This study was designed to identify the bacteria and yeasts from the milk samples of dairy cattle presenting with subclinical mastitis and evaluate their antimicrobial susceptibility. We collected a total of 52 milk samples from cows across three farms in San Salvador El Seco (Puebla, Mexico). Microbial isolation was performed using microbiological techniques followed by taxonomic identification of bacteria and yeasts. Antimicrobial susceptibility was evaluated using the guidelines provided by the Clinical Laboratory Standard Institute (CLSI). 1 We identified three genera and six species of yeasts including Candida glabrata, C. krusei, C. lipolytica, Cryptococcus laurentii, Rhodotorula rubra, and R. glutinis and five species of bacteria, including Staphylococcus saprophyticus, S. aureus, S. hominis, S. epidermidis, and Streptococcus disgalactiae. All of the yeast strains were sensitive to amphotericin B; 1/23 (4.3%) were resistant to ketoconazole and nystatin, 10/23 (43%) were resistant to fluconazole, and 13/23 (53%) were resistant to 5-fluorocytosine. The dominant genus isolated was Candida, with the most abundant groups being C glabrata and C. krusei. Resistance to 5-fluorocytosine was observed in all yeasts except C. lipolytica, while both S. aureus and S. epidermidis were resistant to oxacillin and dicloxacillin. S. hominis was resistant to gentamicin. These antimicrobials are still used in bovine therapy for mastitis, directly affecting healthy cattle and, therefore, raw milk.

En la actualidad el cambio climático, la urbanización y la globalización son los principales factores que afectan la calidad del agua, vehículo primordial para la traslocación y permanencia de los contaminantes emergentes, resultan en un peligro para la salud del humano y el medio ambiente. En los últimos años la presencia de estos compuestos ha ido en aumento, reportándose en diferentes compartimentos del ecosistema reconociéndolos en suelos agrícolas y permeándose hasta aguas subterráneas, de esta manera no es una novedad que alimentos cultivados para consumo humano puedan adsorber y acumular contaminantes emergentes comprometiendo la seguridad alimentaria. El objetivo de este artículo es documentar la problemática que está asociada a estos compuestos a partir de estudios publicados previamente.

Background. Soil constitutes the main reservoir of microorganisms, as well as the greatest source of biological diversity, a group of organisms abundant in the soil are fungi, which can perform various functions, and can exist in any type of environment, including warm ecosystems. The keratinophilic fungi group etiological agents of human dermatomycosis (dermatophytes and non-dermatophytes) that are established in the main causes of dermatological consultation in Mexico. Methodology. In order to determine the diversity of this group of fungi, soil sampling was carried out in the regions: Cerro de las Noas de Torreón, Coahuila (TC) and in the Francisco Villa community of Iguala de la Independencia, Guerrero (GUE); for the isolation and identification of keratinophilic microorganisms, the Vanbreuseghem keratin hook technique, microcultures and biochemical tests were used. On the other hand, soil pH was determined. The ecological determinations applied were the Shannon H index and the Sorensen CC index. Results. From the total of samples obtained (9) in TC 44% (4) was positive for dermatophytes, 88.9% (8) for non-dermatophytic keratinophilic fungi of which Chrysosporium was dominant and 55.6% (5) for actinomycetes, while, in GU of the 9 samples obtained in 55.6% (5) of these were identified dermatophytes, In 100% (9) non-dermatophytic keratinophilic fungi dominating Fusarium and Chaetomium and in 1% (1) actinomycetes. The pH value of soil samples on CT was 7.6 and 7.5 in GU. The Shannon diversity for TC H: 2.13 and for GU H: 2.49. The Sorensen index reported a CC: 68% similarity between the two communities. Conclusion. According to the results obtained it can be seen that the diversity of keratinophilic fungi etiological agents of dermatomycosis is dominated by non-dermatophytes, observing that despite the environmental differences are able to adapt in various environmental conditions.