Archive for March 23, 2013

Pandemic Influenza and Pneumonia Due to Legionella pneumophila – A Frequently Underestimated Coinfection

Clinical Infectiosu Disesase 1July 2010  V.51 P.115

To the Editor—Secondary bacterial pneumonia is recognized as one of the most common causes of death in influenza cases. Coinfection has been found in ∼30% of all influenza cases in persons with seasonal influenza, and the pathogens most often involved are Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenza …



March 23, 2013 at 1:54 pm

Community-acquired pneumonia due to Legionella pneumophila, the utility of PCR, and a review of the antibiotics used.

Int J Gen Med. 2011 Jan 6;4:15-9.

Zarogoulidis P, Alexandropoulou I, Romanidou G, Konstasntinidis TG, Terzi E, Saridou S, Stefanis A, Zarogoulidis K, Constantinidis TC.


Regional Laboratory of Public Health, East Macedonia-Thrace, Komotini, Greece.



There are at least 40 types of Legionella bacteria, half of which are capable of producing disease in humans. The Legionella pneumophila bacterium, the root cause of Legionnaires’ disease, causes 90% of legionellosis cases.


We describe the case of a 60-year-old woman with a history of diabetes mellitus and arterial hypertension who was admitted to our hospital with fever and symptoms of respiratory infection, diarrhea, and acute renal failure. We used real-time polymerase chain reaction (PCR) to detect L. pneumophila DNA in peripheral blood and serum samples and urine antigen from a patient with pneumonia. Legionella DNA was detected in all two sample species when first collected.


Since Legionella is a cause of 2% to 15% of all community-acquired pneumonias that require hospitalization, legionellosis should be taken into account in an atypical pulmonary infection and not be forgotten. Moreover, real-time PCR should be considered a useful diagnostic method.




March 23, 2013 at 9:49 am

Prevention of Legionnaires’ disease in hospitals.

Tidsskr Nor Laegeforen. 2011 Aug 23;131(16):1554-7.

Sarjomaa M, Urdahl P, Ramsli E, Borchgrevink-Lund CF, Ask E.


Medical Clinic, Telemark Central Hospital, Skien, Norway.



The first instance of Legionella infection in a Norwegian hospital was confirmed in 2005. We describe the best-known methods of eradicating Legionella in hospitals.


The article is based on the authors’ experience of measures to prevent Legionnaires’ disease in hospitals and on a non-systematic search in PubMed.


There are several methods of combating Legionella in hospitals. These include chlorination, heat treatment, and the use of filters. However, recontamination easily re-occurs after eradication. The silver and copper ionisation treatment of water is a well-documented method for the systematic and long-term eradication of Legionella in water. The disadvantages of this method are that it is expensive, that there is a risk of discolouring the water, and that there is a possibility of developing resistance in environmental bacteria. This resistance mechanism can theoretically be transferred to bacteria that cause illness.


We recommend the silver and copper ionisation treatment of water as a method of preventing nosocomial Legionnaires’ disease when standard methods fail and there is a high prevalence of Legionella in the water. The discolouration of operation instruments that occurs as a result of high silver concentrations can be avoided by using a separate water supply for operation units.


March 23, 2013 at 9:47 am

Legionella secreted effectors and innate immune responses.

Cell Microbiol. 2012 Jan;14(1):19-27.

Luo ZQ.


Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.


Legionella pneumophila is a facultative intracellular pathogen capable of replicating in a wide spectrum of cells. Successful infection by Legionella requires the Dot/Icm type IV secretion system, which translocates a large number of effector proteins into infected cells. By co-opting numerous host cellular processes, these proteins function to establish a specialized organelle that allows bacterial survival and proliferation. Even within the vacuole, L. pneumophila triggers robust immune responses. Recent studies reveal that a subset of Legionella effectors directly target some basic components of the host innate immunity systems such as phagosome maturation. Others play essential roles in engaging the host innate immune surveillance system. This review will highlight recent progress in our understanding of these interactions and discuss implications for the study of the immune detection mechanisms.


March 23, 2013 at 9:44 am


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