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This study aimed to assess the clinical presentation, antibiotic therapy, surgery, and outcomes in patients with otitis media caused by Mycobacterium abscessus subsp. abscessus and discuss the efficacy of surgery. This is a retrospective case review of three patients diagnosed with otomastoiditis caused by M. abscessus subsp. abscessus. All patients had refractory otorrhea. One patient had granulation tissue in the tympanic membrane. They received medical treatment and underwent surgery. Otorrhea was resolved several months after the initiation of long-term multiantibiotic therapy in all cases. The timing of surgery varied among patients. Before initiating antibiotic therapy, mastoidectomy was performed to achieve definitive diagnosis in two patients, and wound dehiscence developed in these patients. Two patients underwent debridement after the initiation of multiantibiotic therapy. After antibiotic administration, tympanoplasty was performed to improve hearing in one patient. All patients achieved culture negativity after treatment, and no recurrences have been noted. From three cases, it is suggested that the mainstay of treatment for M. abscessus subsp. abscessus is long-term multiantibiotic therapy, and surgery itself may have little effect on achieving ear dryness. Thus, in most patients, drug therapy should be prioritized. Considering postoperative complications, surgery before achieving ear dryness should be avoided, except in emergency cases. In addition, if the diagnosis is not confirmed by repeated bacteriological tests, mastoidectomy should be performed to collect specimens. Tympanoplasty for hearing loss or eardrum perforation is recommended after discontinuation of medications.

Background: The number of bacterial infections that—for various reasons—are challenging to cure continues to increase. One such reason is persister cell infection. To investigate persister formation and persister infections, viable bacteria must be evaluated in the same animal over time. In this study, the feasibility of monitoring viable bacteria by SPECT using two labeled peptides was evaluated. Results: Two types of ubiquicidin (UBI) 29-41 labeled with technetium-99m, 99mTc-HYNIC(GH)2-UBI 29-41 and 99mTc-HYNIC(Tricine)2-UBI 29-41, were synthesized. The in vitro binding of these labeled peptides to Staphylococcus aureus was measured. For the in vivo study, each labeled peptide was injected into S. aureus infected mouse thigh after treatment with various doses of ciprofloxacin (CPFX). Two hours after injection, the accumulation of each labeled peptide at the infection site was assessed by SPECT, and then the number of viable bacteria was determined from the accumulation detected. The peptide labeling was successful, and the radiochemical purity was 91±9% (GH, n=8) and 100% (Tricine, n=8). The in vitro binding of the labeled peptides to S. aureus (5×108 cfu) without serum was 78.9% (GH) and 85.5% (Tricine) of the total 99mTc activity. With serum, the binding rate was 67.5% (GH) and 13.3% (Tricine). The accumulation of labeled peptide was calculated from the SPECT images, and that in the bacterial infection site (left thigh) was higher than that in the non-infection site (right thigh) for both peptides. Good correlation was found between the target-to-non-target (T/NT) ratios of each labeled peptide and the viable bacterial count at the infection site, and 99mTc-HYNIC(Tricine)2-UBI 29-41 had a wider range than 99mTc-HYNIC(GH)2-UBI 29-41.Conclusion: Using the SPECT/labeled peptide method, it was possible to monitor viable bacterial count in the range 103–108 cfu, which is appropriate for tracking viable bacterial counts in the same animal over time.

Potent fungicidal activity is one of the key factors of antifungals to overcome invasive pulmonary aspergillosis (IPA). To date, quantification of Aspergillus DNA in the lungs and galactomannan (GM) in serum or bronchoalveolar lavage fluid have been developed as general methods for measuring fungal burden in IPA animal models. However, GM quantification is not supposed to be a suitable method for precise evaluation of the fungicidal effects of antifungals, because killed Aspergillus hyphae can release GM for a certain period until they are eliminated by the host. Therefore, in terms of detecting viable fungal burden of Aspergillus, quantification of Aspergillus DNA has been thought to be a suitable method. Here, to obtain a method with much higher sensitivity, we applied reverse transcription quantitative PCR (RT-qPCR) for A. fumigatus 18S ribosomal RNA to measure the viable fungal burden in murine IPA models. Prior to in vivo tests, we confirmed that the sensitivity of 18S rRNA was nearly 50-fold higher than that of 18S ribosomal DNA in vitro. This highly sensitive method made it possible to evaluate the fungicidal effects of antifungals in a low-inoculation murine IPA model. In this model, single administrations of higher doses of voriconazole and posaconazole, which have fungicidal activity, were able to display fungicidal effects with ≥1 log10 reductions by 18S rRNA quantification, whereas significant reductions in serum GM were not observed. These results suggest that 18S rRNA quantification is a powerful tool for screening novel antifungals with potent fungicidal activity only after a single administration.

Feline infectious peritonitis (FIP) is a lethal infectious disease affecting domestic and wild cats. Several reports suggested that TNF-alpha is related to the progression of FIP. Thus, the administration of a feline TNF-alpha-neutralizing antibody to cats with FIP may reduce the disease progression. In this study, we have prepared nine monoclonal antibodies (MAbs) that recognize feline TNF-alpha. All MAbs neutralized recombinant TNF-alpha. The 50% inhibitory concentrations (IC50) of the MAbs for the cytotoxicity of recombinant TNF-alpha were 5–684 ng/ml. MAb 2–4 exhibited high neutralizing activity against natural TNF-alpha derived from FIPV-infected macrophages, and was confirmed to inhibit the following feline TNF-alpha-induced conditions in vitro: (i) an increase in the survival rate of neutrophils from cats with FIP, (ii) aminopeptidase N (APN) mRNA expression in macrophages, and (iii) apoptosis of a feline T-lymphocyte cell line.

In addition to skeletal muscle and the nervous system, α-dystroglycan is found in the podocyte basal membrane, stabilizing these cells on the glomerular basement membrane. Fukutin, named after the gene responsible for Fukuyama-type congenital muscular dystrophy, is a putative glycosyltransferase required for the post-translational modification of α-dystroglycan. Chimeric mice targeted for both alleles of fukutin develop severe muscular dystrophy; however, these mice do not have proteinuria. Despite the lack of a functional renal defect, we evaluated glomerular structure and found minor abnormalities in the chimeric mice by light microscopy. Electron microscopy revealed flattening of podocyte foot processes, the number of which was significantly lower in the chimeric compared to wild-type mice. A monoclonal antibody against the laminin-binding carbohydrate residues of α-dystroglycan did not detect α-dystroglycan glycosylation in the glomeruli by immunoblotting or immunohistochemistry. In contrast, expression of the core α-dystroglycan protein was preserved. There was no statistical difference in dystroglycan mRNA expression or in the amount of nephrin and α3-integrin protein in the chimeric compared to the wild-type mice as judged by immunohistochemistry and real-time RT-PCR. Thus, our results indicate that appropriate glycosylation of α-dystroglycan has an important role in the maintenance of podocyte architecture.