CASE HISTORY
Three-year-old Molly was brought to the emergency department crying.She had a stiff neck and high fever (40° C,or 104° F).Gram stain of her cerebrospinal fluid revealed Gram-positive cocci,generally in pairs.The attending physician diagnosed Molly with meningitis and immediately prescribed intravenous ampicillin.Unfortunately,the child's condition worsened,so antibiotic treatment was changed to a third-generation cephalosporin (ceftriaxone).Molly began to improve within hours and was released after two days.A report from the clinical microbiology laboratory two days later identified the organism as Streptococcus pneumoniae.The report also included antibiotic susceptibility results,which revealed that this strain of S.pneumoniae was resistant to ampicillin but remained susceptible to cephalosporin.
The first antibiotic used to treat Molly,ampicillin,has activity against both Gram-negative and Gram-positive bacteria;however,the bacterium that made Molly ill was resistant to this agent.At the time the antibiotic was prescribed,neither the type of agent nor its resistances were known.Based on this information,which of the following is true?

Question

Quizplus · Accepted Answer

Ampicillin is a broad-spectrum antibiotic with activity against both Gram-positive and Gram-negative bacteria. However, the bacterium that caused Molly's illness was resistant to this agent. This highlights the importance of performing microbiological testing and obtaining sensitivity results to guide appropriate antibiotic selection. It does not indicate that Gram-positive bacteria are always resistant to ampicillin or that Molly's infection is resistant to a broad variety of antibiotics. Narrow-spectrum antibiotics may have been appropriate if the specific bacteria causing Molly's infection had been identified prior to treatment.

CASE HISTORY Three-Year-Old Molly Was Brought to the Emergency Department Crying.She Had