Bacterial susceptibilty test


Hello everyone the susceptiblity test of urine culture for 62 years old female patient revealed multidrug resistance e. Coli result as follow
Sensitive cefoperazone /sulbactam zone diameter 21mm
Resistance to ampicillin /sulbactam, amoxicillin /clavulanic acid, impinem, piperacillin /tazobactam, ciprofloxacin, levofloxacin, oflaxacin, gentamycin, amikacin, aztreonam, fosfomycin, nitrofuratoin, sulpha/trimethoprim,ampicillin,cefepime,ceftazidime,ceftriaxone,cefuroxime,cefoxitin
My question is it usual that bacteria be sensitive to cefoperazone/sulbactam and resistant to piperacillin /tazobactam is this result logic however high resistance to every one?!
Patient took antibiotics for a year to treat cellulitis

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Sara 2023-11-18T05:19:51+00:00 1 Answer 23 views New Member 0

Answer ( 1 )


    Indeed, the susceptibility test results you’ve provided are quite noteworthy. In the case of the 62-year-old female patient with multidrug-resistant E. coli, it’s not uncommon to observe variations in bacterial susceptibility patterns. In this instance, the sensitivity to cefoperazone/sulbactam and resistance to piperacillin/tazobactam are intriguing.

    Cefoperazone/sulbactam is a combination antibiotic that consists of a cephalosporin (cefoperazone) and a beta-lactamase inhibitor (sulbactam). It’s effective against certain types of bacterial infections, particularly those caused by gram-negative bacteria like E. coli. The sensitivity observed in this case aligns with the antibiotic’s known spectrum of activity.

    On the other hand, piperacillin/tazobactam is also a combination antibiotic, comprising a penicillin (piperacillin) and a beta-lactamase inhibitor (tazobactam). While it’s effective against many gram-negative and some gram-positive bacteria, resistance to this combination can occur due to various factors, including bacterial production of beta-lactamase enzymes that inactivate the antibiotic.

    The high level of resistance observed across multiple antibiotics is concerning but not unusual, particularly in cases where prolonged antibiotic use has occurred, as in the patient’s history of cellulitis treatment. Prolonged exposure to antibiotics can exert selective pressure on bacterial populations, leading to the development of resistance mechanisms.

    In summary, while the sensitivity to cefoperazone/sulbactam and resistance to piperacillin/tazobactam may seem contradictory at first glance, they can be explained by the distinct mechanisms of action and resistance patterns of these antibiotics. The broader issue of multidrug resistance underscores the importance of judicious antibiotic use and ongoing efforts in antimicrobial stewardship to combat the emergence and spread of resistant bacteria.

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