Silja Mentula - Academia.edu (original) (raw)

Papers by Silja Mentula

Research paper thumbnail of Clostridium difficile -diagnostiikka Suomessa

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Research paper thumbnail of Prospective Evaluation of the mariPOC Test for Detection of Clostridioides difficile Glutamate Dehydrogenase and Toxins A/B

WOS, 2020

The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (Ar... more The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (ArcDia Ltd., Finland), for the detection of Clostridioides difficile glutamate dehydrogenase (GDH) and toxins A and B directly from fecal specimens. The mariPOC test was compared with both the GenomEra C. difficile PCR assay (Abacus Diagnostica Oy, Finland) and the TechLab C. diff Quik Chek Complete (Alere Inc.; now Abbot) membrane enzyme immunoassay (MEIA). Culture and the Xpert C. difficile assay (Cepheid Inc.

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Research paper thumbnail of Surveillance of Clostridium difficile infections in Finnish acute care hospitals, 2008-2014: trends, diagnostics and control measures

Antimicrobial Resistance and Infection Control, Jun 16, 2015

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Research paper thumbnail of Community- vs. healthcare-associated Clostridium difficile infections, Finland, 2008-2013: incidence, case fatality and genotypes

Antimicrobial Resistance and Infection Control, Jun 16, 2015

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Research paper thumbnail of Legionnaires' Disease Associated with Death after Near Drowning in Lake Water

Direct aspiration of water during submersion has caused Legionnaires’ disease (LD) cases. This ch... more Direct aspiration of water during submersion has caused Legionnaires’ disease (LD) cases. This chapter presents one such case caused by Legionella pneumophila with a novel source of infection. Appropriate antimicrobial therapy was given once LD was identified, in addition to the antibiotics targeted against other pathogens. The patient suffered from bilateral lung infiltrates, pleural effusion, and cavitation of lung parenchyma, all symptoms of LD. The patient had LD and Pseudomonas aeruginosa and fungal infections. The pulmonary damage led to multiorgan failure, and the secondary or co-infections contributed to his death. LD cases have also occurred in neonates after water births. Immersion in river water has resulted in at least two reported LD cases caused by L. pneumophila sg 10 and sg 13.

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Research paper thumbnail of Clostridium difficile infections in Finland, 2008–2015: trends, diagnostics and ribotypes

European Journal of Clinical Microbiology & Infectious Diseases, May 30, 2017

We evaluated Clostridium difficile (CD) diagnostics in Finnish clinical microbiology laboratories... more We evaluated Clostridium difficile (CD) diagnostics in Finnish clinical microbiology laboratories during 2006–2011, with an update in 2015, in relation to CD surveillance data of the National Infectious Disease Register (NIDR) and ribotyping data from the national reference laboratory during the years 2008–2015. In 2011, diagnostic activity varied regionally more than three-fold and the positivity rate ranged between 7 and 21%. Nucleic acid amplification testing (NAAT) was implemented in the regions with high activity and NAAT users tested 30% more patients and found 15% more cases per population than those not using it. Culture was performed in 79% of laboratories, primary toxin testing by enzyme immunoassay (EIA) in 83% and by NAAT in 17%. In 2014, 12/19 laboratories used NAAT as the primary detection method and four as the secondary method, and ten cultured. Increasing usage of NAAT was not systematically related to various trends detected regionally in annual CD rates. Polymerase chain reaction (PCR) ribotyping of 1771 CD isolates (4.1% of CD cases) identified 146 distinct profiles, of which 37% were binary toxin positive. The most common ribotype was 027, but its proportion decreased, while 078 slightly increased. Transition from culture to NAAT in CD infection (CDI) diagnostics did not cause a significant increase in the observed CDI incidence. Major differences between diagnostic activity, methods and strategies in different regions have persisted over the years, which should be considered when comparing the regional epidemiology of CDI.

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Research paper thumbnail of Differentiating virulent 027 and non-027<i>Clostridium difficile</i>strains by molecular methods

Expert Review of Molecular Diagnostics, Aug 4, 2015

Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype ... more Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype 027 and also other ribotypes. We present data on additional non-027 strains, identified as presumptive 027 by two commercial molecular C. difficile assays. The tested clinical isolates were selected from the national reference laboratory collection on the basis of toxin gene profile similarities with ribotype 027 and tested with XpertC. difficile/Epi and Amplidiag C. difficile+027 assay. Xpert misclassified five ribotypes (016, 019, 080, 176 and variant of type 046) as presumptive 027 and Amplidiag two ribotypes (016, 176). The misclassified strains were rare, covering 1.6% of reference laboratory strain collection. Our findings confirm the concept that there are closely related outliers to hypervirulent 027 clones that can be misclassified as 027, and that these comprise numerous ribotypes, including previously reported four ribotypes (198, 176, 244, 019), and additional three (016, v046, 080) identified in the present study.

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Research paper thumbnail of Hot Water Systems with Low Concentrations of Legionellae May Be a Risk on Cruise Ships

Water systems contaminated with legionellae cause outbreaks and sporadic cases of Legionella pneu... more Water systems contaminated with legionellae cause outbreaks and sporadic cases of Legionella pneumonia. Legionellae are ubiquitous in water systems. In most clinical cases the source of infection can be confirmed only by using typing methods that discriminate between the patient and the environmental isolates. Water samples were analyzed using Legionella isolation standard method ISO 11731, completed by additional concentration with centrifugation (6,000 X g, 10 min). The legionella concentrations varied from 5 to 2,000 CFU/liter; the highest concentration was found in the tap water sample. The strains were L. pneumophila serogroup 1. The thermophilic heterotrophic bacteria concentration was highest (3.0 X 106 CFU/liter) in the tap water sample that contained the highest legionella counts. The mesophilic bacteria content was the highest in the legionella positive shower sample (5.9 X 107 CFU/liter). The L. pneumonia case of the 61-year-old man was detected only by the urinary antigen method. Therefore, conclusive evidence of the source of this particular infection could not be confirmed. Since the incubation time for legionella infection can vary from 2 to 10 days, it is possible that the infection was contracted elsewhere, such as the patient's home.

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Research paper thumbnail of Diagnostic trends in Clostridium difficile detection in Finnish microbiology laboratories

Anaerobe, Dec 1, 2009

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Research paper thumbnail of Transmission of Drug-Resistant Mycobacterium Tuberculosis Isolates between Finnish- and Foreign-Born Cases, 2014-2021: A Molecular Epidemiological Study

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Research paper thumbnail of Orally Administered Targeted Recombinant Beta-Lactamase Prevents Ampicillin-Induced Selective Pressure on the Gut Microbiota: a Novel Approach to Reducing Antimicrobial Resistance

Antimicrobial Agents and Chemotherapy, 2004

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Research paper thumbnail of First isolation of Clostridium difficile PCR ribotype 027 in Finland

Weekly releases (1997–2007), Nov 8, 2007

On 18 October 2007, the first case of Clostridium difficile PCR ribotype 027-associated disease w... more On 18 October 2007, the first case of Clostridium difficile PCR ribotype 027-associated disease was detected in Finland.

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Research paper thumbnail of Differentiating virulent 027 and non-027 Clostridium difficile strains by molecular methods

WOS, Sep 18, 2015

Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype ... more Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype 027 and also other ribotypes. We present data on additional non-027 strains, identified as presumptive 027 by two commercial molecular C. difficile assays. The tested clinical isolates were selected from the national reference laboratory collection on the basis of toxin gene profile similarities with ribotype 027 and tested with XpertC. difficile/Epi and Amplidiag C. difficile+027 assay. Xpert misclassified five ribotypes (016, 019, 080, 176 and variant of type 046) as presumptive 027 and Amplidiag two ribotypes (016, 176). The misclassified strains were rare, covering 1.6% of reference laboratory strain collection. Our findings confirm the concept that there are closely related outliers to hypervirulent 027 clones that can be misclassified as 027, and that these comprise numerous ribotypes, including previously reported four ribotypes (198, 176, 244, 019), and additional three (016, v046, 080) identified in the present study.

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Research paper thumbnail of P1A Recombinant β-Lactamase Prevents Emergence of Antimicrobial Resistance in Gut Microflora of Healthy Subjects during Intravenous Administration of Ampicillin

Antimicrobial Agents and Chemotherapy, Jun 1, 2009

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Research paper thumbnail of Transmission of drug-resistant Mycobacterium tuberculosis isolates between Finnish- and foreign-born patients, 2014-2021: a molecular epidemiological study

Research Square (Research Square), May 23, 2023

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Research paper thumbnail of External quality assessment by European mycobacterial laboratories: results of AFB microscopy and identification rounds

Diagnostic Microbiology and Infectious Disease, Oct 1, 2022

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Research paper thumbnail of Community- and Healthcare- Associated Clostridium difficile Infections, Finland, 2008-2013

WOS, Oct 20, 2016

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Research paper thumbnail of Clostridium difficile isolates from piglets and humans in rural region in Finland

Veterinary Microbiology, 2015

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Research paper thumbnail of Interactions between diet, intestinal microflora and mucosal morphology in patients with ileal pouch-anal anastomosis

Gastroenterology, Apr 1, 2001

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Research paper thumbnail of Regional differences inClostridium difficileinfections in relation to fluoroquinolone and proton pump inhibitor use, Finland, 2008–2011

Infectious diseases, Apr 2, 2015

Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk facto... more Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk factors for Clostridium difficile infections (CDIs). Nationwide laboratory-based surveillance of CDIs in Finland since 2008 has shown variation in regional CDI rates. We evaluated whether regional differences in CDI rates were associated with antibacterial and PPI use. Data on mean annual incidence rates of CDIs during 2008-2011 in 21 healthcare districts (HDs) were obtained from the National Infectious Disease Register, consumption (median annual use) of antimicrobials and PPIs from the Finnish Medical Agency, availability of molecular diagnostics by a laboratory survey and data on ribotypes from the national reference laboratory. The association over the 4 years was measured by incidence rate ratio (IRR) and we performed both bivariate and multivariate analyses. During 2008-2011, PPI use increased 27% but fluoroquinolone use was stable. The level of fluoroquinolone use was strongly associated with the mean annual CDI incidence rate in different HDs over the 4-year period, but PPI use had less effect. The molecular diagnostics methodology and PCR ribotype 027 were not independently associated with CDI rate. The final multivariable model only included fluoroquinolone and PPI use; IRR for fluoroquinolones was 2.20 (95% confidence interval (CI), 1.32-3.67; p = 0.003). Fluoroquinolone use may play a role in regional differences in CDI rates. Although the use has not recently increased, regionally targeted antimicrobial stewardship campaigns promoting appropriate use of fluoroquinolones should still be encouraged since they may decrease the incidence of CDIs.

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Research paper thumbnail of Clostridium difficile -diagnostiikka Suomessa

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Prospective Evaluation of the mariPOC Test for Detection of Clostridioides difficile Glutamate Dehydrogenase and Toxins A/B

WOS, 2020

The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (Ar... more The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (ArcDia Ltd., Finland), for the detection of Clostridioides difficile glutamate dehydrogenase (GDH) and toxins A and B directly from fecal specimens. The mariPOC test was compared with both the GenomEra C. difficile PCR assay (Abacus Diagnostica Oy, Finland) and the TechLab C. diff Quik Chek Complete (Alere Inc.; now Abbot) membrane enzyme immunoassay (MEIA). Culture and the Xpert C. difficile assay (Cepheid Inc.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Surveillance of Clostridium difficile infections in Finnish acute care hospitals, 2008-2014: trends, diagnostics and control measures

Antimicrobial Resistance and Infection Control, Jun 16, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Community- vs. healthcare-associated Clostridium difficile infections, Finland, 2008-2013: incidence, case fatality and genotypes

Antimicrobial Resistance and Infection Control, Jun 16, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Legionnaires' Disease Associated with Death after Near Drowning in Lake Water

Direct aspiration of water during submersion has caused Legionnaires’ disease (LD) cases. This ch... more Direct aspiration of water during submersion has caused Legionnaires’ disease (LD) cases. This chapter presents one such case caused by Legionella pneumophila with a novel source of infection. Appropriate antimicrobial therapy was given once LD was identified, in addition to the antibiotics targeted against other pathogens. The patient suffered from bilateral lung infiltrates, pleural effusion, and cavitation of lung parenchyma, all symptoms of LD. The patient had LD and Pseudomonas aeruginosa and fungal infections. The pulmonary damage led to multiorgan failure, and the secondary or co-infections contributed to his death. LD cases have also occurred in neonates after water births. Immersion in river water has resulted in at least two reported LD cases caused by L. pneumophila sg 10 and sg 13.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Clostridium difficile infections in Finland, 2008–2015: trends, diagnostics and ribotypes

European Journal of Clinical Microbiology & Infectious Diseases, May 30, 2017

We evaluated Clostridium difficile (CD) diagnostics in Finnish clinical microbiology laboratories... more We evaluated Clostridium difficile (CD) diagnostics in Finnish clinical microbiology laboratories during 2006–2011, with an update in 2015, in relation to CD surveillance data of the National Infectious Disease Register (NIDR) and ribotyping data from the national reference laboratory during the years 2008–2015. In 2011, diagnostic activity varied regionally more than three-fold and the positivity rate ranged between 7 and 21%. Nucleic acid amplification testing (NAAT) was implemented in the regions with high activity and NAAT users tested 30% more patients and found 15% more cases per population than those not using it. Culture was performed in 79% of laboratories, primary toxin testing by enzyme immunoassay (EIA) in 83% and by NAAT in 17%. In 2014, 12/19 laboratories used NAAT as the primary detection method and four as the secondary method, and ten cultured. Increasing usage of NAAT was not systematically related to various trends detected regionally in annual CD rates. Polymerase chain reaction (PCR) ribotyping of 1771 CD isolates (4.1% of CD cases) identified 146 distinct profiles, of which 37% were binary toxin positive. The most common ribotype was 027, but its proportion decreased, while 078 slightly increased. Transition from culture to NAAT in CD infection (CDI) diagnostics did not cause a significant increase in the observed CDI incidence. Major differences between diagnostic activity, methods and strategies in different regions have persisted over the years, which should be considered when comparing the regional epidemiology of CDI.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Differentiating virulent 027 and non-027<i>Clostridium difficile</i>strains by molecular methods

Expert Review of Molecular Diagnostics, Aug 4, 2015

Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype ... more Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype 027 and also other ribotypes. We present data on additional non-027 strains, identified as presumptive 027 by two commercial molecular C. difficile assays. The tested clinical isolates were selected from the national reference laboratory collection on the basis of toxin gene profile similarities with ribotype 027 and tested with XpertC. difficile/Epi and Amplidiag C. difficile+027 assay. Xpert misclassified five ribotypes (016, 019, 080, 176 and variant of type 046) as presumptive 027 and Amplidiag two ribotypes (016, 176). The misclassified strains were rare, covering 1.6% of reference laboratory strain collection. Our findings confirm the concept that there are closely related outliers to hypervirulent 027 clones that can be misclassified as 027, and that these comprise numerous ribotypes, including previously reported four ribotypes (198, 176, 244, 019), and additional three (016, v046, 080) identified in the present study.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Hot Water Systems with Low Concentrations of Legionellae May Be a Risk on Cruise Ships

Water systems contaminated with legionellae cause outbreaks and sporadic cases of Legionella pneu... more Water systems contaminated with legionellae cause outbreaks and sporadic cases of Legionella pneumonia. Legionellae are ubiquitous in water systems. In most clinical cases the source of infection can be confirmed only by using typing methods that discriminate between the patient and the environmental isolates. Water samples were analyzed using Legionella isolation standard method ISO 11731, completed by additional concentration with centrifugation (6,000 X g, 10 min). The legionella concentrations varied from 5 to 2,000 CFU/liter; the highest concentration was found in the tap water sample. The strains were L. pneumophila serogroup 1. The thermophilic heterotrophic bacteria concentration was highest (3.0 X 106 CFU/liter) in the tap water sample that contained the highest legionella counts. The mesophilic bacteria content was the highest in the legionella positive shower sample (5.9 X 107 CFU/liter). The L. pneumonia case of the 61-year-old man was detected only by the urinary antigen method. Therefore, conclusive evidence of the source of this particular infection could not be confirmed. Since the incubation time for legionella infection can vary from 2 to 10 days, it is possible that the infection was contracted elsewhere, such as the patient's home.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Diagnostic trends in Clostridium difficile detection in Finnish microbiology laboratories

Anaerobe, Dec 1, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Transmission of Drug-Resistant Mycobacterium Tuberculosis Isolates between Finnish- and Foreign-Born Cases, 2014-2021: A Molecular Epidemiological Study

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Orally Administered Targeted Recombinant Beta-Lactamase Prevents Ampicillin-Induced Selective Pressure on the Gut Microbiota: a Novel Approach to Reducing Antimicrobial Resistance

Antimicrobial Agents and Chemotherapy, 2004

Bookmarks Related papers MentionsView impact

Research paper thumbnail of First isolation of Clostridium difficile PCR ribotype 027 in Finland

Weekly releases (1997–2007), Nov 8, 2007

On 18 October 2007, the first case of Clostridium difficile PCR ribotype 027-associated disease w... more On 18 October 2007, the first case of Clostridium difficile PCR ribotype 027-associated disease was detected in Finland.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Differentiating virulent 027 and non-027 Clostridium difficile strains by molecular methods

WOS, Sep 18, 2015

Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype ... more Hypervirulent Clostridium difficile clade has been shown to include several lineages of ribotype 027 and also other ribotypes. We present data on additional non-027 strains, identified as presumptive 027 by two commercial molecular C. difficile assays. The tested clinical isolates were selected from the national reference laboratory collection on the basis of toxin gene profile similarities with ribotype 027 and tested with XpertC. difficile/Epi and Amplidiag C. difficile+027 assay. Xpert misclassified five ribotypes (016, 019, 080, 176 and variant of type 046) as presumptive 027 and Amplidiag two ribotypes (016, 176). The misclassified strains were rare, covering 1.6% of reference laboratory strain collection. Our findings confirm the concept that there are closely related outliers to hypervirulent 027 clones that can be misclassified as 027, and that these comprise numerous ribotypes, including previously reported four ribotypes (198, 176, 244, 019), and additional three (016, v046, 080) identified in the present study.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of P1A Recombinant β-Lactamase Prevents Emergence of Antimicrobial Resistance in Gut Microflora of Healthy Subjects during Intravenous Administration of Ampicillin

Antimicrobial Agents and Chemotherapy, Jun 1, 2009

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Research paper thumbnail of Transmission of drug-resistant Mycobacterium tuberculosis isolates between Finnish- and foreign-born patients, 2014-2021: a molecular epidemiological study

Research Square (Research Square), May 23, 2023

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Research paper thumbnail of External quality assessment by European mycobacterial laboratories: results of AFB microscopy and identification rounds

Diagnostic Microbiology and Infectious Disease, Oct 1, 2022

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Research paper thumbnail of Community- and Healthcare- Associated Clostridium difficile Infections, Finland, 2008-2013

WOS, Oct 20, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Clostridium difficile isolates from piglets and humans in rural region in Finland

Veterinary Microbiology, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Interactions between diet, intestinal microflora and mucosal morphology in patients with ileal pouch-anal anastomosis

Gastroenterology, Apr 1, 2001

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Regional differences inClostridium difficileinfections in relation to fluoroquinolone and proton pump inhibitor use, Finland, 2008–2011

Infectious diseases, Apr 2, 2015

Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk facto... more Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk factors for Clostridium difficile infections (CDIs). Nationwide laboratory-based surveillance of CDIs in Finland since 2008 has shown variation in regional CDI rates. We evaluated whether regional differences in CDI rates were associated with antibacterial and PPI use. Data on mean annual incidence rates of CDIs during 2008-2011 in 21 healthcare districts (HDs) were obtained from the National Infectious Disease Register, consumption (median annual use) of antimicrobials and PPIs from the Finnish Medical Agency, availability of molecular diagnostics by a laboratory survey and data on ribotypes from the national reference laboratory. The association over the 4 years was measured by incidence rate ratio (IRR) and we performed both bivariate and multivariate analyses. During 2008-2011, PPI use increased 27% but fluoroquinolone use was stable. The level of fluoroquinolone use was strongly associated with the mean annual CDI incidence rate in different HDs over the 4-year period, but PPI use had less effect. The molecular diagnostics methodology and PCR ribotype 027 were not independently associated with CDI rate. The final multivariable model only included fluoroquinolone and PPI use; IRR for fluoroquinolones was 2.20 (95% confidence interval (CI), 1.32-3.67; p = 0.003). Fluoroquinolone use may play a role in regional differences in CDI rates. Although the use has not recently increased, regionally targeted antimicrobial stewardship campaigns promoting appropriate use of fluoroquinolones should still be encouraged since they may decrease the incidence of CDIs.

Bookmarks Related papers MentionsView impact