A bivalent pneumococcal histidine triad protein D-choline-binding protein A vaccine elicits functional antibodies that passively protect mice from Streptococcus pneumoniae challenge.

Vaccines based on conserved pneumococcal proteins are being investigated because serotype coverage by pneumococcal polysaccharide and polysaccharide conjugate vaccines is incomplete and may eventually decrease due to serotype replacement. Here, we examined the functionality of human antibodies induced by a candidate bivalent choline-binding protein A- pneumococcal histidine triad protein D (PcpA-PhtD) vaccine. Pre- and post-immune sera from subjects who had been vaccinated with the PcpA-PhtD candidate vaccine were tested in an established passive protection model in which mice were challenged by intravenous injection with Streptococcus pneumoniae serotype 3 strain A66.

Safety and immunogenicity of a trivalent recombinant PcpA, PhtD, and PlyD1 pneumococcal protein vaccine in adults, toddlers, and infants: A phase I randomized controlled study.

Background: Pneumococcal protein vaccines (PPrVs) may provide improved protection over currently available polysaccharide and conjugated polysaccharide vaccines. Here, we examined the safety and immunogenicity of a trivalent recombinant PPrV containing PcpA, PhtD, and PlyD1.

Methods: This was a phase I, single-center, randomized, observer-blind study with safety review between cohorts.

Passive protection of mice against Streptococcus pneumoniae challenge by naturally occurring and vaccine-induced human anti-PhtD antibodies.

Currently marketed Streptococcus pneumoniae vaccines are based on polysaccharide capsular antigens from the most common strains. Pneumococcal histidine triad protein D (PhtD) is a conserved surface protein that is being evaluated as a candidate for a vaccine with improved serotype coverage. Here, we measured the functional activity of human anti-PhtD antibodies in a passive protection model wherein mice were challenged with a lethal dose of S.

Safety and immunogenicity of the pneumococcal pneumolysin derivative PlyD1 in a single-antigen protein vaccine candidate in adults.

Background: Pneumococcal vaccines based on conserved protein antigens have the potential to offer expanded protection against Streptococcus pneumoniae.

Objective: This study examined the safety and immunogenicity in adults of three doses of a pneumococcal single-antigen protein vaccine candidate formulated with aluminum hydroxide adjuvant and recombinantly derived, highly detoxified, genetically mutated pneumolysin protein (PlyD1).

Methods: This phase I, randomized, placebo-controlled, observer-blinded, dose-escalating study enrolled adults (18-50 years).

Safety and immunogenicity of pneumococcal protein vaccine candidates: monovalent choline-binding protein A (PcpA) vaccine and bivalent PcpA-pneumococcal histidine triad protein D vaccine.

Background: Pneumococcal vaccines based on protein antigens may provide expanded protection against Streptococcus pneumoniae.

Objective: To evaluate safety and immunogenicity in adults of pneumococcal vaccine candidates comprising S. pneumoniae pneumococcal histidine triad protein D (PhtD) and pneumococcal choline-binding protein A (PcpA) in monovalent and bivalent formulations.

Neutralizing antibodies elicited by a novel detoxified pneumolysin derivative, PlyD1, provide protection against both pneumococcal infection and lung injury.

Streptococcus pneumoniae pneumolysin (PLY) is a virulence factor that causes toxic effects contributing to pneumococcal pneumonia. To date, deriving a PLY candidate vaccine with the appropriate detoxification and immune profile has been challenging. A pneumolysin protein that is appropriately detoxified and that retains its immunogenicity is a desirable vaccine candidate.

Respirable PLGA microspheres containing rifampicin for the treatment of tuberculosis: screening in an infectious disease model.

Purpose: Targeted delivery of rifampicin loaded microspheres to the alveolar macrophage, the host cell for Mycobacterium tuberculosis (MTB), may be an effective targeted approach to pulmonary tuberculosis therapy. A guinea pig infection model has been adopted as a post-treatment screening method for antimicrobial effect. Insufflation and nebulization methods of drug delivery were evaluated.

Airways delivery of rifampicin microparticles for the treatment of tuberculosis.

A Mycobacterium tuberculosis (H37Rv)-infected guinea pig model was used to screen for targeted delivery to the lungs by insufflation (with lactose excipient) or nebulization, of either rifampicin alone, rifampicin within poly(lactide-co-glycolide) microspheres (R-PLGA) or polymer microparticles alone (PLGA). Animals treated with single and double doses of R-PLGA microspheres exhibited significantly reduced numbers of viable bacteria, inflammation and lung damage compared with lactose-, PLGA- or rifampicin-treated animals 28 days post-infection (P < 0.05).

The use of flow cytometry as a tool for monitoring filament formation of fungi.

Flow cytometry (FC) has the ability to discriminate a variety of cell parameters including cell size and complexity, and fluorescence intensity. As yeast cells or fungal spores germinate they undergo a morphological transformation from round oval shaped cells to elongate filamentous forms. To date, monitoring these events has been performed using microscopic examination.

Value of examining three acid-fast bacillus sputum smears for removal of patients suspected of having tuberculosis from the "airborne precautions" category.

We examined the potential risk of tuberculosis transmission if we modified our policy for release of patients from the "airborne precautions" category from three negative acid-fast bacillus (AFB) smears to two, or even one. Over a 4-year period, respiratory cultures from 42 patients grew Mycobacterium tuberculosis. Of these, 36 patients (81%) had a positive AFB smear result on the first submitted specimen.

Treatment and prophylaxis of disseminated Mycobacterium avium complex in HIV-infected individuals.

Objective: To review the pathophysiology, epidemiology, treatment, and prophylaxis of disseminated Mycobacterium avium complex (MAC) infection in HIV-infected individuals.

Data Sources: A MEDLINE (January 1966-July 1997) and AIDSLINE (January 1980-July 1997) search of basic science articles pertinent to the MAC infection in HIV-infected patients.

Study Selection And Data Extraction: All articles were considered for possible inclusion in the review.

Purification of an antigenic vaccine protein by selective displacement chromatography.

A recent advance in the state of the art of displacement chromatography has been the development of selective displacement chromatography. In this process, the bioproduct of interest is selectively displaced while impurities with lower retention are eluted in the induced salt gradient and higher retained impurities are desorbed after the breakthrough of the displacer front. In this manuscript, selective displacement chromatography is employed to purify an antigenic vaccine protein (AVP) from an industrial process stream.

Confirmation of the presence of Mycobacterium tuberculosis and other mycobacteria in mycobacterial growth indicator tubes (MGIT) by multiplex strand displacement amplification.

Multiplex strand displacement amplification (mSDA) is capable of amplifying three distinct DNA sequences simultaneously. These include sequences present in most genera of mycobacteria, a sequence specific for Mycobacterium tuberculosis, and an internal control. mSDA was used to detect the presence of these target sequences in 154 (72 positive, 76 negative, and 6 failed) clinical specimens cultured in the mycobacterial growth indicator tube (MGIT) system.

Comparison of mycobacteria growth indicator tube with BACTEC 460 for detection and recovery of mycobacteria from clinical specimens.

We compared the Mycobacteria Growth Indicator Tube (MGIT) system with the BACTEC 460 (B460) and Lowenstein Jensen (LJ) systems for the recovery of mycobacteria (acid-fast bacteria [AFB]) from 1,441 clinical specimens. Excluding 13 isolates of Mycobacterium gordonae, 178 significant AFB isolates were recovered from 113 patients. Isolates (119) of the Mycobacterium avium complex (MAC) accounted for 67% of all isolates, while isolates (30) of the Mycobacterium tuberculosis complex (MTB) accounted for 17% of isolates.

Use of molecular biological techniques in the diagnostic laboratory for detecting and differentiating fungi.

This review will address the value of nucleic acid amplification techniques used for the laboratory diagnosis of fungal infections. Although detection of all fungi will be considered, the emphasis will be placed on diagnosis of disseminated candidiasis. The diagnosis of most serious life threatening fungal infections in immunosuppressed patients remains a laboratory dilemma.

Elimination of false-positive serum reactivity in latex agglutination test for cryptococcal antigen in human immunodeficiency virus-infected population.

We recently tested serum from a human immunodeficiency virus-infected patient for the presence of cryptococcal antigen using the Meridian latex agglutination (LA) test (Cryptococcal Antigen Latex Agglutination System). Two pronase-treated serum specimens from the patient had LA titers of 80 and 160, but the patient had no evidence of cryptococcal disease. The serum was negative for rheumatoid factor, a well-documented cause of false-positive LA reactions.

Improved recovery of mycobacteria from respiratory secretions of patients with cystic fibrosis.

Pulmonary colonization and infection of patients with cystic fibrosis by Mycobacterium spp. has recently been recognized as a potentially important clinical problem. However, frequent contamination of mycobacterial cultures by pseudomonads has hampered efforts to define the extent of this problem.

Detection and differentiation of fungi in clinical specimens using polymerase chain reaction (PCR) amplification and restriction enzyme analysis.

We have developed a method for processing and detecting fungi in clinical specimens using the polymerase chain reaction (PCR) methodology. This PCR amplification of a segment of a ribosomal DNA gene results in a 310 bp product. The gene sequences used as amplimers have been highly conserved throughout the fungal kingdom and positive PCR results have been obtained for all genera and species of fungi tested (n = 42).

Evaluation of the Septi-Chek AFB system in the recovery of mycobacteria.

The performance of the Septi-Chek AFB System (Roche) in the isolation of mycobacteria was compared to that of culture on Lowenstein-Jensen (LJ) medium and the Bactec radiometric system. The Septi-Chek AFB system detected a significantly higher number of positive specimens (62/66 versus 47/66 for Bactec and 39/56 for LJ medium) and was more often the only medium in which an isolate was recovered. The average time for detection of isolates was very similar for the Septi-Chek AFB and Bactec systems which were both significantly faster than LJ medium in the majority of isolates.

Use of 111In-labelling to follow tissue distribution of Candida albicans in mice.

Two strains of Candida albicans, a wild type and a derived mutant, were labelled with 111Inoxine. Labelled cells were injected into mice and tissue distribution patterns were determined from 0.5 to 48 h.

Amphotericin B susceptibility testing of Candida species by flow cytometry.

We have developed an 8 hr flow cytometry (FCM) method for assessing susceptibility of yeasts to amphotericin B (AmpB). The method detects both high-level and relative-resistance to the drug. Variables found to affect fluorescence of control and AmpB treated cells included pH, presence of glucose, incubation conditions, concentration and length of exposure to both AmpB and ethidium bromide (ETBR), and the degree of resistance to AmpB.

Hydrolysis of fucosyl-GM1 ganglioside by purified pellet-associated human brain and human liver alpha-L-fucosidases without activator proteins or detergents.

Pellet-associated human brain alpha-L-fucosidase was solubilized with 0.5% (w/v) Triton X-100 and purified by affinity chromatography on agarose-6-aminohexanoyl-fucosamine resin. The procedure resulted in a 290,000-fold purification, a 58% yield and a final specific activity of 11,500 nmol/min per mg of protein.

Necrotizing gas-forming infections in cancer patients.

Necrotizing gas-forming infections in cancer patients present some unique characteristics, such as nontraumatic, spontaneous clostridial gangrene and gangrene involving an ischemic tumor mass. These infections can be rapidly progressive and uniformly fatal without surgical debridement. We review ten cases of gas gangrene seen during an 18-year period.