scholarly journals Contribution of the CmeABC Efflux Pump to Macrolide and Tetracycline Resistance in Campylobacter jejuni

2007 ◽  
Vol 51 (9) ◽  
pp. 3212-3216 ◽  
Author(s):  
Amera Gibreel ◽  
Nicole M. Wetsch ◽  
Diane E. Taylor
Keyword(s):  
Campylobacter Jejuni ◽  
Target Gene ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Tetracycline Resistance ◽  
Macrolide Resistance ◽  
23S Rrna

ABSTRACT We investigated the involvement of the CmeABC efflux pump in acquired resistance of Campylobacter jejuni to macrolides and tetracycline. Inactivation of the cmeB gene had no effect on macrolide resistance when all copies of the target gene carried an A2074C mutation. In contrast, the CmeABC pump significantly contributed to macrolide resistance when two or three copies of the 23S rRNA had an A2075G transition. Inactivation of the cmeB gene led to restoration of tetracycline susceptibility in the isolates examined. Complete susceptibility to tetracycline or macrolides, however, was not restored when phenylalanine-arginine β-naphthylamide was used. These data confirm contribution of the CmeABC efflux pump to acquired resistance of Campylobacter jejuni to tetracycline and macrolides.

scholarly journals Macrolide Resistance in Campylobacter jejuni and Campylobacter coli: Molecular Mechanism and Stability of the Resistance Phenotype

2005 ◽  
Vol 49 (7) ◽  
pp. 2753-2759 ◽  
Author(s):  
Amera Gibreel ◽  
Veronica N. Kos ◽  
Monika Keelan ◽  
Cathy A. Trieber ◽  
Simon Levesque ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Target Gene ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Resistance Level ◽  
Resistance Phenotype ◽  
E Coli ◽  
23S Rrna Gene

ABSTRACT A collection of 23 macrolide-resistant Campylobacter isolates from different geographic areas was investigated to determine the mechanism and stability of macrolide resistance. The isolates were identified as Campylobacter jejuni or Campylobacter coli based on the results of the hippurate biochemical test in addition to five PCR-based genotypic methods. Three point mutations at two positions within the peptidyl transferase region in domain V of the 23S rRNA gene were identified. About 78% of the resistant isolates exhibited an A→G transition at Escherichia coli equivalent base 2059 of the 23S rRNA gene. The isolates possessing this mutation showed a wide range of erythromycin and clarithromycin MICs. Thus, this mutation may incur a greater probability of treatment failure in populations infected by resistant Campylobacter isolates. Another macrolide-associated mutation (A→C transversion), at E. coli equivalent base 2058, was detected in about 13% of the isolates. An A→G transition at a position cognate with E. coli 23S rRNA base 2058, which is homologous to the A2142G mutation commonly described in Helicobacter pylori, was also identified in one of the C. jejuni isolates examined. In the majority of C. jejuni isolates, the mutations in the 23S rRNA gene were homozygous except in two cases where the mutation was found in two of the three copies of the target gene. Natural transformation demonstrated the transfer of the macrolide resistance phenotype from a resistant Campylobacter isolate to a susceptible Campylobacter isolate. Growth rates of the resulting transformants containing A-2058→C or A-2059→G mutations were similar to that of the parental isolate. The erythromycin resistance of six of seven representative isolates was found to be stable after successive subculturing in the absence of erythromycin selection pressure regardless of the resistance level, the position of the mutation, or the number of the mutated copies of the target gene. One C. jejuni isolate showing an A-2058→G mutation, however, reverted to erythromycin and clarithromycin susceptibility after 55 subcultures on erythromycin-free medium. Investigation of ribosomal proteins L4 and L22 by sequence analysis in five representative isolates of C. jejuni and C. coli demonstrated no significant macrolide resistance-associated alterations in either the L4 or the L22 protein that might explain either macrolide resistance or enhancement of the resistance level.

scholarly journals Identification and Transferability of Tetracycline Resistance in Streptococcus thermophilus during Milk Fermentation, Storage, and Gastrointestinal Transit

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 65
Author(s):  
Armin Tarrah ◽  
Shadi Pakroo ◽  
Viviana Corich ◽  
Alessio Giacomini
Keyword(s):  
Efflux Pump ◽  
Acquired Resistance ◽  
Gastrointestinal Transit ◽  
Tetracycline Resistance ◽  
Lactobacillus Delbrueckii ◽  
Genomic Islands ◽  
Resistant Bacteria ◽  
Human Pathogens ◽  
Resistance Level ◽  
Milk Fermentation

The existence of antibiotic-resistant bacteria in food products, particularly those carrying acquired resistance genes, has increased concerns about the transmission of these genes from beneficial microbes to human pathogens. In this study, we evaluated the antibiotic resistance-susceptibility patterns of 16 antibiotics in eight S. thermophilus strains, whose genome sequence is available, using phenotypic and genomic approaches. The minimal inhibitory concentration values collected revealed intermediate resistance to aminoglycosides, whereas susceptibility was detected for different classes of β-lactams, quinolones, glycopeptide, macrolides, and sulfonamides in all strains. A high tetracycline resistance level has been detected in strain M17PTZA496, whose genome analysis indicated the presence of the tet(S) gene and the multidrug and toxic compound extrusion (MATE) family efflux pump. Moreover, an in-depth genomic analysis revealed genomic islands and an integrative and mobilizable element (IME) in the proximity of the gene tet(S). However, despite the presence of a prophage, genomic islands, and IME, no horizontal gene transfer was detected to Lactobacillus delbrueckii subsp. lactis DSM 20355 and Lactobacillusrhamnosus GG during 24 h of skim milk fermentation, 2 weeks of refrigerated storage, and 4 h of simulated gastrointestinal transit.

scholarly journals Mutation in 23S rRNA Associated with Macrolide Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 46 (9) ◽  
pp. 3020-3025 ◽  
Author(s):  
Lai-King Ng ◽  
Irene Martin ◽  
Gary Liu ◽  
Louis Bryden
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Promoter Region ◽  
Efflux Pump ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
E Coli ◽  
Single Base Pair ◽  
Resistant Strains ◽  
Domain V

ABSTRACT Fifty-six azithromycin-resistant (MICs, 2.0 to 4.0 μg/ml) Neisseria gonorrhoeae strains with cross-resistance to erythromycin (MICs, 2.0 to 64.0 μg/ml), isolated in Canada between 1997 and 1999, were characterized, and their mechanisms of azithromycin resistance were determined. Most (58.9%) of them belonged to auxotype-serotype class NR/IB-03, with a 2.6-mDa plasmid. Based on resistance to crystal violet (MICs ≥ 1 μg/ml), 96.4% of these macrolide-resistant strains appeared to have increased efflux. Nine of the eleven strains selected for further characterization were found to have a promoter region mtrR mutation, a single-base-pair (A) deletion in the 13-bp inverted repeat, which is believed to cause overexpression of the mtrCDE-encoded efflux pump. The two remaining macrolide-resistant strains (erythromycin MIC, 64.0 μg/ml; azithromycin MIC, 4.0 μg/ml), which did not have the mutation in the mtrR promoter region, were found to have a C2611T mutation (Escherichia coli numbering) in the peptidyltransferase loop in domain V of the 23S rRNA alleles. Although mutations in domain V of 23S rRNA alleles had been reported in other bacteria, including E. coli, Streptococcus pneumoniae, and Helicobacter pylori, this is the first observation of these mutations associated with macrolide resistance in N. gonorrhoeae.

scholarly journals AtetRA-based promoter system for the generation of conditional knockouts inCampylobacter jejuni

2019 ◽  
Author(s):  
Eli J. Cohen ◽  
Rui Tong Quek ◽  
Morgan Beeby
Keyword(s):  
Gene Expression ◽  
Human Health ◽  
Campylobacter Jejuni ◽  
Target Gene ◽  
Tetracycline Resistance ◽  
Future Research ◽  
Human Pathogen ◽  
Target Gene Expression ◽  
Promoter System ◽  
Genetic Toolkit

AbstractCampylobacter jejuniis responsible for tens of millions of cases of gastroenteritis each year. Despite its prevalence and impact on human health, the repertoire of genetic tools available for researchers to studyC. jejuniremains limited. In order to expand upon the genetic toolkit in this species, we have engineered a system for generating conditional knockouts based on thetetRAtetracycline-resistance cassette. This system exhibits tight repressibility and titratability of target-gene expression and will be useful for future research on this important human pathogen.

scholarly journals Mutational and Transcriptomic Changes Involved in the Development of Macrolide Resistance in Campylobacter jejuni

2012 ◽  
Vol 57 (3) ◽  
pp. 1369-1378 ◽  
Author(s):  
Haihong Hao ◽  
Zonghui Yuan ◽  
Zhangqi Shen ◽  
Jing Han ◽  
Orhan Sahin ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Dna Microarray ◽  
Ribosomal Proteins ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
23S Rrna Gene ◽  
Resistant Mutants ◽  
Antibiotic Efflux

ABSTRACTMacrolide antibiotics are important for clinical treatment of infections caused byCampylobacter jejuni. Development of resistance to this class of antibiotics inCampylobacteris a complex process, and the dynamic molecular changes involved in this process remain poorly defined. Multiple lineages of macrolide-resistant mutants were selected by stepwise exposure ofC. jejunito escalating doses of erythromycin or tylosin. Mutations in target genes were determined by DNA sequencing, and the dynamic changes in the expression of antibiotic efflux transporters and the transcriptome ofC. jejuniwere examined by real-time reverse transcription-PCR, immunoblotting, and DNA microarray analysis. Multiple types of mutations in ribosomal proteins L4 and L22 occurred early during stepwise selection. On the contrary, the mutations in the 23S rRNA gene, mediating high resistance to macrolides, were observed only in the late-stage mutants. Upregulation of antibiotic efflux genes was observed in the intermediately resistant mutants, and the magnitude of upregulation declined with the occurrence of mutations in the 23S rRNA gene. DNA microarray analysis revealed the differential expression of 265 genes, most of which occurred in the intermediate mutant, including the upregulation of genes encoding ribosomal proteins and the downregulation of genes involved in energy metabolism and motility. These results indicate (i) that mutations in L4 and L22 along with temporal overexpression of antibiotic efflux genes precede and may facilitate the development of high-level macrolide resistance and (ii) that the development of macrolide resistance affects the pathways important for physiology and metabolism inC. jejuni, providing an explanation for the reduced fitness of macrolide-resistantCampylobacter.

scholarly journals Detection and Quantification of Macrolide Resistance Mutations at Positions 2058 and 2059 of the 23S rRNA Gene by Pyrosequencing

2005 ◽  
Vol 49 (1) ◽  
pp. 457-460 ◽  
Author(s):  
Marjo Haanperä ◽  
Pentti Huovinen ◽  
Jari Jalava
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Streptococcus Pyogenes ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Resistance Mutations ◽  
23S Rrna Gene ◽  
Pyrosequencing Method ◽  
Detection And Quantification

ABSTRACT A pyrosequencing method for detection and quantification of macrolide resistance mutations at positions 2058 and 2059 (Escherichia coli numbering) of the 23S rRNA gene is described. The method was developed and tested for Streptococcus pneumoniae, Streptococcus pyogenes, Mycobacterium avium, Campylobacter jejuni, and Haemophilus influenzae.

scholarly journals Synergy between Efflux Pump CmeABC and Modifications in Ribosomal Proteins L4 and L22 in Conferring Macrolide Resistance in Campylobacter jejuni and Campylobacter coli

2006 ◽  
Vol 50 (11) ◽  
pp. 3893-3896 ◽  
Author(s):  
Cédric Cagliero ◽  
Christian Mouline ◽  
Axel Cloeckaert ◽  
Sophie Payot
Keyword(s):  
Campylobacter Jejuni ◽  
Ribosomal Proteins ◽  
Efflux Pump ◽  
Macrolide Resistance ◽  
Campylobacter Coli ◽  
Resistant Mutants

ABSTRACT Macrolide-resistant mutants of Campylobacter jejuni and Campylobacter coli were selected in vitro using erythromycin and tylosin. These mutants exhibited modifications in the ribosomal proteins L4 (G74D) and L22 (insertions at position 86 or 98). A synergy between the CmeABC efflux pump and these modifications in conferring macrolide resistance was observed.

scholarly journals Impaired Fitness and Transmission of Macrolide-Resistant Campylobacter jejuni in Its Natural Host

2011 ◽  
Vol 56 (3) ◽  
pp. 1300-1308 ◽  
Author(s):  
Taradon Luangtongkum ◽  
Zhangqi Shen ◽  
Virginia W. Seng ◽  
Orhan Sahin ◽  
Byeonghwa Jeon ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Natural Host ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Pathogenic Organism ◽  
Content Type ◽  
Zoonotic Pathogen ◽  
Natural Reservoir ◽  
Antibiotic Selection Pressure ◽  
Human Campylobacteriosis

ABSTRACTCampylobacter jejuniis a major zoonotic pathogen transmitted to humans via the food chain and is prevalent in chickens, a natural reservoir for this pathogenic organism. Due to the importance of macrolide antibiotics in clinical therapy of human campylobacteriosis, development of macrolide resistance inCampylobacterhas become a concern for public health. To facilitate the control of macrolide-resistantCampylobacter, it is necessary to understand if macrolide resistance affects the fitness and transmission ofCampylobacterin its natural host. In this study we conducted pairwise competitions and comingling experiments in chickens using clonally related and isogenicC. jejunistrains, which are either susceptible or resistant to erythromycin (Ery). In every competition pair, Ery-resistant (Eryr)Campylobacterwas consistently outcompeted by the Ery-susceptible (Erys) strain. In the comingling experiments, EryrCampylobacterfailed to transmit to chickens precolonized by ErysCampylobacter, while isogenic ErysCampylobacterwas able to transmit to and establish dominance in chickens precolonized by EryrCampylobacter. The fitness disadvantage was linked to the resistance-conferring mutations in the 23S rRNA. These findings clearly indicate that acquisition of macrolide resistance impairs the fitness and transmission ofCampylobacterin chickens, suggesting that the prevalence of macrolide-resistantC. jejuniwill likely decrease in the absence of antibiotic selection pressure.

scholarly journals Development, Stability, and Molecular Mechanisms of Macrolide Resistance in Campylobacter jejuni

2008 ◽  
Vol 52 (11) ◽  
pp. 3947-3954 ◽  
Author(s):  
Dave Bryson Caldwell ◽  
Ying Wang ◽  
Jun Lin
Keyword(s):  
Ribosomal Protein ◽  
Campylobacter Jejuni ◽  
Molecular Mechanisms ◽  
Prolonged Exposure ◽  
Efflux Pump ◽  
Macrolide Resistance ◽  
Low Level ◽  
Development Stability

ABSTRACT Previous studies of macrolide resistance in Campylobacter were primarily focused on strains from various origins or used in vitro systems. In this study, we conducted both in vitro and in vivo experiments to examine the development, stability, and genetic basis of macrolide resistance in Campylobacter jejuni using erythromycin-resistant (Eryr) mutants derived from the same parent strain. Chickens inoculated with low-level Eryr mutants (MIC = 32 or 64 μg/ml) at 15 days old did not shed highly Eryr mutants (MIC > 512 μg/ml) after prolonged exposure to a low dose of tylosin. The low-level Ery resistance was not stable in vitro or in vivo in the absence of macrolide selection pressure. However, high-level Ery resistance displayed remarkable stability in vitro and in vivo. Ribosomal sequence analysis of 69 selected Eryr mutants showed that specific point mutations (A2074G or A2074C) occurred in all highly Eryr mutants. No mutations in ribosomal protein L4 were observed in any of the in vitro-selected Eryr mutants. However, three specific mutations in L4, G74D, G57D, and G57V, were widely found among in vivo-selected Eryr mutants. Insertion of three amino acids, TSH, at position 98 in ribosomal protein L22 was observed only in mutants selected in vitro. Inactivation of the CmeABC efflux pump dramatically reduced Ery MICs in Eryr mutants. Together, these findings suggest that multiple factors contribute to the emergence of highly Eryr Campylobacter in chicken, reveal resistance level-dependent stability of macrolide resistance in C. jejuni, and indicate that C. jejuni utilizes complex and different mechanisms to develop Ery resistance in vitro and in vivo.

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.

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