scholarly journals The Impact of Simultaneous Inoculation of Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans on Rodent Burn Wounds

Burns ◽  
2021 ◽  
Author(s):  
Kenneth S. Brandenburg ◽  
Alan J. Weaver ◽  
S.L. Rajasekhar Karna ◽  
Kai P. Leung
2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.


2019 ◽  
Vol 202 (8) ◽  
Author(s):  
Courtney E. Price ◽  
Dustin G. Brown ◽  
Dominique H. Limoli ◽  
Vanessa V. Phelan ◽  
George A. O’Toole

ABSTRACT Cystic fibrosis (CF) patients chronically infected with both Pseudomonas aeruginosa and Staphylococcus aureus have worse health outcomes than patients who are monoinfected with either P. aeruginosa or S. aureus. We showed previously that mucoid strains of P. aeruginosa can coexist with S. aureus in vitro due to the transcriptional downregulation of several toxic exoproducts typically produced by P. aeruginosa, including siderophores, rhamnolipids, and HQNO (2-heptyl-4-hydroxyquinoline N-oxide). Here, we demonstrate that exogenous alginate protects S. aureus from P. aeruginosa in both planktonic and biofilm coculture models under a variety of nutritional conditions. S. aureus protection in the presence of exogenous alginate is due to the transcriptional downregulation of pvdA, a gene required for the production of the iron-scavenging siderophore pyoverdine as well as the downregulation of the PQS (Pseudomonas quinolone signal) (2-heptyl-3,4-dihydroxyquinoline) quorum sensing system. The impact of exogenous alginate is independent of endogenous alginate production. We further demonstrate that coculture of mucoid P. aeruginosa with nonmucoid P. aeruginosa strains can mitigate the killing of S. aureus by the nonmucoid strain of P. aeruginosa, indicating that the mechanism that we describe here may function in vivo in the context of mixed infections. Finally, we investigated a panel of mucoid clinical isolates that retain the ability to kill S. aureus at late time points and show that each strain has a unique expression profile, indicating that mucoid isolates can overcome the S. aureus-protective effects of mucoidy in a strain-specific manner. IMPORTANCE CF patients are chronically infected by polymicrobial communities. The two dominant bacterial pathogens that infect the lungs of CF patients are P. aeruginosa and S. aureus, with ∼30% of patients coinfected by both species. Such coinfected individuals have worse outcomes than monoinfected patients, and both species persist within the same physical space. A variety of host and environmental factors have been demonstrated to promote P. aeruginosa-S. aureus coexistence, despite evidence that P. aeruginosa kills S. aureus when these organisms are cocultured in vitro. Thus, a better understanding of P. aeruginosa-S. aureus interactions, particularly mechanisms by which these microorganisms are able to coexist in proximal physical space, will lead to better-informed treatments for chronic polymicrobial infections.


2005 ◽  
Vol 187 (2) ◽  
pp. 554-566 ◽  
Author(s):  
Lauren M. Mashburn ◽  
Amy M. Jett ◽  
Darrin R. Akins ◽  
Marvin Whiteley

ABSTRACT Pseudomonas aeruginosa is a gram-negative opportunistic human pathogen often infecting the lungs of individuals with the heritable disease cystic fibrosis and the peritoneum of individuals undergoing continuous ambulatory peritoneal dialysis. Often these infections are not caused by colonization with P. aeruginosa alone but instead by a consortium of pathogenic bacteria. Little is known about growth and persistence of P. aeruginosa in vivo, and less is known about the impact of coinfecting bacteria on P. aeruginosa pathogenesis and physiology. In this study, a rat dialysis membrane peritoneal model was used to evaluate the in vivo transcriptome of P. aeruginosa in monoculture and in coculture with Staphylococcus aureus. Monoculture results indicate that approximately 5% of all P. aeruginosa genes are differentially regulated during growth in vivo compared to in vitro controls. Included in this analysis are genes important for iron acquisition and growth in low-oxygen environments. The presence of S. aureus caused decreased transcription of P. aeruginosa iron-regulated genes during in vivo coculture, indicating that the presence of S. aureus increases usable iron for P. aeruginosa in this environment. We propose a model where P. aeruginosa lyses S. aureus and uses released iron for growth in low-iron environments.


2021 ◽  
Vol 31 (9) ◽  
pp. 83-89
Author(s):  
Dương Thị Hồng Thắm ◽  
Hồ Văn Quốc ◽  
Lý Thế Vinh ◽  
Nguyễn Tất Hòa ◽  
Đỗ Thái Hùng

Nghiên cứu mô tả cắt ngang năm 2019 trên 150 mẫu khăn ướt dùng 1 lần làm từ vải không dệt, được lấy từ 150 nhà hàng, quán ăn trên địa bàn thành phố Nha Trang nhằm  mô tả thực trạng mức độ ô nhiễm vi sinh vật đếm được, các vi khuẩn gây bệnh Pseudomonas aeruginosa, Staphylococcus aureus và nấm Candida albicans. Kết quả nghiên cứu cho thấy 68% (102/150) nhà hàng quán ăn có mẫu khăn ướt dùng 1 lần đạt tiêu chuẩn khăn ướt dùng cho các đối tượng khác theo TCVN 11528:2016. Tổng số vi sinh vật đếm được trung bình là 5,6 × 106 ± 3,7 × 107 CFU/g (XTB ± SD), thấp nhất là < 10 CFU/g, cao nhất là 3,5 × 108 CFU/g. Có 20,3% (12/59) nhà hàng, quán ăn có mẫu khăn ướt bị nhiễm vi sinh vật phân lập được P. aeruginosa, với số lượng trung bình là: 3,6 × 106 ± 2,0×107 CFU/g, cao nhất là 1,4 × 108 CFU/g và thấp nhất là < 10 CFU/g. Không phát hiện thấy S. aureus và C. albicans trong các mẫu khăn ướt thu thập được. Nghiên cứu này cho thấy có gần 40% nhà hàng, quán ăn có mẫu khăn ướt bị ô nhiễm ít nhất 1 tác nhân vi sinh vật, do vậy các nhà hàng, quán ăn cần lựa chọn các cơ sở cung cấp khăn ướt có chất lượng tốt.


Author(s):  
I. I. Myrko ◽  
T. I. Chaban ◽  
V. V. Ogurtsov ◽  
V. S. Matiychuk

Мета роботи. Здійснити синтез деяких нових піразолзаміщених 7H-[1,2,4]триазоло[3,4-b][1,3,4]тіадіазинів та провести дослідження антимікробних властивостей синтезованих сполук. Матеріали і методи. Органічний синтез, ЯМР-спектроскопія, елементний аналіз, фармакологічний скринінг. Результати й обговорення. У результаті взаємодії eтил (2Z)-хлоро(фенілгідразоно)ацетатів з ацетилацетоном було отримано етил 4-ацетил-5-метил-1-феніл-1H-піразол-3-карбоксилати. Зазначені сполуки піддали бромуванню, що дозволило одержати цільові бромкетони. Синтезовані на даній стадії етил 1-арил-4-(бромацетил)-5-метил-1Н-піразол-3-карбоксилати було введено у взаємодію з 4-аміно-5-арил(гетарил)-2,4-дигідро-3Н-1,2,4-триазол-3-тіонами з подальшим формуванням 1,3,4-тіадіазольного циклу та отриманням відповідних етил 1-арил-4-{3-арил(гетарил)-7H-[1,2,4]триазоло[3,4-b][1,3,4]тіадіазин-6-іл)}-5-метил-1H-піразол-3-карбоксилатів. Структура синтезованих сполук підтверджена даними елементного аналізу та ЯМР спектроскопією. В рамках міжнародного проекту "The Community for Antimicrobial Drug Discovery" (CO-ADD) за підтримки Wellcome Trust (Великобританія) і університету Квінсленда (Австралія) для синтезованих сполук здійснено скринінг антимікробної активності. Як тестові мікроорганізми використовували п'ять штамів бактерій: Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Acinetobacter baumannii ATCC 19606, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 43300 та двох штамів грибків: Candida albicans ATCC 90028 і Cryptococcus neoformans ATCC 208821. Встановлено, що досліджувані сполуки виявляють різноманітну дію, від практично повної її відсутності до виразного антимікробного ефекту. Висновки. Здійснено синтез 12 нових етил 1-арил-4-{3-арил(гетарил)-7H-[1,2,4]триазоло[3,4-b][1,3,4]тіадіазин-6-іл)}-5-метил-1H-піразол-3-карбоксилатів. Зазначені речовини отримані шляхом взаємодії відповідних етил 1-арил-4-(бромацетил)-5-метил-1Н-піразол-3-карбоксилатів з 4-аміно-5-арил(гетарил)-2,4-дигідро-3Н-1,2,4-триазол-3-тіонами. Дослідження антимікробної активності синтезованих сполук демонструють потенціал пошуку антимікробних агентів серед зазначеного класу сполук.


2018 ◽  
Vol 7 (2) ◽  
pp. 125-139
Author(s):  
Thais Nogueira Gonzaga ◽  
Dora Inés Kozusny-Andreani

Nesta pesquisa objetivou-se avaliar a viabilidade técnica da aplicação de ozônio como bactericida e fungicida em amostras de resíduos de serviços de saúde potencialmente infectantes. Foram determinados os     micro-organismos presentes nos resíduos gerados em um hospital particular. Para realização das análises microbiológicas e o tratamento com ozônio o material foi particulado e homogeneizado. As análises microbiológicas foram realizadas antes e após a ozonização.Para os testes de desinfecção foram retirados 10,0g de amostra que foi submetida à ozonização por 5, 10, 15, 20 e 25 minutos com doses de 140,0; 280,0; 420,0; 560,0 e 700,0mg L-1 de ozônio, respectivamente. Verificou-se presença de mesófilos totais, coliformes totais e termotolerantes, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans e Rhizopus spp. O ozônio foi eficiente para eliminação de todos os micro-organismos em 20 minutos; nos primeiros cinco minutos de exposição ao gás verificou-se redução superior a 98%.Palavras-chave: Bactérias patogênicas. Fungos. Ozonização. USING OZONE GAS FOR DISINFECTION OF SOLID WASTE FROM HEALTH CARE SERVICES ABSTRACT: The aim of this research was to evaluate the technical viability of the application of ozone as bactericide and fungicide in samples of potentially infectious health services residues. The microorganisms present in the waste generated in a private hospital were determined. The material was particulated and homogenized to perform the microbiological analysis and to undergo ozone treatment. Microbiological analysis was performed before and after ozonization. For the disinfection tests, 10.0g of sample were removed and submitted to ozonization for 5, 10, 15, 20 and 25 minutes with 140,0; 280,0; 420,0; 560,0 and 700,0mg doses of L-1 of ozone, respectively. It was verified the presence of total mesophiles, total and thermotolerant coliforms, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans and Rhizopus spp. Ozone was efficient while eliminating all microorganisms in 20 minutes; in the first five minutes of gas exposure, the reduction was greater than 98%.Keywords: Pathogenic bacteria. Fungi. Ozonization.


Author(s):  
LUCIANA HELENA MAIA PORTE ◽  
MARIA HELENA MIGUEZ ROCHA LEÃO ◽  
ALEXANDRE PORTE

Lactoferrina bovina (bLF), proveniente do soro de leite, foimicroencapsulada pela técnica de spray drying. Microcápsulascontendo 20 % de bLF foram produzidas, utilizando-se comomaterial de parede dextrina: amido octenilsuccinato (OSA) emdiferentes proporções: 100:00, 75:25, 50:50, 25:75 e 0:100 %.Foram avaliadas a cor e a estabilidade de cor das microcápsulassob armazenamento em ambientes com diferentes umidadesrelativas e a atividade antimicrobiana da lactoferrina liberadadas microcápsulas. As microcápsulas apresentaram cor clara etenderam a escurecer sob armazenamento em ambiente com altaumidade relativa. Verifi cou-se atividade inibitória das microcápsulasde bLF produzidas para diferentes bactérias Gram positivas(Bacillus subtilis CCT 2576, Staphylococcus aureus CCT 2740,Micrococcus luteus CCT 2692, Enterococcus faecium CCT 5079,Streptococcus faecium ATCC 10541, Rhodococcus equi CCT0541), Gram negativas (Pseudomonas aeruginosa ATCC 13388,Salmonella choleraesius CCT 4296, Escherichia coli CCT 0547) elevedura (Candida albicans ATCC 10231). A concentração inibitóriamínima (MIC) das microcápsulas variou de acordo com o microorganismotestado (MIC entre 2,5-100 mg.mL-1). Com exceção deB. subtilis (MIC entre 50-100 mg.mL-1 para as microcápsulas), aconcentração de bLF contida nas microcápsulas necessária parainibir o crescimento dos micro-organismos foi menor do que a bLFnativa. Esses resultados sugerem efeito de potencialização daatividade antimicrobiana da bLF após o processamento por spraydrying.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Paul Briaud ◽  
Laura Camus ◽  
Sylvère Bastien ◽  
Anne Doléans-Jordheim ◽  
François Vandenesch ◽  
...  

Abstract Cystic fibrosis (CF) is the most common life-threatening genetic disease among Caucasians. CF patients suffer from chronic lung infections due to the presence of thick mucus, caused by cftr gene dysfunction. The two most commonly found bacteria in the mucus of CF patients are Staphylococcus aureus and Pseudomonas aeruginosa. It is well known that early-infecting P. aeruginosa strains produce anti-staphylococcal compounds and inhibit S. aureus growth. More recently, it has been shown that late-infecting P. aeruginosa strains develop commensal-like/coexistence interaction with S. aureus. The aim of this study was to decipher the impact of P. aeruginosa strains on S. aureus. RNA sequencing analysis showed 77 genes were specifically dysregulated in the context of competition and 140 genes in the context of coexistence in the presence of P. aeruginosa. In coexistence, genes encoding virulence factors and proteins involved in carbohydrates, lipids, nucleotides and amino acids metabolism were downregulated. On the contrary, several transporter family encoding genes were upregulated. In particular, several antibiotic pumps belonging to the Nor family were upregulated: tet38, norA and norC, leading to an increase in antibiotic resistance of S. aureus when exposed to tetracycline and ciprofloxacin and an enhanced internalization rate within epithelial pulmonary cells. This study shows that coexistence with P. aeruginosa affects the S. aureus transcriptome and virulence.


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