Successful Treatment of Staphylococcus schleiferi Infection after Aortic Arch Repair: In Situ Aortic Arch Replacement and Domino Reconstruction of the Debranching Graft using Autologous Iliac Artery

A 62-year-old Japanese male presented with graft infection by Staphylococcus schleiferi 50 days after debranching of the left subclavian artery and frozen elephant trunk repair for the entry closure of a Stanford type B aortic dissection. The graft was removed, and the patient was successfully treated using in situ reconstruction of the arch with omental flap coverage, removal of the debranching graft, autologous iliac artery grafting, and longterm antibiotics. Domino reconstruction of the infected debranching graft using autologous external iliac artery and a Dacron graft can thus be a good option in similar cases

Paradoxical response to disseminated non-tuberculosis mycobacteriosis treatment in a patient receiving tumor necrosis factor-α inhibitor: a case report

Background: Biological agents such as tumor necrosis factor-α inhibitors are known to cause mycobacterium infections. Here, we report a disseminated non-tuberculosis case caused by TNF-α inhibitor therapy and a probable paradoxical response to antimycobacterial therapy.Case presentation: A 68-year-old man with relapsing polychondritis was refractory to glucocorticoid therapy; adalimumab was therefore administered in combination with oral glucocorticoids. Treatment with 40 mg of adalimumab led to rapid improvement of his clinical manifestations. The administration of tacrolimus (1 mg) was started as the dosage of oral glucocorticoids was tapered. However, the patient developed an intermittent high fever and productive cough 15 months after starting adalimumab treatment. A chest computed tomography scan revealed new granular shadows and multiple nodules in both lung fields with mediastinal lymphadenopathy, and Mycobacterium intracellulare was isolated from 2 sputum samples; based on these findings, the patient was diagnosed with non-tuberculosis mycobacteriosis. Tacrolimus treatment was discontinued and oral clarithromycin (800 mg/day), rifampicin (450 mg/day), and ethambutol (750 mg/day) treatment was initiated. However, his condition continued to deteriorate despite 4 months of treatment; moreover, paravertebral and subcutaneous abscesses developed and increased the size of the mediastinal lymphadenopathy. Biopsy of the mediastinal lymphadenopathy and a subcutaneous abscess of the right posterior thigh indicated the presence of Mycobacterium avium complex (MAC), and the diagnosis of disseminated non-tuberculosis mycobacteriosis was confirmed. Despite 9 months of antimycobacterial therapy, the mediastinal lymphadenopathy and paravertebral and subcutaneous abscesses had enlarged and additional subcutaneous abscesses had developed, although microscopic examinations and cultures of sputum and subcutaneous abscess samples yielded negative results. We considered this a paradoxical reaction similar to other reports in tuberculosis patients who had discontinued biological agent treatments, and increased the dose of oral glucocorticoids. The patient\u27s symptoms gradually improved with this increased dose and his lymph nodes and abscesses began to decrease in size.Conclusions: Clinicians should consider the possibility of a paradoxical response when the clinical manifestations of non-tuberculosis mycobacteriosis worsen in spite of antimycobacterial therapy or after discontinuation of tumor necrosis factor-α inhibitors. However, additional evidence is needed to verify our findings and to determine the optimal management strategies for such cases

Multiplex real-time polymerase chain reaction for rapid detection of beta-lactamase-negative, ampicillin-resistant Haemophilus influenzae.

We evaluated a multiplex real-time quantitative polymerase chain reaction (PCR) method for quantification of Haemophilus influenzae and rapid detection of beta-lactam-resistant strains. We designed 5 PCR primer sets to simultaneously detect the beta-lactam-resistant genes and quantify the pathogen. To demonstrate the validity of this assay, we used 191 clinical isolates, including 141 H. influenzae strains, and 100 purulent sputum samples, including 30 samples from which H. influenzae had been isolated. This assay showed 92.9% sensitivity and 91.8% specificity for detecting beta-lactam-resistant genes, relative to the conventional phenotypic method, and this assay correlated well with conventional quantitative culture counts. By using this assay, we could quantify H. influenzae and identify beta-lactam susceptibility in only 3 h and with only one tube. This method will be helpful for the rapid detection of H. influenzae infections and the selection of appropriate antibiotics

Efficacy of AiiM, an N-Acylhomoserine Lactonase, against Pseudomonas aeruginosa in a Mouse Model of Acute Pneumonia

Quorum sensing (QS) in Pseudomonas aeruginosa regulates the production of many virulence factors and plays an important role in the pathogenesis of P. aeruginosa infection. N-acyl homoserine lactones (AHL) are major QS signal molecules. Recently, a novel AHL-lactonase enzyme, AiiM, has been identified. The aim of this study was to evaluate the effect of AiiM on the virulence of P. aeruginosa in a mouse model of acute pneumonia. We developed a P. aeruginosa PAO1 strain harboring an AiiM-expressing plasmid. The production of several virulence factors by the AiiM-expressing strain was examined. Mice were intratracheally infected with an AiiM-expressing PAO1 strain. Lung histopathology, bacterial burden, and bronchoalveolar lavage (BAL) fluid were assessed at 24 h postinfection. AiiM expression in PAO1 reduced production of AHL-mediated virulence factors and attenuated cytotoxicity against human lung epithelial cells. In a mouse model of acute pneumonia, AiiM expression reduced lung injury and greatly improved the survival rates. The levels of proinflammatory cytokines and myeloperoxidase activity in BAL fluid were significantly lower in mice infected with AiiM-expressing PAO1. Thus, AiiM can strongly attenuate P. aeruginosa virulence in a mammalian model and is a potential candidate for use as a therapeutic agent against P. aeruginosa infection

Characteristics and disease severity of healthcare-associated pneumonia among patients in a hospital in Kitakyushu, Japan.

Healthcare-associated pneumonia (HCAP) is a newly identified condition, and epidemiologic studies in Japan are still limited. We retrospectively observed patients with HCAP and community-acquired pneumonia (CAP) who were hospitalized between December 2004 and March 2005, and compared their disease characteristics. A total of 34 patients (14 with HCAP and 20 with CAP) were evaluated. Of the patients with HCAP, seven (50%) were hospitalized for at least 2 days in the preceding 90 days and five (35.7%) resided in a nursing home or extended care facility. Compared with patients with CAP, patients with HCAP were older, had more complications, including central nerve diseases, had greater disease severity, but lower serum albumin level. More methicillin-resistant Staphylococcus aureus, Pseudomonas spp., and anaerobes were isolated from patients with HCAP than from those with CAP. Conversely, more Streptococcus pneumoniae was detected and more penicillin was used in patients with CAP. This study provides additional evidence that HCAP should be distinguished from CAP and suggests the pathogenesis and therapeutic strategy for HCAP may be similar to those for hospital-acquired pneumonia

Efficacy of ME1036 against meticillin-resistant Staphylococcus aureus and vancomycin-insensitive S. aureus in a model of haematogenous pulmonary infection.

ME1036, a novel parenteral carbapenem, was developed for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate S. aureus (VISA). A model of haematogenous pulmonary infection was induced in mice by tail vein injection of MRSA strain NUMR101 or VISA Mu50 enmeshed in agar beads. After 24h of infection, mice were treated twice daily for 7 days with 200mg/kg/day vancomycin (VCM) or ME1036. Mice infected with VISA were also pre-treated with cyclophosphamide to induce an immunocompromised state. The number of viable bacteria in the lungs was counted 12h after the final drug treatment. VCM decreased the number of viable MRSA in the lungs in comparison with the control, although the difference was not significant (mean+/-standard error of the mean log(10) colony-forming units (CFU)/lung=6.876+/-0.54 vs. 8.25+/-0.41, respectively). In contrast, treatment with ME1036 resulted in a significant decrease in the number of viable MRSA (log(10)CFU/lung=2.69+/-0.44 (n=6); P3 log(10) reduction versus control against both MRSA strains (>5 log for the VCM-susceptible strain and 3.4 log for the VISA), whereas VCM produced <1.3 log for both strains

The definition of healthcare-associated pneumonia (HCAP) is insufficient for the medical environment in Japan: a comparison of HCAP and nursing and healthcare-associated pneumonia (NHCAP)

Healthcare-associated pneumonia (HCAP) is a new concept of pneumonia, which was proposed in the ATS/IDSA guidelines. The guidelines explain that HCAP patients should be treated with broad-spectrum antimicrobial drugs directed at multidrug-resistant pathogens. However, in Japan, there are many elderly people who received in-home care service. These patients seemed to be consistent with the concept of HCAP, but they did not meet the definition of HCAP. Therefore, the Japanese Respiratory Society modified the definition of HCAP according to the medical environmental in Japan. We retrospectively observed HCAP patients and nursing home and healthcare-associated pneumonia (NHCAP) patients who were hospitalized during 24 months at the Japanese Red Cross Nagasaki Genbaku Hospital (Nagasaki, Japan). Patient background, disease severity, identified pathogens, initial antibiotic regimens, and outcomes were compared. A total of 108 patients (77 HCAP and 31 NHCAP except HCAP patients) were evaluated. Of NHCAP except HCAP patients, 27 (87.1 %) were above 3 in the ECOG PS score. There were almost no significant differences between the two groups in characteristics, pneumonia severity, identified bacteria, initial antibiotic regimens, and response rate of initial antibiotic therapy. Although the in-hospital mortality of HCAP patients and NHCAP except HCAP patients was 9.1 % and 19.4 %, respectively, this difference did not reach statistical significance (P > 0.05). Our study suggested that, in the criteria of HCAP, some Japanese patients, who were consistent with the concept of HCAP, were classified as community-acquired pneumonia (CAP). Therefore, there is a need to change the definition of HCAP according to the medical environment in Japan