Prevalence of Cyclomodulin-Positive E. coli and Klebsiella spp. Strains in Mexican Patients with Colon Diseases and Antimicrobial Resistance.

Colon diseases, such as colorectal cancer (CRC), are multifactor diseases that affect more than one million people per year; recently, the microbiota has been associated with an etiologic factor, specifically bacterial cyclomodulin positivity (CM+). Unfortunately, there are no studies from Mexico that detail the presence of bacterial CM+ in patients with colon diseases. We therefore performed a comprehensive study to investigate the associations and prevalence of cyclomodulin-positive Diarrheagenic E. coli (DEC), non-DEC, and Klebsiella spp. strains isolated from Mexican subjects with colon diseases. In this work, we analyzed 43 biopsies, 87 different bacteria were isolated, and E. coli was the most frequently noted, followed by Klebsiella spp., and Enterococcus spp. E. coli, non-DEC, and EPEC belonging to phylogroup B2 were the most prevalent. More than 80% of E. coli and Klebsiella were CM+. pks, cdt, cnf, and cif were identified. cdt was associated with non-DEC, cif and its combinations with EPEC, as well as cdt and psk with Klebsiella. Lastly, all the CM+ bacteria were resistant to at least one antibiotic (34% were MDR, and 48% XDR). In conclusion, the high prevalence of bacterial CM+ in colon disease patients suggests that these bacteria play an important role in the genesis of these diseases.

Combined Treatments of High Hydrostatic Pressure and CO2 in Coho Salmon (Oncorhynchus kisutch): Effects on Enzyme Inactivation, Physicochemical Properties, and Microbial Shelf Life.

This study focused on applying different high hydrostatic pressure + carbon dioxide (HHP + CO2) processing conditions on refrigerated (4 °C, 25 days) farmed coho salmon (Oncorhynchus kisutch) to inactivate endogenous enzymes (protease, lipase, collagenase), physicochemical properties (texture, color, lipid oxidation), and microbial shelf life. Salmon fillets were subjected to combined HHP (150 MPa/5 min) and CO2 (50%, 70%, 100%). Protease and lipase inactivation was achieved with combined HHP + CO2 treatments in which lipase activity remained low as opposed to protease activity during storage. Collagenase activity decreased approximately 90% during storage when applying HHP + CO2. Combined treatments limited the increase in spoilage indicators, such as total volatile amines and trimethylamine. The 150 MPa + 100% CO2 treatment was the most effective at maintaining hardness after 10 days of storage. Combined treatments limited HHP-induced color change and reduced the extent of changes caused by storage compared with the untreated sample. Microbial shelf life was extended by the CO2 content and not by the HHP treatments; this result was related to an increased lag phase and decreased growth rate. It can be concluded that combining HHP and CO2 could be an effective method of inactivating endogenous enzymes and extend salmon shelf life.

Factores de riesgo asociados al cáncer de tiroides en edad pediátrica / Risk factors associated to thyroid cancer in pediatric ages

El cáncer tiroideo infantojuvenil es raro, aunque no infrecuente. El objetivo de ésta investigación se centra en identificar los factores de riesgo, asociados al cáncer de tiroides en la edad pediátrica. Se realizó un estudio prospectivo-longitudinal con 12 pacientes con diagnóstico de cáncer de tiroides. Se revisaron las historias clínicas y se tomaron los datos siguientes: edad, sexo, raza, procedencia, antecedentes patológicos familiares, resultado de la biopsia con aguja fina y postoperatoria, tipo de cáncer, características del nódulo por ultrasonografía y síntomas acompañantes. La investigación dio como resultado, que los adolescentes fueron los más afectados, con predominio casi exclusivo del sexo femenino. El signo principal de presentación fue el nódulo tiroideo solitario, en el 100 por ciento de los casos. El resultado de la biopsia con aguja fina se correspondió con el examen histológico en todos los casos. La variante más frecuente fue el carcinoma papilar. Lo que arrojó la siguiente conclusión: el cáncer de tiroides se presentó de forma asintomática en el sexo femenino y en la raza blanca en la muestra estudiada(AU)

Thyroid cancer in children and in youngsters is rare although not infrequent. This investigation centers on identifying the risk factors associated to thyroid cancer in pediatric ages. A prospective, longitudinal study was carried out on 12 patients with the diagnosis of thyroid cancer. The case histories were reviewed and the information concerning age, sex, race, origin, familiar pathological precedents, result of the fine needle aspiration biopsy and the postoperative biopsy, type of cancer, characteristics of the nodule on the ultrasonography and the symptoms were also taken into account. The investigation concluded that adolescents were most affected, with almost exclusive predominance of the female sex. The main presentation sign was the solitary thyroid nodule in 100 per cent of the cases. The result of the fine needle aspiration biopsy corresponded to the histological examination in all the cases and the most frequent variant was papillary carcinoma. The conclusion demonstrated that the thyroid cancer appeared in an asymptomatic form in the female sex and the white included in the sample(AU)

Microbiological stabilization of Aloe vera (Aloe barbadensis Miller) gel by high hydrostatic pressure treatment.

The effect of high hydrostatic pressure (HHP) treatment (300, 400 and 500 MPa for 1 and 3 min at 20 °C) on the microbiological shelf-life and microbiota composition of Aloe vera gel during 90 days of storage at 4 °C was investigated. Aerobic mesophilic and psychrotrophic bacteria, as well as moulds and yeasts, were enumerated after HHP treatment and through cold storage. Randomly selected isolates from the count plates were identified by standard methods and the API identification system. Results showed that HHP treatment at or over 400 MPa for 3 min were effective to keep the microbial counts to undetectable levels during the whole storage period, and consequently the microbiological shelf-life of A. vera gel was extended for more than 90 days at 4 °C. The microbiota in the untreated A. vera gel was dominated by Gram-negative bacteria (mostly Rahnella aquatilis) and yeasts (mostly Rhodotorula mucilaginosa). In contrast, Gram-positive bacteria tentatively identified as Arthrobacter spp. and Micrococcus/Kocuria spp. were the predominant microorganisms in samples pressurized at 300 MPa for 1 and 3 min, while Bacillus megaterium predominating in samples treated at 400 MPa for 1 min. At 400 MPa for 3 min and above, the microbial growth was completely suppressed during at least 90 days; however, viable spore-formers were detected by enrichment.

Microbiological quality and safety of fresh cultivated and wild mushrooms commercialized in Spain.

402 samples of 22 species of cultivated and wild fresh mushrooms sold in retail markets and supermarkets in Zaragoza (Spain) were studied to quantify their microbial load (mesophilic aerobic microorganisms, Pseudomonas genus, Enterobacteriaceae, lactic acid bacteria, total and thermotolerant coliform bacteria, Escherichia coli, yeasts and moulds) and to investigate the presence of E. coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Yersinia enterocolitica. The total microbial counts ranged from 4.4 to 9.4 log cfu/g, the genus Pseudomonas being the most prevalent with counts from 3.7 to 9.3 log cfu/g and Auricularia auricula-judae the species with the highest microbial load (9.4 log cfu/g). No significant differences (p > 0.05) were detected between mean counts of wild and cultivated species in all the microbial groups studied. The microbiological safety level of the cultivated mushrooms was excellent since no pathogens were isolated, and the microbial counts of indicator microorganisms were low, being detected in only half of the species. Salmonella spp, E. coli O157:H7 and S. aureus were not isolated from any sample, Y. enterocolitica was detected in only four samples of wild mushrooms whereas twenty-six (6.5%) were positive for L. monocytogenes, their occurrence being relatively high in Calocybe gambosa (40%), Hygrophorus limacinus (40%) and Tuber indicum (100%). These results suggest that a strategy to reduce bacterial populations, and to improve the microbiological safety of some species of fresh mushrooms, should be investigated.

Prevalence of Bacillus cereus in dried milk products used by Chilean School Feeding Program.

The prevalence of Bacillus cereus, in a total of 381 samples of dried milk products (milk with rice, milk substitute, milk powder, milk-cereal-rice, pudding milk, flan, and mousse) used by the Chilean School Feeding Program, was investigated. The potential of 94 selected isolates of B. cereus to produce diarrhoeal enterotoxin (by the BCET-RPLA test) in BHI culture, as well as the ability of enterotoxigenic-strains to grow at psychrotrophic temperatures were also verified. B. cereus was found in 175 of 381 of the samples analysed (45.9%), reaching levels from 3.0 to 10(4) spores g(-1). As expected, the higher prevalence and counts were observed in those products that contained whole rice, cereals and pulses extruded, and food additives. Of the 94 isolates of B. cereus tested for diarrhoeal enterotoxin production, 28 (29.8%) were positive, and none of these was able to grow at < or = 7 degrees C. The prevalence of B. cereus in dried milk products analysed was fairly high, although it was present in low number. However, as they were composed to a large extent of enterotoxigenic mesophilic strains, the potential risk for the safety of reconstituted products held at improper temperature should not be neglected.

Prevalence of Ewingella americana in retail fresh cultivated mushrooms (Agaricus bisporus, Lentinula edodes and Pleurotus ostreatus) in Zaragoza (Spain).

The prevalence and mycopathogenic potential of Enterobacteriaceae (especially Ewingella americana) in cultivated mushrooms were studied. A total of 95 samples of Agaricus bisporus, Lentinula edodes and Pleurotus ostreatus were analyzed to quantify the Enterobacteriaceae and to identify the species isolated. The host pathogenicity test was used to verify their mycopathogenic potential. The genus Pseudomonas was also quantified, since it is the predominant bacterial group in cultivated mushrooms. The counts of Enterobacteriaceae ranged from 2.88 to 3.66 log(10) CFU g(-1), which was significantly lower than the counts of Pseudomonas spp. (4.52-7.80 log(10) CFU g(-1)). Among the 151 strains of Enterobacteriaceae isolated, 112 strains (74.2%) were classified as Ewingella americana by the API 20 E system. Other species identified were Enterobacter amnigenus bgp. 1, Enterobacter cloacae, Klebsiella terrigena, Pantoea spp. bgp. 2 and Serratia rubidaea. Only E. americana showed mycopathogenic effect, causing a browning lesion and necrosis in the center of the A. bisporus stipe. This is the first report of the isolation of E. americana from healthy cultivated button mushroom as well as from other species of cultivated mushrooms different from A. bisporus.