Strain ATCC Research Articles

Chemical Synthesis and Antigenic Evaluation of Inner Core Oligosaccharides from Acinetobacter baumannii Lipopolysaccharide

AbstractAcinetobacter baumannii is currently posing a serious threat to global health. Lipopolysaccharide (LPS) is a potent virulence factor of pathogenic Gram‐negative bacteria. To explore the antigenic properties of A. baumannii LPS, four Kdo‐containing inner core glycans from A. baumannii strain ATCC 17904 were synthesized. A flexible and divergent method based on the use of the orthogonally substituted α‐Kdo‐(2→5)‐Kdo disaccharides was developed. Selective removal of different protecting groups in these key precursors and elongation of sugar chain via α‐stereocontrolled coupling with 5,7‐O‐di‐tert‐butylsilylene or 5‐O‐benzoyl protected Kdo thioglycosides and 2‐azido‐2‐deoxyglucosyl thioglycoside allowed efficient assembly of the target molecules. Glycan microarray analysis of sera from infected patients revealed that the 4,5‐branched Kdo trimer was a potential antigenic epitope, which is attractive for further immunological research to develop carbohydrate vaccines against A. baumannii.

Inhibition of bacterial growth of Leilem leaf extract (Clerodendrum minhassae Teijsm. & Binn)

Leilem (Clerodendrum minhassae Teism. & Binn.) is a plant endemic to Sulawesi. Leilem leaves are used as a typical food vegetable for the Minahasa tribe. However, leilem leaves were used as a medicinal plant for intestinal worms, abdominal pain and chest pain. There has been no research report on the use of leilem leaves as a source of antibacterial bioactivity. This study aims to obtain the best concentration of antibacterial Leilem leaf extract. Leilem leaves are obtained from North Minahasa. Extraction by maceration method using various solvents with a level of polarity. The test concentrations of the extract were 100 mg/L, 200 mg/L, 400 mg/L and 800 mg/L. As a positive control, clindamycin 400 mg/L was used. The results showed that the percentage of solvent yield was ethanol, which was 1.23% at 1:4 (w/v) maceration. The average diameter of bacterial growth is 12.6 mm. The results of the one way ANOVA analysis showed significant differences between test concentrations (p>0.5). Tukey's test showed that the three extracts significantly inhibited the growth of gram-positive bacteria Staphylococcus aureus strain ATCC 25923. The n-hexane extract showed the best antibacterial activity, followed by ethanol extract and ethyl acetate extract. Leilem leaves are potential to be developed as a source of antibacterial bioactive.

Potentiation of the Activity of Antibiotics against ATCC and MDR Bacterial Strains with (+)-α-Pinene and (-)-Borneol.

The increasing rates of antimicrobial resistance have demanded the development of new drugs as conventional antibiotics have become significantly less effective. Evidence has identified a variety of phytocompounds with the potential to be used in the combat of infections caused by multidrug-resistant (MDR) bacteria. Considering the verification that terpenes are promising antibacterial compounds, the present research aimed to evaluate the antibacterial and antibiotic-modulating activity of (+)-α-pinene and (-)-borneol against MDR bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the compounds and antibiotics and further evaluate the intrinsic and associated antibiotic activity. These analyses revealed that (+)-α-pinene showed significant antibacterial activity only against E. coli (MIC = 512 μg.mL−1), while no significant inhibition of S. aureus and P. aeruginosa growth was observed (MIC ≥ 1024 μg mL−1). However, when combined with antibiotics, this compound induced a significant improvement in the activity of conventional antibiotics, as observed for ciprofloxacin, amikacin, and gentamicin against Staphylococcus aureus, as well as for amikacin and gentamicin against Escherichia coli, and amikacin against Pseudomonas aeruginosa. On the other hand, (-)-borneol was found to inhibit the growth of E. coli and enhance the antibiotic activity of ciprofloxacin and gentamicin against S. aureus. The present findings indicate that (+)-α-pinene and (-)-borneol are phytocompounds with the potential to be used in the combat of antibacterial resistance.

Comparative pan-genomic analysis of 51 Renibacterium salmoninarum indicates heterogeneity in the principal virulence factor, the 57kDa protein.

Renibacterium salmoninarum, a Gram-positive intracellular pathogen, is the causative agent of bacterial kidney disease (BKD), the impacts of which are high mortalities and economic losses for the salmon industry. This study provides novel analyses for the whole-genome sequences of 50 R. salmoninarum isolates and the reference strain ATCC 33209 using a pan-genomic approach to elucidate phylogenomic relationships and identify unique and shared genes associated with pathogenicity and infection mechanisms. Genome size varied from 3,061,638 to 3,155,332 bp; gene count from 3452 to 3580; and predicted coding sequences from 3402 to 3527. Comparative analyses revealed an open, but approaching closed, pan-genome. The pan-genome analysis recovered 4064 genes, with a core genome containing 3306 genes. Phylogenetic analysis of R. salmoninarum showed high genomic homogeneity, apart from one isolate obtained from Salmo trutta in Norway. All genomes presented the 57-kDa protein (p57). Strain ATCC 33209 and the Chilean isolates H-2 and DJ2R presented two copies of the msa gene, while the remaining isolates had one copy. The pan-genome analysis further identified differences in the number of copies and length of the signalling peptide for p57, the principal virulence factor reported for this bacterium. This heterogeneity could be associated with the secretion levels of p57, potentially influencing virulence. Additionally identified were numerous common genes related to iron uptake, the stress response and regulation, and cell signalling-all of which constitute the pathogenic repertoire of R. salmoninarum. This investigation provides information that is applicable in future studies for identifying therapeutic targets and/or for designing new strategies (e.g., vaccines) to prevent BKD infections in salmon farming.

Isolation of Fluoroquinolones Resistant Salmonella spp. from Stool Samples of Patients Attending General Hospital Minna and Ibrahim Badamasi Babangida Specialist Hospital, Minna, Nigeria

Typhoid fever continues to be a major health problem despite the use of antibiotics and the development of newer antibacterial drugs. This study aim was to isolate fluoroquinolones resistant Salmonella spp from stool samples of informed and consenting patient attending General Hospital and Ibrahim Badamasi Babangida Specialist Hospital in Minna Niger State Nigeria. A total 450 stool samples were collected from the Hospital. The results showed that 69 (30.4%) of the sample collected were positive for Salmonella species. On the basis of age children within the age range of 0-10 recorded the highest prevalence of 22.7% followed by age range 51-60 having the prevalence of 19.4%, age range >60 had the prevalence of 16.7% and age range 21-30 and 11-20 had a similar prevalence of (10.1% and 10.3% respectively) while age range 31-40 had the least prevalence of 7.8%. There were 69 isolates of Salmonella species Identified, 65(94.2%) were Resistant to the antibiotics used. The highest resistance was shown to Pefloxacin 62 (89.9%) and the lowest was shown to Ciprofloxacin 27 (39.1%). Salmonella species exhibited 52 antibiotic resistant patterns for the ten antibiotics tested with multiple antibiotic resistance index (MARI) ranging from 0.3-1.0. Molecular analysis was carried out on 5 representative isolates to identify their strains. Polymerase chain reaction (PCR) assay showed the identified Salmonella strains were Salmonella enterica subsp. arizonae strain ATCC 13314, Salmonella enterica subsp. enterica serovar Typhi strain 2018K-0756, Salmonella bongori strain SL18, Salmonella bongori strain GH3Rp and Salmonella enterica subsp. arizonae strain ATCC 13314, they all showed resistance to fluoroquinolones.

Efficacy of Three Povidone Iodine Formulations against Cutibacterium acnes Assessed through In Vitro Studies: A Preliminary Study.

Cutibacterium acnes (C. acnes, formerly known as Propionibacterium acnes) is the major causative agent of prosthetic joint infections (PJI). Treatment of PJI with antibiotics is difficult due to antibiotic resistance and adverse side effects on patients’ health. Proper disinfection of the surgical site using a variety of povidone iodine formulations could prevent C. acnes infection. In the current study, the efficacy of the three povidone iodine (PVP-I) formulations, viz: PVP-I 10% dermic solution, PVP-I 5% alcoholic solution and PVP-I 4% scrub, was tested against C. acnes, in vitro, in the presence of interfering substances mimicking soiling conditions. C. acnes strain ATCC 6919 was used to test the bactericidal activity of the povidone iodine formulations according to the modified dilution-neutralization method described in French Norm EN standard 13727. A 3-log reduction in the bacterial cell count in 60 s was considered to be significant. The results showed that under experimental conditions, the three PVP-I formulations displayed bactericidal activity against the micro-organism, Cutibacterium acnes, and that the lowest concentration of povidone-iodine active against C. acnes was 0.4%. These results are encouraging as PVP-I offers a low-cost and efficient method of disinfection.

Single-well push-pull tests evaluating isobutane as a primary substrate for promoting in situ cometabolic biotransformation reactions.

A series of single-well push-pull tests (SWPPTs) were performed to investigate the efficacy of isobutane (2-methylpropane) as a primary substrate for in situ stimulation of microorganisms able to cometabolically transform common groundwater contaminants, such as chlorinated aliphatic hydrocarbons and 1,4-dioxane (1,4-D). In biostimulation tests, the disappearance of isobutane relative to a nonreactive bromide tracer indicated an isobutane-utilizing microbial community rapidly developed in the aquifer around the test well. SWPPTs were performed as natural drift tests with first-order rates of isobutane consumption ranging from 0.4 to 1.4day-1. Because groundwater contaminants were not present at the demonstration site, isobutene (2-methylpropene) was used as a nontoxic surrogate to demonstrate cometabolic activity in the subsurface after biostimulation. The transformation of isobutene to isobutene epoxide (2-methyl-1,2-epoxypropane) illustrates the epoxidation process previously shown for common groundwater contaminants after cometabolic transformation by alkane-utilizing bacteria. The rate and extent of isobutene consumption and the formation and transformation of isobutene epoxide were greater in the presence of isobutane, with no evidence of primary substrate inhibition. Modeled concentrations of isobutane-utilizing biomass in microcosms constructed with groundwater collected before and after each SWPPT offered additional evidence that the isobutane-utilizing microbial community was stimulated in the aquifer. Experiments in groundwater microcosms also demonstrated that the isobutane-utilizing bacteria stimulated in the subsurface could cometabolically transform a mixture of co-substrates including isobutene, 1,1-dichloroethene, cis-1,2-dichloroethene, and 1,4-D with the same co-substrate preferences as the bacterium Rhodococcus rhodochrous ATCC strain 21198 after growth on isobutane. This study demonstrated the effectiveness of isobutane as primary substrate for stimulating in situ cometabolic activity and the use of isobutene as surrogate to investigate in situ cometabolic reactions catalyzed by isobutane-stimulated bacteria.

Complete Genome Sequences of Two Closely Related Paenarthrobacter nicotinovorans Strains.

ABSTRACTPaenarthrobacter nicotinovorans is a soil bacterium that uses the pyridine pathway to degrade nicotine. The genome of strain ATCC 49919 is composed of a ~4.3-Mbp chromosome and a ~165-kbp plasmid. The second strain, termed here nic-, is a cured derivative lacking the plasmid and not able to degrade nicotine.

Multicomponent synthesis of pyranonicotinonitrile and chromene-3-carbonitrile: Studies on bioactivities and molecular docking

Dehydroacetic acid (DHA) and derivatives are widely used in the synthesis of pharmacologically active heterocyclic compounds. In this study, two new series of pyranonicotinonitriles and chromene-3-carbonitriles have been synthesized under microwave irradiation using DHA synthons, as starting materials, through multicomponent reaction (MCR), involving domino Knoevenagel-Michael addition or one pot intramolecular cyclization. All the resulting heterocyclic compounds have been characterized by 1H NMR and 13C NMR, 2D NMR (HSQC, HMBC) and mass spectroscopy. Mass peaks of the synthetized compounds correspond perfectly to molecular ions [M + H] or [M+Na]. Notably, 1H NMR spectra of all the compounds display a characteristic doublet at δH 6.07 ppm, which is assigned to the pyran-2-one heterocycle. Biological activities, such as the antioxidant DPPH radical scavenging and antibacterial/antifungal assays against ATCC strains have been evaluated in-vitro. Results showed that all compounds are capable to reduce DPPH with different IC50 values. The germs sensitivity towards the synthesized compounds is variable with Staphylococcus aureus being the most sensitive bacteria. Further docking simulations have been carried out targeting S. aureus penicillin binding proteins group (PBP2, PBP3 and PBP4) and thymidylate kinase (TMK) and the cell division Z ring protein (FtsZ) using AutoDock Vina software. The validity of docking results have been confirmed based on the best affinity scores and types of interactions. The molecular mechanisms of the synthesized heterocycles towards target proteins involved in S. aureus growth have been predicted through molecular docking studies.

Aerobic Cometabolism of Chlorinated Solvents and 1,4-Dioxane in Continuous-Flow Columns Packed with Gellan-Gum Hydrogels Coencapsulated with ATCC Strain 21198 and TBOS or T2BOS as Slow-Release Compounds

Aerobic Cometabolism of Chlorinated Solvents and 1,4-Dioxane in Continuous-Flow Columns Packed with Gellan-Gum Hydrogels Coencapsulated with ATCC Strain 21198 and TBOS or T2BOS as Slow-Release Compounds

Effect of Ciprofloxacin on Planktonic Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic human pathogen that causes nosocomial, acute, and chronic infections in patients with conditions such as cystic fibrosis, severe burns, and cancer. P. aeruginosa is known for its persistence in infections due largely to its numerous means of antimicrobic resistance, one of which is its ability to form biofilms. This organism has been placed on the World Health Organization list of Priority Pathogens for Research and Development of New Antibiotics at the critical level for many reasons, that includes its high mortality, healthcare burden, prevalence of resistance, and treatability. P. aeruginosa is resistant to many antibiotics; however, >70% of P. aeruginosa are susceptible to ciprofloxacin. For these reasons, the purpose of the current study was to establish antimicrobic levels of ciprofloxacin effective against P. aeruginosa. To accomplish this purpose, antimicrobic levels of bacteria in biofilms and those not associated with a biofilm (planktonic) need separate methods of testing. For planktonic bacteria, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) are performed, whereas other methods are used for biofilm‐associated bacteria. To initiate inhibition studies, a model system was identified of ciprofloxacin effect on standardized strains of P. aeruginosa (ATCC strains 10145, 27853, 1744, CRM‐9027, 9721). These strains were used to establish ciprofloxacin effect, in terms of MIC and MBC levels, on planktonic bacteria. Results indicate that MIC and MBC levels of these strains are in the same range as reported values of P. aeruginosa. These results establish ciprofloxacin efficacy of growth inhibition for each ATCC strain of planktonic P. aeruginosa and will serve as baseline results for future studies, such as effect on biofilm‐associated bacteria and combination antimicrobic treatments.

Colistin Action Against Planktonic Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic human pathogen that causes nosocomial, acute, and chronic infections in patients with conditions such as cystic fibrosis, severe burns, and cancer. P. aeruginosa is associated with increased patient morbidity, mortality, and healthcare costs and is known for its persistence of infections. P. aeruginosa is resistant to many antibiotics; however, most strains are susceptible to colistin. The World Health Organization has identified antimicrobial resistance as a major threat and Antimicrobial Stewardship Programs (ASP) have been initiated. ASP goals are to improve patient outcomes, optimize patient safety, reduce antimicrobial resistance, and control healthcare costs. Recommendations to reduce antimicrobial resistance include optimizing the use of antimicrobials and preventing the transmission of drug‐resistant organisms. Using antimicrobic agents wisely leads to optimization of their use. For these reasons, we sought to adopt a model system for testing minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) levels for standardized strains of P. aeruginosa (ATCC strains 10145, 27853, 1744, CRM‐9027, 9721) using standardized methods. This study sought to compare results of standardized analysis that used Mueller‐Hinton Broth (MHB), the recommended and standardized growth medium, or tryptic soy broth (TSB), the growth medium used in many labs with published MIC and MBC reports. Given the ASP recommendations of optimizing use of antimicrobial agents, it is important to know the impact of variations in and deviations from standardized MIC and MBC methodologies in reporting of research results relevant to antimicrobic agents. This comparison study tested the assumption that MIC and MBC results are the same regardless of whether MHB or TSB is used as the growth medium. Preliminary results suggest that MIC and MBC values obtained by using TSB or MHB may display some degree of variability.

Characteristics of Clinical Isolates of Streptococcus mutans

Dental caries is an infectious disease which remains a significant health problem all over the world. The purpose of the study was to characterise a collection of 60 clinical isolates of S. mutans from adults’ and children’s dental plaque (natural biofilm). The paper describes the process of isolation, identification, analysis of biofilm formation and collection testing for the presence of 13 two-component systems (TCS) identified earlier in reference strain ATCC 700610 (UA159). In the case of S. mutans strains, plaque formation is specifically influenced by binary systems. All isolated strains of S. mutans form biofilm at high levels and possess a set of 26 genes forming TSC binary systems, which have an important role in plaque formation.

Retrieving the in vivo Scopoletin Fluorescence Excitation Band Allows the Non-invasive Investigation of the Plant-Pathogen Early Events in Tobacco Leaves.

In this study, we developed and applied a new spectroscopic fluorescence method for the in vivo detection of the early events in the interaction between tobacco (Nicotiana tabacum L.) plants and pathogenic bacteria. The leaf disks were infiltrated with a bacterial suspension in sterile physiological solution (SPS), or with SPS alone as control. The virulent Pseudomonas syringae pv. tabaci strain ATCC 11528, its non-pathogenic ΔhrpA mutant, and the avirulent P. syringae pv. tomato strain DC3000 were used. At different post-infiltration time–points, the in vivo fluorescence spectra on leaf disks were acquired by a fiber bundle-spectrofluorimeter. The excitation spectra of the leaf blue emission at 460 nm, which is mainly due to the accumulation of coumarins following a bacterial infiltration, were processed by using a two-bands Gaussian fitting that enabled us to isolate the scopoletin (SCT) contribution. The pH-dependent fluorescence of SCT and scopolin (SCL), as determined by in vitro data and their intracellular localization, as determined by confocal microscopy, suggested the use of the longer wavelength excitation band at 385 nm of 460 nm emission (F385_460) to follow the metabolic evolution of SCT during the plant–bacteria interaction. It was found to be directly correlated (R2 = 0.84) to the leaf SCT content, but not to that of SCL, determined by HPLC analysis. The technique applied to the time-course monitoring of the bacteria–plant interaction clearly showed that the amount and the timing of SCT accumulation, estimated by F385_460, was correlated with the resistance to the pathogen. As expected, this host defense response was delayed after P. syringae pv. tabaci ATCC 11528 infiltration, in comparison to P. syringae pv. tomato DC3000. Furthermore, no significant increase of F385_460 (SCT) was observed when using the non-pathogenic ΔhrpA mutant of P. syringae pv. tabaci ATCC 11528, which lacks a functional Type Three Secretion System (TTSS). Our study showed the reliability of the developed fluorimetric method for a rapid and non-invasive monitoring of bacteria-induced first events related to the metabolite-based defense response in tobacco leaves. This technique could allow a fast selection of pathogen-resistant cultivars, as well as the on-site early diagnosis of tobacco plant diseases by using suitable fluorescence sensors.

Diversity of Monofloral Honey Based on the Antimicrobial and Antioxidant Potential.

This study aimed to investigate the antioxidant profile and the antimicrobial activity of four different types of monofloral honey (manuka (MH), brassica rapeseed (BH), acacia (AH), and linden honey (LH)) against some bacterial/fungal ATCC strains and some multidrug-resistant strains isolated from chronic otitis in dogs. For the characterisation of the antioxidant profile of each honey, we extracted the honey samples by hydroalcoholic extraction and analysed them in terms of total polyphenols (TPC), total flavonoids (TFC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) using the spectrophotometric method. The antimicrobial activity was determined using the microdilution method at concentrations of 10%, 15%, and 20%, with the results expressed in OD (optical density) calculated as BIR% (bacterial inhibition rate)/MIR% (mycelial inhibition rate). The antioxidant characterisation of the analysed honey samples showed the highest antioxidant activity and concentrations of TPC and TFC in MH, followed by LH. MH was proven to be the most effective on most clinical isolates concerning the antimicrobial activity in comparison with BH, AH, and LH. Except for B. cepacia and P. vulgaris, all the clinical isolates were sensitive to the antibacterial activity of honey. Regarding the ATCC strains, MH 10% was the most effective in inhibiting all the strains tested except for P. aeruginosa. In conclusion, the efficacy classification in our study was MH > BH > AH > LH.

Identification of novel small-molecular inhibitors of Staphylococcus aureus sortase A using hybrid virtual screening.

Staphylococcus aureus is one of the most dangerous pathogens commonly associated with high levels of morbidity and mortality. Sortase A is considered as a promising molecular target for the development of antistaphylococcal agents. Using hybrid virtual screening approach and FRET analysis, we have identified five compounds able to decrease the activity of sortase A by more than 50% at the concentration of 200 µM. The most promising compound was 2-(2-amino-3-chloro-benzoylamino)-benzoic acid which was able to inhibit S. aureus sortase A at the IC50 value of 59.7 µM. This compound was selective toward sortase A compared to other four cysteine proteases – cathepsin L, cathepsin B, rhodesain, and the SARS-CoV2 main protease. Microscale thermophoresis experiments confirmed that this compound bound sortase A with KD value of 189 µM. Antibacterial and antibiofilm assays also confirmed high specificity of the hit compound against two standard and three wild-type, S. aureus hospital infection isolates. The effect of the compound on biofilms produced by two S. aureus ATCC strains was also observed suggesting that the compound reduced biofilm formation by changing the biofilm structure and thickness.

Cellulose-mediated floc formation by the activated sludge bacterium Shinella zoogloeoides ATCC 19623

BackgroundBacterial floc formation plays a central role in the activated sludge (AS) process. The formation of AS flocs has long been known to require exopolysaccharide biosynthesis. We had demonstrated that both expolysaccharides and PEP-CTERM (a short C-terminal domain includes a near-invariant motif Pro-Glu-Pro (PEP)) proteins were required for floc-forming in Zoogloea resiniphila MMB, a dominant AS bacterium. However, the PEP-CTERM proteins are not encoded in the genome of AS bacterium Shinella zoogloeoides ATCC 19623 (formerly known as Zoogloea ramigera I-16-M) and other sequenced AS bacteria strains. The mechanism underlying floc formation of Shinella and related AS bacteria remained largely unclear.ResultsIn this study, we have sequenced and annotated the complete genome of S. zoogloeoides ATCC 19623 (aka I-16-M), previously isolated in USA and treated as the neotype for the AS floc-forming bacterium Zoogloea ramigera I-16-M, and another AS strain XJ20 isolated in China. Mariner transposon mutagenesis had been conducted to isolate floc-forming-deficient mutants in the strain ATCC 19623 as previously performed by using Tn5 transposon three decades ago. The transposon insertional sites of multiple mutants were mapped to the gene cluster for bacterial cellulose synthesis (bcs) and secretion, and the role played by these genes in floc-formation had been further confirmed by genetic complementation. Interestingly, the restriction map of this bcs locus-flanking region was highly similar to that of the previously identified DNA fragment required for floc-formation in 1980s. Cellulase treatment abolished the floc-forming phenotype of S. zoogloeoides ATCC 19623 but not that of Z. resiniphila MMB strain. The FTIR spectral analyses revealed that the samples extracted from S. zoogloeoides ATCC 19623 were cellulose polymer.ConclusionOur results indicated that we have largely reproduced and completed the unfinished pioneering work on AS floc-formation mechanism, demonstrating that the floc-formation and flocculating capability of Shinella were mediated by extracellular cellulose polymers.

Tannerella forsythia strains differentially induce interferon gamma-induced protein 10 (IP-10) expression in macrophages due to lipopolysaccharide heterogeneity.

Tannerella forsythia is strongly implicated in the development of periodontitis, an inflammatory disease that destroys the bone and soft tissues supporting the tooth. To date, the knowledge of the virulence attributes of T. forsythia species has mainly come from studies with a laboratory adapted strain (ATCC 43037). In this study, we focused on two T. forsythia clinical isolates, UB4 and UB20, in relation to their ability to activate macrophages. We found that these clinical isolates differentially induced proinflammatory cytokine expression in macrophages. Prominently, the expression of the chemokine protein IP-10 (CXCL10) was highly induced by UB20 as compared to UB4 and the laboratory strain ATCC 43037. Our study focused on the lipopolysaccharide component (LPS) of these strains and found that UB20 expressed a smooth-type LPS, unlike UB4 and ATCC 43037 each of which expressed a rough-type LPS. The LPS from UB20, via activation of TLR4, was found to be a highly potent inducer of IP-10 expression via signaling through STAT1 (signal transducer and activator of transcription-1). These data suggest that pathogenicity of T. forsythia species could be strain dependent and the LPS heterogeneity associated with the clinical strains might be responsible for their pathogenic potential and severity of periodontitis.

Molecular and Physiological Properties of Indigenous Strains of Oenococcus oeni Selected from Nero di Troia Wine (Apulia, Italy).

The characterization of Oenococcus oeni strains isolated from Nero di Troia wine (Apulia, Italy) sampled in two distinct production areas was carried out. The two indigenous populations, consisting of 95 and 97 isolates, displayed high genetic diversity when analyzed by amplified fragments length polymorphisms (AFLP). Based on the UPGMA dendrogram obtained by AFLP analysis, the two populations displayed similar genotypes that grouped in the same clusters with a high level of similarity (>95%). One genotype was found in only one of the two areas. Representative strains of each cluster were analyzed for their enzymatic activities (esterase, β-glucosidase, and protease), assayed in whole cells, and tested for their metabolic properties (consumption of L-malic acid, citric acid, acetaldehyde, and arginine) and growth parameters. Significant differences among strains, including the reference strain ATCC BAA-1163, were observed for all of these properties. Principal component analysis evidenced phenotypic differences among strains, and well separated some of them belonging to different genotypes. Strains exhibiting the best performances in most of these traits could be further investigated in order to select possible candidates as malolactic starters for Nero di Troia wine. This study provided insights on the population structure of O. oeni of a local winemaking area useful to the understanding of the regional diversity of this bacterium, an issue not yet completely resolved

Validation of a Lateral Flow Test for the Presumptive Identification of the Presence of Burkholderia mallei or Burkholderia pseudomallei in Environmental Samples.

We conducted a comprehensive, multiphase laboratory evaluation of InBios Active Melioidosis Detect (AMD) rapid test, a lateral flow immunoassay designed to detect capsular polysaccharides produced by Burkholderia mallei or Burkholderia pseudomallei, used in conjunction with the Omni Array Reader (OAR) for the rapid detection of B mallei or B pseudomallei in environmental (nonclinical) samples at 2 sites. The limit of detection, using reference strains B mallei strain ATCC 23344 and B pseudomallei strain ATCC 11668, was determined to be 103 to 104 CFU/mL. In different phases of the evaluation, inclusivity strains that included geographically diverse strains of B mallei (N = 13) and B pseudomallei (N = 22), geographically diverse phylogenetic near neighbor strains (N = 66), environmental background strains (N = 64), white powder samples (N = 26), and environmental filter extracts (N = 1 pooled sample from 10 filter extracts) were also tested. A total of 1,753 tests were performed, which included positive and negative controls. Visual and OAR results showed that the AMD test detected 92.3% of B mallei and 95.5% of B pseudomallei strains. Of the 66 near-neighbor strains tested, cross-reactivity was observed with only B stabilis 2008724195 and B thailandensis 2003015869. Overall, the specificity and sensitivity were 98.8% and 98.7%, respectively. The results of this evaluation support the use of the AMD test as a rapid, qualitative assay for the presumptive detection of B mallei and B pseudomallei in suspicious environmental samples such as white powders and aerosol samples by first responders and laboratory personnel.