Emergence of CTX-M-15 producing E. coli O25b-ST131 clone in a tertiary care hospital of Bangladesh
- Author:
Nurjahan Begum
;
SM Shamsuzzaman
- Publication Type:Journal Article
- Keywords:
E. coli;
blaCTX-M-15;
O25b-ST131 clone;
uropathogens;
Bangladesh
- From:The Malaysian Journal of Pathology
2016;38(3):241-249
- CountryMalaysia
- Language:English
-
Abstract:
Background: Extended-spectrum β-lactamase (ESBL) producing uropathogens has become prevalent
worldwide. E. coli O25b-ST131 clone, associated with blaCTX-M-15, has been reported from
many parts of the world and is frequently associated with multidrug resistance. Thus far, there are
no reports about this clone in Bangladesh. The objective of this study was to investigate ESBL
producing uropathogens and to survey the prevalence of E. coli O25b-ST131 clone among ESBL
positive E. coli isolates. Methods: From symptomatic urinary tract infection cases, a total of 800
urine samples were collected. Bacterial identification and antimicrobial susceptibility testing was
performed using established methods. Screening of ESBL producers was done using the disk diffusion
method. Screening positive isolates were phenotypically confirmed by double disk synergy (DDS)
test. Genes encoding ESBLs (blaCTX-M-15, blaOXA-1) were identified both by PCR and DNA
sequencing. Phenotypic positive ESBL producers were also studied by PCR for existence of class
1 integron. Subsequently, O25b-ST131 clone was identified by allele specific PCR. Results: Of
138 gram-negative uropathogens, 45 (32.6%) were positive for ESBLs. ESBL producers showed
high frequency of antimicrobial resistance except imipenem. Among 45 ESBL producers, 36 (80%)
produced blaCTX-M-15, 18 (40%) produced blaOXA-1. Fifteen (33.3%) strains simultaneously
produced both blaOXA-1 and blaCTX-M-15. Class 1 integron was present in 30 (66.7%) isolates.
Of the 31 blaCTX-M-15 positive E. coli, 22 (71%) were positive for E. coli O25b-ST131 clone and
all (100%) belonged to B2 phylogenetic group. Conclusion: Rising antimicrobial resistance among
uropathogens, and especially the emergence of blaCTX-M-15 positive E. coli O25b-ST131 clone in
Bangladesh has provided urgency to the development of novel preventive and therapeutic strategies.
