Antifungal activity of Myrtus communis against Malassezia sp. isolated from the skin of patients with pityriasis versicolor.

The increasing incidence of fungal infections and antifungal resistance has prompted the search for novel antifungal drugs and alternative agents. We explored the antifungal activity of Myrtus communis essential oil (EO) against Malassezia sp. isolated from the skin of patients with pityriasis versicolor. These broad-spectrum antimicrobial activities of M. communis EO and its potent inhibiting activity on Malassezia growth deserve further research with aim to considerate this EO as candidate for topical use in treatment of skin diseases.

Correction to: Antifungal activity of Myrtus communis against Malassezia sp. isolated from the skin of patients with pityriasis versicolor.

The original version of this article unfortunately contained two mistakes in authors' names.

Effect of teriflunomide on QuantiFERON-TB Gold results.

Multiple sclerosis is a chronic inflammatory disease of the central nervous system characterized by damage to myelin and axons, over time leading to progressive neuronal degeneration and microglial activation. There is still no curative treatment, but during the last 20 years eight different therapies have become available including interferon beta, glatiramer acetate, teriflunomide, dimethyl fumarate, natalizumab, fingolimod, alemtuzumab, mitoxantrone and teriflunomide. Teriflunomide is an immunomodulatory drug that exerts an inhibitory effect on T cell activation in central nervous system of the patients with multiple sclerosis. We determined whether teriflunomide affect the production of interferon-gamma, interleukin-2 and tumor-necrosis-factor-α in the QuantiFERON-TB in-Tube-assay. Blood from 24 adults with latent tuberculosis infection was added to one standard set of QuantiFERON tubes and one further set containing teriflunomide. Teriflunomide resulted in a change in QuantiFERON results from positive to negative in four patients with a marked reduction in interferon-γ. Our data indicated that results from QuantiFERON in patients on teriflunomide therapy should be interpreted with caution.

QuantiFERON-TB Gold Assay on Plasma for Confirmation of Presumed Tuberculosis-Related Uveitis.

The QuantiFERON-TB Gold assay was used to measure interferon gamma levels in plasma from 4 patients with presumed tuberculosis-related uveitis before, during, and after antitubercular therapy. After treatment, all patients showed clinical improvement. The concentrations showed a reversion to an absence of interferon gamma in one case, decreased in two cases, and remained stable in one case. These results suggest that the QuantiFERON assay may be useful for tuberculosis-related uveitis diagnosis and follow-up.

Bacterial agents as a cause of infertility in humans.

Infertility is a problem affecting almost 15% of couples. There are many causes for this condition, among which urogenital bacterial infections seem to play an important role. Many studies have explained the mechanisms by which bacteria cause infertility both in men and women. Therefore we undertook this study to evaluate the presence of genito-urinary infections in infertile couples who sought counselling to investigate their condition. Microbiological analysis was performed on semen and vaginal/cervical samples of both partners of each couple. The percentage of individuals affected by a urogenital bacterial infection was between 14 and 20%. More significantly, most of the species isolated both in men and women have been described in the literature as potential causes of infertility.

Antitubercular activity of quinolizidinyl/pyrrolizidinylalkyliminophenazines.

Novel riminophenazine derivatives, characterized by the presence of the basic and cumbersome quinolizidinylalkyl and pyrrolizidinylethyl moieties, have been synthesized and tested (Rema test) against Mycobacterium tuberculosis H37Rv and H37Ra, and six clinical isolates of Mycobacterium avium and Mycobacterium tuberculosis. Most compounds exhibited potent activity against the tested strains, resulting more active than clofazimine, isoniazid and ethambutol. The best compounds (4, 5, 12 and 13) exhibited a MIC in the range 0.82-0.86µM against all strains of Mycobacterium tuberculosis and, with the exception of 4 a MIC around 3.3µM versus M. avium. The corresponding values for clofazimine (CFM) were 1.06 and 4.23µM, respectively. Cytotoxicity was evaluated against three cell lines and compound 4 displayed a selectivity index (SI) versus the human cell line MT-4 comparable with that of CFM (SI=5.23 vs 6.4). Toxicity against mammalian Vero 76 cell line was quite lower with SI=79.

Myrtus communis L. Essential Oil Exhibits Antiviral Activity against Coronaviruses.

Human coronaviruses are a continuous threat to the human population and have limited antiviral treatments, and the recent COVID-19 pandemic sparked interest in finding new antiviral strategies, such as natural products, to combat emerging coronaviruses. Rapid efforts in the scientific community to identify effective antiviral agents for coronaviruses remain a focus to minimize mortalities and global setbacks. In this study, an essential oil derived from Myrtus communis L. (MEO) is effective against HCoV-229E and HCoV-OC43 virus infections in comparison to two FDA-approved drugs, Remdesivir and Nirmatrelvir. Gas-chromatography and mass spectrometry were used to identify the chemical composition of MEO. Slight antioxidant activity was observed in MEO, indicating a role in oxidative stress. A dose-response curve measuring the EC50 indicates a high potency against HCoV-229E and HCoV-OC43 virus infections on Huh7.5 cells with low cytotoxicity using a PrestoBlue cell viability assay. Our findings demonstrate that MEO exhibits potent antiviral activity against HCoV-229E and HCoV-OC43 on Huh7.5 cells within a low-cytotoxicity range, but not on SARS-CoV-2. Artificial bacterial chromosome plasmids that expressed SARS-CoV-2 used for replicon-to determine viral replication and viral assembly/egress on HEK293T/17 cells-and virus-like particles on Huh7.5-AT cells-to determine viral entry and assembly/egress-showed no antiviral activity with MEO in comparison to Remdesivir. This study reveals the potential effectiveness of MEO as an alternative natural remedy to treat human coronaviruses and a potential antiviral agent for future coronavirus infections.

Multifactorial action of lavender and lavandin oils against filamentous fungi.

AIMS: In this study, five essential oils (EOs) from different species of Lavandula hybrida abrialis, for Lavandula hybrida R.C., Lavandula hybrida 'super A', Lavandula hybrida 'super Z' and Lavandula vera and its hybrids Lavender were evaluated against 26 dust-isolated fungal strains from North Africa. METHODS AND RESULTS: The composition of the different EOs was determined from volume to dry weight. The photochemical analyses were performed via gas chromatography (GC). The cytotoxic effect of five lavender EOs on human epithelial colorectal adenocarcinoma cells (Caco-2) cell line was done. A total of 26 strains of filamentous fungi including Aspergillus spp., Botrytis cinerea, Ceriporia spp., Fusarium spp. and Penicillium glabrum were isolated from sand dust samples via molecular diagnostic tool of PCR. Fungal strains with the lowest minimal lethal concentration (MLC) were Penicillium glabrum, Ceriporia spp. and a strain of Aspergillus spp. CONCLUSIONS: More studies are needed to verify the activity of this EO against more different fungal species, and determine the active ingredients.Significance and impact of study: MIC of the antifungal efficacy relating to EOs was evaluated. The EOs tests showed no cytotoxic effect at very low concentrations, ranging from 0.03% (IC50 0.9132 mg/mL) (L. hybrid Abrialis) to 0.001% (IC50 1.631 mg/mL) (L. hybrid R.C.).

Expression profiling of Mycobacterium tuberculosis H37Rv and Mycobacterium smegmatis in acid-nitrosative multi-stress displays defined regulatory networks.

Several studies regarding the transcriptome of Mycobacterium tuberculosis following the exposure to various in vitro simulated phagosomal stressors, have already tried to elucidate the bacterium behavior during the intracellular infection. An in vitro acid-nitrosative multi-stress was carried out for M. tuberculosis H37Rv and Mycobacterium smegmatis MC(2)155 in order to analyze by DNA-microarray the gene expression changes associated respectively to pathogenic and non-pathogenic mycobacterial species. During acid-nitrosative multi-stress both mycobacteria shift their transcriptome to allow the anaerobic respiratory state and energy pathways characteristic of starvation. M. tuberculosis counteracts the combined acid-nitrosative stress more efficiently than M. smegmatis as also shown by the up-regulation of glbN and hmp genes, that are specifically directed to NO detoxification. Moreover, the down-regulation of some virulence factors involved in phthiocerol dimycocerosates synthesis strengthens the hypothesis that these major virulence determinants may be attenuated by M. tuberculosis in the presence of reactive nitrogen species. In fact, it down-regulates other genes implicated in the synthesis of membrane structural lipids but in contrast to M. smegmatis, M. tuberculosis up-regulates many genes annotated for the synthesis of peptidoglycan. Results suggest a gene regulation of M. tuberculosis which reveals a distinctive expression pattern under stressful environment.

Tuberculin skin test and QuantiFERON in children.

Until some time ago, the tuberculin skin test was the only available screening test for the diagnosis of tubercular infection. Now the new interferon-? release assay QuantiFERON-TB Gold shows promise of greater accuracy in the detection of Mycobacterium tuberculosis-infected subjects. The aim of our study was to evaluate the use of QuantiFERONTB Gold in children and to verify its agreement with the tuberculin skin test. A total of 27 children had a positive tuberculin skin test, 76 subjects were negative and the remaining 2 had a dubious Mantoux test. A positive QuantiFERONTB Gold result was obtained in 21 children while in 84 it was negative. No statistically significant difference was detected between the two assays, which showed a concordance of 90.57%. Our results demonstrated a good concordance between the tuberculin skin test and the interferon-? release assay, though the QuantiFERON-TB may have several advantages over the Mantoux test.

Identification of non-tuberculous mycobacteria from clinical samples.

Non-tuberculous mycobacterial infections cause morbidity worldwide. NTM are considered opportunistic pathogens, and several species have been associated with human disease which has typically pulmonary, skin and soft tissue, lymphatic or disseminated presentation. This study evaluated the distribution of non-tuberculous mycobacteria in Sardinia. Mycobacterium avium, Mycobacterium gordonae and Mycobacterium xenopi were frequently found. Our results agreed with literature data both for the frequent isolation of M. avium, M. xenopi and M. gordonae, and the symptoms and radiological evidence of the patients analysed.

Nanotechnology as a Promising Approach to Combat Multidrug Resistant Bacteria: A Comprehensive Review and Future Perspectives.

The wide spread of antibiotic resistance has been alarming in recent years and poses a serious global hazard to public health as it leads to millions of deaths all over the world. The wide spread of resistance and sharing resistance genes between different types of bacteria led to emergence of multidrug resistant (MDR) microorganisms. This problem is exacerbated when microorganisms create biofilms, which can boost bacterial resistance by up to 1000-fold and increase the emergence of MDR infections. The absence of novel and potent antimicrobial compounds is linked to the rise of multidrug resistance. This has sparked international efforts to develop new and improved antimicrobial agents as well as innovative and efficient techniques for antibiotic administration and targeting. There is an evolution in nanotechnology in recent years in treatment and prevention of the biofilm formation and MDR infection. The development of nanomaterial-based therapeutics, which could overcome current pathways linked to acquired drug resistance, is a hopeful strategy for treating difficult-to-treat bacterial infections. Additionally, nanoparticles' distinct size and physical characteristics enable them to target biofilms and treat resistant pathogens. This review highlights the current advances in nanotechnology to combat MDR and biofilm infection. In addition, it provides insight on development and mechanisms of antibiotic resistance, spread of MDR and XDR infection, and development of nanoparticles and mechanisms of their antibacterial activity. Moreover, this review considers the difference between free antibiotics and nanoantibiotics, and the synergistic effect of nanoantibiotics to combat planktonic bacteria, intracellular bacteria and biofilm. Finally, we will discuss the strength and limitations of the application of nanotechnology against bacterial infection and future perspectives.

Juniperus oxycedrus L. ssp. Essential Oil Microneedles: A Promising Antimicrobial and Wound Healing Activity.

The use of essential oil (EO) in treating infected wounds is still challenging. A lot of effort has been made to make such an application more convenient. Recently, microneedles (MNDs) have been considered as a smart dermal delivery system to overcome the poor absorption and distribution, low bioavailability, and skin penetration of some drugs. The aim of our study is to evaluate the wound healing activity of juniper-EO-loaded MNDs (EO MNDs) against wounds with bacterial and fungal infection. The Polyvinylpyrrolidone (PVP) MNDs were prepared using the gel-filled mold technique and loaded with juniper EO. In vivo models were created and wounds on rats were infected with two clinically isolated bacterial strains Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, Candida albicans was used to mimic fungal infection and juniper EO MNDs were tested. The obtained results showed an improvement in wound healing which started from the third day after application of the juniper EO MNDs, and at the sixth day post-infection, the treated wounds were significantly smaller than untreated wounds. A complete healing was shown by the 12th day after infection. Furthermore, our cytotoxicity results showed a cytotoxic effect of juniper EO MNDs on epithelial cells, which explained the faster wound healing in rats. Our study showed that juniper EO MNDs represent a novel strategy in EO delivery with minimal invasion. Juniper EO MNDs demonstrated significant antimicrobial activity against both the bacterial strains Pseudomonas aeruginosa and Staphylococcus aureus and against one fungal strain, Candida albicans. Finally, application of juniper EO MNDs exerted promising activity in the treatment and healing of wound infection.

Gene expression profiling of Mycobacterium avium subsp. paratuberculosis in simulated multi-stress conditions and within THP-1 cells reveals a new kind of interactive intramacrophage behaviour.

BACKGROUND: Recent studies have identified in Mycobacterium avium subsp. paratuberculosis (MAP), already known as a pathogen in ruminants, a potential zoonotic agent of some autoimmune diseases in humans. Therefore, considering the possible risk for public health, it is necessary a thorough understanding of MAP's gene expression during infection of human host as well as the identification of its immunogenic and/or virulence factors for the development of appropriate diagnostic and therapeutic tools. RESULTS: In order to characterize MAP's transcriptome during macrophage infection, we analyzed for the first time the whole gene expression of a human derived strain of MAP in simulated intraphagosomal conditions and after intracellular infection of the human macrophage cell line THP-1 by using the DNA-microarray technology. Results showed that MAP shifts its transcriptome to an adaptive metabolism for an anoxic environment and nutrient starvation. It up-regulates several response factors to oxidative stress or intracellular conditions and allows, in terms of transcription, a passive surface peptidoglycan spoliation within the macrophage along with an intensification of the anabolic activity for lipidic membrane structures. CONCLUSIONS: These results indicate a possible interactive system between MAP and its host cell based on the internal mimicry unlike other intracellular pathogens, bringing new hypothesis in the virulence and pathogenicity of MAP and its importance in human health.

Evaluation of the Antimicrobial and Antivirulent Potential of Essential Oils Isolated from Juniperus oxycedrus L. ssp. macrocarpa Aerial Parts.

As a consequence of the worsening situation with multidrug-resistant (MDR) pathogens and a disparity in the commercialization of novel antimicrobial agents, scientists have been prompted to seek out new compounds with antimicrobial activity from a wide range of sources, including medicinal plants. In the present study, the antibacterial, antifungal, anti-virulence, and resistance-modulating properties of the essential oil from the Sardinian endemic Juniperus oxycedrus L. ssp. macrocarpa aerial parts were evaluated. The GC/MS analysis showed that the main compounds in the oil were α-pinene (56.63 ± 0.24%), limonene (14.66 ± 0.11%), and ß-pinene (13.42 ± 0.09%). The essential oil showed potent antibacterial activity against Gram-positive bacteria (0.25-2 v/v%) and Salmonella spp. (4 v/v%). The strongest fungicidal activity was recorded against Candida auris sessile cells (median FICI was 0.088) but not against C. albicans biofilms (median FICI was 1). The oil showed potent efflux pump inhibitory properties in the case of Staphylococcus aureus and Escherichia coli. The therapeutic potential of Juniperus may be promising for future more extensive research and in vivo tests to develop new drugs against antibiotic and antifungal resistance.

Relationship between Biofilm-Formation, Phenotypic Virulence Factors and Antibiotic Resistance in Environmental Pseudomonas aeruginosa

The formation of a protective biofilm by Pseudomonas aeruginosa (PA) is one of the hallmarks of their survival both in vivo and in harsh environmental conditions, thus, biofilm-eradication has relevance from therapeutic perspectives and for infection control. The aim of our study was to investigate the possible relationship between antibiotic resistance, biofilm-forming capacity and virulence factors in n = 166 PA isolates of environmental origin. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out using standard protocols. The biofilm-forming capacity of PA was tested using a standardized crystal violet microtiter plate-based method. Motility (swimming, swarming, and twitching) and siderophore production of the isolates were also assessed. Resistance rates were highest for ciprofloxacin (46.98%), levofloxacin (45.18%), ceftazidime (31.92%) and cefepime (30.12%); 19.28% of isolates met the criteria to be classified as multidrug-resistant (MDR). Efflux pump overexpression, AmpC overexpression, and modified Hodge-test positivity were noted in 28.31%, 18.07% and 3.61%, respectively. 22.89% of isolates were weak/non-biofilm producers, while 27.71% and 49.40% were moderate and strong biofilm producers, respectively. Based on MDR status of the isolates, no significant differences in biofilm-production were shown among environmental PA (non-MDR OD570 [mean ± SD]: 0.416 ± 0.167 vs. MDR OD570: 0.399 ± 0.192; p > 0.05). No significant association was observed between either motility types in the context of drug resistance or biofilm-forming capacity (p > 0.05). 83.13% of isolates tested were positive for siderophore production. The importance of PA as a pathogen in chronic and healthcare-associated infections has been described extensively, while there is increasing awareness of PA as an environmental agent in agriculture and aquaculture. Additional studies in this field would be an important undertaking to understand the interrelated nature of biofilm production and antimicrobial resistance, as these insights may become relevant bases for developing novel therapeutics and eradication strategies against PA.

No Correlation between Biofilm-Forming Capacity and Antibiotic Resistance in Environmental Staphylococcus spp.: In Vitro Results.

The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD570 values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens.

Preliminary data of different methods for the indirect diagnosis of Mycobacterium bovis infection.

We compared the response induced by QuantiFERON-TB Gold antigens to that obtained with the Intradermal Comparative Tuberculin Test and BOVIGAM assay. Our results showed that the QuantiFERON-TB Gold technique used in humans could also be applied for the diagnosis of TB infection in cattle.

No Correlation between Biofilm Formation, Virulence Factors, and Antibiotic Resistance in Pseudomonas aeruginosa: Results from a Laboratory-Based In Vitro Study.

Pseudomonas aeruginosa (P. aeruginosa) possesses a plethora of virulence determinants, including the production of biofilm, pigments, exotoxins, proteases, flagella, and secretion systems. The aim of our present study was to establish the relationship between biofilm-forming capacity, the expression of some important virulence factors, and the multidrug-resistant (MDR) phenotype in P. aeruginosa. A total of three hundred and two (n = 302) isolates were included in this study. Antimicrobial susceptibility testing and phenotypic detection of resistance determinants were carried out; based on these results, isolates were grouped into distinct resistotypes and multiple antibiotic resistance (MAR) indices were calculated. The capacity of isolates to produce biofilm was assessed using a crystal violet microtiter-plate based method. Motility (swimming, swarming, and twitching) and pigment-production (pyoverdine and pyocyanin) were also measured. Pearson correlation coefficients (r) were calculated to determine for antimicrobial resistance, biofilm-formation, and expression of other virulence factors. Resistance rates were the highest for ceftazidime (56.95%; n = 172), levofloxacin (54.97%; n = 166), and ciprofloxacin (54.64%; n = 159), while lowest for colistin (1.66%; n = 5); 44.04% (n = 133) of isolates were classified as MDR. 19.87% (n = 60), 20.86% (n = 63) and 59.27% (n = 179) were classified as weak, moderate, and strong biofilm producers, respectively. With the exception of pyocyanin production (0.371 ± 0.193 vs. non-MDR: 0.319 ± 0.191; p = 0.018), MDR and non-MDR isolates did not show significant differences in expression of virulence factors. Additionally, no relevant correlations were seen between the rate of biofilm formation, pigment production, or motility. Data on interplay between the presence and mechanisms of drug resistance with those of biofilm formation and virulence is crucial to address chronic bacterial infections and to provide strategies for their management.

Clinical Outcome and Drug Expenses of Intravitreal Therapy for Diabetic Macular Edema: A Retrospective Study in Sardinia, Italy.

BACKGROUND: Diabetic macular edema (DME) is a leading cause of visual loss in working-age adults. The purpose of this retrospective study was to perform an epidemiological analysis on DME patients treated with intravitreal drugs in a tertiary hospital. The clinical outcome, adverse drug reactions (ADRs), and intravitreal drug expenses were assessed. METHODS: All DME patients treated with Ranibizumab, Aflibercept, Dexamethasone implant, and Fluocinolone Acetonide implant at the Sassari University Hospital, Italy, between January 2017 and June 2020 were included. Central macular thickness (CMT) and best corrected visual acuity (BCVA) were measured. ADRs and drug expenses were analyzed. RESULTS: Two-hundred thirty-one DME patients (mean age: 65 years) received intravitreal agents. Mean CMT and BCVA were 380 µm and 0.5 LogMAR at baseline, 298 µm and 0.44 logMAR after one year (p = 0.04), and 295 µm and 0.4 logMAR at the end of the follow-up period. A total of 1501 intravitreal injections were given; no major ADRs were reported. Treatment cost was €915,000 (€261,429/year). Twenty non-responders to Ranibizumab or Aflibercept were switched to a Dexamethasone implant. In these patients, mean CMT and BCVA were 468 µm and 0.5 LogMar at the time of switching and 362 µm and 0.3 LogMar at the end of the follow-up (p = 0.00014 and p = 0.08, respectively). CONCLUSION: Results confirm that Ranibizumab, Aflibercept, and Dexamethasone implant are effective and safe in DME treatment. A switch to Dexamethasone implant for patients receiving Aflibercept or Ranibizumab with minimal/no clinical benefit should be considered.