ABSTRACT
Objective: Streptococcus pneumoniae (S. pneumoniae) nasopharyngeal carriage has significantly decreased after the generalization of pneumococcal vaccination worldwide. This study sought to investigate changes in S. pneumoniae carriage rates, serotype distribution and penicillin non-susceptibility following the generalization of 10-valent pneumococcal conjugate vaccine. Methods: A prospective study was conducted in Marrakesh, Morocco, between 2017 and 2018, among healthy children attending vaccination centers. We collected nasopharyngeal swabs and questionnaire data for each child. Using univariate logistic regression, we analyzed the association between S. pneumoniae carriage and various risk factors. Comparisons of serotype diversity and penicillin resistance between 2017 and 2018 and the period before introduction of vaccination (2008-2009, n = 660) were performed using Simpson index and the chi-squared test, respectively. Results: During 2017-2018, 515 children aged between 6 and 36 months participated. The S. pneumoniae carriage rate was 43.3%. Looking at the distribution serotypes, the rate of PCV10 serotypes rate was only 9.6%. Among non-vaccine serotypes, an increase in serotypes 6C/6D (22; 14%), 19B/19C (17; 10.8%), and 15B/15C (11; 7%) was observed. A particular increase in serotype diversity was also observed after the generalization of PCV10 (p < 0.001). S. pneumoniae non-susceptible to penicillin decreased, reaching a rate of 26.6% in 2017-2018. Conclusion: The significant change in S. pneumoniae carriage, serotype distribution, and penicillin resistance highlights the effectiveness of the pneumococcal conjugate vaccine among children in Marrakesh, Morocco.
ABSTRACT
Streptococcus pneumoniae (S. pneumoniae) remains one of the most important pathogens causing childhood infections. The spread of antibiotic-resistant bacteria is a leading cause of treatment failure in children. The purpose of this investigation is to report the antibiotic and multidrug resistance (MDR) of S. pneumoniae strains isolated from healthy children throughout the years 2020-2022. Antimicrobial susceptibility testing of S. pneumoniae strains in selected antimicrobials was performed using disk diffusion and E-test methods on bloodMueller-Hinton agar. The antimicrobials tested included oxacillin, amoxicillin, ceftriaxone, norfloxacin, gentamicin, vancomycin, erythromycin, clindamycin, pristinamycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. A total of 201 S. pneumoniae strains were isolated from the nasopharynx of healthy children in Marrakesh, Morocco. The highest rate of resistance of S. pneumoniae was found in penicillin (57.2%), followed by tetracycline (20.9%), and erythromycin (17.9%). The rates of resistance to clindamycin, trimethoprim-sulfamethoxazole, and chloramphenicol were 14.9%, 4%, and 1.5%, respectively. All isolates were susceptible to norfloxacin, gentamicin, vancomycin, and pristinamycin. Approximately 17% of all S. pneumoniae strains were resistant to at least three different antibiotic families. This study showed a low rate of antibiotics resistance among nasopharyngeal S. pneumoniae strains, and it is thus essential to monitor S. pneumoniae susceptibility in healthy children.
ABSTRACT
Background and Objectives: Streptococcus pneumonia (S. pneumoniae) is one of the most frequent pathogens leading to a variety of clinical manifestations. The effects of S. pneumoniae carriage on acute otitis media (AOM) are poorly studied. The study aimed to assess the serotype's distribution and antimicrobial susceptibility in children with AOM after the implementation of the pneumococcal conjugate vaccine (PCV) in Morocco. Materials and Methods: We conducted a prospective study of AOM children aged 6 to 36 months who visited pediatric centers in Marrakesh between January to June 2018. Parents were asked to complete a questionnaire and a swab was collected from each child. The S. pneumoniae strains were further identified (Hemolysis, optochin sensitivity, and agglutination test), serogrouped (IMMULEX PNEUMOTEST agglutination test), serotyped (Real time PCR) and tested for antimicrobial susceptibility. Results: The S. pneumoniae carriage rate was 49.7% (87/175). As estimated, non-vaccine serotypes (NVT) were most prevalent (51/63; 81%). The most frequent serotypes were 6C/6D (12.7%), 10 (9.5%), and 19B/19C (9.5%). The S. pneumoniae strains that were isolated showed a diminished susceptibility to penicillin G with a rate of 27.5%. Penicillin non-susceptible pneumococci (PNSP) was mostly associated with NVT. More than 90% of S. pneumoniae isolates were susceptible to chloramphenicol (97.5%), clindamycin (97.5%), erythromycin (97.5%), levofloxacin (97.5%), pristinamycin (97.5%), gentamicin (92.5%), and teicoplanin (92.5%). Conclusion: Important nasopharyngeal carriage prevalence was reported among children with AOM. The study showed that new NVT are emerging, including 6C/6D and 10. Furthermore, susceptibility was significantly higher against all antibiotics tested except for penicillin G and amoxicillin.
