Comparative genotyping of Campylobacter jejuni by amplified fragment length polymorphism,multilocus sequence typing,and short repeat sequencing: strain diversity,host range,and recombination

Three molecular typing methods were used to study the relationships among 184 Campylobacter strains isolated from humans, cattle, and chickens. All strains were genotyped by amplified fragment length polymorphism (AFLP) analysis, multilocus sequence typing (MLST), and sequence analysis of a genomic region with short tandem repeats designated clustered regularly interspaced short palindromic repeats (CRISPRs). MLST and AFLP analysis yielded more than 100 different profiles and patterns, respectively. These multiple-locus typing methods resulted in similar genetic clustering, indicating that both are useful in disclosing genetic relationships between Campylobacter jejuni isolates. Group separation analysis of the AFLP analysis and MLST data revealed an unexpected association between cattle and human strains, suggesting a common source of infection. Analysis of the polymorphic CRISPR region carrying short repeats allowed about two-thirds of the typeable strains to be distinguished, similar to AFLP analysis and MLST. The three methods proved to be equally powerful in identifying strains from outbreaks of human campylobacteriosis. Analysis of the MLST data showed that intra- and interspecies recombination occurs frequently and that the role of recombination in sequence variation is 50 times greater than that of mutation. Examination of strains cultured from cecum swabs revealed that individual chickens harbored multiple Campylobacter strain types and that some genotypes were found in more than one chicken. We conclude that typing of Campylobacter strains is useful for identification of outbreaks but is probably not useful for source tracing and global epidemiology because of carriage of strains of multiple types and an extremely high diversity of strains in animals.     

Elektronenoptische Untersuchungen von Gewebeschnitten aus silikotischen Granulomen

Ohne ZusammenfassungNach einem Vortrag, gehalten auf der Arbeitsgemeinschaft am 2. 7. 54 in Bochum-Hordel, Steinkohlenbergwerk Hannover-Hannibal AG.     

Genotyping of clinical methicillin-susceptible Staphylococcus aureus isolates in a Dutch teaching hospital

Methicillin-susceptible Staphylococcus aureus isolates, recovered from 204 patients in our hospital in a 22-month period, were characterized by pulsed-field gel electrophoresis. Among the multiple S. aureus types six clonal lineages dominated, comprising isolates from 158 patients. Despite the limited genetic variation, cross-transmission was made plausible only sporadically.     

Characterization of FMR1 proteins isolated from different tissues

FMR1 protein expression was studied in different tissues. Inhuman, monkey and murine tissues, high molecular mass FMR1 proteins(67–80 kDa) are found, as shown in lymphobiastoid celiiines. The identity of these proteins was confirmed by theirabsence in tissues from patients with the fragile X syndromeand a FMR1 knock-out mouse. An IIe367Asn substitution in theFMR1 protein did not aiter the transiation, processing and localizationof FMR1 proteins in lymphoblastoid cells from a patient carryingthis mutation. All the high molecular mass FMR1 proteins isolatedfrom normal lymphoblastoid cells and cells from the patientwith the IIe367Asn substitution were able to bind RNA. However,the FMR1 proteins of the patient had reduced affinity for RNAbinding at high salt concentrations. In some human, monkey andmurine tissues low molecular mass FMR1 proteins (39–41kDa) were found, which had the same N terminus as the 67–90kDa isoforms, but differ in their C terminus and are thereforemost likely the result of carboxy-terminal proteolytic cleavage.These low molecular mass FMR1 proteins did not bind RNA, incontrast with the high molecular mass FMR1 proteins. The significanceof these low molecular mass proteins remains to be studied.     

Relative contribution of vertical,within-farm and between-farm transmission of Mycoplasma synoviae in layer pullet flocks

ABSTRACT

In this study, the relative contribution of vertical transmission, within-farm transmission and between-farm transmission of Mycoplasma synoviae in layer pullet flocks was quantified using logistic regression analysis. Data from 311 Dutch pullet flocks, of which 172 (55%) were positive for M. synoviae, were included in the study. Also the M. synoviae status of the parent stock of these flocks was included. The M. synoviae status was determined with the M. synoviae rapid plate agglutination test. Data analysis showed that vertical transmission was the most important transmission route for M. synoviae in layers as is demonstrated by an odds ratio of 5.8 (P?=?0.000). A positive association with M. synoviae infections was found for layer pullet flocks on a multi-house farm where at least one other flock was M. synoviae-positive compared to single-house farms (odds ratio 3.1, P?=?0.022), while a negative association was found when no other M. synoviae-positive flocks were present (odds ratio?=?0.2, P?=?0.003). No association was found between M. synoviae status of pullet flocks and poultry farm density. Odds ratios were 0.54 (P?=?0.288) and 0.34 (P?=?0.073), respectively, for medium and highest poultry farm density compared to lowest poultry farm density. This is the first time that the relative contribution of horizontal and vertical transmission of M. synoviae has been quantified. These results can be extrapolated to M. synoviae control in general, and emphasize the importance of M. synoviae control in parent stock and practical channelling.     

Examination of the Short-Term Efficacy of a Parent-Based Intervention to Prevent Skin Cancer

The research evaluated an intervention strategy designed to prevent skin cancer in young adolescents. The intervention used parents as change agents to effectively communicate the risks of skin cancer and encourage their children to avoid high-risk sun-related behaviors while increasing positive sun-safe behaviors. Three hundred and forty parents in two regions of the United States were educated about the dangers of risky sun behaviors and how to convey information about skin cancer prevention to their children. Parents were then encouraged to talk with their children about these issues over a 1-month period prior to the onset of summer. Following this time period, children whose parents received and implemented the intervention materials were compared with a control sample of 129 children. These two groups were matched on age, gender, and school on number of sunburns and sunburn severity, attitudes and beliefs, and sunbathing behavior. Children in the treatment condition differed significantly from controls in the predicted directions on all outcome variables. The findings are discussed in terms of reducing skin cancer risk behaviors of children via parent-based intervention approaches.     

Thromboembolic diseases in neonates and children

Acquired and inherited prothrombotic risk factors increase the risk of thrombosis in neonates, infants and children. After suffering thrombosis white paediatric patients should be screened for common gene mutations, i.e. the factor V G1691A, factor II G20210A and MTHFR C677T genotypes, rare inherited prothromboticrisk factors, i.e. deficiencies of protein C,protein S, and antithrombin, plasminogen, probably inherited risk factors, i.e. fibrinogen, factor VIIIC, factor XII, new candidates, i.e. elevation of lipoprotein (a),and fasting homocysteine concentrations (3-6 months after thrombotic onset). Data interpretation is based on age-dependent reference ranges or the identification of causative gene mutations/polymorphisms with respect to individual ethnic backgrounds.     

Die Bedeutung der Glutathionkonzentration der Erythrocyten für die Diagnose der Osteomyelofibrose

Zusammenfassung Bei 16 von 17 Patienten mit Osteomyelofibrose wurden in den Erythrocyten erhöhte Konzentrationen an reduziertem Glutathion nachgewiesen. Die Bestimmung des Glutathions kann als differentialdiagnostisch wertvolles Kriterium für die Charakterisierung der Osteomyelofibrose angesehen werden.

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Summary In 16 of 17 patients with osteomyelofibrosis the concentration of erythrocyte reduced glutathione was increased. It is concluded that the determination of erythrocyte glutathione is of differential diagnostic value in the characterization of osteomyelofibrosis.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Resistance mechanisms to plant viruses: an overview

To obtain virus-resistant host plants, a range of operational strategies can be followed nowadays. While for decades plant breeders have been able to introduce natural resistance genes in susceptible genotypes without knowing precisely what these resistance traits were, currently a growing number of (mostly) dominant resistance genes have been cloned and analyzed. This has led not only to a better understanding of the plant's natural defence systems, but also opened the way to use these genes beyond species borders. Besides using natural resistance traits, also several novel, "engineered" forms of virus resistance have been developed over the past 15 years. The first successes were obtained embarking from the principle of pathogen-derived resistance (PDR) by transforming host plants with viral genes or sequences with the purpose to block a specific step during virus multiplication in the plant. As an unforeseen spin-off of these investments, the phenomenon of post-translational gene silencing (PTGS) was discovered, which to date is by far the most successful way to engineer resistance. It is generally believed that PTGS reflects a natural defence system of the plant, and part of the hypothesized components required for PTGS have been identified. As counteracting strategy, and confirming PTGS to be a natural phenomenon, a considerable number of viruses have acquired gene functions by which they can suppress PTGS. In addition to PDR and PTGS, further strategies for engineered virus resistance have been explored, including the use of pokeweed antiviral protein (PAP), 2',5'-oligoadenylate synthetase and "plantibodies". This paper will give a brief overview of the major strategies that have become operational during the past 10 years.     

Depletion of calcitonin gene-related peptide from the caudal trigeminal nucleus of the rat after electrical stimulation of the Gasserian ganglion

Electrical stimulation of the Gasserian ganglion resulted in partial depletion of calcitonin gene-related peptide (CGRP) from ipsilateral central terminals of pseudounipolar primary sensory ganglion cells. Affected terminals exhibit decreased CGRP immunoreactivity as shown by cytophotometric densitomery of the caudal trigeminal nucleus. The decrease in CGRP immunoreactivity is statistically significant only in the medial one-third of the caudal trigeminal nucleus. Since earlier studies have shown that electrical stimulation of the Gasserian ganglion induces first accumulation then depletion of CGRP from perivascular sensory terminals in the dura mater, the present experiments suggest that CGRP is depleted also from central terminals of primary sensory trigeminal neurons, which might be of importance in the pathogenesis of migraine headache. Received: 18 December 1996 / Accepted: 26 June 1997