Antibiotic resistance pattern, capsular types, and molecular characterization of invasive isolates of Streptococcus pneumoniae in the south of Tunisia from 2012 to 2018

BMC Microbiology

Research

Sonia Ktari¹  Adnene Hammami²  Nourhène Garbi³  Imen Ben Rbeh⁴  Basma Mnif⁵  Faouzia Rhimi⁵  Nourelhouda Ben Ayed⁵  Sonda Maalej⁵ 

[1] Laboratory of Microbiology, Faculty of Medicine Sfax, University of Sfax-Tunisia, Avenue Majida Boulila, 3027, Sfax, Tunisia;Research Laboratory Microorganisms and Human Disease “MPH LR03SP03”, Sfax, Tunisia;Laboratory of Microbiology, Faculty of Medicine Sfax, University of Sfax-Tunisia, Avenue Majida Boulila, 3027, Sfax, Tunisia;Research Laboratory Microorganisms and Human Disease “MPH LR03SP03”, Sfax, Tunisia;Laboratory of Microbiology, Habib Bourguiba University Hospital, Sfax, Tunisia;Medical Genetic Department, HediChaker Hospital, Sfax, Tunisia;Research Laboratory Microorganisms and Human Disease “MPH LR03SP03”, Sfax, Tunisia;Research Laboratory Microorganisms and Human Disease “MPH LR03SP03”, Sfax, Tunisia;Laboratory of Microbiology, Habib Bourguiba University Hospital, Sfax, Tunisia;

关键词: Invasive pneumococcal disease;    Serotype;    Antibiotic resistance;    Clonal complex;    MLST;   

DOI  :  10.1186/s12866-023-02784-2

 received in 2022-11-21, accepted in 2023-01-25,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundStreptococcus pneumoniae remains a leading cause of morbidity and mortality worldwide. In this study, we sought to analyze serotype distributions, antibiotic resistance, and genetic relationships of 106 clinical invasive pneumococcal isolates recovered in Tunisia between 2012 and 2018, prior to the routine use of pneumococcal conjugate vaccines (PCV).MethodsWe used multiplex PCR, the disk diffusion method and/or E-test, and multi-locus sequence typing (MLST).ResultsThe most frequent serotypes were 14 (17%), 19F (14.2%), and 3 (11.3%). Of the 106 S. pneumoniae isolates, 67.9% were penicillin non-susceptible (29.4% were resistant), 45.3% were amoxicillin non-susceptible (17% were resistant), and 16% were cefotaxime non-susceptible. For antibiotics other than β-lactams, resistance rates to erythromycin, tetracycline, cotrimoxazole, and chloramphenicol were 62.3, 33, 22.6, and 4.7%, respectively. Two isolates were non-susceptible to levofloxacin. Among 66 erythromycin-resistant pneumococci, 77.3% exhibited the cMLSB phenotype, and 87.9% carried ermB gene. All tetracycline-resistant strains harbored the tetM gene. The potential coverage by 7-, 10-, and 13-valent pneumococcal conjugate vaccines were 55.7, 57.5, and 81.1%, respectively. A multilocus sequence typing analysis revealed great diversity. Fifty different sequence types (STs) were identified. These STs were assigned to 10 clonal complexes and 32 singletons. The most common STs were 179, 2918, 386, and 3772 – related mainly to 19F, 14, 6B/C, and 19A serotypes, respectively.ConclusionsThis study demonstrated that the majority of the serotypes of invasive pneumococci in the Tunisian population were 14, 19F, and 3. Moreover, we noted a high degree of genetic diversity among invasive S. pneumoniae isolates. The highest proportions of antibiotic non-susceptible isolates were for penicillin, erythromycin, and tetracycline. Further molecular characteristics are required to monitor the genetic variations and to follow the emergence of resistant pneumococci for the post-vaccination era in Tunisia.

【 授权许可】

CC BY   
© The Author(s) 2023

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