Intramuscular injections of botulinum toxin for the treatment of upper back myofascial pain syndrome: A systematic review of randomized controlled trials

BACKGROUND AND OBJECTIVE

Myofascial pain syndrome (MPS) is a chronic musculoskeletal disorder characterized by the presence of trigger points. Among the treatment options, botulinum toxin injections have been investigated. The aim of this paper was to provide a synthesis of the evidence on intramuscular botulinum toxin injections for upper back MPS.

DATABASES AND DATA TREATMENT

A systematic review of the literature was performed on the PubMed, Scopus and Cochrane Library, using the following formula: ("botulinum") AND ("musculoskeletal") AND ("upper back pain") OR ("myofascial pain").

RESULTS

Ten studies involving 651 patients were included. Patients in the control groups received placebo (saline solution) injections, anaesthetic injections + dry needling or anaesthetic injections. The analysis of the trials revealed modest methodological quality: one "Good quality" study, one "Fair" and the other "Poor". No major complications or serious adverse events were reported. Results provided conflicting evidence and did not demonstrate the superiority of botulinum toxin over comparators. Most of the included trials were characterized by a small sample size, weak power analysis, different clinical scores used and non-comparable follow-up periods. Even if there is no conclusive evidence, the favourable safety profile and the positive results of some secondary endpoints suggest a potentially beneficial action in pain control and quality of life.

CONCLUSION

The currently available studies show conflicting results. Their overall low methodological quality does not allow for solid evidence of superiority over other comparison treatments. Further insights are needed to properly profile patients who could benefit more from this peculiar injective approach.

SIGNIFICANCE

The randomized controlled trials included in this review compared using botulinum toxin to treat upper back MPS with placebo or active treatments (e.g., dry needling or anaesthetics) showing mixed results overall. Despite the lack of clear evidence of superiority, our study suggests that the use of botulinum toxin should not be discouraged. Its safety profile and encouraging results in pain control, motor recovery and disability reduction make it an interesting treatment, particularly in the subset of patients with moderate to severe chronic pain and active trigger points. To support the safety and efficacy of botulinum toxin, further high-quality studies are needed.

Traumatic and non-traumatic spinal cord injury: Demographic characteristics, neurological and functional outcomes. A 7-year single centre experience

Objective

The aim of this study is to evaluate demographic and clinical characteristics of a population affected by traumatic and non-traumatic spinal cord injury (SCI) and to analyze functional outcomes after rehabilitation.

Methods

This study involved 112 SCI patients (75 male and 37 female) admitted at the Neurorehabilitation Unit of the University Hospital of Messina. The neurological outcomes were evaluated according to the American Spinal Injury Association Impairment Scale (AIS) and by using length of stay, Functional Independence Measure (FIM) and Barthel Index (BI).

Results

NT-SCI patients were significantly older, numerous (75,89%) and affected by greater lesions when admitted, than T-SCI ones. Most of lesions were incomplete (93%) and associated with paraplegia (71%). FIM and BI outcomes are similar in both groups, even if T-SCI patients showed greater improvement when discharged. No significant differences were found in the length of stay. The most common complication in non-traumatic SCI group was urinary tract infection and this was observed in 25 patients (29,41%). Linear regression models explained 26% of the variance of LOS and 38% of the variance of functional outcome. Functional status on admission was the strongest determinant of LOS and completeness of the lesion was the strongest determinant of functional outcome. Etiology (traumatic versus non-traumatic) was a weak independent determinant of LOS but was not an independent determinant of functional outcome.

Conclusion

SCI patient's rehabilitation should be carried out by taking into account etiology of the injury. It is important to consider this information while developing the targets and planning of the rehabilitation program. In particular, older age negatively influence the degree of disability on admission and the entity of functional recovery in both populations. Non-traumatic lesions could have minor benefits after rehabilitation therapy if compared with traumatic ones.

Tuberculosis transmission of predominant genotypes of Mycobacterium tuberculosis in northern suburbs of Buenos Aires city region

In 2003, the incidence of tuberculosis in Argentina showed an increase compared to 2002. The severe national crisis at the end of the 90s has probably strongly contributed to this situation. The goal of this work was to estimate the extent of the spread of the most predominant Mycobacterium tuberculosis strains and to assess the spread of predominant M. tuberculosis clusters as determined by spoligotyping and IS6110 RFLP. The study involved 590 pulmonary, smear-positive TB cases receiving medical attention at health centers and hospitals in Northern Buenos Aires (NBA) suburbs, from October 2001 to December 2002. From a total of 208 clinical isolates belonging to 6 major clusters, 63 (30.2%) isolates had identical spoligotyping and IS6110 RFLP pattern. Only 22.2% were shown to have epidemiological connections with another member of their respective cluster. In these major clusters, 30.2% of the 208 TB cases studied by both molecular techniques and contact tracing could be convincingly attributable to a recently acquired infection. This knowledge may be useful to assess the clonal distribution of predominant M. tuberculosis clusters in Argentina, which may make an impact on TB control strategies.

Lpp34, a Novel Putative Lipoprotein from Mycobacterium avium subsp. paratuberculosis

A Mycobacterium avium subsp. paratuberculosis expression library in lambda ZAP was screened with immunized mice sera. One clone was selected, sequenced and further characterized. The sequence analysis of the hypothetical open-reading frame (ORF) predicts a protein of 20.8 kDa with a probable signal sequence compatible with Cys-acylation at Cys24, characteristic of lipoproteins. In consequence, the protein was termed Lpp34. Recombinant expression of Lpp34 was achieved by cloning the lpp34 gene into the histidine-tag expression vector pRSET-A. Western blot analysis showed a protein band with a molecular weight of 34 kDa. The native protein was localized in the membrane fraction of M. avium subsp. paratuberculosis and extracted in the detergent phase of Triton X-114. Southern blot and polymerase chain reaction showed that the gene is absent from all the non-M. avium complex mycobacterial genomes tested. Humoral reactivity using bovine sera demonstrated that this protein is widely recognized by both the infected and non-infected animals. This could partly be due to the conserved sequence in close-related environmental bacteria such as M. avium subsp. avium and to the presence of a conserved epitope in other bacteria such as Escherichia coli. In conclusion, these findings show that Lpp34 is a membrane protein and a putative lipoprotein present in M. avium complex mycobacteria and absent in the M. tuberculosis complex.

First description of Mycobacterium tuberculosis Beijing genotype in Argentina

During a population-based study to genotype isolates of Mycobacterium tuberculosis from Buenos Aires Northern suburbs, we found isolates with molecular patterns related to those of the Beijing genotype. Five out of 590 (0.85%) patients had isolates with spoligopattern identical to that of the Beijing family. Since two of these isolates showed identical IS6110RFLP pattern, we found only four different patterns containing 11 to 19 bands. The isolates were obtained from young people (including a 7 years-old child) who were born in Argentina, and were living in a small area of our region. However, conventional contact tracing did not prove epidemiological linkage among them. These isolates were fully drug-susceptible to the first-line drugs. The comparison of the IS6110RFLP patterns from our isolates against a set of 19 reference Beijing patterns from the RIVM (The Netherlands) confirmed that the strains belonged to the Beijing lineage. These findings might be partially explained by the important migration phenomena occurred during the last decade. Further surveillance studies would help in the following of Beijing family strain dissemination in our community.

Identification of Mycobacterium bovis antigens by analysis of bovine T-cell responses after infection with a virulent strain

Purification and characterization of individual antigenic proteins are essential for the understanding of the pathogenic mechanisms of mycobacteria and the immune response against them. In the present study, we used anion-exchange chromatography to fractionate cell extracts and culture supernatant proteins from Mycobacterium bovis to identify T-cell-stimulating antigens. These fractions were incubated with peripheral blood mononuclear cells (PBMC) from M. bovis-infected cattle in lymphoproliferation assays. This procedure does not denature proteins and permits the testing of mixtures of potential antigens that could be later identified. We characterized protein fractions with high stimulation indices from both culture supernatants and cell extracts. Proteins were identified by two-dimensional gel electrophoresis followed by N-terminal sequencing or MALDI-TOF. Culture supernatant fractions containing low molecular weight proteins such as ESAT6 and CFP10 and other proteins (85B, MPB70), and the novel antigens TPX and TRB-B were associated with a high stimulation index. These results reinforce the concept that some low molecular weight proteins such as ESAT6 and CFP10 play an important role in immune responses. Also, Rv3747 and L7/L12 were identified in high stimulation index cell extract fractions. These data show that protein fractions with high lymphoproliferative activity for bovine PBMC can be characterized and antigens which have been already described and new protein antigens can also be identified in these fractions.

Tuberculosis in seals caused by a novel member of the Mycobacterium tuberculosis complex: Mycobacterium pinnipedii sp. nov

A comparison of Mycobacterium tuberculosis complex isolates from seals (pinnipeds) in Australia, Argentina, Uruguay, Great Britain and New Zealand was undertaken to determine their relationships to each other and their taxonomic position within the complex. Isolates from 30 cases of tuberculosis in six species of pinniped and seven related isolates were compared to representative and standard strains of the M. tuberculosis complex. The seal isolates could be distinguished from other members of the M. tuberculosis complex, including the recently defined 'Mycobacterium canettii' and 'Mycobacterium caprae', on the basis of host preference and phenotypic and genetic tests. Pinnipeds appear to be the natural host for this 'seal bacillus', although the organism is also pathogenic in guinea pigs, rabbits, humans, Brazilian tapir (Tapirus terrestris) and, possibly, cattle. Infection caused by the seal bacillus is predominantly associated with granulomatous lesions in the peripheral lymph nodes, lungs, pleura, spleen and peritoneum. Cases of disseminated disease have been found. As with other members of the M. tuberculosis complex, aerosols are the most likely route of transmission. The name Mycobacterium pinnipedii sp. nov. is proposed for this novel member of the M. tuberculosis complex (the type strain is 6482(T)=ATCC BAA-688(T)=NCTC 13288(T)).

Application of different methods for the diagnosis of paratuberculosis in a dairy cattle herd in Argentina

Paratuberculosis (Ptbc) has a high prevalence in Argentina, that affects dairy and beef cattle. The culture is the gold standard to the diagnosis of the disease. Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis), the aetiological agent, is difficult to isolate and grow in culture. In this study, 24 randomly selected cows of the Fresian breed from a dairy herd with a history of Ptbc were used to evaluate the performance of different diagnostic techniques. These animals did not show clinical signs of the disease. However, another animal from this herd presented evidence of clinical disease at the moment of the present study. This animal was necropsied and one strain of M. paratuberculosis was isolated from faeces, lymph nodes and intestine. Serum for indirect absorbed enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) tests and whole blood samples to perform gamma interferon (gammaIFN) release assays were obtained from each animal. Faeces and milk samples to carry out bacteriological cultures, PCR identification of M. paratuberculosis, and direct examinations of smears with Ziehl-Neelsen's (ZN) stain were also collected. Tuberculin test with bovine purified protein derivative (PPD) in the caudal fold was performed. The results showed that 10 out of 24 animals (41.6%) were positive to ELISA. Eight strains of M. paratuberculosis were isolated, six from faeces, two from milk. Five of the animals that excreted the bacteria through faeces were ELISA-positive, whereas the excreters through milk were negative to ELISA. No positive samples by AGID were obtained in clinical asymptomatic animals. Seven samples gave positive gammaIFN results with avian PPD, but only two of these animals were confirmed with culture. Direct PCR, to detect IS900 (M. paratuberculosis) in faeces and milk samples, was negative, but PCR using material taken from faecal and milk cultures gave positive results before visualizing the colonies. No sample was positive by PCR directed to IS6110 (M. tuberculosis complex). There was not always agreement between isolations and ZN in the studied samples. In conclusion, the absorbed ELISA was useful to detect positive animals and excreters through faeces but not through milk. PCR applied to cultures with incipient development before the visualization of colonies was effective to specifically determine the presence of M. paratuberculosis. The gammaIFN test was not able to detect the most positive animals confirmed by culture. The importance of using ELISA and cultures is emphasized by this study but it is necessary to continue with the gammaIFN test development for early detection of the disease.

A low cost, home-made, reverse-line blot hybridisation assay for rapid detection of rifampicin resistance in Mycobacterium tuberculosis

SETTING

Cetrangolo Hospital, Vicente Lopez, Argentina, 1995-1999.

OBJECTIVE

To describe a home-made reverse-line blot hybridisation assay for the detection of rifampicin resistance-associated mutations in the rpoB gene of Mycobacterium tuberculosis, and to evaluate the usefulness of this rifampicin oligonucleotide, or 'RIFO' assay, to predict rifampicin resistance.

DESIGN

A total of 135 M. tuberculosis isolates from the Cetrangolo Hospital were tested using the RIFO assay, the proportion method and the Mycobacterial Growth Indicator Tube (MGIT 960). In addition, 120 drug-susceptible isolates from the Netherlands were included.

RESULTS

The results obtained with the proportion method and the MGIT 960 system were in full agreement. In the RIFO assay, 90 of the 97 rifampicin-resistant isolates were correctly identified (sensitivity 92.8%, positive predictive value 100%). All of the drug-susceptible isolates were correctly predicted by the RIFO assay.

CONCLUSIONS

With this home-made molecular test, rifampicin resistance in M. tuberculosis can be predicted in colonies isolated in culture in only 1 day, and can therefore shorten the laboratory turn around time for rifampicin susceptibility testing by weeks. In principle the test can also be applied directly to Zichl-Neelsen slides and clinical material, as has been demonstrated for another reverse-line blot-based assay for M. tuberculosis, spoligotyping.

[The genotype of the principal Mycobacterium bovis in Argentina is also that of the British Isles: did bovine tuberculosis come from Great Britain?]

Bovine tuberculosis is a highly prevalent animal disease in Argentina. In this work evidence was obtained showing that a major Mycobacterium bovis group in Argentina had been introduced with the bovine bulls imported from the United Kingdom at the end of the XIX century. This evidence came from two sources: historical, obtained by bibliographical references, and from laboratory results, using a molecular typing method called spoligotyping. These strains are also present in other countries that introduced cattle from the same origin.

PCR-restriction fragment length polymorphism analysis (PRA) of Mycobacterium leprae from human lepromas and from a natural case of an armadillo of Corrientes, Argentina

Polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis (PRA) which relies on the amplification of a 439-bp portion of the hsp65 gene present in all mycobacteria, followed by two distinct digestions (with BstEII and HaeIII) of the PCR product, offers a rapid and easy alternative that allows identification of the species without the need for specialized equipment. Wild leprosy in the nine-banded armadillo (Dasypus novemcinctus) is characterized by the presence of multiple bacilli in internal organs such as lymph nodes, spleen and liver, as well as in nerves and skin. We could observe this in 9 out of 132 animals captured in Corrientes, Argentina, an area endemic for leprosy in humans. Mycobacterium leprae were recognized in those naturally infected animals through different techniques. Three samples of extracted DNA of the mycobacteria present in the spleen, liver and popliteal lymph node of a naturally infected animal during the Experimental Program in Armadillo (PEA) and three samples of human lepromas were processed by PRA. The patterns of the six samples analyzed were identical and were characteristic of M. leprae. These studies, made for the first time in Argentina, corroborate the initial discoveries in South America made by our investigative group on the detection of armadillos naturally infected with the Hansen bacillus.

Sequence analysis of the direct repeat region in Mycobacterium bovis

Spoligotyping is a major tool for molecular typing of Mycobacterium bovis. This technique is based on the polymorphism of spacers that separate direct repeats (DRs) in the M. tuberculosis complex DR region. Numerous M. bovis strains show a lack of several spacers which appears as a gap in the spoligotyping pattern. To determine whether these gaps contain alternative spacers not included in the spoligotyping membrane, PCRs using primers that hybridize to the spacers adjacent to the gaps were performed. Comparing the sizes of products obtained by PCR with those deduced from spoligotyping patterns, fragments were selected and sequenced to look for alternative spacers. Upon analysis of the sequences, five alternative spacers were detected, although deletions of spacers are mainly responsible for the observed gaps. The alternative spacers, which are more frequent in M. bovis than in M. tuberculosis, may contribute to increased M. bovis differentiation.

The gene encoding P27 lipoprotein and a putative antibiotic-resistance gene form an operon in Mycobacterium tuberculosis and Mycobacterium bovis

P27 is an antigenic membrane lipoprotein synthesized by members of the Mycobacterium tuberculosis complex. Northern blotting and RT-PCR experiments indicated that the genes encoding P27 and a putative antibiotic transporter (P55) form an operon. A promoter region was identified and characterized by deletion analysis in Mycobacterium smegmatis. Two transcription initiation points were mapped in Mycobacterium bovis BCG by primer extension analysis to 76 bp and 87 bp upstream of the ATG initiation codon. Putative -10 and -35 promoter consensus sequences associated with these showed 66% similarity to previously identified mycobacterial promoters. These results suggest that the P27/P55 operon is transcribed from two promoters in M. bovis BCG.

Evaluation of the polymerase chain reaction for the detection of Mycobacterium tuberculosis

The development of nucleic acid-based technologies has improved the sensitivity, specificity and speed of detection of Mycobacterium tuberculosis in clinical samples. Both commercially available and 'in-house' polymerase chain reaction (PCR) systems are in use, and a significant number of reports compare such systems with more traditional diagnostic tools for tuberculosis. Few studies, however, have focused on the reproducibility of the results when submitting a sample batch to PCR in different laboratories, especially in developing countries. Consequently, PCR results obtained from six laboratories in six different Latin American countries for samples reconstituted with defined amounts of M. tuberculosis cells were evaluated. Each laboratory used specific conditions of sample processing, nucleic acid amplification and amplicon detection. Analysis of results allowed large differences in sensitivity and specificity to be observed. We conclude that in its present setting, in-house PCR cannot be used as a single diagnostic tool for tuberculosis, and that special care needs to be taken upon interpretation of results by inclusion of a proper number of positive and negative controls.

Molecular characterization of mycobacteria isolated from seals

Tuberculosis (TB) was diagnosed in 10 seals from three species (Arctocephalus australis, Arctocephalus tropicalis and Otaria flavescens) found in South America. The mycobacteria isolated from these cases belonged to the Mycobacterium tuberculosis complex, as determined by RFLP using an IS6110 probe, spoligotyping, analysis of the 16S rRNA gene sequence and by PCR-restriction analysis of hsp65. Polymorphisms in gyrA, katG, oxyR and pncA were investigated in some of the isolates, as well as the presence of the MPB70 antigen. The insertion sequence IS6110 was present in three to seven copies in the genome of the mycobacteria isolated from seals. Using the IS6110 probe, six patterns (designated A, B, C, D, E and F) were identified from 10 different isolates. Patterns A and B were found for the mycobacteria isolated from two and four seals, respectively, indicating an epidemiological relationship between isolates grouped according to their IS6110 RFLP. The mycobacteria isolated from seals shared the majority of their IS6110 DNA-containing restriction fragments, and nine isolates had an identical spoligotype; only one isolate showed a minor difference in its spoligotype. In addition, none of these spoligotypes were found in other M. tuberculosis complex strains. These results suggest that the isolates from seals constitute a unique group of closely related strains. The mycobacteria isolated from seals showed polymorphisms at gyrA codon 95 and katG codon 463, as do group 1 M. tuberculosis, and M. bovis. Group 1 mycobacteria are associated with cluster cases. The spoligotypes found in the mycobacteria isolated from seals lack spacers 39-43, as does M. bovis, but the MPB70 antigen, which is highly expressed in M. bovis and minimally expressed in M. tuberculosis, was not detected in these mycobacteria. The mycobacteria isolated from seals also showed oxyR and pncA polymorphisms specific to M. tuberculosis. In conclusion, the mycobacteria that cause TB in seals in the South-Western Atlantic are a related group, and based on the combination of genetic characteristics, belong to a unique genotypic group within the M. tuberculosis complex.

Antigenic characterization of mycobacteria from South American wild seals

Tuberculosis-producing mycobacteria have been previously described in marine mammals (Cousins et al., 1990, 1993; Romano et al., 1995; Bernardelli et al., 1996). The strains belonged to the M. tuberculosis complex (M. tuberculosis, M. bovis, M. microti and M. africanum), but showed genetic and biochemical differences. The antigenic composition of mycobacteria isolated from wild seals was analyzed by Western blots, using antibodies against some selected antigens. The antigenic content was compared with that of M. bovis, M. tuberculosis and M. microti isolates. The lack of Hsp65 protein in supernatants suggested a low degree of cell lysis in the three-week cultures used. SOD, P27 lipoprotein, MPB64 and antigen 85 were observed in all the strains studied. The wild seal strains, as well as M. tuberculosis, did not produce MPB70 and MPB83. Only very weak bands of P36 antigen were observed in culture supernatants from wild seal mycobacteria. Summarizing, the antigenic composition of mycobacterial strains from wild seals is different from M. bovis strains.

The IS6110 restriction fragment length polymorphism in particular multidrug-resistant Mycobacterium tuberculosis strains may evolve too fast for reliable use in outbreak investigation

To study possible nosocomial transmission of multidrug-resistant (MDR) Mycobacterium tuberculosis, strain types and other information on 24, mostly human immunodeficiency virus-positive patients, were collected. Isolates from 11 patients had identical IS6110 restriction fragment length polymorphism (RFLP) patterns as well as spoligotype patterns and resistance profiles. Noticeably, nine other isolates from related cases also exhibited identical spoligotypes but slightly different RFLP patterns. These results indicate that for some MDR strains, the evolutionary clock of IS6110 RFLP may run too fast for reliable interpretation of strain typing results over a period of a few years.

Usefulness of spoligotyping in molecular epidemiology of Mycobacterium bovis-related infections in South America

Two hundred twenty-four Mycobacterium bovis isolates, mainly from South American countries, were typed by spoligotyping, and 41 different spoligotypes were identified. A total of 202 M. bovis isolates (90%) were grouped into 19 different clusters. The largest cluster contained 96 isolates (42.8%) on the basis of the most frequently observed spoligotype, spoligotype 34. Nineteen M. bovis isolates from humans in Argentina had spoligotypes and polymorphic GC-rich repetitive sequence (PGRS) types that represented the most common types found among isolates from cattle. All five isolates from Uruguay and three of the six isolates from Paraguay had spoligotypes that were also detected for isolates from Argentina. The spoligotypes of isolates from Brazil, Costa Rica, and Mexico and of some of the isolates from Paraguay could not be found in Argentina. A total of 154 M. bovis isolates were selected in order to compare the discriminative power of spoligotyping and restriction fragment length polymorphism (RFLP) analysis with direct repeat (DR) and PGRS probes. By spoligotyping, 31 different types were found, while AluI-digested DR probe-associated RFLP analysis identified 42 types, and RFLP analysis with the PGRS probe also detected 42 types; these were partly independent of the DR types. By combining the results obtained by spoligotyping and by RFLP analysis with the DR and PGRS probes, 88 different types were obtained. Although the differentiation of M. bovis by spoligotyping was less discriminatory than differentiation by RFLP analysis with the DR and PGRS probes, spoligotyping is easier to perform and its results are easier to interpret. Therefore, for the purpose of typing of M. bovis isolates, spoligotyping could be performed first and the isolates could be grouped into clusters and then analyzed by RFLP analysis with the DR and PGRS probes.

Expression of the Mycobacterium bovis P36 gene in Mycobacterium smegmatis and the baculovirus/insect cell system

In the present study we evaluated different systems for the expression of mycobacterial antigen P36 secreted by Mycobacterium bovis. P36 was detected by Western blot using a specific antiserum. The P36 gene was initially expressed in E. coli, under the control of the T7 promoter, but severe proteolysis prevented its purification. We then tried to express P36 in M. smegmatis and insect cells. For M. smegmatis, we used three different plasmid vectors differing in copy number and in the presence of a promoter for expression of heterologous proteins. P36 was detected in the cell extract and culture supernatant in both expression systems and was recognized by sera from M. bovis-infected cattle. To compare the expression level and compartmentalization, the MPB70 antigen was also expressed. The highest production was reached in insect cell supernatants. In conclusion, M. smegmatis and especially the baculovirus expression system are good choices for the production of proteins from pathogenic mycobacteria for the development of mycobacterial vaccines and diagnostic reagents.

Molecular epidemiology of Mycobacterium bovis isolates from South America

One hundred seventy-eight isolates of Mycobacterium bovis were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the direct repeat element (DR) and the polymorphic GC-rich repeat sequence (PGRS) as probes. By combining the patterns generated by the two repeat DNA elements, 93 different patterns were observed. One hundred-one isolates were grouped in clusters, which include 25 different clusters. One pattern was the most frequently observed, clustering 18.5% of isolates. It was only found in the Center and northeast regions of Argentina and in one isolate from Paraguay. The isolates from Brazil analyzed here presented exclusive patterns (only found in a particular region). The number of exclusive patterns was high in all argentine regions: northeast 78%, center 81%, and Buenos Aires 81%.

A novel 27 kDa lipoprotein antigen from Mycobacterium bovis

A novel Mycobacterium bovis antigen was identified from an expression library using sera from naturally infected cattle. The Escherichia coli recombinant clone expressed a 27 kDa protein, named P27. A rabbit serum against the recombinant antigen recognized a protein of 27 kDa in cellular extracts from M. bovis and M. tuberculosis. No protein was recognized in the culture supernatant. Sequence analysis indicated that P27 has a molecular mass of 24 kDa, showing a characteristic signal sequence for lipoprotein modification (a signal peptidase type II site). The gene is identical to a gene identified in the M. tuberculosis genome sequencing project. Cellular fractionation experiments suggested that P27 is an integral membrane protein. The antigen was recognized by individual sera and peripheral blood mononuclear cells (PBMC) from diseased cattle. PCR experiments with specific primers directed to the P27 structural gene indicated that it is only present in the M. tuberculosis species complex. In conclusion, a novel immunogenic lipoprotein in M. bovis/M. tuberculosis has been identified. The results presented here and elsewhere suggest that mycobacterial lipoproteins should be considered in the design of new recombinant vaccines and diagnostic methods.

An mpb-64 flanking sequence specific for Mycobacterium bovis

A clone carrying a plasmid with the mpb-64 gene and 3' flanking sequences (plasmid pMBA122) was detected during the screening of a Mycobacterium bovis genomic library with sera from infected cattle. When the pMBA122 insert was used as a probe in Southern blots against PvuII-digested mycobacterial DNA, it distinguished the different M. tuberculosis complex species. This probe hybridized with a 7-kb band in M. tuberculosis, a 5-kb band in M. bovis and a 3-kb band in M. tuberculosis complex strains from wild seals. Smal genomic digestions enabled us to locate this polymorphic region downstream of the mpb-64 gene. In order to clone this particular region, we designed a pair of PCR primers. Unexpectedly, these primers amplified only M. bovis DNA; no amplification was seen in M. tuberculosis DNA. When the annealing temperature was lowered from 70 to 55 degrees C, an amplification product of the same size was obtained with M. tuberculosis. This product was cloned and sequenced, and showed partial homology to the M. bovis amplified fragment. Therefore, this region comprises M. bovis sequences with a lower homology with M. tuberculosis than other compared sequences. This suggests that a more precise differentiation method at the species level for the M. tuberculosis complex could be achieved using PCR directed to this region.

Comparison of different genetic markers for molecular epidemiology of bovine tuberculosis

In the present study three different genetic markers were used in an RFLP study to differentiate Mycobacterium bovis (M. bovis) isolated in Argentina. The markers were: the insertion sequence IS6110, the direct repeat (DR) sequence flanking IS6110, and a polymorphic GC-rich repetitive sequence (PGRS), called pMBA2. Two restriction enzymes were used, PvuII for IS6110 and DR (DR/PvuII) and AluI for DR (DR/AluI) and pMBA2. DNA from 85 of M. bovis isolates was digested with PvuII and hybridized with IS6110 and Dr. IS6110 was not useful to differentiate M. bovis because most of the isolates contain a single monomorphic copy. The use of DR allowed a limited degree of differentiation. DNA from 44 of these isolates was also digested with AluI and hybridized with DR and pMBA2. In this condition these probes differentiated the isolates in many different RFLP types. By combining the patterns generated with DR/AluI and pMBA2 it was possible to increase the differentiation up to obtain 30 different RFLP types and 54% of the isolates were differentiated because they showed a unique pattern. Six isolates of M. bovis involved in two different outbreaks of bovine tuberculosis were correctly identified. Thus, DR and pMBA2 could be, at the moment, the probes of choice for comparisons of M. bovis isolates in different regions and for epidemiological surveillance of bovine tuberculosis.

Genetic characterization of mycobacteria from South American wild seals

Tuberculosis has been recently diagnosed in four wild seals found stranded in the Atlantic coast of Argentina. By bacteriological studies and IS6110 hybridization, these isolates were characterized as belonging to the Mycobacterium tuberculosis complex. A genetic characterization using RFLP (Restriction fragment length polymorphism) and a species-specific probe of M. tuberculosis, called mtp40, showed hybridization with this probe on a single band. A similar band was also found in M. tuberculosis H37Rv. This showed a relationship between M. tuberculosis and the wild seal isolates. However these would also seem to belong to a different genetic group in the M. tuberculosis complex, since they do not grow on glycerol-egg containing medium (Lowenstein-Jensen) as typical M. tuberculosis strains usually do. Repeated sequences pMBA2, pTNB12, DR and IS6110 were used as probes to evaluate the epidemiological relationships between the 4 cases of tuberculosis. A low degree of polymorphism was observed, that suggested that these isolates were epidemiologically related.

Characterization of a novel Mycobacterium bovis secreted antigen containing PGLTS repeats

Serum from naturally infected cattle was used to identify a novel Mycobacterium bovis antigen from an expression library. The first recombinant product identified was a fusion protein with lacZ (55 kDa). A clone containing the whole gene was also obtained. This clone expressed a 38-kDa protein. A rabbit serum against the recombinant antigen reacts in M. bovis supernatants with two proteins of 36 and 34 kDa. The new protein was called P36/P34. The gene cloned has a deduced amino acid sequence with a predicted molecular mass of 28 kDa, showing a characteristic signal sequence for exportation. The protein bears partial homology to a 28-kDa protein from M. leprae. An interesting feature of the P36/P34 sequence is that it contains several PGLTS repeats, which are not present in the M. leprae protein. Antigenic determinants seem also to be conserved between the two proteins because sera from leprosy patients recognized the recombinant M. bovis protein. The discrepancy among the molecular mass deduced from the sequence (28 kDa), that of the recombinant protein in Escherichia coli (38 kDa), and that of the native protein in M. bovis (36 and 34 kDa) could be attributed to posttranslational modifications or to the high proline content that may alter the migration properties of the protein. This antigen seems to be immunodominant during bovine tuberculosis, because 8 of 9 serum specimens from diseased cattle are reactive. The homology among the M. leprae 28-kDa protein, the protein described in this article, and a recently described M. tuberculosis protein suggests the existence of a new protein family in mycobacteria.

Cloning of a novel polymorphic GC-rich repetitive DNA from Mycobacterium bovis

A repetitive DNA from a wild-type Mycobacterium bovis isolate was cloned and characterized. The repeated segment was present in M. bovis and M. tuberculosis but was absent from the six other mycobacteria tested. Sequence analysis demonstrated that this repetitive element belonged to the polymorphic GC-rich repeat sequence type, a family of interspersed repeated DNA. This fragment, when used as a probe in restriction fragment length polymorphism analyses, was able to detect polymorphism in M. bovis genotypes that went undetected when the established IS6110 was used as a probe. This repetitive element should be useful in epidemiological studies of bovine tuberculosis.

Use of various genetic markers in differentiation of Mycobacterium bovis strains from animals and humans and for studying epidemiology of bovine tuberculosis

One hundred fifty-three Mycobacterium bovis strains from cattle, various animal species from zoos and wild parks, and humans were analyzed for three different genetic markers for use in the epidemiology of bovine tuberculosis. M. bovis strains isolated from cattle were found to carry a single IS6110 element, whereas the majority of strains from other animals such as antelopes, monkeys, and seals harbored multiple IS6110 elements, suggesting that the reservoirs in cattle and wild animals are separated. Because the single IS6110 element in cattle strains is located at the same chromosomal position, strain differentiation by insertion sequence fingerprinting was hampered. Therefore, we investigated the usefulness of the direct repeat and polymorphic GC-rich repeat elements for strain differentiation. Both markers allowed sufficient strain discrimination for epidemiological purposes. Evidence is presented that in Argentina, most human M. bovis infections are due to transmission from cattle, whereas M. bovis infections among humans in the Netherlands are mainly contracted from animals other than cattle. Various outbreaks of M. bovis among animals and humans are described, including a small one which likely involved transmission from human to human.