[Clinical characteristics of a case of severe pneumonia caused by coinfection of COVID-19 and Chlamydia Psittaci]

A 69-year-old female patient was admitted to the Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Xuzhou Medical University due to a "cough and fever for eight days". On admission, a coronavirus disease (COVID-19) nucleic acid test was positive, and a chest CT scan showed progressive patchy shadows and consolidation shadows in both lungs. Arterial blood gas analysis showed type Ⅰ respiratory failure. The primary diagnosis was severe community-acquired pneumonia in an older adult without underlying disease. However, oxygen inhalation, steroid, anti-inflammatory, and antibacterial empirical treatment with piperacillin/tazobactam was ineffective. Metagenomic next-generation sequencing of bronchoscopy alveolar lavage fluid showed Chlamydia psittaci(C. psittaci). Severe pneumonia was confirmed, caused by coinfection with severe acute respiratory syndrome coronavirus 2 and C. psittaci. A combination of doxycycline and moxifloxacin significantly improved the targeted and symptomatic treatment of the underlying cause. After discharge, the patient recovered within four weeks of follow-up. Therefore, clinicians should be alert to the possibility of coinfection of C. psittaci in patients already diagnosed with COVID-19.

Low sensitivity of T-cell based detection of tuberculosis among HIV co-infected Tanzanian in-patients

OBJECTIVE

To evaluate the performance of QuantiFERON-TB GOLD (QFTG) in a resource-poor setting among patients with and without HIV infection.

DESIGN

Cross-sectional study.

SETTING

Two hospitals in Northern Tanzania.

SUBJECTS

Eighty three adult male and female inpatients.

INTERVENTION

All patients were screened for HIV infection and underwent tuberculin skin test (TST) and QFTG.

RESULTS

Eighty-three subjects were enrolled, and 29 (35%) of 83 were HIV-infected. QFTG yielded indeterminate results in 12 (22%; 95% CI 12%-34%) of 54 HIV-uninfected and 13 (45%; 95% CI 26%-64%) of 29 HIV-infected subjects (p = 0.0323). Among those with smear-positive pulmonary tuberculosis, TST was positive in 40 (100%; 95% CI 91%-100%) of 40 HIV-uninfected subjects compared with seven (54%; 95% CI 25%-81%) of 13 HIV-infected subjects (p < 0.0001), and QFTG was positive in 28 (70%; 95% CI 53%-83%) of 40 HIV-uninfected subjects compared with three (23%; 95% CI 5%-54%) of 13 HIV-infected subjects (p = 0.0029). Among medical inpatients at risk for latent tuberculosis infection, TST was positive in seven (50%) of 14 HIV-uninfected patients and three (19%) of 16 HIV-infected patients (p = 0.0701) and QFTG was positive among two (14%) of 14 HIV-uninfected patients and three (19%) of 16 HIV-infected patients (p = 0.7437).

CONCLUSIONS

The presence of HIV co-infection was associated with a significant reduction in sensitivity of both the TST (p < 0.0001) and QFTG (p = 0.0029) for the diagnosis of active M. tuberculosis infection. The high proportion of indeterminate QFTG and lack of sensitivity, particularly among HIV-infected patients, may limit its applicability in settings like Tanzania. Larger studies in resource-poor settings are required.

Coimmunization of Agaricus blazei Murill extract with hepatitis B virus core protein through DNA vaccine enhances cellular and humoral immune responses

DNA vaccines induce protective humoral and cell-mediated immune responses in several animal models. Agaricus blazei Murill (ABM) is particularly rich in polysaccharides, and has shown particularly strong results in treating and preventing cancers. The goal of this study was to investigate whether co-immunization of the fungus ABM with hepatitis B virus (HBV) core DNA vaccine could increase the immune responses. Compared with the control mice which received hepatitis B virus core antigen (HBcAg) alone, significant increase in not only the HBcAg-specific antibody response but also T cell proliferation was observed in mice which received HBcAg DNA vaccine plus ABM extract. These results suggest that ABM extract might represent an adjuvant to improve the efficacy of DNA vaccines in vivo.

DNA Fragment Encoding Human IL-1β 163–171 Peptide Enhances the Immune Responses Elicited in Mice by DNA Vaccine against Foot-and-Mouth Disease

DNA vaccine has been tested for protection against foot-and-mouth disease. However, the relatively low efficacy of DNA vaccine in inducing immune responses in large animals has restricted its practical use. Interleukin-1 plays an essential role in amplifying both the cellular and humoral immune responses to foreign antigens, and may therefore represent a good candidate as an adjuvant of DNA vaccines. Since the inflammatory activity of IL-I may restrict its application in DNA vaccine treatment, we explored the possibilities of augmenting immune responses without unwanted inflammatory effects using the IL-1beta fragment (amino acids (aa) 163-171), which is essential for IL-1 receptor-1 binding. The DNA fragment encoding the human IL-1beta fragment (aa 163-171) was fused to foot-and-mouth disease virus (FMDV) DNA vaccine, and injected into mice to analyse its immune response. Compared with control mice receiving FMDV DNA vaccine alone, significant increases in the FMDV-specific antibody response and also in T cell proliferation were observed in mice receiving IL-1beta (163-171)-FMDV. These results suggested that DNA fragment encoding IL-1beta 163-171 peptide might represent a good candidate for an adjuvant of FMDV DNA vaccine.

Enhancement of immune responses to the hepatitis B virus core protein through DNA vaccines with a DNA fragment encoding human IL-1beta 163-171 peptide

DNA vaccines have been widely used as effective means of eradicating a variety of viruses, parasites, bacteria as well as means of alleviating allergic and autoimmune diseases and tumors. As interleukin 1 (IL-1) plays an essential role in augmenting both cellular and humoral immune responses to foreign antigens, it may represent a good candidate for an adjuvant to DNA vaccines. Since the inflammatory activity of IL-1 may have a restricted application to DNA vaccines, we explored the possibility of augmenting immune response without unwanted inflammatory effect using IL-1beta 163-171 peptide, which is essential for IL-1 receptor 1 binding. A DNA fragment encoding the human IL-1beta 163-171 peptide of concern was fused to the Hepatitis B virus (HBV) core DNA vaccine, and injected into mice to analyze its immune responses. Compared with the control mice which received hepatitis B virus core antigen (HBcAg) alone, significant increase in not only the HBcAg-specific antibody response but also in T cell proliferation was observed in mice which received IL-1beta 163-171-HBcAg. These results suggest that the DNA fragment encoding the IL-1beta polypeptide of aa 163-171 might represent a good candidate for an adjuvant of DNA vaccines.