51
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Jensen TK, Boye M, Ahrens P, Korsager B, Teglbjaerg PS, Lindboe CF, Møller K. Diagnostic examination of human intestinal spirochetosis by fluorescent in situ hybridization for Brachyspira aalborgi, Brachyspira pilosicoli, and other species of the genus Brachyspira (Serpulina). J Clin Microbiol 2001; 39:4111-8. [PMID: 11682538 PMCID: PMC88495 DOI: 10.1128/jcm.39.11.4111-4118.2001] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Human intestinal spirochetosis, characterized by end-on attachment of densely packed spirochetes to the epithelial surface of the large intestines as a fringe has been associated with the weakly beta-hemolytic spirochetes Brachyspira aalborgi and Brachyspira (Serpulina) pilosicoli. In this study, fluorescent in situ hybridization with oligonucleotide probes targeting 16S or 23S rRNA of B. aalborgi, B. pilosicoli, and the genus Brachyspira was applied to 40 sections of formalin-fixed, paraffin-embedded intestinal biopsy specimens from 23 Danish and 15 Norwegian patients with histologic evidence of intestinal spirochetosis. Five biopsy specimens from patients without intestinal spirochetosis and three samples from pigs with experimental B. pilosicoli colitis were examined as well. In addition, the 16S ribosomal DNAs of two clinical isolates of B. aalborgi were sequenced, and a PCR procedure was developed for the identification of B. aalborgi in cultures. The genotypic characteristics of the two clinical isolates showed very high (99.5%) similarity with two existing isolates, the type strain of B. aalborgi and a Swedish isolate. Hybridization with the Brachyspira genus-specific probe revealed a brightly fluorescing fringe of spirochetes on the epithelia of 39 biopsy specimens, whereas 1 biopsy specimen was hybridization negative. The spirochetes in biopsy specimens from 13 Danish and 8 Norwegian patients (55.3%) were identified as B. aalborgi. The spirochetes in the biopsy specimens from the other 17 patients hybridized only with the Brachyspira probe, possibly demonstrating the involvement of as-yet-uncharacterized Brachyspira spirochetes in human intestinal spirochetosis.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Animals
- Biopsy
- Brachyspira/classification
- Brachyspira/genetics
- Brachyspira/isolation & purification
- Culture Media
- DNA, Bacterial/analysis
- DNA, Bacterial/genetics
- DNA, Ribosomal/analysis
- DNA, Ribosomal/genetics
- Female
- Genes, rRNA
- Humans
- In Situ Hybridization, Fluorescence
- Intestinal Diseases/diagnosis
- Intestinal Diseases/microbiology
- Intestines/microbiology
- Male
- Middle Aged
- Molecular Sequence Data
- Oligonucleotide Probes
- Polymerase Chain Reaction
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/genetics
- Sequence Analysis, DNA
- Spirochaetales Infections/diagnosis
- Spirochaetales Infections/microbiology
- Swine
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52
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Pichler M, Herrmann G, Schmidt H, Ahrens P, Zielen S. Persistent adenoviral infection and chronic obstructive bronchitis in children: is there a link? Pediatr Pulmonol 2001; 32:367-71. [PMID: 11596161 DOI: 10.1002/ppul.1145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Chronic obstructive bronchitis with inadequate response to inhaled steroid and bronchodilator therapy is a rather rare disorder in children. Persistence of an adenoviral infection has been described as a possible cause of unremitting airway obstruction. We studied a group of 11 children with the clinical feature of chronic bronchial obstruction. A high-resolution computed tomography (HR-CT) scan was performed and typically showed hyperinflation and ground-glass-like opacities. All children underwent either bronchoscopic transbronchial or open lung biopsy. Biopsy specimens were stained with monoclonal antibodies detecting adenoviral antigen and analyzed by light-microscopy. Bronchoalveolar lavage (BAL) fluid was cultured for adenovirus, and antigen detection tests were performed. While some children had a history of proven adenoviral infection at the onset of their disease, in none of the cases could a persistence of adenovirus be shown. We conclude that adenoviral infection might act as a starter of chronic obstructive bronchitis in children, but that pathogenetic mechanisms other than persistent infection must be responsible for the chronicity of the disease.
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53
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Boye M, Jensen TK, Ahrens P, Hagedorn-Olsen T, Friis NF. In situ hybridisation for identification and differentiation of Mycoplasma hyopneumoniae, Mycoplasma hyosynoviae and Mycoplasma hyorhinis in formalin-fixed porcine tissue sections. APMIS 2001; 109:656-64. [PMID: 11890568 DOI: 10.1034/j.1600-0463.2001.d01-129.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Oligonucleotide probes targeting 16S ribosomal RNA were designed for species-specific identification of the porcine mycoplasmas Mycoplasma hyopneumoniae, Mycoplasma hyorhinis and Mycoplasma hyosynoviae using a fluorescent in situ hybridisation assay. The specificity of the probes was evaluated using pure cultures as well as porcine tissue sections with artificial presence of mycoplasma, and the probes were found specific for the target organisms. The assay was applied on sections of 28 tissue samples from pigs infected with one or more of the three Mycoplasma species as determined by cultivation. M. hyopneumoniae and M. hyorhinis were identified in accordance with cultivation in lung sections from nine pigs affected by catarrhal to purulent bronchopneumonia. Likewise, in eight cases of fibrinous pericarditis, M. hyopneumoniae, M. hyorhinis and M. hyosynoviae were the infectious agents according to cultivation and were correctly identified by in situ hybridisation. Out of 11 joints cultivation positive for M. hyosynoviae, the probe was only able to identify M. hyosynoviae in eight cases probably due to a low number of microorganisms in the tissue sections. The in situ hybridisation assay is well suited for use in diagnostic and experimental work as well as a tool for pathogenesis studies.
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54
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Kusiluka LJ, Ojeniyi B, Friis NF, Kokotovic B, Ahrens P. Molecular analysis of field strains of Mycoplasma capricolum subspecies capripneumoniae and Mycoplasma mycoides subspecies mycoides, small colony type isolated from goats in Tanzania. Vet Microbiol 2001; 82:27-37. [PMID: 11423192 DOI: 10.1016/s0378-1135(01)00352-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A molecular analysis of strains of Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and Mycoplasma mycoides subsp. mycoides, small colony type (M. mycoides SC) isolated from goats was performed using the amplified fragment length polymorphism (AFLP) and pulsed-field gel electrophoresis (PFGE) fingerprinting techniques. Among the 11 field strains of M. capripneumoniae from Tanzanian goats, two AFLP patterns were demonstrated, with 10 of the strains showing indistinguishable patterns. Five Kenyan strains of M. capripneumoniae produced three AFLP patterns, with two of them being indistinguishable from the 10 identical Tanzanian and one Ugandan strain (M74/93) isolated from sheep. The AFLP pattern of the type strain (F38(T)) was identical to two Kenyan strains (Baringo and G183/82). On PFGE analysis, all the examined M. capripneumoniae strains exhibited identical PFGE profiles.Five field strains of M. mycoides SC isolated from goats displayed identical AFLP patterns except for one strain which differed from others at only one position. The AFLP pattern of the type strain of M. mycoides SC (PG1(T)) was different from the field strains. The five field strains of M. mycoides SC produced identical PFGE profiles, which were, however, different from the type strain. The AFLP and PFGE profiles of M. mycoides SC strains from goats were identical to those of six strains isolated from cattle affected with contagious bovine pleuropneumonia (CBPP) in the same areas. The results of this study suggest a close epidemiological linkage between strains of M. capripneumoniae and between M. mycoides SC type, respectively, isolated from goats in Tanzania.
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55
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Kielstein P, Wuthe H, Angen O, Mutters R, Ahrens P. Phenotypic and genetic characterization of NAD-dependent Pasteurellaceae from the respiratory tract of pigs and their possible pathogenetic importance. Vet Microbiol 2001; 81:243-55. [PMID: 11390108 DOI: 10.1016/s0378-1135(01)00351-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nicotinamide adenine dinucleotide (NAD)-dependent Pasteurellaceae other than Actinobacillus pleuropneumoniae and Haemophilus parasuis are frequently isolated from the respiratory tract of pigs. The taxonomic classification and relevance for pathogenicity of these bacteria deserves further attention. In the present study, 107 of these NAD-dependent isolates from the porcine respiratory tract, primarily from lungs with pathological changes, were investigated. On the basis of phenotypic criteria, such as haemolysis, urease, catalase, and indole formation as well as other fermentative activities, 50 of the isolates were assigned to Actinobacillus minor, 36 isolates to Actinobacillus porcinus and 21 isolates to Actinobacillus indolicus. However, many isolates among the three species showed fermentative activities differing from those of the respective type strain of the species. Serotyping on the basis of heat-stable polysaccharide antigens and 16 rDNA sequencing also revealed substantial heterogeneity within each of the three species although they clustered together in three distinct groups in the phylogenetic analysis. These three groups of NAD-dependent bacteria are different from, or in a borderline position, to the existing species or genera within the family Pasteurellaceae. A considerable number of isolates of these three groups were isolated in pure cultures from pneumonic lungs. Consequently, it will be necessary to critically review the opinion, that these NAD-dependent Pasteurellaceae are only "agents colonizing the mucosa". Further, taxonomic examinations of the strains within these three groups are indispensable to testing isolates for their virulence in gnotobiotic pigs.
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56
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Abstract
More attention has been given to vocal cord dysfunction (VCD) in the past years. Even though the disease is known since 1983 and was brought to mind at least casuistically through the years, often VCD was not diagnosed as such, being mistaken for bronchial asthma - at times with grave consequences for the patient. VCD causes the acute onset of stridulous respiration with acute dyspnea making the differential diagnosis of asthma quite suggestive. The inspirational stridor and a peracute progression of the disease should cause doubts as to the diagnosis of asthma. We collected case reports and describe the symptoms and diagnostic approaches to VCD as well as showing discriminating findings towards bronchial asthma. We report on five children suffering from VCD (4 girls, 1 boy) aged from 2 to 13 years. It could be shown that VCD is caused by a multifactoral pathomechanism, which has both somatic and psychological aspects. A surprising find was that all of the children were diagnosed with a pathological gastroesophageal reflux, partly in serious dimensions, without showing the typical symptoms such as retrosternal pain, stomach-ache or recurrent vomiting (so called silent reflux). Since there is a multitude of pathomechanisms involved and the disease often coincides with allergic asthma, an individual therapy plan is needed for each patient.
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57
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Geipel A, Berg C, Germer U, Ahrens P, Gloeckner-Hofmann K, Möller J, Gembruch U. Diagnostic and therapeutic problems in a case of prenatally detected fetal hydrocolpos. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2001; 18:169-172. [PMID: 11530001 DOI: 10.1046/j.1469-0705.2001.00410.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report on a female fetus with prenatally suspected hydrometrocolpos. Postnatal evaluation additionally revealed ambiguous genitalia, anorectal atresia, vertebral segmentation anomalies and congenital intestinal aganglionosis. Colostomy was performed, but postoperative recovery was complicated by pulmonary hypertension and renal failure, resulting in death at day 18. Postmortem examination furthermore revealed a small ventricular septal defect, as well as rectovaginal and urethrovaginal fistulae, causing massive dilatation of the septated vagina (hydrocolpos). The possibility of an overlapping VACTERL and MURCS association is discussed.
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58
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Fonnesbech Vogel B, Huss HH, Ojeniyi B, Ahrens P, Gram L. Elucidation of Listeria monocytogenes contamination routes in cold-smoked salmon processing plants detected by DNA-based typing methods. Appl Environ Microbiol 2001; 67:2586-95. [PMID: 11375167 PMCID: PMC92911 DOI: 10.1128/aem.67.6.2586-2595.2001] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2000] [Accepted: 03/12/2001] [Indexed: 11/20/2022] Open
Abstract
The contamination routes of Listeria monocytogenes in cold-smoked salmon processing plants were investigated by analyzing 3,585 samples from products (produced in 1995, 1996, 1998, and 1999) and processing environments (samples obtained in 1998 and 1999) of two Danish smokehouses. The level of product contamination in plant I varied from 31 to 85%, and no L. monocytogenes was found on raw fish (30 fish were sampled). In plant II, the levels of both raw fish and product contamination varied from 0 to 25% (16 of 185 raw fish samples and 59 of 1,000 product samples were positive for L. monocytogenes). A total of 429 strains of L. monocytogenes were subsequently compared by random amplified polymorphic DNA (RAPD) profiling, and 55 different RAPD types were found. The RAPD types detected on the products were identical to types found on the processing equipment and in the processing environment, suggesting that contamination of the final product (cold-smoked salmon) in both plants (but primarily in plant I) was due to contamination during processing rather than to contamination from raw fish. However, the possibility that raw fish was an important source of contamination of the processing equipment and environment could not be excluded. Contamination of the product occurred in specific areas (the brining and slicing areas). In plant I, the same RAPD type (RAPD type 12) was found over a 4-year period, indicating that an established in-house flora persisted and was not eliminated by routine hygienic procedures. In plant II, where the prevalence of L. monocytogenes was much lower, no RAPD type persisted over long periods of time, and several different L. monocytogenes RAPD types were isolated. This indicates that persistent strains may be avoided by rigorous cleaning and sanitation; however, due to the ubiquitous nature of the organism, sporadic contamination occurred. A subset of strains was also typed by using pulsed-field gel electrophoresis and amplified fragment length polymorphism profiling, and these methods confirmed the type division obtained by RAPD profiling.
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59
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Kusiluka LJ, Ojeniyi B, Friis NF, Kokotovic B, Ahrens P. Molecular Epidemiology of Contagious Bovine Pleuropneumonia in Tanzania Based on Amplified Fragment Length Polymorphism and Pulsed-field Gel Electrophoresis Analysis. ACTA ACUST UNITED AC 2001; 48:303-12. [PMID: 15129585 DOI: 10.1046/j.1439-0450.2001.00453.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The genetic diversity of 60 field strains of Mycoplasma mycoides ssp. mycoides, small colony type (M. mycoides SC), comprising 56 isolates from cattle in Tanzania, one from Kenya, two from Botswana and one from Portugal, as well as the type (PG1T) and vaccine (T1-SR49) strains, was investigated. The strains were analyzed for variations in the EcoRI and Csp6I restriction sites in the genomic DNA using the amplified fragment length polymorphism (AFLP) technique, and variations in the BamHI restriction sites using pulsed-field gel electrophoresis (PFGE). Six AFLP types were detected among the analysed strains. The AFLP profiles of the type and vaccine strains were indistinguishable from each other. Indistinguishable AFLP profiles were found for 55 Tanzanian field strains, one of them isolated in 1990 and the other 54 isolated in 1998/1999, although one strain isolated in 1999 showed a different profile. Strains from different countries revealed different AFLP profiles. Six PFGE types were detected among the analysed strains, with all the 56 Tanzanian field strains displaying indistinguishable PFGE profiles. Strains from different countries revealed different PFGE profiles, and so did the type and vaccine strains. The strong genomic homogeneity among M. mycoides SC strains associated with outbreaks of contagious bovine pleuropneumonia in different regions of Tanzania suggests that the outbreaks of the disease in the 1990-99 period might have been caused by a single epidemic clone. Moreover, this study has demonstrated that AFLP and PFGE are potential tools for molecular epidemiological studies of M. mycoides SC infections.
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60
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Jung M, Jung EM, Brokof A, Ahrens P, Rhodius U. [Physical therapy techniques with infants and school children with primary ciliary dyskinesia (Kartagener syndrome)]. KINDERKRANKENSCHWESTER : ORGAN DER SEKTION KINDERKRANKENPFLEGE 2001; 20:209-14. [PMID: 14584156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
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61
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Giese SB, Ahrens P. Detection of Mycobacterium avium subsp. paratuberculosis in milk from clinically affected cows by PCR and culture. Vet Microbiol 2000; 77:291-7. [PMID: 11118714 DOI: 10.1016/s0378-1135(00)00314-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Milk and faeces samples from cows with clinical symptoms of paratuberculosis were examined for the presence of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) by culture and PCR. M. paratuberculosis was cultivated in variable numbers from faeces or intestinal mucosa in eight of 11 animals. In milk from five cows (all faeces culture positive), we cultivated a few colonies of M. paratuberculosis (<100 CFU per ml). Milk samples from two cows were PCR positive (both animals were faeces culture positive, and one cow was milk culture positive). One cow was culture negative on intestinal mucosa, but culture positive in milk, and two cows were negative in culture and PCR from both faeces and milk. In conclusion, the presence of M. paratuberculosis could be detected in raw milk by PCR, but cultivation of milk was more sensitive.
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62
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Kusiluka LJ, Kokotovic B, Ojeniyi B, Friis NF, Ahrens P. Genetic variations among Mycoplasma bovis strains isolated from Danish cattle. FEMS Microbiol Lett 2000; 192:113-8. [PMID: 11040438 DOI: 10.1111/j.1574-6968.2000.tb09368.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The genetic heterogeneity of Mycoplasma bovis strains isolated in Denmark over a 17-year period was investigated. Forty-two field strains isolated from different geographic locations and specimens, including strains from 21 herds involved in two outbreaks of M. bovis-induced mastitis, and the type strain of M. bovis (PG45(T)) were assayed for variations in the BglII and MfeI restriction sites in the chromosomal DNA by using the amplified fragment length polymorphism (AFLP) fingerprinting technique. The obtained genomic fingerprints consisted of 62-68 AFLP fragments in the size range of 50-500 bp. Among the analyzed strains, 18 different AFLP profiles were detected. The similarity between individual fingerprints, calculated by Dice similarity coefficient, ranged from 0.9 to 1.0. Twenty-five strains, including 23 which were isolated during two outbreaks of M. bovis-induced mastitis which occurred 2 years apart, showed indistinguishable AFLP patterns. More genetic diversity was observed among the recent strains. The similarity of the genotypes of the field strains to that of the M. bovis type strain (PG45(T)) was 97.7%. The results of this study have demonstrated a remarkable genomic homogeneity of Danish strains of M. bovis that were probably epidemiologically related and which have remained stable for a considerable length of time. Furthermore, this study has demonstrated that AFLP can be used for genomic fingerprinting and discrimination of M. bovis strains.
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63
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Lorenzen N, Cupit PM, Einer-Jensen K, Lorenzen E, Ahrens P, Secombes CJ, Cunningham C. Immunoprophylaxis in fish by injection of mouse antibody genes. Nat Biotechnol 2000; 18:1177-80. [PMID: 11062437 PMCID: PMC7097139 DOI: 10.1038/81169] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2000] [Accepted: 08/11/2000] [Indexed: 01/07/2023]
Abstract
Antibodies are a crucial part of the body's specific defense against infectious diseases and have considerable potential as therapeutic and prophylactic agents in humans and animals. The development of recombinant single-chain antibodies allows a genetic application strategy for prevention of infectious diseases. To test this in a fish model, a gene construct encoding a neutralizing single-chain antibody to the fish-pathogenic rhabdovirus VHSV (viral hemorrhagic septicemia virus) was administered to rainbow trout by intramuscular injection of plasmid DNA. Circulating recombinant antibodies could later be detected in the fish, and protective immunity to the viral disease was established.
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64
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Tegtmeier C, Angen O, Ahrens P. Comparison of bacterial cultivation, PCR, in situ hybridization and immunohistochemistry as tools for diagnosis of Haemophilus somnus pneumonia in cattle. Vet Microbiol 2000; 76:385-94. [PMID: 11000534 DOI: 10.1016/s0378-1135(00)00259-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of the present study was to compare the potential of bacterial cultivation (BC), PCR, in situ hybridisation (ISH), and immunohistochemistry (IHC) in the diagnosis of Haemophilus somnus, when applied to pneumonic bovine tissue. Lungs from 65 field cases submitted for bacteriological examination were included in the study. The PCR-detection was performed on three different samples: plate-PCR (detection on plate washes after incubation of lung tissue on agar plates); swab-PCR (direct detection on a swab from the cut surface); and, whenever possible, a bronchus-PCR (direct detection on a swab from the main bronchus of the right cranial lung lobe). In order to examine the pathological significance of the findings, a histopathological examination of the cases was performed. H. somnus was detected by one or more techniques in 33 cases in total. By BC the bacterium was isolated from 10 cases, IHC and ISH were positive in 17 and 19 cases, and plate- and swab-PCR were positive in 21 and 29 cases, respectively. The bronchus-PCR was positive in 30 out of 61 cases examined. The PCR-technique was the most sensitive method, and as this technique is fast and relatively inexpensive, it should be considered as a supplementary tool in the diagnosis of H. somnus induced calf pneumonia.
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65
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Hoorfar J, Ahrens P, Rådström P. Automated 5' nuclease PCR assay for identification of Salmonella enterica. J Clin Microbiol 2000; 38:3429-35. [PMID: 10970396 PMCID: PMC87399 DOI: 10.1128/jcm.38.9.3429-3435.2000] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2000] [Accepted: 06/26/2000] [Indexed: 11/20/2022] Open
Abstract
A simple and ready-to-go test based on a 5' nuclease (TaqMan) PCR technique was developed for identification of presumptive Salmonella enterica isolates. The results were compared with those of conventional methods. The TaqMan assay was evaluated for its ability to accurately detect 210 S. enterica isolates, including 100 problematic "rough" isolates. An internal positive control was designed to use the same Salmonella primers for amplification of a spiked nonrelevant template (116 bp) in the sample tube. The PCR test correctly identified all the Salmonella strains by resulting in positive end-point fluorescence (FAM) signals for the samples and positive control (TET) signals (relative sensitivity [DeltaRn], >0. 6). The diagnostic specificity of the method was assessed using 120 non-Salmonella strains, which all resulted in negative FAM signals (DeltaRn, < or =0.5). All 100 rough Salmonella strains tested resulted in positive FAM and TET signals. In addition, it was found that the complete PCR mixture, predispensed in microwell plates, could be stored for up to 3 months at -20 degrees C. Thus, the diagnostic TaqMan assay developed can be a useful and simple alternative method for identification of Salmonella, particularly in large reference laboratories.
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66
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Gram T, Ahrens P, Andreasen M, Nielsen JP. An Actinobacillus pleuropneumoniae PCR typing system based on the apx and omlA genes--evaluation of isolates from lungs and tonsils of pigs. Vet Microbiol 2000; 75:43-57. [PMID: 10865151 DOI: 10.1016/s0378-1135(00)00206-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The genetic variability of a gene coding for an outer membrane lipoprotein (omlA) was used to develop a PCR typing system for Actinobacillus pleuropneumoniae. Sequence differences in the middle region of the gene divided the A. pleuropneumoniae serotypes in five distinct groups. Group I included serotypes 1, 9, 11 and 12 (omlA l), Group II consisted of serotypes 2 and 8 (omlA II), Group III included serotypes 3, 6 and 7 (omlA III), Group IV (omlA IV) consisted of serotype 4 and Group V of serotypes 5a, 5b and 10 (omlA V). The sequence differences were utilized to construct PCR primers specific for each group, except of Group IV, as the amplicon of serotype 4 could be separated from Group III by size. Together with a PCR apx typing system, the omlA PCR typing system could discriminate the majority of A. pleuropneumoniae serotypes of biovar 1 except of serotypes 1, 9 and 11 and serotypes 2 and 8. The PCR typing system was tested on 102 field strains of A. pleuropneumoniae isolated from lungs of diseased pigs. The serotyping results of the investigated field strains were in agreement with the apx and omlA gene patterns found in the reference strains of the bacteria, with the exception of the omlA gene of five strains of serotype 8. To examine the apx and omlA gene pattern of tonsil isolates, the PCR typing system was tested on a total of 280 A. pleuropneumoniae field strains isolated from tonsils of pigs. Agreement between serotyping and DNA typing was found in 96% of the isolates using the apx gene patterns and in 89% of the isolates using the omlA gene. The same serotype specific apx/omlA gene pattern was thus found in the majority of the tonsil isolates and in isolates from diseased lungs. Most of the differences in the omlA gene were found in 18 tonsil isolates of serotype 12. The omlA/apx PCR typing system described in the present study makes it possible to determine the type specificity of the majority of A. pleuropneumoniae isolates by simple PCR technique and enables phenotype independent characterization of isolates non-typable by serotyping.
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67
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Braden B, Posselt HG, Ahrens P, Kitz R, Dietrich CF, Caspary WF. New immunoassay in stool provides an accurate noninvasive diagnostic method for Helicobacter pylori screening in children. Pediatrics 2000; 106:115-7. [PMID: 10878159 DOI: 10.1542/peds.106.1.115] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The noninvasive (13)C-urea breath test (UBT) is a reliable diagnostic method for detection of Helicobacter pylori infection in children, and it avoids invasive gastrointestinal endoscopy. In this study, we compared a noninvasive, newly developed fecal H pylori antigen test with the UBT. METHODOLOGY One hundred sixty-two children (76 girls and 86 boys) were tested for H pylori infection using the UBT and a new antigen test in stool samples. The H pylori stool test is based on a sandwich enzyme immunoassay with antigen detection. RESULTS Twenty-four of the children (14.8%) with dyspepsia tested positive for H pylori according to the breath test results. In 22 of the 24 patients, H pylori antigen could be detected in the stool (sensitivity: 91.6%). Of 138 patients with negative UBT results, 136 were H pylori-negative in the stool test (specificity: 98.6%). CONCLUSIONS The new, noninvasive, low-cost H pylori antigen test in stool can replace the UBT for detection of H pylori infection in children with comparable reliability and accuracy.
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68
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Aarestrup FM, AgersŁ Y, Ahrens P, JŁrgensen JC, Madsen M, Jensen LB. Antimicrobial susceptibility and presence of resistance genes in staphylococci from poultry. Vet Microbiol 2000; 74:353-64. [PMID: 10831857 DOI: 10.1016/s0378-1135(00)00197-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The species distribution, susceptibility to 19 antimicrobial agents and presence of selected genes encoding resistance to macrolides, streptogramins and tetracyclines were examined among 118 staphylococcal isolates from infections of poultry in Denmark. Isolates were identified using a combination of conventional biochemical testing and 16S rDNA sequencing. The most common species were Staphylococcus aureus (83), Staphylococcus hyicus (11), Staphylococcus xylosus (9) and Staphylococcus cohnii (6). The isolates were susceptible to most antimicrobials tested. A high frequency of S. aureus (30%) was resistant to ciprofloxacin. Only six (7%) S. aureus isolates and one Staphylococcus saprophyticus were penicillin resistant. Resistance to sulphamethoxazole was observed among 16 (19%) of S. aureus isolates and two coagulase negative staphylococci (CNS). Twenty (24%) of the S. aureus isolates were resistant to erythromycin and 19 of these isolates contained the ermA gene, whereas the remaining isolate contained the ermC gene. Eleven (48%) of the novobiocin resistant CNS were resistant to erythromycin and all these isolates contained the ermA gene. Two isolates identified as S. xylosus, were found to be resistant to streptogramins and both contained the vatB- and the vgaB-genes. Thirty-nine (47%) of the S. aureus isolates, three of nine S. hyicus and eight of the 23 novobiocin resistant CNS were tetracycline resistant and all contained the tet(K) gene. A single S. aureus isolate also contained the tet(M) gene. The present study showed a frequent occurrence of resistance to fluoroquinolones, tetracycline and macrolides among staphylococci isolated from broilers in Denmark, whereas the occurrence of resistance to other antimicrobial agents remains low. Similar genes, encoding resistance to erythromycin, tetracycline and streptogramins to those previously observed, were detected.
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Jørgensen PH, Handberg KJ, Ahrens P, Manvell RJ, Frost KM, Alexander DJ. Similarity of avian paramyxovirus serotype 1 isolates of low virulence for chickens obtained from contaminated poultry vaccines and from poultry flocks. Vet Rec 2000; 146:665-8. [PMID: 10883855 DOI: 10.1136/vr.146.23.665] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
At present Denmark has the status of a 'non-vaccinating' country for Newcastle disease and its poultry population should therefore be free of antibodies to avian paramyxovirus 1 (APMV-1). Three live avian vaccines against infectious bronchitis, avian encephalomyelitis, and chick anaemia which had been found to be contaminated with APMV-1 viruses of low virulence for chickens were examined. The vaccines were produced by the same company and the affected batches had been used in Denmark in 1996/97. Furthermore, APMV-1 isolates of low virulence were obtained from three commercial broiler breeder flocks, one of which had been vaccinated with two of the contaminated vaccines. The flocks belonged to the same hatchery organisation. A comparison of viral F0 gene sequences and typing of virus isolates with a panel of monoclonal antibodies showed that the vaccine and field isolates were identical.
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Abstract
The concentration and distribution of immunoglobulin isotypes (IgG, IgM, sIgA) and IgG-subclass levels (IgG-1-4) were measured in bronchoalveolar lavage fluid (BALF) in 47 children with chronic chest disease (age range 1.0-9.9 years) and 18 healthy controls (age range 1.0-6.25 years). Of these patients, 19 had nonallergic asthma (Group A), 19 suffered from recurrent pneumonia or chronic bronchitis (Group B), and 9 patients had IgG-2 deficiency (Group C). In all individuals, IgG was the predominant immunoglobulin in the lower respiratory tract, followed by IgA and IgM. In patients of Group A and B, IgG, IgM and IgA levels in BALF were significantly elevated when compared to controls. Assessment of IgG-subclass concentrations in BALF revealed that IgG-1 levels were increased in Group A and B when compared to controls (P < 0.05). Since this difference could not be explained by difference in age, it is possibly due to the inflammatory process at the mucosal level. IgG-2 levels were elevated in all patients except those with IgG-2 deficiency. IgG-2 concentration in the IgG-2 deficent group was lower compared to controls (P < 0.005) and patients in Group A (P < 0.0005) and B (P < 0.005). IgG-3 levels were elevated in asthmatics in group A compared to healthy controls (P < 0.005). IgG-4 concentrations were the same in all study groups. Since IgG-subclasses in percentage of total IgG were similar in BALF and serum, our results do not indicate a local production of any of the IgG-subclasses in the respiratory tract.
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71
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Kokotovic B, Bölske G, Ahrens P, Johansson K. Genomic variations of Mycoplasma capricolum subsp. capripneumoniae detected by amplified fragment length polymorphism (AFLP) analysis. FEMS Microbiol Lett 2000; 184:63-8. [PMID: 10689167 DOI: 10.1111/j.1574-6968.2000.tb08991.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The genetic diversity of Mycoplasma capricolum subsp. capripneumoniae strains based on determination of amplified fragment length polymorphisms (AFLP) is described. AFLP fingerprints of 38 strains derived from different countries in Africa and the Middle East consisted of over 100 bands in the size range of 40-500 bp. The similarity between individual AFLP profiles, calculated by Jaccard's coefficient, ranged from 0.92 to 1.0. On the basis of the polymorphisms detected, the analysed strains can explicitly be grouped into two major clusters, equivalent to two evolutionary lines of the organism found by 16S rDNA analysis. The present data support previous observations regarding genetic homogeneity of M. capricolum subsp. capripneumoniae, and confirm the two evolutionary lines of descent found by analysis of 16S rRNA genes.
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72
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Møller K, Agerholm JS, Ahrens P, Jensen NE, Nielsen TK. Abscess disease, caseous lymphadenitis, and pulmonary adenomatosis in imported sheep. JOURNAL OF VETERINARY MEDICINE. B, INFECTIOUS DISEASES AND VETERINARY PUBLIC HEALTH 2000; 47:55-62. [PMID: 10780173 DOI: 10.1046/j.1439-0450.2000.00310.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The occurrence of abscess disease, caseous lymphadenitis, and pulmonary adenomatosis in sheep in Denmark is reported for the first time. Subcutaneous abscesses were observed in imported 4- to 5-month-old lambs of the Lacaune breed 10 days after arrival in Denmark. Abscesses were mostly located in the head, neck and shoulder regions close to the regional lymph nodes. Bacteriological examinations revealed growth of Staphylococcus aureus ssp. anaerobius in all animals with subcutaneously located abscesses containing a viscous white-yellow odourless mass. In addition, Corynebacterium pseudotuberculosis was isolated from abscesses in one animal and lesions consistent with pulmonary adenomatosis were found in four animals.
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MESH Headings
- Abscess/epidemiology
- Abscess/microbiology
- Abscess/pathology
- Abscess/veterinary
- Adenomatosis, Pulmonary/epidemiology
- Adenomatosis, Pulmonary/microbiology
- Adenomatosis, Pulmonary/pathology
- Adenomatosis, Pulmonary/veterinary
- Animals
- DNA Primers/chemistry
- DNA, Bacterial/chemistry
- DNA, Bacterial/isolation & purification
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/isolation & purification
- Denmark/epidemiology
- Disease Outbreaks/veterinary
- Lymph Nodes/microbiology
- Lymph Nodes/pathology
- Lymphadenitis/epidemiology
- Lymphadenitis/microbiology
- Lymphadenitis/pathology
- Lymphadenitis/veterinary
- Polymerase Chain Reaction/veterinary
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Sheep
- Sheep Diseases/epidemiology
- Sheep Diseases/microbiology
- Sheep Diseases/pathology
- Staphylococcal Infections/epidemiology
- Staphylococcal Infections/microbiology
- Staphylococcal Infections/pathology
- Staphylococcal Infections/veterinary
- Staphylococcus aureus/genetics
- Staphylococcus aureus/isolation & purification
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Gram T, Ahrens P, Angen O. Two Actinobacillus pleuropneumoniae serotype 8 reference strains in circulation. J Clin Microbiol 2000; 38:468. [PMID: 10681209 PMCID: PMC88757 DOI: 10.1128/jcm.38.1.468-468.2000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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74
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Ahrens P, Schultz C, Reiss I, Möller J, Gloeckner K, Gembruch U, Gortner L. Pleuraerguß und Gasansammlung in den Lebergefäßen. Monatsschr Kinderheilkd 1999. [DOI: 10.1007/s001120050507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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75
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Kokotovic B, Friis NF, Jensen JS, Ahrens P. Amplified-fragment length polymorphism fingerprinting of Mycoplasma species. J Clin Microbiol 1999; 37:3300-7. [PMID: 10488196 PMCID: PMC85551 DOI: 10.1128/jcm.37.10.3300-3307.1999] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amplified-fragment length polymorphism (AFLP) is a whole-genome fingerprinting method based on selective amplification of restriction fragments. The potential of the method for the characterization of mycoplasmas was investigated in a total of 50 strains of human and animal origin, including Mycoplasma genitalium (n = 11), Mycoplasma pneumoniae (n = 5), Mycoplasma hominis (n = 5), Mycoplasma hyopneumoniae (n = 9), Myco plasma flocculare (n = 5), Mycoplasma hyosynoviae (n = 10), and Mycoplasma dispar (n = 5). AFLP templates were prepared by the digestion of mycoplasmal DNA with BglII and MfeI restriction endonucleases and subsequent ligation of corresponding site-specific adapters. The amplification of AFLP templates with a single set of nonselective primers resulted in reproducible fingerprints of approximately 60 to 80 fragments in the size range of 50 to 500 bp. The method was able to discriminate the analyzed strains at species and intraspecies levels as well. Each of the tested Mycoplasma species developed a banding pattern entirely different from those obtained from other species under analysis. Subtle intraspecies genomic differences were detected among strains of all of the Mycoplasma species analyzed. The extent of polymorphism varied markedly between the analyzed mycoplasmas, comprising pattern similarity levels from 61.7% detected among M. dispar strains to 95.9% detected among M. genitalium strains. The results of the present study provide evidence of the high discriminatory power of AFLP analysis, suggesting the possible applicability of this method to the molecular characterization of mycoplasmas.
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