Microbiology spectrum最新文献

{"title":"Prevalence and impact of multidrug-resistant bacteria in solid cancer patients with bloodstream infection: a 25-year trend analysis.","authors":"Carlos Lopera, Patricia Monzó, Tommaso Francesco Aiello, Mariana Chumbita, Olivier Peyrony, Antonio Gallardo-Pizarro, Cristina Pitart, Guillermo Cuervo, Laura Morata, Marta Bodro, Sabina Herrera, Ana Del Río, José Antonio Martínez, Alex Soriano, Pedro Puerta-Alcalde, Carolina Garcia-Vidal","doi":"10.1128/spectrum.02961-23","DOIUrl":"https://doi.org/10.1128/spectrum.02961-23","url":null,"abstract":"<p><p>The study aimed to describe the epidemiology of multidrug-resistant (MDR) bacteria among solid cancer (SC) patients with bloodstream infections (BSIs), evaluating inappropriate empiric antibiotic treatment (IEAT) use and mortality trends over a 25-year period. All BSI occurrences in adult SC patients at a university hospital were analyzed across five distinct five-year intervals. MDR bacteria were classified as extended-spectrum beta-lactamases (ESBL)-producing and/or Carbapenem-resistant Enterobacterales, non-fermenting Gram-negative bacilli (GNB) resistant to at least three antibiotic classes, methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), and Vancomycin-resistant <i>Enterococci</i>. A multivariate regression model identified the risk factors for MDR BSI. Of 6,117 BSI episodes, Gram-negative bacilli (GNB) constituted 60.4% (3,695/6,117), being the most common are <i>Escherichia coli</i> with 26.8% (1,637/6,117), <i>Klebsiella</i> spp. with 12.4% (760/6,117), and <i>Pseudomonas aeruginosa</i> with 8.6% (525/6,117). MDR-GNB accounted for 644 episodes (84.8% of MDR or 644/759), predominantly ESBL-producing strains (71.1% or 540/759), which escalated significantly over time. IEAT was administered in 24.8% of episodes, mainly in MDR BSI, and was associated with higher mortality (22.9% vs. 14%, <i>P</i> < 0.001). Independent factors for MDR BSI were prior antibiotic use [odds ratio (OR) 2.93, confidence interval (CI) 2.34-3.67], BSI during antibiotic treatment (OR 1.46, CI 1.18-1.81), biliary (OR 1.84, CI 1.34-2.52) or urinary source (OR 1.86, CI 1.43-2.43), admission period (OR) 1.28, CI 1.18-1.38, and community-acquired infection (OR 0.57, CI 0.39-0.82). The study showed an increase in MDR-GNB among SC patients with BSI. A quarter received IEAT, which was linked to increased mortality. Improving risk assessment for MDR infections and the judicious prescription of empiric antibiotics are crucial for better outcomes.</p><p><strong>Importance: </strong>Multidrug-resistant (MDR) bacteria pose a global public health threat as they are more challenging to treat, and they are on the rise. Solid cancer patients are often immunocompromised due to their disease and cancer treatments, making them more susceptible to infections. Understanding the changes and trends in bloodstream infections in solid cancer patients is crucial, to help physicians make informed decisions about appropriate antibiotic therapies, manage infections in this vulnerable population, and prevent infection. Solid cancer patients often require intensive and prolonged treatments, including surgery, chemotherapy, and radiation therapy. Infections can complicate these treatments, leading to treatment delays, increased healthcare costs, and poorer patient outcomes. Investigating new strategies to combat MDR infections and researching novel antibiotics in these patients is of paramount importance to avoid these negative impacts.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Milteforan, a promising veterinary commercial product against feline sporotrichosis.","authors":"Laura C García Carnero, Camila Figueiredo Pinzan, Camila Diehl, Patricia Alves de Castro, Lais Pontes, Anderson Messias Rodrigues, Thaila F Dos Reis, Gustavo H Goldman","doi":"10.1128/spectrum.00474-24","DOIUrl":"10.1128/spectrum.00474-24","url":null,"abstract":"<p><p>Sporotrichosis, the cutaneous mycosis most commonly reported in Latin America, is caused by the <i>Sporothrix</i> clinical clade species, including <i>Sporothrix brasiliensis</i> and <i>Sporothrix schenckii sensu stricto</i>. Due to its zoonotic transmission in Brazil, <i>S. brasiliensis</i> represents a significant health threat to humans and domestic animals. Itraconazole, terbinafine, and amphotericin B are the most used antifungals for treating sporotrichosis. However, many strains of <i>S. brasiliensis</i> and <i>S. schenckii</i> have shown resistance to these agents, highlighting the importance of finding new therapeutic options. Here, we demonstrate that milteforan, a commercial veterinary product against dog leishmaniasis, whose active principle is miltefosine, is a possible therapeutic alternative for the treatment of sporotrichosis, as observed by its fungicidal activity <i>in vitro</i> against different strains of <i>S. brasiliensis</i> and <i>S. schenckii</i>. Fluorescent miltefosine localizes to the <i>Sporothrix</i> cell membrane and mitochondria and causes cell death through increased permeabilization. Milteforan decreases <i>S. brasiliensis</i> fungal burden in A549 pulmonary cells and bone marrow-derived macrophages and also has an immunomodulatory effect by decreasing TNF-α, IL-6, and IL-10 production. Our results suggest milteforan as a possible alternative to treat feline sporotrichosis.</p><p><strong>Importance: </strong>Sporotrichosis is an endemic disease in Latin America caused by different species of Sporothrix. This fungus can infect domestic animals, mainly cats and eventually dogs, as well as humans. Few drugs are available to treat this disease, such as itraconazole, terbinafine, and amphotericin B, but resistance to these agents has risen in the last few years. Alternative new therapeutic options to treat sporotrichosis are essential. Here, we propose milteforan, a commercial veterinary product against dog leishmaniasis, whose active principle is miltefosine, as a possible therapeutic alternative for treating sporotrichosis. Milteforan decreases <i>S. brasiliensis</i> fungal burden in human and mouse cells and has an immunomodulatory effect by decreasing several cytokine production.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of exopolysaccharides Psl and Pel in resistance of <i>Pseudomonas aeruginosa</i> to the oxidative stressors sodium hypochlorite and hydrogen peroxide.","authors":"Waleska S da Cruz Nizer, Kira N Allison, Madison E Adams, Mario A Vargas, Duale Ahmed, Carole Beaulieu, Deepa Raju, Edana Cassol, P Lynne Howell, Joerg Overhage","doi":"10.1128/spectrum.00922-24","DOIUrl":"https://doi.org/10.1128/spectrum.00922-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> is well-known for its antimicrobial resistance and the ability to survive in harsh environmental conditions due to an abundance of resistance mechanisms, including the formation of biofilms and the production of exopolysaccharides. Exopolysaccharides are among the major components of the extracellular matrix in biofilms and aggregates of <i>P. aeruginosa</i>. Although their contribution to antibiotic resistance has been previously shown, their roles in resistance to oxidative stressors remain largely elusive. Here, we studied the function of the exopolysaccharides Psl and Pel in the resistance of <i>P. aeruginosa</i> to the commonly used disinfectants and strong oxidizing agents NaOCl and H₂O₂. We observed that the simultaneous inactivation of Psl and Pel in <i>P. aeruginosa</i> PAO1 mutant strain ∆<i>pslA pelF</i> resulted in a significant increase in susceptibility to both NaOCl and H₂O₂. Further analyses revealed that Pel is more important for oxidative stress resistance in <i>P. aeruginosa</i> and that the form of Pel (i.e., cell-associated or cell-free) did not affect NaOCl susceptibility. Additionally, we show that Psl/Pel-negative strains are protected against oxidative stress in co-culture biofilms with <i>P. aeruginosa</i> PAO1 WT. Taken together, our results demonstrate that the EPS matrix and, more specifically, Pel exhibit protective functions against oxidative stressors such as NaOCl and H₂O₂ in <i>P. aeruginosa</i>.</p><p><strong>Importance: </strong>Biofilms are microbial communities of cells embedded in a self-produced polymeric matrix composed of polysaccharides, proteins, lipids, and extracellular DNA. Biofilm bacteria have been shown to possess unique characteristics, including increased stress resistance and higher antimicrobial tolerance, leading to failures in bacterial eradication during chronic infections or in technical settings, including drinking and wastewater industries. Previous studies have shown that in addition to conferring structure and stability to biofilms, the polysaccharides Psl and Pel are also involved in antibiotic resistance. This work provides evidence that these biofilm matrix components also contribute to the resistance of <i>Pseudomonas aeruginosa</i> to oxidative stressors including the widely used disinfectant NaOCl. Understanding the mechanisms by which bacteria escape antimicrobial agents, including strong oxidants, is urgently needed in the fight against antimicrobial resistance and will help in developing new strategies to eliminate resistant strains in any environmental, industrial, and clinical setting.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slow clearance of histidine-rich protein-2 in Gabonese with uncomplicated malaria.","authors":"Carlos Lamsfus Calle, Frieder Schaumburg, Thorsten Rieck, Anne Marie Nkoma Mouima, Pablo Martinez de Salazar, Saskia Breil, Johannes Behringer, Peter G Kremsner, Benjamin Mordmüller, Rolf Fendel","doi":"10.1128/spectrum.00994-24","DOIUrl":"https://doi.org/10.1128/spectrum.00994-24","url":null,"abstract":"<p><p>Malaria rapid diagnostic tests (RDTs), which detect <i>Plasmodium falciparum</i> (Pf)-specific histidine-rich protein-2 (HRP2), have increasing importance for the diagnosis and control of malaria, especially also in regions where routine diagnosis by microscopy is not available. HRP2-based RDTs have a similar sensitivity to expert microscopy, but their reported low specificity can lead to high false positivity rates, particularly in high-endemic areas. Despite the widespread use of RDTs, models investigating the dynamics of HRP2 clearance following Pf treatment focus rather on short-term clearance of the protein. The goal of this observational cohort study was to determine the long-term kinetic of HRP2-levels in peripheral blood after treatment of uncomplicated malaria cases with Pf mono-infection using a 3-day course of artesunate/amodiaquine. HRP2 levels were quantified at enrollment and on days 1, 2, 3, 5, 7, 12, 17, 22, and 28 post-treatment initiation. The findings reveal an unexpectedly prolonged clearance of HRP2 after parasite clearance from capillary blood. Terminal HRP2 half-life was estimated to be 9 days after parasite clearance using a pharmacokinetic two-compartmental elimination model. These results provide evidence that HRP2 clearance has generally been underestimated, as the antigen remains detectable in capillary blood for up to 28 days following successful treatment, influencing RDT-based assessment following a malaria treatment for weeks. A better understanding of the HRP2 clearance dynamics is critical for guiding the diagnosis of malaria when relying on RDTs.</p><p><strong>Importance: </strong>Detecting <i>Plasmodium falciparum</i>, the parasite responsible for the severest form of malaria, typically involves microscopy, polymerase chain reaction (PCR), or rapid diagnostic tests (RDTs) targeting the histidine-rich protein 2 or 3 (HRP2/3). While microscopy and PCR quickly turn negative after the infection is cleared, HRP2 remains detectable for a prolonged period. The exact duration of HRP2 persistence had not been well defined. Our study in Gabon tracked HRP2 levels over 4 weeks, resulting in a new model for antigen clearance. We discovered that a two-compartment model accurately predicts HRP2 levels, revealing an initial rapid reduction followed by a much slower elimination phase that can take several weeks. These findings are crucial for interpreting RDT results, as lingering HRP2 can lead to false positives, impacting malaria diagnosis and treatment decisions.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multicenter study of the performance of NTM Elite agar for the detection of nontuberculous mycobacteria from patients with cystic fibrosis.","authors":"Emmanuel André, Natalie Lorent, Kurt Beuselinck, Susanne Deiwick, Lieven Dupont, Johanne Gafsi, Lies Laenen, Lise Raymaekers, Pascal Van Bleyenbergh, John D Perry, Barbara C Kahl","doi":"10.1128/spectrum.02736-23","DOIUrl":"https://doi.org/10.1128/spectrum.02736-23","url":null,"abstract":"<p><p>The performance of a novel selective agar was evaluated against the performance of conventional mycobacterial cultures, i.e., a combination of the mycobacterial growth indicator tube (MGIT) with Löwenstein-Jensen (LJ), for the detection of nontuberculous mycobacteria (NTM) in sputum samples from people with cystic fibrosis (pwCF). Two hundred eighty-three sputum samples (231 fresh sputum and 52 spiked sputum) from 143 pwCF were collected. They were inoculated without prior decontamination on NTM Elite agar (30°C ± 2°C for 28 days) and inoculated on both MGIT and LJ (35°C-37°C for 6-8 weeks) after N-acetyl-L-cysteine-2% sodium hydroxide decontamination. NTM were identified by Matrix-Assisted Laser Desorption Ionization/Time of Flight Mass Spectrometry and/or PCR, and whole-genome sequencing. A total of 67 NTM were recovered overall by the combination of all culture media. NTM Elite agar allowed the recovery of 65 NTM (97%), compared to 22 for the conventional MGIT and LJ media combination (32.8%), including 22 NTM for MGIT (32.8%) and 3 NTM with the LJ medium (4.5%). For <i>Mycobacterium abscessus</i> complex, the sensitivity of NTM Elite agar was 95% compared with a sensitivity of 30% for the conventional MGIT and LJ media combination. Overall, 17.3% of cultures on NTM Elite agar were contaminated with other micro-organisms vs 46.3% on MGIT and 77% on LJ. This study shows that the novel selective agar (NTM Elite agar) significantly outperforms the conventional MGIT and LJ media combination in terms of sensitivity, selectivity, and ease of culture, without the requirement of an L3 laboratory.IMPORTANCENontuberculous mycobacteria (NTM) are significant pulmonary pathogens in patients with pre-existing structural lung conditions such as cystic fibrosis, bronchiectasis, or chronic obstructive pulmonary disease. <i>Mycobacterium avium</i> complex and <i>Mycobacterium abscessus</i> complex (MABSC) are the most frequently isolated organisms. Compared to the recommended culture method for NTM, which combines solid and liquid culture media, NTM Elite agar enables a faster/easier diagnosis and speeds up identification and susceptibility testing as the final reading is at 28 days instead of 6-8 weeks for the conventional mycobacterial cultures. In addition, for the NTM Elite agar, no decontamination stage before inoculation is necessary, unlike the conventional mycobacterial cultures. NTM Elite agar is derived from a formulation of medium adapted to rapidly growing mycobacteria (RGM). The medium enables the growth of RGM while suppressing other flora. It is supported with published clinical data showing the benefits of this medium.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeted phage hunting to specific <i>Klebsiella pneumoniae</i> clinical isolates is an efficient antibiotic resistance and infection control strategy.","authors":"Celia Ferriol-González, Robby Concha-Eloko, Mireia Bernabéu-Gimeno, Felipe Fernández-Cuenca, Javier E Cañada-García, Silvia García-Cobos, Rafael Sanjuán, Pilar Domingo-Calap","doi":"10.1128/spectrum.00254-24","DOIUrl":"https://doi.org/10.1128/spectrum.00254-24","url":null,"abstract":"<p><p><i>Klebsiella pneumoniae</i> is one of the most threatening multi-drug-resistant pathogens today, with phage therapy being a promising alternative for personalized treatments. However, the intrinsic capsule diversity in <i>Klebsiella</i> spp. poses a substantial barrier to the phage host range, complicating the development of broad-spectrum phage-based treatments. Here, we have isolated and genomically characterized phages capable of infecting each of the acquired 77 reference serotypes of <i>Klebsiella</i> spp.<i>,</i> including capsular types widespread among high-risk <i>K. pneumoniae</i> clones causing nosocomial infections. We demonstrated the possibility of isolating phages for all capsular types in the collection, revealing high capsular specificity among taxonomically related phages, in contrast to a few phages that exhibited broad-spectrum infection capabilities. To decipher the determinants of the specificity of these phages, we focused on their receptor-binding proteins, with particular attention to depolymerases. We also explored the possibility of designing a broad-spectrum phage cocktail based on phages isolated in reference capsular-type strains and determining the ability to lyse relevant clinical isolates. A combination of 12 phages capable of infecting 55% of the reference <i>Klebsiella</i> spp. serotypes was tested on a panel of carbapenem-resistant <i>K. pneumoniae</i> clinical isolates. Thirty-one percent of isolates were susceptible to the phage cocktail. However, our results suggest that in a highly variable encapsulated bacterial host, phage hunting must be directed to the specific <i>Klebsiella</i> isolates. This work is a step forward in the understanding of the complexity of phage-host interactions and highlights the importance of implementing precise and phage-specific strategies to treat <i>K. pneumoniae</i> infections worldwide.IMPORTANCEThe emergence of resistant bacteria is a serious global health problem. In the absence of effective treatments, phages are a personalized and effective therapeutic alternative. However, little is still known about phage-host interactions, which are key to implementing effective strategies. Here, we focus on the study of <i>Klebsiella pneumoniae,</i> a highly pathogenic encapsulated bacterium. The complexity and variability of the capsule, where in most cases phage receptors are found, make it difficult for phage-based treatments. Here, we isolated a large collection of <i>Klebsiella</i> phages against all the reference strains and in a cohort of clinical isolates. Our results suggest that clinical isolates represent a challenge, especially high-risk clones. Thus, we propose targeted phage hunting as an effective strategy to implement phage-derived therapies. Our results are a step forward for new phage-based strategies to control <i>K. pneumoniae</i> infections, highlighting the importance of understanding phage-host interactions to design personalized treatments against <i>Kle","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the quickmic system in the rapid diagnosis of Gram-negative bacilli bacteremia.","authors":"Celia García-Rivera, Andrea Ricart-Silvestre, Mónica Parra Grande, María Paz Ventero, Iryna Tyshkovska-Germak, Antonia Sánchez-Bautista, Esperanza Merino, Juan Carlos Rodríguez","doi":"10.1128/spectrum.04011-23","DOIUrl":"https://doi.org/10.1128/spectrum.04011-23","url":null,"abstract":"<p><p>Rapid microbiological diagnosis of the antibiotic susceptibility of Gram-negative bacilli is a priority in clinical microbiology, especially in cases of bacteremia. The rapid advancement of antimicrobial resistance proposes a challenge for empirical antibiotic therapy and shows the need for fast antibiotic susceptibility diagnostics to guide treatments. The QuickMIC System (Gradientech AB, Uppsala, Sweden) is a recently developed rapid diagnostic tool for antibiotic susceptibility testing. Our study evaluates a rapid phenotypic system (QuickMIC) that provides information on the susceptibility of 12 antibiotics against <i>Escherichia coli</i>, <i>Klebsiella spp</i>., <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter baumannii</i>, <i>Enterobacter cloacae</i>, <i>Proteus spp</i>., <i>Citrobacter spp.,</i> and <i>Serratia marcescens</i>. A total of 816 antibiotic/microorganism combinations were tested, resulting in eight discrepancies. The concordance between the antibiotics offered by QuickMIC and reference methods (MicroScan WalkAway plus system, Beckman Coulter; Etest (BioMerieux microdilution system (Bruker); Real-time PCR (GeneXpert, Cepheid); and immunochromatography (Biotech) was 99.02%. Time elapsed to obtain a valid minimal inhibitory concentration (MIC) was between 2 and 4 h. The QuickMIC system allows for the early adjustment of antibiotic treatment in these infections. Given the existing limitations of currently available rapid methods, its clinical utility is particularly relevant in the management of <i>P. aeruginosa</i> infections and AmpC-producing Enterobacterales. The use of rapid methods can help diversify antibiotic use and reduce carbapenem consumption.</p><p><strong>Importance: </strong>The rapid diagnosis of antibiotic sensitivity in Gram-negative bacilli is of paramount importance in clinical microbiology, particularly in cases of bacteremia. The escalating challenge of antimicrobial resistance underscores the need for expeditious antibiotic susceptibility diagnostics to guide empirical antibiotic therapy effectively. In light of this, we present our study that evaluates the QuickMIC System, a recently developed rapid diagnostic antibiogram. QuickMIC System, offers a novel approach to phenotypic testing, providing information on the activity of 12 antibiotics against key pathogens, including <i>Escherichia coli</i>, <i>Klebsiella spp</i>., <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter baumannii</i>, <i>Enterobacter cloacae</i>, <i>Proteus spp</i>., <i>Citrobacter spp</i>., and <i>Serratia marcescens</i>. Our investigation involved testing a total of 816 antibiotic/microorganism combinations. The study demonstrated an impressive 99.02% concordance between the QuickMIC System and the reference methods, with only eight discrepancies observed. The time to actionable minimum inhibitory concentration (MIC) ranged between 2 and 4 h, highlighting the system's efficiency in providing rapid results.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-tube detection of <i>Salmonella</i> Typhimurium using LAMP and CRISPR-Cas12b.","authors":"Jiansen Gong, Yi Jiang, Di Zhang, Tingting Li, Lixia Fu, Xinhong Dou","doi":"10.1128/spectrum.01271-24","DOIUrl":"https://doi.org/10.1128/spectrum.01271-24","url":null,"abstract":"<p><p><i>Salmonella enterica</i> serovar Typhimurium (ST) is a predominant serovar causing foodborne illnesses worldwide. Traditional detection methods often face challenges, including the need for specialized equipment, skilled operators, and lengthy procedures. To address these limitations, we developed a rapid, sensitive, and specific ST detection method by integrating loop-mediated isothermal amplification (LAMP) with the clustered regularly interspaced short palindromic repeats and associated protein 12b (CRISPR/Cas12b) system, all within a single tube. Our results indicate that the LAMP-CRISPR/Cas12b reaction can be completed isothermally in under 1 h without requiring specialized instruments. The platform's limit of detection (LoD) is 12.5 copies per reaction. Additionally, the system demonstrated 100% inclusivity and exclusivity when tested against 30 reference strains, highlighting its specificity. In practical applications, the LoDs for ST in pure nucleic acid and contaminated fecal samples were 2.32 and 23.2 CFU/mL, respectively, with higher sensitivity observed in pure nucleic acid samples. Overall, our findings underscore the potential of the one-tube LAMP-CRISPR/Cas12b platform as a rapid, sensitive, and specific tool for ST detection, particularly in resource-limited settings.</p><p><strong>Importance: </strong>Here, we have provided a novel one-step method for <i>Salmonella</i> Typhimurium detection in one pot by integrating the LAMP assay with the CRISPR/Cas12b system, offering significant advantages in terms of simplicity, speed, and accuracy.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142073288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut <i>Lactococcus garvieae</i> promotes protective immunity to foodborne <i>Clostridium perfringens</i> infection.","authors":"Xue-Yin Wang, Fan-Hua Meng, Ming-Yue Zhang, Fen-Xin Li, Yu-Xin Lei, Zhao-Guo Ma, Jia-Qi Li, Ya-Nan Lou, Yue-Feng Chu, Ke Ma, Shui-Xing Yu","doi":"10.1128/spectrum.04025-23","DOIUrl":"https://doi.org/10.1128/spectrum.04025-23","url":null,"abstract":"<p><p>The gut microbiota, a pivotal component of the intestinal mucosal barrier, is critical for host resistance to enteric pathogen infection. Here, we report a novel function of the potentially probiotic <i>Lactococcus garvieae</i> strain LG1 (<i>L. garvieae</i> strain LG1) in maintaining intestinal mucosal barrier integrity and protecting against foodborne <i>Clostridium perfringens</i> (<i>C. perfringens</i>) infection. <i>L. garvieae</i> was isolated from the intestinal contents of Chinese Mongolian sheep (MS) and exhibited potential probiotic properties. In a <i>C. perfringens</i> enterocolitis model, <i>L. garvieae-</i>pretreated mice were less susceptible to <i>C. perfringens</i> infection compared with Phosphate buffered solution (PBS)<i>-</i>pretreated mice, which manifested as higher survival rates, lower pathogen loads, less weight loss, mild clinical symptoms and intestinal damage, and minor inflammation. Further mechanistic analysis showed that <i>L. garvieae</i> could ameliorate the disruption of intestinal permeability and maintain the integrity of the intestinal mucosal barrier by promoting the expression of tight junction proteins and mucoproteins. Moreover, <i>L. garvieae</i> was also able to facilitate antimicrobial peptide expression and ameliorate dysbiosis of the gut microbiota caused by <i>C. perfringens</i>. Together, these findings highlight the prospect of immunomodulatory potentially probiotic <i>L. garvieae</i> and might offer valuable strategies for prophylaxis and/or treatment of pathogenic <i>C. perfringens</i> mucosal infection.</p><p><strong>Importance: </strong><i>C. perfringens</i> necrotic enteritis leads to losses of about US $2 billion to the poultry industry worldwide every year. Worse, US Centers for Disease Control and Prevention (CDC) has estimated that <i>C. perfringens</i> causes nearly 1 million foodborne illnesses in the United States annually. Nowadays, the treatment recommendation is a combination of a broad-spectrum synergistic penicillin with clindamycin or a carbapenem, despite growing scientific concern over antibiotic resistance. The global understanding of the gut microbiome for <i>C. perfringens</i> infection may provide important insights into the intervention. <i>L. garvieae</i> originated from Mongolian sheep intestine, exhibited potentially probiotic properties, and was able to limit <i>C. perfringens</i> enterocolitis and pathogenic colonization. Importantly, we found that <i>L. garvieae</i> limits <i>C. perfringens</i> invasion via improving intestinal mucosal barrier function. Also, <i>L. garvieae</i> alleviates <i>C. perfringens</i>-induced gut microbiota dysbiosis. It allowed us to convince that utilization of probiotics to promote protective immunity against pathogens infection is of pivotal importance.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Honeybee gut bacterial strain improved survival and gut microbiota homeostasis in <i>Apis mellifera</i> exposed <i>in vivo</i> to clothianidin.","authors":"Sarah El Khoury, Jeff Gauthier, Pierre Luc Mercier, Stéphane Moïse, Pierre Giovenazzo, Nicolas Derome","doi":"10.1128/spectrum.00578-24","DOIUrl":"https://doi.org/10.1128/spectrum.00578-24","url":null,"abstract":"<p><p>Pesticides are causing honeybee mortality worldwide. Research carried out on honeybees indicates that application of pesticides has a significant impact on the core gut community, which ultimately leads to an increase in the growth of harmful pathogens. Disturbances caused by pesticides also affect the way bacterial members interact, which results in gut microbial dysbiosis. Administration of beneficial microbes has been previously demonstrated to be effective in treating or preventing disease in honeybees. The objective of this study was to measure under <i>in vivo</i> conditions the ability of two bacterial strains (the <i>Enterobacter</i> sp. and <i>Pantoea</i> sp.) isolated from honeybee gut to improve survival and mitigate gut microbiota dysbiosis in honeybees exposed to a sublethal clothianidin dose (0.1 ppb). Both gut bacterial strains were selected for their ability to degrade clothianidin <i>in vitro</i> regardless of their host-microbe interaction characteristics (e.g., beneficial, neutral, or harmful). To this end, we conducted cage trials on 4- to 6-day-old newly emerging honeybees. During microbial administration, we jointly monitored the taxonomic distribution and activity level of bacterial symbionts quantifying 16S rRNA transcripts. First, curative administration of the <i>Pantoea</i> sp. strain significantly improved the survival of clothianidin-exposed honeybees compared to sugar control bees (i.e., supplemented with sugar [1:1]). Second, curative administration of the <i>Enterobacter</i> sp. strain significantly mitigated the clothianidin-induced dysbiosis observed in the midgut structural network, but without improving survival.</p><p><strong>Importance: </strong>The present work suggests that administration of bacterial strains isolated from honeybee gut may promote recovery of gut microbiota homeostasis after prolonged clothianidin exposure, while improving survival. This study highlights that gut bacterial strains hold promise for developing efficient microbial formulations to mitigate environmental pesticide exposure in honeybee colonies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142073286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}