Abstract:
Objective To investigate the colonization status and strain characteristics of resistant Enterobacterales in the intestine of neonates.
Methods 277 fecal samples of neonates in the maternity ward of a hospital were collected from September 2017 to May 2018 in Yunnan province. We analyzed the status of carriage of drug-resistant bacteria in the intestinal tract of neonates, strain resistance phenotypes, resistance genotypes and sequence types (STs) characteristics by isolation and culture in extended spectrum β-lactamase (ESBL) chromogenic medium, strain drug susceptibility testing and genome sequencing of Illumina, a representative strain.
Results 113 fecal samples out of 77 samples were ESBL-positive strains, with a positivity rate of 40.79%. 113 Enterobacterales strains of 11 species from 4 genera were isolated and identified, including Klebsiella 53.10% (60/113), Escherichia 30.10% (34/113), Enterobacter 15.04% (17/113), and Leuconostoc 1.77% (2/113). The strains presenting multidrug-resistant profiles. Except for highly resistant to second and third-generation cephalosporin, the resistance rates of carbapenems, sulfonamides, tetracyclines and ciprofloxacin were 52.21% (59/113), 72.57% (82/113), 65.49% (74/113), and 54.87% (62/113), respectively. The genome sequences of 84 representaive strains were screened, and al of 70 drug r(esis)tance genes were detected, including sul1 (84.52%, 71/84), fosA (71.43%, 60/84), tet(A) (67.86%, 57/84), blaSHV (63.10%, 53/84) and blaNDM (61.90%, 52/84). 53 Klebsiella pneumoniae showed a concentrated distribution of clones, ST17 carrying blaNDM-1 gene accounted for 92.45% (49/53). The STs of other species were diverse. Enterobacter cloacae and Enterobacter hormaechei carrying blaNDM-1, Klebsiella gordonii carrying blaIMP-26, Leclercia carrying blaIMP-1, and Enterobacter albus, E. hormaechei and Escherichia hermannii carrying mcr were detected.
Conclusion It is found that a high proportion of neonates in a maternity ward carried ESBL-resistant enterobacters in their intestines, revealing that drug-resistant strains are highly susceptible to inter-neonatal transmission and intestinal colonization. Attention should be paid to the environmental exposure risk of neonatal drug-resistant bacteria and its impact on the establishment of intestinal microecology.