Pub Date : 2025-05-07DOI: 10.1016/j.ijmm.2025.151654
Peijun Han , Wei Ye , Hongwei Ma , Yangchao Dong , Xin Lv , He Liu , Linfeng Cheng , Liang Zhang , Sumin Li , Yingfeng Lei , Fanglin Zhang
Dengue virus (DENV) is one of the major arboviruses that pose a serious threat to global human health. However, there is currently no specific antiviral drug available for the treatment of DENV infection. DDX17, a member of the DExD/H-box helicase family, has been implicated in the replication processes of various viruses. Our research group discovered that during the early stages of dengue virus replication, DDX17 promotes viral replication and suppresses the activity of the IFN promoter. Furthermore, DDX17 binds to viral dsRNA and interacts with G3BP1, a component of stress granules (SGs), to inhibit SG formation, thereby enhancing viral replication. By elucidating the role of DDX17 in the early stages of dengue virus replication, our findings provide valuable insights into host-pathogen interactions during DENV infection, offering potential therapeutic perspectives.
{"title":"DDX17 promotes DENV-2 replication via interaction with viral dsRNA and G3BP1","authors":"Peijun Han , Wei Ye , Hongwei Ma , Yangchao Dong , Xin Lv , He Liu , Linfeng Cheng , Liang Zhang , Sumin Li , Yingfeng Lei , Fanglin Zhang","doi":"10.1016/j.ijmm.2025.151654","DOIUrl":"10.1016/j.ijmm.2025.151654","url":null,"abstract":"<div><div>Dengue virus (DENV) is one of the major arboviruses that pose a serious threat to global human health. However, there is currently no specific antiviral drug available for the treatment of DENV infection. DDX17, a member of the DExD/H-box helicase family, has been implicated in the replication processes of various viruses. Our research group discovered that during the early stages of dengue virus replication, DDX17 promotes viral replication and suppresses the activity of the IFN promoter. Furthermore, DDX17 binds to viral dsRNA and interacts with G3BP1, a component of stress granules (SGs), to inhibit SG formation, thereby enhancing viral replication. By elucidating the role of DDX17 in the early stages of dengue virus replication, our findings provide valuable insights into host-pathogen interactions during DENV infection, offering potential therapeutic perspectives.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"319 ","pages":"Article 151654"},"PeriodicalIF":4.5,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.ijmm.2025.151653
Imke Johanna Temme, Petya Berger, Ulrich Dobrindt, Alexander Mellmann
To investigate the adaptation of hybrid Escherichia coli to the intestinal and extraintestinal milieu, we compared our model hybrid Shiga toxin-producing (STEC) and uropathogenic (UPEC) E. coli O2:H6 strains with non-pathogenic E. coli and canonical UPEC and STEC strains in a carbon source utilization assay testing 95 common carbon sources under aerobic and anaerobic conditions. Comparison of anaerobic to aerobic growth showed a 2-fold decrease and 2.5-fold increase in the growth capacity and lag phase, respectively. While the UPEC and STEC/UPEC hybrids retained the utilization of several organic acids, amino acids, and peptides, the STEC and non-pathogenic strains relied almost exclusively on the utilization of sugar compounds under anaerobic conditions. Cluster analysis indicated a higher degree of difference and separation between all strains under aerobic conditions. The UPEC, hybrids, and STEC strain B2F1 showed high similarities in aerobic carbon utilization following growth patterns observed in previous phenotype assays. Additionally, we observed known UPEC virulence traits, such as the aerobic utilization of D-serine in our model STEC/UPEC hybrids. Combined, these findings suggest that the intestinal STEC/UPEC O2:H6 isolates originated from a UPEC background and acquired the ability to cause intestinal disease with the addition of Shiga toxin as a virulence factor.
{"title":"Carbon source utilization in hybrid Shiga toxin-producing and uropathogenic Escherichia coli indicates uropathogenic origin","authors":"Imke Johanna Temme, Petya Berger, Ulrich Dobrindt, Alexander Mellmann","doi":"10.1016/j.ijmm.2025.151653","DOIUrl":"10.1016/j.ijmm.2025.151653","url":null,"abstract":"<div><div>To investigate the adaptation of hybrid <em>Escherichia coli</em> to the intestinal and extraintestinal milieu, we compared our model hybrid Shiga toxin-producing (STEC) and uropathogenic (UPEC) <em>E. coli</em> O2:H6 strains with non-pathogenic <em>E. coli</em> and canonical UPEC and STEC strains in a carbon source utilization assay testing 95 common carbon sources under aerobic and anaerobic conditions. Comparison of anaerobic to aerobic growth showed a 2-fold decrease and 2.5-fold increase in the growth capacity and lag phase, respectively. While the UPEC and STEC/UPEC hybrids retained the utilization of several organic acids, amino acids, and peptides, the STEC and non-pathogenic strains relied almost exclusively on the utilization of sugar compounds under anaerobic conditions. Cluster analysis indicated a higher degree of difference and separation between all strains under aerobic conditions. The UPEC, hybrids, and STEC strain B2F1 showed high similarities in aerobic carbon utilization following growth patterns observed in previous phenotype assays. Additionally, we observed known UPEC virulence traits, such as the aerobic utilization of D-serine in our model STEC/UPEC hybrids. Combined, these findings suggest that the intestinal STEC/UPEC O2:H6 isolates originated from a UPEC background and acquired the ability to cause intestinal disease with the addition of Shiga toxin as a virulence factor.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"319 ","pages":"Article 151653"},"PeriodicalIF":4.5,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.1016/j.ijmm.2025.151651
Misti D. Finton , Roger Meisal , Davide Porcellato , Lin T. Brandal , Bjørn-Arne Lindstedt
The global rise of hybrid Escherichia coli (E. coli) is a major public health concern, as enhanced virulence from multiple pathotypes complicates the traditional E. coli classification system and challenges clinical diagnostics. Hybrid strains are particularly concerning as they can infect both intestinal and extraintestinal sites, complicating treatment and increasing the risk of severe disease. This study analyzed virulence-associated genes (VAGs) in 13 E. coli isolates from fecal samples of patients with symptoms of gastrointestinal (GI) infection in Norwegian hospitals and clinics. Whole genome sequencing (WGS) was conducted using Oxford Nanopore’s MinION and Illumina’s MiSeq platforms. Eleven strains harbored molecular diagnostic markers of atypical enteropathogenic E. coli (aEPEC), enteroinvasive E. coli (EIEC), Shiga toxin-producing E. coli (STEC), enterotoxigenic E. coli (ETEC), or typical enteropathogenic E. coli (tEPEC). Two of those isolates were identified as triple intestinal hybrids with molecular diagnostic markers for aEPEC, EIEC, and STEC. Notably, two isolates lacked any IPEC-specific molecular diagnostic markers, yet were suspected of causing the patient’s GI infection. Furthermore, genes associated with extraintestinal pathogenic E. coli (ExPEC)—including adhesins, toxins, protectins, siderophores, iron acquisition systems, and invasins—were identified in all the isolates. Thus, most of the isolates were classified as hybrid aEPEC/ExPEC, STEC/ExPEC, tEPEC/ExPEC, or aEPEC/EIEC/STEC/ExPEC. These findings emphasize the genomic plasticity of E. coli and highlight the need to revise the classification system for enteric pathogens.
{"title":"Comparative genomics of clinical hybrid Escherichia coli strains in Norway","authors":"Misti D. Finton , Roger Meisal , Davide Porcellato , Lin T. Brandal , Bjørn-Arne Lindstedt","doi":"10.1016/j.ijmm.2025.151651","DOIUrl":"10.1016/j.ijmm.2025.151651","url":null,"abstract":"<div><div>The global rise of hybrid <em>Escherichia coli</em> (<em>E. coli</em>) is a major public health concern, as enhanced virulence from multiple pathotypes complicates the traditional <em>E. coli</em> classification system and challenges clinical diagnostics. Hybrid strains are particularly concerning as they can infect both intestinal and extraintestinal sites, complicating treatment and increasing the risk of severe disease. This study analyzed virulence-associated genes (VAGs) in 13 <em>E. coli</em> isolates from fecal samples of patients with symptoms of gastrointestinal (GI) infection in Norwegian hospitals and clinics. Whole genome sequencing (WGS) was conducted using Oxford Nanopore’s MinION and Illumina’s MiSeq platforms. Eleven strains harbored molecular diagnostic markers of atypical enteropathogenic <em>E. coli</em> (aEPEC), enteroinvasive <em>E. coli</em> (EIEC), Shiga toxin-producing <em>E. coli</em> (STEC), enterotoxigenic <em>E. coli</em> (ETEC), or typical enteropathogenic <em>E. coli</em> (tEPEC). Two of those isolates were identified as triple intestinal hybrids with molecular diagnostic markers for aEPEC, EIEC, and STEC. Notably, two isolates lacked any IPEC-specific molecular diagnostic markers, yet were suspected of causing the patient’s GI infection. Furthermore, genes associated with extraintestinal pathogenic <em>E. coli</em> (ExPEC)—including adhesins, toxins, protectins, siderophores, iron acquisition systems, and invasins—were identified in all the isolates. Thus, most of the isolates were classified as hybrid aEPEC/ExPEC, STEC/ExPEC, tEPEC/ExPEC, or aEPEC/EIEC/STEC/ExPEC. These findings emphasize the genomic plasticity of <em>E. coli</em> and highlight the need to revise the classification system for enteric pathogens.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151651"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Urine samples are frequently analyzed in microbiology laboratories, but a large proportion of them are culture-negative. The aim of this study was to test whether positive urine cultures can be predicted from routine flow cytometric data. Urine samples (n = 1325) were used for a train dataset (n = 1032) and three independent test datasets (n = 93–100 samples) that were collected three months apart. Predictors from flow cytometry were total counts per µl of bacteria, erythrocytes, yeast-like cells, hyaline casts, crystals, leukocytes, squamous epithelial cells, non-hyaline casts and non-squamous epithelial cells in addition to age, sex and type of urine sample. Labels were positive culture and detection of clinically relevant uropathogens. Three classifiers (decision tree, random forest classifier, CatBoost) were 5-fold cross-validated on the train dataset to select an optimized model with ≥ 95 % sensitivity. The optimized model was trained on the complete train dataset and evaluated on the three independent test sets. In total, 72.5 % (960/1325) samples were culture positive with a predominance of Escherichia coli (n = 295). CatBoost outperformed the other classifiers in terms of balanced accuracy (train data) and was selected as the classifier for predictions. With optimised hyperparameters, the balanced accuracy was 62–74 % for the prediction of a positive culture (test data) and had a sensitivity that was stable over a period of six months (94–96 %, negative predictive value [NPV]: 67–77 %, positive predictive value [PPV]: 78–81 %). For the prediction of uropathogens, the balanced accuracy was 57–63 % with a stable sensitivity (95–100 %, NPV: 83–100 %, PPV: 48–59 %). In conclusion, the ML algorithms showed high sensitivity for detecting positive urine cultures.
{"title":"Validation of ML-algorithms for the prediction of positive urine cultures from flow cytometry routine data in patients with suspected bacteriuria","authors":"Alexander Brenner , Jutta Esser , Franziska Schuler , Julian Varghese , Frieder Schaumburg","doi":"10.1016/j.ijmm.2025.151652","DOIUrl":"10.1016/j.ijmm.2025.151652","url":null,"abstract":"<div><div>Urine samples are frequently analyzed in microbiology laboratories, but a large proportion of them are culture-negative. The aim of this study was to test whether positive urine cultures can be predicted from routine flow cytometric data. Urine samples (n = 1325) were used for a train dataset (n = 1032) and three independent test datasets (n = 93–100 samples) that were collected three months apart. Predictors from flow cytometry were total counts per µl of bacteria, erythrocytes, yeast-like cells, hyaline casts, crystals, leukocytes, squamous epithelial cells, non-hyaline casts and non-squamous epithelial cells in addition to age, sex and type of urine sample. Labels were positive culture and detection of clinically relevant uropathogens. Three classifiers (decision tree, random forest classifier, CatBoost) were 5-fold cross-validated on the train dataset to select an optimized model with ≥ 95 % sensitivity. The optimized model was trained on the complete train dataset and evaluated on the three independent test sets. In total, 72.5 % (960/1325) samples were culture positive with a predominance of <em>Escherichia coli</em> (n = 295). CatBoost outperformed the other classifiers in terms of balanced accuracy (train data) and was selected as the classifier for predictions. With optimised hyperparameters, the balanced accuracy was 62–74 % for the prediction of a positive culture (test data) and had a sensitivity that was stable over a period of six months (94–96 %, negative predictive value [NPV]: 67–77 %, positive predictive value [PPV]: 78–81 %). For the prediction of uropathogens, the balanced accuracy was 57–63 % with a stable sensitivity (95–100 %, NPV: 83–100 %, PPV: 48–59 %). In conclusion, the ML algorithms showed high sensitivity for detecting positive urine cultures.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151652"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Currently, diagnosis of bacterial infections is based on culture, possibly followed by the amplification and sequencing (Sanger method) of the 16S rDNA - encoding gene when cultures are negative. Clinical metagenomics (CMg), i.e. the sequencing of a sample’s entire nucleic acids, may allow for the identification of bacteria not detected by conventional methods. Here, we tested the performance of CMg compared to 16S rDNA sequencing (Sanger) in 50 patients with suspected bacterial infection but negative cultures.
Methods
This is a prospective cohort study. Fifty patients (73 samples) with negative culture and a 16S rDNA sequencing demand (Sanger) were recruited from two sites. On the same samples, CMg (Illumina NextSeq) was also performed and compared to 16S rDNA Sanger sequencing. Bacteria were identified using MetaPhlAn4.
Results
Among the 73 samples, 20 (27 %, 17 patients) had a clinically relevant 16S rDNA Sanger sequencing result (used for patient management) while 11 (15 %, 9 patients) were considered contaminants. At the patient level, the sensitivity of CMg was 70 % (12/17) compared to 16S rDNA. In samples negative for 16S rDNA Sanger sequencing (n = 53), CMg identified clinically-relevant bacteria in 10 samples (19 %, 10 patients) with 14 additional bacteria.
Conclusions
CMg was not 100 % sensitive when compared to 16S, supporting that it may not be a suitable replacement. However, CMg did find additional bacteria in samples negative for 16S rDNA Sanger. CMg could therefore be positioned as a complementary to 16S rDNA Sanger sequencing.
{"title":"Comparison of clinical metagenomics with 16S rDNA Sanger sequencing for the bacteriological diagnosis of culture-negative samples","authors":"Camille d’Humières , Skerdi Haviari , Marie Petitjean , Laurène Deconinck , Signara Gueye , Nathan Peiffer-Smadja , Lynda Chalal , Naima Beldjoudi , Geoffrey Rossi , Yann Nguyen , Charles Burdet , Ségolène Perrineau , Diane Le Pluart , Roza Rahli , Michael Thy , Piotr Szychowiak , Xavier Lescure , Véronique Leflon-Guibout , Victoire de Lastours , Etienne Ruppé","doi":"10.1016/j.ijmm.2025.151650","DOIUrl":"10.1016/j.ijmm.2025.151650","url":null,"abstract":"<div><h3>Background</h3><div>Currently, diagnosis of bacterial infections is based on culture, possibly followed by the amplification and sequencing (Sanger method) of the 16S rDNA - encoding gene when cultures are negative. Clinical metagenomics (CMg), i.e. the sequencing of a sample’s entire nucleic acids, may allow for the identification of bacteria not detected by conventional methods. Here, we tested the performance of CMg compared to 16S rDNA sequencing (Sanger) in 50 patients with suspected bacterial infection but negative cultures.</div></div><div><h3>Methods</h3><div>This is a prospective cohort study. Fifty patients (73 samples) with negative culture and a 16S rDNA sequencing demand (Sanger) were recruited from two sites. On the same samples, CMg (Illumina NextSeq) was also performed and compared to 16S rDNA Sanger sequencing. Bacteria were identified using MetaPhlAn4.</div></div><div><h3>Results</h3><div>Among the 73 samples, 20 (27 %, 17 patients) had a clinically relevant 16S rDNA Sanger sequencing result (used for patient management) while 11 (15 %, 9 patients) were considered contaminants. At the patient level, the sensitivity of CMg was 70 % (12/17) compared to 16S rDNA. In samples negative for 16S rDNA Sanger sequencing (n = 53), CMg identified clinically-relevant bacteria in 10 samples (19 %, 10 patients) with 14 additional bacteria.</div></div><div><h3>Conclusions</h3><div>CMg was not 100 % sensitive when compared to 16S, supporting that it may not be a suitable replacement. However, CMg did find additional bacteria in samples negative for 16S rDNA Sanger. CMg could therefore be positioned as a complementary to 16S rDNA Sanger sequencing.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151650"},"PeriodicalIF":4.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-06DOI: 10.1016/j.ijmm.2025.151648
Shuhui Wang , Xinlin Guo , Ye Tao , Xuemei Zhang , Weicai Suo , Yapeng Zhang , Li Lei , Yibing Yin , Yuqiang Zheng
Uracil metabolism is an important step in the growth and metabolism of Streptococcus pneumoniae, and pyrimidine nucleotides play an important role in the expression and production of S. pneumoniae capsules. MgaSpn(spd_1587),as a transcriptional ragulator of host environment adaptation, regulates the biosynthesis of the capsules and phosphorylcholine. However, the underlying regulation mechanism between uracil metabolism and biosynthesis of capsules remains incompletely understood. Here, we first described the relationship between uracil metabolism and capsule expression via the pyrR gene(spd_1134) in S. pneumoniae. Electrophoretic mobility-shift assays (EMSAs) and DNase I footprinting assays showed a direct interaction between MgaSpn and the pyrR promoter (PpyrR) at two specific binding sites. MgaSpn negatively regulated capsule production through pyrR as confirmed by complementing pyrR expression in D39ΔmgaSpnΔpyrR (mgaSpn and pyrR double-defective strain). Virulence experiments showed that the MgaSpn-pyrR interaction was necessary for both pneumococcal colonization and invasive infection. For the first time, the present study demonstrated that the de novo synthesis gene pyrR of S. pneumoniae is regulated by the MgaSpn transcriptional regulator.Taken together,these results provide an insight into the regulation of capsule production mediated by uracil metabolism and its important roles in pneumococcal pathogenesis.
{"title":"The MgaSpn global transcriptional regulator mediates the biosynthesis of capsular polysaccharides and affects virulence via the uracil synthesis pathway in Streptococcus pneumoniae","authors":"Shuhui Wang , Xinlin Guo , Ye Tao , Xuemei Zhang , Weicai Suo , Yapeng Zhang , Li Lei , Yibing Yin , Yuqiang Zheng","doi":"10.1016/j.ijmm.2025.151648","DOIUrl":"10.1016/j.ijmm.2025.151648","url":null,"abstract":"<div><div>Uracil metabolism is an important step in the growth and metabolism of <em>Streptococcus pneumoniae</em>, and pyrimidine nucleotides play an important role in the expression and production of <em>S. pneumoniae</em> capsules. Mga<em>Spn</em>(<em>spd_1587</em>),as a transcriptional ragulator of host environment adaptation, regulates the biosynthesis of the capsules and phosphorylcholine. However, the underlying regulation mechanism between uracil metabolism and biosynthesis of capsules remains incompletely understood. Here, we first described the relationship between uracil metabolism and capsule expression via the <em>pyrR</em> gene(<em>spd_1134</em>) in <em>S. pneumoniae</em>. Electrophoretic mobility-shift assays (EMSAs) and DNase I footprinting assays showed a direct interaction between Mga<em>Spn</em> and the <em>pyrR</em> promoter (P<sub><em>pyrR</em></sub>) at two specific binding sites. MgaSpn negatively regulated capsule production through <em>pyrR</em> as confirmed by complementing <em>pyrR</em> expression in D39Δ<em>mgaSpn</em>Δ<em>pyrR</em> (<em>mgaSpn</em> and <em>pyrR</em> double-defective strain). Virulence experiments showed that the Mga<em>Spn</em>-<em>pyrR</em> interaction was necessary for both pneumococcal colonization and invasive infection. For the first time, the present study demonstrated that the de novo synthesis gene <em>pyrR</em> of S. pneumoniae is regulated by the Mga<em>Spn</em> transcriptional regulator.Taken together,these results provide an insight into the regulation of capsule production mediated by uracil metabolism and its important roles in pneumococcal pathogenesis.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151648"},"PeriodicalIF":4.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-05DOI: 10.1016/j.ijmm.2025.151647
Eliška Vrbová , Petra Pospíšilová , Eliška Dastychová , Martina Kojanová , Miluše Kreidlová , Daniela Vaňousová , Filip Rob , Přemysl Procházka , Alena Krchňáková , Vladimír Vašků , Radim Strnadel , Olga Faustmannová , Monika Dvořáková Heroldová , Ivana Kuklová , Hana Zákoucká , David Šmajs
Syphilis is a multistage sexually transmitted disease caused by Treponema pallidum ssp. pallidum (TPA). This study analyzed clinical samples collected from patients with a diagnosed syphilis infection from 2004–2022, isolated in the Czech Republic. Mucocutaneous swab samples (n = 543) from 543 patients were analyzed, and from these samples, 80.11 % (n = 435) were PCR positive, and 19.89 % (n = 108) were PCR negative for TPA DNA. Swabs were more often positive when collected from syphilis patients in the primary and secondary stages, compared to the latent or unknown stage. There was no significant difference in PCR positivity between the primary and secondary stages (p = 0.099). In IgM-positive patients, a statistically significant association with PCR-positivity was found in samples from seropositive (p = 0.033) and serodiscrepant (RPR negative) patients (p = 0.0006). When assessing our laboratory-defined cases of syphilis, the RPR, IgM, and PCR tests were similarly effective (within the range of 80.1–86.1 %). However, parallel testing with these methods was even more effective, i.e., RPR + PCR was 96.1 % effective and RPR + IgM + PCR was 97.8 % effective. A combination of RPR + PCR, or a combination of all three tests (RPR, IgM, and PCR) can therefore be used to reliably detect active syphilis cases, including reinfections. Our findings show that the reverse algorithm for detecting syphilis could be substantially improved by adding IgM and PCR testing.
{"title":"PCR-detection rates of T. pallidum ssp. pallidum in swab samples from the Czech Republic (2004–2022): Combined RPR, IgM, and PCR tests efficiently detect active syphilis","authors":"Eliška Vrbová , Petra Pospíšilová , Eliška Dastychová , Martina Kojanová , Miluše Kreidlová , Daniela Vaňousová , Filip Rob , Přemysl Procházka , Alena Krchňáková , Vladimír Vašků , Radim Strnadel , Olga Faustmannová , Monika Dvořáková Heroldová , Ivana Kuklová , Hana Zákoucká , David Šmajs","doi":"10.1016/j.ijmm.2025.151647","DOIUrl":"10.1016/j.ijmm.2025.151647","url":null,"abstract":"<div><div>Syphilis is a multistage sexually transmitted disease caused by <em>Treponema pallidum</em> ssp. <em>pallidum</em> (TPA). This study analyzed clinical samples collected from patients with a diagnosed syphilis infection from 2004–2022, isolated in the Czech Republic. Mucocutaneous swab samples (n = 543) from 543 patients were analyzed, and from these samples, 80.11 % (n = 435) were PCR positive, and 19.89 % (n = 108) were PCR negative for TPA DNA. Swabs were more often positive when collected from syphilis patients in the primary and secondary stages, compared to the latent or unknown stage. There was no significant difference in PCR positivity between the primary and secondary stages (p = 0.099). In IgM-positive patients, a statistically significant association with PCR-positivity was found in samples from seropositive (p = 0.033) and serodiscrepant (RPR negative) patients (p = 0.0006). When assessing our laboratory-defined cases of syphilis, the RPR, IgM, and PCR tests were similarly effective (within the range of 80.1–86.1 %). However, parallel testing with these methods was even more effective, i.e., RPR + PCR was 96.1 % effective and RPR + IgM + PCR was 97.8 % effective. A combination of RPR + PCR, or a combination of all three tests (RPR, IgM, and PCR) can therefore be used to reliably detect active syphilis cases, including reinfections. Our findings show that the reverse algorithm for detecting syphilis could be substantially improved by adding IgM and PCR testing.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151647"},"PeriodicalIF":4.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-05DOI: 10.1016/j.ijmm.2025.151649
Liwen Zhong , Danjun Xu , Jingyi He , Lianhui Sun , Guangjian Fan , Ting Zhu , Yufeng Yao , Tingting Feng , Zelin Cui
Objectives
phage therapy is a promising approach for infections caused by drug-resistant bacteria; this study evaluated the impact of pre-exposure to phage particles on subsequent therapy. Mice were exposed intradermally (i.d.) to Staphylococcus aureus wide-host-range phage JD007, a member of the Myoviridae family.
Methods
phage-specific antibodies were detected using ELISA. Mice were infected with S. aureus in the same way to establish a dermal abscess model, and then the efficacy of phage therapy for the mice pre-exposed to JD007 was evaluated.
Results
JD007 could induce their specific IgM and IgG. IgM levels peaked on the 7th day following exposure, and IgG levels peaked on the 30th day after final immunization. Neutralization assays demonstrated that specific antibodies could reduce JD007’s infectivity to S. aureus in vitro. Furthermore, mice previously exposed to JD007 three times showed decreased phage therapeutic efficacies, leading to delayed recovery and even exacerbating abscesses. White blood cells and lymphocytes also increased. Despite pre-exposing the mice to JD007 once, the abscess areas following phage treatment did not differ from those of the infection group with naive mice. The western blot results showed that anti-phage antibodies could recognize the predicted major capsid protein and phage tail protein.
Conclusions
pre-exposure to phage particles may induce phage-neutralization antibodies and inhibit their therapeutic efficacies, delaying recovery or even exacerbating S. aureus-associated dermal abscesses for later treatment.
{"title":"Pre-exposure to phage particles reduces their antibacterial therapeutic efficacy both in vitro and in vivo","authors":"Liwen Zhong , Danjun Xu , Jingyi He , Lianhui Sun , Guangjian Fan , Ting Zhu , Yufeng Yao , Tingting Feng , Zelin Cui","doi":"10.1016/j.ijmm.2025.151649","DOIUrl":"10.1016/j.ijmm.2025.151649","url":null,"abstract":"<div><h3>Objectives</h3><div>phage therapy is a promising approach for infections caused by drug-resistant bacteria; this study evaluated the impact of pre-exposure to phage particles on subsequent therapy. Mice were exposed intradermally (i.d.) to <em>Staphylococcus aureus</em> wide-host-range phage JD007, a member of the <em>Myoviridae</em> family.</div></div><div><h3>Methods</h3><div>phage-specific antibodies were detected using ELISA. Mice were infected with <em>S. aureus</em> in the same way to establish a dermal abscess model, and then the efficacy of phage therapy for the mice pre-exposed to JD007 was evaluated.</div></div><div><h3>Results</h3><div>JD007 could induce their specific IgM and IgG. IgM levels peaked on the 7th day following exposure, and IgG levels peaked on the 30th day after final immunization. Neutralization assays demonstrated that specific antibodies could reduce JD007’s infectivity to <em>S. aureus</em> in vitro. Furthermore, mice previously exposed to JD007 three times showed decreased phage therapeutic efficacies, leading to delayed recovery and even exacerbating abscesses. White blood cells and lymphocytes also increased. Despite pre-exposing the mice to JD007 once, the abscess areas following phage treatment did not differ from those of the infection group with naive mice. The western blot results showed that anti-phage antibodies could recognize the predicted major capsid protein and phage tail protein.</div></div><div><h3>Conclusions</h3><div>pre-exposure to phage particles may induce phage-neutralization antibodies and inhibit their therapeutic efficacies, delaying recovery or even exacerbating <em>S. aureus-</em>associated dermal abscesses for later treatment.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151649"},"PeriodicalIF":4.5,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cardiovascular diseases, primarily caused by atherosclerosis, are a major public health concern worldwide. Atherosclerosis is characterized by chronic inflammation and lipid accumulation in the arterial wall, leading to plaque formation. In this process, macrophages play a crucial role by ingesting lipids and transforming into foam cells, which contribute to plaque instability and cardiovascular events. Recent studies have suggested that various pathogens are involved in the development of atherosclerosis, with Mycoplasma pneumoniae considered one of the potential candidates. Therefore, this study investigated whether this bacterium induces lipid accumulation in macrophages, which play a crucial role in the development of atherosclerosis, using the Raw264.7 model. Our findings revealed that M. pneumoniae infection promotes lipid droplet formation in macrophages. Glycerol 3-phosphate oxidase, GlpD, in the bacterium is involved in this process by producing reactive oxygen species, which in turn causes the oxidation of low-density lipoprotein. Furthermore, the significant increase in the expression of oxidized lipid receptors involved in the uptake of this oxidized lipid indicates that the bacteria promote lipid uptake in infected macrophages. These results suggest that M. pneumoniae has a direct pro-atherogenic effect, promoting the formation of atherosclerotic lesions through foam cell formation. Understanding the mechanisms by which M. pneumoniae influences atherosclerosis provides valuable insights for devising new therapeutic strategies for the prevention and management of cardiovascular diseases.
{"title":"Mycoplasma pneumoniae drives macrophage lipid uptake via GlpD-mediated oxidation, facilitating foam cell formation","authors":"Takeshi Yamamoto, Miki Okuno, Koichi Kuwano, Yoshitoshi Ogura","doi":"10.1016/j.ijmm.2025.151646","DOIUrl":"10.1016/j.ijmm.2025.151646","url":null,"abstract":"<div><div>Cardiovascular diseases, primarily caused by atherosclerosis, are a major public health concern worldwide. Atherosclerosis is characterized by chronic inflammation and lipid accumulation in the arterial wall, leading to plaque formation. In this process, macrophages play a crucial role by ingesting lipids and transforming into foam cells, which contribute to plaque instability and cardiovascular events. Recent studies have suggested that various pathogens are involved in the development of atherosclerosis, with <em>Mycoplasma pneumoniae</em> considered one of the potential candidates. Therefore, this study investigated whether this bacterium induces lipid accumulation in macrophages, which play a crucial role in the development of atherosclerosis, using the Raw264.7 model. Our findings revealed that <em>M. pneumoniae</em> infection promotes lipid droplet formation in macrophages. Glycerol 3-phosphate oxidase, GlpD, in the bacterium is involved in this process by producing reactive oxygen species, which in turn causes the oxidation of low-density lipoprotein. Furthermore, the significant increase in the expression of oxidized lipid receptors involved in the uptake of this oxidized lipid indicates that the bacteria promote lipid uptake in infected macrophages. These results suggest that <em>M. pneumoniae</em> has a direct pro-atherogenic effect, promoting the formation of atherosclerotic lesions through foam cell formation. Understanding the mechanisms by which <em>M. pneumoniae</em> influences atherosclerosis provides valuable insights for devising new therapeutic strategies for the prevention and management of cardiovascular diseases.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151646"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143042877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-06DOI: 10.1016/j.ijmm.2025.151645
Nahed Al Laham , Ahmed Al Afifi , Alexander Mellmann , Frieder Schaumburg
Background
Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a difficult to treat organism owing to limited therapeutic options. So far, little is known about the molecular characteristics of CRKP in Palestine.
Objectives
The aim of this study was to investigate the antimicrobial resistance patterns, multilocus sequence types (ST) and resistance genes among clinical K. pneumoniae isolates from hospitalized patients in Gaza Strip, Palestine.
Methods
K. pneumoniae from blood cultures (n = 55) were collected at two hospitals in Gaza Strip (2023) and identified by MALDI-TOF-MS. Antimicrobial susceptibility testing was done using VITEK-2 automated systems. Carbapenemases were phenotypically detected. Whole genome sequencing (WGS) of all CRKP isolates was performed to assess determinants for carbapenem resistance and genotypes.
Results
Of all K. pneumoniae isolates, 40 % (n = 22/55) were CRKP. Among CRKP, cefiderocol showed the least resistance (46 %, n = 10/22) while ceftazidime/avibactam showed a synergistic effect with aztreonam (36 %, n = 8/22). The majority (86 %, n = 19/22) of CRKP carried metallo-β-lactamases, and only 9 % (n = 2/22) encoded OXA-48 carbapenemase. WGS of CRKP revealed that the predominant genotype is multilocus sequence type ST147 harboring blaNDM-5 and blaCTX-M-15.
Conclusion
The proportion of CRKP among all K. pneumoniae from bloodstream infection in Gaza Strip is high (40 %) and mainly associated with the blaNDM-5-positive high-risk clone ST147.
{"title":"Characterization of carbapenem-resistant Klebsiella pneumoniae from blood cultures in Gaza Strip hospitals, Palestine","authors":"Nahed Al Laham , Ahmed Al Afifi , Alexander Mellmann , Frieder Schaumburg","doi":"10.1016/j.ijmm.2025.151645","DOIUrl":"10.1016/j.ijmm.2025.151645","url":null,"abstract":"<div><h3>Background</h3><div>Carbapenem-resistant <em>Klebsiella pneumoniae</em> (CRKP) is a difficult to treat organism owing to limited therapeutic options. So far, little is known about the molecular characteristics of CRKP in Palestine.</div></div><div><h3>Objectives</h3><div>The aim of this study was to investigate the antimicrobial resistance patterns, multilocus sequence types (ST) and resistance genes among clinical <em>K. pneumoniae</em> isolates from hospitalized patients in Gaza Strip, Palestine.</div></div><div><h3>Methods</h3><div><em>K. pneumoniae</em> from blood cultures (n = 55) were collected at two hospitals in Gaza Strip (2023) and identified by MALDI-TOF-MS. Antimicrobial susceptibility testing was done using VITEK-2 automated systems. Carbapenemases were phenotypically detected. Whole genome sequencing (WGS) of all CRKP isolates was performed to assess determinants for carbapenem resistance and genotypes.</div></div><div><h3>Results</h3><div>Of all <em>K. pneumoniae</em> isolates, 40 % (n = 22/55) were CRKP. Among CRKP, cefiderocol showed the least resistance (46 %, n = 10/22) while ceftazidime/avibactam showed a synergistic effect with aztreonam (36 %, n = 8/22). The majority (86 %, n = 19/22) of CRKP carried metallo-β-lactamases, and only 9 % (n = 2/22) encoded OXA-48 carbapenemase. WGS of CRKP revealed that the predominant genotype is multilocus sequence type ST147 harboring <em>bla</em><sub>NDM-5</sub> and <em>bla</em><sub>CTX-M-15</sub>.</div></div><div><h3>Conclusion</h3><div>The proportion of CRKP among all <em>K. pneumoniae</em> from bloodstream infection in Gaza Strip is high (40 %) and mainly associated with the <em>bla</em><sub>NDM-5</sub>-positive high-risk clone ST147.</div></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"318 ","pages":"Article 151645"},"PeriodicalIF":4.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142958167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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