Leprosy - one of the many forgotten tropical diseases.

Leprosy or Hansen disease is caused by an infection of Mycobacterium leprae. The large number of undetected cases (2000-2012 years 4 mln people) remains a threat to the elimination of leprosy. Leprosy is an unheard in Poland and generally is considered a condition so "exotic" that it is not worth to spend more attention to it. Forgotten disease in developed countries still thrives in an environment of poor and uneducated. Regardless of the conclusion that in the 21st century none infectious disease should not be treated as a disease on the designated regions of the world, other than our own, it should be recalled that the M. leprae was discovered in Europe, where for many years there were leprosaria and still infectious hospitals in Great Brittan, France or Spain get patients suspected of leprosy. The mobility of the inhabitants of the globe caused by wars, ethnic conflicts or a simple tourism causes that any infectious disease can not be treated as solely limited to distant us regions. The best proof of this were the viral diseases, formerly found in only in Asia or Africa, and currently transmitted to Europe [1]. At any moment, we can stand up against the problem of diagnostics of humans toward leprosy. Many medical reports indicate that leprosy as a disease with many symptoms encountered difficulties in its diagnosis. Only the experience of medical professionals and good microbiological diagnosis may speed up the diagnosis of leprosy.

Mutation profiling for detection of isoniazid resistance in Mycobacterium tuberculosis clinical isolates.

OBJECTIVES: Progress in the detection of drug-resistant TB has been underpinned by the development and implementation of new, reliable and rapid diagnostic tools. These rely mostly on the detection of specific mutations conferring resistance to anti-TB drugs. The aim of this study was to search for mutations associated with isoniazid resistance among Mycobacterium tuberculosis clinical isolates. METHODS: A collection of 150 M. tuberculosis strains, including 50 MDR, 50 isoniazid-monoresistant and 50 pan-susceptible strains, was used. For all the strains, seven structural genes (katG, inhA, ahpC, kasA, ndh, nat and mshA) and two regulatory regions (mabA-inhA promoter and oxyR-ahpC intergenic region) were PCR amplified and sequenced in their entirety. RESULTS: Sixty-six distinct mutations were detected at all nine loci investigated, accounting for 109 (72.7%) of the strains tested. The number of strains with any mutation among the MDR, isoniazid-monoresistant and pan-susceptible groups was 49 (98%), 37 (74%) and 23 (46%), respectively. Mutations in the katG gene predominated, with 29 different types distributed among 46 (92%) MDR, 31 (62%) isoniazid-monoresistant and 2 (4%) pan-susceptible strains. Twenty-nine and 19 mutations were found exclusively in MDR and isoniazid-monoresistant strains, respectively. CONCLUSIONS: This study revealed 17 mutations, previously unreported, that might be of potential use as new surrogate markers of isoniazid resistance. Their diagnostic accuracy needs to be confirmed on larger strain samples and from different geographical settings. For isoniazid resistance detection, molecular approaches should still be a complement to rather than a replacement for conventional drug susceptibility testing. This is supported by the lack of mutations in any of the nine genetic loci investigated in 18 isoniazid-resistant strains from this study.

Detection of mutations associated with isoniazid resistance in multidrug-resistant Mycobacterium tuberculosis clinical isolates.

OBJECTIVES: To determine the prevalence of isoniazid resistance-conferring mutations among multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis from Poland. METHODS: Nine genetic loci, including structural genes (katG, inhA, ahpC, kasA, ndh, nat and mshA) and regulatory regions (i.e. the mabA-inhA promoter and oxyR-ahpC intergenic region) of 50 MDR M. tuberculosis isolates collected throughout Poland were PCR-amplified in their entirety and screened for mutations by direct sequencing methodology. RESULTS: Forty-six (92%) MDR M. tuberculosis isolates had mutations in the katG gene, and the katG Ser315Thr substitution predominated (72%). Eight (16%) isolates (six with a mutated katG allele) had mutations in the inhA promoter region and two such isolates also had single inhA structural gene mutations. Mutations in the oxyR-ahpC locus were found in five (10%) isolates, of which all but one had at least one additional mutation in katG. Mutations in the remaining genetic loci (kasA, ndh, nat and mshA) were detected in 12 (24%), 4 (8%), 5 (10%) and 17 (34%) MDR isolates, respectively. All non-synonymous mutants for these genes harboured mutations in katG. One isolate had no mutations in any of the analysed loci. CONCLUSIONS: This study accentuates the usefulness of katG and inhA promoter mutations as predictive markers of isoniazid resistance. Testing only for katG 315 and inhA -15 mutations would detect isoniazid resistance in 84% of the MDR M. tuberculosis sample. This percentage would increase to 96% if the sequence analysis was extended to the entire katG gene. Analysis of the remaining genetic loci did not contribute greatly to the identification of isoniazid resistance.

[Interferon-Gamma Release Assays in the diagnosis of latent tuberculosis infection in clinical situations]. / Testy IGRA w diagnostyce zakazenia pratkami gruzlicy w wybranych sytuacjach klinicznych.

Until recently, the basic test to identify latent tuberculosis infection (LTBI) was the tuberculin skin test, despite its limitations in the form of low sensitivity and specificity. Currently, Interferon Gamma Release Assays from peripheral blood are used for a rapid diagnosis of LTBI and measurement of the interferon gamma (IFN-g) levels secreted by specific T cells stimulated with Mycobacterium tuberculosis antigens. Detection of LTBI is important in the control of people potentially at risk of TB disease, such as people remaining in close contact with BK (+) tb patient and for patients evaluated for biological treatment. The paper presents the value of IGRA in three selected clinical situations: in two cases of latent tuberculosis infection and in one case of active tuberculosis.

[The biological role of prokaryotic and eukaryotic N-acetyltransferase]. / Rola biologiczna prokariotycznych i eukariotycznych N-acetylotransferaz.

The N-acetyltransferases (NAT; E.C.2.3.1.5) are involved in the metabolism of drugs and environmental toxins. They catalyse the acetyl transfer from acetyl coenzyme A to an aromatic amine, heterocyclic amine, or hydrazine compound. NAT homologues are present in numerous species from bacteria to human. Sequence variations in the human NAT1 and NAT2 result in the production of NAT proteins with variable enzyme activity or stability, leading to slow or rapid acetylation. Therefore, genetic polymorphisms in NAT1 and NAT2 influence drug metabolism and drug-related toxicity. Epidemiological studies suggest that the NAT1 and NAT2 acetylation polymorphisms modify the risk of developing cancers of the urinary bladder, colorectal, breast, head and neck, and lung.

Identification and analysis of mutations in the katG gene in multidrug-resistant Mycobacterium tuberculosis clinical isolates.

INTRODUCTION: A major role in the development of resistance of Mycobacterium tuberculosis to isoniazid (INH) is attributed to mutations in the katG gene coding for the catalase/peroxidase, an enzyme required for obtaining a pharmacologically active form of the drug. Analysis of mutations in the katG gene in M. tuberculosis strains may contribute to the development of reliable and rapid tests for detection of INH resistance. The aim of the study was to identify and characterize mutations in the katG gene in multidrug-resistant M. tuberculosis clinical isolates. MATERIAL AND METHODS: The study included 46 strains of M. tuberculosis, recovered from MDR-TB patients in Poland in 2004. Mutations in the katG gene were detected by comparing DNA sequences with the corresponding sequence of a wild-type reference laboratory strain (M. tuberculosis H37Rv). The obtained results were interpreted in the context of MIC values of INH and catalase activity of the strains tested. RESULTS: A total of 43 (93%) strains contained mutations in the katG gene. The most frequently observed were mutations at codon 315, found in 34 (74%) strains. Mutations at other codons were rare: 4 strains contained mutations at codon 463, 2 at codon 131 and another 2 at codon 234. Mutations at codons 68, 91, 101, 126, 128 and 194 were found in single strains only. Two strains, for which no mutations at codon 315 of the katG gene were identified, had a unique translation termination mutation, which would invariably result in polypeptide truncation leading to the generation of dysfunctional catalase polypeptides. Both these strains presented the highest MIC values for INH (80 and 100 µg/mL) and showed a complete loss of catalase activity. For the remaining 41 strains with katG mutations, the MICs of INH were within the range 0.2-10 µg/mL. Thirty-six (88%) of those strains retained their catalase activity. CONCLUSIONS: Mutations at codon 315 within the katG gene, depending on their type might be useful for the prediction of INH resistance. Whereas the missense mutations do not affect the catalase activity or the level of INH resistance, the nonsense mutations result in high-level resistance to INH and a total loss of catalase activity.

Synthesis, structure and biological evaluation of novel bicyclic nitroimidazole derivatives.

A new series of 3-hydroxy-8-nitroimidazo[5,1-b]-1,4,5,6-tetrahydropyrimidine systems, being potential tuberculostatic agents, were synthesized. These products are close structural analogs of the basic structure of the known antitubercular bicyclic nitroimidazooxazine PA-824. The structures of the products obtained were confirmed by X-ray methods on the example of 3-hydroxy-8-nitro-1-phenylaminoimidazo[5,1-b]-1,4,5,6-tetrahydropyrimidine. Evaluation of these products for their anti-tuberculosis effects revealed interesting structure-activity relationships.

The capacity of Mycobacterium tuberculosis complex species and M. bovis BCG substrains specific identification - implications for optimized PCR-based diagnostics in adverse events following vaccination suspected cases.

The capacities of differentiation of Mycobacterium bovis BCG from other members of M. tuberculosis complex species using PCR-RFLP, multiplex PCR, and PCR-based genomic deletion analysis approaches were compared. In the study, mycobacteria isolated from patients suspected of adverse events following vaccination with BCG, primarily classified according presence of RD1 marker as virulent and avirulent mycobacteria, were used. The PCR-based genomic deletion analysis was found the best option for mycobacteria diagnostics improvement, as it was capable precisely differentiate virulent and avirulent mycobacteria or virulent species of M. tuberculosis complex. The routine confirmation of mycobacteria species in the cases of adverse events following BCG vaccination is highly expected, especially in clinical practice of patients with primary immunodeficiency.

[Molecular analysis of strains from tuberculosis patients in Polish prisons in 2004-2008. Initial analysis of the project]. / Molekularne dochodzenia epidemiologiczne wsród polskich wiezniów chorych na gruzlice w latach 2004­2008. Badania wstepne.

INTRODUCTION: Correctional facilities are recognised breeding ground for infectious diseases. As The World Health Organization reported the incidence of infectious diseases in prison's population is 10-100 times higher than in general population. The incidence of tuberculosis among correctional inmates in Poland in 2008 was 270/100000, that is around 10 times higher than among non-prisoners. MATERIALS AND METHODS: The study included 57 M. tuberculosis isolates from patients in Polish prisons in 2004-2008 (5% of all diagnosed TB patient in Polish prisons 2004-2008). Primary isolation was performed with Löwenstein-Jensen (L-J) medium, species identification was done with the niacin test and gene probes test. Bacterial DNA was extracted from the L-J medium slants with the cetyltrimethylammonium bromide (CTAB) method. Mycobacterium tuberculosis strains were analyzed with two methods: screening for epidemiological discrimination of M. tuberculosis - spoligotyping and high-throughput - MIRU/VNTR. RESULTS: Isolates that are grouped in clusters (33 isolates) were analyzed by means of MIRU/VNTRs. In MIRU/VNTRs all strains showed different genetic patterns. Most isolates of the prisoners were grouped into two clusters: T1 53 and H3 50. CONCLUSIONS: 1. MIRU/VNTR is a high-throughput method. 2. MIRU/VNTR is a promising method to diagnose TB transmission in Polish jails. 3. To identify the probable source of transmission, molecular analysis of strains from patients of the general population is needed.

[Polymorphism in the N-acetyltransferase 2 gene in patients with lung cancer. Short communication]. / Polimorfizm w genie N-acetylotransferazy 2 u chorych na raka pluca. Doniesienie wstepne.

INTRODUCTION: Individual's risk of developing lung cancer depends not only on exposure to tobacco smoke, but also on the activity of enzymes involved in the activation or deactivation of carcinogens. Arylamine N-acetyltransferase (EC 2.3.1.5) is an enzyme involved in biotransformation of xenobiotics, mainly aromatic and heterocyclic amines and hydrazines. The different acetylation phenotypes within a population are derived from mutations in the NAT 2 gene. These mutations influence the activity (specifically resulting in high or low activity) of the NAT enzyme. Some authors have demonstrated lung cancer predisposing role of slow acetylator phenotype, whereas other reported increased lung cancer risk for fast acetylators or neutral effect of the NAT2 polymorphism. The aim of this preliminary report was to determine the NAT2 gene polymorphism in patients with lung cancer. MATERIAL AND METHODS: 39 patients with inoperable lung cancer (29 - NSCLC and 10 - SCLC), median age 59 years (42- -72) entered the study. Acetylation genotype was determined in the genomic DNA using an allele-specific polymerase chain reaction. We investigated four genetic mutations, C481T, G590A, A803G i G857A, of the gene NAT2. RESULTS: There were 10 different NAT2 genotypes among the 39 patients. Fourteen patients with a NAT2*2 4/4, *4/5, *4/6 and *4/7 were classified as fast acetylators; and 25 patients with a NAT2*5/5, *5/6, *5/7, *6/6, *6/7 or *7/7 genotype were classified as slow acetylators. Among the 10 patients with SCLC - 4 were fast acetylators, and among 29 patients with NSCLC dominated slow acetylation type found in 19 patients (genotypes NAT2 *5/5 and NAT2 *5/6). CONCLUSIONS: Among patients with small cell lung cancer, there was no predominance of genotype of acetylation, whereas among patients with non-small cell lung cancer predominated NAT2*5/5 and NAT2*5/6 genotypes (slow acetylators).

A two-step strategy for molecular typing of multidrug-resistant Mycobacterium tuberculosis clinical isolates from Poland.

Tuberculosis (TB) continues to be one of the most challenging public health problems in the world. An important contributor to the global burden of the disease is the emergence and spread of drug-resistant and particularly multidrug-resistant Mycobacterium tuberculosis strains (MDR), defined as being resistant to at least isoniazid and rifampicin. In recent years, the introduction of different DNA-based molecular typing methods has substantially improved the knowledge of the epidemiology of TB. The purpose of this study was to employ a combination of two PCR-based genotyping methods, namely spoligotyping and IS6110-Mtb1/Mtb2 PCR to investigate the clonal relatedness of MDR M. tuberculosis clinical isolates recovered from pulmonary TB patients from Poland. Among the 50 isolates examined, 28 (56%) were clustered by spoligotyping, whereas IS6110-Mtb1/Mtb2 PCR resulted in 16 (32%) clustered isolates. The isolates that clustered in both typing methods were assumed to be clonally related. A two-step strategy consisting of spoligotyping as a first-line test, performed on the entire pool of isolates, and IS6110-Mtb1/Mtb2 PCR typing as a confirmatory subtyping method, performed only within spoligotype-defined clusters, is an efficient approach for determining clonal relatedness among M. tuberculosis clinical isolates.

[Drug resistant tuberculosis]. / Gruzlica lekooporna.

Drug-resistant tuberculosis, and particularly multidrug-resistant tuberculosis (MDR-TB) and extensive drug resistant TB (XDR-TB) as an increasing health problem and a serious challenge to TB control programs. MDR-Tb and XDR-TB are highly lethal in people living with HIV, with case of fatality rates of over 90%. At the same time, there are not many drugs effective in TB chemotherapy. Information about susceptibility patterns of Mycobacterium tuberculosis isolates against antituberculosis drugs is important aspect of tuberculosis control, and surveillance and analysis of local rates of TB drug resistance is helpful in the detection and monitoring of the extent of MDR and XDR strains, indicating the quality of TB control in the country. In 1994, The World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (IUATLD) launched a global project on anti-tuberculosis drug resistance surveillance. From 1994 through 2009, the global project has collected data from areas representing almost 60% of the world's TB cases. A survey found that multi-drug tuberculosis has become established worldwide. WHO estimated that 50 million people were infected with drug-resistant strains of M. tuberculosis. The classification of drug resistance as primary or acquired is used as an indicator of the efficiency of national tuberculosis programs and in the adjustment and development of these programs. The rate of primary drug resistance is interpreted as an epidemiological indicator for long-term surveillance of the quality of tuberculosis treatment in the community. The rate of acquired drug resistance reflects the efficacy of management of individual patients Since 1999, WHO developed DOTS-Plus strategy which can help how to manage MDR-TB using second line drugs in low- and middle-income countries within DOTS strategy. Poland joined the global project and in 1997 carried out its first simultaneous survey on primary and acquired drug resistance in tuberculosis patients exactly according WHO/IUATLD recommendations and protocols. Until now 4 surveys have been performed. Drug resistance in tuberculosis patients have been monitored in Poland for a long time. In period of recent 30 years the mean frequency of resistant was on the similar level with very low rate of RMP mono-resistance to M. tuberculosis. Both type of resistance MDR and XDR have been found in Polish tuberculosis patients.

[MDR, pre-XDR and XDR drug-resistant tuberculosis in Poland in 2000-2009]. / Gruzlica lekooporna typu MDR, pre-XDR i XDR w Polscew latach 2000­2009.

INTRODUCTION: Tuberculosis (TB) is a curable disease and its spread can be prevented by using appropriate diagnostic methods and effective treatment. The obstacle to the rapid eradication of the disease from a population may be strains resistant to essential and most effective antibiotics. In many places in the world MDR, pre-XDR and XDR-TB was reported. These forms of TB do not respond to the standard six-month treatment with first-line anti-TB drugs and the therapy should be conducted two years or more with drugs that are less potent, more toxic and much more expensive. MATERIAL AND METHODS: This study included MDR-TB strains isolated from 297 patients in 2000-2009. To determine the XDR-TB population structure, the 19 isolates were genotyped by spoligotyping and MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats) method. RESULTS: Among 297 MDR-TB cases, 36 (12.1%) were pre-extensively drug-resistant (pre-XDR), 19 (6.4%) were XDR and 1 (0.3%) was pre-totally drug-resistant (pre-TDR). Four of the 19 XDR isolates exhibit a unique spoligopattern, while the rest 15 belonged to one of 5 clusters. The MIRU-VNTR analysis reduced the number of clustered isolates to 11. CONCLUSIONS: The study documented the emergence of pre-extensively and extensively drug-resistant tuberculosis in Poland among patients with multidrug-resistant TB. Genotyping methods showed clonal similarity among XDR strains and may suggest the possible transmission among patients with newly diagnosed and with recurrent TB.

[Interferon-gamma assays T-SPOT.TB for the diagnosis of latent tuberculosis infection]. / Interferonowy test T-SPOT.TB w diagnostyce latentnego zakazeniapratkiem gruzlicy.

INTRODUCTION: The diagnosis of latent tuberculosis infection (LTBI) is currently based on the century-old tuberculin skin test (TST). However a positive reaction can result from infection by Mycobacterium tuberculosis, BCG vaccination or cross-reaction with nontuberculous mycobacteria. T-SPOT.TB assay is a new test to diagnose tuberculosis infection by measuring in vitro T-cell interferon gamma release in response to two Mycobacterium tuberculosis-specific antigens: ESAT-6 and CFP 10. MATERIAL AND METHODS: T-SPOT.TB assay has been performed on whole blood samples (n = 137) from March to September 2010. A tuberculin skin test result was available for 96 of participants. A positive TST result was considered if the induration was 10 mm or more. RESULTS: Of the 137 patients tested, T-SPOT.TB assay results were positive in 37 (27%), negative in 98 (71.5%) and indeterminate in only 2 (1.5%) persons. We analyzed T-SPOT.TB and TST results in the 96 patients for whom both test were available. Concordance between T-SPOT.TB and TST results (10 mm skin reaction interpreted as positive) was 79%. Fifteen (15.6%) patients had a positive TST result and a negative T-SPOT.TB and 5 (5.2%) patients had a negative TST result and a positive T-SPOT.TB. We observed good correlation between positive T-SPOT.TB results and the size of induration ≥ 15 mm in TST results. CONCLUSIONS: T-SPOT.TB offers a more accurate approach than TST for identification tuberculosis infection. The study shows that the test T-SPOT.TB is a good diagnostic tool in identifying persons with tuberculosis infection. For full confirmation of this assessment, it is necessary to examine more cases.

Spoligotype-based comparative population structure analysis of multidrug-resistant and isoniazid-monoresistant Mycobacterium tuberculosis complex clinical isolates in Poland.

The spoligotyping-based population structure of multidrug-resistant (MDR) Mycobacterium tuberculosis strains isolated in Poland (n = 46), representing all culture-positive MDR tuberculosis (MDR-TB) cases, was compared to that of isoniazid (INH)-monoresistant strains (n = 71) isolated in 2004. The latter data set from a previous study (E. Augustynowicz-Kopec, T. Jagielski, and Z. Zwolska, J. Clin. Microbiol. 2008, 46:4041-4044) represented 87% of all INH-monoresistant strains. The clustering rates and genotypic-diversity indexes for the 2 subpopulations were not significantly different (P = 0.05). The results were entered in the SITVIT2 database to assign specific shared type designations, corresponding genotypic lineages, and geographical distributions and compared to available data from neighboring countries (Germany, n = 704; Czech Republic, n = 530; Sweden, n = 379; Kaliningrad, Russia, n = 90) and strains from previous studies in Poland (n = 317). MDR strains resulted in 27 patterns (20 unique strains within the study and 7 clusters containing 2 to 6 isolates per cluster with a clustering rate of 56.5%) and belonged to the following genotypic lineages: ill-defined T family (28.3%), Haarlem (17.4%), Latin American and Mediterranean (LAM) (13%), Beijing (8.7%), S family (4.35%), and the X clade (2.17%). Comparison of the genetic structure of the MDR strains with that of INH-monoresistant strains showed that a total of 9 patterns were shared by both groups; these represented 1/3 of the MDR strains and 2/3 of the INH-monoresistant strains. Interestingly, 76.1% of the MDR isolates and 71.8% of the INH-resistant isolates yielded spoligotypes that were previously reported from Poland. The observation that nearly half of the spoligotypes identified among both MDR (48.1%) and INH-monoresistant (43.3%) M. tuberculosis isolates were present in Poland's neighboring countries suggested that a significant proportion of MDR and INH-resistant TB cases in Poland were caused by strains actively circulating in Poland or its neighbors. Our results corroborate the leading role of the T and Haarlem genotypes in the epidemiology of drug-resistant TB in Poland. Nevertheless, the LAM and Beijing family strains that infected, correspondingly, 13% and 9% of patients with MDR-TB were absent among the strains from patients with INH-monoresistant TB, suggesting that a proportion of MDR-TB cases in Poland are due to ongoing transmission of MDR clones exhibiting specific genotypes. Study of the population genetic relationships between MDR and INH-monoresistant strains by drawing minimum spanning trees showed that ill-defined T1 sublineage strains (1/3 of all INH-monoresistant strains), represented by its prototype, SIT53, constituted the central node of the tree, followed by strains belonging to the well-defined H3, H1, and S subgroups. However, the MDR group, in addition, contained LAM (n = 6) and Beijing (n = 4) lineage isolates. With the exception of the 4 Beijing lineage strains in the latter group and a single orphan isolate in the INH-monoresistant group, none of the remaining 112/117 isolates belonged to principal genetic group 1 (PGG1) in our study. Given the high rate of clustering and the near absence of immigrants in the study, the persistence of MDR-TB in Poland seems to result from active transmission of MDR strains within the autochthonous population, the bulk of it caused by evolutionarily recent tubercle bacilli.

[Genotyping of Mycobacterium tuberculosis. An overview of the major research techniques (Part I)]. / Typowanie genetyczne pratków Mycobacterium tuberculosis. Przeglad wazniejszych technik badawczych (Cz. I).

The recent development of molecular biology methods has substantially improved the identification of many bacterial pathogens, both at the species and strain level. Microbial strain genotyping refers to the process of discriminating among individuals within particular species based on the detection of genomic DNA polymorphisms by means of different molecular markers. Genetic variability arises mainly from genetic recombinations and spontaneous mutations. Each genotyping assay yields strain-specific genetic profiles, allowing assessment of inter-strain relationships. The ability to differentiate between strains, the so-called discriminatory power of particular genotyping methods depends heavily on the type and level of polymorphism detected. In the case of tuberculosis, a wide variety of methods have already been implemented to genotype its causative agent Mycobacterium tuberculosis. Most of these methods are based on the polymorphic repetitive DNA sequences in tubercle bacilli genome. This review briefly recapitulates the major research techniques used for genotyping of M. tuberculosis.

[Genotyping of Mycobacterlum tuberculosis. An overview of the major research techniques (Part II)]. / Typowanie genetyczne pratków Mycobacterium tuberculosis. Przeglad wazniejszych technik badawczych (Cz. II).

At present, molecular typing methods of Mycobacterium tuberculosis have become increasingly integrated into the epidemiological studies of tuberculosis. Molecular typing is a process of discriminating between strains of tubercle bacilli, based on the detection of genomic DNA polymorphisms, most frequently associated with repetitive DNA elements. The ability to assess the inter-strain genetic relationships provides a powerful means of resolving a number of epidemiological issues, such as tracing of chains of transmission, determining sources of infection, differentiating recent transmission from reactivation and reinfection from relapse or treatment failure, detecting laboratory cross-contaminations, monitoring the geographic distribution and spread of particular genetic strains (including those of special epidemiological importance), or investigating the evolution of M. tuberculosis. In this review, some major techniques used for genotyping of M. tuberculosis were summarized, as well as selected examples of the application of molecular epidemiological studies to the clinical practice.

[Epidemiology of tuberculosis: a global, European and Polish perspective]. / Epidemiologia gruzlicy w perspektywie swiata, Europy i Polski.

Tuberculosis (TB) still remains a significant global health problem. At present, it has been estimated that one-third of the world's population is infected with Mycobacterium tuberculosis, the causative agent of TB. A total of 8-9 million new cases and 2 million deaths are recorded annually, ranking TB as the leading cause of morbidity and mortality from infectious diseases. According to the World Health Organization, by 2015 almost 1 billion people will become newly infected, about 200 million will develop the disease, and 35 million will die of TB, if the current trends continue. A number of factors have contributed to the global TB crisis, among which low case detection rates, the emergence of drug-resistant M. tuberculosis strains, coinfection with HIV, increased influx of immigrants from countries with a high incidence of TB, socioeconomic decline and deterioration of health care services seem to be most crucial. Although TB occurs predominantly in low-income and middle-income countries that account for as much as 95% of all new cases and 98% of all TB deaths, the disease persists in the populations of the developed countries, posing a potential risk for its resurgence. This review provides an update of the epidemiological situation of TB in the world, Europe, and Poland.

[Phenotypic characterization of pyrazinamide-resistant Mycobacterium tuberculosis isolated in Poland]. / Fenotyp opornosci pratków gruzlicy na pirazynamid (PZA) w badaniach ogólnopolskich.

INTRODUCTION: Pyrazinamide (PZA) is an important first-line antituberculous drug, which is applied together with INH, RMP, EMB and SM. This drug plays a unique role in the first phase of TB therapy because it is active within macrophages and kills tubercule bacilli. Testing of the resistibility of Mycobacterium tuberculosis to PZA is technically difficult because PZA is active only at acid pH. Therefore routine drug resistibility testing of M. tuberculosis for PZA is not performed in many laboratories. The objective of our study was to estimate the resistibility for PZA among M. tuberculosis isolates from polish patients in 2000-2008 years. MATERIAL AND METHODS: We analyzed M. tuberculosis strains with different resistibility to first-line antituberculous drugs. The strains were isolated from 1909 patients with tuberculosis. The strains were examined for PZA resistibility by the radiometric Bactec 460-TB method. The PZA-resistant strains were examined for following MIC PZA for drug concentration: 100, 300, 600, 900 microg/mL. RESULTS: PZA resistance among M. tuberculosis strains was found in 6.7% untreated patients and in 22.2% previously treated patients (p < 0.001). In both groups resistance to PZA was correlated with drug resistance for INH + RMP + SM + EMB in 32.7% untreated patients and in 34.5% previously treated ones (p < 0.8). The PZA-monoresistant strains were observed in 20.8% untreated patients groups. Among resistant strains: in 3.4% MIC for PZA was > 100 microg/mL, in 11.6% >or= 300 microg/mL, in 8.9% >or= 600 microg/mL and in 76% >or= 900 microg /mL. CONCLUSIONS: Among M. tuberculosis strains PZA resistance was found in 6.7% of untreated patients and in 22.2% of previously treated patients. Among the PZA-resistant strains very high MIC value for PZA (>or= 900 microg/mL) was revealed for 76% M. tuberculosis strains.

[Epidemiology of drug-resistant tuberculosis: world--Europe--Poland]. / Epidemiologia gruzlicy lekoopornej: swiat--Europa--Polska.

The phenomenon of drug resistance in tubercle bacilli (Mycobacterium tuberculosis) has been recognized since the early years of chemotherapy of tuberculosis (TB). However it was not until the mid-1990s, that the magnitude of the problem was highlighted by the first global report of the World Health Organization on the prevalence of anti-TB drug resistance. Up to now, four such reports have been released. Not only have they shown that drug resistance is present worldwide, but they have also demonstrated its expansiveness and a high tendency for progression. The two most detrimental forms of drug-resistant TB are multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. Whereas MDR-TB implies resistance to at least isoniazid and rifampicin, the most potent drugs in the first-line regimen, XDR-TB is defined as MDR-TB with resistance to any of the fluoroquinolones and any of the second-line injectable drugs (amikacin, kanamycin, or capreomycin). The emergence and spread of drug-resistant TB are among the key factors contributing to the persistence of TB within the human population. This article outlines the current epidemiological status of drug-resistant TB in the world, Europe, and Poland.