Use Of Antibiotics In Animals Research Articles

Nanoformulations for lysozyme-based additives in animal feed: An alternative to fight antibiotic resistance spread

Abstract The problem of antibiotic resistance (AR) in pathogenic bacteria due to the massive use of antibiotics in animals is an underestimated issue. Finding alternatives to reduce or eliminate the appearance and spread of AR is a pressing issue for humanity. Enzymes with antibiotic properties may serve as antimicrobial agents, less prone to generating AR due to their proteic nature and mode of action. Lysozyme is a natural antimicrobial agent, amenable to replacing small-molecule antibiotics in animal farming (poultry and livestock) due to its similar effects on animal health and growth. Moreover, it is safe for human and animal consumption and environmentally friendly due to its biodegradability. The development and testing against pathogens of lysozyme-containing nanomaterials fabricated with biocompatible polymers, particularly polysaccharides is reviewed, focusing on their antimicrobial properties, often superior to lysozyme alone due to a synergistic effect of the nanoscaled materials.

THE USE OF ANTIBIOTICS IN FOOD ANIMALS – A THREAT TO HUMAN HEALTH

Background: Antibiotics are widely used in food animals to prevent disease, promote growth and maintain productivity. Modern animal production practices involve regular use of antimicrobials, but abusive use can lead to harmful consequences. The aim of this review was to provide comprehensive information regarding the risk of regular application of antibiotics in food animals, the potential consequences and impact on human health, and options for the prevention of antibiotic resistance in the food chain. Review Results: Although organizations such as WHO, UN, and EU have taken steps to reduce and limit the use of antibiotics in animals, these are proving insufficient in developing countries. In many countries, the antibiotics used in animals appear to exceed that in humans. The abuse in food animals promotes the development of antibiotic-resistant bacteria and resistance genes that can be transmitted to humans through food consumption and direct contact with animal food or environment mechanisms. This can lead to human infections with antibiotic-resistant bacteria, causing treatment failure and, therefore, more severe and longer-lasting illnesses, increased hospitalization rates, more deaths and higher costs to society. Furthermore, as food animals and animal-derived foods are traded globally, they contribute to antibiotic resistance in countries far from where the problem originates. Conclusion: Overcoming the problem of antibiotic resistance requires a multidisciplinary approach with effective action coordination and information exchange between the agricultural, food, veterinary and health sectors. Through international cooperation, efforts should focus on reducing unnecessary antibiotics use and reducing the spread of antibiotic-resistant bacteria, but national-level action on antibiotic resistance and food safety is also essential.

Occurrence of antimicrobial residues in broiler chickens from selected farms and markets in Kano Metropolis, Nigeria

The indiscriminate use of antibiotics in animal meant for human and animal’s consumption lead to occurrence of antibiotic residues which threaten the health of both animals and humans. The aim of the study was to detect the presence of antimicrobial residues in broiler chicken in Kano state, Nigeria. Samples of fresh breast muscle, thigh muscle, liver and kidney were collected from 100 birds and examined using microbial inhibition test and ELISA test to determine the occurrence of antimicrobial residues and Enrofloxacin residues. A questionnaire was also administered to 33 workers and managers of the selected bird’s farms to assess their knowledge on the use of antibiotics and presence of antimicrobial residues. The result of the study revealed that 43% of the studied birds tested positive to antibiotic residue. Kidney samples recorded the highest (43%) residue present while thigh muscles (35%) recorded the least. The result indicated that among the birds detected with positive antibiotic residues, 36.4% were also positive for Enrofloxacin residue. All the respondents were using one or more antibiotic for treatment, prophylaxis or both and to a lesser extent as growth promoters. Majority (55.5%) of the respondents were not aware of the presence of residues in poultry. Most of the respondents (63.7%) have knowledge of withdrawal period but all of them were not observing withdrawal practice before disposing their birds. Doxycycline antibiotic was found to be the most indiscriminately use antibiotic, while erythromycin and chloramphenicol are the least. The study advocates the need for awareness campaigns for the farmers on the correct way of administering the antibiotics with special emphasis on withdrawal periods as well as continuous monitoring of the residues for public health reasons.

Challenges and opportunities when moving food production and consumption toward sustainable diets in the Nordics: a scoping review for Nordic Nutrition Recommendations 2023.

The terms 'Nordic countries' or 'The Nordics' include the five countries Denmark, Finland, Island, Norway, and Sweden. This review includes evaluation of the Nordic countries against Food and Agricultural Organisation (FAO)/World Health Organizations' (WHO) guiding principles for healthy, sustainable diets with respect to environmental impact (principles #9 - #13) and sociocultural aspects (principles #14 - #16). A food systems perspective is taken to summarize and discuss the most important challenges and opportunities for achieving sustainable diets. Food system, food security, self-sufficiency, and resilience perspectives are applied. The information can underpin decisions when developing and implementing Food Based Dietary Guidelines (FBDG) in the Nordics. None of the Nordic countries are on track to reach the 2030 UN climate and biodiversity goals. We describe how food production, processing, and consumption contribute to these and other environmental challenges, and what kinds of dietary changes/transitions consistent with these goals are required. A major challenge is the high production and consumption of meat and too low consumption of fish, vegetables, and fruits. Meat production is a major source of emissions and, together with farmed fish, heavily dependent on imported feed ingredients, leaving a large land-use and water footprint in exporting countries while domestic land resources are not used optimally. Dietary patterns have changed drastically over the past 50 years, and in large parts of the population, meat consumption has doubled since the 1970s, rendering historic food culture less useful as a basis for present-day recommendations. The Nordics have Europe's lowest use of antibiotics in animal and fish production and have made some progress in reducing food waste along the food chain. A major opportunity is better alignment of food production and consumption based on local or regional production potentials, in conjunction with better and more constructive integration with the global food system while integrating novel technologies to reduce emissions and resource use.

Antibiotic Resistance of Foodborne Microorganisms Isolated in the Republic of Tajikistan

Introduction: The sanitary and epidemiological well-being of the population is mainly determined by food quality. The World Health Organization is alarmed by the increasing widespread use of antibiotics in animal, poultry, and fish production. The number of drugs used in agriculture is almost twice as high as the number of those used to treat humans. Objective: To establish antibiotic resistance of microorganisms isolated from food products. Materials and methods: Bacteria isolated from 261 samples of food products (eggs, meat and dairy products) on the territory of the Republic of Tajikistan in 2022 were used as materials for the study. Microorganisms (n = 138) were isolated and identified by the bacteriological method using differential diagnostic media. The phenotypic sensitivity of bacteria to nine antimicrobials was determined by the disc diffusion method (DDM). The statistical significance of the results was assessed by calculating the arithmetic mean (M) and standard error of the mean (m) in Microsoft Excel (2010). Results: A total of 138 Enterobacterales (52.2 %) and Staphylococcus (47.8 %) bacteria were tested. Analysis of the phenotypic profile of antibiotic sensitivity of cultures in the genus Staphylococcus showed that most of them were resistant to kanamycin and rifampicin (66.7 %); 54.6 % and 45.5 % were resistant to ceftriaxone and lincomycin, respectively. About 30 % of the staphylococci were resistant to erythromycin, tobramycin, levofloxacin, and gentamicin, while the share of staphylococci resistant to ciprofloxacin was the smallest (15.2 %). Enterobacteria showed high resistance to kanamycin (94.5 %), more than 61.2 % of cultures were resistant to tobramycin; 41.7 % and 33.4 % of cultures were resistant to ceftriaxone and gentamicin. Conclusion: Our findings demonstrate the importance of continuous surveillance over the spread of antibiotic-resistant bacteria in food products.

Antimicrobial Susceptibility Profiles of Bacteria Isolated from Traditionally Fermented Bovine Milk from Selected Farms of Kajiado- Central Sub-County, Kenya

Introduction: Fermented bovine milk provides a conducive environment for the growth of bacteria some of which could be of zoonotic importance. These bacteria can develop antimicrobial resistance (AMR) due to the regular use of antibiotics in animals. Materials and methods: This cross-sectional study was undertaken to determine the antibiotic sensitivity of bacteria isolated from traditionally fermented milk obtained and processed from 114 indigenous cows kept by Maasai pastoralists in Kajiado County, Kenya. The Kirby-Bauer Disk diffusion method was used to determine the antimicrobial susceptibility profiles of the isolated Staphylococcus spp., Escherichia coli, Klebsiella spp., and Salmonella typhi. Results: The susceptibility of the isolated bacteria was determined using nine antibiotics namely chloramphenicol (10μg), kanamycin (30μg), penicillin G (10μg), streptomycin (10μg), oxytetracycline (30μ) tetracycline (30μg), vancomycin (30μg), gentamycin (10μg) and Ampicillin (10μg). The Staphylococcus (S.) aureus isolates exhibited diverse resistance patterns to the antibiotics with the greatest resistance observed against oxytetracycline (69.2%), streptomycin (69.2%), and kanamycin (61.5%). However, a significant proportion of the S. aureus strains demonstrated a 100% susceptibility rate to gentamycin and vancomycin. Escherichia coli isolates exhibited resistance to vancomycin (100%), tetracycline (80%), oxytetracycline (80 %), and ampicillin (60 %) and were highly (100%) sensitive to the other antibiotics. Salmonella typhi isolates were resistant to vancomycin (88.8%) and highly (100%) sensitive to chloramphenicol, penicillin G, gentamycin, and streptomycin. Klebsiella spp. were highly resistant to vancomycin (100%) and were sensitive to gentamycin (100%) and streptomycin (100%). Conclusion: The study showed a high prevalence of AMR in bacteria isolated from traditional milk consumed by the pastoralists and thus there is a high risk of zoonotic spread of the pathogenic bacteria. There is a need to educate the local households on strategies to minimize the occurrence of AMR in animals and also improve hygiene practices in the preparation of traditionally fermented milk.

Comparison of Antimicrobial Resistance in Escherichia coli Strains Isolated From Swine, Poultry, and Farm Workers in the Respective Livestock Farming Units in Greece.

Human health is at risk because commensal intestinal bacteria in livestock have been developing increased antibiotic resistance, mainly due to antibiotics' extensive use in recent years. In this study, we compared the antibiotic resistance of E. coli strains isolated from fecal samples obtained from swine, poultry, and farm workers in the corresponding livestock farming units. The study aimed to investigate the correlation between the antibiotic resistance patterns of E. coli in livestock and in humans closely interacting with them. Antibiotic resistance is determined using the microdilution method, which measures the minimum inhibitory concentration (MIC) for seven commonly used antimicrobial agents. Most E. coli isolates displayed significant resistance to tetracycline and ampicillin. Resistance to sulfamethoxazole was observed, too, in swine and swine farmers. In contrast, high resistance rates to nalidixic acid were observed in E. coli strains isolated from poultry and poultry farmers, with percentages of 66.7% and 50%, respectively. Furthermore, 31.57% of the isolated strains from swine and swine farmers were resistant to at least one antibiotic. In comparison, 44.44% of the poultry strains and 33.33% of the poultry farmers' strains were resistant to at least two antibiotics. Additionally, a high prevalence of multidrug resistance was observed among the E. coli strains isolated from all four categories. The study's results provide evidence that the use of antibiotics and the increased resistance of intestinal bacteria affect the resistance of intestinal bacteria in people working on farms. These findings highlight the potential role of antibiotic use in animals as a contributing factor to the development of antibiotic resistance in both animals and humans. Additionally, it suggests that individuals working on farms may be at an increased risk of acquiring antibiotic-resistant strains of E. coli due to their proximity to and interaction with animals.

A systematic review of tetracycline resistance genes in animals and derived products in Latin America and the Caribbean

We aimed to systematize and assess scientific information on tetracycline (TET) resistance genes in animals, products, and by-products in the Latin America and the Caribbean (LAC) region. PRISMA guidelines were followed. Only original articles published in peer-reviewed journals were considered. Sixty articles published between 2003 and 2023 met the inclusion criteria. The geographical areas of study were Brazil, Mexico, Chile, and Costa Rica, and, to a lesser extent, Colombia, Bolivia, Cuba, Jamaica, Puerto Rico, and Uruguay. The studies were related to livestock, wild animals, and pets. The most common isolated bacteria were Escherichia coli and Salmonella spp. The tet genes found in higher frequency in the samples or isolates evaluated were tetA, tetB, tetM, tetL, tetK, tetC, tetO, tetD, tetG, tetW, tetS, tetQ, tetE, tetH, tetJ, tetZ, and tetY. Studies evaluating the presence of tet genes in animals in LAC are limited despite TET being antibiotics widely used in animals. It is necessary to establish cross border public policies that allow the constant training of medical and related personnel regarding the responsible use of antibiotics in animals and the effective monitoring of the phenomenon in the region.

Chlortetracycline Concentration Impact on Salmonella Typhimurium Sustainability in the Presence of Porcine Gastrointestinal Tract Bacteria Maintained in Continuous Culture.

Concern exists that the continued use of antibiotics in animal feeds may lead to an increased prevalence of resistant bacteria within the host animal's gastrointestinal tract. To evaluate the effect of chlortetracycline on the persistence of Salmonella enterica serotype Typhimurium within a diverse population of porcine cecal bacteria, we cultured a mixed population of cecal bacteria without or with added chlortetracycline. When grown at a 24 h vessel turnover rate, chlortetracycline-susceptible S. Typhimurium exhibited more than 2.5 times faster (p < 0.05) disappearance rates than theoretically expected (0.301 log10 colony-forming unit/mL per day) but did not differ whether treated or not with 55 mg of chlortetracycline/L. Chlortetracycline-resistant S. Typhimurium was not recovered from any of these cultures. When the mixed cultures were inoculated with a chlortetracycline-resistant S. Typhimurium, rates of disappearance were nearly two times slower (p < 0.05) than those observed earlier with chlortetracycline-susceptible S. Typhimurium, and cultures persisted at >2 log10 colony-forming units/mL for up to 14 days of treatment with 110 mg of chlortetracycline/L. Under the conditions of this study, chlortetracycline-resistant S. Typhimurium was competitively enabled to persist longer within the mixed populations of porcine gut bacteria than chlortetracycline-susceptible S. Typhimurium, regardless of the presence or absence of added chlortetracycline.

Generating evidence on antibiotic use across human and animal health sectors using the World Health Organization’s Access, Watch, Reserve (AWaRe) classification: Exploratory pilot study in rural Pune, India

Background and Aim: Human antibiotic formulations in animal feed for therapeutic and non-therapeutic purposes have contributed to antimicrobial resistance worldwide; however, little evidence is available in low- and middle-income countries. We aimed to generate evidence of antibiotic use across the human and animal health sectors by investigating the overlap in antibiotic use in community settings in rural blocks of Pune District, India, following the World Health Organization’s (WHO) Access, Watch, Reserve (AWaRe) classification. Materials and Methods: An exploratory pilot study using a cross-sectional design in two randomly selected rural blocks of the Pune district included 138 interviews with general physicians (GPs, n = 62), pharmacists (n = 60), and veterinary practitioners (n = 16) using semi-structured interview schedules and the WHO AWaRe classification. IBM-Statistical Package for the Social Sciences, Version 21.0 software was used for descriptive statistics and to calculate the proportions of the different antibiotic groups. The WHO AWaRe classification was used to describe antibiotic use by the study participants and to assess the overlap in antibiotic use. Results: Our study provides evidence of an overlap in human and animal antibiotic use in rural community settings across the human and animal health sectors. Amoxicillin (access group), penicillin (access group), and ofloxacin (watch group) were used in both human and animal health. Amoxicillin and penicillin were used to treat common bacterial infections, ofloxacin was used to treat skin infections in humans and animals, and ofloxacin was used to treat pneumonia in animals and urinary bladder infections in humans. In contrast, azithromycin (watch group), cefixime (watch group), and amoxicillin (Access Group), with or without other antibiotics, were the most commonly used antibiotics by GPs in humans. Conclusion: We confirmed the overlap in antibiotic use across the human and animal health sectors in rural community settings, suggesting the need for interventions following the One Health approach. Further, research is required to assess the patterns of this overlap, as well as behavior, knowledge, and potential solutions to help avoid this overlap and prevent the rampant use of antibiotics in the animal and human health sectors in rural community settings. Keywords: antimicrobial resistance, antibiotics use, overlap, rural India, WHO AWaRe.

Occurrence and ecological risk assessment of antibiotics in manure and the surrounding soil from typical chicken farms in Hangzhou, China

The widespread use of antibiotics in animal and human medication has raised global concerns over environmental contamination caused by antibiotic residues. This research investigated the occurrence of 12 kinds of antibiotics belonging to three groups, sulfonamides (SAs), tetracyclines (TCs), and fluoroquinolones (FQs), in chicken manure and the surrounding soil from different chicken farms in Hangzhou, South China, were detected in the samples via ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) and the contamination characteristics of each type of antibiotic and the correlations between each antibiotic and environmental factors were analyzed to identify the key influencing factors. An ecological risk assessment of antibiotics in the soil environment was conducted using the risk quotient (RQ) method to analyze the potential hazard level. The results indicated that: the total concentration of FQs was much higher than those of SAs and TCs in chicken manures and the soil samples. The mean concentration of FQs (39.17 μg·kg–1), TCs (34.37 μg·kg–1), and SAs (20.24 μg·kg–1) in chicken manure were significantly higher than those in the soil samples. Ciprofloxacin (CIP) was the main antibiotics detected in manure (19.42 μg·kg–1) and the soils samples (near soil: 18.42 μg·kg–1, far soil: 10.29 μg·kg–1), followed by enrofloxacin (ENR), tetracycline (TC), and ofloxacin (OFL). The redundancy analysis (RDA) showed that moisture content (MS), total organic carbon (TOC) and total nitrogen (TN) had a greater influence on the antibiotic concentration in the soil samples. Basis on the calculated risk quotient (RQs) values, the risk assessment indicated Sulfamerazine (SD) and Sulfamethoxazole (SMX) in soil posed a high risk, while trimethoprim (TMP), TC, CIP, and OFL in soils posed a medium or low risk. This research provides control and environmental monitoring data about chicken farms and scientific information that can be used to alleviate antibiotics pollution.

The opinions of farm animal veterinarians in Ireland on antibiotic use and their role in antimicrobial stewardship

BackgroundAntibiotic use and resistance in animal production are a concern to public health, and there is an urgent need to reduce antibiotic use in farm animals. To prevent blame shifting, professionals from human medicine, animal medicine and environmental backgrounds must collaborate to tackle this issue. Veterinarians are typically responsible for overseeing and prescribing antibiotic use in animals. There are currently no available studies on the opinions of Irish farm animal veterinarians on antibiotic use, reduction opportunities and their relationships with farmers. A digital survey was developed and sent out to Irish farm animal veterinarians. This paper presents the results of a cross-sectional study of Irish farm animal veterinarians’ attitudes towards antimicrobial stewardship, their prescribing behaviours, antibiotic reduction opportunities and their attitudes for the future of antibiotic use. The veterinarian-farmer relationship is examined and potential interventions to reduce antibiotic use on farms are identified.ResultsIn total, 114 complete questionnaires were received, representing approximately 11 per cent of all farm animal veterinarians in Ireland. Respondents were aware of the problem of antibiotic resistance and recognise their role in the fight against it. They realise what actions they must take to reduce antibiotic use and identify barriers that prevent their farmer clients from implementing their advice. Many of them say that they can reduce antibiotic use on farms in the future, but some remain doubtful. There was no statistical difference between veterinarians that had less experience working than those that had more experience in their attitudes towards future reduction in antibiotic use.ConclusionMost of the respondents seek to use antibiotics as judiciously as they can. The majority agree that antibiotic overuse is the main contributor to antibiotic resistance. Possible solutions to reduce antibiotic use include the development of antibiotic treatment guidelines, assigning one unique practice to each farm and compulsory CPD (Continuous Professional Development) courses.

Antibiotic Residues in fresh Chicken, Fish and Beef Meat samples in ‎Maiduguri, Nigeria

Prudent use of antibiotics in animal industry is essential for treatment of diseases and preventive measure. However, uncontrolled use of these agents in large amounts and consistently could result in the formation of antibiotic residues in muscle and organs of animal. This study aimed to determine the occurrence of antibiotic residue in fresh meats in Maiduguri. A cross-sectional study was conducted from September 2022 to December 2022 to determine the antibiotic residue in 3 sources of meat samples. A total of 150 fresh meat samples (chicken, fish and beef) were collected from different sale points Maiduguri, and analyzed using a Premi® Test kit (R-Biopharm AG, Germany), a microbial screening commercial test kit for the detection of antibiotic residues. The results showed an overall antibiotic residue of 127/150 (84.7%) meat samples were positive for antibiotic residues. High antibiotic residues was found in Chicken meats 47/50 (94%), followed by fish 43/50 (86%), and beef 37/50 (74%). The results in this study show the presence of antibiotic residues in meat. Therefore, it is recommended that effective legislation on antibiotic use in animals should be enforced.

MOLECULAR CHARACTERIZATION, ANTIBIOTIC SUSCEPTIBILITY AND BIOFILM FORMING ABILITY OF PASTEURELLA MULTOCIDA ISOLATED FROM THE RESPIRATORY MICROBIOTA OF HEALTHY BOVINES

Livestock plays an important role in the economy of the country because it provides food producing animals. Pasteurella multocida which is an opportunistic pathogen of upper respiratory tract of animals and it has been known to cause many harmful diseases may survive in animal body by forming biofilm in different organs. So, the presence of this bacterium in animals may lead to transfer and threaten the human health by food chain. In the last few years, one of the major problems that alarms and evokes a major horrific threat to human being is the bacterial resistance to antimicrobial agents. Due to deficiency of antimicrobial agents in pipeline and emergence of new mechanisms of intra antimicrobial resistance, many surveillance programs have been set up for its containment. Many factors are responsible for this grave situation like high use of antibiotics in animals. So, the current study concluded that all of the 76 isolates of Pasteurella multocida out of 100 samples were confirmed through PCR and found sensitive to florfenicol (100%), gentamycin (92.11%), chloramphenicol (84.21%) and kanamycin (72.37%) respectively. For tetracycline and neomycin sensitivity were (69.73%) and (64.47%) respectively against the bacteria. Whereas tilmicosin and spectinomycin sensitivity were recorded as (30.27%) and (23.69%). Streptomycin (19.73%), sulfadiazine (7.89%), erythromycin (3.94%) and clindamycin (0.0 %) were least sensitive. It was also concluded that when all pure isolates of Pasteurella multocida were tested for Biofilm assay out of 76 isolates categorized as: non biofilm producer (7.89%), weak biofilm producer (34.21%), moderate biofilm producer (46.05%) and strong biofilm producer (11.84%). Hence, it was concluded that Pasteurella multocida isolated from cattle and buffaloes were found to form biofilm in in-vitro condition.

Novel macrolide-lincosamide-streptogramin B resistance gene erm(56) in Trueperella pyogenes.

Whole-genome sequence analysis of a macrolide, lincosamide, streptogramin B (MLSB)-resistant Trueperella pyogenes from a dog revealed a new 23S ribosomal RNA methylase gene erm(56). Expression of the cloned erm(56) confers resistance to MLSB in T. pyogenes and Escherichia coli. The erm(56) gene was flanked by two IS6100 integrated on the chromosome next to a sul1-containing class 1 integron. GenBank query revealed additional erm(56)-containing elements in another T. pyogenes and in Rothia nasimurium from livestock. IMPORTANCE A novel 23S ribosomal RNA methylase gene erm(56) flanked by insertion sequence IS6100 was identified in a Trueperella pyogenes isolated from the abscess of a dog and was also present in another T. pyogenes and in Rothia nasimurium from livestock. It was shown to confer resistance to macrolide, lincosamide, streptogramin B antibiotics in T. pyogenes and E. coli, indicating functionality in both Gram-positive and Gram-negative bacteria. The detection of erm(56) on different elements in unrelated bacteria from different animal sources and geographical origins suggests that it has been independently acquired and likely selected by the use of antibiotics in animals.

Metaproteomic Analysis of Gut Resistome in the Cecal Microbiota of Fattening Pigs Raised without Antibiotics.

Improper use of antibiotics in swine could reduce commensal bacteria and possibly increase pathogen infections via the gut resistome. This study aimed to compare the metaproteomic profiles of the gut resistome and related metabolism in the cecal microbiota of fattening pigs raised under antibiotic-free (ABF) conditions with those of ordinary industrial pigs (controls [CTRL]). The top three relatively abundant microbes in both groups were Escherichia coli, Ruminococcus, and Lactobacillus, followed by Bacteroides and Bifidobacterium. E. coli, Lactobacillus, and Bacteroides were found to be increased in the CTRL group, whereas Ruminococcus and Clostridium were greater in the ABF group. The highest abundances of antibiotic resistance proteins (log2 expression levels [ELs] of >10) were found to be for tetracycline resistance (Tetr) and aminoglycoside resistance (AMGr) proteins found in Bacteroides, with a significant increase in the CTRL group. High Tetr (ELs of 5.32) was found in Ruminococcus in the CTRL group, although pigs in both groups had never received tetracycline, possibly reflecting the influence of environments in farms. In E. coli, AMGr and β-lactamase family proteins were observed in both groups (ELs of 3 to 6), whereas multidrug resistance protein MdtL was significantly expressed in the CTRL group (ELs of around 3). In the ABF group, CRISPR-associated endonucleases Cas1 and Cas9, which function to defend against viruses, were markedly observed in Ruminococcus and Lactobacillus, respectively, with ELs of 8.6 and 4.15, respectively. In conclusion, this study demonstrated that CRISPR-associated endonucleases were markedly observed in the ABF group, whereas higher levels of Tetr, AMGr, and multidrug resistance protein MdtL was markedly observed in dominant bacterial species in the CTRL group. IMPORTANCE In order to control and reduce antibiotic use in animals, the Department of Livestock Development, Thailand, has launched a campaign for antibiotic-free livestock production. The present study has shown for the first time that CRISPR-associated endonucleases Cas1 and Cas9, which function to defend against viruses, were markedly observed in Ruminococcus and Lactobacillus, respectively, in ceca of pigs raised without antibiotics (ABF). The highest abundances of antibiotic resistance proteins were for tetracycline (Tetr) and aminoglycoside resistance (AMGr) proteins found in Bacteroides, with a significant increase in the controls. In E. coli, the microbe with the highest relative abundance, AMGr and β-lactamase family proteins were observed in both groups, whereas multidrug resistance protein MdtL was significantly expressed in the controls. Pigs in both ABF and control groups had never received tetracycline, possibly reflecting the influence of farm environments. We suggest that pigs raised without antibiotics may have more beneficial microorganisms for the gut than pigs raised with antibiotics.

Preventing bacterial disease in poultry in the post-antibiotic era: a case for innate immunity modulation as an alternative to antibiotic use.

The widespread use of antibiotics in the poultry industry has led to the emergence of antibiotic-resistant bacteria, which pose a significant health risk to humans and animals. These public health concerns, which have led to legislation limiting antibiotic use in animals, drive the need to find alternative strategies for controlling and treating bacterial infections. Modulation of the avian innate immune system using immunostimulatory compounds provides a promising solution to enhance poultry immune responses to a broad range of bacterial infections without the risk of generating antibiotic resistance. An array of immunomodulatory compounds have been investigated for their impact on poultry performance and immune responses. However, further research is required to identify compounds capable of controlling bacterial infections without detrimentally affecting bird performance. It is also crucial to determine the safety and effectiveness of these compounds in conjunction with poultry vaccines. This review provides an overview of the various immune modulators known to enhance innate immunity against avian bacterial pathogens in chickens, and describes the mechanisms involved.

The Prevalence of Vibrio cholerae and Vibrio parahaemolyticus Virulence Genes and Multiple Antibiotics Resistant (MAR) Assessment from Local Shrimp Farm in Sarawak

Excessive and improper antibiotic use in animals raised for human consumption can increase the risk of antibiotic-resistant infections, causing more harm and higher treatment costs. This study examined the virulence genes and antibiotic susceptibility of Vibrio cholerae and V. parahaemolyticus, two bacteria that can affect public health. A total of 32 water samples were collected from August to December 2021 from a shrimp farm in Sarawak. Ten (n = 10) V. cholerae and ten (n = 10) V. parahaemolyticus presumptive isolates were identified and purified using selective agar and duplex-PCR method. The results showed that 70% of V. cholerae isolates contained rtxA and 90% of V. cholerae isolates contained rtxC while tdh and trh were not found in V. parahaemolyticus isolates. Antibiotic susceptibility testing showed that all V. cholerae and V. parahaemolyticus isolates were resistant to at least one antibiotic with the mean Multiple Antibiotic Resistance (MAR) indices of 0.34 for V. cholerae and 0.24 for V. parahaemolyticus. The MAR index of 0.20 and greater indicates that antibiotics are heavily contaminating the shrimp farm water. This study highlights the need for the proper administration of antibiotics in shrimp farming environments to reduce the risk of antibiotic-resistant infections caused by V. cholerae and V. parahaemolyticus. Water treatment should also be implemented before being released back to the environment to lessen the negative impact brought by the rearing of shrimp from a highly contaminated source.&#x0D;

Understanding the background and clinical significance of the WHO, WOAH, and EMA classifications of antimicrobials to mitigate antimicrobial resistance.

In Europe, the classification systems of the WHO, WOAH (founded as OIE), and EMA are the prevailing standard documents guiding the prudent use of antibiotic substances. While the WHO document "Critically important antimicrobials for human medicine" eponymously focusses on the use in humans, the other two documents, "OIE List of Antimicrobial Agents of Veterinary Importance" and "EMA Categorization of antibiotics for use in animals," concentrate exclusively on the prudent use of antibiotics in animals. One common purpose of these classification systems is to provide guidance in making sound decisions on the choice of antibiotics for treating humans as well as animals. Although the latest editions of these compendia refer to one another and bear a clear resemblance at the category levels, some of the substances are grouped into unequal classes. This review illustrates the specific perspectives of the three categorization systems under consideration. The arguments raised for different classifications between the WHO and the EMA are exemplified for amoxicillins without beta-lactamase inhibitors, macrolides, sulfonamides, and colistin. For the daily clinical use of antibiotics, veterinarians should consider the EMA document, and, under tentative circumstances, consult the OIE list.

Understanding networks in rural Cambodian farming communities and how they influence antibiotic use: A mixed methods study.

Biosecurity and preventive animal health services in Cambodian smallholder backyard farming systems are often limited, leading to an over-reliance on antibiotics. However, data on factors influencing antibiotic use in these settings are lacking. We conducted a study in two rural Cambodian farming communities to investigate how social and contextual influences affect both human and animal antibiotic use behaviours. Data were collected in three phases: a baseline household census to enumerate village residents, a social network survey to understand village-level social ties, and in-depth interviews to elicit information about the influence of social ties on their decision-making processes. Primary outcome measures included knowledge, attitudes and practices surrounding antibiotic use, and awareness of issues relating to antibiotic resistance. Participants commonly accessed antibiotics or learned animal antibiotic use practices through village-level informal sources such as pharmacies or animal health workers. While most participants reported not using antibiotics for animal growth promotion or illness prevention, misconceptions surrounding both antibiotic effectiveness and resistance were common. Social networks capturing informal, work-related and health-related social ties showed that familial connections and geographic proximity were of primary importance for information sharing. Using exponential random graph models, we demonstrated that familial ties, and closer geographic and geodesic distance, were associated with similarity in overall antibiotic knowledge and attitudes. The informal private sector plays a major role in provision of antibiotics and antibiotic-related information in backyard farming communities, but such information is maintained within close social groups. This demonstrates the importance of engaging village-level informal sources in the provision of antibiotic-related information for both human and animal health, as well as in potential interventions to encourage appropriate antibiotic behaviours in lower-resourced settings.