Summary
A
comparative study was made of 22 strains of Salmonella Hadar
isolated from victims of an outbreak of food illness in the Abruzzi
region of Italy in 2000 and 21 strains of the same serotype isolated
from poultry meat and human stool samples in the Abruzzi and Molise
regions between 2000 and 2001. The aim of the investigation was
to provide an epidemiological interpretation of the food illness
outbreak to establish the degree of similarity between the S.
Hadar strains isolated from victims of the outbreak and those isolated
from poultry meat (identified but unconfirmed as the possible source
of infection) and from other human samples received in the laboratory.
Pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic
DNA (RAPD) were used to identify the genotypes and antimicrobial
resistance patterns were determined. PFGE analysis of the restriction
patterns obtained with XbaI and BlnI led to the identification
of 12 pulsotypes in three groups. RAPD did not provide any information,
as it was unable to differentiate between the strains isolated from
food illness victims with gastroenteritis. Antimicrobial resistance
tests revealed multiple resistance patterns and no strains were
found to be resistant to ciprofloxacin or to the other quinolones
tested. The poultry strains were found to be resistant to nalidixic
acid, while the resistance in human strains was 31.8%. A combined
analysis of resistance patterns and pulsotypes revealed four resistance
patterns; the pattern associated with the outbreak was not correlated
with the others present in the same period. This work suggests that
a study of the relationship between different strains of the same
serovar requires the implementation of different analytical methods.
Keywords
Antibiogram,
Animal, Food, Hadar, Humans, Illness, Poultry, Pulsed-field gel
electrophoresis, Random amplified polymorphic DNA, Salmonella,
Zoonosis. |