scholarly journals Is there any association between antibiotic resistance and virulence genes in Enterococcus isolates?

2019 ◽  
Vol 6 (12) ◽  
pp. 310-315
Author(s):  
Nergis Aşgın ◽  
Emre Taşkın
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Automated System ◽  
High Frequencies ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
High Level

Objective: In this study, we aim to determine the frequency of antibiotic resistance and five virulence genes in Enterococcus species and the relationship between antibiotic resistance and virulence genes. Material and Methods: A total of 86 Enterococcus strains isolated from inpatients between 2015 and 2016 were included. Identification and antibiotic susceptibilities of strains were determined using a BD Phoenix fully automated system. The presence of virulence-associated genes (esp, gel E, asa1, hyl, and cyl) were investigated by using PCR method. Results: Of the 86 Enterococcus strains, 53 (61.6%) and 33 (38.4%) were Enterococcus faecium and Enterococcus faecalis, respectively. Vancomycin and high-level gentamicin resistance (HLGR) in E. faecalis strains were 0.6% and 60.6%, respectively. Furthermore, 52 of the 53 E. faecium strains were both vancomycin-resistant and HLGR. The frequency of esp, gel E, asa1, cyl, and hyl was 91.9%, 60.5%, 54.7%, 43%, and 26.7%, respectively.  The asa 1, cyl, and gel E genes were detected at high frequencies in vancomycin-susceptible and non-HLGR strains, whereas hyl gene was detected at high frequencies in vancomycin-resistant and HLGR strains. Conclusion: Virulence genes were more frequent in vancomycin-susceptible and non-HLGR Enterococcus strains than in the resistant strains. Although infections caused by multidrug-resistant strains are difficult to treat, it should be considered that susceptible strains have more virulence genes. This may reduce the in vivo efficacy of drugs and lead to treatment failures. Therefore, in addition to the in vitro susceptibilities of drugs, clinical efficacy should be monitored.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals Genomic and Functional Analysis of Emerging Virulent and Multidrug-Resistant Escherichia coli Lineage Sequence Type 648

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Katharina Schaufler ◽  
Torsten Semmler ◽  
Lothar H. Wieler ◽  
Darren J. Trott ◽  
Johann Pitout ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Risk ◽  
Multidrug Resistant ◽  
Phenotypic Analysis ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
Niche Adaptation ◽  
High Level

ABSTRACT The pathogenic extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli lineage ST648 is increasingly reported from multiple origins. Our study of a large and global ST648 collection from various hosts (87 whole-genome sequences) combining core and accessory genomics with functional analyses and in vivo experiments suggests that ST648 is a nascent and generalist lineage, lacking clear phylogeographic and host association signals. By including large numbers of ST131 (n = 107) and ST10 (n = 96) strains for comparative genomics and phenotypic analysis, we demonstrate that the combination of multidrug resistance and high-level virulence are the hallmarks of ST648, similar to international high-risk clonal lineage ST131. Specifically, our in silico, in vitro, and in vivo results demonstrate that ST648 is well equipped with biofilm-associated features, while ST131 shows sophisticated signatures indicative of adaption to urinary tract infection, potentially conveying individual ecological niche adaptation. In addition, we used a recently developed NFDS (negative frequency-dependent selection) population model suggesting that ST648 will increase significantly in frequency as a cause of bacteremia within the next few years. Also, ESBL plasmids impacting biofilm formation aided in shaping and maintaining ST648 strains to successfully emerge worldwide across different ecologies. Our study contributes to understanding what factors drive the evolution and spread of emerging international high-risk clonal lineages.

scholarly journals In Vitro and In Vivo Anti-Salmonella Evaluation of Pectin Extracts and Hydrolysates from “Cas Mango” (Spondias dulcis)

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Denis Zofou ◽  
Golda Lum Shu ◽  
Josepha Foba-Tendo ◽  
Merveille Octavie Tabouguia ◽  
Jules-Clement N. Assob
Keyword(s):  
Multidrug Resistant ◽  
Positive Control ◽  
Resistant Bacteria ◽  
Therapeutic Effects ◽  
Diffusion Technique ◽  
Resistant Strains ◽  
Almost All ◽  
Broth Dilution

Background. The threat to human health posed by multidrug-resistant strains of Salmonella typhi (S. typhi) and Salmonella paratyphi (S. paratyphi) is of growing concern. Generally, there has been increasing resistance and even multidrug resistance to almost all classes of antibiotics. This has rendered treatment with antibiotics difficult and costly. The present study investigated the bioactivity of pectin and pectin hydrolysates derived from a local fruit, Spondias dulcis, against four strains of Salmonellae. Methods. Pectin was extracted from alcohol extractives-free peel by acidic hydrolysis at a temperature of 80°C for one hour at pH 2 and 4. The pectin was precipitated with 95% alcohol at an extract to alcohol ratio of 1:10 v/v. Antimicrobial activity was determined using agar well diffusion technique. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined using the broth dilution technique. An in vivo study was then carried out with the bioactive extracts against the most resistant bacteria strain, to fully establish the therapeutic effect of these extracts. Balb/C mice were used, and ciprofloxacin was the positive control antibiotic. The extracts were administered to mice at two doses, 5mg/Kg and 10mg/Kg. The efficacy of extracts in the treatment of typhoid was evaluated based on survival rate, change in body weight, and change in bacteria load. Results. Only one of the extracts (crude pectin pH 2.5) was active against all the Salmonellae by well diffusion, and the growth inhibition varied from 12mm to 15mm at100 μg/ml. Three of the extracts (crude pectin pH 2.5, pH 4, 12h hydrolysate, and pH 4, 1h hydrolysate) had MIC and MBC against all four Salmonellae strains with MIC ranging from 5.68 to 44.45 μg/ml and MBC from 11.36 to 44.45 μg/mL. Three treatments, namely, the pH4-12 hr, hydrolysate at 10mg/Kg and 5mg/Kg, and the pH4-1hr, hydrolysate at 10mg/Kg, had therapeutic effects against Salmonella infection in mice. Conclusion. The present study highlights the potential of pectin oligosaccharides as new source of anti-Salmonella drugs. Further investigations including exploration of mechanism of action of the most active pectin extracts/hydrolysates are envisaged.

scholarly journals Detection of Virulence Genes in Multidrug Resistant Enterococci Isolated from Feedlots Dairy and Beef Cattle: Implications for Human Health and Food Safety

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Frank Eric Tatsing Foka ◽  
Collins Njie Ateba
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Efflux Pump ◽  
Health Sector ◽  
Multidrug Resistant ◽  
North West ◽  
The North ◽  
Vancomycin Resistant ◽  
The Impact

The misuse/abuse of antibiotics in intensive animal rearing and communities led to the emergence of resistant isolates such as vancomycin-resistant enterococci (VREs) worldwide. This has become a major source of concern for the public health sector. The aim of this study was to report the antibiotic resistance profiles and to highlight the presence of virulence genes in VREs isolated from feedlots cattle of the North-West Province of South Africa. 384 faecal samples, 24 drinking troughs water, and 24 soil samples were collected aseptically from 6 registered feedlots. Biochemical and molecular methods were used to identify and categorise the enterococci isolates. Their antibiotic resistance profiles were assessed and genotypic methods were used to determine their antibiotic resistance and their virulence profiles. 527 presumptive isolates were recovered, out of which 289 isolates were confirmed asEnterococcussp. Specifically,E. faecalis(9%),E. faecium(10%),E. durans(69%),E. gallinarum(6%),E. casseliflavus(2%),E. mundtii(2%), andE. avium(2%) were screened after molecular assays.VanA(62%),vanB(17%), andvanC(21%) resistance genes were detected in 176Enterococcussp., respectively. Moreover,tetK(26),tetL(57),msrA/B(111), andmefA(9) efflux pump genes were detected in 138 VRE isolates.Multiple antibiotic resistances were confirmed in all the VRE isolates of this study; the most common antibiotic resistance phenotype wasTETR-AMPR-AMXR-VANR-PENR-LINR-ERYR.CylA,hyl,esp,gelE, andasa1virulence genes were detected in 86 VREs with the exception of vancomycin-resistantE. mundtiiisolates that did not display any virulence factor. Most VRE isolates had more than one virulence genes but the most encountered virulence profile wasgelE-hyl. Potentially pathogenic multidrug resistant VREs were detected in this study; this highlights the impact of extensive usage of antimicrobials in intensive animal rearing and its implications on public health cannot be undermined.

scholarly journals In Vitro Activities of RWJ-54428 (MC-02,479) against Multiresistant Gram-Positive Bacteria

2001 ◽  
Vol 45 (5) ◽  
pp. 1422-1430 ◽  
Author(s):  
Suzanne Chamberland ◽  
Johanne Blais ◽  
Monica Hoang ◽  
Cynthia Dinh ◽  
Dylan Cotter ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Penicillin G ◽  
Significant Activity ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Level Of Activity ◽  
Resistant Strains ◽  
High Level

ABSTRACT RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC90) of 2 μg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC90 of 2 μg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, ≤0.0625 to 1 μg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC90, 0.5 μg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC90 of 0.125 μg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between ≤0.0625 and 1 μg/ml for ampicillin-susceptible strains and 0.125 and 8 μg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains ofStreptococcus pneumoniae (MIC90s, 0.25, 0.125, and ≤0.0625 μg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae andMoraxella catarrhalis (MIC90s, 0.25 and 0.5 μg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.

scholarly journals Sontochin as a Guide to the Development of Drugs against Chloroquine-Resistant Malaria

2012 ◽  
Vol 56 (7) ◽  
pp. 3475-3480 ◽  
Author(s):  
Sovitj Pou ◽  
Rolf W. Winter ◽  
Aaron Nilsen ◽  
Jane Xu Kelly ◽  
Yuexin Li ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Plasmodium Yoelii ◽  
Significant Activity ◽  
Drug Resistant ◽  
Content Type ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Derivatives Of

ABSTRACTSontochin was the original chloroquine replacement drug, arising from research by Hans Andersag 2 years after chloroquine (known as “resochin” at the time) had been shelved due to the mistaken perception that it was too toxic for human use. We were surprised to find that sontochin, i.e., 3-methyl-chloroquine, retains significant activity against chloroquine-resistant strains ofPlasmodium falciparum in vitro. We prepared derivatives of sontochin, “pharmachins,” with alkyl or aryl substituents at the 3 position and with alterations to the 4-position side chain to enhance activity against drug-resistant strains. Modified with an aryl substituent in the 3 position of the 7-chloro-quinoline ring, Pharmachin 203 (PH-203) exhibits low-nanomolar 50% inhibitory concentrations (IC50s) against drug-sensitive and multidrug-resistant strains andin vivoefficacy against patent infections ofPlasmodium yoeliiin mice that is superior to chloroquine. Our findings suggest that novel 3-position aryl pharmachin derivatives have the potential for use in treating drug resistant malaria.

scholarly journals Curcumin Analogues as a Potential Drug against Antibiotic Resistant Protein, β-Lactamases and L, D-Transpeptidases Involved in Toxin Secretion in Salmonella typhi: A Computational Approach

2021 ◽  
Vol 2 (1) ◽  
pp. 77-100
Author(s):  
Tanzina Akter ◽  
Mahim Chakma ◽  
Afsana Yeasmin Tanzina ◽  
Meheadi Hasan Rumi ◽  
Mst. Sharmin Sultana Shimu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Typhoid Fever ◽  
Homology Modeling ◽  
Salmonella Typhi ◽  
Multidrug Resistant ◽  
Drug Candidate ◽  
In Vivo Experiments ◽  
Curcumin Analogs

Typhoid fever caused by the bacteria Salmonella typhi gained resistance through multidrug-resistant S. typhi strains. One of the reasons behind β-lactam antibiotic resistance is -lactamase. L, D-Transpeptidases is responsible for typhoid fever as it is involved in toxin release that results in typhoid fever in humans. A molecular modeling study of these targeted proteins was carried out by various methods, such as homology modeling, active site prediction, prediction of disease-causing regions, and by analyzing the potential inhibitory activities of curcumin analogs by targeting these proteins to overcome the antibiotic resistance. The five potent drug candidate compounds were identified to be natural ligands that can inhibit those enzymes compared to controls in our research. The binding affinity of both the Go-Y032 and NSC-43319 were found against β-lactamase was −7.8 Kcal/mol in AutoDock, whereas, in SwissDock, the binding energy was −8.15 and −8.04 Kcal/mol, respectively. On the other hand, the Cyclovalone and NSC-43319 had an equal energy of −7.60 Kcal/mol in AutoDock, whereas −7.90 and −8.01 Kcal/mol in SwissDock against L, D-Transpeptidases. After the identification of proteins, the determination of primary and secondary structures, as well as the gene producing area and homology modeling, was accomplished. The screened drug candidates were further evaluated in ADMET, and pharmacological properties along with positive drug-likeness properties were observed for these ligand molecules. However, further in vitro and in vivo experiments are required to validate these in silico data to develop novel therapeutics against antibiotic resistance.

scholarly journals In Vitro Activity of 3 Commercial Bacteriophage Cocktails Against Salmonella and Shigella spp. Isolates of Human Origin

2018 ◽  
Vol 3 (1) ◽  
pp. 72 ◽  
Author(s):  
Odette J. Bernasconi ◽  
Valentina Donà ◽  
Regula Tinguely ◽  
Andrea Endimiani
Keyword(s):  
Multidrug Resistant ◽  
In Vivo Studies ◽  
Salmonella Spp ◽  
Salmonella Infections ◽  
Shigella Spp ◽  
Resistant Strains ◽  
Emergence Of Resistance ◽  
First Time

Background: Salmonella and Shigella spp. are 2 of the most frequent and deadly enteric bacterial pathogens recorded worldwide. In developing countries Salmonella infections are responsible for many deaths annually and these mortality rates are prone to increase due to the emergence of resistance to antibiotics. In this overall scenario new alternative therapeutic approaches are needed.Methods: For the first time, we investigated the activity of 3 commercial bacteriophage cocktails (INTESTI, Septaphage, PYO) against a collection of contemporary Salmonella spp. (n = 30) and Shigella spp. (n = 20) strains isolated in Switzerland. Phage susceptibility was determined by implementing the spot test.Results: The overall susceptibility of Salmonella spp. to INTESTI and Septaphage was 87% and 77%, respectively. With regard to Shigella spp., the overall susceptibility to INTESTI and Septaphage was 95% and 55%, respectively. PYOwas observed to be active against only 10% of Salmonella spp. but against 95% of Shigella spp.Conclusions: Our results seem promising, especially for the INTESTI biopreparation against Salmonella enterica infections. Nevertheless, such speculation should be supported by further in vivo studies to confirm efficacy and safety of the cocktails. We also emphasize the importance of large in vitro screening analyses aimed to assess the activity of such biopreparations against contemporary multidrug-resistant strains that are emerging worldwide.Keywords: commercial; bacteriophages; Salmonella; Shigella cocktails

scholarly journals Comparative Analysis of Prevalence and Antibiotic Resistance in Vancomycin-Resistant Enterococcus from Clinical Samples – Demographics and Phenotypes

2021 ◽  
Vol 8 (2) ◽  
pp. 57-65
Author(s):  
Folasade Muibat Adeyemi ◽  
Nana-Aishat Yusuf ◽  
Rashidat Ronke Adeboye ◽  
Odunola Oluwaseun Oluwajide ◽  
Ajibade Kwashie Ako-Nai
Keyword(s):  
Antibiotic Resistance ◽  
Skin Lesions ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Phenotypic Characterization ◽  
Clinical Samples ◽  
Vancomycin Resistant Enterococcus ◽  
Southwest Nigeria ◽  
Vancomycin Resistant

Background: Of all enterococci species, the most renowned clinically as multidrug-resistant pathogens are Enterococcus faecium and Enterococcus faecalis. Vancomycin-resistant Enterococcus (VRE) species are the principal cause of opportunistic hospital-acquired infections, due to numerous resistance mechanisms. Methods: In this study, the prevalence and antibiotic resistance profiles of VRE according to clinical sources from three selected hospitals in Southwest-Nigeria were investigated. Altogether, 431 samples (urine, rectal, and wound swabs - caesarian section (CS), automobile accidents, and other skin lesions and abrasions) were collected from three selected hospitals in Osun State, Nigeria. Established techniques were employed for the recovery of enterococci and screening for VRE while antibiotic susceptibility tests were carried out by disc diffusion technique. Results: Altogether, 208 (48.3%) enterococci strains were recovered from which 85 (40.9%) were VRE. E. faecium predominated at 71.8% (61/85) and E. faecalis at 28.2% (24/85) as determined by phenotypic characterization. VRE isolates exhibited 100%, 97.6%, and 92.9% resistance to ampicillin, clindamycin, and quinupristin-dalfopristin (Q/D) respectively. The least resistance in-vitro was to tigecycline (27.1%). None of the antibiotics exhibited 100% activity against all the isolates. vanA resistant phenotype was prevalent at 65.9%. E. faecium from all study locations displayed higher levels of resistance than E. faecalis. Multiple antibiotic resistance (MAR) indices in all VRE isolates were ≥0.2, all being multidrug-resistant. Conclusions: The high prevalence rate along with the high level of multidrug resistance observed in the present study is worrisome and poses a continuous threat in the therapy of illnesses triggered by VRE as vancomycin was perceived as a drug of choice to curb enterococcal infections.

scholarly journals In Vitro Antimicrobial Activity of Fosfomycin, Rifampin, Vancomycin, Daptomycin Alone and in Combination Against Vancomycin-Resistant Enterococci

2021 ◽  
Author(s):  
Wei Yu ◽  
Yiheng Jiang ◽  
Hao Xu ◽  
Li Zhang ◽  
Xuehang Jin ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Therapeutic Option ◽  
Bactericidal Effect ◽  
Resistance Determinant ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
High Level ◽  
Time Kill ◽  
Level Resistance

Abstract OBJECTIVESThe emergence of vancomycin resistant enterococci (VRE) is shortening the choices for clinical anti-infective therapy. The aim of this study was to investigate the mechanism of vancomycin resistance and evaluate the effect of fosfomycin (FM), rifampin (RIF), vancomycin (VAN), linezolid (LNZ), daptomycin (DAP) alone or in combination against VRE.METHODSEight VRE isolates were collected. A total of 18 antibiotics susceptibility tests were further done for VRE. Whole genome sequencing and bioinformatics analysis were performed. The effect of FM, RIF, VNA, LNZ, DAP alone or in combination was determined using anti-biofilm testing and the time-kill assay.RESULTSAll isolates were susceptible to LNZ and DPA. The high-level resistance determinant of VAN in these strains was due to VanA-type cassette. MLST revealed two different STs for vancomycin-resistant Enterococcus faecium (VREm) and four different STs for vancomycin-resistant E. faecalis (VREs). Virulence genes in VREs were more than VREm, especially for 4942 isolated from blood. Gene acm and uppS were only identified in VREm, while virulence genes related to cytolysin were only found in E. faecalis. Further in vitro anti-biofilm testing and time-kill assay found FM (83 mg/L) combined with DAP (20.6 mg/L) and DAP monotherapy (47.1 mg/L) showed bactericidal effect against 8 tested VRE strains at 24h. CONCLUSIONSThe high-level resistance determinant of VAN in these strains was due to VanA-type cassette. FM combined with DAP might be greater potential therapeutic option against VRE.

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