Composite mobile genetic elements disseminating macrolide resistance in Streptococcus pneumoniae

ABSTRACTMacrolide resistance rates ofMycoplasma pneumoniaein the Beijing population were as high as 68.9%, 90.0%, 98.4%, 95.4%, and 97.0% in the years 2008 to 2012, respectively. Common macrolide-resistant mobile genetic elements were not detected with any isolate. These macrolide-resistant isolates came from multiple clones rather than the same clone. No massive aggregation of a particular clone was found in a specific period.

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Antibiotic Resistance Is Associated with Integrative and Conjugative Elements and Genomic Islands in Naturally Circulating Streptococcus pneumoniae Isolates from Adults in Liverpool, UK

Genes ◽

10.3390/genes11060625 ◽

2020 ◽

Vol 11 (6) ◽

pp. 625

Author(s):

Elissavet Nikolaou ◽

Alasdair T. M. Hubbard ◽

João Botelho ◽

Taylor A. M. Marschall ◽

Daniela M. Ferreira ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Pneumococcal Infection ◽

Mobile Genetic Elements ◽

Genomic Islands ◽

Mortality And Morbidity ◽

Genetic Elements ◽

Integrative And Conjugative Elements ◽

Genetic Context

Pneumonia is the sixth largest cause of death in the UK. It is usually caused by Streptococcus pneumoniae, which healthy individuals can carry in their nose without symptoms of disease. Antimicrobial resistance further increases mortality and morbidity associated with pneumococcal infection, although few studies have analysed resistance in naturally circulating pneumococcal isolates in adult populations. Here, we report on the resistome and associated mobile genetic elements within circulating pneumococcus isolated from adult volunteers enrolled in the experimental human pneumococcal colonisation (EHPC) research program at the Liverpool School of Tropical Medicine, UK. Pneumococcal isolates collected from 30 healthy asymptomatic adults who had volunteered to take part in clinical research were screened for antibiotic susceptibility to erythromycin and tetracycline, and whole-genome sequenced. The genetic context of resistance to one or both antibiotics in four isolates was characterised bioinformatically, and any association of the resistance genes with mobile genetic elements was determined. Tetracycline and macrolide resistance genes [tet(M), erm(B), mef(A), msr(D)] were detected on known Tn916-like integrative and conjugative elements, namely Tn6002 and Tn2010, and tet(32) was found for the first time in S. pneumoniae located on a novel 50 kb genomic island. The widespread use of pneumococcal conjugate vaccines impacts on serotype prevalence and transmission within the community. It is therefore important to continue to monitor antimicrobial resistance (AMR) genes present in both vaccine types and non-vaccine types in response to contemporary antimicrobial therapies and characterise the genetic context of acquired resistance genes to continually optimise antibiotic therapies.

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Population genomics reveals distinct temporal association with the emergence of ST1 serotype V Group B Streptococcus and macrolide resistance in North America

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00714-21 ◽

2021 ◽

Author(s):

M. Belén Cubria ◽

Luis Alberto Vega ◽

William C. Shropshire ◽

Misu A. Sanson ◽

Brittany J. Shah ◽

...

Keyword(s):

Population Genomics ◽

Young Infant ◽

Mobile Genetic Elements ◽

Invasive Disease ◽

Macrolide Resistance ◽

Temporal Association ◽

Bacterial Disease ◽

Genetic Elements ◽

Young Infants ◽

Group B

Identified in the 1970s as the leading cause of invasive bacterial disease in neonates and young infants, Group B Streptococcus (GBS) is now also recognized as a significant cause of morbidity and mortality among adults with underlying medical conditions and the elderly. Concomitant with the increasing incidence of GBS invasive disease in adults is the rise of resistance among GBS isolates to second line antibiotics. Previous research shows that among serotype V GBS – one of the most common capsular types causing adult invasive disease – sequence type 1 (ST1) – accounts for an overwhelming majority of adult invasive disease isolates and frequently harbors macrolide resistance. In this study, using whole genome sequencing data from strains isolated in the USA and Canada over a 45-year period, we examined the association of antimicrobial resistance with the emergence of invasive serotype V ST1 GBS. Our findings show a strong temporal association between increased macrolide resistance and the emergence of serotype V ST1 GBS subpopulations that currently co-circulate to cause adult as well as young infant invasive disease. ST1 GBS subpopulations are defined, in part, by the presence of macrolide resistance genes in mobile genetic elements. Increased frequency of macrolide resistance-encoding mobile genetic elements among invasive GBS ST1 strains suggests the presence of such elements contributes to GBS virulence. Our work provides a foundation for the investigation of genetic features contributing to the increasing prevalence and pathogenesis of serotype V GBS in adult invasive disease.

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The novel macrolide resistance genes mef(F) and msr(G) are located on a plasmid in Macrococcus canis and a transposon in Macrococcus caseolyticus

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa405 ◽

2020 ◽

Vol 76 (1) ◽

pp. 48-54

Author(s):

Javier Eduardo Fernandez ◽

Vincent Perreten ◽

Sybille Schwendener

Keyword(s):

Resistance Genes ◽

Resistance Mechanism ◽

Mobile Genetic Elements ◽

Bioinformatic Analysis ◽

Membered Ring ◽

Macrolide Resistance ◽

The Novel ◽

Bacterial Strains ◽

Chloramphenicol Resistance ◽

Genetic Elements

Abstract Objectives To analyse macrolide resistance in a Macrococcus canis strain isolated from a dog with an ear infection, and determine whether the resistance mechanism is also present in other bacteria, and associated with mobile genetic elements. Methods The whole genome of M. canis Epi0082 was sequenced using PacBio and Illumina technologies. Novel macrolide resistance determinants were identified through bioinformatic analysis, and functionality was demonstrated by expression in Staphylococcus aureus. Mobile genetic elements containing the novel genes were analysed in silico for strain Epi0082 as well as in other bacterial strains deposited in GenBank. Results M. canis Epi0082 contained a 3212 bp operon with the novel macrolide resistance genes mef(F) and msr(G) encoding a efflux protein and an ABC-F ribosomal protection protein, respectively. Cloning in S. aureus confirmed that both genes individually confer resistance to the 14- and 15-membered ring macrolides erythromycin and azithromycin, but not the 16-membered ring macrolide tylosin. A reduced susceptibility to the streptogramin B pristinamycin IA was additionally observed when msr(G) was expressed in S. aureus under erythromycin induction. Epi0082 carried the mef(F)–msr(G) operon together with the chloramphenicol resistance gene fexB in a novel 39 302 bp plasmid pMiCAN82a. The mef(F)–msr(G) operon was also found in macrolide-resistant Macrococcus caseolyticus strains in the GenBank database, but was situated in the chromosome as part of a novel 13 820 bp or 13 894 bp transposon Tn6776. Conclusions The identification of mef(F) and msr(G) on different mobile genetic elements in Macrococcus species indicates that these genes hold potential for further dissemination of resistance to the clinically important macrolides in the bacterial population.

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The Macrolide Resistance Genes erm(B) and mef(E) Are Carried by Tn2010 in Dual-Gene Streptococcus pneumoniae Isolates Belonging to Clonal Complex CC271

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00598-07 ◽

2007 ◽

Vol 51 (11) ◽

pp. 4184-4186 ◽

Cited By ~ 32

Author(s):

Maria Del Grosso ◽

John G. E. Northwood ◽

David J. Farrell ◽

Annalisa Pantosti

Keyword(s):

Streptococcus Pneumoniae ◽

Resistance Genes ◽

Clonal Complex ◽

Macrolide Resistance ◽

Genetic Element ◽

Genetic Elements

ABSTRACT The genetic elements carrying macrolide resistance genes in Streptococcus pneumoniae isolates belonging to CC271 were investigated. The international clone Taiwan19F-14 was found to carry Tn2009, a Tn916-like transposon containing tet(M) and mef(E). The dual erm(B) mef(E) isolates carried Tn2010, which is similar to Tn2009 with the addition of a putative new transposon, the erm(B) genetic element.

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