Evaluation of microbiological safety in bioinputs produced in Mexico

Objective: This work aimed to evaluate the microbiological safety of bioinputs produced in Mexico. The main reason for this evaluation is that bioinputs are products made from the region's manures, plant residues and raw materials. The transformation of these raw materials is carried out by microorganisms present. The process goes through three stages: initial, thermophilic and final. The thermophilic stage is critical because weeds and microorganisms with pathogenic potential disappear in processes under optimal conditions. Methodology: 1345 bioinputs samples were received from different states of Mexico. The samples were evaluated for the presence of total and fecal coliforms and Escherichia coli under the provisions of the Official Mexican STANDARDS, NOM-210-SSA1-2014 and NOM-114-SSA1-1994. Results: It was possible to identify 79% of the samples with Most Probable Number values <3 of total coliforms, fecal coliforms and Escherichia coli, the minimum permissible by the Official Mexican STANDARD NOM-210-SSA1-2014, also identified 99% of samples free of Salmonella. Conclusions: The results obtained allow us to conclude that the bioinputs produced in Mexico are free of pathogens for humans, which can also be represented as innocuous bioinputs.  Objective: This work aimed to evaluate the microbiological safety of bioinputs produced in Mexico. The main reason for this evaluation is that bioinputs are products made from the region's manures, plant residues and raw materials. The transformation of these raw materials is carried out by microorganisms present. The process goes through three stages: initial, thermophilic and final. The thermophilic stage is critical because weeds and microorganisms with pathogenic potential disappear in processes under optimal conditions. Methodology: 1345 bioinputs samples were received from different states of Mexico. The samples were evaluated for the presence of total and fecal coliforms and Escherichia coli under the provisions of the Official Mexican STANDARDS, NOM-210-SSA1-2014 and NOM-114-SSA1-1994. Results: It was possible to identify 79% of the samples with Most Probable Number values <3 of total coliforms, fecal coliforms and Escherichia coli, the minimum permissible by the Official Mexican STANDARD NOM-210-SSA1-2014, also identified 99% of samples free of Salmonella. Conclusions: The results obtained allow us to conclude that the bioinputs produced in Mexico are free of pathogens for humans, which can also be represented as innocuous bioinputs

Actividad esporicida de la solución electrolizada con pH neutro en hongos de importancia poscosecha

The electroless water with neutral pH (7) is a novel antimicrobial agent, which has an effect on a large variety of microorganisms, safe for humans and the environment. The efficiency of electrolyzed super oxidation water with neutral pH (SES) in the reduction of spore germination and development of the germinative tube in fungi of postharvest importance was determined. A suspension of 8 × 10 7 mL -1 spores of the fungi Botrytis cinerea isolated from blackberry, Colletotrichum gloeosporioides isolated from mango, guava and lychee, Fusarium solani isolated from chili and stevia, Monilinia fructicola isolated from peach, Penicillium digitatum isolated from Mexican lemon and Persian lemon, Penicillium sp., papaya isolate and Rhizopus stolonifer isolated from yaca and soursop, were in contact with the SES for 5 min at concentrations of 3, 5, 6, 8, 18, 24, 27, 29, 36 and 43 ppm free chlorine, and sterile distilled water (control). Spores were seeded in culture medium potato dextrose agar (Bioxon ® ); the evaluations were carried out at 24 and 48 hours after sowing. The 100% inhibition of spore germination and Botrytis germ length was observed in the concentration range of 18-43 ppm, Colletotrichum (6-43 ppm), Fusarium (6-43 ppm), Monilinia (8 and 24-43 ppm), Penicillium (18-43 ppm), Rhizopus isolated from soursop (5-24 and 29-43 ppm) and Rhizopus of yaca (18-43 ppm). The results suggest that SES could be used as an alternative control of post-harvest fungi. Palabras clave: Disease, fruit, pathogen, rot, spores.El agua electrolizada con pH neutro (7) es un novedoso agente antimicrobiano, que tiene efecto en una gran variedad de microorganismos, seguro para los seres humanos y el medio ambiente. Se determinó la eficacia del agua electrolizada de súper oxidación con pH neutro (SES) en la reducción de la germinación de esporas y desarrollo del tubo germinativo en hongos de importancia postcosecha. Una suspensión de 8 × 10 7 esporas mL -1 de los hongos Botrytis cinerea aislado de zarzamora, Colletotrichum gloeosporioides aislado de mango, guayaba y lichi, Fusarium solani aislado de chile y estevia, Monilinia fructicola aislado de durazno, Penicillium digitatum aislado de limón mexicano y limón persa, Penicillium sp., aislado de papaya y Rhizopus stolonifer aislado de yaca y guanábana, estuvieron en contacto con la SES por 5 min a concentraciones de 3, 5, 6, 8, 18, 24, 27, 29, 36 y 43 ppm de cloro libre, y agua destilada estéril (testigo). Las esporas se sembraron en medio de cultivo papa dextrosa agar (Bioxon ® ); las evaluaciones se realizaron a las 24 y 48 horas posteriores a la siembra. La inhibición de 100% en la germinación de esporas y longitud del tubo germinativo de Botrytis se observó en el rango de concentración de 18-43 ppm, Colletotrichum (6-43 ppm), Fusarium (6 - 43 ppm), Monilinia (8 y 24-43 ppm), Penicillium (18-43 ppm), Rhizopus aislado de guanábana (5-24 y 29-43 ppm) y Rhizopus de yaca (18-43 ppm). Los resultados sugieren que la SES podría ser utilizada como alternativa de control de hongos poscosecha. Palabras clave: Enfermedad, esporas, fruto, pudrición, patógeno

Serogroups, K1 antigen, and antimicrobial resistance patterns of Aeromonas spp. strains isolated from different sources in Mexico

A total of 221 strains of Aeromonas species isolated in Mexico from clinical (161), environmental (40), and food (20) samples were identified using the automated system bioMérieux-Vitek®. Antisera for serogroups O1 to 044 were tested using the Shimada and Sakazaki scheme. The K1 antigen was examined using as antiserum the O7:K1C of Escherichia coli . Besides, we studied the antimicrobial patterns according to Vitek AutoMicrobic system. Among the 161 clinical strains 60% were identified as A. hydrophila, 20.4% as A. caviae, and 19.25% as A. veronii biovar sobria. Only A. hydrophila and A. veronii biovar sobria were found in food (55 and 90% respectively) and environmental sources (45 and 10% respectively). Using "O" antisera, only 42.5% (94/221) of the strains were serologically identified, 55% (121/221) were non-typable, and 2.5% (6/221) were rough strains. Twenty-two different serogroups were found, O14, O16, O19, O22, and O34 represented 60% of the serotyped strains. More than 50% of Aeromonas strain examined (112/221) expressed K1 encapsulating antigen; this characteristic was predominant among Aeromonas strains of clinical origin. Resistance to ampicillin/sulbactam and cephazolin was detected in 100 and 67% of Aeromonas strain tested for their susceptibility to antibiotics. In conclusion, antibiotic-resistant Aeromonas species that possess the K1 encapsulating antigen and represent serogroups associated with clinical syndrome in man are not uncommon among Aeromonas strains isolated from clinical, food and environmental sources in Mexico

Bacterial Succession through the Artisanal Process and Seasonal Effects Defining Bacterial Communities of Raw-Milk Adobera Cheese Revealed by High Throughput DNA Sequencing

The bacterial community of the artisanal Adobera cheese from Los Altos de Jalisco was described through high-throughput sequencing of 16S rRNA gene libraries. Samples were collected in two different seasons (dry and rainy) during four key steps of the manufacturing process (raw milk, fresh curd, matured curd, and cheese). Bacterial diversity was higher in early steps in comparison with the final elaboration stages. Firmicutes and Proteobacteria were the most abundant phyla, strongly represented by the Streptococcaceae, Enterobacteriaceae and Lactobacillaceae families, and core bacteria genera such as Streptococcus spp., Lactococcus spp., and Lactobacillus spp. Undesirable bacteria, including Pseudomonas spp. and Acinetobacter spp., were also detected in raw milk but almost undetectable at the end of the cheese manufacturing process, and seemed to be displaced by lactic-acid bacteria-related genera. Seasonal effects were observed on the community structure but did not define the core microbiota composition. Predictive metabolism was related to membrane transport, and amino-acid, lipid, and carbohydrate metabolism pathways. Our results contribute to deduce the role of bacteria involved in Adobera cheese manufacturing in terms of the metabolism involved, cheese microbial safety, and how undesirable bacterial populations could be regulated by process standardization as a potential tool to improve safety