Observation et étude expérimentale de mycobactéries atypiques en aquariums d'eau douce et d'eau de mer

L'eau des aquariums est source de Mycobactéries atypiques qui peuvent être pathogènes pour l'homme et les poissons.Une étude a été réalisée à l'aquarium du Musée de Zoologie de Nancy. La recherche de Mycobactéries a été effectuée dans 40 aquariums équipés de lampes germicides à UV : 11 bassins étaient alimentés en eau douce et 29 en eau de mer. Deux aquariums non équipés de système de désinfection ont également été analysés, les propriétaires de ces derniers ayant présenté un granulome cutané à M. marinum. L'action des UV sur M. marinum en suspension dans l'eau a été testée expérimentalement dans des bassins d'eau douce peuplés de Cichlidés.Pour chaque aquarium, un échantillon de 250 ml a été prélevé. Les cultures après décontamination au lauryl sulfate de soude ont été réalisées sur milieu de Loewenstein.Les résultats indiquent que, quel que soit l'aquarium, la présence de mycobactéries est constante. L'isolement des mycobactéries peut être gêné par la présence d'une flore bactérienne ou fongique importante (≥ 103 U.F.C./ml).Les espèces les plus fréquemment isolées sont M. gordonae et M. fortuitum ; M. kansasii et M. marinum ont rarement été isolées (6140 aquariums). Différents facteurs peuvent intervenir sur la sélection des espèces. La salinité de l'eau limite le développement de certaines espèces, alors qu'elle permet la croissance de M. fortuitum. Dans notre étude, la température de l'eau n'a pas été un facteur sélectif. L'utilisation de lampes UV limite le nombre de Mycobactéries. Dans les bassins expérimentaux, les radiations UV se sont révélées très actives sur M. marinum en présence ou en l'absence de poissons. A l'inverse de M. gordonae, M. fortuitum est rarement isolée en présence d'UV. Un nombre important de poissons par aquarium augmente la flore bactérienne et mycobactérienne.La prévention des infections à Mycobactéries atypiques chez l'homme comme chez les poissons devrait pouvoir être assurée par des mesures d'hygiène élémentaire.Water is a natural habitat of mycobacteria. In aquaria 3 species of atypical mycobacteria are frequently present : M. marinera, M. kansasitand M. fortuitum. They are potential pathogen for fishes and men. Tuberculosis has been recognized as the cause of mortality in marine and fresh water fishes. Clinical signs of fish tuberculosis are variable : ascites, skin ulcerations, skeletal deformities. The human infection is cutaneous granuloma occuring after in jury in aquaria.In the aquaria, of which two patients with cutaneous lesions due to M. marinum were analysed, UV lamps were not used. Many factors have an influence on the number of mycobacterial organisms in aquaria waters : number of fishes per tank, decontamination system, salinity, temperature.To determine the consequence of each factor, a study has been conducted at the “Aquarium du Musée de Zoologie de Nancy”. Research of mycobacteria was carried out in the water of 40 tanks : 11 were supplied with fresh water and 29 with salt water. Each tank was equipped with germicide UV (λ : 253,7 nm) : the intensity was 15 watts for aquaria smaller than 1 000 liters and 36 watts for aquaria larger than 5 000 liters. The effectiveness of UV radiation against M. marinum was tested in 3 experimental fresh water tanks of 280 liters. The first part of the experiment was tested without fish. Tank n° 1 was a control, lamp was switched on during the complete study, M. marinum was not added. In tank n° 2 (with UV) and n° 3 (without UV), 2 ml of M. marinum (of suspension 107 CF/ml) was added. Samples of water were analysed every two weeks. After six weeks tanks n° 2 and n° 3, were prepared for the next study : UV lamps were switched on in n° 2 and switched off in n° 3 both of which were contaminated by M. marinum. After 4 weeks 27 fishes, Cichlids, were introduced in the three aquaria. The day after, M. marinum was added to tanks n° 2 and n° 3. Every week water analysis was done, as well as an identification and quantification of all species of mycobacteria.From each tank 250 ml of water were collected. The water was passed through a 0,2 mµ membrane. The filters were introduced in distilled water and decontaminated by lauryl sulfate. The culture of mycobacteria was grown with Loewenstein medium at 30 and 37 °C. Each colony type was identified by cultural and biochemical characteristics.This study shows the richness in aquaria of mycobacteria; whatever the tanks, mycobacteria presence was constant. In non-treated home aquaria, the presence of mycobacteria was very important, 4 to 6 species per tank, (but in this case M. marinum was not found). In aquaria with UV lamps, the number of species per tank was lower (1 to 3).The growth of mycobacleria could be prevented when the samples were contaminated by fungi and bacteria. However, inability to recover mycobacteria from water occurred only when a massive over-growth by non-mycobacterial contaminant was present (103 CFU/ml). This was the case of non-treated tanks, belonging to patients who developed a chronic granuloma on their hands, M. marinum was not isolated in these aquaria. The evaluation of slowly growing mycobacteria could be altered by the important development of fast growing mycobacteria on the same culture tube. Among isolated species, M. fortuitum and M. gordonae saprophytic strains were frequent; M. kansasii and M. marinum involved in human cutaneous granuloma were unusual, as were the non-pigmented strains of groupe III of Runyon ; M. avium was not isolated.During this study, we observed a relationship between the mycobacteria presence and the cleanness of tank and the fishes population. A great number of fishes per tank was a factor which increased the bacterial and mycobacterial contamination. During this experiment fishes didn't present tubercular-lesions but when a dead fish was examinated, the culture from post-modem samples revealed the presence of M. marinum. The microbiological examination of skip and viscera was negative.The comparison of results in non-treated home tanks and UV treated tanks of the Museum indicates the role of water treatment by UV lamps on the number of isolated mycobacteria.The germicide UV camps are frequently used for the decontamination of tanks. The efficiency is good for bacteria, but unknown for mycobacteria. This study shows that UV radiation decreased the mycobacterial contamination. The species of mycobacteria differ in their sensitivity to UV radiation. In experimental tanks, the results showed the great susceptibility of M. marinum to UV lamps such they were used in aquaria. Presence of fish dues not change the results. If the addition of M. marinum and the lighting of lamps were simultaneous, M. marinum was not isolated in water. If the contamination by M. marinum preceded the lighting of UV lamps, must of bacteria was eliminated in one week and the totality in 4 weeks. For the other species, we observed that the mycobacterial sensitivity to UV light decreases in the following order : quickly growing mycobacteria, photochromogen and scotochromogen strains. During our experimental study, M. gordonae was isolated more frequently when UV lamps were switched on. The results obtained in the 40 tanks with UV lamps allowed the evaluation of the influence of salinity and temperature of water on mycobacterial survival and the selection of species. We did not observed a difference in the concentration of mycobacteria in two types of aquaria, fresh water and salt water. Na Cl is known as an inhibitor of the mycobacterial growth. The sensitivity of strains differs. The salinity of water appears to be a selection factor. M. forfuitum was isolated more frequently in salt water.M. marinum was isolated only in salt water and M. kansasii in fresh water. These results are surprising, as these strains have about the same metabolism. The temperature of water can also be a selection factor for mycobacteria, but in our study the temperature was similar in each aquarium (25°-26°). In this study, we did not observe thermophile strains such as M. avium.Aquarists must be informed of the aquarium contamination by atypical mycobacteria and their role in the evolution of skin lesions after injury of hands and arms. The use of germicide UV lamps improves the bacteriological quality of water

Isolation of non-tuberculous mycobacteria from pastoral ecosystems of Uganda: Public Health significance

<p>Abstract</p> <p>Background</p> <p>The importance of non-tuberculous mycobacteria (NTM) infections in humans and animals in sub-Saharan Africa at the human-environment-livestock-wildlife interface has recently received increased attention. NTM are environmental opportunistic pathogens of humans and animals. Recent studies in pastoral ecosystems of Uganda detected NTM in humans with cervical lymphadenitis and cattle with lesions compatible with bovine tuberculosis. However, little is known about the source of these mycobacteria in Uganda. The aim of this study was to isolate and identify NTM in the environment of pastoral communities in Uganda, as well as assess the potential risk factors and the public health significance of NTM in these ecosystems.</p> <p>Method</p> <p>A total of 310 samples (soil, water and faecal from cattle and pigs) were examined for mycobacteria. Isolates were identified by the INNO-Lipa test and by 16S rDNA sequencing. Additionally, a questionnaire survey involving 231 pastoralists was conducted during sample collection. Data were analysed using descriptive statistics followed by a multivariable logistic regression analysis.</p> <p>Results</p> <p>Forty-eight isolates of NTM were detected; 25.3% of soil samples, 11.8% of water and 9.1% from animal faecal samples contained mycobacteria. Soils around water sources were the most contaminated with NTM (29.8%). Of these samples, <it>M. fortuitum-peregrinum </it>complex, <it>M. avium </it>complex, <it>M. gordonae</it>, and <it>M. nonchromogenicum </it>were the most frequently detected mycobacteria. Drinking untreated compared to treated water (OR = 33), use of valley dam versus stream water for drinking and other domestic use (OR = 20), sharing of water sources with wild primates compared to antelopes (OR = 4.6), sharing of water sources with domestic animals (OR = 5.3), and close contact with cattle or other domestic animals (OR = 13.8) were the most plausible risk factors for humans to come in contact with NTM in the environment.</p> <p>Conclusions</p> <p>The study detected a wide range of potentially pathogenic NTM from the environment around the pastoral communities in Uganda. Drinking untreated water and living in close contact with cattle or other domestic animals may be risk factors associated with the possibility of humans and animals acquiring NTM infections from these ecosystems.</p

An overview on the reactors to study drinking water biofilms

The development of biofilms in drinking water distribution systems (DWDS) can cause pipe degradation, changes in the water organoleptic properties but the main problem is related to the public health. Biofilms are the main responsible for the microbial presence in drinking water (DW) and can be reservoirs for pathogens. Therefore, the understanding of the mechanisms underlying biofilm formation and behavior is of utmost importance in order to create effective control strategies. As the study of biofilms in real DWDS is difficult, several devices have been developed. These devices allow biofilm formation under controlled conditions of physical (flow velocity, shear stress, temperature, type of pipe material, etc), chemical (type and amount of nutrients, type of disinfectant and residuals, organic and inorganic particles, ions, etc) and biological (composition of microbial community e type of microorganism and characteristics) parameters, ensuring that the operational conditions are similar as possible to the DWDS conditions in order to achieve results that can be applied to the real scenarios. The devices used in DW biofilm studies can be divided essentially in two groups, those usually applied in situ and the bench top laboratorial reactors. The selection of a device should be obviously in accordance with the aim of the study and its advantages and limitations should be evaluated to obtain reproducible results that can be transposed into the reality of the DWDS. The aim of this review is to provide an overview on the main reactors used in DW biofilm studies, describing their characteristics and applications, taking into account their main advantages and limitations.This work was supported by the Operational Programme for Competitiveness Factors COMPETE and by Portuguese Foundation for Science and Technology through Project Phyto disinfectants - PTDC/DTPSAP/1078/2012 (COMPETE: FCOMP-01-0124-FEDER-028765), the Post-Doc grant awarded to Lucia Simoes (SFRH/BPD/81982/2011). Also, this work was undertaken as part of the European Research Project SUS-CLEAN (Contract n_FP7-KBBE-2011-5, project number: 287514) and the COST Action FA1202. The authors are solely responsible for this work. It does not represent the opinion of the Community, and the Community is not responsible for any use that might be made of data appearing herein

Epidemiology and Clinical Features of Pulmonary Nontuberculous Mycobacteriosis in Nagasaki, Japan

Background and Objectives: Recent reports indicate that the incidence of nontuberculous mycobacterial-lung disease (NTM-LD) is increasing. This study aimed to investigate the epidemiology and clinical features of NTM-LD patients in Nagasaki prefecture, Japan to identify the negative prognostic factors for NTM-LD in Japan. Methods: The medical records of patients newly diagnosed with NTM-LD in eleven hospitals in Nagasaki prefecture between January 2001 and February 2010 were reviewed. Data regarding the annual population of each region and the incidence of all forms of tuberculosis were collected to assess geographic variations in NTM-LD incidence, isolates, and radiological features. Results: A total 975 patients were diagnosed with NTM-LD. The incidence increased over the study period and reached 11.0 and 10.1 per 100,000 population in 2008 and 2009, respectively. M. intracellulare was the most common pathogen in the southern region, and M. avium most common in other regions. The most common radiographic pattern was the nodular-bronchiectatic pattern. Age >60 years, body mass index <18.5 kg/m2, underlying lung disease, and cavitary pattern were the negative prognostic factors at the 1-year follow-up. Conclusions: The incidence of NTM-LD has been increasing in Nagasaki prefecture. The isolates and radiographic features of patients vary markedly by region

Mycobacterium xenopi and Drinking Water Biofilms

The ability of Mycobacterium xenopi to colonize an experimental drinking water distribution system (a Propella reactor) was investigated. M. xenopi was present in the biofilm within an hour following its introduction. After 9 weeks, it was always present in the outlet water (1 to 10 CFU 100 ml(−1)) and inside the biofilm (10(2) to 10(3) CFU cm(−2)). Biofilms may be considered reservoirs for the survival of M. xenopi

Sentinel-site surveillance of Mycobacterium avium complex pulmonary disease

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