Drinking water quality of various sources in Peshawar, Mardan, Kohat and Swat districts of Khyber Pakhtunkhwa province, Pakistan / Qualidade de água potável de váris fontes dos distritos de Peshawar, Mardan, Kohat e Swat da província de Khyber Pakhtunkhwa, Paquistão

Abstract The present study involves the chemical and bacteriological analysis of water from different sources i.e., bore, wells, bottle, and tap, from Peshawar, Mardan, Swat and Kohat districts of Khyber Pakhtunkhwa (KP) province, Pakistan. From each district, 50 water samples (10 samples from each source), regardless of urban and rural status, were collected from these sources and analysed for sulphates, nitrates, nitrites, chlorides, total soluble solids and coliforms (E. coli). Results indicated that majority of the water sources had unacceptable E. coli count i.e.> 34 CFU/100mL. E. coli positive samples were high in Mardan District, followed by Kohat, Swat and Peshawar district. Besides this, the some water sources were also chemically contaminated by different inorganic fertilizers (nitrates/nitrites of sodium, potassium) but under safe levels whereas agricultural and industrial wastes (chloride and sulphate compounds) were in unsafe range. Among all districts, the water quality was found comparatively more deteriorated in Kohat and Mardan districts than Peshawar and Swat districts. Such chemically and bacteriologically unfit water sources for drinking and can cause human health problems.

Resumo O presente estudo envolve a análise química e bacteriológica de água de diferentes fontes, ou seja, furo, poços, garrafa e torneira, dos distritos de Peshawar, Mardan, Swat e Kohat da província de Khyber Pakhtunkhwa (KP), Paquistão. De cada distrito, 50 amostras de água (10 amostras de cada fonte), independentemente do status urbano e rural, foram coletadas dessas fontes e analisadas para sulfatos, nitratos, nitritos, cloretos, sólidos solúveis totais e coliformes (E. coli). Os resultados indicaram que a maioria das fontes de água tinha uma contagem inaceitável de E. coli, ou seja, > 34 UFC / 100 mL. As amostras positivas para E. coli foram elevadas no distrito de Mardan, seguido por Kohat, Swat e distrito de Peshawar. Além disso, algumas fontes de água também foram contaminadas quimicamente por diferentes fertilizantes inorgânicos (nitratos/nitritos de sódio, potássio), mas em níveis seguros, enquanto os resíduos agrícolas e industriais (compostos de cloreto e sulfato) estavam em níveis inseguros. Entre todos os distritos, a qualidade da água foi considerada comparativamente mais deteriorada nos distritos de Kohat e Mardan do que nos distritos de Peshawar e Swat. Essas fontes de água química e bacteriologicamente impróprias para beber podem causar problemas à saúde humana.

Screening, biochemical characterization and antibiotics resistance/susceptibility of bacteria isolated from native soil and water samples / Triagem, caracterização bioquímica e resistência/suscetibilidade a antibióticos de bactérias isoladas de amostras nativas de solo e água

The present study was conducted to isolate and characterize bacteria from water and soil sample taken from the Lahore Canal at different sites i.e. Mall Road, Mohlanwal and Khera site. Isolated bacterial strains were identified on the basis of morphological and biochemical tests. Identification was confirmed by culturing bacteria on selective media. Antibiotic resistance test was also performed to observe the resistance of bacteria against different antibiotics. Blood agar test was performed for identification of different pathogenic bacteria. The result revealed that water and soil samples of Lahore Canal Lahore from different sites were contaminated with Escherichia coli, Salmonella sp., Vibrio sp., Bacillus spp., Enterococcus sp. and Staphylococcus spp. Due to presence of these pathogens, this water is not suitable for any domestic and irrigation use. Study also revealed that water of the Lahore Canal is harmful for human health as it is contaminated with bacteria that can cause severe disease e.g., Escherichia coli can cause gastroenteritis, Bacillus spp. can cause nausea and vomiting, Enterococcus may infect urinary tract, Salmonella sp. is responsible for Bacteremia, Staphylococcus spp. can cause mild fever and Vibrio sp. can be the reason of cholera. Thus it is rendered unfit for any kind of human use even other than drinking like swimming, bathing, washing etc., until and unless some remedial measures are employed to eradicate pathogenic microorganisms by WASA and LWMS according to standards of WHO. Similarly, it is quite harmful, when and where ever it is used for irrigation without proper treatment.

O presente estudo foi realizado para isolar e caracterizar bactérias de amostras de água e solo retiradas do Canal Lahore, em Lahore, em diferentes locais, ou seja, Mall Road, Mohlanwal e Khera. As cepas bacterianas isoladas foram identificadas com base em testes morfológicos e bioquímicos. A identificação foi confirmada por cultura de bactérias em testes de meios seletivos. O teste de resistência aos antibióticos também foi realizado para observar a resistência das bactérias a diferentes antibióticos. Foi realizado o teste de ágar sangue para identificar diferentes bactérias patogênicas. O resultado revelou que amostras de água e solo do Canal Lahore, Lahore, de diferentes localidades estavam contaminadas com Escherichia coli, Salmonella sp., Vibrio sp., Bacillus spp., Enterococcus sp. e Staphylococcus spp. Por causa da presença desses patógenos, essa água não é adequada para qualquer uso doméstico e de irrigação. O estudo revelou que a água do Canal Lahore é prejudicial à saúde humana, pois está contaminada com bactérias que podem causar doenças graves, por exemplo: Escherichia coli pode ocasionar gastroenterite; Bacillus spp. pode causar náuseas e vômitos; Enterococcus sp. pode infectar o trato urinário; Salmonella sp. é responsável pela bacteremia; Staphylococcus spp. pode causar febre leve; e Vibrio sp. pode ser a razão da cólera. Assim, torna-se imprópria para uso humano, como natação, banho, lavagem etc., até que algumas medidas corretivas sejam empregadas para erradicar microrganismos patogênicos por WASA e LWMS de acordo com os padrões da OMS. Da mesma forma, é bastante prejudicial, quando usada para irrigação sem tratamento adequado.

Prevalencia de sepsis neonatal confirmada microbiológicamente en una maternidad de la Ciudad Autó noma de Buenos Aires / Prevalence of microbiologically confirmed neonatal sepsis at a maternity center in the City of Buenos Aires

Introducción. En neonatos internados es frecuente sospechar sepsis neonatal, pero solo en el 25 % al 30 % se confirma con cultivos positivos. La selección del esquema antibiótico basándose en la epidemiología local favorece el uso racional y minimiza sus efectos colaterales. Objetivo primario. Describir la prevalencia de sepsis precoz y tardía con rescate microbiológico y sus características clínicas. Población y método. Estudio transversal retrospectivo, realizado del 1 de enero de 2013 al 31 de diciembre de 2017, en una maternidad pública de Argentina, que incluyó todos los recién nacidos internados en la unidad con diagnóstico de sepsis precoz y tardía con rescate microbiológico, y aquellos reingresados dentro del mes de vida. Resultados. Ingresaron 3322 recién nacidos, 1296 evaluados por sospecha de sepsis precoz, cultivos positivos en 25 (1,9 %; tasa: 0,86 ‰). El 52 % eran menores de 33 semanas de edad gestacional. Microorganismos: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Sepsis tardía (tasa 8,73 ‰), el 68 % ocurridas en menores de 33 semanas. Microorganismos intrahospitalarios: Staphylococcus coagulasa negativos 115, Staphylococcus aureus 47, Escherichia coli 30, Cándida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11 y Streptococcus agalactiae 10. En los reingresos: E. coli 11, S. aureus 12, SGB 3 y Haemophilus influenzae 3. Conclusiones. Se observa en el período estudiado una frecuencia de sepsis precoz similar a los reportes internacionales, con predominio de E. coli y L. monocytogenes. La tasa de sepsis tardía presentó una tendencia descendente en los años analizados, con predominio de los cocos grampositivos

Introduction. Neonatal sepsis is often suspected in hospitalized newborn infants, but only in 25­30% of cases it is confirmed via a positive culture. Selecting the antibiotics based on local epidemiology favors their rational use and minimizes their side effects. Primary objective. To describe the prevalence of early- and late-onset sepsis with microorganism isolation and their clinical characteristics. Population and method. Retrospective, cross-sectional study conducted between 01-01-2013 and 12-31-2017 in a public maternity center of Argentina in all hospitalized newborn infants with a diagnosis of early- and late-onset sepsis with microorganism isolation, and those re-admitted in their first month of life. Results. A total of 3322 newborn infants were admitted; 1296 were assessed for suspected early- onset sepsis; 25 had a positive culture (1.9%; rate: 0.86‰). Of these, 52% were born before 33 weeks of gestation. Microorganisms: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Also, 68% of late-onset sepsis cases (rate: 8.73‰) occurred in infants born before 33 weeks of gestation. Hospital-acquired microorganisms: coagulase-negative Staphylococcus 115, Staphylococcus aureus 47, Escherichia coli 30, Candida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11, and Streptococcus agalactiae 10. In re-admissions: E. coli 11, S. aureus 12, SGB 3, and Haemophilus influenzae 3. Conclusions. During the study period, the frequency of early-onset sepsis was similar to international reports, with a predominance of E. coli and L. monocytogenes. The rate of late-onset sepsis showed a downward trend in the analyzed years, with a predominance of Gram-positive cocci.

Características clínicas y microbiológicas de la infección de vías urinarias bajas en población ambulatoria / Clinical and Microbiological Characteristics of Lower Urinary Tract Infections in an Outpatient Population

Introducción: El tratamiento de las infecciones del tracto urinario es casi siempre empírico, lo que genera una serie de problemas en la consulta diaria. Objetivo: Caracterizar clínica y microbiológicamente las infecciones de vías urinarias bajas no complicadas en pacientes de una clínica de primer nivel. Métodos: Se realizó un estudio transversal descriptivo. La identificación de las bacterias del cultivo de orina se efectuó por métodos establecidos. La prueba de susceptibilidad a los antimicrobianos se realizó por la técnica Kirby-Bauer. Se utilizó el programa estadístico SPSS versión 26, con la prueba de ji al cuadrado y un análisis multivariado discriminante. Se calculó también razón de momios con el programa Epi-Info. Resultados: Se incluyeron 270 pacientes, con frecuencia de 39,3 por ciento de cultivos positivos, y Escherichia coli como la especie predominante. Se identificaron, además, 31,3 por ciento de bacterias Gram positivas. Se presentó significancia estadística entre la infección urinaria y factores como el sexo, y la infección del tracto urinario previa en las mujeres. Se obtuvo 100 por ciento de cepas resistentes a ampicilina. En general, se obtuvieron porcentajes de resistencia altos en los antimicrobianos probados. Conclusiones: Escherichia coli fue la especie más frecuentemente aislada, sin embargo, existe una serie de microorganismos implicados en enfermedades del tracto genital como Gardnerella vaginalis, que parecen estar involucrados en la etiología de las infecciones del tracto urinario. Se identificaron factores de riesgo como el sexo biológico y las infecciones previas en mujeres. Se obtuvieron porcentajes de resistencia altos en los antimicrobianos probados(AU)

Introduction: The management of urinary tract infections is almost always empirical, which generates a series of problems in the daily consultation. Objective: To characterize, clinically and microbiologically, uncomplicated lower urinary tract infections in patients of a primary level clinic. Methods: A descriptive and cross-sectional study was carried out. Bacterial identification in urine culture was performed by established methods. Antimicrobial susceptibility testing was performed using the Kirby-Bauer technique. The statistical software SPSS (version 26) was used, with the chi squared test and multivariate discriminant analysis. Odds ratios were also calculated with the Epi-Info program. Results: A total of 270 patients were included, with a 39.3percent frequency of positive cultures and Escherichia coli as the predominant species. In addition, 31.3percent of Gram-positive bacteria were identified. There was statistical significance between urinary tract infection and factors such as sex or previous urinary tract infection in women. One result was 100percent of ampicillin-resistant strains. In general, high percentages of resistance were obtained for the tested antimicrobials. Conclusions: Escherichia coli was the most frequently isolated species; however, there is a number of microorganisms implicated in genital tract diseases, such as Gardnerella vaginalis, which appear to be involved in the etiology of urinary tract infections. Risk factors such as biological sex and previous infections in women were identified. High percentages of resistance were obtained for the tested antimicrobials(AU)

Atividade in vitro de extratos e frações de Copernicia prunifera (Arecaceae) contra bactérias de importância clínica em saúde pública / In vitro activity of extracts and fractions of Copernicia prunifera (Arecaceae) against bacteria of clinical importance in public health / Actividad in vitro de extractos y fracciones de Copernicia prunifera (Arecaceae) frente a bacterias de importancia clínica en salud pública

Introdução: O aumento contínuo da resistência bacteriana aos antibióticos convencionais é um problema de importância global. Encontrar produtos como alternativas terapêuticas naturais é essencial. As plantas medicinais possuem uma composição química muito rica, que podem ser estruturalmente otimizadas e processadas em novos antimicrobianos. Objetivo: Avaliar o potencial antibacteriano frente a microrganismos humanos potencialmente patogênicos do extrato etanólico e frações de Copernicia prunifera. Metodologia: A triagem fitoquímica de plantas foi realizada usando métodos de precipitação e coloração e a atividade antibacteriana utilizando o método de difusão em disco e microdiluição em caldo contra cepas padronizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus. Resultados: A triagem fitoquímica revela a presença de taninos, flavonoides, esteroides, triterpernóides, saponinas e alcaloides. Os extratos etanólico e frações da casca do caule e folhas tiveram atividade inibitória contra S. aureus e K. pneumonie com zona de inibição que variou de 7,0±1,73 a 9,33±0,58 mm pelo método de difusão em disco. Pelo método de microdiluição em caldo os extratos foram satisfatórios somente contra K. pneumoniae (CIM = 125 a 1000 µg/mL) S. aureus, P. aeruginosa e E. coli se mostraram resistentes aos testes (CIM > 1000 µg/mL). Conclusão: Esses resultados fornecem uma base para futuras investigações em modelos in vivo, para que os compostos de C. prunifera possam ser aplicados no desenvolvimento de novos agentes antimicrobianos contra K. pneumoniae.

Introduction: The continuous increase in bacterial resistance to conventional antibiotics is a problem of global importance. Finding products as natural therapeutic alternatives is essential. Medicinal plants have a very rich chemical composition, which can be structurally optimized and processed into novel antimicrobials. Objective: To evaluate the antibacterial potential against potentially pathogenic human microorganisms of the ethanolic extract and fractions of Copernicia prunifera. Methodology: Phytochemical screening of plants was performed using precipitation and staining methods and antibacterial activity using the disk diffusion and broth microdilution method against standardized strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Results: Phytochemical screening reveals the presence of tannins, flavonoids, steroids, triterpernoids, saponins and alkaloids. The ethanolic extracts and fractions of stem bark and leaves had inhibitory activity against S. aureus and K. pneumonie with zone of inhibition ranging from 7.0±1.73 to 9.33±0.58 mm by disc diffusion method. By broth microdilution method the extracts were satisfactory only against K. pneumoniae (MIC = 125 to 1000 µg/mL) S. aureus, P. aeruginosa and E. coli were resistant to the tests (MIC > 1000 µg/mL). Conclusion: These results provide a basis for further investigation in in vivo models, so that compounds from C. prunifera can be applied in the development of new antimicrobial agents against K. pneumoniae.

Introducción: El continuo aumento de la resistencia bacteriana a los antibióticos convencionales es un problema de importancia mundial. Es esencial encontrar productos como alternativas terapéuticas naturales. Las plantas medicinales tienen una composición química muy rica, que puede optimizarse estructuralmente y transformarse en nuevos antimicrobianos. Objetivo: Evaluar el potencial antibacteriano frente a microorganismos humanos potencialmente patógenos del extracto etanólico y fracciones de Copernicia prunifera. Metodología: Se realizó el cribado fitoquímico de las plantas mediante los métodos de precipitación y tinción y la actividad antibacteriana mediante el método de difusión en disco y microdilución en caldo frente a cepas estandarizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Resultados: El cribado fitoquímico revela la presencia de taninos, flavonoides, esteroides, triterpernoides, saponinas y alcaloides. Los extractos etanólicos y las fracciones de la corteza del tallo y las hojas presentaron actividad inhibitoria contra S. aureus y K. pneumonie con una zona de inhibición que osciló entre 7,0±1,73 y 9,33±0,58 mm por el método de difusión en disco. Por el método de microdilución en caldo, los extractos sólo fueron satisfactorios frente a K. pneumoniae (CMI = 125 a 1000 µg/mL). S. aureus, P. aeruginosa y E. coli fueron resistentes a las pruebas (CMI > 1000 µg/mL). Conclusiones: Estos resultados proporcionan una base para futuras investigaciones en modelos in vivo, de modo que los compuestos de C. prunifera puedan aplicarse en el desarrollo de nuevos agentes antimicrobianos contra K. pneumoniae.

A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies / 中华血液学杂志

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing / 生物医学与环境科学（英文）

OBJECTIVE@#To explore the genotyping characteristics of human fecal Escherichia coli( E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.@*METHODS@#Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS).@*RESULTS@#This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24).@*CONCLUSION@#We developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.

Evaluation of antibacterial activity of vitamin C against human bacterial pathogens / Avaliação da atividade antibacteriana da vitamina C contra patógenos bacterianos humanos

Now a day’s multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.

Agora, a resistência antimicrobiana de um dia em patógenos aos antibióticos tornou-se a principal causa de preocupação e houve uma realização inadequada no desenvolvimento de novos antibióticos para tratar infecções bacterianas. Portanto, há uma necessidade de pesquisar um novo adjuvante, e a vitamina C é um desses adjuvantes promissores. O objetivo do presente estudo foi elucidar o efeito antibacteriano da vitamina C em diferentes temperaturas (4 °C, 37 °C e 50 °C) e pH (3, 8 e 11), contra Gram-positivos e Gram-cepas bacterianas negativas em várias concentrações (5-20 mg / ml) através do método de difusão em ágar bem. A inibição do crescimento de todas as cepas bacterianas pela vitamina C era dependente da concentração. A vitamina C inibiu significativamente o crescimento de bactérias Gram-positivas: Bacillus licheniformis (25,3 ± 0,9 mm), Staphylococcus aureus (22,0 ± 0,6 mm), Bacillus subtilis (19,3 ± 0,3 mm) e bactérias Gram- negativas: Proteus mirabilis (27,7 ± 0,9 mm), Klebsiella pneumoniae (21,3 ± 0,9 mm), Pseudomonas aeruginosa (18,0 ± 1,5 mm) e Escherichia coli (18,3 ± 0,3 mm). A estabilidade da vitamina C foi observada em vários valores de pH e várias temperaturas. A vitamina C mostrou atividade antibacteriana significativa em pH ácido contra todas as cepas bacterianas. A estabilidade da vitamina C permaneceu nas mesmas diferentes temperaturas (4 °C, 37 °C e 50 °C). Concluímos que a vitamina C é um agente antibacteriano eficaz e seguro que pode ser usado no futuro como uma opção de tratamento auxiliar para combater infecções em humanos, pois pode apoiar o sistema imunológico diretamente.

Isolation and characterization of bacteria residing in the oral, gut, and fecal samples of different pheasant species / Isolamento e caracterização de bactérias residentes nas amostras orais, intestinais e fecais de diferentes espécies de faisão

There is a paucity of research conducted on microbial prevalence in pheasants. The microbiota of captive birds has zoonotic significance and must be characterize. Present study is therefore planned to assess the microbiota from oral, fecal and gut content of captive avian species. It will be helpful in characterization of harmful microbes. Different samples taken from oral, gut and feces of ring-necked pheasants (Phasianus colchicus), green pheasants (Phasianus versicolor), golden pheasant (Chrysolophus pictus) and silver pheasant (Lophura nycthemera). Samples were collected, diluted, and inoculated onto different agar plates (MacConkey, SS agar, MSA and nutrient agar) for cultivation of bacterial species. Colonies of E.coli, Staphylococcus spp. Brachyspira spp. and Campylobacter spp were observed based on colony morphology. Colony forming unit showed E. coli as frequently found bacteria in fecal, oral and gut contents of all the above pheasants. The overall significance difference was found among bacterial species of golden pheasants, green pheasant, ring-necked pheasant, and silver pheasants. It was concluded that E.coli is predominant isolated from heathy pheasants followed by Campylobacter, Staphylococcus and Brachyspira.

Há uma escassez de pesquisas realizadas sobre a prevalência microbiana em faisões. A microbiota de aves em cativeiro tem significado zoonótico e deve ser caracterizada. O presente estudo está, portanto, planejado para avaliar a microbiota do conteúdo oral, fecal e intestinal de espécies aviárias em cativeiro. Será útil na caracterização de micróbios nocivos. Diferentes amostras retiradas da boca, intestino e fezes de faisões de pescoço redondo (Phasianus colchicus), faisões verdes (Phasianus versicolor), faisões dourados (Chrysolophus pictus) e faisão prateado (Lophura nycthemera). As amostras foram coletadas, diluídas e inoculadas em diferentes placas de ágar (MacConkey, ágar SS, MSA e ágar nutriente) para o cultivo de espécies bacterianas. Colônias de E. coli, Staphylococcus spp., Brachyspira spp. e Campylobacter spp foram observados com base na morfologia da colônia. A unidade formadora de colônia mostrou E. coli como bactéria frequentemente encontrada no conteúdo fecal, oral e intestinal de todos os faisões acima. A diferença de significância geral foi encontrada entre as espécies bacterianas de faisões dourados, faisões verdes, faisões de pescoço anelado e faisões prateados. Verificou-se que a E.coli é predominantemente isolada de faisões saudáveis, seguida por Campylobacter, Staphylococcus e Brachyspira.

Temporal association between antibiotic use and resistance in Gram-negative bacteria / Associação temporal entre o uso de antibióticos e resistência em bactérias gram-negativas

Abstract The β-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.

Resumo Os medicamentos combinados de β-lactâmicos / inibidores da lactamase (BLBLIs) são considerados uma alternativa eficaz aos carbapenêmicos. No entanto, existe uma preocupação crescente de que o aumento do uso de BLBLIs pode levar ao aumento da resistência. Este estudo determinou a associação temporal entre o consumo de BLBLI e a resistência antimicrobiana em bactérias gram-negativas. Neste estudo retrospectivo, os dados eletrônicos sobre as bactérias gram-negativas isoladas, incluindo A. baumannii, P. aeruginosa, E. coli e K. pneumoniae de pacientes internados e os resultados dos testes de suscetibilidade foram recuperados dos registros médicos do laboratório clínico. Uma regressão linear e análise de correlação cruzada foram realizadas nos dados adquiridos. Foram observadas tendências crescentes (p < 0,05) no consumo de BIBLI e carbapenem com uma mediana de uso de 27,68 e 34,46 DDD/1000 PD por trimestre, respectivamente. Foi observada uma tendência de diminuição (p = 0,023) no consumo de fluoroquinolonas com uma mediana de uso de 29,13 DDD/1000 PD por trimestre. A taxa de resistência de K. pneumoniae foi sincronizada com os consumos de BIBLI e carbapenem com coeficiente de correlação de 0,893 (p = 0,012) e 0,951 (p = 0,016), respectivamente. A análise de correlação cruzada contra o consumo de BIBLI e K. pneumoniae resistente ao meropenem atingiu o pico no intervalo de 0 quarto (r = 951, p = 0,016). Houve uma tendência de aumento no consumo de BLBLI e carbapenêmicos. A tendência crescente nas taxas de resistência a piperacilina/tazobactam, em linha com o consumo crescente de BLBLI, sugere que BLBLI deve ser usado com cautela e não pode ser considerado diretamente como alternativa de longo prazo aos carbapenêmicos.

Detection of microorganisms with antibacterial activities from different industrial wastes and GC-MS analysis of crude microbial extract / Detecção de microrganismos com atividades antibacterianas de diferentes resíduos industriais e análise por GC-MS do extrato microbiano bruto

Abstract Many soil microorganisms' i.e., bacteria and fungi produce secondary metabolites called antibiotics. These are used for the treatment of some of the bacterial, fungal and protozoal diseases of humans. There is a need for isolation of a broad spectrum of antibiotics from microorganisms due to the emergence of antibiotic resistance. In the present study two antibiotic producing bacteria Klebsiella pneumoniae and Bacillus cereus were isolated from pharmaceutical and poultry feed industry of Hattar, Haripur Pakistan. Total 10 waste samples were collected from different industries (Marble, Ghee, Soap, Mineral, Steel, Poultry Feed, Pharmaceutical, Qarshi, Cosmetic and Glass). Thirty-three bacterial strains were isolated from industrial wastes of these ten different industries. Fourteen out of thirty-three bacterial strains exhibited antimicrobial activities against at least one of the test microbes considered in this study including Escherchia coli, Staphylococcus aureus and Salmonella typhi. The bacteria were isolated by standard serial dilution spread plate technique. Morphological characterization of the isolates was done by Gram staining. Nine bacterial isolates out of fourteen were initially identified as B. cereus and five as K. pneumoniae through biochemical characterization. The antibacterial activities were tested by well diffusion method. Maximum number of antibiotic producing bacteria were isolated from pharmaceutical and poultry feed industry based on the results of primary screening, the most potential isolates S9, S19, S20, S22 and S23 were selected for secondary screening. The maximum activity against E. coli and S. aureus was recorded by bacterial isolate S19 i.e zones of inhibition of 6.5mm and 9mm while S20 showed 7.5mm and 6mm zones respectively. Molecular identification was carried out on the basis of 16S rRNA sequence analysis. Finally, the isolates were identified as B. cereus accession number LC538271and K. pneumoniae accession number MT078679. Analysis of bacterial extract S20 through GC-MS indicated the presence of 8 compounds of diverse nature and structure. Present study suggests that wastes of pharmaceutical and poultry feed industry may have antibiotic producing bacteria. These bacteria could be utilized for the production of antibiotics. B. cereus and K. pneumoniae isolated from wastes of poultry feed and pharmaceutical industries have the potential to produce antibiotics and could be used to control the microbial growth.

Resumo Muitos microrganismos do solo, ou seja, bactérias e fungos produzem metabólitos secundários chamados antibióticos. Eles são usados ​​para tratamento de algumas doenças bacterianas, fúngicas e protozoárias em humanos. Há necessidade de isolamento de um amplo espectro de antibióticos de microrganismos devido ao surgimento de resistência aos antibióticos. No presente estudo, duas bactérias produtoras de antibióticos, Klebsiella pneumoniae e Bacillus cereus, foram isoladas da indústria farmacêutica e de ração avícola de Hattar, Haripur, Paquistão. Um total de 10 amostras de resíduos foi coletado de diferentes indústrias (mármore, ghee, sabão, mineral, aço, ração para aves, farmacêutica, Qarshi, cosmética e vidro). Trinta e três cepas bacterianas foram isoladas de resíduos industriais dessas dez diferentes indústrias. Quatorze das 33 cepas bacterianas exibiram atividades antimicrobianas contra pelo menos um dos micróbios de teste considerados neste estudo, incluindo Escherchia coli, Staphylococcus aureus e Salmonella typhi. As bactérias foram isoladas pela técnica de placa de diluição em série padrão. A caracterização morfológica dos isolados foi feita por coloração de gram. Nove isolados bacterianos de 14 foram inicialmente identificados como B. cereus e cinco como K. pneumoniae por meio de caracterização bioquímica. As atividades antibacterianas foram testadas pelo método de difusão em poço. O número máximo de bactérias produtoras de antibióticos foi isolado da indústria farmacêutica e de ração avícola com base nos resultados da triagem primária, os isolados mais potenciais S9, S19, S20, S22 e S23 foram selecionados para a triagem secundária. A atividade máxima contra E. coli e S. aureus foi registrada pelo isolado bacteriano S19, ou seja, zonas de inibição de 6,5 mm e 9 mm, enquanto S20 mostrou zonas de 7,5 mm e 6 mm, respectivamente. A identificação molecular foi realizada com base na análise da sequência 16S rRNA. Finalmente, os isolados foram identificados como B. cereus número de acesso LC538271 e K. pneumoniae número de acesso MT078679. A análise do extrato bacteriano S20 por meio de GC-MS indicou a presença de oito compostos de natureza e estrutura diversas. O presente estudo sugere que resíduos da indústria farmacêutica e de ração para aves podem conter bactérias produtoras de antibióticos. Essas bactérias podem ser utilizadas para a produção de antibióticos B. cereus e K. pneumoniae isolados de resíduos de rações de aves e indústrias farmacêuticas têm potencial para produzir antibióticos e podem ser usados ​​para controlar o crescimento microbiano.

Isolation and characterization of bacteria residing in the oral, gut, and fecal samples of different pheasant species / Isolamento e caracterização de bactérias residentes nas amostras orais, intestinais e fecais de diferentes espécies de faisão

Abstract There is a paucity of research conducted on microbial prevalence in pheasants. The microbiota of captive birds has zoonotic significance and must be characterize. Present study is therefore planned to assess the microbiota from oral, fecal and gut content of captive avian species. It will be helpful in characterization of harmful microbes. Different samples taken from oral, gut and feces of ring-necked pheasants (Phasianus colchicus), green pheasants (Phasianus versicolor), golden pheasant (Chrysolophus pictus) and silver pheasant (Lophura nycthemera). Samples were collected, diluted, and inoculated onto different agar plates (MacConkey, SS agar, MSA and nutrient agar) for cultivation of bacterial species. Colonies of E.coli, Staphylococcus spp. Brachyspira spp. and Campylobacter spp were observed based on colony morphology. Colony forming unit showed E. coli as frequently found bacteria in fecal, oral and gut contents of all the above pheasants. The overall significance difference was found among bacterial species of golden pheasants, green pheasant, ring-necked pheasant, and silver pheasants. It was concluded that E.coli is predominant isolated from heathy pheasants followed by Campylobacter, Staphylococcus and Brachyspira.

Resumo Há uma escassez de pesquisas realizadas sobre a prevalência microbiana em faisões. A microbiota de aves em cativeiro tem significado zoonótico e deve ser caracterizada. O presente estudo está, portanto, planejado para avaliar a microbiota do conteúdo oral, fecal e intestinal de espécies aviárias em cativeiro. Será útil na caracterização de micróbios nocivos. Diferentes amostras retiradas da boca, intestino e fezes de faisões de pescoço redondo (Phasianus colchicus), faisões verdes (Phasianus versicolor), faisões dourados (Chrysolophus pictus) e faisão prateado (Lophura nycthemera). As amostras foram coletadas, diluídas e inoculadas em diferentes placas de ágar (MacConkey, ágar SS, MSA e ágar nutriente) para o cultivo de espécies bacterianas. Colônias de E. coli, Staphylococcus spp., Brachyspira spp. e Campylobacter spp foram observados com base na morfologia da colônia. A unidade formadora de colônia mostrou E. coli como bactéria frequentemente encontrada no conteúdo fecal, oral e intestinal de todos os faisões acima. A diferença de significância geral foi encontrada entre as espécies bacterianas de faisões dourados, faisões verdes, faisões de pescoço anelado e faisões prateados. Verificou-se que a E.coli é predominantemente isolada de faisões saudáveis, seguida por Campylobacter, Staphylococcus e Brachyspira.

Antibacterial and antifungal activity of methanolic extracts of Salix alba L. against various disease causing pathogens / Atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra vários patógenos que causam doenças

Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.

Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.

Immobilization of mutated xylanase from Neocallimastix patriciarum in E. coli and application for kraft pulp biobleaching / Imobilização de xilanase mutada de Neocallimastix patriciarum em E. coli e aplicação para polpa kraft

Abstract As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.

Resumo Como importante enzima, a xilanase é amplamente utilizada na indústria alimentícia, de celulose e têxtil. Diferentes aplicações de xilanase garantem condições específicas, incluindo temperatura e pH. Este estudo teve como objetivo realizar grânulos de alginato de sódio como carreador para imobilizar xilanase mutada relatada anteriormente de Neocallimastix patriciarum que expressa em E. coli, a atividade de imobilização da xilanase mutada foi elevada em cerca de 4% em pH 6 e 13% a 62 °C. Além disso, a xilanase mutada imobilizada reteve uma proporção maior de sua atividade do que o tipo amplo em termoestabilidade. Essas propriedades sugerem que a imobilização da xilanase mutada tem potencial para aplicação na indústria de biobranqueamento.

Portrayal of Punica granatum L. peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L. por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

Abstract Increasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These infections can be life-threatening to young children and the elderly. There is an incentive to find alternative control measures, such as plant and herbal extracts, especially in lesser-developed countries where traditional antibiotics may not be readily available.

Resumo A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia hemorrágica em crianças. Essas infecções podem ser fatais para crianças pequenas e idosos. Há um incentivo para encontrar medidas de controle alternativas, como extratos de plantas e ervas, especialmente em países menos desenvolvidos, onde os antibióticos tradicionais podem não estar prontamente disponíveis.

Porphyromonas gingivalis infection causes umbilical vein endothelial barrier dysfunction in vitro by down-regulating ZO-1, occludin and VE-cadherin expression / 南方医科大学学报

OBJECTIVE@#To explore the molecular mechanisms of Porphyromonas gingivalis infection-induced umbilical vein endothelial barrier dysfunction in vitro.@*METHODS@#Human umbilical vein endothelial cells (HUVECs) were cultured in vitro, and after the formation of the endothelial barrier, the cells were infected with P. gingivals at a multiplicity of infection (MOI). The transepithelial electrical resistance (TEER) of the cell barrier was measured, and FITC-dextran trans-endothelial permeability assay and bacterial translocation assay were performed to assess the endothelial barrier function. The expression levels of cell junction proteins including ZO-1, occludin and VE-cadherin in the cells were examined by qRT-PCR and Western blotting.@*RESULTS@#In freshly seeded HUVECs, TEER increased until reaching the maximum on Day 5 (94 Ωcm2), suggesting the formation of the endothelial barrier. P. gingivals infection caused an increase of the permeability of the endothelial barrier as early as 0.5 h after bacterial inoculation, and the barrier function further exacerbated with time, as shown by significantly lowered TEER, increased permeability of FITC-dextran (40 000/70 000), and increased translocation of SYTO9-E. coli cross the barrier. MTT assay suggested that P. gingivals infection did not significantly affect the proliferation of HUVECs (P>0.05), but in P. gingivalsinfected cells, the expressions of ZO-1, occludin and VE-cadherin increased significantly at 24 and 48 h after bacterial inoculation (P < 0.05).@*CONCLUSION@#P. gingivals may disrupt the endothelial barrier function by down-regulating the expressions of the cell junction proteins (ZO-1, occludin, VE-cadherin) and increasing the permeability of the endothelial barrier.

Pinpointing Synechococcus Rubisco large subunit sections involved in heterologous holoenzyme formation in Escherichia coli

Aims@#Heterologous holoenzyme formation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) has been a challenge due to a limited understanding of its biogenesis. Unlike bacterial Rubiscos, eukaryotic Rubiscos are incompatible with the Escherichia coli (E. coli) chaperone system to fold and assemble into the functional hexadecameric conformation (L8S8), which comprises eight large subunits (RbcL) and eight small subunits (RbcS). Our previous study reported three sections (residues 248-297, 348-397 and 398-447) within the RbcL of Synechococcus elongatus PCC6301, which may be important for the formation of L8S8 in E. coli. The present study further examined these three sections separately, dividing them into six sections of 25 residues (i.e., residues 248-272, 273-297, 348-372, 373-397, 398-422 and 423-447).@*Methodology and results@#Six chimeric Rubiscos with each section within the RbcL from Synechococcus replaced by their respective counterpart sequence from Chlamydomonas reinhardtii were constructed and checked for their effect on holoenzyme formation in E. coli. The present study shows that Section 1 (residues 248-272; section of Synechococcus RbcL replaced by corresponding Chlamydomonas sequence), Section 2 (residues 273-297), Section 3 (residues 348-372) and Section 6 (residues 423-447) chimeras failed to fold and assemble despite successful expression of both RbcL and RbcS. Only Section 4 (residues 373-397) and 5 (residues 398-422) chimeras could form L8S8 in E. coli.@*Conclusion, significance and impact of study@#GroEL chaperonin mediates the folding of bacterial RbcL in E. coli. Therefore, residues 248-297, 348-372 and 423-447 of Synechococcus RbcL may be important for interacting with the GroEL chaperonin for successful holoenzyme formation in E. coli.

Antibacterial efficacy of chemically and plant-synthesized zinc oxide nanocomposite against Staphylococcus aureus and Escherichia coli inoculated in Tilapia fillet

Aims@#Edible coatings developed from biodegradable materials such as starch and zinc oxide nanoparticles (ZnO-NPS) are efficient antimicrobials that could be used as a food additive to reduce the bacterial load on the food surface. Therefore, this study was aimed to examine the effect of chemical and green synthesized ZnO-NPS with different concentrations on the survival of Escherichia coli and Staphylococcus aureus in fish fillets during chilling storage at 4 ± 1°C.@*Methodology and results@#ZnO-NPS were chemically prepared by mixing zinc acetate dihydrate with sodium hydroxide. Lavandula officinalis was used for the green synthesis of ZnO-NPS. The sterile biodegradable coating containing 2 and 5% of both chemically and green synthesized ZnO-NPS were made using starch, gelatin, xanthan gum and glycerol. Different bacterial cocktail strains of both E. coli and S. aureus were inoculated onto Tilapia fillet samples. The coating solution with different antimicrobials was aseptically spread in Tilapia fillets and examined periodically within two days intervals for the survival of S. aureus and E. coli during chilling at 4 ± 1 °C. Both chemically and plantsynthesized ZnO-NPS reduced the growth of both S. aureus and E. coli by about 3.7 log10 CFU/cm2 of Tilapia fillet. The incorporation of L. officinalis increased the antibacterial activity of ZnO-NPS. Staphylococcus aureus was more sensitive than E. coli for both chemically and plant-synthesized ZnO-NPS. Moreover, zinc oxide biodegradable coating extended the shelf-life of chilled Tilapia fillets by about 4 days.@*Conclusion, significance and impact of study@#The results of the current study demonstrated the incorporation of L. officinalis into ZnO-NPS biodegradable coating which may be promising in reducing microbial growth on food surfaces.

Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020 / 中华预防医学杂志

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

Analysis of endogenous plasmids in Lacticaseibacillus paracasei ZY-1 and development of expression vectors / 生物工程学报

The construction of efficient and stable Lactobacillus expression vector is critical for strain improvement and development of customized strains. In this study, four endogenous plasmids were isolated from Lacticaseibacillus paracasei ZY-1 and subjected to functional analysis. The Escherichia coli-Lactobacillus shuttle vectors pLPZ3N and pLPZ4N were constructed by combining the replicon rep from pLPZ3 or pLPZ4, the chloramphenicol acetyltransferase gene cat from pNZ5319 and the replicon ori from pUC19. Moreover, the expression vectors pLPZ3E and pLPZ4E with the promoter Pldh3 of lactic acid dehydrogenase and the mCherry red fluorescent protein as a reporter gene were obtained. The size of pLPZ3 and pLPZ4 were 6 289 bp and 5 087 bp, respectively, and its GC content, 40.94% and 39.51%, were similar. Both shuttle vectors were successfully transformed into Lacticaseibacillus, and the transformation efficiency of pLPZ4N (5.23×102-8.93×102 CFU/μg) was slightly higher than that of pLPZ3N. Furthermore, the mCherry fluorescent protein was successfully expressed after transforming the expression plasmids pLPZ3E and pLPZ4E into L. paracasei S-NB. The β-galactosidase activity of the recombinant strain obtained from the plasmid pLPZ4E-lacG constructed with Pldh3 as promoter was higher than that of the wild-type strain. The construction of shuttle vectors and expression vectors provide novel molecular tools for the genetic engineering of Lacticaseibacillus strains.