fThe increasing prevalence of drug-resistant pathogens highlights the need to identify novel antibiotics. Here we investigated the efficacies of four new antimicrobial peptides (AMPs) for potential drug development. The antibacterial activities, synergistic effects, and antibiofilm properties of the four chimeric AMPs were tested against Acinetobacter baumannii, an emerging Gramnegative, nosocomial, drug-resistant pathogen. Nineteen A. baumannii strains resistant to ampicillin, cefotaxime, ciprofloxacin, tobramycin, and erythromycin were isolated at a hospital from patients with cholelithiasis. All four peptides exhibited significant antibacterial effects (MIC ‫؍‬ 3.12 to 12.5 M) against all 19 strains, whereas five commercial antibiotics showed little or no activity against the same pathogens. An exception was polymyxin, which was effective against all of the strains tested. Each of the peptides showed synergy against one or more strains when administered in combination with cefotaxime, ciprofloxacin, or erythromycin. The peptides also exhibited an ability to prevent biofilm formation, which was not seen with cefotaxime, ciprofloxacin, or erythromycin, though polymyxin also inhibited biofilm formation. Indeed, when administered in combination with ciprofloxacin, the AMP HPMA exerted a potent synergistic effect against A. baumannii biofilm formation. Collectively, our findings indicate that the AMPs tested have no cytotoxicity but possess potent antibacterial and antibiofilm activities and may act synergistically with commercial antibiotics.

SIBO in cirrhosis patients was observed at a very high frequency, and SIBO showed a high correlation with bacterial translocation, suggesting that SIBO could be a major risk factor of bacterial translocation, especially in ascitic patients.

The prevalence of group B streptococcus (GBS) among pregnant women and disease burdens in neonates and adults are increasing in Korea. Colonizing isolates, collected by screening pregnant women (n=196), and clinical isolates collected from clinical patients throughout Korea (n=234), were serotyped and screened for antibiotic resistance. Serotype III (29.8%) and V (27.7%) predominated, followed by Ia (17.0%). Antibiotic resistance was higher among clinical than colonizing isolates for erythromycin (35.1% and 26.9%; P=0.10) and for clindamycin (49.4% and 42.1%; P=0.17). erm(B) occurred in 91.9% of erythromycin resistant isolates, and 84.0% of isolates resistant to clindamycin. Only five isolates (4.2%) resistant to erythromycin were susceptible to clindamycin; by contrast, and unique to Korea, 34% of isolates resistant to clindamycin were erythromycin susceptible. Among these 60 erythromycin-susceptible & clindamycin-resistant isolates, 88% was serotype III, and lnu(B) was found in 89% of strains. Four fifths of the serotype V isolates were resistant to both erythromycin and clindamycin. Further characterization of the genetic assembly of these resistance conferring genes, erm(B) and lnu(B), will be useful to establish the clonal lineages of multiple resistance genes carrying strains.

BackgroundVitamin D insufficiency could be associated with the prevalence of atopic dermatitis (AD).ObjectiveTo examine vitamin D status and the relations between serum 25-hydroxyvitamin D levels, SCORAD score, serum LL-37 level, and body mass index (BMI) in Korean AD patients, and to explore whether these associations differ between adults and children.MethodsSerum 25-hydroxyvitamin D levels, serum LL-37, and clinical features were analyzed in a total of 72 Korean patients with AD (39 adults and 33 children) and 140 healthy control subjects (70 adults and 70 children).ResultsSerum 25-hydroxyvitamin D levels were significantly reduced in children with AD (15.06±4.64 ng/ml) compared with normal children in the control group (16.25±6.60 ng/ml) (p=0.036). Significant inverse correlations were found between BMI and 25-hydroxyvitamin D level (r=-0.315, p=0.007) and between the SCORAD score and serum LL-37 level (r=-0.3, p=0.011) in the total AD patients.ConclusionThe results showed that serum vitamin D levels were lower in children with AD than in healthy children; however, the same relation was not observed between adults with AD and healthy adults. Serum 25-hydroxyvitamin D concentration was not significantly correlated with AD severity or serum LL-37 levels in our study population.