Sequence analysis of bla _CTX-M-28 , an ESBL responsible for third-generation cephalosporin resistance in <i>Enterobacteriaceae</i>, for the first time in India

• Main Authors: Kingsley Jemima, Verghese Susan
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2008-04-01
• Series: Indian Journal of Pathology and Microbiology
• Subjects: &#946;-lactamases; <i> bla</i> _CTX-M-28; <i>Enterobacteriaceae</i>; ESBL; point mutation
• Online Access: http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2008;volume=51;issue=2;spage=218;epage=221;aulast=Kingsley

The most common group of ESBLs not belonging to the <i>bla</i> _TEM or <i>bla</i> _SHV families were termed <i>bla</i> _CTX-M , to highlight their ESBLs&#x2032; greater activity against cefotaxime than against ceftazidime. The presence of nosocomial <i>bla</i> _CTX-M-28 -producing <i>Enterobacteriaceae</i> strains has not been reported earlier in Indian hospitals. The sequences of <i>bla</i> _CTX-M-28 gene from cephalosporin-resistant <i>Enterobacteriaceae</i> were analyzed. The structural gene encodes a 290 amino-acid protein, which is most related to the <i>bla</i> _CTX-M &#946;-lactamases. The conserved K-T-G was identified in the <i>bla</i> _CTX-M-28 protein sequence, but significantly, two point mutations (N&#8594;T) and (F&#8594;S) were identified in the Y-G-N- and S-T-F-K-conserved motifs respectively. These point mutations were seen in all the three sequenced isolates