, 2007; Mouhamadou et al., 2008) fuelled the speculation of the use of the cox1 gene as the molecular marker of the Fungal Kingdom. Except for the recent study (Seifert et al., 2007) carried out in the genus Penicillium, which shows that 67% of the species studied were discriminated by the cox1 gene, no studies are available on the potentiality of the cox1 gene conducted on several species of genera belonging to different fungal phyla.

The aim of our study is to explore the potential of the cox1 gene in the taxonomic resolution of fungal species allowing the determination of the species composition of environmental samples described as DNA barcoding sensu lato (Valentini et al., 2009). Indeed, the latter are estimated at about 1 million species and <5% of these fungi Osimertinib manufacturer NVP-BKM120 nmr are described (Hawksworth, 2004). Their study, based on morphological criteria, raises a twofold problem: it requires a long and careful study and the subjectivity of expertise, because the analysis is based on microscopic or macroscopic

criteria that shift, in most cases, depending on the culture conditions. In this context, we determined the partial sequences of the cox1 gene from different strains isolated in alpine soils (Massif of Galibier, Alpes, France) including four ascomycetous genera and two genera belonging to Zygomycota phylum. The percentages of nucleotide divergence between the species belonging to each genus were quantified and compared with those obtained with the SSU-rDNA and ITS sequences, which are the most investigated

sequences in fungal identification. Analyses of partial cox1-coding sequences were conducted to determine their potential for the taxonomic resolution and molecular phylogeny of soil fungi. Fungal isolates were obtained from soil samples collected in the Hautes-Alpes (France). Culture media containing malt extract (1.5% w/v) were seeded with 100 μL of soil suspension (2% w/v) in distilled water containing 0.05% SDS (w/v) and incubated at 5 and 20 °C. The isolates were characterized by their morphological characteristics using the microscopic observations based on the fungal keys (Zycha & Siepmann, 1969; Ellis, 1971; Booth, 1977a, b; Gams, 1977; Domsch & Gams, Fluorometholone Acetate 1993; Leslie & Summerell, 2006; Crous et al., 2007). Total fungal DNA was extracted using the FastDNA® SPIN Kit (Carlsbad). The PCRs were carried out according to conventional protocols using AmpliTaq Gold DNA polymerase (Applied Biosystems) and primers were synthesized by Eurogentec (Belgium). For the amplification of the cox1 gene, the couple of primers coxu1 (5′-ACAAATGCTAAAGATATAGG-3′) and coxr1 (5′-GTATTAAAGTTTCTATCTGTT-3′), corresponding to the nt 22–41 and nt 2004–2024 referring to Mortierella verticillata cox1 sequence, was defined from the alignment of orthologous sequences of nine fungal species.

Direct and inverted repeat regions were identified with the Repseek software integrated in the MaGe platform (Achaz

et al., 2007). To insertionally inactivate xbpS1, a 736 base pair internal fragment located near the 5′ end of the gene was amplified and subsequently ligated into the EcoRV site of pSTBlue-1 (Novagen). The xbpS1 fragment from the recombinant plasmid was ligated into the PstI-XbaI sites of the conjugal suicide vector pKnock-Cm. The resultant plasmid was transformed into E. coli S17-λpir and subsequently transferred into X. bovienii-SF43. The xbpS1 mutant strain (SF70) was selected on LB supplemented with ampicillin (50 μg mL−1) and chloramphenicol (25 μg mL−1), and gene disruption was confirmed by PCR. The xenorhabdicin activity assay was performed as described previously (Morales-Soto & Forst, 2011). SF31 and TT01 strains (Table 1) were separately subcultured in 5 mL of http://www.selleckchem.com/products/pd-0332991-palbociclib-isethionate.html LB and grown at 30 °C to an OD600 nm of 0.5–0.6. Cultures were diluted 1200-fold, and 100 μL mixed with 50 μL of each

polyethylene glycol (PEG)-precipitated xenorhabdicin preparations in a 96-well microplate. Experiments were performed in triplicate. Microplate cultures were incubated at 30 °C with shaking. The OD600 nm was measured at 0 and 24 h of incubation. R-type phage tail structures derived from different strains of X. bovienii induced with mitomycin C were analyzed by transmission electron microscopy (Fig. 1). X. bovienii strains, http://www.selleckchem.com/products/r428.html SF43, SF44,

and SF32 isolated from the Steinernema nematodes S. jollieti, S. feltiae, and almost S. kraussei, respectively, produced higher levels of phage tail structures (Fig. 1). The xenorhabdicin preparations contained extended tails (Ext), empty sheaths (Emt), and contracted sheaths (CS). Other structures such as uncharacterized filamentous strands were also visualized. SF31 (S. oregonense) and SF35 (S. puntauvense) produced lower levels of phage tail structures, and SF36 (S. intermedium) produced hardly any tail structures. These findings suggest that the contribution of R-type bacteriocin to intraspecies and interspecies competition may vary depending on the level of xenorhabdicin production by the individual strains. As X. bovienii-SF43 produced phage tail structures, its genome was analyzed for P2-like phage clusters. Xenorhabdus bovienii-SF43 contained two P2-type prophage and six other clusters of mostly hybrid lambdoid-like phage genes (Table S1). One P2-type phage locus was a remnant cluster (Fig. 2) consisting of mostly tail synthesis genes (xbp1), while the second cluster (xbp2) also contained capsid, lysis, and replication genes (data not shown). A 400 kb inversion in X. bovienii on the right side of the chromosome (Ogier et al., 2010) places the xbp1 cluster in the opposite orientation in the chromosome relative to X. nematophila.

When men reporting any of these three risk factors were excluded, the HIV incidence SAHA HDAC supplier was <1 per 100 PY in all remaining men. A total of 844 HIM participants responded to the question on willingness to participate in rectal microbicide trials. Among this group, 29% of the 244 ‘high-incidence’ participants were willing to participate in rectal microbicide trials compared with

23% of the remaining cohort [odds ratio (OR) 1.38; 95% CI 0.97–1.95; P=0.073]. When the 233 men who reported that they did not know how likely they were to participate were excluded, 40% of ‘high-incidence’ men were willing to participate compared with 32% of the remainder of the responding cohort (OR 1.44; 95% CI 0.99–2.10; P=0.056). Of the 895 HIM participants who responded to the question on willingness to participate in trials using ARVs to prevent HIV infection, men in the ‘high-incidence’ subgroup were significantly more willing selleck chemicals to participate compared with the rest of the respondents, both when the 69 men who reported

that they did not know how likely they were to participate were included (51 and 41%, respectively; OR 1.52; 95% CI 1.13–2.05; P=0.006) and when they were excluded (55 and 44%, respectively; OR 1.54; 95% CI 1.13–2.11; P=0.006). Factor analysis of participants’ last responses to the three questions about willingness to participate in HIV vaccine trials confirmed the reliability of the scale (Cronbach α=0.72). A total of 1218 participants responded at least once to all three questions and the mean of the total score was 8.15

Monoiodotyrosine [standard deviation (SD) 2.10]. The 324 men in the ‘high-incidence’ subgroup had a higher mean score on the scale (8.39; SD 1.97) than the remaining 894 participants (8.06; SD 2.14; P=0.01), indicating that they were more willing to participate in HIV vaccine trials. Despite an overall HIV incidence in this cohort of Australian gay men of less than 1 per 100 PY, a readily identified subgroup comprising approximately a quarter of the cohort had an HIV incidence of 2.7 per 100 PY. Men in this ‘high-incidence’ subgroup were significantly more willing than others to participate in HIV prevention trials using ARVs or vaccines. These findings confirm that there are populations in low-incidence settings such as Australia who have sufficiently high HIV incidence and are willing to take part in HIV prevention trials, including those of the newer biomedical prevention technologies. In the HIM cohort, nine overlapping risk variables were associated with an HIV incidence of ≥2 per 100 PY. Three of these risk variables were included in the final ‘high-incidence’ subgroup: UAI with a known HIV-positive partner, receptive UAI with casual partners, and reporting use of both oral erectile dysfunction medication and methamphetamines. Over a quarter of all HIV seroconversions (13; 27.

“
“The selleck capsular polysaccharide (CPS) synthesis locus of 13 Streptococcus suis serotypes (serotype 1, 3, 4, 5, 7, 8, 9, 10, 14, 19, 23, 25 and 1/2) was sequenced and compared with that of serotype 2 and 16. The CPS synthesis locus of these 15 serotypes falls into two genetic groups. The locus is located on the chromosome between orfZ and aroA. All the translated proteins in the CPS synthesis locus were clustered into 127 homology groups using the tribemcl algorithm. The general organization of the locus suggested that the CPS of S. suis could be synthesized by the Wzy-dependent pathway. The capsule of serotypes 3, 4, 5, 7, 9, 10, 19 and 23 was predicted to be amino-polysaccharide. Sialic acid

was predicted to be present in the capsule of serotypes 1, 2, 14, 16 and 1/2. The characteristics of the CPS synthesis locus suggest that some genes may have been imported into S. suis (or their ancestors) on multiple occasions from different and unknown sources. Streptococcus suis can cause meningitis,

learn more septicaemia, endocarditis, arthritis and septic shock in pigs. Based on variation in capsular antigens, 33 serotypes (1–31, 33 and 1/2) of S. suis have been identified so far (Lun et al., 2007). Each serotype has a structurally distinct capsular polysaccharide (CPS), composed of repeating oligosaccharide units joined by glycosidic linkages. The expression of the capsule is strongly associated with the ability of S. suis to cause invasive disease (Smith et al., 1999a). The S. suis serotype 2 strains without CPS proved to be avirulent in murine and pig models of infection (Charland et al., 1998). The biosynthesis of CPS requires crotamiton a complex pathway and, generally, the genes involved in this process are clustered in a single locus (Roberts, 1996). Moreover, in many gram-positive and gram-negative bacteria, these CPS synthesis loci (cps loci) show a common genetic organization. The cps locus typically encodes the enzymes to build the repeat unit, including an initial glycosyl phosphate transferase, and

additional transferases responsible for the formation of the linkages, and allows for the addition of sugars (or other moieties) or other modifications of the repeat unit, as well as a repeat-unit flippase and polymerase (Roberts, 1996). The cps locus of S. suis serotype 2 was certified to be closely linked on the chromosome (Smith et al., 2000). With the exception of the entire cps locus sequence of serotype 2, only partial sequences of cps locus in serotypes 1, 7 and 9, and the entire serotype 16 cps locus are available (Smith et al., 1999a, b, c; Wang et al., 2011); those of all the other serotypes remain unknown. Studies on the cps locus would contribute to unravelling the CPS biosynthetic pathway and the evolution of cps locus, and open up the prospect of the design of inhibitors capable of obstructing the virulence factor production.

fatigans larvae collected from the drains around

Chirala in Andhra Pradesh, India (Rao & Mahajan, 1990). The standard strains of B. sphaericus, 1593 and 2362, were obtained from the Pasteur Institute, Paris, France. All bacterial cultures were maintained on a standard nutrient broth (NB) medium supplemented with 0.3% sugar cane molasses (NB medium). A single colony suspension was heat shocked at 80 °C for 12 min to synchronize the culture. This culture was first inoculated in a sterile 50 mL NB medium and incubated as a static culture at room temperature for 16 h. The 5% v/v inoculum from the static culture was transferred to 250 mL NB medium and incubated at 28±2 °C on a rotary shaker at 180 r.p.m. (Orbitek, Sciegenics, Chennai, India). The culture was harvested Omipalisib when it showed >90% sporulation as observed by phase-contrast microscopy

(Axioscop-40, Carl Zeiss, Göttingen, Germany). The culture usually reached a spore count of 1–2 × 109 spores mL−1 at the time of harvest. The pellet was washed twice with sterile-distilled water and lyophilized. The lyophilized powder was stored in an airtight container for further use. The cultures of Culex quinquefasciatus, Culex tritaeniorhynchus, Aedes aegypti and Aedes albopictus were maintained at 28±2 °C and 85% relative humidity in our laboratory. The adults were reared separately in closed cages and fed with a chicken bloodmeal. Eggs were collected and allowed to hatch in plastic bowls containing 1 L of tap water supplemented with 0.13 g of sterilized larval food (13 : 6 : 1 of wheat flour, chickpea flour and yeast extract) (Hadapad et al., 2008). PI3K inhibitor For all bioassays, third-instar larvae of the same age and size were used. The total viable counts (TVC) of all the strains were determined from lyophilized powder as described in Hire et al. (2006). Statistically significant differences between different means were calculated using Fisher’s least significant difference multiple comparison test (spss 12.0 for Windows). For preliminary screening

of the larvicidal activity, the stock suspensions of all B. sphaericus strains were prepared in sterile-distilled water and tested against the third-instar larvae of C. quinquefasciatus. Etoposide clinical trial Different concentrations of all these strains, along with the control, were tested in 100 mL tap water containing 20 larvae in each beaker (150 mL), with four replications for each concentration. Based on the preliminary bioassay studies, ISPC-8 was found to be highly toxic and was hence selected to determine the spectrum of larvicidal activity against different mosquito species. The different concentrations of ISPC-8 were tested against third-instar larvae of C. tritaeniorhynchus, A. aegypti and A. albopictus. All the experiments were repeated three times on different days. The total larval mortality was scored after 48 h of treatment.

We describe our experience of EFV dose reduction in a clinical see more setting (Infectious Diseases Outpatient Clinic, University of Verona, Verona, Italy) in 33 HIV-infected patients treated with two NRTIs plus EFV. Blood samples collected 9–16 hours

after the last dose intake were stored for subsequent measurement of EFV plasma levels [3]. Three groups of patients were included in the study (Table 1). In group 1 patients, EFV was reduced to 400 mg after 33–119 months (mean 66.4 months) on the full dose and when HIV RNA was <50 HIV-1 RNA copies/mL. EFV was reduced, because of sleep disturbances and on the basis of pharmacokinetic data, to 400 mg in all but one patient (who switched to 200 mg). After a mean of 12.6 months, all the patients continue to have undetectable HIV RNA, and side effects have disappeared. Mean EFV plasma levels decreased by 65.9% at 6 months, and in five subjects the post-dose reduction Ivacaftor mouse EFV concentration was below 1000 ng/mL, i.e. the supposed minimum effective concentration (MEC) [4]. 41 (30–61) 2380.5 (1181–6585) 48 (27–68) 3045.1 (913–6872) 1049.1 (402–2376) 48 (34–67) 1579.9 (1046–2163)* Group 2 patients had a mean treatment duration of 35.4 months (range 21–60 months) and HIV RNA <50 copies/mL before a reduction of EFV to 400 mg by the physicians in charge because of sleep disturbances

and prior to having knowledge of the pharmacokinetic data. Ten to twelve months after the reduction of EFV, all patients continue to have undetectable HIV RNA, with no side effects. Mean EFV plasma levels decreased by

34.4% at 6 months, and in five subjects the post-dose reduction EFV concentration was below the MEC. Group 3 patients were naïve to antiretrovirals, and had a pretreatment mean HIV RNA level of 104 529 copies/mL. Four patients were started on EFV 400 mg by the physicians in charge, and four had decided to take only 400 mg and two only 200 mg despite being prescribed the full dose. The latter six patients informed physicians of their decision after a few months on the reduced doses, and then pharmacokinetic analysis was performed. After 9–86 (mean 30) months on reduced doses, all patients have undetectable HIV RNA. The mean EFV level was 1579.9 ng/mL at 6 months. Although 10 patients (in groups 1 and 2) had EFV levels that Anacetrapib were below the MEC after dose reduction, no virological failure was observed over a follow-up period of up to 15 months. These results confirm those of previous studies that questioned the relationship between plasma levels and efficacy and are consistent with those of the FOTO study [5], suggesting that the long-term maintenance phase of an EFV-containing fully suppressive first-line regimen could require lower pharmacological pressure. In conclusion, a dose reduction of EFV to 400 mg once daily warrants further investigation as a therapeutic option.

AOB were traditionally considered to be responsible for most ammonia oxidation in natural environments, but AOA amoA genes are now known to be ubiquitous and to outnumber those of AOB in many environments, including soils GDC-0068 supplier (Leininger et al., 2006), oceans (Wuchter et al., 2006), streams (Merbt et al., 2011) and alpine lakes (Auguet et al., 2011). Although AOA and AOB coexist in many ecosystems, differential sensitivities to pH (Nicol et al., 2008), temperature (Tourna et al., 2008) and ammonium concentration

(Martens-Habbena et al., 2009; Verhamme et al., 2011) appear to control their relative abundances and activities, suggesting distinct physiological adaptations for each group. Photoinhibition of ammonia oxidation has been investigated in laboratory cultures of AOB (e.g. Hooper & Terry, 1974, Guerrero & Jones, 1996a, b). Hyman & Arp (1992) found that light may completely inhibit nitrite production and de novo synthesis of ammonia monooxygenase is required after exposure of cultures to light, leading to suggestions that light may be responsible for the inhibition of nitrification in ocean surface waters (Horrigan et al., 1981), coastal areas (Olson, 1981), estuaries (Horrigan &

Springer, 1990) and eutrophic rivers (Lipschultz et al., 1985). The low availability of laboratory cultures has restricted physiological studies of photoinhibition in AOB and, particularly, AOA. This has prevented assessment of the role of light exposure in niche separation and distribution of AOA and AOB in natural environments. Recent observations of the distribution buy AZD2281 of archaeal amoA genes in stream biofilms exposed to light and dark conditions (Merbt et al., 2011) and along a vertical profile in the Atlantic Ocean (Church et al., 2010) suggest, however, that AOA could also be sensitive to light and that sensitivity of AOA and AOB may differ. The aims of this study were to determine the effects of different light intensities on

bacterial and archaeal ammonia oxidation using several Adenosine laboratory cultures of AOA and AOB and to assess their potential to explain AOB and AOA differential distribution and activity in aquatic ecosystems. Photoinhibition of two AOB (Nitrosomonas europaea ATCC19718 and Nitrosospira multiformis ATCC25196) and two AOA (Nitrosopumilus maritimus and Nitrosotalea devanaterra) strains was investigated during growth in batch culture. Nitrosomonas europaea and N. multiformis were obtained from NCIMB (http://www.ncimb.com/). Nitrosopumilus maritimus and N. devanaterra were obtained from existing laboratory cultures (Könneke et al., 2005; Lehtovirta-Morley et al., 2011). All strains were grown aerobically in 100-ml quartz flasks containing 50 mL inorganic growth medium. AOB were grown in Skinner & Walker (1961) medium containing 1.78 mM ammonia sulphate, adjusted to pH 8.0 with Na2CO3 (5% w/v). Nitrosopumilus maritimus was grown in HEPES-buffered, synthetic medium (pH 7.

, 2008; Brasch, 2009). Comprehensive up-to-date review articles covering dermatophyte epidemiology and clinical importance as well as genetic approaches in taxonomy and diagnosis are already available (Binstock, 2007; Abdel-Rahman, 2008; Gräser et al., 2008; Kanbe, 2008; Seebacher

et al., 2008; Ameen, 2010). These topics will not be a part of the present overview. Nevertheless, some basic information on species diversity and medical impact will be provided in order to better convey the recent achievements in molecular genetic research in this fascinating group of microorganisms. Dermatophytoses belong to the most common infectious diseases in humans, affecting 10–20% of the population worldwide. These infections PFT�� nmr selleck chemical are usually not life threatening, but occur even in immunocompetent hosts, and in many cases, are long lasting, recurrent and difficult to cure (Borgers et al., 2005). Depending on their predominant natural reservoir, dermatophyte species are classified into three groups: anthropophilic, zoophilic and geophilic (Weitzman & Summerbell, 1995). The natural hosts of anthropophilic and zoophilic species are humans and animals, respectively, whereas geophilic dermatophytes are soil saprophytes. Symptoms of dermatophytosis can vary from chronic to highly inflammatory, depending on the causative agent and the body location affected. The given disease is

described with the word ‘tinea,’ followed by a term referring to the infected body site, for example tinea pedis (feet), tinea capitis (scalp or head), tinea corporis (body or trunk) and tinea unguium (nails, also called Tolmetin onychomycosis) (Degreef, 2008). Major prominent anthropophilic species, for example, Trichophyton rubrum, Trichophyton interdigitale and Trichophyton tonsurans, are mostly associated with more chronic, less inflammatory infections. In contrast,

zoophilic species, for example, Microsporum canis, Arthroderma benhamiae, Arthroderma vanbreuseghemii, Trichophyton erinacei and Trichophyton verrucosum as well as geophilic dermatophytes such as Microsporum gypseum often induce highly inflamed lesions in humans. Dermatophytes are ascomycete fungi. The anamorphs (asexual forms) are classified into three genera: Trichophyton, Microsporum and Epidermophyton. Teleomorphs (sexual forms) belong to the Arthroderma genus in the Ascomycotina subphylum. Dermatophytes are heterothallic (mating types are designated as either ‘+’ or ‘−’); however, in many zoophilic and anthropophilic species, sexual reproduction has not been observed. Recent progress in molecular taxonomy and insights into mating revealed that Trichophyton mentagrophytes was a complex of anthropophilic and zoophilic species that produce different teleomorphs, leading to a current confusion in species denomination. For example, A.

FMD changes rapidly in response to beneficial or noxious stimuli, making it a useful tool for

assessing the immediate impact of interventions on the vasculature. Studies in healthy volunteers have used changes in FMD as an end-point for vaccine assessment. We have previously shown that vaccination adversely affects FMD, and this effect is mitigated by pretreatment with statins [14]. Consistent with and extending click here previously published data, the novel influenza A/H1N1 vaccine significantly impaired FMD in HIV-infected patients, and this effect lasted for at least 48 h. The clinical implications of our study pertain to cardiovascular risk in HIV-infected patients. Viraemia represents a low-grade stimulus; vaccination Epacadostat in vivo may be superimposed as an acute insult, thus creating a highly pro-inflammatory milieu accompanied by worsening endothelial function. In the presence of an already dysfunctional endothelium, as is the case for HIV infection [17], the combination could result in untoward events. However, no short-term adverse cardiovascular events

have been reported following vaccinations in the setting of HIV infection [22]. In the general population, conflicting data exist regarding the potential of seasonal vaccination to defer acute myocardial infarction [23,24]. A number of studies have linked influenza infection with elevated cardiovascular risk [25]. Such a link has been found for the seasonal influenza strains

in the general population; indeed, the prevalence of acute myocardial infarction rises following an influenza infection. In the light of such reports, seasonal influenza infection has been acknowledged as a novel risk factor for cardiovascular events [26]. However, no such data exist on the pandemic H1N1 influenza strain, or for HIV-infected patients [27]. Regarding vaccination against the seasonal strains of influenza, it has been reported PAK5 that vaccination reduces the risk of myocardial infarction in the general population [28], as well as in patients with coronary heart disease [29]. To date, however, there is a paucity of studies regarding vaccination in HIV-infected patients [30]. Apart from providing clinical insights into the effects of vaccination in a high-risk group, the combination of HIV infection and the novel influenza A/H1N1 vaccine in our study has utility as a new model for studying endothelial responses to vaccination. Vaccines may not be equal with respect to their inflammatory and endothelial effects. The inclusion of different antigens (bacterial or viral) and the use of booster substances may result in different degrees of vascular reactivity. However, it should be noted that people with different immunological backgrounds may respond in different ways to vaccination, and our results cannot be directly extrapolated to the general population.

These observations support the application of gyrB analyses for differentiating and identification of the species of Stenotrophomonas. Furthermore, these results lend support to the notion that many strains identified as S. maltophilia, often on the basis of limited or inadequate data, in fact represent distinct species. Further investigations of gyrB variation within the ‘S. maltophilia complex’, as well as among all the species of the genus, will be necessary to evaluate the full potential of this

taxonomic and identification tool. However, the low gyrB similarities between some strains with very high 16S rRNA gene sequence similarities offer a caveat to relying too heavily upon 16S rRNA gene sequence analyses for identifications, not only among GSK3235025 molecular weight strains of S. maltophilia, but also between different species of the Stenotrophomonas genus. This study was supported by funding from The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, Sweden (Project Nos. ALFGBG-3238, ALFGBG 11574, VGREG-30781 and VGFOU-72241). “
“Indole is most commonly known as a diagnostic marker and a malodorous chemorepellent. 5-FU concentration More recently, it has been recognized that

indole also functions as an extracellular signaling molecule that controls bacterial physiology and virulence. The gene (tnaA) for tryptophanase, which produces indole, ammonia, and pyruvate via β-elimination of l-tryptophan, was cloned from Prevotella intermedia ATCC 25611 and recombinant TnaA was purified and enzymatically characterized. Analysis by reverse transcriptase-mediated PCR showed that the gene was not cotranscribed with flanking genes in P. intermedia. The results of gel-filtration chromatography suggested that P. intermedia TnaA forms homodimers, unlike other reported TnaA proteins. Cyclin-dependent kinase 3 Recombinant TnaA exhibited a Km of 0.23 ± 0.01 mM and kcat of 0.45

± 0.01 s−1. Of 22 Prevotella species tested, detectable levels of indole were present in the culture supernatants of six, including P. intermedia. Southern hybridization showed that tnaA-positive signals were present in the genomic DNA from the six indole-producing strains, but not the other 16 strains tested. The indole-producing strains, with the exception of Prevotella micans, formed a phylogenetic cluster based on trees constructed using 16S rRNA gene sequences, which suggested that tnaA in P. micans might have been transferred from other Prevotella species relatively recently. Strains of the genus Prevotella are strictly anaerobic, non-spore-forming, gram-negative, moderately saccharolytic, bile-sensitive rods that are frequently recovered as members of the polymicrobial flora, including in humans, of the oral, intestinal, and urogenital tracts (Shah & Collins, 1990).