Nalidixic acid inhibition of post-ultraviolet recovery by nalidixic acid sensitive and resistant strains of Candida albicans

ABSTRACT We performed susceptibility testing with Shigella sonnei isolates from imported and domestic cases of infection in Japan during 2001 and 2002. Some S. sonnei isolates were resistant to nalidixic acid, tetracycline, and trimethoprim-sulfamethoxazole. Most of the nalidixic acid-resistant strains showed reduced susceptibility to fluoroquinolones but did not show fluoroquinolone resistance.

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Candida Albicans ERG11 Gene Polymorphism: Impact on Its In Vivo Virulence and Susceptibility to Fluconazole According to the Galleria Mellonella Model

10.20944/preprints202102.0045.v1 ◽

2021 ◽

Author(s):

Marcel Patindoilba Sawadogo ◽

Adama Zida ◽

Issiaka Soulama ◽

Samuel S Sermé ◽

Thierry Kiswendsida Guiguemdé ◽

...

Keyword(s):

Candida Albicans ◽

Molecular Mechanisms ◽

Reference Strain ◽

Galleria Mellonella ◽

Larval Mortality ◽

Fungal Burden ◽

Significant Difference ◽

Strain Sc5314 ◽

Resistant Strains

The aim of this study is to have an idea on the molecular mechanisms of C. albicans resistance to fluconazole in Burkina Faso, by studying the polymorphism of the ERG11 gene, and its implication in the C. albicans virulence and resistance in vivo according to the Galleria mellonella model; (2) Methods: Ten (10) clinical strains including, 5 resistant and 5 susceptible and 1 virulent and susceptible reference strain SC5314 are used. For the estimation of virulence, the larvae were inoculated with 10 μL of C. albicans cell suspension at variable concentrations: 2,5.105, 5.105, 1.106, and 5.106 CFU/larva of each strain. For the in vivo efficacy study, fluconazole was administered at 1, 4 and 16 mg/kg respectively to G. mellonella larvae, after infection by inoculum 5.106 CFU / larvae of each strain; (3) Results: Six (6) non-silent mutations in the ERG11 gene (K143R, F145L, G307S, S405F, G448E, V456I on ERG11p) were found in 4 resistant isolates. Larval mortality depended on fungal burden and strain. The inoculum 5.106 CFU caused 100% mortality in 2 days for the 2 CAAL-1 and CAAL-2 strains carrying the F145L mutation, in 3 days for the reference strain SC5314, in 4 days for the ensemble of resistant strains, and in 5 days for the ensemble of susceptible strains. The comparison of the mortality due to the reference strain SC5314 CFU / larva and the average mortality due to the two mutant F145L strains, shows a significant difference (P <0.05).Fluconazole significantly protected (P> 0.05) the larvae from infection by susceptible strains and the reference strain. However, 100% mortality in 6 days after injection of the resistant strains, was observed (4) Conclusions: Certain mutations in the ERG11 gene such as the F145L mutation are thought to be a source of increased virulence in Candida albicans. Fluconazole effectively protected larvae from infection by susceptible strains in vivo, unlike resistant strain

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Synergistic Antifungal Activity of Chitosan with Fluconazole against Candida albicans, Candida tropicalis, and Fluconazole-Resistant Strains

Molecules ◽

10.3390/molecules25215114 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5114

Author(s):

Wei-Hsuan Lo ◽

Fu-Sheng Deng ◽

Chih-Jung Chang ◽

Ching-Hsuan Lin

Keyword(s):

Candida Albicans ◽

Antifungal Activity ◽

Candida Tropicalis ◽

Inhibitory Effect ◽

Antifungal Drugs ◽

Drug Resistant ◽

Combinational Treatment ◽

Fluconazole Resistant ◽

Resistant Strains ◽

Drug Resistant Strains

(1) Background: Few antifungal drugs are currently available, and drug-resistant strains have rapidly emerged. Thus, the aim of this study is to evaluate the effectiveness of the antifungal activity from a combinational treatment of chitosan with a clinical antifungal drug on Candida albicans and Candida tropicalis. (2) Methods: Minimum inhibitory concentration (MIC) tests, checkerboard assays, and disc assays were employed to determine the inhibitory effect of chitosan with or without other antifungal drugs on C. albicans and C. tropicalis. (3) Results: Treatment with chitosan in combination with fluconazole showed a great synergistic fungicidal effect against C. albicans and C. tropicalis, but an indifferent effect on antifungal activity when challenged with chitosan-amphotericin B or chitosan-caspofungin simultaneously. Furthermore, the combination of chitosan and fluconazole was effective against drug-resistant strains. (4) Conclusions: These findings provide strong evidence that chitosan in combination with fluconazole is a promising therapy against two Candida species and its drug-resistant strains.

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In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.10.2503 ◽

1998 ◽

Vol 42 (10) ◽

pp. 2503-2510 ◽

Cited By ~ 58

Author(s):

Maurizio Del Poeta ◽

Wiley A. Schell ◽

Christine C. Dykstra ◽

Susan K. Jones ◽

Richard R. Tidwell ◽

...

Keyword(s):

Antimicrobial Activity ◽

Candida Albicans ◽

Fusarium Solani ◽

Antifungal Agents ◽

Antifungal Drugs ◽

Inhibitory Compounds ◽

Wide Range ◽

Fluconazole Resistant ◽

Resistant Strains

ABSTRACT Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities againstCandida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active againstAspergillus fumigatus, Fusarium solani,Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents.

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Drug Resistance of Enterobacteriaceae Isolated from Chicken Carcasses

Journal of Food Protection ◽

10.4315/0362-028x-60.8.1001 ◽

1997 ◽

Vol 60 (8) ◽

pp. 1001-1005 ◽

Cited By ~ 4

Author(s):

MARIA A. TESSI ◽

MARIA S. SALSI ◽

MARIA I. CAFFER ◽

MARIA A. MOGUILEVSKY

Keyword(s):

Nalidixic Acid ◽

Processing Plant ◽

Antibiotic Resistant ◽

E Coli ◽

Resistance Patterns ◽

R Plasmids ◽

Resistant Strains ◽

Different Strains ◽

K 12 ◽

R Factors

The antibiotic resistance profiles and transferable R factors of Salmonella and Escherichia coli isolates from 104 broiler carcasses taken from one processing plant were determined. Carcasses were sampled after immersion chilling. All samples were transported iced and immediately analyzed upon arrival to the laboratory. The resistance patterns of isolates to 12 antibiotics were determined (i.e., ampicillin, cephalothin, streptomycin, sulfisoxazole, trim-ethoprim-sulfamethoxazole, nalidixic acid, tetracycline, neomycin, chloramphenicol, gentamicin, colistin, and nitrofurantoin). Isolates resistant to one or more antibiotics were utilized as donors of resistance to completely antibiotic-sensitive strains, an E. coli K-12, F−, J5, azide-resistant strain and a Salmonella serovar Enteritidis. Transfer of the different R plasmids was confirmed by the determination of the resistance patterns of the transconjugants. Of the 93 Salmonella and 71 E. coli strains isolated from these samples, the largest numbers were resistant to tetracycline (52.7% and 49.3%), sulfisoxazole (45.2% and 42.3%), and streptomycin (37.6% and 39.4%). Large percentages of the Salmonella (33.3%) and the E. coli (30.0%) strains transferred all or part of their resistance to E. coli K-12 in mixed cultures. Great variation was observed between different strains in the frequency at which they transferred resistance. Resistance to tetracycline, sulfisoxazole, and streptomycin was found to be conferred by 31.7%, 29.8%, and 21.6% of the 19 R factors identified. No transfer of resistance to nalidixic acid, gentamicin, cephalothin, nitrofurantoin, and chloramphenicol was detected. When 30 antibiotic-resistant E. coli strains were cultured with a sensitive strain of Salmonella serovar Enteritidis,7 (23.3%) of the resistant strains were found capable of transferring R factors. Only 2 (6.7%) of the resistant strains could transfer R factors and unusual β-galactosidase activity.

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The yeast, the antifungal, and the wardrobe: a journey into antifungal resistance mechanisms of Candida tropicalis

Canadian Journal of Microbiology ◽

10.1139/cjm-2019-0531 ◽

2020 ◽

Vol 66 (6) ◽

pp. 377-388

Author(s):

Jonathas Sales de Oliveira ◽

Vandbergue Santos Pereira ◽

Débora de Souza Collares Maia Castelo-Branco ◽

Rossana de Aguiar Cordeiro ◽

José Júlio Costa Sidrim ◽

...

Keyword(s):

Candida Albicans ◽

Intensive Care ◽

Candida Tropicalis ◽

Clinical Management ◽

Candida Species ◽

Genetic Basis ◽

Antifungal Susceptibility ◽

Resistance Mechanisms ◽

Antifungal Resistance ◽

Resistant Strains

Candida tropicalis is a prominent non-Candida albicans Candida species involved in cases of candidemia, mainly causing infections in patients in intensive care units and (or) those presenting neutropenia. In recent years, several studies have reported an increase in the recovery rates of azole-resistant C. tropicalis isolates. Understanding C. tropicalis resistance is of great importance, since resistant strains are implicated in persistent or recurrent and breakthrough infections. In this review, we address the main mechanisms underlying C. tropicalis resistance to the major antifungal classes used to treat candidiasis. The main genetic basis involved in C. tropicalis antifungal resistance is discussed. A better understanding of the epidemiology of resistant strains and the mechanisms involved in C. tropicalis resistance can help improve diagnosis and assessment of the antifungal susceptibility of this Candida species to improve clinical management.

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Quinolone Resistance in EnterotoxigenicEscherichia coli Causing Diarrhea in Travelers to India in Comparison with Other Geographical Areas

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.6.1731-1733.2000 ◽

2000 ◽

Vol 44 (6) ◽

pp. 1731-1733 ◽

Cited By ~ 41

Author(s):

Jordi Vila ◽

Martha Vargas ◽

Joaquim Ruiz ◽

Manuel Corachan ◽

M. Teresa Jimenez de Anta ◽

...

Keyword(s):

Escherichia Coli ◽

Clavulanic Acid ◽

Nalidixic Acid ◽

Antimicrobial Therapy ◽

Antimicrobial Agents ◽

Quinolone Resistance ◽

Moderate Activity ◽

Good Activity ◽

Resistant Strains ◽

Traveler's Diarrhea

ABSTRACT Enterotoxigenic Escherichia coli isolates were identified as a cause of traveler's diarrhea in 82 of 520 (16%) patients and tested for resistance to seven antimicrobial agents. Thirty patients (36%) needed antimicrobial therapy: 17 (56%) for persistence of symptoms and 13 (44%) for severity of symptoms. Ampicillin, tetracycline, and trimethoprim-sulfamethoxazole resistance was high. Chloramphenicol showed moderate activity, and amoxicillin plus clavulanic acid, nalidixic acid, and ciprofloxacin showed very good activity. Five nalidixic acid-resistant strains were isolated, four from patients visiting India.

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