scholarly journals Significant contribution of the CmeABC Efflux pump in high-level resistance to ciprofloxacin and tetracycline in Campylobacter jejuni and Campylobacter coli clinical isolates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Saeed Sharifi ◽  
Bita Bakhshi ◽  
Shahin Najar-peerayeh
Keyword(s):  
Gene Expression ◽  
Point Mutation ◽  
Campylobacter Jejuni ◽  
Significant Contribution ◽  
Efflux Pump ◽  
Campylobacter Coli ◽  
Rapd Pcr ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance

Abstract Background Campylobacter resistance to antimicrobial agents is regarded as a major concern worldwide. The aim of this study was to investigate the expression of the CmeABC efflux pump and the RAPD-PCR pattern in drug-resistant Campylobacter isolates. Methods A total of 283 stool specimens were collected from children under the age of five with diarrhea. The minimum inhibitory concentration (MIC) of tetracycline and ciprofloxacin was determined by broth microdilution method and E-test, respectively. Detection of tetracycline and ciprofloxacin determinants was done by amplification of tetO gene and PCR-sequencing of the gyrA gene. The cmeABC transcriptional expression was analyzed by Real-time (RT)-PCR. Clonal correlation of resistant strains was determined by RAPD-PCR genotyping. Results Out of 283 fecal samples, 20 (7.02%) samples were positive for Campylobacter spp. Analysis of duplex PCR assay of the cadF gene showed that 737 and 461 bp amplicons were corresponding to Campylobacter jejuni and Campylobacter coli, respectively. All of the 17 phenotypically tetracycline-resistant Campylobacter isolates harbored the tetO gene. Also, four phenotypically ciprofloxacin-resistant Campylobacter isolates had a point mutation at codon 257 of the gyrA gene (ACA to ATA; Thr > Ile). High-level expression of the cmeA gene was observed in ciprofloxacin-resistant and high-level tetracycline-resistant Campylobacter isolates, suggesting a positive correlation between the cmeA gene expression level and tetracycline resistance level. Moreover, a statistically significant difference was observed in the cmeA gene expression between ciprofloxacin-resistant and ciprofloxacin-susceptible strains, which signifies the crucial contribution of the efflux pump in conferring multiple drug resistance phenotype among Campylobacter spp. RAPD analysis of Campylobacter isolates exhibited 16 different patterns. Simpsone`s diversity index of RAPD-PCR was calculated as 0.85, showing a high level of homogeneity among the population; however, no clear correlation was detected among tetracycline and/or ciprofloxacin resistant isolates. Conclusion Significant contribution of the CmeABC efflux pump in conferring high-level resistance to tetracycline and ciprofloxacin was observed in C. jejuni and C. coli clinical isolates. The resistant phenotype is suggested to be mediated by CmeABC efflux pumps, the tetO gene, and point mutation of the gyrA gene. Genotyping revealed no clonal correlation among resistant strains, indicating distinct evolution of tetracycline and ciprofloxacin resistant genotypes among the isolates.

scholarly journals Campylobacter jejuni and Campylobacter coli originated from chicken carcasses modulate their transcriptome to translate virulence genes in human cells

2019 ◽  
Vol 39 (8) ◽  
pp. 592-599
Author(s):  
Roberta T. Melo ◽  
Eliane P. Mendonça ◽  
Edson C. Valadares Júnior ◽  
Guilherme P. Monteiro ◽  
Phelipe A.B.M. Peres ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Gene Transcription ◽  
Virulence Genes ◽  
Human Cells ◽  
Campylobacter Coli ◽  
Rt Pcr ◽  
Rapd Pcr ◽  
Pcr Multiplex ◽  
Before And After ◽  
High Level

ABSTRACT: The aim was to determine the spread of genetically similar profiles of Campylobacter in chicken carcasses and evaluate their ability to produce transcripts for ciaB, dnaJ, p19 and sodB genes, before and after cultivation in Caco-2 cells. The strains used were isolated from 420 samples of chicken carcasses chilled and frozen ready for marketing. The species were identified by PCR-multiplex, the phylogeny was determined by RAPD-PCR and the presence of transcripts was performed by RT-PCR. We identified 74 (17.6%) of Campylobacter strains, being 55 (74.3%) C. jejuni and 19 (25.7%) C. coli. The phylogenetic relationship demonstrated heterogeneity between isolates of the same species, with absence of clones, indicating the high level of diversity of circulating genotypes. The gene transcription showed conflicting results before and after the culture in Caco-2 cell, so that before cultivation isolates showed greater capacity to transcribe genes related to survival and after the interaction with human cells, the strains showed higher potential to transcribe genes associated with virulence. The result of this study contributes to the understanding of how these seemingly fragile microorganisms are the most prevalent bacterial agents in human gastroenteritis.

Role of the plasmid-encoded tet(O) gene in tetracycline-resistant clinical isolates of Campylobacter jejuni and Campylobacter coli

2007 ◽  
Vol 56 (6) ◽  
pp. 833-837 ◽  
Author(s):  
Javid Iqbal Dasti ◽  
Uwe Groß ◽  
Sven Pohl ◽  
Raimond Lugert ◽  
Michael Weig ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Campylobacter Jejuni ◽  
Acute Gastroenteritis ◽  
Tetracycline Resistance ◽  
Gene Localization ◽  
Campylobacter Coli ◽  
Low Level ◽  
High Level ◽  
Level Resistance

The prevalence of tetracycline resistance, tetracycline MICs and tet(O) gene localization were investigated in 83 Campylobacter isolates from patients suffering from acute gastroenteritis in Germany. Combined biochemical and molecular markers identified 74 isolates (89 %) as Campylobacter jejuni, including seven atypical isolates that failed to hydrolyse hippurate, and nine isolates (11 %) as Campylobacter coli. Tetracycline resistance was detected in six out of nine Campylobacter coli isolates (67 %) and 13 out of 74 C. jejuni isolates (18 %). Low-level tetracycline resistance was observed for C. coli (MIC 16 μg ml−1 for all strains), whereas C. jejuni showed high-level resistance (MIC >256 μg ml−1 for all strains). Both low- and high-level tetracycline resistance was associated with the presence of the tet(O) gene. In C. jejuni, tet(O) was plasmid-encoded in 54 % of tetracycline-resistant isolates, whereas in C. coli, tet(O) appeared to be located on the chromosome.

scholarly journals Activity of a New Cephalosporin, CXA-101 (FR264205), against β-Lactam-Resistant Pseudomonas aeruginosa Mutants Selected In Vitro and after Antipseudomonal Treatment of Intensive Care Unit Patients

2010 ◽  
Vol 54 (3) ◽  
pp. 1213-1217 ◽  
Author(s):  
Bartolome Moya ◽  
Laura Zamorano ◽  
Carlos Juan ◽  
José L. Pérez ◽  
Yigong Ge ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Pseudomonas Aeruginosa ◽  
Intensive Care ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Icu Patients ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance

ABSTRACT CXA-101, previously designated FR264205, is a new antipseudomonal cephalosporin. We evaluated the activity of CXA-101 against a highly challenging collection of β-lactam-resistant Pseudomonas aeruginosa mutants selected in vitro and after antipseudomonal treatment of intensive care unit (ICU) patients. The in vitro mutants investigated included strains with multiple combinations of mutations leading to several degrees of AmpC overexpression (ampD, ampDh2, ampDh3, and dacB [PBP4]) and porin loss (oprD). CXA-101 remained active against even the AmpD-PBP4 double mutant (MIC = 2 μg/ml), which shows extremely high levels of AmpC expression. Indeed, this mutant showed high-level resistance to all tested β-lactams, except carbapenems, including piperacillin-tazobactam (PTZ), aztreonam (ATM), ceftazidime (CAZ), and cefepime (FEP), a cephalosporin considered to be relatively stable against hydrolysis by AmpC. Moreover, CXA-101 was the only β-lactam tested (including the carbapenems imipenem [IMP] and meropenem [MER]) that remained fully active against the OprD-AmpD and OprD-PBP4 double mutants (MIC = 0.5 μg/ml). Additionally, we tested a collection of 50 sequential isolates that were susceptible or resistant to penicillicins, cephalosporins, carbapenems, or fluoroquinolones that emerged during treatment of ICU patients. All of the mutants resistant to CAZ, FEP, PTZ, IMP, MER, or ciprofloxacin showed relatively low CXA-101 MICs (range, 0.12 to 4 μg/ml; mean, 1 to 2 μg/ml). CXA-101 MICs of pan-β-lactam-resistant strains ranged from 1 to 4 μg/ml (mean, 2.5 μg/ml). As described for the in vitro mutants, CXA-101 retained activity against the natural AmpD-PBP4 double mutants, even when these exhibited additional overexpression of the MexAB-OprM efflux pump. Therefore, clinical trials are needed to evaluate the usefulness of CXA-101 for the treatment of P. aeruginosa nosocomial infections, particularly those caused by multidrug-resistant isolates that emerge during antipseudomonal treatments.

Prevalence, Antibiograms, and Transferable tet(O) Plasmid of Campylobacter jejuni and Campylobacter coli Isolated from Raw Chicken, Pork, and Human Clinical Cases in Korea

2010 ◽  
Vol 73 (8) ◽  
pp. 1430-1437 ◽  
Author(s):  
JUN MAN KIM ◽  
JOONBAE HONG ◽  
WONKI BAE ◽  
HYE CHEONG KOO ◽  
SO HYUN KIM ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Campylobacter Jejuni ◽  
Susceptibility Testing ◽  
Campylobacter Coli ◽  
High Prevalence ◽  
Resistance Patterns ◽  
High Level ◽  
Antibiotic Resistance Patterns ◽  
Pork Samples ◽  
Level Resistance

The antibiotic resistance patterns and prevalence of the transferable tet(O) plasmid were investigated in Campylobacter jejuni and Campylobacter coli isolates from raw chicken, pork, and humans with clinical campylobacteriosis. A total of 180 C. jejuni and C. coli isolates were identified, and the prevalence rates of C. jejuni and C. coli in raw chicken samples were 83% (83 of 100) and 73% (73 of 100), respectively. Twelve percent (6 of 50) and 10% (5 of 50) of pork samples were contaminated with C. jejuni and C. coli, respectively. Disk diffusion susceptibility testing revealed that the most frequently detected resistance was to tetracycline (92.2%), followed by nalidixic acid (75.6%), ciprofloxacin (65.0%), azithromycin (41.5%), ampicillin (33.3%), and streptomycin (26.1%). Of the C. jejuni and C. coli isolates, 65.7% (n = 109) contained plasmids carrying the tet(O) gene. Six C. jejuni isolates and two C. coli isolates with high-level resistance to tetracycline (MIC = 256 μg/ml) harbored the tet(O) plasmid, which is transferable to other C. jejuni and C. coli isolates. These results demonstrate the presence of an interspecies transferable plasmid containing the tet(O) gene and a high prevalence of antibiotic resistance in Korean Campylobacter isolates and provide an understanding of the antibiotic resistance distribution among Campylobacter species in Korea.

scholarly journals Molecular pathways to high-level azithromycin resistance in Neisseria gonorrhoeae

2021 ◽  
Author(s):  
J G E Laumen ◽  
S S Manoharan-Basil ◽  
E Verhoeven ◽  
S Abdellati ◽  
I De Baetselier ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Ribosomal Proteins ◽  
Efflux Pump ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene ◽  
Evolution Of Resistance ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance

Abstract Background The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide. Objectives To characterize the genetic pathways leading to high-level azithromycin resistance. Methods A customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. We tracked stepwise evolution of resistance by whole genome sequencing. Results Within 26 days, all cultures evolved high-level azithromycin resistance. Typically, the first step towards resistance was found in transitory mutations in genes rplD, rplV and rpmH (encoding the ribosomal proteins L4, L22 and L34 respectively), followed by mutations in the MtrCDE-encoded efflux pump and the 23S rRNA gene. Low- to high-level resistance was associated with mutations in the ribosomal proteins and MtrCDE efflux pump. However, high-level resistance was consistently associated with mutations in the 23S ribosomal RNA, mainly the well-known A2059G and C2611T mutations, but also at position A2058G. Conclusions This study enabled us to track previously reported mutations and identify novel mutations in ribosomal proteins (L4, L22 and L34) that may play a role in the genesis of azithromycin resistance in N. gonorrhoeae.

scholarly journals Overexpression of the MtrC-MtrD-MtrE Efflux Pump Due to an mtrR Mutation Is Required for Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 184 (20) ◽  
pp. 5619-5624 ◽  
Author(s):  
Wendy L. Veal ◽  
Robert A. Nicholas ◽  
William M. Shafer
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Base Pair ◽  
Efflux Pump ◽  
Penicillin Resistance ◽  
Single Base ◽  
Base Pair Deletion ◽  
Resistance To Penicillin ◽  
Single Base Pair ◽  
High Level ◽  
Level Resistance

ABSTRACT The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) expressing high-level resistance to penicillin and antimicrobial hydrophobic agents (HAs). When introduced into strain FA19 by transformation, a single base pair deletion in the mtrR promoter sequence from strain FA6140 was sufficient to provide high-level resistance to HAs (e.g., erythromycin and Triton X-100) but only a twofold increase in resistance to penicillin. When subsequent mutations in penA and porIB were introduced from strain FA6140 into strain WV30 (FA19 mtrR) by transformation, resistance to penicillin increased incrementally up to a MIC of 1.0 μg/ml. Insertional inactivation of the gene (mtrD) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. Genetic analyses revealed that mtrR mutations, such as the single base pair deletion in its promoter, are needed for phenotypic expression of penicillin and tetracycline resistance afforded by the penB mutation. As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics.

Evaluation of efflux pump gene expression among drug susceptible and drug resistant strains of Mycobacterium tuberculosis from Iran

2015 ◽  
Vol 36 ◽  
pp. 23-26 ◽  
Author(s):  
Jalil Kardan Yamchi ◽  
Mehri Haeili ◽  
Seifu Gizaw Feyisa ◽  
Hossein Kazemian ◽  
Abdolrazagh Hashemi Shahraki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Efflux Pump ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

scholarly journals Efflux-Related Resistance to Norfloxacin, Dyes, and Biocides in Bloodstream Isolates of Staphylococcus aureus

2007 ◽  
Vol 51 (9) ◽  
pp. 3235-3239 ◽  
Author(s):  
Carmen E. DeMarco ◽  
Laurel A. Cushing ◽  
Emmanuel Frempong-Manso ◽  
Susan M. Seo ◽  
Tinevimbo A. A. Jaravaza ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Efflux Pump Inhibitor ◽  
Qrt Pcr ◽  
Reverse Transcription Pcr ◽  
Environmental Surfaces ◽  
Genes Encoding ◽  
High Level

ABSTRACT Efflux is an important resistance mechanism in Staphylococcus aureus, but its frequency in patients with bacteremia is unknown. Nonreplicate bloodstream isolates were collected over an 8-month period, and MICs of four common efflux pump substrates, with and without the broad-spectrum efflux pump inhibitor reserpine, were determined (n = 232). A reserpine-associated fourfold decrease in MIC was considered indicative of efflux. Strains exhibiting efflux of at least two of the four substrates were identified (“effluxing strains” [n = 114]). For these strains, MICs with or without reserpine for an array of typical substrates and the expression of mepA, mdeA, norA, norB, norC, and qacA/B were determined using quantitative real-time reverse transcription-PCR (qRT-PCR). A fourfold or greater increase in gene expression was considered significant. The most commonly effluxed substrates were ethidium bromide and chlorhexidine (100 and 96% of effluxing strains, respectively). qRT-PCR identified strains overexpressing mepA (5 [4.4%]), mdeA (13 [11.4%]), norA (26 [22.8%]), norB (29 [25.4%]), and norC (19 [16.7%]); 23 strains overexpressed two or more genes. Mutations probably associated with increased gene expression included a MepR-inactivating substitution and norA promoter region insertions or deletions. Mutations possibly associated with increased expression of the other analyzed genes were also observed. Effluxing strains comprised 49% of all strains studied (114/232 strains), with nearly half of these overexpressing genes encoding MepA, MdeA, and/or NorABC (54/114 strains). Reduced susceptibility to biocides may contribute to persistence on environmental surfaces, and efflux of drugs such as fluoroquinolones may predispose strains to high-level target-based resistance.

scholarly journals Natural Transformation-Mediated Transfer of Erythromycin Resistance in Campylobacter coli Strains from Turkeys and Swine

2006 ◽  
Vol 72 (2) ◽  
pp. 1316-1321 ◽  
Author(s):  
Joo-Sung Kim ◽  
Donna K. Carver ◽  
Sophia Kathariou
Keyword(s):  
Point Mutation ◽  
Natural Transformation ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Erythromycin Resistance ◽  
23S Rrna Gene ◽  
High Level ◽  
Human Infections ◽  
Spontaneous Mutants

ABSTRACT Erythromycin resistance in Campylobacter coli from meat animals is frequently encountered and could represent a substantial barrier to antibiotic treatment of human infections. Erythromycin resistance in this organism has been associated with a point mutation (A2075G) in the 23S rRNA gene. However, the mechanisms responsible for possible dissemination of erythromycin resistance in C. coli remain poorly understood. In this study, we investigated transformation-mediated acquisition of erythromycin resistance by genotypically diverse C. coli strains from turkeys and swine, with total genomic DNA from erythromycin-resistant C. coli of either turkey or swine origin used as a donor. Overall, transformation to erythromycin resistance was significantly more frequent in C. coli strains from turkeys than in swine-derived strains (P < 0.01). The frequency of transformation to erythromycin resistance was 10−5 to 10−6 for turkey-derived strains but 10−7 or less for C. coli from swine. Transformants harbored the point mutation A2075G in the 23S rRNA gene, as did the erythromycin-resistant strains used as DNA donors. Erythromycin resistance was stable in transformants following serial transfers in the absence of the antibiotic, and most transformants had high MICs (>256 μg/ml), as did the C. coli donor strains. In contrast to the results obtained with transformation, spontaneous mutants had relatively low erythromycin MICs (32 to 64 μg/ml) and lacked the A2075G mutation in the 23S rRNA gene. These findings suggest that natural transformation has the potential to contribute to the dissemination of high-level resistance to erythromycin among C. coli strains colonizing meat animals.

Rapid Emergence of High-Level Resistance to Quinolones in Campylobacter jejuni Associated with Mutational Changes in gyrA and parC

1998 ◽  
Vol 42 (12) ◽  
pp. 3276-3278 ◽  
Author(s):  
Amera Gibreel ◽  
Eva Sjögren ◽  
Bertil Kaijser ◽  
Bengt Wretlind ◽  
Ola Sköld
Keyword(s):  
Campylobacter Jejuni ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
High Level ◽  
Chromosomal Mutations ◽  
Rapid Emergence ◽  
Level Resistance

ABSTRACT Quinolone resistance in clinical isolates of Campylobacter jejuni in Sweden increased more than 20-fold at the beginning of the 1990s. Resistance to 125 μg of ciprofloxacin per ml in clinical isolates was associated with chromosomal mutations in C. jejuni leading to a Thr-86-Ile substitution in thegyrA product and a Arg-139-Gln substitution in theparC product.

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