Clémence Prudhomme, Brune Joannard, Gérard Lina, Eleonore De Launay, Oana Dumitrescu, Elisabeth Hodille
{"title":"Drug susceptibility testing of Nocardia spp. using the disk diffusion method.","authors":"Clémence Prudhomme, Brune Joannard, Gérard Lina, Eleonore De Launay, Oana Dumitrescu, Elisabeth Hodille","doi":"10.1186/s12941-024-00768-2","DOIUrl":"https://doi.org/10.1186/s12941-024-00768-2","url":null,"abstract":"<p><strong>Background: </strong>Drug susceptibility testing (DST) for Nocardia spp. is essential to initiate effective antibiotic therapy. Currently, the only recommended technique is the determination of minimum inhibitory concentrations (MICs) by microdilution. This method can be tedious to perform, despite the availability of ready-to-use plates. Herein, the aim was to determine the critical inhibition diameters specific to Nocardia spp.</p><p><strong>Methods: </strong>MICs of 134 Nocardia isolates were determined by microdilution. Interpretative categories (Susceptible/Intermediate/Resistant) were determined using Clinical and Laboratory Standards Institute breakpoints. In parallel, disk diffusion DST was performed. Receiver-operating-characteristic (ROC) curves were constructed to determine the inhibition diameter value that best discriminated between susceptible and non-susceptible strains (intermediate/resistant). The category agreement (CA), the rate of major (maj) and very major (vmj) discrepancies between microdilution and disk diffusion method was calculated.</p><p><strong>Results: </strong>For tobramycin, the critical diameter of 19 mm (diameter ≤ 19 mm = resistant strain; diameter > 19 mm = susceptible strain) provided a CA of 98.5%, 0.0% vmj, and 2.9% maj discrepancies, reaching strictly the acceptable performance criteria defined by the U.S. Food and Drug Administration (FDA). For amikacin, the critical diameter of 25 mm (diameter ≤ 25 mm = resistant strain; diameter > 25 mm = susceptible strain) provided a CA of 98.5%, 0.0% vmj, and 1.5% maj discrepancies. For imipenem, excluding N. farcinica and N. cyriacigeorgica, the critical diameter of 29 mm (diameter ≤ 29 mm = resistant strain; diameter > 29 mm = susceptible strain), provided a CA of 98.6%, 0.0% vmj, and 0.0% maj discrepancies. Despite an estimated vmj rate 0.0%, the 95%-confident-interval exceeded the FDA criteria due to an insufficient number of amikacin/imipenem-resistant strains. For other tested antibiotics (ciprofloxacin, moxifloxacin, amoxicillin-clavulanate, ceftriaxone, cotrimoxazole, linezolid), the FDA criteria were not reached.</p><p><strong>Conclusions: </strong>Although the FDA criteria were mostly unmet, disk diffusion DST was suitable to accurately categorize Nocardia isolates into interpretative categories for the aminoglycosides and imipenem only, excluding species N. farcinica and N. cyriacigeorgica.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"105"},"PeriodicalIF":4.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142852224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Meningitis due to Gemella sp. in a patient with severe ENT conditions: case report and review of the literature.","authors":"Ilyès Benhalima, Lola Jacquemont, Laurine Milière, Alina Tone, Nicolas Ettahar, Gisèle Dewulf, Edith Mazars","doi":"10.1186/s12941-024-00765-5","DOIUrl":"https://doi.org/10.1186/s12941-024-00765-5","url":null,"abstract":"<p><p>In June 2022, a 73-year-old man with a history of laryngeal and esophageal carcinoma was admitted to the emergency unit with sudden fever, confusion, and general condition deterioration. Initial assessments showed a fever of 38.5 °C, elevated C-reactive protein (CRP) at 209 mg/L, and a neutrophil count of 10.4 G/L, with negative results for urine analysis, blood cultures, and multiple infectious pathogens, including Legionella pneumophila, pneumococcal antigen, and SARS-CoV-2. Computed tomography (CT) scans revealed no significant infectious focus.Empirical treatment with Ceftriaxone and Ciprofloxacin was initiated. Despite treatment, the patient's condition remained unchanged, and a lumbar puncture revealed turbid cerebrospinal fluid (CSF) with 14,300 white blood cells (WBC)/mm³, predominantly neutrophils, elevated proteins, and decreased glucose. Gram staining suggested Neisseria meningitidis, but further testing was necessary. Antibiotic therapy was switched to Cefotaxime and Dexamethasone, and the patient was transferred to the Tropical and Infectious Disease Unit.Multiplex PCR assays and additional CSF tests were negative for common pathogens. Sequencing of 16S ribosomal RNA identified Gemella sp. The patient's condition improved with continued Cefotaxime treatment, and he recovered without neurological sequelae. Subsequent dental CT revealed poor dental hygiene but no signs of osteo-meningeal breach or bone lysis.A literature review identified 22 reported cases of central nervous system (CNS) infections caused by various Gemella species from 1980 to 2022. Of these, 59% presented with meningitis, and 41% had additional encephalitis or brain abscesses. Complete recovery occurred in 77% of cases, with 9% resulting in neurological damage and another 9% in fatal outcomes. Relapses occurred in 14% of the cases. The review highlighted that CNS infections by Gemella spp. primarily affect immunocompromised adults with ENT (ear nose throat) or neurological breaches, although some cases involved healthy individuals.This case underscores the diagnostic challenges posed by uncommon pathogens like Gemella and highlights the utility of molecular microbiology in identifying causative agents, thus guiding appropriate treatment. The patient's history of ENT and esophageal cancers, along with recent radiotherapy and chemotherapy, likely contributed to the infection's development. The case emphasizes the importance of thorough investigation in febrile confusion cases and the potential role of Gemella spp. in CNS infections.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"106"},"PeriodicalIF":4.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142852238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Claudia Alteri, Antonio Teri, Maria Francesca Liporace, Antonio Muscatello, Leonardo Terranova, Margherita Carnevale Schianca, Federica Salari, Beatrice Silvia Orena, Flaminia Gentiloni Silverj, Mara Bernazzani, Simona Biscarini, Giulia Renisi, Lisa Cariani, Caterina Matinato, Ciro Canetta, Alessandra Bandera, Annapaola Callegaro
{"title":"Transmission cluster of cefiderocol-non-susceptible carbapenem-resistant Acinetobacter baumannii in cefiderocol-naïve individuals.","authors":"Claudia Alteri, Antonio Teri, Maria Francesca Liporace, Antonio Muscatello, Leonardo Terranova, Margherita Carnevale Schianca, Federica Salari, Beatrice Silvia Orena, Flaminia Gentiloni Silverj, Mara Bernazzani, Simona Biscarini, Giulia Renisi, Lisa Cariani, Caterina Matinato, Ciro Canetta, Alessandra Bandera, Annapaola Callegaro","doi":"10.1186/s12941-024-00763-7","DOIUrl":"10.1186/s12941-024-00763-7","url":null,"abstract":"<p><strong>Background: </strong>During prolonged FDC therapy, the emergence of FDC non-susceptibility in CRAB has been reported. Here, we report a transmission cluster of FDC-non-susceptible CRAB in four patients, all naïve to FDC treatment, characterized by a premature stop codon and amino acid deletion in the PirA protein.</p><p><strong>Methods: </strong>CRAB strains obtained from patients admitted in a single medicine ward of the IRCCS Fondazione Ospedale Maggiore Policlinico between March and July 2024 were analyzed by WGS and antimicrobial susceptibility testing. Phylogenetic analysis was used to assess their genetic relatedness.</p><p><strong>Results: </strong>Between March and July 2024, an outbreak of 33 CRAB was observed among hospitalized patients in a single ward at IRCCS. Genomic analysis, available in 29 cases, revealed that 24 isolates belonged to ST208/1806, 4 to ST369, and one to ST195/1816 (according to the Oxford scheme). FDC susceptibility was affected only in the four ST369 isolates (Kirby-Bauer disk diffusion diameter: 13 mm; UMIC<sup>®</sup> method MIC: 4 mg/L), all characterized by a premature stop codon followed by a 52 amino acid deletion located between the amino acids 377 and 428 of the siderophore-drug receptor PirA. No other relevant mutations were detected in the iron-uptake genes. Core-genome ML tree including ST369 reference strains revealed that the four ST369 isolates were highly related and formed a distinct cluster (SNP distance: 3 [IQR: 1-6]). Of note, the four isolates were collected from four FDC-naïve individuals, two experiencing a CRAB-mediated infection.</p><p><strong>Conclusions: </strong>Our findings alert about the circulation of clones carrying modified siderophore-drug receptors without evidence of previous FDC treatment and support the importance of testing FDC susceptibility appropriately before its administration.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"104"},"PeriodicalIF":4.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11607823/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cristina Elías-López, Montserrat Muñoz-Rosa, Julia Guzmán-Puche, Elena Pérez-Nadales, Eduardo Chicano-Galvez, Luis Martínez-Martínez
{"title":"Porin expression in clinical isolates of Klebsiella pneumoniae: a comparison of SDS-PAGE and MALDI-TOF/MS and limitations of whole genome sequencing analysis.","authors":"Cristina Elías-López, Montserrat Muñoz-Rosa, Julia Guzmán-Puche, Elena Pérez-Nadales, Eduardo Chicano-Galvez, Luis Martínez-Martínez","doi":"10.1186/s12941-024-00761-9","DOIUrl":"10.1186/s12941-024-00761-9","url":null,"abstract":"<p><strong>Background: </strong>The permeability of the outer membrane barrier modulates the susceptibility of microorganisms to antimicrobial agents. Loss or structural alterations of porins contribute to decreased antibiotic concentration of multiple antimicrobial agents. Precise definition of porin profiles is of critical importance to understand the role of porins in antimicrobial resistance. The objectives of this study are to compare the expression patterns of major outer membrane proteins (OMP) of clinical isolates of Klebsiella pneumoniae obtained with Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry (MALDI-TOF/MS), with those obtained with sodium-dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and to correlate porin expression patterns with the sequences of porins genes defined with whole genome sequencing (WGS).</p><p><strong>Methods: </strong>The OMP profiles of 26 clinical isolates of K. pneumoniae and of strain ATCC 13883 (wild-type) and ATCC 700603 (producing SHV-18) have been determined using both SDS-PAGE and MALDI-TOF/MS. SDS-PAGE was performed using both homemade and commercial gels, and protein bands were identified by liquid chromatography coupled to mass spectrometry. A rapid extraction method was used to analyse OMPs by MALDI-TOF/MS. The sequences of porin genes were obtained by WGS and mutations were defined by BLAST.</p><p><strong>Results: </strong>Same results were obtained for all strains either using SDS-PAGE or MALDI-TOF/MS. SDS-PAGE showed protein bands of ~ 35, ~36, and ~ 37 kDa, identified as OmpA, OmpK36 and OmpK35, respectively. By MALDI-TOF/MS, peaks at ~ 35,700 (OmpA), ~ 37,000 (OmpK35), and ~ 38,000 (OmpK36) m/z were detected. ompK35 was intact in nine wild-type isolates and was truncated in 13 isolates, but OmpK35 was not observed in 3 isolates without mutations in ompK35. One point mutation was detected in another isolate and multiple mutations were detected in the remaining isolate. ompK36 was truncated in two isolates lacking this protein and presented one point mutation (n = 1) or multiple mutations in the remaining isolates.</p><p><strong>Conclusion: </strong>MALDI-TOF/MS was reliable for porin detection, but because of the complex regulation of porin genes, WGS cannot always anticipate protein expression, as observed with SDS-PAGE and MALDI-TOF/MS.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"103"},"PeriodicalIF":4.6,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11587576/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Emergence of carbapenem resistance in persistent Shewanella algae bacteremia: the role of pdsS G547W mutation in adaptive subpopulation dynamics.","authors":"Yao-Ting Huang, Po-Yu Liu","doi":"10.1186/s12941-024-00759-3","DOIUrl":"10.1186/s12941-024-00759-3","url":null,"abstract":"<p><p>This study elucidates the in vivo genetic mechanisms contributing to the emerging resistance to carbapenem in Shewanella algae through a lens of adaptive microbial evolution. Leveraging PacBio amplification-free sequencing, we tracked the evolution of β-lactam resistance in clinical isolates from a persistent S. algae bacteremia case amidst antimicrobial therapy. Our investigation spotlighted a recurrent G547W mutation in the sensor histidine kinase (pdsS), which was associated with the overexpression of an OmpA-like protein (pdsO) within a proteobacteria-specific sortase system. Intriguingly, we observed a recurrent switch between wild-type and G547W alleles, revealing an adaptive expansion and contraction of underlying cell subpopulations in response to β-lactam exposure. Comparative transcriptome analyses further demonstrated the overexpression of genes pivotal for membrane integrity, biofilm formation, immune evasion, and β-lactamase activation in resistant samples. This underscores the pre-existence of resistant cells at minuscule frequencies even without antibiotic pressure, potentially explaining the within-host emergence of resistance during antibiotic treatments. Our findings provide pivotal insights into the dynamic genetic adaptations of S. algae under therapeutic pressures, unmasking intricate resistance mechanisms and highlighting the critical role of subpopulation dynamics in treatment outcomes.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"102"},"PeriodicalIF":4.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11580497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohsen Nazari, Mohammad Taheri, Fatemeh Nouri, Maryam Bahmanzadeh, Mohammad Yousef Alikhani
{"title":"The antimicrobial and antibiofilm effects of gentamicin, imipenem, and fucoidan combinations against dual-species biofilms of Staphylococcus aureus and Acinetobacter baumannii isolated from diabetic foot ulcers.","authors":"Mohsen Nazari, Mohammad Taheri, Fatemeh Nouri, Maryam Bahmanzadeh, Mohammad Yousef Alikhani","doi":"10.1186/s12941-024-00760-w","DOIUrl":"10.1186/s12941-024-00760-w","url":null,"abstract":"<p><strong>Introduction: </strong>Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia due to impaired insulin production or utilization, leading to severe health complications. Diabetic foot ulcers (DFUs) represent a major complication, often exacerbated by polymicrobial infections involving Staphylococcus aureus and Acinetobacter baumannii. These pathogens, notorious for their resistance to antibiotics, complicate treatment efforts, especially due to biofilm formation, which enhances bacterial survival and resistance. This study explores the synergistic effects of combining gentamicin, imipenem, and fucoidan, a sulfated polysaccharide with antimicrobial properties, against both planktonic and biofilm forms of S. aureus and A. baumannii.</p><p><strong>Methods: </strong>Isolates of S. aureus and A. baumannii were collected from DFUs and genetically confirmed. Methicillin resistance in S. aureus was identified through disk diffusion and PCR. Biofilm formation, including dual-species biofilms, was analyzed using the microtiter plate method. The antimicrobial efficacy of gentamicin, imipenem, and fucoidan was assessed by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC). Synergistic interactions were evaluated using the fractional inhibitory concentration index (FICi) and fractional bactericidal concentration index (FBCi). The expression of biofilm-associated genes (icaA in S. aureus and bap in A. baumannii) was analyzed, and the cytotoxicity of fucoidan was assessed.</p><p><strong>Results: </strong>The study revealed that 77.4% of S. aureus and all A. baumannii isolates showed multidrug resistance. Among 837 tested conditions for dual-species biofilm formation, 72 resulted in strong biofilm formation and 67 in moderate biofilm formation. The geometric mean MIC values for gentamicin were 12.2 µg/mL for S. aureus, 22.62 µg/mL for A. baumannii, and 5.87 µg/mL for their co-culture; for imipenem, they were 19.84, 9.18, and 3.70 µg/mL, respectively, and for fucoidan, 48.50, 31.20, and 19.65 µg/mL, respectively. The MBC values for gentamicin were 119.42, 128, and 11.75 µg/mL; for imipenem, they were 48.50, 14.92, and 8 µg/mL; and for fucoidan, they were 88.37, 62.62, and 42.48 µg/mL. The MBIC values were 55.71, 119.42, and 18.66 µg/mL for gentamicin; 68.59, 48.50, and 25.39 µg/mL for imipenem; and 153.89, 101.49, and 53.53 µg/mL for fucoidan. The MBEC values were 315.17, 362.03, and 59.25 µg/mL for gentamicin; 207.93, 157.58, and 74.65 µg/mL for imipenem; and 353.55, 189.46, and 99.19 µg/mL for fucoidan. When cultured in planktonic form, the geometric mean FICi and FBCi values indicated additive effects, while co-culture showed FICi values of ≤ 0.5, suggesting a synergistic interaction. Treatment with gentamicin and fucoidan led to significant downregulation of the icaA","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"101"},"PeriodicalIF":4.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11568526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142643269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ceftazidime-avibactam treatment dilemma of bla<sub>KPC-2</sub>-containing Klebsiella pneumoniae due to the development of co-existence of mixed strains carrying bla<sub>KPC-2</sub> or bla<sub>KPC-33</sub> in lung transplant recipients.","authors":"Zichen Lei, Ziyao Li, Yulin Zhang, Lingbing Zeng, Yongli Wu, Feilong Zhang, Xinrui Yang, Xinmeng Liu, Qi Liu, Yiqun Ma, Binghuai Lu","doi":"10.1186/s12941-024-00743-x","DOIUrl":"10.1186/s12941-024-00743-x","url":null,"abstract":"<p><strong>Background: </strong>Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant threat to immunocompromised populations, including lung transplant recipients. This study investigates mixed CRKP strains carrying either bla<sub>KPC-2</sub> or bla<sub>KPC-33</sub> following ceftazidime-avibactam (CAZ/AVI) exposure, particularly in the context of lung transplantation. Mixed CRKP strains with shifting resistance phenotypes were frequently identified in patients exposed to CAZ/AVI. We aimed to elucidate the transitional state of bla<sub>KPC</sub> variants by selecting CAZ/AVI-sensitive and -resistant CRKP strains from a lung transplantation patient.</p><p><strong>Methods: </strong>The bla<sub>KPC</sub>-variant-carrying CRKP strains were collected from lung transplant recipients exposed to CAZ/AVI in less than two years. Antibiotic susceptibility testing (AST) was conducted using microbroth dilution, and whole-genome sequencing (WGS) was used to identify genotypes and resistance mechanisms. Limiting dilution, drop-plate, and in vitro induction experiments determined bla<sub>KPC</sub>-variant changes during CAZ/AVI administration. qPCR primers/probes were designed to identify bla<sub>KPC-2</sub> mutations.</p><p><strong>Results: </strong>Among 104 lung transplant recipients infected by bla<sub>KPC</sub>-harboring CRKP strains and receiving CAZ/AVI, 10 (9.6%) experienced changing resistance phenotypes. The limiting dilution method found that Patient 10's CRKP strains carried either bla<sub>KPC-2</sub> or bla<sub>KPC-33</sub>. The drop-plate experiment showed differing growth patterns on CAZ/AVI mediums. The in vitro induction experiment demonstrated shifting from bla<sub>KPC-2</sub> to bla<sub>KPC-33</sub>.</p><p><strong>Conclusions: </strong>The study identified a \"transitional state\" of the mixed CRKP strains carrying either bla<sub>KPC-2</sub> or bla<sub>KPC-33</sub> in CAZ/AVI-exposed patients. Molecular diagnostics are crucial for identifying mixed strains and the transitional state of bla<sub>KPC</sub> variants, guiding treatment decisions in this complex landscape.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"99"},"PeriodicalIF":4.6,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11549737/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guanyi Zhang, Yisheng Chen, Jia Chen, Dongting Yao
{"title":"Association of multilocus sequence typing, MSH2 gene mutations, and antifungal resistance in Candida glabrata: implications for clinical outcomes in Chinese hospitals.","authors":"Guanyi Zhang, Yisheng Chen, Jia Chen, Dongting Yao","doi":"10.1186/s12941-024-00758-4","DOIUrl":"10.1186/s12941-024-00758-4","url":null,"abstract":"<p><strong>Background: </strong>Candida glabrata is the second most common cause of invasive candidiasis worldwide. In this study, we determined the clinical characteristics and drug sensitivity of C. glabrata isolates and investigated the associations between MSH2 gene mutations, sequence types (ST), and drug resistance.</p><p><strong>Methods: </strong>A total of 154 C. glabrata isolates were collected from patients being treated in three hospitals in China. The antifungal sensitivity of the strains was assessed using the broth microdilution method. Multilocus sequence typing (MLST) was also performed, followed by MSH2 sequencing. The clinical features and outcomes of C. glabrata infection were analysed for a total of 49 strains, which were collected from patients with invasive Candida infection at Longhua Hospital.</p><p><strong>Results: </strong>All 154 isolates were found to be susceptible to amphotericin, 5-fluorocytosine, anidulafungin, caspofungin, and micafungin, whereas 11.7% were fluconazole-resistant, 18.8% were itraconazole non-wild type, and 35.7% were voriconazole non-wild type. ST7 (62.34%) was the most common ST genotype, followed by ST10 (16.88%) and ST15 (7.79%). The total azole resistance rates for all isolates, ST7, ST10, and other STs were 36.4, 42.7, 34.6, and 18.8%, respectively. The ST7 and ST10 isolates were characterised by a higher drug resistance rate than the other minor ST isolates. Moreover, 59.09% of isolates had one or more MSH2 non-synonymous mutations, with V239L being the most commonly detected mutation. The frequency of MSH2 mutations was significantly higher in azole-resistant isolates than in other isolates, whereas P6L or L87P mutations were associated with the highest azole resistance rates of up to 87.5% and 80%, respectively. Our results indicated that ST7 and ST15 are independent predictors of mortality caused by C. glabrata infection and revealed a higher 30-day mortality in patients infected with these strains than in those infected with other ST isolates.</p><p><strong>Conclusions: </strong>Our findings revealed the relationships between MLST, MSH2 gene mutations, and drug resistance in the common pathogenic fungus C. glabrata, and thereby enabled us to identify strains that are associated with higher rates of mortality. These findings will contribute to enhancing our understanding of the pathogenesis of C. glabrata infection.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"100"},"PeriodicalIF":4.6,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11549793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Augustine Yeboah, Monikamira Vivekanandan, Ernest Adankwah, Dorcas O Owusu, Wilfred Aniagyei, Difery Minadzi, Isaac Acheampong, Joseph F Arthur, Millicent Lamptey, Mohammed K Abass, Francis Kumbel, Francis Osei-Yeboah, Amidu Gawusu, Linda Batsa Debrah, Alexander Debrah, Ertan Mayatepek, Julia Seyfarth, Richard O Phillips, Marc Jacobsen
{"title":"Concomitant parasite infections influence tuberculosis immunopathology and favor rapid sputum conversion of pulmonary tuberculosis patients.","authors":"Augustine Yeboah, Monikamira Vivekanandan, Ernest Adankwah, Dorcas O Owusu, Wilfred Aniagyei, Difery Minadzi, Isaac Acheampong, Joseph F Arthur, Millicent Lamptey, Mohammed K Abass, Francis Kumbel, Francis Osei-Yeboah, Amidu Gawusu, Linda Batsa Debrah, Alexander Debrah, Ertan Mayatepek, Julia Seyfarth, Richard O Phillips, Marc Jacobsen","doi":"10.1186/s12941-024-00756-6","DOIUrl":"10.1186/s12941-024-00756-6","url":null,"abstract":"<p><p>Immunopathology of human tuberculosis (TB) in a subgroup of patients is characterized by aberrantly high concentrations of inflammatory cytokines, for example Interleukin (IL)-6. Concomitant (co-)infections by parasites can affect host immunity, but the impact on immunopathology in TB patients is poorly defined. Here we characterized a group of patients with TB ( n = 76) from Ghana with different protozoan and helminth co-infections. Plasma cytokines were measured at the onset of disease and anti-mycobacterial treatment efficacy was monitored during disease course. A subgroup of TB patients had co-infections with protozoan (n = 19) or helminth (n = 16) parasites. Plasma analyses for candidate cytokines identified lower levels of IL-6 in parasite co-infected patients with TB. Moreover, it took less time for co-infected patients to become sputum-negative for Mycobacterium tuberculosis during treatment. These results indicated an influence of parasite co-infections on immunopathology in TB and suggested positive effects on treatment efficacy.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"97"},"PeriodicalIF":4.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11545981/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142602839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Epidemiological and molecular characteristics of carbapenem-resistant Klebsiella pneumoniae from pediatric patients in Henan, China.","authors":"Jiayue Ma, Kaijie Gao, Mingchao Li, Juanjuan Zhou, Xiaorui Song, Yaodong Zhang, Zhidan Yu, Zengyuan Yu, Weyland Cheng, Wancun Zhang, Adong Shen, Junmei Yang, Huiqing Sun, Lifeng Li","doi":"10.1186/s12941-024-00757-5","DOIUrl":"10.1186/s12941-024-00757-5","url":null,"abstract":"<p><strong>Purpose: </strong>Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging global threat, whereas its epidemiological characteristics in children are rarely reported. This study aims to analyze clinical and epidemiological characteristics of CRKP from children in Henan, China.</p><p><strong>Methods: </strong>CRKP strains were isolated from pediatric patients, and the antimicrobial susceptibility of CRKP was determined using broth microdilution methods. The epidemiological characteristics of CRKP, including specimen sources, clinical data, carbapenemase types, virulence factors, MLST and PBRT typing were analyzed.</p><p><strong>Results: </strong>In total, 108 CRKP isolates were isolated from specimens including sputum, blood and urine, mainly from preterm pediatric department and internal medical intensive care unit (ICU). Newborns and staying in the ICU were risk factors for crude mortality. 107 isolates exhibited a multi-drug resistant (MDR) phenotype, and one isolate was extensively drug-resistant (XDR). Bacterial susceptibility to colistin, tigecycline and trimethoprim/sulfamethoxazole was 98.10%, 78.50% and 91.43%, respectively. Carbapenemase bla<sub>KPC</sub> (86.11%) was predominant, followed by bla<sub>NDM</sub> (5.56%) and bla<sub>IMP</sub> (2.78%). Two strains co-harbored bla<sub>KPC</sub>-bla<sub>NDM</sub>, one had bla<sub>KPC</sub>-bla<sub>IMP</sub>, whereas three isolates did not carry any of the analyzed carbapenemase genes. All strains possessed fimH, and 98% of the isolates possessed mrkD. Hypervirulent factors rmpA2 and iucA showed high positive rates (71.30% and 49.07%), with 48.15% of strains containing both genes. MLST analysis identified nine distinct sequence types (STs), with ST11 (82.41%) being the most common, followed by ST2154 (4.63%) and ST307 (3.70%). PBRT analysis revealed IncFII (85.19%) as the most prevalent plasmid.</p><p><strong>Conclusion: </strong>In summary, this study reported the epidemiological features of CRKP in pediatric patients in Henan, China, highlighting the high prevalence of multi-drug-resistant and hypervirulent strains, and underscoring the significance of continuous surveillance.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"98"},"PeriodicalIF":4.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11545200/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142602841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}