Evaluation of mycobacteria infection prevalence and optimization of the identification process in North Sardinia, Italy

IMPORTANCE

Mycobacterial infection is a major threat to public health worldwide. Accurate identification of infected species and drug resistance detection are critical factors in treatment. We focused on shortening the turn-around time of identifying mycobacteria species and antibiotic resistance tests.

Drug resistance and the genotypic characteristics of rpoB and katG in rifampicin- and/or isoniazid-resistant Mycobacterium tuberculosis isolates in central Vietnam

BACKGROUND

Tuberculosis (TB) and drug-resistant TB (DR-TB) are national health burdens in Vietnam. In this study, we investigated the prevalence of rifampicin (RIF) and/or isoniazid (isonicotinic acid hydrazide, INH) resistance in patients with suspected TB, and applied appropriate techniques to help rapidly target DR-TB.

METHODS

In total, 1,547 clinical specimens were collected and cultured using the BACTEC MGIT system (Becton Dickinson and Co.). A resazurin microtiter assay (REMA) was used to determine the proportions of RIF and/or INH resistance. A real-time polymerase chain reaction panel with TaqMan probes was employed to identify the mutations of rpoB and katG associated with DR-TB in clinical isolates. Genotyping of the identified mutations was also performed.

RESULTS

A total of 468 Mycobacterium tuberculosis isolates were identified using the REMA. Of these isolates, 106 (22.6%) were found to be resistant to 1 or both antibiotics. Of the resistant isolates, 74 isolates (69.8%) were resistant to isoniazid (INH) only, while 1 isolate (0.94%) was resistant to RIF only. Notably, 31 isolates (29.24%) were resistant to both antibiotics. Of the 41 phenotypically INH-resistant isolates, 19 (46.3%) had the Ser315Thr mutation. There were 8 different rpoB mutations in 22 (68.8%) of the RIF-resistant isolates. The most frequently detected mutations were at codons 531 (37.5%), 526 (18.8%), and 516 (6.3%).

CONCLUSION

To help prevent new cases of DR-TB in Vietnam, it is crucial to gain a comprehensive understanding of the genotypic DR-TB isolates.

A rare presentation of tubercular osteomyelitis of the foot

Tuberculosis is a communicable disease that is a major cause of ill health. It is one of the top ten causes of death worldwide and the leading cause of death from a single infectious agent. Its most common clinical presentation is pulmonary involvement. However, approximately 23‐30% of tuberculosis patients have extrapulmonary symptoms. A rare (1%) clinical presentation of tuberculosis is foot and ankle infection. This is complicated by the fact that the diagnosis of osteoarticular tuberculosis is difficult. Our case was a 66-year-old multi-pathological pensioner, who, while working in the countryside, had an ankle sprain on the left foot, with a lacerated wound of about 2 cm diameter. The non-endemic area and the negative chest X-ray made the diagnosis extremely complex. However, a multidisciplinary approach with the radiologists and the infectious disease department led to clinical stabilization of the patient. Therefore, awareness and high index of suspicion of the disease is essential and referral to experts should be made if diagnosis is indeterminate despite extensive investigations. The knowledge allows early identification of the disease and prompt therapy in order to avoid long-standing untreated infections which typically cause bone destruction and loss of function. The knowledge is also mandatory for western physicians due to increasing international travel, immigration from less developed countries and increased use of immunosuppressive medications. We believe that this article can bring awareness around osteoarticular tuberculosis and help with improving outcome and eradication of the infection. Level of clinical evidence: 4.

Use of bedaquiline in spinal osteomyelitis and soft tissue abscess caused by multidrug-resistant Mycobacterium tuberculosis: A case report

Introduction

Spinal Tuberculosis (STB) represents between 1% and 2% of total tuberculosis cases. STB management remains challenging; the first-line approach consists of medical treatment, while surgery is reserved for patients with complications. No data regarding STB treatment with bedaquiline-containing regimens are available in the literature.

Case description

Herein, we report the case of a 21-year-old man from Côte d'Ivoire with a multidrug resistance STB with subcutaneous abscess. After approval of the hospital off-label drug committee, we started bedaquiline 400 mg daily for two weeks, followed by 200 mg three times per week, for 22 weeks, associated with linezolid 600 mg daily, rifabutin 450 mg daily, and amikacin 750 mg daily (interrupted after eight weeks). During treatment, we performed a weekly EKG. No QT prolongation was shown, but inverted T waves appeared, requiring several cardiological consultations and cardiac MRI, but no cardiac dysfunction was found. After 24 weeks, bedaquiline was replaced with moxifloxacin 400 mg daily. The patient continued treatment for another year. We performed another computer tomography at the end of treatment, confirming the cure.

Discussion

A salvage regimen containing bedaquiline proved effective in treating multidrug-resistance tuberculosis spinal infection without causing severe adverse effects. However, further studies are needed to evaluate better bedaquiline bone penetration and the correct duration of treatment with bedaquiline in MDR spinal tuberculosis.

Quinoxaline-based efflux pump inhibitors restore drug susceptibility in drug-resistant nontuberculous mycobacteria

Nontuberculous mycobacteria (NTM) comprise several ubiquitous, environmentally localized bacteria that may be responsible for serious human diseases. NTM-associated pulmonary infections largely affect individuals with underlying respiratory disease or chronic disease and immunosuppressed patients. Mycobacterium simiae and M. abscessus are two NTMs responsible for lung disease in immunocompetent and immunocompromised individuals. In this study, two NTM strains were isolated from two patients admitted to an Italian hospital and were identified as M. simiae and M. abscessus. The two NTMs were tested for drug susceptibility against different antibiotics. To restore drug susceptibility, a new series of 2-aryl-3-phenoxymethyl-quinoxaline derivatives (QXs) was designed, synthesized, and investigated as efflux pump inhibitors (EPIs) against two clinical isolates of the above-cited NTMs, evaluating how EPIs can influence the drug minimal inhibitory concentration values and, therefore, the activity. The different\ resistance levels tracked in the clinical strains were reduced by EPIs, and in several cases, the susceptibility was completely restored. QXs also resulted as potential chemical probes to be used in drug susceptibility tests to identify the resistance origin when detected.

Solid Lipid Nanoparticles as Formulative Strategy to Increase Oral Permeation of a Molecule Active in Multidrug-Resistant Tuberculosis Management

The role of mycobacterial efflux pumps in drug-resistant tuberculosis has been widely reported. Recently, a new compound, named SS13, has been synthesized, and its activity as a potential efflux inhibitor has been demonstrated. In this work, the chemical-physical properties of the SS13 were investigated; furthermore, a formulative study aimed to develop a formulation suitable for oral administration was performed. SS13 shows nonintrinsic antitubercular activity, but it increases the antitubercular activity of all the tested drugs on several strains. SS13 is insoluble in different simulated gastrointestinal media; thus, its oral absorption could be limited. Solid lipid nanoparticles (SLNs) were, therefore, developed by using two different lipids, Witepsol and/or Gelucire. Nanoparticles, having a particle size (range of 200-450 nm with regards to the formulation composition) suitable for intestinal absorption, are able to load SS13 and to improve its permeation through the intestinal mucosa compared to the pure compound. The cytotoxicity is influenced by the concentration of nanoparticles administered. These promising results support the potential application of these nanocarriers for increasing the oral permeation of SS13 in multidrug-resistant tuberculosis management.

Phytochemical Compositions and Biological Activities of Essential Oils from the Leaves, Rhizomes and Whole Plant of Hornstedtia bella Škorničk

The rapid emergence of drug-resistant strains and novel viruses have motivated the search for new anti-infectious agents. In this study, the chemical compositions and cytotoxicity, as well as the antibacterial, antifungal, antitrichomonas, and antiviral activities of essential oils from the leaves, rhizomes, and whole plant of Hornstedtia bella were investigated. The GC/MS analysis showed that β-pinene, E-β-caryophyllene, and α-humulene were found at high concentrations in the essential oils. The essential oils exhibited (i) inhibition against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis with minimum inhibitory concentrations (MIC) and minimum lethal concentration (MLC) values from 1 to 4% (v/v); (ii) MIC and MLC values from 2 to 16% (v/v) in Candida tropicalis and Candida parapsilosis; (iii) MIC and MLC values from 4 to 16% in Enterococcus faecalis; and (iv) MIC and MLC values from 8 to greater than or equal to 16% (v/v) in the remaining strains, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Candida albicans, and Candida glabrata. In antitrichomonas activity, the leaves and whole-plant oils of Hornstedtia bella possessed IC₅₀, IC₉₀, and MLC values of 0.008%, 0.016%, and 0.03% (v/v), respectively, whilst those of rhizomes oil had in turn, 0.004%, 0.008%, and 0.016% (v/v).Besides, the leaf oil showed a weak cytotoxicity against Vero 76 and MRC-5; meanwhile, rhizomes and whole-plant oils did not exert any toxic effects on cell monolayers. Finally, these oils were not active against EV-A71.

Levels of different cytokines in women and men with asymptomatic genital infection caused by Chlamydia

INTRODUCTION

Immune response to genital Chlamydia trachomatis infection is involved in both immunity and pathology. The cytokine profile during infection has been implicated in the disease outcome, either resolution or severe sequelae.

METHODOLOGY

In total, 3900 patients were analyzed for presence of genital infections caused by Chlamydia using molecular assays. Interleukins (IL) IL-10, IL-17, IL-6, IL-2 and chemokine IP-10 were estimated by ELISA in urine, cervical swabs and semen samples. Statistical analysis was performed using the T student test.

RESULTS

A total of 47 out of 3900 samples (1.2%) were found to be positive for Chlamydia trachomatis based on the Real Time (RT) PCR results. Statistical analysis revealed that the differences between Chlamydia trachomatis positive and negative samples regarding levels of cytokines were not significant.

CONCLUSIONS

Our results demonstrated that no significant difference in cytokine concentrations exists in Chlamydia trachomatis infected patients when compared to healthy controls. In further study, we aim to test on a greater number of positive samples a greater number of cytokines involved in the immune response to Chlamydia trachomatis infections.

Enhancement of antimicrobial activity of pump inhibitors associating drugs

INTRODUCTION

with the continuous emergence of pathogenic resistance to conventional drugs through efflux pumps, increasing efforts are directed toward discovering efflux inhibitory molecules.

METHODOLOGY

in this study three P-glycoprotein (P13CP, P22CP, P34CP) efflux-inhibitors (EIs), belonging to the series of phenoxymethylquinoxalines capable to restore/potentiate the antiproliferative activity of doxorubicin and vincristine against human tumor cell lines and different antibiotics against clinical isolates, were investigated on 10 clinical strains of Candida and 12 clinical and ATCC strains of Gram positive and Gram-negative bacteria.

RESULTS

MFC values of FLC were reduced in all Candida strains by the P22CP and P34CP inhibitors, and in 5/10 fungal strains by the P13CP inhibitor.

CONCLUSION

novel antibiotics with new modes of action are urgently required to suppress the rise of MDR bacteria. An alternative approach would be to identify molecules that can interfere with the process of efflux.

Antifungal activity of oils macerates of North Sardinia plants against Candida species isolated from clinical patients with candidiasis

Antibiotic resistance is one of the bigger problem of public health: the rise of multi-drug resistant organisms causes a challenge in the treatment of infective diseases. Anti-Candida resistance to conventional antifungal agents has increased in the last period. Our research was intended to evaluate antimicrobial activity of oil macerate (OM) of Helichrysum microphyllum Cambess. subsp. tyrrhenicum Bacch., Brullo & Giusso and OM of Hypericum perforatum subsp. angustifolium against several clinical strains. The study included 30 patients with candidiasis who had not received any antifungal treatment before they were enrolled. A collection of 30 clinical isolates belonging to 5 different species of Candida spp. was selected for this study. The data obtained showed an interesting activity of both Oil Macerate especially against C. krusei and C. parapsilosis. On the contrary, H. microphyllum Oil Macerate has had a better activity than the H.perforatum especially in relation to C. glabrata and C. krusei.

In vitro activity of essential oils against Pseudomonas aeruginosa isolated from infected hip implants

INTRODUCTION

Essential oils have been used since ancient times and are known for their anti-inflammatory, anti-depressive, antiseptic, antifungal and antimicrobial properties.

METHODOLOGY

in this study the antimicrobial activity of two essential oils from Melaleuca alternifolia and Thymus vulgaris-red thyme geraniol was tested against 16 multidrug-resistant P. aeruginosa strains from infected hip implants as well as the "in vitro" cytotoxic activity on normal human Wong-Kilbourne derivative (WKD) cells.

RESULTS

Thymus vulgaris-red thyme geraniol showed lower antimicrobial activity when compared to Melaleuca alternifolia. All tested oils were cytotoxic at concentrations lower than 0.12%.

CONCLUSION

Increase in drug resistance and lack of new antibiotics may encourage the development of natural treatments together with higher concern on environmental issues and natural lifestyle.

Design, synthesis and antitubercular activity of 4-alkoxy-triazoloquinolones able to inhibit the M. tuberculosis DNA gyrase

A number of new F-triazolequinolones (FTQs) and alkoxy-triazolequinolones (ATQs) were designed, synthesized and evaluated for their activity against Mycobacterium tuberculosis H37Rv. Five out of 21 compounds exhibited interesting minimum inhibitory concentration (MIC) values (6.6-57.9 μM), ATQs generally being more potent than FTQs. Two ATQs, 21a and 30a, were endowed with the best anti-Mtb potency (MIC = 6.9 and 6.6 μM, respectively), and were not cytotoxic in a Vero cell line. Tested for activity against M. tuberculosis DNA gyrase in a DNA supercoiling activity assay, 21a and 30a showed IC₅₀ values (27-28 μM) comparable to that of ciprofloxacin (10.6 μM). 21a was next selected for screening against several Mtb strains obtained from clinical isolates, including multi-drug-resistant (MDR) variants. Importantly, this compound was effective in all cases, with very promising MIC values (4 μM) in the case of some isoniazid/rifampicin-resistant Mtb strains. Finally, computer-based simulations revealed that the binding mode of 21a in the Mtb gyrase cleavage core complexed with DNA and the relevant network of intermolecular interactions are utterly similar to those described for ciprofloxacin, yielding a molecular rationale for the comparable anti-mycobacterial and DNA gyrase inhibition activity of this quinolone.

Potential of Borojoa patinoi Cuatrecasas water extract to inhibit nosocomial antibiotic resistant bacteria and cancer cell proliferation in vitro

Borojó (Borojoa patinoi Cuatrec.) is a fruit used in Colombian traditional medicine with supposed antihypertensive, antitumoral, diuretic, healing, immunological, anti-inflammatory and aphrodisiac effects. To explore the relative merits in terms of biological activities of borojó aqueous extract (BAE), we investigated in vitro its antimicrobial activity on nosocomial pathogenic and multidrug resistant (MDR) strains of Pseudomonas aeruginosa (6), Staphylococcus aureus (1) and Candida species (6), as well as its cytotoxicity on human conjunctive Wong-Kilbourne derivative (WKD) cells and Caco-2 cells from heterogeneous human epithelial colorectal adenocarcinoma. The bacteriostatic activity was observed overall on P. aeruginosa strains, as evidenced by the increase of the lag phase (43 hours) and reduction of the maximum growth rate detected using 187.5 mg BAE per mL. The bactericidal activity, instead, was observed at 375 mg BAE per mL. On the other hand, BAE showed an anti-proliferative effect against the Caco-2 cell line and was shown to be toxic on the WKD cell line at concentrations ranging from 0.05 to 187.5 μg mL-1. The analysis of the phenolic fraction of the fruit aqueous extract (BAE) using UHPLC-MS/MS showed the presence of 26 compounds, with vanillic, syringic and o-coumaric acids as the most abundant. Among these molecules, 7.81 ng mL-1 luteolin and myricetin, singly tested, were able to reduce bacterial growth. To the best of our knowledge, we are unaware of any previous studies demonstrating the anti-bacterial activity of borojó aqueous extract against antibiotic resistant strains of P. aeruginosa, and its anti-proliferative effect against WKD and Caco-2 cell lines. The latter result offers a potential base for new interest and investigations in relation to colon carcinoma models and borojó fruit consumption, since in Colombia this fruit is consumed also for its supposed antitumoral effects.

In vitro activity of hybrid lavender essential oils against multidrug resistant strains of Pseudomonas aeruginosa

INTRODUCTION

Lavender is an evergreen shrub native to Northern Africa and other mountainous Mediterranean regions. It grows throughout Southern Europe, the United States, and Australia. Lavender essential oil has been used since ancient times and is known for its anti-inflammatory, antidepressant, antiseptic, antifungal and antimicrobial properties.

METHODOLOGY

in this study, the antimicrobial activity of two Lavender essential oils (Lavanda sumian and Lavanda grosso) against 16 multidrug-resistant P. aeruginosa strains from clinical ocular samples taken from migrant patients has been investigated. The in vitro cytotoxic activity on human Wong-Kilbourne derivative (WKD) conjunctiva cells from healthy patients and nitric oxide synthase (NOS) activity on murine macrophage (J774.1A) were also evaluated.

RESULTS

L. sumian showed lower antimicrobial activity when compared to L. grosso. Both lavender oils tested had no cytotoxic effect at very low concentrations, mostly L. grosso. The essential oils extracted from L. sumian and L. grosso significantly reduced NOS in a cell model.

CONCLUSION

Increase in drug resistance and lack of new antibiotics may encourage the development of natural antimicrobial treatments.

Antimicrobial activity of Austroeupatorium inulaefolium (H.B.K.) against intracellular and extracellular organisms

The antimicrobial activity of Austroeupatorium inulaefolium (H.B.K.) essential oil was studied in different pathogens species and its cytotoxicity activity was determinated on different cellular lines. Despite the good antibacterial activity of A. inulaefolium, it has been cytotoxic at low concentrations. Consequently it might be interesting to determine the antimicrobial activity and cytotoxicity of the major compounds of this essential oil.

Beyond pulmonary nontuberculous mycobacteria disease: do extra-pulmonary forms represent an emerging clinical and public health threat?

Nontuberculous mycobacteria (NTM) are a heterogeneous group of pathogens including all mycobacteria other than Mycobacterium tuberculosis complex and Mycobacterium leprae [1]. The rate of NTM infection has increased substantially over the last decades, especially in high-income countries, as recently illustrated by Diel et al. [2] who have highlighted the relevant clinical and economic burden of NTM disease in Germany. The main reasons include the aging of the population, the increasing number of patients with immunodepressive disorders, the use of immunosuppressive agents and a substantial increase in awareness of the disease [3]. Epidemiological data on NTM worldwide are lacking and very few reports have been published based on the Italian population [4, 5].

Pulmonary and extra-pulmonary diseases caused by nontuberculous mycobacteria: new clinical and public health threatshttp://ow.ly/87Dm30eMFd9

Change in Caco-2 cells following treatment with various lavender essential oils

Lavender is an aromatic evergreen shrub diffused in the Mediterranean basin appreciated since antiquity. The genus Lavandula is part of Lamiaceae family and includes more than 20 species, among which true lavender (L. vera D.C. or L. angustifolia Miller.) and spike lavender (L. latifolia Medikus); there are also numerous hybrids known as lavandins (L. hybrida Rev.). L. vera, spike lavender and several hybrids are the most intensely used breeding species for the production of essential oils. Lavender and lavandin essential oils have been applied in food, pharmaceutical and other agro industries as biological products. In their chemical composition, terpenes linalool and linalyl acetate along with terpenoids such as 1,8-cineole are mostly responsible for biological and therapeutic activities. This study evaluates cytotoxic activity of essential oils derived from four lavender species on human epithelial colorectal adenocarcinoma cells. Analysis of pre- and post-treatment cell morphology has been performed using scanning electron microscope.

Tuberculosis in Sardinia: An investigation into the relationship between natives and immigrants

OBJECTIVE/BACKGROUND

Tuberculosis (TB) has had a recrudescence in the last few decades in Italy as a result of many factors, among which migration from countries where TB is endemic is one of them. In Sardinia, a major island of Italy, there was no knowledge of the mechanisms of transmission of TB in the immigrant subpopulation and the impact it may have on the native subpopulation and on the community as a whole. Therefore, a molecular epidemiological study was carried out to get a clearer picture of the number and genetic features of Mycobacterium tuberculosis strains isolated from immigrants and from natives in Sardinia.

METHODS

Two groups of clinical isolates of M. tuberculosis, one collected from immigrants and the other one from Sardinians, were analyzed in this study. The genotyping was executed through the variable number tandem repeat-mycobacterial interspersed repetitive units technique and a first-line antimycobacterial drug-susceptibility test was also carried out.

RESULTS

Thirty-six clinical isolates from immigrants and 25 from Sardinians were analyzed. Variable number tandem repeat-mycobacterial interspersed repetitive units technique showed that all of them belonged to different strains and there was a quite high allelic diversity among them. Moreover, data collected allowed the finding of, with a good approximation, the phylogenetic relations among the strains isolated and the best-known phylogenetic groups.

CONCLUSION

The study pointed out that since every strain is different, there was no TB transmission in any of the subpopulations and between immigrants and natives. This showed that the presence of immigrants was not a risk factor for contracting TB in the community.

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.

Chemical composition, cytotoxicity, antimicrobial and antifungal activity of several essential oils

Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models.

Essential oils in ocular pathology: an experimental study

INTRODUCTION

The antimicrobial activity of essential oils (EOs) has been known for ages; in particular, the EOs of Melaleuca alternifolia, Thymus vulgaris, Mentha piperita, and Rosmarinus officinalis have been used for the treatment of fungal and bacterial infections.

METHODOLOGY

This study focused on the in vitro cytotoxicity to normal human conjunctiva cells and antimicrobial activity of 20 EOs.

RESULTS

The oils tested showed no cytotoxic effect at very low concentrations. Rosmarinus officinalis, Melaleuca alternifolia, and Thymus vulgaris L. red thyme geraniol sel oils had good antimicrobial activity against Gram-positive and Gram-negative strains.

CONCLUSIONS

The results of this study are of great interest and may have a major impact on public health, providing useful tips to optimize the therapeutic use of some natural drugs.

Could inducible protein-10 and heparin-binding hemagglutinin improve the detection of Mycobacterium tuberculosis-infected subjects in a country with low incidence of tuberculosis?

BACKGROUND

This study aimed to evaluate inducible protein-10 (IP-10) as a biomarker besides interferon-gamma (IFN-γ) to improve the identification of active tuberculosis (TB) and latent tubercular infection (LTBI) in a country with a low incidence of TB.

METHODS

Whole blood from Mycobacterium tuberculosis-infected subjects was stimulated with region-of-difference-1 (RD1)-specific peptides and with heparin-binding hemagglutinin (HBHA) to determine the release of IP-10 and IFN-γ.

RESULTS

No statistically significant difference was observed between positive rates of IP-10 and IFN-γ after RD1-specific peptide stimulation in the TB and LTBI groups; a different response was detected in QuantiFERON TB-gold test-negative (QFT-) subjects. A significantly different proportion of positive responses was observed between IP-10 and IFN-γ following HBHA stimulation in the TB group and in the QFT- group but not in the LTBI group.

CONCLUSIONS

The IP-10 test seemed to identify false-negative QFT results in some subjects with a positive IFN-γ/IP-10/HBHA pattern.

Antifungal, anti-biofilm and adhesion activity of the essential oil of Myrtus communis L. against Candida species

Candida species belong to the normal microbiota of the oral cavity, gastrointestinal tract and vagina. The increasing incidence of drug-resistant pathogens and the toxicity of the antifungal compounds have drawn the attention towards the antimicrobial activity of natural products, an inexpensive alternative. The aim of this work was to evaluate the adhesion activity, the biofilm formation and the action of the Myrtus communis L. essential oil (EO) on the biofilm formation towards three species isolated from clinical samples: Candida albicans, Candida parapsilosis and Candida tropicalis. Furthermore, we evaluated the antimycotic activity of the EO towards the three species, and the results were compared with the minimum inhibitory concentration of six antimycotics. The activity of the EO against C. albicans and C. parapsilosis was better than that obtained against C. tropicalis; moreover, the strains used in the assay were adhesive and biofilm producer, and the effect of myrtle EO on the biofilm formation yielded encouraging results.

Cost-effectiveness in the diagnosis of tuberculosis: choices in developing countries

Tuberculosis remains one of the major causes of global death from a single infectious agent. This situation is worsened by the HIV/AIDS pandemic because one-third of HIV/AIDS patients are co-infected with Mycobacterium tuberculosis. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely manner, allowing continued M. tuberculosis transmission within communities. Diagnosis of tuberculosis can be made using indirect and direct methods. The indirect tests, such as interferon-gamma release assays, provide a new diagnostic method for M. tuberculosis infection, but do not discriminate between infection and active disease. The most common direct method for diagnosing TB worldwide is sputum smear microscopy (developed more than 100 years ago), where bacteria are observed in sputum samples examined under a microscope. In countries with more developed laboratory capacities, cases of tuberculosis may also be diagnosed using culture methods (the current gold standard) or, increasingly, using rapid molecular tests. In this review, we discuss the traditional methods for the diagnosis of tuberculosis. We also discuss other inexpensive assays that can be used to detect the presence of M. tuberculosis.

Clinical considerations on Buruli ulcer employing two molecular tests for the detection of Mycobacterium ulcerans in 100 skin biopsies

OBJECTIVES

Buruli ulcer (BU) is an infected cutaneous lesion, the etiological agent of which is Mycobacterium ulcerans. Diagnosis is confirmed by the identification of acid-fast bacilli and culture. In clinically suspicious forms with negative bacteriological or Ziehl-Neelsen (ZN) findings, molecular tests are used. This study compared the concordance of nested polymerase chain reaction (PCR) (targeting IS2404) and PCR (targeting IS2606) in different clinical situations.

METHODS

A total of 57 samples were sourced from 39 BU patients. Control samples (n = 43) were obtained from non-BU ulcers in 38 patients. Samples were divided into two pieces and submitted to, respectively, histological examination and ZN staining, and PCR. Subsamples submitted to PCR were divided and submitted to nested PCR IS2404 and PCR IS2606, respectively.

RESULTS

Of the 57 BU biopsies, positive results were obtained by nested PCR in 18 (31.6%) and by IS2606 PCR in 37 (64.9%) cases. Sequencing of the positive samples confirmed the specificity of amplicons in all nested PCR samples and in 26 of 37 (70.2%) samples positive to IS2606. Hence, nested PCR was more specific (100% vs. 93%) and less sensitive (32% vs. 46%) than IS2606 PCR. In the BU samples, nested PCR was negative in 15 instances, and IS2606 PCR was negative in 11 instances in which ZN histology had been positive (false negatives). Both PCRs were positive in six ZN-negative smears.

CONCLUSIONS

We considered 57 samples from 39 BU patients in various clinical stages and at different times after the beginning of therapy. These provided positive results in 18 cases with IS2404 nested PCR and in 37 cases with PCR IS2606; only 26 of the latter remained positive subsequent to sequencing. Hence, even if IS2404 PCR is considered more specific, in subjects who appear to fail to respond to therapy, it is advisable to also carry out IS2606 PCR. A possible interpretation of the discordance between the two techniques due to unavoidable technical errors as well as to different sensitivity of the two tests at M. ulcerans DNA low concentration (i.e. in recent infection and in well-treated cases) is discussed.

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.

Molecular identification of Mycobacterium avium subspecies paratuberculosis in oral biopsies of Crohn's disease patients

Oral lesions may be found in patients with Crohn’s disease (CD), in a percentage up to 20%. The aim of this study was to investigate a possible relationship between Mycobacterium avium subsp. paratuberculosis (MAP) and oral lesions in CD patients. 23 oral biopsies were examined performing IS900 Nested PCR; 9 of them were positive: 8 from CD patients and 1 from a control. Our purpose is to go on with this study, amplifying the number of subjects examined and testing subjects with oral lesions related to diseases other than CD to verify the specific association between MAP and oral lesions in CD patients.

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.

Antimycotic activity of Myrtus communis L. towards Candida spp. from clinical isolates

This item has no abstact. Follow the link below to access the full text.

In honor of Professor Giovanni Fadda: a fighter against tuberculosis

This item has no abstract. Use the link below to access the full text.

Chest tuberculosis with mediastinal asymptomatic lymphadenitis without lung involvement in an immunocompetent patient

Tuberculosis remains the major cause of morbidity and mortality by a single infectious agent, particularly in developing countries. In recent years, we have witnessed the emergence of uncommon radiographic patterns of chest tuberculosis. Lymphadenitis is the most common extrapulmonary tuberculosis (TB) manifestation which, in developed countries, occurs more frequently in childhood, but also among adult immigrants from endemic countries and in HIV-infected people. Isolated and asymptomatic mediastinal lymphadenitis is uncommon in immunocompetent adults. We report a case of a young adult man from Senegal affected by sovraclavear and mediastinal TB lymphadenitis, which contains some uncommon elements: no compromised immunity, especially no HIV-infection, no lung lesions, no symptoms of infection or of mediastinum involvement, and rapid response to therapy in terms of mass size reduction. Examination of extra-thoracic lymph nodes and the patient’s characteristics guided our diagnostic process to suspect TB. Surgical biopsy and subsequent histopathological and microbiological examinations of lymph material, first by Lowestein-Jensen and BACTEC cultures that remain the gold standard of diagnosis, confirmed the diagnosis. Chest X-ray was inconclusive; however, CT played an important role in the diagnostic course and in the management of the patient, particularly in determining disease activity, offering mediastinum and parenchymal details, as well as in identifying typical features of tuberculous lymph nodes and also of active/non active disease. Six months of antimycobacterial regimen is the recommended treatment in TB lymphadenitis of HIV-negative adults.

Comparison of two molecular methods for diagnosis of Chlamydia trachomatis

This item has no abstract. Follow the links below to access the full text.

Tuberculosis patients are characterized by a low-IFN-γ/high-TNF-α response to methylated HBHA produced in M. smegmatis

Whole blood from Mycobacterium tuberculosis-infected subjects was stimulated with heparin-binding hemagglutinin (HBHA). Tuberculosis (TB) patients showed an HBHA-specific T-cell response characterized by low-IFN-γ/high-TNF-α secretion, while asymptomatic subjects with latent infection (LTBI) and TB patients under therapy showed a pattern with high IFN-γ/low TNF-α. These results underscore the usefulness of HBHA in helping to distinguish LTBI subjects versus TB patients.

Interaction between Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium subspecies paratuberculosis with the enteric glia and microglial cells

Background

We investigated the interaction of Mycobacterium avium subspecies paratuberculosis, M. bovis and M. tuberculosis and different glial cells (enteric glial and microglial cells) in order to evaluate the infecting ability of these microorganisms and the effects produced on these cells, such as the evaluation of cytokines expression.

Results

Our experiments demonstrated the adhesion of M. paratuberculosis to the enteroglial cells and the induction of IL-1A and IL-6 expression; M. tuberculosis and M. bovis showed a good adhesive capability to the enteric cell line with the expression of the following cytokines: IL-1A and IL-1B, TNF-α, G-CSF and GM-CSF; M. bovis induced the expression of IL-6 too.

The experiment performed with the microglial cells confirmed the results obtained with the enteroglial cells after the infection with M. tuberculosis and M. bovis, whereas M. paratuberculosis stimulated the production of IL-1A and IL-1B.

Conclusion

Enteroglial and microglial cells, could be the target of pathogenic mycobacteria and, even if present in different locations (Enteric Nervous System and Central Nervous System), show to have similar mechanism of immunomodulation.

Performance of QuantiFERON TB in a student population at low risk of tuberculosis

This item has no abstract. Follow the links below to access the full text.

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.

Interferon-γ release assay in people infected with immunodeficiency virus

The present study aimed to use QuantiFERON TB Gold in tube (Cellestis Limited, Carnegie, Victoria, Australia) as a tool for the screening for tubercular infection in HIV-positive patients. Seventy-three HIV-positive subjects were tested. For each individual, QuantiFERON TB in tube was performed. The immunoassay was negative in 53 subjects, positive in eight and indeterminate in 12. The data obtained indicate that factors such as the CD4 cell count and their percentage, as well as the stage of the disease, could affect the performance of the interferon-γ release assay in populations at risk such as HIV-positive subjects.

Methylated HBHA produced in M. smegmatis discriminates between active and non-active tuberculosis disease among RD1-responders

Background

A challenge in tuberculosis (TB) research is to develop a new immunological test that can help distinguish, among subjects responsive to QuantiFERON TB Gold In tube (QFT-IT), those who are able to control Mtb replication (remote LTBI, recent infection and past TB) from those who cannot (active TB disease). IFN-γ response to the Heparin-binding-hemagglutinin (HBHA) of Mtb has been associated with LTBI, but the cumbersome procedures of purifying the methylated and immunological active form of the protein from Mtb or M. bovis Bacillus Calmette et Guerin (BCG) have prevented its implementation in a diagnostic test. Therefore, the aim of the present study was to evaluate the IFN-γ response to methylated HBHA of Mtb produced in M. smegmatis (rHBHAms) in individuals at different stages of TB who scored positive to QFT-IT.

Methodology/Principal Findings

87 individuals at different stages of TB who scored positive to QFT-IT were selected. IFN-γ response to in vitro whole blood stimulation with rHBHAms was evaluated by short-term and long-term tests and detected by ELISA or flow cytometry. We demonstrated that the IFN-γ response to rHBHAms is mediated by CD4⁺ T-cells with an effector-memory phenotype. This response, evaluated by short-term-tests, is significantly lower in active TB than in remote LTBI (p = 0.0010) and past TB (p = 0.0152). These results were confirmed by long-term tests. The qualitative data confirmed that IFN-γ responses higher than the cut-off point identified by ROC analysis are associated with the status of non-active disease.

Conclusions

In this study we show that the T-cell response to a recombinant and methylated HBHA of Mtb produced in M. smegmatis is useful to discriminate between active and non-active TB disease among those responsive to QFT-IT in a whole blood system. Further studies are needed to improve the accuracy of the assay.

Essential oil composition of leaves of Stachys yemenensis obtained by supercritical CO₂

This article reports the composition of the essential oil from the leaves of Stachys yemenensis. The essential oil was extracted by supercritical CO₂ (90 bar; 40 °C) and its chemical composition was determined by gas chromatography and gas chromatography-mass spectrometry. The major components of the sample were α-phellandrene (13.9%), β-phellandrene (11.7%), elemol (12.0%), spathulenol (6.7%), β-eudesmol (5.0%), α-eudesmol (4.75%) and squalene (4.8%). On the exhausted matrix, deprived of the volatiles, we carried out a high-pressure (250 bar) treatment for the extraction of squalene (49.7%). The antimicrobial activity of the essential oils has been assayed by using the broth dilution method on two American Type Culture Collection (ATCC) strains, Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and two clinical strains, Candida albicans and Candida glabrata.

Essential Oils of Daucus carota subsp. carota of Tunisia Obtained by Supercritical Carbon Dioxide Extraction

The essential oils and supercritical CO2 extracts of wild Daucus carota L. subsp. carota from two different sites in Tunisia were investigated. The main components of the essential oil of the flowering and mature umbels with seeds from Sejnane were eudesm-7(11)-en-4-ol (8.2 – 8.5%), carotol (3.5 - 5.2%), sabinene (12.0 −14.5%), α-selinene (7.4 - 8.6) and 11-α-(H)-himachal-4-en-1-β-ol (12.7 – 17.4%), whereas the oils from Tunis were predominantly composed of elemicin (31.5 – 35.3%) and carotol (48.0 – 55.7%). The antimicrobial activity of the essential oils were assayed by using the broth dilution method on Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and clinical strains of Candida albicans and C. tropicalis 1011 RM. The MIC values obtained were all > 2.5% (v/v).

Essential oils of Daucus carota subsp. carota of Tunisia obtained by supercritical carbon dioxide extraction

The essential oils and supercritical CO2 extracts of wild Daucus carota L. subsp. carota from two different sites in Tunisia were investigated. The main components of the essential oil of the flowering and mature umbels with seeds from Sejnane were eudesm-7(11)-en-4-ol (8.2 - 8.5%), carotol (3.5 - 5.2%), sabinene (12.0 -14.5%), a-selinene (7.4 - 8.6) and 11-alpha-(H)-himachal-4-en-1-beta-ol (12.7 - 17.4%), whereas the oils from Tunis were predominantly composed of elemicin (31.5 - 35.3%) and carotol (48.0 - 55.7%). The antimicrobial activity of the essential oils were assayed by using the broth dilution method on Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and clinical strains of Candida albicans and C. tropicalis 1011 RM. The MIC values obtained were all > 2.5% (v/v).

Molecular characterization of Sardinian Mycobacterium tuberculosis isolates by IS6110 restriction fragment length polymorphism, MIRU-VNTR and rep-PCR

An evaluation of the utility of rep PCR typing compared to the 15 loci discriminatory set of MIRU-VNTR was undertaken. Twenty-nine isolates of Mycobacterium tuberculosis from patients were examined. Genomic DNA was extracted from the isolates by standard method. The number of copies of tandem repeats of the 15 MIRU-VNTR loci was determined by PCR amplification and agarose gel electrophoresis of the amplicons. M. tuberculosis outbreak-related strains were distinguished from other isolates. MIRU-VNTR typing identified 4 major clusters of strains. The same isolates clustered together after RFLP typing, but rep-PCR identified only 3 of them. The concordance between RFLP and MIRU-VNTR typing was complete, with the exception of two isolates with identical RFLP patterns that differed in the number of tandem repeat copies at two MIRU-VNTR alleles. A further isolate, even sharing the same RFLP pattern, differed by one repeat from the rest of its cluster. We also tested the use of an automated rep-PCR for clinical laboratory applications but it failed to identify the link between two pairs of epidemiologically related strains clustered by the other 2 techniques. For superior discrimination, ease of comparison of results and lower cost, MIRU-VNTR typing should be the favored PCR-based typing tool.

Usefulness of the QuantiFERON-TB-Gold in tube in a population at risk of bovine tubercular infection

The effectiveness of the QuantiFERON-TB-Gold in tube was compared with PPD to detect tuberculosis infection in the staff of cattle-farms, as a consequence of an outbreak of bovine tuberculosis in livestock. The data revealed the advantage of the immunological test for the specific detection of subjects infected by Mycobacterium tuberculosis complex.