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1.
Toxins (Basel) ; 16(6)2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38922140

RESUMO

Diphtheria toxin (DT) is the main virulence factor of Corynebacterium diphtheriae, C. ulcerans and C. pseudotuberculosis. Moreover, new Corynebacterium species with the potential to produce diphtheria toxin have also been described. Therefore, the detection of the toxin is the most important test in the microbiological diagnosis of diphtheria and other corynebacteria infections. Since the first demonstration in 1888 that DT is a major virulence factor of C. diphtheriae, responsible for the systemic manifestation of the disease, various methods for DT detection have been developed, but the diagnostic usefulness of most of them has not been confirmed on a sufficiently large group of samples. Despite substantial progress in the science and diagnostics of infectious diseases, the Elek test is still the basic recommended diagnostic test for DT detection. The challenge here is the poor availability of an antitoxin and declining experience even in reference laboratories due to the low prevalence of diphtheria in developed countries. However, recent and very promising assays have been developed with the potential for use as rapid point-of-care testing (POCT), such as ICS and LFIA for toxin detection, LAMP for tox gene detection, and biosensors for both.


Assuntos
Toxina Diftérica , Difteria , Toxina Diftérica/genética , Humanos , Difteria/diagnóstico , Difteria/microbiologia , Corynebacterium/genética , Corynebacterium diphtheriae
2.
Viruses ; 15(9)2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37766194

RESUMO

The outbreak of COVID-19 started in December 2019 and spread rapidly all over the world. It became clear that the development of an effective vaccine was the only way to stop the pandemic. It was the first time in the history of infectious diseases that the process of the development of a new vaccine was conducted on such a large scale and accelerated so rapidly. At the end of 2020, the first COVID-19 vaccines were approved for marketing. At the end of March 2023, over three years after the outbreak of the COVID-19 pandemic, 199 vaccines were in pre-clinical development and 183 in clinical development. The candidate vaccines in the clinical phase are based on the following platforms: protein subunit, DNA, RNA, non-replication viral vector, replicating viral vector, inactivated virus, virus-like particles, live attenuated virus, replicating viral vector combined with an antigen-presenting cell, non-replication viral vector combined with an antigen-presenting cell, and bacterial antigen-spore expression vector. Some of the new vaccine platforms have been approved for the first time for human application. This review presents COVID-19 vaccines currently available in the world, procedures for assurance of the quality and safety of the vaccines, the vaccinated population, as well as future perspectives for the new vaccine platforms in drug and therapy development for infectious and non-infectious diseases.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Pandemias/prevenção & controle
3.
Pathogens ; 11(11)2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36365015

RESUMO

Only three Corynebacterium species are known to produce a lethal exotoxin called diphtheria toxin. These are C. diphtheriae, C. ulcerans and C. pseudotuberculosis. The diphtheria toxin gene (tox) is carried in a family of closely related corynebacteriophages and therefore the toxin can be produced only through lysogenisation, in which the corynephage encoding tox is stably inserted into the chromosome. However, 'nontoxigenic tox gene-bearing' (NTTB) strains, which are genotypically tox-positive but do not express the protein, have been described. The emergence of NTTB strains was first observed during the 1990s diphtheria epidemic in Eastern Europe and nowadays such isolates have been detected in many countries in the world. Recently, novel species of Corynebacterium genus have been described which might have the potential of producing the diphtheria toxin due to the possession of the diphtheria toxin gene but it has not produced toxin in laboratory tests. The circulation of NTTB strains could be related to the increased risk for diphtheria disease arising from the risk of re-emerging toxin expression. The article presents the mechanism of diphtheria toxin expression and action, recently described novel species of NTTB corynebacteria as well as the taxonomic changes within the C. diphtheriae group.

4.
Biomedicines ; 10(9)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36140431

RESUMO

Rapid and accurate detection and identification of pathogens in clinical samples is essential for all infection diseases. However, in the case of epidemics, it plays a key role not only in the implementation of effective therapy but also in limiting the spread of the epidemic. In this study, we present the application of two nucleic acid isothermal amplification methods-reverse transcription helicase dependent amplification (RT-HDA) and reverse transcription loop-mediated amplification (RT-LAMP)-combined with lateral flow assay as the tools for the rapid detection of SARS-CoV-2, the etiological agent of COVID-19, which caused the ongoing global pandemic. In order to optimize the RT-had, the LOD was 3 genome copies per reaction for amplification conducted for 10-20 min, whereas for RT-LAMP, the LOD was 30-300 genome copies per reaction for a reaction conducted for 40 min. No false-positive results were detected for RT-HDA conducted for 10 to 90 min, but false-positive results occurred when RT-LAMP was conducted for longer than 40 min. We concluded that RT-HDA combined with LFA is more sensitive than RT-LAMP, and it is a good alternative for the development of point-of-care tests for SARS-CoV-2 detection as this method is simple, inexpensive, practical, and does not require qualified personnel to perform the test and interpret its results.

5.
BMC Infect Dis ; 20(1): 308, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32334517

RESUMO

BACKGROUND: Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains. METHODS: Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria. RESULTS: The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 min of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks. CONCLUSION: The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.


Assuntos
Colorimetria/métodos , Corynebacterium diphtheriae/genética , Difteria/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas de Bactérias/genética , Colorimetria/instrumentação , Corynebacterium diphtheriae/isolamento & purificação , Proteínas de Ligação a DNA/genética , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Humanos , Limite de Detecção , Testes Imediatos
6.
Postepy Biochem ; 66(4): 316-322, 2020 12 31.
Artigo em Polonês | MEDLINE | ID: mdl-33470072

RESUMO

Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2), a new highly emerging and pathogenic for human RNA virus, is responsible for the present COVID-19 pandemic. Molecular diagnostic methods, including real-time reverse transcription-PCR (RT-PCR) assay are the recommended methods for the identification and laboratory confirmation of COVID-19 cases. RT-PCR allows for detection the RNA of the virus in clinical specimens from patients suspected of COVID-19 with high specificity and sensitivity. Testing is still crucial for rapid detection of infected persons, implementation of appropriate measures to suppress further virus transmission and mitigate its impact. In response to demand of a molecular diagnostic test for SARS-CoV-2, within a first few months ongoing pandemic many commercial kits has become available on the market. However, these tests have varied in number and type of molecular targets, time of reaction as well as quality. In this study we compared different commercial tests for the detection of SARS-CoV-2 in clinical samples sending to Laboratory of Department of Virology, NIPH-NIH.


Assuntos
COVID-19 , COVID-19/diagnóstico , Teste para COVID-19 , Humanos , SARS-CoV-2
7.
Ticks Tick Borne Dis ; 11(2): 101322, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31711731

RESUMO

We investigated the genotypes of Francisella tularensis (F. tularensis) strains isolated in Poland during the period 1953-2013 and studied their genetic relationship to F. tularensis strains isolated in other countries using MLVA. We examined the mosquito and tick samples collected in Poland for the presence of F. tularensis DNA using PCR. Our results revealed a high genetic diversity among the strains of F. tularensis collected from Poland, suggesting that the bacterium is commonly found in the environment. However, we did not detect F. tularensis DNA in ticks and mosquitoes, showing that the arthropod bites might not be the main source of infection. We also propose the application of a practical assay called v4-genotyping that can be directly performed on the clinical and environmental samples. In addition, we discovered genetic variations among Schu S4 reference strains used in various laboratories and showed that MLVA analysis should not be based on amplicon sizes only because point mutations occurring within the MLVA loci might not always be manifested by a change in the amplicon size.


Assuntos
Francisella tularensis/genética , Variação Genética , Técnicas de Genotipagem/métodos , Repetições Minissatélites , Tipagem de Sequências Multilocus/instrumentação , Polônia
8.
Anal Biochem ; 560: 60-66, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30217500

RESUMO

The recently developed methods of nucleic acids isothermal amplification are promising tools for point-of-care diagnostics and in the field detection of pathogenic microorganisms. However, application of these methods outside a laboratory faces some challenges such as the rapid and sensitive detection of amplified products and the absence of cross-reactivity with genetically related microorganisms. In the presented study we compared three methods of isothermal DNA amplification loop-mediated isothermal amplification (LAMP), recombinase polymerase amplification (RPA) and thermophilic helicase-dependent isothermal DNA amplification (tHDA), for detection of highly dangerous pathogens, such as Bacillus anthracis, Francisella tularensis and Yersinia pestis, and combined them with lateral flow dipsticks for the rapid visualization of amplified products. We observed low specificity of the three methods for B. antharcis, medium for Y. pestis and high for F. tularensis detection. Sensitivity and the detection limit were high and comparable for all the methods. We concluded that the lateral flow dipsticks have been a very useful tool for product detection of the isothermal amplification methods and enable reading the results without the use of any equipment. However, our results showed that the use of isothermal amplification methods is strongly related to the risk of false positive results.


Assuntos
Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Armas Biológicas , Francisella tularensis/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico , Yersinia/isolamento & purificação , Bacillus/classificação , Bacillus/genética , DNA Bacteriano/isolamento & purificação , Francisella tularensis/classificação , Francisella tularensis/genética , Limite de Detecção , Sensibilidade e Especificidade , Yersinia/classificação , Yersinia/genética
9.
Pol J Microbiol ; 67(2): 241-244, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30015465

RESUMO

Francisella tularensis are highly infectious bacteria causing a zoonotic disease called tularemia. Identification of this bacterium is based on antigen detection or PCR. The paper presents a latex agglutination test (LAT) for rapid identification of clinically relevant F. tularensis subspecies. The test can be performed within three minutes with live or inactivated bacteria. The possibility to test the inactivated samples reduces the risk of laboratory acquired infection and allows performing the test under BSL-2 conditions.


Assuntos
Francisella tularensis/patogenicidade , Testes de Fixação do Látex/métodos , Tularemia/diagnóstico , Animais , Francisella tularensis/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase , Zoonoses/diagnóstico , Zoonoses/microbiologia
10.
BMC Infect Dis ; 18(1): 121, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523087

RESUMO

BACKGROUND: Corynebacterium diphtheriae is a re-emerging pathogen in Europe causing invasive infections in vaccinated persons and classical diphtheria in unvaccinated persons. In the presented study we analysed genetic changes in C. diphtheriae isolates collected in Poland from the period before the introduction of the mass anti-diphtheria vaccination to the present time when over 98% of the population is vaccinated. METHODS: A total of 62 C. diphtheriae isolates collected in the 1950s-1960s, 1990s and 2000-2016 in Poland were investigated. Examined properties of the isolates included toxigenic status, presence of tox gene, biotype, MLST type (ST) and type of infection. RESULTS: A total of 12 sequence types (STs) were identified among the analysed C. diphtheriae isolates. The highest variability of STs was observed among isolates from diphtheria and asymptomatic carriers collected in the XX century. Over 95% of isolates collected from invasive and wound infections in 2004-2016 belonged to ST8. Isolates from the XX century represented all four biotypes: mitis, gravis, intermedius and belfanti, but the belfanti biotype appeared only after the epidemic in the 1990s. All except three isolates from the XXI century represented the biotype gravis. CONCLUSIONS: During a diphtheria epidemic period, non-epidemic clones of C. diphtheriae might also disseminate and persist in a particular area after the epidemic. An increase of the anti-diphtheria antibody level in the population causes not only the elimination of toxigenic strains from the population but may also influence the reduction of diversity of C. diphtheriae isolates. MLST types do not reflect the virulence of isolates. Each ST can be represented by various virulent variants representing various pathogenic capacities, for example toxigenic non-invasive, nontoxigenic invasive and nontoxigenic non-invasive.


Assuntos
Corynebacterium diphtheriae/classificação , Corynebacterium diphtheriae/isolamento & purificação , Difteria/epidemiologia , Técnicas de Tipagem Bacteriana , Corynebacterium diphtheriae/genética , Corynebacterium diphtheriae/patogenicidade , Difteria/microbiologia , Surtos de Doenças , Humanos , Tipagem de Sequências Multilocus , Polônia/epidemiologia
11.
Med Dosw Mikrobiol ; 68(3-4): 161-166, 2016.
Artigo em Polonês | MEDLINE | ID: mdl-30376615

RESUMO

INTRODUCTION: Corynebacterium diphtheriae can cause various infections such as diphtheria, wound infections, septic arthritis, bacteraemia and endocarditis. Different virulence properties of the isolates might be related to different virulence factors expressed by the isolates. The objective of this study was to explore whether whole cell protein profiling might be useful in prediction of pathogenic properties of C. diphtheriae isolates. METHODS: C. disphtheriae isolates collected from diphtheria, invasive and local infections and from asymptomatic carriers in Poland, France, New Caledonia and Canada in 1950-2014 were investigated using whole cell protein profile analysis. RESULTS: All the examined isolates were divided into two clades: A and B with similarity about 47%, but clade B was represented by only one isolate. The clade A was divided in two subclades A.I NS .II with similarity 53,2% and then into four groups: A.Ia, A.Ib, A.Ic and A.Id. The comparative analysis did not distinguish clearly toxigenic and nontoxigenic isolates as well as invasive and noninvasive isolates. CONCLUSIONS: Whole cell protein profile analysis of C. diphtheria exhibits good concordance with other genotyping methods but this method is not able to distinguish clearly invasive from non-invasive isolates.


Assuntos
Corynebacterium diphtheriae/patogenicidade , Difteria/metabolismo , Proteínas de Bactérias , Técnicas de Tipagem Bacteriana , Corynebacterium diphtheriae/classificação , Difteria/genética , Eletroforese em Gel de Poliacrilamida , Humanos
12.
Ann Agric Environ Med ; 22(3): 443-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26403111

RESUMO

The study describes four cases of tularaemia - one developed after contact with rabbits and three developed after an arthropod bite. Due to non-specific clinical symptoms, accurate diagnosis of tularaemia may be difficult. The increasing contribution of the arthropod vectors in the transmission of the disease indicates that special effort should be made to apply sensitive and specific diagnostic methods for tularaemia, and to remind health-care workers about this route of Francisella tularensis infections. The advantages and disadvantages of various diagnostic methods - molecular, serological and microbiological culture - are discussed. The PCR as a rapid and proper diagnostic method for ulceroglandular tularaemia is presented.


Assuntos
Francisella tularensis/isolamento & purificação , Tularemia/diagnóstico , Tularemia/transmissão , Adulto , Animais , Antibacterianos/uso terapêutico , Vetores Artrópodes/fisiologia , Criança , Diagnóstico Diferencial , Feminino , Francisella tularensis/efeitos dos fármacos , Humanos , Mordeduras e Picadas de Insetos/microbiologia , Masculino , Pessoa de Meia-Idade , Polônia , Reação em Cadeia da Polimerase , Resultado do Tratamento , Tularemia/tratamento farmacológico , Tularemia/microbiologia
13.
Ann Agric Environ Med ; 21(3): 460-3, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25292110

RESUMO

INTRODUCTION AND OBJECTIVE: Anthrax spores remain viable and infectious in soil for decades. Flood water can percolate towards the surface the spores buried in soil. Moreover, the flood water might transport spores to areas previously unaffected. After the water recedes the spores located on the surface of the ground can be consumed by grazing animals and cause outbreaks of anthrax. MATERIALS AND METHOD: Soil samples were collected in areas of Poland most affected by floods in 2010 (Lubelskie, Swietokrzyskie, Podkarpackie and Mazowieckie provinces). After heating with the aim to kill vegetative forms of bacteria, the samples were cultured on PLET agar and the resulted colonies were investigated in terms of motility and presence of anthrax specific chromosomal (SG-749, plcR) and plasmid markers (capB, pagA). RESULTS: In total, 424 spore-forming, aerobically growing isolates were collected from the tested soil samples. Eighty-nine of them were non-motile. All the isolates were negative in PCR for anthrax specific chromosomal and plasmid markers. CONCLUSIONS: Spores of B. anthracis that could be related to risk of anthrax outbreaks were not detected in soil samples tested in this study. The negative results presented may not be proof that Poland is country free of anthrax. The results, however, may suggest a relatively low risk of anthrax outbreaks being triggered in the sampled areas.


Assuntos
Antraz/epidemiologia , Bacillus anthracis/isolamento & purificação , Microbiologia do Solo , Antraz/microbiologia , Bacillus anthracis/genética , Proteínas de Bactérias/genética , Monitoramento Ambiental , Inundações , Marcadores Genéticos , Polônia/epidemiologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Estações do Ano , Esporos Bacterianos/genética , Esporos Bacterianos/isolamento & purificação
14.
Pol J Microbiol ; 62(4): 453-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24730142

RESUMO

Rapid and accurate diagnostic tools for detection and identification of Y pestis, B. anthracis and F. tularensis are essential for timely initial appropriate treatment of exposed individuals, which will be critical to their survival, as well as for reduction of the public health impact and the spread of the disease. The paper presents application of fast polymerases and fast dry electrophoresis in conventional PCR as an alternative for real-time PCR application for detection and identification of the above pathogens. The proposed method takes less than 50 min. to obtain final results of the tests and is cheaper than real-time PCR.


Assuntos
Bacillus anthracis/isolamento & purificação , Francisella tularensis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Yersinia pestis/isolamento & purificação , Eletroforese/métodos , Fatores de Tempo
15.
Przegl Epidemiol ; 66(3): 389-93, 2012.
Artigo em Polonês | MEDLINE | ID: mdl-23230707

RESUMO

THE AIM: The aim of the studies was analysis of methods applied and results of detection and identification of Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucella sp., Bulkholderia mallei and B. pseudomallei in inactivated samples obtained within the framework of the third external quality assessment exercise (EQAE) in the project ,,Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk (EQADeBa)". MATERIAL AND METHODS: Fifteen samples in the form of water, calf serum and milk spiked with bacteria mentioned above were investigated. Detection and identification of highly pathogenic bacteria were carried out using a PCR technique. RESULTS. Y. pestis, F. tularensis ssp. holarctica, B. anthracis, B. mallei and B. pseudomallei were detected in the investigated samples. The most problematic were samples of milk, probably because of presence of PCR inhibitors such as milk proteins and calcium ions and a low number of bacterial cells contained in the samples. CONCLUSIONS. Inactivation of samples spiked with highly pathogenic microorganisms ensure safety of labora- tory workers, but investigation of such samples needs very precise selection and validation diagnostics methods due to possibility of obtaining false negative results. Results of the third international external quality assessment exercise have confirmed competences of laboratory of Department of Bacteriology NIZP-PZH in the area of detection and identification highly pathogenic bacteria covered by the EQAE.


Assuntos
Bioterrorismo , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Leite/microbiologia , Soro/microbiologia , Microbiologia da Água , Animais , Bacillus anthracis/isolamento & purificação , Brucella/isolamento & purificação , Burkholderia mallei/isolamento & purificação , Burkholderia pseudomallei/isolamento & purificação , Bovinos , Francisella tularensis/isolamento & purificação , Bactérias Gram-Negativas/patogenicidade , Bactérias Gram-Positivas/patogenicidade , Viabilidade Microbiana , Virulência , Yersinia pestis/isolamento & purificação
16.
Med Dosw Mikrobiol ; 64(2): 101-8, 2012.
Artigo em Polonês | MEDLINE | ID: mdl-23072054

RESUMO

INTRODUCTION: Bacillus genus comprises about 215 species. The most closely related are B. cereus, B. thuringiensis, B. anthracis, B. mycoides, B. pseudomycoides and B. weihenstephanensis. These bacterial species belong to the Bacillus cereus group. Identification and differentiation of Bacillus cereus group bacteria is difficult because of genetic and phenotypic similarity. Many molecular methods have already been suggested to differentiate B. cereus group members. However easier and more convenient methods are still sought. The aim of this study was to evaluate of multiplex PCR method to identify and distinguish strains of Bacillus cereus group, as proposed by Park et al. (J Microbiol Biotechnol 2007; 17: 1177-82). MATERIALS AND METHOD: Twenty four strains of Bacillus cereus group included B. cereus, B. anthracis, B. thuringiensis and B. weihestephanensis was examined. A multiplex-PCR assay for the differentiation of the species has been applied by using three pairs specific oligonucleotide primers based on sequences of gyrB genes which identify species from Bacillus cereus group and one pair specific primers based on sequences of groEL gene, which are used to identify Bacillus cereus group. RESULTS: Using a specific primers complementary to fragment of groEL gene, we received all PCR products and thus we identified Bacillus cereus group. We have not recived a specific products characteristic for each of the species. Oligonucleotide primers recognized by Park et al. as specific for each species were complementary (often 100%) for the gyrB gene sequence in almost all species of the B. cereus group. CONCLUSIONS: The multiplex PCR method proposed by Park et al. multiplex PCR method for identification ofB. cereus group and individual bacterial species has been proved to be useful only for identification the entire group of B. cereus. This method does not provide specific identification of the individual species. Lack of specificity of the primers used in this study creates a risk of obtaining PCR product in more than one species of the entire examined group of bacteria and does not allow the precise identification to the species level.


Assuntos
Bacillus cereus/classificação , Bacillus cereus/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Bacillus cereus/genética , Especificidade da Espécie
17.
Med Dosw Mikrobiol ; 64(1): 19-27, 2012.
Artigo em Polonês | MEDLINE | ID: mdl-22808726

RESUMO

INTRODUCTION: Adhesion of pathogenic bacteria to host cells is a crucial step during infection. The presence of specific adhesion factors on the bacterial cell surface determines the tropism of the pathogen to the tissues expressing certain surface receptors. The adhesion is mediated primarily by filamentous structures called pili. Three distinct pilus structures can be produced by Corynebacterium diphtheriae: SpaA-, SpaD- and SpaH-type pili. Pilus genes encode a total of nine pilus proteins, named SpaA through SpaI, and six sortases, named SrtA through SrtF. All the pilus genes are located on pathogenicity islands and can be acquired and lost by different strains. The aim of presented studies was assessment of occurence of pili genes among C. diphtheriae strains isolated from different infections, including invasive infections, in Poland. METHODS: Thirty-one toxigenic and nontoxigenic C. diphtheriae strains isolated from wounds, blood, nose and pharynx were investigated for presence of 15 pili genes. The studies were conducted using PCR. Gene specific primers were designed on the basis of the complete genome sequence of C. diphtheriae NCTC 13129. RESULT: All the nontoxigenic C. diphtheriae strains isolated from invasive infections possess every tested genes in contrast to toxigenic strains that revealed highly mosaic structure of pili gene clusters. Differences in gene content were detected in SpaA- and SpaH-type pili gene clusters. Complete set of genes in SpaD-type pili gene cluster was detected in all but two strains. The two strains did not possess any of SpaD-type pili genes. CONCLUSIONS: Invasiveness of C. diphtheriae strains could be related to adhesive factors. Results of our studies suggest that ability to express all types of pili is indispensable for causing invasive infections by nontoxigenic C. diphtheriae. Whereas full set ofpili genes is not necessary for causing classical diphtheria.


Assuntos
Adesinas Bacterianas/genética , Aderência Bacteriana/genética , Infecções por Corynebacterium/microbiologia , Corynebacterium diphtheriae/classificação , Corynebacterium diphtheriae/genética , Sequência de Bases , Corynebacterium diphtheriae/isolamento & purificação , Corynebacterium diphtheriae/patogenicidade , Difteria/microbiologia , Humanos , Dados de Sequência Molecular , Especificidade da Espécie
18.
Ann Agric Environ Med ; 19(1): 69-74, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22462448

RESUMO

The aim of current studies was to validate the direct plating of a stool sample for Listeria monocytogenes detection, using selective medium Palcam agar with Palcam selective supplement. Validation was performed using stool samples collected from healthy humans inoculated with Listeria sp. strains. Stool samples were frozen to determine the influence of freezing on method robustness. The presented research defines the Listeria monocytogenes limit of detection (LOD) as 10(3) cfu/g of stools for fresh and frozen samples. Repeatability and reproducibility of the method has been confirmed using statistical methods. We show the effectiveness of direct plating of stool samples on Palcam agar with Palcam selective supplement collected for Listeria monocytogenes detection. This method could be useful for this pathogen detection in stool samples collected from patients with diarrhoea.


Assuntos
Ágar/química , Técnicas Bacteriológicas/métodos , Meios de Cultura/química , Fezes/microbiologia , Listeria monocytogenes/isolamento & purificação , Criança , Contagem de Colônia Microbiana , Enterococcus faecalis/isolamento & purificação , Escherichia coli/isolamento & purificação , Humanos , Limite de Detecção , Listeria/isolamento & purificação , Listeria monocytogenes/classificação , Reprodutibilidade dos Testes , Staphylococcus aureus/isolamento & purificação
19.
Przegl Epidemiol ; 65(3): 401-7, 2011.
Artigo em Polonês | MEDLINE | ID: mdl-22184939

RESUMO

Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucella sp., Bulkholderia mallei are B. pseudomallei are highly pathogenic bacteria of potential bioterrorism risk. To support the early warning and rapid response capacity to ensure an effective reaction to bioterrorist attacks the international project "Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk" (EQADeBa) has been established. The aim of the project was establishment the network of European laboratories that possess a suitable infrastructure and experts and laboratory workers trained in detection and identification of the highly pathogenic bacteria. This work presents methods used in investigation of samples containing living pathogens and results obtained in Department of Bacteriology NIZP-PZH in the third international test organized within the framework of the EQADeBa. The test evaluated competence of laboratories in detection and identification of pathogens mentioned above. In the work methods used in other laboratories were discussed and the results were compared. Results of the test confirmed competence of NIZP-PZH in detection and identification of highly pathogenic bacteria covered by EQADeBa project.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Bioterrorismo/prevenção & controle , Substâncias Perigosas/isolamento & purificação , Bacillus anthracis/isolamento & purificação , Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Brucella/isolamento & purificação , Burkholderia pseudomallei/isolamento & purificação , Europa (Continente) , Francisella tularensis/isolamento & purificação , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Polônia , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Yersinia pestis/isolamento & purificação
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