scholarly journals Antibacterial Activity of Manuka Honey Against Azithromycin Resistant Extensively Drug Resistant Salmonella Typhi Clinical Isolates: In-Vitro Study

Author(s):  
Kokab Jabeen ◽  
Sidrah Saleem ◽  
Faiqa Arshad ◽  
Zill-e-Huma ◽  
Shah Jahan ◽  
...  

Abstract Typhoid fever is a significant health problem in developing countries like Pakistan. Salmonella Typhi the causative agent of typhoid has developed resistant to almost all recommended antibiotics. Emergence of resistance to third generation cephalosporins has further complicated the situation and such strains are called as extensively drug resistant (XDR) Salmonella Typhi. Currently only available options are azithromycin and cabapenems. Recently few reports of azithromycin resistance have emerged from countries like Pakistan, India, Bangladesh and Nepal. As azithromycin is the only oral option available to treat XDR Typhoid, development of resistance may change treatment strategy altogether from out patient management to hospitalization of every patient. This may increase the burden on already weak health care system of countries like Pakistan. So there is dire need to look for the alternative treatment options. Manuka honey is well known for its therapeutic potential against wide range of bacteria including Salmonella Typhimurium. In this study 3 azithromycin resistant isolates were isolated and identified using disc diffusion, E-test and broth micro dilution methods and antibacterial activity, MIC and MBC of manuka honey was performed by agar well diffusion assay and broth micro dilution assay respectively. Manuka honey manifested significant antibacterial activity against all test isolates with zone of inhibition ranging from 7.3mm to 7.5mm, MIC and MBC values were between 10 to 15% v/v Here, we conclude that Manuka honey possess potent antibacterial activity and might be used as an alternative treatment option against azithromycin resistant XDR Typhid. However, further clinical trials are mandatory to validate our initial findings.

2021 ◽  
Author(s):  
Elli Mylona ◽  
Phat Voong Vinh ◽  
Sonia Qureshi ◽  
Abhilasha Karkey ◽  
Sabina Dongol ◽  
...  

Abstract The emergence of multi-drug (MDR) and extensive-drug resistance (XDR) in Salmonella Typhi and Paratyphi A hinder efficacious out-patient enteric fever treatment. We show that non-XDR and XDR S. Typhi and S. Paratyphi A are susceptible to the carbapenem tebipenem in vitro. Tebipenem demonstrated partial synergy with antimicrobials including azithromycin, signifying combination therapy may limit the emergence of resistance. Given recent evidence on tebipenem inhibitory activity against MDR Shigella, its broad-spectrum activity against MDR/XDR organisms renders it a good clinical trial candidate.


2021 ◽  
Author(s):  
Mahasin Ahmed Wadi

Abstract BackgroundThe emergence of multi–drug resistant organisms has created a lot of clinicalproblems. Hence there is a need to find natural alternative treatment to counter the multi–drug resistant organisms. Honey has a well-established usage as wound dressing in ancient and traditional medicine. The aim of this work is to establish a base-line of the antibacterial activity of 32 natural and commercial various honey samples against 8 clinical isolates.MethodsThirty two honey samples (raw and commercial honey) collected from different countries with different floral origin were tested in vitro for antibacterial activity against 8 clinical isolates collected from patients, at private Hospital from Sudan, using disk diffusion technique. The following 6 Epsilometer test (E Test), Amoxicillin, Augamentin, Ceftaxime, Chloramphenicol, Gentamicin and tetracycline were used against 8 clinical isolates for Minimum Inhibitory Concentration.ResultsThe following 8 clinical isolates were identified by conventional bacteriological methods; Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aerouginosa, Proteus.vulgaris, Salmonella typhi, Shigella sonnei and Methicillin Resistant Staphylococcus aureus (MRSA). Honey has been shown to have antibacterial properties against both Gram-positive and Gram-negative bacteria. The tested organisms showed low sensitivity to antibiotics E test.ConclusionMost of the bacterial species studied were uniformly receptive to all the tested honey. In contrast The tested organisms showed low sensitivity to antibiotics with low MIC.


Author(s):  
Jerzy Karczewski ◽  
Christine M Brown ◽  
Yukari Maezato ◽  
Stephen P Krasucki ◽  
Stephen J Streatfield

Abstract Objectives To evaluate the efficacy of a novel lantibiotic, CMB001, against MRSA biofilms in vitro and in an in vivo experimental model of bacterial infection. Methods Antibacterial activity of CMB001 was measured in vitro after its exposure to whole blood or to platelet-poor plasma. In vitro efficacy of CMB001 against a Staphylococcus aureus biofilm was studied using scanning electron microscopy. The maximum tolerable dose in mice was determined and a preliminary pharmacokinetic analysis for CMB001 was performed in mice. In vivo efficacy was evaluated in a neutropenic mouse thigh model of infection. Results CMB001 maintained its antibacterial activity in the presence of blood or plasma for up to 24 h at 37°C. CMB001 efficiently killed S. aureus within the biofilm by causing significant damage to the bacterial cell wall. The maximum tolerable dose in mice was established to be 10 mg/kg and could be increased to 30 mg/kg in mice pretreated with antihistamines. In neutropenic mice infected with MRSA, treatment with CMB001 reduced the bacterial burden with an efficacy equivalent to that of vancomycin. Conclusions CMB001 offers potential as an alternative treatment option to combat MRSA. It will be of interest to evaluate the in vivo efficacy of CMB001 against infections caused by other pathogens, including Clostridioides difficile and Acinetobacter baumannii, and to expand its pharmacokinetic/pharmacodynamic parameters and safety profile.


2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Zhaojing Zong ◽  
Wei Jing ◽  
Jin Shi ◽  
Shu'an Wen ◽  
Tingting Zhang ◽  
...  

ABSTRACT Oxazolidinones are efficacious in treating mycobacterial infections, including tuberculosis (TB) caused by drug-resistant Mycobacterium tuberculosis. In this study, we compared the in vitro activities and MIC distributions of delpazolid, a novel oxazolidinone, and linezolid against multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) in China. Additionally, genetic mutations in 23S rRNA, rplC, and rplD genes were analyzed to reveal potential mechanisms underlying the observed oxazolidinone resistance. A total of 240 M. tuberculosis isolates were included in this study, including 120 MDR-TB isolates and 120 XDR-TB isolates. Overall, linezolid and delpazolid MIC90 values for M. tuberculosis isolates were 0.25 mg/liter and 0.5 mg/liter, respectively. Based on visual inspection, we tentatively set epidemiological cutoff (ECOFF) values for MIC determinations for linezolid and delpazolid at 1.0 mg/liter and 2.0 mg/liter, respectively. Although no significant difference in resistance rates was observed between linezolid and delpazolid among XDR-TB isolates (P > 0.05), statistical analysis revealed a significantly greater proportion of linezolid-resistant isolates than delpazolid-resistant isolates within the MDR-TB group (P = 0.036). Seven (53.85%) of 13 linezolid-resistant isolates were found to harbor mutations within the three target genes. Additionally, 1 isolate exhibited an amino acid substitution (Arg126His) within the protein encoded by rplD that contributed to high-level resistance to linezolid (MIC of >16 mg/liter), compared to a delpazolid MIC of 0.25. In conclusion, in vitro susceptibility testing revealed that delpazolid antibacterial activity was comparable to that of linezolid. A novel mutation within rplD that endowed M. tuberculosis with linezolid, but not delpazolid, resistance was identified.


2021 ◽  
Author(s):  
Moataz Dowaidar

A feasible alternative to state-of-the-art enzymatic nucleases was created by regulating the cleavage activity of metal complexes using (covalent or non-covalent) homing agents. Targeted AMNs, unlike enzymatic nucleases, break DNA by an oxidative mechanism and can therefore permanently knock off genes. Compared to larger enzymatic nucleases, the modest size of the metal complex may aid cellular transfection. Furthermore, the painstaking construction of the sequence-specific probe permits a metal complex to be directed to dsDNA's minor or major groove. To direct the chemical reactivity of several small-molecule compounds to dsDNA's minor groove, covalently bonded polyamide samples were used. PNA and DNA were also used to construct antisense and antigen hybrids, with Watson–Crick or Hoogsteen base pairing with major groove nucleobases giving sequence recognition. Click chemistry created chimeric AMN-TFOs with desirable focused effects and negligible off-target cleavage. Clip-Phen-modified TFOs, 230 polypyridyl-modified TFOs, 232 and intercalating phenanthrene-modified TFOs are three contemporary instances of copper AMN–TFOs. All three systems have distinct advantages in maintaining the desired 2:1 phenthroline/copper ratio for DNA cleavage (clip-Phen TFOs), caging the copper center and facilitating efficient ROS-mediated strand scission (polypyridyl-modified TFO) and improving triplex stability (polypyridyl-modified TFO) (phenanthrene-TFOs). Cerium (IV)/EDTA complexes, recently shown to bind and hydrolytically cleave ssDNA/dsDNA junctions and used in conjunction with PNA to successfully introduce genome changes in vitro and in vivo, are another important class of targeted chemical nucleases. The chemical reactivity and wide flexibility of metal complex design, combined with their coupling to sequence specific samples for directed applications, show that these compounds have a wide range of untapped applications in biological fields such as chemotherapy, protein engineering, DNA footprinting, and gene editing. Parallel advancements in cell and tissue targeting will be essential to maximise their therapeutic potential, either by using specific ligands or creating new targeting modalities.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Susanne Jacobsson ◽  
Susanne Paukner ◽  
Daniel Golparian ◽  
Jörgen S. Jensen ◽  
Magnus Unemo

ABSTRACT We evaluated the activity of the novel semisynthetic pleuromutilin lefamulin, inhibiting protein synthesis and growth, and the effect of efflux pump inactivation on clinical gonococcal isolates and reference strains (n = 251), including numerous multidrug-resistant and extensively drug-resistant isolates. Lefamulin showed potent activity against all gonococcal isolates, and no significant cross-resistance to other antimicrobials was identified. Further studies of lefamulin are warranted, including in vitro selection and mechanisms of resistance, pharmacokinetics/pharmacodynamics, optimal dosing, and performance in randomized controlled trials.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Helio S. Sader ◽  
Mariana Castanheira ◽  
Dee Shortridge ◽  
Rodrigo E. Mendes ◽  
Robert K. Flamm

ABSTRACT The in vitro activity of ceftazidime-avibactam and many comparator agents was determined against various resistant subsets of organisms selected among 36,380 Enterobacteriaceae and 7,868 Pseudomonas aeruginosa isolates. The isolates were consecutively collected from 94 U.S. hospitals, and all isolates were tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories). Enterobacteriaceae isolates resistant to carbapenems (CRE) and/or ceftazidime-avibactam (MIC ≥ 16 μg/ml) were evaluated for the presence of genes encoding extended-spectrum β-lactamases and carbapenemases. Ceftazidime-avibactam inhibited >99.9% of all Enterobacteriaceae at the susceptible breakpoint of ≤8 μg/ml and was active against multidrug-resistant (MDR; n = 2,953; MIC50/90, 0.25/1 μg/ml; 99.2% susceptible), extensively drug-resistant (XDR; n = 448; MIC50/90, 0.5/2 μg/ml; 97.8% susceptible), and CRE (n = 513; MIC50/90, 0.5/2 μg/ml; 97.5% susceptible) isolates. Only 82.2% of MDR Enterobacteriaceae (n = 2,953) and 64.2% of ceftriaxone-nonsusceptible Klebsiella pneumoniae (n = 1,063) isolates were meropenem susceptible. Among Enterobacter cloacae (22.2% ceftazidime nonsusceptible), 99.8% of the isolates, including 99.3% of the ceftazidime-nonsusceptible isolates, were ceftazidime-avibactam susceptible. Only 23 of 36,380 Enterobacteriaceae (0.06%) isolates were ceftazidime-avibactam nonsusceptible, including 9 metallo-β-lactamase producers and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. Ceftazidime-avibactam showed potent activity against P. aeruginosa (MIC50/90, 2/4 μg/ml; 97.1% susceptible), including MDR (MIC50/90, 4/16 μg/ml; 86.5% susceptible) isolates, and inhibited 71.8% of isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n = 628). In summary, ceftazidime-avibactam demonstrated potent activity against a large collection (n = 44,248) of contemporary Gram-negative bacilli isolated from U.S. patients, including organisms resistant to most currently available agents, such as CRE and meropenem-nonsusceptible P. aeruginosa.


Author(s):  
Md. Abdur Rahman ◽  
Md. Saddam Hussain ◽  
Md. Shalahuddin Millat ◽  
Md. Mizanur Rahman Moghal

Excoecaria agallocha plant (Leaves) was analyzed to explore In Vitro antimicrobial and membrane stabilizing activities as a crude methanolic extract. Antimicrobial activity was performed against a wide range of Gram positive(+Ve) and Gram negative(-Ve) bacteria by using disc diffusion method and various methanolic extracts of leaves of E.agallocha was tested for determining membrane stabilizing activity at hypotonic solution and heat induce condition and standard acetyl salicylic acid (0.10 mg/mL) was employed as standard. the zones of inhibition created was found to be 1.3 cm at a concentration of 100 µL/ disc in case of Gram negative(-Ve) bacteria Salmonella typhi. The results obtained were compared with that of a standard Ampicillin (10 µL) and imipenem (10µL), penicillin (10µl), cefoxitine(30µl). Crude methanolic extract of 10mg/ml concentration showed maximum value of 17.67±0.0102 and 18.92±0.086% respectively under hypotonic solution and heat induced condition. Thus the result suggest that, crude methanolic extracts of E.agallocha possessed slight to moderate antimicrobial and membrane stabilizing properties.


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