Microbiology spectrum最新文献

{"title":"New insights into the testicular tropism of porcine reproductive and respiratory syndrome virus.","authors":"Kassandra Durazo-Martínez, Fernando A Osorio, Gustavo Delhon, Jesús Hernández, Hiep L X Vu","doi":"10.1128/spectrum.02964-24","DOIUrl":"10.1128/spectrum.02964-24","url":null,"abstract":"<p><p>Porcine reproductive and respiratory syndrome virus (PRRSV) has a restricted host specificity, primarily infecting porcine macrophages. Notably, an exception to such macrophage-restricted tropism has been observed in sexually active boars, where the virus infects and induces apoptosis in the germinal epithelium, resulting in viral dissemination in the ejaculate. Whether this phenomenon occurs in prepubertal animals remains unclear. In this study, we isolated spermatogonia stem cells (SSCs) from neonatal pigs and cultured them <i>in vitro</i>. These SSC cultures formed morula-like colonies, exhibited alkaline phosphatase activity-a characteristic of stem cells-and expressed protein gene product 9.5, a marker of SSCs. Notably, the SSC cultures supported PRRSV replication with kinetics similar to that observed in porcine alveolar macrophages. To assess the testicular tropism of PRRSV in prepuberal animals, 28-day-old male pigs were infected with a virulent PRRSV strain. Testicular tissues were sequentially analyzed using a combination of <i>in situ</i> hybridization for PRRSV RNA and immunohistochemistry for specific cellular markers. Unlike in sexually active boars, PRRSV did not infect the spermatogonia cells within the seminiferous tubules of prepubertal pigs. Instead, the virus primarily infected macrophages and myoid cells located in the interstitium and peritubular areas. It appeared that the anatomical separation of spermatogonia from the basal membrane of the seminiferous tubules in prepubertal pigs prevents these cells from being infected by PRRSV. Overall, our findings offer valuable insights into the age-dependent testicular tropism of PRRSV.IMPORTANCEContaminated boar semen used in artificial insemination has significantly contributed to the global spread of porcine reproductive and respiratory syndrome virus (PRRSV), a virus that typically infects only cells within the monocyte and macrophage lineages. Our study reveals that spermatogonia stem cells (SSCs) from neonatal piglets are also susceptible to PRRSV, suggesting that non-macrophage cells can be infected by the virus. However, despite this susceptibility, PRRSV-infected cells were not found in the seminiferous tubules of prepubertal male pigs inoculated with a virulent PRRSV strain. This contrasts with sexually mature boars, where PRRSV-infected cells were prominently observed within the seminiferous tubules. The discrepancy is likely due to anatomical differences between the seminiferous tubules of sexually mature boars and prepubertal pigs. These findings provide new insights into PRRSV pathogenesis. Additionally, the <i>ex vivo</i> SSC culture provides a valuable model for identifying new viral receptors necessary for PRRSV infection and for investigating the virus's impact on spermatogenesis.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0296424"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960452/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143449550","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":"Impact of first-void urine volume on chlamydia and gonorrhea positivity rates in men who have sex with men and transgender women.","authors":"Clayton W Hall, Adam Pyke, Mikhail Davydov, Katelin Urbanoski, Tim H Guimond, Kevin Woodward","doi":"10.1128/spectrum.03072-24","DOIUrl":"10.1128/spectrum.03072-24","url":null,"abstract":"","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0307224"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483423","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":"Revealing the clinical relevance of <i>Staphylococcus borealis</i>.","authors":"Jorunn Pauline Cavanagh, Claus Klingenberg, Hermoine Jean Venter, Jan Egil Afset, Olaf Stromme, Paul Christoffer Lindemann, Therese Johansen, Kyriakos Zaragkoulias, Hege Vangstein Aamot, Ståle Tofteland, Pia Littauer","doi":"10.1128/spectrum.01988-24","DOIUrl":"10.1128/spectrum.01988-24","url":null,"abstract":"<p><p><i>Staphylococcus borealis</i>, previously misidentified as <i>Staphylococcus haemolyticus</i>, was first described as a new species in 2020. In this study, we aimed to describe the clinical relevance of <i>S. borealis</i> by combining clinical data, antibiotic susceptibility profiles, and biofilm formation in isolates obtained from hospitalized and non-hospitalized patients. We established a collection of 129 <i>S</i>. <i>borealis</i> isolates from 129 adult patients from seven Norwegian hospitals. We describe clinical data at the time of microbiological specimen collection. Antibiotic susceptibility and biofilm formation were tested using established methods. Of 129 isolates (37%), 48 were from patients admitted to a hospital, the remaining from outpatients. The median (IQR) age was 62 (51-78) years, and 85/129 (66%) of the isolates were from male patients. The majority (81/129, 63%) of the <i>S. borealis</i> isolates were isolated from urine cultures, followed by isolation from skin and soft tissue cultures (35/129, 27%), blood cultures (8/129, 6%), and two implant-associated infections (2/129, 2%). Resistance to ≥3 antibiotic classes was observed in 43/129 (33%) of the isolates. All isolates formed a biofilm under the conditions tested; 59/129 (46%) weak, 40/129 (31%) medium, and 29/129 (23%) were strong biofilm producers. <i>S. borealis</i> clinical samples were predominately obtained from elderly male patients, and the majority of samples were from patients with suspected urinary tract or skin and soft tissue infections. The level of multidrug resistance was comparable to other coagulase-negative staphylococcal species, but resistance toward methicillin and penicillin was lower than in clinical <i>S. haemolyticus</i> isolates.</p><p><strong>Importance: </strong>This study contributes novel knowledge on the clinical relevance of <i>Staphylococcus borealis</i>; this is of importance when clinical microbiologists encounter <i>S. borealis</i> identified in patient samples. <i>S. borealis</i> was mainly identified in microbiological specimens from middle-aged to elderly patients, predominantly males. Hospitalized patients were also frequently immunocompromised and had other underlying conditions accompanying a suspected S. borealis infection.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0198824"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143605684","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":"Pathological characterization of female reproductive organs prior to miscarriage induced by Zika virus infection in the pregnant common marmoset.","authors":"Toshifumi Imagawa, Kazuo Tanaka, Masahiko Ito, Mami Matsuda, Tadaki Suzuki, Tsuyoshi Ando, Chizuko Yaguchi, Kazuyoshi Miyamoto, Shuji Takabayashi, Ryosuke Suzuki, Tomohiko Takasaki, Hiroaki Itoh, Isao Kosugi, Tetsuro Suzuki","doi":"10.1128/spectrum.02282-24","DOIUrl":"10.1128/spectrum.02282-24","url":null,"abstract":"<p><p>While Zika virus (ZIKV) infection in pregnant women is known to increase the risk of miscarriage and stillbirth, the mechanism by which ZIKV infection leads to the inability to continue a pregnancy is not clear. In our common marmoset models of ZIKV infection in pregnant individuals, miscarriage was observed in dams infected in the first or second trimester, and preterm delivery was observed in a dam infected in the third trimester. Serum progesterone levels were significantly lower prior to miscarriage or preterm delivery in the infected marmosets. To elucidate the pathology of the placental region just before the onset of ZIKV-induced miscarriage, we newly prepared an infected marmoset in the first trimester of pregnancy and euthanized it when the serum progesterone concentration was markedly reduced. Pathological analysis revealed significant degeneration in cells at the maternal-fetal interface, presumably trophoblasts. Cleaved-caspase was widely observed in the endometrial to placental region, and TNFα at 200 pg/mL was detected in the amniotic fluid, suggesting that apoptosis may progress in the endometrium and placenta, leading to decreased trophoblast function and miscarriage. ZIKV NS1 protein was found sporadically in the cellular degeneration area and widely in the basal layer of the endometrium. Furthermore, the viral protein was frequently detected in the follicles and corpus luteum of the ovary. The developed ZIKV infection model in pregnant marmosets would be useful not only to better understand the mechanism of ZIKV-induced miscarriage but also to analyze the effects of the viral infection on female reproductive tissues.</p><p><strong>Importance: </strong>Although several viruses, including Zika virus (ZIKV), are known to increase the risk of miscarriage upon viral infection, the mechanism by which miscarriage is induced by viral infection is largely unknown. This is partly due to the difficulty of pathological analysis of maternal tissues in the period following viral infection and prior to miscarriage. In this study, we predicted the occurrence of miscarriage by monitoring serum progesterone levels and performed pathological analysis of peri-placental tissues at a time point assumed to be just before miscarriage. This is the first report of trophoblast degeneration prior to miscarriage, suggesting that the experimental method used here is useful for analyzing the pathogenesis of virus infection-related miscarriage. Further immunostaining revealed that ZIKV NS1 was distributed not only in the uterus but also in the ovaries, with particularly pronounced staining of oocytes. Whether ZIKV infection affects female reproductive function should be clarified in the future.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0228224"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960083/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492958","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":"Identification of <i>Escherichia coli</i> 166 isolate as an effective inhibitor of African swine fever virus replication.","authors":"Jinya Zhang, Hongyu Cui, Zhenjiang Zhang, Wenqing Wang, Fengwei Jiang, Encheng Sun, Yuanmao Zhu, Fang Li, Zhigao Bu, Dongming Zhao","doi":"10.1128/spectrum.03009-24","DOIUrl":"10.1128/spectrum.03009-24","url":null,"abstract":"<p><p>African swine fever is a lethal disease with mortality rates approaching 100% in both domestic pigs and wild boars. With no effective vaccines or treatments available, there is an urgent need for new biologics to combat the African swine fever virus (ASFV). In this study, we isolated bacteria from the intestinal contents of wild boar using culture-based methods and identified them through 16S ribosomal DNA (rDNA) sequencing. These isolates underwent high-throughput screening to evaluate their immunomodulatory effects on J774-Dual cells and their ability to inhibit ASFV replication <i>in vitro</i>. Among them, an <i>Escherichia coli</i> strain, designated as <i>E. coli</i> 166, exhibited strong inhibitory effects on various ASFV strains' replication, including three genotype II strains: virulent strain HLJ/18, moderately virulent strain HLJ/HRB1/20, genetically modified low-virulent strain HLJ/18-6GD, and one genotype I low-virulent strain SD/DY-I/21. Notably, this inhibition did not require direct interaction between the bacteria and porcine alveolar macrophages (PAMs). Both live and heat-inactivated <i>E. coli</i> 166 demonstrated a strong inhibitory effect on ASFV replication. Genetic modification of <i>E. coli</i> 166 did not alter its inhibitory phenotype. Further analysis revealed that PAMs pretreated with <i>E. coli</i> 166 showed upregulation of NF-κB and downregulation of CD163 at different time points post-infection, whereas PAMs only infected with ASFV exhibited the opposite trend. These findings suggest that <i>E. coli</i> 166 holds promise as a biological agent for controlling ASFV infection, through indirect mechanisms involving bacterial metabolites or lysis products. Future studies should focus on identifying the specific components responsible for its antiviral effects.IMPORTANCEThe emergence of the African swine fever virus (ASFV) as a devastating pathogen in swine populations necessitates the development of novel strategies for its control. In this study, <i>Escherichia coli</i> strain 166 (<i>E. coli</i> 166) demonstrated a remarkable ability to inhibit the replication of multiple ASFV strains in porcine alveolar macrophages (PAMs), even without direct bacterial contact. Both live and heat-inactivated <i>E. coli</i> 166 retained this inhibitory effect, suggesting that secreted metabolites or lysis products may play a key role. Furthermore, pretreatment of PAMs with <i>E. coli</i> 166 resulted in upregulated NF-κB activity and downregulated expression of the ASFV entry receptor CD163, presenting an immune-modulatory mechanism distinct from PAMs solely infected with ASFV. These findings highlight the potential of <i>E. coli</i> 166 as a biological agent to combat ASFV, offering a promising alternative or complementary approach to traditional antiviral strategies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0300924"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960076/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502483","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 novel double-antibody sandwich ELISA based on monoclonal antibodies against the viral spike protein detects porcine deltacoronavirus infection.","authors":"Yingjie Bai, Ruiming Yu, Guangqing Zhou, Liping Zhang, TianTian Wang, Ya Liu, Dongsheng Wang, Zhongwang Zhang, Yonglu Wang, Huichen Guo, Li Pan, Xinsheng Liu","doi":"10.1128/spectrum.02854-24","DOIUrl":"10.1128/spectrum.02854-24","url":null,"abstract":"<p><p>Porcine deltacoronavirus (PDCoV) is a significant emerging pathogen that causes severe enteric disease in swine, and therefore significant economic losses in the pig farming industry. Here, we developed a novel double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on two monoclonal antibodies directed against the PDCoV spike protein. These two monoclonal antibodies were obtained through hybridoma fusion and screening, and they can specifically react with the PDCoV spike protein. The detection limits of the DAS-ELISA for the recombinant spike protein and viral titer were approximately 0.12 ng/mL and 1.96 × 10³ copies/μL, respectively. The DAS-ELISA did not cross-react with other swine enteric coronaviruses, including porcine epidemic diarrhea virus, transmissible gastroenteritis virus, or porcine rotavirus. A total of 145 rectal swab samples were collected and tested for the presence of PDCoV with the DAS-ELISA and reverse transcription-quantitative PCR (RT-qPCR). The coincidence rate between the DAS-ELISA and RT-qPCR was 91.03%, with a kappa value of 0.814, indicating that the DAS-ELISA is a reliable method for viral antigen detection in clinical samples. DAS-ELISA had a sensitivity of 92.85% and a specificity of 89.89%. The positive predictive value and negative predictive value of this method are 85.25% and 95.24%, respectively. Furthermore, the DAS-ELISA can also be used to detect the spike protein in PDCoV vaccines, making it a valuable tool for assessing the efficacy of PDCoV vaccines.</p><p><strong>Importance: </strong>Since 2014, porcine deltacoronavirus (PDCoV) has spread widely across multiple countries and regions, causing significant economic losses to the global livestock industry. Currently, no commercially available vaccine exists for the prevention of PDCoV infection; therefore, accurate and effective diagnostic methods are crucial for its control and prevention. In this study, the PDCoV S protein expressed in Chinese Hamster Ovary (CHO) cells was used to immunize mice, and a novel double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was established based on two monoclonal antibodies. The DAS-ELISA had high sensitivity, good repeatability, strong specificity, and high consistency for detecting clinical samples and spike protein in PDCoV vaccines. Therefore, the DAS-ELISA established in this study may be a reliable and effective tool for detecting PDCoV infection and the efficacy of PDCoV vaccines.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0285424"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143516126","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":"Clinical presentation, treatment, and antimicrobial susceptibility of 155 sequential <i>Staphylococcus lugdunensis</i> infections.","authors":"Kurt D Palumbo, Natasia F Jacko, Michael Z David","doi":"10.1128/spectrum.02749-24","DOIUrl":"10.1128/spectrum.02749-24","url":null,"abstract":"<p><p><i>Staphylococcus lugdunensis</i> is known to be virulent, but there are few large-scale epidemiologic studies of this species to define types of infection, susceptibility patterns, and severity. <i>S. lugdunensis</i> isolates from any culture at four U.S. tertiary care hospitals between 1 April 2021 and 1 April 2022 were identified. For the first isolate from each subject, clinical, demographic, and outcome data were recorded. Of 291 isolates, 223 were obtained from a clinically significant infection. Of these 223 isolates, 86 (38.6%) were from monomicrobial cultures; additionally, <i>S. lugdunensis</i> was considered a true pathogen in 69/137 polymicrobial infections. Among 155 subjects with <i>S. lugdunensis</i> infections, 49.7% were female, 46.5% were black, and 41.9% were white; 51.6% of infections were community associated. The most common infection sites were skin and soft tissue (SSTI) (<i>n</i> = 98, 63.2%), urinary tract (<i>n</i> = 16, 10.3%), and sinusitis (<i>n</i> = 14, 9%). Of nine monomicrobial bloodstream infections (BSIs), two were fatal, three involved foreign bodies, and two had infective endocarditis. Greater than half of SSTIs required an invasive procedure for cure. Among 138/291 isolates from colonization or infection, tetracycline, trimethoprim-sulfamethoxazole, oxacillin, and vancomycin susceptibility rates were 94.8% (128/135), 95.9% (94/98), 84.1% (116/138), and 100% (138/138), respectively. There were similarities in types of infection comparing <i>S. lugdunensis</i> in this study and prior reports on <i>Staphylococcus aureus</i>. SSTI was the predominant <i>S. lugdunensis</i> infection type; more than 50% of SSTIs required procedural intervention. Of nine BSIs, three involved a foreign body, and there were two cases of infective endocarditis. Oxacillin resistance was identified in 16% of isolates.</p><p><strong>Importance: </strong>In recent years, <i>Staphylococcus lugdunensis</i> has been identified with increasing frequency as a human pathogen causing a wide variety of clinical syndromes, from soft tissue infections to fatal cases of bloodstream infection. Despite this, there are few large-scale epidemiologic studies examining this highly virulent organism. Our study adds to the growing literature on this emerging pathogen by analyzing a large case series of sequential <i>S. lugdunensis</i> infections at four U.S. hospitals to define its contemporary epidemiology, including the types of infections it causes, their outcomes, treatment approaches, and antimicrobial susceptibilities. These data provide valuable insights for clinicians in diagnosing and treating patients with these often debilitating infections. The findings also improve upon our understanding of the incidence of each infection syndrome and variability in antimicrobial susceptibilities of isolates to guide the design of future studies on the genomic epidemiology of this important pathogen.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0274924"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960052/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586264","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":"Intra-serotype variation of <i>Streptococcus pneumoniae</i> capsule and its quantification.","authors":"Hannes Eichner, Cindy Wu, Michael Cammer, Elizabeth N H Tran, Timothy R Hirst, James C Paton, Jeffrey N Weiser","doi":"10.1128/spectrum.03087-24","DOIUrl":"10.1128/spectrum.03087-24","url":null,"abstract":"<p><p><i>Streptococcus pneumoniae</i> (<i>Spn</i>) is a leading respiratory pathogen that depends on a thick layer of capsular polysaccharide (CPS) to evade immune clearance. Disease prevention by CPS-based vaccines is limited because of the species' high genome plasticity and ability to express over 100 different capsule types (serotypes). Generally, intra-serotype variations in capsulation are overlooked, despite the genetic variability of the bacterium. This oversight may result from a lack of standardized, reliable, and easily available methodology to quantify capsulation. Here, we have modified two methods to analyze the <i>Spn</i> capsule: immunoblot quantification of CPS in bacterial lysates and light microscopy to assess capsule thickness. Two assays were used because each measures distinct aspects of capsulation that could be differentially affected by the density of CPS. Quantification of either CPS amount or capsule thickness predicted the effectiveness of immune serum in opsonophagocytic killing assays for isogenic strains. Our standardized approaches both revealed significant differences in both CPS amount and capsule thickness among clinical isolates of the same serotype, challenging the assumption that intra-serotype capsulation is a conserved feature. As expected, these two methods show limited intra-strain correlation between amounts of CPS production and capsule thickness.</p><p><strong>Importance: </strong>Despite the availability of vaccines, <i>Streptococcus pneumoniae</i> remains a leading cause of respiratory and invasive diseases. These vaccines target a polysaccharide capsule the bacterium uses to evade the immune system. Variation of the capsule composition subdivides the organism into serotypes and influences its protective potency. Another critical factor affecting this protection is capsule size. It is commonly assumed that <i>S. pneumoniae</i> strains of the same serotype produce capsules of consistent size, despite the organism's heterogeneity. In this study, we challenge this assumption by analyzing clinical isolates of the same serotype. Existing methods were modified to achieve high reproducibility and increase accessibility. Our data reveal significant fluctuations in capsule production within a given serotype. Our findings suggest that <i>S. pneumoniae</i> research should consider capsule size, not just its presence and type. The results imply that standardized vaccine efficacy tests may yield variable results depending on the capsule production of target strains.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0308724"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960111/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414695","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":"Performance characteristics of an automated, high-throughput RT-PCR assay for the detection of <i>Candida auris</i> on 3-point and nasal swabs.","authors":"Nhi T Nhan, Tianxi Liu, Abdulaala A Almushajrah, Ashish Mozumder, Momka Narlieva, Wendy A Szymczak, Phyu M Thwe, Erika P Orner, Doctor Y Goldstein","doi":"10.1128/spectrum.02114-24","DOIUrl":"10.1128/spectrum.02114-24","url":null,"abstract":"<p><p><i>Candida auris</i> is a multidrug-resistant yeast responsible for invasive infections with high mortality rates, primarily spread through prolonged colonization on biotic and abiotic surfaces and traveling. Effective control necessitates comprehensive screening protocols, as recommended by the Centers for Disease Control and Prevention, which endorses a real-time polymerase chain reaction-based assay for <i>C. auris</i> screening. This study evaluates the performance of this assay on the Hologic Panther Fusion System using nasal and 3-point swab specimens (nares/axilla/groin) compared with culture. The assay was assessed for accuracy, sensitivity, specificity, and reproducibility, alongside an evaluation of probe primer reagent (PPR) onboard stability over 30 working days. Analytical sensitivity studies determined limits of detection of 1.95 Log CFU/mL for nasal swabs and 2.18 Log CFU/mL for 3-point swabs, both with >95.0% confidence intervals. The assay demonstrated 100% specificity (<i>n</i> = 25), with no false positives from genetically similar or clinically relevant species, and no significant interference from co-infecting microbes on cycle threshold (CT) values. Both swab types exhibited high intra- and inter-reproducibility, with low coefficients of variation (1.79% and 1.06%, respectively). The assay detected <i>C. auris</i> in 100% of 108 spiked-positive samples across both swab types. Clinical analysis showed 100% concordance with culture for 3-point swabs. Additionally, the nasal swab method showed 96.0% overall agreement, with 86.2% sensitivity and 100.0% specificity. The PPR mixes remained stable over 30 working days, with no significant CT value changes. This study confirms the assay's robust sensitivity, specificity, reproducibility, and accuracy for both nasal and 3-point screening swabs.</p><p><strong>Importance: </strong><i>Candida auris</i> is a multidrug-resistant yeast responsible for severe infections with high mortality rates. Rapid and accurate detection is critical for preventing the spread of this pathogen in healthcare settings. This study assesses the performance of an automated real-time PCR screening assay for detecting <i>C. auri</i>s using nasal and 3-point swabs. The findings demonstrate the assay's high sensitivity, specificity, and reproducibility, making it a valuable tool for infection control. By providing a reliable and efficient screening method, this assay can significantly enhance efforts to control <i>C. auris</i> outbreaks, ultimately improving patient outcomes and reducing the spread of this dangerous pathogen.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0211424"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960114/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414697","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 type-specific B-cell epitope at the apex of outer surface protein C (OspC) of the Lyme disease spirochete, <i>Borreliella burgdorferi</i>.","authors":"David J Vance, Grace Freeman-Gallant, Kathleen McCarthy, Carol Lyn Piazza, Yang Chen, Clint Vorauer, Beatrice Muriuki, Michael J Rudolph, Lisa Cavacini, Miklos Guttman, Nicholas J Mantis","doi":"10.1128/spectrum.02883-24","DOIUrl":"10.1128/spectrum.02883-24","url":null,"abstract":"<p><p>Broadly protective immunity to the Lyme disease spirochete, <i>Borreliella burgdorferi</i>, is constrained by antibodies against type-specific epitopes on outer surface protein C (OspC), a homodimeric helix-rich lipoprotein essential for early stages of spirochete dissemination in vertebrate hosts. However, the molecular basis for type-specific immunity has not been fully elucidated. In this report, we produced and characterized an OspC mouse monoclonal antibody, 8C1, that recognizes native and recombinant OspC type A (OspC_A) but not OspC type B or K. Epitope mapping by hydrogen-deuterium exchange mass spectrometry (HDX-MS) localized 8C1's epitope to a protruding ridge on the apex of OspC_Aα-helix 3 (residues 130-150) previously known to be an immunodominant region of the molecule. Alanine scanning pinpointed 8C1's core binding motif to a solvent exposed patch consisting of residues K₁₄₁, H₁₄₂, T₁₄₃, and D₁₄₄. Analysis of 26 Lyme disease-positive serum samples confirmed human antibody reactivity with this region of OspC_A, with residues E₁₄₀ and D₁₄₄ as being the most consequential. Our results underscore the importance of α-helix 3 as a target of type-specific epitopes on OspC_A that should be taken into consideration in Lyme disease vaccine design.IMPORTANCEA central challenge in the development of vaccines against Lyme disease, the most common vector-borne infection in the United States, is the antigenically variable nature of the lipoproteins displayed on the surface of the disease-causing spirochete, <i>Borreliella burgdorferi</i>. For example, antibodies against one type of outer surface protein C (OspC), a lipoprotein involved in <i>B. burgdorferi</i> transmission and early stages of infection, may have little or no cross reactivity with another seemingly closely related variant of OspC, thereby hampering the use of a single OspC type as a vaccine antigen. For the sake of vaccine design, it is critical to identify the specific epitopes on OspC that both restrict and enable cross-reactivity.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0288324"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960070/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414676","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}