Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital

OBJECTIVES: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19) METHODS: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed. RESULTS: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for >12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11% versus 0%, p=0.030), lymphopenia (42% versus 18%, p=0.020), C-reactive protein level of >30 mg/L (35% versus 0%, p=0.0001), and D-dimer level of >1000 ng/mL (43% versus 6%, p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11% versus 2%, p=0.178) and cardiac alterations on echocardiogram (33% versus 22%, p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100] versus 81 [34-100], p=0.012), and school score (60 [15-100] versus 70 [15-95], p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls. CONCLUSIONS: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19.

Microbiology of organic and conventionally grown fresh produce

ABSTRACT Fresh produce is a generalized term for a group of farm-produced crops, including fruits and vegetables. Organic agriculture has been on the rise and attracting the attention of the food production sector, since it uses eco-agricultural principles that are ostensibly environmentally-friendly and provides products potentially free from the residues of agrochemicals. Organic farming practices such as the use of animal manure can however increase the risk of contamination by enteric pathogenic microorganisms and may consequently pose health risks. A number of scientific studies conducted in different countries have compared the microbiological quality of produce samples from organic and conventional production and results are contradictory. While some have reported greater microbial counts in fresh produce from organic production, other studies do not. This manuscript provides a brief review of the current knowledge and summarizes data on the occurrence of pathogenic microorganisms in vegetables from organic production.

Microbiology of organic and conventionally grown fresh produce

ABSTRACT Fresh produce is a generalized term for a group of farm-produced crops, including fruits and vegetables. Organic agriculture has been on the rise and attracting the attention of the food production sector, since it uses eco-agricultural principles that are ostensibly environmentally-friendly and provides products potentially free from the residues of agrochemicals. Organic farming practices such as the use of animal manure can however increase the risk of contamination by enteric pathogenic microorganisms and may consequently pose health risks. A number of scientific studies conducted in different countries have compared the microbiological quality of produce samples from organic and conventional production and results are contradictory. While some have reported greater microbial counts in fresh produce from organic production, other studies do not. This manuscript provides a brief review of the current knowledge and summarizes data on the occurrence of pathogenic microorganisms in vegetables from organic production.

Optimization of growth and bacteriocin production by Lactobacillus sakei subsp. sakei2a

Lactobacillus sakei subsp. sakei 2a is a bacteriocinogenic lactic acid bacterium isolated from Brazilian pork sausage, capable of inhibiting the growth of microbial pathogens, mainly Listeria monocytogenes. In order to optimize bacteriocin production for industrial applications, this study evaluated the effect of supplementation of MRS broth with glucose, Tween 20, Tween 80, sodium citrate, potassium chloride and cysteine, and effect of the initial pH and temperature of incubation of the medium on production of bacteriocins by L. sakei 2a. Adding glucose and Tween 20 to the medium, an initial pH of 5.0 or 5.5, and incubation temperatures of 25 °C or 30 °C resulted to the highest bacteriocin yields. Thus, a 2⁴ factorial design with the four variables was performed, and statistical analysis showed that it was an adequate model (R² = 0.8296). In the studied range, the four parameters significantly influenced bacteriocin production, with the maximum yield produced at an initial pH between 5.5 and 7.0, a temperature between 25 and 30 °C and supplementation of the MRS broth with glucose from 3.25 to 6.0 g L⁻¹ and Tween 20 from 0.575 to 1.15% (v/v). Response Surface Methodology analysis indicated that the highest bacteriocin production (12800 AU mL⁻¹) occurred in the MRS broth supplemented with 5.5 g L⁻¹ glucose and 1.05% Tween 20 at an initial pH of 6.28 and an incubation temperature of 25 °C. The amount of bacteriocin produced in commercial MRS broths under the same conditions was only 5600AU mL⁻¹.

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: Application in the control of Listeria monocytogenes in fresh Minas-type goat cheese

Listeria monocytogenes is a pathogen frequently found in dairy products. Its control in fresh cheeses is difficult, due to the psychrotrophic properties and salt tolerance. Bacteriocinogenic lactic acid bacteria (LAB) with proven in vitro antilisterial activity can be an innovative technological approach but their application needs to be evaluated by means of in situ tests. In this study, a novel bacteriocinogenic Lactococcus lactis strain (Lc. lactis DF4Mi), isolated from raw goat milk, was tested for control of growth of L. monocytogenes in artificially contaminated fresh Minas type goat cheese during storage under refrigeration. A bacteriostatic effect was achieved, and counts after 10 days were 3 log lower than in control cheeses with no added LAB. However, this effect did not differ significantly from that obtained with a non-bacteriocinogenic Lc. lactis strain. Addition of nisin (12.5 mg/kg) caused a rapid decrease in the number of viable L. monocytogenes in the cheeses, suggesting that further studies with the purified bacteriocin DF4Mi may open new possibilities for this strain as biopreservative in dairy products.

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: characterization of the bacteriocin

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality.

Bacteriocinogenic Lactococcus lactis subsp: lactis DF04Mi isolated from goat milk: Evaluation of the probiotic potential

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.

Correlation between API 20 STREP and multiplex PCR for identification of Enterococcus spp. isolated from Brazilian foods

We evaluated the suitability of API 20 STREP and multiplex PCR to speciate 52 Enterococcus spp. obtained from Brazilian foods. A high percentage of isolates (78.9 percent) presented discrepant results between evaluated tests. Similar results were obtained for six E. faecalis and five E. faecium. The PCR multiplex was more effective than API 20 STREP for complete identification of the isolates.

A identificação das espécies de 52 Enterococcus spp. isolados de amostras de alimentos foi realizada empregando-se duas metodologias: sistema API 20 STREP e PCR multiplex. Os resultados obtidos revelaram que 78,9 por cento dos isolados apresentaram resultados diferentes nos dois testes utilizados. Apenas seis E. faecalis e cinco E. faecium apresentaram resultados concordantes pelos dois métodos. PCR multiplex permitiu a identificação completa de um número significantemente maior de enterococos do que o sistema API 20 STREP.

Hazards in non-pasteurized milk on retail sale in Brazil: prevalence of Salmonella spp, Listeria monocytogenes and chemical residues

A instabilidade do mercado de leite no Brasil força pequenos produtores de leite a procurar alternativas de comércio de sua produção, o que inclui a venda de leite cru para indivíduos que dão preferência a esse tipo de leite. Considerando a importância desse mercado e os conhecidos riscos à saúde que o consumo de leite cru pode representar, este estudo avaliou a qualidade microbiológica e a presença de Listeria monocytogenes, Salmonella spp., resíduos de cloretos, antimicrobianos e inseticidas (organofosforados e carbamatos) em leite cru produzido em 210 propriedades leiteiras localizadas em quatro importantes estados produtores de leite no Brasil (Paraná, São Paulo, Minas Gerais e Rio Grande do Sul). Em 66% das propriedades selecionadas, a ordenha era manual. Em 33% a ordenha era semi-automática (ordenha mecânica balde ao pé) e em apenas 1% o sistema de ordenha e armazenamento era totalmente mecânico (sistema fechado). Todas as amostras de leite cru foram negativas para L. monocytogenes, Salmonella spp e resíduos de cloretos. As contagens de aeróbios mesófilos foram superiores a 105 UFC/mL em 75,7% das amostras. Em 80,4%, as contagens de coliformes foram superiores a 102 UFC/mL. Escherichia coli foi detectada em 36,8% das amostras. Inseticidas e resíduos de antibióticos foram observados em 74,4% e 11,5% das amostras, respectivamente. Níveis inaceitáveis de microrganismos indicadores de higiene, inseticidas e resíduos de antibióticos foram considerados fatores de risco mais importantes que os dois patógenos estudados.

Detecçäo de bacteriocinas produzidas por Lactobacillus plantarum BN em melaço de cana-de-açúcar sob fermentaçäo submersa / Detection of bacteriocin produced by Lactobacillus plantarum BN in sugar-cane molasses by submerse fermentation

Verificou-se a presença de baqcteriocinas produzidas por Lactobacillus plantarum BN (microorganismo teste) em caldo com 3 por cento de melaço de cana-de-açúcar, centrifugado e enriquecido com extrato de leveduras,a cetato de sódio e citrato de amônia. Os testes foram realizados em fermentador com volume de trabalho de 3,0 L, sob agitaçäo contínua a 100 rpm, temperatura de 30 +- 0,1 §C, aeraçäo de 0,7 vvm, tempo de fermentaçäo de 24 horas e inóculo aproximado de 6,0 Log 10 UFC/mL, com tomada de amostras em intervalos de 2 horas. O maior número médio de células viáveis foi de 10 Log10 ciclos logarítmicos, nos intervalos de 12 a 18 horas de fermentaçäo. O pH inicial de 6,49, após 24 horas diminuiu para 5,05. A detecçäo de bacteriocinas foi realizada no sobrenadante obtido por centrifugaçä do meio de cultivo, pelo método de difusäo em orifícios, usando Lactobacillus sakei ATCC 15521 como microroganismo indicador. Verificou-se a presença de bacteriocinas no meio de cultivo a partir de 8 horas de fermentaçäo pela formaçäo de halo inibitório, quando o microorganismo encontrava-se na fase exponencial de crescimento. Comprovou-se a natureza protéica da bacteriocina produzida pelo uso da enzima alfa-quimotripsina. A bacteriocina produzida por L. plantarum BN apresentou efeito inibitório sobre Listeria monocytogenes ATCC 19112, mas säo sobre Staphylococcus aureus ATCC 15489

Inactivation of Escherichia coli O157: H7 in hamburgers by gamma irradiation

Escherichia coli O157:H7 causes bloody diarrhoea, haemorrhagic colitis and life-threatening complications like haemolytic uremic syndrome and thrombotic thrombocitopenic purpura. Among foods associated with outbreaks caused by this pathogen, hamburger is the most common one. The aim of this research was to determine the radiation dose to reduce the population of E. coli O157:H7 in hamburgers to non-detectable levels in order to render a safer product. Hamburgers, inoculated with Escherichia coli O157:H7, were exposed to gamma radiation (60Co) treatment, with doses ranging from 0 to 0.7 kGy. The average temperature during the process was 5.6§C. Non-inoculated hamburgers were submitted to sensory evaluation after being exposed to irradiation doses of 0.8 kGy and 1.0 kGy. The D10 for the pathogen varied from 0.17 kGy to O.27 kGy in hamburger. Considering the highest D10 value in hamburger, a dose of 1.08 kGy would be sufficient to reduce E. coli O157:H7 contamination in 4 log cycles, without affecting the sensory attributes of the product.

Influence of bacteriocins produced by Lactobacillus Plantarum BN in the shelf-life of refrigerated bovine meat

Sugar cane molasses is a cheap by-product of the sugar cane industry. This product was used for growth and production of bacteriocins by Lactobacillus plantarum BN and evaluated for its potential application in the extension of the shelf-life of raw meat. Bovine meat cubes were dipped in the filtered and neutralized supernatant of the fermented broth (Treatment A) and stored at 5(o)C. Counts of psychrotrophic and mesophilic aerobic microorganisms, pH determination and total acidity were performed on meat cubes after 0, 3, 6, 9, 12 and 15 days. These determinations were also done in cubes dipped in a 6 per cente lactic acid solution (treatment B) and distilled water (treatment C). After 3 days, the counts of psychrotrophic microorganisms in cubes submitted to treatment A, B and C increased 0.38, 1.42 and 2.04 log cycles, respectively. The same happened with mesophilic microorganisms (0.31, 0.33 and 1.04 log cycles increases, respectively). On the sixth day, the psychrotrophic population in samples submitted to treatments A and B were 2.07 and 0.64 log cycles, respectively, lower than in the control samples (treatment C). Mesophilic microorganisms in these samples were 1.58 and 1.12 log cycles, respectively, lower than the controls. On the sixth day, only samples submitted to treatment A presented lower counts than those recommended by ICMSF as quality standards for raw meat (<10(7) CFU/g). After nine days of storage under refrigeration, samples submitted to treatment A still maintained acceptable quality. From the twelfth day on, all samples exceeded the microbial quality limits. These results indicate that dipping of raw meat in filtered sugar cane molasses containing bacteriocins produced by L. plantarum BN may be an interesting technological option to extend the shelf life of refrigerated bovine meat.

Biochemical characteristics of typical and atypical "Staphylococcus aureus" in mastitic milk and environmental samples of brazilian dairy farms

This study results on the biochemical characteristics of 274 "Staphylococcus aureus" strains isolated from mastitic milk, hands of milkmen and milking machines. Features included colony morphology on Baird Parker agar (BPA), catalase, coagulase, and thermonuclease tests. API-Staph (BioMérieux, France) was used as reference identification system. 39.4(per cent) of the colonies on BPA identified as "S. aureus" were atypical. They were more frequent in milk samples (94.4(per cent)). All "S. aureus" strains were coagulase positive but intensify of the test varied according to the source: enviromental strains were 3+ or 4+, while 17.1(per cent) of strains isolated from milk presented only 1+ or 2+ results. The majority of atypical "S. aureus" strains presented a 4+ coagulase result. 2.2(per cent) of "S. aureus" strains were thermonuclease negative. Sixteen thermonuclease positive and coagulase positive strains were identified as "S. hyicus"

Influence of raw meat natural background flora on growth of Escherichia coli 0157: H7 in ground beef

Escherichia coli 0157 : H7 foodborne pathogen of increasing importance. It has been involved in several threatening outbreaks, most of them associated with meat products. In this study, the influence of some bacteria from the natural background flora of raw meat over E.coli 0157 : H7 in ground beef stored under refrigeration and at room temperature was evaluated. Different levels of E.coli 0157 : H7 (10 1 - 10 2, 10 3 - 10 4, and 10 6 - 10 7 CFU/g), inoculated in ground beef samples, were challenged with strains of non-pathogenic E.coli, Psudomonas putida or Leuconostoc sp. Growth of the pathogen was monitored using standard cultural methods and an Elisa-type rapid method. Non-pathogenic E.coli, Pseudomonas putida and Leuconostoc sp. did not affect growth of E.coli 0157 : H7 in ground beef, both under refrigeration and at room temperature. Based on these findings, the low occurrence of E.coli 0157 : H7 in raw meat may not be attributed to antagonistic effects of bacteria from the natural background flora.

Doenças microbianas de origem alimentar provocadas por enteropatógenos / Foodborne diseases cauded by enteropathogens

Os alimentos de origem animal ou vegetal podem veicular diversos microrganismos patogênicos. A ingestäo desses microrganismos ou de suas toxinas poderá causar gastrenterite, no caso de enteropatógenos, botulismo e listeriose caracterizada por aborto e menigoencefalite. Seräo abordadas apenas as doenças microbianas provocadas por enteropatógenos veiculados por alimentos

Recuperaçäo de salmonelas injuriadas pelo pH ácido de maionese artificialmente contaminada / Recovery of acid injured salmonellae from artificially contaminated mayonnaise

Este estudo refere-se à avaliaçäo de métodos laboratoriais para o isolamento de salmonelas (10 elevado à terceira potência UFC/g) de amostras de maionese artificialmente contaminadas (pH entre 4.0 e 4.5), mantidas a 4ºC em temperatura ambiente. De cada amostra contaminada, alíquotas foram retiradas a cada 24h e submetidas aos seguintes procedimentos: plaqueamento direto em superfície em agar soja tríptica (TSA) seguido de período de reparo de 4h em temperatura ambiente e posterior adiçäo de agar SS e incubaçäo a 35ºC por 24h; plaqueamento direto em superfície em TSA seguido de período de reparo de 4h em temperatura ambiente e posterior adiçäo de agar Hektoen enteric e incubaçäo a 35ºC por 24h;pré-enriqueciemtno em água peptonada tamponada a 35ºC por 24h, enriqueciemtno seletivo em caldo tetrationato de Kauffmann, em caldo selenito-cistina e em caldo Rappaport-Vassiliadis, com incubaçäo a 35ºC por 24h, a 35ºC por 24h e a 43ºC por 24h, respectivamente, seguido de plaqueamento em agar SS e agar Hektoen enteric com incubaçäo a 35ºC por 24h. Näo foi notada nenhuma diferença significativa no comportamento dos três caldos de enriquecimento utilizados.

Occurrence of Campylobacter Jejuni and Campylobacter Coli in retail raw chiken meat and giblets in Säo Paulo, Brazil

Estudou-se a incidência de Campylobacter jejuni e Campylobacter coli em duzentas amostras de carne e de miúdos de frango crus, coletados em supermecados da cidade de Säo Paulo, Brasil. As amostras incluíram carcaças inteiras, pedaços de carne e miúdos (moelas, fígado, coraçäo e pés). Campylobacter foi detectado em 13,5% das amostras estudadas. Maior incidência foi observada nos pedaços de carne. Das 100 cepas de Campylobacter isoladas, 14 foram caracterizadas como C.jejuni e 86 como C.coli