Composite Structure of
 Streptococcus pneumoniae
 Containing the Erythromycin Efflux Resistance Gene
 mef
 (I) and the Chloramphenicol Resistance Gene
 catQ

Mingoia, Marina; Vecchi, Manuela; Cochetti, Ileana; Tili, Emily; Vitali, Luca A.; Manzin, Aldo; Varaldo, Pietro E.; Montanari, Maria Pia

doi:10.1128/aac.00790-07

Cited by 42 publications

(43 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In conjugation experiments, MB56Spyo029 carrying the 5216IQ-like complex appeared unable to transfer the genetic determinants of resistance to a recipient S. pyogenes strain, in line with the nontransferability of the 5216IQ complex carried by S. pneumoniae (17).…”

Section: Resultsmentioning

confidence: 99%

“…This result is in accordance with the previously reported ob- (iii) Defective IQ element. Five S. pyogenes isolates carried mef(I) and catQ, which in S. pneumoniae are found associated in the IQ element, a component of the 5216IQ complex that also includes tet(M) (17).…”

Section: Resultsmentioning

confidence: 99%

“…Several allelic variants or subclasses of the mef gene have been described for S. pyogenes and S. pneumoniae, including the more common mef(A) and mef(E) and the rarely encountered mef(I) and mef(O) (3,15,17,20).…”

mentioning

confidence: 99%

“…This element, designated the 5216IQ complex of 30.5 kb, includes portions derived from Tn5252 and Tn916, genetic elements frequently found in S. pneumoniae, in association with a novel element enclosing mef(I) and catQ and designated the IQ element (17). Some elements, such as Tn1207.3 and ⌽m46.1 of S. pyogenes and mega of Streptococcus salivarius, are transferable by conjugation (22,23), while the mef-containing elements of S. pneumoniae appear to be nonconjugative.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Genetic Resistance Elements Carrying mef Subclasses Other than mef (A) in Streptococcus pyogenes

Grosso

Camilli

Barbabella

et al. 2011

Antimicrob Agents Chemother

View full text Add to dashboard Cite

In Streptococcus pyogenes, efflux-mediated erythromycin resistance is associated with the mef gene, represented mostly by mef(A), although a small portion of strains carry different mef subclasses. We characterized the composite genetic elements, including mef subclasses other than mef(A), associated with other resistance genes in S. pyogenes isolates. Determination of the genetic elements was performed by PCR mapping. The strains carrying mosaic mef(A/E), in which the 5 region was identical to mef(A) and the 3 region was identical to mef(E), also carried tet(O). The two genes were found enclosed in an element similar to S. pyogenes prophage ⌽m46.1, designated the ⌽m46.1-like element. In S. pyogenes strains carrying mef(E) and tet(M), mef(E) was included in a typical mega element, and in some strains, it was physically associated with tet(M) in the composite element Tn2009. S. pyogenes strains carrying mef(I) also carried catQ; the two genes were linked in a fragment representing a portion of the 5216IQ complex of Streptococcus pneumoniae, designated the defective IQ element. In the only isolate carrying a novel mef gene, this was associated with catQ and tet(M) in a genetic element similar to the 5216IQ complex of S. pneumoniae (5216IQ-like complex), suggesting that the novel mef is in fact a variant of mef(I). This study demonstrates that the composite elements containing mef are shared between S. pyogenes and S. pneumoniae and suggests that it is important to distinguish the mef subclass on the basis of the genetic element containing it.Efflux-mediated macrolide resistance in Streptococcus pyogenes and Streptococcus pneumoniae is conferred by mef and the adjacent msr(D) gene, which code for a two-component transport system (1). The resistance phenotype acquired by the microorganisms is defined as M, since the efflux mechanism confers resistance to macrolides only, as opposed to the MLS B phenotype (resistance to macrolides, lincosamides, and streptogramin B) conferred by the Erm methylase (16).Several allelic variants or subclasses of the mef gene have been described for S. pyogenes and S. pneumoniae, including the more common mef(A) and mef(E) and the rarely encountered mef(I) and mef(O) (3,15,17,20).Although the mef subclasses show a high level of identity at the nucleotide level (from 88% to 94%), each is found embedded in a different genetic element, suggesting a different evolutionary and transmission route (23). In S. pyogenes the most common mef subclass is mef(A) (5, 14), which is carried by two similar genetic elements: Tn1207.3, of approximately 52 kb, and ⌽10394.4, a prophage of approximately 59 kb (2, 21). In S. pneumoniae, mef(A) is carried by Tn1207.1, a defective element of 7.2 kb corresponding to the leftmost mef-containing region of Tn1207.3 (21). In S. pyogenes, a sequence similar to that of Tn1207.1 including mef(A) was found associated with tet(O) in ⌽m46.1, a prophage element of 55.1 kb, also present as a free circular form in the bacterial culture (4).The mef(E) subclass is common in S. ...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Genetic Resistance Elements Carrying mef Subclasses Other than mef (A) in Streptococcus pyogenes

Grosso

Camilli

Barbabella

et al. 2011

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…In 2005, a new mef subclass, mefI, was identified in S. pneumoniae [40]. Moreover, mefI was found to be located on the right-hand side of a newly characterized nonmobile composite structure, the 5216IQ complex, adjacent to the msr and catQ genes [41]. Recently, it was proved that this IQ element is actually inserted within a larger genetic element, conjugative transposon Tn5253, an integrative conjugative element [42].…”

Section: Aminoglycoside Resistancementioning

confidence: 99%

Molecular mechanisms and epidemiology of resistance in Streptococcus pneumoniae in the Middle East region

Moujaber

Osman

Rafei

et al. 2017

Journal of Medical Microbiology

View full text Add to dashboard Cite

Purpose. Streptococcus pneumoniae is a commensal bacterium that normally colonizes the human nasopharyngeal cavity. Once disseminated, it can cause several diseases, ranging from non-invasive infections such as acute otitis media and sinusitis through to invasive infections with higher mortality, including meningitis and septicaemia. Since the identification of the first S. pneumoniae strain with decreased susceptibility to penicillin in the 1960s, antibiotic resistance among S. pneumoniae has increased disturbingly and the mechanisms of resistance have begun to unfold.Methodology. This work briefly reviewed the available data on the molecular mechanisms underlying antimicrobial resistance and its epidemiology among pneumococcal strains in Middle Eastern countries.Key findings. Both intrinsic and acquired mechanisms (mutations, acquisition of novel mobile genetic elements and sometimes gene duplication and overexpression) affect susceptibility to a large variety of antibiotics. In Middle Eastern countries, including Lebanon, Iran, Saudi Arabia and Turkey, surveillance showed a disturbing increase in the strength and prevalence of resistance to antibiotics over the years, especially in the last decade. However, no surveillance reports were found in other Middle Eastern countries, such as Syria and Iraq.Conclusion. In order to better survey, control and prevent the emergence of multidrug-and extremely drug-resistant S. pneumoniae strains, antimicrobial stewardship, national surveillance and public awareness programmes should be developed urgently in Middle Eastern countries.

show abstract

Mechanisms of Resistance to Antibacterial Agents

Bradford,

Castanheira

2023

ClinMicroNow

View full text Add to dashboard Cite

Bacterial pathogens have developed resistance to antibacterial agents via multiple routes. The emergence of antimicrobial resistance phenotypes is directly linked to the use of any given anti microbial agent. Resistance to aminoglycosides occurs by several different mechanisms that can coexist in the same bacterial cell. β‐Lactam antibiotics act by inhibiting penicillin‐binding proteins, which are transpeptidases and transglycosylases that synthesize the peptidogly can that composes the bacterial cell wall. The main bacterial resistance mechanism against fluoroquinolonesis is the alteration of their target in the deoxyribonucleic acid synthesis process. Tetracyclines are bacteriostatic antibiotics that inhibit bacterial growth by binding to the ribosome, thereby preventing protein synthesis. Nitrofurantoin is a synthetic antibacterial agent that is only used in the treatment of urinary tract infections. Rifampin is particularly active against Gram‐positive bacteria and mycobacteria. Daptomycin is a cyclic lipopeptide antibiotic with activity exclusively against Gram‐positive bacteria.

show abstract

Composite Structure of Streptococcus pneumoniae Containing the Erythromycin Efflux Resistance Gene mef (I) and the Chloramphenicol Resistance Gene catQ

Cited by 42 publications

References 30 publications

Genetic Resistance Elements Carrying mef Subclasses Other than mef (A) in Streptococcus pyogenes

Genetic Resistance Elements Carrying mef Subclasses Other than mef (A) in Streptococcus pyogenes

Molecular mechanisms and epidemiology of resistance in Streptococcus pneumoniae in the Middle East region

Mechanisms of Resistance to Antibacterial Agents

Contact Info

Product

Resources

About