title: Serotype Distribution, Antibiotic Resistance and Clonality of Streptococcus pneumoniae Isolated from Immunocompromised Patients in Tunisia.
abstract: BACKGROUND
  Pneumococcal disease, a major cause of morbidity and mortality globally, has higher incidence among young children, the elderly and the immunocompromised of all ages. In Tunisia, pneumococcal conjugate vaccines (PCVs) are not included in the national immunization program. Also, few studies have described the epidemiology of S. pneumoniae in this country and, in particular, no molecular typing studies have been performed. The aim of this study was to evaluate serotype distribution, antimicrobial resistance and clonality of Streptococcus pneumoniae isolated from neutropenic patients in Tunisia.
  
  
  METHODS
  Fifty-nine S. pneumoniae were isolated from infection (n = 31) and colonization (n = 28) sites of patients (children and adults) attending the National Centre of Bone Marrow Transplantation in Tunis between 2005-2011. All isolates were characterized by serotype, antimicrobial resistance pattern and multilocus sequence typing (MLST).
  
  
  RESULTS
  The majority (66.1%) of the isolates belonged to five serotypes all included in PCVs: 6B, 9V, 14, 19F and 23F. The potential coverage of the 10-valent and 13-valent PCV was of 71.2% and 76.3% respectively. Resistance rates were very high and 69.5% of the isolates were multidrug resistant: non-susceptibility rates to penicillin, amoxicillin and cefotaxime were 66.1%, 40.7% and 27.1%, respectively; resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole, were 69.5%, 61.0%, 37.3%, 22.0% and 67.8%, respectively. The most frequent serotypes had STs characteristic of multidrug resistant international clones known to be highly successful and important causes of pneumococcal infection: Spain 23F-ST81, France 9V/14-ST156, Spain 6B-ST90, 19F-ST320, and Portugal 19F-ST177.
  
  
  CONCLUSIONS
  The majority of S. pneumoniae strains recovered from immunocompromised patients in Tunisia are representatives of multidrug resistant pandemic clones that express serotypes targeted by PCVs. To contain the burden of pneumococcal disease and improve treatment choices among Tunisian immunocompromised patients PCVs should be offered to all of them.
authors.affiliation: Laboratory of the National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie; University of Carthage, Faculty of Sciences of Bizerte, Tunis, Tunisie.
authors.forename: Anis
authors.initials: A
authors.lastname: Raddaoui
authors.affiliation: Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Alexandra S
authors.initials: AS
authors.lastname: Simões
authors.affiliation: Laboratory of the National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie; UR12ES02, Microbiologie de la Greffe de Moelle Osseuse, Université Tunis El Manar, 2092, Tunis, Tunisie.
authors.forename: Rekaya
authors.initials: R
authors.lastname: Baaboura
authors.affiliation: Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Félix
authors.affiliation: Laboratory of the National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie; UR12ES02, Microbiologie de la Greffe de Moelle Osseuse, Université Tunis El Manar, 2092, Tunis, Tunisie.
authors.forename: Wafa
authors.initials: W
authors.lastname: Achour
authors.affiliation: Hematology Ward, National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie.
authors.forename: Tarek
authors.initials: T
authors.lastname: Ben Othman
authors.affiliation: Pediatric Immuno-hematology Ward, National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Béjaoui
authors.affiliation: Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Sá-Leão
authors.affiliation: Laboratory of the National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisie; UR12ES02, Microbiologie de la Greffe de Moelle Osseuse, Université Tunis El Manar, 2092, Tunis, Tunisie.
authors.forename: Assia
authors.initials: A
authors.lastname: Ben Hassen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D002999:Clone Cells; D004352:Drug Resistance, Microbial / Q000187:drug effects; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification*; D014416:Tunisia; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents