scholarly journals Intrinsic Resistance ofBurkholderia cepaciaComplex to Benzalkonium Chloride

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Youngbeom Ahn ◽  
Jeong Myeong Kim ◽  
Ohgew Kweon ◽  
Seong-Jae Kim ◽  
Richard C. Jones ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Efflux Pump ◽  
The United States ◽  
Resistance Mechanisms ◽  
Pharmaceutical Products ◽  
Intrinsic Resistance ◽  
Efflux Pump Inhibitor ◽  
Proteomic Data ◽  
Vulnerable Patients ◽  
Carbonyl Cyanide

ABSTRACTPharmaceutical products that are contaminated withBurkholderia cepaciacomplex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanidem-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.IMPORTANCEBenzyldimethylalkylammonium chloride is commonly used as an antiseptic in the United States. Several recent microbial outbreaks were linked to antiseptics that were found to contain strains of theBurkholderia cepaciacomplex.Burkholderiaspecies survived in antiseptics, possibly because of the degradation of antiseptic molecules or regulation of relevant gene expression. In this study, we assessed the efflux pump and the potential ofB. cepaciacomplex bacteria to degrade benzyldimethylalkylammonium chloride and improved our understanding of the resistance mechanisms, by using proteomic and metabolic information. To our knowledge, this is the first systematic report of the intrinsic mechanisms ofB. cepaciacomplex strain resistance to benzyldimethylalkylammonium chloride, based on the metabolic and proteomic evidence for efflux pumps and the complete biodegradation of benzyldimethylalkylammonium chloride.

scholarly journals Efflux mediated chlorpyrifos tolerance in Escherichia coli BL21(DE3)

2020 ◽  
Author(s):  
Aswathi Aswathi ◽  
Ashok Pandey ◽  
Rajeev K Sukumaran
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Resistance Mechanisms ◽  
Cross Resistance ◽  
Antibiotics Resistance ◽  
High Tolerance ◽  
Intrinsic Resistance ◽  
Efflux Pump Inhibitor ◽  
Environmental Strain

AbstractBacteria are continually challenged with variety of synthetic chemicals/xenobiotics in their immediate surroundings, including pesticides. Chlorpyrifos is one of the most commonly used organophosphate pesticides in the world. The non-environmental strain of Escherichia coli, BL21 (DE3) displayed high tolerance to chlorpyrifos but with no/negligible degradation. The intrinsic resistance mechanisms that aid the organism in its high tolerance are probed. Efflux pumps being ubiquitous in nature and capable of conferring resistance against wide variety of xenobiotics were found to be over-expressed in the presence of CP. Also, an efflux pump inhibitor PAβN increased the susceptibility of E. coli to chlorpyrifos due to the intracellular accumulation of CP. The tripartite efflux pump EmrAB-TolC with increased expression in both transcript and protein on CP exposure, might play a major role in CP tolerance. The transcriptional regulators involved in multidrug resistance along with transporters belonging to all the major families conferring antimicrobial resistance were up-regulated. Also up-regulated were the genes involved in phopshonate metabolism and all the genes in the copper or silver export system. The common resistance mechanisms i.e, activation of efflux pumps between CP, antibacterial metals and antibiotics resistance might result in cross-resistance, ultimately increasing the prevalence of multidrug resistant strains, making infections hard to treat.

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.

Determination of imipenem efflux-mediated resistance in Acinetobacter spp., using an efflux pump inhibitor

2019 ◽  
Author(s):  
Ghazale Amiri ◽  
Maryam Abbasi Shaye ◽  
Masoumeh Bahreini ◽  
Asghar Mafinezhad ◽  
Kiarash Ghazvini ◽  
...  
Keyword(s):  
Efflux Pump ◽  
Efflux Pumps ◽  
Diffusion Method ◽  
Efflux Pump Inhibitor ◽  
Acinetobacter Species ◽  
Fold Reduction ◽  
Carbonyl Cyanide ◽  
Acinetobacter Spp

Background and Objectives: In recent years, reports of Acinetobacter strains resistant to all known antibiotics have caused a great concern in medical communities. Overexpression of efflux pumps is one of the major causes of resistance in bacteria. The aim of this study was to investigate the role of efflux pumps in conferring resistance to imipenem in clinically important Acinetobacter spp; Acinetobacter baumannii and Acinetobacter lwoffii. Materials and Methods: A total number of 46 clinical Acinetobacter isolates, including 33 A. baumannii and 13 A. lwoffii isolates, previously collected from Shahid Kamyab and Ghaem hospitals of Mashhad, Iran were used in this study. Imipenem susceptibility testing was carried out by the disc diffusion method. Imipenem minimum inhibitory concentration (MIC) for resistant Acinetobacter isolates were determined both in the presence and absence of the efflux pumps inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Results: Resistance to imipenem was observed in 38 isolates including 30 A. baumannii and 8 A. lwoffii isolates. Experiments in the presence of CCCP showed a 2 to 16384 fold reduction in imipenem MICs in 14 A. baumannii and 2 A. lwoffii isolates. Conclusion: The results obtained showed high levels of resistance to imipenem and contribution of efflux pumps in conferring resistance in both Acinetobacter species in this study. Moreover, imipenem efflux mediated resistance highlights the importance of this mechanism not only in A. baumannii but also in non-baumannii Acinetobacter Spp. which have been neglected in antibiotic resistance studies.

scholarly journals CmeABC Functions as a Multidrug Efflux System in Campylobacter jejuni

2002 ◽  
Vol 46 (7) ◽  
pp. 2124-2131 ◽  
Author(s):  
Jun Lin ◽  
Linda Overbye Michel ◽  
Qijing Zhang
Keyword(s):  
Campylobacter Jejuni ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Wild Type ◽  
Multidrug Efflux ◽  
Intrinsic Resistance ◽  
Multidrug Efflux Pump ◽  
Efflux Pump Inhibitor ◽  
Gram Negative ◽  
Multidrug Efflux Pumps

ABSTRACT Campylobacter jejuni, a gram-negative organism causing gastroenteritis in humans, is increasingly resistant to antibiotics. However, little is known about the drug efflux mechanisms in this pathogen. Here we characterized an efflux pump encoded by a three-gene operon (designated cmeABC) that contributes to multidrug resistance in C. jejuni 81-176. CmeABC shares significant sequence and structural homology with known tripartite multidrug efflux pumps in other gram-negative bacteria, and it consists of a periplasmic fusion protein (CmeA), an inner membrane efflux transporter belonging to the resistance-nodulation-cell division superfamily (CmeB), and an outer membrane protein (CmeC). Immunoblotting using CmeABC-specific antibodies demonstrated that cmeABC was expressed in wild-type 81-176; however, an isogenic mutant (9B6) with a transposon insertion in the cmeB gene showed impaired production of CmeB and CmeC. Compared to wild-type 81-176, 9B6 showed a 2- to 4,000-fold decrease in resistance to a range of antibiotics, heavy metals, bile salts, and other antimicrobial agents. Accumulation assays demonstrated that significantly more ethidium bromide and ciprofloxacin accumulated in mutant 9B6 than in wild-type 81-176. Addition of carbonyl cyanide m-chlorophenylhydrazone, an efflux pump inhibitor, increased the accumulation of ciprofloxacin in wild-type 81-176 to the level of mutant 9B6. PCR and immunoblotting analysis also showed that cmeABC was broadly distributed in various C. jejuni isolates and constitutively expressed in wild-type strains. Together, these findings formally establish that CmeABC functions as a tripartite multidrug efflux pump that contributes to the intrinsic resistance of C. jejuni to a broad range of structurally unrelated antimicrobial agents.

scholarly journals Prevalence and mechanisms of azole resistance in clinical isolates of Aspergillus section Fumigati species in a Canadian tertiary care centre, 2000 to 2013

2019 ◽  
Vol 75 (4) ◽  
pp. 849-858
Author(s):  
Maxime Parent-Michaud ◽  
Philippe J Dufresne ◽  
Eric Fournier ◽  
Benjamin Folch ◽  
Christine Martineau ◽  
...  
Keyword(s):  
Efflux Pump ◽  
Tertiary Care ◽  
Geographic Area ◽  
Resistance Mechanisms ◽  
Sensu Stricto ◽  
Azole Resistance ◽  
Intrinsic Resistance ◽  
Tertiary Care Centre ◽  
Combined Use ◽  
Aspergillus Section

Abstract Objectives Azole resistance among Aspergillus fumigatus isolates is a growing concern worldwide. Induction of mutations during azole therapy, environment-acquired mutations caused by azole fungicides and intrinsic resistance of cryptic Fumigati species all contribute to the burden of resistance. However, there is a lack of data in Canada on this emerging threat. Methods To gain insights into the magnitude and mechanisms of resistance, a 14 year collection of Aspergillus section Fumigati comprising 999 isolates from 807 patients at a Montreal hospital was screened for azole resistance, and resistance mechanisms were investigated with the combined use of genome sequencing, 3D modelling and phenotypic efflux pump assays. Results Overall azole resistance was low (4/807 patients; 0.5%). A single azole-resistant A. fumigatus sensu stricto strain, isolated from a patient with pulmonary aspergillosis, displayed efflux-pump-mediated resistance. Three patients were colonized or infected with azole-resistant cryptic Fumigati species (one Aspergillus thermomutatus, one Aspergillus lentulus and one Aspergillus turcosus). Evidence is presented that azole resistance is efflux-pump-mediated in the A. turcosus isolate, but not in the A. lentulus and A. thermomutatus isolates. Conclusions Azole resistance is rare in our geographic area and currently driven by cryptic Fumigati species. Continued surveillance of emergence of resistance is warranted.

scholarly journals Extensive Drug-Resistant Salmonella enterica Isolated From Poultry and Humans: Prevalence and Molecular Determinants Behind the Co-resistance to Ciprofloxacin and Tigecycline

2021 ◽  
Vol 12 ◽  
Author(s):  
Norhan K. Abd El-Aziz ◽  
Yasmine H. Tartor ◽  
Rasha M. A. Gharieb ◽  
Ahmed M. Erfan ◽  
Eman Khalifa ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Efflux Pump ◽  
Point Mutations ◽  
Drug Resistant ◽  
Limited Data ◽  
Genetic Determinants ◽  
Efflux Pump Inhibitor ◽  
Loop Region ◽  
Carbonyl Cyanide ◽  
Molecular Determinants

The emergence of extensive drug-resistant (XDR) Salmonella in livestock animals especially in poultry represents a serious public health and therapeutic challenge. Despite the wealth of information available on Salmonella resistance to various antimicrobials, there have been limited data on the genetic determinants of XDR Salmonella exhibiting co-resistance to ciprofloxacin (CIP) and tigecycline (TIG). This study aimed to determine the prevalence and serotype diversity of XDR Salmonella in poultry flocks and contact workers and to elucidate the genetic determinants involved in the co-resistance to CIP and TIG. Herein, 115 Salmonella enterica isolates of 35 serotypes were identified from sampled poultry (100/1210, 8.26%) and humans (15/375, 4.00%), with the most frequent serotype being Salmonella Typhimurium (26.96%). Twenty-nine (25.22%) Salmonella enterica isolates exhibited XDR patterns; 25 out of them (86.21%) showed CIP/TIG co-resistance. Exposure of CIP- and TIG-resistant isolates to the carbonyl cyanide 3-chlorophenylhydrazone (CCCP) efflux pump inhibitor resulted in an obvious reduction in their minimum inhibitory concentrations (MICs) values and restored the susceptibility to CIP and TIG in 17.24% (5/29) and 92% (23/25) of the isolates, respectively. Molecular analysis revealed that 89.66% of the isolates contained two to six plasmid-mediated quinolone resistance genes with the predominance of qepA gene (89.66%). Mutations in the gyrA gene were detected at codon S83 (34.62%) or D87 (30.77%) or both (34.62%) in 89.66% of XDR Salmonella. The tet(A) and tet(X4) genes were detected in 100% and 3.45% of the XDR isolates, respectively. Twelve TIG-resistant XDR Salmonella had point mutations at codons 120, 121, and 181 in the tet(A) interdomain loop region. All CIP and TIG co-resistant XDR Salmonella overexpressed ramA gene; 17 (68%) out of them harbored 4-bp deletion in the ramR binding region (T-288/A-285). However, four CIP/TIG co-resistant isolates overexpressed the oqxB gene. In conclusion, the emergence of XDR S. enterica exhibiting CIP/TIG co-resistance in poultry and humans with no previous exposure to TIG warrants an urgent need to reduce the unnecessary antimicrobial use in poultry farms in Egypt.

scholarly journals In VitroSusceptibility of Burkholderia vietnamiensis to Aminoglycosides

2011 ◽  
Vol 55 (5) ◽  
pp. 2256-2264 ◽  
Author(s):  
Agatha N. Jassem ◽  
James E. A. Zlosnik ◽  
Deborah A. Henry ◽  
Robert E. W. Hancock ◽  
Robert K. Ernst ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Efflux Pump ◽  
Severe Disease ◽  
Resistant Isolate ◽  
Aminoglycoside Resistance ◽  
Efflux Pump Inhibitor ◽  
Content Type ◽  
Active Efflux ◽  
Burkholderia Vietnamiensis

ABSTRACTBurkholderia cepaciacomplex (BCC) bacteria are opportunistic pathogens that can cause severe disease in cystic fibrosis (CF) patients and other immunocompromised individuals and are typically multidrug resistant. Here we observed that unlike other BCC species, most environmental and clinicalBurkholderia vietnamiensisisolates were intrinsically susceptible to aminoglycosides but not to cationic antimicrobial peptides or polymyxin B. Furthermore, strains acquired aminoglycoside resistance during chronic CF infection, a phenomenon that could be induced under tobramycin or azithromycin pressurein vitro. In comparing susceptible and resistantB. vietnamiensisisolates, no gross differences in lipopolysaccharide structure were observed, all had lipid A-associated 4-amino-4-deoxy-l-arabinose residues, and all were resistant to the permeabilizing effects of aminoglycosides, a measure of drug entry via self-promoted uptake. However, susceptible isolates accumulated 5 to 6 times more gentamicin than a resistant isolate, and aminoglycoside susceptibility increased in the presence of an efflux pump inhibitor.B. vietnamiensisis therefore unusual among BCC bacteria in its susceptibility to aminoglycosides and capacity to acquire resistance. Aminoglycoside resistance appears to be due to decreased cellular accumulation as a result of active efflux.

Carbapenem-resistance mechanisms of multidrug-resistant Pseudomonas aeruginosa

2013 ◽  
Vol 62 (9) ◽  
pp. 1317-1325 ◽  
Author(s):  
Ester Fusté ◽  
Lídia López-Jiménez ◽  
Concha Segura ◽  
Eusebio Gainza ◽  
Teresa Vinuesa ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Class 1 Integron ◽  
Carbonyl Cyanide ◽  
Class 1

Clonal dissemination of multidrug-resistant Pseudomonas aeruginosa (MDRPA) is a major concern worldwide. The aim of this study was to explore the mechanisms leading to the carbapenem resistance of an MDRPA clone. Isolates were obtained from a surgical wound, sputum, urine and a blood culture. Pulsed-field gel electrophoresis (PFGE) showed high genomic homogeneity of these isolates and confirmed the circulation of an endemic clone belonging to serotype O4. Outer membrane protein (OMP) bands were visualized by SDS-PAGE, meropenem accumulation was measured in a bioassay and integrons were detected by PCR. Efflux pumps were studied for several antimicrobial agents and synergic combinations thereof in the presence or absence of both carbonyl cyanide m-chlorophenylhydrazone (CCCP) and Phe-Arg-β-naphthylamide (PAβN) at final concentrations of 10 and 40 mg l−1, respectively. On OMP electrophoretic profiles, MDRPA showed a reduction of outer membrane porin D (OprD) and PCR demonstrated the presence of a class 1 integron with a cassette encoding aminoglycoside adenyltransferase B (aadB). Meropenem accumulation was slightly higher in bacilli than in the filamentous cells that formed in the presence of antibiotics. Overexpression of the efflux pump MexAB-OprM and a functional MexXY-OprM were detected in all isolates.

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