scholarly journals Pathogenicity Levels of Colombian Strains of Candida auris and Brazilian Strains of Candida haemulonii Species Complex in Both Murine and Galleria mellonella Experimental Models

2020 ◽  
Vol 6 (3) ◽  
pp. 104
Author(s):  
Julián E. Muñoz ◽  
Laura M. Ramirez ◽  
Lucas dos Santos Dias ◽  
Laura A. Rivas ◽  
Lívia S. Ramos ◽  
...  
Keyword(s):  
Survival Rate ◽  
Species Complex ◽  
Galleria Mellonella ◽  
Experimental Models ◽  
Candida Auris ◽  
Candida Haemulonii ◽  
Virulent Strains ◽  
Inert Surface ◽  
Phagocytosis Index ◽  
Different Levels

Candida auris and Candida haemulonii complex (C. haemulonii, C. haemulonii var. vulnera and C. duobushaemulonii) are phylogenetically related species that share some physiological features and habits. In the present study, we compared the virulence of these yeast species using two different experimental models: (i) Galleria mellonella larvae to evaluate the survival rate, fungal burden, histopathology and phagocytosis index and (ii) BALB/c mice to evaluate the survival. In addition, the fungal capacity to form biofilm over an inert surface was analyzed. Our results showed that in both experimental models, the animal survival rate was lower when infected with C. auris strains than the C. haemulonii species complex. The hemocytes of G. mellonella showed a significantly reduced ability to phagocytize the most virulent strains forming the C. haemulonii species complex. Interestingly, for C. auris, it was impossible to measure the phagocytosis index due to a general lysis of the hemocytes. Moreover, it was observed a greater capability of biofilm formation by C. auris compared to C. haemulonii species complex. In conclusion, we observed that C. auris and C. haemulonii complex have different levels of pathogenicity in the experimental models employed in the present study.

Surface, adhesiveness and virulence aspects of Candida haemulonii species complex

2020 ◽  
Vol 58 (7) ◽  
pp. 973-986 ◽  
Author(s):  
Lívia S Ramos ◽  
Simone S C Oliveira ◽  
Laura N Silva ◽  
Marcela Q Granato ◽  
Diego S Gonçalves ◽  
...  
Keyword(s):  
Species Complex ◽  
Galleria Mellonella ◽  
Fungal Infections ◽  
Neutral Lipids ◽  
Clinical Manifestations ◽  
Cell Surface Hydrophobicity ◽  
Candida Spp ◽  
Murine Macrophages ◽  
Candida Haemulonii

Abstract The emerging opportunistic pathogens comprising the Candida haemulonii complex (C. haemulonii [Ch], C. duobushaemulonii [Cd] and C. haemulonii var. vulnera[Chv]) are notable for their intrinsic antifungal resistance. Different clinical manifestations are associated with these fungal infections; however, little is known about their biology and potential virulence attributes. Herein, we evaluated some surface properties of 12 clinical isolates of Ch (n = 5), Cd (n = 4) and Chv (n = 3) as well as their virulence on murine macrophages and Galleria mellonella larvae. Scanning electron microscopy demonstrated the presence of homogeneous populations among the species of the C. haemulonii complex, represented by oval yeasts with surface irregularities able to form aggregates. Cell surface hydrophobicity was isolate-specific, exhibiting high (16.7%), moderate (25.0%) and low (58.3%) hydrophobicity. The isolates had negative surface charge, except for one. Mannose/glucose- and N-acetylglucosamine-containing glycoconjugates were evidenced in considerable amounts in all isolates; however, the surface expression of sialic acid was poorly detected. Cd isolates presented significantly higher amounts of chitin than Ch and Chv. Membrane sterol and lipid bodies, containing neutral lipids, were quite similar among all fungi studied. All isolates adhered to inert surfaces in the order: polystyrene > poly-L-lysine-coated glass > glass. Likewise, they interacted with murine macrophages in a quite similar way. Regarding in vivo virulence, the C. haemulonii species complex were able to kill at least 80% of the larvae after 120 hours. Our results evidenced the ability of C. haemulonii complex to produce potential surface-related virulence attributes, key components that actively participate in the infection process described in Candida spp.

scholarly journals Antimicrobial Peptides Epinecidin-1 and Beta-Defesin-3 Are Effective against a Broad Spectrum of Antibiotic-Resistant Bacterial Isolates and Increase Survival Rate in Experimental Sepsis

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Albert Bolatchiev
Keyword(s):  
Antibacterial Activity ◽  
Survival Rate ◽  
Antimicrobial Peptides ◽  
Lethal Dose ◽  
Experimental Models ◽  
Experimental Sepsis ◽  
Epinephelus Coioides ◽  
Sterile Saline

The antimicrobial peptides human Beta-defensin-3 (hBD-3) and Epinecidin-1 (Epi-1; by Epinephelus coioides) could be a promising tool to develop novel antibacterials to combat antibiotic resistance. The antibacterial activity of Epi-1 + vancomycin against methicillin-resistant Staphylococcus aureus (22 isolates) and Epi-1 + hBD-3 against carbapenem-resistant isolates of Klebsiella pneumoniae (n = 23), Klebsiella aerogenes (n = 17), Acinetobacter baumannii (n = 9), and Pseudomonas aeruginosa (n = 13) was studied in vitro. To evaluate the in vivo efficacy of hBD-3 and Epi-1, ICR (CD-1) mice were injected intraperitoneally with a lethal dose of K. pneumoniae or P. aeruginosa. The animals received a single injection of either sterile saline, hBD-3 monotherapy, meropenem monotherapy, hBD-3 + meropenem, or hBD-3 + Epi-1. Studied peptides showed antibacterial activity in vitro against all studied clinical isolates in a concentration of 2 to 32 mg/L. In both experimental models of murine sepsis, an increase in survival rate was seen with hBD-3 monotherapy, hBD-3 + meropenem, and hBD-3 + Epi-1. For K. pneumoniae-sepsis, hBD-3 was shown to be a promising option in overcoming the resistance of Klebsiella spp. to carbapenems, though more research is needed. In the P. aeruginosa-sepsis model, the addition of Epi-1 to hBD-3 was found to have a slightly reduced mortality rate compared to hBD-3 monotherapy.

Combined treatment with benznidazole and allopurinol in mice infected with a virulentTrypanosoma cruziisolate from Nicaragua

Parasitology ◽  
2013 ◽  
Vol 140 (10) ◽  
pp. 1225-1233 ◽  
Author(s):  
NOELIA L. GROSSO ◽  
MICAELA LOPEZ ALARCON ◽  
JAQUELINE BUA ◽  
SUSANA A. LAUCELLA ◽  
ADELINA RIARTE ◽  
...  
Keyword(s):  
Survival Rate ◽  
Trypanosoma Cruzi ◽  
Endemic Area ◽  
Low Dose ◽  
Combined Treatment ◽  
Chronic Phase ◽  
Experimental Models ◽  
Specific Antibodies ◽  
Histopathological Studies ◽  
Virulent Parasite

SUMMARYWe evaluated the effect of chemotherapy with a sequential combined treatment of a low dose of benznidazole and allopurinol, in different schedules of administration, in experimental models of acute and chronicTrypanosoma cruziinfection. Mice were infected with NicaraguaT. cruziisolate, a virulent parasite from an endemic area of Nicaragua, genotyped asTcI (Grossoet al. 2010). We assessed survival rate, IgG levels, histopathological studies and quantified parasitaemia. A 15% survival rate was recorded in untreated mice during the acute phase ofT. cruziinfection. Allopurinol administered immediately after benznidazole treatment was able to reduce parasitaemia and attenuate tissue damage by reducing inflammation.Trypanosoma cruzi-specific antibodies also decreased in 40–50% of the treated mice. The addition of allopurinol during the chronic phase showed the highest beneficial effect, not only by reducing parasitaemia but also by lowering the degree of inflammation and fibrosis.

scholarly journals Candida duobushaemulonii: An Old But Unreported Pathogen

2020 ◽  
Vol 6 (4) ◽  
pp. 374
Author(s):  
Irene Jurado-Martín ◽  
Cristina Marcos-Arias ◽  
Esther Tamayo ◽  
Andrea Guridi ◽  
Piet W. J. de Groot ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Related Species ◽  
Antifungal Drugs ◽  
Candida Auris ◽  
Closely Related Species ◽  
Identification Methods ◽  
Phenotypic Identification ◽  
Candida Intermedia ◽  
Candida Haemulonii

Candidiasis caused by species of the Candida haemulonii complex (Candida haemulonii and Candida duobushaemulonii) and closely related species, Candida auris and Candida pseudohaemulonii are increasing. These species often show reduced susceptibility to antifungal drugs, such as azoles and amphotericin B or, less frequently, echinocandins. However, conventional phenotypic identification methods are unable to accurately differentiate these species and, therefore, their prevalence may have been underestimated. In this study, 150 isolates that were probably misidentified were reanalyzed using two novel PCR approaches. We found that one isolate previously identified in 1996 as Candida intermedia was C. duobushaemulonii, being one of the oldest isolates of this species described to date. We also found that this isolate had reduced susceptibility to fluconazole, itraconazole, and amphotericin B.

scholarly journals MULTIPLICATION AND SURVIVAL OF TUBERCLE BACILLI IN THE ORGANS OF MICE

1953 ◽  
Vol 97 (2) ◽  
pp. 189-206 ◽  
Author(s):  
Cynthia H. Pierce ◽  
René J. Dubos ◽  
Werner B. Schaefer
Keyword(s):  
Peritoneal Cavity ◽  
Guinea Pigs ◽  
Bacterial Population ◽  
Progressive Disease ◽  
Blood Stream ◽  
Experimental Animals ◽  
Virulent Strains ◽  
Different Levels

Cultures of tubercle bacilli (typical bovine and human strains) known to differ in the severity of the lesions they induce in experimental animals, were injected in various doses into the cerebrum, peritoneal cavity, or blood stream of mice. Quantitative determinations of the numbers of living bacilli present in the tissues at different intervals of time after infection led to the following classification of the cultures tested:— (a) Certain well known variant forms of tubercle bacilli were found to be unable to multiply in vivo, although they could survive for many weeks in the tissues of mice. These organisms proved to be truly avirulent. (b) Other variant forms underwent multiplication in vivo, even when extremely small infective doses were used, but could not give rise to progressive disease. It is proposed to designate these strains, which produce only abortive infections, as "attenuated." Different levels of attenuation could be detected. The maximum numbers of living bacilli that were recovered from the tissues corresponded directly to the severity and duration of the abortive lesions that could be produced by the strain in guinea pigs or in mice and were characteristic for each strain tested. The two BCG substrains tested were found to differ markedly in their level of attenuation. (c) The cultures virulent for guinea pigs were also capable of establishing a progressive infection in mice even when small infective doses were used. In the case of the attenuated and virulent strains, the population of living bacilli present in the lungs was at first much lower than that in the spleen, but it continued to increase in the former organs throughout the period of observation. This was notably true in the case of the virulent cultures. In contrast, the numbers of living bacilli in the spleen rapidly reached a maximum in the case of all cultures and then decreased progressively. For a given infective dose, and a given interval of time after inoculation, the maximum levels of living bacterial population attained in the spleen and in the lungs proved to be a direct expression of the virulence of the strain.

scholarly journals Increasing Prevalence of Multidrug-Resistant Candida haemulonii Species Complex among All Yeast Cultures Collected by a Reference Laboratory over the Past 11 Years

2020 ◽  
Vol 6 (3) ◽  
pp. 110 ◽  
Author(s):  
Soraia Lopes Lima ◽  
Elaine Cristina Francisco ◽  
João Nóbrega de Almeida Júnior ◽  
Daniel Wagner de Castro Lima Santos ◽  
Fabiane Carlesse ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Species Complex ◽  
Antifungal Susceptibility ◽  
Its Region ◽  
Multidrug Resistant ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Reference Laboratory ◽  
Yeast Cultures ◽  
Candida Haemulonii

There is worldwide concern with the increasing rates of infections due to multiresistant Candida isolates reported in tertiary medical centers. We checked for historical trends in terms of prevalence rates and antifungal susceptibility of the Candida haemulonii species complex in our yeast stock culture collected during the last 11 years. The isolates were identified by sequencing the rDNA internal transcribed spacer (ITS) region, and antifungal susceptibility tests for amphotericin B, voriconazole, fluconazole, anidulafungin, and 5-fluorocytosine were performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method. A total of 49 isolates were identified as Candida haemulonii sensu stricto (n = 21), followed by C. haemulonii var. vulnera (n = 15) and C. duobushaemulonii (n = 13), including 38 isolates cultured from patients with deep-seated Candida infections. The prevalence of the C. haemulonii species complex increased from 0.9% (18 isolates among 1931) in the first period (December 2008 to June 2013) to 1.7% (31 isolates among 1868) in the second period (July 2014 to December 2019) of analysis (p = 0.047). All isolates tested exhibited high minimum inhibition concentrations for amphotericin B and fluconazole, but they remained susceptible to 5-fluorocytosine and anidulafungin. We were able to demonstrate the increased isolation of the multiresistant Candida haemulonii species complex in our culture collection, where most isolates were cultured from patients with deep-seated infections.

The effects of different levels of nutrition from weaning to seventeen months of age on the lifetime production of Merino ewes

1968 ◽  
Vol 8 (31) ◽  
pp. 149 ◽  
Author(s):  
JR Giles
Keyword(s):  
Survival Rate ◽  
Death Rate ◽  
Weaning Weight ◽  
Wool Production ◽  
Fleece Weight ◽  
Different Levels ◽  
Staple Length

One hundred and seventy-nine ewe weaners from five experimental selection flocks were allocated at random, within sire lines, to one of two groups which were subjected to different nutritional regimes from weaning to 17 months of age. Liveweight and wool production were examined over an eight-year period and survival rate and reproduction data over the lifetime of the ewes. The treatments produced a maximum liveweight difference of 30.5 lb at 14 months of age when the liveweights of ewes receiving a high plane of nutrition averaged 98 lb. There were significant selection flock X plane of nutrition interactions in greasy fleece weight and staple length. Clean fleece weight of sheep on the low plane of nutrition was depressed by 25 per cent at the first shearing, and there were small differences in the fleece weights of low and high plane sheep in the following six years. Death rate, lifetime reproduction, and weaning weight of progeny were not significantly depressed by the low plane treatment.

USING OF LARGE WAX MOTH LARVAE PRODUCTS EXCRETED IN CLONAL MICROREPRODUCTION OF GARDEN STRAWBERRY

1970 ◽  
pp. 66-68
Author(s):  
М. G. Markova ◽  
Е. N. Somova
Keyword(s):  
Aqueous Solution ◽  
Survival Rate ◽  
Nutrient Medium ◽  
Galleria Mellonella ◽  
Waste Product ◽  
Biologically Active ◽  
Clonal Micropropagation ◽  
Wax Moth

Work on the clonal micropropagation of strawberries comes down to the search for new growth regulators, which include a biologically active substance - the waste product of the wax moth Galleria mellonella L. The effect of the waste product of the wax moth on the efficiency of clonal micropropagation of strawberries (Fragaria х ananassa duch) in vitro and in vivo conditions in 2018-2020 is shown. The object of research is micro-cuttings, rooted micro-cuttings and adapted micro-plants of garden strawberries of the Korona variety and of the remontant strawberries of the Brighton variety. It was revealed that at the proliferation stage, the propagation coefficient of the Korona variety increased significantly with the introduction of the waste product of the wax moth in doses of 4.0 mg/L and 6.0 mg/L and amounted to 4.2 and 3.8 pcs./explant, respectively; for Brighton variety, the coefficient increased significantly when the dose of the waste product of the wax moth 2.0 mg/L and amounted to 4.6 pcs./explant. The introduction of the waste product of the wax moth in doses of 4.0 mg/L and 6.0 mg/L into the nutrient medium had a significant effect on the yield of Brighton micro-cuttings suitable for rooting: the yield was 95.5 and 94.1%, respectively 87.7% in the control. For the Korona variety, no significant positive effect of the waste product of the wax moth on this indicator was noted. The rooting of micro-cuttings of strawberries of both varieties significantly increased with the introduction of the waste product of the wax moth into the nutrient medium in all studied doses and amounted to 86.4-100% in the Korona variety, and 88.9-100% in the Brighton variety.  The survival rate of adaptable micro-cuttings of Corona variety strawberries when sprayed with an aqueous solution of the waste product of the wax moth at a dose of 4.0 mg/L was 100%; the maximum survival rate of micro-cuttings Brighton variety is 99.8% in the variant with spraying with an aqueous solution of the waste product of the wax moth at a dose of 6.0 mg/L.

Galleria mellonella for systemic assessment of anti-Candida auris using amphotericin B loaded in nanoemulsion

2021 ◽  
pp. 151023
Author(s):  
Gabriel Davi Marena ◽  
Matheus Aparecido dos Santos Ramos ◽  
Laura Caminitti Lima ◽  
Marlus Chorilli ◽  
Tais Maria Bauab
Keyword(s):  
Amphotericin B ◽  
Galleria Mellonella ◽  
Candida Auris
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