Substance P acts on postsynaptic neurokinin 1 (NK1) receptors. These NK1 receptors are G protein-coupled receptors, which are removed from the cell surface through internalization after activation by substance P. The number of cells showing internalization of NK1 receptor can thus be used as an index of substance P release and, therefore,

of the density of nociceptive input to the spinal dorsal horn. Rather unexpectedly, http://www.selleckchem.com/products/ldk378.html the authors found that CB1 receptor activation increased rather than decreased NK1 receptor internalization. Together with the findings from appropriate controls described in this study, this result indicates that CB1 receptor activation leads to increased substance P release, suggesting a pronociceptive action. Indeed, the authors demonstrate that AM251, an antagonist (or strictly speaking an inverse agonist) at CB1 receptors, possesses antinociceptive properties against noxious heat stimuli. The authors explain this surprising result primarily by a disinhibitory action of spinal CB1 receptors. According to their model, substance Lenvatinib P release by C-fiber nociceptors is modulated indirectly by endocannabinoids acting on inhibitory interneuron terminals, which release GABA and opioid peptides to activate presynaptic GABAB and μ-opioid receptors located on C-fiber nociceptors.

Their model is supported by evidence showing that numerous inhibitory (GABAergic and glycinergic)

axon terminals carry functional CB1 receptors. By activating these CB1 receptors, THC would reduce presynaptic inhibition of C-fiber nociceptors, thereby allowing increased substance P release. However, this model apparently contradicts previously published results indicating LY294002 the presence of CB1 receptors on peptidergic, substance P-releasing, C-fiber nociceptors. Nyilas et al. (2009) (cited by authors) localized CB1 receptors on spinal nociceptor terminals, and Hegyi et al. (2009) demonstrated that CB1 receptor immunoreactivity co-localizes with CGRP and IB4, markers of peptidergic and non-peptidergic C-fiber terminals, respectively. Moreover, in mouse models of inflammatory and neuropathic pain, spinal injection of the CB1 receptor agonist, CP 55 940 causes analgesia in wild type mice, but not in CB1 receptor-deficient mice (Pernia-Andrade et al., 2009). However, antinociceptive effects of CB1 receptor antagonists (or inverse agonists) were previously reported in certain models of inflammatory or activity-dependent hyperalgesia (Croci & Zarini, 2007; Pernia-Andrade et al., 2009) as well as in a hypoalgesic phenotype of mice lacking CB1 receptors in formalin-induced pain (Zimmer et al., 1999). An explanation is required to reconcile the model presented by Zhang et al. (2010) with the findings described in this literature.

“
“The aim of the study was to compare prospectively indicator-condition (IC)-guided testing versus testing of those with non-indicator conditions (NICs) in four primary care centres (PCCs) in Barcelona, Spain. From October 2009 to February 2011, patients aged from 18 to 65

years old who attended a PCC for a new herpes zoster infection, seborrhoeic eczema, mononucleosis syndrome or leucopenia/thrombopenia were included in the IC group, and one in every 10 randomly selected patients consulting for other reasons were included in the NIC group. A proportion of patients in each group were offered an HIV test; those who agreed to be tested were given a rapid finger-stick HIV test (€6 per test). Epidemiological and clinical

data were collected and analysed. During the study period, 775 patients attended with one of the four selected ICs, while 66 043 patients presented with an NIC. HIV screening was offered to 89 patients with ICs (offer rate selleck screening library 11.5%), of whom 85 agreed to and completed testing (94.4 and 100% acceptance and completion rates, respectively). In the NIC Z-VAD-FMK in vivo group, an HIV test was offered to 344 persons (offer rate 5.2%), of whom 313 accepted (90.9%) and 304 completed (97.1%) testing. HIV tests were positive in four persons [prevalence 4.7%; 95% confidence interval (CI) 1.3–11.6%] in the IC group and in one person in the NIC group (prevalence 0.3%; 95% CI 0.01–1.82%; P < 0.009). If every eligible person had taken an HIV test, we would have spent €4650 in the IC group and €396 258 in the NIC group, and an estimated 36 (95% CI 25–49) and 198 persons (95% CI 171–227), respectively, would have been diagnosed with HIV infection. The estimated cost per new HIV diagnosis would TCL have

been €129 (95% CI €107–153) in the IC group and €2001 (95% CI €1913–2088) in the NIC group. Although the number of patients included in the study was small and the results should be treated with caution, IC-guided HIV testing, based on four selected ICs, in PCCs seems to be a more feasible and less expensive strategy to improve diagnosis of HIV infection in Spain than a nontargeted HIV testing strategy. The large majority of sexually transmitted infection (STI) prevention, diagnosis, and treatment occurs in primary care centres (PCCs) [1, 2]. In Spain, access to the health service is universal and free, and PCCs are the settings most frequently visited in order to take an HIV test (approximately 30% of all HIV tests are carried out in PCCs) [3, 4], and where 72% of people receive health care at least once a year [5]. As such, they appear to be suitable settings for HIV screening strategies [6]. Moreover, as a consequence of the reduction in morbidity and mortality in HIV-infected patients associated with highly active antiretroviral therapy, an increased number of patients have stable, chronic HIV infection, and this health care challenge may require new approaches.

, 1988). Rabbit anti-Leptospira this website antisera to serogroup Icterohaemorrhagiae serovars: Copenhageni, Icterohaemorrhagiae (strain RGA), Icterohaemorrhagiae (strain Kantorowics), and Lai; serogroup Canicola serovars: Canicola (strain Hond Utrecht IV), Galtoni (strain LT1014), Jonsis (strain Jones); serogroup Sarmin serovars: Sarmin (strain Sarmin), Machiguenga (strain MMD3), Waeveri (strain CZ 390); serogroup Grippotyphosa serovars: Grippotyphosa (strain Moskva

V), Valbuzzi (strain Valbuzzi), Liangguang (strain 1880); serogroup Sejroe serovars: Hardjo (strain Hardjoprajitno), Sejroe (strain M84), Wolffi (strain 3705); serogroup Pomona serovar Pomona; and serogroup Australis serovars: Bratislava (strain Jez Bratislava), Australis (strain Ballico), Fugis

(strain Fudge) were generated as described previously (Stallman, 1984). The medium used for the selection of escape mutants was EMJH containing 10% v/v mouse ascites fluid containing the mAb F70C7. Initially, a stationary-phase culture of Lai wild type (LaiWT) grown in EMJH medium was supplemented with mouse ascites fluid (mAb: F70C7) to 10% v/v and incubated at 30 °C for a week. One millilitre of the culture was then inoculated into 10 mL of EMJH, 10% mouse ascites (mAb: F70C7) selection medium. This procedure was repeated five times until no agglutination with the F70C7 mAb was observed by MAT, indicating the loss of the reactive epitope 3-oxoacyl-(acyl-carrier-protein) reductase (Zuerner & Trueba, 2005). The mutant

strain Selleck PTC124 was then cloned by performing 10 serial 10-fold dilutions in EMJH liquid medium and selecting the tube showing growth obtained from the highest dilution. The genetic relatedness of LaiMut and LaiWT was investigated by restriction fragment length polymorphism (RFLP) using EcoRI and BamHI and by sequencing regions of the lipopolysaccharide locus using a series of primers designed to provide double-stranded coverage of the targeted region of the genome (Victoria et al., 2008; Ahmed et al., 2009). For sequencing, DNA extraction was performed using the QIAamp DNA extraction kit according to the manufacturer’s instructions (Qiagen GmbH, D-40724 Hilden, Germany). DNA sequencing was carried out using the BigDye Ready Reaction Dye Deoxy terminator cycle sequencing kit. Sequence products were resolved on an Applied Biosystems 3730 capillary sequencer. The MAT was performed with 16 mAbs reacting with serogroup Icterohaemorrhagiae antigens (Table 1) and three polyclonal antisera reacting with other serogroups using a standard protocol (Cole et al., 1973). The use of a 1/10 starting dilution was intended to increase the sensitivity of the assay.

, 2007). In contrast, three species of the genus Kionochaeta (Okada et al., 1997), four species of Pseudogymnoascus (Sugiyama et al., 1999; Rice & Currah, 2006), and six species of Lecythophora (Weber et al., 2002) have been described in the NCBI taxonomy database and rarely isolated from soils. Some of the fungal antagonists C59 wnt supplier isolated here exhibited low levels of similarity between their 18S rRNA gene sequences and those of their closest species: two strains, MK-100 and HB-296, showed 96.5–97.1% sequence similarities to the closest species, Kionochaeta spissa (accession no. AB003790). Strain HB-92 also showed

a low sequence similarity (96.5%) to Penicillium radicum (accession no. AY256855). These results suggest that at least three strains (MK-100, HB-296, and HB-92) were phylogenetically novel, although further investigations such as morphological and

biochemical characterizations will be needed. Using the agar diffusion assay, we compared the strength of the antagonistic activities of the fungal isolates toward buy Nivolumab potato scab pathogens (Fig. 2). The results showed that strains HB-54, NO-14, NO-21, and NO-28 exhibited higher antagonistic activities against all scab pathogens tested than the other fungal isolates. Interestingly, strains MK-100 and CO-21 effectively inhibited the growth of S. turgidiscabiei, Org 27569 although they did not show high antagonistic activities toward S. scabiei and S. acidiscabiei. Furthermore, strains HB-52 and HB-236 showed higher

activities against S. acidiscabiei than against the other pathogens. Strain KY-108 showed higher activities against S. acidiscabiei and S. turgidiscabiei than against S. scabiei, while strain HB-92 showed higher activities against S. scabiei and S. acidiscabiei than against S. turgidiscabiei. Thus, some fungal isolates showed different levels of antagonism against individual species of potato scab pathogens. These differences may have been attributable to the different susceptibilities of the pathogens to antibiotics and other growth-inhibiting compounds, as reported previously (Lambert & Loria, 1989a, b; Miyajima et al., 1998). We consider that the fungal antagonists examined in the present study produced some kind of extracellular compounds to prevent the growth of potato scab pathogens. For instance, species of the genera Penicillium/Eupenicillium are the best known antibiotic-producing fungi (Elander, 2003). Kionochaeta sp. was also reported to produce an antibiotic substance, pughiinin A (Pittayakhajonwut et al., 2002). Thus, such antibiotics may inhibit the growth of potato scab pathogens.

macleodii was acclimated for 7 days to iron-limited conditions, by daily transfer in AQUIL medium (Price et al., 1989) containing 5.4 nM of non-radioactive Fe-EDTA. The experiments were conducted with cells transferred into

freshly prepared AQUIL medium containing 5.4 nM of 55Fe-EDTA. Triplicate live incubations (20 mL) were performed in the dark, at 20 °C and under agitation. For triplicate controls, formaldehyde (FA, 2% final concentration) was added to the A. macleodii culture and kept for 1 h before the addition of 55Fe. A second set of experiments was performed with natural bacterial communities. In the NW Mediterranean Sea, seawater samples were collected five nautical miles offshore at Station POLA (42°28′300N – 03°15′500E, 90 m overall depth). Vorinostat Seawater (2 L) was pumped at 5 m using a trace metal clean Teflon pump (ASTI) connected to an acid-washed PVC tube. The samples were stored in 1 L acid-washed PC bottles in the dark until arrival to the laboratory about 1 h later. In the Southern

Ocean, samples were collected during this website the Kerguelen Ocean and Plateau Compared Study 2 cruise (KEOPS2, October–November 2011) at Station E-4W (48°45′900S – 71°25′500E, 1384 m overall depth). Samples were collected at 20 m using trace metal clean 12L modified Niskin bottles and further processed in a clean laboratory. At both sites, seawater was filtered at low pressure (< 200 mm Hg) through 0.8 μm acid-washed PC filters (47 mm; Millipore). Subsamples (100 mL) of filtered seawater were spiked with 55Fe at a final concentration of 15 nM. This concentration was chosen to limit isotope dilution as determined by saturation curves (data not shown) and to allow a maximum number of cells to obtain the critical amount of 55Fe for silver grain production (see 'Results and discussion' Section). Samples from the NW Mediterranean Sea were incubated on a rotary

shaking platform at in situ temperature (20 °C), in the dark, for periods ranging between 24 h and 7 days. Experiments Depsipeptide cost were carried out in triplicate. In the Southern Ocean, the PC bottles were incubated at 1% PAR irradiance in an on-deck incubator supplied with circulating surface seawater. For both sites, control treatments of the seawater samples were killed with formaldehyde and kept for 1 h before the addition of 55Fe. Following incubation with 55Fe, subsamples for the determination of the radioactivity incorporated into bacterial cells were collected on nitrocellulose filters (NC, 25 mm diameter, 0.2 μm pore size; Nuclepore), and subsamples for microscopic observations were collected on 0.2-μm PC filters (25 mm diameter; Millipore) (Fig. 1). To investigate the efficiency of eliminating extracellular 55Fe, two rinsing solutions and 0.2-μm-filtered seawater were tested. Subsamples of the A. macleodii culture (1 mL) and the natural seawater (10 mL) were filtered onto 0.2-μm NC filters. In the case of A.

We report that an in vivo-induced protein HP0245 was located at the cell surface of SS2. The extracellular peptide of HP0245 was produced in Escherichia coli BL21 (DE3). Its immunogenicity was compared with SS2 bacterin. Like SS2 bacterin, protein HP0245EC formulated in aluminum hydroxide adjuvant provided 100% protection in mice challenged

with a low dose (2 × LD50) of SS2. However, 80% and 50% survival rates were observed in mice vaccinated with see more HP0245EC and SS2 bacterin, respectively, challenged with a high dose (5 × LD50) of SS2. Immunization with HP0245EC induced significantly higher IgG2a titers compared with SS2 bacterin, which was more effective for opsonophagocytosis. No obvious histopathological change was found in the HP0245EC-vaccinated mice after challenge with the low dose of SS2, whereas a mild lesion was observed

in the meninges of the mice vaccinated with SS2 bacterin. Homologous hp0245 genes with the highly conserved coding sequence of the extracellular peptide exist in all sequenced SS2 strains as selleck screening library well as most S. suis reference strains. Thus, HP0245 could be considered as a promising vaccine candidate for SS2. Streptococcus suis is an important swine pathogen causing a range of diseases, such as meningitis, septicemia, pneumonia, endocarditis and arthritis. Among the 33 known serotypes (1–31, 33, 1/2), S. suis serotype 2 Florfenicol (SS2) is the most virulent and prevalent serotype. The two large outbreaks of human infection caused by SS2 in China in 1998 and 2005, and sporadic cases in Southeast Asia and other countries have led to this serotype being regarded as an emerging zoonotic pathogen (Lun et al., 2007; Wertheim et al., 2009). SS2 was reported to be the predominant serotype isolated from swine with systemic infection and the main causative

agent of streptococcal diseases in China and Europe (Wisselink et al., 2000; Wei et al., 2009). Therefore, effective vaccines for S. suis, especially for SS2, are urgently needed to reduce the economic losses caused by this pathogen as well as the threat to public health. SS2 is generally known as an extracellular pathogen (Gottschalk & Segura, 2000). Protection against this kind of bacteria is mainly mediated by antibodies against their surface or secreted antigens (Haesebrouck et al., 2004). Intensive studies were therefore focused on identification of the surface protective antigens of SS2. The virulence factors muramidase-released protein (MRP), extracellular factor protein (EF) and suilysin were assessed as vaccine candidates for SS2 (Jacobs et al., 1996; Wisselink et al., 2001). However, the absence of these virulence factors in some isolates reduced their application potential. Other S.

The results were best demonstrated by sigmoidal curves (pFe 18.8–21.7, Fe3+ = 10−18.8–10−21.7 M) with the linear range extending from pFe 19.6–21.5 (Fe3+ = 10−19.6–10−21.5 M) after a 12-h incubation time. Optimal conditions for the use of this bioreporter to sense the iron bioavailability were determined to be: a 12-h exposure time, initial cell density of OD730 nm = 0.06, high nitrate (100 μM), high phosphate (10 μM), moderate Co2+ (0.1–22.5 nM), Zn2+ (0.16–12 nM), Cu2+ (0.04–50 nM),

and wide range of Mn2+ concentration (0.92–2300 nM). The applicability of using this iron bioreporter to assess iron availability in the natural environment Ceritinib has been tested using water samples from eutrophic Taihu, Donghu, and Chaohu lakes. It is indicated that the bioreporter is a useful tool to assess bioavailable iron in various water quality samples, especially in eutrophic lakes with high bioavailable iron. Iron is an essential nutrient for organisms. As the fourth most abundant element in the crust of the earth, it generally exists in two forms, Fe2+ and Fe3+, in aquatic environments. In oxic environments, Fe2+ can be quickly oxidized into Fe3+ and then

transformed into insoluble and inaccessible ferric hydroxide. In addition, iron also exists in the form of colloids and can be complexed www.selleckchem.com/products/Adrucil(Fluorouracil).html by organic ligands. Although various iron chelates, including siderophores and grazing byproducts, and iron-organic compounds have been shown to act as sources of iron to phytoplankton (Hutchins et al., 1999; Poorvin et al., 2004), iron bioavailability is still low in many aquatic environments and constrains phytoplankton growth in areas of the open ocean characterized as ‘high-nutrient, low-chlorophyll’ regions (Martin et al., 1991; Coale et al., 1996), coastal waters (Hutchins et al., 1998), and some freshwater systems (Twiss et al., 2000). Although rapid and reliable chemical protocols are available to measure absolute

levels of iron in water samples, whole-cell bioreporters provide data on the capacity of the biota to acquire and assimilate iron. Recombinant bioluminescent bacterial Farnesyltransferase strains have been successfully applied in monitoring iron (Durham et al., 2002; Mioni et al., 2003) and the availability of other metal ions (Peca et al., 2008) in environmental samples. The bicistronic isiAB operon is in part regulated by the iron-dependent repressor Fur (ferric uptake regulator) in cyanobacteria (Ghassemian & Straus, 1996). The first gene isiA codes for a protein that is very similar to CP43, a chlorophyll-binding core protein of photosystem II. Flavodoxin coded by gene isiB has been revealed to have the ability to replace ferredoxin as carrier in the electron transfer chain.

The results imply close relations between LH motivational amplification functions and attention, and may inform our understanding of disorders in which motivational and attentional impairments co-occur. “
“The nuclei of the human amygdaloid complex can be distinguished from each other on the basis of their cytoarchitecture, Ion Channel Ligand Library clinical trial chemistry and connections, all of which process the information needed for the different functions (ranging from attention to memory and emotion) of the amygdala. This complex receives dopaminergic input that exerts modulatory

effects over its intrinsic network and is critical for reward-related learning and fear conditioning. To determine the specific distribution of the dopaminergic input through the different nuclei and

nuclear subdivisions of this structure we used stereological tools to quantify the fibers containing the dopamine transporter (used to signal the dopaminergic phenotype) in post-mortem samples from control individuals. Dopaminergic axons targeted every nucleus of the amygdaloid complex, and the density of dopamine transporter-containing axons varied considerably among its nuclear groups. The central group showed the greatest density of dopamine transporter-positive fibers, more than double the density of the basolateral group, the second most densely innervated structure. The dopamine transporter-positive innervation is very scant in the corticomedial group. The density of dopamine transporter-positive fibers did not vary among the nuclei of the basolateral group – i.e. basal, lateral and accessory basal nuclei – although there were significant density gradients among the subdivisions of these nuclei. screening assay These detailed quantitative data on dopamine transporter-positive innervation in the human amygdaloid complex

can offer a useful reference in future studies aimed at analysing putative dysfunctions of this system in diseases involving brain dopamine, such as certain anxiety disorders, tetracosactide Parkinson′s disease and schizophrenia. “
“School of Biology, University of St. Andrews, Scotland, Fife, UK Exercise is known to have a strong effect on neuroproliferation in mammals ranging from rodents to humans. Recent studies have also shown that fatty acids and other dietary supplements can cause an upregulation of neurogenesis. It is not known, however, how exercise and diet interact in their effects on adult neurogenesis. We examined neuronal recruitment in multiple telencephalic sites in adult male European starlings (Sturnus vulgaris) exposed to a factorial combination of flight exercise, dietary fatty acids and antioxidants. Experimental birds were flown in a wind tunnel following a training regime that mimicked the bird’s natural flight behaviour. In addition to flight exercise, we manipulated the composition of dietary fatty acids and the level of enrichment with vitamin E, an antioxidant reported to enhance neuronal recruitment.

The pulvinar neurons displayed a broad distribution of response latencies, ranging from 30 to 500 ms. The mean latency of the short latency group was 63.38 ± 1.89 ms, which was comparable to previous studies (Felsten et al., 1983; Benevento & Port, 1995). Because the mean latency in V1, which projects to the pulvinar, is 66 ± 10.7 ms (Schmolesky et al.,

1998), some pulvinar neurons with short latencies, especially those with latencies < 60 ms, might receive inputs from the superior colliculus or directly from the retina. The remaining pulvinar neurons in the short latency group with latencies > 66 ms might receive inputs from the various visual cortices. Rapamycin in vitro In comparison, the pulvinar neurons in the long latency group might receive inputs from some other structures, such as the temporal association cortices, prefrontal cortex or the amygdala, which project to the pulvinar (Shipp, 2003). In addition, response latencies to frontal faces were significantly lower than those to profile faces. This suggests that the subcortical visual pathway might be tuned better to frontal faces than to profile faces. Total luminance of the face-like patterns was smaller than those of the square and eye-like stimuli, and luminance of the white

areas of the face-like patterns was the same as that of selleck compound the simple geometric patterns, indicating that specific early responses to the face-like patterns are not due to differences in total luminance or luminance. Furthermore, scrambling of the images greatly reduced the pulvinar

responses in the present study. This is the first evidence that pulvinar neuronal responses are dependent on coherent facial patterns. The results also indicate that selective responses to some visual stimuli are attributable to factors other than luminance differences. These findings are consistent with previous studies on face neurons in the prefrontal cortex (Ó Scalaidhe et al., 1999), inferotemporal cortex (Desimone et al., 1984) and superior temporal cortex (Bruce et al., 1981). However, in contrast to these cortical facial areas and the amygdala (Tazumi et al., 2010), the responses of the pulvinar neurons were not specific BCKDHB to faces; pulvinar neurons also responded to other visual stimuli, such as simple geometric patterns, in the present study. Furthermore, although there was no significant difference in mean response magnitude toward faces with direct and averted gazes, many individual pulvinar neurons differentially responded to gaze directions (i.e. gaze-differential neurons). Neurophysiological and human imaging studies have shown that the amygdala responds stronger to faces with direct gaze (Kawashima et al., 1999; Wicker et al., 2003; Sato et al., 2004; Tazumi et al., 2010). These findings suggest that the pulvinar sends information on gaze direction to higher upstream brain areas in the visual pathway, such as the amygdala (Tazumi et al.

The divergent malX and malI promoters share a common DNA site for CRP. As for other divergent bacterial promoters that share an activator-binding site, activation in one direction is largely independent of activation in the opposite direction and this is likely to be due to the low frequency of initiation at most promoters (El-Robh & Busby, 2002). Although the malX and malI promoters share a DNA site for CRP,

each has a separate and independent DNA site for MalI. The malX promoter MalI operator is located upstream of the transcript start and overlaps the upstream end of the −10 hexamer, while the Ixazomib supplier malI promoter MalI operator is located downstream of the transcript start. This organization is well conserved in the genomes of different strains of E. coli and related Shigella. Figure 3 shows a comparison of the base sequences upstream of the malX and malI translation start sites in these genomes, and the comparison emphasizes how the precise locations of −10 elements and MalI operator sequences have been maintained. This provides yet another example of how efficient repression can result from a repressor interacting

at different locations at a bacterial promoter (Rojo, 2001; Barnard et al., 2004). Interestingly, repression is marginally greater at the malX promoter than at the malI promoter, and this is consistent with MalI action at the malI promoter being autoregulatory. The E. coli K-12 malX-malI Reverse transcriptase intergenic regulatory region provides a simple example of ‘evolution and tinkering’ (Jacob, 1977). The malX promoter is an unremarkable Selleckchem Galunisertib CRP-dependent

promoter that resembles scores of Class II promoters (Busby & Ebright, 1999) and it can be shut off by MalI. In contrast, although the divergent malI promoter resembles a Class II CRP-dependent promoter, it has adapted to ensure that the MalI repressor is always made. Thus, MalI-dependent repression is marginally less efficient compared with the malX promoter, the dependence on CRP is relaxed by the DNA site for CRP being located at position −43.5, and the promoter carries seven repeats of a 5′-TAN8-3′ motif, to facilitate RNA polymerase recruitment (Lloyd et al., 2008). This work was funded by a Wellcome Trust program grant. We thank undergraduate project students, Clare Mensley, James Fuller, and Maria Jesus Pina, for some of the constructions. “
“Molecular ecology methods are now well established for the culture-independent characterization of complex bacterial communities associated with various environmental and animal habitats and are revealing the extent of their diversity. By comparison, it has become clear that only a small minority of microorganisms are readily cultivated in vitro, with the majority of all bacteria remaining ‘unculturable’ using standard methods.