A rapid simultaneous antigen detection of Haemophilus influenzae and Streptococcus pneumoniae for predicting the prognosis of acute otitis media.

BACKGROUND: Rapid identification of causative bacteria in treatment of acute otitis media (AOM) is of paramount importance for appropriate antibiotic use. MATERIALS AND METHODS: This prospective observational study was conducted in 15 hospitals and clinics in Japan between 2018 and 2020. A new rapid antigen test kit (AOS-116), which simultaneously detects antigens for Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi), was applied for middle ear fluids (MEFs) and nasopharyngeal secretions (NPSs) in patients with moderate to severe AOM. We investigated relationship between the results of rapid test, severity at initial visit, and clinical course. RESULTS: Regarding performance accuracy based on culture results, AOS-116 showed 1) high (>80%) sensitivity, specificity, and negative predictive value (NPV) in MEFs for both antigens, 2) high sensitivity, specificity, and positive predictive value (PPV) in NPSs for Hi antigen, and 3) high specificity, and PPV in NPSs for Sp antigen. Regarding predictive value of nasopharyngeal culture and antigen detection for causative middle ear pathogens, similar results were observed between AOS-116 and culture, which was characterized with high sensitivity and NPV for both pathogens. MEFs/NPSs positive for Hi antigen were significantly associated with eardrum findings, and severity. MEFs/NPSs positive for pneumococcal antigen were significantly associated with severity of otalgia, fever, and otorrhea. Among patients with prior antimicrobial treatment, improvement tended to be slower in cases positive for Hi than in cases negative. CONCLUSION: The rapid antigen detection test is useful as a decision-making tool for prescribing antimicrobial agents and may play an important role in promoting appropriate antimicrobial use.

Cyclic AMP represses the hypoxic induction of hypoxia-inducible factors in PC12 cells.

Hypoxia-inducible factor 1 (HIF-1) is a master regulator for hypoxic activation of genes for angiogenesis, hormone synthesis, glycolysis and cell survival. In addition to hypoxic stimulus, various effectors and reagents were reported to affect HIF-1 activity. Here, we show that cyclic AMP (cAMP) down-regulates the HIF-1 activity in pheochromocytoma PC12 cells but not in Hep3B and HeLa cells. Hypoxia response element-dependent reporter activity was decreased by the addition of dibutyryl cAMP. Expression of protein kinase A (PKA) catalytic alpha-subunits repressed the HIF-1 activity. HIF-1alpha and HLF (HIF-2alpha or EPAS1) protein levels were decreased by the treatment with dibutyryl cAMP. Although CREB was served as a negative factor for the HIF-1 activity, it may not be a major PKA target in the cAMP-dependent HIF-alpha repression pathway. Induction of hypoxia responsive genes was suppressed by dibutyryl cAMP. Our results provide additional insight into a regulatory mechanism of hypoxic response.