Letter to the editor regarding the article: comparison of obstetric to institutional antibiogram as an approach to advance antimicrobial stewardship in maternal care

To the Editor,

We read with great interest the article by Boyd et al. [1], in which the authors compared their institutional annual antibiogram with an obstetric-specific antibiogram. Their most remarkable finding was the significantly lower resistance exhibited by Enterobacterales in the obstetric population, particularly Escherichia coli and Klebsiella pneumoniae isolated from urine cultures. Sidra Medicine is a women’s and children’s hospital in Doha that serves as a national referral center for the pediatric population of Qatar for all medical subspecialties, including oncology, neonatal intensive care, and pediatric intensive care, and surgical specialties, including cardiac surgery and neurosurgery. Our laboratory generates an institutional cumulative antibiogram along with a specific antibiogram for uropathogens for the hospital’s full patient population (HFPP) on an annual basis. We compared antimicrobial susceptibly data for urinary isolates of E. coli and K. pneumoniae isolated in obstetric sections (OBS) (OB triage, labor and delivery room, antepartum and postpartum wards, and women special care) with susceptibility patterns for the same uropathogens in the HFPP between January 2018 and December 2021. Overall, there were 289 and 1610 E. coli isolates, and 70 and 442 K. pneumoniae isolates collected from OBS and the HFPP. The proportion of susceptible E. coli was significantly higher in OBS for ampicillin (43 versus 33%, p < .01), cefazolin (71 versus 63%, p = .02), cefuroxime (72 versus 64%, p = .01) ceftriaxone (75 versus 68%, p = .03), gentamicin (95 versus 88%, p < .01), trimethoprim-sulfamethoxazole (TMP-SMX) (64 versus 54%, p < .01), ciprofloxacin (69 versus 61%, p = .01), and nitrofurantoin (100 versus 96%, p < .01). Among K. pneumoniae, the proportion of susceptible isolates was significantly higher among OBS for amoxicillin-clavulanate (83 versus 63%, p = .01), cefazolin (88 versus 66%, p < .01), cefuroxime (83 versus 64%, p < .01), ceftriaxone (87 versus 72%, p < .01), cefepime (89 versus 74%, p < .01), aztreonam (87 versus 73%, p < .01), ertapenem (100 versus 94%, p = .04), ciprofloxacin (86 versus 65%, p < .01), and TMP-SMX (86 versus 64%, p < .01). Furthermore, the proportion of extended-spectrum beta-lactamase producers was significantly higher in E. coli (32 versus 25%, p = .03) and K. pneumoniae (28 versus 13%, p < .01) isolated in the HFPP. Our findings revealed striking differences in the susceptibility patterns of the main uropathogens between the hospital-wide population and the obstetric population. We believe that these differences could be mainly explained by the fact that our institution provides nationwide free medical care to a large proportion of children with complex medical and surgical conditions that increase the risk for infections by multi-resistant bacteria. By contrast, our center provides chargeable maternity care to a female population with mostly low-risk pregnancies. It is worth noting that the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America recommend the generation of stratified antibiograms over solely hospital-wide antibiograms to help antimicrobial stewardship programs optimize empirical antimicrobial prescribing guidelines [2]. Therefore, we agree with the authors that an obstetric-specific antibiogram that accurately reflects susceptibility patterns in this unique population is needed to optimize empiric antimicrobial selection in obstetrics.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Open Access funding provided by the Qatar National Library.