Phenotypic and genomic profiling of Staphylococcus argenteus in Canada and the United States and recommendations for clinical result reporting

Staphylococcus argenteus is a newly described species, formerly known as S. aureus clonal complex 75 (CC75). Here, we describe the largest collection of S. argenteus isolates in North America, highlighting identification challenges. We present phenotypic and genomic characteristics and provide recommendations for clinical reporting. Between 2017 and 2019, 22 isolates of S. argenteus were received at 2 large reference laboratories for identification. Identification with routine methods (biochemical, matrix-assisted laser desorption ionization–time of flight mass spectrometry [MALDI-TOF MS], 16S rRNA gene analysis) proved challenging to confidently distinguish these isolates from S. aureus. Whole-genome sequencing analysis was employed to confirm identifications. Using several different sequence-based analyses, all clinical isolates under investigation were confirmed to be S. argenteus with clear differentiation from S. aureus. Seven of 22 isolates were recovered from sterile sites, 11 from nonsterile sites, and 4 from surveillance screens. While sequence types ST1223/coa type XV, ST2198/coa type XIV, and ST2793/coa type XId were identified among the Canadian isolates, the majority of isolates (73%) belonged to multilocus sequence types (MLST) ST2250/coa type XId and exhibited a high degree of homology at the genomic level. Despite this similarity, 5 spa types were identified among ST2250 isolates, demonstrating some diversity between strains. Several isolates carried mecA, as well as other resistance and virulence determinants (e.g., PVL, TSST-1) commonly associated with S. aureus. Based on our findings, the growing body of literature on S. argenteus, the potential severity of infections, and possible confusion associated with reporting, including use of incorrect breakpoints for susceptibility results, we make recommendations for clinical laboratories regarding this organism

The first Canadian pediatric case of extensively drug-resistant Salmonella Typhi originating from an outbreak in Pakistan and its implication for empiric antimicrobial choices

We report on a three year-old male who contracted enteric fever during a visit to the Sindh province of Pakistan in the summer of 2018. He was diagnosed after returning to Canada and blood cultures isolated Salmonella enterica serovar Typhi which harbored extensive drug-resistance (XDR) to all first-line antibiotics including ceftriaxone. Empiric ceftriaxone was switched to meropenem and he was successfully treated with a two-week course. An outbreak of XDR typhoid is currently emerging from Pakistan and several outbreak-related cases have been identified in the U.K and U.S. Whole genome sequencing confirmed that our child was infected with the XDR outbreak-strain. Current empiric antimicrobial choices will result in treatment failure if an XDR strain is encountered, therefore clinicians must adapt their empiric approach for those returning from high risk regions. This is the first XDR typhoid case in Canada and the first pediatric case to be diagnosed and treated outside of Pakistan. Clinicians must be vigilant of future cases. Keywords: Salmonella Typhi, Typhoid, Pediatric, Extensive drug resistance, Antimicrobial resistance, Canad

Whole genome sequencing of increased number of azithromycin-resistant Shigella flexneri 1b isolates in Ontario

Abstract Azithromycin (AZM) resistance among Shigella is a major public health concern. Here, we investigated the epidemiology of Shigella flexneri serotype 1b recovered during 2016–2018 in Ontario, to describe the prevalence and spread of AZM resistance. We found that 72.3% (47/65) of cases were AZM–resistant (AZMR), of which 95.7% (45/47) were among males (P  95% nucleotide similarity to pKSR100. Plasmid-borne resistance limiting treatment options to AZM, ceftriaxone (CRO) and CIP was noted in a single isolate. We characterized AZMR isolates circulating locally among males and found that genomic analysis can support targeted prevention and mitigation strategies against antimicrobial-resistance

Use of whole genome sequencing for the molecular comparison of Neisseria gonorrhoeae isolates with decreased susceptibility to extended spectrum cephalosporins from two geographically different regions in America

Fil: Gianecini, Ricardo A. Public Health Ontario Laboratories, Toronto; Canada.Fil: Zittermann, Sandra. Public Health Ontario Laboratories, Toronto; Canada.Fil: Oviedo, Claudia . ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Galas, Marcelo F. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Ramon Pardo, Pilar. Pan American Health Organization/World Health Organization (PAHO/ WHO), Washington, DC; Estados Unidos.Fil: Allen, Vanessa G. Public Health Ontario Laboratories, Toronto; Canada.Fil: Galarza, Patricia G. Public Health Ontario Laboratories, Toronto; Canada.Fil: Melano, Roberto. Public Health Ontario Laboratories, Toronto; Canada.Neisseria gonorrhoeae isolates with reduced susceptibility or resistance to the recommended first-line antimicrobial therapy have been described in several countries. The purpose of this study was to use genome analyses to compare the molecular characteristics of N. gonorrhoeae isolates with decreased susceptibility to extended-spectrum cephalosporin (ESC) from Ontario, Canada, and Argentina

Exercise and calcium combined results in a Greater osteogenic effect than either factor alone: a blinded randomized placebo-controlled trial in boys

We examined the combined effects of exercise and calcium on BMC accrual in pre- and early-pubertal boys. Exercise and calcium together resulted in a 2% greater increase in femur BMC than either factor alone and a 3% greater increase in BMC at the tibia&ndash;fibula compared with the placebo group. Increasing dietary calcium seems to be important for optimizing the osteogenic effects of exercise.Introduction: Understanding the relationship between exercise and calcium during growth is important given that the greatest benefits derived from these factors are achieved during the first two decades of life. We conducted a blinded randomized-controlled exercise&ndash;calcium intervention in pre- and early-pubertal boys to test the following hypotheses. (1) At the loaded sites (femur and tibia&ndash;fibula), exercise and calcium will produce greater skeletal benefits than either exercise or calcium alone. (2) At nonloaded sites (humerus and radius&ndash;ulna), there will be an effect of calcium supplementation.Materials and Methods: Eighty-eight pre- and early-pubertal boys were randomly assigned to one of four study groups: moderate impact exercise with or without calcium (Ca) (Ex + Ca and Ex + placebo, respectively) or low impact exercise with or without Ca (No-Ex + Ca and No-Ex + Placebo, respectively). The intervention involved 20 minutes of either moderate- or low-impact exercise performed three times a week and/or the addition of Ca-fortified foods using milk minerals (392 &plusmn; 29 mg/day) or nonfortified foods over 8.5 months. Analysis of covariance was used to determine the main and combined effects of exercise and calcium on BMC after adjusting for baseline BMC.Results: At baseline, no differences were reported between the groups for height, weight, BMC, or bone length. The increase in femur BMC in the Ex + Ca group was 2% greater than the increase in the Ex + placebo, No-Ex + Ca, or No-Ex + Placebo groups (all p &lt; 0.03). At the tibia&ndash;fibula, the increase in BMC in the Ex + Ca group was 3% greater than the No-Ex + placebo group (p &lt; 0.02) and 2% greater than the Ex + Placebo and the No-Ex + Ca groups (not significant). No effect of any group was detected at the humerus, ulna&ndash;radius, or lumbar spine for BMC, height, bone area, or volume.Conclusions: In this group of normally active boys with adequate calcium intakes, additional exercise and calcium supplementation resulted in a 2&ndash;3% greater increase in BMC than controls at the loaded sites. These findings strengthen the evidence base for public health campaigns to address both exercise and dietary changes in children for optimizing the attainment of peak BMC. <br /

Listeria monocytogenes Associated with Pasteurized Chocolate Milk, Ontario, Canada

In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015–June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization

Escherichia coli O104:H4 Infections and International Travel

We analyzed travel-associated clinical isolates of Escherichia coli O104:H4, including 1 from the 2011 German outbreak and 1 from a patient who returned from the Philippines in 2010, by genome sequencing and optical mapping. Despite extensive genomic similarity between these strains, key differences included the distribution of toxin and antimicrobial drug–resistance determinants

Basic Fibroblast Growth Factor (bFGF, FGF-2) Potentiates Leukocyte Recruitment to Inflammation by Enhancing Endothelial Adhesion Molecule Expression

Basic fibroblast growth factor (bFGF, FGF-2) is a potent angiogenic factor and endothelial cell mitogen. Although bFGF levels are increased in chronically inflamed tissue, its role in inflammation is unclear. We investigated the effect of bFGF on acute dermal inflammation and the recruitment of monocytes, T cells, and neutrophils. Leukocyte recruitment to inflamed sites was quantified with radiolabeled leukocytes. Intradermal injection of bFGF in rats did not induce leukocyte recruitment or inflammation. However, the recruitment of leukocytes to inflammation induced by tumor necrosis factor-α, interferon-γ, C5a, or a delayed hypersensitivity reaction was enhanced by bFGF by 55 to 132% (P < 0.05). Either acute or prolonged bFGF treatment of dermal sites had this effect. The potentiating effect of bFGF on leukocyte recruitment was also seen in joints. There was no associated modulation of vascular permeability, blood flow, or angiogenesis in the sites by bFGF. However, the expression of the endothelial cell adhesion molecules (CAMs) for leukocytes, P-selectin, E-selectin, and ICAM-1, was significantly up-regulated in the inflamed tissue by bFGF, as quantified by radiolabeled anti-CAM antibody binding in vivo. Thus, although not directly proinflammatory, bFGF synergistically potentiates inflammatory mediator-induced leukocyte recruitment, at least in part, by enhancing CAM up-regulation on endothelium