Legionella: From Protozoa to Humans

International audiencePathogens that are able to enter and multi- ply within human cells are responsible for multiple diseases and millions of deaths worldwide. Thus, the challenge is to elu- cidate these pathogen-specific and cell biological mechanisms involved in intra- cellular growth and spread. Bacteria from the genus Legionella belong to this group of pathogens. They are environmental bac- teria and ubiquitous in nature, where they parasitize protozoa

Massage Therapy Effects on Pain and Distress/Anxiety in Breast Cancer Patients

Pain and distress/anxiety are likely to result from breast cancer and/or the medical treatment associated with this illness. Breast cancer researchers have focused on massage therapy and its influence on pain and distress in breast cancer patients; however, these research efforts were limited by small sample sizes, homogeneous populations, and small to medium effect sizes. This study explores the effectiveness of massage therapy for decreasing pain and distress in a larger, heterogeneous population of breast cancer patients and across all durations and frequencies of treatment by pooling the findings of former studies. The gate control theory which relates to the experience of pain, the psychotherapy theory which suggests massage acts much like psychotherapy, and the physical touch theory all suggest that massage may decrease pain and distress/anxiety. In order to be included in the meta-analysis, the study needed to be printed in English between the years 2004 and 2012, use the same variables and same method of treatment, and report an effect size or statistics that allowed for effect size calculation. The meta-analysis was quantitative and the effect sizes for each study were calculated using Comprehensive Meta-Analysis (CMA) software. CMA also calculated the overall pooled effect size. Findings indicated that individual studies showed some improvements in pain and distress after receiving treatment; however, when pooled, the results indicated that massage therapy did not significantly improve levels of pain and distress in breast cancer patients. Although findings were non significant, the use of massage therapy improved symptoms of pain and distress in breast cancer patients

Legionella pneumophila adaptation to intracellular life and the host response: Clues from genomics and transcriptomics

AbstractLegionella pneumophila is the causative agent of the pneumonia-like Legionnaires’ disease. The bacterium’s survival and spread depend on the ability to replicate inside eukaryotic phagocytic cells. A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa like Acanthamoeba castellanii, and during infection in human alveolar macrophages. Genome analysis and comparisons as well as expression profiling of the pathogen and the host helped to identify regulatory circuits mediating adaptation of the L. pneumophila transcriptome to the intracellular environment and gave clues for the metabolic needs of intracellular Legionella. This review will summarize what is currently known about intracellular gene expression of L. pneumophila, the transcriptional host response of the model host Dictyostelium discoideum and will present hypotheses drawn from these data with respect to subversion of host cell functions and virulence of L. pneumophila

Comparative and Functional Genomics of Legionella Identified Eukaryotic Like Proteins as Key Players in Host–Pathogen Interactions

Although best known for its ability to cause severe pneumonia in people whose immune defenses are weakened, Legionella pneumophila and Legionella longbeachae are two species of a large genus of bacteria that are ubiquitous in nature, where they parasitize protozoa. Adaptation to the host environment and exploitation of host cell functions are critical for the success of these intracellular pathogens. The establishment and publication of the complete genome sequences of L. pneumophila and L. longbeachae isolates paved the way for major breakthroughs in understanding the biology of these organisms. In this review we present the knowledge gained from the analyses and comparison of the complete genome sequences of different L. pneumophila and L. longbeachae strains. Emphasis is given on putative virulence and Legionella life cycle related functions, such as the identification of an extended array of eukaryotic like proteins, many of which have been shown to modulate host cell functions to the pathogen’s advantage. Surprisingly, many of the eukaryotic domain proteins identified in L. pneumophila as well as many substrates of the Dot/Icm type IV secretion system essential for intracellular replication are different between these two species, although they cause the same disease. Finally, evolutionary aspects regarding the eukaryotic like proteins in Legionella are discussed

In Vivo Transcriptional Profiling of Listeria monocytogenes and Mutagenesis Identify New Virulence Factors Involved in Infection

Listeria monocytogenes is a human intracellular pathogen able to colonize host tissues after ingestion of contaminated food, causing severe invasive infections. In order to gain a better understanding of the nature of host–pathogen interactions, we studied the L. monocytogenes genome expression during mouse infection. In the spleen of infected mice, ≈20% of the Listeria genome is differentially expressed, essentially through gene activation, as compared to exponential growth in rich broth medium. Data presented here show that, during infection, Listeria is in an active multiplication phase, as revealed by the high expression of genes involved in replication, cell division and multiplication. In vivo bacterial growth requires increased expression of genes involved in adaptation of the bacterial metabolism and stress responses, in particular to oxidative stress. Listeria interaction with its host induces cell wall metabolism and surface expression of virulence factors. During infection, L. monocytogenes also activates subversion mechanisms of host defenses, including resistance to cationic peptides, peptidoglycan modifications and release of muramyl peptides. We show that the in vivo differential expression of the Listeria genome is coordinated by a complex regulatory network, with a central role for the PrfA-SigB interplay. In particular, L. monocytogenes up regulates in vivo the two major virulence regulators, PrfA and VirR, and their downstream effectors. Mutagenesis of in vivo induced genes allowed the identification of novel L. monocytogenes virulence factors, including an LPXTG surface protein, suggesting a role for S-layer glycoproteins and for cadmium efflux system in Listeria virulence

Fatal Vibrio vulnificus Infection Associated with Eating Raw Oysters, New Caledonia

International audienceTo the Editor: The bacterium Vi-brio vulnifi cus is a marine fl ora sap-rophyte that can cause necrotic skin infection and septicemia in humans who eat shellfi sh. Symptoms of sep-ticemia (mortality rate >50%) have been described mostly in Florida and Japan among persons who ate raw fi lter-feeding shellfi sh when seawater temperatures are >20°C (1). V. vulnifi cus–related septicemia introduced through the digestive system appears within 7 days after inges-tion (2). Clinical signs and symptoms include fever, collapse, and metastatic necrotic skin lesions. We report 3 patients from New Caledonia who died after V. vulnifi cus infection, which they probably acquired by eating contaminated oysters. These patients were hospitalized during February–May 2008 at Noumea Hospital (Noumea, New Caledonia). Patient 1 was a 51-year-old man with fever, muscle pains, bleeding gums, and a history of alcohol abuse; within 48 hours after symptom onset, he died of septic shock, with diffuse ecchymoses and purpura. Patient 2 was a 67-year-old woman with no known concurrent conditions who was admitted to the hospital with chills, diarrhea, and vomiting; septic shock developed, with painful erythematous plaques on the lower limbs becoming foamy, confl uent, and necrotic. Patient 3 was a 74-year-old woman with untreated lupus who was hospitalized with lower-limb edema, hypotension, hypothermia, and erythematous skin lesions. All 3 patients received cepha-losporins but died of multiple organ failure within 12 hours after hospital admission. Peripheral blood aerobic–anaer-obic samples were taken from all patients , stored in BacT/Alert FA vials (bioMérieux, Marcy-l'Etoile, France), and incubated in the BacT/Alert 3D system (bioMérieux). Curved mobile gram-negative bacilli were isolated from blood samples cultured on conventional media without additional salt within 24 h after incubation at 37°C in a 5% CO 2-enriched atmosphere. V. vulnifi cus was identifi ed through the Vitek2 system (bioMérieux) and con-fi rmed by using the Api 20E system (bioMérieux). Strains were sent to the Centre National de Reference des Vibrions et du Choléra, (Institut Pasteur, Paris, France), which by PCR confi rmed the gene encoding virulence-associated hemolysin, a species-specifi c marker (3). Molecular typing by pulsed-fi eld gel electrophoresis was performed to assess possible clonality of the strains. Several studies have shown the genomic diversity among environmental and clinical V. vulnifi cus isolates. The use of genotyping methods has identifi ed >100 V. vulnifi cus strains in a single oyster (4) and notable hetero-geneity among clinical isolates from multiple patients, even if a unique pathogenic strain causes the infection in each patient. Thus, V. vulnifi cus infections within a large population at risk may result from rare events controlled more by the host than by the bacterial strain (5). Pulsed-fi eld gel electrophoresis genotype analysis enabled us to divide the strains into 2 groups. One group included the isolate from patient 1, and the other group included isolates from patients 2 and 3, which despite having slightly different NotI and Sfi I patterns refl ecting genetic rearrangement , clearly belonged to a single clone. Isolation of strains with such a high degree of homogeneity is not common, raising the question of the existence of V. vulnifi cus clones that are particularly virulent or adapted to humans. Currently, however, reliable markers for determining V. vulnifi cus virulence do not exist. Thus, no geno-typing system is likely to be useful for rapidly identifying strains that affect public health (6). V. vulnifi cus–related analysis requires the assumption that all strains are virulent. Epidemiologic information collected from patients' families indicated recent consumption of raw oysters. Two of the 3 cases occurred within a short time frame and were associated with eating local oysters harvested on the west coast of New Caledonia. The literature mentions few cases of V. vulnifi cus infection in the South Pacifi c. Cases described were isolated, rarely fatal, and involved infection through the skin (7–10). The V. vulnifi-cus infections we report may be related to the emergence of a new clone or to changes in the climate or environmental conditions. New Caledonia experienced unusual weather conditions during the fi rst half of 2008 (heavy rains and exceptionally high temperatures). These specifi c conditions may have favored higher sea surface temperatures, lower salinity, increased turbidity, and subsequent multiplication of V. vulnifi-cus in seawater. A range of projects were implemented to train practitioners to recognize potential V. vulnifi cus infections. Local health authorities issued criteria for defi ning suspected cases of V. vulnifi cus infection and recommendations for early medical care of patients with clinical symptoms. Methods of detecting the bacterium in human and animal health laboratories were improved , particularly by the systematic use of selective media in the event of suspected clinical V. vulnifi cus infection and standardized reporting of V. vulnifi cus isolation. Preventive measures , such as improving microbial surveillance and warning consumers about risks associated with eating raw seafood, are essential to help reduce the risk for V. vulnifi cus–induced illness. 136 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 17, No. 1, January 2011 LETTERS Acknowledgments We thank Jacob Kool, Martha Iwa-moto, Rajal Mody, and Dominique Hervio-Heath for help in investigating these cases and for formulating recommendations