A Case of Immediate Anastomotic Leakage After Low Anterior Resection for Rectal Cancer.

A man in his seventies was referred to our hospital for radical therapy for advanced rectal cancer with multiple liver metastases. A colonic stent had already been placed in his rectum at the previous hospital because of malignant colorectal obstruction, so our therapeutic strategy was to perform systematic chemotherapy after resection of the primary tumor. Laparoscopic low anterior resection with a covering stoma was performed under general anesthesia. At about one hour after the surgery, the patient had sudden abdominal pain with watery diarrhea, and a similar discharge from his drainage tube. We suspected peritonitis caused by bowel perforation and emergency surgery was performed. The operative findings showed that his peritonitis was caused by anastomotic leakage from the rectum. Radical lavage of the abdominal space and reconstruction of colostomy was performed. The patient gradually recovered and we were able to start systematic chemotherapy at one month after the surgery. Anastomotic leakage immediately after anterior resection caused by watery diarrhea is rare, and it may be concerned with several issues. The covering stoma is intended to stop anastomotic leakage but it cannot prevent all cases of leakage especially when obstruction is present. We recommend that preventive measures be taken against anastomotic leakage, including intraoperative leakage tests or anal decompression tube placement.

Interstitial pneumonia in a patient treated with TAS-102 for metastatic colorectal cancer: a case report.

BACKGROUND: TAS-102, a new treatment option for patients with metastatic colorectal cancer that is refractory or intolerant to standard therapies, has been improving survival with acceptable tolerability and adverse events. Adverse hematological events associated with TAS-102 treatment were extensively profiled in the RECOURSE trial, but pulmonary toxicities associated with TAS-102 therapy are distinctly uncommon. In a recent early post-marketing phase vigilance on TAS-102 in Japan, seven cases of pulmonary disease were reported, but patient follow-up in this study was incomplete. Here, we present the first case of interstitial lung disease occurring in association with TAS-102 treatment. CASE PRESENTATION: A 57-year-old Japanese man who had previously received two standard treatments was admitted in 2014, at which time we administered TAS-102 (110 mg/day) as a third-line chemotherapy. He was safely treated with TAS-102 for the first planned cycle; however, approximately 4 days after receiving the second cycle of TAS-102, he complained of high fever and subsequent dyspnea with severe hypoxemia and went to the emergency room. A chest X-ray revealed diffuse coarse reticular shadows with ground-glass opacity on both lungs. Furthermore, a chest computed tomography scan showed thickening of the bronchovascular bundles with extensive ground-glass opacification and pleural effusions in both lung fields. In addition, a peripheral blood lymphocyte stimulation test with TAS-102 showed higher values compared with control samples. Consequently, we suspected drug-induced interstitial pneumonia, and discontinued treatment. Our patient was given an initial administration of high-dose methylprednisolone (1000 mg/day) for 3 days and oxygen. Our patient was discharged with oral prednisolone (20 mg/day) and improved symptomatically and radiologically. CONCLUSIONS: These findings suggest that interstitial pneumonia is a rare complication of TAS-102 chemotherapy, but the possibility of interstitial pneumonia should always be considered when a patient presents with a respiratory disorder while undergoing TAS-102 systemic chemotherapy. Prompt discontinuation of TAS-102 and treatment with high-dosage corticosteroids is needed to avoid exacerbating respiratory symptoms.

[Stevens-Johnson syndrome induced by regorafenib in a patient with progressive recurrent rectal carcinoma].

A 55-year-old man with rectal carcinoma underwent lower anterior resection. Eight years after surgery, multiple metastases were detected in the liver, lung, and abdominal lymph nodes. The metastatic cancers were resistant to standard chemotherapy. Thus, regorafenib was administered to the patient. The patient presented symptoms of Stevens-Johnson syndrome (SJS) nine days after regorafenib administration, and hence, treatment was terminated. To treat SJS, he received oral and topical steroid therapies. SJS is an important adverse event that hinders the continuation of regorafenib treatment. Thus, it is necessary to continually check the patient's skin condition carefully, especially at early stages of treatment. To our knowledge, this is the first report of SJS arising during the course of regorafenib treatment.

Fecoflowmetric analysis of anorectal motor function in postoperative anal-preserving surgery patients with low rectal cancer comparison with the wexner score and anorectal manometry.

The aim of this study was to elucidate whether fecoflowmetry (FFM) could evaluate more detailed evacuative function than anorectal manometry by comparing between FFM or anorectal manometric findings and the clinical questionnaires and the types of surgical procedure in the patients who received anal-preserving surgery. Fifty-three patients who underwent anal-preserving surgery for low rectal cancer were enrolled. The relationships between FFM or the manometric findings and the clinical questionnaires and the types of procedure of anal-preserving surgery were evaluated. There were significant differences between FFM markers and the clinical questionnaire and the types of the surgical procedure, whereas no significant relationship was observed between the manometric findings and the clinical questionnaire and the types of the surgical procedure. FFM might be feasible and useful for the objective assessment of evacuative function and may be superior to manometry for patients undergoing anal-preserving surgery.

Identification of high-risk factors as indicators for adjuvant therapy in stage II colon cancer patients treated at a single institution.

Although post-operative adjuvant chemotherapy (ACT) is only recommended for patients with stage II colon cancer who are at a high risk of recurrence, the definition of high risk remains unclear. The present study aimed to identify the risk factors for recurrence, which may also be indicators for adjuvant therapy, using a retrospective analysis of clinicopathological data obtained from stage II colon cancer patients who had undergone a curative resection. The present study also investigated the effects of ACT in patients who displayed the risk factors for recurrence. Univariate and multivariate analyses of the data collected from 377 stage II colon cancer patients, treated at Kurume University Hospital (Fukuoka, Japan) between 1982 and 2005, was conducted in order to determine and compare the risk factors for recurrence between the 163 patients who had undergone adjuvant therapy and the 214 patients who had not undergone adjuvant therapy. The risk factors for recurrence in patients who had not undergone adjuvant therapy were a serum carcinoembryonic antigen (CEA) level that was twice the cut-off value and pre-operative bowel obstruction. Adjuvant therapy provided no benefit to patients who presented with neither risk factor, but significantly decreased the recurrence rate in patients presenting with one or both risk factors. Based on these findings, serum CEA levels of twice the cut-off value and pre-operative bowel obstruction were proposed as indicators in the assessment for adjuvant chemotherapy following a curative resection for stage II colon cancer. These results warrant further clinical study of ACT in patients with one or both risk factors.

Evaluation of Camellia sinensis catechins as a swine antimicrobial feed additive that does not cause antibiotic resistance.

Antimicrobial growth promoters (AGPs) have been banned and phased out because their use has been linked to the emergence and spread of antibiotic-resistant pathogens; however, the ban has had a marked impact on livestock production, and feed additive alternatives to AGPs are required. We focused on green tea leaves as potential alternatives to AGPs because they contain significant amounts of polyphenol catechins, which have antivirus and antimicrobial effects. We examined cross-resistance between epigallocatechin gallate (EGCG), which is the most abundant catechin of green tea leaves, and commercially available antimicrobials in clinically problematic antimicrobial-resistant bacteria, and whether bacteria have the ability to acquire resistance by consecutive passage in sub-inhibitory concentrations of EGCG. EGCG did not display any cross-resistance with reference antimicrobials and the bacteria did not acquire EGCG resistance. Further, we examined the growth-promoting effects of dried green tea leaves on the breeding of a new Japanese breed, Tokyo-X pigs. While the mortality rates of the green tea leaf (GTL) and AGP groups were both 11.1% (one in nine piglets), the mortality rate was 50% for the control group with an additive-free diet (four in eight piglets). The rate of body weight increase in both the GTL and AGP groups was approximately the same. The growth-promoting effects of green tea leaves and AGPs were similar, and there was no possibility that the antimicrobial properties of catechins caused the same problem as AGPs. Thus, it can be concluded that green tea leaves are a safe feed additive alternative to AGPs.

Increased claudin-1 protein expression in hepatic metastatic lesions of colorectal cancer.

BACKGROUND: The molecular and morphological alterations of the tight junctions in hepatic metastatic lesions are poorly understood. The possible involvement of claudin-1 (CL-1), which is one of the major tight junctional proteins, was investigated in the tumorigenesis of hepatic metastasis in patients with colorectal cancer (CRC). PATIENTS AND METHODS: A total of 14 patients with hepatic metastasis of CRC who underwent surgical treatment from January 2007 until December 2010 at the Kurume University Hospital in Fukuoka, were examined. CRC tissue specimens were analyzed to determine whether the levels of CL-1 correlated with clinicopathological factors and to determine the roles of CL-1, ß-catenin, and E-cadherin in the alterations of the tight junctions during tumorigenesis. RESULTS: In seven cases, the tumors were located in the colon, while the other seven tumors were found in the rectum. There were eight cases of synchronous liver metastasis, while there were six cases of metachronous liver metastasis. The levels of the CL-1 protein were up-regulated in CRC and in hepatic metastatic lesions. The levels of ß-catenin were positive or up-regulated in the primary CRC lesions and in hepatic metastatic lesions. Despite the finding that the levels of E-cadherin were decreased in CRC, they were clearly up-regulated in hepatic metastatic lesions in this study. CONCLUSION: This study demonstrated that CL-1 levels were up-regulated in liver metastatic lesions from primary CRC lesions. Moreover, the levels of E-cadherin were increased in liver metastatic lesions, which may point to the existence of interactions between CL-1 and E-cadherin in hepatic metastatic lesions. These observations suggest that CL-1 plays a pivotal role in the regulation of cellular morphology and in the behavior of metastatic processes in CRC.

Amphiregulin is a prognostic factor in colorectal cancer.

Amphiregulin is an epidermal growth factor (EGF) which is a ligand of epidermal growth factor receptor (EGFR). Amphiregulin is the most enhanced EGFR ligand in colon cancer. Here we report on the expression of Amphiregulin using immunohistochemical staining in primary colorectal cancer, and the correlations between prognosis and various clinicopathological factors. We examined 174 consecutive patients who underwent curative resection of colorectal cancer, from January 2002 to December 2004. Amphiregulin was positive in 156 (90%) patients. Amphiregulin was found to be an independent predictor of overall survival [hazard ratio=6.25 (95% confidence interval=1.3-111.5; p=0.0144)] and relapse-free survival [hazard ratio=6.94 (95% confidence interval=1.5-123.2; p=0.0075)]. We conclude that the expression of Amphiregulin in a primary colorectal tumor is useful as an indicator of prognosis and as a predictor of recurrence.

A peptide based on homologous sequences of the ß-barrel assembly machinery component BamD potentiates antibiotic susceptibility of Pseudomonas aeruginosa.

OBJECTIVES: The ß-barrel assembly machinery (BAM) complex plays a critical role in outer membrane protein (OMP) biogenesis. The outer membrane (OM) of Pseudomonas aeruginosa is centrally involved in mechanisms of antibiotic resistance. This study aimed to identify effects of a synthetic peptide based on conserved sequences in the putative BamA-binding region of BamD, focusing on antibiotic susceptibility and OMP characteristics in P. aeruginosa. METHODS: We synthesized a peptide FIRL (Phe-Ile-Arg-Leu-CONH(2)) with a sequence related to that of the BamD protein. We assessed antibiotic susceptibility of P. aeruginosa PAO1 using the chequerboard method and a time-kill assay. Changes in OMPs and in OM permeability were examined using SDS-PAGE, western blot analysis and nitrocefin assays. The combined effects of the peptide and antibiotics were investigated using a mouse pneumonia model. RESULTS: Although the peptide alone exerted no antimicrobial effect, it reduced the MICs of colistin, levofloxacin, erythromycin, vancomycin and rifampicin for P. aeruginosa PAO1 by 4-fold or more. Time-kill tests revealed bacterial numbers were significantly reduced after 2 h of incubation with the peptide plus colistin or levofloxacin. Moreover, in the presence of the peptide, expression of OprM was reduced by a third, and OM permeability was increased. The combination of the peptide (2.08 mg/kg) and colistin (1.25 mg/kg) significantly reduced P. aeruginosa by more than 1 log cfu/mL in a mouse pneumonia model. CONCLUSIONS: We show, for the first time, that a synthetic peptide based on homologous sequences of BamD can potentiate antibiotic susceptibility of P. aeruginosa.

Virulence-suppressing effects of linezolid on methicillin-resistant Staphylococcus aureus: possible contribution to early defervescence.

In the present study, immunomodulatory effects of linezolid (LZD) on methicillin-resistance Staphylococcus aureus (MRSA) infections were evaluated. We have retrospectively reviewed treatment effects of LZD on 52 patients with severe MRSA infections. Sixty-four percent of the febrile patients demonstrated significant defervescence within 3 days, despite the presence of positive culture results. We speculated that this finding might be due to early anti-inflammatory effects of LZD, and to investigate this further we initiated in vivo experiments using mice MRSA pneumonia models. Mice were treated with either LZD or vancomycin (VCM) immediately after intranasal administration of MRSA. Bacterial numbers and levels of inflammatory cytokines in the lungs were determined. Although the bacterial burden in the lungs was not apparently different between the two groups, LZD but not VCM treatment significantly reduced induction of inflammatory cytokines in the lungs (P < 0.05). To evaluate whether this anti-inflammatory response was due to suppression of virulence factor expression, filter-sterilized supernatants of MRSA incubated in broth overnight with sub-MICs of LZD were subcutaneously administered to mice. To clarify whether LZD possesses direct host-modulating activity, cytokine responses to the supernatants were examined in mice pretreated with LZD. Interestingly, MRSA solutions prepared in the presence of sub-MICs of LZD revealed significant suppression of interleukin 6 (IL-6) in a dose-dependent manner (P < 0.05), but pretreatment of mice with LZD revealed no changes in cytokines. These findings suggest that sub-MICs of LZD might suppress virulence factors of MRSA, which may be associated with a reduction in endogenous pyrogens. These data may explain at least in part early defervescence observed in LZD-treated individuals.

Roles of interleukin-17 in an experimental Legionella pneumophila pneumonia model.

Interleukin-17 (IL-17) is a key factor in T helper type 17 (Th17) lineage host responses and plays critical roles in immunological control of a variety of infectious diseases. Although Legionella pneumophila, an intracellular bacterium found widely in the environment, often causes a serious and life-threatening pneumonia in humans, the contribution of IL-17 to immune function during Legionella pneumonia is unknown. In the present study, we used an experimental Legionella pneumonia infection to clarify the role of IL-17 in the resulting immune response. We observed robust production of pulmonary IL-17A and IL-17F (IL-17A/F), peaking on day 1 and declining thereafter. Upregulated production of tumor necrosis factor alpha (TNF-α), IL-6, and IL-1ß, but not monocyte chemotactic protein 1 (MCP-1), was observed in Legionella-infected bone marrow-derived macrophages from BALB/c mice that had been stimulated with IL-17A or IL-17F. A significant decrease in the production of proinflammatory cytokines IL-6 and TNF-α was observed in IL-17A/F-deficient mice (BALB/c background) infected with L. pneumophila. Moreover, we found impaired neutrophil migration and lower numbers of chemokines (KC, LIX, and MIP-2) in IL-17A/F-deficient mice. IL-17A/F-deficient mice also eliminated L. pneumophila more slowly and were less likely to survive a lethal challenge. These results demonstrate that IL-17A/F plays a critical role in L. pneumophila pneumonia, probably through induction of proinflammatory cytokines and accumulation of neutrophils at the infection site.

In vitro and in vivo antibacterial activity of modithromycin against streptococci and Haemophilus influenzae.

OBJECTIVES: In vitro and in vivo antibacterial activities of modithromycin against Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae were examined. METHODS: MICs were determined by the broth microdilution method. Experimental infection of epithelial cell line A549 was performed to compare the intracellular activity and lasting effects of the antimicrobial agents. To evaluate in vivo efficacy, the rat pulmonary infection model was used. RESULTS: Modithromycin had MICs of ≤ 1 mg/L against all the clinical strains of both streptococci, including erythromycin-resistant strains. In particular, the MICs of modithromycin for erm(B)- or mef(A)-carrying S. pyogenes were 16-32 times or 2-4 times lower than those of telithromycin, respectively. The MIC(90) of modithromycin for H. influenzae was 8 mg/L, which was 4 times higher than that of telithromycin. Modithromycin, as well as azithromycin, showed a lasting inhibitory effect on bacterial growth of cell-associated H. influenzae compared with telithromycin and levofloxacin after removal of the agents from the apical medium. In the pulmonary infection model, modithromycin showed greater or comparable efficacy against erm(B)-carrying S. pneumoniae and H. influenzae, respectively, than telithromycin, regardless of having an MIC that was 2 or 4 times higher for these strains. CONCLUSIONS: Modithromycin has the most potent anti-S. pyogenes activity of the antimicrobial agents tested. Modithromycin also has the better in vivo efficacy against S. pneumoniae and H. influenzae, which might be due to its lasting intracellular activity.

[Treatment and outcome in small bowel cancer].

In adenocarcinoma of the small intestine, delays in diagnosis are frequent, and the majority of patients present with advanced- stage disease and either lymph node involvement or distant metastatic disease. Surgical resection is a mainstay in treatment of this disease, but the role of adjuvant therapy is unclear. Recent retrospective and prospective studies have helped to clarify the optimal chemotherapy approach for advanced small bowel adenocarcinoma. The combination of capecitabine and oxaliplatin is reportedly highly effective. Further clinical studies on this rare type of tumor are needed. This article reviews the focuses on recent advances in management. The 72nd Japanese Society for Cancer of the Colon and Rectum have conducted a retrospective review of Japanese patients with adenocarcinoma of the jejunum or ileum. The data indicated that although not statistically significant, there was a trend in median overall survival favoring the chemotherapy for advanced jejunal or ileal adenocarcinoma (17 months vs. 8 months, p=0.114).

Sequential changes of Legionella antigens and bacterial load in the lungs and urines of a mouse model of pneumonia.

Legionella pneumophila is an important cause of community- and hospital-acquired pneumonia. In spite of the introduction of the urinary antigen detection method, Legionella pneumonia may be still underdiagnosed. We performed kinetic and quantitative analysis of diagnostic markers, such as bacterial loads, DNA assays, and antigen titers, in a 28-day time course murine model of L. pneumophila pneumonia. L. pneumophila replicated approximately 100-fold in the lungs of A/J mice in the first 48 h, and then became undetectable on day 14. Unexpectedly, pathogens other than L. pneumophila were consistently recovered from the lungs and livers at the acute phases, although those numbers were far below Legionella loads in the lungs. The peaks of specific antigen titer were observed on 48 h in the lungs, bronchoalveolar lavage (BAL) fluids, and urines and sustained positive even at 28 days after the infection. Especially, the lung homogenates and BAL fluids demonstrated 16 to 64 times higher levels of antigen titer than the urines by the end of observation. Legionella-specific DNA in the lungs was detected by polymerase chain reaction and loop-mediated isothermal amplification methods until 7 and 14 days after the infection, respectively. The inflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, interleukin 6, and MIP-2, exhibited a peak on the acute phase, whereas the maximal production of high mobility group box 1 in the serum was observed on day 7. These results characterized the kinetic nature of diagnostic markers in L. pneumophila pneumonia. The present data suggested prolonged and compartmentalized deposition of antigen in the lungs, which may have an impact on the diagnosis of L. pneumophila pneumonia, especially in missed cases even after recovery from disease.

[Therapeutic results of hepatic resection using thermal ablation for unresectable colorectal liver metastases].

We have retrospectively reviewed the therapeutic results of hepatic resection with or without thermal ablation therapy (TA) for colorectal liver metastases in 138 patients between 1994 and 2006. A total of 88 unresectable liver metastatic lesions were selectively treated with TA as initial treatment (42 patients) basically in combination with hepatectomy. Overall, TA achieved a high local tumor control rate of 94.3%. Multivariate analysis revealed that initial TA therapy was not a significantly predictive factor of hepatic recurrence or any recurrence. TA therapies in combination with hepatectomy may offer improving resectability without risk to intrahepatic dissemination or to extrahepatic recurrence.

Interleukin-1 deficiency in combination with macrophage depletion increases susceptibility to Pseudomonas aeruginosa bacteremia.

We evaluated the role of IL-1 during Pseudomonas aeruginosa bacteremia by intravenously injecting P. aeruginosa strain D4 into IL-1-deficient and WT mice. The two strains showed equivalent mortality rates. However, when the mice were pretreated with cyclophosphamide, bacteremia-induced mortality was significantly greater in the IL-1-deficient mice than in the WT mice (P < 0.01). We then investigated the role of neutrophils and macrophages in protecting IL-1-deficient mice from bacteremia by administering anti-Gr-1 antibody or liposomes containing dichloromethylene diphosphonate, respectively. After P. aeruginosa inoculation survival was significantly lower in the macrophage-depleted IL-1-deficient mice than in the WT mice. In contrast, neutrophil depletion did not have this effect. Compared to the macrophage-depleted WT mice, the macrophage-depleted IL-1-deficient bacteremic mice had higher bacterial counts in various organs 48 and 72 hr post-infection. They also had lower TNF-alpha, IL-6, and INF-gamma concentrations in their livers during the early phase of sepsis. Thus, IL-1 deficiency becomes disadvantageous during P. aeruginosa bacteremia when it is accompanied by immunosuppression, particularly when macrophage functions are seriously impaired.

[Novel model of replicative Legionella pneumophila lung infection in DBA/2 mice].

We present here a new model of Legionella pneumophila lung infection in DBA/2 mice. By intranasal inoculation with 106 colony-forming units of L. pneumophila strain suzuki serogoup 1, persistent non-lethal lung infection was established as reflected by the detection of more than 10(4) CFU/lung of the organism 14 days after infection. Treatment of mice with cyclophosphamide before infection enhanced bacterial replication in the lungs and all cyclophosphamide-treated mice experienced lethal infection. Histopathologically, the course of non-lethal lung infection was characterized by early response of neutrophiles, then monocyte/macrophages response in the alveoli with disease progression, and diffuse alveolar wall thickening with lymphocyte migration at later phase of infection. Transmission electron microscopic evaluation of the lungs confirmed that L. pneumophila located intracellularly within neutrophiles and infrequently intracellular bacteria were observed undergoing binary fission. Therefore, the mouse model of replicative L. pneumophila lung infection provides method for evaluating pathogenesis of L. pneumophila lung infection and antibacterial therapy.

Suppression of Pseudomonas aeruginosa quorum-sensing systems by macrolides: a promising strategy or an oriental mystery?

A breakthrough in antibiotic chemotherapy for patients with chronic Pseudomonas aeruginosa pulmonary infections was brought about by findings in a patient with diffuse panbronchiolitis (DPB), who had been treated with erythromycin over a period of years. Recent clinical trials have demonstrated that long-term macrolide therapy can be used not only for DPB patients but also for those with other chronic infections, including patients with cystic fibrosis (CF). The pathogenesis of chronic P. aeruginosa infection is considered to arise from a bacterial cell-to-cell signaling mechanism, named "quorum-sensing", which enables the bacteria to coordinately turn on and off their virulence genes through the production of autoinducer molecules. Accumulating evidence from clinical and basic science fields suggests the potential of macrolides as Pseudomonas quorum-sensing inhibitors. In this review, we briefly summarize the data on the clinical efficacy of macrolides in DPB and CF patients. Then we discuss the mechanisms of action of macrolides from the viewpoint of sub-minimum inhibitory concentration (sub-MIC) macrolide effects on P. aeruginosa, particularly the potential activity of this antibiotic to suppress the bacterial quorum-sensing system.

Multicenter study to evaluate bloodstream infection by Helicobacter cinaedi in Japan.

Helicobacter cinaedi has being recognized as an important human pathogen which causes bloodstream infections. Although the first case of bacteremia with this pathogen in Japan was reported in 2003, the true prevalence of H. cinaedi as a pathogen of bloodstream infections in this country is not yet known. Therefore, the aim of our study was to assess the incidence of bacteremia with H. cinaedi in Japan. We conducted a prospective, multicenter analysis in 13 hospitals during 6 months in Tokyo, Japan. Among positive blood cultures from 1 October 2003 to 31 March 2004, isolates suspected of being Helicobacter species were studied for further microbial identification. Identification of the organisms was based on their biochemical traits and the results of molecular analysis of their 16S rRNA gene sequences. A total of 16,743 blood culture samples were obtained during the study period, and 2,718 samples (17.7%) yielded positive culture results for coagulase-negative staphylococci. Among nine isolates suspected to be Helicobacter species, six isolates were finally identified as H. cinaedi. The positivity rate for H. cinaedi in blood culture was 0.06% of total blood samples and 0.22% of blood samples with any positive culture results. All patients with bacteremia with H. cinaedi were found to have no human immunodeficiency virus (HIV) infection, but many of them had complications with either malignancy, renal failure, or a history of surgical operation. Therefore, our results suggest that bacteremia with H. cinaedi is rare but can occur in compromised hosts other than those with HIV infection in Japan.

Role of Toll-like receptor 2 in recognition of Legionella pneumophila in a murine pneumonia model.

Legionella pneumophila is an intracellular organism and the major aetiological agent of Legionnaires' disease. Although recent progress has identified Toll-like receptors (TLRs) as receptors for recognition of pathogen-associated molecular patterns in a variety of micro-organisms, understanding the contribution of TLRs to the host response in L. pneumophila infection is still limited. This study examined the roles of TLR2 and TLR4 in murine L. pneumophila pneumonia and an in vitro infection model using bone-marrow-derived macrophages. TLR2-deficient mice, but not TLR4-deficient mice, demonstrated higher lethal sensitivity to pulmonary challenge with L. pneumophila than wild-type mice (P<0.05). Although no differences in pulmonary bacterial burden were observed among the mouse strains examined, lower values of macrophage inflammatory protein-2 (MIP-2), keratinocyte-derived cytokine and interleukin (IL)-6 and higher IL-12 levels were noted in lung homogenates of TLR2-deficient mice compared with the wild-type control and TLR4-deficient mice. Recruitment of inflammatory cells, particularly neutrophils, was severely disturbed in the lungs of TLR2-deficient mice. Reduced MIP-2 production was demonstrated in bone-marrow-derived macrophages from TLR2-deficient mice in response to live L. pneumophila and purified LPS of this strain, but not Escherichia coli LPS. These data highlight the involvement and importance of TLR2 in the pathogenesis of L. pneumophila pneumonia in mice. The results showed that TLR2-mediated recognition of Legionella LPS and subsequent chemokine-dependent cellular recruitment may be a crucial host innate response in L. pneumophila pneumonia.