Evaluation of the SLOMYCO Sensititre(®) panel for testing the antimicrobial susceptibility of Mycobacterium marinum isolates.

BACKGROUND: The agar dilution method is currently considered as the reference method for Mycobacterium marinum drug susceptibility testing (DST). As it is time-consuming, alternative methods, such as the E-test, were evaluated for M. marinum DST, but without success. The SLOMYCO Sensititre(®) panel, recently commercialized by TREK Diagnostic Systems (Cleveland, OH), can be used for DST in slow-growing mycobacteria and for antimicrobial agents recommended by the Clinical and Laboratory Standards Institute (CLSI) for M. marinum DST. The main goal of this work was to evaluate the SLOMYCO Sensititre(®) panel method for DST in M. marinum isolates from human patients and fish relative to the reference agar dilution method. METHODS/RESULTS: The reproducibility of the minimum inhibitory concentration (MIC) determination (±1 log2 dilution) was very good for both the agar dilution method and SLOMYCO Sensititre(®) panel (>90 % agreement). The percentage essential agreement between methods varied, depending on the drug: between 97 and 75 % for ciprofloxacin, moxifloxacin, linezolid, isoniazid, clarithromycin, amikacin, rifabutin and rifampin, 74 % for trimethoprim, 72 % for doxycycline, 70 % for sulfamethoxazole, 59 % for streptomycin, 33 % for ethambutol and only 2.2 % for ethionamide. When the agar dilution and SLOMYCO Sensititre(®) panel results were converted into interpretive criteria, the category agreement was 100 % for amikacin, ciprofloxacin, clarithromycin, moxifloxacin, rifabutin, sulfamethoxazole and trimethoprim, 98 % for ethambutol and 96 % for rifampin and no agreement for doxycycline. CONCLUSIONS: The SLOMYCO Sensititre(®) panel method could provide a potential alternative to the reference agar dilution method, when DST in M. marinum is required, except for doxycycline.

Propagation method of saving valuable strains from a Mycobacterium liflandii infection in Western clawed frogs (Silurana tropicalis).

Mycobacterium liflandii has been responsible for an emerging infection reported in the international trade of Western clawed frogs (Silurana tropicalis). This study shows that this mycolactone-producing Mycobacterium (MPM) has expanded its distribution range to France. The results of this study suggest that the use of in vitro fertilization to maintain genetic lines could be a temporary solution for valuable S. tropicalis propagation.

Treatment of peritoneal carcinomatosis in patients with digestive cancers with combination of intraperitoneal hyperthermia and mitomycin C.

Peritoneal carcinomatosis in patients with digestive cancer carries a poor prognosis, with a majority of patients dying within 6 months. Mitomycin C has been reported to have some antitumor efficacy in this setting. We performed combination intraperitoneal hyperthermia and mitomycin to potentiate the effect of mitomycin C in 83 patients with peritoneal involvement due to digestive cancers. Eighty six IPCH procedures were performed using inflow temperature 46 to 49 degrees Celsius, using a closed circuit, during 90 minutes. Mitomycin C was administered as a perfusate at 10 mg/l. Primary tumors were essentially gastric (42) and colorectal (27). Mortality and morbidity rates were 3/83 and 5/83 respectively. For resectable tumors, the median survival time was 16 months in stage 1 and 2 carcinomatosis (malignant granulations less than 5 mm in diameter). For resectable gastric cancers with stage 1 and 2 carcinomatosis, one, two and three year actuarial survival rates were 80, 61 and 41% respectively. In conclusion, IPCH appears to be an interesting therapeutic option in patients with digestive cancers and small malignant peritoneal granulations (stage 1 and 2).

[Acute poisoning caused by intravenous arsenic]. / Une intoxication aiguë à l'arsenic par voie veineuse.

INTRODUCTION: During acute sodium arsenite intoxication, absorption is usually oral and rarely respiratory. We report the first case of acute intoxication by intravenous administration, with pharmacokinetic modelling. OBSERVATION: A 38 year-old man had attempted suicide by injecting a solution of sodium arsenite. The first symptoms upon admission to an emergency unit were hypotension, electrocardiographical disorders with prolonged QT and aqueous diarrhoea. Dimercaprol therapy was immediately set-up but was stopped on 48 hours later because of acute renal failure. Eleven successive blood and urine samples were drawn. Hairs and nails were sampled at the 130th hour. Results of the confirmed the elevated arsenic concentrations in all the samples. The pharmacokinetic parameters were computed following a two-compartment model with intravenous administration and with elimination from the central compartment. DISCUSSION: During this acute intravenous induced arsenic poisoning, the symptomatology was comparable to that following oral intoxication. The chelating treatment, although rapidly suspended, obviously contributed to survival. The eventual occurrence of other cases should permit the adaptation of therapeutic protocols to these types of intoxication.

Antioxidants to reduce sperm DNA fragmentation: an unexpected adverse effect.

Reactive oxygen species (ROS) have a negative impact on sperm DNA, leading to the formation of oxidative products such as 8-oxo-7,8-dihydroxyguanosine. This compound causes fragmentation and, thus, has a mutagenic effect. Patient treatment with oral antioxidant vitamins is, therefore, standard practice for male infertility, in an attempt to decrease formation of ROS and improve fertility. In this study, the DNA fragmentation index and the degree of sperm decondensation were measured using the sperm chromatin structure assay before and after 90 days treatment with antioxidant vitamins associated with zinc and selenium. Antioxidant treatment led to a decrease in sperm DNA fragmentation (-19.1%, P < 0.0004), suggesting that at least part of the decay was linked to ROS. However, it also led to an unexpected negative effect: an increase in sperm decondensation with the same order of magnitude (+22.8%, P < 0.0009). The opening of interchain disulphide bridges in protamines may explain this aspect, as antioxidant vitamins, especially vitamin C, are able to open the cystin net, thus interfering with paternal gene activity during preimplantation development. This observation might explain the discrepancy observed concerning the role of these antioxidant treatments in improving male fertility.

Evaluating human sperm DNA integrity: relationship between 8-hydroxydeoxyguanosine quantification and the sperm chromatin structure assay.

In our work, we have used 8-hydroxy-deoxyguanosine (8-OH-dG), one of the major oxidative products of sperm DNA, in a population of patients consulting for infertility. We found an inverse relationship between sperm concentration and the log of the ratio of 8-OH-dG to dG (P < 0.01). On the same patients' sperm samples, the sperm chromatin structure assay (SCSA) was performed. An inverse relationship was observed between the DNA fragmentation index and sperm concentration (P < 0.001). There was also a positive relationship between SCSA and log 8-OH-dG/dG. This indicates that DNA fragmentation measured by the SCSA originates in part from oxidative products. In a few patients, antioxidant treatment decreased the DNA fragmentation index below the threshold of 30% that is crucial for subfertility.