Invasive pneumococcal disease caused by serotypes 22F and 33F in Canada: the SAVE study 2011-2018.

A 15-valent conjugate vaccine that provides protection against Streptococcus pneumoniae serotypes 22F and 33F is in development. Here we report on the prevalence, antimicrobial susceptibility, and clonal structure of these serotypes in Canada. From 2011 to 2018, the SAVE study collected 11,044 invasive S. pneumoniae isolates. Of these, 9.3% (1024/11,044) and 3.8% (416/11,044) were 22F and 33F, respectively. Serotype 22F isolates were susceptible to most antimicrobials tested except clarithromycin, where susceptibility significantly decreased over time (2011: 80.4%, 2018: 52.9%, P < 0.0001). Only 1.6% of serotype 22F isolates were multidrug-resistant (MDR), while 96% of typed strains were clonal cluster (CC) 433. Serotype 33F isolates demonstrated low susceptibility to clarithromycin and trimethoprim/sulfamethoxazole (22.4% and 24.6%, respectively) and 4.8% MDR. Most serotype 33F isolates were CC100, CC673 and CC717. CC100 prevalence increased significantly over time (2011: 50.0%, 2018: 84.8%, P < 0.006). Continued surveillance of these serotypes is crucial to identify further changes in prevalence, antimicrobial susceptibility, and clonal spread.

Ignatzschineria indica bloodstream infection associated with maggot infestation of a wound in a patient from Canada.

We describe a case of Ignatzschineria indica bacteremia in a patient with maggot infestation of a necrotic left leg wound. Ignatzschineria spp are an infrequent cause of infection in patients with wound myiasis. We review 16 cases described in published literature. Microbiologists and clinicians should be aware of uncommon bacteria, including Ignatzschineria spp, that may cause infection in patients with maggot-infested wounds such that these organisms are appropriately worked up and treated when found in clinical specimens.

Les auteurs décrivent un cas de bactériémie à Ignatzschineria indica chez un patient présentant une infestation de larves dans une plaie nécrotique de la jambe gauche. Les espèces d'Ignatzschineria sont une cause peu courante d'infection chez les patients présentant une myiase des plaies. Ils analysent 16 cas décrits dans des publications. Les microbiologistes et les cliniciens doivent connaître les bactéries rares, y compris les espèces à Ignatzschineria, susceptibles d'être responsables d'une infection chez les patients ayant une plaie infestée par des larves, afin que ces organismes fassent l'objet de bilans appropriés et soient traités lorsqu'ils sont présents dans des échantillons cliniques.

Influence of vaccination with CVI988/Rispens on load and replication of a very virulent Marek's disease virus strain in feathers of chickens.

Several highly efficacious vaccines are currently available for control of Marek's disease, a lymphoproliferative disease in chickens. However, these vaccines are unable to prevent infection with Marek's disease virus (MDV) in vaccinated birds. This leads to shedding of virulent MDV from feather follicle epithelium and skin epithelial cells of vaccinated and infected chickens. The objective of the present study was to study the interactions between a vaccine strain (CVI988/Rispens) and a very virulent strain of MDV (RB1B) in feathers. We examined genome load and replication of CVI988 and MDV-RB1B strains at various time points post infection. Moreover, we evaluated cytokine expression in feathers as indicators of immunity generated in response to vaccines against MDV. Analysis of feathers collected between 4 and 21 days post infection (d.p.i.) revealed a steady level of CVI988 genome load in the presence or absence of RB1B. Infection with MDV resulted in a significant increase in RB1B genome load peaking at 14 d.p.i. Importantly, vaccination with CVI988 resulted in a significant reduction in accumulation of MDV-RB1B in feathers. RB1B genome accumulation in feather tips was associated with increased expression of interferon-α at 14 d.p.i. and interferon-Sγ at earlier time points, 4 and 7 d.p.i. compared with 10 and 14 d.p.i. Interleukin-10 and interleukin-6 were up-regulated at 14 d.p.i. in the infected groups. This study expands our understanding of the dynamics of replication of vaccine and virulent MDV strains in the feathers and illuminates mechanisms associated with immunity to Marek's disease.