scholarly journals Genomic and RT-qPCR analysis of trimethoprim-sulfamethoxazole and meropenem resistance in Burkholderia pseudomallei clinical isolates

2021 ◽  
Vol 15 (2) ◽  
pp. e0008913
Author(s):  
Marine Schnetterle ◽  
Olivier Gorgé ◽  
Flora Nolent ◽  
Aïda Boughammoura ◽  
Véronique Sarilar ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Clinical Presentation ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Clinical Samples ◽  
Northern Australia ◽  
Chronic Case ◽  
Routine Examination ◽  
Transient Nature ◽  
Qpcr Analysis

Background Melioidosis is an endemic disease in southeast Asia and northern Australia caused by the saprophytic bacteria Burkholderia pseudomallei, with a high mortality rate. The clinical presentation is multifaceted, with symptoms ranging from acute septicemia to multiple chronic abscesses. Here, we report a chronic case of melioidosis in a patient who lived in Malaysia in the 70s and was suspected of contracting tuberculosis. Approximately 40 years later, in 2014, he was diagnosed with pauci-symptomatic melioidosis during a routine examination. Four strains were isolated from a single sample. They showed divergent morphotypes and divergent antibiotic susceptibility, with some strains showing resistance to trimethoprim-sulfamethoxazole and fluoroquinolones. In 2016, clinical samples were still positive for B. pseudomallei, and only one type of strain, showing atypical resistance to meropenem, was isolated. Principal findings We performed whole genome sequencing and RT-qPCR analysis on the strains isolated during this study to gain further insights into their differences. We thus identified two types of resistance mechanisms in these clinical strains. The first one was an adaptive and transient mechanism that disappeared during the course of laboratory sub-cultures; the second was a mutation in the efflux pump regulator amrR, associated with the overexpression of the related transporter. Conclusion The development of such mechanisms may have a clinical impact on antibiotic treatment. Indeed, their transient nature could lead to an undiagnosed resistance. Efflux overexpression due to mutation leads to an important multiple resistance, reducing the effectiveness of antibiotics during treatment.

scholarly journals Investigation of Ciprofloxacin Resistance and Its Mechanisms in Clinical Pseudomonas aeruginosa Isolates

ANKEM Dergisi ◽  
2021 ◽  
Author(s):  
Nilüfer Uzunbayır Akel ◽  
Yamaç Tekintaş ◽  
Fethiye Ferda Yılmaz ◽  
İsmail Öztürk ◽  
Mustafa Ökeer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Regulatory Genes ◽  
Quinolone Resistance ◽  
University Hospital ◽  
Clinical Samples ◽  
Genetic Groups ◽  
Ciprofloxacin Resistance ◽  
Polymerase Chain

Pseudomonas aeruginosa is one of the most important causes of hospital infections. Although different antibiotic groups are used for the treatment of P.aeruginosa infections, quinolone groups are distinguished by the advantages of oral administration. However, in recent years, resistance against members of this group has made treatment more difficult. The aim of this study was to investigate the epidemiological relationship and possible mechanisms of resistance in ciprofloxacin resistant P. aeruginosa isolates from Ege University Hospital. The identification of P.aeruginosa bacteria isolated from clinical samples in Ege University Medical Faculty Medical Microbiology Laboratory was determined by VITEK MS automated systems by VITEK compact, antimicrobial susceptibility. The epidemiological relationships of the ciprofloxacin resistant isolates were determined by Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The presence of qnrA, qnrB, qnrS, qepA genes, the quinolone resistance genes and nfxB, mexR, the regulatory genes of the efflux pump, was determined by PCR. The phenylalanine-arginine β-naphthylamide (PAβN) assay was used to determine the activation of the efflux pump. Twenty-two isolates (26.5 %) were found resistant to ciprofloxacin. According to the ERIC-PCR results, 11 unrelated clones were detected. Ciprofloxacin minimum inhibitory concentration (MIC) values were decreased 2-64 times in 10 isolates in the presence of PAIN. No ciprofloxacin MIC change was detected in one isolate. The presence of pump regulatory genes was determined in 10 of the 11 representative isolates, while only qnrB of the genes associated with quinolone resistance was detected in seven representative isolates. qnrA, qnrS, qepA genes were not detected in any isolate. Ciprofloxacin resistant P.aeruginosa isolates are isolated from our hospital. It is noteworthy that the isolates belonging to different genetic groups are in circulation in clinics. Basic resistance mechanisms are thought to be efflux pumps and qnrB genes.

scholarly journals Conservation of resistance nodulation cell division efflux pump mediated antibiotic resistance in Burkholderia cepacia complex and Burkholderia pseudomallei complex species

2021 ◽  
Author(s):  
Nawarat Somprasong ◽  
Jinhee Yi ◽  
Carina M. Hall ◽  
Jessica R. Webb ◽  
Jason W. Sahl ◽  
...  
Keyword(s):  
Cell Division ◽  
Burkholderia Cepacia ◽  
Burkholderia Pseudomallei ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Burkholderia Cepacia Complex ◽  
Complex Species ◽  
Functional Studies ◽  
Rnd Efflux Pump

Burkholderia cepacia complex (Bcc) and Burkholderia pseudomallei complex (Bpc) species include pathogens that are typically multidrug resistant. Dominant intrinsic and acquired multidrug resistance mechanisms are efflux mediated by pumps of the resistance nodulation cell division (RND) family. From comparative bioinformatic and, in many instances, functional studies we infer that RND pump-based resistance mechanisms are conserved in Burkholderia . We propose to use these findings as a foundation for adoption of a uniform RND efflux pump nomenclature.

scholarly journals Disseminated melioidosis with native valve endocarditis: a case report

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Hariharan Subramony ◽  
Sengottuvelu Gunasekaran ◽  
Vinodh Kumar Paul Pandi
Keyword(s):  
Infective Endocarditis ◽  
Burkholderia Pseudomallei ◽  
Cardiac Involvement ◽  
Clinical Presentation ◽  
South East Asia ◽  
Northern Australia ◽  
Native Valve ◽  
Gram Negative ◽  
Native Valve Endocarditis ◽  
Case Summary

Abstract Background  Burkholderia pseudomallei is a Gram negative, soil-water saprophytic bacterium endemic in South-East Asia and Northern Australia. Melioidosis is being increasingly diagnosed in other regions like India, China, and Sri Lanka during recent years. The clinical presentation of melioidosis is extremely variable. Case summary  We present a case of melioidosis presenting as native valve infective endocarditis with concomitant hepatic and splenic abscesses. This is the second case of melioidosis with infective endocarditis reported from India. Discussion  Melioidosis can present with pneumonia, pleural effusion, subcutaneous abscesses, visceral abscesses, osteomyelitis, and septicaemia, but cardiac involvement is rare. Endocarditis due to melioidosis is rare (∼1%) and is rarely reported in literature. This case highlights the unusual presentation of this emerging disease.

scholarly journals Parallel evolution and local differentiation in quinolone resistance in Pseudomonas aeruginosa

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 937-944 ◽  
Author(s):  
Alex Wong ◽  
Rees Kassen
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Parallel Evolution ◽  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Clinical Samples ◽  
Resistance Mutations ◽  
Topoisomerase Iv ◽  
Therapeutic Implications ◽  
Local Differentiation

The emergence and spread of antibiotic resistance in pathogens is a major impediment to the control of microbial disease. Here, we review mechanisms of quinolone resistance in Pseudomonas aeruginosa, an important nosocomial pathogen and a major cause of morbidity in cystic fibrosis (CF) patients. In this quantitative literature review, we find that mutations in DNA gyrase A, the primary target of quinolones in Gram-negative bacteria, are the most common resistance mutations identified in clinical samples of all origins, in keeping with previous observations. However, the identities of non-gyrase resistance mutations vary systematically between samples isolated from CF patients and those isolated from acute infections. CF-derived strains tend to harbour mutations in the efflux pump regulator nfxB, while non-CF strains tend to bear mutations in the efflux regulator mexR or in parC, which encodes one of two subunits of DNA topoisomerase IV. We suggest that differences in resistance mechanisms between CF and non-CF strains result either from local adaptation to different sites of infection or from differences in mutational processes between different environments. We further discuss the therapeutic implications of local differentiation in resistance mechanisms to a common antibiotic.

scholarly journals The BpeEF-OprC Efflux Pump Is Responsible for Widespread Trimethoprim Resistance in Clinical and Environmental Burkholderia pseudomallei Isolates

2013 ◽  
Vol 57 (9) ◽  
pp. 4381-4386 ◽  
Author(s):  
Nicole L. Podnecky ◽  
Vanaporn Wuthiekanun ◽  
Sharon J. Peacock ◽  
Herbert P. Schweizer
Keyword(s):  
Dihydrofolate Reductase ◽  
Burkholderia Pseudomallei ◽  
Efflux Pump ◽  
Eradication Therapy ◽  
Northern Australia ◽  
Northeast Thailand ◽  
Environmental Isolates ◽  
Transcriptional Terminator ◽  
Content Type ◽  
Primary Drug

ABSTRACTTrimethoprim-sulfamethoxazole (co-trimoxazole) is the primary drug used for oral eradication therapy ofBurkholderia pseudomalleiinfections (melioidosis). Here, we demonstrate that trimethoprim resistance is widespread in clinical and environmental isolates from northeast Thailand and northern Australia. This resistance was shown to be due to BpeEF-OprC efflux pump expression. No dihydrofolate reductase target mutations were involved, although frequent insertion of ISBma2 was noted within the putativefolAtranscriptional terminator. All isolates tested remained susceptible to trimethoprim-sulfamethoxazole, suggesting that resistance to trimethoprim alone in these strains probably does not affect the efficacy of co-trimoxazole therapy.

scholarly journals Molecular Epidemiology and Characterization of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Urine at a Teaching Hospital in Taiwan

2021 ◽  
Vol 9 (2) ◽  
pp. 271
Author(s):  
Yuarn-Jang Lee ◽  
Chih-Hung Huang ◽  
Noor Andryan Ilsan ◽  
I-Hui Lee ◽  
Tzu-Wen Huang
Keyword(s):  
Klebsiella Pneumoniae ◽  
Teaching Hospital ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Pcr Analysis ◽  
Carbapenem Resistant ◽  
High Prevalence ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Tract Infections

Urinary tract infections (UTIs) are common in clinics and hospitals and are associated with a high economic burden. Enterobacterium Klebsiella pneumoniae is a prevalent agent causing UTIs. A high prevalence of carbapenem-resistant K. pneumoniae (CRKP) has emerged recently and is continuing to increase. Seventeen urinary CRKP isolates collected at a teaching hospital in Taiwan from December 2016 to September 2017 were analyzed to elucidate their drug resistance mechanisms. Two-thirds of the isolates were obtained from outpatients. Antimicrobial susceptibility tests demonstrated multidrug resistance in all the isolates. Multilocus sequence typing analysis showed high diversity among the isolates. PCR analysis demonstrated the presence of carbapenemases in three isolates. All isolates carried at least one other extended-spectrum β-lactamase, including TEM, DHA, and CTX-M. Fifteen isolates contained mutations in one of the outer membrane porins that were assessed. The expression levels of the acrB and/or oqxB efflux pump genes, as determined by qRT-PCR, were upregulated in 11 isolates. Six isolates might have utilized other efflux pumps or antimicrobial resistance mechanisms. These analyses demonstrated a highly diverse population and the presence of complex resistance mechanisms in urinary isolates of K. pneumoniae.

scholarly journals 1280. In-Vitro Activity of Cefiderocol, Imipenem/Relebactam, & Ceftazidime/Avibactam in Ceftolozane/Tazobactam Resistant Strains of Multidrug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander
Keyword(s):  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Resistance Testing ◽  
Clinical Samples ◽  
In Vitro Activity ◽  
Carbapenemase Gene ◽  
Resistant Strains

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

scholarly journals Bioactive constituents with antibacterial, resistance modulation, anti-biofilm formation and efflux pump inhibition properties from Aidia genipiflora stem bark

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel Anokwah ◽  
Evelyn Asante-Kwatia ◽  
Abraham Y. Mensah ◽  
Cynthia Amaning Danquah ◽  
Benjamin K. Harley ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Efflux Pump ◽  
Ethyl Acetate Fraction ◽  
Stem Bark ◽  
Resistance Mechanisms ◽  
Bioactive Constituents ◽  
Biofilm Inhibition ◽  
E Coli ◽  
Efflux Pump Inhibition ◽  
Oleanonic Acid

Abstract Background Antimicrobial resistance is a global health challenge. The involvement of bacterial biofilms and efflux pumps in the development of multidrug resistance (MDR) is well established. Medicinal plants have been proposed as alternatives for combating MDR focusing on their bioactive constituents with resistance modulatory activities. This study was aimed at investigating the stem bark of Aidia genipiflora for bioactive constituents with anti-biofilm, efflux pump inhibition and resistance modulatory activities. Method The crude methanol extract was purified by column chromatography and isolated compounds characterized by mass and nuclear magnetic resonance spectrometry. Antibacterial activity was determined by the High-throughput spot culture growth inhibition and the broth micro-dilution assay. The ethidium bromide accumulation assay was used to determine efflux pump inhibition property. Biofilm inhibition was determined in a microplate crystal violet retention assay. Results Purification of the ethyl acetate fraction led to the isolation of oleanonic acid (1), 4-hydroxy cinnamic acid docosyl ester (2), β-stigmasterol/β-sitosterol (mixture 3a/b) and D-mannitol (4). The minimum inhibitory concentrations (MICs) ranged from 250 to > 500 μg/mL for extracts and fractions and from 15 to 250 μg/mL for compounds. In the presence of sub-inhibitory concentrations of the compounds, the MIC of amoxicillin against E. coli (20 μg/mL) and P. aeruginosa (320 μg/mL) was reduced by 32 and 10 folds respectively. The whole extract demonstrated anti-biofilm formation and efflux pump inhibition in E. coli, S. aureus and P. aeruginosa. The sterol mixture (3a/b) at concentration of 100 μg/mL caused the highest inhibition (73%) of biofilm formation in S. aureus. Oleanonic acid (1) demonstrated remarkable efflux pump inhibition at MIC of 7.8 μg/mL in E. coli better than the standard drugs verapamil and chlorpromazine. Conclusion This study confirms the prospects of A. genipiflora as a source of new antibacterial agents and adjuvants that could interact with some resistance mechanisms in bacteria to enhance the activity of hitherto ineffective antibiotics. “A small portion of the study has been presented in a conference in the form of poster”.

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