A heptavalent O-antigen bioconjugate vaccine exhibits differential functional antibody responses against diverse Klebsiella pneumoniae isolates

Klebsiella pneumoniae is the leading cause of neonatal sepsis and is increasingly difficult to treat due to antibiotic resistance. Vaccination represents a tractable approach to combat this resistant bacterium; however, there is currently not a licensed vaccine. Surface polysaccharides, including O-antigens of lipopolysaccharide, have long been attractive candidates for vaccine inclusion. Herein we describe the generation of a bioconjugate vaccine targeting seven predominant O-antigen subtypes in K. pneumoniae. Each bioconjugate was immunogenic in isolation, with limited cross-reactivity among subtypes. Vaccine-induced antibodies demonstrated varying degrees of binding to a wide variety of K. pneumoniae strains. Further, sera from vaccinated mice induced complement-mediated killing of many of these strains. Finally, increased capsule interfered with O-antigen antibodies' ability to bind and mediate killing of some K. pneumoniae strains. Taken together, these data indicate that this novel heptavalent O-antigen bioconjugate vaccine formulation exhibits limited efficacy against some, but not all, K. pneumoniae isolates.

A heptavalent O-antigen bioconjugate vaccine exhibits differential functional antibody responses against diverse Klebsiella pneumoniae isolates

Klebsiella pneumoniae is a concerning pathogen that is now the leading cause of neonatal sepsis and is increasingly difficult to treat due to heightened antibiotic resistance. Thus, there is an urgent need for preventive and effective immunotherapies targeting K. pneumoniae. Vaccination represents a tractable approach to combat this resistant bacterium in some settings; however, there is currently not a licensed K. pneumoniae vaccine available. K. pneumoniae surface polysaccharides, including the terminal O-antigen polysaccharides of lipopolysaccharide, have long been attractive candidates for vaccine inclusion. Herein we describe the generation of a bioconjugate vaccine targeting seven of the predominant O-antigen subtypes in K. pneumoniae. Each of the seven bioconjugates were immunogenic in isolation, with limited cross-reactivity among subtypes. Vaccine-induced antibodies demonstrated varying degrees of binding to a wide variety of K. pneumoniae strains, including suspected hypervirulent strains, all expressing different O-antigen and capsular polysaccharide combinations. Further, sera from vaccinated mice induced complement-mediated killing of many of these K. pneumoniae strains. Finally, we found that increased quantity of capsule interferes with O-antigen antibodies' ability to bind and mediate killing of some K. pneumoniae strains, including those carrying hypervirulence-associated genes. Taken together, these data indicate that this novel heptavalent O-antigen bioconjugate vaccine formulation exhibits promising efficacy against some, but not all, K. pneumoniae isolates.

Capsular polysaccharide inhibits vaccine-induced O-antigen antibody binding and function across both classical and hypervirulent K2:O1 strains of Klebsiella pneumoniae

Klebsiella pneumoniae presents as two circulating pathotypes: classical K. pneumoniae (cKp) and hypervirulent K. pneumoniae (hvKp). Classical isolates are considered urgent threats due to their antibiotic resistance profiles, while hvKp isolates have historically been antibiotic susceptible. Recently, however, increased rates of antibiotic resistance have been observed in both hvKp and cKp, further underscoring the need for preventive and effective immunotherapies. Two distinct surface polysaccharides have gained traction as vaccine candidates against K. pneumoniae: capsular polysaccharide and the O-antigen of lipopolysaccharide. While both targets have practical advantages and disadvantages, it remains unclear which of these antigens included in a vaccine would provide superior protection against matched K. pneumoniae strains. Here, we report the production of two bioconjugate vaccines, one targeting the K2 capsular serotype and the other targeting the O1 O-antigen. Using murine models, we investigated whether these vaccines induced specific antibody responses that recognize K2:O1 K. pneumoniae strains. While each vaccine was immunogenic in mice, both cKp and hvKp strains exhibited decreased O-antibody binding in the presence of capsule. Further, O1 antibodies demonstrated decreased killing in serum bactericidal assays with encapsulated strains, suggesting that the presence of K. pneumoniae capsule blocks O1-antibody binding and function. Finally, the K2 vaccine outperformed the O1 vaccine against both cKp and hvKp in two different murine infection models. These data suggest that capsule-based vaccines may be superior to O-antigen vaccines for targeting hvKp and some cKp strains, due to capsule blocking the O-antigen.

Discovery and characterization of a new class of O-linking oligosaccharyltransferases from the Moraxellaceae family

Bacterial protein glycosylation is commonly mediated by oligosaccharyltransferases (OTases) that transfer oligosaccharides en bloc from preassembled lipid-linked precursors to acceptor proteins. Natively, O-linking OTases usually transfer a single repeat unit of the O-antigen or capsular polysaccharide to the side chains of serine or threonine on acceptor proteins. Three major families of bacterial O-linking OTases have been described: PglL, PglS, and TfpO. TfpO is limited to transferring short oligosaccharides both in its native context and when heterologously expressed in glycoengineered Escherichia coli. On the other hand, PglL and PglS can transfer long-chain polysaccharides when expressed in glycoengineered E. coli. Herein, we describe the discovery and functional characterization of a novel family of bacterial O-linking OTases termed TfpM from Moraxellaceae bacteria. TfpM proteins are similar in size and sequence to TfpO enzymes but can transfer long-chain polysaccharides to acceptor proteins. Phylogenetic analyses demonstrate that TfpM proteins cluster in distinct clades from known bacterial OTases. Using a representative TfpM enzyme from Moraxella osloensis, we determined that TfpM glycosylates a C-terminal threonine of its cognate pilin-like protein and identified the minimal sequon required for glycosylation. We further demonstrated that TfpM has broad substrate tolerance and can transfer diverse glycans including those with glucose, galactose, or 2-N-acetyl sugars at the reducing end. Last, we find that a TfpM-derived bioconjugate is immunogenic and elicits serotype-specific polysaccharide IgG responses in mice. The glycan substrate promiscuity of TfpM and identification of the minimal TfpM sequon renders this enzyme a valuable additional tool for expanding the glycoengineering toolbox.

Differential Immune Response to Klebsiella pneumoniae O-antigen subtypes O2v1 and O2v2

Klebsiella pneumoniae (Kp) infections are sharply on the rise among at-risk populations. We have previously shown that use of bioconjugate vaccines targeting Kp are beneficial in preventing disease and seek to increase our vaccine breadth of coverage. Kp has nine serogroups of O-antigens. Recently, additional O-antigen subtypes within these serogroups have been identified; yet, the pathogenic fitness, immunogenicity, functional antibody response, and cross-protection between subtypes is unknown. We investigated how the addition of the single branched galactose in O-antigen subtype O2v2 compared to O2v1 changes its bacterial fitness and host immune susceptibility. We knocked out the gmlABC region of an O2v2 strain of Kp, converting it to O2v1. Complementation of this mutant allowed us to identify the specific gene responsible for the addition of the single branched galactose of O2v2. Further, experiments using the O2v1 mutant and its parent O2v2 strain confirmed similar phenotypic expression of virulence factors beyond the O-antigen. Well-established murine models of pneumonia were used to determine the pulmonary fitness of the pathogens and assess the host innate immune responses. Neutrophil and complement-mediated killing assays suggested differences in susceptibility to innate immune defenses. Further, differences in IgG subclass were observed 4 weeks post respiratory infection with the O2v2 parent and O2v1 mutant strains. Lastly, using novel bioconjugate vaccines against these specific O-antigen subtypes, we determined only partial cross-protection is elicited. These studies advance our understanding of the immune response to Kp O-antigens and aid in vaccine design to combat this drug-resistant pathogen.

Supported by the W.M. Keck Postdoctoral Fellowship in Molecular Medicine Dr. Wantuch is a W.M. Keck Fellow

Development and Immunogenicity of a Prototype Multivalent Group B Streptococcus Bioconjugate Vaccine

Group B Streptococcus (GBS) is a leading cause of neonatal infections and invasive diseases in nonpregnant adults worldwide. Developing a protective conjugate vaccine targeting the capsule of GBS has been pursued for more than 30 years; however, it has yet to yield a licensed product. In this study, we present a novel bioconjugation platform for producing a prototype multivalent GBS conjugate vaccine and its subsequent analytical and immunological characterizations. Using a glycoengineering strategy, we generated strains of Escherichia coli that recombinantly express the type Ia, type Ib, and type III GBS capsular polysaccharides. We then combined the type Ia-, Ib-, and III-capsule-expressing E. coli strains with an engineered Pseudomonas aeruginosa exotoxin A (EPA) carrier protein and the PglS oligosaccharyltransferase. Coexpression of a GBS capsule, the engineered EPA protein, and PglS enabled the covalent attachment of the target GBS capsule to an engineered serine residue on EPA, all within the periplasm of E. coli. GBS bioconjugates were purified, analytically characterized, and evaluated for immunogenicity and functional antibody responses. This proof-of-concept study signifies the first step in the development of a next-generation multivalent GBS bioconjugate vaccine, which was validated by the production of conjugates that are able to elicit functional antibodies directed against the GBS capsule.

A minimal sequon sufficient for O-linked glycosylation by the versatile oligosaccharyltransferase PglS

Bioconjugate vaccines, consisting of polysaccharides attached to carrier proteins, are enzymatically generated using prokaryotic glycosylation systems in a process termed bioconjugation. Key to bioconjugation are a group of enzymes known as oligosaccharyltransferases (OTases) that transfer polysaccharides to engineered carrier proteins containing conserved amino acid sequences known as sequons. The most recently discovered OTase, PglS, has been shown to have the broadest substrate scope, transferring many different types of bacterial glycans including those with glucose at the reducing end. However, PglS is currently the least understood in terms of the sequon it recognizes. PglS is a pilin-specific O-linking OTase that naturally glycosylates a single protein, ComP. In addition to ComP, we previously demonstrated that an engineered carrier protein containing a large fragment of ComP is also glycosylated by PglS. Here we sought to identify the minimal ComP sequon sufficient for PglS glycosylation. We tested >100 different ComP fragments individually fused to Pseudomonas aeruginosa exotoxin A (EPA), leading to the identification of an 11-amino acid sequence sufficient for robust glycosylation by PglS. We also demonstrate that the placement of the ComP sequon on the carrier protein is critical for stability and subsequent glycosylation. Moreover, we identify novel sites on the surface of EPA that are amenable to ComP sequon insertion and find that Cross-Reactive Material 197 fused to a ComP fragment is also glycosylated. These results represent a significant expansion of the glycoengineering toolbox as well as our understanding of bacterial O-linking sequons.

Glycoengineering bioconjugate vaccines, therapeutics, and diagnostics in E. coli

The first, general glycosylation pathway in bacteria, the N-linked glycosylation system of Campylobacter jejuni, was discovered two decades ago. Since then, many diverse prokaryotic glycosylation systems have been characterized, including O-linked glycosylation systems that have no homologous counterparts in eukaryotic organisms. Shortly after these discoveries, glycosylation pathways were recombinantly introduced into E. coli creating the field of bacterial glycoengineering. Bacterial glycoengineering is an emerging biotechnological tool that harnesses prokaryotic glycosylation systems for the generation of recombinantly glycosylated proteins using E. coli as a host. Over the last decade, as our understanding of prokaryotic glycosylation systems has advanced, so too has the glycoengineering toolbox. Currently, glycoengineering utilizes two broad approaches to recombinantly glycosylate proteins, both of which can generate N- or O-linkages: oligosaccharyltransferase (OTase)-dependent and OTase-independent. This review discusses the applications of these bacterial glycoengineering techniques as they relate to the development of glycoconjugate vaccines, therapeutic proteins, and diagnostics.

A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host

Chemical synthesis of conjugate vaccines, consisting of a polysaccharide linked to a protein, can be technically challenging, and in vivo bacterial conjugations (bioconjugations) have emerged as manufacturing alternatives. Bioconjugation relies upon an oligosaccharyltransferase to attach polysaccharides to proteins, but currently employed enzymes are not suitable for the generation of conjugate vaccines when the polysaccharides contain glucose at the reducing end, which is the case for ~75% of Streptococcus pneumoniae capsules. Here, we use an O-linking oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end. In addition, we show that different vaccine carrier proteins can be glycosylated using this system. Pneumococcal bioconjugates are immunogenic, protective and rapidly produced within E. coli using recombinant techniques. These proof-of-principle experiments establish a platform to overcome limitations of other conjugating enzymes enabling the development of bioconjugate vaccines for many important human and animal pathogens.

Bioconjugation is a promising process to manufacture conjugate vaccines, but currently employed enzymes cannot generate the full spectrum of bacterial glycoproteins. Here, the authors use an O-linking oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end.

Distinct amino acid residues confer one of three UDP-sugar substrate specificities in Acinetobacter baumannii PglC phosphoglycosyltransferases

Acinetobacter baumannii is an opportunistic human pathogen with the highest reported rates of multidrug resistance among Gram-negative pathogens. The capsular polysaccharide of A. baumannii is considered one of its most significant virulence factors providing resistance against complemented-mediated killing. Capsule synthesis in A. baumannii is usually initiated by the phosphoglycosyltransferase PglC. PglC transfers a phosphosugar from a nucleotide diphosphate-sugar to a polyprenol phosphate generating a polyprenol diphosphate-linked monosaccharide. Traditionally, PglC was thought to have stringent specificity towards UDP-N-N'-diacetylbacillosamine (UDP-diNAcBac). In this work we demonstrate that A. baumannii PglC has the ability to utilize three different UDP-sugar substrates: UDP-N-acetylglucosamine (UDP-GlcNAc), UDP-N-acetylgalactosamine (UDP-GalNAc) or UDP-diNAcBac. Using phylogenetic analyses, we first demonstrate that A. baumannii PglC orthologs separate into three distinct clades. Moreover, all members within a clade are predicted to have the same preference for one of the three possible sugar substrates. To experimentally determine the substrate specificity of each clade, we utilized in vivo complementation models and NMR analysis. We demonstrate that UDP-diNAcBac is accommodated by all PglC orthologs, but some orthologs evolved to utilize UDP-GlcNAc or UDP-GalNAc in a clade-dependent manner. Furthermore, we show that a single point mutation can modify the sugar specificity of a PglC ortholog specific for UDP-diNAcBac and that introduction of a non-native PglC ortholog into A. baumannii can generate a new capsule serotype. Collectively, these studies begin to explain why A. baumannii strains have such highly diverse glycan repertoires.

Uncovering the mechanisms of Acinetobacter baumannii virulence

Acinetobacter baumannii is a nosocomial pathogen that causes ventilator-associated as well as bloodstream infections in critically ill patients, and the spread of multidrug-resistant Acinetobacter strains is cause for concern. Much of the success of A. baumannii can be directly attributed to its plastic genome, which rapidly mutates when faced with adversity and stress. However, fundamental virulence mechanisms beyond canonical drug resistance were recently uncovered that enable A. baumannii and, to a limited extent, other medically relevant Acinetobacter species to successfully thrive in the health-care environment. In this Review, we explore the molecular features that promote environmental persistence, including desiccation resistance, biofilm formation and motility, and we discuss the most recently identified virulence factors, such as secretion systems, surface glycoconjugates and micronutrient acquisition systems that collectively enable these pathogens to successfully infect their hosts.

Pathogenic Acinetobacter species have a functional type I secretion system and contact-dependent inhibition systems

Pathogenic Acinetobacter species, including Acinetobacter baumannii and Acinetobacter nosocomialis, are opportunistic human pathogens of increasing relevance worldwide. Although their mechanisms of drug resistance are well studied, the virulence factors that govern Acinetobacter pathogenesis are incompletely characterized. Here we define the complete secretome of A. nosocomialis strain M2 in minimal medium and demonstrate that pathogenic Acinetobacter species produce both a functional type I secretion system (T1SS) and a contact-dependent inhibition (CDI) system. Using bioinformatics, quantitative proteomics, and mutational analyses, we show that Acinetobacter uses its T1SS for exporting two putative T1SS effectors, an Repeats-in-Toxin (RTX)-serralysin-like toxin, and the biofilm-associated protein (Bap). Moreover, we found that mutation of any component of the T1SS system abrogated type VI secretion activity under nutrient-limited conditions, indicating a previously unrecognized cross-talk between these two systems. We also demonstrate that the Acinetobacter T1SS is required for biofilm formation. Last, we show that both A. nosocomialis and A. baumannii produce functioning CDI systems that mediate growth inhibition of sister cells lacking the cognate immunity protein. The Acinetobacter CDI systems are widely distributed across pathogenic Acinetobacter species, with many A. baumannii isolates harboring two distinct CDI systems. Collectively, these data demonstrate the power of differential, quantitative proteomics approaches to study secreted proteins, define the role of previously uncharacterized protein export systems, and observe cross-talk between secretion systems in the pathobiology of medically relevant Acinetobacter species.

The Secrets of Acinetobacter Secretion

Infections caused by the bacterial pathogen Acinetobacter baumannii are a mounting concern for healthcare practitioners as widespread antibiotic resistance continues to limit therapeutic treatment options. The biological processes used by A. baumannii to cause disease are not well defined, but recent research has indicated that secreted proteins may play a major role. A variety of mechanisms have now been shown to contribute to protein secretion by A. baumannii and other pathogenic species of Acinetobacter, including a type II secretion system (T2SS), a type VI secretion system (T6SS), autotransporter, and outer membrane vesicles (OMVs). In this review, we summarize the current knowledge of secretion systems in Acinetobacter species, and highlight their unique aspects that contribute to the pathogenicity and persistence of these emerging pathogens.

Structural Diversity in the Type IV Pili of Multidrug-resistant Acinetobacter

Acinetobacter baumannii is a Gram-negative coccobacillus found primarily in hospital settings that has recently emerged as a source of hospital-acquired infections. A. baumannii expresses a variety of virulence factors, including type IV pili, bacterial extracellular appendages often essential for attachment to host cells. Here, we report the high resolution structures of the major pilin subunit, PilA, from three Acinetobacter strains, demonstrating that A. baumannii subsets produce morphologically distinct type IV pilin glycoproteins. We examine the consequences of this heterogeneity for protein folding and assembly as well as host-cell adhesion by Acinetobacter Comparisons of genomic and structural data with pilin proteins from other species of soil gammaproteobacteria suggest that these structural differences stem from evolutionary pressure that has resulted in three distinct classes of type IVa pilins, each found in multiple species.

Characteristics of invasive Acinetobacter species isolates recovered in a pediatric academic center

Background

Acinetobacter species are associated with increasing mortality due to emerging drug-resistance. Pediatric Acinetobacter infections are largely undefined in developed countries and clinical laboratory identification methods do not reliably differentiate between members of the Acinetobacter calcoaceticus-baumannii complex, leading to improper identification. Therefore we aimed to determine risk factors for invasive Acinetobacter infections within an academic, pediatric setting as well as defining microbiologic characteristics of predominant strains.

Methods

Twenty-four invasive Acinetobacter isolates were collected from 2009–2013. Comparative sequence analysis of the rpoB gene was performed coupled with phenotypic characterization of antibiotic resistance, motility, biofilm production and clinical correlation.

Results

Affected patients had a median age of 3.5 years, and 71 % had a central catheter infection source. rpoB gene sequencing revealed a predominance of A. pittii (45.8 %) and A. baumannii (33.3 %) strains. There was increasing incidence of A. pittii over the study. Two fatalities occurred in the A. pittii group. Seventeen percent of isolates were multi-drug resistant. A pittii and A. baumannii strains were similar in motility, but A pittii strains had significantly more biofilm production (P value = 0.018).

Conclusions

A. pittii was the most isolated species highlighting the need for proper species identification. The isolated strains had limited acute mortality in children, but the occurrence of more multi-drug resistant strains in the future is a distinct possibility, justifying continued research and accurate species identification.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1678-9) contains supplementary material, which is available to authorized users.

KatG and KatE confer Acinetobacter resistance to hydrogen peroxide but sensitize bacteria to killing by phagocytic respiratory burst

AIMS

Catalase catalyzes the degradation of H2O2. Acinetobacter species have four predicted catalase genes, katA, katE, katG, and katX. The aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to H2O2, and to assess the role of catalase in Acinetobacter virulence.

MAIN METHODS

Mutants of Acinetobacter baumannii and Acinetobacter nosocomialis with deficiencies in katA, katE, katG, and katX were tested for sensitivity to H2O2, either by halo assays or by liquid culture assays. Respiratory burst of neutrophils, in response to A. nosocomialis, was assessed by chemiluminescence to examine the effects of catalase on the production of reactive oxygen species (ROS) in neutrophils. Bacterial virulence was assessed using a Galleria mellonella larva infection model.

KEY FINDINGS

The capacities of A. baumannii and A. nosocomialis to degrade H2O2 are largely dependent on katE. The resistance of both A. baumannii and A. nosocomialis to H2O2 is primarily determined by the katG gene, although katE also plays a minor role in H2O2 resistance. Bacteria lacking both the katG and katE genes exhibit the highest sensitivity to H2O2. While A. nosocomialis bacteria with katE and/or katG were able to decrease ROS production by neutrophils, these cells also induced a more robust respiratory burst in neutrophils than did cells deficient in both katE and katG. We also found that A. nosocomialis deficient in both katE and katG was more virulent than the wildtype A. nosocomialis strain.

SIGNIFICANCE

Our findings suggest that inhibition of Acinetobacter catalase may help to overcome the resistance of Acinetobacter species to microbicidal H2O2 and facilitate bacterial disinfection.

Acinetobacter strains carry two functional oligosaccharyltransferases, one devoted exclusively to type IV pilin, and the other one dedicated to O-glycosylation of multiple proteins

Multiple species within the Acinetobacter genus are nosocomial opportunistic pathogens of increasing relevance worldwide. Among the virulence factors utilized by these bacteria are the type IV pili and a protein O-glycosylation system. Glycosylation is mediated by O-oligosaccharyltransferases (O-OTases), enzymes that transfer the glycan from a lipid carrier to target proteins. O-oligosaccharyltransferases are difficult to identify due to similarities with the WaaL ligases that catalyze the last step in lipopolysaccharide synthesis. A bioinformatics analysis revealed the presence of two genes encoding putative O-OTases or WaaL ligases in most of the strains within the genus Acinetobacter. Employing A. nosocomialis M2 and A. baylyi ADP1 as model systems, we show that these genes encode two O-OTases, one devoted uniquely to type IV pilin, and the other one responsible for glycosylation of multiple proteins. With the exception of ADP1, the pilin-specific OTases in Acinetobacter resemble the TfpO/PilO O-OTase from Pseudomonas aeruginosa. In ADP1 instead, the two O-OTases are closely related to PglL, the general O-OTase first discovered in Neisseria. However, one of them is exclusively dedicated to the glycosylation of the pilin-like protein ComP. Our data reveal an intricate and remarkable evolutionary pathway for bacterial O-OTases and provide novel tools for glycoengineering.

Fast simulation of a kolmogorov phase screen

A previously presented method for modeling Kolmogorov phase fluctuations over a finite aperture is both formalized and improved on. The method relies on forming an initial low-resolution Kolmogorov phase screen from direct factorization of a covariance. The resolution of the screen is then increased by a randomized interpolation to produce a Kolmogorov phase screen of the desired size. The computational requirement is asymptotically proportional to the number of points in the phase screen.

The Maine and Vermont three-decade studies of serious mental illness. I. Matched comparison of cross-sectional outcome

BACKGROUND

This study compared long-term outcome of serious mental illness in two states using a matched design to assess psychiatric rehabilitation programmes; Vermont subjects participated in a model psychiatric rehabilitation programme, while the Maine group received more traditional care.

METHOD

Maine and Vermont subjects (n = 269) were matched by age, sex, diagnosis, and chronicity. Demographic, illness, and life history information were abstracted from hospital records by clinicians blind to outcome. DSM-III criteria were applied retrospectively. Outcome was assessed by clinicians blind to history.

RESULTS

Vermont subjects alive at follow-up (n = 180) were more productive (P < 0.0009), had fewer symptoms (P < 0.002), better community adjustment (P < 0.001) and global functioning (P < 0.001) than Maine subjects (n = 119).

CONCLUSIONS

Outcome differences may be due to Vermont's model programme and a policy of allowing an earlier opportunity for community life.

The Maine and Vermont three-decade studies of serious mental illness. II. Longitudinal course comparisons

BACKGROUND

This paper supplements the cross-sectional outcome comparisons of the companion paper by providing a brief account of the longitudinal courses of the Maine and Vermont samples across several outcome domains.

METHOD

A Life Chart method was used to document changes in individual lives over the domains of residence, work, income source, and use of community resources over a 20-year period. Reliability studies between states were conducted.

RESULTS

Throughout much of the period, more Vermont subjects lived independently, were working, and were less likely to use community resources compared to Maine subjects.

CONCLUSIONS

Differences in both policies and programmes contributed to course differences between the groups. System characteristics that may lead to better outcomes are discussed.

Empirical correction of seven myths about schizophrenia with implications for treatment

This paper presents empirical evidence accumulated across the last two decades to challenge seven long-held myths in psychiatry about schizophrenia which impinge upon the perception and thus the treatment of patients. Such myths have been perpetuated across generations of trainees in each of the mental health disciplines. These myths limit the scope and effectiveness of treatments offered. These myths maintain the pessimism about outcome for these patients thus significantly reducing their opportunities for improvement and/or recovery. Counter evidence is provided with implications for new treatment strategies.

Excess spontaneous-emission factor in unstable-resonator lasers

The spontaneous-emission factor in an unstable-resonator semiconductor laser is enhanced by more than 2 orders of magnitude compared with that of a Fabry-Perot semiconductor laser having the same volume. A clear linkage has been observed among the spontaneous-emission factor, the waveguiding property, and the width of the lasing spectral envelope.

Omissions in assessment of work roles: implications for evaluating social functioning and mental illness

An analysis of data from a longitudinal study of individuals during and after psychiatric hospitalization found that multiple work roles often remain unconsidered in assessments of social functioning and psychiatric status. The inclusion of such multiple roles was found to be important for adequate measurement of productive functioning and to illuminate their interaction with individuals' psychopathology.

The Program for Public Psychiatry: state-university collaboration in Colorado

A major focus of state-university collaboration programs in psychiatry has been providing services and manpower from the university to the public mental health system, which in turns provides valuable educational experiences to the university. The Program for Public Psychiatry, a state-university collaboration program in Colorado, was founded on a 25-year relationship between the department of psychiatry at the University of Colorado Health Sciences Center and the Colorado Division of Mental Health. The program has enabled Colorado's two state hospitals and most of its urban community mental health centers to almost completely fill previously vacant psychiatric positions. The collaboration has expanded to include programs for forensic psychiatry and developmental disabilities, as well as to fund educational and research missions in developing the public psychiatric work force.

A controlled evaluation of inpatient crisis treatment for acute schizophrenic episodes

Acutely ill chronic schizophrenic patients requiring hospitalization were assigned to either an intensive crisis oriented (five day) or a short term (twenty-one day) inpatient unit. Despite intensive psychosocial treatment and initial rapid symptom reduction, the crisis patients could not be successfully discharged earlier than the short term patients. The crisis patients more frequently utilized day hospital aftercare and did not differ from the short term patients in symptom level or global functioning at three month follow-up. Limitations of very brief crisis oriented inpatient care for acutely ill schizophrenia patients are discussed.

Gender, premorbid social functioning, and long-term outcome in DSM-III schizophrenia

The present study examined the relationships among premorbid social functioning, gender, and long-term outcome in a group of 82 subjects (41 men and 41 women) who were retrospectively rediagnosed to meet the criteria for DSM-III schizophrenia. The Premorbid Adjustment Scale was used to assess premorbid social functioning along a developmental continuum. The Community Adjustment Scale provided outcome data related to the subjects' degree of productivity, ability to maintain close relationships, and presence/absence of symptomatology an average of 32 years after initial admission. The results indicated that females tended to exhibit better premorbid functioning than males. Although the outcome data did not reveal a statistically significant relationship between gender and long-term functioning, the results were in the predicted direction, with females again demonstrating more favorable outcome than males. Despite the absence of a statistically significant gender effect, a relationship did appear to exist between premorbid functioning and very long-term outcome, with premorbid asocial functioning predicting poor outcome.

Course types in schizophrenia: an analysis of European and American studies

There have only been a dozen studies in the world literature which have followed patients across decades after their first admissions. Persistent findings of wide heterogeneity in long-term outcome functioning have broadened and challenged the pessimistic view of outcome held by many clinicians with short-term and narrowly defined caseloads. This report compares and contrasts three very long-term followup studies completed in the past 15 years which have also documented course as well as outcome. Ciompi's schematic representation of longitudinal courses has been augmented by data from the Vermont and Burghölzli studies and sheds new light on the underlying hidden heterogeneity within samples. Two case studies present vivid portraits of very different trajectories taken over time and illuminate the processes under scrutiny.

The Vermont longitudinal study of persons with severe mental illness, II: Long-term outcome of subjects who retrospectively met DSM-III criteria for schizophrenia

The authors present the findings from a long-term follow-up study of 118 patients from Vermont State Hospital who, when rediagnosed retrospectively, met DSM-III criteria for schizophrenia at their index hospitalization in the mid-1950s. The patients were studied with structured, reliable, multivariate instrument batteries by raters who were blind to information in their records. The rediagnostic process is described, and results of the follow-up are presented. Outcome varied widely, but one-half to two-thirds of the sample had achieved considerable improvement or recovered, in contrast to statements in DSM-III that predict a poor outcome for schizophrenic patients.

Work and mental illness. I. Toward an integration of the rehabilitation process

For centuries, philosophers and physicians have noted the beneficial impact of work for the restoration and maintenance of mental health. This paper reports the findings from a survey in which all the principal components (both providers and consumers in one catchment area) contributed data about the degree to which vocational rehabilitation was integrated into systems of care for the mentally ill. The major repetitive themes found at the interface of each participating sector were: rigidity, isolation, compensatory ad hoc operations, and narrow frames of reference. Vocational and other forms of rehabilitation were accomplished by persistent, energetic personnel inventing ingenious solutions to the roadblocks set up at system interfaces. Their problem-solving techniques pointed to ingredients that might help to integrate treatment and rehabilitation efforts. These key elements were flexibility, collaboration, data-based training, and a unified theoretical framework.

The Vermont longitudinal study of persons with severe mental illness, I: Methodology, study sample, and overall status 32 years later

The authors report the latest findings from a 32-year longitudinal study of 269 back-ward patients from Vermont State Hospital. This intact cohort participated in a comprehensive rehabilitation program and was released to the community in a planned deinstitutionalization effort during the mid-1950s. At their 10-year follow-up mark, 70% of these patients remained out of the hospital but many were socially isolated and many were recidivists. Twenty to 25 years after their index release, 262 of these subjects were blindly assessed with structured and reliable protocols. One-half to two-thirds of them had achieved considerable improvement or recovery, which corroborates recent findings from Europe and elsewhere.

Chronicity in schizophrenia: fact, partial fact, or artifact?

Clinical experience has appeared to support the view that persons with repeated episodes of schizophrenia can expect to have a chronic course with residual symptoms and lasting deficits in such areas as work, social relations, and self-care. However, the authors' review of recent long-term follow-up studies and of the clinical experiences of early researchers strongly challenges this pervasive expectation. This report suggests that there is considerable heterogeneity in the long-term outcome of schizophrenia, with marginal or deteriorated states more the exception than the rule. Among the contributors to the misperception of chronicity are biased sampling, both past and present, as well as a multitude of environmental and psychosocial factors that affect patient outcome.

Is there a substitute for Structured Interview assessments of type A behaviour?

Discriminant analyses, attempting to predict the Type A behaviour categorization achieved by means of the Structured Interview (SI), were carried out on the responses of 93 British males to the Jenkins Activity Survey and the Framingham Scale, together with information regarding their smoking habits, alcohol consumption, tea and coffee drinking and obesity levels, all of which have been suggested as risk factors for coronary heart disease. Where classification agreements with the SI were found to be above 50 per cent, classification functions based on the discriminant analyses were calculated from the responses of 36 additional male subjects. The actual SI categories were compared with the predicted categories for this second subject group. The results indicated that no reliable and robust alternative was available to predict the SI categorization. The implications of these results for the substitution of the SI by self-report questionnaires are discussed.

Effect of oral contraceptives and some psychological factors on the menstrual experience

Fifty-seven women (mean age = 23·5 years), half of whom used an oral contraceptive, completed Moos' menstrual distress questionnaire at each of the three menstrual phases. In addition they kept menstrual diary cards for 50 days, recording days on which menstrual blood loss occurred. During an intermenstrual phase, they completed: a general information questionnaire with questions on menstrual, socialization and demographic variables; Eysenck's personality inventory; the multidimensional health locus of control scale; the Bern sex role inventory; and a measure of preventive health behaviour. Analyses investigating the effects of pill use and psychological factors on the incidence and intensity of menstrual distress found few significant associations between these measures, especially when symptom changes over the menstrual cycle were the dependent variables. The implications of these results for the aetiology of menstrual distress are discussed.

The course of psychiatric disorder, III: Longitudinal principles

The authors studied 28 patients hospitalized for functional psychiatric disorder in an attempt to explore systematically the course of psychiatric disorder. Data collected over the 2-year period following discharge suggested the existence of eight longitudinal principles for understanding the course of psychiatric disorder. These principles reflect identifiable phases and some of the factors involved in a patient's remaining in one phase or moving on to a new phase. The clinical and research implications of these principles are described.

Whooping cough vaccination: the case presented by the British national press

The coverage of whooping cough and its vaccine by the British press was content-analysed and compared with that of four other diseases for which articles were relatively common over the same time period. The results indicated that the topics were dealt with differently by the press, with whooping cough vaccination being seen as more risky than the others, requiring both medical advice and a decision before being accepted. The rather negative attitude to this vaccine emphasizes the problems associated with it rather than its preventive qualities. There was little evidence of a balanced discussion of the issues found in the medical literature, although accusations against the lay-press for providing largely inaccurate and sensationalized articles were found to be unsupported. The press were found, however, to publish many event-orientated articles, particularly those about specific individuals.

A psychometric investigation of two measures of type A behaviour in a British sample

Item-total correlations and principal components factor analyses were carried out on the responses of British males to the Jenkins Activity Survey (JAS) and the Framingham Scale (FRAM). The two male subject groups aged between 35 and 65 years, consisting of 150 and 58 men respectively, took part. The results indicated that neither Type A scale was particularly reliable, as measured by Cronbach's alpha coefficient (JAS alpha = 0.54 for the larger subject group and 0.39 for the smaller; FRAM alpha = 0.68 for the larger group and 0.61 for the smaller). The factor analyses indicated that a single factor was being measured by the scales, but that the amount of variance unaccounted for was large (83% for the JAS and 68% for the FRAM using the larger subject group). It is concluded that the JAS and Framingham Type A scales appear unsuitable for assessing Type A behaviour in individuals. The advantages of questionnaire measures of Type A behaviour generally are discussed and possible improvements to the existing scales are suggested.

Effects of information about specific nutrient content on ratings of "goodness" and "pleasantness" of common foods

In a study of the effects of information concerning nutrient content on ratings of foods, subjects (247 male and female school students aged 13-14 years) rated a list of 21 common foods on two scales "good for you" and "pleasant", either without prior information (control group) or after being shown, and asked to memorize, a classification of the foods as "high" "medium" and "low" in terms of a specified nutrient. There were five experimental groups, each receiving classificatory information about a different nutrient (iron, protein, carbohydrate, calorie or fat). Compared with controls, experimental subjects rated the value of the foods in a way corresponding more closely with the specific classification presented to them. Ratings of pleasantness, however, showed no such consistent effects. These findings are interpreted in terms of models of attitudinal judgement concerned with factors influencing the salience to individuals of different stimulus attributes. Implications for the effects of selective information on judgements are discussed, with specific reference to advertising and nutrition education.

The social desirability of preventive health behavior

The relationship between measures of social desirability and various preventive health behaviors was examined directly for 235 females and 171 males from the British public and 182 females and 49 males from the University of Toronto, Canada. Both simple and partial correlations controlling for age showed that social desirability scores were related to total preventive behavior scores formed on the basis of the responses to 42 items, as well as many of the individual preventive behavior items. To ensure that this relationship was not unique to the present study, the response frequencies for 15 behavior items in this study were compared with those reported by another investigator who also used these 15 behavior items, and were found to be quite similar. Simple and partial correlations controlling for age showed that social desirability scores were significantly correlated with more of these 15 behaviors than one would expect by chance. The implications of the association of social desirability and preventive health behavior for the measurement of preventive health behavior, future research, and health education are discussed.

Vulnerability to depressive and schizophrenic disorders--conference report

A conference was held to foster improved research on vulnerability to psychiatric disorder. By bringing together groups studying vulnerability to depression and those studying vulnerability to schizophrenia, commonalities and differences across these two fields were clarified, and research approaches and problems were shared. Five major areas of particular importance were covered: (1) diagnosis and the assessment of function and intermediate clinical states, (2) statistical analysis and project design, (3) personality and family variables, (4) biochemical and physiological markers, and (5) comparison of vulnerability to schizophrenia and depression: models of causation and possibilities for collaborative research. Potential directions for increasing progress in the important area of vulnerability research were outlined.

Whooping cough vaccination: a review of the controversy since the 1981 DHSS report

This article reviews the literature on the whooping cough controversy subsequent to the publication of the DHSS report in 1981. The report's reception is outlined and its influence on specific, topical issues such as contraindications, vaccine efficacy, and the calculation of 'risk' statistics is considered. The seriousness of the disease, the age of its victims and its treatment by antibiotics are also discussed with specific reference to recent epidemics. The implications of recent research findings for the continuation of the immunization programme are presented. It is concluded that the controversy continues.