P404 CAN THE BASELINE NT–PROBNP LEVEL BE USED AS A PROGNOSTIC MARKER IN PATIENTS HOSPITALIZED FOR COVID–19? A SINGLE CENTRE EXPERIENCE

Background

NT–proBNP is commonly used a reliable prognostic biomarker in heart failure. Although SARS–CoV–2 is primarily a respiratory virus, it can also cause a myocardial injury. Previous observations indicate that COVID–19 patients can show a pathological rise of NT–proBNP during the disease course.

Aim

To assess the in–hospital prognostic significance of baseline NT–proBNP levels in COVID–19 patients.

Methods

We retrospectively analysed the data of one–hundred and ninety–two consecutive patients (mean age 70±15, 54.6 % males), hospitalized in our institution for COVID–19 disease. Demographic parameters, clinical history, pharmacological treatments and laboratory data at the admission were analysed. According to the baseline NT–proBNP levels, the whole population was divided into normal (Group A) and elevated (Group B) NT–proBNP, considering ≥ 125 pg/mL level as the pathological cut off. The length–of–stay, the orotracheal intubation rate, non–invasive ventilation and in–hospital mortality were taken into account as prognostic parameters.

Results

Forty–seven patients and one–hundred and forty–five patients belonged to Group A and Group B, respectively. Group A patients were significantly younger (57±13 vs 74±13 yrs, p < 0.001), with a lower rate of previous cardiac disease (6.4% vs 39.3%, p < 0.001) and atrial fibrillation (4.3% vs 16.7%, p < 0.033) and a better eGFR (94±20 vs 71±29 ml/m’, p < 0.001). No differences were noted between the two groups in the prevalence of diabetes, hypertension, ACE/ARBs treatment. The length–of–stay was similar (20±13 days in Group A vs 22±19 days in Group B, respectively, p=ns). Although patients of Group B showed a higher rate for orotracheal intubation (4.3% vs 13.8%) and non–invasive ventilation (13.8% vs 32.4%,), these differences were not significantly different. The in–hospital mortality was considerably lower in patients with normal baseline NT–proBNP level, as compared to Group B patients (2.1% vs 23.4% p < 0.001). When stratified by quartiles of NT–proBNP, the subgroups showed a prognosis clearly related to the expression of the biomarker.

Conclusion

In patients hospitalized for COVID–19, normal baseline NT–proBNP level identifies a population with a short–term better outcome. This widely diffuse biomarker could be used in the initial phase of admission as a prognostic tool to characterize the in–hospital prognosis.

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.

Comparative compositional analysis of cassava brown streak disease resistant 4046 cassava and its non-transgenic parental cultivar

Compositional analysis is an important component of an integrated comparative approach to assessing the food and feed safety of new crops developed using biotechnology. As part of the safety assessment of cassava brown streak disease resistant 4046 cassava, a comprehensive assessment of proximates, minerals, amino acids, fatty acids, vitamins, anti-nutrients, and secondary metabolites was performed on leaf and storage root samples of 4046 cassava and its non-transgenic parental control, TME 204, collected from confined field trials in Kenya and Uganda over two successive cropping cycles. Among the 100 compositional components that were assessed in samples of 4046 and control TME 204 cassava roots (47 components) and leaves (53 components), there were no nutritionally relevant differences noted. Although there were statistically significant differences between the transgenic and control samples for some parameters, in most cases the magnitudes of these differences were small (<20%), and in every case where comparative literature data were available, the mean values for 4046 and control cassava samples were within the range of normal variation reported for the compositional component in question. Overall, no consistent patterns emerged to suggest that biologically meaningful adverse changes in the composition or nutritive value of the leaves or storage roots occurred as an unintended or unexpected consequence of the genetic modification resulting in 4046 cassava. The data presented here provide convincing evidence of the safety of 4046 cassava with respect to its biochemical composition for food and feed, and it could be considered as safe as its non-transgenic control.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Phages specific for mycobacterial lipoarabinomannan help serodiagnosis of tuberculosis

This study evaluated the possibility to use six phages specific to the Mycobacterium tuberculosis lipoarabinomannan (LAM) as tools for tubercular serodiagnosis. We analysed sera samples from 30 subjects with active tuberculosis (TB+), 30 with latent tubercular infection (LTBI) and 60 healthy subjects as controls (K). Our data indicated a good antibody response of the TB+ and LTBI patients against the phage Ri(7)17; the optical density (OD) values obtained from sera patients was statistically significant when compared to the control samples. Our results confirm that phage display technology might be useful to develop new tools for diagnosis of tuberculosis.

Heparin binding haemagglutin as potential diagnostic marker of Mycobacterium bovis

In this study, we characterized the humoral responses in cattle of Sardinia. The animals were divided into three groups: 1) 28 cattle infected with Mycobacterium bovis; 2) 48 cattle from herds in which foci of infection was notified; 3) 50 cattle from herds that were TB-free. Levels of IgG antibody were measured against the following antigens of M. tuberculosis: Heparin-Binding-Haemagglutin (HBHA), Ag85B, PPE44, and PE_PGRS33 to investigate their potential to diagnose TB in animals. Our results indicated that HBHA is a potential candidate for the development of a serological assay for rapid diagnosis of cattle infected with M. bovis.

Diversity of begomoviruses associated with mosaic disease of cultivated cassava (Manihot esculenta Crantz) and its wild relative (Manihot glaziovii Mull. Arg.) in Uganda

Cassava (Manihot esculenta) growing in Uganda during 2001-2002 has been screened for the presence of begomoviruses using PCR-RFLP, cloning full-length genomic components and nucleotide sequence analysis. In contrast with a recent survey in neighbouring Kenya, which identified three distinct strains of East African cassava mosaic virus (EACMV, EACMV-UG and EACMV-KE2) as well as East African cassava mosaic Zanzibar virus and the new species East African cassava mosaic Kenya virus, only EACMV-UG and, to a lesser extent, African cassava mosaic virus (ACMV) were found associated with cassava in Uganda. The integrity of the cloned genomic components of representative virus isolates was confirmed by demonstrating their infectivity in Nicotiana benthamiana and cassava using biolistic inoculation, providing a convenient means to screen cassava varieties for disease resistance. Both EACMV-UG and ACMV were also associated with Manihot glaziovii. Infectivity studies using cloned components confirmed that viruses from one host could infect the other, suggesting that this wild relative of cassava might be a reservoir host for the disease. The relatively low level of diversity of begomoviruses associated with cassava mosaic disease in Uganda is consistent with reports that EACMV-UG has displaced other begomovirus species and strains during the recent epidemic that swept through the country.

Identification of mycobacterial infections in wild boars in Northern Sardinia, Italy

During a six-month period a region of Northern Sardinia was monitored to check the presence of mycobacterial infections in wild boars. Forty-eight serum and 229 biopsy samples were collected from different animals and examined by both traditional diagnostic techniques (culture, bacterioscopic and molecular tests) and enzyme-linked immunosorbent assay (ELISA). The latter was used to determine the antibody response against both methylated and nonmethylated Heparin-Binding Haemagglutinin (HBHA) protein. Nine mycobacterial strains were isolated: three M. avium ssp. paratuberculosis (Map), three M. avium, one M. interjectum and two M. scrofulaceum strains. By PCR, only one animal was positive for M. bovis, whereas 10 animals were positive for Map. Out of the 48 sera tested, 19 showed a good humoral response to methylated HBHA and 17 to nonmethylated HBHA. Our data provide new information on the prevalence of mycobacterial infection among wild boars in Northern Sardinia and suggest that a more effective program should be developed to monitor mycobacterial infections in the wild animal population.

QuantiFERON TB Gold: a new method for latent tuberculosis infection

QuantiFERON-TB Gold obtained approval in 2003 by the Food and Drug Administration as a valid tool for the diagnosis of latent tuberculosis. In this report, we evaluated its potential use in the immunological diagnosis of Mycobacterium tuberculosis infections in different groups of subjects. Our data indicate that QuantiFERON-TB Gold is specific for identifying subjects who have come into contact with M. tuberculosis and its use alongside traditional diagnostic techniques may be an important instrument for controlling tuberculosis.

[Analysis of type 2 diabetes disease management: cross-study of a sanitary district]

AIM

We studied type 2 diabetes prevalence in the Sicilian country, and the disease management, trough the analysis of some indicators.

METHODS

A cohort of 385 subjects with type 2 diabetes was selected in a sanitary district. Anamnestic, anthropometric, pharmacological data were recorded by a self-controlled software (Gipac-2). We used Student's t-test for statistical data analysis.

RESULTS

The cohort of diabetic people represents 3.97% of the studied population in toto, 206 women and 179 men: only 2/3 of the studied people followed the therapeutic indications, using prevalently oral hypoglycemic therapy, with poor agreement to specialised centres for diabetes. Hypertension was present in 52.51% of men, in 68.21% of women; most of 50% of people, men and women, showed an obesity/overweight condition. The observations of eventual diabetes complications (eye, foot etc.) was poor by doctors: a 1/3 of patients had diabetes complications undefined. The disease management analysis showed the use of antiplatelet-adhesion drugs involved a half of the studied people; 55-60% of people agreed to diet restriction, no sex-related; the self-control of glucose blood value was present in 65-70% of subjects. The indicators analysis showed that only 40% of men and women performed a HbA1C measurement; 40-50% of people did not control blood pressure in 90 days, 65% did not perform a LDL measurement in one year, more than 70% did not perform a fundus oculi check up.

CONCLUSION

The study confirms the incidence of diabetes similar to national and European standards. The disease management appears lacunose in half of the population, the use of indicators is limited; guidelines on chronic disease management and on prevention of complications are partially applied. The use of sensitization strategies of sanitary operators, trough formation periods, is very important in order to implement the chronic disease management.

Re-emergence of Cassava Brown Streak Disease in Uganda

During November 2004, veinal chlorosis on mature cassava leaves, typical of cassava brown streak disease (CBSD), was observed at Mukono in central Uganda. Five out of 11 cultivars at the site showed CBSD symptoms (incidence range 4 to 64%). In a survey of farmers' fields, CBSD was observed in Wakiso and Mukono districts. Incidence of cassava mosaic disease was also recorded and averaged 60% for landraces (range 16.7 to 100%) and 20% for resistant varieties (range 0 to 65%). Leaf samples of plants with CBSD symptoms produced an amplicon of 222 bp using reverse transcription-polymerase chain reaction with primers that amplify a fragment of the coat protein (CP) gene of Cassava brown streak virus. Sequence comparisons based on the amplified CP gene fragment indicated that the isolates have 77 to 82.9% nucleotide and 43.9 to 56.8% amino acid identity with those from Mozambique and Tanzania. There was 95.9 to 99.5% nucleotide and 85.1 to 90.5% amino acid identity among the Ugandan isolates. These results confirm the re-emergence of CBSD in Uganda after it was first observed in the 1930s in cassava introduced from Tanzania and controlled by eradication. Prior to this report, CBSD was known to be restricted to the coastal lowlands of East Africa.

In vitro efficacy of Linezolid on clinical strains of Mycobacterium tuberculosis and other mycobacteria

Linezolid, an oxazolidinone that acts by inhibiting protein synthesis, was evaluated in strains of tuberculosis and non-tubercular mycobacteria resistant to one or more drugs isolated in northern Sardinia. The in vitro activity of Linezolid (Pfizer) was assessed on different isolates of Mycobacterium spp. from clinical samples by the Proportional Method. Linezolid demonstrated an excellent activity against the 24 strains of M. tuberculosis and against M. gordonae, M. marinum, M. aurum, M. phlei, and M. avium, with MIC values ranging from 0.5 to 2 microg/ml. Linezolid can be used in combination with the standard antitubercular medications, or as an effective therapeutic alternative in infections caused by M. tuberculosis or by other species of non-tubercular mycobacteria.

PE_PGRS proteins are differentially expressed by Mycobacterium tuberculosis in host tissues

Characterization of PE_PGRS gene expression will help define the role of this protein family in the biology of Mycobacterium tuberculosis. In this report, quantitative real-time RT-PCR (QRT-PCR) was implemented to assess expression of three PE_PGRS genes (rv0746, rv1651c and rv1818c) under different experimental conditions. The three PE_PGRS genes showed a similar expression profile in axenic cultures, with a significant up-regulation occurring at late log and early stationary phases. rv1651c gene expression increased following intracellular growth in bone marrow-derived macrophages but not in type-II human pneumocytes, while rv0746 was induced in both in vitro systems. Following the infection of mice with M. tuberculosis, expression levels of rv1651c and rv0746 normalized to ftsZ and 16S rRNA were highest in the spleen tissue during the chronic stages of murine tuberculosis, with a >20- and >30-fold up-regulation, respectively. Levels of expression remained lower in the lung over the same time period. Expression of the rv1818c gene did not change significantly under different experimental conditions tested. The results of this study indicate that M. tuberculosis can differentially regulate expression of PE_PGRS genes and that genes such as rv0746 and rv1651c are significantly induced while M. tuberculosis persists in host cells and tissues.

Immunogenicity and cytoadherence of recombinant heparin binding haemagglutinin (HBHA) of Mycobacterium avium subsp. paratuberculosis: functional promiscuity or a role in virulence?

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's Disease, a chronic granulomatous enteritis of ruminants. Recently, an association of MAP bacilli with Crohn's disease in humans has been proposed. Due to genetic similarities and serological cross-reactivity of the M. avium complex with other mycobacteria, functional analysis of species-specific proteins may allow new insights into the pathogenesis of mycobacterial diseases. We report production and molecular characterization of the recombinant HBHA from the MAP complex bacilli. The HBHA was expressed in Escherichia coli and Mycobacterium smegmatis using efficient expression vector systems. The recombinant HBHA was found to be immunogenic and therefore induced antibody responses in cattle against the MAP bacilli with a possible cross reactivity with M. bovis infection. The MAP complex HBHA was thus found to be a target of the host humoral responses in Johne's disease. The recombinant HBHA protein was also found to be adherent to the Caco2 cell lines in-vitro, a significant observation to understand possible virulence mechanisms. Since M. tuberculosis HBHA was earlier shown to be involved in dissemination of the tubercle bacilli, the immunogenicity and cytoadherent nature of this MAP protein possibly suggests functional promiscuity.

Patients with pulmonary tuberculosis develop a strong humoral response against methylated heparin-binding hemagglutinin

Reactivities of human sera against selected recombinant Mycobacterium tuberculosis antigens were assessed by enzyme-linked immunosorbent assay. The results obtained indicate that patients with tuberculosis (TB) do not develop a strong humoral response against PE_PGRS and PPE proteins or against the Ag85B and heparin-binding hemagglutinin (HBHA) recombinant antigens. Conversely, purified methylated HBHA was strongly recognized by sera obtained from TB patients compared to controls.

Expression and purification of recombinant methylated HBHA inMycobacterium smegmatis

The Heparin-Binding Haemagglutinin (HBHA) is a mycobacterial adhesin involved in the dissemination of Mycobacterium tuberculosis from the site of primary infection and a potential candidate for the development of a new vaccine against tuberculosis. Methylation of HBHA is a novel post-translational event that imparts important immunological properties to the protein. Since recombinant HBHA expressed in Escherichia coli is not methylated, we investigated the possibility of producing recombinant methylated HBHA in fast growing mycobacteria for use in immunological and biochemical studies. The complete coding sequence of HBHA was cloned in the plasmid pMV206, under the control of a strong promoter (hsp60) or its own promoter. The constructs generated were electroporated into Mycobacterium smegmatis and the recombinant strains obtained were analyzed for the presence of the HBHA protein using the anti-HBHA monoclonal antibodies D2 and E4. Our results indicate that expression of high amounts of intact protein can be toxic for the mycobacteria, that methylated HBHA can be obtained in M. smegmatis only when using a promoter sequence weaker than hsp60 and that the expression of the complete structural gene is required in order to obtain methylated HBHA. We constructed a recombinant M. smegmatis strain (pMV3-38) that expresses a histidine-tagged methylated HBHA that can be easily purified. The use of fast-growing strains of M. smegmatis to obtain significant amounts of purified HBHA protein within a short timeframe, should be an effective strategy for the evaluation of a new HBHA-based vaccine candidate for tuberculosis.

Rv1818c-encoded PE_PGRS protein of Mycobacterium tuberculosis is surface exposed and influences bacterial cell structure

Identification of the novel PE multigene family was an unexpected finding of the genomic sequencing of Mycobacterium tuberculosis. Presently, the biological role of the PE and PE_PGRS proteins encoded by this unique family of mycobacterial genes remains unknown. In this report, a representative PE_PGRS gene (Rv1818c/PE_PGRS33) was selected to investigate the role of these proteins. Cell fractionation studies and fluorescence analysis of recombinant strains of Mycobacterium smegmatis and M. tuberculosis expressing green fluorescent protein (GFP)-tagged proteins indicated that the Rv1818c gene product localized in the mycobacterial cell wall, mostly at the bacterial cell poles, where it is exposed to the extracellular milieu. Further analysis of this PE_PGRS protein showed that the PE domain is necessary for subcellular localization. In addition, the PGRS domain, but not PE, affects bacterial shape and colony morphology when Rv1818c is overexpressed in M. smegmatis and M. tuberculosis. Taken together, the results indicate that PE_PGRS and PE proteins can be associated with the mycobacterial cell wall and influence cellular structure as well as the formation of mycobacterial colonies. Regulated expression of PE genes could have implications for the survival and pathogenesis of mycobacteria within the human host and in other environmental niches.