Head-to-head comparison of CAMPYAIR aerobic culture medium versus standard microaerophilic culture for Campylobacter isolation from clinical samples.

Campylobacter spp. are considered the most frequent cause of acute gastroenteritis worldwide. However, outside high-income countries, its burden is poorly understood. Limited published data suggest that Campylobacter prevalence in low- and middle-income countries is high, but their reservoirs and age distribution are different. Culturing Campylobacter is expensive due to laboratory equipment and supplies needed to grow the bacterium (e.g., selective culture media, microaerophilic atmosphere, and a 42°C incubator). These requirements limit the diagnostic capacity of clinical laboratories in many resource-poor regions, leading to significant underdiagnosis and underreporting of isolation of the pathogen. CAMPYAIR, a newly developed selective differential medium, permits Campylobacter isolation without the need for microaerophilic incubation. The medium is supplemented with antibiotics to allow Campylobacter isolation in complex matrices such as human feces. The present study aims to evaluate the ability of the medium to recover Campylobacter from routine clinical samples. A total of 191 human stool samples were used to compare the ability of CAMPYAIR (aerobic incubation) and a commercial Campylobacter medium (CASA, microaerophilic incubation) to recover Campylobacter. All Campylobacter isolates were then identified by MALDI-TOF MS. CAMPYAIR showed sensitivity and specificity values of 87.5% (95% CI 47.4%-99.7%) and 100% (95% CI 98%-100%), respectively. The positive predictive value of CAMPYAIR was 100% and its negative predictive value was 99.5% (95% CI 96.7%-99.9%); Kappa Cohen coefficient was 0.93 (95% CI 0.79-1.0). The high diagnostic performance and low technical requirements of the CAMPYAIR medium could permit Campylobacter culture in countries with limited resources.

Fetal bovine serum-a cell culture dilemma.

Ethical and possible reproducibility issues arise when using fetal bovine serum in cell culture media.

The use of BCYE medium for the detection of Legionella in environmental water samples: an appropriate update to ISO 11731:2017 standard?

We evaluated the diagnostic performances of 2 media (BCYE, MWY) on 951 Legionella-positive hospital water samples. MWY allowed detecting Legionella in 89.2% of samples, but in 10.8% (103/951) Legionella was found on BCYE plates only. In samples where Legionella was isolated with other microorganisms (663/951), MWY was essential to detect the majority of positive samples (349/663, 52.6%), as fewer plates resulted unreadable; however, in those containing Legionella only, a higher frequency of positive samples was recorded with BCYE (94.8%, 273/288) compared to MWY (85.1%, 245/288). Considering the 484 concordant positive samples, overall Legionella counts were significantly higher on BCYE (P = 0.0029), with 47% of samples showing higher counts on BCYE compared to MWY plates. Furthermore, discordant samples (positive on only one medium) showed different relative proportions between Legionella pneumophila and non-pneumophila, the latter being found more frequently on BCYE only (P = 0.0296).Our findings confirm the appropriateness of the ISO 11731:2017 update.

A Simple and Efficient Solution to Eliminate Evaporation in Mammalian Embryo Cultures.

The aim of this brief report is to offer a solution for a problem that compromises the quality of in vitro-produced mammalian embryos. The harmful effects of evaporation-induced osmotic changes in mammalian embryo cultures have been recognized only recently. In this technical report, we describe a modified embryo culture dish (Humdish) that provides consistent >97% humidity and fully eliminates osmotic changes in the commonly used drop-under-oil culture systems from day 0 to 6. As an additional benefit, the Humdish also increases the temperature stability of cultures. If subsequent laboratory and clinical experiments prove its value, our suggested approach may help to improve the in vitro environment and quality of all preimplantation stage mammalian embryos, including the most sensitive ones produced from artificial gametes or by somatic cell nuclear transfer.

Isolation of third generation cephalosporin resistant Enterobacteriaceae from retail meats and detection of extended spectrum beta-lactamase activity.

Various methods have been described to isolate third generation cephalosporin (3GC) resistant Enterobacteriaceae from foods, but it is not known how comparable they are between studies. Here, the performance of five enrichment broths and two selective agars are compared for their ability to isolate 3GC resistant Enterobacteriaceae from retail chicken, beef, pork, and veal samples. The results showed equivalence between Enterobacteriaceae enrichment broth (EE), lauryl sulfate broth (LST), and modified typtone soy broth (mTSB). Lower isolation rates were observed when LST and mTSB were supplemented with the 3GC antibiotic cefotaxime. The overall performance of MacConkey agar supplemented with cefotaxime and a proprietary selective agar (ESBL CHROMagar) was equivalent, although differences linked to the microbiota of specific meat commodities were noted. Regardless of the isolation method, further screening was required to confirm the taxonomy and resistance of the presumptive positive strains. Approximately 40% of confirmed 3GC resistant foodborne Enterobacteriaceae strains tested positive for extended spectrum beta-lactamase (ESBL) activity. Strains that were resistant to ceftriaxone and susceptible to cefoxitin were more likely to test positive for ESBL activity, as were strains that possessed either of two ESBL genes (blaSHV or blaTEM). Based on our results, we recommend using an antibiotic-free enrichment broth, two selective agars, and an isolate screening strategy to isolate 3GC resistant Enterobacteriaceae from retail meats. Antibiotic susceptibility testing and/or PCR screening for blaSHV or blaTEM can then be used to identify ESBL producing strains among the 3GC resistant meat isolates. The adoption of this approach by the research community will enable more effective monitoring of antibiotic resistance rates and trends among foodborne Enterobacteriaceae over time and across jurisdictions.

Comparison of BCYEα+AB agar and MWY agar for detection and enumeration of Legionella spp. in hospital water samples.

BACKGROUND: This study illustrates for the first time the performance (sensitivity and selectivity) of the selective medium BCYEα +AB suggested by the new edition of ISO 11731 for legionella isolation and enumeration. We compared the efficacy of the selective BCYEα +AB medium with that of the highly selective MWY medium. RESULTS: Legionella spp. was detected in 48.2 and 47.1% of the samples by BCYEα +AB and MWY agar, respectively. For optimal detection of Legionella spp., most protocols recommend using selective media to reduce the number of non-Legionella bacteria. Agreement between the two media was 86.7%. CONCLUSIONS: According to the results, both media have a very similar performance and they both have advantages and disadvantages over each other. In AB medium there is the risk of being less selective so more interfering microbiota may grow but in MWY medium there is the risk of being too selective. The low selectivity of the AB medium could be resolved if other treatments are applied after filtration, e.g. acid and/or heat treatment, but it must be taken into account that these treatments still reduce the number of viable Legionella. In conclusion, we recommend using MWY as a selective medium for the detection of Legionella spp. as it is easier discern suspected colonies and facilitate the final Legionella spp.

Effect of particle size distribution on filtration performance of cell culture medium.

Cell culture media used in CHO-based biologic processes are typically sterile filtered to prevent microbial contamination prior to inoculation. In this study, the impact of common sterile filter throughput on a different, commercially available cell culture media was evaluated from the intermediate-adsorption fouling model of the filtration model. The key particle size range for optimum filter performance was discussed and identified by measuring the submicron order particle size distribution. It may be possible to predict the performance of filter capacity with size-exclusive separation by understanding the media particle counts and size distribution.

Misidentification of Candida dubliniensis isolates with the VITEK MS.

The phylogenetic relatedness of Candida dubliniensis and C. albicans may lead to misidentification of C. dubliniensis and underestimation of its clinical significance. We evaluated the performance of VITEK-MS in identifying C. dubliniensis isolates following growth on different culture media. Correct identification was documented in 98% of the isolates grown on blood agar media whereas only 44% were correctly identified from SDA or CHROMagar. The use of non-manufacturer validated media for identifying C. dubliniensis with VITEK-MS, may result in misidentification of these isolates as C. albicans. This finding calls for reassessing the accuracy of fungal isolates identification in local workflows using non-validated culture media.

Validation of the Media Fill Method for Solid Tissue Processing in Good Manufacturing Practice-Compliant Cell Production.

Over the past few years, a large number of clinical studies for advanced therapy medicinal products have been registered and/or conducted for treating various diseases around the world and many have generated very exciting outcomes. Media fill, the validation of the aseptic manufacturing process, is the simulation of medicinal product manufacturing using nutrient media. The purpose of this study is to explain the media fill procedure stepwise in the context of cellular therapy medicinal products. The aseptic preparation of patient individual cellular product is simulated by using tryptic soy broth as the growth medium, and sterile vials as primary packaging materials.

Analysing culture methods of frozen human ovarian tissue to improve follicle survival.

In vitro follicle growth is a potential fertility preservation method for patients for whom current methods are contraindicated. Currently, this method has only been successful using fresh ovarian tissue. Since many patients who may benefit from this treatment currently have cryopreserved ovarian tissue in storage, optimising in vitro follicle growth (IVG) for cryopreserved-thawed tissue is critical. This study sought to improve the first step of IVG by comparing different short-term culture systems for cryopreserved-thawed human ovarian tissue, in order to yield a higher number of healthy multilayer follicles. We compared two commonly used culture media (αMEM and McCoy's 5A), and three plate conditions (300 µL, 1 mL on a polycarbonate membrane and 1 mL in a gas-permeable plate) on the health and development of follicles after 6 days of culture. A total of 5797 follicles from three post-pubertal patients (aged 21.3 ± 2.3 years) were analysed across six different culture conditions and non-cultured control. All culture systems supported follicle development and there was no difference in developmental progression between the different conditions tested. Differences in follicle morphology were evident with follicles cultured in low volume conditions having significantly greater odds of being graded as morphologically normal compared to other conditions. Furthermore, culture in a low volume of αMEM resulted in the highest proportion of morphologically normal primary and multilayer follicles (23.8% compared to 6.3-19.9% depending on condition). We, therefore, recommend culturing cryopreserved human ovarian tissue in a low volume of αMEM to support follicle health and development. LAY SUMMARY: Ovaries contain a large number of follicles, each containing an immature egg and other important cells. Cancer treatments can lead to long-lasting negative side effects to the ovaries including the destruction of follicles, resulting in infertility. One strategy to preserve fertility is freezing of ovaries or ovarian tissue in girls and women undergoing cancer treatment. The long-term aim is to thaw and grow their ovarian tissue in the laboratory to obtain mature eggs, which can then be fertilised. In this study, we compared six different methods of growing previously frozen human ovarian tissue in order to best support follicle growth and health. We found that using the lowest amount of αMEM medium (a specific type of nutrient-rich growth solution) resulted in the highest proportion of healthy follicles. Improving the methods used to grow ovarian tissue, particularly frozen tissue, is important for future fertility preservation.

Review: High temperature short time treatment of cell culture media and feed solutions to mitigate adventitious viral contamination in the biopharmaceutical industry.

Events of viral contaminations occurring during the production of biopharmaceuticals have been publicly reported by the biopharmaceutical industry. Upstream raw materials were often identified as the potential source of contamination. Viral contamination risk can be mitigated by inactivating or eliminating potential viruses of cell culture media and feed solutions. Different methods can be used alone or in combination on raw materials, cell culture media, or feed solutions such as viral inactivation technologies consisting mainly of high temperature short time, ultraviolet irradiation, and gamma radiation technologies or such as viral removal technology for instance nanofiltration. The aim of this review is to present the principle, the advantages, and the challenges of high temperature short time (HTST) technology. Here, we reviewed effectiveness of HTST treatment and its impact on media (filterability of media, degradation of components), on process performance (cell growth, cell metabolism, productivity), and product quality based on knowledge shared in the literature.

Optimization and Comparison of Three-Dimensional Culture Conditions in Different Media of Coculture and Encapsulation System for In Vitro Follicular Development in Bubalus bubalis.

The establishment of an in vitro culture system for complete oocyte maturation from the early stages of ovarian follicles is still a challenge. The aim of the present study was to assess the effect of different matrix with different culture media on the developmental growth of ovarian follicles in vitro. An ovarian histoarchitectural study was carried out to identify the primordial (0.027-0.039 mm), primary (0.041-0.079 mm), small preantral (0.085-0.131 mm), large preantral (0.132-0.294 mm), small antral (0.387-0.589 mm), and large antral (1.188-1.366 mm) follicles. Thus, large preantral follicles (0.2-0.3 mm) were mechanically isolated and cultured subsequently in different microconditions such as Dulbecco's modified Eagle's medium, Tissue Culture Medium-199 (TCM-199) and Opti-minimum essential medium, with same supplements where control (without matrix) was compared with matrix (coculture and encapsulation), which includes (1) buffalo fetal fibroblast cells, (2) cumulus cells, (3) ovarian mesenchymal cells, (4) collagen, (5) gelatin, and (6) Matrigel, cultured for 7 days in CO2 incubator at 38.5°C (5% CO2 in air). Cultured follicles were evaluated for growth rate (107.88% ± 10.24%), maturation rate (51.06% ± 6.53%), survivability rate (56.52% ± 3.42%), and antioxidant (catalase; CAT [1.58 ± 0.04 U/mg], superoxide dismutase; SOD [4.63 ± 0.05 U/mg], lactate dehydrogenase; LDH [1.48 ± 0.01 U/mg]) enzymatic activities, which showed significantly (p < 0.05) positive results in growth model with media TCM-199 than other studied groups. Furthermore, the development of large preantral follicles augmented significantly (p < 0.05) for growth rate (248.54% ± 9.51%), maturation rate (75.81% ± 7.07%), survivability rate (81.82% ± 3.02%), antioxidant (CAT [2.05 ± 0.03 U/mg], SOD [3.13 ± 0.12 U/mg], LDH [2.55 ± 0.51 U/mg]), and estradiol (175.83 ± 5.92 pg/mL) activities when they were encapsulated in Matrigel with nutritional requirements fulfilled by media TCM-199. These results provide better insight for the optimization of culture conditions for in vitro follicular development in the water buffalo, which will eventually assist in resolving the limitation of obtaining fewer competent oocytes for the embryo production in the species.

Valorization of low-cost, carbon-rich substrates by edible ascomycetes and basidiomycetes grown on liquid cultures.

Three ascomycetes (Morchella vulgaris AMRL 36, M. elata AMRL 63, Tuber aestivum AMRL 364) and four basidiomycetes strains (Lentinula edodes AMRL 124 and 126, Agaricus bisporus AMRL 208 and 209) were screened for their ability to grow on liquid static flask cultures of glucose, glycerol, molasses and waste flour-rich hydrolysates with C/N ratio of 20 and produce biomass, exopolysaccharides and lipids. The profile of lipid fatty acids was also assessed. Selected strains were furthermore cultivated in C/N = 50. Results showed that substrate consumption, biomass formation and secondary metabolites production were strain, substrate and C/N ratio dependent. The maximum biomass (X), lipid (L) and exopolysaccharides (EPS) values noted were Xmax = 25.2 g/L (C/N = 20; molasses) and Lmax = 6.51 g/L (C/N = 50; rice cereal hydrolysates) by T. aestivum strain AMRL 364 and EPSmax = 2.41 g/L by M. elata strain AMRL 63 (C/N = 50; molasses), respectively. When C/N ratio of 50 was applied, biomass, lipid production and substrate consumption seem to be negatively affected in most of the trials. The adaptation and capability of the mushroom strains to be cultivated on substrates based on agro-industrial waste streams and infant food of expired shelf date offers the opportunity to set a circular oriented bioprocess.

Ex vivo cultures and drug testing of primary acute myeloid leukemia samples: Current techniques and implications for experimental design and outcome.

New treatment options of acute myeloid leukemia (AML) are rapidly emerging. Pre-clinical models such as ex vivo cultures are extensively used towards the development of novel drugs and to study synergistic drug combinations, as well as to discover biomarkers for both drug response and anti-cancer drug resistance. Although these approaches empower efficient investigation of multiple drugs in a multitude of primary AML samples, their translational value and reproducibility are hampered by the lack of standardized methodologies and by culture system-specific behavior of AML cells and chemotherapeutic drugs. Moreover, distinct research questions require specific methods which rely on specific technical knowledge and skills. To address these aspects, we herein review commonly used culture techniques in light of diverse research questions. In addition, culture-dependent effects on drug resistance towards commonly used drugs in the treatment of AML are summarized including several pitfalls that may arise because of culture technique artifacts. The primary aim of the current review is to provide practical guidelines for ex vivo primary AML culture experimental design.

Elemental metal variance in cell culture raw materials for process risk profiling.

Elemental metals are critical raw material attributes which can impact cell culture performance and associated therapeutic protein product quality profiles. Metals such as copper and manganese act as cofactors and reagents for numerous metabolic pathways which govern cell growth, protein expression, and glycosylation, thus mandating elemental monitoring. The growing complexity of modern cell culture media formulations adds additional opportunities for elemental variance and its associated impact risks. This article describes an analytical technique applying inductively coupled plasma mass spectrometry to characterize a list of common raw materials and media powders used in mammalian cell culture and therapeutic protein production. We aim to describe a method qualification approach suitable for biopharmaceutical raw materials. Furthermore, we present detailed profiles of many common raw materials and discuss trends in raw material subtypes. Finally, a case study demonstrating the impact of an unexpected source of raw material variation is presented along with recommendations for raw material elemental risk profiling and control.

The Production of Trypanosoma Brucei Rhodesiense, Cause of African Sleeping Sickness, and Trypanosoma Cruzi, Cause of American Chagas Disease, on Different Medias and Testing a New Media

Objective: Human African trypanosomiasis, also known as sleeping sickness, is a parasitic disease in which Glossina is transmitted by human intervention and Trypanosoma b. rhodosiense and Trypanosoma b. gambiense are the causative agents Production of parasites in axenic cultures provides great advantage in parasite biochemistry, immunological, physiological and molecular studies. In this study, it is aimed to determine the medium which will produce in vigorous amount of Trypanosoma b. rhodosiense and Trypanasoma cruzi and to establish a new medium. Methods: In this study, Trypanosoma b. rhodosiense and Trypanasoma cruzi strains stored in Manisa Celal Bayar University Parasite Bank will be removed from liquid nitrogen tank under suitable conditions, planted in Medium I, Medium II, Medium III and newly developed medium. Reproductive densities of the media will be statistically analyzed on Thoma lamina depending on the time, using the Sidak's multiplequality test. Results: As a result of this study, it has been concluded that the best medium, to produce abundantly Trypanosoma b. rhodosiense and Trypanasoma cruzi strains, to be used in diagnosis and active substance screenings, molecular studies, metabolic analyzes and drug studies is the medium IV. Conclusion: This study is one of the first studies related to the production of Trypanosoma species in Turkey and planned to provide a basis for the studies of African sleeping disease, Chagas disease and their agents.

Development of a selective and differential media for the isolation and enumeration of Bacillus cereus from food samples.

AIM: Identification and enumeration of foodborne pathogens in food stuffs are valuable concerns. In the present study, starch-blood-egg yolk-polymyxin B-trimethoprim-ceftazidime (SBYPTC) agar was established to isolate and specify the number of Bacillus cereus in food products. METHODS AND RESULTS: The effectiveness of the developed medium in selecting for B. cereus from pure cultures and food matrixes naturally contaminated by high levels of microbiota was estimated, and the results were compared with that of two commercially available MYPA and PMBA media. In pure cultures, there were no significant differences in the recoverability of B. cereus among the three media, however, SBYPTC agar showed a greater exclusivity. To examine SBYPTC performance in food, B. cereus were artificially inoculated into lettuce and potato samples with high background microbiota in two separated experiments. There were no significant differences between MYPA and PEMBA. However, SBYPTC manifested greater selectivity and exclusivity and made the differentiation easier by allowing growth of B. cereus in separated colonies and inhibiting competing microflora. CONCLUSION: Our results showed that SBYPTC has high selective properties in comparison with MYPA and PEMBA. Thus, it can be considered as a useful tool to monitor the existence and the number of B. cereus in foods especially those contaminated with high levels of microflora. SIGNIFICANCE AND IMPACT OF THE STUDY: In the food industry, SBYPTC can be employed for food quality assurance to monitor B. cereus in food products contaminated with high levels of microbiota.

Metabolic and proliferation evaluation of human adipose-derived mesenchymal stromal cells (ASC) in different culture medium volumes: standardization of static culture.

Adipose-derived mesenchymal stromal/stem cells (ASC) have acquired a prominent role in tissue engineering and regenerative medicine. However, the standardization of basic culture procedures in this cellular type is still not well established according to the main qualitative cellular attributes. We evaluate the cell growth profile of human ASC in a different culture medium volumes and their nutritional composition utilizing static cultivation. Culture medium volumes (5, 10 and 15 mL/25 cm2) in T-flasks were evaluated by kinetic parameters and the metabolic composition was determined by biochemical analysis and Fourier transform infrared (FT-IR) absorption spectroscopy. 50% renewal of culture medium volume every 48 h was adopted. Immunophenotypic characterization and cell differentiation were performed. There was no difference (p > 0.05) in the kinetic parameters of cell proliferation between the culture medium volumes or in FT-IR composition. However, the concentrations of glucose, glutamine, lactate, and glutamate varied significantly during the cultivation process as a function of the medium volume. ASC presented specific antigens and differentiation potential of mesenchymal stromal/stem cells. It was concluded that the minimal culture medium volume (5 mL/25 cm2 in static culture) was sufficient to maintain the stability, potency, and growth of ASC, representing an economic and safe standardization for this cell culture process.

[Optimization of incubation duration of culture media in microbiology]. / Optimisation des durées d'incubation des milieux de culture en microbiologie.

In order to perform biological analysis, clinical laboratories apply the instructions of reagent suppliers. For culture media these instructions are often incomplete and poorly adapted to the variety of clinical samples and micro-organisms. The REMIC can help to overcome these shortcomings. Required time of incubation for culture media are proposed based on the nature of the sample and the type of micro-organism suspected. Nevertheless, they are most often expressed in multiple of 24 hours and they are often considered as minimal by the laboratories. As the samples are inoculated "continuously", while the readings are most often done at a single definite time of the day, we propose a strategy to optimize incubation duration of cultures medium. A time of incubation in the day so-called "limit" is defined. From this, the incubations are stopped or prolonged according to the results of the culture and the direct examination. As the instructions of suppliers of culture media are not adapted, it appears necessary that these suppliers relies on the repositories of professional societies as this is the case for agars medias used for antibiotic susceptibility testing.

Comparación de medios de cultivo selectivos para el aislamiento de especies del Taxón K perteneciente al complejo Burkholderia cepacia / Comparison of selective culture media for the isolation of Taxon K species belonging to the Burkholderia cepacia complex

Objetivo: Dentro del complejo Burkholderia cepacia (cBc), el Taxón K, integrado por B. contaminans y B. lata, es frecuentemente aislado de muestras clínicas e industriales. Los métodos para aislar bacterias del cBc están consensuados en el ámbito clínico pero no para muestras de origen industrial y tampoco hay información documentada sobre la capacidad de recuperación de los medios de cultivo frente a especies del Taxón K. Dada la importancia del uso correcto de medios selectivos para la recuperación de microorganismos, el objetivo de este trabajo fue comparar el agar Trypan Blue-Tetraciclina (TB-T), el agar selectivo para Burkholderia cepacia (BCSA) y el BCSA comercial modificado (BCSAm) en el aislamiento de cepas del Taxón K. Métodos: empleamos el método ecométrico utilizado en el control de calidad de medios de cultivo. Analizamos criterios de productividad, selectividad y especificidad frente a cepas de referencia del cBc, aislamientos clínicos e industriales del Taxón K y cepas de otras especies. Resultados: no se observaron diferencias de productividad y selectividad entre los medios BCSA. Con ambos se obtuvo adecuada productividad y selectividad parcial por permitir el crecimiento de especies taxonómicamente cercanas al cBc. El medio TB-T presentó menor productividad (especialmente con B. contaminans) y menor selectividad. Por otra parte, no se observaron diferencias atribuibles al origen clínico o industrial de los aislamientos. Conclusión: los resultados permiten sugerir al BCSA o BCSAm como los medios selectivos de elección para el aislamiento del Taxón K, tanto en muestras de origen clínico como industrial

Objective: Within the Burkholderia cepacia complex (Bcc), the so called Taxon K, integrated by B. contaminans and B. lata, is frequently isolated from clinical and industrial samples. There is consensus in the use of culture media for the isolation of Bcc from clinical origin but not for industrial samples. By the other side there is no documented information about the performance of culture media recovering Taxon K species. Regarding the importance of the proper use of selective media in the recovery of microorganisms from clinical and industrial samples, the objective of this work was to compare Trypan Blue-Tetracycline agar (TB-T), Burkholderia cepacia selective agar (BCSA) and commercial modified Burkholderia cepacia selective agar (BCSAm) in the isolation of Taxon K strains. Methods: we employed the ecometric method for culture media quality control. Productivity, selectivity and specificity criteria were analyzed by testing Bcc reference strains, clinical and industrial Taxon K isolates and non Bcc strains. Results: no differences in terms of productivity and selectivity were observed between BCSA and BCSAm. Both medium, displayed adequate productivity and partial selectivity since the growth of non Bcc isolates was observed. Productivity (especially with B. contaminans isolates) and selectivity in TB-T was lower than BCSA medium. No differences were observed related to the clinical or industrial origin of isolates. Conclusion: results allow us to suggest BCSA or BCSAm selective media for the isolation of Taxon K strains in clinical or industrial samples