Resistance rates to Nitrofurantoin, Nalidixic acid
and Ampicillin were high.
Strain type###AMP (10 Mu g)###C (30 Mu g)###SXT (25 Mu g)###CRO (30 Mu g)###CFM (5 Mu g) Nalidixic acid
(30 Mu g)###CIP (5 Mu g)
typhi isolates should be screened for Nalidixic acid
resistance along with Ciprofloxacin and it is advised to change the antibiotic if the isolate found to be is Nalidixic acid
flexneri, the commonest isolate in our study, showed a high degree of resistance to most commonly-used drugs, such as nalidixic acid
All Bt isolates were sensitive to erythromycin, kanamycin, neomycin, nalidixic acid
, oxytetracyclin, polymixin, streptomycin, tetracyclin and vancomycin except for SBS-Bt 11 which was resistant to nalidixic acid
, oxytetracyclin, polymixin and vancomycin; SBS-Bt 18 which was resistant to nalidixic acid
; SBS-Bt 23 which was resistant to nalidixic acid
, polymixin and tetracycline; SBS-Bt 26 which was resistant to erytheromycin, nalidixic acid
, polymixin and tetracycline; SBS-Bt 29 and 32 were resistant to polymixin and streptomycin; SBS-Bt 34 was resistant to oxytetracyclin; SBS-Bt 37 was resistant to neomycin, polymixin and streptomycin; SBS-Bt 41 was resistant to erytheromycin,
We observed more frequent resistance to nalidixic acid
than to norfloxacin and ciprofloxacin (9% and 4%, respectively).
cholerae O1 isolates were resistant to some of the commonly used antibiotics like co-trimoxazole, nalidixic acid
Antimicrobial susceptibility patterns were determined using commercial antimicrobial disks (HiMedia, Mumbai): Chloramphenicol (30 [micro]g), nalidixic acid
(30 [micro]g), ampicillin (10 [micro]g), azithromycin (15 [micro]g), co-trimoxazole (1.
Sulfamethoxazole/trimethoprim resistance was observed initially, followed by resistance to nalidixic acid
, erythromycin, and chloramphenicol during the early 2000s.
Single mutations in gyrA or parC can cause resistance to the older quinolones, such as nalidixic acid
, as well as a reduction in the potency of fluoroquinolones, which is reflected in an increase in the minimal inhibitory concentration (MIC) [6,8,17].
Each isolate was tested for susceptibility to ampicillin, chloramphenicol, trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid
, ciprofloxacin, mecillinam, ceftriaxone, and gentamicin by the Kirby-Bauer disc-diffusion method in 1991-1992 (11,18).
coli showed greater sensitivity to nitrofurantoin (47%) and lesser sensitivity to nalidixic acid
(15%) as compared to Klebsiella pneumoniae which showed 15% sensitivity to nitrofurantoin and 24% to nalidixic acid
in our study similar to another study.