Background The study objective was to determine the carriage and serotype distribution of Streptococcus pneumoniae among children in Accra, Ghana, five years after the introduction of the pneumococcal conjugate vaccine (PCV-13) in 2012. Methods Nasopharyngeal swab samples were collected from 410 children below 5 years of age in Accra, Ghana, from September to December, 2016. Pneumococcal isolates were identified by optochin sensitivity and bile solubility. Serotyping was performed using the latex agglutination kit and Quellung reaction. The isolates were furthermore tested for antimicrobial susceptibility for different antimicrobials, including penicillin (PEN). Twelve isolates including seven non-typeable (NT) isolates were characterized using whole-genome sequencing analysis (WGS). Results The overall carriage prevalence was found to be 54% (95% CI, 49–59%), and 20% (95% CI, 49–59%) of the children were carrying PCV-13 included serotypes, while 37% (95% CI, 33–42%) of the children were carrying non-PCV-13 serotypes. Based on the serotype distribution, 33% of all observed serotypes were included in PCV-13 while 66% were non-PCV-13 serotypes. The dominating non-PCV-13 serotypes were 23B, 16F, and 11A followed by PCV-13 serotypes 23F and 19F. The PCV-13 covers the majority of resistant isolates in Accra. A proportion of 22.3% of the isolates showed intermediate resistance to penicillin G, while only one isolate showed full resistance. Forty-five isolates (20.5%) were defined as multidrug-resistant (MDR) as they were intermediate/resistant to three or more classes of antimicrobials. Of the seven NT isolates characterized by WGS, four showed highest match to genotype 38, while the remaining three showed highest match to genotype 14. Four MDR serotype 19A isolates were found to be MLST 320. Conclusion PCV-13 introduced in Ghana did not eliminate PCV-13 covered serotypes, and the carriage rate of 54% in this study is similar to carriage studies from pre PCV-13 period. However, the penicillin non-susceptible isolates have been reduced from 45% of carriage isolates before PCV-13 introduction to 22.3% of the isolates in this study. Continuous monitoring of serotype distribution is important, and in addition, an evaluation of an alternative vaccination schedule from 3 + 0 to 2 + 1 will be important to consider. Electronic supplementary material The online version of this article (10.1186/s12887-019-1690-5) contains supplementary material, which is available to authorized users.

Nasopharyngeal carriage of aerobic Gram-negative bacilli (GNB) may precede the development of invasive respiratory infections. We assessed the prevalence of nasopharyngeal carriage of aerobic GNB and their antimicrobial resistance patterns among healthy under-five children attending seven selected day-care centres in the Accra metropolis of the Greater Accra region of Ghana from September to December 2016. This cross-sectional study analysed a total of 410 frozen nasopharyngeal samples for GNB and antimicrobial drug resistance. The GNB prevalence was 13.9% (95% CI: 10.8–17.6%). The most common GNB were Escherichia coli (26.3%), Klebsiella pneumoniae (24.6%), and Enterobacter cloacae (17.5%). Resistance was most frequent for cefuroxime (73.7%), ampicillin (64.9%), and amoxicillin/clavulanic acid (59.6%). The organisms were least resistant to gentamicin (7.0%), amikacin (8.8%), and meropenem (8.8%). Multidrug resistance (MDR, being resistant to ≥3 classes of antibiotics) was observed in 66.7% (95% CI: 53.3–77.8%). Extended-spectrum beta-lactamase (ESBL)-producing bacteria constituted 17.5% (95% CI: 9.5–29.9%), AmpC-producing bacteria constituted 42.1% (95% CI: 29.8–55.5%), and carbapenemase-producing bacteria constituted 10.5% (95% CI: 4.7–21.8%) of isolates. The high levels of MDR are of great concern. These findings are useful in informing the choice of antibiotics in empiric treatment of GNB infections and call for improved infection control in day-care centres to prevent further transmission.