Provided by Cognitive Sciences ePrint Archive
Published Quarterly
Mangalore, South India
ISSN 0972-5997
Vol ume 3, Issue 4; October-December 2004
Original Article
Plasmid-Encoded Multidrug Resistance of Salmonella typhi and some Enteric
Bacteria in and around Kolkata, India: A Preliminary Study
Shyamapada Mandal, Research Fellow,
Manisha Deb Mandal, Research Fellow,
Nishith Kumar Pal, Professor and Head,
Department of Bacteriology and Serology, Calcutta School of Tropical Medicine,
C. R. Avenue, Kolkata-700 073, India.
Address for Correspondence:
Nishith Kumar Pal,
Professor and Head,
Department of Bacteriology and Serology,
Calcutta School of Tropical Medicine,
C. R. Avenue, Kolkata-700 073, India.
E-mail: [email protected]
Citation: Mandal S, Mandal MD, Pal NK. Plasmid-Encoded Multidrug Resistance of Salmonella typhi and
some Enteric Bacteria in and around Kolkata, India: A Preliminary Study. Online J Health Allied Scs.
2004;4:2
URL: http://www.ojhas.org/issue12/2004-4-2.htm
Open Access Archive: http://cogprints.ecs.soton.ac.uk/view/subjects/OJHAS.html
Abstract:
The present study investigates the occurrence of R-
plasmid in Salmonella typhi isolates from enteric fever
cases in and around Kolkata (1991-2001), India
following in vitro conjugation experiments, isolation
of plasmid DNAs and agarose gel electrophoretic
analysis. The multidrug resistant (MDR) S. typhi
strains contained a transferable plasmid conferring
resistance to ampicillin, chloramphenicol,
cotrimoxazole and tetracycline. The plasmid encoding
ACCoT-resistance of Escherichia coli, Klebsiella
pneumoniae and Proteus vulgaris were conjugative and
co-migrated with the plasmid of MDR S. typhi
isolates. The antibiotic sensitive S. typhi isolates did
not contain any plasmid. Thus the findings of the
present study confirmed the instability of the R-
plasmid in S. typhi, and that the antibiotic sensitive S.
typhi strains acquired the R-plasmid from other
enteric bacteria such as E. coli, K. pneumoniae and
P.vulgaris to undergo a suitable adaptation for
survival in the changing antibiotic environment.
Key Words: Salmonella typhi, multidrug resistance,
conjugative R-plasmid
Introduction
Salmonella typhi is noteworthy in the etiology of
outbreaks and sporadic cases of typhoid fever, which
remains as an important public health problem,
causing 16 million cases of the disease and about
600,000 deaths, annually, all over the world.(1) There
has been increasing concern about the prevalence of
multidrug resistant (MDR) S. typhi strains in
developing countries. Several reports indicated MDR
S. typhi with plasmid-mediated resistance to
conventional antityphoid antibiotics: chloramphenicol
(C), ampicillin (A) and cotrimoxazole (Co) thriving in
different parts of the world including India.(2-11) In
the present study, in order to search the probable host
bacteria of a plasmid conferring resistance to A, C, Co
and tetracycline (T) among outbreak causing as well
as sporadic isolates of S. typhi in and around Kolkata,
India, we investigated the occurrence of R-plasmids
among MDR isolates of Escherichia coli, Proteus
vulgaris, and Klebsiella pneumoniae from different
clinical cases.