Vertebral osteomyelitis caused by the novel pathogen Cutibacterium modestum: a case report.

BACKGROUND: Cutibacterium modestum is one of the five species of the genus Cutibacterium. While C. acnes has been reported as an important pathogen in bone and joint infections, the clinical characteristics of C. modestum infections remain unclear. Moreover, thus far, there has been no clinical case report regarding C. modestum infections. CASE PRESENTATION: An 82-year-old man with a history of repeated trigger point injections for lumbago at the L4 level presented with fever and an exacerbation of lumbago. Physical examination indicated knocking pain at the L4-L5 levels; magnetic resonance imaging showed irregular bone destruction of the L4 vertebral body, and low T1 and high T2 intensity lesions at the L4-L5 intervertebral disc. Two sets of blood cultures (two aerobic and two anaerobic) were performed. Intravenous cefazolin was administered, considering the common pathogens of vertebral osteomyelitis, such as Staphylococcus aureus. The patient's condition did not improve; thereafter, anaerobic culture bottles revealed Gram-positive rods on day 11 of incubation. There was no evidence of infective endocarditis upon transthoracic echocardiography. Needle aspiration from the L4-L5 intervertebral disc was performed on day 13 that also showed the presence of Gram-positive rods. The patient was diagnosed with vertebral osteomyelitis caused by C. modestum using a combination of characteristic peak analysis with matrix-assisted laser desorption ionization (MALDI), microbial biochemistry examinations, and 16S rRNA gene sequencing from the blood and pus cultures. He was successfully treated with alternative intravenous ampicillin, followed by oral amoxicillin for 10 weeks, according to the tests for ampicillin susceptibility, with a minimum inhibitory concentration of 0.016 µg/mL using E-test® under aerobic conditions. CONCLUSIONS: Cutibacterium modestum is a microorganism that is difficult to identify. A combination of characteristic peaks with MALDI, appropriate microbial biochemical examinations, and 16S rRNA gene sequencing may serve as an efficient guide for the identification of C. modestum.

Lactobacillus paragasseri as a novel causative pathogen of cavernosal abscess.

Most cases of cavernosal abscesses result from the progression of sexually transmitted diseases (STDs) commonly caused by Neisseria gonorrhoeae; however, cavernosal abscesses without STDs are rare events. Herein, we describe the first case report of a Lactobacillus paragasseri cavernosal abscess. A 63-year-old man with diabetes and a history of foreign object insertion into the urethra one year prior presented with high-grade fever and slight local pain. The patient was diagnosed with L. paragasseri cavernosal abscess based on computed tomography and microbial biochemical examinations in addition to matrix-assisted laser desorption ionization (MALDI) and 16S rRNA sequencing from blood and pus cultures. The patient was successfully treated with a surgical procedure and appropriate antimicrobials. Hence, L. paragasseri, a commensal bacterium of the gastrointestinal or genitourinary tract, can cause cavernosal abscesses. Notably, L. paragasseri is difficult to distinguish from L. gasseri using MALDI or 16S rRNA sequencing without microbial biochemical examinations owing to morphological similarities. Therefore, special attention should be paid, clinically and microbiologically, to the potential of L. paragasseri cavernosal abscess in clinical settings.

Successfully treated infected aneurysm caused by Listeria monocytogenes.

Infected aneurysms caused by Listeria monocytogenes are extremely rare. Therefore, there is no standard procedure for their diagnosis and treatment. A 76-year-old Japanese man with diabetes and hypertension was diagnosed with a left common iliac aneurysm caused by L. monocytogenes, using multidetector computed tomographic angiography and rapid diagnostic testing of the positive blood culture. He was successfully treated with a combination of ampicillin administration, timely surgical debridement, and in-situ Y-graft placement with revascularization and omental implantation. Vancomycin and third-generation cephalosporins, to which L. monocytogenes is resistant, are used as an empirical regimen for infected aneurysms. Therefore, the use of a rapid diagnostic testing is important as it identifies L. monocytogenes within 24 h from obtaining the blood cultures, and guides the administration of the appropriate antibiotics. In-situ Y-graft placement restores nearly normal blood flow, following the confirmation of negative conversion of blood culture in response to the intensive intravenous ampicillin therapy. Appropriate and timely microbiological examinations, in addition to radiographic examinations, can be the key for selecting the optimal therapeutic procedures for each patient and achieving the best possible outcomes.

Salmonella enterica var. Enteritidis osteomyelitis with pulmonary involvement in an immunocompetent young woman.

Primary bacteremia due to non-typhoid Salmonella often occurs in immunocompromised individuals, but may also occur in immunocompetent individuals. Contrastingly, vertebral osteomyelitis with respiratory involvement caused by non-typhoid Salmonella in immunocompetent individuals is extremely rare. A 21-year-old healthy woman with histories of eating ready-to-eat roasted beef and a recent vertebral compression fracture developed high-grade fever and was diagnosed with bacteremia, complicated by vertebral osteomyelitis with pulmonary involvement characterized as an extra-intestinal infection. The pathogen was identified as Salmonella enterica var. Enteritidis using molecular and serotyping techniques. The appropriate antibiotic therapy and focal detection were based on antimicrobial susceptibility testing (including fluoroquinolone resistance), medical histories (eating ready-to-eat roasted beef and vertebral compression fracture), and diagnostic imaging. This case highlights the potential of vertebral osteomyelitis and pulmonary involvement caused by S. enterica var. Enteritidis in an immunocompetent individual, and misinterpretation of fluoroquinolone susceptibility with conventional methods.

Central administration of metastin increases food intake through opioid neurons in chicks.

Metastin, an RFamide peptide, has been isolated from human placenta and possesses several physiological actions in mammals. However, little is known about this bioactive peptide in avian species. This study was conducted to assess the effect of metastin on feeding behavior of chicks (Gallus gallus). The food intake of chicks is significantly increased by the intracerebroventricular injection of metastin. Beta-funaltrexamine, a mu-opioid receptor antagonist, significantly attenuates metastin-induced food intake in chicks. In contrast, delta- and kappa-opioid receptor antagonists did not show any influence on metastin-induced food intake in chicks. In addition, administration of N(G)-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, did not influence metastin-induced food intake. Taken together, this study shows the orexigenic effect of metastin in chicks and suggests that this effect is mediated by mu-opioid receptor.

The orexigenic effect of GnIH is mediated by central opioid receptors in chicks.

Gonadotropin-inhibiting hormone (GnIH) is a newly discovered hypothalamic hormone which suppresses gonadotropin synthesis and release from the anterior pituitary. Recently, we found that intracerebroventricular (ICV) injection of GnIH stimulated feeding behavior of chicks (Gallus gallus) and suggested that GnIH is one of orexigenic peptides. However, the mechanism underlying the orexigenic effect is still unknown. In the present study, we examined whether the orexigenic effect of GnIH is related to opioid and nitric oxide (NO) systems. The orexigenic effect of ICV-injected GnIH was attenuated by co-injection of beta-funaltrexamine (an opioid mu-receptor antagonist) but not ICI-174,864 and nor-binaltorphimine (antagonists of opioid delta- and kappa-receptors, respectively). The co-injection of non-selective NO synthase inhibitor did not affect GnIH-induced feeding behavior. The present study demonstrated that the GnIH-induced feeding might be mediated by opioid mu-receptor in chicks.

Peripheral or central administration of nitric oxide synthase inhibitor affects feeding behavior in chicks.

We investigated the effect of peripheral or central administration of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor, on food intake in layer and broiler chicks (Gallus gallus). The intraperitoneal administration of L-NAME significantly decreased food intake in both broiler and layer chicks while the administration of D-NAME, an inactive form of L-NAME, had no effect. The intracerebroventricular (ICV) injection of L-NAME did not affect food intake in broiler chicks. However, ICV injection of L-NAME increased food intake in layer chicks while the injection of D-NAME had no effect. In addition to this, L-NAME-induced feeding was negated with the co-injection of L-arginine, suggesting that NO acts as a feeding-inhibitor signal in the brain of layer chicks. The present study revealed that administration of NO synthase inhibitor affected food intake in chicks, but the effect might be changed by chick strain and position of the injection.