Genetic Diversity and Clonal Patterns among Antibiotic-Susceptible and -Resistant Streptococcus pneumoniae Colonizing Children: Day Care Centers as Autonomous Epidemiological Units

Characterization by antibiotype of the 1,096 Streptococcus pneumoniae recovered from 2,111 nasopharyngeal samples of children attending 16 day care centers (DCCs) in Lisbon, Portugal, and molecular typing of 413 drug-resistant pneumococci (DRPn) and 89 fully drug-susceptible pneumococci (DSPn) has allowed several conclusions. (i) There was an increase in the frequency of DRPn colonizing children in DCCs from 40% in 1996 to 45% in 1997 to 50% in 1998. (ii) Drug resistance spread by cross-transmission of DRPn clones. A few (8 out of 57) DRPn clones were repeatedly isolated from a large number of children in several DCCs and during each period of surveillance, suggesting the epidemic nature of these clones, which included lineages representing internationally spread S. pneumoniae clones. (iii) Dissemination of resistance determinants among pneumococci colonizing the nasopharynx occurred. Association of identical pulsed-field gel electrophoresis patterns with diverse antibiotypes among pneumococci colonizing children suggests that the high prevalence of DRPn involves not only cross-transmission of resistant strains but also dispersal of resistance genes through recombinational mechanisms. (iv) DCCs are autonomous epidemiological units. Among the 413 DRPn, 57 different lineages were detected; these lineages were dispersed among the 16 DCCs to produce unique microbiological profiles for each of the DCCs. Higher genetic diversity and less sharing of clonal types were observed among the DSPn.

Download Full-text

Resistance Determinants and Their Association with Different Transposons in the Antibiotic-ResistantStreptococcus pneumoniae

BioMed Research International ◽

10.1155/2015/836496 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

Izabela Korona-Glowniak ◽

Radoslaw Siwiec ◽

Anna Malm

Keyword(s):

Antibiotic Resistance ◽

Streptococcus Pneumoniae ◽

Horizontal Transfer ◽

Multiple Resistance ◽

Antibiotic Resistant ◽

Conjugative Transposons ◽

Resistance Determinants ◽

High Prevalence ◽

Resistant Strains ◽

Related Element

Multiple resistance ofStreptococcus pneumoniaeis generally associated with their unique recombination-mediated genetic plasticity and possessing the mobile genetic elements. The aim of our study was to detect antibiotic resistance determinants and conjugative transposons in 138 antibiotic-resistant pneumococcal strains isolated from nasopharynx of healthy young children from Lublin, Poland. These strains resistant to tetracycline and/or to chloramphenicol/erythromycin/clindamycin were tested by PCR using the specific genes as markers. The presence of Tn916family transposons, carryingtet(M) andint/xisTn916, was observed in all of the tested strains. Tn916was detected in 16 strains resistant only to tetracycline. Tn6002and Tn3872-related element were found among 99erm(B)-carrying strains (83.8% and 3.0%, resp.). Eight strains harbouringmef(E) anderm(B) genes were detected, suggesting the presence of Tn2010and Tn2017transposons. Among 101 chloramphenicol-resistant strains, two variants of Tn5252-related transposon were distinguished depending on the presence ofint/xis5252genes specific forcatgene-containing Tn5252(75.2% of strains) orintSp23FST81gene, specific forcat-containing ICESp23FST81 element (24.8% of strains). In 6 strains Tn916-like and Tn5252-like elements formed a Tn5253-like structure. Besides clonal dissemination of resistant strains of pneumococci in the population, horizontal transfer of conjugative transposons is an important factor of the high prevalence of antibiotic resistance.

Download Full-text

High prevalence of children colonized with penicillin-resistant <i>Streptococcus pneumoniae</i> in public day-care centers

Jornal de Pediatria ◽

10.2223/jped.1949 ◽

2009 ◽

Vol 85 (6) ◽

pp. 516-522 ◽

Cited By ~ 1

Author(s):

Patrícia A. G. Velasquez ◽

Leandro Parussolo ◽

Celso L. Cardoso ◽

Maria Cristina B. Tognim ◽

Lourdes B. Garcia

Keyword(s):

Streptococcus Pneumoniae ◽

Day Care ◽

Day Care Centers ◽

High Prevalence

Download Full-text

Trends in Drug Resistance, Serotypes, and Molecular Types of Streptococcus pneumoniae Colonizing Preschool-Age Children Attending Day Care Centers in Lisbon, Portugal: a Summary of 4 Years of Annual Surveillance

Journal of Clinical Microbiology ◽

10.1128/jcm.43.3.1285-1293.2005 ◽

2005 ◽

Vol 43 (3) ◽

pp. 1285-1293 ◽

Cited By ~ 34

Author(s):

S. Nunes ◽

R. Sa-Leao ◽

J. Carrico ◽

C. R. Alves ◽

R. Mato ◽

...

Keyword(s):

Drug Resistance ◽

Streptococcus Pneumoniae ◽

Day Care ◽

Preschool Age ◽

Day Care Centers ◽

Preschool Age Children

Download Full-text

Injuries in Swedish Day-Care Centers

PEDIATRICS ◽

10.1542/peds.94.6.1033 ◽

1994 ◽

Vol 94 (6) ◽

pp. 1033-1036

Author(s):

Eva Sellström ◽

Sven Bremberg ◽

Albert Chang

Keyword(s):

Day Care ◽

Care Center ◽

Health And Safety ◽

Developed Countries ◽

Day Care Centers ◽

Number Of Children ◽

Common Coding ◽

Risk Of Injury ◽

Local Injury ◽

Set Up

In the developed countries, an increasing number of children are enrolled in day-care centers. When parents leave their child in a day-care center they expect high standards of health and safety. Accidental injuries are a major threat in this age group. In a comparable institution that serves children, the school, the risk of injury is higher than in the home environment.1-2 Thus, safety in day-care centers cannot be taken for granted. A few studies of injuries in day-care centers have been reported, from the Nordic countries2,3-5 and from the US.6-10 Most of these studies, however, have been small and most lack information on time of exposure. Information about the risk of injury in Swedish day-care centers might be of interest as enrollment has been high for a long time. In Sweden, within the frame of a national injury program,11 a number of local hospital- and health center-based injury report systems have been set up. All have a basic common coding. These systems enable compilation of injuries in day-care centers on a national basis. The aim of our study was to analyze child injuries in day-care centers as reported in 10 local injury registry systems in Sweden regarding incidence, type, and mechanism of injury. METHOD Data were compiled from 10 local injury registry systems, covering 1- to 2-year periods. The earliest registers were from the years 1983 to 1984 and the latest from 1991. These systems were set up in all medical institutions at a predefined level, covering all individuals in a total or a part of a county.

Download Full-text

What is the mechanism for persistent coexistence of drug-susceptible and drug-resistant strains of Streptococcus pneumoniae ?

Journal of The Royal Society Interface ◽

10.1098/rsif.2009.0400 ◽

2009 ◽

Vol 7 (47) ◽

pp. 905-919 ◽

Cited By ~ 58

Author(s):

Caroline Colijn ◽

Ted Cohen ◽

Christophe Fraser ◽

William Hanage ◽

Edward Goldstein ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Infectious Diseases ◽

Multiple Infection ◽

Drug Resistant ◽

Host Interactions ◽

Resistant Strains ◽

Neutral Models ◽

Drug Resistant Strains ◽

And Control

The rise of antimicrobial resistance in many pathogens presents a major challenge to the treatment and control of infectious diseases. Furthermore, the observation that drug-resistant strains have risen to substantial prevalence but have not replaced drug-susceptible strains despite continuing (and even growing) selective pressure by antimicrobial use presents an important problem for those who study the dynamics of infectious diseases. While simple competition models predict the exclusion of one strain in favour of whichever is ‘fitter’, or has a higher reproduction number, we argue that in the case of Streptococcus pneumoniae there has been persistent coexistence of drug-sensitive and drug-resistant strains, with neither approaching 100 per cent prevalence. We have previously proposed that models seeking to understand the origins of coexistence should not incorporate implicit mechanisms that build in stable coexistence ‘for free’. Here, we construct a series of such ‘structurally neutral’ models that incorporate various features of bacterial spread and host heterogeneity that have been proposed as mechanisms that may promote coexistence. We ask to what extent coexistence is a typical outcome in each. We find that while coexistence is possible in each of the models we consider, it is relatively rare, with two exceptions: (i) allowing simultaneous dual transmission of sensitive and resistant strains lets coexistence become a typical outcome, as does (ii) modelling each strain as competing more strongly with itself than with the other strain, i.e. self-immunity greater than cross-immunity. We conclude that while treatment and contact heterogeneity can promote coexistence to some extent, the in-host interactions between strains, particularly the interplay between coinfection, multiple infection and immunity, play a crucial role in the long-term population dynamics of pathogens with drug resistance.

Download Full-text