Comparison of disk susceptibility test of gram-negative rods with MIC for cefoperazone- sulbactam compination

Multi drug resistance [MDR] Acinetobacter to almost all antibiotics has now become a major problem in most hospitals world wide. Cefoperazone /sulbactam and Polymyxin are among the only antibiotics still sensitive against MDR Acinetobacter species. Since Clinical and Laboratory Standards Institute [CLSI] and British Society of Antimicrobial Chemotherapy [BSAC] working party have not included these antibiotics, most clinical laboratories are not performing in-vitro susceptibility against them. We performed a comparative study to find out the sensitivity and specificity of disk diffusion [DD] for in vitro susceptibility test of cefoperazone /subactam with MIC against isolates of Acinetobacter. In-vitro susceptibilities of a total of 42 isolates of Acinetobacter species were performed by MIC [Estrip method] and DD methods. Sensitivity and specificity of the DD was calculated with MIC as standard. Results were analyzed on SPSS version 13.0 and expressed as scattergram. A total of 42 Acinetobacter species were isolated. All were resistant to Cefoperazone alone when checked by DD method. Twenty two were sensitive to Cefoperazone/sulbactam by MIC [< 32/16 Mu g/ml] and 20 were resistant to Cefoperazone/sulbactam [> 32/16 Mu g/ml]. 19 [86%] of sensitive isolates were also sensitive by DD, 18 [86%] of resistant isolates were also resistant by DD. Sensitivity and Specificity of DD were 86% each. Correlation was significant at the 0.01 level [2-tailed]. Among 6/42 discrepancies, 5 were minor and 1 was major. DD method for reporting antimicrobial sensitivity of Acinetobacter species against Cefoperazone/Sulbactam is consistent with MIC with a sensitivity and specificity of 86% each

Mechanism of neuronal injury in cerebral venous thrombosis

The impact of CVT on the brain is wide spectrum, ranging from completely normal parenchyma to brain oedema and/or haemorrhage. Multiple factors relate to neuronal injury in CVT including; dural sinus pressure, increased venous flow velocities, collateralization of venous channels, rate of occlusion, development of cytotoxic and vasogenic oedema, recanalization and accelerated myelination. It is suggested that recanalization of occluded vein, as well as, the presence or absence and the efficiency of intracranial venous collaterals, may have an impact on the extent of brain tissue damage and hence the prognosis of acute CVT

Rapidly developing Optic Neuritis secondary to Ethambutol: possible mechanism of injury

Optic neuritis has been described among the toxic effects of Ethambutol. This side effect is dose related. The mean duration of Ethambutol induced optic neuritis [EON] is three months. We report a case of EON after few days of exposure to Ethambutol and the symptoms resolved after discontinuation of Ethambutol. This most likely represents an idiosyncratic reaction which is different as compared to dose related optic neuritis