Prevalence of anti-HLA antibodies in COVID-19 convalescent plasma donors: an Indian experience.

BACKGROUND: COVID-19 convalescent plasma is one of the experimental therapies used widely in moderately sick COVID-19 patients. However, there are a few risks involved in plasma transfusion; notably, transfusion-related acute lung injury (TRALI) caused by antibodies against human leukocyte antigens (HLA). This study was designed to assess the prevalence of anti-HLA antibodies in convalescent plasma donors using the single antigen bead method. STUDY DESIGN AND METHODS: This was a hospital-based observational study of consecutive plasma donors. A total of 252 samples were screened for anti-HLA Class I and Class II antibodies using the microbead assay with the identification of anti-HLA Ab in positive samples being performed using a single antigen bead assay. Luminex-based normalized background cutoff ratios of 10.8 for Class I and 6.9 for Class II and mean fluorescence intensity cutoffs of 2500 for Class I and 1500 for Class II were used for screening and the single bead assay, respectively. RESULTS: Of 252 screened samples, 28 (11.1 %) were positive for Class I, Class II or both Class I and Class II anti-HLA antibodies in donors with no history of a previous immunizing event. Moreover, 20/252 (7.9%) donors without any history of prior immunization had specific anti-HLA antibodies of Class I or Class II or both by the single bead assay. CONCLUSIONS: The high prevalence of anti-HLA antibodies in our cohort of donors raises an urgent and immediate need for anti-HLA antibody screening in all convalescent plasma donors for safe therapy of COVID-19 patients.

Enhancing breast cancer treatment through pharmacogenomics: A narrative review.

Pharmacogenomics has become integral to personalised medicine in breast cancer, utilising genetic insights to customize treatment strategies and enhance patient outcomes. Understanding how genetic variations influence drug metabolism, response, and toxicity is crucial for guiding treatment selection and dosing regimens. Genetic polymorphisms in drug-metabolizing enzymes and transporters significantly impact pharmacokinetic variability, influencing the efficacy and safety of chemotherapy agents and targeted therapies. Biomarkers associated with the hormone receptor status of breast cancer and mutations serve as key determinants of treatment response, aiding in the selection of therapies. Despite substantial progress in understanding the pharmacogenomic landscape of breast cancer, efforts to identify novel genetic markers and refine treatment optimisation strategies are required. Genome-wide association studies and advanced sequencing technologies hold promise for uncovering genetic determinants of drug response variability and elucidating complex pharmacogenomic interactions. The future of pharmacogenomics in breast cancer lies in real-time treatment monitoring, the discovery of additional predictive markers, and the seamless integration of pharmacogenomic data into clinical decision-making processes. However, translating pharmacogenomic discoveries into routine clinical practice requires collaborative efforts among stakeholders to address implementation challenges and ensure equitable access to genetic testing. By embracing pharmacogenomics, clinicians can tailor treatment approaches to individual patients, maximizing therapeutic benefits while minimizing adverse effects. This review discusses the integration of pharmacogenomics in breast cancer treatment, highlighting the significance of understanding genetic influences on treatment response and toxicity, and the potential of advanced technologies in refining treatment strategies.

Impact of exosomes in oral lichen planus: A review with insights into pathogenesis and biomarkers.

Oral Lichen Planus (OLP) presents a significant challenge in diagnosis due to its varied clinical manifestations and the absence of specific biomarkers. Timely and accurate diagnosis is crucial, particularly given its association with oral squamous cell carcinoma (OSCC). This review aims to explore the potential role of exosomes, small extracellular vesicles, in the pathogenesis of OLP and their utility as diagnostic biomarkers. Exosomes facilitate the exchange of information between cells and modulate immune responses by carrying various bioactive molecules such as proteins, lipids, and nucleic acids. In the context of OLP, exosomes derived from affected tissues or immune cells are thought to contribute to disease progression by mediating the transfer of pro-inflammatory molecules, including cytokines like interleukin-6 and tumour necrosis factor-alpha and chemokines such as CCL2, CCL5 and microRNAs such as miR-155, miR-146a, miR-21, and miR-34a, etc. Additionally, the distinct molecular contents of exosomes derived from OLP lesions may accurately represent the pathological changes occurring in these tissues. This suggests the potential of exosomes to be used as non-invasive biomarkers for diagnosing and tracking the progression of the disease. Understanding the immune microenvironment of OLP and the role of exosomes within this context is critical for advancing our knowledge of OLP pathogenesis and identifying new diagnostic and therapeutic strategies. However, challenges remain in identifying and characterising exosomes and their clinical translation. Further research is warranted to address these challenges and fully exploit exosomes' diagnostic and therapeutic potential in OLP and other inflammatory oral diseases.

Exosomal microRNAs: impact on cancer detection, treatment, and monitoring.

Exosomes, measuring between 30 and 150 nm in diameter, are small vesicles enclosed by a lipid bilayer membrane. They are released by various cells in the body and carry a diverse payload of molecules, including proteins, lipids, mRNA, and different RNA species such as long non-coding RNA, circular RNA, and microRNA (miRNA). With lengths of approximately 19-22 nucleotides, miRNAs constitute the predominant cargo in exosomes and serve as crucial regulators of protein biosynthesis. In cancer detection, exosomal miRNAs show promise as non-invasive biomarkers due to their stability and presence in various bodily fluids, aiding in early detection and precise diagnosis with specific miRNA signatures linked to different cancer types. Moreover, exosomal miRNAs influence treatment outcomes by affecting cellular processes like cell growth, cell death, and drug resistance, thereby impacting response to therapy. Additionally, they serve as indicators of disease progression and treatment response, providing insights that can guide treatment decisions and improve patient care. Through longitudinal studies, changes in exosomal miRNA profiles have been observed to correlate with disease progression, metastasis, and response to therapy, highlighting their potential for real-time monitoring of tumor dynamics and treatment efficacy. Understanding the intricate roles of exosomal miRNAs in cancer biology offers opportunities for developing innovative diagnostic tools and therapeutic strategies tailored to individual patients, ultimately advancing precision medicine approaches and improving outcomes for cancer patients. This review aims to provide an understanding of the role of exosomal miRNAs in cancer detection, treatment, and monitoring, shedding light on their potential for revolutionising oncology practices and patient care.

Home range, habitat use and capture-release of translocated leopards in Gir landscape, Gujarat, India.

Understanding the spatial ecology of translocated leopards (Panthera pardus fusca) is crucial for their conservation and the effective assessment of conflict management strategies. We investigated the home range and habitat preferences of five radio-collared leopards (n = 5; 2 males; 3 females) in the Gir landscape. Additionally, we examined the usefulness of the capture-release strategy for these animals. We assessed home range and habitat selection using kernel density estimation (at 95% and 50% levels) and compositional analysis. Our findings revealed that leopards exhibited distinct patterns of movement, often returning to their original capture site or nearby locations or exploring new areas within 3 to 25 days, covering distances ranging from 48 to 260 km. The average home range (95% FK) was estimated at 103.96±36.37 (SE) km2, with a core area usage (50% FK) of 21.38±5.95 km2. Seasonally, we observed the largest home ranges during summer and the smallest during winter. Males exhibited larger home ranges (95% FK, 151±64.28 km2) compared to females (56.18±14.22 km2). The habitat analysis indicated that agricultural areas were consistently preferred in the multi-use landscape at the 2nd order habitat selection level. Additionally, habitat around water bodies was highly favoured at the 3rd order, with distinct variations in habitat selection observed during day and night. This study highlights the significance of riverine and scrubland habitats, as leopards exhibited strong preferences for these habitats within their home ranges. We emphasize the importance of conserving natural habitat patches, particularly those surrounding water bodies. We also report on the characteristics of the capture-release strategy and provide our observations indicating no escalated aggression by leopards' post-release. In conclusion, this study evaluates widely employed approaches to conflict mitigation and suggests the continuous review and assessment of management strategies for mitigating human-leopard conflicts.

Integration of beta counting system with ORION-DSP coupled to NaI(Tl) detector-a comparative study with an HPGe detector.

The integration of the ORION digital signal processing-based MCA system coupled with a 3″ × 3″ NaI(Tl) detector assembly with a GM detector for counting beta (ß) has eliminated the need for a standalone ß-γ method in which U3O8 is determined by gross ß and gross γ counting. Uraniferous and mixed U-Th samples were taken up for study and compared with the results obtained from Canberra p-type coaxial high resolution gamma ray spectrometry detector. In uraniferous samples, U3O8 values obtained are within ±10%, whereas in the case of mixed U-Th samples, U3O8 values are within ±15%. Regression graphs drawn between the outcomes from the two analytical systems indicate R2 > 0.95 for Ra(eU3O8) and ThO2. In uraniferous samples, the R2 value for U3O8 was found to be > 0.99, but in mixed U-Th samples, it is 0.92. The closeness of agreement between the results obtained from two methods at various concentrations over the analytical range shows that the integrated system is suitable for the quantitative determination of eU3O8, U3O8, Ra(eU3O8), ThO2 and K in geological rock samples.

Breast cancer derived exosomes: Theragnostic perspectives and implications.

Breast cancer (BC) is the most prevalent malignancy affecting women worldwide. Although conventional treatments such as chemotherapy, surgery, hormone therapy, radiation therapy, and biological therapy are commonly used, they often entail significant side effects. Therefore, there is a critical need to investigate more cost-effective and efficient treatment modalities in BC. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, play a crucial role in modulating recipient cell behaviour and driving cancer progression. Among the EVs, exosomes provide valuable insights into cellular dynamics under both healthy and diseased conditions. In cancer, exosomes play a critical role in driving tumor progression and facilitating the development of drug resistance. BC-derived exosomes (BCex) dynamically influence BC progression by regulating cell proliferation, immunosuppression, angiogenesis, metastasis, and the development of treatment resistance. Additionally, BCex serve as promising diagnostic markers in BC which are detectable in bodily fluids such as urine and saliva. Targeted manipulation of BCex holds significant therapeutic potential. This review explores the therapeutic and diagnostic implications of exosomes in BC, underscoring their relevance to the disease. Furthermore, it discusses future directions for exosome-based research in BC, emphasizing the necessity for further exploration in this area.

Identifying Biomarkers and Therapeutic Targets by Multiomic Analysis for HNSCC: Precision Medicine and Healthcare Management.

Background: Head and neck squamous cell carcinoma (HNSCC) is one of the major types of cancer, with 900,000 cases and over 400,000 deaths annually. It constitutes 3-4% of all cancers in Europe and western countries. As early diagnosis is the key to treating the disease, reliable biomarkers play an important role in the precision medicine of HNSCC. Despite treatments, the survival rate of cancer patients remains unchanged, and this is mainly due to the failure to detect the disease early. Thus, the objective of this study is to identify reliable biomarkers for head and neck cancers for better healthcare management. Methods: In this study, all available, curated human genes were screened for their expression against HNSCC TCGA patient samples using genomic and proteomic data by various bioinformatic approaches and datamining. Docking studies were performed using AutoDock or online virtual screening tools for identifying potential ligands. Results: Sixty genes were short-listed, and most of them show a consistently higher expression in head and neck patient samples at both the mRNA and the protein level. Irrespective of human papillomavirus (HPV) status, all of them show a higher expression in cancer samples. The higher expression of 30 genes shows adverse effects on patient survival. Out of the 60 genes, 12 genes have crystal structures and druggable potential. We show that genes such as GTF2H4, HAUS7, MSN, and MNDA could be targets of Pembrolizumab and Nivolumab, which are approved monoclonal antibodies for HNSCC. Conclusion: Sixty genes are identified as potential biomarkers for head and neck cancers based on their consistent and statistically significantly higher expression in patient samples. Four proteins have been identified as potential drug targets based on their crystal structure. However, the utility of these candidate genes has to be further tested using patient samples.

Tar Formation in Gasification Systems: A Holistic Review of Remediation Approaches and Removal Methods.

Gasification is an advanced thermochemical process that converts carbonaceous feedstock into syngas, a mixture of hydrogen, carbon monoxide, and other gases. However, the presence of tar in syngas, which is composed of higher molecular weight aromatic hydrocarbons, poses significant challenges for the downstream utilization of syngas. This Review offers a comprehensive overview of tar from gasification, encompassing gasifier chemistry and configuration that notably impact tar formation during gasification. It explores the concentration and composition of tar in the syngas and the purity of syngas required for the applications. Various tar removal methods are discussed, including mechanical, chemical/catalytic, and plasma technologies. The Review provides insights into the strengths, limitations, and challenges associated with each tar removal method. It also highlights the importance of integrating multiple techniques to enhance the tar removal efficiency and syngas quality. The selection of an appropriate tar removal strategy depends on factors such as tar composition, gasifier operating and design factors, economic considerations, and the extent of purity required at the downstream application. Future research should focus on developing cleaning strategies that consume less energy and cause a smaller environmental impact.

Disease diagnostics using machine learning of immune receptors.

Clinical diagnosis typically incorporates physical examination, patient history, and various laboratory tests and imaging studies, but makes limited use of the human system's own record of antigen exposures encoded by receptors on B cells and T cells. We analyzed immune receptor datasets from 593 individuals to develop MAchine Learning for Immunological Diagnosis (Mal-ID) , an interpretive framework to screen for multiple illnesses simultaneously or precisely test for one condition. This approach detects specific infections, autoimmune disorders, vaccine responses, and disease severity differences. Human-interpretable features of the model recapitulate known immune responses to SARS-CoV-2, Influenza, and HIV, highlight antigen-specific receptors, and reveal distinct characteristics of Systemic Lupus Erythematosus and Type-1 Diabetes autoreactivity. This analysis framework has broad potential for scientific and clinical interpretation of human immune responses.

Development and validation of Empagliflozin and Linagliptin simultaneous estimation in rat plasma using freezing lipid precipitation and SCX-SPE assisted HPLC-MS/MS method and its application in pharmacokinetic studies.

A quick and sensitive liquid chromatography-mass spectrometry technique was designed, improved, and validated for simultaneous determination of Empagliflozin (EPG) and Linagliptin (LNG) using Empagliflozin-d4 (EPG-d4) and linagliptin-d4 (LNG-d4) as internal standards (IS) in rat plasma. Target analytes and the IS were extracted using freezing lipid precipitation (FLP) and optimized using the strong cation exchange solid phase extraction (SCX-SPE) method to achieve the maximum sample clean-up. In particular, when combined with SPE clean-up, FLP can efficiently eliminate the plasma sample's high lipid content. More than 84.14% of plasma lipids were rapidly removed during the FLP procedure, with minimal loss of EPG and LNG. We used LC-atmospheric chemical ionization (APCI)-mass spectrometry was employed to assess the efficiency of FLP in lipid removal. The SCX-SPE cartridges removed the remaining impurities from EPG and LNG, allowing for further purification. The samples were chromatographically separated using a Spherisorb RP/Cyano column by pumping a gradient mobile phase comprised of acetonitrile and 25 mM ammonium acetate buffer (pH 8.1) in positive ion mode at a flow rate of 0.8 mL/min. The selected reaction monitoring technique was performed using a Waters triple-stage quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source. The chromatographic separation was accomplished using a Waters Acquity® high-performance liquid chromatography (HPLC) system. Mass transition (m/z) of 451.15/71.12 for EPG, m/z 473.27/419.94 for LNG; m/z 455.19/71.12 for EPG-d4, and 477.27/423.94 for LNG-d4 was successfully achieved. This study successfully examined the concentration ranges of 25-1050 ng/mL for EPG and 0.35-15 ng/mL for LNG. The results showed that the linearity of EPG ranged from 25.14 to 985.26 ng/mL, while the linearity of LNG ranged from 0.59 to 14.86 ng/mL. The relative standard deviation (RSD) for both EPG and LNG, within and between days, were below 3.83%, indicating that they fall within acceptable limits. This novel approach demonstrated favourable outcomes in a pharmacokinetic study involving healthy rats, where EPG and LNG were co-administered. This study found that the co-administration of both drugs did not have a significant impact on their pharmacokinetic behavior, suggesting the absence of any drug-drug interactions.

Re-visiting humoral constitutive antibacterial heterogeneity in bloodstream infections.

Although cellular immunity has garnered much attention in the era of single-cell technologies, humoral innate immunity has receded in priority due to its presumed limited roles. Hence, despite the long-recognised bactericidal activity of serum-a functional characteristic of constitutive humoral immunity-much remains unclear regarding mechanisms underlying its inter-individual heterogeneity and clinical implications in bloodstream infections. Recent work suggests that the immediate antimicrobial effect of humoral innate immunity contributes to suppression of the excessive inflammatory responses to infection by reducing the amount of pathogen-associated molecular patterns. In this Personal View, we propose the need to re-explore factors underlying the inter-individual heterogeneity in serum antibacterial competence as a new approach to better understand humoral innate immunity and revisit the clinical use of measuring serum antibacterial activity in the management of bacterial bloodstream infections. Given the current emphasis on subtyping sepsis, a serum bactericidal assay might prove useful in defining a distinct sepsis endotype, to enable more personalised management.

Unravelling the secrets of lesser florican: a study of their home range and habitat use in Gujarat, India.

The home range of a species is determined by a complex interplay of extrinsic and intrinsic factors, which can have profound impacts on the species' resource use. Understanding these dynamics is especially important for conserving critically endangered species. In this study, we used satellite telemetry to investigate the home range of the critically endangered lesser florican (Sypheotides indicus) in Gujarat, India. We analysed GPS locations from 10 lesser floricans deployed with GPS/GSM transmitters between 2020 and 2022. The average home range size (95% KDE) was 10.73 ± 10.70 km2 (mean ± SD), while the average core area (50% KDE) was 1.95 ± 1.56 km2 (mean ± SD). The monthly and daily distances covered were 286.29 ± 599.42 km and 10.11 ± 19.78 km, respectively. Our analysis indicated that suitable habitats and movement patterns were the most important factors explaining the variation in home range size. Specifically, our results suggest that lesser floricans prefer multi-use agro-grassland habitat systems with heterogeneous structures to accommodate different life history requirements. This preference may reflect the depletion and degradation of grasslands across the species' range. Therefore, managing grassland habitats amidst croplands should be one of the key conservation strategies for the lesser florican.

Neutrophil Extracellular Traps have DNAzyme activity that drives bactericidal potential.

The mechanisms of bacterial killing by neutrophil extracellular traps (NETs) are unclear. DNA, the largest component of NETs is believed to merely be a scaffold with minimal antimicrobial activity through the charge of the backbone. Here, we report that NETs DNA is beyond a scaffold and produces hydroxyl free radicals through the spatially concentrated G-quadruplex/hemin DNAzyme complexes, driving bactericidal effects. Immunofluorescence staining showed colocalization of G-quadruplex and hemin in extruded NETs DNA, and Amplex UltraRed assay portrayed its peroxidase activity. Proximity labeling of bacteria revealed localized concentration of radicals resulting from NETs bacterial trapping. Ex vivo bactericidal assays revealed that G-quadruplex/hemin DNAzyme is the primary driver of bactericidal activity in NETs. NETs are DNAzymes that may have important biological consequences.

Detailed Morphometric Analysis on Left Coronary Artery in the Population of North-East India.

Introduction The left ventricle, the cardiac chamber responsible for blood supply to the whole of systemic vasculature, receives most of its blood supply from the left coronary arteries (LCAs). Atherosclerosis of these vessels leading to myocardial infarction is a leading cause of death. Several invasive diagnostic or therapeutic coronary interventions are available for such patients. Just like any vascular procedure, a prior comprehensive knowledge of the dimensions of these vessels and their branching pattern is essential to perform these procedures uneventfully. No previous study in the population of North-Eastern India documents the population-specific reference for morphometric values of left coronary arteries and their anatomic variations. So, this study aims to fill up this lacuna. Methods This study was conducted in the Department of Anatomy in collaboration with the Catheterization Lab, Department of Cardiology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences (NEIGRIHMS), Shillong. Coronary angiograms (CAG) of 100 subjects - 38 females and 62 males - were obtained from the Cardiac Catheterization Lab. Coronary angiograms were studied for the normal variant anatomy and morphometry of the LCAs - the left main coronary artery (LMCA), left anterior descending (LAD), and left circumflex (LCX).  Results The mean length and luminal diameter of LMCA were found to be 9.13±3.23 mm and 4.38±0.58 mm, respectively. The mean length of LAD and LCX were 109.46±14.49 mm and 66.27±11.56 mm, respectively. Ramus intermedius was present in 32% of the subjects, whereas the remaining subjects had bifurcations of LMCA. We also found that 86% of patients had "wrap-around LAD", while in 11% of our subjects, LAD failed to reach the apex. Diagonal branches originating from LAD were single, duplicated, and multiple in 14%, 62%, and 24% respectively. The marginal branches were found to be single, double, and multiple in 20%, 51%, and 29% respectively. Conclusion This study establishes a baseline reference on morphometry of the left coronary artery specific to the population of North-East India. This study may be of assistance to radiologists and cardiologists when performing procedures on the left coronary arteries in the population of North-Eastern India, with respect to the prevalence of anatomic variations.

The semi-arid ecosystem of Asiatic Lion Landscape in Saurashtra, Gujarat: Population density, biomass and conservation of nine wild prey species.

The present study aimed to assess the population density, structure, and population change of nine wild prey species in the semi-arid landscape of Saurashtra, Gujarat, India. A total of eight sites, representing a gradient from highly protected woodlands and grasslands to unreserved grasslands, were selected for sampling. We employed the road transect methodology under a distance sampling framework to achieve our objectives. We evaluated the realized growth rate of the Gir ungulate population through linear regression analysis. Our findings revealed that deer species exhibited higher density and biomass in woodlands compared to grasslands and coastal forests. On the other hand, antelopes showed higher density and biomass in grasslands and coastal forests compared to woodlands. The density gradient of wild prey species was influenced by various factors, including habitat structure, social organization, grouping tendencies, and topography. Over the last four decades, the population of wild prey species in Gir showed minimal changes. Our study provides a comprehensive understanding of wild prey species' density and biomass patterns at the landscape level. The inclusion of findings from ecologically significant and unique areas, such as coastal forests, further enhances the importance of this study. The implications of this study extend beyond the conservation of wild prey species alone; they also contribute to the conservation of the large carnivore guild in the Saurashtra landscape.

Peutz-Jeghers Syndrome: Lessons to be Learned in the Clinical Diagnosis.

Introduction: Peutz-Jeghers Syndrome (PJS) is an autosomal dominant disease presenting with hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on lips and oral mucosa. The incidence of this syndrome is approximately 1 in 1,20,000 births. Materials and Methods: In this article, we are presenting 11 cases of PJS which were misdiagnosed and patients were compelled to visit hospital repeatedly. All these cases were diagnosed based on clinical suspicion, family history, and histopathological examination of specimens. Most of the cases presented with intussusception and required emergency surgical management. Results: PJS can be diagnosed by the presence of microscopically confirmed hamartomatous polyps and a minimum of two of the following clinical criteria: Family history, mucocutaneous melanotic spots, and small bowel polyps with bleeding per rectally. The diagnosis can be missed if the melanotic spots on the face are missed. Routine investigations, imaging, and endoscopy were done in all cases. PJS patients need regular follow-up due to chance of recurrence of symptoms and susceptibility to cancer. Conclusion: PJS needs a high index of suspicion for diagnosis in cases of recurrent abdominal pain with bleeding per rectum. Proper family history and meticulous clinical examination for melanosis are very important to prevent the misdiagnosis of these cases.

Perspectives on Rapid Antigen Tests for Downstream Validation and Development of Theranostics.

Point-of-care SARS-CoV-2 rapid antigen tests have proven to be useful over the years and have become more apparent to the public eye during COVID-19 pandemic due to their ease of use, rapid processing and result times, and low cost. Here, we have assessed the effectiveness and accuracy of rapid antigen tests in comparison to the standard real-time polymerase chain reaction analyses of the same samples.

Phage diversity in cell-free DNA identifies bacterial pathogens in human sepsis cases.

Bacteriophages, viruses that infect bacteria, have great specificity for their bacterial hosts at the strain and species level. However, the relationship between the phageome and associated bacterial population dynamics is unclear. Here we generated a computational pipeline to identify sequences associated with bacteriophages and their bacterial hosts in cell-free DNA from plasma samples. Analysis of two independent cohorts, including a Stanford Cohort of 61 septic patients and 10 controls and the SeqStudy cohort of 224 septic patients and 167 controls, reveals a circulating phageome in the plasma of all sampled individuals. Moreover, infection is associated with overrepresentation of pathogen-specific phages, allowing for identification of bacterial pathogens. We find that information on phage diversity enables identification of the bacteria that produced these phages, including pathovariant strains of Escherichia coli. Phage sequences can likewise be used to distinguish between closely related bacterial species such as Staphylococcus aureus, a frequent pathogen, and coagulase-negative Staphylococcus, a frequent contaminant. Phage cell-free DNA may have utility in studying bacterial infections.