Outbreak of serogroup C meningococcal disease associated with campus bar patronage

Between February 1991 and April 1992, eight undergraduates at a US residential university and one at a nearby 2-year college contracted serogroup C meningococcal disease. A case-control investigation with 20 controls per case, oropharyngeal carriage surveys, and multilocus enzyme electrophoresis (MEE) of serogroup C isolates were used to identify factors contributing to the outbreak. All eight sterile-site isolates from cases were closely related by MEE and were similar (though not identical) to the strain associated with the 1991-1992 epidemic of meningococcal disease in eastern Canada. Disease was associated with cigarette smoking (p = 0.012), recent patronage of campus-area bars (p = 0.034), estimated amount of time spent in campus-area bars (p = 0.0003), and, especially, recent patronage of one specific bar, bar A (p = 0.0006; odds ratio = 23.1, 95% confidence interval 3.0-571.5). In carriage surveys, 1,528 throat cultures taken from (primarily student) noncases yielded only five (0.3%) strains that were identical by MEE to those from cases. Two of these were found among 22 cultures obtained from bar A employees in spring 1992. Some cases in this outbreak may have followed transmission of the epidemic strain in bar A. Campus bar environments may facilitate the spread of meningococcal disease among teenagers and young adults.     

Molecular epidemiology of recent belgian isolates of Neisseria meningitidis serogroup B

In Belgium an increase in the incidence of meningococcal disease has been noted since the early 1990s. Four hundred twenty clinical strains isolated during the period from 1990 to 1995, along with a set of 30 European reference strains, and 20 Dutch isolates were examined by random-primer and repetitive-motif-based PCR. A subset was investigated by multilocus enzyme electrophoresis and pulsed-field gel electrophoresis. The data were compared with results obtained by serotyping (M. Van Looveren, F. Carion, P. Vandamme, and H. Goossens, Clin. Microbiol. Infect. 4:224-228, 1998). Both phenotypic and molecular epidemiological data suggest that the lineage III of Neisseria meningitidis, first encountered in The Netherlands in about 1980, has been introduced in Belgium. The epidemic clone, as defined by oligonucleotide D8635-primed PCR, encompasses mainly phenotypes B:4:P1.4 and B:nontypeable:P1.4, but strains with several other phenotypes were also encountered. Therefore, serotyping alone would underestimate the prevalence of the epidemic clone.     

Molecular epidemiology of hepatitis C in Australia

The aim of this study was to determine the distribution of hepatitis C virus (HCV) genotypes in Australian patients with hepatitis C and to identify factors associated with particular genotypes. Serum isolates of HCV-RNA were genotyped using a commercial oligonucleotide hybridization (line probe) assay. Relationships between demographic factors, mode of HCV transmission and HCV genotype were assessed by logistic regression analysis. Among 463 patients with hepatitis C, 425 tested positive for HCV-RNA and a single HCV genotype was identified in 420 cases. The patients' places of birth were Australia or New Zealand (62%), Asia (13%), Europe (12%), Mediterranean (6%), Middle East (6%) and other countries (< 1%). The most common genotypes were type 1 (52%) or type 3 (32%); type 2 (9.3%), type 4 (5.5%) and type 6 (1.7%) were less common. Patients with genotype 1b were older (48 +/- 13 years, P< 0.001) and patients with genotype 3 were younger than the remaining patients (37 +/- 11 years vs 42 +/- 12 years, P< 0.001). Among type 1 isolates, 1b was more common for patients born outside Australia compared with those born in Australia (50% vs 13%, P< 0.001) whereas non-1b subtypes were more common among Australian-born patients. Likewise, 21 of 23 (91%) patients with type 4 were from Egypt and six of seven (86%) with type 6 were from Vietnam. The relative importance of parenteral risk factors for HCV also varied according to geographic origin. Thus, a definite risk factor for HCV acquisition was identified in > 95% of Australian-born patients, but in only 33% of Asian or Mediterranean-born patients. Logistic regression analysis indicated that region of birth and risk factor (intravenous drug use or not) would allow 98% of type 4 cases and 76% of type 1b cases to be identified correctly. In summary, region of birth, patterns of migration over time and risk factors for transmission of HCV interact to determine the distribution of HCV genotypes in a multi-racial community like Australia.     

The molecular parameters of a meningococcal serogroup B protein-polysaccharide vaccine

Methods for the evaluation of the molecular parameters of B polysaccharide (B-PS) in meningococcal protein-polysaccharide vaccine of group B are proposed. The comparison of two proposed methods, the passive hemagglutination inhibition test and rocket immunoelectrophoresis (RIEP), has shown that the latter method has the highest degree of correlation with the chemical method of the detection of B-PS, which is often hindered by lactose added as a bulking agent. RIEP may be recommended for the standardization and control of the commercial preparations of group B meningococcal vaccine. B-PS contained in the vaccine is known to be in a highly polymeric state: its yield is 66.4 +/- 1.7% to Kd = 0.25 and 85.3 +/- 1.2% to Kd = 0.5. B-PS contained in the prepared vaccine has been found to be highly stable. Outer membrane proteins of meningococci, forming a noncovalent complex with capsular B-PS, seem to stabilize its structure and prevent the depolymerization of molecules.     

Protein C in the treatment of coagulopathy in meningococcal disease

OBJECTIVE: To evaluate the clinical and laboratory effects of the substitution of protein C (PC) as an adjunct to conventional therapy in the treatment of purpura fulminans associated with meningococcal sepsis. DESIGN: case series. SETTING: Medical and medical-surgical intensive care units of two university hospitals. PATIENTS: Three patients with purpura fulminans and multiple organ failure caused by Neisseria meningitidis. INTERVENTION: Intravenous administration of PC concentrate (100 IU/kg every 6 to 8 hrs). MEASUREMENTS AND MAIN RESULTS: The administration of PC resulted in normal or above normal levels of the plasma PC activity in all patients. The laboratory and clinical parameters reflecting the severity of coagulopathy improved during the treatment, as did peripheral ischemia and the clinical manifestations of multiple organ failure. No adverse events were noted. One patient died of cerebral edema. CONCLUSION: The administration of PC had a beneficial effect on coagulopathy and peripheral gangrene formation associated with meningococcal disease and showed no adverse effects.     

Molecular epidemiology of oral treponemes associated with periodontal disease

Periodontitis, a disease responsible for tooth loss worldwide, is characterized by chronic inflammation of the periodontium, eventually leading to destruction of periodontal ligaments and supporting alveolar bone. Spirochetes, identified by dark-field microscopy as being the most predominant bacteria in advanced lesions, are thought to play a causative role. Various spirochetal morphotypes were observed, but most of these morphotypes are as yet uncultivable. To assess the role of these organisms we designed oligonucleotide probes for the identification of both cultivable and so far uncultivable spirochetes in periodontitis patients. Subgingival plaque specimens taken from diseased sites (n = 200) and healthy control sites (n = 44) from 53 patients with rapidly progressive periodontitis (RPP) were submitted to direct in situ hybridization or dot blot hybridization after prior amplification with eubacterial primers. Spirochetes were found in all patients, but their distributions varied considerably. Parallel use of oligonucleotide probes specific for cultivable or so far uncultivable treponemes suggested the presence of novel yet unknown organisms at a high frequency. These uncultivable treponemes were visualized by fluorescence in situ hybridization, and their morphologies, sizes, and numbers could be estimated. All RPP patients included in this study harbored oral treponemes that represent either novel species, e.g., Treponema maltophilum, or uncultivable phylotypes. Therefore, it is necessary to include these organisms in etiologic considerations and to strengthen efforts to cultivate these as yet uncultivable treponemes.     

Molecular epidemiology of Vibrio cholerae O1 isolated from sporadic cholera cases in Okinawa, Japan

In July 1994, 6 cholera cases due to Vibrio cholerae O1 El Tor Ogawa sporadically appeared in Okinawa. All 6 patients had no history of traveling abroad. In the period of this cholera outbreak, a strain of V. cholerae O1 El Tor Ogawa was detected from an imported fish at the Naha port quarantine station. The isolates were characterized to clarify whether or not, they belonged to a common clone. Phenotypes were identical except that one strain revealed cured Celebes and the others were original Celebes in kappa phage typing. The restriction fragment patterns of DNA of the isolates hybridized with an enzyme-labeled oligonucleotide probe for cholera toxin gene (ctx) were identical. Randomly amplified polymorphic DNA of the isolates were identical when a primer was used, but 2 patterns were seen when another primer was used. Pulsed-field gel electrophoresis of the chromosomal DNA digested with NotI restriction enzyme showed 3 patterns. The DNA fragment pattern of the strain isolated from the imported fish was different from the clinical isolates. These results suggested that there was no epidemiological relation among the strains of V. cholerae O1 isolated during this period.     

Molecular evidence for an African origin of the Hawaiian endemic Hesperomannia (Asteraceae)

Identification of the progenitors of plants endemic to oceanic islands often is complicated by extreme morphological divergence between island and continental taxa. This is especially true for the Hawaiian Islands, which are 3,900 km from any continental source. We examine the origin of Hesperomannia, a genus of three species endemic to Hawaii that always have been placed in the tribe Mutisieae of the sunflower family. Phylogenetic analyses of representatives from all tribes in this family using the chloroplast gene ndhF (where ndhF is the ND5 protein of chloroplast NADH dehydrogenase) indicate that Hesperomannia belongs to the tribe Vernonieae. Phylogenetic comparisons within the Vernonieae using sequences of both ndhF and the internal transcribed spacer regions of nuclear ribosomal DNA reveal that Hesperomannia is sister to African species of Vernonia. Long-distance dispersal northeastward from Africa to southeast Asia and across the many Pacific Ocean island chains is the most likely explanation for this unusual biogeographic connection. The 17- to 26-million-year divergence time between African Vernonia and Hesperomannia estimated by the DNA sequences predates the age of the eight existing Hawaiian Islands. These estimates are consistent with an hypothesis that the progenitor of Hesperomannia arrived at one of the low islands of the Hawaiian-Emperor chain between the late Oligocene and mid-Miocene when these islands were above sea level. Subsequent to its arrival the southeast Pacific island chains served as steppingstones for dispersal to the existing Hawaiian Islands.     

Molecular epidemiology of Ornithobacterium rhinotracheale

Ornithobacterium rhinotracheale is a recently described gram-negative rod-shaped bacterium associated with respiratory tract infections in poultry. In order to determine the molecular epidemiology of this bacterium, we characterized 55 O. rhinotracheale isolates from eight countries on four continents by multilocus enzyme electrophoresis (MLEE), repetitive sequence based-PCR (rep-PCR), and 16S rRNA gene sequencing. MLEE discriminated the O. rhinotracheale isolates into six electrophoretic types (ETs), of which only three ETs were recovered from domesticated poultry. The 16S rRNA gene sequence and rep-PCR analyses confirmed the results obtained by MLEE and indicated limited heterogeneity among isolates of O. rhinotracheale recovered from poultry. Taken together, the results of our analysis demonstrate that the majority of O. rhinotracheale isolates recovered from domesticated poultry throughout the world are represented by a small group of closely related clones and suggest that the bacterium was recently introduced to domesticated poultry from wild bird populations.     

Molecular genetic studies of sporadic pituitary tumors

Tumor formation may result from the activation of dominant oncogenes or by inactivation of recessive, tumor suppressor genes. The role of such mutations in the development of pituitary tumors has been studied. Tumors from 88 patients, representing the 4 major classes of adenoma, were investigated. In DNA extracted from matched leukocyte and tumor samples, allelic deletions were sought with 15 probes identifying restriction fragment length polymorphisms on chromosomes 1, 5, 10, 11, 13, 17, 20, and 22. Evidence of amplification or rearrangement of 10 recognized cellular oncogenes (N-ras, mycL1, mycN, myc, H-ras, bcl1, H-stf1, sea, kraS2, and fos) was sought in tumor DNA. Activating dominant mutations of Gs alpha were detected using the polymerase chain reaction to amplify exons 7-10 and hybridizing the product to normal and mutant allele-specific oligonucleotides. Allelic deletions on chromosome 11 were identified in 16 tumors (18%) representing all 4 major subtypes. Deletions on other autosomes were observed in less than 6% of tumors. Three adenomas had deletions on multiple autosomes, 2 of these were aggressive and recurrent. Mutations of Gs alpha were confirmed to be specific to somatotrophinomas, being identified in 36% of such tumors in this series. No evidence of amplification or rearrangement of other recognized cellular oncogenes was found. Inactivation of a recessive oncogene on chromosome 11 is an important and possibly early event in the development of the four major types of pituitary adenoma, whereas activating mutations of Gs alpha are confirmed to be specific to somatotropinomas. Two aggressive tumors were found to have multiple autosomal losses, suggesting a multistep progression in the development of tumors of this phenotype.     

Molecular genetics (HLA) of Beh?et's disease

Beh?et's disease (BD) has been known to be strongly associated with the human leukocyte antigen (HLA) B51. This B51 association has been confirmed in many different ethnic groups between the Middle East and Japan, and it has been proposed that BD is prevalent in those ethnic groups along the old Silk Route. The hypothesis could be made that B51 molecules are primarily involved in BD development through specific antigen presentation. However, polymorphic analyses of the TNFB gene and Tau-a microsatellite between the HLA-B and TNF genes indicate that the pathogenic gene of BD is not the HLA-B51 gene itself but another gene located around the HLA-B gene. HLA-C genotyping by the PCR-SSP method also suggests that the BD pathogenic gene is not the HLA-C gene itself but other gene located near the HLA-B gene. Recently we sequenced a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C and identified 8 novel genes designated NOB1-8 (NOB: new organization associated with HLA-B). During the course of the genomic sequence analysis we clarified the genetic structure of the MICA (MHC class I chain-related gene A) gene and found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmebrane (TM) region. Furthermore, the microsatellite allele consisting of 6 repetitions of GCT/AGC (MICA A6 allele) was present at a significantly higher frequency in the BD patient group than in the control group and a significant fraction of B51-negative patients were positive for this MICA A6 allele. These results suggest the possibility of a primary association of BD with MICA rather than HLA-B.     

Outbreak of meningococcal disease in a family

An outbreak of three cases of meningococcal disease occurring in a family of 14 is presented. Three of the children, between the ages of 10 months to 10 years, were hospitalized. Two of them showed positive signs of meningitis, and one had evidence of bacteremia. Neisseria meningitidis was isolated from a blood sample of one patient and a CSF sample of another. The organism was also recovered from the nasopharyngeal secretion of four other adult members of the family. All three hospitalized children were treated with parenteral penicillin and responded well to therapy. The rest of the family was treated with oral rifampin, and subsequent cultures of the nasopharynx were negative.     

The new features of meningococcal meningitis (author's transl)

According to a previous pattern epidemics of meningococcal meningitis (MM) were localized in North tropical Africa, caused by A serotype, easily treated with sulfanilamides and prevented by a polyosidic vaccine, A type. Changes have occured : epidemics in Finland and Brazil, with an African A type germ, in place of the American, sulfa-resistant, C type; outburst of epidemics in South tropical Africa; presence of C type in Tchad, Niger and Nigeria. In the same time dramatic evolutions due to endotoxinic processes and drug-resistances are more frequently observed.     

Molecular epidemiology of rabies epizootics in Texas

Glucocorticoids are potent osteopenic agents, producing negative calcium and bone balance via actions at many sites. The most significant adverse effects of glucocorticoid drugs on the skeleton are probably a direct inhibition of matrix synthesis by the osteoblast, reductions in calcium absorption in both the gut and the renal tubule, and the production of hypogonadism, particularly in men. Reductions in bone density of 10-40% result, the loss being more marked in trabecular bone and in patients receiving a high cumulative dose of the steroid. Fractures occur in about 30% of individuals who take these drugs for an average of 5 years. Bone loss is reversible when glucocorticoid treatment is withdrawn. Bone density can also be increased by sex hormone replacement in those with demonstrable deficiency, by bisphosphonates, and possibly by vitamin D metabolites. All patients treated with glucocorticoids for more than 6 months should be considered for bone densitometry and be offered appropriate drug treatment if values are towards the lower end of the young normal range or if there is already evidence of fractures occurring after minimal trauma. With this approach, the significant morbidity associated with steroid osteoporosis might be substantially avoided.     

Molecular identification and epidemiology of animal mycoplasmas

Molecular genetic techniques show a high potential for rapid and accurate identification of Mycoplasma species isolated from animals. An important field of application for such methods is the differentiation of species and/or subspecies which are phenotypically closely related, but which show significant differences in epidemiological impact. This need is particularly important for the mycoplasmas of the "mycoides group", which are phenotypically and phylogenetically very closely related. Molecular typing techniques based on 16S rRNA genes give straightforward phylogenetic answers on the species level. For more refined methods of subtyping at the subspecies level, the use of defined genes characteristic of certain Mycoplasma species or clusters is recommended. Genetic fingerprinting, especially insertion sequence typing has proved to be a valuable tool for subtyping and strain identification in particular of vaccine strains and for epidemiological investigations.     

Effectiveness of the massive campaign for immunization against Meningococcus (serogroup C) in the Autonomic Community of the Basque Province

A prospective study was conducted on 27 dogs with recurrent urinary tract infections (UTIs) and urolithiasis. Four sampling methods (i.e., urine obtained by cystocentesis, bladder mucosal swab, bladder mucosal biopsy, and urolith) were compared to identify UTI. Identical culture results were obtained from urine collected by cystocentesis and from the swab of bladder mucosa. In the presence of a positive urine culture, the same organism also was cultured from the bladder mucosal biopsy and urolith. However, in the presence of a negative urine culture, an organism was cultured from the bladder mucosal biopsy or the urolith in 18.5% of the cases. Therefore, when the culture from urine obtained by cystocentesis is negative, it is recommended that aerobic cultures of a bladder mucosal biopsy and a urolith be performed in cases of urolithiasis.     

Molecular epidemiology of tuberculosis in Denmark in 1992

The incidence of tuberculosis (TB) is increasing all over the world, including in countries with a high standard of living and good social security. Denmark represents such a region. Furthermore, it is a small country (5 million inhabitants) with a long tradition in TB control, including a centralization of the bacteriological diagnostic facility. The present study was intended to analyze the transmission of Mycobacterium tuberculosis in a country in which TB has low endemicity by a combination of conventional epidemiological approaches and DNA fingerprinting techniques, whereby individual bacterial strains can be traced. M. tuberculosis isolates from 92% of all new cases of bacteriologically verified TB in Denmark during 1992 were subjected to IS6110 DNA fingerprinting to visualize the DNA restriction fragment length polymorphism (RFLP) patterns of the isolated strains. The data obtained from the RFLP analyses were interpreted by using demographic data, such as age, sex, ethnicity, and residence, for the patients. The risk factors among the patients for being part of an active chain of transmission, as opposed to demonstrating reactivation of a previously acquired latent infection, were estimated by statistical analyses. The magnitude of TB transmission in 1992 in Denmark was determined, and transmitted infections were shown to comprise at least one quarter of the total number of cases. Almost half of the TB cases involved patients of foreign origin. However, most of these isolates showed unique DNA fingerprint patterns and were rarely part of an active chain of transmission. The major chains of recent transmission were localized to distinct geographical regions in the country. TB is frequent among immigrants, especially from Asia and Africa, but it is apparently readily suspected, diagnosed, and treated by the health care system. Danish patients with pulmonary symptoms are not primarily suspected to have TB and, therefore, play an important role in recent TB transmission in Denmark.