Background: Although gut microbiota dysbiosis has been reported in HIV infected individuals recently, the relationship between the gut microbiota and immune activation in patients with different immune responses to highly active antiretroviral therapy (HAART) is still not well understood. Gut microbiota and immune activation were studied in 36 non-HIV-infected subjects (healthy controls) and 58 HIV-infected individuals, including 28 immunological responders (IR) and 30 immunological non-responders (INR) (≥500 and < 200 CD4+ T-cell counts/μl after 2 years of HIV-1 viral suppression respectively) without comorbidities.Results: Metagenome sequencing revealed that HIV-infected immunological responders and immunological non-responders could not recover completely from the gut microbiota dysbiosis. At a 97% similarity level, the relative abundances ofFusobacterium, Ruminococcus gnavusandMegamonaswere greater, whereasFaecalibacterium, Alistipes, Bifidobacterium, Eubacterium rectaleandRoseburiawere more depleted in the IR and INR groups than those in the healthy controls.RuminococcaceaeandAlistipeswere positively correlated with nadir and current CD4+ T-cell counts, but negatively correlated with CD8 + CD57+ T-cell counts.Inflammation markers and translocation biomarkers (LPS) levels were positively correlated with the abundances of generaRuminococcusandFusobacteriumbut were negatively correlated with the genusFaecalibacterium. The relative abundances ofEscherichia-ShigellaandBlautiawere significantly higher in the IR than those in the INR group.Escherichia-Shigellawere negatively correlated with the CD4/CD8 ratio but positively correlated with the amount ofCD8 + CD57+ T-cells.RoseburiaandBlautiawere negatively associated with nadir CD4+ T-cell and positively associated with CD8 + CD57+ T-cell counts.Conclusions: Gut microbiota dysbiosis may be one of the factors contributing to different immune responses and treatment outcomes to HAART.

The role of the oral microbiota in HIV-infected individuals deserves attention as either HIV infection or antiretroviral therapy (ART) may have effect on the diversity and the composition of the oral microbiome. However, few studies have addressed the oral microbiota and its interplay with different immune responses to ART in HIV-infected individuals. Salivary microbiota and immune activation were studied in 30 HIV-infected immunological responders (IR) and 34 immunological non-responders (INR) (≥500 and < 200 CD4 + T-cell counts/μl after 2 years of HIV-1 viral suppression, respectively) with no comorbidities. Metagenome sequencing revealed that the IR and the INR group presented similar salivary bacterial richness and diversity. The INR group presented a significantly higher abundance of genus Selenomonas_4, while the IR group manifested higher abundances of Candidatus_Saccharimonas and norank_p_Saccharimonas. Candidatus_Saccharimonas and norank_p_Saccharimonas were positively correlated with the current CD4 + T-cells. Candidatus_Saccharimonas was positively correlated with the markers of adaptive immunity CD4 + CD57 + T-cells, while negative correlation was found between norank _p_Saccharimonas and the CD8 + CD38 + T-cells as well as the CD4/CD8 + HLADR + CD38 + T-cells. The conclusions are that the overall salivary microbiota structure was similar in the immunological responders and immunological non-responders, while there were some taxonomic differences in the salivary bacterial composition. Selenomona_4, Candidatus_Saccharimonas, and norank _p_Saccharimonas might act as important factors of the immune recovery in the immunodeficiency patients, and Candidatus_Saccharimonas could be considered in the future as screening biomarkers for the immune responses in the HIV-infected individuals.

Background: To evaluate the value and challenges of real-world clinical application of metagenomic next-generation sequencing (mNGS) for bronchoalveolar lavage fluid (BALF) in HIV-infected patients with suspected multi-pathogenic pneumonia. Methods: Fifty-seven HIV-infected patients with suspected mixed pneumonia who were agreed to undergo the bronchoscopy were recruited and retrospectively reviewed the results of mNGS and conventional microbiological tests (CMTs) of BALF from July 2020 to June 2022. Results: 54 patients were diagnosed with pneumonia including 49 patients with definite pathogens and five patients with probable pathogens. mNGS exhibited a higher diagnostic accuracy for fungal detection than CMTs in HIV-infected patients with suspected pulmonary infection. The sensitivity of mNGS in diagnosis of pneumonia in HIV-infected patients was much higher than that of CMTs (79.6% vs 61.1%; P < 0.05). Patients with mixed infection had lower CD4 T-cell count and higher symptom duration before admitting to the hospital than those with single infection. The detection rate of mNGS for mixed infection was significantly higher than that of CMTs and more co-pathogens could be identified by mNGS. The most common pattern of mixed infection observed was fungi-virus (11/29, 37.9%), followed by fungi-virus-bacteria (6/29, 20.7%) coinfection in HIV-infected patients with multi-pathogenic pneumonia. Conclusion: mNGS improved the pathogens detection rate and exhibited advantages in identifying multi-pathogenic pneumonia in HIV-infected patients. Early performance of bronchoscopy and mNGS are recommended in HIV-infected patients with low CD4 T cell counts and long duration of symptoms. The most common pattern of mixed infection observed was fungi-virus, followed by fungi-virus-bacteria coinfection in HIV infected patients with multi-pathogenic pneumonia.

The profile of T-cell receptor beta-chain variable (TRBV) genes usually skews in subjects with virus infection or cancer. The gene melting spectral pattern (GMSP) can be used to determine the profile of the TRBV gene family. To explore the portrait of the TRBV family in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection (AHI), peripheral blood mononuclear cells (PBMCs) were separated and further sorted into CD4⁺ and CD8⁺ T-cell subsets. The molecular features of the TRBV complementary determining region 3 (CDR3) motifs were determined using GMSP analysis. When a GMSP profile showed a single peak, the monoclonally expanded TRBV gene was cloned and sequenced. Skewed expansions of multiple TRBV genes were observed among the CD4⁺ and CD8⁺ T-cell subsets and the PBMCs. The frequency of monoclonally expanded TRBV genes in the CD8⁺ T-cell subset was significantly higher than that of the CD4⁺ T-cell subset and the PBMCs. Compared to other members of the TRBV gene family, TRBV11, BV15 and BV20 were predominantly expressed in the repertoire of peripheral blood lymphocytes in recovered AHI subjects. The relatively conserved amino acid motifs of TRBV5.1 and BV20 CDR3 were also detected in the CD4⁺ and CD8⁺ T-cell subsets. These results demonstrate the presence of multiple biased TRBV families in recovered AHI subjects. TRBV11, BV15 and BV20, especially from the CD8⁺ T-cell subset, may be relevant to the pathogenesis of subjects with AHI. The preferentially selected TRBV5.1 and BV20 with the relatively conserved CDR3 motif may be potential targets for personalized treatments of chronic HBV infection.

Background: Pulmonary infections remain a significant cause of morbidity and mortality in immunocompromised patients. The pathogens spectrum of pulmonary infection that can affect patients with human immunodeficiency virus (HIV) is wide such as bacterial, fungal, viral, parasitic organisms, and so on. The risk of multi-pathogenic pneumonia is higher in HIV-infected patients. However, the fast and accurate diagnosis of multi-pathogenic pneumonia is challenging because of the limitations of current conventional tests.Case Presentation: Here, we report a case of pneumonia due to Pneumocystis jirovecii and cytomegalovirus (CMV) in a 22-year-old male with newly diagnosed HIV infection. Blood tests revealed a low CD4 count, a chest computed tomography (CT) scan showed extensive ground-glass opacities in the bilateral lung with multiple cavity lesions in the left upper lung. Microscopic examination of stained sputum and bronchoalveolar lavage fluid (BALF) smear specimens did not find any pathogens. There was also no evidence of pathogens known to cause pneumonia in bacteria and fungi culture tests and virus antibodies such as EBV, CMV, and COVID-19. The nucleic acid of CMV in blood was reported by quantitative PCR. Next-generation sequencing (NGS) analysis of BALF specimens identified a large number of P. jirovecii and CMV reads, and confirmed the diagnosis of pneumonia due to P. jirovecii and CMV. Following the patient's treatment with anti-PCP and anti-CMV, the patient was cured and discharged.Conclusions: This case highlights the combined application of NGS in the clinical diagnosis of multi-pathogenic pneumonia in an HIV-infected patient. NGS is proposed as an important adjunctive diagnostic approach for identifying pathogens of multi-pathogenic pneumonia in HIV-infected patients.

Background: Streptococcus suis has been recognized as a zoonotic pathogen that may cause infections in humans. Although rarely described, it is not surprising that both cryptococcal and streptococcus suis meningitis infections can co-exist in a HIV-infected patient with a low CD4 count. However, a fast and accurate diagnose of meningitis of multipathogenic infections is challenging. In this report, we describe such a case of a HIV-infected patient with meningitis of multipathogenic infections.Case Presentation: The patient was a 34-year-old Chinese male who was diagnosed with cryptococcal meningitis and HIV at the same time about 1 year ago. During the same time period, he had received (with good compliance) fluconazole and tenofovir-lamivudine- dolutegravir based antiretroviral therapy (ART). However, symptom of progressively worsening occipital headache appeared after he was exposed to a truck which was used for transporting pigs. Initial workup indicated an increase of the cerebrospinal fluid (CSF) opening pressure (OP) and an increase in the number of lymphocytes and proteins in CSF. A magnetic resonance imaging (MRI) scan revealed that partial cerebellar surface enhancement. The cryptococcus capsular antigen test of CSF was positive. The results of the India Ink microscopy for cryptococcus, nucleic acid of CMV and EBV and mycobacterium tuberculosis (MTB) tests of CSF were negative. The results of the bacteria and fungi smear and culture of CSF were also negative. Eventually, streptococcus suis was detected using next-generation sequencing (NGS) in CSF. The diagnosis of Streptococcus suis meningitis was made based on the patient's contact history with carrier pigs and the clinical findings addressed above. The treatment of 2 weeks of intravenous ceftriaxone and 1 week of oral moxifloxacin resulted in improvement of the condition of CSF. The anti-fungal treatment using fluconazole continued until the CFS OP went down to a normal level and the cryptococcus capsular antigen test of CSF was negative 6 months later.Conclusion: This case highlights that NGS might be beneficial to HIV-infected patients who have meningitis with negative CSF culture results. Multiple etiologies for such condition in the immunocompromised patients must be taken into consideration and early stage NGS is recommended.