Anne-Marie Bernier

Akwaton, polyhexamethylene-guanidine hydrochloride-based sporicidal disinfectant: a novel tool to fight bacterial spores and nosocomial infections.

Bacterial spores are of continuing interest to the food and medical industries. In efforts to eliminate bacterial spore contamination, a number of sporicidal agents have been developed. Most of these compounds must be used carefully in very specific circumstances as they are toxic to humans. The sporicidal activity of Akwaton, a polyhexamethylene-guanidine hydrochloride (PHMGH)-based disinfectant, was tested against Bacillus subtilis spores. PHMGH is a colourless, odourless, non-corrosive and non-irritating antimicrobial biocide of the guanidine family. Spores suspended in distilled water and spores placed on solid surfaces (stainless steel and glass) were used to determine the log(10) reduction after exposure to varying concentrations of Akwaton. The minimum sporostatic concentration, the minimum sporicidal concentration and the time required for sporicidal activity corresponded to 0.06% (w/v), 0.08 % (w/v) and 8.5 min, respectively. Disinfectant concentrations of 0.24 % (w/v) and 0.44 % (w/v) killed all spores suspended in distilled water within 3 min and 90 s, respectively. The sporicidal activity against suspended spores was linearly dependent with respect to the concentration of PHMGH and contact time (y(3 min) = 40x-1.6 and y(90 s) = 20x-0.8 thus y(3 min) = 2y(90 s)). Spores placed on surfaces were more resistant to the effect of the disinfectant and the positive linear correlation between the sporicidal activity and concentration was not observed. The concentration required to kill all spores placed on a surface (stainless steel or glass) corresponded to 0.52 % (w/v) for 90 s of contact and 0.36 % (w/v) for 3 min. This study demonstrated that PHMGH is an effective sporicidal disinfectant with great potential for use in hospitals, laboratories, food industries and households.

Impact of Hydroxychloroquine-Loaded Polyurethane Intravaginal Rings on Lactobacilli

ABSTRACT The use of polymeric devices for controlled sustained delivery of drugs is a promising approach for the prevention of HIV-1 infection. Unfortunately, certain microbicides, when topically applied vaginally, may be cytotoxic to vaginal epithelial cells and the protective microflora present within the female genital tract. In this study, we evaluated the impact of hydroxychloroquine (HCQ)-loaded, reservoir-type, polyurethane intravaginal rings (IVRs) on the growth of Lactobacillus crispatus and Lactobacillus jensenii and on the viability of vaginal and ectocervical epithelial cells. The IVRs were fabricated using hot-melt injection molding and were capable of providing controlled release of HCQ for 24 days, with mean daily release rates of 17.01 ± 3.6 μg/ml in sodium acetate buffer (pH 4) and 29.45 ± 4.84 μg/ml in MRS broth (pH 6.2). Drug-free IVRs and the released HCQ had no significant effects on bacterial growth or the viability of vaginal or ectocervical epithelial cells. Furthermore, there was no significant impact on the integrity of vaginal epithelial cell monolayers, in comparison with controls, as measured by transepithelial electrical resistance. Overall, this is the first study to evaluate the effects of HCQ-loaded IVRs on the growth of vaginal flora and the integrity of vaginal epithelial cell monolayers.

Brevibacterium massiliense (Roux and Raoult 2009) is a later heterotypic synonym of Brevibacterium ravenspurgense (Mages, Frodl, Bernard and Funke 2009), using whole-genome sequence analysis as a comparative tool

A patient strain derived from urine was found by 16S rRNA gene sequencing to be closely related (99.6 % identity) to sequences derived from both Brevibacterium ravenspurgense CCUG 56047T and Brevibacterium massilienseCCUG 53855T. Those species had been described during the same 11 month period in 2008-2009. Further characterization revealed that those isolates could not be readily distinguished from each other biochemically, by cellular fatty acids, antimicrobial susceptibility, MALDI-TOF MS, 16S rRNA gene sequencing or by whole-genome sequence (WGS) analyses. By WGS comparison, these isolates had an aerage nucleotide identity using blastn (ANIb) scores of 95.7 % or higher to each other, DNA G+C content in the range of 62.3 mol%-62.4 mol%, with genome sizes ranging from 2.28×106 to 2.41×106 bases. Based on these data, we propose that the name B. massiliense is a later heterotypic synonym of B. ravenspurgense and provide an emended description of B. ravenspurgense.

Draft Genome Sequence of Trueperella bernardiae LCDC 89-0504T, Isolated from a Human Blood Culture.

ABSTRACT We report here the draft genome sequence of Trueperella bernardiae LCDC 89-0504T, an organism linked to mild to severe infections in humans and animals. The genome size is 2,028,874 bp, with a G+C content of 65.44%. Annotation of the genome revealed 5 rRNA sequences, 48 tRNA genes, and 1,762 coding sequences.

Draft Whole-Genome Sequence of a Catalase-Negative Staphylococcus aureus subsp. aureus (Sequence Type 25) Strain Isolated from a Patient with Endocarditis and Septic Arthritis

ABSTRACT Staphylococcus aureus strains without catalase activity are rare, challenging to identify with conventional biochemical methods, and, despite a supposed decreased pathogenicity, can still cause disease. The first whole-genome sequence of a catalase-negative S. aureus isolate causing severe recurrent invasive infection with two novel missense mutations in the katA gene is reported here.

Draft Genome Sequences of Microbacterium hominis LCDC-84-0209T Isolated from a Human Lung Aspirate and Microbacterium laevaniformans LCDC 91-0039 Isolated from a Human Blood Culture

ABSTRACT Draft genomes for Microbacterium hominis 84-0209T and M. laevaniformans 91-0039 were studied. Genome sizes (bps, [G+C contents]) were 3,506,522 (70.96%) and 2,999,965 (69.51%), respectively. Annotation revealed: (M. hominis) three rRNA sequences, 45 tRNA genes, and 3,218 coding sequences; (M. laevaniformans) three rRNA sequences, 49 tRNA genes, and 2,874 coding sequences.

Fungicidal activity of AKWATON and in vitro assessment of its toxic effects on animal cells.

Acquired superficial fungal infections are among the most common infections. It is necessary to create new effective and non-toxic disinfectants. AKWATON is a new disinfectant of the polymeric guanidine family. Its fungicidal activity against Trichophyton mentagrophytes and its in vitro toxicity assessment were determined in this study. The MIC, minimum fungicidal concentration (MFC) and time required for its fungicidal activity at the MFC were evaluated using the official methods of analysis of the Association of Official Analytical Chemists, with modifications as recommended by the Canadian General Standards Board. The toxic effects of AKWATON and of four commercial disinfectants were evaluated on rat pancreatic (C2C12) and muscle (RnM5F) cells, using the trypan blue and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] methods. The MIC, MFC and time required for the fungicidal activity of AKWATON at the MFC were 0.025 % (w/v), 0.045 % (w/v) and 2.5 min, respectively. Cell cultures and the different tests carried out showed that the AKWATON-based disinfectant killed fewer cells than the commercial disinfectants, sparing 80 % of C2C12 cells and 65 % of RnM5F cells, whilst some of the well-known disinfectants currently on the market killed 85-100 % of cells. This study demonstrates that AKWATON has great potential as an odourless, colourless, non-corrosive and safe disinfectant for use in hospitals, the agriculture industry, farming and household facilities.

Clostridium neonatale sp. nov. linked to necrotizing enterocolitis in neonates and a clarification of species assignable to the genus Clostridium (Prazmowski 1880) emend. Lawson and Rainey 2016

A description of an outbreak of necrotizing enterocolitis among neonates, linked to the putative novel species Clostridium neonatale and assignable to the genus Clostridium, was previously reported in brief but that name had never been validly published (Alfa et al. Clin Inf Dis 2002;35:S101-S105). Features of this taxon group and its phylogenetic position with respect to contemporary species in the genus Clostridium were recently reviewed and still found to be unique. Therefore, we provide here a description based on biochemical, chemotaxonomic and antimicrobial susceptibility testing (AST), matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS, 16S rRNA gene sequencing as well as information obtained by whole genome sequencing (WGS) for strains 99A005T and 99A006. Those two C. neonatale strains were essentially identical to each other, with genome sizes of 4 658 596-4 705 520 bp and G+C content of 28.4-28.5 mol% (WGS). AST inferred susceptibility to 14 antibiotics. MALDI-TOF spectra were unique and could potentially be used for identification. The type strain is (NML) LCDC 99A005T [=ATCC BAA-265T=CCUG 46077T=St. Boniface Hospital 30686T]. While performing this review, we found that the names of 24 validly published species assignable to the genus Clostridium had been omitted from the emended description of the genus (Lawson and Rainey Int J Syst Evol Microbiol 2016;66 :1009-1016). Those species are listed in brief here. Lastly, based on this review, we also propose that Eubacterium budayi, Eubacterium nitritogenes and Eubacterium combesii be transferred to the emended genus Clostridium, as Clostridium budayi comb. nov., Clostridium nitritogenes comb. nov. and Clostridium combesii comb. nov., respectively.

Whole-Genome Sequences of Four Corynebacterium CDC Group F-1 Strains Isolated from Urine

ABSTRACT Three draft and one complete genome sequence from strains isolated from urine and consistent with Corynebacterium CDC group F-1 were assembled and studied. Genome sizes ranged between 2.3 and 2.44 Mb, with G+C content between 60.4% and 60.7%.

Draft Genome Sequence for the Type Strain of Corynebacterium afermentans LCDC 88-0199T, Isolated from a Human Blood Culture

ABSTRACT A draft genome for Corynebacterium afermentans LCDC 88-0199T was investigated. The size of the genome was 2,345,615 bp with an observed G+C content of 64.85%. Annotation revealed 2 rRNA sequences, 54 tRNA genes, and 2,164 coding sequences. Genome coverage was 85× and consisted of 24 contigs with an N50 of 187,988 bp.