Biomedical subjects

M L Katila

Publications and source records attributed to M L Katila.

At least 19 recordsLinked to original sources

PubMed2000

Low virulence of Escherichia coli strains causing urinary tract infection in renal disease patients.

The distribution of urinary bacterial species was determined and the virulence factors of Escherichia coli urinary strains analysed by molecular and phenotyping methods in episodes of urinary tract infection in renal disease patients (n =68) in comparison with other immunocompromised patients (n =59) and non-immunocompromised patients (n =21). Escherichia coli was isolated in 116 (78%) of the 148 patients, being the species most frequently isolated in all groups (75% of renal disease patients, 76% of other immunocompromised patients, 95% of non-immunocompromised patients). All other pathogens showed a similar distribution in the renal disease and other immunocompromised patient groups. All virulence factors of Escherichia coli tested for (genes for G adhesins, expression of MR adhesins, production of haemolysin, presence of certain O and K antigens) were found more often in non-immunocompromised than in immunocompromised patients. The factors allowing the highest degree of discrimination between immunocompromised and non-immunocompromised patients were the prevalence of genes for G adhesins (35% vs. 65%) and expression of MR adhesins (32% vs. 55%). It is concluded that there is a lower prevalence of G adhesins and MR adhesins in Escherichia coli strains from immunocompromised patients than non-immunocompromised patients, suggesting that less virulent Escherichia coli strains may cause urinary tract infections more frequently in renal disease patients and other immunocompromised patients. Moreover, the spectrum of urinary pathogens other than Escherichia coli is similar in both immunocompromised patient groups investigated.

Adhesins, Escherichia coli↗

PubMed2000

Development of tuberculin reactivity and sensitization to M. scrofulaceum and M. fortuitum in children BCG-vaccinated at birth.

Since the incidence of tuberculosis is steadily declining in Finland and infections by environmental mycobacteria may be increasing, the aim of the present study was to evaluate the development of tuberculin reactivity and sensitization to environmental mycobacteria. Healthy Finnish schoolchildren aged 10.4-12.4 yrs (n=201) were tested with tuberculin purified protein derivative RT23, Mycobacterium scrofulaceum RS95 and M. fortuitum RS20 sensitins. The same children had been previously tested with the same antigens and methods at the age of 4-6 yrs in 1989. Rapid waning of tuberculin reactivity and decrease in sensitization to environmental mycobacteria were observed between 4-6 yrs. Both tuberculin and sensitin skin reaction sizes decreased significantly over the 6-yrs period. The mean tuberculin skin reaction size was 3.2 mm in diameter, which was significantly (p<0.001) smaller than the mean induration size (4.8 mm) at the age of 4-6 yrs. Similarly, the mean skin reaction sizes to M. scrofulaceum and M. fortuitum sensitins were 3.4 and 1.7 mm, respectively, which were significantly (p<0.001) smaller than 6 yrs earlier (mean 4.5 and 3.1 mm). The number of zero reactions to all antigens increased significantly during the follow-up period. Contacts with pets or farm animals were associated with larger reactions. In contrast, children suffering from allergic symptoms had smaller reactions. Contacts with mycobacteria, either with Mycobacterium tuberculosis or environmental mycobacteria, seem to be too rare to maintain tuberculin responsiveness and a high sensitivity to other mycobacteria. Different bacille Calmette-Guérin vaccine products and dosages used, the declining incidence of tuberculosis and geographical factors, which can influence environmental mycobacterial exposure, may explain the disparity between the present and previous Finnish studies.

BCG Vaccine↗

PubMed2000

Intrauterine inflammation at term: a histopathologic study.

This study was undertaken to examine the presence of inflammation of the uterine and gestational tissues as defined by histopathology in clinically noninfected women with term gestation and intact fetal membranes and to evaluate its correlation with measured clinical variables and neonatal and maternal clinical outcome. Two hundred sixteen clinically noninfected term parturients who underwent cesarean section with intact membranes were analyzed for the presence of inflammatory lesions of the gestational tissues and uterus. Nine hundred eighty-one histologic samples were studied, including 212 samples from both chorion membranes and umbilical cords, and 209 placental, 192 myometrial, and 156 decidual samples. In 208 (96%) cases, either amniotic fluid (AF) or endometrial swab samples were cultivated for bacteria. In 148 (69%) cases, the AF leukocyte count was analyzed by the Gram stain method, and in 77 (36%), AF leukocyte esterase activity (LEA) was evaluated. Leukocytic infiltrations were present in samples from 41 (19%) women, varying from 2% to 10% in the different anatomic sites examined. However, after onset of labor, low-grade decidual inflammation was observed in 29% of cases. Cervical dilation (odds ratio, 4.7; 95% confidence interval, 2.4 to 9.3; P < .00003) and meconium-stained AF at the operation (odds ratio, 5.3; 95% confidence interval, 2.2 to 12.5; P < .00015) were associated with the histologic inflammatory lesions observed in decidual samples, independently of AF or endometrial microbial detection, AF leukocytes, or LEA.

Amniotic Fluid↗

PubMed2000

Mycobacterium xenopi and related organisms isolated from stream waters in Finland and description of Mycobacterium botniense sp. nov.

Three scotochromogenic Mycobacterium xenopi-like organisms were isolated from stream waters in Finland. These strains grew at 36-50 degrees C but not at 30 degrees C. One of the three strains was fully compatible with the M. xenopi type strain according to GLC-MS, biochemical tests, and 16S rDNA and 16S-23S rDNA internal transcribed spacer (ITS) sequencing. Two of the strains closely resembled M. xenopi in lipid analyses and biochemical tests, but analysis by GLC-MS verified the presence of two new marker fatty acids (2,4,6,x-tetramethyl-eicosanoic acid and 2,4,6,x,x-pentamethyl-docosanoic acid). The 16S rDNA and ITS region sequences of these two strains differed from those of M. xenopi and other previously described mycobacterial sequences. Therefore, the strains are regarded as new species of slow-growing mycobacteria, for which the name Mycobacterium botniense sp. nov. is proposed. The chemical, physical and microbiological quality of the water reservoirs of M. xenopi and M. botniense are described. As far as is known, this is the first time that M. xenopi has been isolated from natural waters. The strains of M. botniense sp. nov. (E347T and E43) have been deposited in the ATCC as strains 700701T and 700702, respectively.

Base Sequence↗

PubMed2000

Accelerated detection and identification of mycobacteria with MGIT 960 and COBAS AMPLICOR systems.

An automated cultivation system for mycobacteria, the MGIT 960 system (MGIT system), was compared in the clinical routine with two variants of Löwenstein-Jensen (L-J) medium. A total of 152 isolates were recovered from 2,015 specimens: 139 (91%) with the MGIT system and 127 (84%) with L-J media (P = 0.05). These included 68 isolates of Mycobacterium tuberculosis, of which 88% grew in the MGIT system and 93% grew in L-J media (P = 0.389), and 84 isolates of mycobacteria other than M. tuberculosis (MOTT), of which 94% grew in the MGIT system and 76% grew in L-J media (P = 0.003). More M. avium complex isolates were detected in the MGIT system (n = 65) than in L-J media (n = 50) (P = 0.001). Growth in the MGIT system was detected in 2 weeks for 78% of the isolates, whereas growth was detected in the two L-J media for 17 and 25% of the isolates, respectively. The mean times to detection of M. tuberculosis were 12 days in the MGIT system and 20 days in L-J media, and for M. avium complex the mean times to detection were 8 and 22 to 25 days, respectively. The contamination rates were similar (8.7 to 8.9%) in all media. A commercial amplification system (COBAS AMPLICOR) was evaluated for its ability to rapidly identify M. tuberculosis, M. avium, and M. intracellulare directly from 393 samples in MGIT system broth. A correct PCR result, as evaluated by culture or clinical data, was obtained for 96% of the samples, with inhibition being detected for 2% of the samples. Of the 89 results positive for M. tuberculosis, 91% were regarded as true positive, 8% were regarded as inconclusive, and 2% were considered false positive. For results positive for M. avium and M. intracellulare, 97 and 79%, respectively, were regarded as true positive. Increased rapidity and enhanced isolation of MOTT were obtained with the MGIT system. COBAS AMPLICOR was suitable for rapid identification of these three common pathogens from MGIT system broth.

Automation↗

PubMed1999

Environmental factors affecting the occurrence of mycobacteria in brook sediments.

The occurrence of mycobacteria was studied in aerobic brook sediments from 39 drainage areas in Finland. The culturable counts of mycobacteria were related to climatic conditions, characteristics of the drainage area, chemical characteristics of the sediment and water, culturable counts of other heterotrophic bacteria, and microbial respiration rate in the sediment. The counts of mycobacteria varied from 1.1 x 10(2) to 1.5 x 10(4) cfu g-1 dry weight of sediment. They correlated positively with the proportion of the drainage area consisting of peatland, total content of C, content of Pb, microbial respiration rate in the sediment, and chemical oxygen demand of the water. The correlations of the mycobacterial counts with pH of sediment and alkalinity of water were negative. The results of the present sediment study and of the forest soil study published earlier strongly suggest that an increase in acidity increases the counts of mycobacteria and decreases the counts and activity of other heterotrophic bacteria. Mycobacterial counts were more than 100 times higher (per dry weight) in forest soils with pH 3.5-4.3 than in sediments with pH 4.5-6.3.

Climate↗

PubMed1999

Hospital water supply as a source of disseminated Mycobacterium fortuitum infection in a leukemia patient.

Nosocomial acquisition of Mycobacterium fortuitum led to a disseminated infection in a leukemia patient. A linkage to showerhead water was supported by molecular typing of clinical and environmental isolates. Contamination of the hospital water system with microbes that are relatively resistant to common sanitation processes poses an increased risk of infection to neutropenic patients.

Cross Infection↗

PubMed1999

Isolation of mycobacteria from indoor swimming pools in Finland.

The presence of mycobacteria in seven indoor pools in Finland was evaluated by multiple culture methods. Replicate samples, with and without inactivation of chlorine by sodium thiosulfate, were cultured in two laboratories. Laboratory I used two methods: (A) no decontamination and (B) cetylpyridinium chloride (0.005%, 20 min); and Laboratory II two methods: (C) cetylpyridinium chloride (0.005%, 18 h) and (D) oxalic acid (5%, 15 min). Samples processed by methods (A) and (B) were cultured on different egg media of pH 6.3 or 5.8; by method (C) on Middlebrook and Cohn 7H10 (+OADC) agar of pH 5.5; and by method (D) on Middlebrook and Cohn 7H10 agar (+OADC) with cycloheximide (500 microg/ml). Mycobacteria were recovered from five (71%) of seven pools. Detection of mycobacteria depended on the method used. High isolation rates (36-46% of the samples) were obtained by methods (A), (B) and (D). Contamination was a problem only with method (A). Inactivation of chlorine had a variable impact on mycobacterial detection. Isolates included M. kansasii, M. gordonae, M. fortuitum complex, M. sphagni, and M. vaccae, as well as M. simiae-like and M. chubuense-like organisms. In addition, a group of slowly growing and a group of rapidly growing isolates with previously unknown fatty acid and alcohol composition were isolated. No M. avium was detected. Mycobacterial counts were highest in a small pool with high temperature, low pH, and low content of free available chlorine.

Finland↗

PubMed1999

Mycobacterium malmoense-specific nested PCR based on a conserved sequence detected in random amplified polymorphic DNA fingerprints.

Mycobacterium malmoense is an opportunistic human pathogen of increasing clinical importance. Since it is difficult to detect and identify the organism by conventional techniques, it was decided to seek a nucleic acid amplification method specific for M. malmoense. The method was based on detection of a conserved band in random amplified polymorphic DNA (RAPD) fingerprints of 45 M. malmoense strains. This band was a 1,046-bp product which was proven to be M. malmoense specific in dot blot hybridization analysis with a panel of mycobacterial strains belonging to 39 other species. The fragment was sequenced, and oligonucleotide primers were synthesized to evaluate the specificity of the PCR. Two primer pairs were found to be specific and sensitive in the nested PCR that was developed. All 49 M. malmoense strains analyzed produced a PCR product of the expected size. In contrast, no strains belonging to the other mycobacterial species tested produced amplicons with these primers under specified reaction conditions. The results of the electrophoresis were confirmed by the hybridization with the M. malmoense-specific oligonucleotide probe. This method could be applied to the analysis of clinical or environmental samples, permitting the rapid detection of M. malmoense.

Base Sequence↗

PubMed1998

Clinical relevance of Ureaplasma urealyticum colonization in preterm infants.

A cohort of 78 infants of gestational age less than 34 weeks was examined for Ureaplasma urealyticum colonization and neonatal morbidity. Ureaplasma urealyticum was cultured from nasopharyngeal, endotracheal and blood-culture samples. A child was considered as being colonized if any sample was positive. The children with perinatal U. urealyticum colonization (n = 11; 14%) differed from those with no colonization (n = 67) in two important aspects: (i) they had higher leucocyte counts on the first (18.6 vs 12.4 10(9)) and the second (29.0 vs 15.4 10(9)) days of life (p = 0.01, both days); and (ii) they more often needed high-frequency oscillatory ventilation (45% vs 13%, p = 0.02). This study showed that U. urealyticum colonization is associated with signs of the host defence response together with symptoms of respiratory tract involvement suggesting the pathogenicity of U. urealyticum in premature infants.

Exudates and Transudates↗

PubMed1998

Separation among species of Mycobacterium terrae complex by lipid analyses: comparison with biochemical tests and 16S rRNA sequencing.

Fatty acids, alcohols, and mycolic acid cleavage products were determined for 13 ATCC strains and 24 clinical isolates, which were initially identified by biochemical and growth characteristics as the Mycobacterium terrae complex. The clinical isolates were also analyzed by partial sequencing of the 16S rRNA gene, which divided them into five genetic entities, M. triviale (three strains), M. terrae (four strains), M. nonchromogenicum sensu stricto (seven strains), Mycobacterium sp. strain MCRO 6 (seven strains), and Mycobacterium sp. strain 31958 (one strain). After acidic methanolysis, secondary alcohols were a characteristic feature in all members of the M. terrae complex but M. triviale. In addition to the prominent secondary alcohols, 2-octadecanol and 2-eicosanol, two previously unidentified alcohols, 2-(8,15-dimethyl)docosenol and 2-(8,17-dimethyl)tetracosenol, were detected in M. nonchromogenicum, Mycobacterium sp. strain MCRO 6, and Mycobacterium sp. strain 31958. Only 2-(8,17-dimethyl)tetracosenol was detected in trace amounts in M. terrae. Genetic differences were associated with differences in phenotypic characteristics, including growth at 42 degrees C and pyrazinamidase production. Based on fatty acid and alcohol composition and biochemical and genetic characteristics, M. non-chromogenicum and Mycobacterium sp. strains MCRO 6 and 31958 were found to be a closely related group, named the M. nonchromogenicum complex. Detected genetic variations associated with phenotypic characteristics may indicate further species separation of this complex. In conclusion, the results of gas-liquid chromatography fatty acid analysis, combined with those of a Tween 80 test, enable identification of the species of the M. terrae complex and their separation from other nonpigmented slowly growing mycobacteria.

Amidohydrolases↗

PubMed1997

Amniotic fluid U. urealyticum colonization: significance for maternal peripartal infections at term.

The aim of this study was to examine the relationship between maternal peripartal infectious morbidity and amniotic fluid colonization by U. urealyticum. Amniotic fluid specimens for bacterial and mycoplasmal cultures were obtained by aspiration at nonelective cesarean section from 98 pregnant women. Amniotic fluid cultures revealed micro-organisms in 70 (71%) parturients and U. urealyticum was the most frequently isolated species, detected in the specimens from 38 (39%) women. In the total study population, the prevalence of clinically defined infectious morbidity was 26%, including 8 (8%) patients with chorioamnionitis, 11 (11%) with endometritis, 5 (5%) with urinary tract infection, and 4 (4%) with wound infection. A significant association between the amniotic fluid U. urealyticum colonization and increased maternal peripartal infectious morbidity was observed (p < 0.0027; relative risk 4.1; 95% confidence limits 1.6 to 10.7). Amniotic fluids positive for U. urealyticum were significantly more often positive for other potentially pathogenic bacteria (p < 0.0024) and particularly for Bacteroides spp. (p < 0.0074). Our results support the existence of an association between amniotic fluid U. urealyticum invasion and maternal infectious morbidity. However, U. urealyticum was not usually isolated alone from amniotic fluids but combined with other pathogenic bacteria, the severity of infections were not enhanced when U. urealyticum was present and parturients with diagnosed infections managed well without specific antibiotic against U. urealyticum. Hence, it appears that the significance of U. urealyticum in maternal infections in this study population was mainly based on its interactions with other bacteria.

Adult↗

PubMed1997

Comparison of some decontamination methods and growth media for isolation of mycobacteria from northern brook waters.

Two decontamination methods and five media were compared for the isolation of mycobacteria from brook waters of different physical, chemical and bacteriological characteristics. The decontaminants used were: 0.7 mol l-1 NaOH followed by 50 g l-1 oxalic acid and 0.9 mol l-1 H2SO4 combined with 0.5 g l-1 cycloheximide. The media compared were: Mycobacteria 7H11 agar with OADC enrichment (pH 6.6), glycerol egg (pH 6.5 and 5.5), and pyruvate egg (pH 6.5 and 5.5). All media contained cycloheximide, 0.5 g l-1. The NaOH-oxalic acid method generally resulted in lower contamination and higher isolation of mycobacteria than the H2SO4-cycloheximide method. With the NaOH-oxalic acid method, all five media were equal in positivity rates but contamination was a problem on Mycobacteria 7H11 agar. Of the four egg media tested, the highest positivity rate (92% of the samples) was obtained on the pyruvate modification (pH 6.5), and the highest mean colony count of mycobacteria (900 cfu l-1) on the glycerol modification (pH 6.5). Characteristics of water and sampling site had similar effects on the isolation frequencies of mycobacteria obtained by different combinations.

Culture Media↗

PubMed1997

Histopathological and bacteriological findings in prurigo nodularis.

Prurigo nodularis is a chronic disease with unknown aetiology. Biopsy specimens of 43 patients with prurigo nodularis were taken for histopathological and mycobacteriological analyses. By conventional histopathology, 25 (58%) samples, and by immunostaining for S100 protein, 31 (72%) samples had changes relevant to prurigo nodularis. Twelve (28%) of the samples were positive for acid fast bacilli in tissue staining by Ziehl-Neelsen technique, including 4 of the 6 samples also positive for mycobacteria in cultivation. The results verified the usefulness of S100 staining in detection of neural hyperplasia in dermal nerves, a feature regarded as diagnostic for prurigo nodularis. They also indicated that atypical mycobacteria may be a contributing factor in prurigo nodularis.

Adult↗

PubMed1997

Amniotic fluid leukocytes and leukocyte esterase activity in parturients delivered by caesarean section.

Amniotic fluid specimens from parturients undergoing caesarean delivery were examined for leukocytes and leukocyte esterase activity, as well as for amniotic fluid bacteria and mycoplasmas by cultivation. The aim of this study was to evaluate the intrauterine environment in noninfected parturients and the associations between leukocyte test results, amniotic fluid microbial colonization and postcaesarean endometritis. Samples were obtained by direct aspiration at operation from 289 parturients with no clinical intrauterine infection. Among the total study population, leukocytes were found in 41% of the amniotic fluid samples by Gram staining and in 39% of the samples by the leukocyte esterase activity test. Leukocytes and leukocyte esterase activity were observed significantly more often in the amniotic fluids of parturients undergoing operation after onset of labour or ruptured membranes compared with those operated upon with intact membranes and no labour (p < 0.0001 and p < 0.0001). Of 255 amniotic fluid cultures, microbial colonization was observed in 82 (32%) parturients. Positive results in the leukocyte tests were associated significantly with amniotic fluid microbial colonization among parturients who underwent operation with intact membranes, or who underwent operation after rupture of the membranes and had cervical dilatation of < 5 cm at the operation (Gram stain: p < 0.0001; leukocyte esterase: p < 0.003). If cervical dilatation was > or = 5 cm, no such association was observed. In the population studied, endometritis developed in 2% and 4% of the parturients with positive test results. Thus, neither the presence of leukocytes nor detected leukocyte esterase activity were predictive of subsequent postoperative endometritis. In the detection of amniotic fluid microbial colonization, the tests functioned best in non-laboring parturients with intact membranes and in those operated on at the early stage of labour.

Adult↗

PubMed1997

Cesarean delivery. Microbial colonization in amniotic fluid.

OBJECTIVE: To determine the frequency, clinical significance and causative factors behind intraamniotic microbial colonization in uninfected parturients at the time of cesarean delivery. STUDY DESIGN: Amniotic fluid specimens for bacterial and mycoplasmal cultures were obtained by direct aspiration at cesarean section from 251 pregnant women (24-43 completed weeks) who had no clinical infection at the time of the operation. The symptoms of maternal infection were followed postoperatively for the first week of the puerperium. RESULTS: The prevalence of amniotic fluid microbial invasion was 29% (72/251). In patients not in labor and with intact membranes, it was 13% (20/158); in patients in labor and with intact membranes, 23% (5/22); and in those with ruptured membranes, 66% (47/71). The most common species isolated were Ureaplasma urealyticum, Lactobacillus species and coagulase-negative staphylococci. In the total 251 patients, clinically evident postoperative endometritis was observed in 6 (2%) and wound infection in 10 (4%). In patients operated on and with intact membranes, no risk factors were found as regards amniotic fluid microbial colonization. In patients operated on after rupture of the membranes, the only significant risk factor as regards amniotic fluid microbial invasion was use of an internal monitor before the operation (P < .0003) (relative risk 10.7, 95% confidence limit 2.9-39.4). The relative risk of postoperative endometritis was 2.3 (95% confidence limit 1.3-4.3) in patients with microbial invasion of the amniotic cavity as compared to patients without invasion. The corresponding risk value for post-operative wound infection was 1.4 (95% confidence limit 0.6-3.1). CONCLUSION: Though the incidence of microbial invasion of the amniotic fluid before surgery was unexpectedly high, its clinical significance as regards maternal puerperal morbidity appeared to be low. The use of internal monitoring during labor was the only significant risk factor as regards amniotic fluid microbial colonization in patients operated on after membrane rupture.

Amniotic Fluid↗

PubMed1996

Mycobacteria in prurigo nodularis: the cause or a consequence?

BACKGROUND: Prurigo nodularis (PN) is a chronic skin disorder; its cause remains unknown. OBJECTIVE: We evaluated mycobacteria as a possible cause of PN. METHODS: Forty-three patients with PN were examined. Skin biopsy specimens were obtained for microbiologic and histopathologic studies. The patients were tested for intracutaneous reactivity to 12 mycobacterial antigens with the Mantoux technique. RESULTS: Six specimens (14%) grew mycobacteria in culture: M. avium-intracellulare (3), M. malmoense (1), and Mycobacterium sp. (2). Histopathologically, 12 samples (28%) were positive for acid-fast bacilli, and granulomatous changes were present in one sample. Patients whose cultures were positive for mycobacteria had significantly larger skin reactions to mycobacterial antigens. Two patients underwent 2 years of antituberculous chemotherapy; one had an excellent response and the other a partial response. CONCLUSION: Detection of mycobacteria by culture or staining, combined with elevated skin reactivity to mycobacteria in a high proportion of patients with PN, suggests a mycobacterial cause.

Adult↗

PubMed1996

Slowly growing mycobacteria and chronic skin disorders.

We evaluated the role of mycobacteria in chronic skin manifestations. The etiologies of chronic skin disorders in 90 patients were analyzed by culture, histopathologic examination, and skin testing for mycobacteria. There were 20 clinical diagnoses; prurigo nodularis was the most common diagnosis (43 patients). Cultures were incubated at 32 degrees C and 36 degrees C for 6 months. Fourteen cultures (16%) yielded the following mycobacteria: Mycobacterium tuberculosis (5), Mycobacterium avium/Mycobacterium intracellulare complex (3), Mycobacterium malmoense (2), and other mycobacteria (4). Acid-fast bacilli were detected in 24 (28%) of the 86 histopathologic specimens examined, including nine of the 14 culture-positive specimens. Granulomatous infection was present in three specimens (3%); cultures of two of these specimens yielded M. tuberculosis, and culture of one was negative. Skin reactivity to 12 mycobacterial antigens was tested. The patients for whom staining and/or culture was positive for mycobacteria had significantly larger skin reactions to M. malmoense antigen (P < .001) than did the patients with bacteriologically negative skin disorders. There was no correlation between the species isolated and the skin reactivity to the species-specific antigen.

Adolescent↗