The Novel Conjugative Transposon Tn1207.3Carries the Macrolide Efflux Genemef(A) inStreptococcus pyogenes

Santagati, Maria G.; Iannelli, Francesco; Cascone, Carmela; Campanile, F.; Oggioni, Marco; Stefani, Stefania; Pozzi, Gianni

doi:10.1089/107662903322286445

Cited by 89 publications

(84 citation statements)

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“…The sequences of six fragments (F1, F3, F4, F6, F8, and F10) aligned with DNA sequences found in the published genome sequence of S. agalactiae (14,40,41). The sequences of four fragments (F5, F7, F9, and F10) displayed significant alignment with DNA sequences found in published S. pyogenes genome sequences (2,4,13,15,28,32,36,37). On account of our objectives, we studied in more detail the three DNA fragments (F5, F7, and F10) that displayed significant alignment with prophagic DNA sequences (Fig.…”

Section: Resultsmentioning

confidence: 95%

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

et al. 2006

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We identified-by randomly amplified polymorphic DNA (RAPD) analysis at the population level followed by DNA differential display, cloning, and sequencing-three prophage DNA fragments (F5, F7, and F10) in Streptococcus agalactiae that displayed significant sequence similarity to the DNA of S. agalactiae and Streptococcus pyogenes. The F5 sequence aligned with a prophagic gene encoding the large subunit of a terminase, F7 aligned with a phage-associated cell wall hydrolase and a phage-associated lysin, and F10 aligned with a transcriptional regulator (ArpU family) and a phage-associated endonuclease. We first determined the prevalence of F5, F7, and F10 by PCR in a collection of 109 strains isolated in the 1980s and divided into two populations: one with a high risk of causing meningitis (HR group) and the other with a lower risk of causing meningitis (LR group). These fragments were significantly more prevalent in the HR group than in the LR group (P < 0.001). Our findings suggest that lysogeny has increased the ability of some S. agalactiae strains to invade the neonatal brain endothelium. We then determined the prevalence of F5, F7, and F10 by PCR in a collection of 40 strains recently isolated from neonatal meningitis cases for comparison with the cerebrospinal fluid (CSF) strains isolated in the 1980s. The prevalence of the three prophage DNA fragments was similar in these two populations isolated 15 years apart. We suggest that the prophage DNA fragments identified have remained stable in many CSF S. agalactiae strains, possibly due to their importance in virulence or fitness.Streptococcus agalactiae, a bacterial pathogen frequently carried in the normal fecal and/or vaginal flora, is a leading cause of severe bacterial infections in neonates (33). The characterization of S. agalactiae strains, initially by multilocus enzyme electrophoresis (MLEE) (26,29) and then by multilocus sequence typing (16) and various other methods (5, 39), has revealed the existence of two strongly differentiated lineages in the species. The first is a homogeneous lineage composed of serotype III strains, and the second is a genetically diverse lineage composed of isolates from all capsular serotypes, including serotype III.

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Section: Resultsmentioning

confidence: 95%

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

et al. 2006

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“…Resistance to this class of antibiotics can be due to the mefA gene encoding a macrolide efflux pump or ribosomal modification by methylation caused by the ermB or ermTR gene (9,29,44,52). Macrolide resistance genes have been reported to be transferred horizontally by mobile genetic elements, such as phages and transposons (4,18,19,24,41). As assessed by PCR, 1.2% of the 568 strains had the mefA gene, and virtually all of these PCR-positive strains were from pharyngitis cases.…”

Section: Resultsmentioning

confidence: 99%

Genetic Diversity among Type emm28 Group A Streptococcus Strains Causing Invasive Infections and Pharyngitis

et al. 2005

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Genome sequencing of group A Streptococcus (GAS) has revealed that prophages account for the vast majority of gene content differences between strains. Serotype M28 strains are a leading cause of pharyngitis and invasive infections, but little is known about genetic diversity present in natural populations of these organisms. To study this issue, population-based samples of 568 strains from Ontario, Canada; Finland; and Houston, Texas, were analyzed. Special attention was given to analysis of variation in prophage-encoded virulence gene content by a PCR-based method. Thirty and 29 distinct prophage-encoded virulence gene profiles were identified among pharyngitis and invasive infection isolates. Thirteen profiles, representing the majority of the strains, were shared between these two classes of isolates. Significant differences were observed in the frequency of occurrence of certain prophage toxin gene profiles and infection type. M28 strains are highly diverse in prophage-encoded virulence gene content and integration site, supporting the key concept that prophages are critical contributors to GAS genetic diversity and population biology. Nucleotide sequence variation in the emm gene (encodes M protein) was also examined. Only three allelic variants were identified in the hypervariable portion of the emm28 gene. All but one strain had the same inferred amino acid sequence in the first 100 amino acids of the mature M28 protein. In contrast, size differences in the emm28 gene and inferred protein due to variable numbers of C-terminal repeats were common. The presence of macrolide resistance genes (mefA, ermB, and ermTR) was analyzed by PCR, and less than 2% of the strains were positive.Research on group A Streptococcus (GAS) host-pathogen interactions has been aided greatly by the recent publication of genome sequences from serotype M1, M3, M6, and M18 strains (1,5,16,38,48,51). The availability of multiple genome sequences has also increased our understanding of GAS molecular population genetics, species diversity, and strain variation within and between M-protein serotypes. The majority of differences in gene content between strains are located in 35-to 45-kb insertions corresponding to prophages, prophage-like elements, and other exogenous sequences (1-6, 16, 38, 48, 51) (for simplicity, the term prophage will be used to refer to prophages or prophage-like elements). The genome of each sequenced GAS strain is polylysogenic, and 23 distinct prophages have been described (1-6, 16, 38, 48, 51). Twenty of these 23 prophages encode one or two proven or putative extracellular virulence factors, including pyrogenic toxin superantigens (speA, speC, speH, speI, speK, speL, speM, and ssa), DNases (spd1, spd3, spd4, sdn, and sda), a phospholipase A 2 (slaA), macrolide resistance (mefA), and a novel cell surface protein of unknown function (1-5, 16, 37, 38, 48, 51).The contribution of serotype M28 GAS strains to human morbidity and mortality has often been underappreciated in part because serotypes such as M1 and M3 att...

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“…Low-level macrolide resistance in the oral microbiota may also be associated with the expression of genes from the mef family, encoding another efflux pump, and recently have been found on a conjugative transposon Tn1207.3 in Streptococcus pyogenes [121]. There have been described [122] erythromycinresistant α-hemolytic streptococci, such as S. oralis, S. salivarius and S. sanguis in healthy Greek children. P. intermedia isolates carried erm(F) alone or tetQ alone, but in other oral anaerobes, macrolide resistance often occurred in conjunction with tetracycline resistance.…”

Section: Mechanisms Of Dental Plaque Resistance To Antimicrobials Andmentioning

confidence: 99%

Impact of Dental Plaque Biofilms in Periodontal Disease: Management and Future Therapy

Lazăr¹,

Dițu²,

Curuţiu³

et al. 2017

Periodontitis - A Useful Reference

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Oral cavity represents an ideal environment for the microbial cell growth, persistence, and dental plaque establishment. The presence of different microniches leads to the occurrence of different biofilm communities, formed on teeth surface, above gingival crevice or at subgingival level, on tongue, mucosa and dental prosthetics too. The healthy state is regulated by host immune system and interactions between microbial community members, maintaining the predominance of "good" microorganisms. When the complexity and volume of biofilms from the gingival crevice increase, chronic pathological conditions such as gingivitis and periodontitis can occur, predisposing to a wide range of complications. Bacteria growing in biofilms exhibit a different behavior compared with their counterpart, respectively planktonic or free cells. There have been described numerous mechanisms of differences in antibiotic susceptibility of biofilm embedded cells. Resistance to antibiotics, mediated by genetic factors or, phenotypical, due to biofilm formation, called also tolerance, is the most important cause of therapy failure of biofilm-associated infections, including periodontitis; the mechanisms of tolerance are different, the metabolic low rate and cell's dormancy being the major ones. The recent progress in science and technology has made possible a wide range of novel approaches and advanced therapies, aiming the efficient management of periodontal disease.

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The Novel Conjugative Transposon Tn1207.3Carries the Macrolide Efflux Genemef(A) inStreptococcus pyogenes

Cited by 89 publications

References 20 publications

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

Genetic Diversity among Type emm28 Group A Streptococcus Strains Causing Invasive Infections and Pharyngitis

Impact of Dental Plaque Biofilms in Periodontal Disease: Management and Future Therapy

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