Number Of Antibiotic-resistant Bacteria Research Articles

Unde venis? Bacterial resistance from environmental reservoirs to lettuce: tracking microbiome and resistome over a growth period.

Fresh produce is suggested to contribute highly to shaping the gut resistome. We investigated the impact of pig manure and irrigation water quality on microbiome and resistome of field-grown lettuce over an entire growth period. Lettuce was grown under four regimes, combining soil amendment with manure (with/without) with sprinkler irrigation using river water with an upstream wastewater input, disinfected by UV (with/without). Lettuce leaves, soil, and water samples were collected weekly and analysed by bacterial cultivation, 16S rRNA gene amplicon sequencing, and shotgun metagenomics from total community DNA. Cultivation yielded only few clinically relevant antibiotic-resistant bacteria (ARB), but numbers of ARB on lettuce increased over time, while no treatment-dependent changes were observed. Microbiome analysis confirmed a temporal trend. Antibiotic resistance genes (ARGs) unique to lettuce and water included multidrug and β-lactam ARGs, whereas lettuce and soil uniquely shared mainly glycopeptide and tetracycline ARGs. Surface water carried clinically relevant ARB (e.g. ESBL-producing Escherichia coli or Serratia fonticola) without affecting the overall lettuce resistome significantly. Resistance markers including biocide and metal resistance were increased in lettuce grown with manure, especially young lettuce (increased soil contact). Overall, while all investigated environments had their share as sources of the lettuce resistome, manure was the main source especially on young plants. We therefore suggest minimizing soil-vegetable contact to minimize resistance markers on fresh produce.

Graphene oxide influences transfer of plasmid-mediated antibiotic resistance genes into plants

As an emerging contaminant, antibiotic resistance genes (ARGs) are raising concerns about its significant threat to public health. Meanwhile, graphene oxide (GO), which also has a potential ecological damage with increasingly entering the environment, has a great influence on the transfer of ARGs. However, little is known about the effects mechanisms of GO on the migration of antibiotic resistance genes (ARGs) from bacteria into plants. In this study, we investigated the influence of GO on the transfer of ARGs carried by RP4 plasmids from Bacillus subtilis into rice plants. Our results showed that the presence of GO at concentrations ranging from 0 to 400 mg L−1 significantly reduced the transfer of ARGs into rice roots by 13–71 %. Moreover, the migration of RP4 from the roots to aboveground parts was significantly impaired by GO. These effects may be attributed to several factors. First, higher GO concentrations led to low pH in the culture solution, resulting in a substantial decrease in the number of antibiotic-resistant bacteria. Second, GO induced oxidative stress in rice, as indicated by enhanced Evans blue dye staining, and elevated levels of malondialdehyde, nitric oxide, and phenylalanine ammonia-lyase activity. The oxidative stress negatively affected plant growth, as demonstrated by the reduced fresh weight and altered lignin content in the rice. Microscopic observations confirmed the entry of GO into root cells but not leaf mesophyll cells. Furthermore, potential recipients of RP4 plasmid strains in rice after co-cultivation experiments were identified, including Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus cereus. These findings clarify the influence of GO on ARGs in the bacteria–plant system and emphasize the need to consider its potential ecological risks.

A review on antibiotics in the environment, resistance in microbes, impact on human health and treatment and future strategies for tackling the global problem

The introduction of antibiotics was a blessing to human civilization as the antibiotics saved several million human and animal lives. Due to overuse and misuse of antibiotics by humans in the healthcare, and agriculture sectors, the residues of the antibiotics were reported in all the segments of the environment (surface water, groundwater, river water, soil, sediments, wastewater effluent, hospital effluent, livestock, fish, fruits, vegetables and milk) from ng to mg/L or kg that results in the rapid increase in the number of antibiotic resistant bacteria. Antibiotic resistance has been listed by the World Health Organization before Covid 19 as one of the top 10 threats to human health globally. Though antibiotic resistance is inevitable it is mainly anthropogenic and is an important factor of increased healthcare costs, longer hospital stay stress on hospital beds and ICU and higher rates of morbidity and mortality. The invention of new antibiotics to cope the resistant bacterial infection is the need of the hour but as bacterial infections is not an ongoing process (have a lower return) unlike chronic diseases hypertension, and diabetes the pharmaceutical companies are not very interested in the inventions. This article discusses the antibiotics in the different compartments of the environment, the antibacterial mechanisms of the antibiotics, causes of development and mechanisms of antibiotic resistance in bacteria and mechanisms/methods to combat antibiotic resistance.

Cattle-compost-soil: The transfer of antibiotic resistance in livestock agriculture.

Antibiotic resistance is a major global health threat. Agricultural use of antibiotics is considered to be a main contributor to the issue, influencing both animals and humans as defined by the One Health approach. The purpose of the present study was to determine the abundance of antibiotic-resistant bacterial populations and the overall bacterial diversity of cattle farm soils that have been treated with animal manure compost. Soil and manure samples were collected from different sites at Tullimba farm, NSW. Cultures were grown from these samples in the presence of 11 commonly used antibiotics and antibiotic-resistant bacteria (ARB) colonies were identified. Soil and manure bacterial diversity was also determined using 16S ribosomal RNA next-generation sequencing. Results showed that ARB abundance was greatest in fresh manure and significantly lower in composted manure. However, the application of composted manure on paddock soil led to a significant increase in soil ARB abundance. Of the antibiotics tested, the number of ARB in each sample was greatest for antibiotics that inhibited the bacterial cell wall and protein synthesis. Collectively, these results suggest that the transfer of antibiotic resistance from composted animal manure to soil may not be solely mediated through the application of live bacteria and highlight the need for further research into the mechanism of antibiotic resistance transfer.

The Spreading of Antibiotic-Resistant Bacteria in Terrestrial Ecosystems and the Formation of Soil Resistome

Terrestrial ecosystems play a crucial role in the formation of soil resistome and the spread of antibiotic-resistant bacteria. Comprehensive studies of soil microbial communities, their structure, integrity, and level of antibiotic resistance (AR) in various terrestrial ecosystems were conducted. In total, 389 strains of dominant bacteria were isolated from the studied ecosystems, 57 of which were resistant to antibiotics, with levels of antibiotic resistance exceeding 70%. The soil microbiome of primeval forests was characterized by a low content of bacteria resistant to antibiotics; only two species, Bacillus cereus and Pantoea agglomerans, showed a high resistance to antibiotics. In the soil of agroecosystems of medicinal plants, among 106 strains of bacteria, a high level of resistance to antibiotics was found in 13 species. It was established that the number of antibiotic-resistant bacteria is highest in the soil of agroecosystems contaminated by enrofloxacin. Among 190 tested bacterial strains, 42 (22%) were characterized by a high level of antibiotic resistance. Therefore, the soil ecosystem is a key link in the formation and spread of antibiotic-resistant bacteria, which is a potential danger to humans. To reduce the risk of AR for humans, it is necessary to take appropriate measures to manage the soil microbiome and avoid soil contamination with antibiotics.

Spontaneous Resistance of Erwinia amylovora Against Bacteriophage Y2 Affects Infectivity of Multiple Phages

Broad application of antibiotics gave rise to increasing numbers of antibiotic resistant bacteria. Therefore, effective alternatives are currently investigated. Bacteriophages, natural predators of bacteria, could work as such an alternative. Although phages can be highly effective at eliminating specific bacteria, phage resistance can be observed after application. The nature of this resistance, however, can differ depending on the phage. Exposing Erwinia amylovora CFBP 1430, the causative agent of fire blight, to the different phages Bue1, L1, S2, S6, or M7 led to transient resistance. The bacteria reversed to a phage sensitive state after the phage was eliminated. When wild type bacteria were incubated with Y2, permanently resistant colonies (1430Y2R) formed spontaneously. In addition, 1430Y2R revealed cross-resistance against other phages (Bue1) or lowered the efficiency of plating (L1, S2, and S6). Pull down experiments revealed that Y2 is no longer able to bind to the mutant suggesting mutation or masking of the Y2 receptor. Other phages tested were still able to bind to 1430Y2R. Bue1 was observed to still adsorb to the mutant, but no host lysis was found. These findings indicated that, in addition to the alterations of the Y2 receptor, the 1430Y2R mutant might block phage attack at different stage of infection. Whole genome sequencing of 1430Y2R revealed a deletion in the gene with the locus tag EAMY_2231. The gene, which encodes a putative galactosyltransferase, was truncated due to the resulting frameshift. The mutant 1430Y2R was monitored for potential defects or fitness loss. Weaker growth was observed in LB medium compared to the wild type but not in minimal medium. Strain 1430Y2R was still highly virulent in blossoms even though amylovoran production was observed to be reduced. Additionally, LPS structures were analyzed and were clearly shown to be altered in the mutant. Complementation of the truncated EAMY_2231 in trans restored the wild type phenotype. The truncation of EAMY_2231 can therefore be associated with manifold modifications in 1430Y2R, which can affect different phages simultaneously.

Development of a new antimicrobial concept for boar semen preservation based on bacteriocins

The conventional storage temperature of 16–18 °C provides optimal conditions for the preservation of boar sperm quality, which are extremely cold sensitive cells. On the other hand, however, it requires the addition of antibiotics to inhibit bacterial growth. Rising numbers of antibiotic resistant bacteria call for alternatives to this conventional storing method. As potential alternative, three different bacteriocin candidates with known bacteriolytic activity against E. coli were examined on possible negative effects concerning the sperm quality and on their impact on bacterial growth of E. coli ILSH 02692 in BTS-extended semen w/o antibiotics. Although the lower concentrations (0.01 and 0.25%) of all bacteriocins did not show any impact on the quality of the semen, the higher concentrations (0.5 and 1.0%) of two bacteriocins led to a significant (P < 0.05) reduction in several sperm quality characteristics. The bacteriocin 860/1c after AMS/dialysis did not affect the sperm quality in any of the tested concentrations and in all tested extenders (BTS, MIII, Androstar Premium and Androhep all w/o antibiotics) at 16 °C as well as at 6 °C. This bacteriocin reduced growth of E. coli ILSH 02692 in BTS-extended semen by 50% compared to the control w/o bacteriocin. Furthermore, a preliminary insemination trial indicated no impact of the selected bacteriocin on fertility. These promising results show that the application of bacteriocins in liquid-preserved semen is a feasible possibility in the future.

Time-Resolved Transcriptional Profiling of Epithelial Cells Infected by Intracellular Acinetobacter baumannii

The rise in the number of antibiotic-resistant bacteria has become a serious threat to health, making it important to identify, characterize and optimize new molecules to help us to overcome the infections they cause. It is well known that Acinetobacter baumannii has a significant capacity to evade the actions of antibacterial drugs, leading to its emergence as one of the bacteria responsible for hospital and community-acquired infections. Nonetheless, how this pathogen infects and survives inside the host cell is unclear. In this study, we analyze the time-resolved transcriptional profile changes observed in human epithelial HeLa cells after infection by A. baumannii, demonstrating how it survives in host cells and starts to replicate 4 h post infection. These findings were achieved by sequencing RNA to obtain a set of Differentially Expressed Genes (DEGs) to understand how bacteria alter the host cells’ environment for their own benefit. We also determine common features observed in this set of genes and identify the protein–protein networks that reveal highly-interacted proteins. The combination of these findings paves the way for the discovery of new antimicrobial candidates for the treatment of multidrug-resistant bacteria.

In vivo efficacy of carvacrol on Campylobacter jejuni prevalence in broiler chickens during an entire fattening period

Carvacrol, a primary constituent of plant essential oils (EOs), and its antimicrobial activity have been the subject of many in vitro studies. Due to an increasing demand for alternative antimicrobials and an emerging number of antibiotic resistant bacteria, the use of essential oils has played a major role in many recent approaches to reduce Campylobacter colonization in poultry before slaughter age. For that purpose, the reducing effect of carvacrol on Campylobacter jejuni prevalence in broilers was determined in vivo in an experimental broiler chicken model during an entire fattening period. Carvacrol was added to the feed in a concentration of 120 mg/kg feed four days post hatch until the end of the trial. In this study, we demonstrated a statistically significant decrease of C. jejuni counts by 1.17 decadic logarithm (log10) most probable number (MPN)/g in cloacal swabs during starter and grower periods (corresponding to a broilers age between 1 and 28 days). Similar results were observed for colon enumeration at the end of the trial where C. jejuni counts were significantly reduced by 1.25 log10 MPN/g. However, carvacrol did not successfully reduce Campylobacter cecal colonization in 33-day-old broilers.

Response of the Bacterial Community and Antibiotic Resistance in Overnight Stagnant Water from a Municipal Pipeline.

Although drinking water safety has raised considerable concern, to date, the hidden health risks in newly released overnight water from a municipal pipeline have seldom received attention. In this study, bacterial community composition and the response of antibiotic-resistant bacteria (ARB) to ciprofloxacin, azithromycin, tetracycline, penicillin, and cephalosporin in overnight stagnant water were analyzed. With increases in heterotrophic bacteria plate count (HPC) during water stagnation, the numbers of ARB and the ARB/HPC ratios for the five antibiotics in resident water were observed to increase, which illustrated that the prevalence of ARB rose in the pipe network water during stagnation time (ST). Furthermore, during water stagnation for 12 h, an increase in bacteria related to fermentation was also observed. When the ST rose to 48 h, the fermentation bacteria become non-significant, and this was related to the exchange of pipe network water during daytime stagnation within the 48-h period. The antibiotic resistance index (ARI) showed that tetracycline had the highest resistance level in fresh water, and then decreased during water stagnation. When ST increased to 12 h, all ARI values of the five antibiotics were low, which was associated with changes in parameters during water retention and reduced resistance during short-term stagnation. When the ST increased to 24 and 48 h, the resistance to most antibiotics (except for tetracycline) increased, which showed that increasing antibiotic resistance is caused by the formation of biofilms in the pipeline during water stagnation.

Spread of chloramphenicol and tetracycline resistance genes by plasmid mobilization in agricultural soil

Spread of antibiotic resistance genes (ARGs) poses a worldwide threat to public health and food safety. However, ARG spread by plasmid mobilization, a broad host range transfer system, in agricultural soil has received little attention. Here, we investigated the spread of chloramphenicol resistance gene (CRG) and tetracycline resistance gene (TRG) in agricultural soil by mobilization of pSUP106 under different conditions, including different concentrations of nutrients, temperatures, soil depths, rhizosphere soils, and soil types. The number of resistant bacteria isolated in non-sterilized soil from the experiments was approximately 104 to 107 per gram of soil, belonging to 5–10 species from four genera, including nonpathogen, opportunistic pathogen, pathogen bacteria, and gram-positive and gram-negative bacteria, depending on the experiment conditions. In sterilized soil, higher levels of nutrients and higher temperatures promoted plasmid mobilization and ARG expression. Topsoil and deep soil might not support the spread of antibiotic resistance, while ARG dissemination by plasmid mobilization was better supported by maize rhizosphere and loam soils. All these factors might change bacterial growth and the activity of bacteria and lead to the above influence. Introduction of only the donor and helper, or the donor alone also resulted in the transfer of ARGs and large numbers of antibiotic resistant bacteria (ARB), indicating that some indigenous bacteria contain the elements necessary for plasmid mobilization. Our results showed that plasmid mobilization facilitated dissemination of ARGs and ARB in soil, which led to the disturbance of indigenous bacterial communities. It is important to clear ARG dissemination routes and inhibit the spread of ARGs.

Antivirulence Therapy- A Promising Alternative Technique for Antibiotic Resistance

Antibiotic resistance is increasing at an alarming rate. Over the years there has been a steep rise in number of antibiotic resistant bacteria. This in turn has led to a dip in overall efficacy of a wide range of antibiotics. The last new class of antibiotics was introduced in 2003, but after that there has not been any significant discovery in this area. To overcome this problem of antibiotic resistance Antivirulence therapy has been introduced, this reduces pressure to discover new classes of antibiotics and improves efficacy of existing ones. It mainly focuses on preventing bacterial pathogenesis rather than having bactericidal effect. This overall reduces selective pressure on bacteria thus, slowing its mutation, leading to lower emergence of antibiotic resistance, as opposed to the conventional antibiotics. This review paper discusses various Antivirulence strategies like Quench Pathogen Quorum Sensing (QS) systems; disassemble of bacterial functional membrane microdomains (FMMs), disruption of biofilm formation and bacterial toxin neutralization. Keywords: Antivirulence therapy, QS systems, FMMs, Biofilm formation, Toxin neutralization. Cite this Article Dr.S.P.Zine, Ms. Ankita Rai, Mr. Parth Mehta, Ms. Sayli Sawant. Antivirulence Therapy- A Promising Alternative Technique for Antibiotic Resistance. Research & Reviews: A Journal of Bioinformatics . 2020; 7(3): 1–14p.

Antibiotic resistance profile of Staphylococcus aureus, Streptococcus spp. and Klebsiella spp. isolated form chicken farm in Bogor, Sukabumi, and Cianjur, West Java

West Java province has largest population of chicken poultry, with Bogor, Sukabumi, and Cianjur has highest chicken population. Farmers used antibiotics for prophylaxis and therapy to maintain the production. However, extensive use of antibiotic increased the number of antibiotic resistant bacteria. Staphylococcus aureus, Streptococcus spp, and Klebsiella spp are the example of flora normal in chicken that affected with abusive use of antibiotic. The aim of this study was to determine the antibiotic resistance profile of S. aureus, Streptococcus spp., and Klebsiella spp. isolated from cloacal swab of chicken poultry in 3 regions. Total of 320 samples were collected and the positive number of S. aureus, Streptococcus spp., and Klebsiella spp were 61, 8, and 58 isolates respectively. The result of antibiotics susceptibility test showed that S. aureus was resistant to ampicillin (98%), erythromycin (95%), nalidixic acid (93%), tetracycline (92%), oxytetracycline (90%), enrofloxacin (69%), and ciprofloxacin (56%). Streptococcus spp. was resistant to tetracycline (100%) and doxycycline (87.5%). Klebsiella spp. was resistant to erythromycin (100%), ampicillin (94.83%) oxytetracycline (93.10%), tetracycline and nalidixic acid (89.66%), enrofloxacin (86.21%), and ciprofloxacin (81.03%). S. aureus, Streptococcus spp., and Klebsiella spp. has a high level of resistance to antibiotics and most of the isolates were multi-resistant.

Antibiotic sensitivity and resistance of bacteria from odontogenic maxillofacial abscesses.

ObjectivesThis study investigated the types and antibiotic sensitivity of bacteria in odontogenic abscesses.Materials and MethodsPus specimens from 1,772 patients were collected from affected areas during incision and drainage, and bacterial cultures and antibiotic sensitivity tests were performed. The number of antibiotic-resistant bacteria was analyzed relative to the total number of bacteria that were tested for antibiotic susceptibility.ResultsBacterial cultures from 1,772 patients showed a total of 2,489 bacterial species, 2,101 gram-positive and 388 gram-negative. For penicillin G susceptibility tests, 2 out of 31 Staphylococcus aureus strains tested showed sensitivity and 29 showed resistance. For ampicillin susceptibility tests, all 11 S. aureus strains tested showed resistance. In ampicillin susceptibility tests, 46 out of 50 Klebsiella pneumoniae subsp. pneumoniae strains tested showed resistance.ConclusionWhen treating odontogenic maxillofacial abscesses, it is appropriate to use antibiotics other than penicillin G and ampicillin as the first-line treatment.

Az antibiotikumok és maradványanyagaik hatása és akkumulálódása kertészeti növényekben: áttekintés

Antibiotics have been used in the agriculture in large quantities since they were discovered. In animal husbandry these compounds are used not only to do treatment for sick animals but for prevention of diseases and also for growth promotion. The extreme usage of these antibiotics led to increasing numbers of antibiotic resistant bacteria. Today it is a danger that is considered very seriously worldwide. In the European Union, the usage of antibiotics as growth promoter is forbidden since 2006, but according to different statistics collected by administration departments there are big differences in antibiotics usage among EU countries. The antibiotics that are used in animal husbandry get to the fields through the manure, where the plants will take them up and absorb them into their own tissues. There are only a few studies demonstrating the harmful effects of antibiotics in humans or animals, however, several experiments were conducted to prove the deleterious effects of antibiotics in plants. The aim of this study was to explore the effect of antibiotics and their residues in horticultural plants. The consumption of the raw or processed vegetables accumulating antibiotics and their metabolites may mean the highest risk on human health. The results of studies in this subject showed that the use of antibiotics must be continuously controlled in both human and animal applications. The information of farmers, producing or using manure on their fields, about the dangers of over expose of antibiotics could be one of the keys to reduce the danger of antibiotics in health.

The influence of antibiotics on wastewater treatment processes and the development of antibiotic-resistant bacteria.

The influence of antibiotics, namely doxycycline, gentamicin, penicillin, nitrofurantoin, and rifampicin, on wastewater treatment was assessed. The presence of 100-300 μg/L of antibiotics (63.52-134.41 mg/g.d.w·d) marginally influenced organic matter degradation, without impacting nitrogen or phosphorus concentrations. However, a significant increase in the number of antibiotic-resistant bacteria was observed, which varied with different antibiotics. The largest number of bacteria became resistant to nitrofurantoin and penicillin. After the process, some multi-resistant strains were isolated from the sludge. Two of them revealed the activity of carbapenamase, the enzyme directly related to resistance against β-lactam antibiotics.

Occurence of antibiotic resistant bacteria in raw cow milk from vending machines

Abstract The prevalence of antibiotic resistant coliform bacteria and enterococci in fresh raw cow milk obtained from four vending machines in Slovakia was assessed. Also, differences in the number of antibiotic-resistant bacteria in milk according to season (winter and summer) were compared. Number of total coliform bacteria ranged from 2.45 to 4.18 log CFU/mL. Majority of them were resistant to ampicillin. This was expected due to their intrinsic resistance apart from Escherichia coli which is sensitive to ampicillin. In addition, we observed also tetracycline and gentamicin resistance. Each of our samples contained E.coli. Number of total enterococci ranged from 1.95 to 3.78 log CFU/mL. We have observed predominantly vancomycin resistance in all tested samples. In samples taken during winter we have found higher number of total and resistant coliforms as well as total enterococci compared to those taken during summer.

Production of Chicken Egg Yolk Antibody (IgY) Against Recombinant Cholera Toxin B Subunit and Evaluation of Its Prophylaxis Potency in Mice.

Cholera toxin (CT), responsible for the harmful effects of cholera infection, is made up of one A subunit (enzymatic), and five B subunits (cell binding). The release of cholera toxin is the main reason for the debilitating loss of intestinal fluid. Inhibition of the B subunit (CTB) may block CT activity. To determine the effect of anti CTB-IgY against oral challenge with V. cholera in suckling infant mice. The binding domain of cholera toxin was amplified and ligated into pET28a vector. The pET28a (+)/ctb expression vector was confirmed by endonuclease digestion and sequence analysis. The expression of recombinant CTB in E. coli was performed by induction with IPTG. After immunizing the chickens with recombinant CTB, IgY was purified by water dilution method and NaCl precipitation and analyzed by SDS-PAGE. Moreover, the activity and specificity of the IgY antibody were assessed by ELISA. The SDS-PAGE and western blot techniques showed that CTB protein was successfully expressed and specifically recognized by polyclonal antibodies against the cholera toxin. The oral administration of anti- (V. cholera+CTB) in infant mice in challenge with active V. cholera bacterium demonstrated high rate of survival. The increase in the number of antibiotic resistant bacteria implies the necessity of finding novel antibiotics. Our results suggest the possibility of passive protection from purified IgY, hence implying that anti CTB-IgY may be useful in the treatment of cholera infections.

Impact of direct application of biogas slurry and residue in fields: In situ analysis of antibiotic resistance genes from pig manure to fields

Biogas slurry and residue contaminated with antibiotics are widely used as fertilizers in vegetable crop planting. However, their impact on the spreading of antibiotic resistance genes (ARGs) in vegetable fields is still largely unknown. In the present study, antibiotic resistant bacteria (ARB), ARGs and bacterial communities from pig manure to fields were monitored by using viable plate counts, high-throughput fluorescent quantitative PCR (HT-qPCR) and Illumina MiSeq sequencing. Eighty-three ARGs and 3 transposons genes were detected. Anaerobic digestion reduced relative abundance of tetracycline and Macrolide-Lincosamide-Streptogramin (MLSB) resistance genes. However, the number of ARB and the relative abundance of sulfa, aminoglycoside and florfenicol, chloramphenicol, and amphenicol (FCA) resistance genes, respectively, enriched up to 270 times and 52 times in biogas residue. Long-term application of biogas slurry and residue contaminated with antibiotics in fields increased the rate of ARB as well as relative abundance of ARGs and transposons genes. Additionally, bacterial communities significantly differed between the soil treated with biogas slurry and residue and the control sample, especially the phyla Bacteroidetes and Actinobacteria. Based on network analysis, 19 genera were identified as possible hosts of the detected ARGs. Our results provide an important significance for reasonable application of biogas slurry and residue.

English

Due to the rapid increase in the number of antibiotic-resistant bacteria, medicinal plants are being studied as new and promising alternatives to conventional antibiotic treatment. The crude hexane, ethyl acetate and methanol extracts from Pimenta dioica, Pimenta jamaicensis and Pimenta racemosa were quantitatively assessed to determine their antimicrobial susceptibility and potency using zones of inhibition methods, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations minimum (MBC) or fungicidal concentrations concentration (MFC) against Streptococcus A, Streptococcus B, Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Salmonella species, Proteus mirabilis and Candida albicans. The crude ethyl acetate extract of the P. dioica was most active against Candida albicans (MFC of 1.3 mg/mL and MIC of 0.63 mg/mL) while the crude hexane extract of P. jamaicensis was most active against Streptococcus A (MBC of 0.63 and MIC of 1.3 mg/mL). The crude ethyl acetate extract of P. racemosa was most active against Streptococcus A and Salmonella (MBC of 2.5 mg/mL and MIC of 1.3 mg/mL; MBC of 0.63 and MIC of 0.63 mg/mL, respectively). Extracts from selected species of Pimenta may potentially provide a source of new antimicrobial agents for the treatment of infectious diseases. &nbsp; Key words: Pimenta dioica, Pimenta jamaicensis, Pimenta racemosa, antimicrobial.