Emergence, spread, and environmental effect of antimicrobial resistance: how use of an antimicrobial anywhere can increase resistance to any antimicrobial anywhere else

American crocodiles (Crocodylus acutus: Reptilia: Crocodilidae) visiting the facilities of a freshwater aquaculture of the Northern Pacific region, Costa Rica, carry tetracycline-resistant Escherichia coli

Apex predators are exposed to antimicrobial compounds and resistant microbes, which accumulate at different trophic levels of the related ecosystems. The study aimed to characterize the presence and the antimicrobial resistance patterns of fecal Escherichia coli isolated from cloacal swab samples obtained from wild-living American crocodiles (Crocodylus acutus) (n = 53). Sampling was conducted within the distinctive context of a freshwater-intensive aquaculture farm in Costa Rica, where incoming crocodiles are temporarily held in captivity before release. Phenotypic antimicrobial susceptibility profiles were determined in all isolates, while resistant isolates were subjected to whole-genome sequencing and bioinformatics analyses. In total, 24 samples contained tetracycline-resistant E. coli (45.3%). Isolates carried either tet(A), tet(B), or tet(C) genes. Furthermore, genes conferring resistance to ß-lactams, aminoglycosides, fosfomycin, sulfonamides, phenicol, quinolones, trimethoprim, and colistin were detected in single isolates, with seven of them carrying these genes on plasmids. Genome sequencing further revealed that sequence types, prevalence of antibiotic resistance carriage, and antibiotic resistance profiles differed between the individuals liberated within the next 24 h after their capture in the ponds and those liberated from enclosures after longer abodes. The overall presence of tetracycline-resistant E. coli, coupled with potential interactions with various anthropogenic factors before arriving at the facilities, hinders clear conclusions on the sources of antimicrobial resistance for the studied individuals. These aspects hold significant implications for both the aquaculture farm's biosecurity and the planning of environmental monitoring programs using such specimens. Considering human-crocodile conflicts from the One Health perspective, the occurrence of antimicrobial resistance underscores the importance of systematical surveillance of antibiotic resistance development in American crocodiles.

Determining the prevalence and genetic diversity of plasmid-mediated sulfonamide resistance in Escherichia coli from commercial broiler samples

Sulfonamides are commonly used antibacterials in commercial poultry, contributing toward the development of multidrug-resistant (MDR) phenotypes among Escherichia coli and that has emerged as global concern. The current study aimed to assess the sulfonamide resistance among isolated E. coli strains among commercial broilers. The bacterial strains were identified from fecal samples (n = 100) using selective media, followed by initial identification based on biochemical profiles. The susceptibility was determined by measuring the minimum inhibitory concentration (MIC) against sulfamethoxazole. The study also evaluated mobile genetic elements (MGEs), the mediators of antibiotic resistance, by amplification of plasmid DNA using specific primer PCR. Additionally, the isolates were subjected to multilocus sequence typing (MLST) analysis to investigate the genetic diversity among E. coli carrying sulfonamide resistance genes. The results revealed that 58% (58/100) E. coli strains were resistant to sulfonamides, with 36.20% (21/58) of the strains exhibiting an MIC breakpoint ≥512 µg/mL. PCR analysis showed that 42.85% (9/21) of the strains harbored the sul-1 gene, while 38.09% (8/21) carried the sul-2 gene, and 19.04% (4/21) had both genes. No isolate showed the presence of the sul-3 gene. Furthermore, class 1 and class 2 integrons were identified among 80.95% (17/21) and 19.04% (4/21) of the strains, respectively. MLST analysis confirmed that the strains belonged to sequence types (STs) including ST1638, ST155, ST48, ST350, ST23, ST156, and ST746. These findings underscore the diversity among E. coli strains in commercial poultry, which poses a significant risk.

Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections

Salmonella is a major foodborne pathogen and a leading cause of gastroenteritis in humans and animals. Salmonella is highly pathogenic and encompasses more than 2600 characterized serovars. The transmission of Salmonella to humans occurs through the farm-to-fork continuum and is commonly linked to the consumption of animal-derived food products. Among these sources, poultry and poultry products are primary contributors, followed by beef, pork, fish, and non-animal-derived food such as fruits and vegetables. While antibiotics constitute the primary treatment for salmonellosis, the emergence of antibiotic resistance and the rise of multidrug-resistant (MDR) Salmonella strains have highlighted the urgency of developing antibiotic alternatives. Effective infection management necessitates a comprehensive understanding of the pathogen's epidemiology and transmission dynamics. Therefore, this comprehensive review focuses on the epidemiology, sources of infection, risk factors, transmission dynamics, and the host range of Salmonella serotypes. This review also investigates the disease characteristics observed in both humans and animals, antibiotic resistance, pathogenesis, and potential strategies for treatment and control of salmonellosis, emphasizing the most recent antibiotic-alternative approaches for infection control.

Analysis of Resistance Gene Diversity in the Intestinal Microbiome of Broilers from Two Types of Broiler Farms in Hebei Province, China

The crucial reservoir of antibiotic resistance genes (ARGs) within the chicken intestinal microbiome poses a serious threat to both animal and human health. In China, the overuse of antibiotics has significantly contributed to the proliferation of ARGs in the chicken intestinal microbiome, which is a serious concern. However, there has been relatively little research on the diversity of resistance genes in the chicken intestinal microbiome since the implementation of the National Pilot Work Program for Action to Reduce the Use of Veterinary Antimicrobial Drugs in China. The objective of this study was to analyze the diversity of antibiotic resistance genes carried by the chicken intestinal microbiome in both standard farms (SFs), which implement antibiotic reduction and passed national acceptance, and nonstandard farms (NSFs), which do not implement antibiotic reductions, in Hebei Province. Fresh fecal samples of broiler chickens were collected from SFs (n = 4) and NSF (n = 1) and analyzed using high-throughput qPCR technology. Our findings revealed that all five farms exhibited a wide range of highly abundant ARGs, with a total of 201 ARGs and 7 MGEs detected in all fecal samples. The dominant ARGs identified conferred resistance to aminoglycosides, macrolide-lincosamide-streptomycin B (MLSB), and tetracycline antibiotics. Cellular protection mechanisms were found to be the primary resistance mechanism for these ARGs. The analysis of the co-occurrence network demonstrated a significant positive correlation between the abundance of MGEs and ARGs. The SF samples showed a significantly lower relative abundance of certain ARGs than the NSF samples (p < 0.05). The results of this study show that the abundance of ARGs demonstrated a downward trend after the implementation of the National Pilot Work Program for Action to Reduce the Usage of Veterinary Antimicrobial Drugs in Hebei Province, China.

Sage Essential Oil as an Antimicrobial Agent against Salmonella enterica during Beef Sous Vide Storage

Sous-vide is a process comprising vacuum-sealing food, heating it to the desired temperature, and circulating it in a water bath in a sous vide machine. This cooking technique is increasingly common in homes and catering establishments due to its simplicity and affordability. However, manufacturers and chef's recommendations for low-temperature and long-term sous-vide cooking in media raise food safety concerns, particularly when preparing beef tenderloin. In this study, Salmonella enterica was found to be inactivated by heat and sage essential oil (EO) in beef samples from musculus psoas major that had been sous vide processed. To determine whether heat treatment was likely to increase the sous vide efficiency, S. enterica and sage EO were mixed. After being vacuum-packed and injected with S. enterica, the samples were cooked at 50-65 °C through the sous vide technique for the prescribed time. On days 1, 3, and 6, the amounts of S. enterica, total bacteria, and coliform bacteria were measured in the control and treated groups of beef processed sous vide. Mass spectrometry was used to identify bacterial isolates on different days. On each day that was measured, a higher number of all the microbiota was found in the samples exposed to 50 °C for 5 min. The most frequently isolated microorganisms from both groups of samples were Pseudomonas fragi (17%), Pseudomonas cedrina (8%), and Proteus vulgaris (8%); in the treated group, also S. enterica (21%), Pseudomonas fragi (13%), and Pseudomonas veronii (6%). After the heat treatment of samples at 65 °C for 20 min, the total count of bacteria and coliform bacteria was zero. It has been shown that adding sage essential oil (EO) in combination with sous vide processing technique leads to the stabilization and safety of beef tenderloin.

Identification, Typing, and Drug Resistance Analysis of Escherichia coli in Two Different Types of Broiler Farms in Hebei Province

Hebei Province is an important area for breeding broiler chickens in China, but the antimicrobial resistance and prevalence of Escherichia coli (E. coli) are still unclear. A total of 180 cloacal samples from broiler farms in Hebei Province were collected and used for the isolation and identification of E. coli. The isolates were subjected to resistance phenotyping, resistance profiling, and genotyping, and some multiresistant strains were subjected to multilocus sequence typing (MLST). The results showed that 175 strains were isolated. Among both types of broiler farms, the ampicillin resistance rate was the highest, and the meropenem resistance rate was the lowest. Serious multiresistance was present in both types of broiler farms. Thirty strains of multidrug-resistant E. coli were typed by MLST to obtain a total of 18 ST types, with ST10 being the most prevalent. This study was to simply analyze the antimicrobial resistance and prevalence of E. coli in broiler chickens in Hebei Province after the implementation of the pilot work program of action to reduce the use of veterinary antimicrobials in standard farms (SFs) and nonstandard farms (NSFs). This study will provide a research basis and data support for the prevention and control of E. coli in Hebei.

LSPR-Based Biosensing Enables the Detection of Antimicrobial Resistance Genes

The development of rapid, simple, and accurate bioassays for the detection of nucleic acids has received increasing demand in recent years. Here, localized surface plasmon resonance (LSPR) spectroscopy for the detection of an antimicrobial resistance gene, sulfhydryl variable β-lactamase (blaSHV), which confers resistance against a broad spectrum of β-lactam antibiotics is used. By performing limit of detection experiments, a 23 nucleotide (nt) long deoxyribonucleic acid (DNA) sequence down to 25 nm was detected, whereby the signal intensity is inversely correlated with sequence length (23, 43, 63, and 100 nt). In addition to endpoint measurements of hybridization events, the setup also allowed to monitor the hybridization events in real-time, and consequently enabled to extract kinetic parameters of the studied binding reaction. Performing LSPR measurements using single nucleotide polymorphism (SNP) variants of blaSHV revealed that these sequences can be distinguished from the fully complementary sequence. The possibility to distinguish such sequences is of utmost importance in clinical environments, as it allows to identify mutations essential for enzyme function and thus, is crucial for the correct treatment with antibiotics. Taken together, this system provides a robust, label-free, and cost-efficient analytical tool for the detection of nucleic acids and will enable the surveillance of antimicrobial resistance determinants.

On the use of antibiotics to control plant pathogenic bacteria: a genetic and genomic perspective

Despite growing attention, antibiotics (such as streptomycin, oxytetracycline or kasugamycin) are still used worldwide for the control of major bacterial plant diseases. This raises concerns on their potential, yet unknown impact on antibiotic and multidrug resistances and the spread of their genetic determinants among bacterial pathogens. Antibiotic resistance genes (ARGs) have been identified in plant pathogenic bacteria (PPB), with streptomycin resistance genes being the most commonly reported. Therefore, the contribution of mobile genetic elements (MGEs) to their spread among PPB, as well as their ability to transfer to other bacteria, need to be further explored. The only well-documented example of ARGs vector in PPB, Tn5393 and its highly similar variants (carrying streptomycin resistance genes), is concerning because of its presence outside PPB, in Salmonella enterica and Klebsiella pneumoniae, two major human pathogens. Although its structure among PPB is still relatively simple, in human- and animal-associated bacteria, Tn5393 has evolved into complex associations with other MGEs and ARGs. This review sheds light on ARGs and MGEs associated with PPB, but also investigates the potential role of antibiotic use in resistance selection in plant-associated bacteria.

Antibacterial effect of kitchen herbs against pathogenic multidrug-resistant E. coli isolates from calf diarrhoea

Calf diarrhoea remains the biggest challenge both in the small and large farms. Infectious diarrhoea is associated with many pathogens, Escherichia coli being one, but majority are systematically treated with antibiotics. Since antimicrobial resistance (AMR) is a growing menace, the need to find alternative prophylactic solutions using popular kitchen herbs such as Trachyspermum ammi (carom seeds), Curcuma longa (turmeric) and cinnamon (Cinnamomum sp.) extracts is been investigated against virulent form of E. coli isolated from calf diarrhoea. The virulence factors identified in these isolates were ST (32.5%), LT (20%), eaeA (15%), stx1 (2.5%) and stx2 (5%) with the occurrence of the most common serogroups as O18 (15%) followed by O111 (12.5%). Highest resistance was seen with beta lactam + beta lactamase inhibitor (amoxicillin/clavulanic acid) followed by beta lactams (ampicillin, cefuroxime and cefepime). The zone of inhibition due to cinnamon (methanol) and carom seed (ethanol) extracts (500 to 250 μg/mL concentration) on E. coli bacteria was >19 mm, respectively. Turmeric, cinnamon and carom had the potency of inhibiting the pathogenic E. coli which maybe suggestive of its use in calf diets as prophylaxis against diarrhoea.

Antimicrobial Resistance Profiles and Molecular Characteristics of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Healthy Cattle and Pigs in Korea

Antimicrobial-resistant bacteria isolated from food animals pose a major health threat to the public on this planet. This study aimed to determine the susceptibility profiles of Escherichia coli isolated from cattle and pig fecal samples and investigate the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing E. coli using gene identification, conjugation, and Southern blot approach. Overall 293 E. coli were recovered from cattle (120 isolates) and pigs (173 isolates) in 7 provinces of Korea during 2017-2018. Ampicillin, chloramphenicol, streptomycin, and sulfisoxazole resistance rates were the highest in pigs' isolates (>60%, p ≤ 0.001) compared to that in cattle (3-39%). Multidrug resistance (MDR) was higher in pig isolates (73%) than in cattle (31%), and the MDR profile usually includes streptomycin, sulfisoxazole, and tetracycline. Resistance to critically important antimicrobials such as ceftiofur, colistin, and ciprofloxacin was higher in weaners than those from finishers in pigs. The qnrS gene was detected in 13% of the pig isolates. Eight isolates from pigs and one isolate from cattle were identified as ESBL-producers and ESBL genes belonged to bla_CTX-M-55 (n = 4), bla_CTX-M-14 (n = 3), and bla_CTX-M-65 (n = 2). Notably, the bla_CTX-M-65 and qnrS1 genes were found to be carried together in an identical plasmid (IncHI2) in two isolates from finisher pigs. The bla_CTX-M-carrying isolates belonged to phylogenetic groups B1 (n = 4), B2 (n = 2), A (n = 2), and D (n = 1). The bla_CTX-M genes and non-β-lactam resistance traits were transferred to the E. coli J53 recipient from seven bla_CTX-M-positive strains isolated from pigs. The bla_CTX-M genes belonged to the IncI1α, IncFII, and IncHI2 plasmids and are also associated with the ISEcp1, IS26, IS903, and orf477 elements. These findings suggested the possibility of bla_CTX-M-carrying E. coli transmission to humans through direct contact with cattle and pigs or contamination of food products.

Evaluation of Antimicrobial Resistance of Different Phylogroups of Escherichia coli Isolates from Feces of Breeding and Laying Hens

Animal and food sources are seen as a potential transmission pathway of multi-drug resistance (MDR) micro-organisms to humans. Escherichia. coli is frequently used as an indicator of fecal contamination in the food industry and known as a reservoir of antimicrobial resistance genes (ARGs). Microbial contamination as a major outcome for the poultry and egg industry and is a serious public health problem. In the present study we performed the quantification of β-glucoronidase positive E. coli in 60 fecal samples of breeding and laying hens collected in Portugal in 2019. Phylogenetic and pathotypic characterization, antimicrobial susceptibility, and detection of resistant extended-spectrum β-lactamase (ESBL) genes were assessed. The phylogenetic and pathogenic characterization and detection of ESBL genes were assessed by real-time PCR and antimicrobial susceptibility was evaluated using the disk diffusion method. Overall, E. coli quantification was 6.03 log CFU/g in breeding hens and 6.02 log CFU/g in laying hens. The most frequent phylogroups were B1. None of the isolates was classified as diarrheagenic E. coli (DEC). In total, 57% of the isolates showed MDR and 3.8% were positive for ESBL. Our study highlights that consumers may be exposed to MDR E. coli, presenting a major hazard to food safety and a risk to public health.

Association between Antibiotic Consumption and Resistance in Mink Production

Antibiotic consumption is considered to be a main driver of antibiotic resistant bacteria. Mink breeding follows a distinctive seasonal reproduction cycle, and all of the mink produced in the northern hemisphere are bred, born, and pelted around the same time of year. Some of the diseases are age-related, which is reflected in the seasonal variation of antibiotic consumption. The seasonality makes mink a good model for the investigation of the association between antibiotic consumption and resistance. The objectives of this study were (1) to monitor the farm level of antibiotic resistance during one production cycle and (2) to assess the potential associations between antibiotic consumption and resistance. Twenty-four farms were included in this study (Denmark n = 20, Iceland n = 2, and The Netherlands n = 2), following a cohort of animals born in 2018. Staphylococcus delphini and Escherichia coli were isolated from samples of the carcasses and faeces and were collected randomly. The isolates were susceptibility tested and subsequently divided into the sensitive wildtype (WT) and the resistant non-wildtype (NWT) populations. The antibiotic consumption relative to the sampling periods was assessed as having a short-term or a long-term impact, i.e., in two explanatory factors. For both S. delphini and E. coli, a large between-farm variation of NWT profiles was detected. In the final multivariable, generalized linear mixed models, significant associations between NWT isolates and the consumption of specific antibiotics were found: the short-term use of tetracyclines in the growth period was associated with the occurrence of tetracycline NWT E. coli in the growth period (OR: 11.94 [1.78; 89.28]), and the long-term use of macrolide and tetracyclines was associated with the occurrence of erythromycin NWT S. delphini in the weaning period (OR: 18.2 [2.26; 321.36]) and tetracycline NWT S. delphini in the growth period (OR: 8.2 [1.27; 63.31]), respectively. Farms with zero consumption in the study years prior to sampling also had a substantial proportion of NWT isolates, indicating that NWT isolates are persistent and/or widely spread in the environment. Generally, a high occurrence of tetracycline NWTs was observed. NWT isolates with resistance against the most commonly used antibiotics were found on all the farms, stressing the need for routine surveillance and the prudent use of antibiotics. The results offer a preview of the complex relationship between consumption and resistance, demonstrating some significant associations between use and resistance. Moreover, antibiotic-resistant bacteria are present even on farms with no antibiotic consumption over extended periods, and theoretical explanations supported by the data are offered.

Antibiotic susceptibility of Lactobacillus plantarum strains, isolated from katak

Several Lactobacillus species are accepted as microorganisms with Qualified Presumption of Safety (QPS) in the EFSA’s list. One of them, Lactobacillus plantarum is a widely distributed species with a proven probiotic potential and technological relevance. In addition, every strain must complete several requirements, before implementation. Antibiotic susceptibility is one of EFSA’s important criteria regarding the safety of probiotics. The reason is to avoid any possibility of antibiotic resistance genes transfer to opportunistic pathogens in the gut. In the present study 14 Lactobacillus plantarum strains were assessed for susceptibility to 21 antibiotics from different groups. A high number of resistant strains was determined toward 12 antibiotics (penicillins – penicillin, piperacillin; IIIth generation cephalosporins – cefotaxime, ceftriaxone, ceftazidime; glycopeptides – vancomycin; tetracyclines – tetracycline; aminoglycosides – gentamicin; macrolides – clarithromycin; quinolones – nalidixic acid, ciprofloxacin, levofloxacin). Concerning the other tested antibiotics, strain-specific antibiotic-sensitivity patterns were observed. Antibiotic resistance was also discussed as an advantage in the selection of probiotic strains, however only when it is not transferable. Estimated susceptibility patterns of some of tested candidate probiotic strains are also important, considering the use of the latter as agents accompanying antibiotic therapy

Removal of Emerging Contaminants from Wastewater Streams Using Membrane Bioreactors: A Review

Water is a very valuable natural resource. As the demand for water increases the presence of emerging contaminants in wastewater has become a growing concern. This is particularly true when one considers direct reuse of wastewater. Obtaining sufficient removal of emerging contaminants will require determining the level of removal for the various unit operations in the wastewater treatment process. Membrane bioreactors are attractive as they combine an activated sludge process with a membrane separation step. They are frequently used in a wastewater treatment process and can operate at higher solid loadings than conventional activated sludge processes. Determining the level of removal of emerging contaminants in the membrane bioreactor step is, therefore, of great interest. Removal of emerging contaminants could be by adsorption onto the biomass or membrane surface, biotransformation, size exclusion by the membrane, or volatilization. Given the fact that most emerging contaminants are low molecule weight non-volatile compounds, the latter two methods of removal are usually unimportant. However, biotransformation and adsorption onto the biomass are important mechanisms of removal. It will be important to determine if the microorganisms present at given treatment facility are able to remove ECs present in the wastewater.

Phloretin is protective in a murine salmonella enterica serovar typhimurium infection model

Salmonella, an important zoonotic pathogen, causes significant morbidity and mortality in both humans and animals. Phloretin mainly isolated from strawberries and apples has the effects of treating inflammation and pathogenic bacteria, but its protective efficacy and mechanism of action against Salmonella spp. are less clear. In this study, we found that phloretin alleviated body weight loss, colon length shortening, and colonic pathological damage caused by S. Typhimurium. Phloretin also decreased S. Typhimurium translocation to the mesenteric lymph nodes (MLN) and spleen. Further mechanism studies showed that phloretin significantly inhibited inflammation and oxidative stress levels in the colonic tissue. Phloretin also prevented S. Typhimurium-mediated impairment in the colon epithelium barrier by the regulation ZO-1 and occludin levels. Interestingly, phloretin did not inhibit S. typhimurium growth in vitro, but reduced the internalization of S. Typhimurium into Caco-2 cells. Taken together, these findings indicated that phloretin may be a new dietary strategy to combat the disease.

RETRACTED ARTICLE: Molecular detection of pathogenic Escherichia coli strains and their antibiogram associated with risk factors from diarrheic calves in Jimma Ethiopia

Diarrheagenic Escherichia coli are a number of pathogenic E. coli strains that cause diarrheal infection both in animal and human hosts due to their virulence factors. A cross sectional study was conducted between November, 2016 and April, 2017 to isolate and molecularly detect pathogenic E. coli from diarrheic calves to determine the pathogenic strains, antibiogram and associated risk factors in Jimma town. Purposive sampling technique was used to collect 112 fecal samples from diarrheic calves. Conventional culture and biochemical methods were conducted to isolate E. coli isolates. Molecular method was followed to identify virulence factors of pathogenic E. coli strains. Antimicrobial sensitivity patterns of the isolates were tested using the Kirby-Bauer disk diffusion method. A structured questionnaire was also used to collect information from dairy farms and socio-demographic data. The overall isolation rate of E. coli in calves was 51.8% (58/112) (95% CI 42.0-61.0). The occurrence of the bacterium differed significantly by age, colostrum feeding time, amount of milk given per time and navel treatment (P < 0.05). Multivariable analysis revealed that the odds of being infected was significantly highest in calves which fed 1-1.5 L amount of milk per a time (OR 5.38, 95% CI 1.66-17.45, P = 0.005). The overall virulence genes detection rate was 53.5% (95% CI 40.0-67.0). Eleven (19.6%) of eaeA, 6 (10.7%) of Stx1 and 13 (23.2%) of Stx2 genes were detected from calves isolates. Except ciprofloxacillin, all isolates were resistant to at least one drug. Multi drug resistance was recorded in 68.0% (38/56) of calves isolates. Neomycin, 83.3% (25/30), followed by amoxicillin, 53.3% (16/30) were the highest resisted virulence genes. The study demonstrated considerable isolation rate, multiple antimicrobial resistant isolates and high resistant virulent genes in diarrheic calves. It also indicated that the potential importance of calves as source of pathogenic E. coli strains and resistant genes for human diarrhea infection. Improving the hygienic practice of farms and wise use of antimicrobials could help to reduce the occurrence of pathogenic E. coli in farms. Hence, further studies are needed to describe all virulent factors and serotypes associated with the emergence of drug resistant pathogenic E. coli strains in calves.

Role of Recent Therapeutic Applications and the Infection Strategies of Shiga Toxin-Producing Escherichia coli

Shiga toxin-producing Escherichia coli (STEC) is a global foodborne bacterial pathogen that is often accountable for colon disorder or distress. STEC commonly induces severe diarrhea in hosts but can cause critical illnesses due to the Shiga toxin virulence factors. To date, there have been a significant number of STEC serotypes have been evolved. STECs vary from nausea and hemorrhoid (HC) to possible lethal hemolytic-based uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP). Inflammation-based STEC is usually a foodborne illness with Shiga toxins (Stx 1 and 2) thought to be pathogenesis. The STEC's pathogenicity depends significantly on developing one or more Shiga toxins, which can constrain host cell protein synthesis leading to cytotoxicity. In managing STEC infections, antimicrobial agents are generally avoided, as bacterial damage and discharge of accumulated toxins are thought the body. It has also been documented that certain antibiotics improve toxin production and the development of these species. Many different groups have attempted various therapies, including toxin-focused antibodies, toxin-based polymers, synbiotic agents, and secondary metabolites remedies. Besides, in recent years, antibiotics' efficacy in treating STEC infections has been reassessed with some encouraging methods. Nevertheless, the primary role of synbiotic effectiveness (probiotic and prebiotic) against pathogenic STEC and other enteropathogens is less recognized. Additional studies are required to understand the mechanisms of action of probiotic bacteria and yeast against STEC infection. Because of the consensus contraindication of antimicrobials for these bacterial pathogens, the examination was focused on alternative remedy strategies for STEC infections. The rise of novel STEC serotypes and approaches employed in its treatment are highlighted.

Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain

The role of food-producing environments in the emergence and spread of antimicrobial resistance (AMR) in EU plant-based food production, terrestrial animals (poultry, cattle and pigs) and aquaculture was assessed. Among the various sources and transmission routes identified, fertilisers of faecal origin, irrigation and surface water for plant-based food and water for aquaculture were considered of major importance. For terrestrial animal production, potential sources consist of feed, humans, water, air/dust, soil, wildlife, rodents, arthropods and equipment. Among those, evidence was found for introduction with feed and humans, for the other sources, the importance could not be assessed. Several ARB of highest priority for public health, such as carbapenem or extended-spectrum cephalosporin and/or fluoroquinolone-resistant Enterobacterales (including Salmonella enterica), fluoroquinolone-resistant Campylobacter spp., methicillin-resistant Staphylococcus aureus and glycopeptide-resistant Enterococcus faecium and E. faecalis were identified. Among highest priority ARGs bla CTX -M, bla VIM, bla NDM, bla OXA -48-like, bla OXA -23, mcr, armA, vanA, cfr and optrA were reported. These highest priority bacteria and genes were identified in different sources, at primary and post-harvest level, particularly faeces/manure, soil and water. For all sectors, reducing the occurrence of faecal microbial contamination of fertilisers, water, feed and the production environment and minimising persistence/recycling of ARB within animal production facilities is a priority. Proper implementation of good hygiene practices, biosecurity and food safety management systems is very important. Potential AMR-specific interventions are in the early stages of development. Many data gaps relating to sources and relevance of transmission routes, diversity of ARB and ARGs, effectiveness of mitigation measures were identified. Representative epidemiological and attribution studies on AMR and its effective control in food production environments at EU level, linked to One Health and environmental initiatives, are urgently required.

Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli and Klebsiella isolated from dairy farm milk, farm slurry and water in Punjab, India

Antibiotic resistance is a mushrooming pandemic at national and international levels which if not controlled at this very moment, can lead to global problems. Main reason for emerging bacterial resistance is repeated exposure of bacteria to antimicrobial agents and access of bacteria to increasingly large pools of antimicrobial resistance genes in mixed bacterial populations. A total of 51 villages were sampled in the current study contributing to a total of 153 farms. A total of 612 samples comprising 153 each of raw pooled milk samples, slurry, animal drinking water and human drinking water were gathered from small, medium and large farms located in all seven tehsils of Ludhiana district of Punjab. In addition to that, 37 samples of village pond water were also collected from the targeted villages. Out of total 153 slurry, raw pooled milk samples, animal drinking water and human drinking water samples (each), the prevalence of 24.8%, 60%, 26.7% and 16.3% was found for E. coli respectively. On the other hand, for Klebsiella, the overall prevalence of 19.6%, 51%, 20.2% and 5.8% was found from slurry, raw pooled milk samples, animal drinking water and human drinking water respectively. In all matrices, the comparative frequency of resistance genes in positive isolates of E. coli and K. pneumoniae was: tetA > tetB > tetC, qnrS > qnrB > qnrA, sulII > sulI > sulIII. The highest proportion of resistance genes was found in slurry (193 genes) followed by milk (71 genes). The overall pattern of resistant genes was tetA > sulII > qnrS. In conclusion, data from the present study suggested that commensal E. coli and Klebsiella may act as reservoirs of antimicrobial drug resistance genes which may be mobilised into human populations and untreated animal waste may be considered an important source of resistant bacteria leading to environmental pollution.

Properties affecting transfer and expression of degradative plasmids for the purpose of bioremediation

Plasmids, circular DNA that exist and replicate outside of the host chromosome, have been important in the spread of non-essential genes as well as the rapid evolution of prokaryotes. Recent advances in environmental engineering have aimed to utilize the mobility of plasmids carrying degradative genes to disseminate them into the environment for cost-effective and environmentally friendly remediation of harmful contaminants. Here, we review the knowledge surrounding plasmid transfer and the conditions needed for successful transfer and expression of degradative plasmids. Both abiotic and biotic factors have a great impact on the success of degradative plasmid transfer and expression of the degradative genes of interest. Properties such as ecological growth strategies of bacteria may also contribute to plasmid transfer and may be an important consideration for bioremediation applications. Finally, the methods for detection of conjugation events have greatly improved and the application of these tools can help improve our understanding of conjugation in complex communities. However, it remains clear that more methods for in situ detection of plasmid transfer are needed to help detangle the complexities of conjugation in natural environments to better promote a framework for precision bioremediation.

Investigation of Stress Response Genes in Antimicrobial Resistant Pathogens Sampled from Five Countries

Pathogens, which survive from stressed environmental conditions and evolve with antimicrobial resistance, cause millions of human diseases every year in the world. Fortunately, the NCBI Pathogen Detection Isolates Browser (NPDIB) collects the detected stress response genes and antimicrobial resistance genes in pathogen isolates sampled around the world. While several studies have been conducted to identify important antimicrobial resistance genes, little work has been done to analyze the stress response genes in the NPDIB database. In order to address this, this work conducted the first comprehensive statistical analysis of the stress response genes from five countries of the major residential continents, including the US, the UK, China, Australia, and South Africa. Principal component analysis was first conducted to project the stress response genes onto a two-dimensional space, and hierarchical clustering was then implemented to identify the outlier (i.e., important) genes that show high occurrences in the historical data from 2010 to 2020. Stress response genes and AMR genes were finally analyzed together to investigate the co-occurring relationship between these two types of genes. It turned out that seven genes were commonly found in all five countries (i.e., arsR, asr, merC, merP, merR, merT, and qacdelta1). Pathogens E. coli and Shigella, Salmonella enterica, and Klebsiella pneumoniae were the major pathogens carrying the stress response genes. The hierarchical clustering result showed that certain stress response genes and AMR genes were grouped together, including golT~golS and mdsB~mdsC, ymgB and mdtM, and qacEdelta1 and sul1. The occurrence analysis showed that the samples containing three stress response genes and three AMR genes had the highest detection frequency in the historical data. The findings of this work on the important stress response genes, along with their connection with AMR genes, could inform future drug development that targets stress response genes to weaken antimicrobial resistance pathogens.

A novel toxoflavin-quenching regulation in bacteria and its application to resistance cultivars

The toxoflavin (Txn), broad host range phytotoxin produced by a variety of bacteria, including Burkholderia glumae, is a key pathogenicity factor of B. glumae in rice and field crops. Two bacteria exhibiting Txn‐degrading activity were isolated from healthy rice seeds and identified as Sphingomonas adhaesiva and Agrobacterium sp. respectively. The genes stdR and stdA, encoding proteins responsible for Txn degradation of both bacterial isolates, were identical, indicating that horizontal gene transfer occurred between microbial communities in the same ecosystem. We identified a novel Txn‐quenching regulation of bacteria, demonstrating that the LysR‐type transcriptional regulator (LTTR) StdR induces the expression of the stdA, which encodes a Txn‐degrading enzyme, in the presence of Txn as a coinducer. Here we show that the bacterial StdR^Txn‐quenching regulatory system mimics the ToxR^Txn‐mediated biosynthetic regulation of B. glumae. Substrate specificity investigations revealed that Txn is the only coinducer of StdR and that StdA has a high degree of specificity for Txn. Rice plants expressing StdA showed Txn resistance. Collectively, bacteria mimic the mechanism of Txn biosynthesis regulation, employ it in the development of a Txn‐quenching regulatory system and share it with neighbouring bacteria for survival in rice environments full of Txn.

Estimation of the Prevalence of Antimicrobial Resistance in Badgers (Meles meles) and Foxes (Vulpes vulpes) in Northern Ireland

Antimicrobial resistant (AMR) bacteria can be shared between humans and animals, through food, water, and the environment. Wild animals are not only potential reservoirs of AMR, but are also sentinels mirroring the presence of AMR zoonotic bacteria in the environment. In Northern Ireland, little is known about levels of AMR in bacteria in wildlife, thus the current study aimed to estimate the prevalence of AMR bacteria in wildlife using wildlife species from two ongoing surveys as a proxy. Nasopharyngeal swabs and faecal samples from European badgers (Meles meles) (146 faecal samples; 118 nasal samples) and red foxes (Vulpes vulpes) (321 faecal samples; 279 nasal samples) were collected throughout Northern Ireland and were used to survey for the presence of extended spectrum beta lactamase resistant and AmpC-type beta lactamases Escherichia coli (ESBL/AmpC), Salmonella spp. (only in badgers) and methicillin resistant Staphylococcus aureus (MRSA). ESBLs were detected in 13 out of 146 badger faecal samples (8.90%) and 37 out of 321 of fox faecal samples (11.53%), all of them presenting multi-drug resistance (MDR). Fourteen out of 146 (9.59%) badger faecal samples carried Salmonella spp. [S. Agama (n = 9), S. Newport (n = 4) and S. enterica subsp. arizonae (n = 1)]. Overall, AMR was found only in the S. enterica subsp. arizonae isolate (1/14, 7.14%). No MRSA were detected in nasopharyngeal swabs from badgers (n = 118) and foxes (n = 279). This is the first attempt to explore the prevalence of AMR in the two common wildlife species in Northern Ireland. These findings are important as they can be used as a base line for further research exploring the origin of the found resistance. These results should encourage similar surveys where environmental samples are included to bring better understanding of AMR dynamics, and the impact on wildlife, domestic livestock and humans.

Vancomycin prophylaxis for revision hip arthroplasty in penicillin and cephalosporin sensitive patients: Is dose adjustment necessary in accordance with blood loss and fluid replacement?

OBJECTIVE

The aims of this study were (1) to investigate the changes in the serum concentration of prophylactically administrated vancomycin in the perioperative period of revision hip arthroplasty in penicillin/cephalosporin-allergic patients, (2) to assess whether the postoperative re-administration of vancomycin is needed, and (3) to determine the relationships of vancomycin serum concentration with blood loss, body weight, and fluid replacement in such patients.

METHODS

This study consisted of 29 patients (20 females, 9 males; mean age=63.3 years; age range=45-79 years) with a history of penicillin/cephalosporin allergy undergoing revision hip arthroplasty secondary to aseptic loosening or periprosthetic fractures. Serum vancomycin levels were measured (1) before administration of vancomycin, (2) at the time of skin incision, (3) every 1,5 hours thereafter until the end of the operation, (4) during the skin closure, and (5) after three and 12 hours from the initial dosage. Data regarding body weight, amounts of intraoperative blood loss, fluid and blood replacements and postoperative wound drainage were recorded.

RESULTS

The average blood loss, fluid replacement, and drain volume were 1280.3±575.8 (500-2700) mL, 2922.6±768.8 (1700-4600) mL, and 480.2±163.7 (200-850) mL, respectively. The mean levels of serum vancomycin were 46.3±21.8 (14.1-80.7) mg/L at the time of skin incision, 17.9±4.7 (9.4-30.9) and 9.8±2.2 (4.3-13.8) mg/L after 1.5 and 3 hours from the beginning of the surgery and 5.1±1.1 (2.9-6.8)mg/L after 12th hour postoperatively. The measured vancomycin levels were below the effective serum concentrations (< 5 mg/L) for 18 patients at 12 hours the administration of the first dose. A moderate level negative correlation between the blood loss/body weight ratio and vancomycin levels was found (p=0.004, r=-0.493). Predictive ROC curve analysis resulted in determining a blood loss volume higher than 1150 ml and a blood loss/body weight ratio higher than 18,5 is significant to estimate the vancomycin level below the minimum effective serum level at 12th hour postoperatively (AUC=0.793±0.16, p=0.009, AUC=0.753) 26±0.12, p=0.025, respectively).

CONCLUSION

Evidence from this study has indicated vancomycin concentration at 12th hour is below the effective level in most patients. Thus, earlier repetitive infusion of vancomycin seems to be necessary in penicillin/cephalosporin-allergic patients undergoing revision hip arthroplasty, especially in those with high blood loss.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Extended Spectrum β-Lactamase (ESBL) Producing Escherichia coli in Pigs and Pork Meat in the European Union

The aim of this article is to review the fast and worldwide distribution of ESBL enzymes and to describe the role of the pork production chain as a reservoir and transmission route of ESBL-producing Escherichia coli and ESBLs in the European Union (EU). The use of β-lactam antibiotics in swine production and the prevalence of ESBL producing E. coli in fattening pigs and pork meat across Europe is analyzed. Overall, an increasing trend in the prevalence of presumptive ESBL producing E. coli in fattening pigs in the EU has been observed in the last decade, although with major differences among countries, linked to different approaches in the use of antimicrobials in pork production within the EU. Moreover, the various dissemination pathways of these bacteria along the pork production chain are described, along with factors at farm and slaughterhouse level influencing the risk of introducing or spreading ESBL producing bacteria throughout the food chain.

Soil protein as a potential antimicrobial agent against methicillin -resistant Staphylococcus aureus

Recently, the interest is increasing to find alternatives to replace the usage of antibiotics since their massive and improper usage enhance the antibiotic resistance in human pathogens. In this study, for the first time we showed that the soil proteins have very high antibacterial activity (98% of growth inhibition) against methicillin resistant Staphylococcus aureus (MRSA), one of the most threatening human pathogens. We found that the protein extract (C3) from the forest with past intensive management showed higher antibacterial activity than that of unmanaged forest. The MIC and IC₅₀ were found to be 30 and 15.0 μg protein g^-1 dry soil respectively. C3 was found to kill the bacteria by cell wall disruption and genotoxicity which was confirmed by optical and fluorescent microscopy and comet assay. According to qPCR study, the mecA (the antibiotic resistant gene) expression in MRSA was found to be down-regulated after C3 treatment. In contrast, C3 showed no hemolytic toxicity on human red blood cells which was confirmed by hemolytic assay. According to ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), 144 proteins were identified in C3 among which the majority belonged to Gram negative bacteria (45.8%). Altogether, our results will help to develop novel, cost-effective, non-toxic and highly efficient antibacterial medicines from natural sources against antibiotic resistant infections.

Substandard Quality of the Antimicrobials Sold in the Street Markets in Haiti

This pilot study was conducted to analyze the quality of the antimicrobials sold in the street markets in Port-au-Prince, Haiti. A total of 258 packs containing antimicrobials were bought in 28 street markets in Port-au-Prince (Haiti). Tablets and contents of capsules included in 196 packs were analyzed using a Raman handheld spectrometer (NanoRAM of BWTEK, Model: BWS456-785) during the first quarter of 2019. Three out of 11 antimicrobials (Amoxicillin, Metronidazole, and Cotrimoxazole) had a high spectral match with an HQI ≥ 90 to the respective authentic medicine for more than 95% of their tablets/capsules. For six antimicrobials (Tetracycline, Erythromycin, Cloxacillin, Azithromycin, Clarithromycin, and the combination Amoxicillin + Clavulanic Acid) none of their tablets/capsules showed a sufficient spectral match with the authentic medicine. This finding indicates that these products sold in the markets did not contain the labeled drug and/or contained a degraded drug. In addition to the fact that prescription antimicrobials can be purchased in street markets, the present field study found that for most of them (including "Watch" antimicrobials according to the AWaRe classification) were substandard, which contributes to the present antimicrobials resistance epidemic.

Akkermansia muciniphila protects intestinal mucosa from damage caused by S. pullorum by initiating proliferation of intestinal epithelium

Akkermansia muciniphila, a novel mucin-degrading bacterium, has been demonstrated to prevent the development of obesity and related complications. However, whether it can protect poultry from intestinal mucosal damage by enteropathogens has never been mentioned. In this study, we found that A. muciniphila colonized in the intestine and then relieved intestinal mucosal damage in chicks caused by S. pullorum, including anatomical and morphological damage, alleviation of body weight and intestinal inflammation. The repair process activated by A. muciniphila is accompanied by an increase in the number of goblet cells in the chick’s intestine and an up-regulation of Mucin 2 and trefoil factor 2 (Tff2). In addition, we also demonstrate that A. muciniphila improved colon length, crypt depth, increased the proliferating cell nuclear antigen, with the accelerated proliferation of intestinal epithelium through Wnt/β-catenin signaling pathway, thereby restoring the damaged intestinal mucosa. This study suggests that A. muciniphila activates the proliferation of intestinal cells protecting the intestinal barrier, thus relieving infection with S. pullorum in chickens.

Antimicrobial resistance in a One Health context: exploring complexities, seeking solutions, and communicating risks

Four articles presented in this special issue of Annals of the New York Academy of Sciences stem from a meeting of experts on antimicrobial resistance (AMR) in food animal production hosted by the New York Academy of Sciences on May 8 and 9, 2018. The articles discuss (1) competing considerations of the criticality of different classes of antimicrobials used for human and animal health and how guidelines and regulations might result in more prudent patterns of use; (2) the increasingly recognized importance of the environment (i.e., soil, water, and air) as a reservoir of resistant bacteria and resistance genes as well as a pathway for the dissemination of AMR between human and animal host populations; (3) established and novel solutions for measuring and containing the AMR problem; and (4) effective strategies for communicating to consumers the risks of AMR spreading from food production and other nonhuman sources. The authors of this commentary served as the scientific advisory committee to the meeting.

Isolation and characterization of E. coli strains causing intramammary infections from dairy animals and wild birds

The study was conducted to estimate the prevalence of Escherichia coli (E. coli) in sub-clinically mastitic (SCM) animals, and in wild and migratory birds which may act as reservoir disseminating such pathogen. Farm hygiene, management and milking procedures were listed through a questionnaire. Thirty lactating cows and 15 lactating buffaloes from five small-scale dairy farms were randomly selected and screened for subclinical mastitis (SCM) using California Mastitis Test (CMT) and somatic cell count (SCC). In addition, 80 teat skin swabs, 5 drinking water samples and 38 wild and migratory bird faecal matter were also collected. All samples were processed for E. coli isolation by culturing on Levine’s Eosin Methylene Blue (L-EMB) agar, followed by purification and biochemical identification. Positive samples were subjected to molecular identification and serotyping. In addition, the presence of extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing E. coli have been reported by antimicrobial sensitivity testing. Escherichia coli were isolated from 7.7%, 50% and 50% of the positive CMT cows’ quarters, cows’ composite and buffaloes’ composite milk samples, respectively. In addition, 14% of cows’ teats, 20% of water samples, 70% of faecal matter from wild bird, and 33.3% of faecal matter from migratory waterfowls were carrying E. coli. Serotyping, antibiotic-resistant pattern and phylogenetic analysis have pointed the bearable implication of milking hygiene and wild birds in disseminating E. coli strains causing intramammary infections.

Microbiological quality of mink feed raw materials and feed production area

BACKGROUND

The quality of mink feed and raw ingredients affect health and growth. The objectives of this study were to examine the microbiological quality of ready-to-eat mink feed and its raw ingredients, screen the plant part of the feed for mycotoxins, and determine the hygiene of the production environment in the feed processing facilities. The results of the study are important for identification of critical steps in the feed production and for formulation of recommendations for improvements of production processes to obtain better quality feed. Feed and swab samples were taken at three Danish mink feed producers October 2016 and May 2017, respectively. Viable counts, detection of methicillin-resistant Staphylococcus aureus (MRSA), influenza virus and filamentous fungi were performed together with qualitative chemical analyses for bioactive fungal metabolites and mycotoxins. Swab samples were analyzed for total viable counts.

RESULTS

Viable counts varied between 7.2 × 102 and 9.3 × 107 cfu/g in raw ingredients and between 107 and 109 cfu/cm2 on different surfaces at the feed production facilities. A pork meat product, pork haemoglobin, pork liver and a poultry mix was found positive for MRSA, while monophasic Salmonella [4,5,12:i:-] was detected in a pork meat product. Neither MRSA nor Salmonella was detected in any ready-to-eat feed. Influenza A virus was not detected in any sample. Filamentous fungi were detected in all analysed samples of ready-to-eat feed while dihydro-demethyl-sterigmatocystin was found in almost 50% of all ready-to-eat feed samples and in 80% of the sugar beet pulp. Fumonisins and other Fusarium toxins were found especially in corn gluten meal and extruded barley and wheat.

CONCLUSIONS

Mink feed contained a cocktail of mycotoxins and bacteria, which may not per se cause clinical disease, but may affect organ function and animal performance and well-being.

Translating antibiotic prescribing into antibiotic resistance in the environment: A hazard characterisation case study

The environment receives antibiotics through a combination of direct application (e.g., aquaculture and fruit production), as well as indirect release through pharmaceutical manufacturing, sewage and animal manure. Antibiotic concentrations in many sewage-impacted rivers are thought to be sufficient to select for antibiotic resistance genes. Yet, because antibiotics are nearly always found associated with antibiotic-resistant faecal bacteria in wastewater, it is difficult to distinguish the selective role of effluent antibiotics within a 'sea' of gut-derived resistance genes. Here we examine the potential for macrolide and fluoroquinolone prescribing in England to select for resistance in the River Thames catchment, England. We show that 64% and 74% of the length of the modelled catchment is chronically exposed to putative resistance-selecting concentrations (PNEC) of macrolides and fluoroquinolones, respectively. Under current macrolide usage, 115 km of the modelled River Thames catchment (8% of total length) exceeds the PNEC by 5-fold. Similarly, under current fluoroquinolone usage, 223 km of the modelled River Thames catchment (16% of total length) exceeds the PNEC by 5-fold. Our results reveal that if reduced prescribing was the sole mitigating measure, that macrolide and fluoroquinolone prescribing would need to decline by 77% and 85%, respectively, to limit resistance selection in the catchment. Significant reductions in antibiotic prescribing are feasible, but innovation in sewage-treatment will be necessary for achieving substantially-reduced antibiotic loads and inactivation of DNA-pollution from resistant bacteria. Greater confidence is needed in current risk-based targets for antibiotics, particularly in mixtures, to better inform environmental risk assessments and mitigation.

Detection of Virulence Genes in Multidrug Resistant Enterococci Isolated from Feedlots Dairy and Beef Cattle: Implications for Human Health and Food Safety

The misuse/abuse of antibiotics in intensive animal rearing and communities led to the emergence of resistant isolates such as vancomycin-resistant enterococci (VREs) worldwide. This has become a major source of concern for the public health sector. The aim of this study was to report the antibiotic resistance profiles and to highlight the presence of virulence genes in VREs isolated from feedlots cattle of the North-West Province of South Africa. 384 faecal samples, 24 drinking troughs water, and 24 soil samples were collected aseptically from 6 registered feedlots. Biochemical and molecular methods were used to identify and categorise the enterococci isolates. Their antibiotic resistance profiles were assessed and genotypic methods were used to determine their antibiotic resistance and their virulence profiles. 527 presumptive isolates were recovered, out of which 289 isolates were confirmed as Enterococcus sp. Specifically, E. faecalis (9%), E. faecium (10%), E. durans (69%), E. gallinarum (6%), E. casseliflavus (2%), E. mundtii (2%), and E. avium (2%) were screened after molecular assays. VanA (62%), vanB (17%), and vanC (21%) resistance genes were detected in 176 Enterococcus sp., respectively. Moreover, tetK (26), tetL (57), msrA/B (111), and mefA (9) efflux pump genes were detected in 138 VRE isolates. Multiple antibiotic resistances were confirmed in all the VRE isolates of this study; the most common antibiotic resistance phenotype was TET^R-AMP^R-AMX^R-VAN^R-PEN^R-LIN^R-ERY^R. CylA, hyl, esp, gelE, and asa1 virulence genes were detected in 86 VREs with the exception of vancomycin-resistant E. mundtii isolates that did not display any virulence factor. Most VRE isolates had more than one virulence genes but the most encountered virulence profile was gelE-hyl. Potentially pathogenic multidrug resistant VREs were detected in this study; this highlights the impact of extensive usage of antimicrobials in intensive animal rearing and its implications on public health cannot be undermined.

Antimicrobial Efficiency of Essential Oils from Traditional Medicinal Plants of Asir Region, Saudi Arabia, over Drug Resistant Isolates

Antimicrobial resistance (AMR) is a recurring global problem, which constantly demands new antimicrobial compounds to challenge the resistance. It is well known that essential oils (EOs) have been known for biological activities including antimicrobial properties. In this study, EOs from seven aromatic plants of Asir region of southwestern Saudi Arabia were tested for their antimicrobial efficacy against four drug resistant pathogenic bacterial isolates (Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Streptococcus typhimurium) and one fungal isolate (Candida albicans). Chemical compositions of EOs were determined by gas chromatography-mass spectrometry (GC-MS). The results revealed that EOs from Mentha cervina, Ocimum basilicum, and Origanum vulgare proved most active against all isolates with inhibitory zone range between 17 and 45 mm. The lowest minimum inhibitory concentration (MIC) of 0.025mg/ml was observed for Staph. aureus and Streptococcus pyogenes with EO of Origanum vulgare. All the three EOs showed significant anticandida activity. The results related to EOs from Mentha cervina, Ocimum basilicum, and Origanum vulgare demonstrated significant antimicrobial efficacy against drug resistant microorganisms.

Prevalence and Characterization of β-Lactamases Genes and Class 1 Integrons in Multidrug-Resistant Escherichia coli Isolates from Chicken Meat in Korea

Antimicrobial resistance has become a serious public health threat throughout the world, and therapeutic options for several infectious diseases are currently limited by the presence of multidrug-resistant (MDR) bacteria. This study was designed to examine the drug resistance patterns, the prevalence of the β-lactamases, and class 1 integrons in MDR Escherichia coli isolates from chicken meat in Korea. Among 200 chicken meat samples, 101 isolates were observed to be positive for E. coli, of which 57 were identified as MDR E. coli. Among 57 MDR E. coli isolates, the prevalence of bla gene, bla_CTX-M-1, bla_CTX-M-14, and bla_TEM-1, were identified in 2, 4, and 16 E. coli strains, respectively; only 1 E. coli strain had both, bla_TEM-1 and bla_CTX-M-1 genes. Twenty-one of the 57 MDR E. coli isolates also carried class 1 integrons, and 5 different gene cassette arrangements were found in 14 of the 21 class 1 integron-positive isolates. The β-lactamase-producing E. coli and integron-positive E. coli had significantly higher resistance to 16 antimicrobial drugs than the non-β-lactamase-producing E. coli and the integron-negative E. coli (p < 0.05). Our findings suggest that β-lactamase and class 1 integrons are widely distributed in E. coli isolates from chicken meat, and directly contribute to resistance to diverse antimicrobial agents. Therefore, continuous investigation of integron gene cassette arrays will provide useful information regarding antimicrobial resistance mechanisms.

Serotype Diversity and Antimicrobial Resistance among Salmonella enterica Isolates from Patients at an Equine Referral Hospital

Although Salmonella enterica can produce life-threatening colitis in horses, certain serotypes are more commonly associated with clinical disease. Our aim was to evaluate the proportional morbidity attributed to different serotypes, as well as the phenotypic and genotypic antimicrobial resistance (AMR) of Salmonella isolates from patients at an equine referral hospital in the southern United States. A total of 255 Salmonella isolates was obtained from clinical samples of patients admitted to the hospital between 2007 and 2015. Phenotypic resistance to 14 antibiotics surveilled by the U.S. National Antimicrobial Resistance Monitoring System was determined using a commercially available panel. Whole-genome sequencing was used to identify serotypes and genotypic AMR. The most common serotypes were Salmonella enterica serotype Newport (18%), Salmonella enterica serotype Anatum (15.2%), and Salmonella enterica serotype Braenderup (11.8%). Most (n = 219) of the isolates were pansusceptible, while 25 were multidrug resistant (≥3 antimicrobial classes). Genes encoding beta-lactam resistance, such as bla_CMY-2, bla_SHV-12, bla_CTX-M-27, and bla_TEM-1B, were detected. The qnrB2 and aac(6')-Ib-cr genes were present in isolates with reduced susceptibility to ciprofloxacin. Genes encoding resistance to gentamicin (aph(3')-Ia, aac(6')-IIc), streptomycin (strA and strB), sulfonamides (sul1), trimethoprim (dfrA), phenicols (catA), tetracyclines [tet(A) and tet(E)], and macrolides [ere(A)] were also identified. The main predicted incompatibility plasmid type was I1 (10%). Core genome-based analyses revealed phylogenetic associations between isolates of common serotypes. The presence of AMR Salmonella in equine patients increases the risk of unsuccessful treatment and causes concern for potential zoonotic transmission to attending veterinary personnel, animal caretakers, and horse owners. Understanding the epidemiology of Salmonella in horses admitted to referral hospitals is important for the prevention, control, and treatment of salmonellosis.IMPORTANCE In horses, salmonellosis is a leading cause of life-threatening colitis. At veterinary teaching hospitals, nosocomial outbreaks can increase the risk of zoonotic transmission, lead to restrictions on admissions, impact hospital reputation, and interrupt educational activities. The antimicrobials most often used in horses are included in the 5th revision of the World Health Organization's list of critically important antimicrobials for human medicine. Recent studies have demonstrated a trend of increasing bacterial resistance to drugs commonly used to treat Salmonella infections. In this study, we identify temporal trends in the distribution of Salmonella serotypes and their mechanisms of antimicrobial resistance; furthermore, we are able to determine the likely origin of several temporal clusters of infection by using whole-genome sequencing. These data can be used to focus strategies to better contain the dissemination and enhance the mitigation of Salmonella infections and to provide evidence-based policies and guidelines to steward antimicrobial use in veterinary medicine.

Use of antibiotics in broiler production: Global impacts and alternatives

Antibiotics are used to fight bacterial infections. However, a selective pressure gave rise to bacteria resistant to antibiotics. This leaves scientists worried about the danger to human and animal health. Some strategies can be borrowed to reduce the use of antibiotics in chicken farms. Much research has been carried out to look for natural agents with similar beneficial effects of growth promoters. The aim of these alternatives is to maintain a low mortality rate, a good level of animal yield while preserving environment and consumer health. Among these, the most popular are probiotics, prebiotics, enzymes, organic acids, immunostimulants, bacteriocins, bacteriophages, phytogenic feed additives, phytoncides, nanoparticles and essential oils.

Research progress on distribution, migration, transformation of antibiotics and antibiotic resistance genes (ARGs) in aquatic environment

Antimicrobial and antibiotics resistance caused by misuse or overuse of antibiotics exposure is a growing and significant threat to global public health. The spread and horizontal transfer of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) by the selective pressure of antibiotics in an aquatic environment is a major public health issue. To develop a better understanding of potential ecological risks die to antibiotics and ARGs, this study mainly summarizes research progress about: (i) the occurrence, concentration, fate, and potential ecological effects of antibiotics and ARGs in various aquatic environments, (ii) the threat, spread, and horizontal gene transfer (HGT) of ARGs, and (iii) the relationship between antibiotics, ARGs, and ARB. Finally, this review also proposes future research direction on antibiotics and ARGs.

Acquisition and dissemination of cephalosporin-resistant E. coli in migratory birds sampled at an Alaska landfill as inferred through genomic analysis

Antimicrobial resistance (AMR) in bacterial pathogens threatens global health, though the spread of AMR bacteria and AMR genes between humans, animals, and the environment is still largely unknown. Here, we investigated the role of wild birds in the epidemiology of AMR Escherichia coli. Using next-generation sequencing, we characterized cephalosporin-resistant E. coli cultured from sympatric gulls and bald eagles inhabiting a landfill habitat in Alaska to identify genetic determinants conferring AMR, explore potential transmission pathways of AMR bacteria and genes at this site, and investigate how their genetic diversity compares to isolates reported in other taxa. We found genetically diverse E. coli isolates with sequence types previously associated with human infections and resistance genes of clinical importance, including bla_CTX-M and bla_CMY. Identical resistance profiles were observed in genetically unrelated E. coli isolates from both gulls and bald eagles. Conversely, isolates with indistinguishable core-genomes were found to have different resistance profiles. Our findings support complex epidemiological interactions including bacterial strain sharing between gulls and bald eagles and horizontal gene transfer among E. coli harboured by birds. Results suggest that landfills may serve as a source for AMR acquisition and/or maintenance, including bacterial sequence types and AMR genes relevant to human health.

Drug Resistance Patterns of Escherichia coli in Ethiopia: A Meta-Analysis

Background

Antimicrobial drug resistance is a global threat for treatment of infectious diseases and costs life and money and threatens health delivery system's effectiveness. The resistance of E. coli to frequently utilized antimicrobial drugs is becoming a major challenge in Ethiopia. However, there is no inclusive countrywide study. Therefore, this study intended to assess the prevalence of E. coli resistance and antimicrobial-specific resistance pattern among E. coli clinical isolates in Ethiopia.

Methods

Articles were retrieved from PubMed, Embase, and grey literature from 2007 to 2017. The main outcome measures were overall E. coli and drug-specific resistance patterns. A random-effects model was used to determine pooled prevalence with 95% confidence interval (CI), using DerSimonian and Laird method. In addition, subgroup analysis was conducted to improve the outcome. The study bias was assessed by Begg's funnel plot. This study was registered in PROSPERO as follows: PROSPERO 2017: CRD42017070106.

Results

Of 164 articles retrieved, 35 articles were included. A total of 19,235 study samples participated in the studies and 2,635 E. coli strains were isolated. Overall, E. coli antibacterial resistance was 45.38% (95% confidence interval (CI): 33.50 to 57.27). The resistance pattern ranges from 62.55% in Addis Ababa to 27.51% in Tigray region. The highest resistance of E. coli reported was to ampicillin (83.81%) and amoxicillin (75.79%), whereas only 13.55% of E. coli isolates showed resistance to nitrofurantoin.

Conclusion

E. coli antimicrobial resistance remains high with disparities observed among regions. The bacterium was found to be highly resistant to aminopenicillins. The finding implies the need for effective prevention strategies for the E. coli drug resistance and calls for multifaceted approaches with full involvement of all stakeholders.

Identifying non-traditional stakeholders with whom to engage, when mitigating antimicrobial resistance in foodborne pathogens (Canada)

Objective

Antimicrobial resistance (AMR) is a critical public health issue that involves interrelationships between people, animals, and the environment. Traditionally, interdisciplinary efforts to mitigate AMR in the food chain have involved public health, human and veterinary medicine, and agriculture stakeholders. Our objective was to identify a more diverse range of stakeholders, beyond those traditionally engaged in AMR mitigation efforts, via diagramming both proximal and distal factors impacting, or impacted by, use and resistance along the Canadian food chain.

Results

We identified multiple stakeholders that are not traditionally engaged by public health when working to mitigate AMR in the food chain, including those working broadly in the area of food (e.g., nutrition, food security, international market economists) and health (e.g., health communication, program evaluation), as well as in domains as diverse as law, politics, demography, education, and social innovation. These findings can help researchers and policymakers who work on issues related to AMR in the food chain to move beyond engaging the ‘traditional’ agri-food stakeholders (e.g., veterinarians, farmers), to also engage those from the wider domains identified here, as potential stakeholders in their AMR mitigation efforts.

A Review on the Rising Prevalence of International Standards: Threats or Opportunities for the Agri-Food Produce Sector in Developing Countries, with a Focus on Examples from the MENA Region

Food safety standards are a necessity to protect consumers' health in today's growing global food trade. A number of studies have suggested safety standards can interrupt trade, bringing financial and technical burdens on small as well as large agri-food producers in developing countries. Other examples have shown that economical extension, key intermediaries, and funded initiatives have substantially enhanced the capacities of growers in some countries of the Middle East and North Africa (MENA) region to meet the food safety and quality requirements, and improve their access to international markets. These endeavors often compensate for the weak regulatory framework, but do not offer a sustainable solution. There is a big gap in the food safety level and control systems between countries in the MENA region and those in the developed nations. This certainly has implications for the safety of fresh produce and agricultural practices, which hinders any progress in their international food trade. To overcome the barriers of legal and private standards, food safety should be a national priority for sustainable agricultural development in the MENA countries. Local governments have a primary role in adopting the vision for developing and facilitating the implementation of their national Good Agricultural Practices (GAP) standards that are consistent with the international requirements and adapted to local policies and environment. Together, the public and private sector's support are instrumental to deliver the skills and infrastructure needed for leveraging the safety and quality level of the agri-food chain.

Disparities in the regional, hospital and individual levels of antibiotic use in gallstone surgery in Sweden

Background

Antimicrobial resistance may be promoted by divergent routines and lack of conformity in antibiotic treatment, especially regarding the practice of antibiotic prophylaxis. The aim of the present study was to assess differences in gallstone surgery regarding antibiotic use in Sweden.

Methods

The study was based on data from the Swedish Register for Gallstone Surgery and ERCP (GallRiks) 2005–2015. Funnel plots were used to test impact of grouping factors, including, hospital and surgeon and to identify units that deviated from the rest of the population.

Results

After adjusting for cofounders including age, gender, ASA classification, indication for surgery, operation time, gallbladder perforation and emergency status, there were 0/21 (0%) at the regional level, 18/76 (24%) at the hospital level and 128/1038 (12%) at the surgeon level outside the 99.9% confidence interval (CI). The estimated median odds ratios were 1.13 (95% CI 1.00–1.31) at the regional level, 1.93 (95% CI 1.70–2.19) at the hospital level and 2.38 (95% CI 2.26–2.50) at the surgeon level.

Conclusion

There are significant differences between hospitals and surgeons, but little or no differences between regions. These deviations confirm the lack of standardization in regards to prescription of antibiotic prophylaxis and the need more uniform routines regarding antibiotic usage. Randomized controlled trials and large population-based studies are necessary to assess assessing the effectiveness and safety of antibiotic prophylaxis in gallstone surgery.

Bacteriophages in the Dairy Environment: From Enemies to Allies

The history of dairy farming goes back thousands of years, evolving from a traditional small-scale production to the industrialized manufacturing of fermented dairy products. Commercialization of milk and its derived products has been very important not only as a source of nourishment but also as an economic resource. However, the dairy industry has encountered several problems that have to be overcome to ensure the quality and safety of the final products, as well as to avoid economic losses. Within this context, it is interesting to highlight the role played by bacteriophages, or phages, viruses that infect bacteria. Indeed, bacteriophages were originally regarded as a nuisance, being responsible for fermentation failure and economic losses when infecting lactic acid bacteria, but are now considered promising antimicrobials to fight milk-borne pathogens without contributing to the increase in antibiotic resistance.

Agriculture and Agri-Food Canada's research program on antimicrobial resistance

A key strategy for attenuating the development of antimicrobial resistance (AMR) is ensuring judicious use of antimicrobials in human and veterinary medicine and in agriculture. Research on AMR in agriculture includes risk assessment, risk management, and identifying the role of agricultural practices in development of AMR. Risk assessment includes an impact assessment of antimicrobial use in livestock and on the environment; for example, many antimicrobials are excreted unchanged and thus reach the environment through manure application. This creates the potential for AMR transmission through the food processing chain and into agro-ecosystems receiving the agricultural waste. Risk management includes the assessment of cost-effective methods to keep animals healthy without the need for antimicrobial use, such as the use of vaccines, nutritional supplements and pre-, pro- or synbiotics and of waste management strategies to avoid AMR transmission. Currently, there is an important gap in understanding the degree of human exposure to AMR that is generated through agriculture, the burden of illness of AMR pathogens in human populations and the relationship between exposure and burden of illness. It is important that research on the agricultural, environmental and human medicine dimensions of AMR not be undertaken in silos, which is why the United Nations and countries around the world are working together within the One Health Framework that considers the inter-relatedness of humans, animals and the environment.