ABSTRACT
Bacterial biofilm is a major factor in delayed wound healing and high levels of biofilm production have been repeatedly described in multidrug resistant organisms (MDROs). Nevertheless, a quantitative correlation between biofilm production and the profile of antimicrobial drug resistance in delayed wound healing remains to be determined. Microbial identification, antibiotic susceptibility and biofilm production were assessed in 135 clinical isolates from 87 patients. Gram-negative bacteria were the most represented microorganisms (60.8%) with MDROs accounting for 31.8% of the total isolates. Assessment of biofilm production revealed that 80% of the strains were able to form biofilm. A comparable level of biofilm production was found with both MDRO and not-MDRO with no significant differences between groups. All the methicillin-resistant Staphylococcus aureus (MRSA) and 80% of Pseudomonas aeruginosa MDR strains were found as moderate/high biofilm producers. Conversely, less than 17% of Klebsiella pneumoniae extended-spectrum beta-lactamase (ESBL), Escherichia coli-ESBL and Acinetobacter baumannii were moderate/high biofilm producers. Notably, those strains classified as non-biofilm producers, were always associated with biofilm producer bacteria in polymicrobial colonization. This study shows that biofilm producers were present in all chronic skin ulcers, suggesting that biofilm represents a key virulence determinant in promoting bacterial persistence and chronicity of ulcerative lesions independently from the MDRO phenotype.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacterial Infections/microbiology , Biofilms/drug effects , Drug Resistance, Multiple, Bacterial , Skin Ulcer/microbiology , Anti-Bacterial Agents/therapeutic use , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/pathogenicity , Bacterial Infections/drug therapy , Chronic Disease , Humans , Microbial Sensitivity Tests , Skin Ulcer/drug therapy , VirulenceABSTRACT
We report a case of Listeria monocytogenes bacteremia in a leukemic patient having a positive assay for aspergillus galactomannan (GM), although no evidence of aspergillosis was found. Supernatant obtained from L. monocytogenes strain suspension was reactive with GM-assay. L. monocytogenes produces a soluble antigen that is cross-reactive with Aspergillus GM.
Subject(s)
Antigens, Fungal/blood , Aspergillus/chemistry , Bacteremia/microbiology , Listeria monocytogenes/immunology , Mannans/immunology , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Antineoplastic Agents/therapeutic use , Aspergillosis/diagnosis , Bacteremia/drug therapy , Cross Reactions , Galactose/analogs & derivatives , Humans , Leukemia/drug therapy , Leukemia/immunology , Leukemia/microbiology , Listeria monocytogenes/isolation & purification , Male , Mannans/analysis , Middle AgedABSTRACT
S. aureus represents a critical cofactor in atopic dermatitis (AD). In this paper, the prevalence of S. aureus infection/colonization was evaluated in 117 children as well as in their cohabitants, in order to assess the value of S. aureus characterization in predicting disease onset and severity and in providing indications for prophylaxis. Results showed that children with AD as well as their cohabitants had a significantly greater incidence of S. aureus infection/colonization as compared to controls. The genetic characterization showed a virtual identity of the bacteria strains collected at different sites of the patients with those found in the cohabitants, suggesting both a direct transmission between the nasal reservoir and the lesions in the same atopic subject and a risk for reinfection within family cohabitants. These data stress the need of preliminary laboratory assessment and posttherapy control in both AD patients and their close contacts for effective S. aureus eradication.
