Host State Research Articles

Novel Populations of Mycobacterium smegmatis Under Hypoxia and Starvation: Some Insights on Cell Viability and Morphological Changes

The general features of the shift to a dormant state in mycobacterial species include several phenotypic changes, reduced metabolic activities, and increased resistance to host and environmental stress conditions. In this study, we aimed to provide novel insights into the viability state and morphological changes in dormant M. smegmatis that contribute to its long-term survival under starvation or hypoxia. To this end, we conducted assays to evaluate cell viability, morphological changes and gene expression. During starvation, M. smegmatis exhibited a reduction in cell length, the presence of viable but non-culturable (VBNC) cells and the formation of anucleated small cells, potentially due to a phenomenon known as reductive cell division. Under hypoxia, a novel population of pleomorphic mycobacteria with a rough surface before the cells reached nonreplicating persistence 1 (NRP1) was identified. This population exhibited VBNC-like behaviour, with a loss of cell wall rigidity and the presence of lipid-body-like structures. Based on dosR and hspX expression, we suggest that M. smegmatis encounters reductive stress conditions during starvation, while lipid storage may induce oxidative stress during hypoxia. These insights into the heterogeneous populations presented here could offer valuable opportunities for developing new therapeutic strategies to control dormant mycobacterial populations.

The afterlife of ISDS awards: post-award settlements and the limits of transparency reforms

Abstract Post-award settlements in investor–state dispute settlement (ISDS) remain largely unstudied. One of the reasons for this gap in knowledge is the lack of transparency in the post-award phase of the relationship between investors and host states. The primary objective of this article is to use novel empirical data to explore the transparency gaps and absences in the post-award phase of ISDS. We seek to challenge the prevailing notions of finality of ISDS awards and highlight the need to re-think the end goals of transparency considering the significant public policy implications post-award agreements may engender. The veil of secrecy that continues to shroud the world of post-award settlements raises a number of issues that go to the heart of the ongoing debate about the workings of ISDS, its legitimacy and the role of openness and accountability therein.

A Retrospective Report on the Infestation and Distribution of Chiggers on an Endemic Rodent Species (Apodemus latronum) in Southwest China

Chiggers are the exclusive vector of Orientia tsutsugamushi, which is the causative agent of scrub typhus. Based on the field surveys in southwest China between 2001 and 2022, this paper retrospectively reported the chigger infestation and distribution on the large-eared field mouse (Apodemus latronum), an endemic rodent species in the region, for the first time. A total of 933 chiggers were collected from 501 mice, and these chiggers were identified as 2 families, 8 genera, and 61 species. The overall infestation prevalence (PM) and mean abundance (MA) of A. latronum with chiggers reached 19.76% and 1.86 mites/per mouse, respectively. The chigger infestation indices on adult A. latronum (PM = 38.28%, MA = 5.11) were higher than those on juvenile mice (PM = 12.63%, MA = 0.97) with p < 0.01, showing an age bias of infestation. The relative fatness (K) was used to reflect the nutrition status of the mouse host. The mouse hosts with good nutrition (K = 3.4 ± 0.89 g/cm3) harbored fewer chiggers than the hosts with poor nutrition (K = 2.2 ± 0.90 g/cm3) (p < 0.01). The infestation indices of chiggers on A. latronum obviously fluctuated along different altitude gradients (p < 0.01). With the increase in altitudes, the β diversity of the chigger community showed a gradually increasing tendency. The spillover chord diagram, which was based on indices of PAC (potential for apparent competition), revealed high spillover potentials of dominant chigger species dispersing from high altitude gradients to the lowest one. The chigger abundance was positively correlated with the mean monthly temperature (tmp), mean monthly humidity (hum), the mean monthly precipitation (pre), and the human footprint (hfp), and it was negatively correlated with the altitude (ele) (p < 0.05). The temperature and humidity are the most important factors which influence the chigger infestation.

Comparison of three methods for generating the coccoid form of Helicobacter pylori and proteomic analysis

BackgroundHelicobacter pylori changes from spiral to coccoid depending on the host state, environmental factors, and surrounding microbial communities. The coccoid form of H. pylori still maintains its complete cellular structure, retains virulence genes, and thus plays a role in pathogenicity. To understand the coccoid form, it is crucial to establish the in vitro generation of the coccoid H. pylori. Although some conditions have been studied for the generation of the coccoid form, few studies have compared these conditions for coccoid generation. Here, we generated coccoid forms via three methods and compared the differences in morphology, viability, culturability, and protein expression.ResultsThe coccoid H. pylori was generated in vitro via three methods: a starvation method, a method using amoxicillin, and a method using the culture supernatant of Streptococcus mitis. The morphology and viability of the cells were examined by fluorescence microscopy after staining with SYTO9 and propidium iodide. The culturability of H. pylori was examined by counting colony-forming units on chocolate agar plates. In the starvation group, no colonies formed after 7 days, but viable coccoids were continuously observed. In the amoxicillin-treated group, the culturability decreased rapidly after 12 h, and showed a viable but non culturable (VBNC) state after the third day. Most cells treated with S. mitis supernatant changed to coccoid forms after 7 days, but colonies were continuously formed, probably due to living spiral forms. We performed proteomics to analyse the differences in protein profiles between the spiral and coccoid forms and protein profiles among the coccoid forms generated by the three methods.ConclusionAmoxicillin treatment changed H. pylori to VBNC cells faster than starvation. Treatment with the S. mitis supernatant prolonged the culturability of H. pylori, suggesting that the S. mitis supernatant may contain substances that support spiral form maintenance. Proteomic analysis revealed that the expression of proteins differed between the spiral form and coccoid form of H. pylori, and this variation was observed among the coccoid forms produced via three different methods. The proteins in the coccoid forms produced by the three methods differed from each other, but common proteins were also observed among them.

Navigating Intersectional Complexities: A Narrative Analysis of Syrian Refugee Women With Disabilities in Turkey

Refugee women with disabilities experience a multiplicity of insecurities before, during, and after their displacement, including exposure to violence during conflicts, barriers to their mobility, challenges along their routes to safety, difficulties in accessing rights and services in the host state, and hardships while navigating the means of survival in the host community. Despite the intertwined convergence of gender and ableism in exile affecting refugee women’s experiences, international and national laws and policies fail to address this intersectional reality. This study examines the lived experiences of Syrian refugee women with disabilities in Gaziantep, Turkey. Through an analysis of qualitative data with a narrative approach, the study not only depicts the interactions of gender, disability, and displacement that shape Syrian women’s lives but also contests the traditional discourse on their vulnerabilities. Through specific stories of Syrian women, this study highlights their strategies for survival and their future plans within the context of the intersectionality of the challenges they face.

Multidisciplinary approach and host optimization for fracture-related infection management

In orthopaedic trauma, fracture-related infections (FRI) are still dreadful challenges that can cause non-union, amputation and even death. Standardization of general treatment strategies for FRI is still lacking. Due to the complexity of FRI, a multidisciplinary approach addressing host status, state of the fracture and causative microorganism has been applied in the management of FRI. Surgical treatment, antibiotic therapy and host optimization for FRI were summarized and discussed. The goal of this review is to provide an overview and summary of current approaches of FRI management and to make suggestions on FRI prevention and treatment based on multidisciplinary principles.

Constitucionalismo transformador y derecho internacional de inversionesTransformative constitutionalism and international investment law

Abstract International investment law faces five core legitimacy challenges: the state-dependency challenge, the human and constitutional rights challenge, the equality challenge, the standard of protection challenge, and the investor state dispute settlement system challenge. This article endorses the claim that constitutional courts can contribute to the solution of those legitimacy challenges when they exercise the power to review the constitutionality of international investment treaties. From a transformative perspective, constitutional courts of host states can: (i) create public deliberation and raise awareness concerning the legitimacy challenges of international investment law; (ii) grant equal treatment to national and foreign investors; (iii) require governments to negotiate less open-textured provisions in international investment treaties; (iv) safeguard the protection of human and constitutional rights, and other common goods; and (v) raise due process, predictability, transparency, and proportionality standards concerning the investor state dispute settlement system. These judicial undertakings can strengthen the bargaining power of host executive branch authorities in the negotiation of international investment treaties and can narrow down the space of discretion of international investment arbitral tribunals. Both outcomes could render international investment treatises’ creation and enforcement more legitimate.

Imaging Quantum Interference in a Monolayer Kitaev Quantum Spin Liquid Candidate

Single atomic defects are prominent windows to look into host quantum states because collective responses from the host states emerge as localized states around the defects. Friedel oscillations and Kondo clouds in Fermi liquids are quintessential examples. However, the situation is quite different for quantum spin liquid (QSL), an exotic state of matter with fractionalized quasiparticles and topological order arising from a profound impact of quantum entanglement. Elucidating the underlying local electronic property has been challenging due to the charge neutrality of fractionalized quasiparticles and the insulating nature of QSLs. Here, using spectroscopic-imaging scanning tunneling microscopy, we report atomically resolved images of monolayer α−RuCl3, the most promising Kitaev QSL candidate, on metallic substrates. We find quantum interference in the insulator manifesting as incommensurate and decaying spatial oscillations of the local density of states around defects with a characteristic bias dependence. The oscillation differs from any known spatial structures in its nature and does not exist in other Mott insulators, implying it is an exotic oscillation involved with excitations unique to α−RuCl3. Numerical simulations suggest that the observed oscillation can be reproduced by assuming that itinerant Majorana fermions of Kitaev QSL are scattered across the Majorana Fermi surface. The oscillation provides a new approach to exploring Kitaev QSLs through the local response against defects like Friedel oscillations in metals. Published by the American Physical Society 2024

Genomics unveils country-to-country transmission between animal hospitals of a multidrug-resistant and sequence type 2 Acinetobacter baumannii clone.

Acinetobacter baumannii is a globally distributed opportunistic pathogen in human health settings, including in intensive care units (ICUs). We investigated the contamination of a French small animal ICU with A. baumannii. We discovered repeated animal contamination by A. baumannii, and phylogenetic analysis traced contamination back to a potential foreign animal origin. Genomic analysis combined with antibiotic susceptibility testing revealed heteroresistance to penicillin and aminoglycoside mediated by insertion sequence dynamics and also suggest a potential cross-resistance to human-restricted piperacillin-tazobactam combination. The A. baumannii isolates of the animal ICU belong to the International Clone 2 commonly found in human health settings. Our results suggest a high adaptation of this lineage to healthcare settings and provide questions on the requirements for genetic determinants enabling adaptation to host and abiotic conditions.

Host Status of Persian Lime (Citrus latifolia Tan.) to Oriental Fruit Fly and Mediterranean Fruit Fly (Diptera: Tephritidae) in Hawai'i.

We investigated the host status of harvest-ready green Persian lime, Citrus x latifolia Tan. (Rutaceae), to Oriental fruit fly (Bactrocera dorsalis [Hendel]) and Mediterranean fruit fly (Ceratitis capitata [Wiedemann]) (Diptera: Tephritidae) using laboratory and field studies. In forced-infestation small cage exposures (using 25 × 25 × 25 cm screened cages with 50 gravid females) and large olfactometer cage tests (using 2.9 × 2.9 × 2.5 m walk-in screened cages with 100 gravid females), punctured limes were infested by Oriental fruit fly and Mediterranean fruit fly at low rates compared to papaya controls, whereas undamaged intact fruit was not infested. Field collection and packing of 45,958 commercial export-grade fruit and subsequent incubation to look for natural infestation resulted in no emergence of fruit flies. Forced infestation studies in the field using sleeve cages to enclose fruit with a high density of fruit flies (50 gravid females) on the tree also showed no infestation. Commercial export-grade Persian lime fruit should be considered a conditional nonhost for Oriental fruit fly and Mediterranean fruit fly.

Can virus infection induce sepsis?

Sepsis is a clinical syndrome caused by a dysregulated host response to infection that can lead to multiple organ dysfunction syndrome and death. Severe viral infections can also induce sepsis, which is essentially similar to bacterial sepsis in physiological mechanism and management strategies, but slightly different in detail. Anti-microbial treatment and restoration of immune homeostasis are key to breaking the vicious circle of sepsis. Therefore, it is important to develop more accurate and convenient measures for pathogen detection and research into targeted anti-microbial agents, as well as to explore ways of evaluating the dynamic immune status of host and individualized immunotherapies based on immune status.

Phyllosphere of Agathis australis Leaves and the Impact of the Soil-Borne Pathogen Phytophthora agathidicida

Leaf surface microbial communities play an important role in forest ecosystems and are known to be affected by environmental and host conditions, including diseases impacting the host. Phytophthora agathidicida is a soil-borne pathogen that causes severe disease (kauri dieback) in one of New Zealand’s endemic trees, Agathis australis (kauri). This research characterised the microbial communities of the A. australis phyllosphere (i.e. leaf surface) using modern molecular techniques and explored the effects of P. agathidicida on those communities. Fresh leaves were collected from trees where P. agathidicida was and was not detected in the soil and characterisation of the leaf surface microbial community was carried out via high-throughput amplicon sequencing of the internal transcribed spacer (ITS) and 16S ribosomal RNA regions. Nutrients in leaf leachates were also measured to identify other possible drivers of microbial diversity. The dominant phyllosphere microbial phylum was Proteobacteria followed by Acidobacteria. The phyllosphere microbial richness of A. agathis associated with P. agathidicida-infected soils was found to be generally lower than where the pathogen was not detected for both prokaryote (bacterial) and fungal phyla. Leaf leachate pH as well as boron and silicon had significant associations with bacterial and fungal community structure. These findings contribute to the development of a comprehensive understanding of A. australis leaf surface microbial communities and the effects of the soil pathogen P. agathidicida on those communities.

Early Mortality Stratification with Serum Albumin and the Sequential Organ Failure Assessment Score at Emergency Department Admission in Septic Shock Patients.

Background: Early risk stratification is crucial due to septic patients' heterogeneity. Serum albumin level may reflect the severity of sepsis and host status. This study aimed to evaluate the prognostic ability of the initial sequential organ failure assessment (SOFA) score alone and combined with serum albumin levels for predicting 28-day mortality in patients with septic shock. Methods: We conducted an observational study using a prospective, multicenter registry of septic shock patients between October 2015 and May 2022 from 12 emergency departments in the Korean Shock Society and the results were validated by examining those from the septic shock cohort in Asan Medical Center. The primary outcome was 28-day mortality. The area under the receiver operating characteristic (ROC) curve was used to compare the predictive values of SOFA score alone and SOFA score combined with serum albumin level. Results: Among 5805 septic shock patients, 1529 (26.3%) died within 28 days. Mortality increased stepwise with decreasing serum albumin levels (13.6% in albumin ≥3.5, 20.7% in 3.5-3.0, 29.7% in 3.0-2.5, 44.0% in 2.5-2.0, 56.4% in <2.0). The albumin SOFA score was calculated by adding the initial SOFA score to the 4 points assigned for albumin levels. ROC analysis for predicting 28-day mortality showed that the area under the curve for the albumin SOFA score was 0.71 (95% CI 0.70-0.73), which was significantly higher than that of the initial SOFA score alone (0.68, 95% CI: 0.67-0.69). Conclusions: The combination of the initial SOFA score with albumin can improve prognostic accuracy for patients with septic shock, suggesting the albumin SOFA score may be used as an early mortality stratification tool.

Avian malaria in a feral-pet pigeon: a case report

BackgroundAvian malaria is caused by diverse parasite species of the genus Plasmodium, and it affects various bird species. The occurrence of this disease in some wild bird species is sparsely documented due to the scarce availability of samples. Hence the pathogenicity in some hosts is not completely known. In addition, feral birds may act as reservoirs bridging the transmission cycle from wild migratory birds to domestic and zoo-kept bird species.Case presentationAn owner of pigeons adopted a feral pigeon (Columba livia forma domestica) and housed it together with his other pet-pigeons. The bird died unexpectedly a few weeks after a surgical procedure and necropsy revealed a severely anaemic carcass, with pale organs and hydropericardium. Histopathologic analysis revealed inflammatory infiltrates in the lung and liver, and monocytes and Kupffer cells contained haemozoin pigment indicative of phagocytosis of Plasmodium-infected erythrocytes. A high erythrocytic infection rate of 18% was evident in tissues and blood vessels in various organs. Furthermore, the thyroid had masses classified as thyroid carcinomas. Immunohistochemistry with anti- Plasmodium falciparum HSP70 antibody revealed positive signals in erythrocytes and intravascular leucocytes. Further microscopy analysis using a Hemacolor-stained impression smear revealed a high parasitaemia with an asynchronous infection showing all erythrocytic stages. Molecular diagnosis by PCR identified Plasmodium relictum, lineage GRW11 as the aetiological agent. The bird presented died most likely due to an acute infection as evidenced by the high blood parasitaemia, leading to major erythrocyte destruction. Further analyses of feral pigeons (n = 22) did not reveal any additional cases of Plasmodium infections.ConclusionThis study reports the first mortality associated with P. relictum lineage GRW11. The study supports previous studies, suggesting that Plasmodium infections are not frequent in pigeons. Host conditions like immunosuppression due to the tumour may have influenced the infection outcome in this fatal case. Use of anti-P. falciparum HSP70 antibody for detection of P. relictum antigens for immune assays in blood and tissue samples will be a useful tool for future studies.

Article: The Neglected Public Interest in Investor-State Dispute Settlement: Environmental and Human Rights Considerations

With the rapid expansion of bilateral investment treaties (BITs), investor-state arbitration has paved its way to becoming the most preferred dispute settlement method by investors. However, the investment arbitration system has also attracted ‘backlash’. One reason is the challenge to balance between protection of foreign investors and the recognition of host states’ legitimate public interests. With the current pressures to reform the investor-state dispute settlement (ISDS) system, there is a pressing need to offer a better balance between investor protection and host states’ sovereign right to regulate, as well as the wider public good such regulatory measures might have, especially in the context of environmental protection and human rights. This article argues for a better symmetry between foreign investor’s treaty-based claims and host states’ environmental and human rights (EHR) claims to acknowledge the public interests – social, economic, welfare, etc. In particular, it advocates for: the strengthened presence of independent experts and amicus curiae, a proportionality approach; and the overarching development of counterclaims as a consideration not only of the host state’s capacity to regulate but also the wider repercussions of such regulations on the public as well as the conduct of foreign investors.

Mucor mycosis of tibia: A case report of An unsolved entity

Mucormycosis of tibia is a highly aggressive fungal infection. It is an uncommon affection especially in immunocompromised host who have more propensity for such affections.The nonhealing ulcer of the left leg in an immunocompromised host status of a 45-year-old male presented with a radiological lytic lesion of the distal lower fourth of tibia. The initial biopsy confirmed tubercular affection which responded to antitubercular medications to allow radiological healing. However, the repeat biopsy showed Mucormycosis which remained recalcitrant to antifungal medications with unresponsive wound healing and persisting suppuration. The case presented unique scenario of superadded fungal infection in a healing tubercular osteomyelitis tibia with alcoholic liver disease compromised host immunity.The fungal infection of tibia remains an unsolved entity with poor clinical and functional outcomes. An early detection, high degree of suspicion with an adequate dosage of antifungal medications may allow resolution of the dreaded infection though an effective treatment remains an unsolved entity.

Integrating short- and full-length 16S rRNA gene sequencing to elucidate microbiome profiles in Pacific white shrimp (Litopenaeus vannamei) ponds.

Despite their immense economic value as a key aquaculture species, the production of Pacific white shrimp (Litopenaeus vannamei) faces significant challenges from intensive farming practices and disease outbreaks. Routine microbial profiling for disease surveillance could be a promising approach to anticipate and control disease outbreaks. To achieve this, accuracy in microbial profiling in shrimp ponds is crucial for enabling targeted action and prevention. Extensive documentation emphasizes that, beyond biological factors (related to the host, diet, or health status during the rearing period), technical elements, including sequencing techniques significantly influence bacterial community profiling. This study investigated the influence of short- and long-read sequencing of 16S rRNA genes on the microbial profiles in shrimp intestines, water, and sediments. The origin of the samples (intestine or environmental) in shrimp culture ponds primarily drove the observed differences in core microbial species. The ecological niches accounted for 56% of bacterial community variations in culture ponds. Both sequencing approaches showed consistent results in identifying higher-rank taxa and assessing alpha and beta diversity. However, at the species level, full-length 16S rRNA gene sequences provided better resolution than V3-V4 sequences. For routine microbial profiling in shrimp culture ponds, our study suggests that short-read sequences were sufficient for determining overall bacterial community.IMPORTANCEThis interdisciplinary study investigated the influence of sequencing techniques on bacterial communities profiling within Pacific white shrimp (Litopenaeus vannamei) ponds. By integrating aquaculture, microbiology, and environmental science, we revealed the role of ecological niches and factors like salinity and pH on microbiota diversity and composition in shrimp intestines, pond water, and sediment. Additionally, we compared the taxonomic resolution using partial versus full-length 16S rRNA gene sequences, highlighting the value of longer amplicons for precise identification of key taxa. These findings provide novel insights into microbial dynamics underlying environmental effects in shrimp aquaculture. Comprehensive characterization of the pond microbiome could lead to management strategies that promote shrimp health and productivity. Furthermore, the potential of a multi-omics approach for integrating complementary data streams to elucidate environment-microbiome-host interactions was highlighted.

Phylogenetic position of the pigeon mite, Ornithonyssus sylviarum, with amplification of its immunogenetic biomarkers in Egypt

Ornithonyssus sylviarum (O. sylviarum) is an obligatory, blood-sucking ectoparasite widely distributed among poultry and other mammals, causing significant economic losses. This study represented the first report of molecular genotypic identification of O. sylviarum from pigeons, Columba livia domestica, in Egypt. PCR and sequencing of the 28S rRNA gene were conducted. The resulting mite sequences were subjected to BLAST analysis, revealing 90–100% similarity to O. sylviarum in all tested samples. The sequences were deposited in GenBank under the accession numbers PP049086 and PP033720. A phylogenetic tree was constructed to compare the obtained species with related species worldwide. Additionally, infected pigeons showed increased expression of IL-1, IL-10, IFN-γ, and TGF-β3 genes and elevated serum levels of stress biomarkers. The increased level of these cytokines indicates there was a disturbance in the immune status of the infected host with parasite compared with control healthy ones. This increases the susceptibility to infection with other pathogens.

The role of ISDS in the Russian–Ukrainian conflict

AbstractInvestor-State Dispute Settlement (ISDS) has long served as an effective remedy for disputes between foreign investors and host states. In the context of the Russian–Ukrainian conflict, ISDS has gained particular prominence as a potential tool for advancing the legal claims of private persons even in wartime or otherwise hostile situations. In particular, we had a slew of ISDS cases between Ukrainian investors and Russia, especially in relation to Crimea. This has also raised a number of questions regarding territory and annexation within the context of international law, which the arbitration tribunals had to address. The purpose of this study was to evaluate the utility of ISDS for enforcing private claims in wartime, and to assess the judgments of the arbitration tribunals, with the addition of Russian ISDS cases against Ukraine as well, to serve as a contrast.

Essential genes for Haemophilus parainfluenzae survival and biofilm growth.

Haemophilus parainfluenzae (Hp) is a Gram-negative, highly prevalent, and abundant commensal in the human oral cavity, and an infrequent extraoral opportunistic pathogen. Hp occupies multiple niches in the oral cavity, including the supragingival plaque biofilm. Little is known about how Hp interacts with its neighbors in healthy biofilms nor its mechanisms of pathogenesis as an opportunistic pathogen. To address this, we identified the essential genome and conditionally essential genes in in vitro biofilms aerobically and anaerobically. Using transposon insertion sequencing (TnSeq) with a highly saturated mariner transposon library in two strains, the ATCC33392 type-strain (Hp 392) and oral isolate EL1 (Hp EL1), we show that the essential genomes of Hp 392 and Hp EL1 are composed of 395 (20%) and 384 (19%) genes, respectively. The core essential genome, consisting of 341 (17%) essential genes conserved between both strains, was composed of genes associated with genetic information processing, carbohydrate, protein, and energy metabolism. We also identified conditionally essential genes for aerobic and anaerobic biofilm growth, which were associated with carbohydrate and energy metabolism in both strains. RNAseq analysis determined that most genes upregulated during anaerobic growth are not essential for Hp 392 anaerobic survival. The completion of this library and analysis under these conditions gives us a foundational insight into the basic biology of H. parainfluenzae in differing oxygen conditions, similar to its in vivo habitat. This library presents a valuable tool for investigation into conditionally essential genes for an organism that lives in close contact with many microbial species in the human oral habitat.IMPORTANCEHaemophilus parainfluenzae is a highly abundant human commensal microbe, present in most healthy individuals where it colonizes the mouth. H. parainfluenzae correlates with good oral health and may play a role in preservation of healthy host status. Also, H. parainfluenzae can cause opportunistic infections outside of the oral cavity. To date, little is known about how H. parainfluenzae colonizes the human host, despite being such a frequent and abundant part of our human microbiome. Here, we demonstrate the creation and use of a powerful tool, a TnSeq library, used to identify genes necessary for both the outright growth of this organism and also genes conditionally essential for growth in varying oxygen status which it can encounter in the human host. This tool and these data serve as a foundation for further study of this relatively unknown organism that may play a role in preserving human health.