Taxonomic diversity and environmental tolerance of cultivable extremophilic bacteria from a high-altitude meltwater pond on Ojos del Salado (Chile).

Earth harbors unique environments where only microorganisms adapted to extreme conditions, known as extremophiles, can survive. This study focused on a high-altitude meltwater pond, located in the Puna de Atacama, Dry Andes. The extremophilic bacteria of this habitat must adapt to a range of extremities, including cold and dry climate, high UV radiation, high daily temperature fluctuations, low-nutrient availability, and negative water balance. This study aimed to explore the taxonomic diversity of cultivable extremophilic bacteria from sediment samples of a desiccated, high-altitude, meltwater pond using media with different organic matter contents and different incubation temperatures. Based on the 16S rRNA gene sequence analysis, the isolates were identified as members of the phyla Actinobacteria, Proteobacteria, and Firmicutes. The most abundant genera were Arthrobacter and Pseudoarthrobacter. The isolates had oligocarbophilic and psychrotrophic properties, suggesting that they have adapted to the extreme environmental parameters of their natural habitats. The results indicate a positive correlation between nutrient concentration and temperature tolerance.

Assessing the Microbial Quality of Shrimp (Xiphonaeus kroyeri) and Mussels (Perna perna) Illegally Sold in the Vitória Region, Brazil, and Investigating the Antimicrobial Resistance of Escherichia coli Isolates.

The consumption of seafood is crucial for food security, but poor hygiene along the food production chain can result in low microbiological quality, posing significant risks for public health and seafood quality. Thus, this study aimed to assess the microbiological quality and antimicrobial sensitivity of E. coli from 69 samples of illegally marketed shrimp and mussels in the Vitória Region, Brazil. These foods exhibited poor microbiological quality due to high counts of mesophilic, psychrotrophic, and enterobacteria microorganisms. While this issue is widespread in this area, shrimp samples displayed higher microbial counts compared to mussels, and fresh mussels had elevated counts of enterobacteria compared to frozen ones. Among the 10 E. coli isolates, none carried the genes blaCTX-M-1, blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, mcr-1, mcr-2, mcr-3, mcr-4, and tet, associated with antibiotic resistance. Phenotypical resistance to tetracycline and fosfomycin was not observed in any isolate, while only 20% demonstrated resistance to ciprofloxacin. Regarding ampicillin and amoxicillin with clavulanic acid, 60% of isolates were resistant, 10% showed intermediate susceptibility, and 30% were sensitive. One isolate was considered simultaneously resistant to ß-lactams and quinolones, and none were conserved as ESBL producers. These findings highlight the inherent risks to local public health that arise from consuming improperly prepared seafood in this area.

Influence of dry and wet beef maturation on the microbiological quality and safety / Influência da maturação a seco e a vácuo na qualidade e segurança microbiológica da carne

The most used methods for the maturation process are vacuum (wet-aged) and dry (dry-aged), which can influence the microbiological quality and safety of meat for consumption. In this study, we aimed to verify the differences in microbiological quality between beef (Longissimus dorsi) that was wet-aged and dry-aged for 30 days, by quantification of indicator microorganism groups and molecular identification of Salmonella, Listeria monocytogenes, and diarrheagenic Escherichia coli. This study verified that the meat matured by the dry-aged method showed significantly lower counts of total coliforms, aerobic mesophiles, psychrotrophs, and molds and yeasts as compared to wet-aged meat. While the Salmonella spp. was not isolated in any beef sample, L. monocytogenes and enteropathogenic E. coli (EPEC), and shiga toxin-producing E. coli (STEC) and enterohemorrhagic E. coli (EHEC) were isolated only from wet-aged beef. Thus, it was concluded that the superficial dehydration of the meat during dry-aged maturation, if carried out correctly and hygienically, confers higher microbiological quality and can reduce the occurrence of microbiological hazards.

A maturação da carne agrega características sensoriais desejáveis ao consumidor. Os métodos mais utilizados são a vácuo (wet-aged) e à seco (dry-aged), que podem influenciar na qualidade e segurança microbiológica da carne para o consumo. O objetivo desse estudo foi verificar as diferenças de qualidade microbiológica entre cortes de contra-filé (Longissimus dorsi) maturados a vácuo e a seco por 30 dias, através da quantificação de grupos de micro-organismos indicadores e identificação molecular de Samonella, Listeria monocytogenes e Escherichia coli diarreiogênica. A carne maturada a seco apresentou contagens significativamente menores de coliformes totais, aeróbios mesófilos, psicrotróficos e bolores e leveduras em relação à carne maturada a vácuo. Salmonella spp. não foi isolada de nenhuma das amostras de carne analisadas. L. monocytogenes e E. coli enteropatogênica (EPEC), E. coli produtora de toxina shiga (STEC) e E. coli enterohemorrágica (EHEC) foram identificadas somente das carnes maturadas a vácuo. A desidratação superficial das peças durante a maturação a seco, desde que realizada de forma correta e higiênica, pode conferir maior qualidade e menor risco microbiológico para o consumo.

Influence of dry and wet beef maturation on the microbiological quality and safety / Influência da maturação a seco e a vácuo na qualidade e segurança microbiológica da carne

The most used methods for the maturation process are vacuum (wet-aged) and dry (dry-aged), which can influence the microbiological quality and safety of meat for consumption. In this study, we aimed to verify the differences in microbiological quality between beef (Longissimus dorsi) that was wet-aged and dry-aged for 30 days, by quantification of indicator microorganism groups and molecular identification of Salmonella, Listeria monocytogenes, and diarrheagenic Escherichia coli. This study verified that the meat matured by the dry-aged method showed significantly lower counts of total coliforms, aerobic mesophiles, psychrotrophs, and molds and yeasts as compared to wet-aged meat. While the Salmonella spp. was not isolated in any beef sample, L. monocytogenes and enteropathogenic E. coli (EPEC), and shiga toxin-producing E. coli (STEC) and enterohemorrhagic E. coli (EHEC) were isolated only from wet-aged beef. Thus, it was concluded that the superficial dehydration of the meat during dry-aged maturation, if carried out correctly and hygienically, confers higher microbiological quality and can reduce the occurrence of microbiological hazards.

A maturação da carne agrega características sensoriais desejáveis ao consumidor. Os métodos mais utilizados são a vácuo (wet-aged) e à seco (dry-aged), que podem influenciar na qualidade e segurança microbiológica da carne para o consumo. O objetivo desse estudo foi verificar as diferenças de qualidade microbiológica entre cortes de contra-filé (Longissimus dorsi) maturados a vácuo e a seco por 30 dias, através da quantificação de grupos de micro-organismos indicadores e identificação molecular de Samonella, Listeria monocytogenes e Escherichia coli diarreiogênica. A carne maturada a seco apresentou contagens significativamente menores de coliformes totais, aeróbios mesófilos, psicrotróficos e bolores e leveduras em relação à carne maturada a vácuo. Salmonella spp. não foi isolada de nenhuma das amostras de carne analisadas. L. monocytogenes e E. coli enteropatogênica (EPEC), E. coli produtora de toxina shiga (STEC) e E. coli enterohemorrágica (EHEC) foram identificadas somente das carnes maturadas a vácuo. A desidratação superficial das peças durante a maturação a seco, desde que realizada de forma correta e higiênica, pode conferir maior qualidade e menor risco microbiológico para o consumo.(AU)

Evaluation of plant growth promoting activity and heavy metal tolerance of psychrotrophic bacteria associated with maca (Lepidium meyenii Walp.) rhizosphere.

The high Andean plateau of Peru is known to suffer harsh environmental conditions. Acidic soils containing high amount of heavy metals due to mining activities and withstanding very low temperatures affect agricultural activities by diminishing crop quality and yield. In this context, plant growth promoting rhizobacteria (PGPR) adapted to low temperatures and tolerant to heavy metals can be considered as an environment-friendly biological alternative for andean crop management. The aim of this work was to select and characterize psychrotrophic PGPR isolated from the rhizosphere of maca (Lepidium meyenii Walp.) a traditional andean food crop. A total of 44 psychrotrophic strains isolated from 3 areas located in the Bombon plateu of Junin-Peru were tested for their PGPR characteristics like indole acetic acid (IAA) production, phosphate solubilization and for their ability to improve seed germination. In addition, their capacity to grow in the presence of heavy metals like cadmium (Cd), lead (Pb), cobalt (Co) and mercury (Hg) was tested. Of the total number of strains tested, 12 were positive for IAA production at 22 °C, 8 at 12 °C and 16 at 6 °C. Phosphate solubilization activities were higher at 12 °C and 6 °C than at 22 °C. Red clover plant assays showed that 16 strains were capable to improve seed germination at 22 °C and 4 at 12 °C. Moreover, 11 strains showed tolerance to Cd and Pb at varying concentrations. This study highlight the importance of obtaining PGPRs to be used in high andean plateu crops that are exposed to low temperatures and presence of heavy metals on soil.

Qualidade do leite cru refrigerado de uma planta de processamento, no norte do Paraná, após a implementação das mudanças impostas pela NI 62 de 2011 / Refrigerated raw milk quality of a processing plant in the north of Parana after the implementation of changes imposed by NI 62 of 2011

Este estudo teve como objetivo comparar a qualidade microbiológica e físico-química de leite cru proveniente de tanques individuais e coletivos, identificar a microbiota psicrotrófica do leite cru refrigerado e verificar o cumprimento da legislação vigente para este alimento. Realizou-se a contagem da microbiota de psicrotróficos, proteolíticos, lipolíticos, aeróbios mesófilos, coliformes totais, E. coli e enterobactérias. A microbiota psicrotrófica foi caracterizada através de testes morfotintoriais. Análises dos teores de gordura, proteína, lactose, sólidos totais, acidez titulável, índice crioscópico e contagem de células somáticas (CCS) também foram realizados. As contagens médias de aeróbios mesófilos não atenderam aos requisitos mínimos de qualidade, já os resultados médios de CCS e os parâmetros físicoquímicos estudados estavam de acordo com a legislação vigente. A contagem de psicrotróficos foi, em média, 90% da contagem total de aeróbios mesófilos, com contagens de psicrotróficos menores que 6 log UFC/ml. Foi encontrada alta porcentagem de proteolíticos e lipolíticos em relação à contagem total de psicrotróficos. Considerando as duas semanas de análise, houve diferença significativa (P>0,05) entre as amostras de leite provenientes de tanques coletivos e individuais somente para coliformes totais e para os teores de proteína e lactose. A microbiota psicrotrófica pred

This study aimed to compare the microbiological and physicochemical quality of raw milk from individual and collective tanks, identify the psychrotrophic microbiota of refrigerated raw milk and verify compliance with current legislation. The enumeration of proteolytic and lipolytic psychrotrophs, as well as, populations of mesophilic aerobes, total coliforms, E. coli and enterobacteria was carried out. The psychrotrophic microbiota was characterized by morpho-tinctorial tests. Determination of fat content, protein, lactose, total solids, titratable acidity, cryoscopic index and somatic cells count (SCC) were also conducted. The average counts of mesophilic aerobes did not met the minimum quality requirements; however, the average results of SCC and the physicochemical parameters were in accordance with Brazilian legislation. The psychrotrophs counts were on average 90% of the total count of mesophilic aerobes, with psychrotrophic population of less than 6 log CFU/ml. A high percentage of proteolytic and lipolytic psychrotrophs in relation to psychrotrophs total counts was found. Considering the two weeks testing, there was a significant difference (P> 0.05) between milk samples from collective and individual tanks only for total coliforms and for protein and lactose contents. Although the predominant psychrotrophic microbiota was Gram negative bacilli, but Gram positive bact

Qualidade do leite cru refrigerado de uma planta de processamento, no norte do Paraná, após a implementação das mudanças impostas pela NI 62 de 2011 / Refrigerated raw milk quality of a processing plant in the north of Parana after the implementation of changes imposed by NI 62 of 2011

Este estudo teve como objetivo comparar a qualidade microbiológica e físico-química de leite cru proveniente de tanques individuais e coletivos, identificar a microbiota psicrotrófica do leite cru refrigerado e verificar o cumprimento da legislação vigente para este alimento. Realizou-se a contagem da microbiota de psicrotróficos, proteolíticos, lipolíticos, aeróbios mesófilos, coliformes totais, E. coli e enterobactérias. A microbiota psicrotrófica foi caracterizada através de testes morfotintoriais. Análises dos teores de gordura, proteína, lactose, sólidos totais, acidez titulável, índice crioscópico e contagem de células somáticas (CCS) também foram realizados. As contagens médias de aeróbios mesófilos não atenderam aos requisitos mínimos de qualidade, já os resultados médios de CCS e os parâmetros físicoquímicos estudados estavam de acordo com a legislação vigente. A contagem de psicrotróficos foi, em média, 90% da contagem total de aeróbios mesófilos, com contagens de psicrotróficos menores que 6 log UFC/ml. Foi encontrada alta porcentagem de proteolíticos e lipolíticos em relação à contagem total de psicrotróficos. Considerando as duas semanas de análise, houve diferença significativa (P>0,05) entre as amostras de leite provenientes de tanques coletivos e individuais somente para coliformes totais e para os teores de proteína e lactose. A microbiota psicrotrófica pred

This study aimed to compare the microbiological and physicochemical quality of raw milk from individual and collective tanks, identify the psychrotrophic microbiota of refrigerated raw milk and verify compliance with current legislation. The enumeration of proteolytic and lipolytic psychrotrophs, as well as, populations of mesophilic aerobes, total coliforms, E. coli and enterobacteria was carried out. The psychrotrophic microbiota was characterized by morpho-tinctorial tests. Determination of fat content, protein, lactose, total solids, titratable acidity, cryoscopic index and somatic cells count (SCC) were also conducted. The average counts of mesophilic aerobes did not met the minimum quality requirements; however, the average results of SCC and the physicochemical parameters were in accordance with Brazilian legislation. The psychrotrophs counts were on average 90% of the total count of mesophilic aerobes, with psychrotrophic population of less than 6 log CFU/ml. A high percentage of proteolytic and lipolytic psychrotrophs in relation to psychrotrophs total counts was found. Considering the two weeks testing, there was a significant difference (P> 0.05) between milk samples from collective and individual tanks only for total coliforms and for protein and lactose contents. Although the predominant psychrotrophic microbiota was Gram negative bacilli, but Gram positive bact