Antibiograms of uropathogens in obstetric patients

Background: Urinary tract infections (UTI) are the most commonly encountered infections in obstetric patients. Aim: The current study was undertaken to find the spectrum of micro-organisms responsible for causing UTI in obstetric patients and to find out the most appropriate antibiotic. Materials and Methods: Consecutive patients in different stages of pregnancy with or without symptoms of UTI attending the antenatal clinic from June 2019 to November 2020 were screened for significant bacteriuria. The bacterial uropathogens isolated were then subjected to antimicrobial susceptibility testing and screened for ESBL production and methicillin resistance. Results: During the 18-month study period, out of the 110 samples screened, a total of 66 (60%) samples of urine from pregnant females, in different stages of pregnancy were found to be positive on culture. The Enterobacteriaceae accounted for nearly 69.69% of the isolates and E. coli alone accounted for 42.42% of the urinary isolates followed by Acinetobacter 19.69%. Among the Gram-positive cocci, Enterococcus 25.75% were more frequently isolated than Staphylococcus aureus (4.54%). Significantly high resistance was noted to the beta-lactam group of antimicrobials, fluoroquinolones and cotrimoxazole, both by the Gram-negative bacilli as well as Gram-positive cocci. Resistance was quite low against the aminoglycosides and nitrofurantoin and virtually absent against imipenem. Conclusion: The susceptibility patterns seen in our study seem to suggest that it is necessary to obtain sensitivity reports before initiation of antibiotic therapy in cases of suspected UTI.

progressive renal damage (4). The emergence and spread of antimicrobial resistance is a cause of increasing concern (5).
It is one of the major causes of failure in the treatment of infectious diseases that result in increased morbidity, mortality, and economic burden (6). Since most UTIs are treated empirically the selection of antimicrobial agent should be determined not only by the most likely pathogen but also by its expected susceptibility pattern. Thus, knowledge of local antimicrobial susceptibility patterns of common uropathogens is essential for prudent empiric therapy of community-acquired UTIs.
Thus the present study was carried out to determine the spectrum of bacterial isolates causing UTI and their antibiotic susceptibility among pregnant women attending antenatal clinic.

Study Design and Sample Collection
This study was conducted prospectively in the  Screening of possible ESBL production was done using ceftriaxone (30 μg) and cefoperazone (75 μg).
Those isolates with zone diameters less than 25 mm for ceftriaxone and less than 22 mm for cefoperazone were subsequently confirmed for ESBL production. Confirmation was done by Double Disk Synergy Test (DDST) as per CLSI guidelines. [6] Cefoperazone (75 μg) and Ceftazidime (30 μg) disks with and without Clavulanic acid (10 μg) were used.
The organisms were phenotypically confirmed as ESBL producers only when they showed an increase in zone of inhibition greater than or equal to 5 mm when evaluated in combination with clavulanic acid.   Although the usage of beta-lactam antimicrobials is considered safe in pregnancy, the resistance to these drugs, by the common pathogens is alarmingly high as seen in our study which restricts their use to only the sensitive strains. There are similar reports of high-level resistance in the general population to these drugs by urinary pathogens. [15] Fluoroquinolones have been shown to impair cartilage development in animal studies. Although this adverse effect has not been described in humans, quinolones should rather be avoided in pregnancy. As it is a high level of resistance to the tune of 85% resistance was noted in the current study. Other studies have also reported high resistance to the fluoroquinolones, to even the newer ones such as ofloxacin and pefloxacin. [15,20,21] Aminoglycosides were found to have a better profile than another group of drugs but unfortunately these cannot be used in pregnant women. Similarly the carbapenems to which most of the isolates were found to be highly sensitive cannot be given in pregnancy. Regarding cotrimoxazole, concerns have been raised over the use in the first trimester due to association with neural tube and other birth defects.
However, its use near term may lead to the displacement of bilirubin causing jaundice and kernicterus in the infant. [13,20] For this reason its use in pregnant women nearing term is also discouraged. Overall a high rate of resistance (77.5%) was seen among the urinary isolates in the current study. Similar discouraging results are also seen in another contemporary study. [ What does the study add to the existing knowledge?
Routine surveillance and monitoring studies need to be constantly conducted to update clinicians on the prevalent pathogens and the rational and empirical treatment of UTIs. Aggressive and consistent health education using all possible social media is also recommended to combat the menace of drug resistance occasioned by inappropriate antibiotic use. Collection of data, and written the manuscript.

Shrikrishna Kumar Agrawal:
Clinical examination and collection of data, and contributed to the manuscript.
Anju Pungale: Data Collection and data entry