Subject(s)
Eyelid Neoplasms/diagnosis , Lymphoma, B-Cell, Marginal Zone/diagnosis , Salivary Gland Neoplasms/diagnosis , Salivary Glands, Minor , Stomach Neoplasms/diagnosis , Aged , Antibodies, Monoclonal, Murine-Derived/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Eyelid Neoplasms/therapy , Humans , Immunologic Factors/therapeutic use , Lymphoma, B-Cell, Marginal Zone/therapy , Male , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/therapy , Rituximab , Salivary Gland Neoplasms/therapy , Stomach Neoplasms/therapy , Tomography, X-Ray ComputedABSTRACT
The reservoir for hospital-acquired Legionnaires' disease has been shown to be the potable water distribution system. The objectives of the present study were as follows: (1) to examine the possible relationship between physical-chemical characteristics of water such as temperature, pH, hardness, conductivity, and residual chlorine and the presence of amoebae as growth-promoting factors for Legionella species and (2) to determine eradication measures for water distribution systems to seek ways of reducing the risk of legionellosis. Ten hospitals in southwest France took part in this study. Water samples were collected from 106 hot water faucets, showers, hot water tanks, and cooling towers. Two analyses were performed to analyze the association between water characteristics and (1) the presence of Legionella species and (2) the proliferation of Legionella species. Of the 106 water samples examined, 67 (63.2%) were positive for Legionella species. Amoebae were detected in 73 of 106 (68.9%) samples and in 56 of 67 (86.6%) Legionella species-positive samples (P < 10(-6)). In these positive samples, conductivity was lower than 500 microOmega(-1).cm(-1) in 58.2% (P = .026), temperature was below 50 degrees C in 80.6% (P = .004), and hardness was significantly higher (P = 002) than in Legionella species-negative samples. Neither Legionella species nor amoebae were isolated from any sampling point in which the water temperature was above 58.8 degrees C. Multivariate analysis shows that high hardness and presence of amoebae were strongly correlated statistically with the presence of Legionella when showers, tanks, pH, and temperature promoted their proliferation. This study shows the importance of water quality evaluation in assessing environmental risk factors and in selecting the most appropriate prevention and control measures in hospital water systems.
Subject(s)
Amoeba/isolation & purification , Legionella/isolation & purification , Water Microbiology , Water/chemistry , Amoeba/growth & development , Animals , Chlorine/analysis , Cross Infection/prevention & control , Electric Conductivity , France , Hospitals , Humans , Hydrogen-Ion Concentration , Infection Control/methods , Legionella/growth & development , Legionellosis/prevention & control , Multivariate Analysis , Statistics as Topic , TemperatureABSTRACT
Escherichia coli 0157:H7 biofilms were studied by a new method of cultivation in order to identify some of the proteins involved in the biofilm phenotype. A proteomic analysis of sessile or planktonic bacteria of the same age was carried out by two-dimensional electrophoresis, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and database searching. Comparison of two-dimensional gels showed clear differences between protein patterns of sessile and planktonic cells. Fourteen proteins increased in biofilms, whereas three decreased. From these 17 proteins, 10 were identified by MALDI-TOF-MS and could be classified into four categories according to their function: (1) general metabolism proteins (malate dehydrogenase, thiamine-phosphate pyrophosphorylase), (2) sugar and amino acid transporters (D-ribose-binding periplasmic protein, D-galactose-binding protein, YBEJ), (3) regulator proteins (DNA starvation protein and H-NS) and (4) three proteins with unknown function. The results of this study showed that E. coli O157:H7 modified the expression of several proteins involved in biofilm growth mode.
