Gut colonization of extended-spectrum β-lactamase-producing antibiotic-resistant bacteria in premature infants and its concordance with nosocomial sepsis

Abstract

Objective To investigate the characteristics and risk factors of extended-spectrum β-lactamase(ESBLs)- producing antibiotic-resistant bacterial gut colonization in premature infants and to explore its concor-dance with nosocomial sepsis. Methods A prospective surveillance was performed in Fujian Provincial Maternity and Children′s Health Hospital from May 2013 to May 2014.Preterm infants(gestational age < 36 weeks, admission within 24 h of birth and hospitalization time ≥ 14 d)were enrolled, and rectal swabs were collected for ESBLs-producing antibiotic-resistant bacteria culture, on the 1st, 3rd, 7th day after birth, and every 7 days until the 28th day or discharge.The clinical data and the results of blood culture were collected, and statistical analysis was performed. Results A total of 300 patients were enrolled in this study, of whom 221 patients (73.7%) were identified as gut colonization with ESBLs-producing bacteria, but the most common was ESBLs-producing klebsiella pneumoniae.No ESBLs-producing bacteria colonized in the gut on the first day after birth, and ESBLs-producing bacteria gut colonization mainly appeared in the first 2 weeks after birth.Multivariate Logistic regression indentified: the use of antenatal antibiotics(OR=2.091, 95%CI: 1.089-4.014)was the independent risk factor for ESBLs-producing bacterial gut colonization in premature infants on the 3rd day after birth, the age of first enteral feeding after birth ≥72 h(OR=3.356, 95%CI: 1.540-7.312)was the independent risk factor on the 7th day, gestational age < 34 weeks(OR=4.011, 95%CI: 1.864-8.629), birth weight ≤1 500 g(OR=7.271, 95%CI: 3.301-16.016)and hospitalization in neonatal intensive care unit (NICU) after birth(OR=2.675, 95%CI: 1.135-6.303)were the independent risk factors on the 14th day, birthweight ≤1 500 g(OR=58.371, 95%CI: 6.517-522.854)was the independent risk factor on the 21th day, using of the third generation cephalosporin(OR=48.000, 95%CI: 2.404-958.237)was the independent risk factor on the 28th day.Application of penicillin antibiotics(OR=0.150, 95%CI: 0.059-0.386)was the protective factor in reducing gut colonization with ESBLs - producing bacteria on the 7th day after birth, while application of probiotics was the protective factor on the 14th day(OR=0.221, 95%CI: 0.106-0.461)and 21th day(OR=0.061, 95%CI: 0.007-0.539)(all P<0.05). The premature infants with ESBLs-producing bacteria in the gut had higher incidence of clinical sepsis than those without ESBLs-producing bacteria in the gut(χ2=25.155, P=0.000). Among the cases the blood cultures were positive, 80% had the same species of ESBLs-producing bacteria and antibiogram matched in the rectal swabs cultures. Conclusions The premature infants were more at risk of colonization with ESBLs-producing bacteria.The premature infants with ESBLs-producing bacteria in the gut had higher incidence of clinical sepsis.Colonization surveillance showed significant concordance with infection pathogens, and surveillance strategy for ESBLs-producing bacterial gut colonization can serve as an effective aid to empiric therapy, and reduce the spread of resistant organism.Taking measures to control risk factors can reduce the gut colonization with ESBLs - producing bacteria. Key words: Resistant organism; Colonization; Nosocomial infection; Sepsis; Infant, premature