H. influenzae has been isolated from the CSF of a 2 year old boy suffering from meningitis. The strain is beta lactamase producing and resistant to chloramphenicol, The most appropriate antimicrobial is

HI Inlluenzae type b produces J3 lactamases and therefore are resistant to ampicillin. These 3 lactamase producing strains remain sensitive to the extended spectrum cephalosporins * Ceftriaxone or cefotaxime IV are used as a single agents * Infections caused by ampicillin - resistant strains can be treated with 1. Trimethoprim - sulfamethoxazole 2. Amoxicillin I clavulanic acid 3. Extended spectrum cephalosporins 4. Azithromycin and clarithromycin * F'loraquin lones are highly active against H. influenzae but are not currently recommended for the treatment of children or pregnailt women because of possible effects on aicular cailage