Phenotypic and Genotypic Characterization of Extended-
Spectrum Beta-Lactamases Produced by Escherichia coli
Colonizing Pregnant Women
Abstract
Introduction. Infections caused by extended spectrum beta lactamase (ESBL) producing bacteria continue to be a challenge for
choosing the appropriate therapy since they may exhibit coresistance to many other classes of antibiotics. e aim of the study was to
screen pregnant women for ESBL producing bacteria in Beirut, Lebanon, to examine their phenotypic and genotypic characterization
and to study the association between ESBL colonization with adverse neonatal outcomes. Method. In this cross-sectional study, vaginal
samples from 308 pregnant women at 35–37 weeks of gestation were studied during a one-year period. e samples were plated on
MacConkey agar and selective MacConkey agar supplemented with ceazidime. Phenotypic confirmation of ESBL production was
performed by double-disc synergy test and all isolates were screened by PCR for the resistance genes blaSHV, blaTEM, and blaCTX-M.
Clonal relatedness of Escherichia coli isolates was investigated by pulsed-field gel electrophoresis. Results. In total, 59 women out
of 308 (19.1%) were colonized by ESBL producing gram negative bacteria. Two babies born to mothers colonized with ESBL were
diagnosed with sepsis. e susceptibility rates of isolates to other antibiotics were 39% to co-trimoxazole, 49.2% to ciprofloxacin,
91.5% to gentamicin, 18.6% to aztreonam and 35.6% to cefepime. Most of isolates were highly sensitive to meropenem and imipenem,
with a susceptibility of 93.2%. PCR was performed on all E. coli isolates to detect the most common ESBL producing genes; blaCTX-M
was the predominant gene (90.7%), followed by blaTEM (88.4%) and finally blaSHV (44.2%). PFGE analysis of 34 E. coli isolates
revealed 22 distinct clusters showing more than 85% similarity. Conclusion. In conclusion, this study showed that Lebanon has a
high prevalence of ESBL carriage in pregnant women. Further studies that include a continuous screening of pregnant women and
follow up of their newborn clinical status should be conducted to foresee the risk of transmission.
Journal/Conference Information
Infectious Diseases in Obstetrics and Gynecology,DOI: https://doi.org/10.1155/2020/4190306, ISSN: 1098-0997, Volume: 2020, Issue: 1, Pages Range: 1-7,