Consecutive bacillary angiomatosis and Rhodococcus equi bacteremia during acute leukemia: zoonoses may cause fever in neutropenic patients

Is Bartonella sp. infection relevant in hematological malignancies in HIV-negative patients? A literature review

Bartonelloses are diseases caused by Bartonella sp., transmitted to humans by blood sucking arthropod vectors. Clinical presentations include bacillary angiomatosis, cat scratch disease and atypical forms. We performed a review of cases of bartonelloses and hematological malignancies published in HIV-negative patients. Terms used were Bartonella or Bacillary Angiomatosis and Leukemia, Lymphoma, Multiple Myeloma, or Cancer. Fifteen cases met our criteria. Clinical presentations included bacillary angiomatosis, chronic fever, chronic lymphadenopathy, osteomyelitis, neuroretinitis, chronic anemia and hepatosplenic peliosis. Fourteen patients were asymptomatic after antibiotic therapy, and one died before antibiotic treatment. Clinicians should be suspicious of Bartonella sp. infections in immunocompromised patients.

Diagnosis and management of pulmonary infection due to Rhodococcus equi

BACKGROUND

Rhodococcus equi is a recognized cause of disease in humans, especially in individuals who are immunocompromised. Because diphtheroids are regarded as part of normal respiratory flora, the importance of R. equi as a pulmonary pathogen may not be fully appreciated and its prevalence may be underestimated. Most treatment recommendations for R. equi infection were established before antiretroviral drugs became available for human immunodeficiency virus/AIDS therapy, and therapeutic strategies may need to be updated.

OBJECTIVES

To review the role of R. equi as a cause of pulmonary infection; to highlight its importance for clinicians and microbiologists; and to challenge current approaches to treatment, whether in immunodeficient or immunocompetent individuals.

SOURCES

A PubMed search using combinations of the following terms: 'Rhodococcus (automatically including Corynebacterium) equi' AND 'pneumonia' OR 'pulmonary' infection, then cross-checking references in the resulting cases, case series and reviews.

CONTENT

We provide a review that details the challenges in the diagnosis, microbiology and pathogenesis of pulmonary infection caused by R. equi and the options for treatment.

IMPLICATIONS

Ten to 14 days of treatment may be effective for pneumonia due to R. equi. Our review suggests that longer courses of therapy are needed for cavitary lesions and lung masses. However, recommendations for excessively prolonged treatment of all pulmonary infections arose during a time when many cases occurred in individuals with AIDS and before effective antiretroviral therapy was available. We suggest that the rationale for prolonged therapy with multiple antibiotics needs to be re-evaluated.

Allergic broncho pulmonary aspergillosis complicated by nocardiosis

We describe a 70-year-old male with a history of diabetes mellitus, hypertension, and asthma who presented with increasing breathlessness for 5 months. He was diagnosed to have allergic bronchopulmonary aspergillosis (ABPA) by serological and radiographic criteria. He was treated with steroids and itraconazole. After initial improvement, he developed fever with cough and mucopurulent sputum. X-ray chest revealed multiple cavities with air fluid level. Patient was treated with antibiotics without any response. Sputum was negative for acid fast bacilli (AFB). Sputum culture for bacteria and fungus did not reveal any significant growth; however a delayed growth of Nocardia was noted on fungal plates. Modified Ziehl Nelsen stain was positive for AFB. Patient was treated with cotrimoxazole. We discuss the serological and radiological criteria of ABPA, presentation and treatment of nocardia pulmonary infection and other possible causes of necrotizing pneumonia in immunocompromised settings.

Brief Tale of a Bacteraemia by Rhodococcus equi, With Concomitant Lung Mass: What Came First, the Chicken or The Egg?

Rhodococcus equi is an uncommon Gram positive, variably acid-fast pathogen, that appears as hard to treat mostly owing to the establishment of intracellular niches. Lack of interpretive criteria for susceptibility testing may lead to under-reporting or overestimation of resistances, whereas knowledge about this pathogen’s clinical impact may be affected by erroneous phenotype-based characterization at a genus and species level.

We present the case of a bacteraemia with a concomitant lung mass in a lymphoma patient, that further highlights the emergence of rhodococcal diseases as a matter for concern in the fields of infectious diseases and haematology.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

[Rhodococcus equi infection]

<zakljucak> Humana R. equi infekcija jos uvek je retko oboljenje koje se javlja uglavnom kod osoba sa teskim stepenom imunodeficijencije. Najcesce se ispoljava u vidu subakutne bakterijske pneumonije sa kavitacijama, a karakterise se cestim recidivima, bakterijemijama i visokom stopom mortaliteta. Terapija R. equi infekcije bazira se na kombinaciji baktericidnih i antibiotika sa dobrom intracelijskom penetracijom koji se primenjuju u duzem periodu, dok su drenaza apscesnih kolekcija i/ili operativni zahvati indikovani samo u slucajevima izostanka adekvatnog odgovora na antibiotsku terapiju. Uzimajuci u obzir cinjenicu da je R. equi infekciju veoma tesko eradikovati, a u cilju sto ranijeg postavljanja prave dijagnoze i blagovremenog pocetka adekvatne terapije, od velikog znacaja je poznanje najvaznijih karakteristika ove bolesti.

Sepsis associated with immunosuppressive medications: an evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for sepsis associated with immunosuppressive medications that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSION

Immunosuppressed patients, by definition, are susceptible to a wider spectrum of infectious agents than immunologically normal patients and, thus, require a broader spectrum antimicrobial regimen when they present with sepsis or septic shock. Special expertise managing immunosuppressed patient populations is needed to predict and establish the correct diagnosis and to choose appropriate empiric and specific agents and maximize the likelihood that patients will survive these microbial challenges.

Virulence of Rhodococcus equi isolated from cats and dogs

Nine cat isolates and nine dog isolates of Rhodococcus equi from clinical material were investigated for the presence of the virulence-associated antigens (VapA and VapB) and virulence plasmids. Five of the cat isolates and one dog isolate were VapA positive and contained an 85-kb type I or an 87-kb type I plasmid. The remaining 12 isolates were avirulent R. equi strains and contained no virulence plasmids.

Bartonella quintana and Mycobacterium tuberculosis coinfection in an HIV-infected patient with lymphadenitis

Cat scratch disease (CSD) is usually associated with Bartonella henselae infection in patients with a history of cat exposure, but Bartonella quintana may also be a cause of chronic lympadenopathy in patients with cat or flea contact. The lymph node histopathology of CSD and tuberculosis may be indistinguishable. We report herein the first description of lymph node coinfection with B. quintana and M. tuberculosis in a 32-year HIV-infected woman. Culture of lymph node biopsy material on Columbia agar with sheep blood and on human endothelial cells in shell vial allowed us to isolate not only B. quintana, but also M. tuberculosis hominis.

[Laryngeal infection by Rhodococcus equi in patient with AIDS]

The Rhodococcus equi is an aerobic gram positive pleomorphic bacillus, that was isolated for the first time like a producer of bronchopneumonia in young horses. Every time more often, it is being recognized as a pathogen in humans, mainly in the immunodepressed population. We described a case, until now exceptional, of laryngeal infection by Rhodococcus equi in a patient with positive serology for the virus of the human immunodeficiency (HIV), and we reviewed some clinical and epidemiological characteristics of the infections by this germ. The treatment is riphampicine and/or erythromycin, being the prognosis bad, because usually they are immunodepressed patients.