Heat-shock protein peptide DiaPep277 treatment in children with newly diagnosed type 1 diabetes: a randomised, double-blind phase II study

BACKGROUND

Type 1 diabetes mellitus (T1DM) is a T-cell-mediated autoimmune disease that leads to the destruction of insulin-producing beta cells. Treatment with DiaPep277, a peptide derived from heat-shock protein 60 (hsp60), has been found to slow the deterioration of beta-cell function after clinical onset of diabetes in NOD mice and human adults. Our aim was to evaluate the efficacy and safety of DiaPep277 treatment in attenuating beta-cell destruction in children with recent-onset T1DM.

METHODS

A prospective, randomized, double-blind, phase II design was used. The sample included 30 children (19 males) aged 7-14 years who had been diagnosed with T1DM from 53 to 116 days previously, and had basal C-peptide concentrations above 0.1 nmol/L. The children were randomized to receive subcutaneous injections of 1 mg DiaPep277 (15 patients) or 40 mg mannitol (placebo) at entry and at 1, 6, and 12 months. The duration of follow-up was 18 months. The groups were compared for stimulated C-peptide level, exogenous insulin dose, and HbA1c concentration.

RESULTS

C-peptide levels similarly decreased over time in the DiaPep277- and placebo-treated patients. There was no significant difference in insulin dose or HbA1c concentration between the groups at any time point. No serious drug-related adverse effects were recorded throughout the study period.

CONCLUSIONS

One-year treatment with DiaPep277 at a dosage of 1 mg is safe for use and well tolerated in children with recent-onset T1DM. However, it appears to have no beneficial effect in preserving beta-cell function or improving metabolic control.

Treatment of new-onset type 1 diabetes with peptide DiaPep277 is safe and associated with preserved beta-cell function: extension of a randomized, double-blind, phase II trial

BACKGROUND

Treatment with DiaPep277, a peptide derived from HSP60, has been shown to preserve beta-cell function in non-obese diabetic mouse (NOD) mice and in a trial with newly diagnosed human patients with type 1 diabetes treated over a 10-month period. This article extends the clinical trial observations to a total of 20 months of treatment to determine the safety and the effects of repeated doses of DiaPep277 on endogenous insulin secretion, metabolic control, and exogenous insulin requirements.

METHODS

Thirty-five male patients (aged 16-58) with a basal C-peptide greater than 0.1 nmol/L were assigned to periodic treatment with DiaPep277 (1 mg) or placebo for a 12-month treatment and 18-month observation protocol, later extended to an additional year of treatment. Stimulated C-peptide, HbA1c, and an exogenous insulin dose were the clinical endpoints.

RESULTS

At 18 months, stimulated C-peptide concentrations had fallen in the placebo group (p = 0.0005) but were maintained in the DiaPep277 group. The need for exogenous insulin was higher in the placebo group than in the DiaPep277 group. Mean HbA1c concentrations were similar in both groups. After extension of the study, patients continuing treatment with DiaPep277 and those switched from placebo to DiaPep277 manifested a trend towards a greater preservation of beta-cell function compared to patients maintained on or switched to placebo. The safety profile of DiaPep277 was similar between the treatment and placebo groups, and no drug-related adverse events occurred.

CONCLUSIONS

Periodic treatment of subjects with DiaPep277 over 2 years was safe and associated preservation of endogenous insulin secretion up to 18 months was observed.

Therapy with the hsp60 peptide DiaPep277 in C-peptide positive type 1 diabetes patients

BACKGROUND

Type 1 diabetes results from a T-cell mediated autoimmune destruction of insulin-producing pancreatic beta-cells. The 60-kDa heat-shock protein (hsp60) is one of the known target self-antigens. An immunogenic peptide from hsp60, p277, arrested beta-cell destruction and maintained insulin production in newly diabetic non-obese diabetic (NOD) mice. A randomized, double-blind, phase Ib/II study of peptide treatment was undertaken in recent onset type 1 diabetes patients with remaining insulin production.

METHODS

Forty-eight recent onset type 1 diabetes patients were assigned subcutaneous injections of 0.2, 1.0 or 2.5 mg peptide DiaPep277 (n = 12 per dosage) at entry, and 1, 6 and 12 months, or four placebo injections (n = 12). The primary clinical endpoints were safety and efficacy (glucagon-stimulated C-peptide production at 6 and 12 months); secondary endpoints were HbA1c levels and daily insulin dose adjusted for body weight at 2, 6, 12 and 18 months.

RESULTS

C-peptide levels decreased over time in all groups except the 2.5 mg-treated. The decrease in C-peptide production was less in treated patients versus placebo, mostly in the 2.5 mg group. HbA1c increased significantly in the 1.0 mg group and in the 2.5 mg group at 2 and 18 months, respectively. No differences were seen in daily insulin doses. One patient was withdrawn from the study possibly owing to a treatment-related adverse event.

CONCLUSIONS

Multiple DiaPep277 peptide administration seems safe and may have a beneficial effect on C-peptide levels over time, but this finding is not supported by lower HbA1c levels or daily insulin requirement. Further investigation on a larger scale is warranted.

Effect of heat shock protein peptide DiaPep277 on beta-cell function in paediatric and adult patients with recent-onset diabetes mellitus type 1: two prospective, randomized, double-blind phase II trials

BACKGROUND

Aim of this trial was to test whether heat shock protein peptide DiaPep277 treatment in adult and paediatric patients with recent-onset type 1 diabetes (T1D) is safe and whether it can preserve endogenous insulin production.

METHODS

Two studies were performed in a prospective, multicentre, double-blind, placebo-controlled trial. Fifty adult (study p520, aged 16-44 years) and 49 paediatric patients (study p521, 4-15 years) with recent-onset T1D were treated subcutaneously at four different time points with 0.2 mg or 1.0 mg DiaPep277 versus placebo and followed for 18 months. Adult patients were treated with 0.2 mg, 1.0 mg or 2.5 mg DiaPep277 versus placebo. Stimulated C-peptide served as readout for functional beta-cell-mass.

RESULTS

DiaPep277-treatment was not associated with severe side effects. No differences were found in placebo and DiaPep277 treated groups. In adults, a modest trend towards better maintenance of beta-cell function was observed in the 0.2 mg and 1.0 mg group, while there was significant loss of stimulated C-peptide in the placebo and 2.5 mg group. Paediatric patients with low HLA risk showed stable C-peptide levels until 13 months upon treatment with 1 mg DiaPep277. Despite similar stimulated C-peptide levels at baseline, children exhibited a more pronounced loss of beta-cell function over 18 months than adults (p = 0.0003).

CONCLUSION

Administration of DiaPep277 seems safe and may have beneficial effects on C-peptide levels over time in some patients with T1D, but this finding was not accompanied by reduced HbA1c or insulin requirement. Studies with more patients and longer follow-up are needed to further study the effect of DiaPep277.

Identification of mycobacteria of the MAIS Complex and M. tuberculosis by restriction fragment length polymorphism analysis of hsp65 gene

Restriction fragment length polymorphism analysis of hsp65 gene was performed on museum strains of mycobacteria using Hin6I restrictase. Study of restriction profiles allowed us to distinguish mycobacterial species of the MAIS complex and several strains of nontuberculous mycobacteria.

A novel mutation in the HSPD1 gene in a patient with hereditary spastic paraplegia

A mutation in the HSPD1 gene has previously been associated with an autosomal dominant form of spastic paraplegia in a French family. HSPD1 encodes heat shock protein 60, a molecular chaperone involved in folding and quality control of mitochondrial proteins. In the present work we have investigated 23 Danish index patients with hereditary spastic paraplegia (HSP) for mutations in the HSPD1 gene. One patient was found to be heterozygous for a c.1381C > G missense mutation encoding the mutant heat shock protein 60 p.Gln461Glu. The mutation was also present in two unaffected brothers, but absent in 400 unrelated Danish individuals. We found that the function of the p.Gln461Glu heat shock protein 60 was mildly compromised. The c.1381C > G mutation likely represents a novel low-penetrance HSP allele.

Identification of an emerging pathogen, Mycobacterium massiliense, by rpoB sequencing of clinical isolates collected in the United States

Mycobacterium massiliense is a rapidly growing mycobacterium that is indistinguishable from Mycobacterium chelonae/M. abscessus by partial 16S rRNA gene sequencing. We sequenced rpoB, sodA, and hsp65 genes from isolates previously identified as being M. chelonae/M. abscessus and identified M. massiliense from isolates from two patients with invasive disease representing the first reported cases in the United States.

Mycobacterium avium in the postgenomic era

The past several years have witnessed an upsurge of genomic data pertaining to the Mycobacterium avium complex (MAC). Despite clear advances, problems with the detection of MAC persist, spanning the tests that can be used, samples required for their validation, and the use of appropriate nomenclature. Additionally, the amount of genomic variability documented to date greatly outstrips the functional understanding of epidemiologically different subsets of the organism. In this review, we discuss how postgenomic insights into the MAC have helped to clarify the relationships between MAC organisms, highlighting the distinction between environmental and pathogenic subsets of M. avium. We discuss the availability of various genetic targets for accurate classification of organisms and how these results provide a framework for future studies of MAC variability. The results of postgenomic M. avium study provide optimism that a functional understanding of these organisms will soon emerge, with genomically defined subsets that are epidemiologically distinct and possess different survival mechanisms for their various niches. Although the status quo has largely been to study different M. avium subsets in isolation, it is expected that attention to the similarities and differences between M. avium organisms will provide greater insight into their fundamental differences, including their propensity to cause disease.

Recombinant heat shock protein 65 carrying hepatitis B core antigen induces HBcAg-specific CTL response

Many studies have provided evidence that heat shock protein 65 (Hsp65) can elicit potent specific cellular adaptive immune responses (e.g. CD8(+) cytotoxic T-cell effectors or classic CTLs) based on their ability to chaperone antigenic peptides. Hsp65 is thus an effective carrier for heterologous peptide epitopes for therapeutic vaccines against cancer or chronic infectious diseases. The core antigen of hepatitis B virus (HBcAg) is extremely immunogenic, and functions as both a T-cell-dependent and a T-cell-independent antigen. Therefore, HBcAg may be a promising candidate target for therapeutic vaccine control of chronic HBV infection. Here, a chimeric protein, Hsp65Bc, was created by fusing the HBcAg sequence to the carboxyl terminus of the Hsp65 sequence in E. coli. Analysis of its antigenicity and immunogenicity revealed that HBc epitopes are surface accessible. Hsp65Bc induced moderate anti-HBc immune responses as well as a strong specific T-cell response in BALB/c mice. These results indicate that Hsp65Bc may have potential as a vaccine for treatment of HBV chronic infection.

Identification of novel hsp65 RFLPs for Mycobacterium leprae

Leprosy or Hansen's disease is a chronic infectious disease caused by an acid-fast bacillus, Mycobacterium leprae (M. leprae). The bacilli proliferate in macrophages infiltrating the skin and gain entry to the dermal nerves via the laminar surface of Schwann cells where they replicate. After entry, the Schwann cells proliferate and then die. Conclusive identification of M. leprae DNA in a sample can be obtained by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the heat shock 65 gene (hsp65). Molecular epidemiology will make it possible to study the global distributions of M. leprae, explore the relationship between genotypes-incidence rates, mode of transmission, and the type of disease (tuberculoid vs. lepromatous). We amplified DNA using PCR for the hsp65 gene from 24 skin lesions from patients diagnosed with various types of leprosy. Fifteen out of 24 were positive for the hsp65 gene. Digestion with HaeIII-PAGE for the RFLP confirmation of the presence of M. leprae DNA showed the typical pattern in 5 out of 24 and 2 novel patterns in 10 out of 24 patients. We confirmed the presence of M. leprae DNA by sequencing the genes for gyraseA or B and folP, which contained only M. leprae specific single nucleotide polymorphisms (SNPs). Thus, we describe novel hsp65 RFLPs for M. leprae found in a high frequency making them ideal for future epidemiology and transmission studies.

Mycobacterium monacense sp. nov

Four bacterial strains were isolated from independent clinical specimens in different countries and their genotypic and phenotypic characters support their classification in a novel species within the genus Mycobacterium. One strain was clearly responsible for a severe, post-traumatic wound infection in a healthy boy. The novel species, for which the name Mycobacterium monacense sp. nov. is proposed, is yellow-pigmented, non-photochromogenic and grows in less than a week on solid medium. Based on phenotypic investigations alone, distinction of these four strains from known scotochromogenic rapidly growing strains is problematic. However, the novel strains differ from any other mycobacterium in each of the molecular species markers investigated: the 16S rRNA gene, the 16S-23S rRNA gene internal transcribed spacer and the hsp65 gene. Of the strains investigated, two different sequevars were detected for the hsp65 region. Phylogenetic analysis revealed that these four strains were most closely related to Mycobacterium doricum. The type strain of Mycobacterium monacense sp. nov. is B9-21-178T (=DSM 44395T=CIP 109237T).

Prevalence of non-tuberculous mycobacteria in a hospital environment

In recent years, non-tuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections but there is little known about the isolation and identification of NTM in Korea. The aim of this study was to assess the prevalence of NTM in the hospital environment and identify the species. A total of 150 samples were collected from different parts of the hospital. NTM were isolated and identified by restriction fragment length polymorphism analysis of the gene encoding rpoB and partial sequencing analysis of hsp65 and rpoB. In this study, 60 strains of NTM were isolated from 50 of the 150 samples. Half of the tap water samples (50 of 100) were positive for mycobacteria. An estimated 73.3% of the isolates were saprophytic, 21.7% were potentially pathogenic and 5% were unidentified. The presence of NTM in hospital tap water is not uncommon. Such water isolates might cause true nosocomial infection in immunocompromised patients, in addition to the risk of false-positive culture results.

Mycobacterium sherrisii isolation from a patient with pulmonary disease

The characterization of 2 clinical isolates of Mycobacterium sherrisii provides further phenotypic and genotypic information beyond that reported in the article that originally described this species. One of our strains was responsible for pulmonary disease in a middle-aged non-HIV patient; thus, confirming the potential pathogenicity of this species previously reported only in an HIV-positive patient.

DiaPep277 preserves endogenous insulin production by immunomodulation in type 1 diabetes

DiaPep277 is an immunomodulatory peptide that arrests beta cell destruction in mouse models of type 1 diabetes mellitus (T1DM). This article extends an original pilot observation to two studies of 61 patients (age > 16 years), diagnosed with T1DM within 6 months, and with measurable beta cell function. Patients were treated with placebo (n = 27) or 1.0 mg DiaPep277 (n = 34). After 13 months, 1.0 mg Dia Pep277 treatment significantly (P = 0.02) preserved beta cell function as compared to the control with a trend for reduced HbA1c. This was achieved without an increase in insulin dose in the DiaPep277 group and with excellent safety. DiaPep277-treated patients also had fewer Th1 DiaPep277-specific T cells.

Antibody responses to mycobacterial and self heat shock protein 65 in autoimmune arthritis: epitope specificity and implication in pathogenesis

Many autoimmune diseases are believed to involve primarily T cell-mediated effector mechanisms. There is increasing realization, however, that Abs may also play a vital role in the propagation of T cell-driven disorders. In this study, on the rat adjuvant-induced arthritis (AA) model of human rheumatoid arthritis, we examined the characteristics of serum Ab response to mycobacterial heat shock protein (hsp) 65 (Bhsp65), self (rat) hsp65 (Rhsp65), and linear peptides spanning these two molecules. The AA-resistant WKY (RT.1(l)) rat responded to the heat-killed Mycobacterium tuberculosis immunization with a rapid burst of Abs to both Bhsp65 and Rhsp65. These Abs reacted with numerous peptide epitopes; however, this response was reduced to a few epitopes with time. On the contrary, the susceptible Lewis (RT.1(l)) rat developed a relatively lower Ab response to Bhsp65, and Abs to Rhsp65 did not appear until the recovery from the disease. The Ab response in Lewis rats diversified with progression of AA, and there was an intriguing overlap between the repertoire of Bhsp65-reactive B and T cells during the recovery phase of AA. Nonetheless, subsets of the repertoire of the late Abs in both rat strains became focused on the same epitope regions of Bhsp65 and Rhsp65. The functional relevance of these Abs was evident from the results showing that sera from recovery phase Lewis or WKY rats, but not that of naive rats, afforded protection against subsequent AA. These results are of significance in further understanding of the role of humoral immunity in the pathogenesis of autoimmune arthritis.

Purification of a non-tagged recombinant BCG heat shock protein 65-Her2 peptide fusion protein from Escherichia coli

Bacille Calmette-Guerin (BCG)-derived heat shock protein 65 (HSP65) has been demonstrated capable of assisting a fused peptide to generate the peptide-specific cellular immunity. Various HSP65 fusion proteins have been developed as therapeutic cancer vaccines. Purifying a recombinant HSP65 fusion protein with no purification tags for human use is routinely a challenge. Here, we report a scheme for purifying a non-tagged recombinant HSP65-Her2 peptide fusion protein (HSP65-Her2) from Escherichia coli. The HSP65-Her2 is being developed as an immunotherapeutic for the treatment of Her2-positive tumors. After fermentation in a 10-L fermentor, the HSP65-Her2 expressing E. coli were harvested and lysed by sonication. The recombinant HSP65-Her2 was then purified with four successive steps including Butyl-Sepharose FF, DEAE-Sepharose FF, 1% Triton X-114 phase separation and Sephadex G-25. Results showed that HSP65-Her2 was purified up to 97% purity and was able to generate Her2-specific cytotoxic T lymphocytes (CTLs), suggesting that the scheme is efficient for purifying the non-tagged HSP65-Her2 fusion protein with biological activity.

Long-lasting specific antibodies against P277 induced by mucosal administration of P277 repeat sequences carried by Hsp65 in the absence of adjuvants

To improve the weak immunogenicity of peptide P277, the recombinant expression plasmid pET28-Hsp65-6 x P277 was constructed by inserting 5 x P277 which was amplified by PCR into the vector pET28-Hsp65-P277. It was transformed into Escherichia coli BL21 (DE3) and the fusion protein (Hsp65-6 x P277) was expressed effectively as soluble protein after inducing by lactose. The fusion protein was purified by means of cell disruption, ammonium sulfate precipitation, double-distilled H2O dialysis, DEAE52-cellulose column chromatography, and then used to immunize female NOD mice with three i.n. inoculations in the absence of adjuvants. Serum samples from the immunized mice were collected at 3 weeks interval. Antibodies against P277 and HSP65 were detected in immunized mice sera by enzyme-linked immunosorbent assay (ELISA) and Western blot. Specific antibodies were successfully induced and lasted for more than 20 weeks in animals immunized with the fusion protein via intranasal route even in the absence of adjuvants.

Male serum Chlamydia trachomatis IgA and IgG, but not heat shock protein 60 IgG, correlates with negatively affected semen characteristics and lower pregnancy rates in the infertile couple

BACKGROUND

The objective of this study was to evaluate whether serum Chlamydia trachomatis immunoglobulin-A (IgA), IgM and C. trachomatis heat shock protein 60 (CHSP60) IgG are of additional value to C. trachomatis IgG regarding the impact on fecundity in infertile couples, and to relate C. trachomatis serum antibodies to semen characteristics, diagnoses and pregnancy outcome.

METHODS

A total of 226 infertile couples, previously tested for C. trachomatis IgG, were tested for C. trachomatis IgA, IgM and CHSP60 IgG, and semen samples from all men were analysed.

RESULTS

Chlamydia trachomatis serum IgA in men (but not in women) correlated with reduced chances of achieving pregnancy [p = 0.021, relative risk (RR) =0.65, 95% confidence interval (CI) 0.42-1.005] and in combination with C. trachomatis IgG the chance was further reduced (p =0.001, RR = 0.35, 95% CI 0.15-0.84). Chlamydia trachomatis serum IgA was also significantly correlated with reduced motility of the spermatozoa (-8.7%, p = 0.023), increased number of dead spermatozoa (+10.5%, p = 0.014) and higher prevalence of leucocytes in semen (+122%, p = 0.005), and in combination with C. trachomatis IgG positivity, there was also a decrease in sperm concentration (-35%, p = 0.033), the number of progressive spermatozoa (-14.8%, p = 0.029) and a rise in the teratozoospermia index (+4.4%, p = 0.010). CHSP60 IgG correlated with reduced motility (-5.6%, p = 0.033), and in the women to tubal factor infertility (p = 0.033), but no correlations of C. trachomatis serum IgM or CHSP60 IgG with pregnancy rates were found.

CONCLUSIONS

Chlamydia trachomatis serum IgA in the male partner of the infertile couple has an additive value to IgG in predicting pregnancy chances, and serum IgA and IgG are associated with subtle negative changes in semen characteristics.

An outbreak of keratitis caused by Mycobacterium immunogenum

From 8 October to 12 November 2003, 36 patients underwent surgical correction of myopia in a São Paulo, Brazil, clinic. Five patients had clinical signs of infectious keratitis, and a Mycobacterium species with previously unreported patterns determined by PCR restriction enzyme analysis of the hsp65 gene and PCR restriction enzyme analysis of the 16S-23S rRNA internal transcribed spacer (ITS) was isolated from corneal scrapings from four of these patients. Subsequent evaluation by phenotypic tests and partial sequencing of the hsp65, sodA, rpoB, and 16S rRNA genes and the ITS supported the species identification as a variant of Mycobacterium immunogenum. The source of infection was not determined. The outbreak was caused by a single clone, as evidenced by identical pulsed-field gel electrophoresis and enterobacterial repetitive intergenic consensus-PCR profiles. This is the first report of an outbreak where this species was isolated from infected tissues.

Hip prosthesis infection due to Mycobacterium wolinskyi

Mycobacterium wolinskyi, first described in 1999, is a rapidly growing mycobacterium related to the Mycobacterium smegmatis group. Only eight cases of infection due to this microorganism have been reported, including three cases of bone infection. Here, we present the first case of a joint prosthesis infection cured with the combination of surgery and prolonged antibiotic therapy. The microorganism was identified by biochemical tests and 16S rRNA and Hsp65 gene sequence analysis.

Mycobacterium tuberculosis complex and mycobacterial heat shock proteins in lymph node tissue from patients with pulmonary sarcoidosis

We demonstrated that not whole Mycobacterium tuberculosis but its particular antigens, hsp70(Mtb), hsp65(Mtb), and hsp16(Mtb), are present in lymph node tissues of patients with sarcoidosis (SA). hsp16(Mtb) occurs in the early stage of SA, whereas hsp70(Mtb) occurs in stage II of SA. hsp65(Mtb) is highly expressed in the capillary vessels in lymph node tissues in patients with SA.

Clinical and Molecular Analysis of Macrolide Resistance inMycobacterium aviumComplex Lung Disease

RATIONALE

The clinical features and outcome of macrolide-resistant Mycobacterium avium complex (MAC) lung disease are not known.

OBJECTIVES

Characterize patients, treatment, and isolates in macrolide-resistant MAC lung disease.

METHODS

Retrospective chart review, susceptibility testing, molecular fingerprinting, and DNA sequence analyses of resistant MAC isolates.

MEASUREMENTS AND MAIN RESULTS

We identified 51 patients over a 15-yr period with clarithromycin-resistant MAC (minimum inhibitory concentration (MIC)>or=32 microg/ml) lung disease at a single referral center. Twenty-four (47%) patients had nodular disease with bronchiectasis and 27 (53%) had upper lobe cavitary disease. Most patients (77%) had M. intracellulare. Sequencing of the 23S r-RNA gene showed 49 of 51 isolates (96%) with the expected mutation in adenine 2058 or 2059. Risk factors for resistance included macrolide monotherapy or combination with a quinolone only (39/51 or 76%). Macrolide resistance developed in 12 of 303 (4.0%) patients started on the American Thoracic Society-recommended two companion drugs, with no risk difference in clarithromycin versus azithromycin and daily versus intermittent therapy. Sputum conversion with macrolide-resistant MAC occurred in 11 of 14 (79%) patients who received more than 6 mo of injectable aminoglycoside therapy and lung resection, compared with 2 of 37 (5%) who did not. The 1-yr mortality in patients who remained culture positive was 34% (13/38) compared with 0% (0/13) of patients who became culture negative (converted).

CONCLUSIONS

Macrolide resistance rarely occurs in patients also receiving ethambutol and a rifamycin. Macrolide-resistant MAC lung disease requires aggressive drug and surgical therapy for cure.

Detection of 65 kD heat shock protein in cerebrospinal fluid of tuberculous meningitis patients

Background

Diagnosis of tuberculous meningitis (TBM) is difficult. Rapid confirmatory diagnosis is essential to initiate required therapy. There are very few published reports about the diagnostic significance of 65 kD heat shock protein (hsp) in TBM patients, which is present in a wide range of Mycobacterium tuberculosis species and elicits a cellular and humoral immune response. In the present study we have conducted a prospective evaluation for the demonstration of 65 kD hsp antigen in cerebrospinal fluid (CSF) of TBM patients, by indirect ELISA method using monoclonal antibodies (mAb) against the 65 kD hsp antigen, for the diagnosis of TBM.

Methods

A total of 160 CSF samples of different groups of patients (confirmed TBM {n = 18}, clinically suspected TBM {n = 62}, non TBM infectious meningitis {n = 35} and non-infectious neurological diseases {n = 45}) were analyzed by indirect ELISA method using mAb to 65 kD hsp antigen. The Kruskal Wallis test (Non-Parametric ANOVA) with the Dunnett post test was used for statistical analysis.

Results

The indirect ELISA method yielded 84% sensitivity and 90% specificity for the diagnosis of TBM using mAb to 65 kD hsp antigen. The mean absorbance value of 65 kD hsp antigen in TBM patients was [0.70 ± 0.23 (0.23–1.29)], significantly higher than the non-TBM infectious meningitis group [0.32 ± 0.14 (0.12–0.78), P < 0.001] and also higher than the non-infectious neurological disorders group [0.32 ± 0.13 (0.20–0.78), P < 0.001]. A significant difference in the mean absorbance of 65 kD hsp antigen was noted in the CSF of culture-positive TBM patients [0.94 ± 0.18 (0.54–1.29)] when compared with clinically suspected TBM patients [0.64 ± 0.20 (0.23–0.98), P < 0.05].

Conclusion

The presence of 65 kD hsp antigen in the CSF of confirmed and suspected cases of TBM would indicate that the selected protein is specific to M. tuberculosis and could be considered as a diagnostic marker for TBM.

Differentiation of Mycobacterial species by hsp65 duplex PCR followed by duplex-PCR-based restriction analysis and direct sequencing

Here we describe a novel duplex PCR method which can differentiate Mycobacterium tuberculosis and nontuberculosis mycobacteria (NTM) strains by amplifying hsp65 DNAs of different sizes (195 and 515 bp, respectively). The devised technique was applied to 54 reference and 170 clinical isolates and differentiated all strains into their respective groups with 100% sensitivity and specificity. Furthermore, a duplex PCR-restriction analysis (duplex PRA) and a direct sequencing protocol were developed to differentiate NTM strains at the species and subspecies levels based on previously reported hsp65 DNA sequences (H. Kim et al., Int. J. Syst. Evol. Microbiol. 55:1649-1656, 2005) and then applied to 105 NTM clinical isolates. All NTM isolates were clearly differentiated at the species and subspecies levels by subsequent procedures (PRA or direct sequencing) targeting 515-bp NTM duplex PCR amplicons. Our results suggest that novel duplex PCR-based methods are sensitive and specific for identifying mycobacterial culture isolates at the species level.

Distribution of hsp65 PCR-restriction enzyme analysis patterns among Mycobacterium avium complex isolates in Thailand

A total of 227 clinical Mycobacterium avium complex isolates from Thailand were differentiated into species and types by using PCR-restriction enzyme analysis of hsp65. The distribution of types showed the predominance of M. avium I (77%) in blood specimens, whereas M. intracellulare I was more commonly found in pulmonary specimens (44.2%). In addition, infections with M. avium were more likely to be found in younger adults (20 to 39 years old), while infections with M. intracellulare were more likely to be found in older adults (> or =60 years old). Our results provide the useful epidemiological information that some particular types have more invasive and virulent characters than others.

Peptide p277 of HSP60 signals T cells: inhibition of inflammatory chemotaxis

Peptide p277 is a 24-amino acid fragment of the heat shock protein 60 molecule, first discovered to be an antigen for diabetogenic T-cell clones in non-obese diabetic (NOD) mice. Therapeutic vaccination with p277 can arrest the spontaneous diabetogenic process both in NOD mice and in humans associated with a T(h)1 to T(h)2 cytokine shift specific for the autoimmune T cells. We now report that p277 can directly signal human T cells via innate toll-like receptor (TLR)-2, leading to up-regulation of integrin-mediated adhesion to fibronectin, and inhibition of chemotaxis to the chemokine SDF-1alpha in vitro. Resting CD45RA(+) T cells responded to lower concentrations of p277 than resting CD45RO(+) T cells, but activation of CD45RO(+) T cells greatly increased their sensitivity to p277. Mouse T cells, but not macrophages, were also sensitive to the innate effects of peptide p277, and adoptive transfer of diabetes by splenic T cells from NOD mice could be inhibited by p277 treatment before transfer. Thus, T cells do respond innately to p277, and signaling by soluble p277 through TLR2 could contribute to the treatment of type 1 diabetes; p277 may stop the destruction of beta cells by signaling in concert both innate and adaptive receptors on T cells.

Application of four molecular typing methods for analysis of Mycobacterium fortuitum group strains causing post-mammaplasty infections

A cluster of cases of post-augmentation mammaplasty surgical site infections occurred between 2002 and 2004 in Campinas, in the southern region of Brazil. Rapidly growing mycobacteria were isolated from samples from 12 patients. Eleven isolates were identified as Mycobacterium fortuitum and one as Mycobacterium porcinum by PCR-restriction digestion of the hsp65 gene. These 12 isolates, plus six additional M. fortuitum isolates from non-related patients, were typed by pulsed-field gel electrophoresis (PFGE) and three PCR-based techniques: 16S-23S rRNA internal transcribed spacer (ITS) genotyping; randomly amplified polymorphic DNA (RAPD) PCR; and enterobacterial repetitive intergenic consensus (ERIC) PCR. Four novel M. fortuitum allelic variants were identified by restriction analysis of the ITS fragment. One major cluster, comprising six M. fortuitum isolates, and a second cluster of two isolates, were identified by the four methods. RAPD-PCR and ITS genotyping were less discriminative than ERIC-PCR. ERIC-PCR was comparable to PFGE as a valuable complementary tool for investigation of this type of outbreak.

[Characterization of two new pigmented mycobacteria isolates]

Two pigmented mycobacteria isolated from sputum specimens were described by biochemical tests, whole-cell fatty acid analyses by High Performance Liquid Chromatography (HPLC) and sequencing of 65-kDa heat shock protein gene and 16S rRNA gene. The hsp65 gene and 16S rRNA gene sequences of the Mycobacterium sp. G1368 and Mycobacterium sp. E498 were deposited in DDBJ/EMBL/GenBank under accession numbers AY553874, DQ324791 and AY379074, DQ324792, respectively. Mycobacterium sp. G1368 grew in about one week at 37 degrees C and 42 degrees C and produced smooth, yellow colonies. It reduced tellurite and hydrolyzed urea. Nitrate reduction, aryl sulfatase, pyrazin amidase, heat stable catalase and semiquantitative catalase tests were also positive, while Tween 80 hydrolysis was weakly positive. Mycobacterium sp. E498 grew in about 9 days at 37 degrees C and formed smooth, yellow colonies. It hydrolyzed Tween 80, possessed aryl sulfatase, pyrazin amidase and heat stable catalase, however, it did not possess urease and nitrate reductase. These data, in addition to their position in the phylogenetic tree, strongly support the status of novel species at least for Mycobacterium sp. G1368.

Mycobacterium szulgai identification by hsp65 gene sequencing in an HIV-positive patient with non-Hodgkin's lymphoma

Mycobacterium szulgai, described for the first time in 1972, is a rare human pathogen that mainly causes pulmonary non-tubercular mycobacteriosis. We report its isolation and identification from a bronchoalveolar lavage specimen by hsp65 gene sequencing analysis in an HIV-positive patient with non-Hodgkin's lymphoma.

Characterization of Mmp37p, a Saccharomyces cerevisiae mitochondrial matrix protein with a role in mitochondrial protein import

Many mitochondrial proteins are encoded by nuclear genes and after translation in the cytoplasm are imported via translocases in the outer and inner membranes, the TOM and TIM complexes, respectively. Here, we report the characterization of the mitochondrial protein, Mmp37p (YGR046w) and demonstrate its involvement in the process of protein import into mitochondria. Haploid cells deleted of MMP37 are viable but display a temperature-sensitive growth phenotype and are inviable in the absence of mitochondrial DNA. Mmp37p is located in the mitochondrial matrix where it is peripherally associated with the inner membrane. We show that Mmp37p has a role in the translocation of proteins across the mitochondrial inner membrane via the TIM23-PAM complex and further demonstrate that substrates containing a tightly folded domain in close proximity to their mitochondrial targeting sequences display a particular dependency on Mmp37p for mitochondrial import. Prior unfolding of the preprotein, or extension of the region between the targeting signal and the tightly folded domain, relieves their dependency for Mmp37p. Furthermore, evidence is presented to show that Mmp37 may affect the assembly state of the TIM23 complex. On the basis of these findings, we hypothesize that the presence of Mmp37p enhances the early stages of the TIM23 matrix import pathway to ensure engagement of incoming preproteins with the mtHsp70p/PAM complex, a step that is necessary to drive the unfolding and complete translocation of the preprotein into the matrix.

Survival and stress induced expression of groEL and rpoD of Campylobacter jejuni from different growth phases

Although Campylobacter jejuni is the leading cause of bacterial diarrhoeal disease in humans worldwide, its potential to adapt to the stressful conditions and survive in extra-intestinal environment is still poorly understood. We tested the effect of heat shock (55 degrees C, 3 min) and oxidative stress (3 mM H2O2 for 10 min or prolonged incubation at atmosphere oxygen concentration) on non-starved and starved cells of Campylobacter jejuni from different growth phases. Viability as assessed with the Bacterial Viability Kit LIVE/DEAD BacLighttrade mark dying before fluorescent microscopy and culturability of the cells (CFU ml(-1)) from both growth phases showed that starvation increased heat but not oxidative resistance. High temperature and oxidative stress invoked quick transformation from culturable spiral shaped to nonculturable spiral and coccoid cells. Despite physiological changes of the cells we were not able to document clear differences in the expression of heat shock and starvation genes (dnaK, htpG, groEL), oxidative (ahpC, sodB), virulence (flaA) and housekeeping genes (16S rRNA, rpoD) after heat treatment (55 degrees C, 3 min) or oxidative stresses applied. When starving, no induction of expression of any of these genes was noticed, chloramphenicol had no influence on their gene expression. Quantitative real-time PCR analyses showed that at least 10-20 min of heat shock was necessary to evidently increase the amount of groEL and rpoD transcripts.

Heat shock fusion protein induces both specific and nonspecific anti-tumor immunity

Mucin 1 (MUC1) is a tumor antigen, and the most important epitopes that can induce cytotoxic T lymphocytes (CTL) reside in the variable-number tandem repeats (VNTR). Heat shock protein (HSP) complexes isolated from tumors have been shown to induce specific anti-tumor immunity. HSP alone can also induce nonspecific immunity. To explore the possibility to utilize the specific anti-tumor immunity induced by MUC1 VNTR and the nonspecific immunity induced by HSP, we constructed a recombinant protein (HSP65-MUC1) by fusing Bacillus Calmette-Guérin-derived HSP65 with the MUC1 VNTR peptide and tested its ability to induce anti-tumor activities in a tumor challenge model. The growth of MUC1-expressing tumors was significantly inhibited in mice immunized with HSP65-MUC1, both before and after tumor challenge. A much larger percentage of immunized mice survived the tumor challenge than non-immunized mice. Correlating with the anti-tumor activity, HSP65-MUC1 was shown to induce MUC1-specific CTL as well as nonspecific anti-tumor immunity. In the human system, HSP65-MUC1-loaded human DC induced the generation of autologous MUC1-specific CTL in vitro. These results suggest that exogenously applied HSP65-MUC1 may be used to treat MUC1 tumors by inducing the epitope-specific CTL as well as nonspecific anti-tumor responses mediated by the HSP part of the fusion protein.

Occurrence and characterization of multiple novel genotypes of Mycobacterium immunogenum and Mycobacterium chelonae in metalworking fluids

Rapidly growing mycobacteria colonize metalworking fluids, leading to contamination of occupational environments and exposure-related respiratory illnesses in machine workers. Lately, it has been emphasized that these fluids are colonizable by a single genotype of a rapidly growing mycobacterium species, Mycobacterium immunogenum. Here, we report on the genotypic diversity of mycobacteria in these fluids, including isolation and characterization of multiple novel genotypes of two distinct species, Mycobacterium chelonae and M. immunogenum. Using agar culturing and Mycobacterium-specific PCR, 13 mycobacterial isolates were recovered from 100 geographically diverse in-use metalworking fluid samples. Based on restriction fragment length polymorphism of PCR products, DNA sequencing (hsp65 gene segment), and phylogenetic analysis of 16S-23S rDNA internal transcribed spacer (ITS) sequences, six isolates were identified as M. immunogenum and seven as M. chelonae; an additional isolate from metalworking fluid diluent water was identified as M. diernhoferi. Genomic DNA macro-restriction fragment pattern analysis, using pulsed-field gel electrophoresis with XbaI and SpeI restriction digestions, showed intraspecies variation among the isolates of M. immunogenum and M. chelonae. Visual and computer-assisted dendrogram analysis of the XbaI macro-restriction patterns revealed three novel genotypes of M. immunogenum and two of M. chelonae, whereas SpeI macro-restriction patterns revealed only two genotypes for each isolate. None of the identified genotypes matched the reportedly dominant one of M. immunogenum from metalworking fluids. Both mycobacterial species are prevalent in metalworking fluids and there is a considerable strain-level genetic diversity within them.

Immunogenicity of Mycobacterium ulcerans Hsp65 and protective efficacy of a Mycobacterium leprae Hsp65-based DNA vaccine against Buruli ulcer

Buruli ulcer, a disease caused by Mycobacterium ulcerans, is emerging as an increasingly important cause of morbidity throughout the world, for which surgery is the only efficient treatment to date. The aim of this work was to identify potential vaccine candidates in an experimental model of mouse infection. In BALB/c mice infected with M. ulcerans subcutaneously, Hsp65 appeared to be an immunodominant antigen eliciting both humoral and cellular responses. However, vaccination of mice with a DNA vector encoding Mycobacterium leprae Hsp65 only poorly limited the progression of M. ulcerans infection. In contrast, a substantial degree of protection was conferred by subcutaneous vaccination with BCG, suggesting that BCG antigens that are conserved in M. ulcerans, such as TB10.4, the 19 kDa antigen, PstS3 and Hsp70, may be interesting to consider as subunit vaccines in future prospects.

A trial of SGN-00101 (HspE7) to treat high-grade anal intraepithelial neoplasia in HIV-positive individuals

OBJECTIVES

To test a therapeutic vaccine consisting of a fusion of the human papillomavirus (HPV) 16 E7 protein and the Mycobacterium bovis heat shock protein 65 (SGN-00101) to treat high-grade anal intraepithelial neoplasia (HG-AIN) in HIV-positive individuals.

DESIGN

A phase I/II trial with three cohorts of five participants each, sequentially assigned to receive 100, 500 or 1000 microg SGN-00101, injected three times subcutaneously in alternating thighs at 4-week intervals. Anal disease was assessed at baseline, 8, 12, 24 and 48 weeks and was classified as the more severe of anal cytology and anal biopsy. Anal HPV DNA was detected using L1 consensus primer-based PCR followed by type-specific probing and dot-blot hybridization (DBH). HPV16, 18 and 31 DNA copy numbers were measured using quantitative real-time PCR.

SETTING

University-based research clinic.

PARTICIPANTS

Thirteen HIV-positive men and two HIV-positive women with HG-AIN.

RESULTS

There were no drug-related serious adverse events or significant changes in HIV viral load and CD4/CD8 ratio. At 48 weeks, two of five participants in both the 100 and 500 microg cohorts regressed to AIN 1 and one of five participants in the 1000 microg cohort regressed to atypical squamous cells of undetermined significance (ASC-US). All participants had at least one oncogenic HPV type at baseline. Three of five (60%) participants who regressed to AIN 1 or ASC-US became HPV-negative using DBH and real-time PCR, compared with none of 10 participants with no clinical response (P = 0.02).

CONCLUSIONS

SGN-00101 was well tolerated in HIV-positive individuals, with preliminary evidence for clinical activity.

Ten tandem repeats of beta-hCG 109-118 enhance immunogenicity and anti-tumor effects of beta-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65

The beta-subunit of human chorionic gonadotropin (beta-hCG) is secreted by many kinds of tumors and it has been used as an ideal target antigen to develop vaccines against tumors. In view of the low immunogenicity of this self-peptide,we designed a method based on isocaudamer technique to repeat tandemly the 10-residue sequence X of beta-hCG (109-118), then 10 tandemly repeated copies of the 10-residue sequence combined with beta-hCG C-terminal 37 peptides were fused to mycobacterial heat-shock protein 65 to construct a fusion protein HSP65-X10-betahCGCTP37 as an immunogen. In this study, we examined the effect of the tandem repeats of this 10-residue sequence in eliciting an immune by comparing the immunogenicity and anti-tumor effects of the two immunogens, HSP65-X10-betahCGCTP37 and HSP65-betahCGCTP37 (without the 10 tandem repeats). Immunization of mice with the fusion protein HSP65-X10-betahCGCTP37 elicited much higher levels of specific anti-beta-hCG antibodies and more effectively inhibited the growth of Lewis lung carcinoma (LLC) in vivo than with HSP65-betahCGCTP37, which should suggest that HSP65-X10-betahCGCTP37 may be an effective protein vaccine for the treatment of beta-hCG-dependent tumors and multiple tandem repeats of a certain epitope are an efficient method to overcome the low immunogenicity of self-peptide antigens.

Mycobacterium marinum, a further infectious agent associated with sarcoidosis: the polyetiology hypothesis

A 39-y-old male had a diagnosis of sarcoidosis and corticosteroid therapy was started. Surprisingly, following his discharge from hospital, Mycobacterium marinum was isolated in 1 of 3 sputum samples taken 7 weeks earlier on admission. After this, Mycobacterium marinum-DNA was identified in the stored lung biopsies by the PCR-RFLP of the hsp65 gene.

Sequencing of hsp65 distinguishes among subsets of the Mycobacterium avium complex

The Mycobacterium avium complex consists of epidemiologically distinct subsets. The classification of these subsets is complicated by a number of factors, including the ambiguous results obtained with phenotypic and genetic assays and the recent appreciation that human and avian strains appear to be distinct. In previous work, sequencing based on a 441-bp portion of the hsp65 gene has proven to efficiently classify isolates within the Mycobacterium genus but provides low resolution for distinguishing among members of the M. avium complex. Therefore, in this study, we have targeted the more variable 3' region of the hsp65 gene to determine whether it can effectively discriminate M. avium complex isolates at the levels of species and subspecies. Primers designed for this target consistently generated amplicons for all organisms classified as M. avium complex. Sequences obtained indicate that M. intracellulare is genetically divergent from M. avium organisms, and distinct sequevars were obtained for M. avium subsets, including M. avium subsp. avium (bird type), M. avium subsp. hominissuis, and M. avium subsp. paratuberculosis. In addition, sequence differences served to distinguish bovine from ovine strains of M. avium subsp. paratuberculosis. A unique profile for M. avium subsp. silvaticum was not obtained. These results indicate that sequencing the 3' region of the hsp65 gene can simply and unambiguously distinguish species and subspecies of the M. avium complex.

Description of Mycobacterium conceptionense sp. nov., a Mycobacterium fortuitum group organism isolated from a posttraumatic osteitis inflammation

A nonpigmented rapidly growing mycobacterium was isolated from wound liquid outflow, bone tissue biopsy, and excised skin tissue from a 31-year-old woman who suffered an accidental open right tibia fracture and prolonged stay in a river. The three isolates grew in 3 days at 24 to 37 degrees C. 16S rRNA sequence analyses over 1,483 bp showed that they were identical and shared 99.7% (4-bp difference) sequence similarity with that of Mycobacterium porcinum, the most closely related species. Partial rpoB (723 bp) sequence analyses showed that the isolates shared 97.0% sequence similarity with that of M. porcinum. Further polyphasic approaches, including biochemical tests, antimicrobial susceptibility analyses, and hsp65, sodA, and recA gene sequence analysis, as well as % G+C determination and cell wall fatty acid composition analysis supported the evidence that these isolates were representative of a new species. Phylogenetic analyses showed the close relationship with M. porcinum in the Mycobacterium fortuitum group. The isolates were susceptible to most antibiotics and exhibited evidence for penicillinase activity, in contrast to M. porcinum. We propose the name Mycobacterium conceptionense sp. nov. for this new species associated with posttraumatic osteitis. The type strain is D16(T) (equivalent to CIP 108544(T) and CCUG 50187(T)).

Improved efficacy of DNA vaccination against breast cancer by boosting with the repeat beta-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65

Studies have demonstrated that active-specific immunotherapy has potential for controlling mammary tumor progression. Human chorionic gonadotropin (hCG) is expressed and extremely sensitive, easily detectable and highly correlated with breast cancer. We developed a gene vaccine using a plasmid vector to deliver the six copies of 10-amino acid residues of beta-hCG 109-118 and beta hCG C-terminal 37-amino acid (CTP37). BALB/c female mice were immunized with a combination of pCR-HBc-X6-betahCGCTP37 DNA vaccine and HSP-X6-betahCGCTP37 protein vaccine. pCR-HBc-X6-betahCGCTP37 DNA vaccine were injected intramuscularly three times, on days -46,-25 and -11 and HSP-X6-betahCGCTP37 protein were applied two times, 21 and 14 days before tumor cell challenge. We assessed a combined DNA and protein vaccine for its effect of against murine EMT6 mammary tumor cells. In this study, animals vaccinated DNA vaccination boosting with the repeat beta-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65 induced higher avidity antibodies and effectively inhibited the growth of tumor, compared with treatment using DNA alone or BCG priming HSP-X6-betahCGCTP37 protein boosting. The data presented demonstrate that improve immunogenicity of DNA vaccination by boosting with the repeat beta-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65, which should prove useful in the development of new DNA vaccine against growth factors for cancer immunotherapy.

Comparative study of two typing methods, hsp65 PRA and ITS sequencing, revealed a possible evolutionary link between Mycobacterium kansasii type I and II isolates

One hundred and ninety-eight clinical isolates of Mycobacterium kansasii collected between 2003 and 2004 in Japan were genotyped by PCR and restriction enzyme analysis (PRA) and 16S-23S internal transcribed spacer (ITS) sequencing. The results demonstrated that clinical isolates of M. kansasii in Japan are almost exclusively of the type I PRA genotype, as is the case in other countries. Although the results of subtyping using the 16S-23S ITS sequence were generally consistent with subtyping using hsp65 PRA, four strains showed a discrepancy between the two methods. Sequence analysis of the hsp65, gyrB and 16S rRNA genes and the ITS sequence of the four strains suggests that they branched from type II and could be considered an ancestral strain of the type I strain. The newly recognized strains were designated as intermediate type I.

Direct identification of mycobacteria in primary liquid detection media by partial sequencing of the 65-kilodalton heat shock protein gene

We investigated extending the use of direct partial hsp65 gene sequencing for the identification of mycobacteria to isolates in primary liquid detection media as an economical, feasible, and more rapid means of identification. During the course of the study, the hsp65 sequence-based identifications for isolates from 670 primary liquid detection media determined to be positive for acid-fast bacilli were compared to the identifications derived from Accuprobes, biochemical test panels, or 16S rRNA gene sequencing. Preliminary analysis indicated a 97.6% concordance, with a final agreement of 99.1% between the identification algorithms. hsp65 sequencing costs (32.84 US dollars) were greater than the cost of identification with Accuprobe (9 US dollars) but less than the cost of the biochemical test panel identification (average cost, 98.90 US dollars) and equivalent to the cost of 16S rRNA sequencing, although there was a referral cost (59.85 US dollars) for the shipping of isolates to another reference laboratory. Analysis indicated that our laboratory would have recognized a cost savings of approximately 12,000 US dollars by using hsp65 sequencing to identify isolates from specimens with a negative fluorescent- smear status and would have achieved further savings by using it as an alternative to biochemical panel testing for fluorescent-smear-positive specimens. The time to identification by hsp65 gene sequencing was slightly longer than that required by the Accuprobe assay (1 versus 2 days), shorter than that required by the biochemical test panels (2 days versus 26 days on average), and more rapid than referral for 16S rRNA gene sequencing.

rpoB gene sequence-based characterization of emerging non-tuberculous mycobacteria with descriptions of Mycobacterium bolletii sp. nov., Mycobacterium phocaicum sp. nov. and Mycobacterium aubagnense sp. nov

Over the past 10 years, 16S rRNA gene sequencing has contributed to the establishment of more than 45 novel species of non-tuberculous mycobacteria and to the description of emerging mycobacterial infections. Cumulative experience has indicated that this molecular tool underestimates the diversity of this group and does not distinguish between all recognized mycobacterial taxa. In order to improve the recognition of emerging rapidly growing mycobacteria (RGM), rpoB gene sequencing has been developed. Our previous studies have shown that an RGM isolate is a member of a novel species if it exhibits >3 % sequence divergence in the rpoB gene from the type strains of established species. When applied to a collection of 59 clinical RGM isolates, rpoB gene sequencing revealed nine novel isolates (15.3 %) whereas only two isolates (3.4 %) were deemed to be novel by conventional 16S rRNA gene sequence analysis. A polyphasic approach, including biochemical tests, antimicrobial susceptibility analyses, hsp65, sodA and recA gene sequence analysis, DNA G+C content determination and cell-wall fatty acid composition analysis, supported the evidence that these nine isolates represent three novel species. Whereas Mycobacterium phocaicum sp. nov. (type strain N4T = CIP 108542T = CCUG 50185T) and Mycobacterium aubagnense sp. nov. (type strain U8T = CIP 108543T = CCUG 50186T; Mycobacterium mucogenicum group) were susceptible to most antibiotics, Mycobacterium bolletii sp. nov. (type strain BD(T) = CIP 108541T = CCUG 50184T; Mycobacterium chelonae-abscessus group) was resistant to the quinolones, tetracycline, macrolides and imipenem. Only M. bolletii was resistant to clarithromycin. These data illustrate that rpoB gene sequence-based identification is a powerful tool to characterize emerging RGM and mycobacterial infections and provides valuable help in differentiating RGM at both the intra- and interspecies level, thus contributing to a faster and more efficient diagnosis and epidemiological follow-up.

Characterization of mycobacteria isolated from bovines by PRA-targetting hsp 65 gene region

Bovine tuberculosis caused by the bacterium Mycobacterium bovis is a major infectious disease of animals and has zoonotic importance for humans. Even though the incidence is believed to be very low in India, human tuberculosis caused by M. bovis has been increasingly recognized in many other countries of the world. As differentiation of mycobacterial species take long time, a method for the rapid identification of mycobacteria isolated from bovine samples to the species level was used, which is based on polymerase chain reaction (PCR) of the gene encoding for the 65-kD protein followed by restriction analysis. The method involves restriction enzyme analysis of PCR products obtained with primers common to all mycobacteria and generate M. tuberculosis complex specific pattern. PRA was performed on 33 bovine isolates of which 90.9% (30/33) isolates were identified clearly as M. tuberculosis complex, M. fortuitum, M. phlei and M. smegmatis using restriction enzyme Hae III.

Mycobacterium tuberculosis complex in atherosclerosis

In recent years, the results of some studies have revealed the possible potential role of several infectious agents in the inflammatory mechanism of atherosclerosis. The detection of specific antibodies against microorganisms such as and as well as Chlamydia pneumoniae and cytomegalovirus as well as antibodies directed to heat shock proteins in the sera of atherosclerotic patients and the presence of genomic material in atheromatous plaques all provide evidence supporting the presumptive role of infectious agents in atherosclerosis. There are some findings that can be accepted as clues for the possible involvement of Mycobacterium tuberculosis in atherosclerosis. These consist of the presence of high levels of mycobacterial heat shock protein 65 in atherosclerotic patients, and in animal studies, the detection of atherosclerotic changes in the vascular wall of animals vaccinated with recombinant heat shock protein 65, and Mycobacterium tuberculosis containing heat shock protein 65. The probable proatherogenic effect of the specific immune response to BCG-associated heat shock protein was also suggested. The mycobacterium cell wall contains a phospholipid, phosphatidylinositol, which was shown to have a procoagulant effect similar to that of a cytomegalovirus possessing phosphatidylserine, another phospholipid showing a procoagulant effect. These data suggest that Mycobacterium tuberculosis may also be involved in the pathogenesis of atherosclerosis.

Detection of Mycobacterium avium & M. tuberculosis from human sputum cultures by PCR-RFLP analysis of hsp65 gene & pncA PCR

BACKGROUND & OBJECTIVE

Identification of mycobacteria by conventional methods is slow, labour intensive and may at times fail to produce precise results. Molecular techniques developed in the recent past, overcome these disadvantages facilitating rapid identification of most species. We undertook this study to characterize mycobacteria isolated from sputa of human patients suspected to have tuberculosis by conventional methods and later, by polymerase chain reaction-restriction fragment length polymorphism analysis (PRA) of hsp65 gene and pncA PCR.

METHODS

Twenty two mycobacteria isolated from 30 sputum samples were identified based on growth rate, pigmentation, cultural and biochemical properties and subjected to PRA of hsp65 gene involving amplification of hsp65 gene and digestion of the product with BstEII and HaeIII in separate reactions and analysis of digests by 3 per cent agarose gel electrophoresis. The mycobacteria were simultaneously evaluated by M. tuberculosis-specific and M. bovis-specific pncA PCR assays in separate reactions.

RESULTS

With the conventional biochemical tests, the 22 sputum culture isolates were identified as M. tuberculosis (19) and M. avium complex (MAC) (3). PCR of hsp65 gene yielded 439 bp product in all the mycobacteria tested. The RFLP patterns of three MAC isolates with BstEII and HaeIII were identical to reference M. avium strain with two fragments in each of the digest. M. intracellulare reference strain showed a distinct pattern with 3 fragments each in both enzyme digests. The PRA of hsp65 confirmed MAC isolates as M. avium. M. tuberculosis isolates including H37Rv and M. bovis strains could not be discriminated by PRA of hsp65. The two pncA PCR assays (M. bovis-specific and M. tuberculosis-specific) detected specifically the respective organisms with an amplification product of 185 bp. The MAC strains yielded no amplification product in both the pncA PCR assays.

INTERPRETATION & CONCLUSION

PRA profiles of hsp65 could differentiate MAC isolates into M. avium and M. intracellulare but could not distinguish between M. tuberculosis and M. bovis. pncA PCR assays were found specific in detecting the respective mycobacterial species. The study confirms utility of pncA PCR assays in differential identification of M. tuberculosis and M. bovis and that of PRA of hsp65 in the identification of M. avium.