Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco
Abstract Background Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, especially among children and the elderly. The ability to effectively treat pneumococcal infection has been compromised due to the acquisition of antibiotic resistance, particularly to β-lactam drugs....
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doaj-59ae51ae0cf0470eb398a6b72b0adb302020-11-25T02:43:19ZengBMCAnnals of Clinical Microbiology and Antimicrobials1476-07112017-04-011611910.1186/s12941-017-0200-6Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, MoroccoIdrissa Diawara0Abouddihaj Barguigua1Khalid Katfy2Kaotar Nayme3Houria Belabbes4Mohammed Timinouni5Khalid Zerouali6Naima Elmdaghri7Laboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaLaboratoire Polyvalent en Recherche et Développement, département de Biologie-Géologie, Faculté polydisciplinaire, Université Sultan Moulay SlimaneLaboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaLaboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaLaboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaMolecular Bacteriology Laboratory, Institut Pasteur du MarocLaboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaLaboratoire de Microbiologie, Faculté de Médecine et de Pharmacie, Hassan II University of CasablancaAbstract Background Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, especially among children and the elderly. The ability to effectively treat pneumococcal infection has been compromised due to the acquisition of antibiotic resistance, particularly to β-lactam drugs. This study aimed to describe the prevalence and molecular evolution of penicillin non-susceptible S. pneumoniae (PNSP) isolated from invasive diseases before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco. Methods Isolates were obtained from the Microbiology Laboratory of Ibn Rochd University Hospital Centre of Casablanca. Serogrouping was done by Pneumotest Kit and serotyping by the Quellung capsular swelling. Antibiotic susceptibility pattern was determined by disk diffusion and E-test methods. The PNSP were analyzed by pulsed-field gel electrophoresis (PFGE) and by genotyping of pbp1a, pbp2b, and pbp2x genes. Results A total of 361 S. pneumoniae isolates were collected from 2007 to 2014. Of these isolates, 58.7% were obtained before vaccination (2007–2010) and 41.3% after vaccination (2011–2014). Of the 361 isolates, 80 were PNSP (22.2%). Generally, the proportion of PNSP between pre- and post-vaccination periods were 31 and 13% (p = 0.009), respectively. The proportion of PNSP isolated from pediatric and adult (age > 14 years) patients decreased from 34.5 to 22.9% (p = 0.1) and from 17.7 to 10.2% (p = 0.1) before and after vaccine implementation, respectively. The leading serotypes of PNSP were 14 (33 vs. 57%) and 19A (18 vs. 14%) before and after vaccination among children. For adults, serotypes 19A (53%) and 23F (24%) were the dominant serotypes in the pre-vaccination period, while serotype 14 (22%) was the most prevalent after vaccination. There were 21 pbp genotypes in the pre-vaccination period vs. 12 for post-vaccination period. PFGE clustering showed six clusters of PNSP grouped into three clusters specific to pre-vaccination period (clusters I, II and III), two clusters specific to post-period (clusters V and VI) and a cluster (IV) that contained clones belonging to the two periods of vaccination. Conclusion Our observations demonstrate a high degree of genetic diversity among PNSP. Genetic clustering among PNSP strains showed that they spread mainly by a restricted number of PNSP clones with vaccine serotypes. PFGE clustering combined with pbp genotyping revealed that vaccination can change the population structure of PNSP.http://link.springer.com/article/10.1186/s12941-017-0200-6Streptococcus pneumoniaeInvasive pneumococcal diseasePenicillin-binding proteinsβ-lactamsSerotypesAntibiotic resistance |
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DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Idrissa Diawara Abouddihaj Barguigua Khalid Katfy Kaotar Nayme Houria Belabbes Mohammed Timinouni Khalid Zerouali Naima Elmdaghri |
spellingShingle |
Idrissa Diawara Abouddihaj Barguigua Khalid Katfy Kaotar Nayme Houria Belabbes Mohammed Timinouni Khalid Zerouali Naima Elmdaghri Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco Annals of Clinical Microbiology and Antimicrobials Streptococcus pneumoniae Invasive pneumococcal disease Penicillin-binding proteins β-lactams Serotypes Antibiotic resistance |
author_facet |
Idrissa Diawara Abouddihaj Barguigua Khalid Katfy Kaotar Nayme Houria Belabbes Mohammed Timinouni Khalid Zerouali Naima Elmdaghri |
author_sort |
Idrissa Diawara |
title |
Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco |
title_short |
Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco |
title_full |
Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco |
title_fullStr |
Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco |
title_full_unstemmed |
Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco |
title_sort |
molecular characterization of penicillin non-susceptible streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in casablanca, morocco |
publisher |
BMC |
series |
Annals of Clinical Microbiology and Antimicrobials |
issn |
1476-0711 |
publishDate |
2017-04-01 |
description |
Abstract Background Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, especially among children and the elderly. The ability to effectively treat pneumococcal infection has been compromised due to the acquisition of antibiotic resistance, particularly to β-lactam drugs. This study aimed to describe the prevalence and molecular evolution of penicillin non-susceptible S. pneumoniae (PNSP) isolated from invasive diseases before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco. Methods Isolates were obtained from the Microbiology Laboratory of Ibn Rochd University Hospital Centre of Casablanca. Serogrouping was done by Pneumotest Kit and serotyping by the Quellung capsular swelling. Antibiotic susceptibility pattern was determined by disk diffusion and E-test methods. The PNSP were analyzed by pulsed-field gel electrophoresis (PFGE) and by genotyping of pbp1a, pbp2b, and pbp2x genes. Results A total of 361 S. pneumoniae isolates were collected from 2007 to 2014. Of these isolates, 58.7% were obtained before vaccination (2007–2010) and 41.3% after vaccination (2011–2014). Of the 361 isolates, 80 were PNSP (22.2%). Generally, the proportion of PNSP between pre- and post-vaccination periods were 31 and 13% (p = 0.009), respectively. The proportion of PNSP isolated from pediatric and adult (age > 14 years) patients decreased from 34.5 to 22.9% (p = 0.1) and from 17.7 to 10.2% (p = 0.1) before and after vaccine implementation, respectively. The leading serotypes of PNSP were 14 (33 vs. 57%) and 19A (18 vs. 14%) before and after vaccination among children. For adults, serotypes 19A (53%) and 23F (24%) were the dominant serotypes in the pre-vaccination period, while serotype 14 (22%) was the most prevalent after vaccination. There were 21 pbp genotypes in the pre-vaccination period vs. 12 for post-vaccination period. PFGE clustering showed six clusters of PNSP grouped into three clusters specific to pre-vaccination period (clusters I, II and III), two clusters specific to post-period (clusters V and VI) and a cluster (IV) that contained clones belonging to the two periods of vaccination. Conclusion Our observations demonstrate a high degree of genetic diversity among PNSP. Genetic clustering among PNSP strains showed that they spread mainly by a restricted number of PNSP clones with vaccine serotypes. PFGE clustering combined with pbp genotyping revealed that vaccination can change the population structure of PNSP. |
topic |
Streptococcus pneumoniae Invasive pneumococcal disease Penicillin-binding proteins β-lactams Serotypes Antibiotic resistance |
url |
http://link.springer.com/article/10.1186/s12941-017-0200-6 |
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