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F Scheutz

Publications and source records attributed to F Scheutz.

At least 19 recordsLinked to original sources
PubMed2003

PCR detection of seven virulence and toxin genes of Campylobacter jejuni and Campylobacter coli isolates from Danish pigs and cattle and cytolethal distending toxin production of the isolates.

AIMS: To study the prevalence of seven virulence and toxin genes, and cytolethal distending toxin (CDT) production of Campylobacter jejuni and C. coli isolates from Danish pigs and cattle. METHODS AND RESULTS: The presence of the cadF, ceuE, virB11, flaA, cdtA, cdtB, cdtC and the cdt gene cluster among 40 C. jejuni and C. coli isolates was detected by polymerase chain reaction. The CDT production of the isolates was determined on Vero, colon 205 and chicken embryo cells. The cadF, flaA, ceuE and cdtB genes were detected from 100% of the isolates. The cdtA and cdtC genes were found in 95.0 and 90.0% of the isolates, respectively. The cdt gene cluster was detected in 82.5% isolates. Only 7.5% of the isolates were positive for virB11. Ninety-five per cent of the isolates produced CDT in Vero and colon 205 cell assays, and 90% of the isolates produced CDT in chicken embryo cell assays. CONCLUSIONS: High prevalence of the cadF, ceuE, flaA and cdtB genes was found. Data of the prevalence of cdt genes was consistent with the CDT titres produced by the isolates. Campylobacter coli from pigs produced high CDT titres. SIGNIFICANCE AND IMPACT OF THE STUDY: The high prevalence of seven virulence and toxin genes demonstrated that these putative pathogenic determinants are widespread among Campylobacter isolates from pigs and cattle. Campylobacter coli isolates from pigs produced much higher CDT titres compared with C. coli isolates from other sources suggesting that C. coli may be particularly adapted to or associated with this species.

Animals↗
PubMed2003

The effect of choosing different units of analysis when estimating risk of presence of dental caries in the primary dentition.

BACKGROUND: Data on caries are usually collected with the tooth surface or the tooth as the unit, but subsequently analysed by aggregating the data at the level of the individual. AIMS: To evaluate how different units of analysis may affect the result of the statistical analyses in a study of the association between deciduous dental caries and a set of risk factors. METHOD: 293 children (mean age: 7.5 yrs) from two primary schools in Dar es Salaam, Tanzania were examined. Thus the study design was cross-sectional. Logistic regression analysis was used to determine the association between caries experience and nutritional status, socioeconomic background, and microbiological and salivary characteristics using the subject, the tooth, and the tooth surface as unit of analysis, allowing for the fact that teeth and surfaces within the same individual must be considered non-independent. RESULTS: When aggregated data were used, point estimates were larger in some instances. The precision of the estimates increased considerably when the tooth as compared to the individual was used as the unit of analysis. No or limited gain in precision was obtained when the tooth surface as compared to the tooth was used as unit of analysis. CONCLUSIONS: The choice of unit of analysis may strongly influence the result of the statistical analyses and thus the conclusion of an investigation.

Buffers↗
PubMed2001

Eruption pattern of autotransplanted premolars visualized by radiographic color-coding.

Eruption patterns and root growth were visualized with the use of a new technique, radiographic color-coding, for comparison of the development of autotransplanted premolars with contralateral control teeth. Rates of eruption and root growth were studied. The eruption pattern and rate was assessed relative to the first molar. Maximum rates were found to occur between 30 and 60 days after transplantation. There were no significant differences between transplants and their contralaterals. Two distinct categories of eruption patterns were demonstrated. One group showed a tendency toward an initial rate of transplant eruption that was somewhat faster than that of the contralaterals. The other group showed initially retarded eruption. Possible explanations were discussed. Because no significant differences between the transplants and the contralaterals were observed, it was concluded that autotransplantation is a sound treatment option for substitution of missing teeth, at least from a tooth development point of view.

Bicuspid↗
PubMed2001

Determinants of utilization of dental services among 20- to 34-year-old Danes.

Our aim was to identify determinants of utilization of dental services among 20- to 34-year-old Danes as outlined in a conceptual framework. Our sample consisted of a sample of 464 individuals who had been interviewed by 10 experienced interviewers from The Danish National Institute of Social Research. Our questionnaire comprised a battery of questions based on our conceptual model. The analysis was done in a hierarchical manner using a framework with three steps: Predisposing factors --> Enabling factors --> Need factors --> Utilization. Associations were evaluated with multivariate logistic regression analysis and expressed as odds ratios. The following factors were significantly associated with irregular use of dental services: age, sex, exercise habits, cost of dental treatment, dental anxiety, and perceived condition of teeth. Our findings suggest that a strategy aiming to increase young people's dental attendance should focus on the transition period that is, when the youngsters leave the public dental health care system and have to make use of the private system. The strategy should also take into account that young men are more likely to become non-users. A concerted effort could be dedicated to the non-negligible group of individuals with dental anxiety and dental phobia.

Adult↗
PubMed2001

Clinical isolates of non-O157 Shiga toxin-producing Escherichia coli: serotypes, virulence characteristics, and molecular profiles of strains of the same serotype.

All human Shiga toxin-producing Escherichia coli (STEC) non-O157 strains (n = 56) isolated in Finland from 1990 to August 2000 were characterized for the O:H serotype, stx(1) and stx(2) genes, production of enterohemolysin, and sensitivity to 12 antimicrobial agents. Strains of the same serotype were genotyped by pulsed-field gel electrophoresis (PFGE) after XbaI restriction of total DNA. The 56 non-O157 isolates belonged to 29 serotypes. Two of the serotypes (O102:H7 and OX181:H49) have not previously been described as being associated with STEC infections in humans or isolated from animals. Thirty-four strains (61%) within seven serotypes (O103:H2 [14 isolates], O26:H11 [6 isolates], O145:H28 [4 isolates], O145:HNM [3 isolates], O15:HNM [3 isolates], OX174:H21 [2 isolates], and O Rough:HNM [2 isolates]) were represented by more than one isolate. Of these strains, O103:H2 isolates were divided into seven, O26:H11 isolates were divided into four, and the rest within a serotype were divided into two genotypes in PFGE. In PCR, 31 (55%) of the 56 strains were positive for the stx(2) gene only and 24 strains (43%) were positive for stx(1) only. One strain (O43:H2) carried both stx(1) and stx(2). Forty-two strains (75%) produced enterohemolysin, and 39 strains (70%) possessed the eae gene. Of the latter 39 strains, 36 (92%) were enterohemolytic, whereas only 6 (35%) of the 17 isolates lacking the eae gene were enterohemolytic (P < 0.001). The majority of the strains (44 strains, 79%) were sensitive to all 12 antimicrobials tested. Of the 56 strains, 20 (36%) were associated with small family outbreaks in nine families and 14 (25%) were associated with recent travel abroad.

Bacterial Typing Techniques↗
PubMed2001

Determinants of child mortality in a rural Ugandan community.

OBJECTIVE: To estimate the rate of and risk factors associated with child mortality in rural eastern Uganda. DESIGN: A community based cross-sectional study using the preceding birth technique--a robust method of obtaining information of survival of the previous child. SETTING: A rural district in Eastern Uganda. PARTICIPANTS: In total, 2888 multigravidae were interviewed in April and May 1999. MAIN OUTCOME MEASURE: Number of deaths among children born alive. RESULTS: The under-two child mortality rate was 108 per 1000 livebirths. The annual child mortality was 82 per 1000 child-years of risk. Child mortality was associated with low parental education, being born to adolescent mothers or mothers aged 35 or more. Unconditional logistic regression showed that children born to uneducated parents had a doubled risk of not celebrating their second birthday. It was three times more likely for a child to die in the neonatal period than in the first year of life. Child mortality risk decreased by 4% and 6% for every year of education attained by mothers and fathers, respectively. Parity, residence and marital status were not associated with excess risk of child mortality. Seasonal mortality followed the El Nino rainfall pattern. Finally, there were geographical differences in child mortality although this was not statistically significant. CONCLUSION: Monitoring trends in child mortality at district level can be done using the preceding birth technique in antenatal settings. Maternal education, an important predictor of child survival should be included in routine data collection at clinics.

Adolescent↗
PubMed2000

[Verotoxin-producing Escherichia coli infections: study of its prevalence in children in the Auvergne region].

Verotoxin producing Escherichia coli (VTEC) have been associated with disease outbreaks of diarrhea hemorrhagic colitis and hemolytic-uremic syndrome in humans. Contamination occurs mainly by ingestion of beef and dairy products, but water and person to person transmission have also been described. Most of the clinical signs are due to the production of Stx1 and/or Stx2 Shiga toxins, also called verotoxins. Other virulence factors include enterohemolysin, and the product of the eae gene, intimin, involved in the attaching and effacing adherence phenotype. The predominant serotype is O157:H7, but VTEC strains of more than one hundred serotypes can cause human disease. In order to determine the prevalence of VTEC infections among children in the central part of France, stool samples from hospitalized children were examined for stx1 and stx2 genes by using a polymerase chain reaction (PCR) technique. From October 1997 to September 1998, 658 stool samples were analysed: among them 19 (3%) were stx-PCR positive. Only 8 children out of 19 had diarrhea, and for 5 of them, an enteric pathogen other than VTEC was isolated. VTEC strains were isolated from 10 samples: most of the isolates did not produce verotoxins at a high level, and they did not belong to serotypes associated with pathogenicity, which might explain the absence of relationship between VTEC isolation and pathogenicity in our study.

Adolescent↗
PubMed2000

Two cases of human urinary tract infection complicated by hemolytic uremic syndrome caused by verotoxin-producing Escherichia coli.

In 1993, 2 cases of urinary tract infection (UTI) caused by verotoxin-producing Escherichia coli were diagnosed at Rigshospitalet in Copenhagen, Denmark. Neither of the patients had any previous history of diarrhea. We suggest that E. coli strains isolated from UTI be examined for the production of verotoxin when hemolytic uremic syndrome is clinically suspected.

Escherichia coli↗
PubMed2000

Occurrence of oral lesions in relation to clinical and immunological status among HIV-infected adult Tanzanians.

OBJECTIVE: To determine the association, if any, between the presence of oral lesions and clinical and immunological status of untreated HIV-infected adults in Tanzania. DESIGN: A cross-sectional study. SETTING: AIDS Clinical Trial Clinic (ATCC) at Muhimbili Medical Centre in Dar-es-Salaam, Tanzania. SUBJECTS: 192 HIV-infected individuals not receiving treatment; 156 individuals confirmed to be HIV-seronegative acted as a control group. METHODS: Examination of oral structures, determination of HIV serostatus, clinical status, and peripheral CD4+ T cell and total lymphocyte counts. MAIN OUTCOME MEASURE: Presence of oral lesions. RESULTS: Intra-oral lesions were seen among 7.7% of the HIV-seronegative, 10.4% of the HIV-seropositive and 36.8% of the AIDS groups, respectively. Enlarged parotid glands were seen in 20% of the AIDS patients, 11.9% of the HIV-seropositives, and 5.1% of the HIV seronegatives. Enlargement of submandibular salivary glands was seen in 29.6% of the AIDS patients, 31.3% of the HIV-seropositives compared with 14.7% among the HIV-seronegatives. Multiple regression analysis was used to calculate adjusted odds ratio (OR) for presence of oral lesions. OR for an intra-oral lesion was 1.6 (95% CI = 0.5; 5.0) among the HIV-seropositives and 8.2 (95% CI = 3.5; 19.7) among the AIDS patients using the HIV-seronegatives as reference. OR for an intra-oral lesion was 0.9 (95% CI = 0.3; 2.9) in HIV-infected patients with peripheral CD4+ T cell count of between 200-500 cells mm-3 and 2.7 (95% CI = 0.9; 7.7) in patients with less than 200 cells mm-3. OR for an intra-oral lesion was 0.4 (95% CI = 0.2; 0.9) for patients with peripheral total lymphocyte counts of between 1000-2000 cells mm-3 and 0.9 (95 CI = 0.4; 2.0) for patients with less than 1000 cells mm-3. CONCLUSION: The association of oral lesions with the clinical stage of HIV infection and to a lesser extent peripheral CD4+ T cell count does suggest that these lesions could be used as additional markers of immunosuppression and AIDS.

AIDS-Related Opportunistic Infections↗
PubMed2000

Analysis of the F antigen-specific papA alleles of extraintestinal pathogenic Escherichia coli using a novel multiplex PCR-based assay.

Polymorphisms in PapA, the major structural subunit and antigenic determinant of P fimbriae of extraintestinal pathogenic Escherichia coli, are of considerable epidemiological, phylogenetic, and immunotherapeutic importance. However, to date, no method other than DNA sequencing has been generally available for their detection. In the present study, we developed and rigorously validated a novel PCR-based assay for the 11 recognized variants of papA and then used the new assay to assess the prevalence, phylogenetic distribution, and bacteriological associations of the papA alleles among 75 E. coli isolates from patients with urosepsis. In comparison with conventional F serotyping, the assay was extremely sensitive and specific, evidence that papA sequences are highly conserved within each of the traditionally recognized F serotypes despite the diversity observed among F types. In certain strains, the assay detected serologically occult copies of papA, of which some were shown to represent false-negative serological results and others were shown to represent the presence of nonfunctional pap fragments. Among the urosepsis isolates, the assay revealed considerable segregation of papA alleles according to O:K:H serotype, consistent with vertical transmission within clones, but with exceptions which strongly suggested horizontal transfer of papA alleles between lineages. Sequencing of papA from two strains that were papA positive by probe and PCR but F negative in the new PCR assay led to the discovery of two novel papA variants, one of which was actually more prevalent among the urosepsis isolates than were several of the known papA alleles. These findings provide novel insights into the papA alleles of extraintestinal pathogenic E. coli and indicate that the F PCR assay represents a versatile new molecular tool for epidemiological and phylogenetic investigations which should make rapid, specific detection of papA alleles available to any laboratory with PCR capability.

Alleles↗
PubMed2000

Prevalence and characterization of Shiga toxin-producing Escherichia coli isolated from cattle, food, and children during a one-year prospective study in France.

During a 1-year survey of Shiga toxin-producing Escherichia coli (STEC) prevalence in central France, 2,143 samples were investigated by PCR for Shiga toxin-encoding genes. A total of 330 (70%) of 471 fecal samples collected from healthy cattle at the Clermont-Ferrand slaughterhouse, 47 (11%) of 411 beef samples, 60 (10%) of 603 cheese samples, and 19 (3%) of 658 stool specimens from hospitalized children with and without diarrhea were positive for the stx gene(s). A STEC strain was isolated from 34% (162 of 471) of bovine feces, 4% (16 of 411) of beef samples, 1% (5 of 603) of cheese samples, and 1.5% (10 of 658) of stool specimens. Of the 220 STEC strains isolated, 34 (15%) harbored the stx(1) gene, 116 (53%) harbored the stx(2) gene, and 70 (32%) carried both the stx(1) and stx(2) genes. However, 32 (14.5%) were not cytotoxic for Vero cells. The eae gene, found in 12 (5%) of the 220 strains, was significantly associated with the stx(1) gene and with isolates from children. Sequences homologous to ehxA were found in 102 (46%) of the 220 strains. Thirteen serotypes, OX3:H2, O113:H21, O113:H4, OX3:H21, O6:H10, OX178:H19, O171:H2, O46:H38, O172:H21, O22:H16, O91:H10, O91:H21, and O22:H8, accounted for 102 (55%) of 186 typeable isolates, and only one strain (0.5% of the 186 STEC isolates from cattle), belonged to the O157:H7 serotype. We showed that the majority of the STEC isolates from cattle, beef, and cheese were not likely to be pathogenic for humans and that the STEC strains isolated from children in this study were probably not responsible for diarrheal disease. Finally, the strains associated with hemolytic-uremic syndrome in the same geographical area were shown to belong to particular subsets of the STEC population found in the bovine reservoir.

Abattoirs↗
PubMed2000

Molecular analysis of H antigens reveals that human diarrheagenic Escherichia coli O26 strains that carry the eae gene belong to the H11 clonal complex.

Fifty-seven Escherichia coli O26 strains isolated from patients in six countries were investigated by PCR restriction fragment length polymorphism (RFLP) analysis of the flagellin-encoding (fliC) gene (fliC RFLP analysis). The strains were determined by serotyping to belong to five different H types or were nonmotile. The fliC RFLP analysis revealed only two different patterns among the 57 strains. One fliC RFLP pattern was displayed by 54 strains and was identical to that of E. coli H11 reference strain Su4321-41. The other fliC RFLP pattern was observed for three strains and was identical to that for E. coli H32 reference strain K10. The 54 strains with the H11 fliC RFLP pattern included 22 strains of serotype O26:H11, 23 nonmotile strains, and 9 strains that were initially serotyped as H2, H8, H21, and H32 but that were confirmed to express H11 by repeat serotyping. All 54 strains with the H11 fliC RFLP pattern contained the attaching-and-effacing (eae) gene. The three strains with the H32 fliC RFLP pattern belonged to serotype O26:H32, and all were eae negative. The fliC genes of 14 selected E. coli O26:H11 strains isolated between 1964 and 1999 had identical nucleotide sequences. Our results demonstrate that E. coli O26 strains that carry the eae gene belong exclusively to the H11 clonal complex. Since there were no H11 fliC allelic variations among the O26 strains tested, E. coli O26:H11 may have emerged recently. The fliC PCR-RFLP test is a reliable, easy-to-perform, and rapid method for determination of the H types of E. coli O26 isolates.

Adhesins, Bacterial↗
PubMed1999

HIV infection, dental treatment demands and needs among patients seeking dental services at the Muhimbili Medical Centre in Dar-es-Salaam, Tanzania.

The objectives of this cross-sectional study were to determine the frequency of HIV infection among dental patients attending the three dental facilities at Muhimbili Medical Centre (MMC) in Dar-es-Salaam, Tanzania, and to compare the dental treatment demands and needs of the patients found to be HIV-infected with those of their HIV-seronegative counterparts. The facilities were; the dental outpatient department (DOPD) clinic, the dental minor surgery department, and the dental ward. This study which was conducted between March and April, 1996 enrolled a total of 460 patients. The investigations involved detection of anti-HIV IgG antibodies in saliva, examination of oral and peri-oral tissues, and assessment of dental and periodontal status. The overall HIV frequency among the dental patients was 10.9 per cent. The frequencies of HIV infection among patients attending the dental OPD clinic, minor surgery, and those admitted in the dental ward were 9.4 per cent, 26.3 per cent, and 25.0 per cent, respectively. The dental treatment demands and needs of HIV-seropositive patients were not different from that of HIV-seronegative patients. The high frequency of HIV infection calls for institution of infection control measures in the dental clinics. However, such measures need to be tailored for the poor countries, with potentially high frequency of HIV infection and minimal resources, in order to make them relevant.

Adolescent↗
PubMed1999

Serum levels of measles IgG antibody activity in children under 5 years in Dar-es-Salaam, Tanzania.

Measles IgG antibody levels were estimated in sera from 685 Tanzanian children, 374 (54.6%) boys and 311 (45.4%) girls aged 18 months to 5 years, using an enzyme-linked immunosorbent assay (ELISA). The children were screened for HIV-1 and 2 antibodies using ELISA, and reactive sera were confirmed by Western blot. Nutritional status was assessed by anthropometry. Overall measles vaccination coverage was 98.8%. Measles antibody activity was not detected in 41 (6.0%) children, and ten (1.5%) had antibody levels below 200 mIU/ml, the cut-off level considered to be protective. The non-reactive samples were from one unvaccinated child, one child with unknown vaccination status and 39 vaccinated children. Measles IgG antibody levels were higher in girls (3452.1 mIU/ml) than in boys (2928.2 mIU/ml) (p = 0.02). Higher mean levels were found in children with a history of low birthweight (< 2.5 kg) (p = 0.03). There were no significant differences in measles antibody levels with regard to variations in nutritional status. No correlation (r2 = 0.002) was found between antibody levels and time elapsed since vaccination. In a multivariable logistic regression analysis, children who were HIV-seropositive (n = 9) were more likely to have non-protective antibody levels < 200 mIU/ml (OR = 5.85; 95% CI: 1.37-24.93).

Antibodies, Viral↗
PubMed1999

Determining causation in epidemiology.

Epidemiology uses many methods to identify the causes of disease, although it remains impossible to provide proof that any specific factor is a cause. We are only able to present supporting evidence. We subscribe to the pragmatic view that a factor is indeed a cause if its elimination improves health. We describe a deterministic causal model, where disease develops when the necessary component causes exist in one of several possible constellations of causes, each of which constitutes a sufficient set of component causes. If we accept this concept of disease causation, the notion of multifactorial disease becomes meaningless. We should rather turn our attention to component causes that we can eliminate in order to improve public health. The complex nature of diseases and the fact that it is only possible to present supporting evidence for a causal relationship are some of our reasons for basing the identification of causes on a theoretic model or framework. The purpose is to construct and present a model that is complex enough to formalize basic intuitions concerning cause and effect. Finally, conceptual frameworks provide guidance for the use of multivariable statistical techniques and may assist in the interpretation of the results.

Causality↗
PubMed1999

Immunoglobulin profile in HIV-1 infected children in Dar es Salaam.

OBJECTIVE: To determine immunoglobulin levels in HIV-1 seronegative and HIV-1 seropositive children at different clinical stages of HIV infection. DESIGN: Cross-sectional study. SETTING: Lugalo and Mwanayamala mother and child clinics in Dar es Salaam. SUBJECTS: Two hundred and ninety-nine children aged 18 months to five years. MAIN OUTCOME MEASURES: Estimation of immunoglobulin classes (IgG, IgA, IgM, IgD and IgE). RESULTS: Mean serum levels of all immunoglobulin classes were significantly higher (p < 0.0001) among the HIV-1 seropositive children (IgG = 22.9 g/l, IgA = 2.2 g/l, IgM 2.7 g/l, IgD 101.5 IU/ml and IgE 887.7 IU/ml) than among the HIV-1 seronegative children (IgG = 11.3 g/l, IgA = 1.0 g/l, IgM = 1.5 g/l, IgD = 27.8 UI/ml and IgE 341.3 UI/ml). The percentages of HIV-infected children with immunoglobulin concentrations above mean level were 83% for IgG, 77% for IgA, 78% for IgM, 73% for IgD and 78% for IgE. CONCLUSION: HIV seropositive children have higher levels of immunoglobulin than seronegative children. There was no correlation between the levels of immunoglobulin classes and CDC clinical staging.

Case-Control Studies↗