After a longer period of monocular vision (6.5 h) or exclusively discordant binocular experience (strabismus), sequential stimulation was accompanied by a significant increase of this population, whereas during randomized stimulation it was very similar to that in cats with short periods of daily monocular vision. Finally, there were no differences

in populations of ‘unstable’ cells in cats with long monocular or strabismic vision and those with exclusive monocular experience during sequential stimulation, in contrast with a significant increase in the latter during randomized stimulation. I propose that the detrimental effect of abnormal binocular selleck chemical experience on binocular processing in the primary visual cortex is associated with a disruption of the mechanisms involved in both discrimination of binocular disparity signals and evaluation of their temporal profiles. “
“The brain of adult teleost fish exhibits several unique and interesting features, notably an intense neurogenic activity linked to persistence of

radial glial cells acting as neural progenitors, and a high aromatase activity supported by strong expression of the cyp19a1b gene. Strikingly, cyp19a1b expression is restricted to radial glial cells, suggesting that estrogens are able to modulate their activity. This raises the question of the origin, central or peripheral, of C19 androgens available for aromatization. This study aimed to investigate the activity and expression of other main steroidogenic enzymes in the brain of adult zebrafish. We demonstrate by high-performance liquid chromatography that the zebrafish brain has the ability

to convert http://www.selleckchem.com/products/dinaciclib-sch727965.html Phospholipase D1 [3H]-pregnenolone into a variety of radiolabeled steroids such as 17OH-pregnenolone, dehydroepiandrosterone, androstenedione, testosterone, dihydro-testosterone, estrone, estradiol, progesterone, and dihydro- and tetrahydro-progesterone. Next, we show by in situ hybridization that messengers for key steroidogenic enzymes, such as Cyp11a1 (P450SCC), 3β-Hsd, Cyp17 and Cyp19a1b, are widely expressed in the forebrain where they exhibit an overall similar pattern. By combining aromatase B immunohistochemistry with in situ hybridization, we show that cyp11a1, 3β-hsd and cyp17 messengers are found in part in aromatase B-positive radial processes, suggesting mRNA export. This set of results provides the first demonstration that the brain of fish can produce true neurosteroids, possibly in radial glial cells. Given that radial glial cells are brain stem cells during the entire lifespan of fish, it is suggested that at least some of these neurosteroids are implicated in the persisting neurogenic process. “
“Stress during pregnancy in humans is known to be a risk factor for neuropsychiatric disorders in the offspring. Prenatal stress in rats caused depressive-like behavior that was restored to that of controls by maternal treatment with ladostigil (8.

, 2002; Ji et al., 2004) and to discover novel antibacterial inhibitors

(Young et al., 2006; Wang et al., 2007). Furthermore, hundreds of S. aureus asRNA strains have been configured into a TargetArray, which was employed to study mechanisms of selleckchem action of antibacterial inhibitors (Donald et al., 2009; Xu et al., 2010). Thus, regulated asRNA expression has a great potential for antibiotic drug discovery. However, the regulated asRNA approach has seen limited success in Gram-negative bacteria, including E. coli. There have been no published reports describing the adoption of the regulated asRNA approach for comprehensive genome-wide essential gene determination and/or silencing in Gram-negative bacteria. It has been recognized that asRNA-mediated down-regulation of gene expression in E. coli is inefficient for reasons not yet clearly understood (Wagner & Flardh, 2002). Attempts to improve the efficiency were rather frustrating initially (Engdahl et al., 2001). Several years ago, a series of expression vectors were designed such that expressed asRNA molecules have paired-termini to enhance their stability and hence gene knock-down efficiency PD-0332991 ic50 in E. coli (Nakashima et al., 2006). In this report, we present a first genome-wide attempt to obtain cell growth inhibitory E. coli

asRNA constructs through phenotypic screening two shotgun genomic libraries based on a paired-termini expression vector, pHN678 (Nakashima et al., 2006). Our results will stimulate further studies of gene functions, coordinated gene expression on operons and interactions of cellular processes via regulated asRNA in E. coli. Furthermore, the collection of the E. coli asRNA clones generated using this approach will be a valuable tool in the antibiotic drug discovery, especially for therapeutics targeting Gram-negative bacterial pathogens. Genomic Etofibrate DNA was extracted from E. coli MG1655 cells (American Type Culture Collection, Manassas, VA) using the Wizard Genomic DNA Purification Kit (Promega, Madison, WI) followed by partial digest with Sau3AI

or CviKI-1 (NEB, Ipswich, MA). The resulting DNA fragments (200–800 bp) were purified from agarose gels using the Zymoclean Gel DNA Recovery Kit (Zymo Research, Orange, CA). Plasmid vector was digested with BamHI (if Sau3AI was used to digest the genomic DNA) or SnaBI (if CviKI-1 was used), dephosphorylated using Antarctic Phosphatase (NEB) and then ligated with the inserts using the T4 DNA ligase (Life Technologies, Carlsbad, CA). Ligation mixtures were transformed into E. coli DH5α competent cells (Life Technologies) and plated onto LB agar plates plus 34 μg mL−1 chloramphenicol. Cloning efficiency of the pHN678 library was determined by colony PCR using the following primers: 5′-CGACATCATAACGGTTCTGGCAAAT-3′ (forward) and 5′-GACCGCTTCTGCGTTCTGATTT-3′ (reverse) (Eurofins MWG Operon, Huntsville, AL).

Each experimental group contained 20 mice. To investigate the effects of check details IAL treatment, mice were administered 100 μL of IAL subcutaneously 2 h after infection with S. aureus and then at 12-h intervals thereafter for a total of six doses. The control mice were treated with 100 μL

of sterile PBS on the same schedule. For histopathologic analysis, mice were euthanized with anesthesia followed by cervical dislocation. The lungs were placed in 1% formalin. Formalin-fixed tissues were processed, stained with hematoxylin and eosin, and visualized by light microscopy. The experimental data were analyzed with spss 12.0 statistical software. An independent Student’s t-test was used to determine statistical significance, and a P value < 0.05 was considered to be statistically significant. As presented in Table 1, the MIC values for IAL that were tested against S. aureus strains were > 1024 μg mL−1, which indicates that IAL does not inhibit the growth of S. aureus. Four α-toxin-producing S. aureus strains were cultured with increasing concentrations of IAL, and the culture supernatants were tested for the ability to perform hemolysis. As shown in Fig. 2a, treatment with IAL repressed the hemolytic activity in culture supernatants. The hemolytic units (HUs) in drug-free

culture fluids were 42.4, 38.2, 110.7, and 46.4 for S. aureus ATCC 29213, BAA-1717, Wood 46, and 8325-4, respectively. When 8 μg mL−1 of IAL was added to the media, the this website Ureohydrolase HUs were 1.2, 4.5, 14.1, and 0.6, respectively. Notably, a dose-dependent (1–8 μg mL−1) attenuation of hemolysis was observed in all the tested strains. Furthermore, drug-free culture supernatants preincubated with 8 μg mL−1 of IAL exhibited no difference in HUs, indicating that the reduction in hemolytic activity was not owing to direct interaction of IAL on α-toxin (data not shown). α-Toxin is the major toxin produced by S. aureus and can cause hemolysis of rabbit erythrocytes. Therefore, S. aureus culture supernatants were subjected to Western blot analysis to determine whether the reduced hemolytic activity was attributed to a decrease in the production of α-toxin. Ten nanograms of purified

α-toxin was used as a positive control. As expected, IAL reduced the production of α-toxin in a dose-dependent manner (Fig. 2b). The addition of 1 μg mL−1 IAL resulted in an undistinguished reduction in α-toxin; however, at 8 μg mL−1, no immunoreactive α-toxin antigen could be detected in the supernatants of the tested strains. The results were confirmed with hemolysis assay. Transcription of hla in S. aureus 8325-4 was measured using real-time RT-PCR. The expression of virulence factors in S. aureus is controlled by several global regulatory systems such as Agr, Sar, Sae, and Rot (Cheung & Zhang, 2002). The accessory gene regulator (Agr) is one of the best-characterized global regulatory systems and is known to regulate α-toxin.

In HIV-1-uninfected women, the data regarding the effect of screening for and treating BV Bleomycin concentration on premature delivery are conflicting. As outlined above, in HIV-positive pregnant women there

are additional considerations regarding the potential effect of genital infections on MTCT of HIV-1, but these data are largely from the pre-cART era. In the setting of full virological suppression on cART it is unclear to what extent, if any, the presence of any genital infection will contribute to HIV MTCT. Newly diagnosed HIV-positive pregnant women should be screened for sexually transmitted infections as per the routine management of newly diagnosed patients [48]. For pregnant HIV-1-positive women already engaged in HIV care, in the absence of randomized controlled trials but for the reasons outlined above, the Writing Group suggests screening for genital tract infections including evidence of BV. This should be done as early as possible in pregnancy and

consideration should be given to repeating this Selleck Doramapimod at around 28 weeks. Syphilis serology should be performed on both occasions. In addition, any infection detected should be treated according to the BASHH guidelines (www.bashh.org/guidelines), followed by a test of cure. Partner notification should take place where indicated, to avoid re-infection. With regard to cervical cytology, HIV-positive pregnant women should be managed as per the Guidelines for the NHS Cervical Screening Programme 2010 [49]. Routine cytology should be deferred until after the delivery, but if follow-up cytology or colposcopy is advised because of a previously abnormal result, then this should be undertaken. pentoxifylline 4.2.1 Newly diagnosed HIV-positive pregnant women do not require any additional baseline investigations compared with non-pregnant HIV-positive women other than those routinely performed in the general antenatal clinic. Grading: 1D 4.2.2 HIV resistance testing should be performed prior to initiation of treatment (as per BHIVA guidelines for the

treatment of HIV-1 positive adults with antiretroviral therapy 2012; www.bhiva.org/PublishedandApproved.aspx), except for late-presenting women. Post short-course treatment a further resistance test is recommended to ensure that mutations are not missed with reversion during the off-treatment period. Grading: 1D In the case of late-presenting women, cART, based on epidemiological assessment of resistance, should be initiated without delay and modified once the resistance test is available. 4.2.3 In women who either conceive on cART or who do not require cART for their own health there should be a minimum of one CD4 cell count at baseline and one at delivery. Grading: 2D 4.2.4 In women who commence cART in pregnancy a viral load should be performed 2–4 weeks after commencing cART, at least once every trimester, at 36 weeks and at delivery.

Patients who did not disclose their HIV status and who did not use condoms were more likely to be in relationships in which their spouse seroconverted. A study from South Africa reported that non-disclosure of HIV status to partners was associated with increased HIV transmission risk-taking behaviours [44]. Although rates of condom use in the current study increased during the 12 months of follow-up, more patients in seroconverting relationships did not use condoms than patients who were in serodiscordant relationships. The increasing use of condoms may be related to the regular risk reduction

counselling and free condoms provided by counsellors selleck chemical to HIV-infected patients and their spouses at each clinic visit. Earlier studies have documented inconsistent condom use among

serodiscordant couples [3], and that women in particular may find it difficult to negotiate condom use [4]. In India, female sterilization has historically been used as a means of family planning rather than broader reproductive health programmes that include contraception, prevention of STIs and addressing sexual violence against women [45]. Future interventions among serodiscordant couples will need to develop strategies to decrease alcohol consumption, promote HIV disclosure and normalize the use of condoms. The current study shares some of the methodological limitations OSI906 of similar observational studies related to sexual risk behaviour assessment based on self-reported behaviours, which may be affected by social desirability. Also the proportion of infections acquired from outside of marital relationships cannot be quantified. ADAMTS5 The current analysis only included data collected from the index patient who first enrolled into care, and similarly

to other epidemiological studies it was assumed that the index patient had first been infected with HIV and had consequently infected his/her partner. Certain factors that could affect HIV transmission, such as socio-economic characteristics, sexual violence and circumcision, were not systematically collected by clinicians and counsellors at every visit, and hence were not included in the present study. HIV status was assessed using antibody-based tests, and hence detection of acute infection using HIV-1 RNA quantification techniques was not done. Although patients in this study period may have been excluded, this is unlikely as the serostatus of spouses in serodiscordant relationships was examined on follow-up clinic visits. The present study was not designed to examine the pattern of exact transmission. It is very unlikely that transmission occurred outside the partner dyad as most individuals who seroconverted were women and our prior data have shown that most Indian women testing HIV positive at our clinic are in monogamous relationships [24]. The heterosexual transmission of HIV involves the complex interaction of both biological and behavioural factors.

The 20 fastest growing independent mycelia with distinct colony shapes were selected from each parental strain. Mating was conducted by placing mycelial blocks (3 × 3 mm) from opposite strains on the same PDA plate 1 cm apart. Mating was confirmed by the formation of clamp connections under the microscope after incubation at 30 °C for 7 days. RAPD analysis has shown some

strain-specific DNA bands in the gel. To develop the unique DNA bands as the strain-specific DNA markers, the DNA bands were excised and extracted with a DNA gel extraction kit (Solgent Co., Korea). The extracted DNA was cloned into pGEM-T-easy cloning vector (Promega Co., USA). The insert DNA sequence was determined by a commercial DNA sequencing BIRB 796 in vivo service. The determined DNA sequences were deposited into GenBank (NCBI) with the accession numbers given in Table 1. Primer sets of 15 nucleotides in length were designed using the 5′- and 3′-ends of the determined sequences (Table 1). Target-specific

primer sets were employed for the detection selleck of specific strains using the following conditions: 94 °C for 5 min; 30 cycles at 94 °C for 45 s, 60 °C for 45 s, and 72 °C for 2 min; 72 °C for 10 min. RAPD analyses with three random primers were conducted for the verification of nine H. marmoreus strains. The RAPD with primers OPS-1, OPS-10, and OPL-13 yielded 22, 16, and 21 distinct DNA bands, respectively, with the sizes ranging from 0.5 to 3.5 kbp (Fig. 1a). The DNA band pattern was clustered using the UPGMA method. The resulting dendrogram, which was a reflection of genetic background, showed that the H. marmoreus

strains could be clustered into three groups (Fig. 1b). The largest group consisted of Hm0-7, Hm1-1, Hm1-6, Hm2-7, Hm3-6, and Hm3-8. Hm1-1 and Hm1-6 were essentially the same strain. Strains Hm3-6 and Hm3-8 are Korean varieties based on the Japanese strain Hm0-7. Taiwanese Hm2-7 could be derived Megestrol Acetate from Hm0-7. Strains Hm0-4 and Hm2-10 were included in the second cluster. These strains were from a mushroom stock belonging to a commercial farm. Hm3-10 showed the most distinct DNA band pattern and thus formed an independent single-member group in the dendrogram. Hm3-10 was a wild strain collected from a mountain in the middle of Korea. Cultivation characteristics of the strains were investigated in terms of mushroom yield, culture period, and taste of fruiting bodies. The results are summarized in the Table 2. Strains Hm1-1, Hm1-6, and Hm3-6 showed the best results among the strains. The former two strains were identical in RAPD and therefore had the same characteristics. The wild strain Hm3-10, which exhibited a distinct genetic background in the RAPD analysis, showed reasonable cultivation characteristics except for poor fruiting body yield, suggesting a potential to be developed as a commercial strain. The morphology of fully grown Hm3-10 and Hm1-1 are shown in Fig. 1c and d, respectively.

In addition, activation of SK-channels by T-type Ca2+ channels was also observed in voltage-clamp experiments, suggesting that these channels find more could activate SK channels in other circumstances than during the mAHP, for example during synaptic activity. We wish to thank Professor Martin W. Wessendorf (University of Minnesota, Mineapolis, USA) and Melissa Doupagne and Laurence de Nijs (GIGA Neurosciences, University of Liège) for their advice regarding immunostaining of dorsal raphe neurons in thick slices, and Dr Stanislav Koulchitsky (GIGA Neurosciences, University of Liège) for his help with statistical analysis. We also acknowledge Professor J. Roeper (Goethe University, Frankfurt, Germany) for his

useful comments on an earlier version of the manuscript. This work was supported by grants nos 9.4560.03 and 3.4533.09 from the F.R.S.-FNRS (V.S.), PI3K inhibitor by a grant from the Belgian Science Policy (IAP P7/10) to V.S. and by a grant from the ‘Fonds Spéciaux de la Recherche’ of the University of Liège (V.S.). P.A. was supported by an ‘Assistant’ mandate of the University of Liège. C.A.C. is a Research Associate of the F.R.S.-FNRS of the French speaking Community of Belgium. The authors have no conflict of interest to declare. Abbreviations ACSF artificial cerebrospinal fluid BMI bicuculline methiodide DBHQ 2,5-di(tert-butyl)hydroquinone DRN dorsal raphe nucleus mAHP medium-duration afterhyperpolarization

PBS phosphate-buffered sucrose SK small-conductance Ca2+-activated (or

KCa2.x) TEA tetraethylammonium TPH tryptophan hydroxylase TTA-P2 3,5-dichloro-N-[1-(2,2-dimethyl-tetrahydro-pyran-4-ylmethyl)-4-fluoro-piperidin-4-ylmethyl]-benzamide “
“Previous research has shown that the basolateral amygdala (BLA) mediates stimulus-reward learning, including drug-cue associations, whereas the dorsolateral caudate putamen (dlCPu) primarily mediates stimulus-response (habit) learning. Recent evidence Avelestat (AZD9668) has indicated that the dlCPu may be critical in cocaine-seeking following extended self-administration, but it remains unknown whether the dlCPu plays a role in the early formation of drug-cue associations. The current study used a model of Pavlovian learning to compare the roles of the BLA and dlCPu in the consolidation of cocaine-cue associations that maintain cocaine-seeking during cue-induced reinstatement. Male Sprague-Dawley rats self-administered cocaine (0.2 mg/50 μL infusion, i.v.) in the absence of cues for 6 days (2 h/day). Immediately following a single 1-h classical conditioning session in which passive cocaine infusions were paired with a light/tone cue, animals received bilateral infusions of the GABA receptor agonists, baclofen/muscimol (1.0/0.1 mm), or vehicle into the BLA or dlCPu. Following additional cocaine self-administration (5 days) and subsequent extinction (no cocaine or cues, 7 days), the ability of the previously cocaine-paired cues to reinstate cocaine-seeking was assessed.

It was concluded that elevated TrrA expression was consistent with an activated thioredoxin (Trx) system and that cross talk between the GSH and Trx dependent was evident in the absence of glrA. Moreover, depleted H2O2 levels in A. nidulansΔglrA were due to the observed elevation in catalase B and cytochrome c peroxidase levels. Significant upregulation

of an elongation factor 1β (ElfA; 2.5-fold) and a glutathione s-transferase (GstB; 2.6-fold) was also observed in A. nidulansΔglrA. Relevantly, orthologues of both of these proteins had previously been shown to be present and upregulated in response to oxidative stress in A. fumigatus (Burns et al., 2005; Carberry et al., 2006). Thön et al. DAPT clinical trial (2010) observed that the deletion of hapC, a component of the transcriptional regulator AnCF that senses the cellular redox status and coordinates the oxidative stress response, resulted in an impaired oxidative stress response. Characterization of the A. nidulansΔhapC proteome

identified upregulation of a range of redox-active proteins including thioredoxin, peroxiredoxin A and glutathione, compared with the wild type. Pusztahelyi et al. (2011) investigated the A. nidulans proteome, compared with transcriptomic alterations, during long-term exposure to menadione to further exploit the power of comparative proteomics for cellular redox investigations. Lessing et al. (2007) Selleck GSK2118436 used comparative proteomics to explore CHIR-99021 solubility dmso the effect of H2O2 on, and the deletion of a potential transcription factor Afyap1, involved in the oxidative stress response, from A. fumigatus. Differential gel electrophoresis (DIGE) analysis, followed by MALDI-ToF/ToF MS identified 27 and 17 proteins, respectively, whose expression was up- and downregulated (>1.5-fold cut-off) following A. fumigatus exposure to H2O2 (2 mM). Predominant among upregulated proteins were the Allergen Asp f3 (× 10-fold), a mitochondrial

peroxredoxin, Prx1 (× 3.7) and Cu,Zn superoxide dismutase (SOD; × 1.2–2.7). The authors proposed that given the classification of Asp f3 and Prx-1 as thioredoxin peroxidases, an elevation in thioredoxin system activity in response to oxidative stress is of significant importance in A. fumigatus. The altered expression of a range of metabolic enzymes was also evident and some proteins appeared in more than one gel spot, at identical Mr, but with an altered pI and amount. Lessing and colleagues speculated that this was due to either posttranslational modification or isoenzyme occurrence; either way, it revealed a type of information that can only be derived from proteomic, and not microarray, expression analyses. Of three unclassified proteins, or UFPs, the expression of two was downregulated (an NAD-dependent dehydrogenase and a UGP-1 protein), while one, a GMC oxidoreductase, was significantly upregulated (× 6.2).

Persons from resource-poor countries, especially sub-Saharan Africa, often present with TB as their first manifestation of immunosuppression. Others who are diagnosed with HIV have high rates of latent TB infection. Low CD4 cell counts and not being on antiretroviral therapy are also associated with an increased risk of reactivation of latent TB [193,194].

Widespread use of HAART has reduced the risk of developing clinical TB among persons infected with HIV. In several studies, the risk of TB was up to 80% lower in those prescribed Veliparib purchase HAART. The protective effect was greatest in symptomatic patients and those with advanced immune suppression and was not apparent in those with CD4 counts >350 cells/μL [195–197]. The effect is almost certainly related to improvements in systemic immunity (reflected by increasing CD4 cell count) to a point where the risk of new infection or reactivation is greatly diminished. There have been many short-term

controlled trials in HIV-positive persons showing the protective effect of chemo-preventative learn more therapy [198–204]. A significant protective effect of isoniazid is found only in those who are TST-positive, and appears to last only 2–4 years as compared with at least 19 years (suggesting protection is lifelong) in TB control programmes in non-HIV populations where active cases were also treated, limiting the risk of any reinfection occurring. This is an important point, as the HIV-infected populations studied have mainly been in areas of high TB prevalence, where most TB arises from new infection rather than reactivation [53]. Apart from recognized outbreaks, there is little evidence to suggest that reinfection

(as opposed to reactivation) is a major factor in the United Kingdom. Chemo-preventative therapy might therefore have a longer duration of effect in the United Kingdom, but there are no data to support this hypothesis. There are some data from Brazil to suggest that a combination of HAART and isoniazid may be more effective than either alone in controlling TB [196]. The epidemiological situation in the United Kingdom is different, however. Chemo-preventative therapy without HAART seemed to have little effect on HIV progression and mortality in the long term [202]. There are also theoretical concerns that widespread isoniazid monotherapy might speed Nintedanib (BIBF 1120) the emergence of drug-resistant TB [205]. However, in a recent meta-analysis of 13 studies investigating the risk of developing isoniazid resistance as a result of chemo-preventative therapy, the relative risk for resistance was 1.45 (95% CI 0.85–2.47). Results were similar when studies of HIV-uninfected and HIV-infected persons were considered separately. Analyses were limited by small numbers and incomplete testing of isolates, and their findings did not exclude an increased risk for isoniazid-resistant TB after isoniazid preventative therapy [206]. The other risk of isoniazid preventative therapy is hepatotoxicity.

aureus is able to import heme, when supplied as either hemin or hemoglobin, in the absence of isdE and htsA. Thus, the lipoprotein-encoding

genes isdE and htsA are dispensable for heme Idelalisib ic50 acquisition by S. aureus. This precludes the use of the ΔhemBΔisdEΔhtsA strain to definitively study the role of heme acquisition in heme-auxotrophic SCVs in an in vivo model. It also indicates that the reduced virulence of the ΔisdEΔhtsA in a murine systemic infection model cannot be explained by an inability to import heme (Mason & Skaar, 2009). These data lend further weight to the already strong body of evidence that HtsA is solely involved in transport of the siderophore staphyloferrin A (Beasley et al., 2009; Grigg et al., 2010). Furthermore, these experiments contradict the suggestion that IsdE may transfer heme to the HtsBC transporter, as heme import is still functional in the absence of both htsA and isdE (Hammer & Skaar, 2011). The proposed transport pathway from hemoglobin, bound by IsdB and IsdH, via IsdA and IsdC to IsdE (Muryoi et al., 2008; Zhu et al., 2008; Hammer & Skaar, 2011) also cannot be fully dependent on IsdE, given the continued function of heme import from hemoglobin in the ΔhemBΔisdEΔhtsA strain. This strongly suggests that additional components,

which have yet to be identified, are involved in the transport of heme into the S. aureus cytoplasm. To examine the role of heme import in heme-auxotrophic SCVs, identification of these heme transport components is required. This research was supported by Arthritis Research UK project

grant funding SGI-1776 nmr (grant number 18294). “
“Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. Recent reports indicate that gonococci can form a biofilm in vivo and under Selleck Gefitinib laboratory conditions. It is unclear, however, if formation of such biofilms or their dispersal are influenced by host factors that would be encountered during infection. In this respect, physiological levels of polyamines have been reported to influence biofilm structures formed by other Gram-negative bacteria as well those formed by Gram-positive bacteria and can cause dispersal of a biofilm formed by Bacillus subtilis. Based on these reports, we examined the influence of polyamines on gonococcal biofilm formation and their dispersal. We now report that physiological levels of certain polyamines, notably spermine, can significantly decrease the capacity of gonococci to form a biofilm, but do not cause dispersal of a preformed biofilm. In the context of natural gonococcal infection, the presence of physiological levels of spermine may be antagonistic for gonococci to form a biofilm and this may be of importance in the spread of the pathogen from a localized region. “
“Although it is known that Escherichia coli O157 is capable of long-term soil survival, little is known about the mechanisms involved.