In vitro susceptibility of typhoidal Salmonellae against newer antimicrobial agents: a search for alternate treatment options.
OBJECTIVE
To determine the minimum inhibitory concentrations (MICs) of ceftriaxone, azithromycin, pefloxacin, cefipime and imipenem for Salmonella Typhi (S. Typhi) and Paratyphi.


METHODS
One hundred and fifty four isolates of Salmonella Typhi and S. Paratyphi A, B and C growing in blood culture were selected. MICs of ceftriaxone, azithromycin, pefloxacin, cefipime and imipenem were performed by agar dilution method as recommended by clinical laboratory standard institutes.


RESULTS
MIC90 of azithromycin and pefloxacin was 8 microg/ml, cefipime was 0.06 microg/ml and imipenem was 0.5 microg/ml. None of the strains were found to be resistant to ceftriaxone but 3 isolates showed higher MIC value of 2 microg/ml.


CONCLUSIONS
Azithromycin appears a suitable alternate for the treatment of typhoid in the community. Imipenem and cefipime are good options in complicated cases to be treated in hospital settings. Pefloxacin cannot be used as MICs are higher. Presence of isolates with higher MIC of ceftriaxone is serious and stresses upon continuous laboratory surveillance to guide clinicians appropriately.
Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan.
Saba
S
Qaiser
Seema
S
Irfan
Erum
E
Khan
Tanwir
T
Ahsan
Afia
A
Zafar
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D010284:Paratyphoid Fever / Q000188:drug therapy* / Q000382:microbiology; D012482:Salmonella paratyphi A / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D012485:Salmonella typhi / Q000187:drug effects* / Q000302:isolation & purification; D014435:Typhoid Fever / Q000188:drug therapy* / Q000382:microbiology; D055815:Young Adult
D000900:Anti-Bacterial Agents