Productive infection and transduction by bacteriophage P1 in the species Salmonella bongori

Background: Horizontal gene transfer (HGT) is the most important mechanism in the evolution of new genetic capabilities in bacteria, including specific degradative pathways, virulence factors, and resistance to antibiotics. Among the processes involved in HGT, transduction is noteworthy. This is a mechanism for gene transmission mediated by a bacteriophage that functions both as a reservoir and as a vector of exogenous genes, which remain protected from environmental effects in the bacteriophage's capsid. Within this context, this investigation aimed to evaluate the ability of the generalized transducing bacteriophage P1 to productively infect and transduce in the bacterial species Salmonella bongori. Results: We could establish that a derivative of bacteriophage P1, P1Cm, infects strains of S. bongori with frequencies of lysogenization in the order of ~10−2 lysogens/UFP. Through thermal induction, infective viral progeny was obtained, and we could show that P1Cm readily formed plaques on S. bongori lawns, a phenomenon thus far not reported for other members of the genus Salmonella. Finally, we showed P1Cm-mediated transduction of the model plasmid RP4 at frequencies of ~10−7 transductants/donor. Conclusion: Therefore, bacteriophage P1 can be used as a tool for the genetic manipulation in the species S. bongori.

Studies published in indexed journals on lawsuits for medicines in Brazil: a systematic review / Estudios publicados en revistas indexadas acerca de decisiones judiciales para el acceso a los medicamentos en Brasil: una revisión sistemática / Estudos publicados em periódicos indexados sobre decisões judiciais para acesso a medicamentos no Brasil: uma revisão sistemática

The aim of this systematic review was to identify and characterize articles in indexed scientific journals with quantitative data surveys on administrative or legal proceedings for access to medicines. The SciELO, LILACS, MEDLINE via PubMed, Embase, and Scopus databases were used. We identified 45 articles, of which 17 were selected. The larger studies, each covering between 2,000 and 2,927 lawsuits, were done in the states of São Paulo, Rio de Janeiro, and Santa Catarina, Brazil. Eleven studies specified the type of legal representation, of which six examined cases with public attorneys and five with private attorneys. Only two studies reported whether the lawsuit was individual or class action, and in both the claims were individual. Since the majority of the medicines requested in the lawsuits were medium to high-cost, the review indicates that lawsuits contributed to the incorporation of these drugs into current pharmaceutical care in Brazil.

El objetivo de esta revisión sistemática fue identificar y caracterizar los artículos disponibles en revistas científicas indexadas en bases de datos electrónicas, que llevaron a cabo un estudio cuantitativo de datos, procedimientos administrativos o judiciales sobre la cuestión del acceso a los medicamentos a través de demandas judiciales. Los estudios fueron localizados en las bases de datos SciELO, LILACS, MEDLINE vía PubMed, Embase, Scopus. Se identificaron 45 artículos, de los cuales se seleccionaron 17. Los estudios que se llevaron a cabo engloban de 2.000 a 2.927 procesos judiciales en São Paulo, Río de Janeiro y Santa Catarina, Brasil. En once estudios se realizaron encuestas a los representantes legales de la acción judicial. En seis estudios predominó la representación pública legal y en cinco abogados privados. Sólo dos estudios examinaron si la acción era individual o colectiva y en los dos hubo prevalencia de acciones individuales. Como la mayoría de los medicamentos estaba involucrada en acciones legales de medio y alto coste, se cree que las demandas han contribuido a la incorporación de fármacos en la política pública actual.

O objetivo desta revisão sistemática foi identificar e caracterizar artigos disponíveis em periódicos científicos indexados em bases eletrônicas, que realizaram levantamento de dados quantitativo, em processos administrativos ou judiciais, sobre a questão do acesso a medicamentos por meio de ações judiciais. Foram usadas as bases de dados SciELO, LILACS, MEDLINE via PubMed, Embase e Scopus. Identificamos 45 artigos, dos quais foram selecionados 17 artigos. Os estudos com faixa de 2.000 a 2.927 processos foram conduzidos em São Paulo, Rio de Janeiro e Santa Catarina, Brasil. Em 11 estudos foram pesquisadas qual a representação jurídica da ação. Em seis estudos predominaram a representação de advogados públicos e em cinco particulares. Somente dois estudos observaram se a ação era coletiva ou individual, sendo que nas duas pesquisas a prevalência era de ações individuais. Como a maioria dos medicamentos envolvidos nas ações é de médio e alto custo, acredita-se que as demandas judiciais tenham contribuído para incorporação de medicamentos nas ações de assistência farmacêutica atuais.

Detecção de anticorpos séricos produzidos contra as proteínas do bacteriófago 17 do Aggregatibacter actinomycetemcomitans / Serum antibody detection against Aggregatibacter actinomycetemcomitan's bacteriophage 17 proteins

Aggregatibacter actinomycetemcomitans (Aa) é uma bactéria associada à Periodontite Agressiva (PA). Ela invade tecidos moles, com ocorrência de lisogenia e bacteriófagos presentes em até 69% das subespécies. Estudos in vitro sugerem que a indução do bacteriófago (Aa17) ocorre numa co-cultura de Aa lisogênico com fibroblastos humanos. Se esta interação ocorre in vivo, com liberação do vírus, uma reação imunológica contra o Aa17 aconteceria. O objetivo deste estudo é constatar se anticorpos (AC) contra proteínas do Aa17 existem e estão associados à doença periodontal. Um objetivo adicional foi testar a resposta de AC contra os sorotipos do Aa. 52 indivíduos participaram: 31 com PA, 5 com Periodontite Crônica (PC) e 16 com Periodonto Saudável (PS). Soro foi coletado após a classificação clínica. As proteínas do Aa17 foram obtidas de preparações purificadas. As subespécies do Aa utilizadas para amostras de proteínas através de sonicação foram: 43717(American Tissue Culture Collection - ATCC) – sorotipo A, 43718 (ATCC) – sorotipo B, 33384 (ATCC) – sorotipo C, IDH781 – sorotipo D, NJ9500 – sorotipo E and CU1000 – sorotipo F. As proteínas foram separadas em géis de poliacrilamida e transferidas para membranas de nitrocelulose. As reações de Western-blotting ocorreram com o AC primário sendo o soro de cada indivíduo. Todas as membranas foram lidas pelo sistema Odyssey que captura sinais no AC secundário (antihumano). A resposta de AC contra ao menos uma proteína do Aa17, assim como pelo menos um sorotipo do Aa foi observado em todos, com exceção de dois indivíduos (com PS), participantes. Um indivíduo do grupo PC e três do PA tiveram resposta de AC contra alguns, mas não todos os sorotipos do Aa. A resposta de AC contra todos os sorotipos foi o achado mais comum nos grupos PA (28/31), PS (14/16) e PC (4/5). A resposta de AC contra o complexo de proteínas do Aa17 foi observado em 7 indivíduos...

Aggregatibacter actinomycetemcomitans (Aa) is a bacteria associated with Aggressive Periodontitis (AP). It invades soft tissues, with occurrence of lysogeny and bacteriophage presence up to 69% of Aa subspecies. In vitro studies suggested that bacteriophage (Aa17) induction occurs upon co-culture of Aa lysogens subspecies with human fibroblasts. If such an in vivo interaction resulted in Aa17 induction and release of virions, an immunologic reaction to Aa17 proteins could ensue. The purpose of this investigation was to learn whether serum antibodies (AB) to Aa17 proteins are found in human sera, and whether they are associated with periodontal disease. An additional purpose was to test the AB response against known Aa serotypes.52 individuals took part: 31 with AP, 5 with Chronic Periodontitis (CP) and 16 with a Healthy Periodontium (HP). Serum was collected after clinical classification. Aa17 proteins were obtained from purified Aa17 preparations. The Aa strains used for protein sampling through sonication were: 43717(American Tissue Culture Collection - ATCC) – serotype A, 43718 (ATCC) – serotype B, 33384 (ATCC) – serotype C, IDH781 – serotype D, NJ9500 – serotype E and CU1000 – serotype F. Proteins were separated by SDS-PAGE gels and then transferred to nitrocellulose membranes. Western-blotting reactions were carried out with the primary AB being each subject’s serum. All membranes were read through the Odyssey system which captures signals from a dye in a secondary (antihuman) AB. AB response against at least one Aa17 protein, as well as a response to at least one Aa serotype, was observed in all but two individuals (with HP) who participated in the study. Serum from one individual from the CP group and three from the AP group had AB response to some, but not all Aa serotypes. AB response against all Aa serotypes was the most common finding in AP (28/31), HP (14/16) and CP (4/5) groups. AB response to the full complex...

Detecção de anticorpos séricos produzidos contra as proteínas do bacteriófago 17 do Aggregatibacter actinomycetemcomitans / Serum antibody detection against Aggregatibacter actinomycetemcomitan's bacteriophage 17 proteins

Aggregatibacter actinomycetemcomitans (Aa) é uma bactéria associada à Periodontite Agressiva (PA). Ela invade tecidos moles, com ocorrência de lisogenia e bacteriófagos presentes em até 69% das subespécies. Estudos in vitro sugerem que a indução do bacteriófago (Aa17) ocorre numa co-cultura de Aa lisogênico com fibroblastos humanos. Se esta interação ocorre in vivo, com liberação do vírus, uma reação imunológica contra o Aa17 aconteceria. O objetivo deste estudo é constatar se anticorpos (AC) contra proteínas do Aa17 existem e estão associados à doença periodontal. Um objetivo adicional foi testar a resposta de AC contra os sorotipos do Aa. 52 indivíduos participaram: 31 com PA, 5 com Periodontite Crônica (PC) e 16 com Periodonto Saudável (PS). Soro foi coletado após a classificação clínica. As proteínas do Aa17 foram obtidas de preparações purificadas. As subespécies do Aa utilizadas para amostras de proteínas através de sonicação foram: 43717(American Tissue Culture Collection - ATCC) – sorotipo A, 43718 (ATCC) – sorotipo B, 33384 (ATCC) – sorotipo C, IDH781 – sorotipo D, NJ9500 – sorotipo E and CU1000 – sorotipo F. As proteínas foram separadas em géis de poliacrilamida e transferidas para membranas de nitrocelulose. As reações de Western-blotting ocorreram com o AC primário sendo o soro de cada indivíduo. Todas as membranas foram lidas pelo sistema Odyssey que captura sinais no AC secundário (antihumano). A resposta de AC contra ao menos uma proteína do Aa17, assim como pelo menos um sorotipo do Aa foi observado em todos, com exceção de dois indivíduos (com PS), participantes. Um indivíduo do grupo PC e três do PA tiveram resposta de AC contra alguns, mas não todos os sorotipos do Aa. A resposta de AC contra todos os sorotipos foi o achado mais comum nos grupos PA (28/31), PS (14/16) e PC (4/5). A resposta de AC contra o complexo de proteínas do Aa17 foi observado em 7 indivíduos ...

Aggregatibacter actinomycetemcomitans (Aa) is a bacteria associated with Aggressive Periodontitis (AP). It invades soft tissues, with occurrence of lysogeny and bacteriophage presence up to 69% of Aa subspecies. In vitro studies suggested that bacteriophage (Aa17) induction occurs upon co-culture of Aa lysogens subspecies with human fibroblasts. If such an in vivo interaction resulted in Aa17 induction and release of virions, an immunologic reaction to Aa17 proteins could ensue. The purpose of this investigation was to learn whether serum antibodies (AB) to Aa17 proteins are found in human sera, and whether they are associated with periodontal disease. An additional purpose was to test the AB response against known Aa serotypes.52 individuals took part: 31 with AP, 5 with Chronic Periodontitis (CP) and 16 with a Healthy Periodontium (HP). Serum was collected after clinical classification. Aa17 proteins were obtained from purified Aa17 preparations. The Aa strains used for protein sampling through sonication were: 43717(American Tissue Culture Collection - ATCC) – serotype A, 43718 (ATCC) – serotype B, 33384 (ATCC) – serotype C, IDH781 – serotype D, NJ9500 – serotype E and CU1000 – serotype F. Proteins were separated by SDS-PAGE gels and then transferred to nitrocellulose membranes. Western-blotting reactions were carried out with the primary AB being each subject’s serum. All membranes were read through the Odyssey system which captures signals from a dye in a secondary (antihuman) AB. AB response against at least one Aa17 protein, as well as a response to at least one Aa serotype, was observed in all but two individuals (with HP) who participated in the study. Serum from one individual from the CP group and three from the AP group had AB response to some, but not all Aa serotypes. AB response against all Aa serotypes was the most common finding in AP (28/31), HP (14/16) and CP (4/5) groups. AB response to the full complex ...

Effect of bacteriophage lysin on lysogens

<p><b>OBJECTIVE</b>To study the effect of phage lysin on the growth of lysogens.</p><p><b>METHODS</b>Sputum specimens processed by modified Petroff's method were respectively treated with phagebiotics in combination with lysin and lysin alone. The specimens were incubated at 37 °C for 4 days. At the end of day 1, 2, 3 and day 4, the specimens were streaked on blood agar plates and incubated at 37 °C for 18-24 hours. The growth of normal flora observed after day 1 was considered as lysogens.</p><p><b>RESULTS</b>Sputum specimens treated with phagebiotics-lysin showed the growth of lysogens. When specimens treated with lysin alone, lysogen formation was avoided and normal flora was controlled.</p><p><b>CONCLUSIONS</b>Lysin may have no effect on the growth of lysogens.</p>

Assessment of genotoxicity and cytotoxicity of "lixeira" (Curatella americanaL. ) using the prophage λ induction test (SOS inductest) / Avaliação da genotoxicidade e citotoxicidade de "lixeira" (Curatella americana L.) utilizando o teste de indução profago λ (teste de indução SOS)

Curatella americana L., commonly known as "lixeira" in Brazil, has been used in folk medicine to treat ulcers and inflammations. The purpose of the present work was to evaluate the cytotoxic and genotoxic potential of the ethanolic extract of C. americana stem bark using the prophage λ induction test (SOS inductest). To evaluate the cytotoxicity of this plant, after treatment with different concentrations of the extract, Escherichia coli WP2s(λ) cultures were diluted in M9 buffer, inoculated into LB plates, and incubated for 24 h at 37 ºC. To assess genotoxicity, the lysogenic strain E. coli WP2s(λ) was treated with different concentrations of the extract. Then, the lysogenic strain was added to the indicator strain (RJF013), LB(1/2)(malt/amp), seeded into plates with the matches, and incubated for 24 h at 37 ºC. After this period, the total number of colonies and the number of plaques were counted to evaluate C. americana cytotoxicity and genotoxicity, respectively. Our results showed that although the extract of "lixeira" did not modify the survival of bacteria (p > 0.05), it caused a significant increase in prophage λ induction, especially at the higher concentrations (p<0.05). Therefore, we conclude that the ethanolic extract of C. americana stem bark did not present cytotoxic effect, but some genotoxic potential was observed.

Curatella americana L., comumente conhecida como "lixeira" no Brasil, é utilizada em medicina popular para tratamento de úlceras e inflamações. O presente trabalho teve como objetivo avaliar o potencial citotóxico e genotóxico do extrato etanólico das cascas de C. americana utilizando o Induteste SOS. Para avaliar a citotoxicidade da planta, depois de tratadas com diferentes concentrações do extrato, culturas de E. coli WP2s(λ) foram diluνdas em tampão M9 e semeadas em placas LB. Para avaliar a genotoxicidade da planta, a cepa lisogênica WP2s(λ) de E. coli foi tratada com diferentes concentrações do extrato. Em seguida, esta foi adicionada à cepa indicadora (RJF013) e ambas foram semeadas em placas em meio LB(1/2)(malt)(amp). Todas as culturas foram incubadas por 24 h a 37 ºC. Posteriormente, o número total de colônias e o número de centros infecciosos foram computados para a avaliação da citotoxidade e da genotoxicidade desta planta, respectivamente. Os resultados mostraram que embora o extrato de C. americana não tenha modificado a sobrevivência bacteriana (p > 0,05), provocou aumento significativo (p < 0,05) na indução do profago λ, especialmente nas concentrações mais altas. Assim, concluiu-se que o extrato etanólico das cascas de C. americana não apresentou atividade citotóxica, mas foi observada ação genotóxica direta.

Subclassification and targeted characterization of prophage-encoded two-component cell lysis cassette.

Bacteriophage induced lysis of host bacterial cell is mediated by a two component cell lysis cassette comprised of holin and lysozyme. Prophages are integrated forms of bacteriophages in bacterial genomes providing a repertoire for bacterial evolution. Analysis using the prophage database (http://bicmku.in:8082) constructed by us showed 47 prophages were associated with putative two component cell lysis genes. These proteins cluster into four different subgroups. In this process, a putative holin (essd) and endolysin (ybcS), encoded by the defective lambdoid prophage DLP12 was found to be similar to two component cell lysis genes in functional bacteriophages like p21 and P1. The holin essd was found to have a characteristic dual start motif with two transmembrane regions and C-terminal charged residues as in class II holins. Expression of a fusion construct of essd in Escherichia coli showed slow growth. However, under appropriate conditions, this protein could be over expressed and purified for structure function studies.The second component of the cell lysis cassette, ybcS, was found to have an N-terminal SAR (Signal Arrest Release) transmembrane domain. The construct of ybcS has been over expressed in E.coli and the purified protein was functional, exhibiting lytic activity against E.coli and Salmonella typhi cell wall substrate. Such targeted sequence- structure-function characterization of proteins encoded by cryptic prophages will help understand the contribution of prophage proteins to bacterial evolution.

Nodulation competitiveness between contrasting phage phenotypes of pigeonpea rhizobial strains.

Competitiveness between (I) lysogenic vs. phage-indicator strains, (II) phage-resistant vs phage-sensitive strains, and (III) large plaque vs. small plaque developing strains was examined under laboratory and field conditions in order to study the involvement of these crucial phage sensitivity patterns in the competition for nodule occupancy of pigeonpea rhizobia. The phage-indicator strain (A039) exhibited higher competitiveness over the lysogenic strain (A025 Sm(r)); the phage sensitive strain (IHP-195) over the phage resistant strain (IHP 195 Sm(r)V(r)); and the large plaque developing strain (A059) over the small plaque developing strain (IHP195 Sm(r)) in association with pigeonpea cv. bahar both under laboratory and field conditions. Dual inoculation of A025 Sm(r) + A039 and A059 + IHP195 Sm(r) (mixed in equal proportion just before treatment) improved the nodule occupancy by inoculant strains against native rhizobia and resulted into higher plant dry weight and yield as compared to their application as single inoculum. The phage-resistant mutant IHP195 Sm(r)V(r) showed reduced competitiveness against native rhizobia, compared to its parental strain. The dual inoculation of parental strain and phage-resistant mutant gave the same result as the inoculation of parental strain alone.

Isolation of Salmonella senftenberg bacteriophages.

A total of 61 bacteriophages were isolated from 100 strains of Salmonella senftenberg. Six bacteriophages were selected for typing purposes which were specific for S. senftenberg. Five phages, SasL1 to SasL5 were morphologically similar; phage SasL6 was morphologically different from the others. These phages fall into two morphological groups none of which correspond to the known tailed enterobacterial phage species. Hence, two new phage species represented by SasL1 and SasL6 are proposed.

Development of a conjoint phage typing & biotyping schema for Salmonella enterica serovar Senftenberg (S. senftenberg) & the correlation of biotypes with phage types.

A total of 287 strains of S. senftenberg received from various parts of India during 1969 to 1992 were phage typed using six lysogenic phages. The typability was 90.3 per cent and 14 different phage types could be defined excluding a small group of untypable strains. A biotyping scheme was developed utilising six characters and 13 biotypes could be defined. Stern's glycerol medium proved to be the best discriminatory medium. Diversity indeces of phage typing and biotyping schemes were 0.868 and 0.503 respectively. Better discrimination was obtained when phage types were subdivided into different biotypes with a diversity index of 0.931. The schemes were found stable, reproducible and epidemiologically useful.

Mutagenic and genotoxic effects of mate (Ilex paraguariensis) in prokaryotic organisms

1. The mutagenic and genotoxic effects of mate (Ilex paraguariensis) aqueous solutions were analyzed in bacterial cells. 2. Mate solutions showed mutagenic activity in the Ames test (TA97, TA98, TA100 and TA102 strains) at concentrations of 20 to 50 mg/plate (mutagenic factors of 3.5 to 5.6) and genotoxic activity in the inductest (WP2s (lambda) strain), with a maximal phage induction at concentrations of 10 to 20 mg/plate. Above these concentrations the mate solutions were cytotoxic. 3. Addition of 5 U/ml catalase, 20 microliters/ml S9 rat liver microsomal fraction, 100 mM thiourea or 10 mM dipyridyl completely inhibited the lysogenic induction produced by mate; however, the addition of 1,000 U/ml superoxide dismutase was almost ineffective. 4. Oxygen reactive species may be present in mate solutions playing an essential role in its genotoxicity.

Producción y análisis de proteínas recombinantes obtenidas de la cepa lisogénica Ro-531

La expresión del cDNA que codifica al antígeno Ro, fue evaluada usando la clona Ro=531 gt11 cuyos productos de traducción fueron inmunorreconocidos por un suero anti-Ro. La producción de proteína Ro recombinante, fue inducida en la cepa lisogénica E. coli Y1089. La antigenicidad de la proteína fue probada por Western blot y por ELISA. En la primera prueba, 15 de los 20 sueros anti-Ro positivos presentaron fuerte reactividad a la proteína de funsión Ro y 4 de los 20 sueros controles, mostraron reactividad débil. Por la técnica de ELISA, se observó una reacción más específica, ya que 15 de los 20 sueros anti-Ro positivos exhibieron afinidad por la proteína Ro recombinante y ninguno de los controles presentó falsos positivos

Lisogenia e resistência à tetraciclina em estreptococos do grupo A / Lysogeny and resistance to tetracycline in streptococco group A

Lisogenia em amostras de estreptococos do grupo A foi examinada. Verificou-se que entre as lisogênicas a resistência a tetraciclina era mais comum

Genetical studies on Erwinia carotovora III Lyse induction in relation to soft-rot disease in potatoes

Lysogenic isolates were found among mutants and transformants as phage could be isolated. Probably 16 physiologic species of E. carotovora with different genetic backgrounds on three potato cultivars; Alpha, Claudia and Ajax, were obtained using Waldee [1945] method of pathogenicity test. Stabbing method with alpha potato cultivar gave similar results for pathogenicity. No correlation between mutants requirements and isolates virulence was noticed. Highly pathogenic strains were highly lysogenic and those which were unstable lysogenic or lyse were avirulent