Researchers have identified an emergence of Salmonella enterica
serotype Kentucky ST198 isolates with increased resistance to ciprofloxacin in
France, England, Wales, Denmark and the United States between 2005 and
2008.
“This increase is due to the emergence of the ST198-X1 CIPR
Kentucky clone … Although the first infections were reportedly acquired in
Egypt during 2002-2005, the geographic spread has increased to include
countries throughout Africa and the Middle East,”
François-Xavier Weill, MD, PhD, of the WHO Collaborating Center
for Reference and Research on Salmonella, in Paris, and colleagues wrote in the
study.
Data were pooled from national surveillance systems in France, England,
Wales, Denmark, and the United States for comprehensive molecular epidemiologic
analyses on human and nonhuman isolates.
Weill and colleagues identified 489 cases of S. enterica serotype
Kentucky ST198 between 2002 (n=3) and 2008 (n=174).
Among S. enterica serotype Kentucky cases with travel information
available (n=307), 272 reported international travel within the 2 weeks before
illness onset. Between 2002 and 2005, most patients reported travel to
northeastern and eastern Africa; as of 2006, cases reported travel to
northeastern, eastern, western and northern Africa, and the Middle East.
In addition, the researchers identified poultry as a significant agent
for infection by this strain. The strain was isolated from chickens and turkeys
in Ethiopia, Morocco and Nigeria.
“The unregulated use of antimicrobials in food-producing animals is
a major hazard for public health,” Weill told Infectious Disease News.
“Although this issue has been addressed by the majority of developed
countries, this, and food safety in general, is not the first priority of
developing countries. The use of fluoroquinolones for the empirical treatment
of severe human nontyphoidal salmonella infections should be carefully weighed
and eventually guided by the antimicrobial susceptibly testing.”
The researchers said they suggest implementation of continued
surveillance and appropriate control measures by national and international
authorities to limit the spread of the strain. – by Ashley DeNyse
For more information:
- Hedberg CW. J Infect Dis. 2011;doi:10.1093/infdis/jir392.
- Le Hello SL. J Infect Dis. 2011;doi:10.1093/infdis/jir409.
Disclosure: This research was supported by the Institut Pasteur;
the Danish Research Agency (274-05-0117); the WHO Global Foodborne Infections
Network; the Institut National de la Recherche Agronomique; the Health
Protection Agency; the Statens Serum Institute; the CDC; the Institut Pasteur
du Maroc; the University of Ibadan; the Agence Francxaise de
Se’curite’ Sanitaire des Aliments; the Re’seau international des
Instituts Pasteur et instituts associe’s; and the Institut de Veille
Sanitaire. Permanent financial support came from the institutes, universities
or national agencies of the authors. The work conducted at the National Food
Institute, Technical University of Denmark was supported by the WHO Global
Foodborne Infections Network (www.who.int/gfn) and the Danish Research Agency
(274-05-0117).
Herbert L. DuPont, MD
This is one more study showing the emergence of antibiotic-resistant
bacteria that will complicate therapy. For milder cases of salmonella
gastroenteritis in healthy persons, antibiotics are not needed. For bacteremic
salmonellosis, characteristically seen in people at extremes of age and
patients with underlying medical problems, including cancer and
immunosuppression, end-stage renal failure on hemodialysis, sickle cell anemia
and inflammatory bowel disease, antibiotics can be life-saving. The
fluoroquinolone antibiotics are drugs of choice for systemic salmonellosis in
older children and adults. Having a fluoroquinolone-resistant strain of
Salmonella showing widespread geographic dissemination is of great public
health significance and underscores the need for typing of strains of
Salmonella and performing antimicrobial susceptibility testing to guide
therapy.
– Herbert L. DuPont, MD
Infectious Diseases News Editorial Board member
Disclosure: Dr. DuPont reports no relevant
financial disclosures.