scholarly journals Rifabutin and Furazolidone Could Be the Candidates of the Rescue Regimen for Antibiotic-Resistant H. pylori in Korea

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Youn I Choi ◽  
Sang-Ho Jeong ◽  
Jun-Won Chung ◽  
Dong Kyun Park ◽  
Kyoung Oh Kim ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Medical Center ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Asan Medical ◽  
Resistant Strains ◽  
H Pylori ◽  
Resistance Rates ◽  
Reference Strains

Background/Aim. In Korea, the rate of Helicobacter pylori (H. pylori) eradication has declined steadily as a result of increasing resistance to antibiotics, especially dual resistance to clarithromycin and metronidazole. However, microbiological culture data on drug-resistant H. pylori is lacking. This study evaluated the antimicrobial efficacy of candidate antibiotics against resistant H. pylori strains. Methods. After retrospectively reviewing the data from the Helicobacter Registry in Gil Medical Center (GMC) and Asan Medical Center (AMC), along with 4 reference strains, we selected the 31 single- or multidrug-resistant strains. The susceptibility of the H. pylori strains to seven antibiotics (clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, rifabutin, and furazolidone) and minimum inhibitory concentration were tested using the broth microdilution technique. Results. Among 31 antibiotic resistance strains for H. pylori, there were no strains resistant to rifabutin or furazolidone, which had MICs of <0.008 and 0.5 μg/mL, respectively. Only one tetracycline-resistant strain was found (MIC < 2 μg/mL). Amoxicillin and levofloxacin were relatively less effective against the H. pylori strains compared to rifabutin or furazolidone (resistance rates 22.6%, 1.9%, respectively). Tetracycline showed the relatively low resistance rates (3.2%) for H. pylori strains. Conclusions. Therefore, along with tetracycline which has already been used as a component for second-line eradication regimen for Helicobacter, rifabutin and furazolidone, alone or in combination, could be used to eradicate antibiotic-resistant H. pylori strains where drug-resistant Helicobacter spp. are increasing.

scholarly journals Antimicrobial activity of a repurposed harmine-derived compound on extensively drug-resistant Acinetobacter baumannii clinical isolates

2021 ◽  
Author(s):  
Anke Breine ◽  
Megane Van Gysel ◽  
Mathias Elsocht ◽  
Clemence Whiteway ◽  
Chantal Philippe ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Reference Strain ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Resistant Strains ◽  
High Degree

Synopsis Objectives: The spread of antibiotic resistant bacteria is an important threat for human healthcare. Acinetobacter baumannii bacteria impose one of the major issues, as multidrug- to pandrug-resistant strains have been found, rendering some infections untreatable. In addition, A. baumannii is a champion in surviving in harsh environments, being capable of resisting to disinfectants and to persist prolonged periods of desiccation. Due to the high degree of variability found in A. baumannii isolates, the search for new antibacterials is challenging. Here, we screened a compound library to identify compounds active against recent isolates of A. baumannii bacteria. Methods: A repurposing drug screen was undertaken to identify A. baumannii growth inhibitors. One hit was further characterized by determining its IC50 and testing its activity on 43 recent clinical A. baumannii isolates, amongst which 40 are extensively drug- and carbapenem-resistant strains. Results: The repurposing screen led to the identification of a harmine-derived compound, called HDC1, which proved to have bactericidal activity on the multidrug-resistant AB5075-VUB reference strain with an IC50 of 48.23 [mu]M. In addition, HDC1 impairs growth of all 43 recent clinical A. baumannii isolates. Conclusions: We identified a compound with inhibitory activity on all tested, extensively drug-resistant clinical A. baumannii isolates.

Antimicrobial Peptides and their Multiple Effects at Sub-Inhibitory Concentrations

2020 ◽  
Vol 20 (14) ◽  
pp. 1264-1273 ◽  
Author(s):  
Bruno Casciaro ◽  
Floriana Cappiello ◽  
Walter Verrusio ◽  
Mauro Cacciafesta ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Mechanisms Of Action ◽  
New Drugs ◽  
Lead Compounds ◽  
Bacterial Pathogenicity ◽  
Growth Inhibitory ◽  
Resistant Strains ◽  
Conventional Antibiotics

The frequent occurrence of multidrug-resistant strains to conventional antimicrobials has led to a clear decline in antibiotic therapies. Therefore, new molecules with different mechanisms of action are extremely necessary. Due to their unique properties, antimicrobial peptides (AMPs) represent a valid alternative to conventional antibiotics and many of them have been characterized for their activity and cytotoxicity. However, the effects that these peptides cause at concentrations below the minimum growth inhibitory concentration (MIC) have yet to be fully analyzed along with the underlying molecular mechanism. In this mini-review, the ability of AMPs to synergize with different antibiotic classes or different natural compounds is examined. Furthermore, data on microbial resistance induction are reported to highlight the importance of antibiotic resistance in the fight against infections. Finally, the effects that sub-MIC levels of AMPs can have on the bacterial pathogenicity are summarized while showing how signaling pathways can be valid therapeutic targets for the treatment of infectious diseases. All these aspects support the high potential of AMPs as lead compounds for the development of new drugs with antibacterial and immunomodulatory activities.

scholarly journals 1597. Ceftolozane-Tazobactam and Meropenem Synergy Testing Against Multi-Drug and Extensively-Drug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S794-S795
Author(s):  
Mary Francine P Chua ◽  
Syeda Sara Nida ◽  
Jerry Lawhorn ◽  
Janak Koirala
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Synergistic Effect ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Additive Effect ◽  
Teaching Hospitals ◽  
Drug Resistant ◽  
Extensively Drug Resistant ◽  
Synergy Testing ◽  
Concentration Indices

Abstract Background Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa (PA) have limited therapeutic options for treatment. Ceftolozane/tazobactam is a newer anti-pseudomonal drug effective against resistant PA infections, however resistance against this drug has now also developed and is increasing. In this study, we explored the combination of ceftolozane/tazobactam (CT) and meropenem (MP) as a possible effective regimen against MDR and XDR PA. Methods We obtained 33 non-duplicate isolates of MDR and XDR PA grown from blood, urine and respiratory samples collected from patients admitted between 2015 and 2019 at our two affiliate teaching hospitals. MDR PA was defined as resistance to 3 or more classes of anti-pseudomonal antibiotics, and XDR PA as resistance to all but two or less classes of anti-pseudomonal antibiotics. Antimicrobial preparations of both MP and CT were made according to manufacturer instructions. Susceptibility testing was performed using the checkerboard method in accordance to CLSI guidelines (CLSI M100, 2017). The ATCC 27853 strain of PA used as control. Synergy, additive effect, indifference and antagonism were defined as FIC (fractional inhibitory concentration) indices of ≤0.5, &gt;0.5 to &lt;1, &gt;1 to &lt;4, and &gt;4, respectively. Results Thirteen (39%) of 33 PA isolates were classified as XDR, while 20 (61%) PA isolates were MDR. All isolates were resistant to MP (MIC50 &gt;32 ug/mL), while only 2 (6%) isolates were susceptible to CT (MIC50 64 ug/mL). A synergistic effect was seen in 9 (27.3%) of PA isolates (FIC index range 0.28 to 0.5)— 2 of which were XDR PA, and 7 were MDR PA. An additive effect was seen in 12 (36.4%), with indifference seen in 12 (36.4%) of isolates. In this study, no antagonism was seen when CT and MP were combined. Conclusion When used in combination, CT and MP can exert a synergistic effect against MDR and XDR PA. Additive effect and indifference can also be seen when both antibiotics were used. Moreover, there was no antagonism seen when both antibiotics were combined. This study shows that the use of CT and MP in combination may be an option against XDR and MDR PA infections. Disclosures All Authors: No reported disclosures

Streptococcus pneumoniae carriage in school children

2021 ◽  
Vol 1 (30) ◽  
pp. 57-60
Author(s):  
I. N. Protasova ◽  
N. V. Bakhareva ◽  
N. A. Ilyenkova ◽  
E. S. Sokolovskaya ◽  
T. A. Elistratova ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Resistance ◽  
School Children ◽  
Clonal Diversity ◽  
Multidrug Resistant ◽  
Clonal Structure ◽  
Serotype Distribution ◽  
Antibiotic Resistant ◽  
Oropharyngeal Swab ◽  
Resistant Strains

Purpose. To investigate the serotype distribution, clonal structure and antimicrobial resistance of pneumococci isolated from schoolchildren.Materials and methods. During the period from 2012 to 2018 we examined 498 healthy school children aged 6 to 17 years. Oropharyngeal swab was taken from each child for culture, after that all S. pneumoniae strains were genotyped for serotype and ST-type deduction (PCR and sequencing, respectively). Antimicrobial resistance was also determined.Results. Pneumococcal culture was positive in 10.6 % of children. S. pneumoniae isolates belonged to seven serogroups and seven serotypes. Serogroup 6 and serotype 19F strains (15.1% each), and serogroup 9 strains (13.2%) were the most prevalent. S. pneumoniae33FA/37 and 3 (9.4 and 5.7%), serogroups 15 and 18 (7.6 and 5.7%), and 10A serotype (3.8%) were determined at a lower frequency. 20 detected ST-types belonged to 14 clonal complexes (CCs); CC156, CC447, and CC320 were predominant. 1.9% of isolates were penicillin-resistant; 13.2% – macrolide-, clindamycin-, and tetracycline-resistant. S. pneumoniae antibiotic resistant strains belonged to multidrug-resistant CCs 320, 315, and 156.Conclusion. S. pneumoniae prevalence in school children is not high. Pneumococcal population is characterized by serotype and clonal diversity including ‘invasive’ serotypes and genotypes. Most of strains are susceptible to antimicrobials.

scholarly journals In Vitro Activity of the Novel Pleuromutilin Lefamulin (BC-3781) and Effect of Efflux Pump Inactivation on Multidrug-Resistant and Extensively Drug-Resistant Neisseria gonorrhoeae

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Susanne Jacobsson ◽  
Susanne Paukner ◽  
Daniel Golparian ◽  
Jörgen S. Jensen ◽  
Magnus Unemo
Keyword(s):  
Efflux Pump ◽  
Multidrug Resistant ◽  
Cross Resistance ◽  
Drug Resistant ◽  
The Novel ◽  
Extensively Drug Resistant ◽  
Optimal Dosing ◽  
And Performance ◽  
Reference Strains

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.

scholarly journals The Biology and Role of Interleukin-32 in Tuberculosis

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Wu Li ◽  
Wanyan Deng ◽  
Jianping Xie
Keyword(s):  
Multidrug Resistant ◽  
Drug Resistant ◽  
Host Molecule ◽  
Tuberculosis Control ◽  
Promising Alternative ◽  
Extensively Drug Resistant ◽  
Important Host ◽  
Resistant Strains ◽  
Drug Resistant Strains

Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading cause of morbidity and mortality globally, with nearly 10.4 million new cases of incidence and over 1.7 million deaths annually. Drug-resistant M. tuberculosis strains, especially multidrug-resistant or extensively drug-resistant strains, have further intensified the problem associated with tuberculosis control. Host-directed therapy is a promising alternative for tuberculosis control. IL-32 is increasingly recognized as an important host molecule against tuberculosis. In this review, we highlight the proinflammatory properties of IL-32 and the mode of action of IL-32 in mycobacterial infections to inspire the development of novel immunity-based countermeasures and host-directed therapies against tuberculosis.

scholarly journals Synergism of the Combination of Traditional Antibiotics and Novel Phenolic Compounds against Escherichia coli

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 811
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
Min-Goo Seo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rattus Norvegicus ◽  
Inhibitory Concentration ◽  
Epicatechin Gallate ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Resistant Strains ◽  
Novel Approaches ◽  
Rapid Emergence

Pathogenic Escherichia coli (E. coli)-associated infections are becoming difficult to treat because of the rapid emergence of antibiotic-resistant strains. Novel approaches are required to prevent the progression of resistance and to extend the lifespan of existing antibiotics. This study was designed to improve the effectiveness of traditional antibiotics against E. coli using a combination of the gallic acid (GA), hamamelitannin, epicatechin gallate, epigallocatechin, and epicatechin. The fractional inhibitory concentration index (FICI) of each of the phenolic compound-antibiotic combinations against E. coli was ascertained. Considering the clinical significance and FICI, two combinations (hamamelitannin-erythromycin and GA-ampicillin) were evaluated for their impact on certain virulence factors of E. coli. Finally, the effects of hamamelitannin and GA on Rattus norvegicus (IEC-6) cell viability were investigated. The FICIs of the antibacterial combinations against E. coli were 0.281–1.008. The GA-ampicillin and hamamelitannin-erythromycin combinations more effectively prohibited the growth, biofilm viability, and swim and swarm motilities of E. coli than individual antibiotics. The concentration of hamamelitannin and GA required to reduce viability by 50% (IC50) in IEC-6 cells was 988.54 μM and 564.55 μM, correspondingly. GA-ampicillin and hamamelitannin-erythromycin may be potent combinations and promising candidates for eradicating pathogenic E. coli in humans and animals.

CURRENTLY USED ANTI-TUBERCULAR AGENTS, THEIR ANALOGUES AND RECENTLY DEVELOPED DRUGS

INDIAN DRUGS ◽  
2012 ◽  
Vol 49 (07) ◽  
pp. 5-19
Author(s):  
A Mohammad ◽  
Keyword(s):  
Antimicrobial Activity ◽  
Side Effects ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Duration Of Treatment ◽  
Duration Of Therapy ◽  
Drug Molecules ◽  
Prolonged Duration ◽  
Resistant Strains ◽  
Reduced Toxicity

Tuberculosis (TB) is one of most prevailing diseases, responsible for the morbidity and mortality of a large number of populations worldwide. Traditionally, it has relied on a limited number of drugs such as isoniazid, rifampicin, ethambutol, streptomycin, ethionamide and pyrazinamide. However, many of these drugs have different disadvantages such as prolonged duration of treatment, host toxicity and ineffectiveness against resistant strains. This has motivated the search of newer drug molecules, capable of rapid mycobactericidal action with shortened duration of therapy, reduced toxicity and enhanced activity against multidrug resistant strains. These observations have been guiding for the currently used and newly developed anti-tubercular agents that possess potent antimicrobial activity and their side effects, activity against multi drug resistant Mycobacterium, and also in patients co-infected with HIV/AIDS.

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