Probiotics, prebiotics, and COVID-19 infection: A review article.

The beneficial live microbes of humans and animals are termed probiotics, and the chemical compounds that improve the growth of probiotics are known as prebiotics. Paraprobiotics and postbiotics refer to dead or inactivated living cells of probiotics and healthful metabolic products that are produced by the living cells of probiotics, respectively. Although the healthful, functional, nutritional, and immune benefits of probiotics and prebiotics are scientifically well established beyond a reasonable doubt, their potential biological roles against COVID-19 infection still warrant further clinical and laboratory investigation.

Lactose drives Enterococcus expansion to promote graft-versus-host disease.

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

The novel economical synthesis and antimicrobial activity of a trithiocarbonate derivative.

The compound diethyl 2,2'-(thiocarbonyl-bis(sulfanediyl))-diacetate 4 belongs to the trithiocarbonate class containing a trithiocarbonate function group flanked by ethyl acetate. In this procedure, a novel economic synthesis route to obtain compound 4 is described. This compound proved to possess broad-spectrum antimicrobial activity both in vitro and in vivo, and could be used as a lead compound. It is worth mentioning that this compound has been patented [No. US 9,988,348 B1; date of patent: June 5, 2018].

Oral colonization by yeasts in HIV-positive patients in Brazil.

INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56%) followed by non-albicans Candida species (43.73%), Trichosporon mucoides (3.12%) and Kodamaea ohmeri (1.56%). Oral colonization by association of different species was observed in 42% of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

Oral colonization by yeasts in HIV-positive patients in Brazil / Colonização oral por leveduras em pacientes HIV-positivos no Brasil

INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56 percent) followed by non-albicans Candida species (43.73 percent), Trichosporon mucoides (3.12 percent) and Kodamaea ohmeri (1.56 percent). Oral colonization by association of different species was observed in 42 percent of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

INTRODUÇÃO: Em pacientes infectados pelo HIV, a colonização da cavidade bucal por leveduras patogênicas pode levar ao desenvolvimento de fungemias. No presente estudo, avaliamos a prevalência de leveduras na cavidade bucal de pacientes HIV-positivos e verificamos se as espécies isoladas foram enzimaticamente ativas. Além disso, as espécies identificadas foram testadas quanto à suscetibilidade a antifúngicos. MÉTODOS: Amostras de saliva e de candidose orofaríngea foram coletadas de 60 pacientes soropositivos para HIV e identificados pelo sistema API20C. A atividade enzimática foi avaliada pela produção de proteinase e fosfolipase. A suscetibilidade a antifúngicos foi determinada utilizando o método de microdiluição em caldo. RESULTADOS: As espécies mais comumente isoladas foram C. albicans (51,56 por cento), seguido por espécies de Candida não-albicans (43,73 por cento), Trichosporon mucoides (3,12 por cento) e Kodamaea ohmeri (1,56 por cento). A colonização bucal por associação de diferentes espécies foi observada em 42 por cento dos pacientes. A atividade enzimática foi verificada na maioria das espécies isoladas, com exceção de C. glabrata, C. lusitaniae e C. guilliermondii. Resistência ao fluconazol e anfotericina B foi observada em isolados de C. albicans, C. glabrata, C. parapsilosis, C. krusei, e K. ohmeri. CONCLUSÃO: Os pacientes HIV-positivos são colonizados por espécies únicas ou múltiplas de levedura que ocasionalmente são resistentes ao fluconazol ou anfotericina B.

Oral Candida albicans isolates from HIV-positive individuals have similar in vitro biofilm-forming ability and pathogenicity as invasive Candida isolates.

BACKGROUND: Candida can cause mucocutaneous and/or systemic infections in hospitalized and immunosuppressed patients. Most individuals are colonized by Candida spp. as part of the oral flora and the intestinal tract. We compared oral and systemic isolates for the capacity to form biofilm in an in vitro biofilm model and pathogenicity in the Galleria mellonella infection model. The oral Candida strains were isolated from the HIV patients and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, C. norvegensis, and C. dubliniensis. The systemic strains were isolated from patients with invasive candidiasis and included species of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. lusitaniae, and C. kefyr. For each of the acquired strains, biofilm formation was evaluated on standardized samples of silicone pads and acrylic resin. We assessed the pathogenicity of the strains by infecting G. mellonella animals with Candida strains and observing survival. RESULTS: The biofilm formation and pathogenicity in Galleria was similar between oral and systemic isolates. The quantity of biofilm formed and the virulence in G. mellonella were different for each of the species studied. On silicone pads, C. albicans and C. dubliniensis produced more biofilm (1.12 to 6.61 mg) than the other species (0.25 to 3.66 mg). However, all Candida species produced a similar biofilm on acrylic resin, material used in dental prostheses. C. albicans, C. dubliniensis, C. tropicalis, and C. parapsilosis were the most virulent species in G. mellonella with 100% of mortality, followed by C. lusitaniae (87%), C. novergensis (37%), C. krusei (25%), C. glabrata (20%), and C. kefyr (12%). CONCLUSIONS: We found that on silicone pads as well as in the Galleria model, biofilm formation and virulence depends on the Candida species. Importantly, for C. albicans the pathogenicity of oral Candida isolates was similar to systemic Candida isolates, suggesting that Candida isolates have similar biofilm-forming ability and virulence regardless of the infection site from which it was isolated.

Control of coliform bacteria detected from diarrhea associated patients by extracts of Moringa oleifera.

The aims of this study were to determine the total population of coliform bacteria in the samples collected from diarrhea associated patients from the local area of Bangladesh and to examine the antibacterial efficacy of leaf extracts of Moringa oleifera (Moringaceae) against the isolated coliform bacteria. The coliform bacteria detected in these samples by some microbial-biochemical tests such as Escherichia coli, Shigella dysenteriae, Salmonella sp., Enterobacter sp., Klebsiella pneumoniae and Serratia marcescens. The total isolation rate of coliform bacterial species was ranged from 38.01-3.51%. At the concentration of 300 ig/disc, the organic extracts of hexane, chloroform, ethyl acetate and methanol extracts of Moringa oleifera leaf exhibited a remarkable antibacterial effect against all the tested bacterial pathogens. The zones of inhibition against all the tested bacterial pathogens were found in the range of 8.0 to 23.2 mm, along with their respective minimum inhibitory concentration (MIC) values ranging from 62.5-1000 ig/mL. The results obtained in this study suggest that the extracts from Moringa oleifera leaf can be a source of natural antimicrobials with potential applications in pharmaceutical industry to control coliform bacteria.

Efficacy and safety of tenofovir DF vs stavudine in combination therapy in antiretroviral-naive patients: a 3-year randomized trial.

CONTEXT: Tenofovir disoproxil fumarate (DF) is a once-daily nucleotide analogue reverse transcriptase inhibitor. OBJECTIVE: To evaluate the efficacy and safety of tenofovir DF compared with stavudine in antiretroviral-naive patients. DESIGN, SETTING, AND PARTICIPANTS: A prospective, randomized, double-blind study conducted at 81 centers in the United States, South America, and Europe from June 9, 2000, to January 30, 2004. A total of 753 patients infected with HIV who were antiretroviral naive were screened and 602 patients entered the study. INTERVENTION: Patients were randomized to receive either tenofovir DF (n = 299) or stavudine (n = 303), with placebo, in combination with lamivudine and efavirenz. MAIN OUTCOME MEASURE: Proportion of patients with HIV RNA levels of less than 400 copies/mL at week 48. RESULTS: In the primary intent-to-treat analysis in which patients with missing data or who added or switched antiretroviral medications before week 48 were considered as failures, the proportion of patients with HIV RNA of less than 400 copies/mL at week 48 was 239 (80%) of 299 in patients receiving tenofovir DF and 253 (84%) of 301 in patients receiving stavudine (95% confidence interval, -10.4% to 1.5%), exceeding the predefined -10% limit for equivalence. However, equivalence was demonstrated in the secondary analyses (HIV RNA <50 copies/mL) at week 48 and through 144 weeks. Virologic failure was associated most frequently with efavirenz and lamivudine resistance. Through 144 weeks, the K65R mutation emerged in 8 and 2 patients in the tenofovir DF and stavudine groups, respectively (P =.06). A more favorable mean change from baseline in fasting lipid profile was noted in the tenofovir DF group at week 144: for triglyceride levels (+1 mg/dL for tenofovir DF [n = 170] vs +134 mg/dL for stavudine [n = 162], P<.001), total cholesterol (+30 mg/dL [n = 170] vs +58 mg/dL [n = 162], P<.001), direct low-density lipoprotein cholesterol (+14 mg/dL [n = 169] vs +26 mg/dL [n = 161], P<.001), and high-density lipoprotein cholesterol (+9 mg/dL [n = 168] vs +6 mg/dL [n = 154], P =.003). Investigator-reported lipodystrophy was less common in the tenofovir DF group compared with the stavudine group (9 [3%] of 299 vs 58 [19%] of 301, P<.001). The number of bone fractures and the renal safety profile were similar between the 2 groups. CONCLUSIONS: Through 144 weeks, the combination of tenofovir DF, lamivudine, and efavirenz was highly effective and comparable with stavudine, lamivudine, and efavirenz in antiretroviral-naive patients. However, tenofovir DF appeared to be associated with better lipid profiles and less lipodystrophy.

Alterações oculares em pacientes com AIDS tratados com inibidor de protease / Ocular findings in AIDS patients treated with protease inhibitor

Objetivo: estudo visando comparar a eficácia clínica, segurança e toxicidade do indinavir e da zidovudina quando administrados isoladamente e quando administrados concomitantemente. Métodos: Foram estudados, prospectivamente, a partir de abril de 1995, 300 pacientes (599 olhos), soropositivos para o HIV-1, sem infecçäo oportunista e com CD4 entre 50 e 250 células/nm 3, que fizeram parte de um estudo duplo-cego, randomizado. O parâmetro de eficácia determinado era o aparecimento de infecçöes oportunistas. Em julho de 1996 os pacientes que recebiam zidovudina isoladamente passaram a receber lamivudina associada. Em fevereiro de 1997 o estudo passa a ser aberto e todos os pacientes passam a receber a associaçäo das 3 drogas. Resultado: Säo referidos os achados oculares observados no início do estudo e as alteraçöes observadas prospectivamente em um período de 4 anos. Ocorreu retinite por CMV em 3 pacientes (4 olhos, 1,33 por cento), sendo todos do braço inicial do estudo que recebeu zidovudina isoladamente. Conclusäo: Os resultados sugerem reduçäo da incidência de retinite por CMV em pacientes tratados com inibidor de protease.

Molecular basis of clarithromycin-resistance in Mycobacterium avium intracellulare complex.

Nucleotide sequences of domain V and domain II regions of the 23S rRNA gene were determined in both in vitro-made mutants and clinical isolates of Mycobacterium avium and M. intracellulare conferring clarithromycin-resistance. All laboratory-made mutants showed high level resistance to clarithromycin (> 150 micrograms ml-1) and mutation at position 2058 (cognate with Escherichia coli base) in domain V region. In the clinical isolates, while the susceptible ones had no mutation in domain V, the resistant strains showed mutation at 2058 or 2059. Six isolates with low level of resistance exhibited no mutation in domain V. All strains tested had no mutation in domain II region. These results suggested that most of the resistance arose from the mutation in domain V of the 23S rRNA gene, but other unknown mechanisms evidently exist in mycobacteria.

Utility of SPECT DMSA renal scanning in the evaluation of children with primary vesicoureteral reflux.

OBJECTIVES: DMSA renal scanning is more sensitive than ultrasound in detecting renal parenchymal scars. We proposed to determine the utility of single-photon emission computed tomography (SPECT) dimercaptosuccinic acid (DMSA) renal scanning in children with primary vesicoureteral reflux (VUR). METHODS: During a 24-month period, we evaluated the charts of 368 patients who had undergone SPECT DMSA renal scanning for primary VUR. Patients were divided into three age groups: (a) less than 1 year, (b) between 1 and 5 years, and (c) older than 6 years. Renal scars were deemed severe or focal. The data were analyzed to evaluate the utility of SPECT DMSA scanning in children with primary VUR and to determine the indications for performing SPECT DMSA. We also evaluated the sensitivity of recent renal ultrasound technology in detecting focal and diffuse scars. RESULTS: One hundred twenty-eight patients were younger than 1 year at presentation. These included 24 cases that were detected prenatally. One hundred eighty-five were between the ages of 1 and 5 years, and 55 were 6 years or older. Reflux nephropathy at presentation was found in 99 (26.9%) of 368 patients. DMSA scanning changed the treatment in only 13 patients (3.5%). When scarring was diffuse, ultrasound examination correlated 100% with DMSA scanning; when focal scarring was present, the correlation was poor. CONCLUSIONS: Our results suggest that DMSA scans should be tailored to children who have ultrasound abnormalities, high-grade reflux, or recurrent breakthrough urinary tract infections. These guidelines will result in a substantial cost savings and a significant decrease in radiation exposure.