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The high resistance of K. pneumoniae strains to various antibiotics is remarkable. The most important virulence factors for K. pneumoniae include fimbriae, capsule, lipopolysaccharide, outer membrane proteins, and iron transport molecules. The aim of this study was to investigate the prevalence of capsule (wabG) and fimbriae (fimH) coding genes in MDR K. pneumoniae strains isolated from patients admitted to Isfahan (Iran) hospitals. The antibiotic susceptibility pattern of the isolates was carried out by the disk diffusion method. Definitive confirmation of MDR isolates was done by tracing the 16S-23S ITS gene, and the presence of capsule (wabG) and fimbriae (fimH) genes was investigated in the isolates. Data analysis was done using an independent parametric T-test and one-way analysis of variance (ANOVA). One hundred and two K. pneumoniae isolates were detected in the samples, including urine, respiratory tract, blood, throat, cerebrospinal fluid, direct discharge, wound secretions, pleural fluid, joint fluid, abscess discharge, stool, and sputum. Men were significantly more infected with K. pneumoniae than women. The highest frequency of the isolates was related to urine (40%), followed by the respiratory tract (27%). The largest number of isolates were found in the ICU (37%) and emergency (28%) departments. Out of the 102 isolates of K. pneumoniae, 50 isolates (49%) were MDR, and 50 (49%) were carbapenemresistant. Of the 50 MDR isolates, 48 (96%) and 47 (94%) had fimH and wabG genes, respectively. High frequencies of MDR and carbapenem-resistant strains of K. pneumoniae with a high prevalence of fimH and wabG genes are significant and should be considered by healthcare management. [ABSTRACT FROM AUTHOR]

Background: Pili producing genes in different life cycles of Mycobacterium tuberculosis (M. tuberculosis) were assessed. M. tuberculosis has two life cycles: dormant and active states. We aimed to assess the pili producing genes such as curli pili of M. tuberculosis (mtp) encoded by the mtp gene (Rv3312A) and fimbrial low-molecular-weight protein encoded by flp gene (Rv3656c) which were compared and analyzed. Methods: Two hundred M. tuberculosis isolates were investigated both at active and dormant states for production and expression of pili. The dormant M. tuberculosis was achieved by incubation in a sealed tube (modified Wayne method). The susceptibility of M. tuberculosis was evaluated on genes, rpob, inh, katg, and gyra by using multiplex polymerase chain reaction (PCR) and single-strand conformational polymorphism methods. The PCR–restriction fragment length polymorphism was used to express pili genes mtp and flp and then the PCR products was digested using restriction enzyme Fnu4HI, XmaI, and MspJI and AciI, TagII, and HaeII, respectively. The transmission electron microscopy was also used to detect pili in different isolates. The result was compared and analyzed using H37RV as a gold standard. Results: The mtp and flp PCR products were 263 and 122 bp in the studied strains irrespective of M. tuberculosis different life cycles, respectively. The PCR products were analyzed on 8% Polyacrylamide gel electrophoresis (PAGE), and in the 180/200 (20%), producing five fragments of 25,40,45,63,90 bp with the Fun4HI and two fragments of 126,138 bp with the XmaI and uncut with the MspJI for mtp gen were obtained at the dormant and active states of M. tuberculosis (P < 0.05). Similarly in flp gene producing three fragments of 22,35,65 bp with AciI and two fragments of 35.87 bp with TagII and two fragments of 38.84 bp with HaeII were obtained (P < 0.05). In contrast to genotyping analysis, the electron microscopy examination showed protruding of pili from M. tuberculosis, especially in dormant mycobacterium (15/100; 15%), that was multidrug resistance and extensive drug resistance isolates (P > 0.05). Conclusion: Pili were shown by electron microscopy, although at the gene expression, the insignificant difference was observed at the dormant strains in comparison to active states. Therefore, we may conclude that other genes might be involved in pili production of M. tuberculosis that needs further investigation. Although, the resistance phenomena might influence the pili producing gene expression that showed in our results. [ABSTRACT FROM AUTHOR]

Although the presence of an arrector pili smooth muscle is documented in many monkey species, its regional peculiarities are hitherto not well documented. We aimed to study this aspect in the face of rhesus monkeys with different areas of hair coat. Eight different regions of six monkeys (male and female) were studied using light microscopy and immunohistochemistry (antibody against smooth muscle alpha actin). We identified two regions (lips and eyelids) with vellus hairs that did not show an arrector pili muscle. In the eyelids, the hairs are rather small and short; in the lips, the vellus hairs were surrounded by striated muscle fibers from the orbicularis oris muscle. In all other regions (frontal region, forehead, cheek, chin), the vellus hairs contained an arrector pili muscle with comparable morphology. Only in the chin region, where additional striated muscles from the face muscles were present, the arrector pili muscles were thinner. All vibrissae showed a close relation to striated muscle fiber bundles of the facial muscles. They never developed smooth muscle bundles assigned as arrector pili equivalent. [ABSTRACT FROM AUTHOR]

Background: Some bacteria possess fimbriae that support their adherence to host cell surface, colonization of human epithelial cells and resistance to antibiotics. Aim: The expression of type 1 fimbriae and antibiotic resistance by isolates from human immunodeficiency virus (HIV) infected patients. Methods: Bacteriological analysis of mid-stream urine (MSU) samples of HIV infected patients (n=61) was determined using microbiological technique. In vitro type 1 fimbriae expression and antibiotic susceptibility of bacteria was determined using human erythrocytes with D-mannose and disc diffusion technique. Results: Of the 61 MSU samples from subjects, 31.1% had positive bacterial growth ≥ 105 CFU/mL. Forty-nine (49) bacterial isolates, belonging to genera Staphylococcus, Escherichia, Pseudomonas, Streptococcus, Klebsiella, Enterococcus and Proteus were recovered from the MSU samples. Escherichia coli was the predominant isolate with 26.5%, followed by S. aureus (18.4%), while E. faecalis had the lowest occurrence (4.1%). Of the 29 isolates exhibiting hemagglutinating activity, type 1 fimbriae was expressed by 16 isolates, while 13 isolates showed P-fimbriae. The results showed 18.4 % isolates exhibiting resistance to gentamycin; between 30.6 % and 38.8% isolates were tetracycline and nitrofurantoin resistant, while ≤ 44.9% isolates were resistant to chloramphenicol and ampicillin. Proteus sp had a low level of resistance to ciprofloxacin, while ≥ 46.2 % E. coli were resistant to nitrofurantoin. There was significant relationship (p < 0.05) between isolates expressing type 1 fimbriae and resistance to gentamycin, nalidixic acid and ampicillin. Conclusion: This study has shown the phenotypic expression of type 1 fimbriae and antibiotic resistance by isolates from HIV infected patients. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria, in particular Lactococcus lactis, are widely used in the food industry, for the control and/or the protection of the manufacturing processes of fermented food. While L. lactis has been reported to form compact and uniform biofilms it was recently shown that certain strains able to display pili at their surface form more complex biofilms exhibiting heterogeneous and aerial structures. As the impact of those biofilm structures on the biomechanical properties of the biofilms is poorly understood, these were investigated using AFM force spectroscopy and imaging. Three types of strains were used i.e., a control strain devoid of pili and surface mucus-binding protein, a strain displaying pili but no mucus-binding proteins and a strain displaying both pili and a mucus-binding protein. To identify potential correlations between the nanomechanical measurements and the biofilm architecture, 24-h old biofilms were characterized by confocal laser scanning microscopy. Globally the strains devoid of pili displayed smoother and stiffer biofilms (Young Modulus of 4–100 kPa) than those of piliated strains (Young Modulus around 0.04–0.1 kPa). Additional display of a mucus-binding protein did not affect the biofilm stiffness but made the biofilm smoother and more compact. Finally, we demonstrated the role of pili in the biofilm cohesiveness by monitoring the homotypic adhesion of bacteria to the biofilm surface. These results will help to understand the role of pili and mucus-binding proteins withstanding external forces. [ABSTRACT FROM AUTHOR]

A total of 165 clinical sample included Urine, Swab wounds and Burns were collected from Baghdad Governorate. Results showed that rate all isolates of E. coli was 50(30.3%) and rate of urine infection was 46(92%) and rate of swab wounds infection 4(8%). Where was diagnostic based on streaked on MacConkey agar, then single colony was transferred to Eosin Methylene Blue (EMB). Identification some of the biochemical test included: Catalase test, Oxidase test, Indole test, Methyl red, Vogues - Proskauer test and Citrate Utilization test. Then confirmed by the Vitek - 2 Compact System. The ability of E.coli isolate to biofilm formation to be studied it is considered one of the most important factors of virulence and has role in causing injury and increasing resistance to antibiotic of bacteria by Microtiter Plate Method Showed that most isolates gave positive results of 39(78%) isolate in different ratio. csgD (curli subunit gene D) the transcription factor plays a key role in the control of Biofilm Formation in E. coli by controlling the production of Curli Fimbriae and other biofilm Components. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa, like many bacilliforms, are not limited only to swimming motility but rather possess many motility strategies. In particular, twitching-mode motility employs hair-like pili to transverse moist surfaces with a jittery irregular crawl. Twitching motility plays a critical role in redistributing cells on surfaces prior to and during colony formation. We combine molecular dynamics and rule-based simulations to study twitching-mode motility of model bacilliforms and show that there is a critical surface coverage fraction at which collective effects arise. Our simulations demonstrate dynamic clustering of twitcher-type bacteria with polydomains of local alignment that exhibit spontaneous correlated motions, similar to rafts in many bacterial communities. [ABSTRACT FROM AUTHOR]

A number of biomechanical properties of various types of pili expressed by Escherichia coli, predominantly their force-versus-elongation behavior, have previously been assessed in detail on a single pilus level. In vivo, however, bacteria bind in general to host cells by a multitude of pili, which presumably provides them with adhesion properties that differs from those of single pili. Based upon the previously assessed biomechanical properties of individual pili, this work presents a theoretical analysis of the adhesion properties of multipili-attaching bacteria expressing helixlike pili exposed to an external force. Expressions for the adhesion lifetime of dual- and multipili-attaching bacteria are derived and their validity is verified by Monte Carlo simulations. It is demonstrated that the adhesion lifetime of a multipili-binding bacterium depends to a large degree on the cooperativity of the attaching pili, which, in turn, depends strongly on their internal biomechanical properties, in particular their helixlike structure and its ability to elongate, which, in turn, depends on the intrinsic properties of the bonds, e.g., their lengths and activation energies. It is shown, for example, that a decrease in the length of a layer-to-layer bond in the rod of P pili, expressed by E. coli, by 50% leads to a decrease in the adhesion lifetime of a bacterium attaching by ten pili and exposed to a force of 500 pN by three orders of magnitude. The results indicate moreover that the intrinsic properties of the rod for this particular type of pili are optimized for multipili attachment under a broad range of external forces and presumably also to its in vivo environment. For example, P pili seems to be optimized to withstand a force exposure during ∼3 s, which correspond to the time it takes for a bolus to pass a bacterium attached to the ureteral wall. Even though the results presented in this work apply quantitatively to one type of pilus, they are assumed to apply qualitatively to all helixlike pili systems expressing slip bonds. [ABSTRACT FROM AUTHOR]

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Background: Porphyromonas gingivalis is a major pathogen and has a high detection rate in periodontal disease. Fimbriae and hemagglutinin are expressed by P. gingivalis, and these play an important role in the adherence of the bacteria to periodontal tissue and biofilm formation. The aim of this study was to investigate the effects of sub-minimal inhibitory concentrations (sub-MICs) of azithromycin on the adherence of P. gingivalis, focusing on the inhibition of fimbriae expression and hemagglutinin activity.Methods: P. gingivalis ATCC 33277 were incubated anaerobically with sub-MICs of azithromycin at 37°C by gentle shaking for 18 hours. The bacterial cells were harvested, washed twice with phosphate-buffered saline (PBS), and the proteins analyzed by 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. Adherence assay and hemagglutinin activity tests were done with the same culture.Results: The results of SDS-PAGE indicated that the sub-MICs of azithromycin inhibited 41-kDa fimbrial protein expression and hemagglutinin activities. The disappearance of 41-kDa fimbrial protein expression and long fimbriae in 0.4 µg/mL, 0.2 µg/mL, and 0.1 µg/mL of azithromycin was confirmed by western blotting and transmission electron microscopy. The adherence of P. gingivalis to human gingival epithelial cells was reduced by sub-MICs of azithromycin compared with the adherence levels without antibiotic.Conclusions: These results suggest that sub-MICs of azithromycin may reduce the adherence of P. gingivalis to host cells, by inhibiting production of fimbriae and hemagglutinin activities. Therefore, azithromycin can be used as a biofilm treatment of periodontal disease caused by P. gingivalis. [ABSTRACT FROM AUTHOR]

Pathogens rely on a complex virulence gene repertoire to successfully attack their hosts. We were therefore surprised to find that a single fimbrial gene reconstitution can return the virulence-attenuated commensal strain Escherichia coli 83972 to virulence, defined by a disease phenotype in human hosts. E. coli 83972pap stably reprogrammed host gene expression, by activating an acute pyelonephritis-associated, IRF7-dependent gene network. The PapG protein was internalized by human kidney cells and served as a transcriptional agonist of IRF-7, IFN-β and MYC, suggesting direct involvement of the fimbrial adhesin in this process. IRF-7 was further identified as a potent upstream regulator (-log (p-value) = 61), consistent with the effects in inoculated patients. In contrast, E. coli 83972fim transiently attenuated overall gene expression in human hosts, enhancing the effects of E. coli 83972. The inhibition of RNA processing and ribosomal assembly indicated a homeostatic rather than a pathogenic end-point. In parallel, the expression of specific ion channels and neuropeptide gene networks was transiently enhanced, in a FimH-dependent manner. The studies were performed to establish protective asymptomatic bacteriuria in human hosts and the reconstituted E. coli 83972 variants were developed to improve bacterial fitness for the human urinary tract. Unexpectedly, P fimbriae were able to drive a disease response, suggesting that like oncogene addiction in cancer, pathogens may be addicted to single super-virulence factors. [ABSTRACT FROM AUTHOR]

Metastatic diseases rarely develop in the colorectum, and diagnosing colorectal metastasis by biopsy without history of a malignant tumor or clinical information of a primary tumor is challenging. A 65-year-old woman with a 6-month history of constipation and diarrhea was admitted to our hospital and diagnosed with rectosigmoid colonic micropapillary carcinoma. Low anterior resection was performed after neoadjuvant chemotherapy. Because the lipoleiomyoma in the uterus obstructed the operator's vision, total hysterectomy and bilateral salpingo-oophorectomy were performed. Examination of the colon and adnexa, together with immunohistochemical studies, revealed that the colonic tumor was actually serous carcinoma that had metastasized from the left fimbria of the fallopian tube. Retrospective immunohistochemical examination of the colon biopsy specimen suggested carcinoma with a Müllerian immunophenotype. When a colon biopsy reveals carcinoma with an invasive micropapillary pattern without a component of conventional tubular adenocarcinoma, immunohistochemical examination should be performed to rule out the possibility of metastasis. [ABSTRACT FROM AUTHOR]

Highlights • A LC–MS/MS method was developed for determining PT subunits, FIM, PRN and FIM simultaneously. • The developed method is much more selective than ChP method. • The developed method was used to determine target proteins in 10 bathes of DTaP vaccine from 5 manufactures. • The developed method was used to determine target proteins in non-detoxified and detoxified protein products. • The developed method was used to compare PT references from five chief organizations. Abstract A liquid chromatography tandem mass spectrometry method (LC–MS/MS) was developed to determine simultaneously the bioactive proteins including pertussis toxin (PT) subunits, filamentous hemagglutinin (FHA), pertactin (PRN) and fimbriae (FIM) in diphtheria, tetanus and acellular pertussis combined vaccine (DTaP). The trypsin digestion conditions were investigated in detail using PT reference to achieve satisfactory results in detection of the peptides on LC–MS/MS with a Bio-C18 column. The performance of the described method was evaluated using reference proteins and the results showed a wide linear range (0.15–24 ng μL−1), a high sensitivity (0.038 ng. μL-1 for FHA) and a good precision (RSD of peak area <3.3%). This novel LC–MS/MS method was applied to determine PT subunits, FHA, PRN and FIM in DTaP vaccines, a total of ten batches, obtained from five manufacturers. The results revealed clearly that batch-to-batch consistency of the DTaP vaccines in terms of the protein amounts was stable, while those from manufacturers were varied significantly. On the other hand, the amount of bioactive proteins in component DTaP vaccines was generally higher than those in co-purified DTaP vaccines. The described LC–MS/MS method was compared with Chinese Pharmacopeia method (Lowry method) and it was found that FHA and PRN amounts measured by the two methods were in good agreement. The LC–MS/MS method could provide the amounts of PT subunits. However, the Lowry method could not differentiate the subunits. The LC–MS/MS method was not only more selective and sensitive, but it can be used to determine simultaneously different bioactive proteins in complex matrix-formulated vaccines. The method was extended successfully in other purposes, such as the effect of detoxification on bioactive proteins and characterization of PT references from four organizations worldwide. [ABSTRACT FROM AUTHOR]

Uterine serous papillary carcinoma (UPSC) is an aggressive tumor, often diagnosed as a metastatic disease and characterized by a high recurrence rate and poor prognosis. UPSC represents a distinct subtype of endometrial cancer which is different in clinical and pathological behaviors from endometrioid endometrial carcinoma (EEC) and resembles more to serous ovarian carcinoma. Since tumors of serous papillary of the ovary are hypothesized to stem from cells of the fallopian tube's fimbria, we hypothesized that UPSC may also origin in the fallopian tubes. In our previous study, using a novel method of computerized morphometry of the fimbrial epithelium we have found significant differences between fimbriae of healthy women and serous ovarian cancer patients. In this study we showed the presence of morphologic differences between twenty-four fimbriae from healthy women, and twenty six fimbriae from uterus cancer (13 from UPSC patients and 13 from EEC patients). All fimbriae reported by the pathologist as "normal" were subjected to a computerized histomorphometric analysis. Two-step method of computerized histomorphometry, i.e. Fast Fourier transformation (FFT) followed by a co-occurrence matrix analysis and an additional analysis of the nuclear symmetry of the tubal fimbrial epithelium were applied. Using these novel methods, we were able to show differences in the morphometric characteristics of the fimbriae in UPSC patients compared to EEC and healthy patients. It is yet to be determined the clinical significance of this observation. [ABSTRACT FROM AUTHOR]

Summary: Enteroaggregative Escherichia coli (EAEC), is a diarrhoeagenic human pathogen commonly isolated from patients in both developing and industrialized countries. Pathogenic EAEC strains possess many virulence determinants, which are thought to be involved in causing disease, though, the exact mechanism by which EAEC causes diarrhoea is unclear. Typical EAEC strains possess the transcriptional regulator, AggR, which controls the expression of many virulence determinants, including the attachment adherence fimbriae (AAF) that are necessary for adherence to human gut epithelial cells. Here, using RNA‐sequencing, we have investigated the AggR regulon from EAEC strain 042 and show that AggR regulates the transcription of genes on both the bacterial chromosome and the large virulence plasmid, pAA2. Due to the importance of fimbriae, we focused on the two AAF/II fimbrial gene clusters in EAEC 042 (afaB‐aafCB and aafDA) and identified the promoter elements and AggR‐binding sites required for fimbrial expression. In addition, we examined the organization of the fimbrial operon promoters from other important EAEC strains to understand the rules of AggR‐dependent activation. Finally, we generated a series of semi‐synthetic promoters to define the minimal sequence required for AggR‐mediated activation and show that the correct positioning of a single AggR‐binding site is sufficient to confer AggR‐dependence. Enteroaggregative Escherichia coli (EAEC) is a commonly isolated human pathogen that causes mucoid diarrhoea. As EAEC virulence is controlled by the AggR master transcription factor, we use RNA‐sequencing to identify the AggR‐regulated genes in the pathogenic EAEC strain 042. We report the structure of several AggR‐dependent promoters in order to understand the mechanism of AggR‐mediated transcription activation. [ABSTRACT FROM AUTHOR]

Highlights • Pertussis resurgence suggests low efficacy of existing vaccines. • New strategies to improve aP vaccines efficacy are urgently needed. • Pertactin-negative isolates have the potential to negatively impact aP efficacy. • Extra FIM2/3 reduces lung colonization and enhances aP efficacy in murine model. • Additional amounts of FIM2/3 do not change biomarkers of reactogenicity. Abstract Current acellular-pertussis (aP) vaccines appear inadequate for long-term pertussis control because of short-lived efficacy and the increasing prevalence of pertactin-negative isolates which may negatively impact vaccine efficacy. In this study, we added fimbriae (FIM)2 and FIM3 protein to licensed 2-, 3- or 5-component aP vaccines (Pentavac®, Boostrix®, Adacel®, respectively) to assess whether an aP vaccine with enhanced FIM content demonstrates enhanced efficacy. Vaccine-induced protection was assessed in an intranasal mouse challenge model. In addition, potential reactogenicity was measured by biomarkers in a human whole blood assay (WBA) in vitro and benchmarked the responses against licensed whole cell pertussis (wP) and aP vaccines including Easyfive®, Pentavac® and Pentacel®. The results show that commercial vaccines demonstrated reduced efficacy against pertactin-negative versus pertactin-positive strains. However, addition of higher amounts of FIM2/3 to aP vaccines reduced lung colonization and increased vaccine efficacy against a pertactin-negative strain in a dose-dependent manner. Improvements in efficacy were similar for FIM2 and FIM3-expressing strains. Increasing the amount of FIM2/3 proteins in aP formulations did not alter vaccine-induced biomarkers of potential reactogenicity including prostaglandin E 2 , cytokines and chemokines in human newborn cord and adult peripheral blood tested in vitro. These results suggest that increasing the quantity of FIM proteins in current pertussis vaccine formulations may further enhance vaccine efficacy against B. pertussis infection without increasing the reactogenicity of the vaccine. [ABSTRACT FROM AUTHOR]

Abstract Sablefish Anoplopoma fimbria are a highly valued, economically important groundfish in Alaska; however, estimated stock biomass has been in steady decline since the early 1990s, likely as a result of poor recruitment. Among several factors found to impact recruitment strength, ocean temperature often has been to affect early-life condition. Despite the importance of early-life condition in predicting cohort success, few studies have examined the thermal response of young-of-the-year (YOY) sablefish in regards to growth and development, and those focus on only a narrow size range. In this study, we measured the effects of temperature on growth and consumption rates of YOY sablefish (218–289 mm TL) in laboratory trials with fish held over 5 temperature treatments (5 °C, 8 °C, 12 °C, 16 °C and 20 °C) and maintained on ad libitum ration for 3 weeks. We compared growth, consumption, and body condition of fish between treatments. Specific growth rate (SGR; % wet weight gain (g) d−1) was used to derive a temperature-dependent growth model, and consumption rates were used to calculate species-specific parameters for the consumption function of a Wisconsin-type bioenergetics model. Daily growth in length varied from 0.13 mm d−1 to 1.74 mm d−1 and SGR ranged from 0.52 to 2.31. SGR peaked at 15.4 °C, remained high at 12 °C and 16 °C, and steadily declined as temperatures shifted outside this range. Residuals of length-weight regressions were positive at 12 °C and 16 °C, and negative at 5 °C, 8 °C, and 20 °C. Consumption rose sharply with temperature, peaking at 17.6 °C. The narrow thermal range facilitating higher than average condition and optimal SGR indicates that YOY sablefish growth and development may be dramatically influenced by relatively small shifts in water temperatures. Further, when compared to similar studies of smaller-sized sablefish, we observed a shift with size in thermal performance, with larger fish performing better at colder temperatures compared to smaller fish. The shift in thermal performance with size is an important consideration for understanding the result of environmental perturbation on recruitment. While traditional recruitment models rely heavily on information from a single life-stage, resource use and physiological requirements often change with development. Given the widespread occurrence of anomalous thermal events in the Gulf of Alaska, a life-stage specific understanding of the effects of varying temperatures is crucial. [ABSTRACT FROM AUTHOR]

Escherichia coli remain significant problem caused urinary tract infection; Results indicated a higher urinary tract infection in women compared with men across all age groups. Phylogenetic analysis showed that majority of uropathogenic isolated E. coli belong to phylogroup B2 followed by D. The isolates showed the existence of the first type of fimbriae, maximum P fimbriae positive isolates 74/94 (80.43%) were widely correlating with common UTI. colony adhesion factor (CAFÐ) represented in 40 (43.47%) and 5 (5.43%) colony adhesion factor (CAFØ). Six major clusters (A-F) were identified depending on antibiograms typing. B2 is the most phylogenetic type showed wide range of resistant from 1 to 12 resistant to antibiotic of remaining strains. 14 isolates (15.21%) were detected as ESâLs producers and 30 isolates (32.60%) of them were AmpC â-lactamases producers. prevalence of virulent genes occurred in 51 papC (55.43%), 66 fim H (71.73%) and SfaDE detected in low occurrence 21(22.82) . These results emphasize the low or moderate resistant to antibiotics focused in isolates with high genetic content .These results indicated that the greater the resistance to antibiotics the less the genetic expression of the virulence factors, this confirms the reverse relationship. The genes required for uropathogenicity in a single isolate may not reflect virulence in another isolate. Pathogenicity is a multi-factor characteristic, the result of adhesion-related genes which interact in separate set in various genetic backgrounds. [ABSTRACT FROM AUTHOR]

Study Question: Is there perfusion to the fallopian tubes in ex-vivo and in-vivo uteri at the time of total laparoscopic hysterectomy (TLH), as observed using laser angiography with indocyanine green (ICG)?Summary Answer: The fallopian tubes may have perfusion from the utero-ovarian vasculature alone.What Is Known Already: The fallopian tubes are perfused by the uterine and utero-ovarian vessels. Perfusion can be measured using laser angiography with ICG.Study Design, Size, Duration: This prospective pilot cohort study included 15 women, ages 32-59 years old, who underwent TLH with bilateral salpingectomy for benign indications.Participants/materials, Setting, Methods: In five participants, TLH was performed and the utero-ovarian artery was cannulated ex vivo and injected with ICG. The other 10 participants underwent the in-vivo protocol. The mesosalpinx and uterine vessels were transected in the partial protocol. Colpotomy was also performed in the complete protocol. All fallopian tubes were imaged using laser angiography with ICG. The relative fluorescence and the fluorescence intensity ratio (length of fluorescent fallopian tube/total length of fallopian tube) of the fallopian tubes were measured in the ex-vivo and in-vivo protocols, respectively.Main Results and the Role Of Chance: Ex vivo, the fimbria of the ipsilateral fallopian tube had 47% median relative fluorescence as compared to the contralateral fallopian tube, which had 2.4% median relative fluorescence. In vivo, the post-ICG fluorescence intensity ratios were 0.61 ± 0.40 for the partial protocol, and 0.78 ± 0.30 for the complete protocol, with mean differences of 0.37 (95% CI: 0.23-0.50, P < .0001) and 0.22 (95% CI: 0.12-0.31, P < 0.0001), respectively, between the pre-procedure and the post-ICG fluorescence intensity ratios. Greater than 0.75 fluorescence intensity ratios (i.e. >75% tubal length fluorescence) was seen in 60% of fallopian tubes.Limitations, Reasons For Caution: This is a pilot study with a small sample size and pathologic uteri, which would not be appropriate for uterine transplantation. No conclusions can be made regarding the functionality of the fallopian tubes.Wider Implications Of the Findings: The fallopian tubes may have perfusion with the utero-ovarian vasculature alone, potentially allowing for future animal studies regarding tubal viability in recipients of uterine-tubal transplants. If successful, human uterine-tubal transplantation may allow for spontaneous conception rather than IVF.Study Funding/competing Interest(s): No external funding was used. S.F., P.F.P., K.A.S. and R.F. have no conflicts of interest to report. M.L.S. is an educational consultant for Medtronic (Dublin, Republic of Ireland) and Applied Medical (Rancho Santa Margarita, CA, USA), as well as a stockholder for SynDaver Labs (Tampa, FL, USA). S.E.Z. is an educational consultant for Applied Medical (Rancho Santa Margarita, CA, USA) and is on the advisory board for AbbVie Inc. (Chicago, IL, USA).Trial Registration Number: Not applicable. [ABSTRACT FROM AUTHOR]

Background. BRCA gene mutations significantly increase the risk of breast and ovarian cancers where the lifetime risk of the ovarian cancer is about 40%. Therefore, many women with such mutations undergo prophylactic bilateral mastectomy and salpingo-oophorectomy. About 5-6% of these individuals display occult carcinomas in tubo-ovarian locations of which over 85% are tubal in origin. The objective of this case study was to emphasize emergence of benign lesions mimicking cancer under these circumstances. Case Report. We present a case with positive BRCA1 mutation who underwent the prophylactic procedure where a small mass was identified in her fallopian tube. Our initial encounter with this tumor was during intraoperative consultation. The tumor was associated with extensive psammoma bodies arranged in closely packed small tubules, mimicking serous carcinoma. Frozen section limitations including artifact, time constraint, and lack of ancillary studies as well as the clinical history further complicated our diagnostic assessment, which was deferred. A diagnosis of adenomatoid tumor was rendered on permanent sections. Conclusion. It is important to be familiar with this morphologic presentation of adenomatoid tumor as it is a pitfall for carcinoma, particularly on frozen section, and inaccurate diagnosis could lead to further unnecessary extensive procedures. [ABSTRACT FROM AUTHOR]

Summary: The reduction of iron oxide minerals and uranium in model metal reducers in the genus Geobacter is mediated by conductive pili composed primarily of a structurally divergent pilin peptide that is otherwise recognized, processed and assembled in the inner membrane by a conserved Type IVa pilus apparatus. Electronic coupling among the peptides is promoted upon assembly, allowing the discharge of respiratory electrons at rates that greatly exceed the rates of cellular respiration. Harnessing the unique properties of these conductive appendages and their peptide building blocks in metal bioremediation will require understanding of how the pilins assemble to form a protein nanowire with specialized sites for metal immobilization. Also important are insights into how cells assemble the pili to make an electroactive matrix and grow on electrodes as biofilms that harvest electrical currents from the oxidation of waste organic substrates. Genetic engineering shows promise to modulate the properties of the peptide building blocks, protein nanowires and current‐harvesting biofilms for various applications. This minireview discusses what is known about the pilus material properties and reactions they catalyse and how this information can be harnessed in nanotechnology, bioremediation and bioenergy applications. The conductive pili of metal‐reducing Geobacter bacteria show promise to develop novel biomaterials for applications in nanotechnology, bioremediation and bioenergy. [ABSTRACT FROM AUTHOR]

Abstract In February 2017 a case of Hemolytic-Uremic Syndrome (HUS) was reported to the National Registry of HUS in an adult living in Northern Italy. Stool specimens from the patient and his family contacts were collected and the analyses led to the isolation of a Locus of Enterocyte Effacement (LEE)-negative Shiga toxin 2 (Stx2)-producing Escherichia coli. The epidemiological investigations performed brought to collect fecal samples from the animals reared in a farm held by the case's family and a mixture of bovine and swine feces proved positive for Shiga toxin-producing E. coli (STEC) and yielded the isolation of a LEE-negative stx2 -positive E. coli strain. Further characterization by whole genome sequencing led to identify the isolates as two identical O2:H27 hybrid Enterotoxigenic Shiga toxin-producing E. coli (ETEC-STEC). Sequencing of a high molecular weight plasmid present in the human isolate disclosed a peculiar plasmid harboring virulence genes characteristic for both pathotypes, including the enterohemolysin-coding gene and sta1 , encoding the heat stable enterotoxin. Moreover, a complete fae locus encoding the ETEC F4 fimbriae could be identified, including a novel variant of faeG gene responsible for the production of the main structural subunit of the fimbriae. This novel faeG showed great diversity in the nucleotidic sequence when compared with the reference genes encoding the swine F4 allelic variants, whereas at the amino acid sequence level the predicted protein sequence showed some similarity with FaeG from E. coli strains of bovine origin. Further investigation on the plasmid region harboring the newly identified faeG allelic variant allowed to identify similar plasmids in NCBI sequence database, as part of the genome of other previously uncharacterized ETEC-STEC strains of bovine origin, suggesting that the novel F4-like fimbriae may play a role in bovine host specificity. [ABSTRACT FROM AUTHOR]

Streptococcus suis is an important Gram-positive pathogen in the swine industry and is an emerging zoonotic pathogen for humans. In our previous work, we found a virulent S. suis strain, CZ130302, belonging to a novel serotype, Chz, to be associated with acute meningitis in piglets. However, its underlying mechanisms of pathogenesis remain poorly understood. In this study, we sequenced and analyzed the complete genomes of three Chz serotype strains, including strain CZ130302 and two avirulent strains, HN136 and AH681. By genome comparison, we found two putative genomic islands (GIs) uniquely encoded in strain CZ130302 and designated them 50K GI and 58K GI. In mouse infection model, the deletion of 50K and 58K GIs caused 270-fold and 3-fold attenuation of virulence, respectively. Notably, we identified a complete SecY2/A2 system, coupled with its secretory protein SssP1 encoded in the 50K GI, which contributed to the pathogenicity of strain CZ130302. Immunogold electron microscopy and immunofluorescence analyses indicated that SssP1 could form fimbria-like structures that extend outward from the bacterial cell surface. The sssP1 mutation also attenuated bacterial adherence in human laryngeal epithelial (HEp-2) cells and human brain microvessel endothelial cells (HBMECs) compared with the wild type. Furthermore, we showed that two analogous Ig-like subdomains of SssP1 have sialic acid binding capacities. In conclusion, our results revealed that the 50K GI and the inside SecY2/A2 system gene cluster are related to the virulence of strain CZ130302, and we clarified a new S. suis pathogenesis mechanism mediated by the secretion protein SssP1. IMPORTANCE: Streptococcus suis is an important zoonotic pathogen. Here, we managed to identify key factors to clarify the virulence of S. suis strain CZ130302 from a novel serotype, Chz. Notably, it was shown that a fimbria-like structure was significantly connected to the pathogenicity of the CZ130302 strain by comparative genomics analysis and animal infection assays. The mechanisms of how the CZ130302 strain constructs these fimbria-like structures in the cell surface by genes encoding and production transport were subsequently elucidated. Biosynthesis of the fimbria-like structure was achieved by the production of SssP1 glycoproteins, and its construction was dependent on the SecA2/Y2 secretion system. This study identified a visible fimbria-like protein, SssP1, participating in adhesion to host cells and contributing to the virulence in S. suis. These findings will promote a better understanding of the pathogenesis of S. suis. [ABSTRACT FROM AUTHOR]

Ralstonia solanacearum is an important plant pathogen which infects a large number of agriculturally important crops. The Type Three Secretion System (T3SS) plays a major role in its pathogenicity by secreting type III effectors (T3Es) which overthrow the host defence mechanism. The secretion of T3Es is transcriptionally regulated by hrpB and its secretion is dependent on the pili formed by hrcV gene. In this study, two T3SS mutants of R. solanacearum strain Rs-09-161 viz. Rs-HrpB− and Rs-HrcV− were developed through insertional mutagenesis. The method of development of insertional mutant is quite simple and reliable. The plasmid integrates through homologous recombination and in vitro studies have proved that the integration was stable for several generations. The mutants are non-pathogenic on its highly susceptible hosts, brinjal and tomato inoculated by soil drench method and by petiole inoculation directly into the vascular system. Further it was observed that the colonisation ability of the mutants was also highly reduced in the susceptible host. These mutants will be useful in validating putative T3E through translocation studies. [ABSTRACT FROM AUTHOR]

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a zoonotic pathogen of worldwide importance that causes foodborne infections in humans. It is not capable of expressing type I fimbrial because of base deletion in the fim operon. BLAST analysis shows that the open reading frame z3276, a specific genetic marker of EHEC O157:H7, encodes a sequence with high amino acid identity to other E. coli type I fimbrial, but its definitive function in EHEC O157:H7 remains unclear. We are here to report that a z3276 mutant (κz3276) was constructed using the reference EHEC Oκ57:H7, the mutant κz3276 was biologically characterized, and the pathogenicity of κz3276 was assessed in mice in comparison with the wild-type (WT) strain. Motility and biofilm formation assays revealed a smaller twitching motility zone for κz3276 on the agar surface and significantly decreased biofilm formation by κz3276 compared with the parental strain. The adhesion and invasion ability of κz3276 to HEp-2 cells showed no significant change, but the invasion ability of κz3276 to IPEC-J2 cells was attenuated. Furthermore, in the animal study, we observed shortened and lower fecal shedding among the κz3276 mutant-infected animals compared with those infected WT strain. The data in this study indicate that this unique gene of z3276 in EHEC Oκ57:H7 seems to play an important role in bacterial pathogenicity. [ABSTRACT FROM AUTHOR]

Type IV pili (T4P) are surface-exposed protein fibers that play key roles in the bacterial life cycle via surface attachment/adhesion, biofilm formation, motility, and development. The order Myxococcales (myxobacteria) are members of the class Deltaproteobacteria and known for their large genome size and complex social behaviors, including gliding motility, fruiting body formation, biofilm production, and prey hunting. Myxococcus xanthus, the best-characterized member of the order, relies on the appropriate expression of 17 type IVa (T4aP) genes organized in a single cluster plus additional genes (distributed throughout the genome) for social motility and development. Here, we compared T4aP genes organization within the myxobacteria to understand their evolutionary origins and diversity. We found that T4aP genes are organized as large clusters in suborder Cystobacterineae, whereas in other two suborders Sorangiineae and Nannocystineae, these genes are dispersed throughout the genome. Based on the genomic organization, the phylogeny of conserved proteins, and synteny studies among 28 myxobacterial and 66 Proteobacterial genomes, we propose an evolutionary model for the origin of myxobacterial T4aP genes independently from other orders in class Deltaproteobacteria. Considering a major role for T4P, this study further proposes the origins and evolution of social motility in myxobacteria and provides a foundation for understanding how complex-behavioral traits, such as gliding motility, multicellular development, etc., might have evolved in this diverse group of complex organisms. [ABSTRACT FROM AUTHOR]

The bacterial type IV pilus (T4P) is a versatile nanomachine that functions in pathogenesis, biofilm formation, motility, and horizontal gene transfer. T4P assembly is powered by the motor ATPase PilB which is proposed to hydrolyze ATP by a symmetrical rotary mechanism. This mechanism, which is deduced from the structure of PilB, is untested. Here, we report the first kinetic studies of the PilB ATPase, supporting coordination among the protomers of this hexameric enzyme. Analysis of the genome sequence of Chloracidobacterium thermophilum identified a pilB gene whose protein we then heterologously expressed. This PilB formed a hexamer in solution and exhibited highly robust ATPase activity. It displays complex steady-state kinetics with an incline followed by a decline over an ATP concentration range of physiological relevance. The incline is multiphasic and the decline signifies substrate inhibition. These observations suggest that variations in intracellular ATP concentrations may regulate T4P assembly and T4P-mediated functions in vivo in accordance with the physiological state of bacteria with unanticipated complexity. We also identified a mutant pilB gene in the genomic DNA of C. thermophilum from an enrichment culture. The mutant PilB variant, which is significantly less active, exhibited similar inhibition of its ATPase activity by high concentrations of ATP. Our findings here with the PilB ATPase from C. thermophilum provide the first line of biochemical evidence for the coordination among PilB protomers consistent with the symmetrical rotary model of catalysis based on structural studies. [ABSTRACT FROM AUTHOR]

Chitosan-oligosaccharides (COS) are suitable acceptors for β-galactosidase, and galactosylated-COS prevent adhesion of enterotoxigenic Escherichia coli (ETEC) K88 to porcine erythrocytes. The structure and functional relationship of oligosaccharide binding to ETEC K88 fimbriae was investigated. β- or α-galacto-oligosaccharides (βGOS and αGOS), β-galactosylated melibiose, α-galactosylated lactose and β-/ɑ-galactosylated COS were produced with β-/α-galactosidase using lactose or melibiose as galactosyl donor. Oligosaccharides were fractionated with cation exchange and size exclusion chromatography; their ability to prevent pathogen adhesion was measured with a hemagglutination assay, ELISA with ETEC cells, or with purified K88 fimbriae. High molecular weight β-GalCOS, β-galactosylated melibiose, and βGOS had strong anti-adhesion activity. Other oligosaccharides had weak or no anti-adhesive effects against ETEC K88. The ability of oligosaccharides to prevent binding of ETEC K88 or purified K88 fimbriae decreased with decreasing molecular weight. An avenue for valorization of lactose from whey to produce oligosaccharides with specific biological activity is suggested. [ABSTRACT FROM AUTHOR]

Type IV pili are expressed by a wide range of prokaryotes, including the opportunistic pathogen Pseudomonas aeruginosa. These flexible fibres mediate twitching motility, biofilm maturation, surface adhesion, and virulence. The pilus is composed mainly of major pilin subunits while the low abundance minor pilins FimU-PilVWXE and the putative adhesin PilY1 prime pilus assembly and are proposed to form the pilus tip. The minor pilins and PilY1 are encoded in an operon that is positively regulated by the FimS-AlgR two-component system. Independent of pilus assembly, PilY1 was proposed to be a mechanosensory component that—in conjunction with minor pilins—triggers up-regulation of acute virulence phenotypes upon surface attachment. Here, we investigated the link between the minor pilins/PilY1 and virulence. pilW, pilX, and pilY1 mutants had reduced virulence towards Caenorhabditis elegans relative to wild type or a major pilin mutant, implying a role in pathogenicity that is independent of pilus assembly. We hypothesized that loss of specific minor pilins relieves feedback inhibition on FimS-AlgR, increasing transcription of the AlgR regulon and delaying C. elegans killing. Reporter assays confirmed that FimS-AlgR were required for increased expression of the minor pilin operon upon loss of select minor pilins. Overexpression of AlgR or its hyperactivation via a phosphomimetic mutation reduced virulence, and the virulence defects of pilW, pilX, and pilY1 mutants required FimS-AlgR expression and activation. We propose that PilY1 and the minor pilins inhibit their own expression, and that loss of these proteins leads to FimS-mediated activation of AlgR that suppresses expression of acute-phase virulence factors and delays killing. This mechanism could contribute to adaptation of P. aeruginosa in chronic lung infections, as mutations in the minor pilin operon result in the loss of piliation and increased expression of AlgR-dependent virulence factors–such as alginate–that are characteristic of such infections. [ABSTRACT FROM AUTHOR]

The traffic ATPase PilF of Thermus thermophilus powers pilus assembly as well as uptake of DNA. PilF differs from other traffic ATPases by a triplicated general secretory pathway II, protein E, N-terminal domain (GSPIIABC). We investigated the in vivo and in vitro roles of the GSPII domains, the Walker A motif and a catalytic glutamate by analyzing a set of PilF deletion derivatives and pilF mutants. Here, we report that PilF variants devoid of the first two or all three GSPII domains do not form stable hexamers indicating a role of the triplicated GSPII domain in complex formation and/or stability. A pilFΔGSPIIC mutant was significantly impaired in piliation which leads to the conclusion that the GSPIIC domain plays a vital role in pilus assembly. Interestingly, the pilFΔGSPIIC mutant was hypertransformable. This suggests that GSPIIC strongly affects transformation efficiency. A pilF∆GSPIIA mutant exhibited wild-type piliation but reduced pilus-mediated twitching motility, suggesting that GSPIIA plays a role in pilus dynamics. Furthermore, we report that pilF mutants with a defect in the ATP binding Walker A motif or in the catalytic glutamate residue are defective in piliation and natural transformation. These findings show that both, ATP binding and hydrolysis, are essential for the dual function of PilF in natural transformation and pilus assembly. [ABSTRACT FROM AUTHOR]

Using multigenerational, single-cell tracking we explore the earliest events of biofilm formation by Pseudomonas aeruginosa. During initial stages of surface engagement (≤20 h), the surface cell population of this microbe comprises overwhelmingly cells that attach poorly (~95% stay <30 s, well below the ~1-h division time) with little increase in surface population. If we harvest cells previously exposed to a surface and direct them to a virgin surface, we find that these surface-exposed cells and their descendants attach strongly and then rapidly increase the surface cell population. This "adaptive," time-delayed adhesion requires determinants we showed previously are critical for surface sensing: type IV pili (TFP) and cAMP signaling via the Pil-Chp-TFP system. We show that these surface-adapted cells exhibit damped, coupled out-of-phase oscillations of intracellular cAMP levels and associated TFP activity that persist for multiple generations, whereas surface-naïve cells show uncorrelated cAMP and TFP activity. These correlated cAMP-TFP oscillations, which effectively impart intergenerational memory to cells in a lineage, can be understood in terms of a Turing stochastic model based on the Pil-Chp-TFP framework. Importantly, these cAMP-TFP oscillations create a state characterized by a suppression of TFP motility coordinated across entire lineages and lead to a drastic increase in the number of surface-associated cells with near-zero translational motion. The appearance of this surface-adapted state, which can serve to define the historical classification of "irreversibly attached" cells, correlates with family tree architectures that facilitate exponential increases in surface cell populations necessary for biofilm formation. [ABSTRACT FROM AUTHOR]

Introduction: Streptococcus pneumoniae is a Gram-positive, bacterial human pathogen that causes a large number of respiratory tract infections, such as pneumonia and sinusitis, as well as invasive diseases such as septicemia and meningitis. Among the surface-exposed virulence factors, the pneumococcal pilus has been shown to play a role in host-cell adhesion. Hemagglutinin activity has been shown to correlate with adhesion ability. The purpose of this study was to identify of S. pneumoniae pili proteins with hemagglutinin activity, and to proteonomically analyze such proteins as potential vaccine candidates. Materials and Methods: The purification of pili was carried out by a pilus cutter method. After SDS-PAGE separation, pili proteins were purified by electroelution and dialysis. After a hemagglutinination assay with mouse erythrocytes, the hemagglutinin protein was identified with Liquid Chromatography/Mass Spectrometry, along with assessments of antigenicity and epitope mapping. Results: SDS-PAGE showed that pili protein had major bands of molecular weights of 67, 54, 25, and 11 kDa. The 54 kDa pili protein was the hemagglutinin. Computational bioinformatics analysis by Mascot Server revealed this hemagglutinin matched with the Rrgb protein of S. pneumoniae (gi: 299856655). Conclusion: The analysis of its antigenicity, and epitope mapping showed that a novel protein was identified as the pilus backbone (Rrgb) of Streptococcus pneumoniae, and has a high antigenicity suitable for further development as a vaccine candidate. [ABSTRACT FROM AUTHOR]

Although Enterococcus faecalis is known as normal flora in colon, it is also amongst the most common causative agents of infective endocarditis (IE). Platelet activation resulting from adherence to platelets is an essential step in the pathogenesis of IE. One of the factors proposed in adhesion is endocarditis‐ and biofilm‐ associated pili encoded by ebp operon. The aim of this study was to investigate ebp in isolates from different origins and analyze the potential of isolates to activate human platelets of different donors. The ebp distribution was investigated in E. faecalis from different origin infections (n = 103) and fecal flora (n = 20). Then, selected isolates from blood (n = 5), urine (n = 2), and fecal flora (n = 3) were analyzed by flow cytometry assay for the ability to activate platelets of four different donors. No statistically significant difference was found for the ebp presence between infective and fecal isolates. Also, it was found that the ability for platelet activation is independent of the bacterial origin. However, significant difference was found in platelet activation between different donors. The results suggest that the presence or absence of ebp is not a critical factor for platelet activation by E. faecalis isolates. However, host factors seem to contribute in this activity. [ABSTRACT FROM AUTHOR]

Biofilm formation on abiotic surfaces in the food and medical industry can cause severe contamination and infection, yet how biological and physical factors determine the cellular architecture of early biofilms and the bacterial behavior of the constituent cells remains largely unknown. In this study, we examined the specific role of type I fimbriae in nascent stages of biofilm formation and the response of microcolonies to environmental flow shear at the single-cell resolution. The results show that type I fimbriae are not required for reversible adhesion from plankton, but they are critical for the irreversible adhesion of Escherichia coli strain MG1655 cells that form biofilms on polyethylene terephthalate (PET) surfaces. Besides establishing firm cell surface contact, the irreversible adhesion seems necessary to initiate the proliferation of E. coli on the surface. After the application of shear stress, bacterial retention is dominated by the three-dimensional architecture of colonies, independent of the population size, and the multilayered structure could protect the embedded cells from being insulted by fluid shear, while the cell membrane permeability mainly depends on the biofilm population size and the duration of the shear stress. [ABSTRACT FROM AUTHOR]

The NLRP3 inflammasome and IL-1β release have recently been suggested to be important for the progression of urinary tract infection (UTI). However, much is still unknown regarding the interaction of UPEC and the NLRP3 inflammasome. The purpose of this study was to elucidate what virulence factors uropathogenic Escherichia coli (UPEC) use to modulate NLRP3 inflammasome activation and subsequent IL-1β release and the role of NLRP3 for UPEC colonization of bladder epithelial cells. The bladder epithelial cell line 5637, CRISPR/Cas9 generated NLRP3, caspase-1 and mesotrypsin deficient cell lines and transformed primary bladder epithelial cells (HBLAK) were stimulated with UPEC isolates and the non-pathogenic MG1655 strain. We found that the UPEC strain CFT073, but not MG1655, induced an increased caspase-1 activity and IL-1β release from bladder epithelial cells. The increase was shown to be mediated by α-hemolysin activation of the NLRP3 inflammasome in an NF-κB-independent manner. The effect of α-hemolysin on IL-1β release was biphasic, initially suppressive, later inductive. Furthermore, the phase-locked type-1-fimbrial ON variant of CFT073 inhibited caspase-1 activation and IL-1β release. In addition, the ability of CFT073 to adhere to and invade NLRP3 deficient cells was significantly reduced compare to wild-type cells. The reduced colonization of NLRP3-deficient cells was type-1 fimbriae dependent. In conclusion, we found that the NLRP3 inflammasome was important for type-1 fimbriae-dependent colonization of bladder epithelial cells and that both type-1 fimbriae and α-hemolysin can modulate the activity of the NLRP3 inflammasome. [ABSTRACT FROM AUTHOR]

Pertussis or whooping cough is currently the most prevalent vaccine-preventable childhood disease despite >85% global vaccination coverage. In recent years incidence has greatly increased in several high-income countries that have switched from the first-generation, whole-cell vaccine to the newer acellular vaccines, calling for improved vaccination strategies with better vaccines. We have developed a live attenuated pertussis vaccine candidate, called BPZE1, which is currently in clinical development. Unlike other pertussis vaccines, BPZE1 has been shown to provide strong protection against infection by the causative agent of pertussis, Bordetella pertussis , in non-human primates. BPZE1 is a derivative of the B. pertussis strain Tohama I, which produces serotype 2 (Fim2) but not serotype 3 fimbriae (Fim3). As immune responses to fimbriae are likely to contribute to protection, we constructed a BPZE1 derivative, called BPZE1f3, that produces both serotypes of fimbriae. Whereas nasal vaccination of mice with BPZE1 induced antibodies to Fim2 but not to Fim3, vaccination with BPZE1f3 elicited antibodies to both Fim2 and Fim3 at approximately the same level. In mice, both BPZE1 and BPZE1f3 provided equal levels of protection against clinical isolates that either produce Fim2 alone, both Fim2 and Fim3, or no fimbriae. However, vaccination with BPZE1f3 provided significantly stronger protection against Fim3-only producing B. pertussis than vaccination with BPZE1, indicating that immune responses to fimbriae contribute to serotype-specific protection against B. pertussis infection. [ABSTRACT FROM AUTHOR]

Objective: Dichelobacter nodosus is the causative agent of footrot in sheep. Ovine footrot is a major problem in Australia that results in large economic losses and a represents a very significant animal welfare issue. D. nodosus is divided into 10 serogroups (A-I, M), based on sequence variation in the type IV fimbriae gene, fimA. Control of the bacteria is possible through use of serogroup-specific vaccination, however traditional identification of the serogroups of D. nodosus on infected sheep is time-consuming and costly. With the aim of reducing time and cost, a PCR assay was used to identify serogroups of D. nodosus directly from foot swabs of infected sheep in Victoria. Results: It was shown that serogroup B was most common (10 locations), followed by A, G and H (4 locations), I and C (2 locations), D, E and F (1 location). Infections with multiple serotypes were observed in 50% of farms, with the remaining 50% having only a single serogroup detected. The ability to identify serogroups quickly and cheaply direct from foot swabs will aid the understanding of the epidemiology of D. nodosus and support control programs. [ABSTRACT FROM AUTHOR]

Summary: Archaea are ubiquitously present in nature and colonize environments with broadly varying growth conditions. Several surface appendages support their colonization of new habitats. A hallmark of archaea seems to be the high abundance of type IV pili (T4P). However, some unique non T4 filaments are present in a number of archaeal species. Archaeal surface structures can mediate different processes such as cellular surface adhesion, DNA exchange, motility and biofilm formation and represent an initial attachment site for infecting viruses. In addition to the functionally characterized archaeal T4P, archaeal genomes encode a large number of T4P components that might form yet undiscovered surface structures with novel functions. In this review, we summarize recent advancement in structural and functional characterizations of known archaeal surface structures and highlight the diverse processes in which they play a role. [ABSTRACT FROM AUTHOR]

The human pathogen Vibrio parahaemolyticus is a leading cause of seafood-borne illness in the USA, and infections with V. parahaemolyticus typically result from eating raw or undercooked oysters. V. parahaemolyticus has been shown to be highly resistant to oyster depuration, suggesting that the bacterium possesses specific mechanisms or factors for colonizing oysters and persisting during depuration. In this study, we characterized eight different V. parahaemolyticus strains for differences in resistance to oyster depuration, biofilm formation, and motility. While each strain exhibited distinct phenotypes in the various assays, we determined that biofilm formation on abiotic surfaces, such as glass or plastic, does not directly correlate with bacterial retention in oysters during depuration. However, we did observe that the motility phenotype of a strain appeared to be a better indicator for persistence in the oyster. Further studies examining the molecular mechanisms underlying the observed colonization differences by these and other V. parahaemolyticus strains may provide beneficial insights into what critical factors are required for proficient colonization of the Pacific oyster. [ABSTRACT FROM AUTHOR]

Uropathogenic E. coli (UPEC), which cause urinary tract infections (UTI), utilize type 1 pili, a chaperone usher pathway (CUP) pilus, to cause UTI and colonize the gut. The pilus rod, comprised of repeating FimA subunits, provides a structural scaffold for displaying the tip adhesin, FimH. We solved the 4.2 Å resolution structure of the type 1 pilus rod using cryo-electron microscopy. Residues forming the interactive surfaces that determine the mechanical properties of the rod were maintained by selection based on a global alignment of fimA sequences. We identified mutations that did not alter pilus production in vitro but reduced the force required to unwind the rod. UPEC expressing these mutant pili were significantly attenuated in bladder infection and intestinal colonization in mice. This study elucidates an unappreciated functional role for the molecular spring-like property of type 1 pilus rods in host-pathogen interactions and carries important implications for other pilus-mediated diseases. [ABSTRACT FROM AUTHOR]

Background/aim: Biofilm formation is a major determinant factor in the development of urinary tract infections (UTIs) by uropathogenic Escherichia coli (UPEC). Several adhesion factors are involved in attachment of bacterial cells to the urinary tract and biofilm development. Materials and methods: The possible relationship between different adhesion factor genes (AFGs) and biofilm formation among UPEC isolates was investigated. Prevalence of different AFGs including fimA, fimH, papAH, papC, papEF, sfa-S, foc/G, and bmaE and their association to biofilm formation were investigated. Phenotypic expression of type 1 and P fimbriae was also investigated. Results: Our results showed that 84% of UPEC were moderate to strong biofilm producers. Prevalence of the type 1 and P fimbriae associated genes (fimA, fimH, papEF, papC) as well as the F1C fimbriae gene (foc/G) did not show a difference among different biofilm-producing groups, while higher prevalence of papAH, bmaE (M fimbriae), and sfaS (S-fimbriae) was observed for the strains producing moderate to strong biofilms. Phenotypic expression of type 1 fimbriae was associated with biofilm formation, while no association was observed for P fimbriae. Conclusion: Different AFGs (especially M and S fimbria) and their expression levels affect the biofilm formation ability of UPEC. [ABSTRACT FROM AUTHOR]

Electron shuttles extensively exist in various environments. Some kinds of organic substances can be applied by microorganisms to produce electrons, and then the electrons can be transferred to other substances or microorganisms through electron shuttles, resulting in coexistence and interaction of diverse species of microbes. In this review, the functional mechanisms of extracellular electron transfer mediated by different electron shuttles are described. And different subtypes as well as the application of electron shuttles in microbial degradation of pollutants, microbial electricity, and the promotion of energy generation are also discussed. Summary results show that extracellular electron transfer is based on the electrogenesis microorganism with the structure of cytochromes or pili. Materials were usually used in long-distance electron transfer because of their widespread presence and abundance. Therefore, the review is beneficial to perceive the pathways of extracellular electron transfer mediated by electron shuttles and explore the contribution of different electron shuttles in extracellular electron transfer. [ABSTRACT FROM AUTHOR]

In Geobacter sulfurreducens, metal reduction and generation of bioelectricity require the participation of several elements, and among them, the type IV pili has an essential role. The pilus is composed of multiple PilA monomers. Expression of pilA gene depends mainly on the σ54 factor and the response regulator protein PilR. In this work, we characterized the role of the PilS-PilR two-component system in the regulation of the pilA gene expression. Experimental evidence indicates that PilS is autophosphorylated at the His-334 residue, which in turn is transferred to the conserved Asp-53 in PilR. Contrary to other PilS-PilR systems, substitution D53N in PilR resulted in higher activation of the pilA gene. By using a pilA::luxCDABE fusion with different promoter fragments and in vitro DNA-binding assays, we demonstrated the existence of multiple functional PilR binding sites. A regulatory model in which the non-phosphorylated PilR protein directs activation of pilA expression by binding to two sites in the promoter region of this gene is presented. [ABSTRACT FROM AUTHOR]

It is critical for bacteria to recognize surface contact and initiate physiological changes required for surface-associated lifestyles. Ubiquitous microbial appendages called pili are involved in sensing surfaces and facilitating downstream behaviors, but the mechanism by which pili mediate surface sensing has been unclear. We visualized Caulobacter crescentus pili undergoing dynamic cycles of extension and retraction. Within seconds of surface contact, these cycles ceased, which coincided with synthesis of the adhesive holdfast required for attachment. Physically blocking pili imposed resistance to pilus retraction, which was sufficient to stimulate holdfast synthesis without surface contact. Thus, to sense surfaces, bacteria use the resistance on retracting, surface-bound pili that occurs upon surface contact. [ABSTRACT FROM AUTHOR]

Bacteria produce protein polymers on their surface called pili or fimbriae that serve either as attachment devices or as conduits for secreted substrates. This review will focus on the chaperone–usher pathway of pilus biogenesis, a widespread assembly line for pilus production at the surface of Gram-negative bacteria and the archetypical protein-polymerizing nanomachine. Comparison with other nanomachines polymerizing other types of biological units, such as nucleotides during DNA replication, provides some unifying principles as to how multidomain proteins assemble biological polymers. [ABSTRACT FROM AUTHOR]

The Gram-negative bacterium Kingella kingae is part of the normal oropharyngeal mucosal flora of children <4 years old. K. kingae can enter the submucosa and cause infections of the skeletal system in children, including septic arthritis and osteomyelitis. The organism is also associated with infective endocarditis in children and adults. Although biofilm formation has been coupled with pharyngeal colonization, osteoarticular infections, and infective endocarditis, no studies have investigated biofilm formation in K. kingae. In this study we measured biofilm formation by 79 K. kingae clinical isolates using a 96-well microtiter plate crystal violet binding assay. We found that 37 of 79 strains (47%) formed biofilms. All strains that formed biofilms produced corroding colonies on agar. Biofilm formation was inhibited by proteinase K and DNase I. DNase I also caused the detachment of pre-formed K. kingae biofilm colonies. A mutant strain carrying a deletion of the pilus gene cluster pilA1pilA2fimB did not produce corroding colonies on agar, autoaggregate in broth, or form biofilms. Biofilm forming strains have higher levels of pilA1 expression. The extracellular components of biofilms contained 490 μg cm-2 of protein, 0.68 μg cm-2 of DNA, and 0.4 μg cm-2 of total carbohydrates. We concluded that biofilm formation is common among K. kingae clinical isolates, and that biofilm formation is dependent on the production of proteinaceous pili and extracellular DNA. Biofilm development may have relevance to the colonization, transmission, and pathogenesis of this bacterium. Extracellular DNA production by K. kingae may facilitate horizontal gene transfer within the oral microbial community. [ABSTRACT FROM AUTHOR]

It was suggested that minor differences in the structure of FimH are most likely associated with differences in its adhesion specificities and may determine the tropism of various Salmonella serovars to different species and tissues. We have recently shown that FimH adhesins from host-adapted serovars, e.g., Salmonella Choleraesuis (SCh), bind to other glycoprotein receptors compared to FimH from host-unrestricted Salmonella Enteritidis (SE). Here we identify porcine calreticulin expressed by swine intestinal cells as a host-specific receptor for SCh FimH adhesin, suggesting that such an interaction may contribute to SCh host specificity. Calreticulin was identified by 2D electrophoresis and mass spectrometry as a glycoprotein that was bound specifically by recombinant SCh FimH protein, but not by FimH from SE. The functionality of calreticulin as a specific receptor of SCh FimH adhesin was further confirmed by adhesion and invasion of mutated strains of SCh carrying different variants of FimH proteins to IPEC-J2 cells with overexpression and silenced expression of calreticulin. It was found that SCh carrying the active variant of FimH adhered and invaded IPEC-J2 cells with calreticulin overexpression at significantly higher numbers than those of SCh expressing the non-active variant or SE variant of FimH. Moreover, binding of SCh carrying the active variant of FimH to IPEC-J2 with silenced calreticulin expression was significantly weaker. Furthermore, we observed that SCh infection induces translocation of calreticulin to cell membrane. All of the aforementioned results lead to the general conclusion that Salmonella host specificity requires not only special mechanisms and proteins expressed by the pathogen but also specifically recognized receptors expressed by a specific host. [ABSTRACT FROM AUTHOR]

The hair-like cell appendages denoted as type IV pili are crucial for biofilm formation in diverse eubacteria. The protein complex responsible for type IV pilus assembly is homologous with the type II protein secretion complex. In the cyanobacterium Synechococcus elongatus PCC 7942, the gene Synpcc7942_2071 encodes an ATPase homologue of type II/type IV systems. Here, we report that inactivation of Synpcc7942_2071 strongly affected the suite of proteins present in the extracellular milieu (exo-proteome) and eliminated pili observable by electron microscopy. These results support a role for this gene product in protein secretion as well as in pili formation. As we previously reported, inactivation of Synpcc7942_2071 enables biofilm formation and suppresses the planktonic growth of S. elongatus. Thus, pili are dispensable for biofilm development in this cyanobacterium, in contrast to their biofilm-promoting function in type IV pili-producing heterotrophic bacteria. Nevertheless, pili removal is not required for biofilm formation as evident by a piliated mutant of S. elongatus that develops biofilms. We show that adhesion and timing of biofilm development differ between the piliated and non-piliated strains. The study demonstrates key differences in the process of biofilm formation between cyanobacteria and well-studied type IV pili-producing heterotrophic bacteria. [ABSTRACT FROM AUTHOR]