Frequency of four classes of tetracycline resistance determinants in Salmonella and Shigella spp. clinical isolates.

A total of 399 Neisseria gonorrhoeae clinical isolates collected in different regions of the Russian Federation in 20152017 were analyzed for tetracycline susceptibility and genetic markers of resistance. Drug susceptibility testing was performed by serial dilution method in agar and minimum inhibitory concentration (MIC) was measured according to the Russian “Guidelines for microbial susceptibility testing for antibacterial agents No. 4.2.1890-04”. Tetracycline resistance determinants were studied by using hydrogel microarray with immobilized oligonucleotide probes able to identify a series of chromosomal mutations and detect plasmid tetM gene. Different resistance determinants were found in 193 isolates (48.4%). Mutation in codon 57 in the rpsJ gene (41.2%) was most common that decreases tetracycline affinity to ribosome 30S subunit, mainly due to Val57Met substitution both as a point mutation as well as in combination with others. Mutations in the rpsJ gene were found in strains with the intermediate tetracycline susceptibility. Mutations in the porB gene (lower tetracycline influx) held the se cond place in prevalence pattern (23.1%); the Gly120Lys substitution usually led to emergence of tetracycline resistance either as a point mutation or in combination with other substitutions. Substitutions of Gly120 for other residues (Asp, Asn, and Thr) and Ala121 for Asp, Asn, and Gly had much less effect on resistance level. The –35 delA deletion in the promoter region of mtrR gene (increased expression of MtrC-MtrD-MtrE efflux pump) was observed in 11.3% strains. The tetM gene was found in 27 strains including 17 American and 10 Dutch type tetM determinants. Evolutionary tree was constructed for the tetM genes with the estimation of their homology with similar genes in genera Streptococcus, Enterococcus and Mycoplasma. Mutations in chromosomal genes resulted in increase of tetracycline MIC up to 2–4 mg/L; 4 mg/L MIC was observed in case of simultaneous presence of several mutations. Strains bearing tetM gene-containing plasmid showed extremely high resistance level: MIC ≥ 8 mg/L (64 mg/L for the two samples). Thus, long-lasting withdrawal of tetracycline use for treatment of gonococcal infections in Russia (since 2003) resulted in decreased percentage of resistant strains (including strains with intermediate susceptibility) from 75% down to 45.4%. However, currently tetracycline resistance in Russia remains elevated that is explained by the presence of different resistance determinants in the half of isolates under study.

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Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages

Microorganisms ◽

10.3390/microorganisms8081240 ◽

2020 ◽

Vol 8 (8) ◽

pp. 1240

Author(s):

Sangjukta Roy ◽

Meiji Soe Aung ◽

Shyamal Kumar Paul ◽

Salma Ahmed ◽

Nazia Haque ◽

...

Keyword(s):

Drug Resistance ◽

Resistance Gene ◽

Enterococcus Faecalis ◽

Acquired Resistance ◽

Tetracycline Resistance ◽

Clinical Isolates ◽

Multiple Drug ◽

Resistance Level ◽

Resistance Determinants ◽

High Level

Enterococcus faecalis is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for E. faecalis clinical isolates in north-central Bangladesh. Among a total of 210 E. faecalis isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.2, 45.7, and 11.4%, respectively, while no isolates were resistant to ampicillin, vancomycin and teicoplanin. The most prevalent resistance gene was erm(B) (97%), and any of the four genes encoding aminoglycoside modifying enzyme (AME) were detected in 99 isolates (47%). The AME gene aac(6′)-Ie-aph(2”)-Ia was detected in 46 isolates (21.9%) and was diverse in terms of IS256-flanking patterns, which were associated with resistance level to gentamicin. Tetracycline resistance was ascribable to tet(M) (61%) and tet(L) (38%), and mutations in the quinolone resistance-determining region of both GyrA and ParC were identified in 44% of isolates. Five isolates (2.4%) exhibited non-susceptibility to linezolide (MIC, 4 μg/mL), and harbored the oxazolidinone resistance gene optrA, which was located in a novel genetic cluster containing the phenicol exporter gene fexA. The optrA-positive isolates belonged to ST59, ST902, and ST917 (CC59), while common lineages of other multiple drug-resistant isolates were ST6, ST28, CC16, and CC116. The present study first revealed the prevalence of drug resistance determinants of E. faecalis and their genetic profiles in Bangladesh.

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Epidemiology of Tetracycline Resistance Determinants in Shigella spp. and Enteroinvasive Escherichia coli: Characterization and Dissemination of tet(A)-1

Journal of Clinical Microbiology ◽

10.1128/jcm.41.3.1023-1032.2003 ◽

2003 ◽

Vol 41 (3) ◽

pp. 1023-1032 ◽

Cited By ~ 29

Author(s):

A. B. Hartman ◽

I. I. Essiet ◽

D. W. Isenbarger ◽

L. E. Lindler

Keyword(s):

Escherichia Coli ◽

Tetracycline Resistance ◽

Resistance Determinants ◽

Shigella Spp

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ErmB Determinants and Tn916-Like Elements in Clinical Isolates of Clostridium difficile

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.6.2550-2553.2005 ◽

2005 ◽

Vol 49 (6) ◽

pp. 2550-2553 ◽

Cited By ~ 34

Author(s):

Patrizia Spigaglia ◽

Valentina Carucci ◽

Fabrizio Barbanti ◽

Paola Mastrantonio

Keyword(s):

Clostridium Difficile ◽

Tetracycline Resistance ◽

Clinical Isolates ◽

Resistance Determinants

ABSTRACT Erythromycin and tetracycline resistance was analyzed in 37 Clostridium difficile clinical isolates. Strains of different clonal origins showed different erythromycin and tetracycline resistance determinants and different genetic arrangements of the elements. In strains of recent isolation, the presence of Tn916-like elements, never found before in C. difficile clinical isolates, has been demonstrated.

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Tetracycline Resistance and Presence of Tetracycline Resistance Determinants tet(V) and tap in Rapidly Growing Mycobacteria from Agricultural Soils and Clinical Isolates

Microbes and Environments ◽

10.1264/jsme2.me12028 ◽

2012 ◽

Vol 27 (4) ◽

pp. 413-422 ◽

Cited By ~ 12

Author(s):

Martina Kyselkov^|^aacute; ◽

Alica Chroň^|^aacute;kov^|^aacute; ◽

Lucie Voln^|^aacute; ◽

Jan Nĕmec ◽

V^|^iacute;t Ulmann ◽

...

Keyword(s):

Agricultural Soils ◽

Tetracycline Resistance ◽

Clinical Isolates ◽

Rapidly Growing Mycobacteria ◽

Resistance Determinants

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Active efflux of tetracycline encoded by four genetically different tetracycline resistance determinants in Escherichia coli.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.77.7.3974 ◽

1980 ◽

Vol 77 (7) ◽

pp. 3974-3977 ◽

Cited By ~ 299

Author(s):

L. McMurry ◽

R. E. Petrucci ◽

S. B. Levy

Keyword(s):

Escherichia Coli ◽

Tetracycline Resistance ◽

Active Efflux ◽

Resistance Determinants

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Interrelationship between tetracycline resistance determinants, phylogenetic group affiliation and carriage of class 1 integrons in commensal Escherichia coli isolates from cattle farms

BMC Veterinary Research ◽

10.1186/s12917-018-1661-3 ◽

2018 ◽

Vol 14 (1) ◽

Cited By ~ 5

Author(s):

Kuastros Mekonnen Belaynehe ◽

Seung Won Shin ◽

Han Sang Yoo

Keyword(s):

Escherichia Coli ◽

Tetracycline Resistance ◽

Phylogenetic Group ◽

Group Affiliation ◽

Class 1 Integrons ◽

Resistance Determinants ◽

Class 1 ◽

Cattle Farms

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In Vitro and In Vivo Antibacterial Activities of a Novel Glycylcycline, the 9-t-Butylglycylamido Derivative of Minocycline (GAR-936)

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.4.738 ◽

1999 ◽

Vol 43 (4) ◽

pp. 738-744 ◽

Cited By ~ 283

Author(s):

P. J. Petersen ◽

N. V. Jacobus ◽

W. J. Weiss ◽

P. E. Sum ◽

R. T. Testa

Keyword(s):

Anaerobic Bacteria ◽

Tetracycline Resistance ◽

Protective Effects ◽

Gram Negative ◽

E Coli ◽

Resistance Determinants ◽

Aerobic And Anaerobic ◽

Ribosomal Protection

ABSTRACT The 9-t-butylglycylamido derivative of minocycline (TBG-MINO) is a recently synthesized member of a novel group of antibiotics, the glycylcyclines. This new derivative, like the first glycylcyclines, theN,N-dimethylglycylamido derivative of minocycline and 6-demethyl-6-deoxytetracycline, possesses activity against bacterial isolates containing the two major determinants responsible for tetracycline resistance: ribosomal protection and active efflux. The in vitro activities of TBG-MINO and the comparative agents were evaluated against strains with characterized tetracycline resistance as well as a spectrum of recent clinical aerobic and anaerobic gram-positive and gram-negative bacteria. TBG-MINO, with an MIC range of 0.25 to 0.5 μg/ml, showed good activity against strains expressing tet(M) (ribosomal protection), tet(A), tet(B),tet(C), tet(D), and tet(K) (efflux resistance determinants). TBG-MINO exhibited similar activity against methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant streptococci, and vancomycin-resistant enterococci (MICs at which 90% of strains are inhibited, ≤0.5 μg/ml). TBG-MINO exhibited activity against a wide diversity of gram-negative aerobic and anaerobic bacteria, most of which were less susceptible to tetracycline and minocycline. The in vivo protective effects of TBG-MINO were examined against acute lethal infections in mice caused by Escherichia coli, S. aureus, andStreptococcus pneumoniae isolates. TBG-MINO, administered intravenously, demonstrated efficacy against infections caused byS. aureus including MRSA strains and strains containingtet(K) or tet(M) resistance determinants (median effective doses [ED50s], 0.79 to 2.3 mg/kg of body weight). TBG-MINO demonstrated efficacy against infections caused by tetracycline-sensitive E. coli strains as well asE. coli strains containing either tet(M) or the efflux determinant tet(A), tet(B), ortet(C) (ED50s, 1.5 to 3.5 mg/kg). Overall, TBG-MINO shows antibacterial activity against a wide spectrum of gram-positive and gram-negative aerobic and anaerobic bacteria including strains resistant to other chemotherapeutic agents. The in vivo protective effects, especially against infections caused by resistant bacteria, corresponded with the in vitro activity of TBG-MINO.

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Detection of erythromycin-resistant determinants by PCR.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.11.2562 ◽

1996 ◽

Vol 40 (11) ◽

pp. 2562-2566 ◽

Cited By ~ 632

Author(s):

J Sutcliffe ◽

T Grebe ◽

A Tait-Kamradt ◽

L Wondrack

Keyword(s):

Direct Sequencing ◽

Pcr Primers ◽

Efflux Pumps ◽

Clinical Isolates ◽

Gene Products ◽

Mechanisms Of Resistance ◽

Erythromycin Resistance ◽

Surveillance Studies ◽

Resistance Determinants ◽

Pcr Products

Erythromycin resistance determinants include Erm methylases, efflux pumps, and inactivating enzymes. To distinguish the different mechanisms of resistance in clinical isolates, PCR primers were designed so that amplification of the partial gene products could be detected in multiplex PCRs. This methodology enables the direct sequencing of amplified PCR products that can be used to compare resistance determinants in clinical strains. Further, this methodology could be useful in surveillance studies of erythromycin-resistant determinants.

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