Fecal Residues Research Articles

Bacillus CotA laccase improved the intestinal health, amino acid metabolism and hepatic metabolic capacity of Pekin ducks fed naturally contaminated AFB1 diet

BackgroundAflatoxin B1 (AFB1) is a prevalent contaminant in agricultural products, presenting significant risks to animal health. CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading mycotoxins in vitro test. The efficacy of Bacillus CotA laccase in animals, however, remains to be confirmed. A 2 × 2 factorial design was used to investigate the effects of Bacillus CotA laccase level (0 or 1 U/kg), AFB1 challenge (challenged or unchallenged) and their interactions on ducks. The purpose of this study was to evaluate the efficacy of Bacillus CotA laccase in alleviating AFB1 toxicosis of ducks.ResultsBacillus CotA laccase alleviated AFB1-induced declines in growth performance of ducks accompanied by improved average daily gain (ADG) and lower feed/gain ratio (F/G). Bacillus CotA laccase ameliorated AFB1-induced gut barrier dysfunctions and inflammation testified by increasing the jejunal villi height/crypt depth ratio (VH/CD) and the mRNA expression of tight junction protein 1 (TJP1) and zonula occluden-1 (ZO-1) as well as decreasing the expression of inflammation-related genes in the jejunum of ducks. Amino acid metabolome showed that Bacillus CotA laccase ameliorated AFB1-induced amino acid metabolism disorders evidenced by increasing the level of glutamic acid in serum and upregulating the expression of amino acid transport related genes in jejunum of ducks. Bacillus CotA laccase ameliorated AFB1-induced liver injury testified by suppressing oxidative stress, inhibiting apoptosis, and downregulating the expression of hepatic metabolic enzyme related genes of ducks. Moreover, Bacillus CotA laccase degraded AFB1 in digestive tract of ducks, resulting in the reduced absorption level of AFB1 across intestinal epithelium testified by the decreased level of AFB1-DNA adduct in the liver, and the reduced content of AFB1 residues in liver and feces of ducks.ConclusionsBacillus CotA laccase effectively improved the growth performance, intestinal health, amino acid metabolism and hepatic aflatoxin metabolism of ducks fed AFB1 diets, highlighting its potential as an efficient and safe feed enzyme for AFB1 degradation in animal production.Graphical

Identification of Bacteria from Public Toilets of Modern Market (Goico) in Musanze Town, Rwanda

Background: Bacteria are present on all surfaces, to which they were carried by many direct and indirect methods of transmission. A toilet is simply a receptacle into which both solid and liquid waste of human origin, in the form of urine and excreta are discharged. In public toilets, complete strangers mix and use the same sanitary facilities, with all the related risks of bodily fluid exchange, contamination and organism transmission. Unhygienic use of the toilet’s facilities may cause urine and fecal residues after use to serve as a major reservoir or source of human pathogen, which may in turn bring about disease outbreak. Aim: This study aimed at Identification of Bacteria from Public Toilets of Modern Market (Goico) In Musanze Town, Rwanda Method: This cross-sectional study was conducted to identify bacteria from GOICO market toilets. About 40 samples; 20 from male and 20 from female toilets were collected and transported to INES-clinical microbiology laboratory for microbiological analysis. Laboratory techniques including culture, gram stain, biochemical tests and antibiogram were performed. Results: The most predominant bacteria isolated was S. aureus (31.43%), followed by S. typhi (20%), Streptococcus(15.71%), E. coli(12.86%), P. aeuriginosa(10%), P. mirabilis(7.14%), C. freundi(1.43%), S. epidermidis (1.43%). It was noted that female toilets were more contaminated (51.43%) than male toilets (48.57%). All gram positive and gram-negative bacteria were sensitive to Gentamicin. Almost all bacteria except P. mirabilis were sensitive to Norfloxacin, gram negative showed a resistance to Vancomycin and Novobiocin. Conclusion: These results should alert public toilets users that extreme caution must be executed while using these toilets, as they may be a source of pathogenic bacteria. The best way to keep a toilet and its seat free of bacteria is to clean it with bleach. Otherwise, keep the bacteria at bay by washing your hands, and if you just don't trust that toilet seat, wipe it down with a disinfectant or antibacterial wipe before you sit. Keywords: Bacteria, Public toilets, E. coli, S. typhi, Urinary tract

In-vivo evaluation of the adverse effects of ochratoxin A on broiler chicken health and adsorption efficacy of indigenous and commercial clay of Balochistan, Pakistan

Mycotoxins in animal feed pose health risks and economic losses, but using various adsorbent types could potentially protect animals from mycotoxicosis. The study aimed to assess the effect of OTA on the health of broiler chickens and to envisage the ameliorative potential of clay adsorbents. The objectives of this in vivo study were to investigate the effects of OTA on productivity, biochemical parameters, fecal residues, and the preventive effects of indigenous and commercial clay of Balochistan as adsorbents to alleviate the adverse effects of exposure. Male broiler chickens (n = 160) were treated with 400 μg/kg OTA and 0.5 g/kg clay adsorbent for 42 days, with feed and water available in an ad libitum manner. The amount of OTA in diet and fecal residues was assessed through HPLC. The administration of OTA in the diet, resulted in a significant (p < 0.05) decrease in the average daily gain (ADG) and average daily feed intake (ADFI) while increasing the feed conversion ratio (FCR) as compared to the control group. Furthermore, no significant (p > 0.05) differences were found between the weight gain of broiler chickens fed without OTA (positive control) and that of chickens fed adsorbent. The group given a diet containing OTA without adsorbents as compared to the control and adsorbent-supplemented group has shown a significant (p < 0.05) increase in the relative weight of the liver, kidney, gizzard, and proventriculus while decreasing the relative weight of the spleen and bursa of Fabricius. Alterations in the levels of serum total protein (TP), cholesterol (CHL), serum urea (SU), enzymatic activity (aspartate aminotransferase (AST) and alanine transaminase (ALT)), and creatinine were observed in the OTA-intoxicated and adsorbent-supplemented groups as compared to the control group. Adsorbent supplementation resulted in a significantly (p < 0.05) higher OTA content in the faeces. It can be concluded from the results of this study, that OTA intoxication negatively affects the health of broiler chickens, and the clay of Balochistan has shown effective adsorption potential against OTA.

Fecal elimination of fluralaner in different carnivore species after oral administration.

Fluralaner is a recent external parasiticide, first of a new class of drugs (isoxazoline parasiticides). It is widely used in companion animals both for its wide spectrum (fleas, ticks and other mites) but also for its ease of use (oral tablets given once for 1 to three months). It is known to be eliminated primarily via the feces (>90%) as the unchanged compound. In zoo carnivores, controlling external parasites is also important and there are no specific products with a marketing authorization to control them. The first objective of this study was to evaluate the pharmacokinetic profile of fluralaner in zoo carnivores. The second objective was to demonstrate that fluralaner can be eliminated over a prolonged period of time, thereby raising questions about its potential impact on non-target species such as arthropods. After adjusting the oral dose using allometric equations, animals were dosed and fecal samples were collected on a regular basis for up to three months to determine the fecal elimination curve of fluralaner as a surrogate of plasma kinetics (for ethical and safety reasons, plasma samples were not considered). All samples were analyzed with a validated LC-MSMS technique. Our results show that, despite limitations and a limited number of animals included, most carnivores eliminate fluralaner in their feces for several weeks to months (in Lions, fluralaner was still detectable after 89 days). To our knowledge, this is the first study demonstrating such a long elimination period in animals. Further studies would be required to investigate the risk associated with the presence of active residues in other carnivore feces for the environment, especially in dogs and cats, considering the large use of this class of compounds.

Current Status and Spatiotemporal Evolution of Antibiotic Residues in Livestock and Poultry Manure in China

The use of antibiotics in the livestock and poultry industries has raised significant concern about environmental and health problems. In light of this, accurate knowledge of antibiotic residues in livestock and poultry manure is important for pollution management and strategic decision-making at the national level. This study aims to provide a comprehensive report on antibiotic residues in livestock and poultry manure in China using the published data of 3751 livestock and poultry feces in 29 provincial-level units over the past 20 years. In this study, the overall status of antibiotic residues in livestock and poultry feces was analyzed by mathematical statistics. Moreover, the spatio-temporal variation characteristics were analyzed by spatial statistics, and the differences among livestock and poultry species were evaluated by subgroup analysis. The finding indicated that tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and macrolides (MLs) were the most abundant residues in livestock and poultry manure. The spatial and temporal variation revealed that the overall trend of antibiotic residues decreased gradually, and the spatial distribution was primarily concentrated in the southeast of Hu Line, exhibiting a “northeast-southwest” distribution. The distribution range also decreased slightly, with the residues of tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and pleuromutilins (PMs) showing a significant spatial hot spot. The center of gravity of antibiotic residue shifted to the southwest between 2003 and 2021. In comparison to cow and sheep manure, the tetracyclines (TCs), sulfonamides (SAs), and macrolides (MLs) in pig and chicken manure were higher. The results can serve as a reference for the control and reduction of antibiotic pollution in livestock and poultry manure, as well as the wise utilization of those resources and achieving goals for clean agriculture.

Combination of glycyrrhizic acid and compound probiotics alleviates deoxynivalenol-induced damage to weaned piglets

Deoxynivalenol (DON) can affect health and growth performance of pigs, resulting in significant economic losses in swine production. The aim of this study was to investigate the effect of glycyrrhizic acid combined with compound probiotics, i.e. Enterococcus faecalis plus Saccharomyces cerevisiae (GAP) on improving growth performance, intestinal health and its fecal microbiota composition change of piglets challenged with DON. A total of 160 42-day-old weaned piglets (Landrace × Large White) were used and the experimental period was 28 d. The results showed that supplementing GAP in the diet significantly improved the growth performance of piglets challenged with DON and alleviate DON-induced intestinal damage by reducing ALT, AST and LDH concentrations in serum, increasing the morphological parameters of jejunum, and decreasing DON residues in serum, liver and feces. Moreover, GAP could significantly decrease the expressions of inflammation and apoptosis genes and proteins (IL-8, IL-10, TNF-α, COX-2, Bax, Bcl-2 and Caspase 3), and increase the expressions of tight-junction proteins and nutrient transport factor genes and proteins (ZO-1, Occludin, Claudin-1, ASCT2 and PePT1). In addition, it was also found that GAP supplementation could significantly increase the diversity of gut microbiota, maintain microbial flora balance and promote piglet growth by significantly increasing the abundance of beneficial bacterium such as Lactobacillus and reducing the abundance of harmful bacterium such as Clostridium_sensu_stricto_1. In conclusion, GAP addition to piglet diets contaminated with DON could significantly promote the health and growth performance of piglets though alleviating DON-induced hazards. This study provided a theoretical basis for the application of GAP to alleviate DON toxicity for animals.

A non-invasive method to monitor farmland bird exposure to triazole fungicides

The treatment of seeds with pesticides is an extended practice in current agriculture. There is a high risk of exposure in granivorous birds, such as the red-legged partridge (Alectoris rufa), that can consume those seeds remaining on the surface during sowing. Fungicide exposure could in turn affect bird reproductive capacity. To better understand to what extent triazole fungicides are a threat to granivorous birds, we need an easy and reliable method to quantify field exposure. In this study, we tested a novel non-invasive method to detect the presence of triazole fungicide residues in farmland bird faeces. We experimentally exposed captive red-legged partridges to validate the method, and then applied it in a real scenario to assess exposure of wild partridges. We exposed adult partridges to seeds treated with two formulations containing triazole fungicides as active ingredients: Vincit®Minima (flutriafol 2.5%) and Raxil®Plus (prothioconazole 25% and tebuconazole 15%). We collected two types of faeces (caecal and rectal samples) immediately after exposure and 7 days later and quantified the concentrations of the three triazoles and their common metabolite (1,2,4-triazole). The three active ingredients and 1,2,4-triazole were only detected in faeces collected immediately after exposure. Triazole fungicide detection rates in rectal stool were 28.6%, 73.3% and 80% for flutriafol, prothioconazole and tebuconazole, respectively. In caecal samples, detection rates were 40%, 93.3% and 33.3%, respectively. 1,2,4-triazole was detected in 53% of rectal samples. For an applied use of the method in the field, we collected 43 faecal samples from wild red-legged partridges during autumn cereal seed sowing and found detectable levels of tebuconazole in 18.6% of the analysed wild partridges. The results of the experiment were then used to estimate actual exposure levels from this prevalence value found in wild birds. Our study shows that faecal analysis can be a useful tool to assess farmland bird exposure to triazole fungicides, when samples are fresh and the method has been validated for the detection of target molecules.

Findings on agricultural cleaner production in the three Gorges Reservoir Area

The ‘rural revitalization strategy’ is important to achieve sustainable development in the Three Gorges Reservoir Area (TGRA), the largest reservoir in China, located in the poverty alleviation region of the Qinling-Daba mountains, and characterized as mountainous and hilly dominated by backwards resettlements. Pig farming around the reservoir area is a key industry, accounting for 0.90% of the arable land area in the country, while the annual pig market represents a 1.37% share of the national figure. Here, 12 study sites were investigated on-site for understanding agricultural green development in the TGRA. We found two main prevailing models: one of ecological circulation (EC), based on animal husbandry and recycling. Of the 12 site, six cases of the ecological circulation model relied on pig husbandry, combined with cropping (grains/fruits/vegetables) by eco-industrial chains, such as pig-biogas-fruit (grain/vegetables), to prevent environmental pollution, while promoting agricultural economic growth by recycling fecal residues and wastewater (FSW) from pig-husbandry facilities to the fields. Our analysis predicted that a farm holding 10,000 pigs may save inorganic nitrogen and phosphorus fertilizers by as much as 74.36 and 11.15 ton·a−1, respectively. On the other hand, five cases of ecological models oriented towards agritourism provided tourists with high-quality ecological products while coordinating environment protection with economic development. In addition, 11 research points applied water and fertilizer integration system for the purpose of saving water. However, lack of sufficient supporting arable land made intensive pig farming a risk of ecological degradation. Green control technologies are rarely used leading to an increase in the type and amount of pesticides. Our study has theoretical and practical significance for decision-makers to promote agricultural cleaner production (ACP).

Actualidades en el uso de aminoácidos en la industria lechera

The constant demand for high quality dairy products has driven significant changes in the productive capacity of dairy cows in the last 50 years. To maintain high volumes of milk production and quality in terms of the level of protein, fat, and other milk components, it is common to use high levels of crude protein in the diet. However, this practice generates N residues in feces and urine that cause environmental pollution and high costs. Balancing diets to cover metabolizable protein and limiting amino acid requirements allows feeding low-protein diets resulting in higher N utilization efficiency, lower environmental impact, and higher profitability. Lysine, methionine, and histidine are the most limiting amino acids in diets for dairy cows based on corn silage and alfalfa hay. The use of rumen-protected lysine and methionine in transition cow diets positively affects dry matter intake, milk production and milk quality. Whereas supplementation with rumen-protected methionine to cows prior to calving improves metabolic immune status and genetic expression of offspring, which show better productive performance after birth.

Validation of a LC-MS/MS method for the quantitative analysis of four antibiotics in pig tissues and plasma to assess the risk of transfer of residues to edible matrices after exposure to cross-contaminated feed

Cross-contamination between medicated and non-medicated feed can occur during production, processing, transport or storage of animal feed. This may lead to the presence of low concentrations of antibiotics in supposedly drug-free feed for food production animals, which potentially could also harm consumers due to residues. In addition, consumption of sub-therapeutic concentrations of antibiotics may increase the risk of emergence of resistant bacteria. In this study, LC-MS/MS methods were developed to quantify four antibiotics (sulfadimethoxine, oxytetracycline, trimethoprim and amoxicillin) in several pig matrices, i.e. plasma, muscle, liver, kidneys and faeces. All methods were validated using the accuracy profile, except for amoxicillin in faeces, for which extraction could not be optimised for low concentrations. These methods were then applied as part of an animal study during which several pigs received contaminated feed at a concentration corresponding to 2% of therapeutic dose, in order to evaluate the risk of the presence of residues in animal faeces and tissues. The results showed that sulfadimethoxine is well absorbed and accumulates in the muscle, kidneys and liver, where concentrations were higher than the maximum residue limits (MRLs) authorised in EU legislation. Conversely, oxytetracycline was mostly found in faeces as its oral absorption is very low. Trimethoprim concentrations were slightly higher than the tolerated MRL in the kidneys, but they were below this level in the other tissues. Finally, amoxicillin concentrations remained below the lower limit of quantification of the methods in all matrices.

Spatial distribution of bacterial resistance towards antibiotics of rural sanitation system in China and its potential link with diseases incidence

Chinese government is vigorously promoting toilet renovation in rural areas to reduce the risk of human feces exposure, which would cause infectious diseases, especially antibiotic resistance genes (ARGs) and pathogens. However, the distribution of ARGs in human feces from different regions of China remained ill-defined. It is not yet known how the survival of ARGs after toilet treatment is associated with the regional infection rates. Here, we investigated the prevalence of ARGs in human feces in rural areas of China and their potential relationship with infectious diseases for the first large-scale. The results showed that there were still high ARGs residues in human feces after rural toilet treatment, especially tetM-01 and ermB with average relative abundance as high as 1.21 × 10−1 (Eastern) and 1.56 × 10−1 (Northern), respectively. At a large regional scale, the significant differences in human feces resistomes were mainly shaped by the toilet types, TN, NH3-N, and the bacterial community. A critical finding was that toilets still cannot effectively decrease the pathogenicity risk in human feces. The significant positive relationship (P<0.05) between infectious diseases and ARGs can infer that ARGs in human feces exposure might be a critical path for enhancing the incidence of diseases, as these ARGs hinder the effectiveness of antibiotics.

Detection of glyphosate residues in feed, saliva, urine and faeces from a cattle farm: a pilot study

Forty-two samples of feed, saliva, urines, and faeces collected from a cattle farm were investigated with the aim to evaluate the occurrence of glyphosate in faeces, urine and saliva. Glyphosate in the feed was also quantified to understand how it was assimilated by mammals. All cows excreted glyphosate in their faeces at concentrations between 57 and 983 ng g−1. In contrast, only 55% of urine and one sample of saliva tested positive. Most of the feeds demonstrated a non-negligible presence of glyphosate. In particular, a silage containing soybeans from genetically modified cultivation showed a concentration one order of magnitude higher than the other feeds. This study aims to provide the first complete determination of glyphosate in a cattle farm, considering the possible re-entry into the environment through the spreading of liquid and solid sewage and its possible impact on groundwater.

ANTIMICROBIALS IN ANIMAL FAECES (CHICKEN, COW AND SWINE) FROM THE BREEDING FARMS IN THE UPSTREAM OF SAI GON RIVER

The widespread use of antimicrobials in husbandry has increased antimicrobial residues in animal faeces. Therefore, the investigation of antimicrobials in animal faeces is essential because they are the main cause of environmental pollution. This study analyzed and assessed samples of chiken, cow and swine faeces for seven antimicrobials, namely trimethoprim (TRI), ormethoprim (ORM), ofloxacin (OFL), norfloxacin (NOR), tetracycline (TET), chlortetracycline (CTE) and tylosin (TLS). Samples were taken from faeces heaps at breeding farms in the upstream of the Sai Gon river. The samples were analyzed in the laboratory by using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine antimicrobials. TRI, with the highest mean concentration, was found in all fecal samples (10,399 - 47,987 mg/kg) while ORM with the lowest average concentration was only detected in chicken fecal samples (542 mg/kg). CTE, with the second high mean concentration, was also found in all fecal samples (1,085 - 12,385 mg/kg), whereas TET was only detected in chicken fecal samples (9,050 mg/kg). OFL with the third average concentration, was aloso found in all fecal samples (1,516 - 9280 mg/kg), while NOR was detected in cow fecal samples at a low mean concentration (2,479 mg/kg). TLS was only found in chicken and cow fecal samples (798 - 5,802 mg/kg). These numbers show a very large amount of consumption of antimicrobials in livestock production. The results from this study are likely to encourage further monitoring of antimicrobials used in livestock production, and promote discussion of existing policies regarding the inclusion of antimicrobials in animal feed rations and veterinary medicines.

Detection of enteroparasites in foliar vegetables commercialized in street- and supermarkets in Aparecida de Goiânia, Goiás, Brazil.

Foliar vegetables contaminated with fecal residues are an important route of transmission of intestinal parasites to humans. The aim of this study was to evaluate the presence of parasitic forms of protozoa and helminths on lettuces (Lactuca sativa) and collard greens (Brassica oleracea) sold in street- and supermarkets in the city of Aparecida de Goiânia, Goiás, Brazil. A total of 30 samples of each vegetable (15 samples from each supermarkets and street markets) was analyzed. All samples were processed by spontaneous sedimentation method and centrifugal flotation. In 45% of the samples, immature forms of intestinal parasites were identified with 66.7% helminths eggs and 33.3% protozoan cysts or oocysts. Significantly more lettuce samples were contaminated with eggs, cysts or oocyst of at least one parasite than collard green samples (U=216; Z=-3.45; P <0.001). The parasitic forms were identified morphologically up to the family level with eggs of Ancylostomatidae, Strongyloididae, Ascarididae and Taeniidae, or oocysts of Eimeriidae, to the genus with Cystoisospora sp. and Toxocara sp., and to the species level with Cystoisospora canis, Dipylidium caninum and Hymenolepis nana. The presence of these infective agents in lettuce and collard green from both street- and supermarkets highlights the high risk of spreading parasites by eating raw vegetables sold in Aparecida de Goiânia.

Links between microbial compositions and metabolites during aerobic composting under amoxicillin stress was evaluated by 16S rRNA sequencing and gas chromatography-mass spectrometry: Benefit for the plant growth

The purpose of this study was to identify the relationship between core bacteria and metabolites during aerobic composting and analyze the effects of metabolites on plant growth. The results revealed that amoxicillin might affect the generation and transformation of metabolites by reconstructs the bacterial communities. The peak area ratios (PAR) of esters and fatty acids (FAs) were increased, while sterols decreased during composting. Furthermore, the correlation analysis showed that the production of FAs, esters and sterols is strongly correlated with Oceanobacillus, Corynebacterium, Psychrobacter, Xanthomonadaceae, Pusillimonas and Gracilibacillus. Moreover, 36 key metabolites were screened out, the PAR of the propanoic acid ethyl ester and oleic acid that benefit plant growth were increased in amoxicillin groups. However, the PAR of environmental pollutants, such as n-hexadecanoic acid and 3β, 5β-Cholestan-3-ol is the opposite. Therefore, composting can eliminate the environmental risks caused by antibiotic residues in feces and promote plant growth.

Amino Acids Supplementation for the Milk and Milk Protein Production of Dairy Cows.

Simple SummaryThe composition of milk not only has nutritional implications, but is also directly related to the income of dairy producers. As regards milk’s composition, concerns around milk protein have emerged from the increased consumption of casein products. The synthesis of proteins in milk is a highly complex and high-cost process, because the conversion efficiency of dietary protein to milk protein is very low in dairy cows. Thus, some studies have increased milk protein by using protein supplements or a single amino acid (AA) supply. AAs are the building blocks of protein, and can also stimulate the protein synthetic pathway. This review mainly concerns the use of AAs for producing milk protein in high-producing dairy cows, particularly with methionine, lysine, and histidine. Understanding the mechanisms of AAs will help to promote milk protein synthesis in the dairy industry.As the preference of consumers for casein products has increased, the protein content of milk from dairy cows is drawing more attention. Protein synthesis in the milk of dairy cows requires a proper supply of dietary protein. High protein supplementation may help to produce more milk protein, but residues in feces and urine cause environmental pollution and increase production costs. As such, previous studies have focused on protein supplements and amino acid (AA) supply. This review concerns AA nutrition for enhancing milk protein in dairy cows, and mainly focuses on three AAs: methionine, lysine, and histidine. AA supplementation for promoting protein synthesis is related to the mammalian target of rapamycin (mTOR) complex and its downstream pathways. Each AA has different stimulating effects on the mTOR translation initiation pathway, and thus manifests different milk protein yields. This review will expand our understanding of AA nutrition and the involved pathways in relation to the synthesis of milk protein in dairy cows.

Chlortetracycline alters microbiota of gut or faeces in pigs and leads to accumulation and migration of antibiotic resistance genes

In this study, we investigated the effect of long-term use of chlortetracycline (CTC) on the gut microbiota composition and metabolism profiles in pigs, and the variation of antibiotic resistance genes (ARGs) and microbial communities in faeces and manure during aerobic composting (AC) and anaerobic digestion (AD). The pigs were fed the same basal diet supplemented with or without 75 mg/kg CTC, and fresh faeces of 30-, 60-, 90-, and 120-day-old pigs were collected from the CTC group. The results showed that CTC reduced the diversity of the gut microbiota significantly and changed its structure. Metabolomics analysis of intestinal contents revealed 23 differentially abundant metabolites, mainly organic acids, carbohydrates, and amino acids. Metabolic pathways, such as the TCA cycle, propionate metabolism, and pyruvate metabolism, were changed. From 30 to 120 days of age, the amount of CTC residues in faeces and the abundance of 3 tetracycline resistance genes increased significantly, and it was positively correlated with tetC, tetG, tetW, sul1 and intI2. CTC residue levels and ARGs abundance gradually decreased with fermentation time, and AC was better than AD at reducing ARGs abundance. The results suggest that in-feed CTC can reduce the diversity of the gut microbiota, change the structure, function and metabolism of the bacterial community, and increase the abundance of ARGs in faeces.

Small-scale on-site treatment of fecal matter: comparison of treatments for resource recovery and sanitization

On-site small-scale sanitation is common in rural areas and areas without infrastructure, but the treatment of the collected fecal matter can be inefficient and is seldom directed to resource recovery. The aim of this study was to compare low-technology solutions such as composting and lactic acid fermentation (LAF) followed by vermicomposting in terms of treatment efficiency, potential human and environmental risks, and stabilization of the material for reuse in agriculture. A specific and novel focus of the study was the fate of native pharmaceutical compounds in the fecal matter. Composting, with and without the addition of biochar, was monitored by temperature and CO2 production and compared with LAF. All treatments were run at three different ambient temperatures (7, 20, and 38°C) and followed by vermicomposting at room temperature. Materials resulting from composting and LAF were analyzed for fecal indicators, physicochemical characteristics, and residues of ten commonly used pharmaceuticals and compared to the initial substrate. Vermicomposting was used as secondary treatment and assessed by enumeration of Escherichia coli, worm density, and physicochemical characteristics. Composting at 38°C induced the highest microbial activity and resulted in better stability of the treated material, higher N content, lower numbers of fecal indicators, and less pharmaceutical compounds as compared to LAF. Even though analysis of pH after LAF suggested incomplete fermentation, E. coli cell numbers were significantly lower in all LAF treatments compared to composting at 7°C, and some of the anionic pharmaceutical compounds were detected in lower concentrations. The addition of approximately 5 vol % biochar to the composting did not yield significant differences in measured parameters. Vermicomposting further stabilized the material, and the treatments previously composted at 7°C and 20°C had the highest worm density. These results suggest that in small-scale decentralized sanitary facilities, the ambient temperatures can significantly influence the treatment and the options for safe reuse of the material.

Research progress on the effect of antibiotics on anaerobic fermentation gas production and microorganisms of animal manure

Antibiotics are widely used in animal husbandry as veterinary drugs and feed additives, resulting in a large amount of antibiotic residues in animal feces. In order to achieve harmless and resourceful utilization of livestock manure, anaerobic fermentation is the most extensive treatment method in the world. It briefly introduces the residues of antibiotics such as oxytetracycline, chlortetracycline, and tetracycline, which are currently used the amount. The effects of antibiotics on anaerobic fermentation gas production performance and research progress are discussed in recent years. A large number of results indicate that the influence of antibiotics on the fermentation system mainly occurs in the initial stage of fermentation. There are mainly H2 / CH4 reduction path ways, acetic acid fermentation pathways and methyl conversion pathways. Methanogenic and acidogenic microorganisms are closely related to these pathways in the fermentation system. And the effects of antibiotics on the methanogenic microorganisms in the fermentation system are described. It is suggested that the future research direction should further study the effect of antibiotics on antibiotic resistance genes in livestock and poultry manure.

High prevalence of a gene cluster conferring resistance to streptomycin, sulfonamide, and tetracycline in Escherichia coli isolated from indigenous wild birds.

A total of 116 Escherichia coli isolates from cecal contents of 81 indigenous wild birds in Korea were tested for antimicrobial susceptibility. Seventy-one isolates from sparrows (Passer montanus) and one isolate from doves (Columba livia) were resistant to three antimicrobials, including streptomycin, sulfonamide, and tetracycline (SSuT). PCR and subsequent sequence analysis revealed the SSuT gene cluster region (approximately 13 kb) harboring genes encoding resistance to streptomycin (strA and strB), sulfonamide (sul2), and tetracycline (tetB, tetC, tetD, and tetR). In particular, tetracycline resistance genes were located on the transposon Tn10-like element. The SSuT element-harboring E. coli can be an important source of the transmission of antimicrobial resistance to other pathogenic bacteria. Therefore, strict sanitary measures in human and animal environments are necessary to prevent the spread of resistant bacteria through fecal residues of wild birds.