Research progress on the pathogenicity of Porphyromonas gingivalis clinical strains / 口腔疾病防治

@#Porphyromonas gingivalis (P. gingivalis) is closely related to the occurrence and development of periodontitis. It is considered to be one of the important pathogens leading to alveolar bone resorption. At present, research on P. gingivalis mostly adopts standard laboratory strains whose genetic characteristics have been confirmed, are guaranteed and are traceable, such as ATCC 33277. The virulence phenotypes (endotoxin, firmbria, etc.) of clinically extracted isolates are quite different from those of standard strains, and the pathogenic effects and ability of the host are also widely different. In addition, P. gingivalis is considered to have a significant correlation with a variety of systemic diseases, and the virulence characteristics and pathogenic ability of different strains will have different effects on systemic diseases. However, at present, there is a lack of research on clinical strains and standard strains, and there is a lack of systematic comparison between the two sources of bacteria. In this paper, the differences in the virulence phenotypes and pathogenic effects between clinical isolates and standard strains of P. gingivalis in the last 5-10 years are reviewed. The aim is to elucidate the important virulence gene loci in the P. gingivalis gene sequence, which will play an important role in improving therapeutic methods and the development of related drugs.

Research progress on invasion-related virulence factors in Porphyromonas gingivalis / 中华口腔医学杂志

Porphyromonas gingivalis (Pg) is a kind of gram-negative obligate anaerobes. It can invade and internalize within host cells. The invasion ability of Pg is very important for the occurrence and development of diseases and has been a hot topic for a long time. Remaining pathogenic characteristics in cell is one of its pathogenesis. In the process of invading host, the specific bacterial adhesin combine with the ligand of host cells, which activate various signal transduction pathways and trigger bacterial internalization. Virulence factors in Pg, such as fimbriae, gingival protease, hemagglutinins and outer membrane vesicles play significant roles in the process. This review summarized the research progress of the virulence factors which relate to Pg′s invasion, which provided a serious of new ideas on exploring Pg′s pathogenesis and the prevention and treatment of related diseases.

Research progress in the pathogenic mechanisms of Porphyromonas gingivalis fimbriae / 中华口腔医学杂志

FimA has been characterized as an important virulence factor for Porphyromonas gingivalis (Pg). These structures play a major role in the mechanisms of adhesion and invasion of Pg to host cells, and can induce cellular activation and cytokines release. FimA can also promote biofilm formation and induce immuno-inflammatory response of host cells. Many studies have characterized FimA to be associated with periodontitis and cardiovascular disease. Pg strains are classified into six types based on divergent nucleotide sequences of the fimA gene (types Ⅰ、Ⅰb、Ⅱ、Ⅲ、Ⅳ andⅤ). The expression of fimbriae is regulated by the fimA gene, which may be the key factor that leads to virulence diversities of Pg, At present, the research on the pathogenesis of FimA mainly focuses on periodontitis and atherosclerosis, which is of great significance for the prevention and treatment of diseases. This paper reviewed the pathogenic effect of FimA in the development of above mentioned two diseases and its application in the prevention.

FimA plasmid construction and protein purification of Porphyromonas gingivalis / 实用口腔医学杂志

Objective: To construct gine expression plasmid and to purify the protein of fimbriae(FimA) of Porphyromonas gingivalis (P. gingivalis). Methods: The bacteria DNA was extracted from P. gingivalis by using commercial kit. FimA gene was cloned after PCR. Plasmid was constructed and transformed into competent cells. Optimal conditions of protein induction were chosen. The fusionprotein was purified by Glutathione S-Transferase affinity chromatography. Fusion protein was confirmed by Western blot method. Results: The highest protein expression by the constructed plasmid was obtained at the low temperature and high concentration after 12 hours induction. The protein was confirmed by Western blot. Conclusion: A highly purified P. gingivalis FimA protein was successfully obtained.

Association of fimA genotype to kgp genotype in Porphyromonas gingivalis from infected root canals of primary apical periodontitis / 中华口腔医学杂志

Objective@#To investigate the distribution of fimA and kgp genotypes as well as the common genotype combination of Porphyromonas gingivalis (Pg) in infected root canals of primary apical periodontitis for virulent isolates screening in future.@*Methods@#Thirty-four samples harboring Pg were selected from infected root canals of primary apical periodontitis from patients of the Department of Endodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from June 2013 to September 2015. FimA type-specific primers were used to amplify the samples, revealing the distribution of various fimA genotypes. The genotypes of kgp were obtained by using Mse Ⅰ restriction endonuclease. The prevalence of each genotype and common genotype combinations were then calculated. Pearson's chi-squared test was performed to analyze the correlation between genotype combinations and clinical symptoms and major signs of apical periodontitis. In addition, the bioflim architectures between Pg isolates with different fimA and kgp genotype combinations were observed compared using confocal laser scanning microscope.@*Results@#Among the 34 Pg-positive samples, fimA Ⅱ was the most prevalent genotype [47% (16/34)] followed by fimA Ⅰ [26% (9/34)], while fimA Ⅴ was detected in only one sample. The prevalence of kgp Ⅰ [56% (19/34)] was slightly higher than that of kgp Ⅱ [44% (15/34)]. Both fimA Ⅱ+kgp Ⅰ and fimAⅡ+kgp Ⅱ were the most prevalent genotype combinations [24% (8/34) each]. No significant correlation was found between specific genotype combination and such major clinical manifestations as gingival swelling and sinus tract of dental origin (P>0.05). Three Pg isolates with different genotype combinations were acquired. Isolate A (fimAⅠ+kgpⅠ) formed densest biofilm, while the biofilm of isolate C (fimAⅤ+kgp Ⅰ) was much looser. The biofilm feature of isolate B (fimAⅢ+kgp Ⅱ) fell in between A and C.@*Conclusions@#Pg with fimA Ⅱ was most frequently detected in infected root canals of primary apical periodontitis. The prevalence of Pg with kgp Ⅰ was slightly higher than that with kgp Ⅱ, and fimAⅡ+kgp Ⅰ as well as fimA Ⅱ+kgp Ⅱ were the commonest genotype combinations. According to the comparison of Pg biofilms formed by clinical isolates, it might be possible that different genotype combinations may lead to distinct biofilm architectures.

Distribución gen fimA de Porphyromonas gingivalis en pacientes chilenos con periodontitis crónica / Distribution of fimA genotypes of Porphyromonas gingivalis in Chilean patients with chronic periodontitis

RESUMEN: Antecedentes: Gen fimA de Porphyromonas gingivalis es un importante factor de virulencia asociado al desarrollo y la progresión de periodontitis. Objetivo: Cuantificar los niveles de P. gingivalis y la prevalencia de genotipos fimA en pacientes chilenos con diferentes grados de severidad de periodontitis crónica. Metodología: Se analizaron 135 muestras subgingivales de 45 adultos (15 con leve, 15 con moderada y 15 con periodontitis severa) mediante qPCR para P. gingivalis y genotipos fimA (I-V and Ib). Resultados: Se detectó P. gingivalis en el 73,3% de los pacientes con periodontitis crónica (46,6%, 73,3% y 100% para las formas leve, moderada y severa, respectivamente). El gen fimA se detectó en el 66% de los sujetos positivos para P. gingivalis, siendo el fimA IV y I los genotipos más prevalentes. Además, se detectó fimA IV en el 75% y fimA I en el 62,5% de los casos severos y moderados de periodontitis, respectivamente. Los niveles aumentados de fimA IV se asociaron con periodontitis crónica severa. Conclusiones: Los resultados sugieren una alta prevalencia de P. gingivalis y de sus genotipos fimA IV y I en pacientes con periodontitis crónica. Además fimA IV fue asociado con formas más severas de periodontitis crónica en esta población chilena.

ABSTRACT: Background: Porphyromonas gingivalis fimA gene is a key virulence factor and has been associated with development and progression of periodontal diseases. Aim: To quantify the levels of P. gingivalis and the prevalence of fimA genotypes in Chilean patients with different severity of chronic periodontitis. Methodology: One hundred and thirty five subgingival samples from 45 adults (15 with slight, 15 with moderate and 15 with severe chronic periodontitis, respectively) were analyzed by qPCR for P. gingivalis and fimA genotypes (I-V and Ib). Results: P. gingivalis was detected in 73.3% of patients (46.6%, 73.3% and 100% of patients with slight, moderate and severe chronic periodontitis, respectively). The genotype fimA was detected in 66% of positive subjects for P. gingivalis, whereas fimA IV and I were the most prevalent genotypes. In addition, fimA IV was detected in 75% and fimA I in 62.5% of severe and moderate cases, respectively. Increased levels of fimA IV were associated with severe chronic periodontitis. Conclusions: These findings suggest that there is a high prevalence of P. gingivalis and its fimA IV and I genotypes in chronic periodontitis patients. Furthermore, fimA IV was associated with severe chronic periodontitis in this Chilean population.

Adhesion levels in uropathogenic Escherichia coli with various degree of drug resistance / 中华临床感染病杂志

Objective To investigate the adhesion levels in uropathogenic Escherichia coli with various degree of drug resistance.Methods One hundred strains of Escherichia coli isolated from urine specimen were collected from patients admitted to 4 Grade A tertiary hospitals in Tianjin during March 2012 to October 2015.Escherichia coli were divided into drug sensitive group and drug resistant group by drug sensitivity tests with 50 strains in each group.The expressions of fimH,fimA,fimB genes of type I fimbriae and papA,papB,papC,papGII genes of P fimbriae were detected by polymerase chain reaction(PCR)and real-time fluorescence quantitative RCR (RT-PCR),respectively.Adhesion ability of type I fimbriae and P fimbriae were tested by yeast cell adhesion test and erythrocyte agglutination test.Chi square test and t(Z) test were used to analyze the data.Results The positive rate of papGII in drug resistant group (42.0%) was significantly higher than that in the drug sensitive group (16.0%)(χ2 =8.208,P 0.05).The expression levels of fimH,fimB and papC genes in the sensitive group were higher than those in the resistant group(Z =3.427,t =5.182 and 8.120,all P <0.05).The adhesion ability of strains carrying type I fimbriae in sensitive group was stronger than that of resistant group (χ2 =5.769,P <0.05).Conclusions The decline in adhesion ability of type I fimbriae in drug resistant E.coli strains is possibly associated with the adaptive cost of bacteria,the transcription and deficiency of other genes encoded by fim and pap gene cluster will also affect the adhesion function of type I pili and type P pili.

Prevalence of Porphyromonas gingivalis fimA II genotype in generalized aggressive periodontitis patients

Purpose: The objective of this study was to evaluate the prevalence of Porphyromonas gingivalis (Pg) and its filmA II genotype in a sample of Brazilian patients with generalized aggressive periodontitis (GAgP) and to correlate the presence of each pathogen/genotype eith clinical parameters. Methods: We used polymerase chain reaction (PCR) to evaluate the presence of Pg and filmA II genotype in subgingival plaque samples collected from the deepest site of 45 Brazilian patients aged 15-40 years with GAgP and correlated findings with age and clinical parameters (plaque index, gingival bleeding index, probing depth and clinical attachment loss). Results: Pg was identified in 64.4% patients. FilmA II genotype was present in 82.6% of Pg-positive patients. The presence of Pg and filmA II genotype was significantly associated with greater clinical attachment loss at the sampled periodontal site. Pg-positive patients were slightly older than Pg-negative patients. Conclusions: Pg and filmA II genotype were highly prevalente in Brazilian patients with GAgP. Pg was more commonly observed in slightly older individuals and in sites with more clinical attachment loss. (AU)

Prevalence of Porphyromonas gingivalis fimA genotypes in the peri-implant sulcus of Koreans assessed using a new primer

PURPOSE: Porphyromonas gingivalis fimA is a virulence factor associated with periodontal diseases, but its role in the pathogenesis of peri-implantitis remains unclear. We aimed to evaluate the relationship between the condition of peri-implant tissue and the distribution of P. gingivalis fimA genotypes in Koreans using a new primer. METHODS: A total of 248 plaque samples were taken from the peri-implant sulci of 184 subjects. The control group consisted of sound implants with a peri-implant probing depth (PD) of 5 mm or less with no bleeding on probing (BOP). Test group I consisted of implants with a peri-implant PD of 5 mm or less and BOP, and test group II consisted of implants with a peri-implant PD of more than 5 mm and BOP. DNA was extracted from each sample and analyzed a using a polymerase chain reaction (PCR) with P. gingivalis-specific primers, followed by an additional PCR assay to differentiate the fimA genotypes in P. gingivalis- positive subjects. RESULTS: The Prevalence of P. gingivalis in each group did not significantly differ (P>0.05). The most predominant fimA genotype in all groups was type II. The prevalence of type Ib fimA was significantly greater in test group II than in the control group (P<0.05). CONCLUSIONS: The fimA type Ib genotype of P. gingivalis was found to play a critical role in the destruction of peri-implant tissue, suggesting that it may be a distinct risk factor for peri-implantitis.

Prophylactic herbal therapy prevents experimental ascending urinary tract infection in mice / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the preventive effect of herbal formulation on experimental murine urinary tract infection (UTI) induced by Dr Escherichia coli 11128.</p><p><b>METHODS</b>E. coli 11128 carrying Dr fimbriae was isolated from patients with chronic pyelonephritis. The minimal inhibitory concentration (MIC) value of herbal solution for E. coli 11128 was determined for further studies. Forty C3H/HeJ mice were divided into the herb-treated group (n=20, given Chinese herbs by gavage at an average dose of 20 g/kg body weight daily 3 days before inoculation), and control group (n=20, given the same amount of distilled water by gavage). Three and 6 days after infection, bacteria were counted in the urine and the kidneys of the mice. Kidney histopathologic changes were evaluated. Neutrophils infiltration and accumulation were detected.</p><p><b>RESULTS</b>The MIC value of herbal solution was 0.1 g/mL for the E. coli 11128. In herb-treated mice, there was a significant reduction in bacterial counts in urine and colonization densities of kidneys. Microscopic studies revealed signs of inflammation in kidneys. In herb-treated mice, herbal administration resulted in significantly reduced neutrophilic infiltrates (P<0.05). The semi-quantitative scores for renal lesions were significantly lower (P<0.05).</p><p><b>CONCLUSION</b>Prophylactic administration of herbal formulation potentiated the effect in partially preventing experimental murine ascending UTI.</p>

Porphyromonas gingivalis Fim-A genotype distribution among Colombians / Distribución del genotipo Fim-A de Porphyromonas gingivalis entre la población colombiana

Introduction: Porphyromonas gingivalis is associated with periodontitis and exhibit a wide array of virulence factors, including fimbriae which is encoded by the FimA gene representing six known genotypes. Objetive: To identify FimA genotypes of P. gingivalis in subjects from Cali-Colombia, including the co-infection with Aggregatibacter actinomycetemcomitans, Treponema denticola, and Tannerella forsythia. Methods: Subgingival samples were collected from 151 people exhibiting diverse periodontal condition. The occurrence of P. gingivalis, FimA genotypes and other bacteria was determined by PCR. Results: Porphyromonas gingivalis was positive in 85 patients. Genotype FimA II was more prevalent without reach significant differences among study groups (54.3%), FimA IV was also prevalent in gingivitis (13.0%). A high correlation (p= 0.000) was found among P. gingivalis, T. denticola, and T. forsythia co-infection. The FimA II genotype correlated with concomitant detection of T. denticola and T. forsythia. Conclusions: Porphyromonas gingivalis was high even in the healthy group at the study population. A trend toward a greater frequency of FimA II genotype in patients with moderate and severe periodontitis was determined. The FimA II genotype was also associated with increased pocket depth, greater loss of attachment level, and patients co-infected with T. denticola and T. forsythia.

Introducción: Porphyromonas gingivalis es una bacteria asociada con la periodontitis. Expresa una amplia gama de factores de virulencia, incluyendo las fimbrias, las cuales están codificadas por el gen FimA que representa seis genotipos conocidos. Objetivo: Identificar los genotipos de FimA de P. gingivalis en pacientes de Cali - Colombia, incluyendo la co -infección con Aggregatibacter actinomycetemcomitans, Treponema denticola y Tannerella forsythia. Métodos: Se obtuvieron muestras subgingivales de 151 individuos con diferentes diagnósticos periodontales. La ocurrencia de P. gingivalis, los genotipos de FimA y otras bacterias se determinó por PCR. Resultados: Porphyromonas gingivalis fue positiva en 85 pacientes. El genotipo FimA II fue más prevalente, pero no hubo diferencias significativas entre los grupos de estudio (54.3%), FimA IV fue el más frecuente en la gingivitis (13.0%). Una alta correlación (p= 0.000) se encontró entre P. gingivalis , T. denticola y T. forsythia. El genotipo FimA II estuvo correlacionado con la detección de T. denticola y T. forsythia. Conclusiones: Porphyromonas gingivalis tuvo una alta frecuencia incluso en el grupo de individuos sanos. Se encontró una tendencia hacia una mayor frecuencia de FimA II en pacientes con periodontitis moderada y severa. El genotipo FimA II también se asoció con una mayor profundidad de la bolsa, una mayor pérdida de nivel de inserción, y con los pacientes en los que se detectó co-infección con T. denticola y T. forsythia.

stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage-like cells

BACKGROUND: Salmonella enterica serovar Typhi (S. Typhi) stg operon, encoding a chaperone/usher fimbria (CU), contributes to an increased adherence to human epithelial cells. However, one report suggests that the presence of the Stg fimbria impairs the monocyte-bacteria association, as deduced by the lower level of invasion to macrophage-like cells observed when the stg fimbrial cluster was overexpressed. Nevertheless, since other CU fimbrial structures increase the entry of S. Typhi into macrophages, and considering that transcriptomic analyses revealed that stg operon is indeed expressed in macrophages, we reassessed the role of the stg operon in the interaction between S. Typhi strain STH2370 and human cells, including macrophage-like cells and mononuclear cells directly taken from human peripheral blood. RESULTS: We compared S. Typhi STH2370 WT, a Chilean clinical strain, and the S. Typhi STH2370 Astg mutant with respect to association and invasion using epithelial and macrophage-like cells. We observed that deletion of stg operon reduced the association and invasion of S. Typhi, in both cellular types. The presence of the cloned stg operon restored the WT phenotype in all the cases. Moreover, we compared Salmonella enterica sv. Typhimurium 14028s (S. Typhimurium, a serovar lacking stg operon) and S. Typhimurium heterologously expressing S. Typhi stg. We found that the latter presents an increased cell disruption of polarized epithelial cells and an increased association in both epithelial and macrophage-like cells. CONCLUSIONS: S. Typhi stg operon encodes a functional adhesin that participates in the interaction bacteria-eukary-otic cells, including epithelial cells and macrophages-like cells. The phenotypes associated to stg operon include increased association and consequent invasion in bacteria-eukaryotic cells, and cell disruption.

Influence of beryllium ions on genotype of Porphyromonas gingivalis fimbriae gene cluster / 中国组织工程研究

BACKGROUND:In oral warm and moisture circumstance, al oy which contains Be is easily to be eroded to release Be2+. But there is stil no research focusing on beryl ium influence on genotype of Porphyromonas gingivalis fimbriae gene cluster. OBJECTIVE:To investigate Be 2+effect on genotype of Porphyromonas gingivalis fimbriae gene cluster. METHODS:The revived Porphyromonas gingivalis was resuscitated for 48 hours in the anaerobic culture medium with different concentration of Be 2+(10×10-6, 5×10-6, 1.25×10-6). Through PCR amplification and sequencing, we investigated the effects of Be2+RESULTS AND CONCLUSION:(1) When Be on genotypes of Porphyromonas gingivalis fimbriae gene cluster. 2+concentration was 5×10-6, we found the peak of 217 and 257 sites on DNA sequence expressing G/A overlap peak, different from G single peak of the other groups, suggesting the suspicious bases changes, part of the single base G mutated into A. (2) On al concentrations, we found a base group composed of seven A bases was inserted into the 101 site of DNA sequence. Up to now, there is no direct contacts of the mutations occurring to Be2+concentration. Changes of gene may lead to the shifting of the reading frame, the abnormal synthesis of proteins, the change of Porphyromonas gingivalis fimA gene toxicity, and lastly the unbalance of the micro-ecological environment.

Regulatory T-cell vaccination independent of auto-antigen

To date, efforts to treat autoimmune diseases have primarily focused on the disease symptoms rather than on the cause of the disease. In large part, this is attributed to not knowing the responsible auto-antigens (auto-Ags) for driving the self-reactivity coupled with the poor success of treating autoimmune diseases using oral tolerance methods. Nonetheless, if tolerogenic approaches or methods that stimulate regulatory T (Treg) cells can be devised, these could subdue autoimmune diseases. To forward such efforts, our approach with colonization factor antigen I (CFA/I) fimbriae is to establish bystander immunity to ultimately drive the development of auto-Ag-specific Treg cells. Using an attenuated Salmonella vaccine expressing CFA/I fimbriae, fimbriae-specific Treg cells were induced without compromising the vaccine's capacity to protect against travelers' diarrhea or salmonellosis. By adapting the vaccine's anti-inflammatory properties, it was found that it could also dampen experimental inflammatory diseases resembling multiple sclerosis (MS) and rheumatoid arthritis. Because of this bystander effect, disease-specific Treg cells are eventually induced to resolve disease. Interestingly, this same vaccine could elicit the required Treg cell subset for each disease. For MS-like disease, conventional CD25+ Treg cells are stimulated, but for arthritis CD39+ Treg cells are induced instead. This review article will examine the potential of treating autoimmune diseases without having previous knowledge of the auto-Ag using an innocuous antigen to stimulate Treg cells via the production of transforming growth factor-beta and interleukin-10.

Análisis in silico de proteínas potencialmente involucradas en la biogénesis de fimbrias en Helicobacter pylori / In silico analysis of proteins potentially involved in fimbrial biogenesis in Helicobacter pylori

Introducción. La colonización e infección crónica por Helicobacter pylori es el factor de mayor contribución al desarrollo de cáncer gástrico. Se ha descrito un gran repertorio de adhesinas que contribuyen a la adaptación específica de la bacteria al nicho gástrico y, para H. pylori , al igual que en otras bacterias patógenas, la formación de biopelícula es fundamental en la supervivencia a ambientes no favorables. Las fimbrias o pili tipo IV son responsables de la adhesión de diversas bacterias patógenas ( Escherichia coli , Pseudomonas aeruginosa y Vibrio cholerae) a distintas superficies. El objetivo de este trabajo fue identificar y analizar genes que pudieran codificar para proteínas involucradas en la biogénesis de fimbrias en H. pylori y caracterizar su expresión durante la formación de biopelícula. Métodos. Se emplearon herramientas bioinformáticas y moleculares, tales como la base de datos del NCBI para la búsqueda de secuencias de proteínas relacionadas con la biogénesis de fimbrias, así como la herramienta de PSI BLAST. Los alineamientos múltiples se realizaron con el programa T-COFFEE y HMMER. La predicción de las estructuras secundarias se realizó con ANTHEPROT y las estructuras terciarias se predijeron con el programa I-TASSER. Resultados. Se identificaron dos homólogos, jhp0257 y HP0272, de la proteína PilN de Campylobacter rectus y Xilella fastidiosa , la cual es parte de la maquinaria del ensamble de la fimbria tipo IV. Asimismo, las proteínas jhp0887 y HP0953 presentaron homología a nivel del péptido señal de PilA de P. aeruginosa , y la proteína HP0953 se sobreexpresó durante la formación de la biopelícula. Conclusiones. H. pylori posee proteínas homólogas a las proteínas de familias fimbriales, específicamente PilN y PilA, que ensamblan fimbria tipo IV en otras bacterias. Esta última tiene un nivel de expresión mayor durante la etapa inicial del proceso de formación de biopelícula.

Background. Colonization and chronic infection with Helicobacter pylori is the major contributing factor to the development of gastric cancer. A large repertoire of adhesins has been described that contribute to the adaptation of bacteria to a specific gastric niche. As in other pathogenic bacteria, H. pylori biofilm formation is central to survival on unfavorable environments. Type IV pili or fimbriae are responsible for the adhesion of many pathogenic bacteria (e.g., Escherichia coli, Pseudomonas aeruginosa and Vibrio cholerae ) to various surfaces. The aim of this study was to identify and analyze genes that might encode proteins involved in the biogenesis of fimbriae on H. pylori and characterize their expression during biofilm formation. Methods. PSI BLAST, bioinformatics and molecular tools were used as well as the NCBI database search for sequences related to protein biogenesis of fimbriae. Multiple alignments were performed using the HMMer and T-COFFEE programs. The secondary structure prediction was performed with ANTHEPROT and the tertiary structures were predicted with the I-Tasser. Results. We identified two counterparts-jhp0257 and HP0272-from protein of Campylobacter rectus and PilN Xilella fastidiosa , which is part of the machinery of assembly type IV fimbria. Similarly, proteins jhp0887 and HP0953 show homology from peptide PilA level of P. aeruginosa , and the HP0953 protein is overexpressed during the formation of the biofilm. Conclusions. H. pylori possesses proteins homologous to fimbrial protein families, specifically PilN and PilA, which join type IV fimbriae in other bacteria. The latter has a higher expression level during the initial stage of the formation of biofilm.

Efficacy of bacterin-, outer membrane protein- and fimbriae extract-based vaccines for the control of Salmonella Enteritidis experimental infection in chickens / Eficácia de bactéria inativada (bacterina), proteína da membrana externa e extrato de fimbrias no controle de infecção experimental por Salmonella Enteritidis (SE) em galinhas

The efficacy of three vaccines was evaluated in chickens for the control of experimental infection with Salmonella Enteritidis (SE) phage type 4. The vaccines were produced with bacterin, outer membrane proteins (OMP) and fimbriae crude extract (FE). The chickens were vaccinated intramuscularly with two doses of each vaccine at 12 and 15 weeks of age. The chickens were then orally challenged with 10(9) CFU/chicken Salmonella Enteritidis phage type 4 at 18 weeks of age. Fecal swabs were performed for the recovery of shedding SE, and SE was recovered from the liver and spleen. Additionally, antibody titers were measured in the serum by micro-agglutination test. The results indicated that the vaccine produced with bacterin yielded better results and resulted in reduction of fecal shedding and organ invasion by SE after oral challenge, although no vaccine was 100% effective for the control of SE experimental infection.

A eficácia de três vacinas de Salmonella Enteritidis fagotipo 4, produzidas na forma de bacterina, proteínas de membrana externa (OMP) e extrato bruto de fímbrias (FE) foi avaliada para proteção de aves infectadas experimentalmente. As aves foram vacinadas por via intramuscular com duas doses de cada vacina as 12 e 15 semanas de idade e desafiadas com 10(9) UFCs de Salmonella Enteritidis fagotipo 4 às 18 semanas de idade, por via oral. A eficácia foi determinada através do reisolamento da bactéria nas fezes e no fígado e baço, e os anticorpos foram mensurados no soro. Os resultados demonstraram que a vacina produzida com a bacterina foi mais eficaz em comparação às outras vacinas examinadas, para reduzir a excreção fecal e a invasão de órgãos após o desafio por SE.

Effect of fimH gene on type 1 fimbriae adhesion of uropathogenic Escherichia coli: a preliminary study / 中华临床感染病杂志

Objective To investigate the effect of fimH gene on type 1 fimbriae adhesion of uropathogenic Escherichia coli (UPEC) and the gene variations between type 1 fimbriae adhesion positive and negative bacteria.Methods A total of 171 UPEC strains (not catheter associated) were collected from the Second Hospital of Tianjin Medical University,Tianjin First Center Hospital,and Tianjin Children's Hospital during January 2012 and January 2013.fimH gene was detected by PCR technique,and type 1 fimbriae adhesion was detected by yeast agglutination test.RT-PCR was used to exterminate gene transcript factor impacting on adhesion.Chi-square and Yates' chi-squared tests were performed to comparefimH gene sequences between the adhesion positive and negative bacteria.Results Among 171 UPEC strains,142 (83％) werefimH gene positive,and type 1 fimbriae was expressed in 98 strains (57％).All adhesion positive strains carriedfimH gene.Among 44 strains with positivefimH gene and negative adhesion RT-PCR revealed thatfimH gene did not transcript in 8 strains (18％).The sequencing results showed that gene mutation on the 51 st amino acid site was more prevalent in the adhesion positive group compared with the negative group (x2 =6.64,P =0.010).In adhesion,mutations on the 190th and 219th amino acid sites were observed in 6 strains and 7 strains of negative group,respectively; while not observed in the adhesion positive group (x2 =4.69 and 5.87,P ＜ 0.05).Negative adhesion in other 23 strains was not attributed to single nucleotide polymorphism.Conclusion Adhesion function of type 1 fimbriae mignt be affected by mutation and deletion offimH gene.Three key site mutations may also affect the adhesion function of type 1 fimbriae.Besides fimH gene,there may be other genes that can affect the adhesion function of type 1 fimbriae.

PCR for the detection of the gene fel a of escherichia coli in broiler condemned for airsacculitis by the Brazilian Federal Sanitary Inspection / PCR na detecção de gene Fel A de Escherichia Coli em frangos de corte condenados por aerossaculite pela Inspeção Sanitária Federal

Collibacillosis is considered one of the major diseases of the modern poultry industry, due to the significant losses it causes. Escherichia coli contributes not only to the disease itself, by causing weight loss of the birds, but also to the increase in carcasses condemnation during slaughter and processing. Detection of virulence factors in E. coli strains of the APEC pathotype contributes to the characterization and pathogenicity of this agent. PCR techniques have been very helpful in the search for genes that encode those virulence factors. This study aimed to detect the gene Fel A of E. coli by PCR and relate its positivity to low weight in broiler flocks with airsacculitis as diagnosed by the health inspection service. The study involved 40 flocks of broilers slaughtered in a single poultry slaughterhouse, under Federal Sanitary Inspection, located in the state of Rio Grande do Sul, Brazil. Three broilers were randomly selected to obtain one "pool" of three tracheas for each PCR. DNA was extracted using phenol-chloroform and amplified using a pair of primers specific to gene Fel A of E. coli. Of the 40 flocks analyzed by PCR, 35% (14/40) were positive for the gene Fel A. PCR was an effective technique for the detection of gene Fel A in broiler flocks. There was a relationship between the presence of the gene Fel A, weight loss, and increase of the airsacculitis rate...

A colibacilose é considerada uma das principais doenças da indústria avícola moderna, devido aos grandes prejuízos econômicos causados. A Escherichia coli contribui não só para a doença em si, levando à perda de peso das aves, bem como para o aumento da taxa condenação de carcaças durante o abate e processamento. A detecção de fatores de virulência de cepas de E. coli do patotipo APEC colabora para a caracterização de sua patogenicidade e as técnicas de PCR têm sido muito úteis na pesquisa de genes que os codificam. Este estudo objetivou diagnosticar E. coli pela detecção o gene Fel A por PCR e relacionar a positividade para este agente com o baixo peso em frangos de corte provenientes de lotes condenados por aerossaculite. Foram estudados 40 lotes de frangos de corte abatidos em um matadouro avícola sob Inspeção Sanitária Federal, localizado no Estado do Rio Grande do Sul. Foram colhidos aleatoriamente 3 frangos e obtidos "pools" de três traqueias em cada um deles para PCR. O DNA foi extraído pelo método de fenol-clorofórmio e amplificado com pares de "primers" específicos para gene Fel A de E. coli. Dos 40 lotes analisados pela PCR, 35% (14/40) foram positivos para o gene Fel A. A PCR foi eficaz para a detecção do gene Fel A em lotes de frangos de corte e houve relação entre a presença do gene Fel A, a queda de peso e aumento na taxa de aerossaculite...

Virulence factors, antimicrobial resistance, and plasmid content of Escherichia coli isolated in swine commercial farms / Fatores de virulência, resistência aos antimicrobianos, presença de plasmídeos em Escherichia coli isoladas de amostras clínicas e ambientais de suínos

Virulence factors and antimicrobial resistance patterns of Escherichia coli isolates were evaluated. A total of 80 E. coli isolates were evaluated, being 64 from clinical samples (intestinal content and fragments of organs from diarrheic piglets), seven from feces of clinically healthy piglets and sows, and nine environmental samples (five from facilities, two from feed, one from insect, and one from waste). Molecular characterization was performed by PCR detection of fimbriae and toxin genes and plasmid content determination. The isolates were also characterized according to their resistance or sensitivity to the following drugs: ampicillin, trimethoprim:sulfamethoxazole, tetracycline, amikacine, colistin, norfloxacin, florfenicol, enrofloxacin, cefalexin, trimethoprim, neomycin, chloramphenicol, and gentamicin. From 80 E. coli isolates, 53.8 percent were classified as enterotoxigenic E. coli (ETEC), 2.5 percent were shiga toxin-producing E. coli (STEC), and 43.8 percent showed a non specific pattern and were unclassified. One fecal isolate from non-diarrheic piglet was classified as ETEC by PCR. Clinical isolates showed resistance mainly for tetracycline and trimethoprim:sulfamethoxazole. Plasmidial DNA was observed in 70 isolates, being 78.5 percent of clinical isolates, 8.57 percent of non-diarrheic feces, and 12.8 percent of environment.

Os fatores de virulência e a resistência aos antimicrobianos foram avaliados em Escherichia coli. Um total de 80 isolados de E. coli, sendo 64 de amostras clínicas (conteúdo intestinal e fragmentos de órgãos de leitões diarreicos), sete das fezes de porcas e leitões saudáveis e nove de amostras ambientais (cinco de instalações, dois de alimentos, um de inseto e um de esterqueira). A caracterização molecular feita pela PCR objetivou detectar fimbrias e toxinas, bem como a determinação do conteúdo de plasmídeos. Os isolados foram caracterizados quanto à resistência ou sensibilidade às seguintes drogas: ampicilina, sulfazotrim, tetraciclina, amikacina, colistina, norfloxacina, florfenicol, enrofloxacina, cefalexina, trimetoprim, neomicina, cloranfenicol e gentamicina. Dos 80 isolados, 53,8 por cento foram classificados como E. coli enterotoxigênica (ETEC), 2,5 por cento como E. coli produtora de shiga toxina (STEC) e 43,8 por cento, por não apresentarem padrão específico, não foram classificadas. Pela PCR, um isolado de fezes de suíno sem diarreia foi classificado como ETEC. Os isolados das amostras clínicas foram principalmente resistentes à tetraciclina e à sulfazotrim. Em 70 isolados, observaram-se DNA plasmidial, destes 78,5 por cento foram obtidos de amostras clínicas, 8,57 por cento de leitões sadios e 12,8 por cento de amostras ambientais.

Characteristics of the antigenic genes of four clinical Bordetella pertussis strains / 中华检验医学杂志

Objectives To analyze the characteristics of antigenic genes of clinical Bordetella pertussis strains recently isolated by analyzing the sequence of pertussis toxin S1 subunit(ptxS1) , pertactin (Prn) , fimbriae 2 (Fim2) and fimbriae 3 (Fim3 ) genes of four clinical isolates. Methods The 4 clinical isolates were collected in 2002 in Shijiazhuang of Hebei province. Four strains were isolated from pertussis patient's nasopharyngeal aspirate. ptxS1, Prn, Fim2 and Fim3 genes of these strains were amplified and sequenced. The sequences of those genes were compared with those of the isolates in GenBank and the isoaltes used in the production of pertussis vaccine in China. Results The results of the gene sequencing showed the four clinical isolates belonged to ptxS1 A type, which were different from those in vaccine strains. In addition, three Prn and three Fim'3 variants were observed in the four clinical isolates. Sequence analysis showed that the nucleotide sequence and deduced amino acid sequence of those strains had more than 99% identity with those in vaccine strains. The phylogenetic trees of those genes also showed these strains had a higher level of similarity with other Bordetella pertussis strains. Conclusion The four clinical isolates are different from vaccine strains in four antigenic genes, which laid a foundation for further studies on pertussis epidemiology,quality control and development of pertussis vaccine in China.