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Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus colonization of the adenoids and nasopharynx in 103 preschool children who underwent adenoidectomy for recurrent upper respiratory tract infections was examined. Bacterial interactions and risk factors for bacterial colonization of the nasopharynx and adenoids, separately, were analysed statistically. The prevalence of simultaneous isolation from both anatomical sites was 45·6% for S. pneumoniae, 29·1% for H. influenzae, 15·5% for M. catarrhalis and 18·4% for S. aureus. Three pathogens were significantly more frequent together from adenoid samples; nasopharyngeal swabs more often yielded a single organism, but without statistical significance. M. catarrhalis and S. aureus significantly more frequently co-existed with S. pneumoniae and H. influenzae than with each other and a positive association of S. pneumoniae and H. influenzae in adenoid samples was evident. Several differences between risk factors for nasopharyngeal and adenoid colonization by the individual pathogens were observed. We conclude that the adenoids and nasopharynx appear to differ substantially in colonization by pathogenic microbes but occurrence of H. influenzae and S. pneumoniae in the nasopharynx could be predictive of upper respiratory tract infections.

In the present article, we describe the inhibitory potency of nine thiosemicarbazide derivatives against bacterial type IIA topoisomerases, their antibacterial profile and molecular modelling evaluation. We found that one of the tested compounds, compound 7, significantly inhibits activity of Staphylococcus aureus DNA gyrase with an IC 50 below 15 mM. Besides, this compound displays antibacterial activity on reference Staphylococuss spp. and Enterococcus faecalis strains as well as clinical S. aureus isolates at non-cytotoxic concentrations in mammalian cells with MIC values ranging from 16 to 32 mg/mL thereby indicating, in some cases, equipotent or even more effective action than standard drugs such as vancomycin, ampicillin and nitrofurantoin. The computational studies showed that both molecular geometry and the electron density distribution have a great impact on antibacterial activity of thiosemicarbazide derivatives.

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Patients with chronic lymphocytic leukemia (CLL) have defects in both humoral and cellular immunity as a result of their underlying malignancy, as well as chemotherapy-related immune suppression. Upper respiratory tract (URT) colonization can be regarded as a major contributor to infection, so the relationship between carriage rates, disease incidence, or antibiotic resistance should be monitored. This prospective study included 50 newly diagnosed, previously untreated patients with CLL and 38 healthy volunteers. A total of 264 samples obtained from anterior nares and oropharynx were microbiologically examined. A significantly higher frequency of S. aureus and Gram-negative bacilli (GNB) colonization in CLL patients was observed in comparison to healthy volunteers. Information regarding baseline characteristics; the Rai staging system; hematological tests results; immunophenotype of basic lymphocyte subsets, including the expression of programmed cell death-1 protein (PD-1) and its ligand (PD-L1); as well as Epstein-Barr virus (EBV) status were determined to analyze risk factors for infections and bacterial colonization. The data represent the basic information for identification of further risk factors of infection and bacterial oropharyngeal colonization in CLL patients. The rate of disease progression within the time from the CLL diagnosis was significantly higher in patients colonized by GNB. This study highlights EBV infection and frequencies of PD-1 positive T CD3+ cells and B cells as risk factors in CLL patients.

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Extracts from the June collection of aerial parts of Helianthus salicifolius A. Dietr and Helianthus tuberosus L. were obtained using carbon dioxide supercritical fluid extraction with water as co-solvent. The antimicrobial effect in vitro of these extracts was then determined against reference species of bacteria, as well as against fungi (represented by Candida spp.). Both extracts were found to possess antimicrobial activity, with MIC = 0.62–5 mg mL−1 for bacteria and MIC = 5–10 mg mL−1 for yeasts, and both extracts demonstrated suitable bactericidal and fungicidal effect. The highest activity was observed against S. aureus ATCC 29213 (MIC = 0.62 mg mL−1 for H. salicifolius extract; MIC = 2.5 mg mL−1 for H. tuberosus extract) as confirmed by time–kill assay. Higher antioxidant activity was found for H. tuberosus extract (EC50 = 0.332 mg mL−1) as compared to that of H. salicifolius (EC50 = 0.609 mg mL−1). The total polyphenol content (TPC) expressed as gallic acid equivalents (GAE) was 13.75 ± 0.50 mg GAE g−1 of H. salicifolius extract and 33.06 ± 0.80 mg GAE g−1 of H. tuberosus extract. There was a relationship between the antioxidant potential of both extracts and TPC, but not between antistaphylococcal activity and TPC. The ATIR–FTIR spectra of both extracts showed similar main vibrations of the functional groups typical for phytoconstituents possessing bioactivity. The obtained data suggest potential application of these extracts as natural antioxidants and preparations with biocidal activity. Additionally, both extracts may be regarded as potential natural conservants in cosmetics, as well as natural preservatives in food.

The antimicrobial properties of essential oil from Lavandula sp. raise hopes related to its use in phytotherapy. This study aimed to evaluate the antimicrobial activity of essential oils from cultivars of L. angustifolia (‘Hidcote Blue Strain’, ‘Hidcote Blue’) and L. × intermedia (‘Phenomenal’, ‘Grosso’) grown in central-eastern Poland, that is, at the border of the northern lavender cultivation range. The chemical composition of the essential oils was determined by GC/MS. Essential oil concentrations (20, 10, 5, 2.5, 1.25, 0.6, 0.3, 0.16, 0.08, and 0.04 mg/mL) were tested to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) towards ten strains of Gram-positive bacteria, five Gram-negative bacteria, and eight yeasts in vitro culture. Essential oils from the Lavendula cultivars showed antimicrobial activity against all microorganisms analysed. The yeasts were characterised by higher sensitivity to lavender oil compared to bacteria, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The lowest MIC values for bacteria and fungi were obtained for ‘Grosso’. Furthermore, the ‘Grosso’ oil showed the highest fungicidal activity, while the highest bactericidal activity was found in ‘Hidcote Blue’ and ‘Grosso’. Using Staphylococcus aureus as an example, it was shown that different bacterial strains of the same species show varying sensitivity to the essential oil. A higher oil content was noted for the cultivars L. × intermedia, especially for the ‘Phenomenal’. Linalyl acetate and linalool were the main components of the essential oil in all cultivars. However, in the ‘Grosso’ oil, a high content of terpinen-4-ol (18.08%) was also recorded. An analysis of the relationships between the content of the main components in the analysed essential oils and the antimicrobial activity of essential oils suggested that linalool and terpinen-4-ol were compounds potentially responsible for antimicrobial activity. The obtained results allow us to conclude that essential oil with significant antimicrobial activity can be obtained from Lavandula sp. plants harvested in the northern part of the cultivation range.