scholarly journals Molecular Epidemiology of Extensively Drug-Resistant mcr Encoded Colistin-Resistant Bacterial Strains Co-Expressing Multifarious β-Lactamases

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 467
Author(s):  
Hasan Ejaz ◽  
Sonia Younas ◽  
Muhammad Usman Qamar ◽  
Kashaf Junaid ◽  
Abualgasim Elgaili Abdalla ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Inhibitory Concentration ◽  
Therapeutic Option ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Extensively Drug Resistant ◽  
Epidemiology Data ◽  
Polymerase Chain

Plasmid-mediated colistin resistance (Col-R) conferred by mcr genes endangers the last therapeutic option for multifarious β-lactamase-producing bacteria. The current study aimed to explore the mcr gene molecular epidemiology in extensively drug-resistant (XDR) bacteria. Col-R gram-negative bacterial strains were screened using a minimum inhibitory concentration (MIC) breakpoint ≥4 µg/mL. Resistant isolates were examined for mcr variants, extended-spectrum β-lactamase, AmpC, and carbapenemase genes using polymerase chain reaction (PCR). The MIC breakpoints for mcr-positive strains were determined using broth microdilution and E-test strips. Overall, 19/718 (2.6%) gram-negative rods (GNRs) harboring mcr were identified, particularly in pus (p = 0.01) and tracheal secretions (p = 0.03). Molecular epidemiology data confirmed 18/19 (95%) mcr-1 and 1/19 (5%) mcr-2 genes. Integron detection revealed 15/17 (88%) Int-1 and 2/17 (12%) Int-2. Common co-expressing drug-resistant β-lactamase genes included 8/16 (50%) blaCTM-1, 3/16 (19%) blaCTM-15, 3/3 (100%) blaCMY-2, 2/8 (25%) blaNDM-1, and 2/8 (25%) blaNDM-5. The MIC50 and MIC90 values (µg/mL) were as follows: Escherichia coli, 12 and 24; Klebsiella pneumoniae, 12 and 32; Acinetobacter baumannii, 8 and 12; and Pseudomonas aeruginosa, 32 and 64, respectively. Treatment of XDR strains has become challenging owing to the co-expression of mcr-1, mcr-2, multifarious β-lactamase genes, and integrons.

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, >0.5 to <1, >1 to <4, and >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 >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

scholarly journals Enhanced Antibacterial Activity of Meropenem against Extensively Drug-Resistant Acinetobacter baumannii by Myrtaceae Plant Extracts

2020 ◽  
Vol 17 (11) ◽  
pp. 1168-1176
Author(s):  
Dennapa SAELOH ◽  
Monton VISUTTHI ◽  
Marisa LEEHA ◽  
Surasak LIMSUWAN ◽  
Supayang Piyawan VORAVUTHIKUNCHAI
Keyword(s):  
Acinetobacter Baumannii ◽  
Bacterial Infections ◽  
Inhibitory Concentration ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Microdilution Method ◽  
Extensively Drug Resistant ◽  
Resistant Phenotype ◽  
Bacterial Growth Inhibition ◽  
Mic Value

Acinetobacter baumannii (A. baumannii) has been known as a major cause of nosocomial bacterial infections worldwide. The bacteria are increasingly associated with a broad spectrum of antibiotic resistance, and this has become a widespread concern in a variety of hospitals.Antibiotic development and alternative treatment have become priorities for the treatment of bacterial infections.This study investigated the efficacy of meropenem in combination with five ethanolic extracts of plants in Myrtaceae against extensively drug-resistant (XDR) A. baumannii. The resistant phenotype was previously determined by microdilution method. XDR-A. baumannii strains showed resistance to meropenem with the minimum inhibitory concentration (MIC) in a range of 16 - 128 µg/mL, whereas the MIC value of all extracts, including Calistemon lancealatus, Eucalyptus citridora, Rhodomytus tomentasa, Syzygium cumini, and Xanthortemon chrysanthus, was over 1,000 µg/mL. Interestingly, all extracts potentiated the activity of the antibiotic by reducing the MIC values of the antibiotic. Xanthortemon chrysanthus extract displayed excellent synergism against the bacteria by decreasing the MIC value of the drug greater than 8-fold. In addition, the extract, at concentrations of 31.25, 62.5, 125, 250, 500, and 1,000 µg/mL, obviously increased the inhibitory effect of meropenem (1/4´MIC) against A. baumannii. The percentage of bacterial growth inhibition by combination was 87.9, 88.8, 91.8, 93.6, 99.9, and 100, respectively. The results supported that the extract could improve the activity of ineffective antibiotics against drug-resistant pathogens.Therefore, the findings may serve as therapeutic options for XDR-A. baumannii infections in the future.

scholarly journals Molecular epidemiology of mcr gene group

2020 ◽  
Vol 22 (4) ◽  
pp. 287-300
Author(s):  
Elizaveta D. Shedko ◽  
O.Yu. Timoshina ◽  
Ilya Sulejmanovich Azyzov
Keyword(s):  
Molecular Epidemiology ◽  
Plasmid Dna ◽  
Bacterial Infections ◽  
Molecular Detection ◽  
Polymyxin B ◽  
Diagnostic Tools ◽  
Drug Resistant ◽  
Gene Group ◽  
Extensively Drug Resistant ◽  
Highly Sensitive

Colistin and polymyxin B are the “last reserve” antimicrobials for the treatment of extensively drug-resistant Gram-negative bacterial infections. The rapidly increasing prevalence of polymyxin resistance mediated by the mcr gene localized on plasmid DNA currently poses a high epidemiological threat. In order to control a distribution of mcr genes, it is necessary to develop highly accurate, highly sensitive and easy-to-use diagnostic tools. This paper provides a review of the most relevant studies on the molecular epidemiology as well as current approaches to microbiological and molecular detection of mcr group genes.

scholarly journals Multidrug Resistant and Extensively Drug Resistant Bacteria: A Study

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Silpi Basak ◽  
Priyanka Singh ◽  
Monali Rajurkar
Keyword(s):  
Antimicrobial Resistance ◽  
Antibiotic Susceptibility ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Close Monitoring ◽  
Care Hospital ◽  
Drug Resistant ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Extensively Drug Resistant

Background and Objective. Antimicrobial resistance is now a major challenge to clinicians for treating patients. Hence, this short term study was undertaken to detect the incidence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates in a tertiary care hospital.Material and Methods. The clinical samples were cultured and bacterial strains were identified in the department of microbiology. The antibiotic susceptibility profile of different bacterial isolates was studied to detect MDR, XDR, and PDR bacteria.Results. The antibiotic susceptibility profile of 1060 bacterial strains was studied. 393 (37.1%) bacterial strains were MDR, 146 (13.8%) strains were XDR, and no PDR was isolated. All (100%) Gram negative bacterial strains were sensitive to colistin whereas all (100%) Gram positive bacterial strains were sensitive to vancomycin.Conclusion. Close monitoring of MDR, XDR, or even PDR must be done by all clinical microbiology laboratories to implement effective measures to reduce the menace of antimicrobial resistance.

Intravenous fosfomycin in patients with liver disease for extensively drug-resistant Gram-negative bacteria

2018 ◽  
Vol 77 (5) ◽  
pp. 448-454 ◽  
Author(s):  
Athina Pyrpasopoulou ◽  
Georgia Pitsava ◽  
Elias Iosifidis ◽  
George Imvrios ◽  
Eleni Massa ◽  
...  
Keyword(s):  
Liver Disease ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Gram Negative ◽  
Extensively Drug Resistant

scholarly journals Colistin resistance among Gram-negative isolates in Nepal: A review

2020 ◽  
Vol 7 (1) ◽  
pp. 33-39
Author(s):  
Surya Prasad Devkota ◽  
Ashmita Paudel
Keyword(s):  
Public Health ◽  
Public Health Problem ◽  
Clinical Isolates ◽  
Clinical Settings ◽  
Drug Resistant ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Food Industries ◽  
Animal Farms ◽  
Animal Isolates

Background: Colistin resistance among Gram-negative isolates is a tremendous public health problem, and there are very few studies in Nepal about these pathogens. Hence, this review provides comprehensive data on colistin resistance among Gram-negative isolates from various samples in Nepal. Methods: Articles reporting colistin resistance among various Gram-negative isolates from Nepal before July 2019 were selected; analyzed and relevant data was collected. Results: Colistin resistance was low among clinical isolates (less than 6%) in comparison to food and animal isolates (up to 69%). A wide variety of clinical isolates were colistin-resistant in comparison to food and animal isolates. Many of these isolates were highly drug-resistant and also harbored various drug-resistant determinants. Conclusion: Increased colistin resistance among Gram-negative pathogens is a serious concern. Screening of these isolates in clinical settings, animal farms, and food industries, as well as cautious use of colistin in both clinical and animal farms, is imminent.

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