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Legionella pneumophila is a major causative pathogen of community-acquired pneumonia (CAP), but recently the novel coronavirus disease 2019 (COVID-19) became the most common causative pathogen of CAP. Because L. pneumophila CAP is clinically distinct from bacterial CAPs, the Japan Society for Chemotherapy (JSC) developed a simple scoring system, the Legionella Score, using six parameters for the presumptive diagnosis of L. pneumophila pneumonia. We investigated the clinical and laboratory differences of L. pneumophila CAP and COVID-19 CAP and validated the Legionella Score in both CAP groups. We analyzed 102 patients with L. pneumophila CAP and 956 patients with COVID-19 CAP. Dyspnea and psychiatric symptoms were more frequently observed and cough was less frequently observed in patients with L. pneumophila CAP than those with COVID-19 CAP. Loss of taste and anosmia were observed in patients with COVID-19 CAP but not observed in those with L. pneumophila CAP. C-reactive protein and lactate dehydrogenase levels in L. pneumophila CAP group were significantly higher than in the COVID-19 CAP group. In contrast, sodium level in the L. pneumophila CAP group was significantly lower than in the COVID-19 CAP group. The median Legionella Score was significantly higher in the L. pneumophila CAP group than the COVID-19 CAP group (score 4 vs 2, p < 0.001). Our results demonstrated that the JSC Legionella Score had good diagnostic ability during the COVID-19 pandemic. However, physicians should consider COVID-19 CAP when loss of taste and/or anosmia are observed regardless of the Legionella Score., (Copyright © 2022 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: The aim of this study was to evaluate the diagnostic utility of a novel test kit that could theoretically detect all serogroups of Legionella pneumophila for diagnosing Legionella pneumonia, in comparison with existing kits., Methods: This study was conducted in 16 hospitals in Japan from April 2016 to December 2018. Three urinary antigen test kits were used: the novel kit (LAC-116), BinaxNOW Legionella (Binax), and Q-line Kyokutou Legionella (Q-line). In addition, sputum culture and nucleic acid detection tests and serum antibody tests were performed where possible. The diagnostic accuracy and correlations of the novel kit with the two existing kits were analyzed., Results: In total, 56 patients were diagnosed with Legionella pneumonia. The sensitivities of LAC-116, Binax, and Q-line were 79%, 84%, and 71%, respectively. The overall match rate between LAC-116 and Binax was 96.8% and between LAC-116 and Q-line was 96.4%. One patient had L. pneumophila serogroup 2, and only LAC-116 showed a positive result, whereas Binax and Q-line did not., Conclusions: The novel Legionella urinary antigen test kit was useful for diagnosing Legionella pneumonia. In addition, it could detect Legionella pneumonia caused by non-L. pneumophila serogroup 1., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Community-acquired pneumonia (CAP) due to Legionella has a high mortality rate in patients who do not receive adequate antibiotic therapy. In a previous study, we developed a simple Legionella Score to distinguish patients with Legionella and non-Legionella pneumonia based on clinical information at diagnosis. In the present study, we validated this Legionella Score for the presumptive diagnosis of Legionella CAP., Methods: This validation cohort included 109 patients with Legionella CAP and 683 patients with non-Legionella CAP. The Legionella Score includes six parameters by assigning one point for each of the following items: being male, absence of cough, dyspnea, C-reactive protein (CRP) ≥ 18 mg/dL, lactate dehydrogenase (LDH) ≥ 260 U/L, and sodium < 134 mmol/L., Results: When the Legionella CAP and non-Legionella CAP were compared by univariate analysis, most of the evaluated symptoms and laboratory test results differed substantially. The six parameters that were used for the Legionella Score also indicated clear differences between the Legionella and non-Legionella CAP. All Legionella patients had a score of 2 points or higher. The median Legionella Scores were 4 in the Legionella CAP cases and 2 in the non-Legionella CAP cases. A receiver operating characteristics curve showed that the area under the curve was 0.93. The proposed best cutoff, total score ≥3, had sensitivity of 93% and specificity of 75%., Conclusion: Our Legionella Score was shown to have good diagnostic ability with a positive likelihood of 3.7 and a negative likelihood of 0.10., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

To evaluate scoring systems to predict Legionella pneumonia and therapeutic efficacy against Legionella pneumonia, the Japanese Society of Chemotherapy Legionella committee has collected data on cases of Legionella pneumonia from throughout Japan. We analyzed 176 patients with Legionella pneumonia and compared them with 217 patients with Streptococcus pneumoniae pneumonia and 202 patients with Mycoplasma pneumoniae pneumonia. We evaluated four scoring systems, the Winthrop-University Hospital score, Community-Based Pneumonia Incidence Study Group score, and Japan Respiratory Society score, but they demonstrated limited sensitivity and specificity for predicting Legionella pneumonia. Using six clinical and laboratory parameters (high fever, high C-reactive protein, high lactate dehydrogenase, thrombocytopenia, hyponatremia, and unproductive cough) reported by Fiumefreddo and colleagues, only 6% had Legionnella pneumonia when less than 2 parameters were present. The efficacy rates of antibiotics at the time of termination were 94.6% for intravenous antibiotics, including ciprofloxacin and pazufloxacin, and 95.5% for oral antibiotics, including ciprofloxacin, levofloxacin, garenoxacin, moxifloxacin, and clarithromycin. Our results suggested that the previously reported clinical scoring systems to predict Legionnella pneumonia are not useful, but 6 simple diagnostic score accurately ruled out Legionnella pneumonia, which may help to optimize initial empiric therapy. Quinolones and clarithromycin still showed good clinical efficacy against Legionella pneumonia., (Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Interleukin (IL)-17A affects the immune system of the lung. Legionella infection can potentially lead to severe pneumonia. The present study aimed to evaluate the role of IL-17A in Legionella pneumonia. Serum IL-17A levels were quantified in both patients with Legionella pneumonia and control subjects; IL-17 was detected in sera from 4 out of 31 patients with Legionella pneumonia but in any controls. There were no differences in peripheral white blood cell counts or other serum biomarkers (C-reactive protein, and lactate dehydrogenase) between IL-17A-positive and IL-17A-negative patients. All IL-17A-positive patients in this cohort survived, where 8 of 27 IL-17A-negative patients did not. IL-17A was detected in available bronchoalveolar (BA) fluid samples from 7 patients with Legionella pneumonia within our cohort. However, the IL-17A and IFN-γ concentrations in BA fluids did not correlate with each other. IL-17A might play a significant role in some cases of Legionella pneumonia.

High mobility group box 1 (HMGB-1) protein is involved in acute lung injury due to various etiologies. We evaluated HMGB-1 levels in sera and bronchoalveolar fluids in patients with pneumonia caused by Legionella pneumophila. Levels of HMGB-1 in the sera of patients with L. pneumophila pneumonia (32 cases) and control subjects (24 cases) were determined. Serum HMGB-1 levels in Legionella pneumonia were similar to those of the control subjects. No significant correlation between HMGB-1 levels and other biomarkers and the outcome of cases was observed. In contrast, HMGB-1 levels, as well as interferon-γ, in bronchoalveolar (BA) fluids from severe L. pneumophila pneumonia (7 cases) were significantly higher than those in the sera of identical patients. HMGB-1 levels in BA fluids were relatively higher in pneumonia cases with ALI than those without ALI. Our findings suggest that intra-pulmonary HMGB-1 may be involved in the pathophysiology of pneumonia caused by L. pneumophila., (Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The virulence factor known as the macrophage infectivity potentiator (mip) is responsible for the intracellular survival of Legionella species. In this study, we investigated the potential of the mip gene sequence to differentiate isolates of different species of Legionella and different serogroups of Legionella pneumophila. We used 35 clinical L. pneumophila isolates and one clinical isolate each of Legionella micdadei, Legionella longbeachae, and Legionella dumoffii (collected from hospitals all over Japan between 1980 and 2007). We used 19 environmental Legionella anisa isolates (collected in the Okinawa, Nara, Osaka, and Hyogo prefectures between 1987 and 2007) and two Legionella type strains. We extracted bacterial genomic DNA and amplified out the mip gene by PCR. PCR products were purified by agarose gel electrophoresis and the mip gene was then sequenced. The L. pneumophila isolates could be divided into two groups: one group was very similar to the type strain and was composed of serogroup (SG) 1 isolates only; the second group had more sequence variations and was composed of SG1 isolates as well as SG2, SG3, SG5, and SG10 isolates. Phylogenetic analysis displayed one cluster for L. anisa isolates, while other Legionella species were present at discrete levels. Our findings show that mip gene sequencing is an effective technique for differentiating L. pneumophila strains from other Legionella species.

For prevention of nosocomial legionellosis, environmental investigation to identify possible infectious sources is essential. An environmental study in a ward of our hospital revealed that a steam towel warmer was contaminated with legionella whereas no legionella was detected in tap water supplies and shower heads. Water in the apparatus may be a reservoir of legionella. We abandoned the use of all steam towel warmers in our hospital. Based on this finding, we recommend that steam towel warmers in hospital settings be avoided. Otherwise, the apparatus should be drained, cleaned and dried every day., (Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

The main aim of this study was to describe the appearance of the CT pattern of organizing pneumonia in Legionella-infected patients. Serial CT scans obtained from five sporadic cases of Legionella pneumophila pneumonia were retrospectively reviewed. The mean time of follow-up was 14 days. Chest CT was analyzed with regard to frequency and appearance of CT patterns of pulmonary abnormalities. Consolidation and ground-glass opacities, with or without an air bronchogram, were the most common abnormalities detected in CT scans during follow-up patients with L. pneumophila pneumonia. Two patterns were observed: subpleural and peribronchovascular. The subpleural pattern was seen in four patients and the peribronchovascular pattern in one. Interlobular septal thickening was seen in one patient. Pleural effusion was seen in one patient. The CT pattern of organizing pneumonia, a subpleural pattern, was frequently observed after treatment of L. pneumophila pneumonia.

Background: Hepatocyte growth factor (HGF) is known to be involved in the resolution of pulmonary inflammation and repair of acute lung injury. Legionella pneumonia is sometimes complicated by acute lung injury. Our study aimed to determine the role of serum HGF levels in Legionella pneumonia., Methods: Sera from patients with Legionella pneumonia (42 cases), other bacterial pneumonia (33 cases), pulmonary tuberculosis (19 cases), and normal controls (29 cases) were collected. The serum HGF levels for each serum sample were determined by sandwich ELISA. Clinical and laboratory data were collected by reviewing the medical charts., Results: Serum HGF levels were higher in patients with Legionella pneumonia than in those with other bacterial pneumonia, pulmonary tuberculosis, and controls. The HGF levels were compared with white blood cell counts, C-reactive protein, Alanine amino-transferase, and lactate dehydrogenase (LDH). The HGF levels were correlated to serum LDH levels. Moreover, serum HGF levels were significantly higher in non-survivors than in survivors., Conclusions: HGF levels increased in severer pneumonia caused by Legionella, suggesting that HGF might play a significant role in the Legionella pneumonia.

Genotyping of Legionella strains is important for the epidemiologic survey of Legionnaires' disease infections. In this study, we investigated the potential of repetitive element-polymerase chain reaction (rep-PCR) for differentiating various isolates of Legionella spp. We used 38 Legionella pneumophila isolates (collected in clinics all over Japan between 1980 and 2007), 19 environmental Legionella anisa isolates (collected in Okinawa, Nara, Osaka, and Hyogo prefecture between 1987 and 2007), and 2 Legionella-type strains. We extracted bacterial genomic DNA and applied it to rep-PCR. PCR products were then converted into bands by agarose gel electrophoresis. The L. pneumophila serogroup (SG) 1 displayed very diverse patterns. Different bands were produced for each species of Legionella, and each species was clearly distinct. Phylogenetic analysis displayed 1 cluster of L. anisa isolates, while other Legionella spp. were present at discrete levels. Our findings show that rep-PCR is an effective, rapid, and simple technique for differentiation of L. pneumophila strains as well as Legionella spp.

Objective: To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia., Methods: CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia., Results: Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n=20) and segmental (n=4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli., Conclusion: Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

Legionella pneumonia typically presents as lobar pneumonia with multiple-lobe involvement, but Legionella lung abscess is rare. To identify the predisposing factors for Legionella abscess, we analyzed 62 of the 79 case reports on Legionella abscess found in literature; 28 (45.2%) were of hospital-acquired infection and 28 (45.2%), community-acquired infection. Seventeen patients (27.4%) died. L. pneumophila serogroup 1 was the most common, but other serogroups of L. pneumophila, L. micdadei, L. bozemanii, L. dumoffii, and L. maceachernii were also isolated from the abscess. Corticosteroids were administered for underlying diseases to 43 (69.4%) patients. Peripheral neutrophil counts were higher in patients with abscess than in those with only pulmonary infiltration. In certain cases, Legionella abscess developed during neutropenia recovery. However, lymphocyte counts were low in most cases. Clinical factors like corticosteroid treatment, which causes impaired cellular immunity and subsequent neutrophil accumulation in the lesion, might function as predisposing factors for Legionella abscess.

The isolation rate of Legionella pneumophila serogroup 2 from clinical samples is low. In 2007, we encountered the second case known to occur in Japan. As the L. pneumophila serogroup 2 type strain, the Kobe strain isolated in 1988, and the Okinawa strain isolated from the present patient could not be differentiated using the usual biochemical and serological tests, we tried to achieve differentiation by observing colony morphology. In Oxoid BCYEalpha medium, colonies of the Kobe strain developed multiple protuberances on the surface, but these did not develop on the other two strains. In Becton-Dickinson BCYEalpha medium, colonies of the Okinawa strain had several outgrowths from the margin, but the type strain and the Kobe strain did not have any outgrowths. The Okinawa strain isolated from the present case showed intermediate characteristics between the type strain and the Kobe strain in the appearance of colony morphology. It may be useful to conduct an investigation of this rare serogroup.

The immunochromatographic membrane test (ICT) efficacy of Legionella antigen detection (Binax Now Legionella) was evaluated using respiratory samples, including bronchial washings (44 cases) and sputum (128 cases), from suspected Legionella pneumonia patients. The ICT results using respiratory samples agreed well with isolation of L. pneumophila SG1 and ICT using urines.

Fifteen cases of legionella pneumonia experienced in our department or associated hospital were included in this study. Each case was classified with the A-DROP system of the Japanese Respiratory Society Guidelines, and guidelines from the Infectious Diseases Society of America (IDSA) (1998) and then we compared the severity of the cases of pneumonia. Although 10 cases were classified as intermediate, 3 as severe, and 2 as extremely severe with the A-DROP system, most cases were classified as severe according to the IDSA guidelines. Among 5 fatal cases, three were ranked as intermediate with the A-DROP system. However all the fatal cases were ranked as severe in the IDSA guidelines. This study suggested that the A-DROP system might underestimate the severity of pneumonia in cases with legionella pneumonia.

A 56-year-old man with a 3-day history of a chilly sensation and general fatigue presented to a hospital in his neighborhood. He was diagnosed as having pneumonia and immediately treated with intravenous ceftriaxone sodium, but his respiratory condition deteriorated and he developed symptoms of restlessness. Although Legionella urinary antigen detection tests were negative, his clinical course suggested Legionella pneumonia. After his treatment was changed to intravenous ciprofloxacin and oral clarithromycin, his general condition gradually improved. Later, Legionella pneumophila serogroup 2 was isolated from a bronchoalveolar lavage specimen. This was considered to be the causative organism. In our literature search, this was only the second case of Legionella pneumonia caused by Legionella pneumophila serogroup 2 in Japan.

The advantages of diagnosing legionellosis by urinary antigen detection are widely recognized, and include early detection, rapidity of testing, and ease of specimen collection. However, the persistence of Legionella urinary antigen excretion has been suggested in some selected patients, although the clinical features of these patients have not yet been clearly described. Here, we describe the clinical features of two patients with Legionnaires' disease with persistence of Legionella urinary antigen excretion (117 days and 247 days). One patient had an underlying disease, adult T-cell leukemia, and the other patient had ulcerative colitis and was receiving oral corticosteroids. Unusual clinical and radiological findings as well as a review of the literature are presented.

Background: Erythromycin (EM) and rifampicin (RFP) have mainly been used to treat patients with Legionella pneumonia. Since intravenous ciprofloxacin (CPFX) became available in Japan from 2000, many reports have been published detailing successful treatment of Legionella pneumonia with CPFX. In this study, we compared the evolution of patients with Legionella pneumonia treated with CPFX to those treated with EM., Methods: The study included nine patients treated with CPFX and eighteen patients treated with EM. Diagnosis of these patients was made by culture, PCR, urinary antigen assay or a serological method. A comparison was made of the patients' characteristics, severity of pneumonia, efficacy of each agent and the clinical course., Results: No significant differences were observed between the two groups, in regard to age, gender, underlying disease or severity of pneumonia. In addition, the period of time from onset of the disease until appropriate therapy did not differ significantly between the two groups. In the CPFX group, all of the patients were cured and in the EM group 16 out of the 18 patients were cured. Although there were no significant differences, the time to apyrexia, normalization of leukocytosis and a 50% decrease in C-reactive protein (CRP) occurred within a relatively shorter time frame in the CPFX group than in the EM group (3.5 versus 4 days, 4 versus 5.2 days, and 2.9 versus 10.3 days, respectively). And, the duration of antibiotic treatment in the CPFX group was significantly shorter than in the EM group., Conclusion: CPFX was as effective as erythromycin in the treatment of Legionella pneumonia. The effects of treatment may appear relatively earlier and the duration of treatment was significantly shorter in patients treated with CPFX therapy than with EM therapy.

It has been said that the color of sputum from patients with Legionella pneumophila pneumonia is orange. However, why the color is orange has not been clarified. First, orange-colored sputum obtained from a patient with L. pneumophila pneumonia is presented. Then, the formation of an orange-colored pigment in a culture medium (without charcoal) after the growth of L. pneumophila is demonstrated.

We report here a case of culture-proven Legionnaires' disease successfully treated with intravenous injection of pazufloxacin mesilate (PZFX), a fluoroquinolone newly approved in Japan. The patient was a 51-year-old man hospitalized after a diagnosis of community-acquired pneumonia. Legionella pneumophila SG1 was isolated from the patient's bronchoalveolar lavage (BAL) fluid, and the soluble antigen of the bacterium was detected in the fluid as well. Subsequently, intravenous PZFX was administered for a week and proved markedly effective. An in vitro study confirmed that PZFX had excellent extracellular and intracellular activity against the isolate from the patient. This case suggests that PZFX is an option for treating Legionnaires' disease.

The activity of the fluoroquinolone olamufloxacin (HSR-903) against Legionella spp. was studied in vitro and in vivo. The olamufloxacin MIC at which 50% of isolates are inhibited (MIC50) for 81 different Legionella spp. strains (59 type strains and 22 clinical isolates) was 0.008 mg/L, which was identical to sparfloxacin, whereas the MIC50s for erythromycin, levofloxacin and ciprofloxacin were 0.25, 0.032 and 0.032 mg/L, respectively. Olamufloxacin and sparfloxacin (at 0.008 mg/L) inhibited intracellular growth and subsequent cytotoxicity of L. pneumophila 80-045 in J774.1 macrophages, whereas levofloxacin and ciprofloxacin did not, at the same concentration. When olamufloxacin was given to the infected guinea pigs orally (5 mg/kg of body weight), peak levels in the lung were 3.02 mg/kg at 2 h post-administration, with a half-life of 3.41 h and an AUC0-12 of 12.31 mg.h/kg. The 2 day post-infection bacterial burden of the lung in the animals treated with olamufloxacin (5 and 1.25 mg/kg given orally twice a day) was much lower than in those treated with levofloxacin (same dose as olamufloxacin) or erythromycin (10 mg/kg given orally twice a day). When treated with olamufloxacin (5 mg/kg given orally twice a day) for 7 days, 11 of 12 L. pneumophila-infected guinea pigs survived for 14 days post-infection, as did all 12 guinea pigs treated with levofloxacin (5 mg/kg given orally twice a day) for 7 days. In contrast, only two of 12 animals treated with erythromycin survived and 10 of 11 died in the physiological saline group. Olamufloxacin was as effective as levofloxacin in a guinea pig model of Legionnaires' disease. These data warrant further study of whether olamufloxacin is an option for the treatment of Legionella infections.

A 69-year-old man developed a cough and fever during treatment with corticosteroid (p.o. and external use) for erythroderma. Chest X-ray films revealed a consolidation shadow in the right upper lung field. Initial treatment with sulbactam sodium/ampicillin followed by imipenem/cilastatin was not effective. A urinary antigen test for Legionella was positive, making for a diagnosis of Legionella pneumonia. Intravenous treatment with ciprofloxacin (CPFX) was remarkably effective. His symptoms, chest X-ray and laboratory data rapidly improved after its initiation. Our findings strongly suggest that intravenous treatment with fluoroquinolones including CPFX should also be a first choice for Legionella pneumonia in Japan.

Legionella pneumophila is the cause of Legionnaires' disease, which is a form of potentially fatal pneumonia. To identify genes required for virulence of the bacterium, a library of 1,386 L. pneumophila signature tagged transposon mutants was studied for guinea pig virulence. The mutants were screened in pools of 96 each in a guinea pig model of L. pneumophila pneumonia. Sixteen unique mutant clones were determined to have attenuated virulence after being screened twice in the animal model. All 16 mutants failed to multiply in both lungs and spleens. Four of the sixteen had no apparent defect for intracellular multiplication in macrophages. Partial DNA sequences of the interrupted genes adjacent to the transposon insertions showed that six of them had mutations in five known L. pneumophila virulence genes: dotB, dotF/icmG, dotO/icmB, icmX, and proA. Three of the sequenced clones contained mutations in genes without known homology to other published bacterial genes, and seven clones appeared to be homologous to five different known bacterial genes but are still being characterized. With this methodology, we demonstrate the existence of L. pneumophila genes responsible for non-macrophage-related virulence. The discovery of L. pneumophila virulence genes indicates the utility of the signature tagged mutagenesis technique for pulmonary pathogens.

We have evaluated urine specimens of presumptive cases of legionnaires' disease (110 cases, 173 sample), collected in the past eight years (April, 1990-August, 1998) with the Binax EIA kit which detects the soluble antigen of Legionella pneumophila serogroup (SG) 1, and the Biotest EIA kit which detects Legionella species. Seven cases (19 specimens) were positive for the Binax EIA kit, and nine cases (22 specimens) were positive for the Biotest EIA kit. The sensitivity for culture, PCR, IFA method were 100%, 100%, and 50%, the specificity for these method were 93%, 97.1%, and 90% respectively. Overall agreements for these method were 93.5%, 97.4%, 86.8%, these results suggested that the urinary antigen detection test had high sensitivity and specificity. Our study indicated that concentrated urine samples increase sensitivity. We also evaluated the capabilities of both EIAs to detect soluble antigens were extracted from bacterial suspension of 18 strains of 5 Legionella species by heating. Both assays detected L. pneumophila serogroups 1 to 14, L. bozemanii. The Binax EIA proved to be useful as the Biotest EIA for diagnosis of legionellosis caused by Legionella species and serogroups other than L. pneumophila serogroup 1. Some cases have been shown to excrete antigen for prolonged period of times despite recovery from infection, so that the patient's history should be sought. The urine antigen detection EIA methods proved to be rapid and easy to use, detect antigen in the early stage of the disease with high sensitivity and specificity. Its use for the definition of legionellosis should be considered in Japan.

A 48-year-old woman was admitted to our hospital with high fever, chills, cough, and exertional dyspnea. On admission, the chest roentgenogram and computed tomography scan showed bilateral alveolar infiltration in the middle and lower lung fields. Microscopic examination of the bronchial lavage fluid showed flower cells typical for adult T-cell leukemia (ATL) and cysts of Pneumocystis carinii, and Legionella pneumophila serogroup 1 grew on buffered charcoal yeast extract (BCYE)-alpha agar. The patient was successfully treated with antibiotics including trimethoprim/sulfamethoxazole, erythromycin, and sparfloxacin. Remission of ATL was achieved after three courses of antileukemic chemotherapy. Mixed infection of opportunistic pathogens should be considered in patients with ATL.

We had examined antibody titers against Legionella spp. of patients' sera which were mainly sent from other hospitals, performed with the indirect fluorescent antibody (IFA) method. The clinical status of the cases diagnosed as Legionella pneumonia serologically, were also studied. Out of 105 cases with clinically suspected Legionella pneumonia, 15 cases (14.3%) were seropositive. In 9 out of the 15 cases (60.0%) were caused by Legionella pneumophila serogroup 1. Clinical outline of these 15 cases did not contradict those reported in the literature, and erythromycin was effective in many cases. Significant rises (more than four times) of the titer were observed 3 to 4 weeks after onset in most of cases. We would like to emphasize that this should be performed serodiagnosis of Legionella pneumonia.

Recently, two excellent methods have been used for the diagnosis of Legionnaires’ disease: urinary antigen detection and PCR. The purpose of the present study is to analyze and evaluate the sensitivity and specificity of three different urinary antigen detection kits as well as PCR. A total of 148 samples were collected from 33 patients between 1993 and 2004. These consisted of 73 urine samples obtained from 33 patients, 57 serum samples provided by 29 patients, and 18 respiratory tract specimens from 13 patients. Three commercially available kits were used to detect urinary antigen. For the 5S PCR reaction, primers L5SL2 and L5SR84 were used. Positive results were shown in all patients’ urine (representing 79.5% of total samples) using the Binax EIA kit, in 93.9% patients (representing 75.3% samples) using the Binax NOW immunochromatographic kit, and in 90.9% (representing 72.6% samples) using the Biotest EIA kit. Urine samples from 12.1% patients (representing 6.8% of total samples), serum samples from 41.4% patients (representing 35.1% of total samples), and respiratory samples from 84.6% patients (representing 88.9% of total samples) showed positive results with PCR. In testing urine of legionellosis patients, it was suggested that three kits were all valuable tools for diagnosis of legionellosis. Since over one-third of patients’ serum samples and most respiratory specimens showed positive results with PCR, the addition of PCR for testing of these samples might be useful, particularly in cases of culture negative and serum antibody negative patients. [ABSTRACT FROM AUTHOR]

Compares polymerase chain reaction and two urinary antigen detection kits for detecting Legionella in clinical samples. Clinical sample of six patients diagnosed with legionellosis; Collection of urine, serum and sputum samples; Use of Binax and Biotest enzyme immunoassay.