Dopamine Release Dynamics in the Nucleus Accumbens Are Modulated by the Timing of Electrical Stimulation Pulses When Applied to the Medial Forebrain Bundle and Medial Prefrontal Cortex.

Electrical brain stimulation has been used in vivo and in vitro to investigate neural circuitry. Historically, stimulation parameters such as amplitude, frequency, and pulse width were varied to investigate their effects on neurotransmitter release and behavior. These experiments have traditionally employed fixed-frequency stimulation patterns, but it has previously been found that neurons are more precisely tuned to variable input. Introducing variability into the interpulse interval of stimulation pulses will inform on how dopaminergic release can be modulated by variability in pulse timing. Here, dopaminergic release in rats is monitored in the nucleus accumbens (NAc), a key dopaminergic center which plays a role in learning and motivation, by fast-scan cyclic voltammetry. Dopaminergic release in the NAc could also be modulated by stimulation region due to differences in connectivity. We targeted two regions for stimulation─the medial forebrain bundle (MFB) and the medial prefrontal cortex (mPFC)─due to their involvement in reward processing and projections to the NAc. Our goal is to investigate how variable interpulse interval stimulation patterns delivered to these regions affect the time course of dopamine release in the NAc. We found that stimulating the MFB with these variable stimulation patterns saw a highly responsive, frequency-driven dopaminergic response. In contrast, variable stimulation patterns applied to the mPFC were not as sensitive to the variable frequency changes. This work will help inform on how stimulation patterns can be tuned specifically to the stimulation region to improve the efficiency of electrical stimulation and control dopamine release.

A Ten Year Experience of Men's Health Events in a Socioeconomically Diverse City in the United States - Lessons Learned.

Community-based health events provide an opportunity to increase knowledge, awareness, and screening for acute and chronic diseases among individuals living in a socioeconomically diverse community. Because there are limited reports of such events, here we describe our ten-year experience of annual men's health fairs. This retrospective study of the Michigan Institute of Urology Foundation evaluated Men's Health Events held in Detroit, Michigan, from 2012 to 2021. Over 10 years, 11,129 men were screened and > 100,000 screenings were performed. The majority of the attendees were African-American men (61%), had a college degree (67%) or a high school diploma (26%), and had an annual income of <$35K (47%) or $35-60 K (30%). From 2012 to 2021, participants who saw a doctor in the past year rose from 62 to 70%; the median age of men rose from 52 to 58; their median testosterone levels increased from 353 ng/dL to 412 ng/dL, and men with concerning prostate-specific antigen values (≥ 4 ng/mL) doubled from 5% to 10%. Among participants, 59% had cholesterol levels of < 200 mg/dL, 28% of 200-240 mg/dL, and 13% of > 240 mg/dL; 7% had glucose levels of < 70 mg/dL, 68% of 70-105 mg/dL, and 25% of > 105 mg/dL ; 24% had ≥ 140 mmHg systolic and 18% had ≥ 90 mmHg diastolic blood pressure. Our findings suggest that community health events are successful at attracting and screening diverse community members. Such events should emphasize screening of high-risk individuals for acute and chronic diseases and promote other health-related behaviors.

Clean-up of divalent cobalt ions by massive sequestration in a low-cost calcium silicate hydrate material.

Cobalt is a critical resource in industrial economies for the manufacture of electric-vehicle batteries, alloys, magnets, and catalysts, but has acute supply-chain risks and poses a threat to the environment. Large-scale sequestration of cobalt in low-cost materials under mild conditions opens a path to cobalt recycling, recovery and environmental clean-up. We describe such sequestration of cobalt by a widely available commercial calcium silicate material containing the mineral xonotlite. Xonotlite rapidly and spontaneously takes up 40 percent of its weight of cobalt under ambient conditions of temperature and pressure and reduces dissolved cobalt concentrations to low parts per million. A new Sharp Front experimental design is used to obtain kinetic and chemical information. Sequestration occurs by a coupled dissolution-precipitation replacement mechanism. The cobalt silicate reaction product is largely amorphous but has phyllosilicate features.

Hydroxyapatite coatings on cement paste as barriers against radiological contamination.

A novel method for precipitating hydroxyapatite (HAp) onto cement paste is investigated for protecting concrete infrastructure from radiological contamination. Legacy nuclear sites contain large volumes of contaminated concrete and are expensive and dangerous to decommission. One solution is to 'design for decommissioning' by confining contaminants to a thin layer. Current layering methods, including paints or films, offer poor durability over plant lifespans. Here, we present a mineral-HAp-coated cement, which innovatively serves as a barrier layer to radioactive contaminants (e.g. Sr, U). HAp is shown to directly mineralise onto a cement paste block in a layer several microns thick via a two-step process: first, applying a silica-based scaffold onto a cement paste block; and second, soaking the resulting block in a PO4-enriched Ringer's solution. Strontium ingression was tested on coated and uncoated cement paste (~ 40 × 40 × 40mm cement, 450 mL, 1000 mg L- 1 Sr) for a period of 1-week. While both coated and uncoated samples reduced the solution concentration of Sr by half, Sr was held within the HAp layer of coated cement paste and was not observed within the cement matrix. In the uncoated samples, Sr had penetrated further into the block. Further studies aim to characterise HAp before and after exposure to a range of radioactive contaminants and to develop a method for mechanical layer separation.

Factors associated with COVID-19 vaccine receipt at two integrated healthcare systems in New York City: a cross-sectional study of healthcare workers.

OBJECTIVES: To examine the factors associated with COVID-19 vaccine receipt among healthcare workers and the role of vaccine confidence in decisions to vaccinate, and to better understand concerns related to COVID-19 vaccination. DESIGN: Cross-sectional anonymous survey among front-line, support service and administrative healthcare workers. SETTING: Two large integrated healthcare systems (one private and one public) in New York City during the initial roll-out of the COVID-19 vaccine. PARTICIPANTS: 1933 healthcare workers, including nurses, physicians, allied health professionals, environmental services staff, researchers and administrative staff. PRIMARY OUTCOME MEASURES: The primary outcome was COVID-19 vaccine receipt during the initial roll-out of the vaccine among healthcare workers. RESULTS: Among 1933 healthcare workers who had been offered the vaccine, 81% had received the vaccine at the time of the survey. Receipt was lower among black (58%; OR: 0.14, 95% CI 0.1 to 0.2) compared with white (91%) healthcare workers, and higher among non-Hispanic (84%) compared with Hispanic (69%; OR: 2.37, 95% CI 1.8 to 3.1) healthcare workers. Among healthcare workers with concerns about COVID-19 vaccine safety, 65% received the vaccine. Among healthcare workers who agreed with the statement that the vaccine is important to protect family members, 86% were vaccinated. Of those who disagreed, 25% received the vaccine (p<0.001). In a multivariable analysis, concern about being experimented on (OR: 0.44, 95% CI 0.31 to 0.6), concern about COVID-19 vaccine safety (OR: 0.39, 95% CI 0.28 to 0.55), lack of influenza vaccine receipt (OR: 0.28, 95% CI 0.18 to 0.44), disagreeing that COVID-19 vaccination is important to protect others (OR: 0.37, 95% CI 0.27 to 0.52) and black race (OR: 0.38, 95% CI 0.24 to 0.59) were independently associated with COVID-19 vaccine non-receipt. Over 70% of all healthcare workers responded that they had been approached for vaccine advice multiple times by family, community members and patients. CONCLUSIONS: Our data demonstrated high overall receipt among healthcare workers. Even among healthcare workers with concerns about COVID-19 vaccine safety, side effects or being experimented on, over 50% received the vaccine. Attitudes around the importance of COVID-19 vaccination to protect others played a large role in healthcare workers' decisions to vaccinate. We observed striking inequities in COVID-19 vaccine receipt, particularly affecting black and Hispanic workers. Further research is urgently needed to address issues related to vaccine equity and uptake in the context of systemic racism and barriers to care. This is particularly important given the influence healthcare workers have in vaccine decision-making conversations in their communities.

Metabolic Pathway of Topramezone in Multiple-Resistant Waterhemp (Amaranthus tuberculatus) Differs From Naturally Tolerant Maize.

Waterhemp [Amaranthus tuberculatus (Moq.) Sauer] is a problematic dicot weed in maize, soybean, and cotton production in the United States. Waterhemp has evolved resistance to several commercial herbicides that inhibit the 4-hydroxyphenylpyruvate-dioxygenase (HPPD) enzyme in sensitive dicots, and research to date has shown that HPPD-inhibitor resistance is conferred by rapid oxidative metabolism of the parent compound in resistant populations. Mesotrione and tembotrione (both triketones) have been used exclusively to study HPPD-inhibitor resistance mechanisms in waterhemp and a related species, A. palmeri (S. Wats.), but the commercial HPPD inhibitor topramezone (a pyrazolone) has not been investigated from a mechanistic standpoint despite numerous reports of cross-resistance in the field and greenhouse. The first objective of our research was to determine if two multiple herbicide-resistant (MHR) waterhemp populations (named NEB and SIR) metabolize topramezone more rapidly than two HPPD inhibitor-sensitive waterhemp populations (named SEN and ACR). Our second objective was to determine if initial topramezone metabolite(s) detected in MHR waterhemp are qualitatively different than those formed in maize. An excised leaf assay and whole-plant study investigated initial rates of topramezone metabolism (<24 h) and identified topramezone metabolites at 48 hours after treatment (HAT), respectively, in the four waterhemp populations and maize. Results indicated both MHR waterhemp populations metabolized more topramezone than the sensitive (SEN) population at 6 HAT, while only the SIR population metabolized more topramezone than SEN at 24 HAT. Maize metabolized more topramezone than any waterhemp population at each time point examined. LC-MS analysis of topramezone metabolites at 48 HAT showed maize primarily formed desmethyl and benzoic acid metabolites, as expected based on published reports, whereas SIR formed two putative hydroxylated metabolites. Subsequent LC-MS/MS analyses identified both hydroxytopramezone metabolites in SIR as different hydroxylation products of the isoxazole ring, which were also present in maize 48 HAT but at very low levels. These results indicate that SIR initially metabolizes and detoxifies topramezone in a different manner than tolerant maize.

Biogenic Hydroxyapatite: A New Material for the Preservation and Restoration of the Built Environment.

Ordinary Portland cement (OPC) is by weight the world's most produced man-made material and is used in a variety of applications in environments ranging from buildings, to nuclear wasteforms, and within the human body. In this paper, we present for the first time the direct deposition of biogenic hydroxyapatite onto the surface of OPC in a synergistic process which uses the composition of the cement substrate. This hydroxyapatite is very similar to that found in nature, having a similar crystallite size, iron and carbonate substitution, and a semi-crystalline structure. Hydroxyapatites with such a structure are known to be mechanically stronger and more biocompatible than synthetic or biomimetic hydroxyapatites. The formation of this biogenic hydroxyapatite coating therefore has significance in a range of contexts. In medicine, hydroxyapatite coatings are linked to improved biocompatibility of ceramic implant materials. In the built environment, hydroxyapatite coatings have been proposed for the consolidation and protection of sculptural materials such as marble and limestone, with biogenic hydroxyapatites having reduced solubility compared to synthetic apatites. Hydroxyapatites have also been established as effective for the adsorption and remediation of environmental contaminants such as radionuclides and heavy metals. We identify that in addition to providing a biofilm scaffold for nucleation, the metabolic activity of Pseudomonas fluorescens increases the pH of the growth medium to a suitable level for hydroxyapatite formation. The generated ammonia reacts with phosphate in the growth medium, producing ammonium phosphates which are a precursor to the formation of hydroxyapatite under conditions of ambient temperature and pressure. Subsequently, this biogenic deposition process takes place in a simple reaction system under mild chemical conditions and is cheap and easy to apply to fragile biological or architectural surfaces.

A force balance can explain local and global cell movements during early zebrafish development.

Embryonic morphogenesis takes place via a series of dramatic collective cell movements. The mechanisms that coordinate these intricate structural transformations across an entire organism are not well understood. In this study, we used gentle mechanical deformation of developing zebrafish embryos to probe the role of physical forces in generating long-range intercellular coordination during epiboly, the process in which the blastoderm spreads over the yolk cell. Geometric distortion of the embryo resulted in nonuniform blastoderm migration and realignment of the anterior-posterior (AP) axis, as defined by the locations at which the head and tail form, toward the new long axis of the embryo and away from the initial animal-vegetal axis defined by the starting location of the blastoderm. We found that local alterations in the rate of blastoderm migration correlated with the local geometry of the embryo. Chemical disruption of the contractile ring of actin and myosin immediately vegetal to the blastoderm margin via Ca(2+) reduction or treatment with blebbistatin restored uniform migration and eliminated AP axis reorientation in mechanically deformed embryos; it also resulted in cellular disorganization at the blastoderm margin. Our results support a model in which tension generated by the contractile actomyosin ring coordinates epiboly on both the organismal and cellular scales. Our observations likewise suggest that the AP axis is distinct from the initial animal-vegetal axis in zebrafish.

Contribution of energetically reactive surface features to the dissolution of CeO2 and ThO2 analogues for spent nuclear fuel microstructures.

In the safety case for the geological disposal of nuclear waste, the release of radioactivity from the repository is controlled by the dissolution of the spent fuel in groundwater. There remain several uncertainties associated with understanding spent fuel dissolution, including the contribution of energetically reactive surface sites to the dissolution rate. In this study, we investigate how surface features influence the dissolution rate of synthetic CeO2 and ThO2, spent nuclear fuel analogues that approximate as closely as possible the microstructure characteristics of fuel-grade UO2 but are not sensitive to changes in oxidation state of the cation. The morphology of grain boundaries (natural features) and surface facets (specimen preparation-induced features) was investigated during dissolution. The effects of surface polishing on dissolution rate were also investigated. We show that preferential dissolution occurs at grain boundaries, resulting in grain boundary decohesion and enhanced dissolution rates. A strong crystallographic control was exerted, with high misorientation angle grain boundaries retreating more rapidly than those with low misorientation angles, which may be due to the accommodation of defects in the grain boundary structure. The data from these simplified analogue systems support the hypothesis that grain boundaries play a role in the so-called "instant release fraction" of spent fuel, and should be carefully considered, in conjunction with other chemical effects, in safety performance assessements for the geological disposal of spent fuel. Surface facets formed during the sample annealing process also exhibited a strong crystallographic control and were found to dissolve rapidly on initial contact with dissolution medium. Defects and strain induced during sample polishing caused an overestimation of the dissolution rate, by up to 3 orders of magnitude.

Rapid detection of foot-and-mouth disease virus using a field-portable nucleic acid extraction and real-time PCR amplification platform.

Rapid and accurate field diagnostic tools can be used to support clinical diagnosis during outbreaks of exotic livestock diseases. This study evaluated a mobile PCR amplification platform that performs RNA extraction, real-time reverse-transcription PCR (rRT-PCR) and interpretation of results without operator intervention. Initial studies showed that there was equivalence between the detection limit generated by RNA extracted using the mobile platform and an automated laboratory-based system. In subsequent studies, two validated laboratory-based foot-and-mouth disease virus (FMDV)-specific rRT-PCRs were transferred onto the mobile platform and all assay steps (RT incubation and PCR amplification) were performed with non-lyophilised reagents using an optimised protocol of less than 60 min. The limit of detection of the rRT-PCR on the mobile PCR platform was equivalent to an automated laboratory-based assay used for routine diagnosis of FMDV and there was concordance between these methods for results generated using samples in a reference laboratory proficiency panel. Future studies will be directed at the development and validation of commercially-viable consumables using lyophilised PCR reagents for FMDV and the evaluation of this technology in FMD endemic countries using field samples.

Remodeling the oligosaccharides on ß-glucocerebrosidase using hydrophobic interaction chromatography and applications of hydroxyl ethyl starch for improving remodeling and enhancing protein stability.

In this article, we describe a hydrophobic interaction chromatography (HIC) method to remodel the carbohydrates on recombinant human ß-glucocerebrosidase (GCR) and the use of hydroxyl ethyl starch (HES) an ethylated starch polymer, to improve this process. GCR is a therapeutic protein used in the treatment of Gaucher disease, a life threatening condition in which patients lack sufficient functional levels of this enzyme. Gaucher disease is the most common inherited lysosomal storage disorder resulting in hepatomegaly, splenomegaly, and bone and lung pathology due to the accumulation of glucosylceramide in the lysosomes of macrophages (Beutler and Grabowski, 2001). The oligosaccharide remodeling of GCR, performed on HIC using three enzymes that remove sugars, increases macrophage uptake through the mannose receptor and thereby lowers its therapeutic dose versus unmodified GCR (Furbish et al., 1981; Van Patten et al., 2007). In this article we describe findings that the addition of HES lowered the amounts of three deglycosylating enzymes needed for remodeling GCR. HES also stabilized the activity of α-glucosidase, α-galactosidase, and GCR under conditions in which these three enzymes rapidly lose activity in the absence of this polymer. Circular dichroism (CD) and second derivative UV spectroscopy revealed that the secondary and tertiary structure of α-glucosidase was unchanged while for GCR there was a slight compaction of the secondary structure but no apparent affect on the tertiary structure. The thermal stability of both GCR and α-glucosidase were enhanced by HES as both molecules showed an increased transition midpoint (T(m)).

Design, engineering and utility of biotic games.

Games are a significant and defining part of human culture, and their utility beyond pure entertainment has been demonstrated with so-called 'serious games'. Biotechnology--despite its recent advancements--has had no impact on gaming yet. Here we propose the concept of 'biotic games', i.e., games that operate on biological processes. Utilizing a variety of biological processes we designed and tested a collection of games: 'Enlightenment', 'Ciliaball', 'PAC-mecium', 'Microbash', 'Biotic Pinball', 'POND PONG', 'PolymerRace', and 'The Prisoner's Smellemma'. We found that biotic games exhibit unique features compared to existing game modalities, such as utilizing biological noise, providing a real-life experience rather than virtual reality, and integrating the chemical senses into play. Analogous to video games, biotic games could have significant conceptual and cost-reducing effects on biotechnology and eventually healthcare; enable volunteers to participate in crowd-sourcing to support medical research; and educate society at large to support personal medical decisions and the public discourse on bio-related issues.

Immobilized boron-centered heteroscorpionates: heterocycle metathesis and coordination chemistry.

The preparation of a resin-supported boron-scorpionate ligand and its nickel(II) coordination complexes are reported. The supported ligand is prepared as its potassium salt, making it a general reagent suitable for chelation of any transition metal ion. Resin-immobilized benzotriazole (Bead-btz) reacted cleanly with KTp* (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) by heterocycle metathesis in warm dimethylformamide (DMF) to yield bead-Tp'K, {resin-btz(H)B(pz*)(2)}K. Significantly, bead-Tp'K readily bound nickel(II) from simple salts with minimal leaching of the nickel ion. Bead-Tp'NiNO(3) reacts further with cysteine thiolate (ethyl ester), imparting the deep green color to the beads characteristic of a Tp(R)NiCysEt coordination sphere. Bead-Tp'NiCysEt exhibited an oxygen sensitivity similar to Tp*NiCysEt in solution (Inorg. Chem. 1999, p 5690) and also independently verified for a selenocystamine analogue, Tp*NiSeCysAm. Addition of fresh cysteine thiolate ethyl ester to oxidized bead-Tp'NiCysEt reproduced the original green color. Heterocycle metathesis was also used to prepare KTp' as a white solid. Reaction with nickel(II) gave (Tp')(2)Ni, separable into two different isomers. The air-sensitive molybdenum(0) complex, [PPh(4)][Tp'Mo(CO)(3)], was also prepared and the C(s) complex symmetry demonstrated by infrared and (13)C NMR spectroscopies. Immobilized TpmMo(CO)(3) was prepared from the previously reported resin-supported tris(pyrazolyl)methane. In contrast to its weak coordination of nickel(II) (Inorg. Chem. 2009, p 3535), bead-Tpm proved a strong chelate toward this second row metal. The supported scorpionates described here should find use in studies of selective metal-protein binding, metalloprotein modeling, and heterogeneous catalysis, and render such scorpionate applications amenable to combinatorial methods.

Direct measurement of salt-mineral repulsion using atomic force microscopy.

The disjoining pressure between a mineral and soluble salt crystal in concentrated aqueous solution has been successfully measured with atomic force microscopy.

In situ characterization of elusive salt hydrates. The crystal structures of the heptahydrate and octahydrate of sodium sulfate.

An important intermediate phase in the crystallization of aqueous solutions of sodium sulfate is the highly metastable sodium sulfate heptahydrate (Na(2)SO(4).7H(2)O). This has been structurally characterized for the first time by in situ single crystal X-ray diffraction. The crystal structure shows that each sodium cation is octahedrally coordinated to water molecules, with a slight distortion due to one of the water molecules being disordered. The hydrated sodium cations are hydrogen-bonded to form a three-dimensional bonded network, which is markedly different from the architecture of one-dimensional bonded chains observed in sodium sulfate decahydrate (mirabilite). This major structural difference explains the reconstructive nature of the transformation observed between the heptahydrate and mirabilite. High-pressure crystallization of a 3.41 mol/kg water aqueous solution of sodium sulfate at 1.54 GPa in a diamond-anvil cell resulted in the formation of a previously unknown sodium sulfate hydrate, which we have determined by single crystal X-ray diffraction methods to be an octahydrate, Na(2)SO(4).8H(2)O. In this structure the sulfate ions are coordinated directly to sodium ions. This resembles anhydrous sodium sulfate (thenardite) but contrasts with the heptahydrate and decahydrate in which the sodium ions are coordinated exclusively by water molecules. This observation demonstrates how the delicate balance of inter- and intramolecular bonds in the crystal structure can be significantly altered by the application of pressure.

Penicillin-binding protein 1a promotes resistance of group B streptococcus to antimicrobial peptides.

Evasion of host immune defenses is critical for the progression of invasive infections caused by the leading neonatal pathogen, group B streptococcus (GBS). Upon characterizing the factors required for virulence in a neonatal rat sepsis model, we found that a surface-associated penicillin-binding protein (PBP1a), encoded by ponA, played an essential role in resistance of GBS to phagocytic clearance. In order to elucidate how PBP1a promotes resistance to innate immunity, we compared the susceptibility of wild-type GBS and an isogenic ponA mutant to the bactericidal components of human neutrophils. The isogenic strains were found to be equally capable of blocking complement activation on the bacterial surface and equally associated with phagocytes and susceptible to oxidative killing. In contrast, the ponA mutant was significantly more susceptible to killing by cationic antimicrobial peptides (AMPs) of the cathelicidin and defensin families, which are now recognized as integral components of innate host defense against invasive bacterial infection. These observations may help explain the sensitivity to phagocytic killing and attenuated virulence of the ponA mutant. This novel function for PBP1a in promoting resistance of GBS to AMP did not involve an alteration in bacterial surface charge or peptidoglycan cross-linking. While the peptidoglycan polymerization and cross-linking activity of PBPs are essential for bacterial survival, our study is the first to identify a role for a PBP in resistance to host AMPs.

Mutation of the maturase lipoprotein attenuates the virulence of Streptococcus equi to a greater extent than does loss of general lipoprotein lipidation.

Streptococcus equi is the causative agent of strangles, a prevalent and highly contagious disease of horses. Despite the animal suffering and economic burden associated with strangles, little is known about the molecular basis of S. equi virulence. Here we have investigated the contributions of a specific lipoprotein and the general lipoprotein processing pathway to the abilities of S. equi to colonize equine epithelial tissues in vitro and to cause disease in both a mouse model and the natural host in vivo. Colonization of air interface organ cultures after they were inoculated with a mutant strain deficient in the maturase lipoprotein (DeltaprtM(138-213), with a deletion of nucleotides 138 to 213) was significantly less than that for cultures infected with wild-type S. equi strain 4047 or a mutant strain that was unable to lipidate preprolipoproteins (Deltalgt(190-685)). Moreover, mucus production was significantly greater in both wild-type-infected and Deltalgt(190-685)-infected organ cultures. Both mutants were significantly attenuated compared with the wild-type strain in a mouse model of strangles, although 2 of 30 mice infected with the Deltalgt(190-685) mutant did still exhibit signs of disease. In contrast, only the DeltaprtM(138-213) mutant was significantly attenuated in a pony infection study, with 0 of 5 infected ponies exhibiting pathological signs of strangles compared with 4 of 4 infected with the wild-type and 3 of 5 infected with the Deltalgt(190-685) mutant. We believe that this is the first study to evaluate the contribution of lipoproteins to the virulence of a gram-positive pathogen in its natural host. These data suggest that the PrtM lipoprotein is a potential vaccine candidate, and further investigation of its activity and its substrate(s) are warranted.

Lipoprotein signal peptidase of Streptococcus suis serotype 2.

This paper reports the complete coding sequence for a proliprotein signal peptidase (SP-ase) of Streptococcus suis, Lsp. This is believed to be the first SP-ase described for S. suis. SP-ase II is involved in the removal of the signal peptide from glyceride-modified prolipoproteins. By using in vitro transcription/translation systems, it was shown that the lsp gene was transcribed in vitro. Functionality of Lsp in Escherichia coli was demonstrated by using an in vitro globomycin resistance assay, to show that expression of Lsp in E. coli increased the globomycin resistance. An isogenic mutant of S. suis serotype 2 unable to produce Lsp was constructed and shown to process lipoproteins incorrectly, including an S. suis homologue of the pneumococcal PsaA lipoprotein. Five piglets were inoculated with a mixture of both strains in an experimental infection, to determine the virulence of the mutant strain relative to that of the wild-type strain in a competitive challenge experiment. The data showed that both strains were equally virulent, indicating that the knockout mutant of lsp is not attenuated in vivo.