Abstract There is widespread interest in risk factor-based breast cancer screening because of the... more Abstract There is widespread interest in risk factor-based breast cancer screening because of the possibility that it may improve the effectiveness of breast cancer detection and possibly reduce the number of women who need to be screened and associated harms. Risk factors are already used to determine screening: for example, age is used to determine who is eligible for screening and age of onset of screening may be reduced and screening frequency maybe increased in women with a family history. Women with BRCA1 or BRCA2 mutations are screened using MRI in addition to mammography because of the potential for missing cancers and the high risk of interval cancers in mutation positive women. The question arises whether such risk-adapted screening can improve the sensitivity and specificity of screening for all women as well as in National programs. In general, incorporation of additional risk factors such as endocrine factors, mammographic density and genetic factors to age and family history improves the predictive accuracy of risk estimates. Additional screening modalities such as ultrasound, MRI, and digital breast tomosynthesis may increase detection rates and reduce interval cancers. However, it is not clear how these modalities and additional risk factors may be applied in breast screening and national programs, and whether this will be beneficial to the women screened. Here we discuss some of the challenges and potential opportunities of attempting to introduce risk-adapted screening.
Purpose of Review This editorial review aims to provide readers with an introduction to the Curre... more Purpose of Review This editorial review aims to provide readers with an introduction to the Current Clinical Microbiology Report Special Issue “Meat Microbiology and Hygiene.” It will provide an overview of overarching trends and developments in this field, introduce the articles presented in this Special Issue, and attempt to offer a glimpse into the future of meat microbiology and hygiene. Recent Findings Meat production has been subjected to transformative changes within the last decade, and the focus of assuring meat safety has shifted to account for changing consumer demands as well as new microbial risks such as strains carrying antimicrobial resistance determinants. Summary Assuring that meat products meet high safety standards remains crucial to consumers worldwide. New risk-based meat safety assurance systems leveraging latest technological advances are needed to protect consumers and promote public health.
Plant protection products based on Bacillus thuringiensis have been used to fight agricultural pe... more Plant protection products based on Bacillus thuringiensis have been used to fight agricultural pests for decades and are the world's most frequently applied biopesticide. However, there is growing concern that B. thuringiensis residues in food may occasionally cause diarrheal illness in humans. This has recently sparked a plethora of research activities and vivid discussions across the scientific community, competent authorities, and the public. To support this discussion, we provide a structured overview of the current knowledge on the role of B. thuringiensis as a causative agent of foodborne infections in humans and pinpoint research gaps that need to be addressed for improved risk assessment. We review (i) recent taxonomic changes in the B. cereus group; (ii) the role of B. thuringiensis in transforming agrosystems; and (iii) key considerations for assessing the hazard potential of B. thuringiensis strains detected in foods. We conclude that (i) the taxonomy of the B. cereus group is collapsing, (ii) B. thuringiensis based biopesticides play a key role in realizing the UN's sustainable development goals, and (iii) risk assessment needs to move from taxonomy-driven considerations to strain-specific identification of virulence and pathogenicity traits We also provide an overview of relevant risk-related data for commonly used biopesticide strains.
DNA microarray based characterization and resistance phenotypes of clinical MRSA strains from ani... more DNA microarray based characterization and resistance phenotypes of clinical MRSA strains from animal hosts
Respiration; international review of thoracic diseases, Jan 25, 2015
Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations.... more Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations. While pathological changes can be seen in various organs, morbidity and mortality are mainly related to the respiratory tract, with patients suffering from chronic bronchopulmonary infections with characteristic pathogens including Staphylococcus aureus. To date, there is only very limited data on the genetic and phenotypic characteristics of S. aureus in CF patients. Therefore, in our study, we characterized 58 S. aureus isolates collected from CF patients in Austria by spa typing, DNA microarray profiling, as well as antimicrobial susceptibility testing in order to determine common genomic and antimicrobial resistance features. The tested strain collection exhibited high genomic diversity. The 58 isolates were assigned to 16 clonal complexes and 48 spa types and differed greatly regarding their virulence and resistance gene profiles. The predominant clonal complexes were MLST CC30 (22...
Staphylococcal food poisoning is a common food intoxication caused by staphylococcal enterotoxins... more Staphylococcal food poisoning is a common food intoxication caused by staphylococcal enterotoxins. While growth of Staphylococcus aureus is not inhibited by the meat curing agent nitrite, we hypothesize that nitrite has an influence on enterotoxin C (SEC) expression. We investigated the influence of 150 mg/L nitrite on SEC expression at mRNA and protein level in seven strains expressing different SEC variants. Additionally, regulatory knockout mutants (Δagr, ΔsarA, ΔsigB) of high SEC producing strain SAI48 were investigated at mRNA level. Our findings suggest that nitrite effectively increases sec mRNA transcription, but the effects on SEC protein expression are less pronounced. While Δagr mutants exhibited lower sec mRNA transcription levels than wt strains, this response was not stress specific. ΔsigB mutants displayed a nitrite stress specific response. WGS analysis of the strains revealed a defective agr element in one strain (SAI3). In this strain sec transcription and SEC prot...
Enterotoxins (SEs) produced by Staphylococcus aureus are the cause of serious food intoxications.... more Enterotoxins (SEs) produced by Staphylococcus aureus are the cause of serious food intoxications. Staphylococcal enterotoxin C (SEC) is one of the main contributors, as it is often highly expressed. S. aureus possesses a competitive growth advantage over accompanying bacterial flora under stress conditions encountered in foods, such as high NaCl concentrations. However, the influence of NaCl as an external stressor on SEC expression is still unclear. We investigated the influence of 4.5% NaCl on sec mRNA and SEC protein levels. A qRT-PCR assay revealed that NaCl stress leads to time-dependently decreased or elevated sec mRNA levels for most strains. SEC protein levels were generally decreased under NaCl stress. Our findings suggest that NaCl stress lowers overall SEC concentration and time-dependently affects sec mRNA levels.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 2018
Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes ... more Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains we...
Staphylococcal enterotoxin C (SEC) is a major cause of staphylococcal food poisoning in humans an... more Staphylococcal enterotoxin C (SEC) is a major cause of staphylococcal food poisoning in humans and plays a role in bovine mastitis. Staphylococcus aureus (S. aureus) benefits from a competitive growth advantage under stress conditions encountered in foods such as a low pH. Therefore, understanding the role of stressors such as lactic acid on SEC production is of pivotal relevance to food safety. However, stress-dependent cues and their effects on enterotoxin expression are still poorly understood. In this study, we used human and animal strains harboring different SEC variants in order to evaluate the influence of mild lactic acid stress (pH 6.0) on SEC expression both on transcriptional and translational level. Although only a modest decrease in sec mRNA levels was observed under lactic acid stress, protein levels showed a significant decrease in SEC levels for some strains. These findings indicate that post-transcriptional modifications can act in SEC expression under lactic acid ...
On October 1, 2014, children and staff members at a Swiss boarding school consumed Tomme, a soft ... more On October 1, 2014, children and staff members at a Swiss boarding school consumed Tomme, a soft cheese produced from raw cow milk. Within the following 7 h, all 14 persons who ingested the cheese fell ill, including 10 children and 4 staff members. Symptoms included abdominal pain and violent vomiting, followed by severe diarrhea and fever. We aim to present this food poisoning outbreak and characterize the causative agent. The duration of the incubation period was dependent of the age of the patient: 2.5 h in children under 10 yr of age, 3.5 h in older children and teenagers, and 7 h in adults. The soft cheese exhibited low levels of staphylococcal enterotoxin (SE) A (>6 ng of SEA/g of cheese) and high levels of staphylococcal enterotoxin D (>200 ng of SED/g of cheese). Counts of 10(7) cfu of coagulase-positive staphylococci per gram of cheese were detected, with 3 different Staphylococcus aureus strains being present at levels >10(6) cfu/g. The 3 strains were characteriz...
Abstract There is widespread interest in risk factor-based breast cancer screening because of the... more Abstract There is widespread interest in risk factor-based breast cancer screening because of the possibility that it may improve the effectiveness of breast cancer detection and possibly reduce the number of women who need to be screened and associated harms. Risk factors are already used to determine screening: for example, age is used to determine who is eligible for screening and age of onset of screening may be reduced and screening frequency maybe increased in women with a family history. Women with BRCA1 or BRCA2 mutations are screened using MRI in addition to mammography because of the potential for missing cancers and the high risk of interval cancers in mutation positive women. The question arises whether such risk-adapted screening can improve the sensitivity and specificity of screening for all women as well as in National programs. In general, incorporation of additional risk factors such as endocrine factors, mammographic density and genetic factors to age and family history improves the predictive accuracy of risk estimates. Additional screening modalities such as ultrasound, MRI, and digital breast tomosynthesis may increase detection rates and reduce interval cancers. However, it is not clear how these modalities and additional risk factors may be applied in breast screening and national programs, and whether this will be beneficial to the women screened. Here we discuss some of the challenges and potential opportunities of attempting to introduce risk-adapted screening.
Purpose of Review This editorial review aims to provide readers with an introduction to the Curre... more Purpose of Review This editorial review aims to provide readers with an introduction to the Current Clinical Microbiology Report Special Issue “Meat Microbiology and Hygiene.” It will provide an overview of overarching trends and developments in this field, introduce the articles presented in this Special Issue, and attempt to offer a glimpse into the future of meat microbiology and hygiene. Recent Findings Meat production has been subjected to transformative changes within the last decade, and the focus of assuring meat safety has shifted to account for changing consumer demands as well as new microbial risks such as strains carrying antimicrobial resistance determinants. Summary Assuring that meat products meet high safety standards remains crucial to consumers worldwide. New risk-based meat safety assurance systems leveraging latest technological advances are needed to protect consumers and promote public health.
Plant protection products based on Bacillus thuringiensis have been used to fight agricultural pe... more Plant protection products based on Bacillus thuringiensis have been used to fight agricultural pests for decades and are the world's most frequently applied biopesticide. However, there is growing concern that B. thuringiensis residues in food may occasionally cause diarrheal illness in humans. This has recently sparked a plethora of research activities and vivid discussions across the scientific community, competent authorities, and the public. To support this discussion, we provide a structured overview of the current knowledge on the role of B. thuringiensis as a causative agent of foodborne infections in humans and pinpoint research gaps that need to be addressed for improved risk assessment. We review (i) recent taxonomic changes in the B. cereus group; (ii) the role of B. thuringiensis in transforming agrosystems; and (iii) key considerations for assessing the hazard potential of B. thuringiensis strains detected in foods. We conclude that (i) the taxonomy of the B. cereus group is collapsing, (ii) B. thuringiensis based biopesticides play a key role in realizing the UN's sustainable development goals, and (iii) risk assessment needs to move from taxonomy-driven considerations to strain-specific identification of virulence and pathogenicity traits We also provide an overview of relevant risk-related data for commonly used biopesticide strains.
DNA microarray based characterization and resistance phenotypes of clinical MRSA strains from ani... more DNA microarray based characterization and resistance phenotypes of clinical MRSA strains from animal hosts
Respiration; international review of thoracic diseases, Jan 25, 2015
Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations.... more Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations. While pathological changes can be seen in various organs, morbidity and mortality are mainly related to the respiratory tract, with patients suffering from chronic bronchopulmonary infections with characteristic pathogens including Staphylococcus aureus. To date, there is only very limited data on the genetic and phenotypic characteristics of S. aureus in CF patients. Therefore, in our study, we characterized 58 S. aureus isolates collected from CF patients in Austria by spa typing, DNA microarray profiling, as well as antimicrobial susceptibility testing in order to determine common genomic and antimicrobial resistance features. The tested strain collection exhibited high genomic diversity. The 58 isolates were assigned to 16 clonal complexes and 48 spa types and differed greatly regarding their virulence and resistance gene profiles. The predominant clonal complexes were MLST CC30 (22...
Staphylococcal food poisoning is a common food intoxication caused by staphylococcal enterotoxins... more Staphylococcal food poisoning is a common food intoxication caused by staphylococcal enterotoxins. While growth of Staphylococcus aureus is not inhibited by the meat curing agent nitrite, we hypothesize that nitrite has an influence on enterotoxin C (SEC) expression. We investigated the influence of 150 mg/L nitrite on SEC expression at mRNA and protein level in seven strains expressing different SEC variants. Additionally, regulatory knockout mutants (Δagr, ΔsarA, ΔsigB) of high SEC producing strain SAI48 were investigated at mRNA level. Our findings suggest that nitrite effectively increases sec mRNA transcription, but the effects on SEC protein expression are less pronounced. While Δagr mutants exhibited lower sec mRNA transcription levels than wt strains, this response was not stress specific. ΔsigB mutants displayed a nitrite stress specific response. WGS analysis of the strains revealed a defective agr element in one strain (SAI3). In this strain sec transcription and SEC prot...
Enterotoxins (SEs) produced by Staphylococcus aureus are the cause of serious food intoxications.... more Enterotoxins (SEs) produced by Staphylococcus aureus are the cause of serious food intoxications. Staphylococcal enterotoxin C (SEC) is one of the main contributors, as it is often highly expressed. S. aureus possesses a competitive growth advantage over accompanying bacterial flora under stress conditions encountered in foods, such as high NaCl concentrations. However, the influence of NaCl as an external stressor on SEC expression is still unclear. We investigated the influence of 4.5% NaCl on sec mRNA and SEC protein levels. A qRT-PCR assay revealed that NaCl stress leads to time-dependently decreased or elevated sec mRNA levels for most strains. SEC protein levels were generally decreased under NaCl stress. Our findings suggest that NaCl stress lowers overall SEC concentration and time-dependently affects sec mRNA levels.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 2018
Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes ... more Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains we...
Staphylococcal enterotoxin C (SEC) is a major cause of staphylococcal food poisoning in humans an... more Staphylococcal enterotoxin C (SEC) is a major cause of staphylococcal food poisoning in humans and plays a role in bovine mastitis. Staphylococcus aureus (S. aureus) benefits from a competitive growth advantage under stress conditions encountered in foods such as a low pH. Therefore, understanding the role of stressors such as lactic acid on SEC production is of pivotal relevance to food safety. However, stress-dependent cues and their effects on enterotoxin expression are still poorly understood. In this study, we used human and animal strains harboring different SEC variants in order to evaluate the influence of mild lactic acid stress (pH 6.0) on SEC expression both on transcriptional and translational level. Although only a modest decrease in sec mRNA levels was observed under lactic acid stress, protein levels showed a significant decrease in SEC levels for some strains. These findings indicate that post-transcriptional modifications can act in SEC expression under lactic acid ...
On October 1, 2014, children and staff members at a Swiss boarding school consumed Tomme, a soft ... more On October 1, 2014, children and staff members at a Swiss boarding school consumed Tomme, a soft cheese produced from raw cow milk. Within the following 7 h, all 14 persons who ingested the cheese fell ill, including 10 children and 4 staff members. Symptoms included abdominal pain and violent vomiting, followed by severe diarrhea and fever. We aim to present this food poisoning outbreak and characterize the causative agent. The duration of the incubation period was dependent of the age of the patient: 2.5 h in children under 10 yr of age, 3.5 h in older children and teenagers, and 7 h in adults. The soft cheese exhibited low levels of staphylococcal enterotoxin (SE) A (>6 ng of SEA/g of cheese) and high levels of staphylococcal enterotoxin D (>200 ng of SED/g of cheese). Counts of 10(7) cfu of coagulase-positive staphylococci per gram of cheese were detected, with 3 different Staphylococcus aureus strains being present at levels >10(6) cfu/g. The 3 strains were characteriz...
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