Macrolide resistance can be transferred by conjugation from viridans streptococci to Streptococcus pyogenes

Jönsson, Maria; Swedberg, Göte

doi:10.1016/j.ijantimicag.2006.02.023

Cited by 12 publications

(12 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This genetic element has been reported by Brenciani et al to be frequent in viridans group streptococci (15). It can contribute to the dissemination of erythromycin resistance genes, since conjugative mobilization of MEGA from viridans group streptococci to S. pyogenes and S. pneumoniae has been reported (51,52). Forty-six strains that harbor a MEGA element also carry a conjugative element related to ICESt3 or Tn916 that could participate in the conjugative mobilization of MEGA.…”

Section: Discussionmentioning

confidence: 93%

Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius

Chaffanel

Charron-Bourgoin

Libante

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

The diversity of clinical (n ‫؍‬ 92) and oral and digestive commensal (n ‫؍‬ 120) isolates of Streptococcus salivarius was analyzed by multilocus sequence typing (MLST). No clustering of clinical or commensal strains can be observed in the phylogenetic tree. Selected strains (92 clinical and 46 commensal strains) were then examined for their susceptibilities to tetracyclines, macrolides, lincosamides, aminoglycosides, and phenicol antibiotics. The presence of resistance genes tet(M), tet(O), erm(A), erm(B), mef(A/ E), and catQ and associated genetic elements was investigated by PCR, as was the genetic linkage of resistance genes. High rates of erythromycin and tetracycline resistance were observed among the strains. Clinical strains displayed either the erm(B) (macrolide-lincosamide-streptogramin B [MLS B ] phenotype) or mef(A/E) (M phenotype) resistance determinant, whereas almost all the commensal strains harbored the mef(A/E) resistance gene, carried by a macrolide efflux genetic assembly (MEGA) element. A genetic linkage between a macrolide resistance gene and genes of Tn916 was detected in 23 clinical strains and 5 commensal strains, with a predominance of Tn3872 elements (n ‫؍‬ 13), followed by Tn6002 (n ‫؍‬ 11) and Tn2009 (n ‫؍‬ 4) elements. Four strains harboring a mef(A/E) gene were also resistant to chloramphenicol and carried a catQ gene. Sequencing of the genome of one of these strains revealed that these genes colocalized on an IQ-like element, as already described for other viridans group streptococci. ICESt3-related elements were also detected in half of the isolates. This work highlights the potential role of S. salivarius in the spread of antibiotic resistance genes both in the oral sphere and in the gut. Streptococcus salivarius is a Gram-positive commensal bacterium that is a major bacterial constituent of saliva and of biofilms found on the human tongue dorsum (1). It belongs to the early microbial community that colonizes the oral cavities of newborns (2) and persists in the adult oral flora (3). This species is considered to contribute to oral health by preventing the colonization of mucosal surfaces with pathogens involved in upper respiratory tract infections (4). For instance, S. salivarius strains have been reported to inhibit biofilm formation by Streptococcus pyogenes (5) and Streptococcus mutans (6) as well as adherence by Candida albicans (7). S. salivarius is also commonly detected as an inhabitant of the gastrointestinal tracts of healthy humans and has been described as a typical small intestine commensal species (8). However, some strains have been associated with opportunistic infections: a growing number of meningitis cases (9, 10), several cases of endocarditis (11), bacteremia in immunocompromised patients (12, 13), and invasion of the guts of patients with liver cirrhosis (14).Macrolides and tetracyclines are commonly used for the treatment of streptococcal infections, but high rates of resistance to these antibiotics have been observed among pathogenic and commensal strept...

show abstract

Section: Discussionmentioning

confidence: 93%

Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius

Chaffanel

Charron-Bourgoin

Libante

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…In all cases of conjugal transfer of mef (E), the gene was carried on MEGA. [494] Another study suggested that mef (A) and mef (E) genes were also observed in ca. 9% of erythromycin-resistant isolates of Streptococcus agalactiae and transformation was considered the main mechanism for resistance gene acquisition.…”

Section: Drug Efflux In Gram-positive Bacteriamentioning

confidence: 99%

Efflux-Mediated Drug Resistance in Bacteria

Nikaido²

2009

Drugs

916

875

View full text Add to dashboard Cite

Drug efflux pumps play a key role in drug resistance and also serve other functions in bacteria. There has been a growing list of multidrug and drug-specific efflux pumps characterized from bacteria of human, animal, plant and environmental origins. These pumps are mostly encoded on the chromosome although they can also be plasmid-encoded. A previous article (Li X-Z and Nikaido H, Drugs, 2004; 64[2]: 159–204) had provided a comprehensive review regarding efflux-mediated drug resistance in bacteria. In the past five years, significant progress has been achieved in further understanding of drug resistance-related efflux transporters and this review focuses on the latest studies in this field since 2003. This has been demonstrated in multiple aspects that include but are not limited to: further molecular and biochemical characterization of the known drug efflux pumps and identification of novel drug efflux pumps; structural elucidation of the transport mechanisms of drug transporters; regulatory mechanisms of drug efflux pumps; determining the role of the drug efflux pumps in other functions such as stress responses, virulence and cell communication; and development of efflux pump inhibitors. Overall, the multifaceted implications of drug efflux transporters warrant novel strategies to combat multidrug resistance in bacteria.

show abstract

“…Dynamics of different bacterial populations in antibiotic-free niches are the baseline that antibiotic treatments can alter18,19 by shifting the competitive balance in favor of resistant populations. For this reason, antibiotic resistance is increasingly regarded as an ecologic problem.…”

Section: Bacterial Evolution Towards Resistance In Respiratory Tract mentioning

confidence: 99%

“…For this reason, antibiotic resistance is increasingly regarded as an ecologic problem. Once resistance has emerged, physiologic concentrations of different antibiotics may select resistant strains by eradicating the susceptible ones (thus unmasking resistant populations),19 or by selecting intrastrain-resistant subpopulations 20. Because multiple individuals harbor multiple bacterial populations exhibiting different degrees of antibiotic resistance at the community level, the prevalence of resistance is directly related to antibiotic consumption in the community 21…”

Section: Bacterial Evolution Towards Resistance In Respiratory Tract mentioning

confidence: 99%

Drug resistance in community-acquired respiratory tract infections: role for an emerging antibacterial

Aguilar

Giménez²,

Barberán³

2010

IDR

View full text Add to dashboard Cite

The nasopharynx is the ecological niche where evolution towards resistance occurs in respiratory tract isolates. Dynamics of different bacterial populations in antibiotic-free multibacterial niches are the baseline that antibiotic treatments can alter by shifting the competitive balance in favor of resistant populations. For this reason, antibiotic resistance is increasingly being considered to be an ecological problem. Traditionally, resistance has implied the need for development of new antibiotics for which basic efficacy and safety data are required prior to licensing. Antibiotic development is mainly focused on demonstrating clinical efficacy and setting susceptibility breakpoints for efficacy prediction. However, additional information on pharmacodynamic data predicting absence of selection of resistance and of resistant subpopulations, and specific surveillance on resistance to core antibiotics (to detect emerging resistances and its link with antibiotic consumption in the community) are valuable data in defining the role of a new antibiotic, not only from the perspective of its therapeutic potential but also from the ecologic perspective (countering resistances to core antibiotics in the community). The documented information on cefditoren gleaned from published studies in recent years is an example of the role for an emerging oral antibacterial facing current antibiotic resistance in community-acquired respiratory tract infections.

show abstract

Macrolide resistance can be transferred by conjugation from viridans streptococci to Streptococcus pyogenes

Cited by 12 publications

References 11 publications

Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius

Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius

Efflux-Mediated Drug Resistance in Bacteria

Drug resistance in community-acquired respiratory tract infections: role for an emerging antibacterial

Contact Info

Product

Resources

About