Antibiotics In Agriculture Research Articles

Molecular Docking and QSAR Studies of Indole Derivatives as Antifungal Agents

Introduction: Fungal infection and resistance to existing antibiotics is a major problem across the globe, which is associated with the inappropriate use of antibiotics in humans, animals farming, and agriculture. Unfortunately, addressing these difficulties is becoming extremely critical as they arise. In this paper, we used Hansch and Fujita's linear free energy relationship (LFER) model to perform 2D QSAR (quantitative structure activity relationships) on 28 known Indole derivatives. Objective: Molecular docking and 2D QSAR studies of Indole derivatives as antifungal agents. Methods: 2D QSAR was performed on the reported antifungal activity data of 28 selected compounds based on theoretical chemical descriptors to construct statistical models that link structural properties of Indole derivatives to antifungal activity. To represent the structural properties of compounds, a collection of molecular descriptors such as geometric, topological, hydrophobic and electronic characters were determined. Biological activity data was first translated into pMIC values (i.e. -log MIC) and used as a predictor variable in the QSAR analysis. We have also performed molecular docking studies of same compounds by using Maestro module of Schrodinger. Result: All docked compounds had better binding scores with reference to fluconazole. Conclusion: Compounds with high values of electronic energy and dipole moment will be effective against fungi, and Indole derivatives having lowered κ2 values will be effective antifungal agents.

Whole-genome sequencing of Alcaligenes sp. strain MMA: insight into the antibiotic and heavy metal resistant genes.

Introduction: A wide range of pollutants, including the likes of xenobiotics, heavy metals, and antibiotics, are characteristic of marine ecosystems. The ability of the bacteria to flourish under high metal stress favors the selection of antibiotic resistance in aquatic environments. Increased use and misuse of antibiotics in medicine, agriculture, and veterinary have posed a grave concern over antimicrobial resistance. The exposure to these heavy metals and antibiotics in the bacteria drives the evolution of antibiotic and heavy metal resistance genes. In the earlier study by the author Alcaligenes sp. MMA was involved in the removal of heavy metals and antibiotics. Alcaligenes display diverse bioremediation capabilities but remain unexplored at the level of the genome. Methods: To shed light on its genome, the Alcaligenes sp. strain MMA, was sequenced using Illumina Nova Seq sequencer, which resulted in a draft genome of 3.9Mb. The genome annotation was done using Rapid annotation using subsystem technology (RAST). Given the spread of antimicrobial resistance and the generation of multi-drug resistant pathogens (MDR), the strain MMA was checked for potential antibiotic and heavy metal resistance genes Further, we checked for the presence of biosynthetic gene clusters in the draft genome. Results: Alcaligenes sp. strain MMA, was sequenced using Illumina Nova Seq sequencer, which resulted in a draft genome of 3.9Mb. The RAST analysis revealed the presence of 3685 protein-coding genes, involved in the removal of antibiotics and heavy metals. Multiple metal-resistant genes and genes conferring resistance to tetracycline, beta-lactams, and fluoroquinolones were present in the draft genome. Many types of BGCs were predicted, such as siderophore. The secondary metabolites of fungi and bacteria are a rich source of novel bioactive compounds which have the potential to in new drug candidates. Discussion: The results of this study provide information on the strain MMA genome and are valuable for the researcher in further exploitation of the strain MMA for bioremediation. Moreover, whole-genome sequencing has become a useful tool to monitor the spread of antibiotic resistance, a global threat to healthcare.

The African Wastewater Resistome: Identifying Knowledge Gaps to Inform Future Research Directions.

Antimicrobial resistance (AMR) is a growing global public health threat. Furthermore, wastewater is increasingly recognized as a significant environmental reservoir for AMR. Wastewater is a complex mixture of organic and inorganic compounds, including antibiotics and other antimicrobial agents, discharged from hospitals, pharmaceutical industries, and households. Therefore, wastewater treatment plants (WWTPs) are critical components of urban infrastructure that play a vital role in protecting public health and the environment. However, they can also be a source of AMR. WWTPs serve as a point of convergence for antibiotics and resistant bacteria from various sources, creating an environment that favours the selection and spread of AMR. The effluent from WWTPs can also contaminate surface freshwater and groundwater resources, which can subsequently spread resistant bacteria to the wider environment. In Africa, the prevalence of AMR in wastewater is of particular concern due to the inadequate sanitation and wastewater treatment facilities, coupled with the overuse and misuse of antibiotics in healthcare and agriculture. Therefore, the present review evaluated studies that reported on wastewater in Africa between 2012 and 2022 to identify knowledge gaps and propose future perspectives, informing the use of wastewater-based epidemiology as a proxy for determining the resistome circulating within the continent. The study found that although wastewater resistome studies have increased over time in Africa, this is not the case in every country, with most studies conducted in South Africa. Furthermore, the study identified, among others, methodology and reporting gaps, driven by a lack of skills. Finally, the review suggests solutions including standardisation of protocols in wastewater resistome works and an urgent need to build genomic skills within the continent to handle the big data generated from these studies.

Factors influencing dairy farmers' antibiotic use: An application of the COM-B model

In dairy farming, mastitis treatment is the most common reason for antimicrobial use. The overuse or misuse of antibiotics in agriculture has been associated with the development and spread of antimicrobial resistance (AMR). Traditionally, blanket dry cow therapy (BDCT), in which all cows receive antibiotic treatment, was used prophylactically to prevent and manage disease spread. In recent years, there has been a move toward selective dry cow therapy (SDCT), in which only clinically infected cows are treated with antibiotics. This study aimed to explore farmer attitudes toward antibiotic use (ABU), using the COM-B (Capability-Opportunity-Motivation-Behavior) model as a framework, to identify predictors of changing behavior toward SDCT and suggest interventions to encourage its uptake. Participant farmers (n = 240) were surveyed online between March and July 2021. Five items were found to be significant predictors of farmers having stopped BDCT: (1) having lower knowledge of AMR, (2) greater awareness of AMR and ABU (Capability), (3) feeling social pressure to reduce ABU (Opportunity), and (4) having greater professional identity, and (5) having positive emotions associated with stopping BDCT (Motivation). Direct logistic regression found that these 5 factors explained between 22 and 34.1% of the variance in making changes to BDCT practices. Additionally, objective knowledge was not correlated with current positive antibiotic practices, and farmers often perceived their antibiotic practices as more responsible than they actually were. A multifaceted approach, encompassing each of the predictors highlighted, should be taken to encourage farmer behavior change in relation to stopping BDCT. Additionally, as farmers' perceptions of their own behaviors may not align with their actual practices, awareness raising of what constitutes "responsible" behavior should be targeted at dairy farmers to motivate them to take action and adopt more responsible antibiotic practices.

Assessment of antibiotic resistance and biofilm formation of Enterococcus species isolated from different pig farm environments in Poland

BackgroundEnteroccocus spp. are human opportunistic pathogens causing a variety of serious and life-threating infections in humans, including urinary tract infection, endocarditis, skin infection and bacteraemia. Farm animals and direct contact with them are important sources of Enterococcus faecalis (EFA) and Enterococcus faecium (EFM) infections among farmers, veterinarians and individuals working in breeding farms and abattoirs. The spread of antibiotic-resistant strains is one of the most serious public health concerns, as clinicians will be left without therapeutic options for the management of enterococcal infections. The aim of the study was to evaluate the occurrence and antimicrobial susceptibility of EFA and EFM strains isolated from a pig farm environment and to determine the biofilm formation ability of identified Enterococcus spp. strains.ResultsA total numer of 160 enterococcal isolates were obtained from 475 samples collected in total (33.7%). Among them, 110 of genetically different strains were identified and classified into EFA (82; 74.5%) and EFM (28; 25.5%). Genetic similarity analysis revealed the presence of 7 and 1 clusters among the EFA and EFM strains, respectively. The highest percentage of EFA strains (16; 19.5%) was resistant to high concentrations of gentamicin. Among the EFM strains, the most frequent strains were resistant to ampicillin and high concentrations of gentamicin (5 each; 17.9%). Six (7.3%) EFA and 4 (14.3%) EFM strains showed vancomycin resistance (VRE - Vancomycin-Resistant Enterococcus). Linezolid resistance was found in 2 strains of each species. The multiplex PCR analysis was performed to identify the vancomycin resistant enterococci. vanB, vanA and vanD genotypes were detected in 4, 1 and 1 EFA strains, respectively. Four EFA VRE-strains in total, 2 with the vanA and 2 with the vanB genotypes, were identified. The biofilm analysis revealed that all vancomycin-resistant E. faecalis and E. faecium strains demonstrated a higher biofilm-forming capacity, as compared to the susceptible strains. The lowest cell count (5.31 log CFU / cm2) was reisolated from the biofilm produced by the vancomycin-sensitive strain EFM 2. The highest level of re-isolated cells was observed for VRE EFA 25 and VRE EFM 7 strains, for which the number was 7 log CFU / cm2 and 6.75 log CFU / cm2, respectively.ConclusionsThe irrational use of antibiotics in agriculture and veterinary practice is considered to be one of the key reasons for the rapid spread of antibiotic resistance among microorganisms. Owing to the fact that piggery environment can be a reservoir of antimicrobial resistance and transmission route of antimicrobial resistance genes from commensal zoonotic bacteria to clinical strains, it is of a great importance to public health to monitor trends in this biological phenomenon.

Application of nematicide avermectin enriched antibiotic-resistant bacteria and antibiotic resistance genes in farmland soil

The extensive use of antibiotics in medicine and agriculture has resulted in the accumulation of antibiotic-resistant microorganisms and antibiotic resistance genes (ARGs) in environments, which threaten human health and contaminate environment. Nematicide avermectin is widely applied to control root-knot nematodes. The effect of five-years application of avermectin on rhizosphere microbiome and resistome of sick tobacco plants in farmland were investigated in present study. The environmental risks of avermectin was assessed adequately. Metagenomic method was used to analyze antibiotic-resistant bacteria and antibiotic resistance genes in the avermectin-treated soil. The abundance and distribution of antibiotic-resistant bacteria and their antibiotic resistance genes were affected by avermectin application. The antibiotic resistant Proteobacteria occupied the highest percentage (36%) in rhizosphere soil and carried 530 ARGs. Opportunistic human pathogens carrying antibiotic resistance genes were enriched in the avermectin-treated soil. Avermectin application increased the counts of many types of antibiotic resistance genes. The relative abundances of genes adeF, BahA, fusH, ileS, and tlrB in the avermectin-treated soil were significantly greater than in the untreated control soil. Different resistance mechanisms were revealed in the avermectin-treated soil. The efflux of antibiotic (670 ARGs), inactivation of antibiotic (475 ARGs), and alteration of antibiotic target (267 ARGs) were the main resistance mechanisms. Rigid control the avermectin dose and use frequency and other pesticides can decrease soil antibiotic resistance genes and protect agricultural products’ safety and public health. Overall, application of nematicide avermectin enriched antibiotic-resistant bacteria and antibiotic resistance genes in farmland soil, which should be on the alert for environment protection.

Evaluation of antibiotic use patterns among farmers and antibiogram from livestock wastes and fish pond effluents in selected animal farms in Cross River State, Nigeria

The extensive and misuse of antibiotics in animal production has become a public health threat. The evaluation of antibiotic use pattern among farmers and antibiogram from livestock wastes and effluent from animal farms was conducted in Cross River State. A descriptive cross-sectional study was undertaken with 379 animal production farmers and multi-stage sampling technique was employed in the selection of farms and respondents. Bacteriological analysis of animal wastes samples and antibiotics susceptibility testing was also conducted. Results revealed that 66.8% of farmers had a good knowledge on the use of antibiotics and its resistance. Majority (91.0%) of the farmers used antibiotics in their animal farms and for purposes of growth promotion, treatment of disease and prevention. Tetracycline, ampicillin, streptomycin, cotrimoxazole, gentamycin and vancomycin were the most frequently used groups of antibiotics. A total of 240 bacteria were isolated and the percentage occurrence of bacterial isolates were: Pseudomonas aeruginosa (14.2%), Escherichia coli (12.5%), Staphylococus aureus (10.8%), while Staphylococcus hominis (2.1%) had the least prevalence of occurrence. All the isolates showed multi-drugs resistance, Staphylococcus aureus showed the highest resistance to several antibiotics commonly used by farmers (80.8% to chloramphenicol, 80.8% to vancomycin and 73.1% of resistance to tetracycline). Statistical analysis of sociodemographic variables with farmers’ knowledge and antibiotics use showed that respondents’ level of education, years of farming experience, and farm type, were statistically significant (p<0.05). There is a need to improve farmers’ knowledge of antibiotics use and the possible consequences of their inappropriate use of antibiotics in farms.

Uptake of the Plant Agriculture-Used Antibiotics Oxytetracycline and Streptomycin by Cherry Radish─Effect on Plant Microbiome and the Potential Health Risk.

Antibiotics are used to control certain bacterial diseases in plant agriculture. Understanding antibiotic uptake by edible vegetables after application and associated risks on plant microbiome and human health is critical. In this study, oxytetracycline and streptomycin, the two most commonly used antibiotics in plant agriculture, were applied to cherry radish via continuous soil drenching to study their translocations into plant tissues, influence on radish microbiome, and the potential health risk to mice. The results demonstrated that oxytetracycline induced hormesis in radish plants and both antibiotics were translocated into the leaves, fruits, and roots of radishes from the soil, with significantly higher plant uptake of streptomycin than oxytetracycline. Interestingly, the proportion of culturable oxytetracycline or streptomycin-resistant bacteria in the antibiotic-accumulated radish tissues was significantly higher than that in the antibiotic-free radish tissues, although both bacterial and fungal communities in different radish tissues were not affected by the accumulated antibiotics, demonstrating that antibiotic application could enrich antibiotic resistance in the plant microbiome. Feeding mice with antibiotics-accumulated radish tissues did not show significant effects on the weight and blood glucose levels of mice. Overall, this study provides important insights into the risk of using antibiotics in plant agriculture.

Persister-mediated emergence of antimicrobial resistance in agriculture due to antibiotic growth promoters.

The creation and continued development of antibiotics have revolutionized human health and disease for the past century. The emergence of antimicrobial resistance represents a major threat to human health, and practices that contribute to the development of this threat need to be addressed. Since the 1950s, antibiotics have been used in low doses to increase growth and decrease the feed requirement of animal-derived food sources. A consequence of this practice is the accelerated emergence of antimicrobial resistance that can influence human health through its distribution via animal food products. In the laboratory setting, sublethal doses of antibiotics promote the expansion of bacterial persister populations, a low energy, low metabolism phenotype characterized broadly by antibiotic tolerance. Furthermore, the induction of persister bacteria has been positively correlated with an increased emergence of antibiotic-resistant strains. This body of evidence suggests that the use of antibiotics in agriculture at subtherapeutic levels is actively catalyzing the emergence of antimicrobial-resistant bacteria through the expansion of bacterial persister populations, which is potentially leading to increased infections in humans and decreased antibiotic potency. There is an urgent need to address this debilitating effect on antibiotics and its influence on human health. In this review, we summarize the recent literature on the topic of emerging antimicrobial resistance and its association with bacterial persister populations.

Comparison of conventional and dispersive solid phase extraction clean-up approaches for the simultaneous analysis of tetracyclines and sulfonamides in a variety of fresh vegetables

The extensive use of antibiotics in agriculture has led to the occurrence of residual drugs in different vegetables frequently consumed by humans. This could pose a potential threat to human health, not only because of the possible effects after ingestion but also because the transmission of antibiotic-resistant genes could occur. In this work, two accurate sample preparation procedures were developed and validated for the simultaneous analysis of sulfonamides (SAs) and tetracyclines (TCs) in four of the most widely consumed vegetables (lettuce, onion, tomato, and carrot) in Europe. The evaluated protocols were based on QuECHERS for extraction and subsequent clean-up by SPE (solid phase extraction) or dispersive SPE. Parameters affecting both extraction and clean-up were carefully evaluated and selected for accuracy of results and minimal matrix effect. Overall, apparent recoveries were above 70% for most of the target analytes with both analytical procedures, and adequate precision (RSD<30%) was obtained for all the matrices. The procedural limits of quantification (LOQPRO) values for SPE clean-up remained below 4.4 μg kg−1 for TCs in all vegetables except for chlortetracycline (CTC) in lettuce (11.3 μg kg−1) and 3.0 μg kg−1 for SAs, with the exception of sulfadiazine (SDZ) in onion (3.9 μg kg−1) and sulfathiazole (STZ) in carrot (5.0 μg kg−1). Lower LOQPRO values (0.1–3.7 μg kg−1) were obtained, in general, when dSPE clean-up was employed. Both methods were applied to twenty-five market vegetable samples from ecological and conventional agriculture and only sulfamethazine (SMZ) and sulfapyridine (SPD) were detected in lettuce at 1.2 μg kg−1 and 0.5 μg kg−1, respectively.

The extract from aerial part of Scutellaria baicalensis regulates gut microbiota in rabbit fish: Replacement of antibiotic fighting against pathogenic bacteria

The root of Scutellaria baicalensis is being used as herbal medicine, while its stem and leaf (aerial part) are considered as waste. The extract of aerial part of S. baicalensis, named as SBA here, has been shown to replace antibiotics in farming of Siganus fuscescens (rabbit fish), as to fight against marine pathogenic bacteria. To support the usage of SBA as feeding for aquaculture, the gut microbiota, after intake of the herbal extract, was determined. Here, the extract of SBA was mixed into the feeding of S. fuscescens that was cultured with a mixture of pathogenic bacteria. After 2 days of feeding, the gut content of fish was collected for the extraction and sequenced of 16S rDNA. The results indicated that the intake of SBA extract showed strong anti-bacterial effect, which inhibited the growth of pathogenic bacteria, i.e., Deltaproteobacteria and Fusobacteria. In contrast to antibiotic (enrofloxacin), the growth of probiotics, e.g., Erysipelotrichia, was promoted after intake of SBA. Our investigations showed the anti-bacterial effect of SBA extract in vivo, as well as its potential effect to promote the uptake of nutrients. The superiority of using this herbal extract in comparing to antibiotic was illustrated here, and which further suggested the possible development of recycling the waste product of S. baicalensis in fish aquaculture.

Deep Learning and Antibiotic Resistance.

Antibiotic resistance (AR) is a naturally occurring phenomenon with the capacity to render useless all known antibiotics in the fight against bacterial infections. Although bacterial resistance appeared before any human life form, this process has accelerated in the past years. Important causes of AR in modern times could be the over-prescription of antibiotics, the presence of faulty infection-prevention strategies, pollution in overcrowded areas, or the use of antibiotics in agriculture and farming, together with a decreased interest from the pharmaceutical industry in researching and testing new antibiotics. The last cause is primarily due to the high costs of developing antibiotics. The aim of the present review is to highlight the techniques that are being developed for the identification of new antibiotics to assist this lengthy process, using artificial intelligence (AI). AI can shorten the preclinical phase by rapidly generating many substances based on algorithms created by machine learning (ML) through techniques such as neural networks (NN) or deep learning (DL). Recently, a text mining system that incorporates DL algorithms was used to help and speed up the data curation process. Moreover, new and old methods are being used to identify new antibiotics, such as the combination of quantitative structure-activity relationship (QSAR) methods with ML or Raman spectroscopy and MALDI-TOF MS combined with NN, offering faster and easier interpretation of results. Thus, AI techniques are important additional tools for researchers and clinicians in the race for new methods of overcoming bacterial resistance.

Isolation of a Peptide That Binds to Pseudomonas aeruginosa Lytic Bacteriophage.

Antimicrobial resistance is a global health threat that is exacerbated by the overuse and misuse of antibiotics in medicine and agriculture. As an alternative to conventional antimicrobial drugs, phage therapy involves the treatment of infected patients with a bacteriophage that naturally destroys bacterial pathogens. With the re-emergence of phage therapy, novel tools are needed to study phages. In this work we set out to screen and isolate peptide candidates that bind to phages and act as affinity tags. Such peptides functionalized with an imaging agent could serves as versatile tools for tracking and imaging of phages. Specifically, we screened a phage display library for peptides that bind to the Good Vibes phage (GV), which lyses the bacterial pathogen Pseudomonas aeruginosa. Isolated monoclonal library phages featured a highly conserved consensus motif, LPPIXRX. The corresponding peptide WDLPPIGRLSGN was synthesized with a GGGSK linker and conjugated to cyanine 5 or biotin. The specific binding of the LPPIXRX motif to GV in vitro was confirmed using an enzyme-linked immunosorbent assay. We demonstrated imaging and tracking of GV in bacterial populations using the fluorescent targeting peptide and flow cytometry. In conclusion, we developed fluorescent labeled peptides that can bind to bacteriophage GV specifically, which may enable real-time analysis of phage in vivo and monitor the efficacy of phage therapy.

Assessment of potential risks to the health of the population of the Baikal region when using products contaminated with antibiotics

Modern ecological problems are considered - pollution of the natural environment with antibiotics and resistance to antimicrobial drugs, when microorganisms mutate and lose susceptibility to antibiotics. The reasons for this dangerous phenomenon are the ever-growing and uncontrolled use of antibiotics in medicine, veterinary medicine and agriculture. Most antibiotics are not completely metabolized in humans and animals, a significant part of the injected drugs enters the water and soil through urban wastewater, animal manure and sewage sludge transported to agricultural fields as fertilizers and pose environmental risks to human health. Assessment of environmental risks from the accumulation of antibiotics in natural waters and food is extremely important for the Baikal natural territory. This is an area that includes Lake Baikal (a World Heritage site), a water protection zone adjacent to Lake Baikal, its catchment basin on the territory of the Russian Federation, natural zones of primary protection adjacent to Lake Baikal, as well as an area about 200 km wide adjacent to Lake Baikal to the west and northwest of it. It may be at potential risk both for endemic species of Lake Baikal and for the population in case of chronic exposure and accumulation of antibiotics in environmental objects. The purpose of this work was a predictive assessment of the environmental risk to public health with direct oral consumption of water, meat and other products grown in an area contaminated with antibiotics. The initial data were the results of monitoring the quality of food products entering the retail network of the Irkutsk region. It was found that on average, an adult resident of the region receives 0.5718 mg/kg of antibiotics daily with food. A child aged 6 to 12 years receives 1.3803 mg/kg of antibiotic daily with food, and a child aged 2 to 6 years receives 2.6686 mg/kg of the substance. Residents of the Baikal region, adults and children aged 2 to 12 years, have a potential environmental health risk as a result of exposure to antibiotics coming with food on the body an order of magnitude higher than the safe level and it is necessary to take actions aimed at minimizing such risks.

Analysis of policies for use of medically important antibiotics in animals in Namibia: implications for antimicrobial stewardship

ABSTRACT Background In Namibia, overuse of medically important antibiotics in animals is common and is a considerable driver of antimicrobial resistance. The study aims to analyze policies, resistance patterns, and consumption of these antibiotics used in animals in Namibia. Research design and methods A scoping review and retrospective descriptive analysis of policies, resistance patterns, and use of these antibiotics in Namibia was conducted, and assessed against the Access, Watch and Reserve (AWaRe) antimicrobial use guidance. Results Of the forty-five antibiotic products registered for use in animals, 77.8% are Access antibiotics, 68.9% are broad-spectrum and 60% are over-the-counter antibiotics – mainly tetracyclines, penicillins and sulfonamides. There is misalignment of antibiotic use policies for animals and humans and currently no guideline for antibiotic use in animals. Most medically important antibiotics are indicated for control of gastrointestinal (77.7%), musculoskeletal (71.1%), and respiratory (46.7%) infections, and for growth promotion (4.4%). There is high resistance to AWaRe Access antibiotics- sulfonamides (19.5–100%), tetracyclines (56–100%), and penicillin (13.5–100%). Conclusion Whilst Namibia banned the use of antibiotics in farming, current policy frameworks are inconsistent across sectors, and promote overuse of broad-spectrum important antibiotics in animals. A multi-sectoral one health approach is required to harmonize antibiotic use policies and reduce resistance.

Investigation of Antibiotic Resistance in Fresh Beef, FreshPork, Fresh Chicken and Dairy Cow

Background: Chemical contamination in food has been a concern in public health both national and global levels. Contamination from pollution included air, water and soil, in meat from veterinary drugs used in animals, pesticides, food additives. Chemical residues in food are dangerous for health both short and long term. Commercial farming has grown, there are potential of using more drugs, especially antibiotics in farms. Objective: to study on antibiotic residues in fresh beef, fresh pork, fresh chicken and ready-to-drink dairy cow sold for consumers. Methods: A total of 36 samples which were 12 each of fresh meat, fresh pork and fresh chicken were tested by antibiotic residue detection kits from the Department of Medical Sciences, Thailand. These detection kits have 93% accuracy, 78.9% sensitivity, and 96.7% specificity. 72 samples of raw pork and chicken, which were advertised as organic, were tested for Tetracyclines, Macrolide, Aminoglycoside, Sulfonamide and Penicillins. Results: Tetracyclines, Macrolide, Aminoglycoside, Sulfonamide, Penicillins were detected in 12 samples of fresh beef, 12 samples of fresh pork, and 12 samples of fresh chicken. Tetracyclines were detected in 6 samples of dairy cow out of 43 samples. Conclusions: From 79 samples of fresh beef, fresh pork, fresh chicken and dairy cow, Tetracyclines, Macrolide, Aminoglycoside, Sulfonamide and Penicillin had been found in 100% of fresh beef samples, 100% of fresh pork, 100% of fresh chicken and 13.95 of dairy cow samples.

Are Dentists in Agreement with Antibiotic Guidelines for Odontogenic Infections?

Excessive use of antibiotics (Abx) in agriculture and health care has led to negative impacts in both fields.

Novel electrochemical and electrochemiluminescence dual-modality sensing platform for sensitive determination of antimicrobial peptides based on probe encapsulated liposome and nanochannel array electrode.

With the increasing application of antimicrobial peptides (AMPs) to replace antibiotics in medicine, food and agriculture, it is highly desired to develop a fast, reliable, and convenient strategy for sensitive detection of AMPs. Herein, a novel electrochemical (EC) and electrochemiluminescence (ECL) dual-modality sensing platform was developed based on probe encapsulated liposomes and nanochannel array modified electrodes, which enables sensitive determination of nisin in food samples. The bifunctional probe with both EC and ECL signals, tris(2,2-bipyridyl) dichlororuthenium (II) (Ru(bpy)32+), was chosen to be easily encapsulated in liposomes (Ru(bpy)32+@liposome). Based on the unique sterilization mechanism that AMPs can disrupt cell membranes, Ru(bpy)32+@liposome can be destroyed by nisin and release a large number of Ru(bpy)32+ probes. Vertically-ordered mesoporous silica-nanochannel film (VMSF) modified ITO electrodes (VMSF/ITO) prepared by electrochemically assisted self-assembly (EASA) method were applied as the sensing electrode. Due to the efficient enrichment of Ru(bpy)32+ by the negatively charged nanochannel arrays, VMSF/ITO enables detection of the EC/ECL signals of the released Ru(bpy)32+ probes with ultrahigh sensitivity. In consequence, sensitive dual-modality detection of nisin was achieved by the combination of Ru(bpy)32+@liposome and VMSF/ITO. The developed sensing system can realize sensitive determination of nisin in ECL mode in the concentration range of 10 ng/ml to 50 μg/ml with a limit of detection (LOD) of 9.3 ng/ml, or in EC mode from 800 ng/ml to 100 μg/ml with a LOD of 70 ng/ml. Combined with the excellent anti-fouling and anti-interference performance of VMSF, rapid and sensitive detection of nisin in milk or egg white was also achieved by the sensor.

Molecular Characterization of Antibiotic Resistant Bacteria from Soil within Rivers State University, Nigeria

Antibiotic resistance has become a subject of global concern to health systems all over the world and the shedding of antibiotic resistant bacteria from humans and animals into the soil is a threat to public health. This research was carried out to molecularly characterize and assess antibiotic resistant bacteria from soil in Rivers State University. Bacteria from soil in four locations; waste dump site, fish farm, poultry farm and home soil were enumerated and identified using standard microbiological techniques such as serial dilution, plating and incubation, isolation, biochemical testing and molecular identification. Sensitivity testing on the bacterial isolates was done using Kirby-Bauer Disk diffusion method. These resistant isolates were also subjected to molecular testing to ascertain the presence of resistant genes. The results revealed mean total Heterotrophic Bacterial Counts (THBC) for 32 samples ranged from 1.05±0.72 x 107 to 3.63±2.58x 107 CFU/g in fish farm and waste dump samples respectively. Total Coliform Counts (TCC) ranged from 3.65±2.91 x105 to 6.92±4.41 x105 CFU/g in Fish farm and Waste dump samples while Total Staphylococcal count ranged from 3.80±1.71 x104 to 11.46±9.21 x104 CFU/g in Fish farm and Waste dump samples respectively. Total Pseudomonad Count (TPC) ranged from 0.09±0.09 x 103 to 2.47±1.67x 103 CFU/g in Home soil and Fish farm samples. There was a difference (p≤0.05) in total heterotrophic bacterial, Staphylococcal and Pseudomonad counts, but no difference (p≥0.05) in total coliform. Seventy-nine (79) bacterial isolates were identified in this study belonging to the following genera; Bacillus spp, Staphylococcus spp., Micrococcus spp, Pseudomonas spp, Serratia spp, Proteus spp, Klebsiella spp, Salmonella spp and Escherichia spp with Staphylococcus (58.83%) having the highest occurrence and Pseudomonas (11.11%) had the least occurrence from the samples. Antibiotic sensitivity revealed that most isolates were resistant to many antibiotics tested with the highest resistance observed for Cefuroxime, Ceftazidime and Cefixime (100%) for the gram negative organisms and also Cefuroxime, Ceftazidime and Cloxacillin for gram positive bacteria. However, all bacteria showed sensitivity to gentamicin. Multiple Antibiotic resistance (MAR) index for all bacteria were above 0.2. Resistant bacterial isolates were identified molecularly as S. aureus, S. sciuri, M. luteus, B. cereus, B. subtilis, P. aeruginosa, S. mercescens, P. vulgaris, E. coli and Salmonella typhimurium. Pseudomonas aeruginosa, Serratia mercescens, Proteus vulgaris and E. coli had CTX-M gene present in their genome while Staphylococcus aureus, Staphylococcus sciuri, Micrococcus luteus, Bacillus cereus and Bacillus subtilis had the mecA gene present in their genome. This study has highlighted the rise in antibiotic resistance in bacteria from soil, hence, there is need to checkmate indiscriminate use of antibiotics in agriculture.

The effect of the antibiotic tetracycline hydrochloride on the biotransformation of urea when exposed to soil nitrifying strains

Introduction. The consequences of uncontrolled use of antibiotics in agriculture are an urgent problem of environmental hygiene. Tetracycline can enter the soil with the urine of domestic animals, inhibit the vital activity of soil bacterial strains and inhibit the processes of enzymatic hydrolysis of urea (carbamide), disrupting the global nitrogen cycle in nature. The lack of both quantitative and qualitative criteria for assessing this influence determined the relevance of the research. Materials and methods. The studies were carried out using the “Stayer” chromatographic system with cationic and anionic separating columns and exclusive analysis methods developed by the authors. When modelling solutions of heavy metals, an atomic absorption spectrometer MGA - 915MD with ETA was used. The objects of research were model solutions of carbamide with different content of inhibiting substances. As a source of urease and strains of Nitrobacter and Nitrosomonas, sod-podzolic soil from the Educational and Experimental Soil-Ecological Center “Chashnikovo” of Lomonosov Moscow State University was used. Results. An improved, more rapid chromatographic method for the analysis of urea in water is proposed compared to the method described by the authors earlier. The inhibitory effect of the antibiotic tetracycline hydrochloride on the process of biotransformation of nitrite into nitrate caused by Nitrobacter strains has been shown. No significant effect of the antibiotic on the biotransformation of urea into ammonium and ammonium into nitrite under the action of Nitrosomonas strains has been established. Limitations. The studies were carried out on the model of water systems, which included an aqueous phase containing different concentrations of the antibiotic, soil suspension, urea, heavy metal ions at a temperature of t = 30 ○C, pH ~ 6.5. The influence of salt background, pH, and temperature on biotransformation has not been studied, which could, without changing the overall picture, reveal nuances in the kinetics of the main processes. Conclusion. Studies have shown the absence of the effect of the antibiotic tetracycline hydrochloride on the kinetics of the decomposition of urea to ammonium and carbon dioxide due to urease enzymatic activity; there is no effect of the antibiotic on the oxidation of ammonium to nitrites by Nitrosomonas strains. It was found: selective inhibitory effect of an antibiotic during the oxidation of nitrite to nitrate, due to Nitrobacter strains; inhibition of biotransformation processes by chromium ions along the entire chain of transformations from urea to nitrate; and the inhibitory effect of excess oxygen on the totality of biotransformation processes during air bubbling through the aqueous phase.