In vitro synergy of fusidic acid and amikacin against methicillin resistant staphlococcus aureus

To test in vitro combination of fusidic acid and amikacin against infections caused by methicillin resistant Staphlococus aureus [MRSA]. In vitro study conducted in Department of Pharmacology and Microbiology, Dr. Ziauddin Medical University. The duration of study was March 2004- February 2005. Antibiotic susceptibility testing was done by Kirby Bauer"s disc diffusion method and by minimum inhibitory concentration [MIC] by broth macrodilution and checkerboard technique for synergy. FIC [fractional inhibitory concentrations] were calculated. MIC of fusidic acid was 0.03-1micro g/ml and amikacin 0.5-16 micro g/ml respectively. The combination of these demonstrated synergy. Evidence of synergy correlated directly with the MICs of fusidic acid and amikacin. Combination therapy with fusidic acid and amikacin may be a reasonable alternative in the treatment of infections caused by MRSA isolates and encourages clinical evaluation

Frequency of isolation of Shigella Serogroups/Serotypes and their antimicrobial susceptibility pattern in children from slum areas in Karachi

To assess the frequency of serogroups and serotypes, as well as the antimicrobial susceptibility pattern of Shigella species isolated from known cases of diarrhoea and dysentery from Karachi, Pakistan. A cross-sectional study was conducted between January 2002 and March 2003 at Aga Khan University on stool samples received from children with diarrhoea and dysentery from four low socio-economic areas [Sultanabad, Rehri Goth, Hijrat and Sherpao colony] of Karachi. Stool samples yielding growth of Shigella species, were further identified for serotypes by slide agglutination. Antibiotics susceptibility was performed by Kirby Bauer disk diffusion method. Out of 4688 stool samples received, 193 [4.1%] were positive for Shigella species. Shigella flexneri was the predominant serogroup [58%] followed by Shigella sonnei [16%], Shigella boydii [15%] and Shigella dysentriae being the least common [11%]. A number of serotypes were isolated in each serogroup, 8 serotypes in S. flexneri, 8 serotypes in S. dysenteriae, 9 serotypes in S. boydii, and Phase 1 and 2 were found in S. sonnei. 17% isolates remained non-serotypeable. All isolates were susceptible to Ofloxacin and Ceftriaxone, high rate of resistance was observed in Cotrimoxazole [87.75%] and Ampicillin [55.5%]. Emerging resistance against Nalidixic acid [39%] was observed. Shigella still accounts for a significant proportion of bacillary dysentery in many tropical and subtropical countries. Serotype identification can help in devising strategies such as development of effective vaccine for controlling this problem. Increasing antibiotic resistance against commonly prescribed drugs signify that treatment options have become difficult in cases of severe dysentery [JPMA 55:184;2005]

Cephalosporin resistant shigella flexneri from a clinical isolate - a rare finding

Shigellosis is an important public health problem, especially in developing countries. Antibiotic treatment of dysentery aimed at resolving diarrhea or reducing its duration, and to prevent transmission to other close contacts. Isolates with resistance to first line drugs have been reported throughout world, third generation cephalosporins and quinolones are mainstay of treatment. Shigella flexneri resistant to third generation cephalosporins in a clinical isolate is a rare finding, and this has been reported for the first time in Pakistan