First description of Extended-Spectrum β-lactamases and OXA-48 carbapenemase in Enterobacteriaceae isolates in Brazzaville, Congo

Background: To characterize genotypically Extended-spetrum-beta-lactamase (ESBL) and OXA-48 carbapenemases producing Enterobacteriaceae especially Klebsiella, Enterobacter, Serratia (KES) and Citrobacter species in portage and infection processes at the Brazzaville Hospital Center.

Methods: The study was carried out for 7 months. Clinical samples (urine, pus and blood cultures) were collected from inpatients and outpatients at the Brazzaville University Hospital. Strains were identified by API20E and confirmed by MALDI-TOF. Antibiotics susceptiibility testing was performed on isolated strains by diffusion method on MH agar plates. ESBL and OXA-48 phenotypes were identified according to the CA-SFM synergy technique and by a decrease in inhibition diameter around the Ertapenem disk and confirmed by PCR and sequencing. MLST K. pneumoniae genotyping of OXA-48 strains was performed.

Results: Thirty-four no duplicate Enterobacteria strains were isolated from thirty-four patients, of which 12/34 (35.29%) were from outpatients and 22/34 (64.70%) from internal patients. Except for imipenem, colistin; the amykacine and fosfomycin, tested antibiotics show high resistance too much of the beta-lactam, as well as a resistance very frequent aminoglycosides, to sulfamides, tetracyclines and Fluoroquinolones. PCR revealed that 30/34 (88.24%) produced ESBLs, of which 2 strains harbors both ESBL and OXA-48 enzymes. blaSHV gene was the most common ESBL gene detected with 20/30 (66.67%), blaCTX-M was detected in 14 isolates (60.87%), blaTEM 15/30 (50%), blaOXA-48 2/30 (6.67%), blaCTX-M-9 1/30 (3.33%). 70% of the isolates (n=24) were isolated from urinesamples. Sequencing of the amplification products revealed that the blaCTX-M1 strains were all CTX-M15; 13 variant enzymes were detected for blaSHV. Four types for TEM. Both strains OXA-48 were OXA-181 non-plasmid-borne and CTXM-9 was CTX-M-27. These strains were resistant to gentamycin and fluoroquinolone. MLST K. pneumoniae OXA-48 showed two different standard sequences known in the ST464 and ST15 literature.

Author(s):

Fils Landry Mpelle

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