A patient of Acute lymphocytic leukemia with fever and neutropenia develops diarrhoea after administration of amoxicillin therapy, which of the following organism is most likely to be the causative agent -

Ans. is 'b' i.e., Clostridium difficile It is a case of Clostridium difficile - induced diarrhoea.Clostridium difficile should always be considered as a possible cause of diarrhoea in cancer patients who have received antibiotics.Two factor favours this diagnosis a) Cancer patient - Cancer patients are predisposed to the development of clostridium difficile diarrhoea as a consequence of chemotherapy alone, (do not always require antibiotics).This is much more common among patients with AML and ALL, than among those with other types of cancer. So these cancer patient may be positive in cl. difficile toxin tests even before receiving antibiotics, b) Ingestion of amoxicillin - Clostridium difficile induced diarrhoea is associated with antibiotic useAntibiotics associated with Clostridium difficile associated disease are -- Clindamycin}First antibiotics associated- Ampicillin}-with Clostridium difficile- Cephalosporins }associated disease2nd and 3rd generation cephalosporinsCefotaxime Ceftriaxone}These agents are now most- Cefuroxime}-- frequently responsible for- Ceftazidime}this condition- Penicillin/p lactamase combination - Ticarcillin/clavulanate}- Pose significantly less- Piperacillin/tazobactam}riskHowever all antibiotics including Vancomycin and Metronidazole have been found to carry a risk of subsequent Clostridium difficile associated diarrhoea.More about Clostridium difficile induced diarrhoeaAlso knowT/T of Clostridium difficile associated diarrhoea * Discontinuation of precipitating antibiotics and administration of following antibioticsMetronidazoleVancomycinTeicoplaninFusidic acidBacitracin