ABSTRACT
Here, we report the draft genome of Streptococcus halitosis sp. nov. strain VT-4, a novel bacterium isolated from the dorsal part of the tongue of a patient with halitosis. The genome comprised 1,880,608 bp with a GC content of 41.0%. There were 1,782 predicted protein-coding genes, including those associated with virulence and antibiotic resistance.
ABSTRACT
There is an urgent need for new antifungal compounds to treat various types of fungal infections, including pulmonary infections. This study was designed to investigate the potency of a novel compound (Mul-1867) against Candida spp. and Aspergillus spp. isolated from patients with fungal pneumonia, cystic fibrosis and chronic obstructive pulmonary disease. Mul-1867 was highly effective against susceptible control strains as well as resistant clinical isolates, with minimum fungicidal concentrations (MFCs) varying from 0.06 µg/mL to 0.5 µg/mL. It was also highly effective against pre-formed 48-h-old biofilms formed by yeasts and moulds. The half-minimal biofilm eradication concentration (MBEC50) was equal to the MFC. The minimum biofilm eradication concentration to eliminate 90% of biofilms (MBEC90) varied from 1 × to 4 × MFC. Scanning electron microscopy revealed morphological changes accompanied by the release of intracellular material from the fungal cells following exposure to Mul-1867. Furthermore, an increased concentration of nucleic acids was found in the medium after 5 min and 20 min of Mul-1867 treatment, indicating leakage of cytoplasmic contents. Overall, these data indicate that Mul-1867 may be a promising inhaled antifungal agent for the treatment and prevention of fungal respiratory infections.
Subject(s)
Antifungal Agents/pharmacology , Aspergillus/drug effects , Candida/drug effects , Aspergillosis/microbiology , Aspergillus/isolation & purification , Aspergillus/physiology , Biofilms/drug effects , Candida/isolation & purification , Candida/physiology , Candidiasis/microbiology , Culture Media/chemistry , DNA, Fungal/analysis , Humans , Microbial Sensitivity Tests , Microbial Viability/drug effects , Microscopy, Electron, ScanningABSTRACT
BACKGROUND: There is an urgent need for new antimicrobial compounds to treat various lung infections caused by multidrug-resistant Pseudomonas aeruginosa (MDR-PA). METHODS: We studied the potency of Mul-1867 against MDR-PA isolates from patients with cystic fibrosis, chronic obstructive pulmonary disease, and ventilator-associated pneumonia. The minimal inhibitory concentrations (MICs) and minimum biofilm eliminating concentrations (MBECs), defined as the concentrations of drug that kill 50 % (MBEC50), 90 % (MBEC90), and 100 % (MBEC100) of the bacteria in preformed biofilms, were determined by using the broth macrodilution method. RESULTS: Mul-1867 exhibited significant activity against MDR-PA and susceptible control strains, with MICs ranging from 1.0 to 8.0 µg/mL. Mul-1867 also possesses anti-biofilm activity against mucoid and non-mucoid 24-h-old MDR-PA biofilms. The MBEC50 value was equal to onefold the MIC. The MBEC90 value ranged from two to fourfold the MIC. Moreover, Mul-1867 completely eradicated mature biofilms at the concentrations tested, with MBEC100 values ranging between 16- and 32-fold the MIC. Mul-1867 was non-toxic to Madin-Darby canine kidney (MDCK) cells at concentrations up to 256 µg/mL. CONCLUSION: Overall, these data indicate that Mul-1867 is a promising locally acting antimicrobial for the treatment and prevention of P. aeruginosa infections.