International circumpolar surveillance: update on the interlaboratory quality control program for Streptococcus pneumoniae, 2009 to 2020.

The International Circumpolar Surveillance (ICS) program is a population-based surveillance network for invasive bacterial diseases throughout Arctic countries and territories. The ICS quality control program for Streptococcus pneumoniae serotyping and antimicrobial susceptibility testing has been ongoing since 1999. Current participating laboratories include the Provincial Laboratory for Public Health in Edmonton, Alberta; Laboratoire de santé publique du Québec in Sainte-Anne-de-Bellevue, Québec; the Centers for Disease Control's Arctic Investigations Program in Anchorage, Alaska; the Neisseria and Streptococcus Reference Laboratory at Statens Serum Institut in Copenhagen, Denmark; the Department of Clinical Microbiology, Landspitali in Reykjavik, Iceland; and Public Health Agency of Canada's National Microbiology Laboratory in Winnipeg, Manitoba. From 2009 to 2020, 140 isolates of S. pneumoniae were distributed among the six laboratories as part of the quality control program. Overall serotype concordance was 96.9%, with 99.3% concordance to pool level. All participating laboratories had individual concordance rates >92% for serotype and >97% for pool. Overall concordance by modal minimum inhibitory concentration (MIC) for testing done by broth microdilution or Etest was 99.1%, and >98% for all antimicrobials tested. Categorical concordance was >98% by both CLSI and EUCAST criteria. For two laboratories performing disc diffusion, rates of concordance by modal MIC were >97% for most antimicrobials, except chloramphenicol (>93%) and trimethoprim/sulfamethoxazole (>88%). Data collected from 12 years of the ICS quality control program for S. pneumoniae demonstrate excellent (≥95%) overall concordance for serotype and antimicrobial susceptibility testing results across six laboratories. IMPORTANCE: Arctic populations experience several social and physical challenges that lead to the increased spread and incidence of invasive diseases. The International Circumpolar Surveillance (ICS) program was developed to monitor five invasive bacterial diseases in Arctic countries and territories. Each ICS organism has a corresponding interlaboratory quality control (QC) program for laboratory-based typing, to ensure the technical precision and accuracy of reference testing services for these regions, and identify and correct potential problems. Here, we describe the results of the ICS Streptococcus pneumoniae QC program, from 2009 to 2020. Excellent overall concordance was achieved for serotype and antimicrobial susceptibility testing results across six laboratories. Ongoing participation in these QC programs ensures the continuation of quality surveillance systems within Arctic populations that experience health disparities.

Oocyte electroporation prior to in vitro fertilization is an efficient method to generate single, double, and multiple knockout porcine embryos of interest in biomedicine and animal production.

Genetically modified pigs play a critical role in mimicking human diseases, xenotransplantation, and the development of pigs resistant to viral diseases. The use of programmable endonucleases, including the CRISPR/Cas9 system, has revolutionized the generation of genetically modified pigs. This study evaluates the efficiency of electroporation of oocytes prior to fertilization in generating edited gene embryos for different models. For single gene editing, phospholipase C zeta (PLC ζ) and fused in sarcoma (FUS) genes were used, and the concentration of sgRNA and Cas9 complexes was optimized. The results showed that increasing the concentration resulted in higher mutation rates without affecting the blastocyst rate. Electroporation produced double knockouts for the TPC1/TPC2 genes with high efficiency (79 %). In addition, resistance to viral diseases such as PRRS and swine influenza was achieved by electroporation, allowing the generation of double knockout embryo pigs (63 %). The study also demonstrated the potential for multiple gene editing in a single step using electroporation, which is relevant for xenotransplantation. The technique resulted in the simultaneous mutation of 5 genes (GGTA1, B4GALNT2, pseudo B4GALNT2, CMAH and GHR). Overall, electroporation proved to be an efficient and versatile method to generate genetically modified embryonic pigs, offering significant advances in biomedical and agricultural research, xenotransplantation, and disease resistance. Electroporation led to the processing of numerous oocytes in a single session using less expensive equipment. We confirmed the generation of gene-edited porcine embryos for single, double, or quintuple genes simultaneously without altering embryo development to the blastocyst stage. The results provide valuable insights into the optimization of gene editing protocols for different models, opening new avenues for research and applications in this field.

Largest comparison between onset and relapses of acquired thrombotic thrombocytopenic purpura reveals severe neurological involvement and worse analytic parameters at debut.

It has been proposed that the onset of Acquired Thrombotic Thrombocytopenic Purpura (iTTP) is more severe than subsequent relapses; however, existing studies have limitations. We conducted a retrospective observational study to compare analytical and clinical severity of onset and relapse aTTP cases between 2012 and 2023. A total of 370 episodes of aTTP were analyzed, comprising 272 at initial diagnosis and 98 relapses. At onset, analytical parameters indicative of severity (low hemoglobin, low platelet count, and increased LDH) were significantly worse; patients had severe neurological symptoms (p<0.001) and ≥ 3 points in the TMA mortality score (p<0.001). In conclusion, the onset of aTTP is associated with worse analytical parameters and severe neurological involvement.

Infection of Norway lobster (Nephrops norvegicus) by the parasite Hematodinium sp.: insights from 30 years of field observations.

The Norway lobster, Nephrops norvegicus, is an important representative of the benthos and also supports valuable fisheries across Europe. Nephrops are susceptible to infection by Hematodinium sp., an endoparasitic dinoflagellate that causes morbidity and mortality. From an epizootiological perspective, the Clyde Sea Area (CSA; west of Scotland) is the best-studied Hematodinium-Nephrops pathosystem, with historical data available between 1988 and 2008. We have revisited this pathosystem by curating and updating prevalence values, differentiating host traits associated with disease exposure and progression, and comparing Hematodinium sp. disease dynamics in the CSA to other locations and to other decapod hosts (Cancer pagurus, Carcinus maenas). Prevalence from a 2018/2019 survey (involving 1739 lobsters) revealed Hematodinium sp. still mounts a synchronized patent infection in the CSA; hence this pathogen can be considered as enzootic in this location. We highlight for the first time that Nephrops size is associated with high severity infection, while females are more exposed to Hematodinium sp. More generally, regardless of the host (Norway lobster, brown and shore crabs) or the geographical area (Ireland, Wales, Scotland), Hematodinium sp. patent infections peak in spring/summer and reach their nadir during autumn. We contend that Hematodinium must be considered one of the most important pathogens of decapod crustaceans in temperate waters.

Biocontrol of L. monocytogenes with Selected Autochthonous Lactic Acid Bacteria in Raw Milk Soft-Ripened Cheese under Different Water Activity Conditions.

The effect of selected autochthonous Lactic Acid Bacteria (LAB) against Listeria monocytogenes was evaluated in two elaborations of soft-ripened cheese performed under high and low relative humidity (RH) elaborations, to achieve aw ranging from 0.97 to 0.94 in ripened cheeses. Two selected autochthonous strains of Lacticaseibacillus casei 31 and 116 were used. In each elaboration, 8 batches were physicochemically and microbiologically evaluated throughout the ripening process. The aw and pH decreased during ripening to final values ranging from 0.944 to 0.972 aw and 5.0 to 5.3 pH, respectively. LAB was the only microbial group that increased throughout the ripening in high and low RH elaborations. In batches that were uninoculated with LAB strains, L. monocytogenes was either maintained at the initial inoculation level or showed a slight reduction by the end of the ripening process. However, in LAB-inoculated batches in the two elaborations, steady decreases of L. monocytogenes were observed throughout maturation. L. casei 31 alone or in combination with strain 116 provoked reductions of 2 to 4 log CFU/g in L. monocytogenes over 60 days of ripening, which could be enough as a strategy for biocontrol to deal with the usual contamination by L. monocytogenes during cheese processing.

Cost-Effectiveness Analysis of Abrocitinib Compared with Other Systemic Treatments for Severe Atopic Dermatitis in Spain.

INTRODUCTION: Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by itchy, painful, and dry skin. Despite the great number of available therapies, economic evaluations are still needed to provide evidence on their cost efficiency. This research aimed to evaluate the cost effectiveness of the Janus kinase (JAK) inhibitor abrocitinib (200 mg) compared with dupilumab (300 mg), tralokinumab (300 mg), baricitinib (2 and 4 mg), and upadacitinib (15 and 30 mg) for the treatment of patients with severe AD from the Spanish National Health System (NHS) perspective. METHODS: A hybrid model consisting of a decision tree linked to a Markov model was developed to estimate costs, quality-adjusted life-years (QALYs), total years in response and incremental cost-per-QALY gained (willingness-to-pay [WTP] threshold: €25,000/QALY). Adults with severe AD entered the decision tree and response (75% reduction in baseline Eczema Area and Severity Index score, EASI-75) was considered at 16 and 52 weeks. After this time, patients entered the Markov model (remainder of the 10-year time horizon), which consisted of three health states: maintenance with active therapy, subsequent treatment, or death. All costs were presented in 2022 euros (€). Additionally, cost per number-needed-to-treat (NNT) was calculated for abrocitinib and dupilumab based on a head-to-head post-hoc analysis. RESULTS: Abrocitinib 200 mg was dominant (i.e., lower incremental costs and higher incremental benefit) compared with all studied alternatives (dupilumab 300 mg, tralokinumab 300 mg, baricitinib 2 and 4 mg, upadacitinib 15 and 30 mg) with a QALYs gain of 0.49, 0.60, 0.64, 0.43, 0.45, and 0.08, respectively, and per-person costs savings of €22,097, €24,140, €14,825, €7,116, €12,805, and €45,189, respectively. Considering the WTP threshold, abrocitinib was dominant or cost effective compared with all alternatives for most simulations. Additionally, abrocitinib was dominant compared with all alternatives when evaluating the cost effectiveness over a 5-year time horizon. NNT showed that abrocitinib was dominant versus dupilumab. CONCLUSIONS: The results of the study show that abrocitinib is a cost-effective therapy compared with other JAK inhibitors and biological therapies from the Spanish NHS perspective.

Predictors of fall risk in older adults using the G-STRIDE inertial sensor: an observational multicenter case-control study.

BACKGROUND: There are a lot of tools to use for fall assessment, but there is not yet one that predicts the risk of falls in the elderly. This study aims to evaluate the use of the G-STRIDE prototype in the analysis of fall risk, defining the cut-off points to predict the risk of falling and developing a predictive model that allows discriminating between subjects with and without fall risks and those at risk of future falls. METHODS: An observational, multicenter case-control study was conducted with older people coming from two different public hospitals and three different nursing homes. We gathered clinical variables ( Short Physical Performance Battery (SPPB), Standardized Frailty Criteria, Speed 4 m walk, Falls Efficacy Scale-International (FES-I), Time-Up Go Test, and Global Deterioration Scale (GDS)) and measured gait kinematics using an inertial measure unit (IMU). We performed a logistic regression model using a training set of observations (70% of the participants) to predict the probability of falls. RESULTS: A total of 163 participants were included, 86 people with gait and balance disorders or falls and 77 without falls; 67,8% were females, with a mean age of 82,63 ± 6,01 years. G-STRIDE made it possible to measure gait parameters under normal living conditions. There are 46 cut-off values of conventional clinical parameters and those estimated with the G-STRIDE solution. A logistic regression mixed model, with four conventional and 2 kinematic variables allows us to identify people at risk of falls showing good predictive value with AUC of 77,6% (sensitivity 0,773 y specificity 0,780). In addition, we could predict the fallers in the test group (30% observations not in the model) with similar performance to conventional methods. CONCLUSIONS: The G-STRIDE IMU device allows to predict the risk of falls using a mixed model with an accuracy of 0,776 with similar performance to conventional model. This approach allows better precision, low cost and less infrastructures for an early intervention and prevention of future falls.

Genomic analysis of Streptococcus pneumoniae serogroup 20 isolates in Alberta, Canada from 1993-2019.

In the province of Alberta, Canada, invasive disease caused by Streptococcus pneumoniae serogroup 20 (serotypes 20A/20B) has been increasing in incidence. Here, we characterize provincial invasive serogroup 20 isolates collected from 1993 to 2019 alongside invasive and non-invasive serogroup 20 isolates from the Global Pneumococcal Sequencing (GPS) Project collected from 1998 to 2015. Trends in clinical metadata and geographic location were evaluated, and serogroup 20 isolate genomes were subjected to molecular sequence typing, virulence and antimicrobial resistance factor mining, phylogenetic analysis and pangenome calculation. Two hundred and seventy-four serogroup 20 isolates from Alberta were sequenced, and analysed along with 95 GPS Project genomes. The majority of invasive Alberta serogroup 20 isolates were identified after 2007 in primarily middle-aged adults and typed predominantly as ST235, a sequence type that was rare among GPS Project isolates. Most Alberta isolates carried a full-length whaF capsular gene, suggestive of serotype 20B. All Alberta and GPS Project genomes carried molecular resistance determinants implicated in fluoroquinolone and macrolide resistance, with a few Alberta isolates exhibiting phenotypic resistance to azithromycin, clindamycin, erythromycin, tetracycline and trimethoprim-sulfamethoxazole, as well as non-susceptibility to tigecycline. All isolates carried multiple virulence factors including those involved in adherence, immune modulation and nutrient uptake, as well as exotoxins and exoenzymes. Phylogenetically, Alberta serogroup 20 isolates clustered with predominantly invasive GPS Project isolates from the USA, Israel, Brazil and Nepal. Overall, this study highlights the increasing incidence of invasive S. pneumoniae serogroup 20 disease in Alberta, Canada, and provides insights into the genetic and clinical characteristics of these isolates within a global context.

Use of genome sequencing to resolve differences in gradient diffusion and agar dilution antimicrobial susceptibility testing performance of Neisseria gonorrhoeae isolates in Alberta, Canada.

Agar dilution is the gold standard method for phenotypic antimicrobial susceptibility testing (AST) for Neisseria gonorrhoeae. However, this method is laborious and requires expertise, so laboratories that perform N. gonorrhoeae AST may choose alternative methods such as disk diffusion and gradient diffusion. In this study, we retrospectively compare the performance of gradient diffusion to agar dilution for 2,394 unique N. gonorrhoeae isolates identified in Alberta from 2017 to 2020 against azithromycin, cefixime, ceftriaxone, ciprofloxacin, penicillin, and tetracycline. Genome sequencing was utilized to resolve discrepancies between AST methods, detect antimicrobial resistance markers, and identify trends between error rates and sequence types (STs) of isolates. Over 90% of N. gonorrhoeae isolates were susceptible to azithromycin, cefixime, and ceftriaxone, whereas decreased susceptibility was observed for ciprofloxacin, penicillin, and tetracycline. Categorical (CA) and essential agreement (EA) was poorest between the two methods for penicillin (CA: 86.02%; EA: 77.69%) and tetracycline (CA: 47.22%; EA: 55.96%); however, the low CA was primarily attributed to minor errors. Antimicrobial agents with errors outside of acceptable limits included azithromycin (very major error: 18.42%; major error: 7.73%) and tetracycline (very major error: 6.17%). Genome sequencing on a subset of isolates resolved 30.3% of the azithromycin major errors and confirmed the azithromycin or tetracycline very major errors. Significant associations between certain STs and error types for azithromycin and tetracycline were also identified. Overall, gradient diffusion compared well to agar dilution for cefixime, ceftriaxone, and ciprofloxacin, and genome sequencing was identified as a useful tool to arbitrate discrepant susceptibility testing results between gradient diffusion and agar dilution for N. gonorrhoeae.

Clonal diversity of Streptococcus pneumoniae serotype 19A collected from children < 5 years old in Québec, Canada, 2016-2021.

Streptococcus pneumoniae serotype 19A is a highly diverse, often antimicrobial-resistant Gram-positive bacterium which can cause invasive pneumococcal disease (IPD). In 2021, public health authorities in the Canadian province of Québec observed an increase of serotype 19A IPD in children <5 years. The purpose of this study was to determine the clonal composition of serotype 19A isolates collected from this age group in Québec, from 2016 to 2021. Forty-one and 37 IPD isolates from children <5 years from Québec and the remainder of Canada, respectively, were sequenced using the Illumina NextSeq platform. Phylogenetic analysis using SNVPhyl identified three clusters, corresponding to three common clones of serotype 19A: CC199, CC320 and ST695. CC199, predominantly represented by ST416, accounted for similar proportions of serotype 19A isolates collected from children in Québec (19.5 %) and other Canadian jurisdictions (OCJs, 21.6 %), with significant presence of ermB (62.5 % and 60 % of ST416 isolates, respectively). CC320 was more commonly identified from OCJs in comparison to Québec (18.9 % vs. 7.3 %, respectively), but were highly antimicrobial-resistant regardless of region. ST695 was the most common clone of serotype 19A collected in Québec from children <5 years, representing 65.9 % of isolates collected over the study period (40.5 % of isolates collected in OCJs). Phylogenetic analysis identified geographical differences in ST695 across Canada; including a large clade specific to Québec (with both susceptible and macrolide-resistant [ermB] subclades), and a separate macrolide-resistant (mefA) clade associated with OCJs. The Québec-specific ermB-ST695 clone represented 48.1 % of ST695 collected from the province. Continued genomic surveillance of S. pneumoniae serotype 19A is required to: i) track the prevalence and clonal composition of serotype 19A in Québec in future years; ii) characterize the clonal distribution of serotype 19A in adult populations; and iii) monitor whether the currently geographically restricted ermB-ST695 clone observed in Québec expands to OCJs.

Prevalence of Listeria monocytogenes in RTE Meat Products of Quevedo (Ecuador).

Listeria monocytogenes is a foodborne pathogen that causes listeriosis and can be a problem in areas where meat products are sold at unregulated storage temperatures. In this work, the prevalence of L. monocytogenes was determined in the five most widely traded meat products in the province of Quevedo (Ecuador): bacon, "chorizo paisa", grilled hamburger meat, mortadella, and salami. A total of 1000 samples of these products were analyzed in two seasons of the year (dry season/rainy season). All L. monocytogenes isolates were confirmed by PCR with primers designed for the iap gene. Furthermore, the positive samples were quantified for L. monocytogenes. Of the 1000 meat products analyzed, 163 were positive for L. monocytogenes (16.3%). The prevalence of L. monocytogenes in the two seasons in different meat products was as follows: 22.5% in mortadella, 19% in hamburger meat, 15% in bacon, 14.5% in chorizo paisa and 10.5% in salami. In addition, the concentration of L. monocytogenes in most of the positive samples was in the range of 4-6 log CFU/g or even higher. The results show the need for improvements in the hygienic measures and meat storage temperatures in Quevedo (Ecuador) to avoid risks of foodborne listeriosis.

Antilisterial activity of cinnamon essential oil, pomegranate extract, or strawberry tree extract against Listeria monocytogenes in slices of dry-cured ham and pork loin.

Owing to concerns about the antimicrobial resistance of agents that can prevent the growth of Listeria monocytogenes in meat, researchers have investigated natural preservatives with antilisterial effects. However, in vivo application of essential oils and plant extracts usually results in reduced antimicrobial activity in meat products when compared to in vitro studies. This study aimed to evaluate the in vivo antimicrobial activity of cinnamon essential oil, pomegranate, and strawberry tree extracts in slices of dry-cured ham and pork loin against L. monocytogenes. Fragments of sterile dry-cured ham were inoculated with 100 µL cinnamon oil 0.5%, pomegranate, or strawberry crude extract. After 10 min, 100 µL of L. monocytogenes serotype 4b (104 colony-forming unit [CFU]/mL) was inoculated, and samples were incubated at 7 °C for 7 d to simulate the processing and storage temperature conditions of dry-cured meat products. L. monocytogenes was detected and quantified. Only strawberry extract presented significant differences (P < 0.05) from the control; thus, it was selected for the assay with 2% and 4% salt-treated pork loin. The strawberry tree extract significantly (P < 0.05) reduced the growth of L. monocytogenes in dry-cured ham. However, it could not reduce L. monocytogenes growth in pork loin, regardless of the salt concentration. This is the first report on the antimicrobial effect of strawberry tree leaf extract against L. monocytogenes in dry-cured ham.

Specialized Care Resources for Diagnosis and Management of Patients Who Have Suffered Falls: Results of a National Survey in Geriatric Units.

INTRODUCTION: Clinical guidelines recommend comprehensive multifactorial assessment and intervention to prevent falls and fractures in older populations. METHODS: A descriptive study was conducted by the Falls Study Group of the Spanish Geriatric Medicine Society (SEMEG) to outline which types of healthcare-specific resources were assigned for fall assessment in Spanish geriatric departments. A self-reported seven-item questionnaire was delivered from February 2019 to February 2020. Where geriatric medicine departments were not available, we tried to contact geriatricians working in those areas. RESULTS: Information was obtained regarding 91 participant centers from 15 autonomous communities, 35.1% being from Catalonia and 20.8% from Madrid. A total of 21.6% reported a multidisciplinary falls unit, half of them in geriatric day hospitals. Half of them reported fall assessment as part of a general geriatric assessment in general geriatric outpatient clinics (49.5%) and, in 74.7% of cases, the assessment was based on functional tests. A total of 18.7% reported the use of biomechanical tools, such as posturography, gait-rides or accelerometers, for gait and balance analysis, and 5.5% used dual X-ray absorptiometry. A total of 34% reported research activity focused on falls or related areas. Regarding intervention strategies, 59% reported in-hospital exercise programs focused on gait and balance improvement and 79% were aware of community programs or the pathways to refer patients to these resources. CONCLUSIONS: This study provides a necessary starting point for a future deep analysis. Although this study was carried out in Spain, it highlights the need to improve public health in the field of fall prevention, as well as the need, when implementing public health measures, to verify that these measures are implemented homogeneously throughout the territory. Therefore, although this analysis was at the local level, it could be useful for other countries to reproduce the model.

Biocontrol of Pathogen Microorganisms in Ripened Foods of Animal Origin.

Ripened foods of animal origin comprise meat products and dairy products, being transformed by the wild microbiota which populates the raw materials, generating highly appreciated products over the world. Together with this beneficial microbiota, both pathogenic and toxigenic microorganisms such as Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Clostridium botulinum, Escherichia coli, Candida spp., Penicillium spp. and Aspergillus spp., can contaminate these products and pose a risk for the consumers. Thus, effective strategies to hamper these hazards are required. Additionally, consumer demand for clean label products is increasing. Therefore, the manufacturing sector is seeking new efficient, natural, low-environmental impact and easy to apply strategies to counteract these microorganisms. This review gathers different approaches to maximize food safety and discusses the possibility of their being applied or the necessity of new evidence, mainly for validation in the manufacturing product and its sensory impact, before being implemented as preventative measures in the Hazard Analysis and Critical Control Point programs.

Optimization and Clinical Evaluation of an Automated Commercial Analyte-Specific Reagent Assay for Mycoplasmoides genitalium Macrolide Resistance Detection in Primary Clinical Specimens.

With improvement in laboratory diagnosis of Mycoplasmoides genitalium infection through molecular diagnostics, macrolide resistance determination within M. genitalium-positive patients is necessary. In this study, we report baseline parameters for an analyte-specific reagent (ASR) macrolide resistance real-time reverse transcriptase PCR on an open access analyzer and evaluated detection of macrolide resistance-mediated mutation (MRM) within 23S rRNA in a clinical specimen set. Initial use of 1.2 µM M. genitalium primer and 0.8 µM M. genitalium detection probe concentrations yielded an 80% false-positive detection rate when challenged with 10,000 copies of wild-type RNA. Optimization experiments showed that lowering primer/detection probe and MgCl2 concentrations minimized these false-detections of wild-type 23S rRNA, while higher levels of KCl increased rates of MRM detection with concomitant lower cycle threshold values and higher fluorescence emission. Lower limit of A2058G mutation detection was 5000 copies/mL (180 copies/reaction; 20/20 detections). Utilization of a baseline correction slope limit of 250 units further mitigated false-detection from wild-type 23S rRNA at challenges up to 3.3 billion copies/mL. MRM was detected in 583/866 (67.3%) clinical specimens initially positive for M. genitalium by commercial transcription-mediated amplification. These data included 392/564 detections (69.5%) from M. genitalium-positive swab specimens and 191/302 (63.2%) from M. genitalium-positive-positive first-void urine specimens (P = 0.06). Overall resistance detection rates did not vary by gender (P = 0.76). Specificity of the M. genitalium macrolide resistance ASR was 100% (141 urogenital determinations). MRM detection by the ASR was confirmed at a concordance rate of 90.9% by Sanger sequencing of a clinical specimen subset.

Antimicrobial susceptibility testing of invasive isolates of Streptococcus pneumoniae from Canadian patients: the SAVE study, 2011-2020.

OBJECTIVES: To assess the antimicrobial susceptibility of 14 138 invasive Streptococcus pneumoniae isolates collected in Canada from 2011 to 2020. METHODS: Antimicrobial susceptibility testing was performed using the CLSI M07 broth microdilution reference method. MICs were interpreted using 2022 CLSI M100 breakpoints. RESULTS: In 2020, 90.1% and 98.6% of invasive pneumococci were penicillin-susceptible when MICs were interpreted using CLSI meningitis or oral and non-meningitis breakpoints, respectively; 96.9% (meningitis breakpoint) and 99.5% (non-meningitis breakpoint) of isolates were ceftriaxone-susceptible, and 99.9% were levofloxacin-susceptible. Numerically small, non-temporal, but statistically significant differences (P < 0.05) in the annual percentage of isolates susceptible to four of the 13 agents tested was observed across the 10-year study: chloramphenicol (4.4% difference), trimethoprim-sulfamethoxazole (3.9%), penicillin (non-meningitis breakpoint, 2.7%) and ceftriaxone (meningitis breakpoint, 2.7%; non-meningitis breakpoint, 1.2%). During the same period, annual differences in percent susceptible values for penicillin (meningitis and oral breakpoints) and all other agents did not achieve statistical significance. The percentage of isolates with an MDR phenotype (resistance to ≥3 antimicrobial classes) in 2011 and 2020 (8.5% and 9.4%) was not significantly different (P = 0.109), although there was a significant interim decrease observed between 2011 and 2015 (P < 0.001) followed by a significant increase between 2016 and 2020 (P < 0.001). Statistically significant associations were observed between resistance rates to most antimicrobial agents included in the MDR analysis (penicillin, clarithromycin, clindamycin, doxycycline, trimethoprim/sulfamethoxazole and chloramphenicol) and patient age, specimen source, geographic location in Canada or concurrent resistance to penicillin or clarithromycin, but not biological sex of patients. Given the large isolate collection studied, statistical significance did not necessarily imply clinical or public health significance in some analyses. CONCLUSIONS: Invasive pneumococcal isolates collected in Canada from 2011 to 2020 generally exhibited consistent in vitro susceptibility to commonly tested antimicrobial agents.

Analysis of MDR in the predominant Streptococcus pneumoniae serotypes in Canada: the SAVE study, 2011-2020.

OBJECTIVES: To investigate the levels of MDR in the predominant serotypes of invasive Streptococcus pneumoniae isolated in Canada over a 10 year period. METHODS: All isolates were serotyped and had antimicrobial susceptibility testing performed, in accordance with CLSI guidelines (M07-11 Ed., 2018). Complete susceptibility profiles were available for 13 712 isolates. MDR was defined as resistance to three or more classes of antimicrobial agents (penicillin MIC ≥2 mg/L defined as resistant). Serotypes were determined by Quellung reaction. RESULTS: In total, 14 138 invasive isolates of S. pneumoniae were tested in the SAVE study (S. pneumoniae Serotyping and Antimicrobial Susceptibility: Assessment for Vaccine Efficacy in Canada), a collaboration between the Canadian Antimicrobial Resistance Alliance and Public Health Agency of Canada-National Microbiology Laboratory. The rate of MDR S. pneumoniae in SAVE was 6.6% (902/13 712). Annual rates of MDR S. pneumoniae decreased between 2011 and 2015 (8.5% to 5.7%) and increased between 2016 and 2020 (3.9% to 9.4%). Serotypes 19A and 15A were the most common serotypes demonstrating MDR (25.4% and 23.5% of the MDR isolates, respectively); however, the serotype diversity index increased from 0.7 in 2011 to 0.9 in 2020 with a statistically significant linear increasing trend (P < 0.001). In 2020, MDR isolates were frequently serotypes 4 and 12F in addition to serotypes 15A and 19A. In 2020, 27.3%, 45.5%, 50.5%, 65.7% and 68.7% of invasive MDR S. pneumoniae were serotypes included in the PCV10, PCV13, PCV15, PCV20 and PPSV23 vaccines, respectively. CONCLUSIONS: Although current vaccine coverage of MDR S. pneumoniae in Canada is high, the increasing diversity of serotypes observed among the MDR isolates highlights the ability of S. pneumoniae to rapidly evolve.