Longitudinal analysis of differences and similarities in antimicrobial resistance among commensal Escherichia coli isolated from market swine and sows at slaughter in the United States of America, 2013-2019.

The emergence of antimicrobial resistance in swine enteric bacteria poses a significant public health challenge. Our study evaluated publicly available data collected by the National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) between 2013 and 2019 at slaughter plants across the United States of America, focusing on commensal E. coli isolated from swine cecal contents originating from two distinct swine production systems: market hogs (n = 2090) and sows (n = 1147). In both production types, the highest pairwise correlations were detected among ß-lactam antimicrobials, including resistance to amoxicillin-clavulanic acid, ceftriaxone, and cefoxitin, suggesting a co-selection for resistance. Compared to 2013, an increase in the rate of E. coli isolates that were resistant to ß-lactam antimicrobials was higher in 2017, 2018, and 2019, and this increase was more pronounced in isolates obtained from market hogs. Differences in antimicrobial resistance between these two distinct swine production systems warrant production-type focused mitigation efforts.

Evaluating Antimicrobial Resistance Trends in Commensal Escherichia coli Isolated from Cecal Samples of Swine at Slaughter in the United States, 2013-2019.

The emergence of antimicrobial resistance (AMR) in commensal and pathogenic enteric bacteria of swine is a public health threat. This study evaluated publicly available AMR surveillance data collected by the National Antimicrobial Resistance Monitoring System (NARMS) by assessing AMR patterns and temporal trends in commensal E. coli isolated from cecal samples of swine at slaughter across the United States. We applied the Mann-Kendall test (MKT) and a linear regression trend line to detect significant trends in the proportion of resistant isolates to individual antimicrobials over the study period. A Poisson regression model assessed differences among years in the number of antimicrobials to which an E. coli isolate was resistant. Among the 3237 E. coli isolates, a very high prevalence of resistance for tetracycline (67.62%), and high resistance for streptomycin (24.13%), and ampicillin (21.10%) were identified. The MKT and the linear trend line showed a significantly increasing temporal trend for amoxicillin-clavulanic acid, ampicillin, azithromycin, cefoxitin, ceftriaxone, and trimethoprim-sulfamethoxazole. Compared to 2013 the number of antimicrobials to which an E. coli isolate was resistant was significantly higher in the years 2017, 2018, and 2019. The increasing temporal trend of resistance to important antimicrobials for human medicine (e.g., third-generation cephalosporins) and the increase in multidrug resistance in the later years of the study are concerning and should be followed up by studies to identify sources and risk factors for the selection of AMR.

Comparison of antimicrobial resistance among Salmonella enterica serovars isolated from Canadian turkey flocks, 2013 to 2021.

The emergence of antimicrobial resistance (AMR) in Salmonella from turkeys has raised a food safety concern in Canada as certain serovars have been implicated in human salmonellosis outbreaks in recent years. While several studies evaluated AMR in broiler chickens in Canada, there are limited studies that assess AMR in turkey flocks. This study analyzed data collected between 2013 and 2021 by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) farm turkey surveillance program to determine the prevalence of AMR and differences in resistance patterns among Salmonella serovars recovered from turkey flocks. Salmonella isolates were tested for susceptibility to 14 antimicrobials using a microbroth dilution method. Hierarchical clustering dendrograms were constructed to compare the individual AMR status of Salmonella serovars. Differences in the probability of resistance between Salmonella serovars were determined using generalized estimating equation logistic regression models to account for farm-level clustering. Of the 1,367 Salmonella isolates detected, 55.3% were resistant to at least one antimicrobial and 25.3% were multidrug resistant (MDR) (resistant to ≥3 antimicrobial classes). The Salmonella isolates exhibited high resistance to tetracycline (43.3%), streptomycin (47.2%), and sulfisoxazole (29.1%). The 3 most frequently occurring serovars were S. Uganda (22.9%), S. Hadar (13.5%), and S. Reading (12.0%). Streptomycin-sulfisoxazole-tetracycline (n = 204) was the most frequent MDR pattern identified. Heatmaps showed that S. Reading exhibited coresistance to the quinolone class antimicrobials, ciprofloxacin, and nalidixic acid; S. Heidelberg to gentamicin and sulfisoxazole; and S. Agona to ampicillin and ceftriaxone. Salmonella Hadar isolates had higher odds of resistance to tetracycline (OR: 152.1, 95% CI: 70.6-327.4) while the probability of being resistant to gentamicin and ampicillin was significantly higher in S. Senftenberg than in all the other serovars. Moreover, S. Uganda had the highest odds of being MDR (OR: 4.7, 95% CI: 3.7-6.1). The high resistance observed warrants a reassessment of the drivers for AMR, including AMU strategies and other production factors. Differences in AMR patterns highlight the need to implement serovar-specific mitigation strategies.

Comparison of Antimicrobial Resistance among Commensal Escherichia coli Isolated from Retail Table Eggs Produced by Laying Hens from the Cage and Non-Cage Housing Systems in Western Australia.

Antimicrobial resistance (AMR) has become a global public health concern in recent decades. Although several investigations evaluated AMR in commensal and pathogenic bacteria from different foods of animal origin in Australia, there is a lack of studies that compared AMR in commensal E. coli isolated from retail table eggs obtained from different laying hen housing systems. This study aimed to determine AMR and differences in AMR patterns among E. coli isolates recovered from retail table eggs sourced from caged and non-caged housing systems in Western Australia. Commensal E. coli isolates were tested for susceptibility to 14 antimicrobials using a broth microdilution method. Clustering analyses and logistic regression models were applied to identify patterns and differences in AMR. Overall, there were moderate to high frequencies of resistance to the antimicrobials of lower importance used in Australian human medicine (tetracycline, ampicillin, trimethoprim, and sulfamethoxazole) in the isolates sourced from the eggs of two production systems. All E. coli isolates were susceptible to all critically important antimicrobials except the very low level of resistance to ciprofloxacin. E. coli isolates from eggs of non-caged systems had higher odds of resistance to tetracycline (OR = 5.76, p < 0.001) and ampicillin (OR = 3.42, p ≤ 0.01) compared to the isolates from eggs of caged systems. Moreover, the number of antimicrobials to which an E. coli isolate was resistant was significantly higher in table eggs from non-caged systems than isolates from caged systems' eggs. Considering the conservative approach in using antimicrobials in the Australian layer flocks, our findings highlight the potential role of the environment or human-related factors in the dissemination and emergence of AMR in commensal E. coli, particularly in retail table eggs of non-cage system origin. Further comprehensive epidemiological studies are required to better understand the role of different egg production systems in the emergence and dissemination of AMR in commensal E. coli.

Whole-Genome Comparative Analysis Reveals Association Between Salmonella Genomic Variation and Egg Production Systems.

Non-typhoidal Salmonella, particularly Salmonella enterica serovar Typhimurium (S. Typhimurium), is the predominant endemic serovar in the Australian egg production industry and is one of the most frequently reported serovars in foodborne infections in Australia. This study was conducted to investigate the genomic characteristics of Salmonella isolated from retail table eggs in Western Australia and to identify the impact of production systems on genomic characteristics of Salmonella such as virulence and antimicrobial resistance. A total of 40 non-typhoidal Salmonella isolates [S. Typhimurium isolates (n = 28) and Salmonella Infantis isolates (n = 12)] sourced from retail eggs produced by different production systems (barn-laid, cage, and free-range) in Western Australia were sequenced by whole-genome sequencing. The isolates were de novo assembled, annotated, and analyzed. The results indicated an association between Salmonella genomic variation and the system used to raise poultry for egg production (p-value < 0.05). All but one of the S. Infantis isolates were recovered from eggs collected from poultry raised under barn and cage production systems. A higher proportion (83.3%) of S. Typhimurium isolates were recovered from the eggs produced by free-range production system as compared with those produced under barn (76.9%) and cage production systems (53.3%). Our analysis indicated that Salmonella isolated from the eggs produced by barn and cage production systems had more virulence genes than the isolates of the free-range produced eggs. A low carriage of antimicrobial-resistant gene was detected in the isolates of this study. We have built a Salmonella genomics database and characteristics-linked gene pools to facilitate future study, characterization, and tracing of Salmonella outbreaks.

Antimicrobial resistance and genomic characterisation of Escherichia coli isolated from caged and non-caged retail table eggs in Western Australia.

Foodborne exposure to antimicrobial-resistant bacteria is a growing global health concern. Escherichia coli (E. coli) is well recognised as an indicator of food contamination with faecal materials. In the present study, we investigated the occurrence of E. coli in table eggs sold at retail supermarkets in Western Australia (WA). A total of 2172 visually clean and intact retail eggs were purchased between October 2017 and June 2018. A single carton containing a dozen eggs was considered as a single sample resulting a total of 181 samples. The shells and contents of each sample were separately pooled and tested using standard culture-based methods. Overall, generic E. coli was detected in 36 (19.8%; 95% confidence interval: 14.3; 26.4) of the 181 tested retail egg samples. We characterised 100 of the recovered E. coli isolates for their phenotypic antimicrobial resistance using minimum inhibitory concentration (MIC). A subset of E. coli isolates (n = 14) were selected on the basis of their MIC patterns, and were further characterised using whole genome sequencing (WGS). Fifty-seven (57%) of the recovered generic E. coli isolates (n = 100) were resistant to at least one of the 14 antimicrobials included in the MIC testing panel, of which 22 isolates (22%) showed multi-class resistance. The highest frequencies of non-susceptibility of E. coli isolated from WA retailed eggs were against tetracycline (49%) and ampicillin (36%). WGS revealed that tet(A) and blaTEM-1B genes were present in most of the isolates exhibiting phenotypic resistance to tetracycline and ampicillin, respectively. The majority (98%) of the characterised E. coli isolates were susceptible to ciprofloxacin and azithromycin, and none were resistant to the cephalosporin antimicrobials included in the MIC panel. Two isolates demonstrated reduced susceptibility to ciprofloxacin, with MICs of 0.125 and 0.25 mg/L, and WGS revealed the presence of plasmid mediated qnrs1 gene in both isolates. This is the first report on detection of non-wild-type resistance to fluoroquinolones in supermarket eggs in Australia; one of the two isolates was from a cage-laid eggs sample while the other was from a barn-laid retail eggs sample. Fluoroquinolones have never been permitted for use in poultry farms in Australia. Thus, the detection of low-level ciprofloxacin-resistant E. coli in the absence of local antimicrobial selection pressure at the Australian layer farms warrants further research on the potential role of the environment or human-related factors in the transmission of antimicrobial resistance. The results of this study add to the local and global understanding of antimicrobial resistance spread in foods of animal origin.

Non-Typhoidal Salmonella at the Human-Food-of-Animal-Origin Interface in Australia.

Non-typhoidal Salmonella is a major zoonotic pathogen that plays a significant role in foodborne human salmonellosis worldwide through the consumption of contaminated foods, particularly those of animal origin. Despite a considerable reduction in human salmonellosis outbreaks in developed countries, Australia is experiencing a continuous rise of such outbreaks in humans. This review of the literature highlights the reported non-typhoidal Salmonella outbreaks in humans as well as the occurrence of the pathogen in foods from animal sources throughout Australia. Non-typhoidal Salmonella infections from food animals are more often associated with at-risk people, such as immunocompromised and aged people or children. Although several animal-sourced foods were recognised as the catalysts for salmonellosis outbreaks in Australia, egg and egg-based products remained the most implicated foods in the reported outbreaks. This review further highlights the antimicrobial resistance trends of non-typhoidal Salmonella isolates at the human-food interface, with a focus on clinically important antimicrobials in humans, by collating evidence from previous investigations in Australia. The rise in antimicrobial-resistant Salmonella, especially to antimicrobials commonly prescribed to treat human salmonellosis, has become a significant global public health concern. However, the overall prevalence of antimicrobial resistance in Australia is considerably lower than in other parts of the world, particularly in terms of critically important antimicrobials for the treatment of human salmonellosis. The present review adds to our understanding of the global epidemiology of non-typhoidal Salmonella with emphasis on the past few decades in Australia.

A Review of the Public Health Challenges of Salmonella and Turtles.

Non-typhoidal Salmonella serovars are recognized as zoonotic pathogens. Although human salmonellosis is frequently associated with ingestion of contaminated foods of animal origin, contact with animals may also be a significant source of Salmonella infection, especially contact with turtles, which have shown to be an important reservoir of Salmonella, specifically through their intestinal tracts. Turtles are among the most common reptiles kept as house pets that may pose a public health risk associated with Salmonella exposure, especially among infants and young children. This review discusses the literature reporting the link between turtles and Salmonella as well as turtle-associated human salmonellosis in the last ten years. In most outbreaks, a high proportion of patients are children under five years of age, which indicates that children are at the greatest risk of turtle-associated salmonellosis. Therefore, turtles should not be preferred as recommended pets for children under five years of age. Reducing turtle stress to minimise Salmonella shedding as well as providing client education handouts at the points of sale of these animals may reduce the risk of transmitting such significant pathogen to humans. Further studies are required to investigate the role of both direct contact with turtles as well as indirect contact through cross-contamination in the transmission of turtles-associated Salmonella to humans.

Occurrence and Characterization of Salmonella Isolated from Table Egg Layer Farming Environments in Western Australia and Insights into Biosecurity and Egg Handling Practices.

The aim of this study was to investigate the occurrence and distribution of Salmonella in commercial layer farming environments of 26 flocks belonging to seven egg businesses (free-range and barn-laid) in Western Australia (WA). Between November 2017 and June 2018, a total of 265 environmental samples of dust, feed, water, pooled feces, and boot swabs were tested for detection of Salmonella according to standard culture-based methods. Isolates were assayed for serovar and subtyped by multilocus sequence typing (MLST). Salmonella spp. were recovered from 35% (93/265) of all tested samples. Dust (53.8%, 28/52) and pooled fecal (54.5%, 18/33) samples provided the highest Salmonella recovery rates. Nine different Salmonella serovars were characterized across the positive (n = 93) environmental samples, of which S. Typhimurium (60/93, 64.5%) and S. Infantis (21/93, 22.5%) were the most prevalent. MLST revealed that all S. Typhimurium isolates were of sequence type ST-19. Microbiological screening of Salmonella was not routinely practiced in any of the surveyed egg businesses. Some of the egg businesses exhibited variable levels of compliance with basic biosecurity measures as well as high-risk egg handling practices. Egg businesses in WA should be encouraged to adopt a voluntary program of environmental sampling and verification testing for Salmonella. Such voluntary programs will aid in supporting solutions for the management of this pathogen in the human food chain.

Non-typhoidal Salmonella contamination in egg shells and contents from retail in Western Australia: Serovar diversity, multilocus sequence types, and phenotypic and genomic characterizations of antimicrobial resistance.

In recent years, the number of human salmonellosis cases in Western Australia (WA) has increased more dramatically than in any other Australian state. In 2017, the number of cases in WA was more than double the five-year average, and eggs had emerged as the key culprit for several Salmonella foodborne disease outbreaks. To better understand such an epidemiologically intriguing situation, our research goal was to investigate the prevalence, serovar diversity, multilocus sequence types, and antimicrobial resistance of non-typhoidal Salmonella contamination in retail eggs produced and sold in WA. A total of 200 visually clean and intact retail egg samples (each containing a dozen eggs) were purchased for one year (2017-2018) from supermarkets in metropolitan Perth, the capital of WA. For each sample, the contents and shells of the 12 eggs were separately pooled and cultured according to standard methods. Overall, Salmonella was detected in 11.5% (23/200) of the tested egg samples. Salmonella was isolated from 4.5% (9/200) and 3% (6/200) of eggshells and egg contents, respectively. In 4% (8/200) of the samples, Salmonella was recovered from both eggshell and egg contents. Isolates from positive retail egg samples were serotyped as either S. Typhimurium (52.2% [12/23]) or S. Infantis (39.1% [9/23]). Both serotypes were concurrently recovered from two different retail egg samples. We retained a set of both S. Typhimurium (n = 29) and S. Infantis (n = 12) isolates from all Salmonella-positive retail packs (n = 23) for further characterization. Only two (S. Typhimurium) isolates showed resistance to ampicillin, of which one carried ß-lactamase resistance gene blaTEM-1b. The remaining isolates (39/41) were susceptible to all 14 antimicrobials included in the minimum inhibitory concentrations (MICs) testing panel. Multilocus sequence typing and serotyping were perfectly mirrored, as all S. Typhimurium isolates were characterized as sequence type (ST)-19, and all S. Infantis isolates were ST-32. This study points to the noteworthy Salmonella prevalence rate in retail egg samples in WA. Our results illustrate minimal public health risks arising from antimicrobial resistance Salmonella from Australian eggs.

Beliefs, Attitudes and Self-Efficacy of Australian Veterinary Students Regarding One Health and Zoonosis Management.

This study aimed to explore the beliefs and attitudes of a group of senior veterinary students regarding One Health and to evaluate their levels of confidence in advising the general public on preventative health issues at the human-animal interface. An online survey was communicated to senior veterinary students who were in their last two years of study. The questionnaire covered beliefs and attitudes, issues concerning the animal-human interface and participants' confidence in diagnosing zoonoses. In total, 175 students from five Australian veterinary schools/colleges completed the online survey. The majority (96%) of students considered it their duty to promote the One Health approach, but only 36% believed there were sufficient practical frameworks for Australian veterinarian graduates to promote One Health. Interestingly, 81% (142/175) of respondents believed that veterinarians were more knowledgeable than physicians in managing zoonotic cases. Of the final-year students (n = 77), only 39% and 36% were confident in their ability to diagnose zoonoses in common companion animals and production animals, respectively. However, the number of those confident to diagnose zoonoses transmitted from wildlife was notably lower (22% (17/77)). Next-generation Australian veterinarians are keen to embrace their role in interprofessional collaboration; however, training efforts are required to reassure future veterinarians on aspects of zoonoses and One Health.

A mechanistic review on plant-derived natural compounds as dietary supplements for prevention of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a recurrent idiopathic inflammatory condition, characterized by disruption of the gut mucosal barrier. This mechanistic review aims to highlight the significance of plant-derived natural compounds as dietary supplements, which can be used in addition to restricted conventional options for the prevention of IBD and induction of remission. Various clinical trials confirmed the effectiveness and tolerability of natural supplements in patients with IBD. Mounting evidence suggests that these natural compounds perform their protective and therapeutic effect on IBD through numerous molecular mechanisms, including anti-inflammatory and immunoregulatory, anti-oxidative stress, modulation of intracellular signaling transduction pathways, as well as improving gut microbiota. In conclusion, natural products can be considered as dietary supplements with therapeutic potential for IBD, provided that their safety and efficacy is confirmed in future well-designed clinical trials with adequate sample size.

The preventive and therapeutic potential of natural polyphenols on influenza.

Influenza virus belongs to orthomyxoviridae family. This virus is a major public health problems, with high rates of morbidity and mortality. Despite a wide range of pharmacotherapeutic choices inhibiting specific sequences of pathological process of influenza, developing more effective therapeutic options is an immediate challenge. In this paper, a comprehensively review of natural polyphenolic products used worldwide for the management of influenza infection is presented. Cellular and molecular mechanisms of the natural polyphenols on influenza infection including suppressing virus replication cycle, viral hemagglutination, viral adhesion and penetration into the host cells, also intracellular transductional signaling pathways have been discussed in detail. Based on cellular, animal, and human evidence obtained from several studies, the current paper demonstrates that natural polyphenolic compounds possess potential effects on both prevention and treatment of influenza, which can be used as adjuvant therapy with conventional chemical drugs for the management of influenza and its complications.

Antimicrobial Activities of the Combined Use of Cuminum Cyminum L. Essential Oil, Nisin and Storage Temperature Against Salmonella typhimurium and Staphylococcus aureus In Vitro.

BACKGROUND: Foodborne diseases are considered as major health problems in different countries. Concerns over the safety of some chemical preservatives and negative consumer reactions to them have prompted interest in natural alternatives for the maintenance or extension of food shelf life. In this respect, the combination of a plant essential oil and nisin has used for controlling the growth of foodborne pathogens as natural food preservative using the mathematical model. OBJECTIVES: The purpose of this study was to determine the effect of different concentrations of Cuminum cyminum L. essential oil (0, 15, 30 and 45 µL/100 mL) and nisin (0, 0.5 and 1.5 µg/mL) combination at different temperatures (10, 25 and 35°C) on growth of Salmonella typhimurium and Staphylococcus aureus in the Brain-Heart Infusion (BHI) broth model. The concentrations of 0 µL/100 mL for essential oil and 0 µg/mL for nisin imply the negative control. MATERIALS AND METHODS: A multivariate variance experiment was performed. To assess the effect of essential oil, nisin and the incubation temperature on growth probability (log P%) of S. typhimurium and S. aureus, four concentrations of C. cyminum L. essential oil (0, 15, 30 and 45 µL/100 mL), three concentrations of nisin (0, 0.5 and 1.5 µg/mL) and three storage temperatures (10, 25 and 35°C) were considered. RESULTS: The growth of S. typhimurium was significantly decreased by the concentration of essential oil ≥ 30 µL/100 mL in combination with nisin ≥ 0.5 µg/mL at temperature = 10°C (P < 0.05). Also, in combination of the essential oil ≥ 15 µL/100 mL and nisin ≥ 0.5 µg/mL at temperature ≤ 25°C, the growth of S. aureus was significantly reduced (P < 0.05). CONCLUSIONS: These results indicate that the combination of essential oil and nisin inhibits the growth of S. typhimurium and S. aureus bacteria and there is the possibility of using them as substitutes for chemical food preservatives. Moreover, the model (log P%) in this study can be a good tool for the reduction of microbiological hazards in food industry.

Prevalence and antimicrobial resistance of Salmonella serotypes isolated from retail chicken meat and giblets in Iran.

INTRODUCTION: Salmonella is one of the major foodborne pathogens responsible for outbreaks of foodborne illness in humans worldwide. METHODOLOGY: A total of 560 samples of chicken meat and giblets were collected from retail markets for Salmonella identification, serotyping, and antimicrobial resistance testing. RESULTS: Salmonella was detected in 19.8% of samples. Among the five serotypes identified, S. Thompson was the predominant type (48.7%). High antimicrobial resistance rates were observed to nalidixic acid (92.8%), tetracycline (81%), trimethoprim (68.4%), sulfamethoxazole / trimethoprim (61.2%), streptomycin (56.7%), and kanamycin (36.9%). Although resistance to chloramphenicol (3.6%), amoxicillin-clavulanic acid (5.4%), and ampicillin (11.7%) was detected, none of the isolates were resistant to ceftazidime, ceftriaxone, cefotaxime, ciprofloxacin, colistin, gentamicin, nor imipenem. CONCLUSIONS: Restrictions on the irrational use of antibiotics in humans and animals are suggested for the reduction of resistant strains.

Dietary anthocyanins as a complementary medicinal approach for management of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is thought to result from a chronic or relapsing activation of the immune system in the GI tract. A growing body of evidence confirms the health benefits of dietary anthocyanins as plant-derived natural agents. The aim of this review is to provide an overview of several natural products rich in anthocyanins used worldwide for the treatment of IBD. Anthocyanins possess both protective and therapeutic functions in the management of IBD by alleviating oxidative stress processes, cytoprotective functions, downregulation of inflammatory cytokines and suppressing cellular signaling pathways of inflammatory processes. In conclusion, the consumption of anthocyanin-rich natural formulations must be promoted on the basis of their possible function in the prevention and treatment of gastrointestinal inflammatory disorders.