoma retail ground poultry and to characterize representative isolates by serotyping, antimicrobial resistance, PFGE patterns, and large plasmid profiling. A total of 199 retail ground poultry samples (150 ground turkey and 49 ground chicken) were investigated. The overall prevalence of Salmonella in ground poultry was 41% (82/199), and the incidence in conventional samples (47%, 66/141) was higher than in organic samples (27%, 16/58). The prevalence of Salmonella in organic ground chicken and organic ground turkey was 33% (3/9) and 26% (13/49), respectively. Twenty six Salmonella isolates (19 conventional and 7 organic) were chosen for further characterization. The following six serotypes and number of isolates per serotype were identified as follows: Tennessee, 8; Saintpaul, 4; Senftenberg, 4; Anatum, 4 (one was Anatum_var._15+); Ouakam, 3; and Enteritidis, 3. Resistance to 16 tested antimicrobials was as follows: gentamycin, 100% (26/26); ceftiofur, 100% (26/26); amoxicillin/clavulanic acid, 96% (25/26); streptomycin, 92% (24/26); kanamycin, 88% (23/26); ampicillin, 85% (22/26); cephalothin, 81% (21/26); tetracycline, 35% (9/26); sulfisoxazole, 27% (7/26); nalidixic acid, 15% (4/26); and cefoxitin, 15% (4/26). All isolates were susceptible to amikacin, chloramphenicol, ceftriaxone, and trimethoprim/sulfamethoxazole. All screened isolates were multidrug resistant (MDR) and showed resistance to 4-10 antimicrobials; isolates from organic sources showed resistance to 5-7 antimicrobials. PFGE was successful in clustering the Salmonella isolates into distinct clusters that each represented one serotype. PFGE was also used to investigate the presence of large plasmids using S1 nuclease digestion. A total of 8/26 (31%) Salmonella isolates contained a ∼100 Kb plasmid that was present in all Anatum and Ouakam isolates. In conclusion, the presence of multidrug resistant Salmonella with various serotypes, PFGE profiles, and large plasmids in ground poultry stresses the importance of seeking novel interventions to reduce the risk of this foodborne pathogen. Multidrug resistance (MDR) is considered a high additional risk and continued surveillance at the retail level could minimize the risk for the consumer.