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Detection of mutations in
the gyrA of clinical Salmonella spp.
U. Govinden1*, C. Mocktar1, P.
Moodley2, 3, A. W. Sturm2
and S. Y. Essack1
1School
of Pharmacy and Pharmacology, University of KwaZulu-Natal,
Private Bag X54001, Durban, 4000, South Africa.
2Department
of Medical Microbiology, University of
KwaZulu-Natal, Durban, 4000, South Africa.
3Department
of Infection Control, University of KwaZulu-Natal, Durban,
4000, South Africa.
*Corresponding author. E-mail:
Govindenu@ukzn.ac.za.
Tel: + 2731-2608251.
Fax +
2731-2607792.
Accepted
29 December, 2009 |
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The high prevalence of resistance to nalidixic acid and
reduced susceptibility to ciprofloxacin of Salmonella
spp. obtained from stool samples of neonates presenting with
acute diarrhea in 2001 at the King Edward VIII hospital in
Durban, South Africa, prompted this study to determine if
there were any mutations in the QRDR of these isolates and
to search for the qnrA gene. All isolates with
nalidixic acid MICs > 48 µg/ml had the single mutation D87N,
or D87G in the QRDR of the gyrA gene, and only 2
strains had an additional mutation; S83L and S83F
respectively. The mutation S83T was present in only one
isolate with the nalidixic acid MIC of 10 µg/ml whilst the 6
other strains with nalidixic acid MICs < 10 µg/ml had no
changes in the QRDR of the gyrA gene. The qnrA
gene was not found. These findings indicate that there are
mutations in the gyrA of Salmonella isolates which
could contribute to resistance to nalidixic acid with
reduced susceptibility to ciprofloxacin and there is the
co-expression of quinolone and extended-spectrum ß-lactam
resistance among Salmonella spp.
Key
words:
Quinolone resistance, mutations in gyrA. |
