Recurrent soft tissue abscesses caused by Legionella cincinnatiensis

Legionella longbeachae wound infection: case report and review of reported Legionella wound infections

Extrapulmonary manifestations of infection with Legionella species, of which 24 may cause disease in humans, are very rare. Here, we describe a case of a 61-year-old woman with no history of immunosuppression presenting with pain and swelling of her index finger after a prick by rose thorns during gardening. Clinical examination showed fusiform swelling of the finger with mild redness, warmth, and fever. The blood sample revealed a normal white blood cell count and a slight increase in C-reactive protein. Intraoperative observation showed extensive infectious destruction of the tendon sheath, while the flexor tendons were spared. Conventional cultures were negative, while 16S rRNA PCR analysis identified Legionella longbeachae that also could be isolated on buffered charcoal yeast extract media. The patient was treated with oral levofloxacin for 13 days, and the infection healed quickly. The present case report, with a review of the literature, indicates that Legionella species wound infections may be underdiagnosed due to the requirement for specific media and diagnostic methods. It emphasizes the need for heightened awareness of these infections during history taking and clinical examination of patients presenting with cutaneous infections.

Cutaneous Legionella infections in allogeneic hematopoietic cell transplantation recipients

To date, only twenty cases of cutaneous legionellosis have been reported. Cutaneous legionellosis has heterogeneous manifestations including abscesses, nodules, and cellulitis. The detection of most cutaneous Legionella species requires specific diagnostic cultures and assays. Herein, we report a case of cutaneous legionella in a hematopoietic cell transplantation recipient with culture-negative nodules unresponsive to empiric antibiotics. We also discuss the varied morphology of cutaneous legionellosis and important diagnostic considerations.

Septic arthritis due to Legionella cincinnatiensis: case report and review of the literature

Legionella spp. are an important cause of pulmonary and rarely extrapulmonary infections. L. cincinnatiensis has only been implicated in five cases to date. We herein report the first case of L. cincinnatiensis septic arthritis in a 90-year old lady with a past medical history of chronic kidney disease. She developed septic arthritis of her left wrist after having received intraarticular corticosteroid injections and oral corticosteroids administered for presumed chondrocalcinosis. Appropriate antimicrobial treatment of L. cincinnatiensis septic arthritis was delayed until identification of this organism in joint biopsies by broad-range bacterial PCR targeting the 16S rRNA gene with subsequent rDNA sequence analysis and by culture on special media. Reviewing all reported cases of septic arthritis caused by Legionella spp. other than L. cincinnatiensis it is notable that diagnosis was established by PCR in the majority of cases and only subsequently confirmed by special culture. Although most patients were immunosuppressed, outcome was favourable. Treatment consisted of a fluoroquinolone alone or in combination with rifampicin or a macrolide. Our case highlights the need for a high index of suspicion for infections with unusual/fastidious organisms when symptoms are suggestive of septic arthritis but conventional methods fail to identify a causative organism.

Cutaneous legionellosis: case report and review of the medical literature

Discrete nodules developed on the leg of a 27-year-old immunosuppressed woman after an allogeneic stem cell transplant. Biopsy and culture grew Legionella pneumophila serogroup 8. On day 7 of azithromycin treatment, respiratory distress and abnormal liver transaminases developed, and the patient died on day 14. Review of the medical literature identified 19 reports of Legionella species-associated skin or soft tissue infections (total of 20 patients, 13 with confirmed infection). Manifestations of the 13 confirmed cases included erythematous macular rash (n = 7), erythema after thoracentesis (n = 1), abscess formation (n = 4), respiratory symptoms (n = 6), and abnormal chest radiographs (n = 8). Six required surgical exploration and débridement, and 7 were immunocompromised. Rash and respiratory infection improved with antibiotics in 10, but 3 died. Immunosuppression may predispose transplant recipients to Legionella infections. Diagnostic biopsies may facilitate appropriate treatment.

Soft tissue infection caused by Legionella bozemanii in a patient with ongoing immunosuppressive treatment

The Legionellaceae family consists of approximately 50 species, of which the most commonly identified species is L. pneumophila, the causative agent of Legionnaires’ disease. Other Legionella ssp. most often cause clinical infections in the immune-compromised patients, in which L. bozemanii has been known to cause both pneumonia and lung abscesses. In the presented case, a soft tissue infection in a patient with ongoing immunosuppression was determined to be due to L. bozemanii. Hence, in immune-deficient patients, L. bozemanii could be considered a possible agent in soft tissue infections when other common pathogens have been ruled out.

Relapsing Legionella pneumophila cellulitis: a case report and review of the literature

Legionella spp. rarely cause soft tissue infections, with only a few cases reported and usually in the setting of immunocompromise. We report a case of L. pneumophila cellulitis, without pneumonia, in a 65-year-old immunocompromised woman. The patient had a history of interstitial lung disease and idiopathic thrombocytopenic purpura, for which she was receiving high-dose corticosteroids, and had recently experienced an episode of L. pneumophila cellulitis of the lower extremity, which responded to an extended course of levofloxacin. She was initially transferred to this institution for definitive workup of presumed B cell lymphoma and, during her hospital course, suffered a relapse of L. pneumophila-associated cellulitis that responded promptly to azithromycin. More unusual organisms such as Legionella spp. should be considered in the etiology of cellulitis, particularly in the setting of immunocompromise, in cases that are refractory to conventional antibiotics routinely administered for skin and soft tissue infections.

Disseminated Legionella pneumophila infection in an immunocompromised patient treated with tigecycline

We describe an immunocompromised patient with disseminated Legionella pneumophila infection. A chronic leg ulcer was probably the port of entry for the infection. Treatment required several operations and prolonged antimicrobial treatment. To our knowledge, this is the first case report of Legionella soft tissue infection and pneumonia treated with tigecycline.

Legionella maceachernii soft tissue infection

Soft tissue infection caused by Legionella spp. is rare. Infection due to Legionella maceachernii has only been described in 5 cases and none of them had soft tissue infection; they were immunocompromised hosts who presented with pneumonia. To our knowledge, this is the first case report of L. maceachernii soft tissue infection.

Pneumonia and Osteomyelitis Due to Legionella longbeachae in a Woman with Systemic Lupus Erythematosus

A patient with risk factors of systemic lupus erythematosus, corticosteroid use, and malignancy received a diagnosis of concomitant pneumonia and osteomyelitis caused by Legionella longbeachae. In this report, the first description of Legionella osteomyelitis, previous cases of extrapulmonary Legionella infection are detailed.

Legionella pneumophila serogroup 4 isolated from joint tissue

We report the isolation of Legionella pneumophila serogroup 4 from synovial tissue obtained from an 80-year-old female with chronic swelling of her right metacarpophalangeal joint. Synovial tissue infections caused by L. pneumophila are rare. Interestingly, this isolate was recovered from chocolate agar after 5 days of incubation.

Legionella spp.: community acquired and nosocomial infections

PURPOSE OF REVIEW

The key points of this review are the increasingly recognized risk of home-acquired Legionnaires' disease; the significance and potential pathogenic role of other species of Legionella spp., different from L. pneumophila, and of other microorganisms that are phylogenetically close to Legionella and that have been named as Legionella-like amoebal pathogens; the breakthrough in the diagnosis of the disease caused by new commercially available urine antigen detection tests; the controversy over sensitivity and specificity of serological diagnostic methods; the recognition of a variety of possible mixed infections, particularly in the immunocompromised population; and new and controversial aspects of the therapeutic approach to legionellosis.

RECENT FINDINGS

During the last year a number of articles have provided clinically relevant insights into our knowledge of Legionnaires' disease. In view of the fact that Legionella spp. have progressively become recognized as relatively common causative agents of both community-acquired and nosocomial legionellosis, this is an opportune moment for this review.

SUMMARY

If domestic aquatic reservoirs were eventually confirmed as significant agents of transmission of legionellosis, the adoption of preventive measures would then be crucial. The progressive identification of other species, different from L. pneumophila, as causative agents of pneumonia should both encourage microbiologists and clinicians to improve their diagnostic methodology and increase the awareness of these infections. Finally, the awareness of mixed infections, probably far more severe and perhaps not so uncommon as previously thought, has important clinical connotations for both the diagnostic and the therapeutic approach to legionellosis in the immunosuppressed host, particularly in those cases of delayed clinical resolution.

Characterization of members of the Legionellaceae family by automated ribotyping

In order to implement a new and reliable method for characterizing different species of Legionella, a genetic fingerprinting study with an automated ribotyping system (RiboPrinter) was completed with members of this genus which were deposited at the American Type Culture Collection. The RiboPrinter examined the different patterns of EcoRI digestion fragments from the rRNA operons of 110 strains, representing 48 of the 49 described Legionella species as well as 70 serogroups of those species. Distinctive and consistent patterns were obtained for the type strains of the 48 species investigated. Legionella pneumophila subsp. fraseri and L. pneumophila subsp. pascullei each generated a specific pattern, whereas L. pneumophila subsp. pneumophila produced six different fingerprint patterns. No correlation seemed to exist between the ribotypes obtained and the 15 serotypes of L. pneumophila. For the other species, those with two known serogroups presented two distinctive patterns with the RiboPrinter with the exception of L. hackeliae and L. quinlivanii, which yielded only one pattern. We also encountered ribotypes for strains which were not identified to the species level. The ribotypes generated for these strains with the RiboPrinter did not match those generated for known type strains, suggesting the putative description of new serogroups or species. Although the automated system did not have sufficient discriminatory ability to serve as an epidemiological tool in a clinical setting, it appeared to be a powerful tool for general genomic analysis of the Legionella isolates (e.g., determination of new species) and assessment of the interrelationship among Legionella strains through the RiboPrinter database connection.

Infection due to Legionella species other than L. pneumophila

In addition to Legionella pneumophila, 19 Legionella species have been documented as human pathogens on the basis of their isolation from clinical material. Like L. pneumophila, other Legionella species are inhabitants of natural and man-made aqueous environments. The major clinical manifestation of infection due to Legionella species is pneumonia, although nonpneumonic legionellosis (Pontiac fever) and extrapulmonary infection may occur. The majority of confirmed infections involving non-pneumophila Legionella species have occurred in immunosuppressed patients. Definitive diagnosis requires culture on selective media. Fluoroquinolones and newer macrolides are effective therapy. A number of nosocomial cases have occurred in association with colonization of hospital water systems; elimination of Legionella species from such systems prevents their transmission to susceptible patients. It is likely that many cases of both community-acquired and nosocomial Legionella infection remain undiagnosed. Application of appropriate culture methodology to the etiologic diagnosis of pneumonia is needed to further define the role of these organisms in disease in humans.