Naslov
Extended-spectrum beta-lactamases (ESBLs) from various Enterobacteriaceae isolated at Yaounde Central Hospital (YCH), Cameroon

Autori
Gangue-Pieboi, Joseph ; Bedenić, Branka ; Koulla-Shiro, S. ; Randegger, Corinne ; Ndumbe, P. ; Adiogo, D. ; Ngasami, P. ; Haechler, H.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts of the 9^th International Congress on Infectious Diseases / - Buenos Aires, 2000, 25-25

Skup
9^th International Congress on Infectious Diseases

Mjesto i datum
Buenos Aires, Argentina, 10.04.2000. - 13.04.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
extended-spectrum beta-lactamases; Enterobacteriaceae; ceftazidime; microbial resistance

Sažetak
In a recent study, 14 Klebsiella pneumoniae (kp), 11 Escherichia coli ((Eco), 3 Citrobacter freundii (Cfr) and 1 Enterobacter cloacae (Ecl) strains isolated from patients in YCH, were found to be resistant to oxymino-cephalosporins (CAZ-ceftazidime, CTX-cefotaxime, CRO-ceftriaxone) and/or monobactam aztreonam (ATM) by standard disk-diffusion testing. There was a synergy between amoxycillin-clavulanate (AMC) and CAZ, CTX, CRO and ATM suggesting the presence of ESBL. Oxymino-cephalosporin and monobactam resistance was transferred to E. coli recipient (Eco HK 225) by conjugation (frequency of transfer: 2x10^-4 per input donor). Twelve of 29 strains were studied, and 6 Kp, 4 Eco, 1 Cfr and 1 Ecl were shown to possess a conjugative plasmid. Resistance determinants against the following non β -lactam antibiotics were co-transferred to Eco HK 225: (i) Gentamicin (Gm) (5 cases), and Trimethoprim/sulphametozaloe (3 cases). In contrast, resistance to cefoxitin (FOX) was not transferred. Crude extracts of ESBLs obtained by sonication of the transconjugants did not affect the inhibition zones of Eco HK 225 around FOX, AMC and imipenem disks. They did, however, inhibit the activities of amoxycillin, piperacillin, cefazolin, FOX, CRO, CTX, CAZ, and ATM. PCR was performed using plasmid DNA from transonjugants as template, and primers specific for blaSHV and blaTEM genes, respectively. The amplification products were sequenced directly . The deduced amino-acid sequence analysis according to the scheme of Ambler showed: (i) that eleven of twelve enzymes carried substitutions relative to SHV-1 at amino-acid position 35, 238 and 240 indicating SHV-12, and (ii) silent mutations at codons 222 and 268 that are of epidemiological interest. SHV-12 is the most prevalent ESBL at our hospital. The dissemination of this ESBL among various species could be due to 2 or 3 plasmids, which carry blaSHV-12 among other resistance genes, since our transconjugants have different resistance profiles. This is the first description of SHV-12 β -lactamase in Cameroon.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA