Escherichia coli colonization in neonates: prevalence, perinatal transmission, antimicrobial susceptibility, and risk factors.

UNLABELLED: Escherichia coli is one of the leading causes of early-onset neonatal sepsis in many industrialized countries. However, there is a lack of studies on Escherichia coli colonization in women and neonates. The study aimed at determining the prevalence Escherichia coli among pregnant women and newborns, perinatal transmission, antimicrobial susceptibility, and risk factors for neonatal colonization. MATERIAL AND METHODS: In this prospective, cross-sectional study, 827 infants born to 808 mothers were enrolled. The study was carried out from October 1, 2006, to June 30, 2007. Women were screened for E. coli carriage at 35-37 weeks of gestation or on admission for premature rupture of membranes and delivery; neonates, within 15 minutes of their lives. Risk factors for colonization were collected by a questionnaire and were recorded during labor. RESULTS: Maternal E. coli colonization rate was 19.9%; neonatal, 14.4%; and transmission rate, 21.4%. Less than one-fourth (22.7%) of neonatal E. coli strains were resistant to ampicillin. Logistic regression analysis revealed that anal sexual intercourse (OR, 3.91; 95% CI, 1.87-8.19), one sexual partner (OR, 2.01; 95% CI, 1.30-3.11), maternal vaginal Escherichia coli colonization (OR, 1.81; 95% CI, 1.12-2.93), maternal body mass index of ≤27 (OR, 1.77; 95% CI, 1.15-2.73), and maternal education lower than university level (OR, 1.70; 95% CI, 1.06-2.74) were associated with neonatal Escherichia coli colonization. CONCLUSIONS: The prevalence of maternal Escherichia coli colonization was higher in this study than other studies (19.9%). Neonatal Escherichia coli colonization was 14.4%. The resistance of Escherichia coli isolates to ampicillin was not high (22.7%). Improvement of maternal education and modification of mothers' sexual habits need to be undertaken to prevent neonatal Escherichia coli colonization.

Changes in the dependence of Pseudomonas aeruginosa O serogroup strains and their resistance to antibiotics in a university hospital during a 5-year period.

UNLABELLED: The aim of our study was to determine the changes in antibiotic resistance and O serogroup dependence of P. aeruginosa strains isolated from lower respiratory tract specimens of patients in 2003 and 2008; the patients were treated in intensive care units of the biggest treatment facility in Lithuania (Hospital of Lithuanian University of Health Sciences, HLUHS, former Hospital of Kaunas University of Medicine) MATERIAL AND METHODS: The study included 90 P. aeruginosa strains serotyped in 2003 and 101 P. aeruginosa strains serotyped in 2008, which were randomly selected. The resistance of P. aeruginosa strains was determined by the disc diffusion method based on the standard guidelines. The sizes of inhibition zones were interpreted according to the National Committee for Clinical Laboratory Standards (M(2)-A(6)). Isolates were serotyped using sera with specific antibodies against the O antigens of P. aeruginosa (Bio-Rad, France). RESULTS: Comparison of changes in the distribution of P. aeruginosa serogroups in 2003 and 2008 showed that P. aeruginosa strains of serogroups O:1, O:2, and O:3 were more prevalent in 2003 as compared with 2008 (23.3%, n=21; 27.8%, n=25; 12.2%, n=11 vs. 9.9%, n=10; 10.9%, n=11; 4.0%, n=4, P<0.05). P. aeruginosa strains of serogroups O:6 and O:11 were isolated more frequently in 2008 than 2003 (26.7%, n=27; 34.7%, n=35 vs. 4.4%, n=4; 10.0%, n=9, P<0.001). The results showed that 18 of the 90 P. aeruginosa strains in 2003 and 25 of the 101 P. aeruginosa strains in 2008 were resistant to three or more antibiotics tested, i.e., they were multidrug-resistant. Analysis of the distribution of serogroups among these P. aeruginosa strains isolated in 2003 and 2008 revealed a significantly higher frequency of O:11 serogroup than other serogroups. Meanwhile, in the group of nonmultidrug-resistant P. aeruginosa strains, P. aeruginosa O:11 serogroup strains were identified less frequently and accounted only for 2.8% (n=2, P<0.001) of the isolates in 2003 and 27.6% (n=21, P<0.01) in 2008. CONCLUSIONS: During the 5-year period, the isolation rate of P. aeruginosa strains belonging to serogroup O:11 increased. P. aeruginosa strains isolated in 2003 and 2008 belonging to serogroup O:11 were more frequently multidrug resistant. The increasing resistance of P. aeruginosa to reserve antibiotics of carbapenem group was observed.