Microbiology spectrum最新文献

{"title":"The PdxR-PdxKU locus involved in vitamin B₆ salvage is important for group A streptococcal resistance to neutrophil killing and survival in human blood.","authors":"Sarah E Davis, Meaghan T Hart, Rezia Era D Braza, Aolani A Perry, Luis A Vega, Yoann S Le Breton, Kevin S McIver","doi":"10.1128/spectrum.01609-24","DOIUrl":"https://doi.org/10.1128/spectrum.01609-24","url":null,"abstract":"<p><p><i>Streptococcus pyogenes</i> (Group A <i>Streptococcus</i>, GAS) is a Gram-positive bacterium that inflicts both superficial and life-threatening diseases on its human host. Analysis of fitness using a transposon mutant library revealed that genes predicted to be involved in vitamin B₆ acquisition are associated with fitness in whole human blood. Vitamin B₆ is essential for all life and is important for many cellular functions. In several streptococcal species, it has been shown that mutants in B₆ acquisition exhibited reduced virulence phenotypes and were attenuated during infection. In GAS, B₆ acquisition is believed to be controlled by the <i>pdxR-pdxKU</i> locus, where PdxR is a positive regulator of <i>pdxKU</i>, which encodes for a B₆-substrate kinase and permease, respectively. Mutants in the regulator (Δ<i>pdxR</i>) and salvage machinery (Δ<i>pdxKU</i>) both exhibited modest growth defects when grown in oxygenated conditions with limited vitamin B₆ precursors. ∆<i>pdxR</i> and ∆<i>pdxKU</i> mutants also exhibited an impaired ability to survive when challenged with whole human or mouse blood. This defect was characterized by reduced survival in the presence of human neutrophil-like HL60s, primary polymorphonuclear leukocytes, and antimicrobial peptide LL-37. Promoter analysis showed that PdxR is an autoregulator and activated <i>pdxKU</i> in the absence of B₆. Interestingly, ∆<i>pdxR</i> and ∆<i>pdxKU</i> mutants were not attenuated in mouse models of infection, suggesting a species-specific impact on virulence. Overall, it appears that <i>pdxR-pdxKU</i> is associated with GAS vitamin B₆ metabolism as well as pathogen survival during encounters with the human innate immune system.IMPORTANCEBacterial pathogens such as <i>Streptococcus pyogenes</i> (Group A <i>Streptococcus</i>, GAS) must be able to obtain needed nutrients in their human host. Vitamin B₆ or pyridoxal 5' phosphate is essential for all life and is important for many cellular functions. In other streptococcal pathogens, B₆ acquisition has been shown to be important for their ability to cause disease. Here, we show that loss of the putative vitamin B₆ salvage pathway locus <i>pdxR-pdxKU</i> affects GAS pathogenesis when encountering innate immune responses from phagocytic neutrophils and antimicrobial peptides within the host. <i>pdxR-</i>pdxKU may contribute to oxygen tolerance through B₆; however, there appear to be other mechanisms for salvaging vitamin B₆. Overall, <i>pdxR-pdxKU</i> is associated with GAS resistance to the human innate immune response and oxygen tolerance and contributes modestly to B₆ metabolism.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0160924"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624158","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":"Erratum for Wang et al., \"Annotation of 2,507 <i>Saccharomyces cerevisiae</i> genomes\".","authors":"Meng Wang, Xuan Li, Xian Liu, Xiaoping Hou, Yang He, Jun-Hong Yu, Shumin Hu, Hua Yin, Bin-Bin Xie","doi":"10.1128/spectrum.02374-24","DOIUrl":"https://doi.org/10.1128/spectrum.02374-24","url":null,"abstract":"","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0237424"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624115","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 antimicrobial potential of traditional remedies of Indigenous peoples from Canada against MRSA planktonic and biofilm bacteria in wound infection mimetic conditions.","authors":"Colin D Rieger, Ahmed M Soliman, Kateryna Kaplia, Nilrup Ghosh, Alexa Cervantes Lopez, Surya Arcot Venkatesan, Abraham Gildaro Guevara Flores, Matheus Antônio Filiol Belin, Florence Allen, Margaret Reynolds, Betty McKenna, Harold Lavallee, Archie Weenie, Thomas Favel, Fidji Gendron, Vincent E Ziffle, Omar M El-Halfawy","doi":"10.1128/spectrum.02341-24","DOIUrl":"https://doi.org/10.1128/spectrum.02341-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Methicillin-resistant &lt;i&gt;Staphylococcus aureus&lt;/i&gt; (MRSA) is the leading cause of wound infections, often progressing into serious invasive bloodstream infections. MRSA disproportionately affects Indigenous peoples in Canada with higher rates of skin and wound infections, an example of persistent gaps in health outcomes between Indigenous and non-Indigenous peoples precipitated by the legacy of colonialism. Conversely, Indigenous peoples have long used natural remedies for infections and other diseases; however, their knowledge was rarely considered for modern medicine. The stagnant antibiotic discovery pipeline and alarming rise of resistance to current antibiotics prompted us to turn to Indigenous medicine as an untapped source of antimicrobials. As such, we collected and prepared 85 extracts of medicinal plants of value to Indigenous peoples spanning the Canadian Prairies. We explored the antimicrobial potential of these extracts against MRSA under wound infection-mimetic conditions compared with culture media typically used to study bacterial antibiotic responses and biofilms but not adequately representative of infection sites. We identified extracts with MRSA growth inhibitory [&lt;i&gt;e.g.&lt;/i&gt;, bergamot, dock, gaillardia, and dandelion extracts] and biofilm prevention and eradication [&lt;i&gt;e.g.&lt;/i&gt;, gumweed extracts] activities. Extracts, including those of chokecherry, hoary puccoon, and Northern bedstraw, were only active under wound infection-mimetic conditions, highlighting the benefit of antibiotic discovery under host-relevant conditions. Testing growth inhibitory extracts against an &lt;i&gt;S. aureus&lt;/i&gt; cross-resistance platform suggested that they act through mechanisms likely distinct from known antibiotic classes. Together, through an interdisciplinary partnership leveraging Western approaches and traditional Indigenous knowledge, we identified plant extracts with promising antimicrobial potential for drug-resistant MRSA wound infections.IMPORTANCEWe explored the antimicrobial potential of traditional Indigenous remedies against MRSA under wound infection-mimetic conditions. We chose to tackle MRSA wound infections because they constitute an Indigenous health priority, ensuring mutual benefits and reciprocity, which are important principles in partnerships between Indigenous and non-Indigenous researchers. Our partnerships strive to serve as steps towards reconciliation with Indigenous peoples in Canada and a roadmap inspiring similar interdisciplinary collaborations to tackle other healthcare priorities. We identified extracts with promising antibacterial growth inhibitory, biofilm prevention, and eradication activities against MRSA. The antimicrobial potential of some extracts was only observed under wound infection-mimetic conditions, a proof-of-concept that screening under infection-mimetic conditions reveals novel activity undetected under standard conditions. The natural product antimicrobial extracts discovered herein warrant f","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0234124"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624154","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":"Optimization of ultrasound-mediated DNA transfer for bacteria and preservation of frozen competent cells.","authors":"Meng Zhang, Rongkang Tang, Fang-Xia Li, Wen-Yu Jin, Jia-Xin Guo, Lin-Zuo Teng, Guangxun Meng, Philippe J Sansonetti, Yi-Zhou Gao","doi":"10.1128/spectrum.00978-24","DOIUrl":"https://doi.org/10.1128/spectrum.00978-24","url":null,"abstract":"<p><p>The transformation of DNA into cells is the basis of molecular biology. Commonly employed techniques include heat shock transformation, electro-transformation, conjugation, transduction, and protoplast fusion. Recently, ultrasonic transformation technology has been developed to transfer DNA into competent cells. The transformation conditions, such as temperature and ultrasonic power, were preliminarily studied. However, this technique has not been widely applied because competent cells must be prepared <i>de novo</i>. In this study, various factors, such as ultrasonic frequency and power, were optimized for the ultrasonic transformation of <i>Escherichia coli</i>. The study found that the optimal conditions for ultrasonic transformation with a defined ultrasonic transformation vial were a frequency of 28 kHz and a power of 80 W. Meanwhile, this research demonstrated that combining the 42°C heat shock conditions with ultrasonic transformation is the most efficient method compared to using only heat shock. Furthermore, the cryoprotective agent ratio for ultrasonic competent cells was investigated and optimized. These findings provide new insights into enhancing transformation efficiency and lay a foundation for the broader application of ultrasonic transformation.</p><p><strong>Importance: </strong>Plasmid transformation is widely applicable in gene expression and modification. As an efficient, non-invasive, and gentle method of transformation, ultrasonic transformation provides a novel approach for strain modification. This research presents new strategies for enhancing transformation efficiency and lays the groundwork for expanding the utilization of ultrasonic transformation.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0097824"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624042","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":"Genotypic and phylogeographic insights into a pre-epidemic variant of Wesselsbron virus detected in sylvatic <i>Aedes mcintoshi</i> from Semuliki Forest, Uganda.","authors":"Georg Joachim Eibner, Selina Laura Graff, Christian Hieke, James Robert Ochieng, Anne Kopp, Christian Drosten, Julius Lutwama, Innocent Bidason Rwego, Sandra Junglen","doi":"10.1128/spectrum.00914-24","DOIUrl":"https://doi.org/10.1128/spectrum.00914-24","url":null,"abstract":"<p><p>Wesselsbron virus (WSLV) is a neglected mosquito-borne virus within the yellow fever subgroup in the genus <i>Orthoflavivirus</i> of the <i>Flaviviridae</i> family. Despite being primarily a veterinary pathogen able to cause stillbirths, congenital malformations, and mortality in ruminants, WSLV also infects humans, causing a usually self-limiting febrile illness, or may lead to neurological complications in rare cases. WSLV causes sporadic outbreaks in Southern Africa, but findings in mosquitoes from other African countries suggest a wider distribution. Here, we report the detection and isolation of WSLV from an <i>Aedes mcintoshi</i> mosquito collected in a pristine ecosystem within Semuliki National Park, western Uganda. The detected strain M5937-UG-2018 was impaired in infectivity, replication, and production of infectious particles in cell lines derived from different hosts compared to an epidemic reference strain, SA H177. Full-genome sequencing by next-generation sequencing from the mosquito homogenate revealed a maximum nucleotide identity of 98.1% to a WSLV isolate from a human sample collected in South Africa in 1996. M5937-UG-2018 grouped in phylogenetic analyses with strains from South Africa and Senegal. Reconstruction of the temporal and spatial dispersal of WSLV across Africa estimated a likely origin of WSLV in South Africa in the early 19th century and spread in Southern Africa in the following decades. Long-distance movement toward Western and Eastern Africa was modeled to have occurred in the early 21st century. However, displacing the origin of M5937-UG-2018 did not decrease the likelihood of the model supporting the hypothesis that WSLV is widely distributed in Africa.IMPORTANCEWSLV is a neglected mosquito-borne virus causing teratogenicity in ruminants and febrile illness in humans. WSLV is mainly endemic to Southern Africa, but findings in other regions suggest a wider distribution on the continent. Knowledge of the distribution of WSLV is impaired as differential diagnostics are rarely performed in livestock and humans presenting with symptoms compatible with WSLV infection. Our work investigating viral infections in mosquitoes from a remote tropical rainforest region demonstrates that WSLV is endemic in Uganda. The isolated virus was less infective and showed lower replication ability <i>in vitro</i> compared to an epidemic isolate from South Africa. Phylogeographic reconstruction of spatial and temporal movements, along with the displacement of the origin of the newly detected strain<b>,</b> suggests that WSLV may be widely distributed across Africa. Our data show that the geographic distribution of WSLV and its impact on human and animal health are likely underestimated.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0091424"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624130","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":"Doxifluridine effectively kills antibiotic-resistant <i>Staphylococcus aureus</i> in chronic obstructive pulmonary disease.","authors":"Lianshen Zhang, Yingzhang Zhang, Lijie Tian, Qiang Shen, Xiaolong Ma","doi":"10.1128/spectrum.01805-24","DOIUrl":"https://doi.org/10.1128/spectrum.01805-24","url":null,"abstract":"<p><p>Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality globally, often exacerbated by infections such as methicillin-resistant <i>Staphylococcus aureus</i> (MRSA). The rise in antibiotic-resistant strains complicates treatment and underscores the need for novel therapeutic drugs. In this paper, we further investigated the antimicrobial potential of a fluoropyrimidine anticancer drug doxifluridine against multidrug-resistant <i>S. aureus</i>. Determination of minimum inhibitory concentration (MIC) or minimum bactericidal concentration (MBC), monitoring of growth curve, time-kill assays, biofilm bactericidal assays, and chequerboard studies were conducted to evaluate the antibacterial efficacy of doxifluridine. Safety was assessed via hemolysis and cytotoxicity assays, and an <i>in vivo Galleria mellonella</i> larvae model was employed to test protective effects. Doxifluridine demonstrated significant antibacterial activity against clinical multidrug resistance (MDR) <i>S. aureus</i> isolates, with MIC and MBC values ranging from 0.5 to 2 µg/mL and 1 to 4 µg/mL, respectively. The results revealed doxifluridine's potent bactericidal effects within 8 hours. Moreover, doxifluridine-treated bacteria showed a substantial reduction in biofilm mass and viability. Furthermore, chequerboard assays indicated synergistic interactions between doxifluridine and other antibiotics, reducing MIC values by two- to eightfold. More importantly, safety evaluations confirmed that doxifluridine did not exhibit hemolytic toxicity or cytotoxicity. Finally, doxifluridine significantly increased the survival rate of MRSA-infected <i>G. mellonella</i> larvae <i>in vivo</i>. In brief, doxifluridine exhibited promising <i>in vitro</i> and <i>in vivo</i> antibacterial activity against MRSA, suggesting its potential as a repurposed drug for treating resistant bacterial infections in COPD patients.IMPORTANCEThe study provides robust evidence for the antibacterial efficacy of doxifluridine against Methicillin-resistant <i>Staphylococcus aureus</i> in chronic obstructive pulmonary disease (COPD) patients. Its rapid action, ability to disrupt biofilms, and synergistic effects with other antibiotics, combined with a favorable safety profile, highlight its potential as a repurposed therapeutic agent. Future clinical trials will be essential to confirm these findings and pave the way for its integration into clinical practice. This work not only provides candidate for tackling the management of bacterial infections in COPD but also exemplifies the potential of drug repurposing in combating antibiotic-resistant infections.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0180524"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624101","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":"Correction for Pérez-Viso et al., \"A long-term survey of <i>Serratia</i> spp. bloodstream infections revealed an increase of antimicrobial resistance involving adult population\".","authors":"Blanca Pérez-Viso, Marta Hernández-García, Concepción M Rodríguez, Miguel D Fernández-de-Bobadilla, María Isabel Serrano-Tomás, Ana María Sánchez-Díaz, José Avendaño-Ortiz, Teresa M Coque, Patricia Ruiz-Garbajosa, Rosa Del Campo, Rafael Cantón","doi":"10.1128/spectrum.02425-24","DOIUrl":"https://doi.org/10.1128/spectrum.02425-24","url":null,"abstract":"","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0242524"},"PeriodicalIF":3.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624094","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":"Correction for Manohar et al., \"A Multiwell-Plate <i>Caenorhabditis elegans</i> Assay for Assessing the Therapeutic Potential of Bacteriophages against Clinical Pathogens\".","authors":"Prasanth Manohar, Belinda Loh, Namasivayam Elangovan, Archana Loganathan, Ramesh Nachimuthu, Sebastian Leptihn","doi":"10.1128/spectrum.02606-24","DOIUrl":"https://doi.org/10.1128/spectrum.02606-24","url":null,"abstract":"","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0260624"},"PeriodicalIF":3.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624091","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":"Performance of UF-5000 in rapidly screening out urinary tract infection, predicting Gram-negative bacteria infection.","authors":"Wei Lu, Zhaoxing Li, Tong Zhang, Yan Li, Huange Zhu, Ya Zhao, Ke Lei, Zhi Guo, Jing Zhang, Juan Guo, Lei Zhang","doi":"10.1128/spectrum.00301-24","DOIUrl":"https://doi.org/10.1128/spectrum.00301-24","url":null,"abstract":"<p><p>Urine culture is the gold standard for identifying microorganisms in urine. However, the process is time-consuming and usually takes days to get the results, which impedes timely treatment. This study aimed to evaluate the performance of UF-5000 in excluding bacterial urinary tract infection (UTI) and detecting the presence of Gram-negative bacteria. A total of 1,522 urine specimens were subjected to routine urine analysis and culture. Bacteria, white blood cell counts, and UF-5000 bacteria information flags were compared with urine culture. Bacteria forward scatter (B_FSC), and bacteria fluorescent light intensity (B_FLH) parameters were assessed to determine the optimal angle for discriminating bacterial growth patterns, which was verified in the validation cohort. The optimal cut-off values were 42.2/µL and 100.2/µL to rule out UTI for bacteria at ≥10⁴ CFU/mL and ≥10⁵ CFU/mL, respectively. The agreement of UF-5000 bacterial classification and urine culture was fair (Kappa = 0.227). Regarding the discrimination of bacterial groups, \"Gram Neg?\" was associated with a specificity of 94.0% and a positive predictive value of 87.2% in the detection of Gram-negative bacteria. By estimating the B_FSC and B_FLH parameters, the best angle was 28° for distinguishing Gram-negative and Gram-positive bacteria. Among the 136 urine specimens with the low angle pattern (<28°) in the validation cohort, 127 specimens were confirmed to contain Gram-negative bacteria. The UF-5000 analyzer is a suitable and rapid tool to exclude negative urine specimens, and bacterial information flags for Gram-negative bacteria could be trusted by clinicians.IMPORTANCEThe strength of our study relied on being the first study assessing the bacteria forward scatter (B_FSC) and bacteria fluorescent light intensity (B_FLH) research parameters with a UF-5000 urine analyzer and establishing the best angle for distinguishing Gram-negative and Gram-positive bacteria. When the bacterial scatter plot angle is less than 28°, the possibility of Gram-negative bacterial infection is more than 80%. Meanwhile, we find that UF-5000 bacterial information flags have a significant advantage in detecting Gram-negative bacteria with a specificity of over 90% and a positive predictive value of over 80%.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0030124"},"PeriodicalIF":3.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624051","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":"Physiological oxygen concentration during sympathetic primary neuron culture improves neuronal health and reduces HSV-1 reactivation.","authors":"Sara A Dochnal, Patryk A Krakowiak, Abigail L Whitford, Anna R Cliffe","doi":"10.1128/spectrum.02031-24","DOIUrl":"10.1128/spectrum.02031-24","url":null,"abstract":"<p><p>Herpes simplex virus-1 (HSV-1) establishes a latent infection in peripheral neurons and periodically reactivates in response to a stimulus to permit transmission. <i>In vitro</i> models using primary neurons are invaluable to studying latent infection because they use bona fide neurons that have undergone differentiation and maturation <i>in vivo</i>. However, culture conditions <i>in vitro</i> should remain as close to those <i>in vivo</i> as possible. This is especially important when considering minimizing cell stress, as it is a well-known trigger of HSV reactivation. We recently developed an HSV-1 model system that requires neurons to be cultured for extended lengths of time. Therefore, we sought to refine culture conditions to optimize neuronal health and minimize secondary effects on latency and reactivation. Here, we demonstrate that culturing primary neurons under conditions closer to physiological oxygen concentrations (5% oxygen) results in cultures with features consistent with reduced stress. Furthermore, culture in these lower oxygen conditions diminishes the progression to full HSV-1 reactivation despite minimal impacts on latency establishment and earlier stages of HSV-1 reactivation. We anticipate that our findings will be useful for the broader microbiology community as they highlight the importance of considering physiological oxygen concentration in studying host-pathogen interactions.IMPORTANCEEstablishing models to investigate host-pathogen interactions requires mimicking physiological conditions as closely as possible. One consideration is the oxygen concentration used for <i>in vitro</i> tissue culture experiments. Standard incubators do not regulate oxygen levels, exposing cells to oxygen concentrations of approximately 18%. However, cells within the body are exposed to much lower oxygen concentrations, with physiological oxygen concentrations in the brain being 0.55%-8% oxygen. Here, we describe a model for herpes simplex virus 1 (HSV-1) latent infection using neurons cultured in 5% oxygen. We show that culturing neurons in more physiological oxygen concentrations improves neuronal health to permit long-term studies of virus-cell interactions and the impact on reactivation.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0203124"},"PeriodicalIF":3.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142624069","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}