PubMed Health⌕ Search

Biomedical subjects

D van Soolingen

Publications and source records attributed to D van Soolingen.

At least 55 records · Page 3Linked to original sources

Usefulness of IS6110-restriction fragment length polymorphism typing of Brazilian strains of Mycobacterium tuberculosis and comparison with an international fingerprint database.

Strains of Mycobacterium tuberculosis isolated from 219 different tuberculosis patients, 115 from patients residing in Rio de Janeiro, 79 from Rio Grande do Sul and the remaining from other regions of the country, were analyzed by IS6110-restriction fragment length polymorphism fingerprinting. The IS6110-DNA patterns from these strains were highly polymorphic: 174 different patterns were observed and 25 patterns were shared by 70 isolates (32%). Most strains (93.4%) had multicopy patterns and only 17% of clustered strains had less than six IS6110 copies. Strain clustering was significantly higher for isolates from Rio Grande do Sul (36.7%) in comparison with strains from Rio de Janeiro (22.6%), but only when using high stringency during cluster analysis. Upon screening of an international database containing 3,970 fingerprints of M. tuberculosis strains, 15% of the patterns of Brazilian strains (21% of the strains) were identical to a fingerprint of an isolate from another country and one particular eight-band pattern forming the largest Brazilian cluster was detected in seven additional countries, suggesting that international transmission of tuberculosis from and to Brazil could be occurring frequently. Alternatively,preferential use of certain IS6110 integration sites could also be important in high-copy number strains, having important consequences for the use of databases for epidemiological studies on a large scale.

Bacterial Typing Techniques↗

Genetic heterogeneity in Mycobacterium tuberculosis isolates reflected in IS6110 restriction fragment length polymorphism patterns as low-intensity bands.

Mycobacterium tuberculosis isolates with identical IS6110 restriction fragment length polymorphism (RFLP) patterns are considered to originate from the same ancestral strain and thus to reflect ongoing transmission. In this study, we investigated 1,277 IS6110 RFLP patterns for the presence of multiple low-intensity bands (LIBs), which may indicate infections with multiple M. tuberculosis strains. We did not find any multiple LIBs, suggesting that multiple infections are rare in the Netherlands. However, we did observe a few LIBs in 94 patterns (7.4%) and examined the nature of this phenomenon. With single-colony cultures it was found that LIBs mostly represent mixed bacterial populations with slightly different RFLP patterns. Mixtures were expressed in RFLP patterns as LIBs when 10 to 30% of the DNA analyzed originated from a bacterial population with another RFLP pattern. Presumably, a part of the LIBs did not represent mixed bacterial populations, as in some clusters all strains exhibited LIBs in their RFLP patterns. The occurrence of LIBs was associated with increased age in patients. This may reflect either a gradual change of the bacterial population in the human body over time or IS6110-mediated genetic adaptation of M. tuberculosis to changes in the environmental conditions during the dormant state or reactivation thereafter.

Cluster Analysis↗

The first occurrence of a multi-drug resistant tuberculosis epidemic in the Czech Republic caused by genetically closely related Mycobacterium tuberculosis strains.

DNA fingerprinting based on the detection of the insertion sequence IS6110 in Pvull restriction fragments was applied to M. tuberculosis isolates originating in the first microepidemic of multidrug resistant tuberculosis recorded in the Czech Republic. Their disseminators were 21 individuals living in--or roaming between three distant areas. The age of 17 males ranged from 36 to 64 years (average 45 years) and of 4 females aged from 38 to 52 years. The index person was most probably a former male prisoner, aged 49 years, who disseminated multidrug resistant M. tuberculosis over a period of 28 months. In ten of the patients the following risk factors for tuberculosis were found: imprisonment, homelessness, immigration and previous stay in asylum--or in a psychiatric ward. In six cases, M. kansasii infection preceded tuberculosis. Four out of the 21 patients died. The RFLP analysis separated the patients into two distinct groups: group A comprising 14 members of which M. tuberculosis strains were isolated with six IS6110 copies, whereas the isolates of seven individuals of the group B, the RFLP profile displayed highly similar RFLP patterns compared to the isolates of group A, but with two additional IS6110 copies. In one patient, both A and B patterns were found: the first one in a M. tuberculosis strain isolated in 1993 and the second one in the isolate isolated two years later. Both the appearance of pattern B among the isolates of a part of patients and the switch from A to B pattern in one of patients can be plausibly explained by the unstability of DNA genotypes caused by transposition of IS6110 elements.

Adult↗

Distribution of IS900 restriction fragment length polymorphism types among animal Mycobacterium avium subsp. paratuberculosis isolates from Argentina and Europe.

Sixty-one Mycobacterium avium subsp. paratuberculosis isolates from cattle and deer from the Buenos Aires province, an important livestock region in Argentina, were typed by restriction fragment length polymorphisms (RFLP) analysis based on IS900. Four different RFLP patterns (designated 'A', 'B', 'C' and 'E') were identified in BstEII digests of genomic DNA. The most frequently observed type, pattern 'A', was found in 46 isolates (75%). The second, pattern 'E', included 8 isolates (13%), while the third, pattern 'B', included 6 isolates (10%). Pattern 'C' was found for only one isolate. All of the deer isolates were classified as pattern 'A', while cattle isolates represented all four RFLP patterns. Twenty-one isolates representing the four different BstEII-RFLP patterns were digested with PstI. Twenty isolates showed identical PstI-RFLP pattern. BstEII-RFLP patterns from Argentine cattle and deer were compared with patterns found in cattle, goat, deer, rabbit, and human isolates from Europe. The most common pattern in Argentina, pattern 'A', was identical to a less frequently occurring pattern R9 (C17) from Europe. The other Argentine patterns 'B', 'C' and 'E', were not found in the Europe. These results indicate that the distribution of M. avium subsp. paratuberculosis genotypes in the Buenos Aires province of Argentina is different from that found in Europe.

Animals↗

Pathological and immunological effects of respirable coal fly ash in male Wistar rats.

In this study the effects of inhalatory exposure to coal fly ash on lung pathology and the immune system in rats were examined. Rats were exposed to 0, 10, 30, or 100 mg/m(3) coal fly ash (6 h/day, 5 days/wk) for 4 wk, or to 0 and 100 mg/m(3) for 1 wk, and for 1 wk followed by a recovery in clean air of 3 wk. A concentration-related increase in lung weight was found starting from 30 mg/m(3) coal fly ash. After exposure to 100 mg/m(3), a time-related deposition of free particles in the lungs was observed as well as a time-related number of coal fly ash particles phagocytized in alveolar macrophages. Histological examination revealed increased cellularity in alveolar septa, consisting mainly of mononuclear cell infiltrate, proliferated type II cells, and a slight fibrotic reaction. After a recovery period of 3 wk the histological picture was identical to that after 1 wk of exposure, indicating no significant recovery. No toxicological significant changes were found in the hematological, clinical chemistry, or urine parameters. Effects both on nonspecific defense mechanisms and on specific immune responses were noted. With regard to the immune function in the draining lymph nodes of the lung, a significantly increased number of both T and B lymphocytes was observed. The ratio of both cell types was not changed in either of the groups. In serum of exposed rats a significant increase of up to 150% of the immunoglobulin A (IgA) content was found. The number and phagocytic capacity of macrophages were significantly increased, while the killing of Listeria bacteria per cell ex vivo/in vitro remained unchanged. Natural killer (NK) activity in pulmonary cell suspensions was slightly stimulated in rats exposed for 4 wk to 10 and 30 mg/m(3), whereas an exposure to 100 mg/m(3) resulted in a slight decrease; however, both changes were not significant. In conclusion, the alterations in lung histopathology and immunity, observed in a dose and exposure time relation at concentrations up to and including 100 mg/m(3) coal fly ash, may be considered an adverse response of the host to inhalation of particulate matter. Whether these observed alterations may effect the host resistance must be learned from infection studies.

Air Pollutants, Occupational↗

Molecular epidemiology of tuberculosis in the Netherlands: a nationwide study from 1993 through 1997.

To disclose risk factors for active tuberculosis transmission in the Netherlands, restriction fragment length polymorphism (RFLP) patterns of 78% of the Mycobacterium tuberculosis isolates, from the period 1993-1997, were analyzed. Of the respective 4266 cases, 46% were found in clusters of isolates with identical RFLPs, and 35% were attributed to active transmission. The clustering percentage increased strongly with the number of isolates; taking this into account, fewer cases were clustered than has been reported in other studies. Contact investigations in the five largest clusters of 23-47 patients suggested epidemiological linkage between cases. Of patients identified through contact tracing, 91% were clustered. Demographic risk factors for active transmission of tuberculosis included male sex, urban residence, Dutch and Surinamese nationality, and long-term residence in the Netherlands. Human immunodeficiency virus infection was not an independent risk factor for active transmission. Isoniazid-resistant strains were relatively less frequently clustered, suggesting that these generated fewer secondary cases.

Adult↗

Analysis of rate of change of IS6110 RFLP patterns of Mycobacterium tuberculosis based on serial patient isolates.

The rate of change of IS6110 restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis was determined in serial isolates from 544 patients. In 25 patients (4.6%), the RFLP patterns of the follow-up isolates differed from the initial isolates. Patients with different follow-up strains were less likely to cluster with patients whose strains had indistinguishable RFLP patterns. Changes in RFLP patterns were more common for persons with extrapulmonary disease and for those who had both pulmonary and extrapulmonary isolates. Based on serial isolates spanning for the most part <3 months, the half-life was extrapolated to be 3.2 years (95% confidence interval, 2.1-5.0). The main implication of this study is that the rate of change of IS6110-based RFLP of M. tuberculosis supports the use of IS6110 typing in epidemiologic studies of recent transmission of tuberculosis.

Adult↗

Usefulness of spoligotyping in molecular epidemiology of Mycobacterium bovis-related infections in South America.

Two hundred twenty-four Mycobacterium bovis isolates, mainly from South American countries, were typed by spoligotyping, and 41 different spoligotypes were identified. A total of 202 M. bovis isolates (90%) were grouped into 19 different clusters. The largest cluster contained 96 isolates (42.8%) on the basis of the most frequently observed spoligotype, spoligotype 34. Nineteen M. bovis isolates from humans in Argentina had spoligotypes and polymorphic GC-rich repetitive sequence (PGRS) types that represented the most common types found among isolates from cattle. All five isolates from Uruguay and three of the six isolates from Paraguay had spoligotypes that were also detected for isolates from Argentina. The spoligotypes of isolates from Brazil, Costa Rica, and Mexico and of some of the isolates from Paraguay could not be found in Argentina. A total of 154 M. bovis isolates were selected in order to compare the discriminative power of spoligotyping and restriction fragment length polymorphism (RFLP) analysis with direct repeat (DR) and PGRS probes. By spoligotyping, 31 different types were found, while AluI-digested DR probe-associated RFLP analysis identified 42 types, and RFLP analysis with the PGRS probe also detected 42 types; these were partly independent of the DR types. By combining the results obtained by spoligotyping and by RFLP analysis with the DR and PGRS probes, 88 different types were obtained. Although the differentiation of M. bovis by spoligotyping was less discriminatory than differentiation by RFLP analysis with the DR and PGRS probes, spoligotyping is easier to perform and its results are easier to interpret. Therefore, for the purpose of typing of M. bovis isolates, spoligotyping could be performed first and the isolates could be grouped into clusters and then analyzed by RFLP analysis with the DR and PGRS probes.

Animals↗

The IS6110 restriction fragment length polymorphism in particular multidrug-resistant Mycobacterium tuberculosis strains may evolve too fast for reliable use in outbreak investigation.

To study possible nosocomial transmission of multidrug-resistant (MDR) Mycobacterium tuberculosis, strain types and other information on 24, mostly human immunodeficiency virus-positive patients, were collected. Isolates from 11 patients had identical IS6110 restriction fragment length polymorphism (RFLP) patterns as well as spoligotype patterns and resistance profiles. Noticeably, nine other isolates from related cases also exhibited identical spoligotypes but slightly different RFLP patterns. These results indicate that for some MDR strains, the evolutionary clock of IS6110 RFLP may run too fast for reliable interpretation of strain typing results over a period of a few years.

AIDS-Related Opportunistic Infections↗

Prevalence of Mycobacterium avium in slaughter pigs in The Netherlands and comparison of IS1245 restriction fragment length polymorphism patterns of porcine and human isolates.

A significant increase in the incidence of caseous lesions in the lymph nodes of slaughter pigs prompted a large-scale investigation in five slaughterhouses in The Netherlands. In total, 158,763 pigs from 2,899 groups underwent gross examination. At least one pig with caseous lesions in the submaxillary and/or mesenteric lymph nodes was observed in each of 154 of the 2,899 groups examined (5%). In total, 856 pigs (0.5%) were affected. As many as five pigs in each of 141 of the 154 positive groups (91.5%) had lymph node lesions. Greater numbers of pigs with affected lymph nodes were found in 13 groups (8.5%). Four pigs had lesions in the kidneys, liver, or spleen. Acid-fast bacteria were detected by microscopic examination of 121 of 292 Ziehl-Neelsen-stained smears of caseous lesions (41%). In a follow-up study, Mycobacterium avium complex (MAC) bacteria were isolated from 219 of 402 affected lymph nodes (54.2%). Ninety-one of the isolated strains were analyzed by restriction fragment length polymorphism (RFLP) typing with insertion sequence IS1245 as a probe. All but 1 of these 91 strains contained IS1245 DNA, indicating that pigs in The Netherlands carried almost exclusively M. avium bacteria and no other bacteria of MAC. Only one pig isolate exhibited the bird-type RFLP pattern. MAC isolates from 191 human patients in The Netherlands in 1996 were also typed by RFLP analysis. Computer-assisted analysis showed that the RFLP patterns of 61% of the human isolates and 59% of the porcine isolates were at least 75% similar to the RFLP patterns of the other group of strains. This indicates that pigs may be an important vehicle for M. avium infections in humans or that pigs and humans share common sources of infection.

Animals↗

Comparison of methods based on different molecular epidemiological markers for typing of Mycobacterium tuberculosis complex strains: interlaboratory study of discriminatory power and reproducibility.

In this study, the currently known typing methods for Mycobacterium tuberculosis isolates were evaluated with regard to reproducibility, discrimination, and specificity. Therefore, 90 M. tuberculosis complex strains, originating from 38 countries, were tested in five restriction fragment length polymorphism (RFLP) typing methods and in seven PCR-based assays. In all methods, one or more repetitive DNA elements were targeted. The strain typing and the DNA fingerprint analysis were performed in the laboratory most experienced in the respective method. To examine intralaboratory reproducibility, blinded duplicate samples were included. The specificities of the various methods were tested by inclusion of 10 non-M. tuberculosis complex strains. All five RFLP typing methods were highly reproducible. The reliability of the PCR-based methods was highest for the mixed-linker PCR, followed by variable numbers of tandem repeat (VNTR) typing and spoligotyping. In contrast, the double repetitive element PCR (DRE-PCR), IS6110 inverse PCR, IS6110 ampliprinting, and arbitrarily primed PCR (APPCR) typing were found to be poorly reproducible. The 90 strains were best discriminated by IS6110 RFLP typing, yielding 84 different banding patterns, followed by mixed-linker PCR (81 patterns), APPCR (71 patterns), RFLP using the polymorphic GC-rich sequence as a probe (70 patterns), DRE-PCR (63 patterns), spoligotyping (61 patterns), and VNTR typing (56 patterns). We conclude that for epidemiological investigations, strain differentiation by IS6110 RFLP or mixed-linker PCR are the methods of choice. A strong association was found between the results of different genetic markers, indicating a clonal population structure of M. tuberculosis strains. Several separate genotype families within the M. tuberculosis complex could be recognized on the basis of the genetic markers used.

Bacterial Typing Techniques↗

A multidrug-resistant tuberculosis microepidemic caused by genetically closely related Mycobacterium tuberculosis strains.

IS6110 DNA fingerprinting was used to characterize an outbreak of multidrug-resistant tuberculosis in 21 individuals (17 males and 4 females) living in or roaming among four distantly separated areas in the Czech Republic. The restriction fragment length polymorphism (RFLP) analysis separated the collected Mycobacterium tuberculosis strains into group A, including 14 patients with six IS6110 copies, and group B, with 7 patients displaying highly similar RFLP patterns but with two additional IS6110 bands. A switch from pattern A to pattern B was observed in one patient, and the subsequent detection of subclone B in seven more individuals has been explained by the instability of DNA genotypes caused by transposition of IS6110 elements.

Czech Republic↗

Transmission of tuberculosis between people of different ages in The Netherlands: an analysis using DNA fingerprinting.

SETTING: In the period 1950 to 1980 the risk of tuberculous infection in the Netherlands declined more steeply than tuberculosis incidence. This study aimed at determining whether this might be explained by preferential transmission within age groups. METHODS: Using restriction fragment length polymorphism (RFLP) typing on all Mycobacterium tuberculosis isolates in the Netherlands from 1993 to 1996, clusters with identical fingerprints were identified. The correlation between the ages of people in clusters of two Dutch patients was determined. RESULTS: The mean difference in age between the two people, in 81 clusters of two, was 13.9 years, while the mean age difference between all possible pairs of individuals in this data set was 25.5 years. Fisher's intraclass correlation coefficient was 0.62 (95% confidence interval [CI] 0.46-0.74). CONCLUSION: It is concluded that sources of tuberculosis may preferentially transmit infection to people close to their own age. As the average age of cases has increased in the period 1950-1980, sources may have become less likely to infect children in whom the risk of infection has been measured. The annual risk of infection measured in children and young adults in countries with low levels of tuberculosis may not apply to older members of the population.

Adolescent↗

Estimation of serial interval and incubation period of tuberculosis using DNA fingerprinting.

OBJECTIVE: To determine the frequency distributions of serial interval and incubation period of tuberculosis within 4 years of transmission, and to identify correlates of serial intervals and incubation periods. METHODS: DNA fingerprints were obtained for all isolates from all culture-positive patients notified in The Netherlands from 1993 to 1996. Patient information was obtained from the National Tuberculosis Register. Results from contact investigations were provided by public health services. Source cases and secondary cases of tuberculosis were identified, based on 1) identical DNA fingerprints, and 2) epidemiological confirmation of contact. Under-representation of long intervals were corrected for by weighting cases. RESULTS: A total of 69 source-secondary case couples were identified. The geometric mean serial interval was 29.5 weeks (95% confidence interval [CI] 22.8-38.2 weeks) and the geometric mean incubation period 20.8 weeks (95% CI 15.5-27.8 weeks). Serial intervals and incubation periods tended to increase with age (P > 0.05). Three secondary cases with human immunodeficiency virus infection showed very short incubation periods (P > 0.05). CONCLUSION: Using a new methodology, the distribution of incubation periods of tuberculosis gave results consistent with earlier studies.

Adolescent↗

[A micro-epidemic of tuberculosis in the South Moravia Region].

In the South Moravian region which is the area with the lowest prevalence of bacillary tuberculosis in the Czech Republic (6.6 per 100,000 population in 1996) in 1993-1996 a total of six local and family microepidemics of tuberculosis were detected. For their identification the RFLP fingerprinting method was used based on evidence of repeated sequence of IS6110 in the chromosomal DNA of the examined strains of Mycobacterium tuberculosis predigested with restrictive enzyme PvuII. The profiles of fingerprints of each microepidemic were included by means of a computer programme into the hierarchy of the fingerprint dendrogram of 184 strains of M. tuberculosis which made it possible to identify possible identical profiles of strains from patients from remote places in the Czech Republic. In three family microepidemics involving always two members no identical fingerprint profiles of other Czech strains of M. tuberculosis were revealed. To the fourth cluster formed by six members of one family an identical RFLP profile of a female patient living in a nearby locality was added. In another microepidemic recorded in three brothers identical fingerprints were found another four patients from the South Moravian region and in one from the Central Bohemian region. The last cluster of two brothers was surprisingly enlarged by six identical RFLP profiles of patients from the West Bohemian region and one from Prague. These findings suggest that in areas with a low prevalence tuberculosis persists more frequently than in areas with a high prevalence as familial or local microepidemics.

Adolescent↗

[Connection between 2 tuberculosis outbreaks demonstrated after 8 years by DNA-fingerprinting of the causative mycobacteria].

OBJECTIVE: To determine the possible connection between two outbreaks of tuberculosis at an 8-year interval by DNA fingerprinting of the causative mycobacteria. DESIGN: Descriptive. SETTING: Regional Public Health Services Zeeland and Noord-Holland, the Netherlands. METHOD: The source patients of the tuberculosis explosions in an island in the province of Zeeland (28 persons infected) and an island of the Noord-Holland area (36 persons infected) were identified in 1986 and 1994 respectively. In 1994. spoligotyping was performed on dead bacteria from the suspected source from 1986. to analyse the chain of transmission. RESULTS: Identical spoligotyping patterns of the source patients proved the transmission of a Mycobacterium tuberculosis strain from a father to his son around 1986. Lack of a positive Mantoux test in the son prohibited prevention of the 1994 explosion. CONCLUSION: Thanks to the applicability of spoligotyping on non-vital mycobacteria this DNA method contributed retrospectively to demonstration of a connection between two out-breaks of tuberculosis at an 8-year interval.

Adolescent↗