Microbiology spectrum最新文献

{"title":"Assessment of broth disk elution method for aztreonam in combination with ceftazidime/avibactam against <i>Enterobacterales</i> isolates.","authors":"Peipei Song, Jian Xu, Lan Jiang, Qin Zhang, Chenggui Liu","doi":"10.1128/spectrum.00953-24","DOIUrl":"https://doi.org/10.1128/spectrum.00953-24","url":null,"abstract":"<p><p>The combination of aztreonam with ceftazidime/avibactam is considered a potential therapeutic approach for the treatment of infections caused by metallo-β-lactamase (MBL)-producing isolates. In this study, <i>in vitro</i> antibacterial activity of aztreonam with avibactam against 204 carbapenemase-producing <i>Enterobacterales</i> was determined by broth disk elution (BDE) method of two detection volumes (5- and 2-mL broth), with broth microdilution (BMD) method as a reference. For the BDE-5mL test, the categorical agreement (CA) of ATM+CZA_-lo tube (aztreonam/ceftazidime/avibactam: 6/6/4 mg/L) was 99.5%, with 0.5% major error (ME) and 0% very major error (VME); the CA of 2ATM+CZA_-lo tube (12/6/4 mg/L) was 100%, with no ME and VME. For the BDE-2mL test, the CA of ATM+2CZA_-hi tube (15/10/4 mg/L) was 98.5%, with 0% ME and 37.5% VME; the CA of 2ATM+2CZA_-hi tube (30/10/4 mg/L) was 97.1%, with 0% ME and 75% VME. The BDE-5 mL test is an economical and practical method for clinical microbiology laboratories to determine the antibacterial susceptibility of aztreonam with avibactam against <i>Enterobacterales</i>, especially the 2ATM+CZA_-lo tube with a final concentration of 12/6/4 mg/L of aztreonam/ceftazidime/avibactam.</p><p><strong>Importance: </strong>Infections caused by metallo-β-lactamase (MBL)-producing <i>Enterobacterales</i> are increasingly reported worldwide, and it is a significant challenge for clinical infection treatment. MBLs are adept at hydrolyzing almost all traditional β-lactam antibiotics except aztreonam, and the enzyme activity cannot be inhibited by traditional or novel β-lactamase inhibitors. The good thing is that the combination of aztreonam with ceftazidime/avibactam has been proven to be one of the potential therapeutic approaches for treating infections related with MBL-producing isolates. Broth microdilution (BMD) method is recommended as a reference method for its accuracy, but it is too complex to perform in most routine laboratories. Finding a more convenient, practical, and accurate susceptibility testing method for aztreonam/avibactam in clinical microbiology laboratories is very necessary. Here, we evaluated the performance of broth disk elution (BDE) method for aztreonam in combination with ceftazidime/avibactam against <i>Enterobacterales</i> isolates, with BMD as a reference.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120244","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":"Aptamer-associated colorimetric reverse transcription loop-mediated isothermal amplification assay for detection of dengue virus.","authors":"Vitória de Oliveira Arruda, Luiz Ricardo Goulart Filho, Adriana Freitas Neves","doi":"10.1128/spectrum.03583-23","DOIUrl":"10.1128/spectrum.03583-23","url":null,"abstract":"<p><p>Current diagnostic methods for dengue, such as serological tests, have limitations in terms of cross-reactivity with other viruses. To address this issue, we explored the potential of combining the loop-mediated isothermal amplification (LAMP) technique with the affinity of aptamers to develop point-of-care testing. In this study, we utilized 60 serum samples. An aptamer capable of binding to the dengue virus was employed as a platform for capturing genetic material, and its performance was compared to a commercial kit. Dengue virus was detected through RT-PCR and colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP), allowing visual observation of the results without the need for equipment. In the context of the aptamer LAMP assay, our analysis revealed the detection of the dengue virus in 38 out of 60 samples, with 95% sensitivity and 100% specificity compared to RT-PCR and/or APTA-RT-PCR. Importantly, we observed no cross-reaction when assessing samples positive for the zika virus, underscoring the assay's selectivity. This innovative aptameric capture of the viral RNA in combination with the RT-LAMP (APTA-RT-LAMP) method has the potential to offer valuable molecular insights into neglected infectious diseases in a simpler and faster manner.</p><p><strong>Importance: </strong>Dengue is a neglected tropical disease of significant epidemiological importance in tropical and subtropical countries. Current diagnostics for this infection present challenges, such as cross-reactivity in serological tests. Finding ways to enhance the diagnosis of this disease is crucial, given the absence of specific treatments. An accurate, simple, and effective diagnosis contributes to the improved management of infected individuals. In this context, our work combines molecular biology techniques, such as isothermal loop amplification, with aptamers to detect the dengue virus in biological samples. Our method produces colorimetric results based on a color change, with outcomes available in less than 2 hours. Moreover, it requires simpler equipment compared to molecular PCR tests.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370242/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141752049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The epidemic characteristics of <i>Mycoplasma pneumoniae</i> infection among children in Anhui, China, 2015-2023.","authors":"Bing Chen, Ling-Yu Gao, Qiu-Ju Chu, Ting-Dong Zhou, Yang Tong, Ning Han, Ai-Hua Wang, Qiang Zhou","doi":"10.1128/spectrum.00651-24","DOIUrl":"https://doi.org/10.1128/spectrum.00651-24","url":null,"abstract":"<p><p>The number of pediatric respiratory tract infection cases in China has significantly increased this year, and <i>Mycoplasma pneumoniae</i> is one of the main pathogens. This study aimed to investigate the epidemiological characteristics of <i>M. pneumoniae</i> in children in the Anhui region and to provide evidence for the prevention and control strategies of <i>M. pneumoniae</i> in children in this region. A total of 66,488 pediatric patients with respiratory tract infection were enrolled from January 2015 to November 2023 in this study. The results of this study exhibited that <i>M. pneumoniae</i> infection in the Anhui region was characterized by a high positive rate during 2021-2023, especially this year is considered a year of pandemic for <i>M. pneumoniae</i> infection. Moreover, the positive rate of <i>M. pneumoniae</i> in female children is significantly higher than in male children, and the infection rate of <i>M. pneumoniae</i> in children increases significantly with age, particularly in school-aged children.</p><p><strong>Importance: </strong>The number of pediatric respiratory tract infection cases in China has significantly increased this year, and <i>Mycoplasma pneumoniae</i> is one of the main pathogens. This study aimed to investigate the epidemiological characteristics of <i>M. pneumoniae</i> in children in the Anhui region and provide evidence for the prevention and control strategies of <i>M. pneumoniae</i> in children in this region.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120246","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":"Emergence of plasmid-borne <i>tet</i>(X4) resistance gene in clinical isolate of eravacycline- and omadacycline-resistant <i>Klebsiella pneumoniae</i> ST485.","authors":"Xiaojing Liu, Yi Liu, Xiaohan Ma, Ruyan Chen, Chenyu Li, Hongxin Fu, Yu Yang, Kexin Guo, Xiaoping Zhang, Ruishan Liu, Hao Xu, Junfei Zhu, Beiwen Zheng","doi":"10.1128/spectrum.00496-24","DOIUrl":"10.1128/spectrum.00496-24","url":null,"abstract":"<p><p>Omadacycline and eravacycline are gradually being used as new tetracycline antibiotics for the clinical treatment of Gram-negative pathogens. Affected by various tetracycline-inactivating enzymes, there have been reports of resistance to eravacycline and omadacycline in recent years. We isolated a strain carrying the mobile tigecycline resistance gene <i>tet</i>(X4) from the feces of a patient in Zhejiang Province, China. The strain belongs to the rare ST485 sequence type. The isolate was identified as <i>Klebsiella pneumoniae</i> by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The MICs of antimicrobial agents were determined using either the agar dilution method or the micro broth dilution method. The result showed that the isolate was resistant to eravacycline (MIC = 32 mg/L), omadacycline (MIC > 64 mg/L), and tigecycline (MIC > 32 mg/L). Whole-genome sequencing revealed that the <i>tet</i>(X4) resistance gene is located on the IncFII(pCRY) conjugative plasmid. <i>tet</i>(X4) is flanked by IS<i>Vsa3</i>, and we hypothesize that this association contributes to the spread of the resistance gene. Plasmids were analyzed by S1-nuclease pulsed-field gel electrophoresis (S1-PFGE), Southern blotting, and electrotransformation experiment. We successfully transferred the plasmid carrying <i>tet</i>(X4) to the recipient bacteria by electrotransformation experiment. Compared with the DH-5α, the MICs of the transformant L3995-DH5α were increased by eight-fold for eravacycline and two-fold higher for omadacycline. Overall, the emergence of plasmid-borne <i>tet</i>(X4) resistance gene in a clinical isolate of <i>K. pneumoniae</i> ST485 underscores the essential requirement for the ongoing monitoring of <i>tet</i>(X4) to prevent and control its further dissemination in China.IMPORTANCEThere are still limited reports on <i>Klebsiella pneumoniae</i> strains harboring tetracycline-resistant genes in China, and <i>K. pneumoniae</i> L3995hy adds a new example to those positive for the <i>tet</i>(X4) gene. Importantly, our study raises concerns that plasmid-mediated resistance to omadacycline and eravacycline may spread further to a variety of ecological and clinical pathogens, limiting the choice of medication for extensively drug-resistant bacterial infections. Therefore, it is important to continue to monitor the prevalence and spread of <i>tet</i>(X4) and other tetracyclines resistance genes in <i>K. pneumoniae</i> and diverse bacterial populations.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370244/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141748593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathogenicity, phylogenomic, and comparative genomic study of <i>Pseudomonas syringae</i> sensu lato affecting sweet cherry in California.","authors":"Tawanda E Maguvu, Rosa J Frias, Alejandro I Hernandez-Rosas, Erin Shipley, Greta Dardani, Mohamed T Nouri, Mohammad A Yaghmour, Florent P Trouillas","doi":"10.1128/spectrum.01324-24","DOIUrl":"https://doi.org/10.1128/spectrum.01324-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;To gain insights into the diversity of &lt;i&gt;Pseudomonas syringae&lt;/i&gt; sensu lato affecting sweet cherry in California, we sequenced and analyzed the phylogenomic and genomic architecture of 86 fluorescent pseudomonads isolated from symptomatic and asymptomatic cherry tissues. Fifty-eight isolates were phylogenetically placed within the &lt;i&gt;P. syringae&lt;/i&gt; species complex and taxonomically classified into five genomospecies: &lt;i&gt;P. syringae&lt;/i&gt; pv. &lt;i&gt;syringae&lt;/i&gt;, &lt;i&gt;P. syringae&lt;/i&gt;, &lt;i&gt;Pseudomonas cerasi&lt;/i&gt;, &lt;i&gt;Pseudomonas viridiflava&lt;/i&gt;, and &lt;i&gt;A&lt;/i&gt;. We annotated components of the type III secretion system and phytotoxin-encoding genes and correlated the data with pathogenicity phenotypes. Intact probable regulatory protein HrpR was annotated in the genomic sequences of all isolates of &lt;i&gt;P. syringae&lt;/i&gt; pv. &lt;i&gt;syringae&lt;/i&gt;, &lt;i&gt;P. syringae&lt;/i&gt;, &lt;i&gt;P. cerasi&lt;/i&gt;, and &lt;i&gt;A&lt;/i&gt;. Isolates of &lt;i&gt;P. viridiflava&lt;/i&gt; had atypical probable regulatory protein HrpR. Syringomycin and syringopeptin-encoding genes were annotated in isolates of all genomospecies except for &lt;i&gt;A&lt;/i&gt; and &lt;i&gt;P. viridiflava&lt;/i&gt;. All isolates of &lt;i&gt;P. syringae&lt;/i&gt; pv. &lt;i&gt;syringae&lt;/i&gt; caused cankers, leaf spots, and fruit lesions in the field. In contrast, all isolates of &lt;i&gt;P. syringae&lt;/i&gt; and &lt;i&gt;P. cerasi&lt;/i&gt; and some isolates of &lt;i&gt;P. viridiflava&lt;/i&gt; caused only cankers. Isolates of genomospecies &lt;i&gt;A&lt;/i&gt; could not cause any symptoms suggesting phytotoxins are essential for pathogenicity. On detached immature cherry fruit pathogenicity assays, isolates of all five genomospecies produced symptoms (black-dark brown lesions). However, symptoms of isolates of genomospecies &lt;i&gt;A&lt;/i&gt; were significantly (&lt;i&gt;P&lt;/i&gt; &lt; 0.01) less severe than those of other genomospecies. We also mined for genes conferring resistance to copper and kasugamycin and correlated these data with &lt;i&gt;in vitro&lt;/i&gt; antibiotic sensitivity tests.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;Comprehensive identification of phytopathogens and an in-depth understanding of their genomic architecture, particularly virulence determinants and antibiotic-resistant genes, are critical for several practical reasons. These include disease diagnosis, improved knowledge of disease epidemiology, pathogen diversity, and determination of the best possible management strategies. In this study, we provide the first report of the presence and pathogenicity of genomospecies &lt;i&gt;Pseudomonas cerasi&lt;/i&gt; and &lt;i&gt;Pseudomonas viridiflava&lt;/i&gt; in California sweet cherry. More importantly, we report a relatively high level of resistance to copper among the population of &lt;i&gt;Pseudomonas syringae&lt;/i&gt; pv. &lt;i&gt;syringae&lt;/i&gt; (47.5%). This implies copper cannot be effectively used to control bacterial blast and bacterial canker of sweet cherries. On the other hand, no isolates were resistant to kasugamycin, an indication that kasugamycin could be effectively used for the control of bacterial blast and bacterial canker. Our findings are important to improve the man","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120245","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":"Effect of multifunctional cationic polymer coatings on mitigation of broad microbial pathogens.","authors":"Jianliang Gong, Chun-Yin Or, Eric Tung-Po Sze, Sidney Man-Ngai Chan, Pak-Long Wu, Peggy Miu-Yee Poon, Anthony K Y Law, Lucie Ulrychová, Jan Hodek, Jan Weber, Hui Ouyang, My Yang, Stephanie M Eilts, Montserrat Torremorell, Yaakov Knobloch, Christopher J Hogan, Christine Atallah, Juliette Davies, John Winkler, Ryan Gordon, Reza Zarghanishiraz, Mojtaba Zabihi, Cole Christianson, Deanne Taylor, Alan Rabinowitz, Jared Baylis, Joshua Brinkerhoff, Jonathan P Little, Ri Li, Jeanne Moldenhauer, Michael K Mansour","doi":"10.1128/spectrum.04097-23","DOIUrl":"10.1128/spectrum.04097-23","url":null,"abstract":"<p><p>Infection control measures to prevent viral and bacterial infection spread are critical to maintaining a healthy environment. Pathogens such as viruses and pyogenic bacteria can cause infectious complications. Viruses such as SARS-CoV-2 are known to spread through the aerosol route and on fomite surfaces, lasting for a prolonged time in the environment. Developing technologies to mitigate the spread of pathogens through airborne routes and on surfaces is critical, especially for patients at high risk for infectious complications. Multifunctional coatings with a broad capacity to bind pathogens that result in inactivation can disrupt infectious spread through aerosol and inanimate surface spread. This study uses C-POLAR, a proprietary cationic, polyamine, organic polymer with a charged, dielectric property coated onto air filtration material and textiles. Using both SARS-CoV-2 live viral particles and bovine coronavirus models, C-POLAR-treated material shows a dramatic 2-log reduction in circulating viral inoculum. This reduction is consistent in a static room model, indicating simple airflow through a static C-POLAR hanging can capture significant airborne particles. Finally, Gram-positive and Gram-negative bacteria are applied to C-POLAR textiles using a viability indicator to demonstrate eradication on fomite surfaces. These data suggest that a cationic polymer surface can capture and eradicate human pathogens, potentially interrupting the infectious spread for a more resilient environment.</p><p><strong>Importance: </strong>Infection control is critical for maintaining a healthy home, work, and hospital environment. We test a cationic polymer capable of capturing and eradicating viral and bacterial pathogens by applying the polymer to the air filtration material and textiles. The data suggest that the simple addition of cationic material can result in the improvement of an infectious resilient environment against viral and bacterial pathogens.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A low-cost culture- and DNA extraction-free method for the molecular detection of pneumococcal carriage in saliva.","authors":"Chikondi Peno, Tzu-Yi Lin, Maikel S Hislop, Devyn Yolda-Carr, Katherine Farjado, Anna York, Virginia E Pitzer, Daniel M Weinberger, Amy K Bei, Orchid M Allicock, Anne L Wyllie","doi":"10.1128/spectrum.00591-24","DOIUrl":"10.1128/spectrum.00591-24","url":null,"abstract":"<p><p>Molecular methods have improved the sensitivity of the detection of pneumococcal carriage in saliva. However, they typically require sample culture enrichment and nucleic acid extraction prior to performing the detection assay and may limit scalability for extensive surveillance of pneumococcus, particularly in low-resource settings. We evaluated the performance of a DNA-extraction-free method for the detection of pneumococcus in saliva. We developed a streamlined qPCR-based protocol for the detection of pneumococcus, omitting culture enrichment and DNA extraction. Using saliva samples collected from children attending childcare centers (New Haven, CT, USA), we evaluated the detection of pneumococcus using saliva lysates as compared to purified DNA extracted from culture-enriched aliquots of the paired samples using qPCR targeting the pneumococcal <i>piaB</i> gene. Of the 759 saliva samples tested from 92 children [median age 3.65 years; IQR (2.46-4.78)], pneumococcus was detected in 358 (47.2%) saliva lysates prepared using the extraction-free protocol and in 369 (48.6%) DNA extracted from culture-enriched samples. We observed near-perfect agreement between the two protocols (Cohen's kappa: 0.92; 95% CI: 0.90-0.95). Despite a high correlation between <i>C_T</i> values generated by the two methods (<i>r</i> = 0.93, <i>P</i> < 0.0001), the <i>C_T</i> values generated from saliva lysates were higher (lower concentration) than those from culture-enriched samples (Δ<i>C_T</i> = 6.69, <i>P</i> < 0.00001). The cost of detecting pneumococcus using saliva lysates was at least fivefold lower (US$2.53) compared to the cost of the culture-enriched method (range: US$13.60-US$19.46). For pneumococcal carriage surveillance in children, our findings suggest that a DNA extraction-free approach may offer a cost-effective alternative to the resource-intensive culture-enrichment method.IMPORTANCESurveillance for carriage of pneumococcus is a key component of evaluating the performance of pneumococcal vaccines and informing new vaccination strategies. To improve the scalability of pneumococcal carriage surveillance, we show that molecular detection of pneumococcus in saliva from children can be performed without culture enrichment and DNA extraction. Our findings show that using the extraction-free method can improve surveillance efforts for pneumococcal carriage in children, overcoming the resource-intensive hurdle that comes with the use of molecular methods, particularly in low-resource settings.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370248/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141723934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of a microbial and pathogen source tracking toolbox to identify infrastructure problems in stormwater drainage networks: a case study.","authors":"Liam R Carson, Clint Goodman, Bert van Duin, Norman F Neumann","doi":"10.1128/spectrum.00337-24","DOIUrl":"10.1128/spectrum.00337-24","url":null,"abstract":"<p><p>Water scarcity and increasing urbanization are forcing municipalities to consider alternative water sources, such as stormwater, to fill in water supply gaps or address hydromodification of receiving urban streams. Mounting evidence suggests that stormwater is often contaminated with human feces, even in stormwater drainage systems separate from sanitary sewers. Pinpointing sources of human contamination in drainage networks is challenging given the diverse sources of fecal pollution that can impact these systems and the non-specificity of traditional fecal indicator bacteria (FIB) for identifying these host sources. As such, we used a toolbox approach that encompassed microbial source tracking (MST), FIB monitoring, and bacterial pathogen monitoring to investigate microbial contamination of stormwater in an urban municipality. We demonstrate that human sewage frequently contaminated stormwater (in >50% of routine samples), based on the presence of the human fecal marker HF183, and often exceeded microbial water quality criteria. <i>Arcobacter butzleri</i>, a pathogen of emerging concern, was also detected in >50% of routine samples, with 75% of these pathogen-positive samples also being positive for the human fecal marker HF183, suggesting human municipal sewage as the likely source for this pathogen. MST and FIB were used to track human fecal pollution in the drainage network to the most likely point source of contamination, for which a sewage cross-connection was identified and confirmed using tracer dyes. These results point to the ubiquitous presence of human sewage in stormwater and also provide municipalities with the tools to identify sources of anthropogenic contamination in storm drainage networks.IMPORTANCEWater scarcity, increased urbanization, and population growth are driving municipalities worldwide to consider stormwater as an alternative water source in urban environments. However, many studies suggest that stormwater is relatively poor in terms of microbial water quality, is frequently contaminated with human sewage, and therefore could represent a potential health risk depending on the type of exposure (e.g., irrigation of community gardens). Traditional monitoring of water quality based on fecal bacteria does not provide any information about the sources of fecal pollution contaminating stormwater (i.e., animals/human feces). Herein, we present a case study that uses fecal bacterial monitoring, microbial source tracking, and bacterial pathogen analysis to identify a cross-connection that contributed to human fecal intrusion into an urban stormwater network. This microbial toolbox approach can be useful for municipalities in identifying infrastructure problems in stormwater drainage networks to reduce risks associated with water reuse.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141897787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new dynamic <i>in vitro</i> model for evaluating antimicrobial activity against bacterial biofilms on central venous catheters.","authors":"Liangyan Fang, Yunqian Qiao, Xiuting Li, Changbin Wang, Chunqiao Li, Tongqing Luan, Wenqing Wang","doi":"10.1128/spectrum.00237-24","DOIUrl":"10.1128/spectrum.00237-24","url":null,"abstract":"<p><p>Central venous catheters (CVCs) are widely used for intravenous medication administration. However, biofilm formation along the catheter surface is the main most important cause of catheter-related bloodstream infections. Nowadays, several antimicrobial-coated catheters are available to prevent biofilm development. In this study, we introduced a new dynamic <i>in vitro</i> model to evaluate the antimicrobial activity against bacterial biofilms on CVCs. Rifampicin-minocycline-coated catheters and control catheters without antimicrobial component were assembled into the model to test the antimicrobial activity on external surface and internal surface. After 1 h irrigation of <i>Staphylococcus epidermidis</i> or <i>Staphylococcus aureus</i> preculture and 23 h irrigation of Trypticase Soy Broth, the viable adherent organism was collected and counted. The enumeration results showed that the number of bacteria attached to antibacterial catheter was significantly less than that of the control catheter, both on external surface (<i>P</i> < 0.05) and internal surface (<i>P</i> < 0.05). The results were further confirmed by the scanning electron microscopy. In conclusion, the dynamic <i>in vitro</i> model can be applied to evaluate the antimicrobial activity against bacterial biofilms grown on the external and internal surfaces of CVCs used in clinical practice.IMPORTANCEFor the first time, a new dynamic <i>in vitro</i> model was constructed to evaluate the antimicrobial activity against bacterial biofilms on central venous catheters (CVCs) on both external surface and internal surface. This model could be applied to evaluate the antimicrobial activity against bacterial biofilms not only on CVCs but also other types of catheters.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370253/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a TaqMan probe-based multiplex real-time PCR for the simultaneous detection of four clinically important filamentous fungi.","authors":"Yutong Wei, Yangxuan Lin, Jingya Zhao, Dingchen Li, Zhankui Yang, Fangyan Chen, Li Han","doi":"10.1128/spectrum.00634-24","DOIUrl":"10.1128/spectrum.00634-24","url":null,"abstract":"<p><p>Filamentous fungi present significant health hazards to immunocompromised individuals globally; however, the prompt and precise identification of them during infection remains challenging. In this study, a TaqMan probe-based multiplex real-time PCR (M-qPCR) assay was developed to detect simultaneously the target genes of four important pathogenic filamentous fungi: <i>ANXC4</i> gene of <i>Aspergillus fumigatus, EF1-α</i> gene of <i>Fusarium</i> spp<i>.</i>, mitochondrial <i>rnl</i> gene of Mucorales, and <i>hcp100</i> gene of <i>Histoplasma capsulatum</i>. In this M-qPCR assay, the limit of detection (LoD) to all four kinds of fungi was 100 copies and the correlation coefficients (R²) were above 0.99. The specificity of this assay is 100%, and the minimum detection limit is 100 copies/reaction. In conclusion, an M-qPCR detection assay was well established with high specificity and sensitivity for rapid and simultaneous detection on four important filamentous fungi in the clinic.</p><p><strong>Importance: </strong>World Health Organization developed the first fungal priority pathogens list (WHO FPPL) in 2022. <i>Aspergillus fumigatus</i>, Mucorales, <i>Fusarium</i> spp., and <i>Histoplasma</i> spp. are the four types of pathogenic fungi with filamentous morphology in the critical priority group and high priority group of WHO FPPL. These four filamentous fungal infections have become more common and severe in immunocompromised patients with the increase in susceptible populations in recent decades, which resulted in a substantial burden on the public health system. However, prompt and precise identification of them during infection remains challenging. Our study established successfully a TaqMan probe-based multiplex real-time qPCR assay for four clinically important filamentous fungi, <i>A. fumigatus</i>, <i>Fusarium</i> spp., Mucorales, and <i>Histoplasma capsulatum,</i> with high sensitivity and specificity, which shows promising potential for prompt and precise diagnosis against fungal infection.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370266/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}