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Double-checking has been used in high-consequence industries for decades. We aimed to determine the strength of the evidence-base regarding the effectiveness of double-checking which underpins its widespread adoption. We searched for quantitative studies of the effectiveness of two-person checking in industry sectors, excluding healthcare. We performed a systematic literature search across six databases and hand-searched key journals. We completed a narrative synthesis and quality assessment of the nine studies identified. Most studies were of fair quality. Two examined the use of two-person checks in aviation, three investigated tasks in chemical manufacturing, and four studies in psychology involved proofreading and visual search tasks. All studies found that the performance of two-people checking was not superior to that of one-person in detecting errors. Further research to compare the effectiveness of different checking processes along with factors which may support optimisation of safety checks in high-consequence industries is required.

A survey administered to staff at five hospitals investigated changes in unprofessional behaviour, teamwork and co-operation during the COVID-19 pandemic. From 1583 responses, 76.1% (95% confidence interval (CI): 74.0-78.2%) reported no change or a decrease in unprofessional behaviours. Across all professional groups, 43.6% (n = 579, 95% CI: 41.0-46.3%) reported improvements in teamwork and co-operation. Findings suggest that intensifying work demands, such as those resulting from the pandemic, are not a major trigger for unprofessional behaviour, and root causes lie elsewhere.

Background Errors and adverse events in the operating room (OR) are associated with not only poor technical performance but also deficits in nontechnical skills (NTSs). Numerous tools have been developed to assess NTS in the OR. Our aim was to conduct a systematic review of observational tools and report on their implementation and psychometric properties to guide healthcare professionals, educators, and researchers in tool selection and use. Methods A systematic literature search (January 1, 1990–May 28, 2019) was conducted across databases (MEDLINE, Embase, CINAHL, and PsycINFO) and reference lists of included studies. Reviewers independently screened articles for inclusion, assessed study quality, and extracted data. Results Thirty-one tools were identified across 88 studies, most commonly conducted in a real-world OR (n = 50), involving two observers (n = 50). The NTS of individuals (n = 62) were assessed more often than that of subteams (n = 21) or entire teams (n = 20). The NOn-Technical Skills for Surgeons demonstrated content validity, concurrent validity, predictive validity, and face validity across a range of studies. Oxford NOn-TECHnical Skills demonstrated content validity, concurrent validity, and predictive validity with good inter-rater reliability and test-retest validity. Conclusions The NOn-Technical Skills for Surgeons has the strongest evidence of validity and reliability for assessing individuals, whereas the most robust tool for evaluating teams was Oxford NOn-TECHnical Skills. We recommend continued investigation of these observational tools regarding their feasibility and reproducibility of methods. Further research is needed to determine the training requirements for observers and the potential of video and audio recordings in the OR.

Behaviour that is disrespectful towards others occurs frequently in hospitals, negatively impacts staff, and may undermine patient care. Professional accountability programs may address unprofessional behaviour by staff. This article examines a whole-of-hospital program, Ethos, developed by St Vincent’s Health Australia to address unprofessional behaviour, encourage speaking up, and improve organisational culture. Ethos consists of a bundle of tools, training, and resources, including an online system where staff can make submissions regarding their co-workers’ exemplary or unprofessional behaviour. Informal feedback is provided to the subject of the submission to recognise or encourage reflection on their behaviour. Following implementation in eight St Vincent’s Health Australia hospitals, the Ethos Messaging System has had 2497 submissions, 54% about positive behaviours. Peer messengers who deliver ‘Feedback for Reflection’ have faced practical challenges in providing feedback. Guidelines for the team who ‘triage’ Ethos messages have been revised to ensure only feedback that will promote reflection is passed on. Early evidence suggests Ethos has positively impacted staff, although evaluation is ongoing. The COVID-19 pandemic has required some adaptations to the program.

Background While individual countries have gained considerable knowledge and experience in coronavirus disease of 2019 (COVID-19) management, an international, comparative perspective is lacking, particularly regarding the measures taken by different countries to tackle the pandemic. This paper elicits the views of health system staff, tapping into their personal expertise on how the pandemic was initially handled. Methods From May to July 2020, we conducted a cross-sectional, online, purpose-designed survey comprising 70 items. Email lists of contacts provided by the International Society for Quality in Health Care, the Italian Network for Safety in Health Care and the Australian Institute of Health Innovation were used to access healthcare professionals and managers across the world. We snowballed the survey to individuals and groups connected to these organizations. Key outcome measures were attitudes and information about institutional approaches taken; media communication; how acute hospitals were re-organized; primary health organization; personal protective equipment; and staffing and training. Results A total of 1131 survey participants from 97 countries across the World Health Organization (WHO) regions responded to the survey. Responses were from all six WHO regions; 57.9% were female and the majority had 10 or more years of experience in healthcare; almost half (46.5%) were physicians; and all other major clinical professional groups participated. As the pandemic progressed, most countries established an emergency task force, developed communication channels to citizens, organized health services to cope and put in place appropriate measures (e.g. pathways for COVID-19 patients, and testing, screening and tracing procedures). Some countries did this better than others. We found several significant differences between the WHO regions in how they are tackling the pandemic. For instance, while overall most respondents (71.4%) believed that there was an effective plan prior to the outbreak, this was only the case for 31.9% of respondents from the Pan American Health Organization compared with 90.7% of respondents from the South-East Asia Region (SEARO). Issues with swab testing (e.g. delay in communicating the swab outcome) were less frequently reported by respondents from SEARO and the Western Pacific Region compared with other regions. Conclusion The world has progressed in its knowledge and sophistication in tackling the pandemic after early and often substantial obstacles were encountered. Most WHO regions have or are in the process of responding well, although some countries have not yet instituted widespread measures known to support mitigation, for example, effective swab testing and social control measures.

Objective The operating room is a complex environment in which distractions, interruptions and disruptions (DIDs) are frequent. Our aim was to synthesize research on the relationships between DIDs and (i) operative duration, (ii) team performance, (iii) individual performance and (iv) patient safety outcomes in order to better understand how interventions can be designed to mitigate the negative effects of DIDs. Methods Electronic databases (MEDLINE, Embase, CINAHL and PsycINFO) and reference lists were systematically searched. Included studies were required to report the quantitative outcomes of the association between DIDs and team performance, individual performance and patient safety. Two reviewers independently screened articles for inclusion, assessed study quality and extracted data. A random-effects meta-analysis was performed on a subset of studies reporting total operative time and DIDs. Results Twenty-seven studies were identified. The majority were prospective observational studies (n = 15) of moderate quality. DIDs were often defined, measured and interpreted differently in studies. DIDs were significantly associated with extended operative duration (n = 8), impaired team performance (n = 6), self-reported errors by colleagues (n = 1), surgical errors (n = 1), increased risk and incidence of surgical site infection (n = 4) and fewer patient safety checks (n = 1). A random-effects meta-analysis showed that the proportion of total operative time due to DIDs was 22.0% (95% confidence interval 15.7–29.9). Conclusion DIDs in surgery are associated with a range of negative outcomes. However, significant knowledge gaps exist about the mechanisms that underlie these relationships, as well as the potential clinical and non-clinical benefits that DIDs may deliver. Available evidence indicates that interventions to reduce the negative effects of DIDs are warranted, but current evidence is not sufficient to make recommendations about potentially useful interventions.

Objective To identify individual and organisational factors associated with the prevalence, type and impact of unprofessional behaviours among hospital employees. Design, setting, participants Staff in seven metropolitan tertiary hospitals operated by one health care provider in three states were surveyed (Dec 2017 – Nov 2018) about their experience of unprofessional behaviours — 21 classified as incivility or bullying and five as extreme unprofessional behaviour (eg, sexual or physical assault) — and their perceived impact on personal wellbeing, teamwork and care quality, as well as about their speaking-up skills. Main outcome measures Frequency of experiencing 26 unprofessional behaviours during the preceding 12 months; factors associated with experiencing unprofessional behaviour and its impact, including self-reported speaking-up skills. Results Valid surveys (more than 60% of questions answered) were submitted by 5178 of an estimated 15 213 staff members (response rate, 34.0%). 4846 respondents (93.6%; 95% CI, 92.9–94.2%) reported experiencing at least one unprofessional behaviour during the preceding year, including 2009 (38.8%; 95% CI, 37.5–40.1%) who reported weekly or more frequent incivility or bullying; 753 (14.5%; 95% CI, 13.6–15.5%) reported extreme unprofessional behaviour. Nurses and non-clinical staff members aged 25–34 years reported incivility/bullying and extreme behaviour more often than other staff and age groups respectively. Staff with self-reported speaking-up skills experienced less incivility/bullying (odds ratio [OR], 0.53; 95% CI, 0.46–0.61) and extreme behaviour (OR, 0.80; 95% CI, 0.67–0.97), and also less frequently an impact on their personal wellbeing (OR, 0.44; 95% CI, 0.38–0.51). Conclusions Unprofessional behaviour is common among hospital workers. Tolerance for low level poor behaviour may be an enabler for more serious misbehaviour that endangers staff wellbeing and patient safety. Training staff about speaking up is required, together with organisational processes for effectively eliminating unprofessional behaviour.

Objectives: To determine the proportion of care provided to children with acute gastroenteritis (AGE) in Australia consistent with clinical practice guidelines. Methods: Indicators were developed from national and international clinical practice guideline (CPG)recommendations and validated by an expert panel. Medical records from children 15years presenting with AGE in three healthcare settings-Emergency Department (ED), hospital admissions and General Practitioner (GP) consultations-from randomly selected health districts across three Australian States were reviewed. Records were audited against35 indicators by trained paediatric nurses, to determine adherence to CPGs during diagnosis,treatment, and ongoing management. Results: A total of 14,434 indicator assessments were performed from 854 healthcare visits for AGE by 669 children, across 75 GPs, 34 EDs and 26 hospital inpatient services. Documented adherence to guidelines across all healthcare settings was 45.5% for indicators relating to diagnosis (95% CI: 40.7-50.4), 96.1% for treatment (95% CI: 94.8-97.1) and 57.6% for ongoing management (95% CI: 51.3-63.7). Adherence varied by healthcare setting, with adherence in GPs (54.6%; 95% CI: 51.1-58.1) lower than for either ED settings (84.7%;95% CI: 82.4-86.9) or for inpatients (84.3%; 95% CI: 80.0-87.9); p

Research indicates that pregaming (drinking before a social event) and tailgating (drinking before a sporting event) are two culturally ingrained alcohol use behaviors by college students. We examined the prevalence of these two activities in a sample of college students (N = 354) who violated campus alcohol policy and were mandated to receive an alcohol intervention in fall 2010. Results indicated that alcohol consumption and other risk factors were related to pregaming and tailgating. These findings are discussed in the context of clinical implications and future directions for research. This study was funded in part by the National Institutes of Health.

We investigated the population genetics in collections of meningococci sampled in Cuba during the period 1983-2005, thereby covering a period before and after the introduction of an antimeningococcal B-C vaccine. A total of 163 case isolates and 210 isolates from healthy carriers were characterized by multilocus sequence typing (MLST) and sequence determination of porA, porB and fetA genes. A total of 56 sequence types (STs) including 28 new STs were identified among these isolates. The analysis of surface antigens revealed variants 3-1 and 3-8 to be prevalent for porB; variant F5-1 was the most common FetA epitope, and variants 19 and 15 corresponded to the prevalent variable regions 1 (VR1) and VR2 PorA epitopes, respectively. The strongest associations between specific surface protein variants and clonal complexes were detected in lineages ST-32 and ST-53. All ST-32 complex isolates possessed porB3 alleles, and the most frequent antigen combination among ST-32 complex isolates was P1.19,15;F5-1. Variants PorB3-64 at PorB and P1.30 at PorA VR2, in combination with the PorA VR1 variants P1.12-1, P1.7 and P1.7-2 as well as the FetA variants F1-2 and F1-7, dominated the ST-53 complex organisms. Furthermore, we observed a statistically significant association between the most frequent porA, porB and fetA alleles and strain invasiveness. Finally, this study showed that the application of VA-MENGOC-BC((R)), the Cuban antimeningococcal vaccine, reduced the number and frequency of the hypervirulent Clonal Complexes ST-32 and ST-41/44, and also impacted on other lineages. The vaccine also affected the genetic composition of the carrier-associated meningococcal isolates. The number of carrier isolates belonging to hypervirulent lineages decreased significantly after vaccination, and ST-53, a sequence type common in carriers, became the predominant ST.

A comprehensive meningococcal vaccine is yet to be developed. In the absence of a vaccine that immunizes against the serogroup B capsular polysaccharide, this can only be achieved by targeting subcapsular antigens, and a number of outer-membrane proteins (OMPs) are under consideration as candidates. A major obstacle to the development of such a vaccine is the antigenic diversity of these OMPs, and obtaining population data that accurately identify and catalogue these variants is an important component of vaccine design. The recently proposed meningococcal molecular strain-typing scheme indexes the diversity of two OMPs, PorA and FetA, that are vaccine candidates, as well as the capsule and multilocus sequence type. This scheme was employed to survey 323 meningococci isolated from invasive disease in England and Wales from 1975 to 1995, before the introduction of meningococcal conjugated serogroup C polysaccharide vaccines in 1999. The eight-locus typing scheme provided high typeability (99.4 %) and discrimination (Simpson's diversity index 0.94–0.99). The data showed cycling of meningococcal genotypes and antigenic types in the absence of planned interventions. Notwithstanding high genetic and antigenic diversity, most of the isolates belonged to one of seven clonal complexes, with 11 predominant strain types. Combinations of PorA and FetA, chosen on the basis of their prevalence over time, generated vaccine recipes that included protein variants found in 80 % or more of the disease isolates for this time period. If adequate immune responses can be generated, these results suggest that control of meningococcal disease with relatively simple protein component vaccines may be possible.

The authors discuss the European epidemic of contact dermatitis caused by methylchloroisothiazolinone and methylisothiazolinone.

The bacterium Neisseria meningitidis is a major cause of meningitis and septicemia worldwide. Outer membrane proteins (OMPs) are candidates in the search for comprehensive meningococcal vaccines; however, the formulation of OMP vaccines is complicated by antigenic diversity, which is generated by high levels of genetic reassortment and strong positive selection in the meningococcal antigen genes. The genetic and antigenic diversity of three OMPs (FetA, PorA, and PorB) among a global collection of meningococcal isolates representative of the major hyperinvasive clonal complexes was determined. There was evidence for antigenic structuring among the three OMPs that could not be explained purely by descent. These observations violated the predictions of the clonal and epidemic clonal models of population structure but were in concordance with models of strain structure which propose that host immunity selects for nonoverlapping antigen combinations. The patterns of antigenic variant combinations suggested that an OMP-based vaccine with as few as six PorA and five FetA variant sequences could generate homologous immune responses against all 78 isolates examined.

Natural and synthetic rubbers containing rubber accelerators are well-known causes of allergic contact dermatitis (ACD). Latex contact urticaria (CU) has been widely reported, especially when powdered latex glove use was commonplace. Consequently, interventions to reduce latex exposure by altering glove manufacture were introduced.This study aimed to analyse trends in UK-reported incidence of occupational skin disease associated with rubber accelerators.We analysed cases reported to EPIDERM (part of The Health and Occupation Research network) of occupational ACD caused by natural and synthetic rubber products, between 1996 and 2012.For the studied period, a decreasing incidence of ACD associated with rubber products was found, with an average annual change of -1.2% [95% confidence interval (CI) -3.1 to 0.7]. The number of cases of latex CU (n = 580) significantly declined. The number of cases of ACD caused by mercapto mix and mercaptobenzothiazole (n = 177) and thiuram mix (n = 603) also declined. Reports of ACD associated with carba mix and its constituents (n = 219) increased significantly, by an average annual percentage of 10.1% (95%CI: 6.1-14.2). Twenty-six cases of ACD caused by rarer rubber compounds were identified, highlighting skin disease attributable to less widely recognized chemicals.These data show a falling reported incidence of occupational ACD attributed to rubber chemicals, but within this a significant rise attributable to the constituents of the carba mix. Clinicians should recognize the changing diversity of chemicals used in rubber manufacturing, and consider including carba mix in their baseline series and testing beyond this in suspect cases to avoid false-negative results.

Sensitivity to either methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) or MI has increased, with a reported frequency of up to 11.1% among dermatitis patients, the main context being allergic contact dermatitis caused by MCI or MCI/MI in personal care products. Case reports have described occupational allergic contact dermatitis caused by MI in paints and within the beauty industry.This study identified incident cases of occupational allergic contact dermatitis caused by MCI/MI and or MI reported from 1996 to 2012 to a UK-wide surveillance scheme (EPIDERM), with the aim of identifying changes in incidence over the study period.The data show an increase in occupational allergic contact dermatitis caused by MCI/MI and or MI from 1996 to 2012 of 4.1% [95% confidence interval (CI) 1.6-6.9] per annum. Analysis by industry showed a 3.8% (95% CI: -0.3 to 8.0) per annum increase in those exposed to personal care products in the workplace as a primary exposure [healthcare workers, 8.1% (95% CI: 2.1-14.4) per annum; beauty workers, 6.6% (95% CI: -2.2 to 16.2) per annum; hairdressers, 1.5% (95% CI: -4.7 to 8.1) per annum]. There was a 6.3% (95% CI: 1.8-10.9) per annum increase for manufacturing workers. A statistically significant rise in the frequency of occupational allergic contact dermatitis was shown to be attributable to MCI/MI and or MI between 1996 and 2012.The findings support recommendations for a review of the regulations relating to MCI/MI and/or MI in cosmetic and personal care products and in industrial settings.

Individual brief motivational intervention (iBMI) is an efficacious strategy to reduce heavy drinking by students who are mandated to receive an alcohol intervention following an alcohol-related event. However, despite the strong empirical support for iBMI, it is unknown if the results from rigorously controlled research on iBMI translate to real-world settings. Furthermore, many colleges lack the resources to provide iBMI to mandated students. Therefore, group-delivered BMI (gBMI) might be a cost-effective alternative that can be delivered to a large number of individuals. The purpose of this study was to conduct a comparative effectiveness evaluation of iBMI and gBMI as delivered by staff at a university health services center. Participants (N = 278) were college students who were mandated to receive an alcohol intervention following an alcohol-related incident. Participants were randomized to receive an individual (iBMI; n = 133) or a Group BMI (gBMI; n = 145). Results indicated that both iBMI and gBMI participants reduced their peak estimated blood alcohol concentration (BAC) and the number of negative alcohol-related consequences at 1-, 3-, and 6-months postintervention. The iBMI and gBMI conditions were not significantly different at follow-up. These findings provide preliminary support for the use of iBMI and gBMIs for college students in real-world settings.

Multilocus sequence typing and antigen gene sequencing were used to investigate an outbreak of meningococcal disease in a university in the United Kingdom. The data obtained showed that five distinct Neisseria meningitidis strains belonging to the ET-37 complex were present in the student population during the outbreak. Three of these strains were not associated with invasive disease, and two distinct strains caused invasive disease, including several fatalities. The initial case of the disease cluster was caused by a strain distinct from that responsible for at least two subsequent cases and two cases remote from the university, which were epidemiologically linked to the outbreak. These observations were consistent with pulsed-field gel electrophoresis data, but the sequence data alone were sufficient to resolve the strains involved in the disease cluster. Interpretation of the nucleotide sequence data was more straightforward than interpretation of the fingerprint patterns, and the sequence data provided information on the genetic differences among the isolates.

Periodically, new disease-associated variants of the human pathogen Neisseria meningitidis arise. These meningococci diversify during spread, and related isolates recovered from different parts of the world have different genetic and antigenic characteristics. An example is the ET-5 complex, members of which were isolated globally from the mid-1970s onwards. Isolates from a hyperendemic outbreak of meningococcal disease in Worcester, England, during the late 1980s were characterized by multilocus sequence typing and sequence determination of antigen genes. These data established that the Worcester outbreak was caused by ET-5 complex meningococci which were not closely related to the ET-5 complex bacteria responsible for a hyperendemic outbreak in the nearby town of Stroud during the years preceding the Worcester outbreak. A comparison with other ET-5 complex meningococci established that there were at least three distinct globally distributed subpopulations within the ET-5 complex, characterized by particular housekeeping and antigen gene alleles. The Worcester isolates belonged to one of these subpopulations, the Stroud isolates belonged to another, and at least one representative of the third subpopulation identified in this work was isolated elsewhere in the United Kingdom. The sequence data demonstrated that ET-5 variants have arisen by multiple complex pathways involving the recombination of antigen and housekeeping genes and de novo mutation of antigen genes. The data further suggest that either the ET-5 complex has been in existence for many years, evolving and spreading relatively slowly until its disease-causing potential was recognized, or it has evolved and spread rapidly since its first identification in the 1970s, with each of the subpopulations attaining a distribution spanning several continents.

Background. Herd immunity is important in the effectiveness of conjugate polysaccharide vaccines against encapsulated bacteria. A large multicenter study investigated the effect of meningococcal serogroup C conjugate vaccine introduction on the meningococcal population. Methods. Carried meningococci in individuals aged 15-19 years attending education establishments were investigated before and for 2 years after vaccine introduction. Isolates were characterized by multilocus sequence typing, serogroup, and capsular region genotype and changes in phenotypes and genotypes assessed. Results. A total of 8462 meningococci were isolated from 47 765 participants (17.7%). Serogroup prevalence was similar over the 3 years, except for decreases of 80% for serogroup C and 40% for serogroup 29E. Clonal complexes were associated with particular serogroups and their relative proportions fluctuated, with 12 statistically significant changes (6 up, 6 down). The reduction of ST-11 complex serogroup C meningococci was probably due to vaccine introduction. Reasons for a decrease in serogroup 29E ST-254 meningococci (from 1.8% to 0.7%) and an increase in serogroup B ST-213 complex meningococci (from 6.7% to 10.6%) were less clear. Conclusions. Natural fluctuations in carried meningococcal genotypes and phenotypes a can be affected by the use of conjugate vaccines, and not all of these changes are anticipatable in advance of vaccine introduction. © The Author 2011.

In response to epidemic levels of serogroup B meningococcal disease in Cuba during the 1980s, the VA-MENGOC-BC vaccine was developed and introduced into the National Infant Immunization Program in 1991. Since then the incidence of meningococcal disease in Cuba has returned to the low levels recorded before the epidemic. A total of 420Neisseria meningitidisstrains collected between 1983 and 2005 in Cuba were analyzed by multilocus sequence typing (MLST). The set of strains comprised 167 isolated from disease cases and 253 obtained from healthy carriers. By MLST analysis, 63 sequence types (STs) were identified, and 32 of these were reported to be a new ST. The Cuban isolates were associated with 12 clonal complexes; and the most common were ST-32 (246 isolates), ST-53 (86 isolates), and ST-41/44 (36 isolates). This study also showed that the application of VA-MENGOC-BC, the Cuban serogroup B and C vaccine, reduced the frequency and diversity of hypervirulent clonal complexes ST-32 (vaccine serogroup B type-strain) and ST-41/44 and also affected other lineages. Lineages ST-8 and ST-11 were no longer found during the postvaccination period. The vaccine also affected the genetic composition of the carrier-associated meningococcal isolates. The number of carrier isolates belonging to hypervirulent lineages decreased significantly after vaccination, and ST-53, a sequence type common in carriers, became the predominant ST.

Background. In 1999, meningococcal serogroup C conjugate (MCC) vaccines were introduced in the United Kingdom for those under 19 years of age. The impact of this intervention on asymptomatic carriage of meningococci was investigated to establish whether serogroup replacement or protection by herd immunity occurred.Methods. Multicenter surveys of carriage were conducted during vaccine introduction and on 2 successive years, resulting in a total of 48,309 samples, from which 8599 meningococci were isolated and characterized by genotyping and phenotyping.Results. A reduction in serogroup C carriage (rate ratio, 0.19) was observed that lasted at least 2 years with no evidence of serogroup replacement. Vaccine efficacy against carriage was 75%, and vaccination had a disproportionate impact on the carriage of sequence type (ST)-11 complex serogroup C meningococci that (rate ratio, 0.06); these meningococci also exhibited high rates of capsule expression.Conclusions. The impact of vaccination with MCC vaccine on the prevalence of carriage of group C meningococci was consistent with herd immunity. The high impact on the carriage of ST-11 complex serogroup C could be attributed to high levels of capsule expression. High vaccine efficacy against disease in young children, who were not protected long-term by the schedule initially used, is attributed to the high vaccine efficacy against carriage in older age groups.

Six cases of Neisseria meningitidis serogroup W135 meningococcal infection have been reported in Turkey since 2003. Seven isolates recovered from four meningococcal meningitis patients and two asymptomatic carriers produced three distinct pulsed-field gel electrophoresis (PFGE) patterns. Multilocus sequence typing and antigen gene sequencing showed that five isolates were indistinguishable from ST-11 (ET-37) serogroup W135 meningococci, which were first isolated in Saudi Arabia and were responsible for the worldwide outbreak among Hajj pilgrims and their contacts in 2000. The remaining two isolates, which had related PFGE patterns, differed from each other at only one of the genetic loci characterized but were not related to the ST-11 clonal complex. None of the six individuals recalled contact with a pilgrim or had traveled on the Hajj. These six individuals exhibited no time or place relationships to each other, except for the two asymptomatic carriers, who were soldiers and served in the same military unit. These data demonstrate that serogroup W135 meningococci with different genotypes, including the Hajj epidemic strain, are endemic in Turkey.

BACKGROUND: Neisseria meningitidis is a diverse commensal bacterium that occasionally causes severe invasive disease. The relationship between meningococcal genotype and capsular polysaccharide, the principal virulence factor and vaccine component, was investigated in carried meningococci isolated from 8000 children and young adults in Bavaria, Germany. METHODS: Of the 830 meningococci isolated (carriage rate, 10.4%) by microbiological techniques, 822 were characterized by serogrouping, multilocus sequence typing, and genetic analysis of the capsule region. Statistical and population genetic analyses were applied to these data. RESULTS: The rapid increase in carriage rates with age of carrier, the low prevalence of hyperinvasive meningococci, and the relative prevalence of the 4 disease-associated serogroups were consistent with earlier observations. There was no genetic structuring of the meningococcal population by age of carrier or sampling location; however, there was significant geographic structuring of the meningococci isolated in civil, but not military, institutions. The rate of capsule gene expression did not vary with age of carrier or meningococcal genotype, except for serogroup C, for which increased expression was associated with ST-11 (formerly ET-37) complex meningococci. CONCLUSIONS: Serogroup C capsule expression during carriage may contribute to the invasive character of ST-11 complex meningococci and to the high efficacy of meningococcal serogroup C conjugate polysaccharide vaccine.

Nongroupable Neisseria meningitidis may constitute one-third or more of meningococcal isolates recovered from the nasopharynx of human carriers. The genetic basis for nongroupability was determined in isolates obtained from a population-based study in which 60 (30.9%) of 194 meningococcal isolates from asymptomatic carriers were not groupable. Forty-two percent of nongroupable isolates were related to serogroup Y ET-508/ ST-23 clonal complex strains, the most common groupable carrier isolate from the study population. Nongroupable isolates were all rapidly killed by 10% normal human serum. The capsule loci of 6 of the ET-508/ ST-23 complex strains and of 25 other genetically diverse nongroupable meningococci were studied in detail. Serogroup A or novel capsule biosynthesis genes were not found. Nongroupable isolates were genetically serogroup Y, B, or C isolates that did not express capsule but were related to groupable isolates found in the population (class I); capsule deficient because of insertion element‐associated deletions of capsule biosynthesis genes (class II); or isolates that lacked all capsule genes and formed a distinct genetic cluster not associated with meningococcal disease (class III).

Characterization of isolates of Neisseria meningitidis obtained from patients with meningococcal disease or from pharyngeal swabs of asymptomatic carriers can be achieved by several approaches which provide different levels of discrimination. A total of 45 gram negative, oxidase-positive diplococcus strains isolated from 15 individuals with meningococcal disease and 30 of their family contacts were examined by three approaches: serological typing, multilocus enzyme electrophoresis (MLEE), and multilocus sequence typing (MLST). For 10 of the 15 patient and contact groups, all of the isolates were confirmed as meningococci, and the bacteria obtained from the patients and contacts, including their mother or principal caregiver in the case of children, were indistinguishable by all three methods. In the remaining five groups the isolates from the patients were distinct from those recovered from the contacts, and in three examples, in two separate groups, the contacts were shown by MLST to be carrying strains of Neisseria lactamica . The data obtained from the three techniques were consistent, although complete serological typing was possible for only a minority of isolates. Both MLEE and MLST established the genetic relationships of the isolates and identified members of known hypervirulent lineages, but MLST was faster than MLEE and had the additional advantages that it could be performed on noninfective material distributed by mail and that the results from different laboratories could be compared via the internet ( http://mlst.zoo.ox.ac.uk ).

The extent to which recombination disrupts the bifurcating treelike phylogeny and clonal structure imposed by binary fission on bacterial populations remains contentious. Here, we address this question with a study of nucleotide sequence data from 107 isolates of the human pathogen Neisseria meningitidis. Gene fragments from 12 house-keeping loci distributed around the meningococcal chromosome were analyzed, showing that (1) identical alleles are disseminated among genetically diverse isolates, with no evidence for linkage disequilibrium; (2) different loci give distinct and incongruent phylogenetic trees; and (3) allele sequences are incompatible with a bifurcating treelike phylogeny at all loci. These observations are consistent with the hypothesis that meningococcal populations comprise organisms assembled from a common gene pool, with alleles and allele fragments spreading independently, together with the occasional importation of genetic material from other species. Further, they support the view that recombination is an important genetic mechanism in the generation new meningococcal clones and alleles. Consequently, for anything other than the short-term evolution of this species, a bifurcating treelike phylogeny is not an appropriate model.

The porin proteins of the pathogenic Neisseria species, Neisseria gonorrhoeae and Neisseria meningitidis , are important as serotyping antigens, putative vaccine components, and for their proposed role in the intracellular colonization of humans. A three-dimensional structural homology model for Neisseria porins was generated from Escherichia coli porin structures and N. meningitidis PorA and PorB sequences. The Neisseria sequences were readily assembled into the 16-strand β-barrel fold characteristic of porins, despite relatively low sequence identity with the Escherichia proteins. The model provided information on the spatial relationships of variable regions of peptide sequences in the PorA and PorB trimers and insights relevant to the use of these proteins in vaccines. The nucleotide sequences of the porin genes from a number of other Neisseria species were obtained by PCR direct sequencing and from GenBank. Alignment and analysis of all available Neisseria porin sequences by use of the structurally conserved regions derived from the PorA and PorB structural models resulted in the recovery of an improved phylogenetic signal. Phylogenetic analyses were consistent with an important role for horizontal genetic exchange in the emergence of different porin classes and confirmed the close evolutionary relationships of the porins from N. meningitidis , N. gonorrhoeae , Neisseria lactamica , and Neisseria polysaccharea . Only members of this group contained three conserved lysine residues which form a potential GTP binding site implicated in pathogenesis. The model placed these residues on the inside of the pore, in close proximity, consistent with their role in regulating pore function when inserted into host cells.

Changes in the frequency of serogroup B non serotypable (B[ratio ]NT) meningococci isolated in England and Wales were investigated by T-track fingerprint analysis, DNA nucleotide sequence determination, and serotyping by whole cell ELISA and dot blot assay. Seventy-three per cent of the isolates designated as B[ratio ]NT by the Meningococcal Reference Unit (MRU) dot blot assay during 1993–4, expressed variants of the serotyping antigen, PorB, that were serotype 4 by whole cell ELISA. T-track fingerprint patterns of these and other ‘serotype 4’ isolates revealed five distinct porB alleles which were shown by nucleotide sequence determination to encode different peptide sequences. Differential binding of the ‘serotype 4’ mAbs MN14G21 and 5DC4C8G8 in whole cell ELISA and dot blot assays was the result, (i) of differences in the peptide sequence of predicted surface loop I and (ii) an amino acid deletion in predicted loop VI of the PorB protein.

Traditional and molecular typing schemes for the characterization of pathogenic microorganisms are poorly portable because they index variation that is difficult to compare among laboratories. To overcome these problems, we propose multilocus sequence typing (MLST), which exploits the unambiguous nature and electronic portability of nucleotide sequence data for the characterization of microorganisms. To evaluate MLST, we determined the sequences of ≈470-bp fragments from 11 housekeeping genes in a reference set of 107 isolates of Neisseria meningitidis from invasive disease and healthy carriers. For each locus, alleles were assigned arbitrary numbers and dendrograms were constructed from the pairwise differences in multilocus allelic profiles by cluster analysis. The strain associations obtained were consistent with clonal groupings previously determined by multilocus enzyme electrophoresis. A subset of six gene fragments was chosen that retained the resolution and congruence achieved by using all 11 loci. Most isolates from hyper-virulent lineages of serogroups A, B, and C meningococci were identical for all loci or differed from the majority type at only a single locus. MLST using six loci therefore reliably identified the major meningococcal lineages associated with invasive disease. MLST can be applied to almost all bacterial species and other haploid organisms, including those that are difficult to cultivate. The overwhelming advantage of MLST over other molecular typing methods is that sequence data are truly portable between laboratories, permitting one expanding global database per species to be placed on a World-Wide Web site, thus enabling exchange of molecular typing data for global epidemiology via the Internet.