Evidence of class 1 integron transfer between Escherichia coli and Salmonella spp. on livestock farms

Multi-drug resistant (MDR) Gram-negative pathogenic bacteria isolated from poultry in the Noakhali region of Bangladesh

Rapidly increasing antibiotic-resistant bacterial strains in Bangladesh's food and farm animals stem from the excessive and inappropriate use of antibiotics. To assess the prevalence of multi-drug resistant (MDR) Gram-negative bacteria in poultry chicks, we sought to isolate and identify strains carrying antimicrobial resistance genes. Isolation and identification involved biochemical tests, 16S rRNA sequencing, and PCR screening of species-specific genes. MDR patterns were evaluated using CLSI guidelines with seventeen antibiotics across twelve classes. Targeted gene sequences were amplified for the detection of Extended-spectrum β-Lactamase (ESBL), carbapenem, tetracycline, sulfonamide, and colistin resistance genes. Common isolates, such as Escherichia coli, Klebsiella pneumoniae, Proteus penneri, and Enterobacter hormaechei, exhibited average Multiple Antimicrobial Resistance (MAR) indices of 0.66, 0.76, 0.8, 0.84, and 0.81, 0.76, 0.84, 0.41 for broiler and layer chicken, respectively. Providencia stuartii and Salmonella enterica, exclusive to broiler samples, had MAR indices of 0.82 and 0.84, respectively. Additional isolates Morganella morganii, Aeromonas spp., and Wohlfahrtiimonas chitiniclastica were found in layers (Average MAR indices: 0.73, 0.71, and 0.91). Notably, M. morganii, E. hormaechei and W. chitiniclastica were identified for the first time in Bangladeshi poultry chicken, although their evolution is yet to be understood. In this study, Pan-drug resistance was observed in one P. stuartii (broiler) and one Aeromonas spp. (layer) with a MAR index 1, while all isolates exhibited MAR indices >0.2, indicating MDR. Antimicrobial resistance (AMR) gene screening identified blaTEM, blaSHV, tetA, and sul1 in a majority of the MDR strains. Interestingly, E. coli (lactose positive and negative) and E. hormaechei were exclusively found to possess the tetB gene. In addition, E. coli (lactose negative), Klebsiella pneumoniae, Enterobacter hormaechei, M. morganii, and P. stuartii were observed to carry the colistin-resistant mcr-1 gene, whereas sul2 was detected in E. coli (lactose positive and negative), E. hormaechei, P. stuartii, and P. penneri. These findings emphasize the health risk of our consumers of both broiler and layer chickens as they have turned into a potent reservoir of various AMR gene carrying MDR and Pan-drug resistant bacteria.

A study at the wildlife-livestock interface unveils the potential of feral swine as a reservoir for extended-spectrum β-lactamase-producing Escherichia coli

Wildlife is known to serve as carriers and sources of antimicrobial resistance (AMR). Due to their unrestricted movements and behaviors, they can spread antimicrobial resistant bacteria among livestock, humans, and the environment, thereby accelerating the dissemination of AMR. Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is one of major concerns threatening human and animal health, yet transmission mechanisms at the wildlife-livestock interface are not well understood. Here, we investigated the mechanisms of ESBL-producing bacteria spreading across various hosts, including cattle, feral swine, and coyotes in the same habitat range, as well as from environmental samples over a two-year period. We report a notable prevalence and clonal dissemination of ESBL-producing E. coli in feral swine and coyotes, suggesting their persistence and adaptation within wildlife hosts. In addition, in silico studies showed that horizontal gene transfer, mediated by conjugative plasmids and insertion sequences elements, may play a key role in spreading the ESBL genes among these bacteria. Furthermore, the shared gut resistome of cattle and feral swine suggests the dissemination of antibiotic resistance genes at the wildlife-livestock interface. Taken together, our results suggest that feral swine may serve as a reservoir of ESBL-producing E. coli.

Phenotypic and Genotypic Characterizations of Antimicrobial-Resistant Escherichia coli Isolates from Diverse Retail Meat Samples in North Carolina During 2018-2019

Surveillance of antimicrobial-resistant pathogens in U.S. retail meats is conducted to identify potential risks of foodborne illness. In this study, we conducted a phenotypic and genotypic analysis of Escherichia coli recovered from a diverse range of retail meat types during 2018-2019 in North Carolina. The investigation was conducted as part of the National Antimicrobial Resistance Monitoring System (NARMS). Retail meat sampling and E. coli isolation were performed in accordance with NARMS retail meat isolation protocols. We used the Sensititre™ broth microdilution system to determine phenotypic resistance to 14 antimicrobial agents and the Illumina next-generation sequencing platform for genotypic resistance profiling. The highest prevalence of E. coli isolates was found in ground turkey (n = 57, 42.9%) and chicken (n = 27, 20.3%), followed by ground beef (n = 25, 18.9%) and pork (n = 24, 18%). The isolates were divided into seven different phylogroups using the Clermont typing tool, with B1 (n = 59, 44.4%) and A (n = 39, 29.3%) being the most dominant, followed by B2 (n = 14, 10.5%), D (n = 7, 5.3%), F (n = 6, 4.5%), E (n = 3, 2.3%), and C (n = 2, 1.5%). Using multilocus sequence typing (MLST), 128 Sequence types (STs) were identified indicating high diversity. Phenotypic and genotypic resistance was observed toward aminoglycosides, sulfonamides, beta-lactams, macrolides, tetracyclines, phenicols, and fluoroquinolones. Ground turkey samples were more resistant to the panel of tested antimicrobials than chicken, beef, or pork (p < 0.05). All isolates were found to be susceptible to meropenem. A high percentage of turkey isolates (n = 16, 28%) were multidrug-resistant (MDR) compared with 18.5% of chicken (n = 5), 8.4% of pork (n = 2), and 8% of beef isolates (n = 2). This study highlights the benefit of surveillance to identify MDR E. coli for epidemiologic tracking and is a comprehensive report of the phenotypic and genotypic characterization of E. coli isolated from retail meats in North Carolina.

Antimicrobial Resistance in Commensal Escherichia coli of the Porcine Gastrointestinal Tract

Antimicrobial resistance (AMR) in Escherichia coli of animal origin presents a threat to human health. Although animals are not the primary source of human infections, humans may be exposed to AMR E. coli of animal origin and their AMR genes through the food chain, direct contact with animals, and via the environment. For this reason, AMR in E. coli from food producing animals is included in most national and international AMR monitoring programmes and is the subject of a large body of research. As pig farming is one of the largest livestock sectors and the one with the highest antimicrobial use, there is considerable interest in the epidemiology of AMR in E. coli of porcine origin. This literature review presents an overview and appraisal of current knowledge of AMR in commensal E. coli of the porcine gastrointestinal tract with a focus on its evolution during the pig lifecycle and the relationship with antimicrobial use. It also presents an overview of the epidemiology of resistance to extended spectrum cephalosporins, fluoroquinolones, and colistin in pig production. The review highlights the widespread nature of AMR in the porcine commensal E. coli population, especially to the most-used classes in pig farming and discusses the complex interplay between age and antimicrobial use during the pig lifecycle.

Impact of soil supplemented with pig manure on the abundance of antibiotic resistant bacteria and their associated genes

This study was conducted to evaluate the abundance of antibiotic resistant bacteria and their resistance genes from agriculture soil supplemented with pig manure. Uncultivable soil sample was supplemented with pig manure samples under microcosm experimental conditions and plated on Luria-Bertani (LB) agar incorporated with commercial antibiotics. The supplementation of soil with 15% pig manure resulted in the highest increase in the population of antibiotic resistant bacteria (ARB)/multiple antibiotic resistant bacteria (MARB). Seven genera that included Pseudomonas, Escherichia, Providencia, Salmonella, Bacillus, Alcaligenes and Paenalcaligenes were the cultivable ARB identified. A total of ten antibiotic resistant bacteria genes (ARGs) frequently used in clinical or veterinary settings and two mobile genetic elements (MGEs) (Class 1 and Class 2 integrons) were detected. Eight heavy metal, copper, cadmium, chromium, manganese, lead, zinc, iron, and cobalt were found in all of the manure samples at different concentrations. Tetracycline resistance genes were widely distributed with prevalence of 50%, while aminoglycoside and quinolone-resistance gene had 16% and 13%, respectively. Eighteen ARB isolates carried more than two ARGs in their genome. Class 1 integron was detected among all the 18 ARB with prevalence of 90-100%, while Class 2 integron was detected among 11 ARB. The two classes of integron were found among 10 ARB. Undoubtedly, pig manure collected from farms in Akure metropolis are rich in ARB and their abundance might play a vital role in the dissemination of resistance genes among clinically-relevant pathogens.

Isolation, Identification and Genetic Characterization of Antibiotic Resistant Escherichia coli from Frozen Chicken Meat Obtained from Supermarkets at Dhaka City in Bangladesh

Antimicrobials have been used to improve animal welfare, food security, and food safety that promote the emergence, selection, and dissemination of antimicrobial-resistant (AMR) bacteria. In this study, 50 E. coli were isolated from frozen chicken meat samples in Dhaka city. Antibiotic sensitivity patterns were assessed through the disk diffusion method and finally screened for the presence of antimicrobial resistance genes (ARG) using the polymerase chain reaction (PCR). Among the 160 samples, the prevalence of E. coli was observed in fifty samples (31.25%). All of these isolates were found resistant to at least one antimicrobial agent, and 52.0% of the isolates were resistant against 4-7 different antimicrobials. High resistance was shown to tetracycline (66.0%), followed by resistance to erythromycin (42.0%), ampicillin and streptomycin (38.0%), and sulfonamide (28.0%). In addition, the most prevalent ARGs were tet(A) (66.0%), ereA (64.0%), tet(B) (60.0%), aadA1 and sulI (56.0%), blaCITM (48.0%) and blaSHV (40.0%). About 90.0% of isolates were multidrug resistant. This study reveals for the first time the current situation of E. coli AMR in broilers, which is helpful for the clinical control of disease as well as for the development of policies and guidelines to reduce AMR in broilers production in Bangladesh.

Decreasing trend of β-Lactam Resistance in Salmonella Isolates from Broiler Chickens due to the Cessation of Ceftiofur in ovo Administration

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The most prevalence of S. enterica isolated in 2017 and 2018 were S. Manhattan and S. Schwarzengrund.

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S. enterica prevalence showed a declining trend over an extended period.

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β-lactam resistance was absent in the predominant serovars in 2018.

Ceftiofur, a third-generation cephalosporin antimicrobial, was used in Japanese hatcheries for many years before 2012. We continue to study Salmonella in broilers and their antimicrobial resistance. The current study aimed to express how the cessation of ceftiofur affects the antimicrobial resistance of Salmonella isolated from broiler chickens in Kagoshima Prefecture, Japan in 2017 and 2018. A total of 274 Salmonella isolates were recovered from 1535 cecal content samples obtained from 96 broiler flocks over years 2017 and 2018. Among the S. enterica isolates, the predominant serovars were S. Manhattan (128/274, 46.7%), S. Schwarzengrund (120/274, 43.8%), and S. Infantis (26/274, 9.5%). The isolates showed a high proportion of antimicrobial resistance for oxytetracycline, sulfamethoxazole, and streptomycin. However, the β-lactam resistance rates were significantly decreased (p < 0.01) in 2017, while no β-lactam resistant isolates detected in 2018. The highlight of this study was the complete disappearance of β-lactam resistance in Salmonella isolates from broiler chicken in Kagoshima, Japan.

Chicken Gut Microbiome and Human Health: Past Scenarios, Current Perspectives, and Futuristic Applications

Sustainable poultry practices are needed to maintain an adequate supply of poultry products to the increasing human population without compromising human wellbeing. In order to achieve the understanding of the core microbiome that assumes an imperative role in digestion, absorption, and assimilation of feed as well as restrict the growth of pathogenic strains, a proper meta-data survey is required. The dysbiosis of the core microbiome or any external infection in chickens leads to huge losses in the poultry production worldwide. Along with this, the consumption of infected meat also impacts on human health as chicken meat is a regular staple in many diets as a vital source of protein. To tackle these losses, sub-therapeutic doses of antibiotics are being used as a feed additive along with other conventional approaches including selective breeding and modulation in feed composition. Altogether, these conventional approaches have improved the yield and quality of poultry products, however, the use of antibiotics encompasses the risk of developing multi-drug resistant pathogenic strains that can be harmful to human beings. Thus, there is an urgent need to understand the chicken microbiome in order to modulate chicken gut microbiome and provide alternatives to the conventional methods. Although there is now emerging literature available on some of these important microbiome aspects, in this article, we have analysed the relevant recent developments in understanding the chicken gut microbiome including the establishment of integrated gene catalogue for chicken microbiome. We have also focussed on novel strategies for the development of a chicken microbial library that can be used to develop novel microbial consortia as novel probiotics to improve the poultry meat production without compromising human health. Thus, it can be an alternative and advanced step compared to other conventional approaches to improve the gut milieu and pathogen-mediated loss in the poultry industry.

Antibiotics utilization and farmers' knowledge of its effects on soil ecosystem in the coastal drylands of Ghana

Background

There is paucity of information on antibiotics utilization amongst farmers, factors associated with administration of antibiotics and farmers’ knowledge of the effects of antibiotics on the soil ecosystem in Ghana.

Methods

A cross sectional quantitative survey across three coastal regions of Ghana was undertaken amongst poultry and livestock farmers. Six hundred respondents were selected from five districts each across the three regions. Pretested and structured questionnaire were used to collect data through face to face interview. Data were summarized using descriptive statistics and regression analysis. Factors associated with antibiotic administration were determined using binary multiple logistic regression at p ≤ 0.05.

Results

Out of the 600 farmers, 95% administered antibiotics and 84% bought antibiotics over-the-counter without prescription. Approximately 9% of antibiotic administration was carried out by veterinary officers, and the remaining, 91% based on farmer’s experience. Approximately 93% had access to antibiotics without any difficulty. Withdrawal period was always observed by only 16% of farmers. Majority (74%) of farmers never had education on antibiotics and none of the farmers screened manure for the antibiotic residuals. Years of farming, income status, level of education of farmers, type of animal kept, access to extension services, registration with farmers’ association, employing veterinary services, location of farm, system of production, education on antibiotics and access to antibiotics positively and significantly predicted the administration of antibiotics by farmers. Majority of farmers had inadequate knowledge of the effects of antibiotics on soil ecosystem with mean score ranging between 2.87±0.60 and 2.98 ± 0.7 on a scale of 5.0.

Conclusion

The study exposed the poor practices regarding antibiotic use and also inadequate knowledge on its effect on the soil ecosystem amongst farmers in Ghana. This calls for development of strategies to increase awareness on antibiotics because its misuse can negatively impact human, animals, environment and impact food security.

Genomic Microbial Epidemiology Is Needed to Comprehend the Global Problem of Antibiotic Resistance and to Improve Pathogen Diagnosis

Contamination of waste effluent from hospitals and intensive food animal production with antimicrobial residues is an immense global problem. Antimicrobial residues exert selection pressures that influence the acquisition of antimicrobial resistance and virulence genes in diverse microbial populations. Despite these concerns there is only a limited understanding of how antimicrobial residues contribute to the global problem of antimicrobial resistance. Furthermore, rapid detection of emerging bacterial pathogens and strains with resistance to more than one antibiotic class remains a challenge. A comprehensive, sequence-based genomic epidemiological surveillance model that captures essential microbial metadata is needed, both to improve surveillance for antimicrobial resistance and to monitor pathogen evolution. Escherichia coli is an important pathogen causing both intestinal [intestinal pathogenic E. coli (IPEC)] and extraintestinal [extraintestinal pathogenic E. coli (ExPEC)] disease in humans and food animals. ExPEC are the most frequently isolated Gram negative pathogen affecting human health, linked to food production practices and are often resistant to multiple antibiotics. Cattle are a known reservoir of IPEC but they are not recognized as a source of ExPEC that impact human or animal health. In contrast, poultry are a recognized source of multiple antibiotic resistant ExPEC, while swine have received comparatively less attention in this regard. Here, we review what is known about ExPEC in swine and how pig production contributes to the problem of antibiotic resistance.

Detection of Integrase Gene in E. coli Isolated from Pigs at Different Stages of Production System

Integrons are one of the genetic elements involved in the acquisition of antibiotic resistance. The aim of the present research is to investigate the presence of integrons in commensal Escherichia coli (E. coli) strains, isolated from pigs at different stages of production system and from the environment in an Argentinian farm. Five sows postpartum and five randomly chosen piglets from each litter were sampled by rectal swabs. They were sampled again at day 21 and at day 70. Environmental samples from the farm were also obtained. E. coli containing any integron class or combination of both integrons was detected by polymerase chain reaction in 100% of sows and in piglets at different stages of production: farrowing pen stage 68.1%;, weaning 60%, and growing/finishing 85.8%, showing an increase along the production system. From environmental samples 78.4% of E. coli containing any integron class was detected. We conclude that animals and farm environment can act as reservoirs for potential spread of resistant bacteria by means of mobile genetic elements as integrons, which has a major impact on production of food animals and that can reach man through the food chain, constituting a problem for public health.

The antibiotic resistance characteristics of non-typhoidal Salmonella enterica isolated from food-producing animals, retail meat and humans in South East Asia

Antimicrobial resistance is a global problem. It is most prevalent in developing countries where infectious diseases remain common, the use of antibiotics in humans and animals is widespread, and the replacement of older antibiotics with new generation antibiotics is not easy due to the high cost. Information on antibiotic resistance phenotypes and genotypes of Salmonella spp. in food animals and humans in different countries and geographic regions is necessary to combat the spread of resistance. This will improve the understanding of antibiotic resistance epidemiology, tracing of new emerging pathogens, assisting in disease treatment, and enhancing prudent use of antibiotics. However, the extent of antibiotic resistance in food-borne pathogens and humans in many developing countries remains unknown. The goal of this review is to discuss the current state of antibiotic resistance of non-typhoid Salmonella spp. in food-producing animals, retail meat and humans from South East Asia. It is focused on resistance characteristics of traditional and "critically important" antibiotics in this region, and the emergence of multidrug resistant strains and genetic elements that contribute to the development of multidrug resistance, including integrons and the Salmonella Genomic Island (SGI).

A quantitative approach to analyse linkages between antimicrobial resistance properties inSalmonellaTyphimurium isolates

This study used statistical methods to investigate linkages in phenotypic resistance profiles in a population sample of 321SalmonellaTyphimurium isolates from sporadic salmonellosis cases in Lower Saxony, Germany, collected during 2008–2010. A resistance index was applied to calculate the conditional probability of resistance to one antimicrobial agent given the resistance to one or more other antimicrobial agent(s). A susceptibility index was defined analogously. A contingency plot, which visualizes the association between resistances to two antimicrobial agents, facilitated the interpretation. Linkages between minimum inhibitory concentrations (MIC) were analysed using Spearman's rank correlation coefficient and jittered scatter plots. Applying these methods provided a compact description of multi-resistance and linkages between resistance properties in large datasets. Moreover, this approach will improve monitoring of antimicrobial resistance dynamics of bacteria in human or animal populations by identifying linked resistance to antimicrobial agents (cross- or co-resistance) with a non-molecular method.