scholarly journals Characterization of Antibioticproducing Bacterium Isolated From Anthill Sediment With Activity Against ESKAPE Pathogens

Fine Focus ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 189-201
Author(s):  
Cody A. Postich ◽  
Kevin B. Kiser

Healthcare institutions have seen an increase in infections caused by antibiotic-resistant ESKAPE pathogens. Current antibiotics have become less potent against pathogenic bacteria due to their overuse and misuse. In recent years, scientists have revisited local environments in search of novel antibioticproducing microbes to address the increasing threat of resistance. One species of bacteria was isolated from anthill sediment in coastal North Carolina. This environment was selected for its abiotic properties, including organic substrates, moisture saturation and aeration. Anthill isolate A2, inhibited various Grampositive and negative ESKAPE pathogens or their surrogates, including Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter calcoaceticus, in crossstreak tests. 16S rRNA sequencing identified isolate A2 as Pseudomonas koreensis. Mass spectrometry and small-molecule analysis performed on ethyl-acetate extracts of culture supernatant were used to evaluate bioactivity and identify the probable structure of one potential antimicrobial compound, monolauryl maleate. Discovery of novel antimicrobial compounds to replace overused antibiotics may help reduce the impact of antibiotic-resistant pathogens.

2020 ◽  
pp. 240-246
Author(s):  
E. A. Nikitin ◽  
K. V. Kleymenov ◽  
D. D. Batienco ◽  
D. A. Akulenko ◽  
P. V. Seliverstov ◽  
...  

Sepsis is a systemic pathological reaction that arise because of a severe infection. Now, sepsis is considered as one of the most serious diseases and materially expensive nosology’s. For instance, out of 100% of cases of sepsis, only 40% survive. Thus, there is a high mortality rate and a wide prevalence (up to 300 thousand patients with sepsis are registered in Europe), which makes it possible to identify serious problems and the need to improve the clinical approach to the management strategy and tactics of such patients. The number of cases of detection and registration of sepsis has been expanding expansively since the thirties of the last century, and continues to grow dynamically, which obviously requires an improvement in the pathognomonic approach to therapy. The main reasons for the growth of septic conditions are the increasing use of invasive methods in medical practice, the pandemic of diabetes mellitus, the use of cytostatic and immunosuppressants, as well as the increasing number of antibiotic-resistant strains of pathogenic and conditionally pathogenic bacteria, total disruption of mucosal microbiocenoses, unreasonable use of probiotics with production strains containing foci of pathogenicity in patients with primary or secondary immunodeficiencies. Now, the main etiopathogenetic therapy of sepsis remains drugs aimed at the destruction of pathogenic microorganisms. However, based on the pathogenesis of the septic state, it seems effective to search for drugs with new points of application to individual pathogenesis links of the systemic inflammatory response. Today, studies aimed at establishing the effectiveness of influence on any individual links in the pathogenesis of sepsis - inflammatory mediators, have not yet yielded clear results.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2423 ◽  
Author(s):  
Luis Amarillas ◽  
Cristóbal Chaidez ◽  
Arturo González-Robles ◽  
Yadira Lugo-Melchor ◽  
Josefina León-Félix

BackgroundShiga toxin-producingEscherichia coli(STEC) is one of the most common and widely distributed foodborne pathogens that has been frequently implicated in gastrointestinal and urinary tract infections. Moreover, high rates of multiple antibiotic-resistantE. colistrains have been reported worldwide. Due to the emergence of antibiotic-resistant strains, bacteriophages are considered an attractive alternative to biocontrol pathogenic bacteria. Characterization is a preliminary step towards designing a phage for biocontrol.MethodsIn this study, we describe the characterization of a bacteriophage designated phiC119, which can infect and lyse several multidrug-resistant STEC strains and someSalmonellastrains. The phage genome was screened to detect thestx-genes using PCR, morphological analysis, host range was determined, and genome sequencing were carried out, as well as an analysis of the cohesive ends and identification of the type of genetic material through enzymatic digestion of the genome.ResultsAnalysis of the bacteriophage particles by transmission electron microscopy showed that it had an icosahedral head and a long tail, characteristic of the familySiphoviridae. The phage exhibits broad host range against multidrug-resistant and highly virulentE. coliisolates. One-step growth experiments revealed that the phiC119 phage presented a large burst size (210 PFU/cell) and a latent period of 20 min. Based on genomic analysis, the phage contains a linear double-stranded DNA genome with a size of 47,319 bp. The phage encodes 75 putative proteins, but lysogeny and virulence genes were not found in the phiC119 genome.ConclusionThese results suggest that phage phiC119 may be a good biological control agent. However, further studies are required to ensure its control of STEC and to confirm the safety of phage use.


2021 ◽  
Vol 20 (4A) ◽  
pp. 199-209
Author(s):  
Nguyen Kim Hanh ◽  
Nguyen Trinh Duc Hieu ◽  
Nguyen Minh Hieu ◽  
Vo Hai Thi ◽  
Pham Thi Mien ◽  
...  

To assess the impact of antibiotic use in aquaculture in Nha Trang bay, we conducted this study with the aim of assessing antibiotic resistance of opportunistic pathogenic bacteria isolated from water and sediment around shrimp/fish cages in the Nha Trang bay. 109 strains of Vibrio, Salmonella-Shigella and Aeromonas groups were isolated in the surrounding environment of farming areas in Dam Bay and Hon Mieu. Antimicrobial resistance test of these 109 strains showed that in the water environment in Dam Bay, TET (96.6%) and NIT (92.5%) were the two antibiotics with the highest rates of resistant bacteria while no bacteria were resistant to RIF. All 5 types of antibiotics had a statistically insignificant percentage of antibiotic-resistant bacteria in water samples at Hon Mieu, ranging from 33.3% to 68.9%. Also in the water environment, the rate of antibiotic-resistant bacteria in Dam Bay was not influenced by the distance to the cages (42.5–66.6%). Meanwhile, in Hon Mieu, the highest rate of resistant bacteria was observed at the distance of 200 m (100%) away from cages and the lowest rate at the distance of 100 m (20%). In the sediment environment around the cages, both the Dam Bay and Hon Mieu farming areas showed the highest rates of antibiotic-resistant bacteria against TET, NIF and RIF had the lowest rate of resistant bacteria. Among the total of 109 strains tested for antibiotic resistance, 2 strains labeled TCBS_HM200 m and SS_HM200 m were found to be resistant to all 5 tested antibiotics. These two strains were respectively identified as Vibrio harveyi and Oceanimonas sp.


2018 ◽  
Vol 11 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Dominique E. Williams ◽  
Elizabeth M. Boon

Pathogenic bacteria have many strategies for causing disease in humans. One such strategy is the ability to live both as single-celled motile organisms or as part of a community of bacteria called a biofilm. Biofilms are frequently adhered to biotic or abiotic surfaces and are extremely antibiotic resistant. Upon biofilm dispersal, bacteria become more antibiotic susceptible but are also able to readily infect another host. Various studies have shown that low, nontoxic levels of nitric oxide (NO) may induce biofilm dispersal in many bacterial species. While the molecular details of this phenotype remain largely unknown, in several species, NO has been implicated in biofilm-to-planktonic cell transitions via ligation to 1 of 2 characterized NO sensors, NosP or H-NOX. Based on the data available to date, it appears that NO binding to H-NOX or NosP triggers a downstream response based on changes in cellular cyclic di-GMP concentrations and/or the modulation of quorum sensing. In order to develop applications for control of biofilm infections, the identification and characterization of biofilm dispersal mechanisms is vital. This review focuses on the efforts made to understand NO-mediated control of H-NOX and NosP pathways in the 3 pathogenic bacteria Legionella pneumophila, Vibrio cholerae, and Pseudomonas aeruginosa.


2021 ◽  
Vol 80 (3) ◽  
Author(s):  
Maria Belen Sathicq ◽  
Tomasa Sbaffi ◽  
Giulia Borgomaneiro ◽  
Andrea Di Cesare ◽  
Raffaella Sabatino

The World Health Organization considers antibiotic resistance as one of the main threats to human and other animals' health. Despite the measures used to limit the spread of antibiotic resistance, the efforts made are not enough to tackle this problem. Thus, it has become important to understand how bacteria acquire and transmit antibiotic resistant genes (ARGs), in particular in the environment, given the close connection between the latter and human and animal health, as defined by the One-Health concept. Aquatic ecosystems are often strongly impacted by anthropogenic activities, making them a source for ARGs and antibiotic resistant bacteria (ARB). Although freshwater meiofauna have been the object of active research, few studies have focused on the relationship between the spread of antibiotic resistance and these organisms. In this review, we investigated freshwater meiofauna as carriers of resistances since they play a central role in the aquatic environments and can harbor human and animal potential pathogens. We assessed if these animals could contribute to the spread of ARGs and of potentially pathogenic bacteria. Only four taxa (Rotifera, Chironomidae, Cladocera, Copepoda) were found to be the subject of studies focused on antibiotic resistance. The studies we analyzed, although with some limitations, demonstrated that ARGs and ARB can be found in these animals, and several of them showed the presence of potentially pathogenic bacteria for humans and animals within their microbiome. Thus, meiofauna can be considered a source and a reservoir, even if neglected, of ARGs and ARB for the freshwater environments. However, further studies are needed to evaluate the impact of the meiofauna on the spread and persistence of antibiotic resistance in these ecosystems.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 136 ◽  
Author(s):  
Ndegwa ◽  
Almehmadi ◽  
Kim ◽  
Kaseloo ◽  
Ako

There is a scarcity of information on antibiotic resistance in goats. To understand shedding of resistant Escherichia coli in pastured goats, we collected fecal samples from a mixed age cohort over a one-year period. No antibiotic had been used on the study animals one year prior to and during the study period. Resistant isolates were detected in all age groups and prevalence in goat kids was significantly higher than adults; 43–48% vs 8–25% respectively. The proportion of resistant isolates was higher when animals were congregated near handling facility than on pasture. Most isolates were resistant to tetracycline (51%) and streptomycin (30%), but also to antibiotics that had never been used on the farm; ampicillin (19%). TetB, bla-TEM, (aadA and strpA/strpB) genes were detected in 70%, 43%, (44% and 24%) of tetracycline, ampicillin, and streptomycin resistant isolates respectively. Resistant isolates also harbored virulent genes and some belonged to D and B2 phylogenetic groups. Thus, pastured goats, despite minimal exposure to antibiotics, are reservoirs of resistant E. coli that may contaminate the environment and food chain and spread resistant genes to pathogenic bacteria and some that are potential animal and human pathogens. Environmental sources may play a role in acquisition of resistant bacteria in pastured goats.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 144
Author(s):  
Jason Stahlecker ◽  
Erik Mingyar ◽  
Nadine Ziemert ◽  
Mehmet Direnç Mungan

The development of new antibacterial drugs has become one of the most important tasks of the century in order to overcome the posing threat of drug resistance in pathogenic bacteria. Many antibiotics originate from natural products produced by various microorganisms. Over the last decades, bioinformatical approaches have facilitated the discovery and characterization of these small compounds using genome mining methodologies. A key part of this process is the identification of the most promising biosynthetic gene clusters (BGCs), which encode novel natural products. In 2017, the Antibiotic Resistant Target Seeker (ARTS) was developed in order to enable an automated target-directed genome mining approach. ARTS identifies possible resistant target genes within antibiotic gene clusters, in order to detect promising BGCs encoding antibiotics with novel modes of action. Although ARTS can predict promising targets based on multiple criteria, it provides little information about the cluster structures of possible resistant genes. Here, we present SYN-view. Based on a phylogenetic approach, SYN-view allows for easy comparison of gene clusters of interest and distinguishing genes with regular housekeeping functions from genes functioning as antibiotic resistant targets. Our aim is to implement our proposed method into the ARTS web-server, further improving the target-directed genome mining strategy of the ARTS pipeline.


2014 ◽  
Vol 1 (3) ◽  
pp. 3-7
Author(s):  
O. Zhukorskyy ◽  
O. Hulay

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.


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