DODGE: automated point source bacterial outbreak detection using cumulative long term genomic surveillance.

SUMMARY: The reliable and timely recognition of outbreaks is a key component of public health surveillance for foodborne diseases. Whole genome sequencing (WGS) offers high resolution typing of foodborne bacterial pathogens and facilitates the accurate detection of outbreaks. This detection relies on grouping WGS data into clusters at an appropriate genetic threshold. However, methods and tools for selecting and adjusting such thresholds according to the required resolution of surveillance and epidemiological context are lacking. Here we present DODGE (Dynamic Outbreak Detection for Genomic Epidemiology), an algorithm to dynamically select and compare these genetic thresholds. DODGE can analyse expanding datasets over time and clusters that are predicted to correspond to outbreaks (or "investigation clusters") can be named with established genomic nomenclature systems to facilitate integrated analysis across jurisdictions. DODGE was tested in two real-world Salmonella genomic surveillance datasets of different duration, 2 months from Australia and 9 years from the United Kingdom. In both cases only a minority of isolates were identified as investigation clusters. Two known outbreaks in the United Kingdom dataset were detected by DODGE and were recognized at an earlier timepoint than the outbreaks were reported. These findings demonstrated the potential of the DODGE approach to improve the effectiveness and timeliness of genomic surveillance for foodborne diseases and the effectiveness of the algorithm developed. AVAILABILITY AND IMPLEMENTATION: DODGE is freely available at https://github.com/LanLab/dodge and can easily be installed using Conda.

Emergence of Poultry-Associated Human Salmonella enterica Serovar Abortusovis Infections, New South Wales, Australia.

Salmonella enterica serovar Abortusovis is a ovine-adapted pathogen that causes spontaneous abortion. Salmonella Abortusovis was reported in poultry in 2009 and has since been reported in human infections in New South Wales, Australia. Phylogenomic analysis revealed a clade of 51 closely related isolates from Australia originating in 2004. That clade was genetically distinct from ovine-associated isolates. The clade was widespread in New South Wales poultry production facilities but was only responsible for sporadic human infections. Some known virulence factors associated with human infections were only found in the poultry-associated clade, some of which were acquired through prophages and plasmids. Furthermore, the ovine-associated clade showed signs of genome decay, but the poultry-associated clade did not. Those genomic changes most likely led to differences in host range and disease type. Surveillance using the newly identified genetic markers will be vital for tracking Salmonella Abortusovis transmission in animals and to humans and preventing future outbreaks.

Eligibility for antiamyloid treatment: preparing for disease-modifying therapies for Alzheimer's disease.

BACKGROUND: Disease-modifying therapies (DMTs) for Alzheimer's disease (AD) have early evidence of efficacy. Widespread delivery of DMTs will require major service reconfiguration. Treatment pathways will need to include triaging for eligibility, regular infusions and baseline and follow-up MRI scanning. A critical step in planning is provision of real-world estimates of patients likely to be eligible for triaging, but these are challenging to obtain. METHODS: We performed a retrospective service evaluation of patients attending five memory services across North and East London and a national specialist cognitive disorders service. We examined the likely proportion of patients who would (1) be referred for triaging for DMTs and (2) potentially be suitable for treatments. RESULTS: Data from a total of 1017 patients were included, 517 of whom were seen in community memory services and 500 in a specialist clinic. In the memory services, 367/517 (71%) were diagnosed with possible AD. After exclusions of those in whom cognitive and frailty scores, MRI contraindications or anticoagulant use indicated they would be unlikely to be suitable, an estimated 32% would be eligible for triaging. In the specialist cognitive clinic, where additional investigations are available, 14% of those seen (70/500) would be potentially eligible for treatment. CONCLUSIONS: While a sizeable proportion of patients attending memory clinics may be referred for triaging for DMTs for AD, only a minority are likely to be suitable for these, as demonstrated in patients seen in specialist cognitive services. This will need to be considered when designing pathways for DMT delivery.

A Multilocus Sequence Typing Scheme for Rapid Identification of Xanthomonas citri Based on Whole-Genome Sequencing Data.

Xanthomonas citri is a plant-pathogenic bacterium associated with a diverse range of host plant species. It has undergone substantial reclassification and currently consists of 14 different subspecies or pathovars that are responsible for a wide range of plant diseases. Whole-genome sequencing (WGS) provides a cutting-edge advantage over other diagnostic techniques in epidemiological and evolutionary studies of X. citri because it has a higher discriminatory power and is replicable across laboratories. WGS also allows for the improvement of multilocus sequence typing (MLST) schemes. In this study, we used genome sequences of Xanthomonas isolates from the NCBI RefSeq database to develop a seven-gene MLST scheme that yielded 19 sequence types (STs) that correlated with phylogenetic clades of X. citri subspecies or pathovars. Using this MLST scheme, we examined 2,911 Xanthomonas species assemblies from NCBI GenBank and identified 15 novel STs from 37 isolates that were misclassified in NCBI. In total, we identified 545 X. citri assemblies from GenBank with 95% average nucleotide identity to the X. citri type strain, and all were classified as one of the 34 STs. All MLST classifications correlated with a phylogenetic position inferred from alignments using 92 conserved genes. We observed several instances where strains from different pathovars formed closely related monophyletic clades and shared the same ST, indicating that further investigation of the validity of these pathovars is required. Our MLST scheme described here is a robust tool for rapid classification of X. citri pathovars using WGS and a powerful method for further comprehensive taxonomic revision of X. citri pathovars.

Impact of the COVID-19 pandemic on access to HIV testing and condom use among two-spirit, gay, bisexual, and queer (2SGBQ+) men in Manitoba.

This cross-sectional online survey (n = 347) examined the impact of the COVID-19 pandemic on access to HIV testing and condom use among Two-Spirit, gay, bisexual, and queer (2SGBQ+) men in Manitoba. Logistic regression assessed the relationship between socio-demographics and the impact of COVID-19 on access to HIV testing and condom use. Among those who answered a question on testing (n = 282), 27.7% reported reduced access to HIV testing. Among those who answered questions on condom use (n = 327), 54.4% reported decreased use of condoms. Compared to living in Winnipeg, living in a medium-sized city (Brandon) and in rural and remote areas were both associated with higher odds of reporting reduced access to HIV testing due to COVID-19. Participants who were dating (vs. married or partnered) were significantly more likely to report reduced access to HIV testing, but less likely to report decreased use of condoms, while younger age was associated with decreased use of condoms. Service providers must be prepared to respond to the impact of COVID-19 on HIV testing and condom use among younger, sexually active 2SGBQ + men, as well as those who live in small, rural, and remote areas in Manitoba.

Health utility in community-dwelling adults with dysvascular lower limb loss.

PURPOSE: Adults with dysvascular lower extremity amputation (LEA) experience a large number of secondary health conditions yet there is a gap in the literature on health utility scores for this population. A health utility score relates to a person's state of well-being, and is a single metric anchored at 0 (death) and 1 (perfect health). This study aimed to provide a descriptive account of health utility scores in community-dwelling adults with dysvascular LEA. METHODS: Participants were adults with dysvascular LEA who were 3 months post-amputation. Data collected included socio-demographic characteristics, the Special Interest Group in Amputee Medicine (SIGAM) grades, the dysvascular conditions scale (DCS), which is a scale developed for this study, and the Short Form-36 (SF-36). SF-6D health utility scores were derived from the SF-36 using a software algorithm. Participants were grouped into low-impact and high-impact groups based on self-reported severity of symptoms using the DCS. Health utility scores were compared between the low-impact and high-impact groups using independent t-tests. RESULTS: A total of 231 participants were enrolled in the study. The mean SF-6D health utility score was 0.689 (0.127). A significant association was found between health utility score and SIGAM grade (p < 0.001, η2 = .09). Health utility was positively associated with age (r = 0.137, p = 0.037) and months post-amputation (r = 0.141, p = 0.032), and negatively associated with DCS severity (r = -0.526, p < 0.001). Health utility scores were lower for participants in the DCS high-impact groups for conditions such as diabetes mellitus, phantom limb pain, musculoskeletal pain, back pain, psychological distress, depression, vision problems, and other pain. CONCLUSION: Cost-utility analyses rely on health utility estimates and our findings provide data for future economic evaluations that may assist policy makers in evidence informed allocation of healthcare resources for this population.

The Effect of Advanced Age on Prosthetic Rehabilitation Functional Outcomes in People With Lower Limb Amputations: A Retrospective Chart Audit of Inpatient Admissions.

OBJECTIVE: To evaluate the effect of age on functional outcomes at discharge from prosthetic rehabilitation. DESIGN: Retrospective chart audit. SETTING: Rehabilitation hospital. PARTICIPANTS: Individuals ≥50 years with a transtibial level lower limb amputation (LLA) and above admitted to the inpatient prosthetic rehabilitation program from 2012 to 2019 (n=504). A secondary analysis included a subset of matched participants (n=156). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The L-Test of Functional Mobility (L-Test), 2-Minute Walk Test (2MWT), 6-Minute Walk Test (6MWT), and Activities-specific Balance Confidence scale. RESULTS: A total of 504 participants (66.7±10.1 years) met the inclusion criteria, 63 participants (84.9±3.7 years) were part of the oldest old group. The sample was stratified into 4 age groups (50-59, 60-69, 70-79, and 80+) for data analysis. The analysis of variances were statistically significant for all outcome measures (P<.001). Post-hoc testing for the L-Test, 2MWT, and 6MWT demonstrated that the oldest old had significantly reduced performance compared with people 50-59 years old (P<.05), but there were no significant differences between the oldest old and the 60-69 [(L-Test, P=.802), (2MWT, P=.570), (6MWT, P=.772)] and 70-79 [(L-Test, P=.148), (2MWT, P=.338), (6MWT, P=.300)] age groups. The oldest old reported significantly lower balance confidence compared with all 3 age groups (P<.05). CONCLUSION: The oldest old achieved similar functional mobility outcomes as people 60-79 years, the most common age group of people with an LLA. Advanced age alone should not disqualify individuals from prosthetic rehabilitation.

Migration and health study: a socio-ecological analysis of sexual health among migrants in Manitoba, Canada.

BACKGROUND: To develop effective public health policies, programs, and services tailored to the unique sexual health needs of migrant populations, it is essential to understand the myriad socio-ecological factors that influence their sexual health. This qualitative community-based participatory study aimed to explore factors influencing migrants' sexual health at different socio-ecological levels in a Canadian setting. METHODS: Participants (n = 34) from African, Caribbean, Black; Latin American; South Asian; Middle Eastern, as well as East and Southeast Asian communities were recruited across Manitoba using printed flyers, community organizations, and social media. Individual interviews, conducted in English, French, Mandarin, Cantonese, Tagalog, Arabic, Swahili, and Tigrinya languages, explored questions relating to sexual health and experiences with service providers. Data were analyzed using reflexive thematic analysis and socio-ecological systems theory. RESULTS: The study uncovered a range of individual, interpersonal, institutional, and socio-structural factors that affect the sexual health of migrants in Manitoba. Individual factors such as sexual health knowledge and testing practices, interpersonal factors like the type of sexual partnerships, institutional factors such as sexual health information needs, language, and service access barriers, and structural-level factors like gender norms and HIV stigma exerted a significant influence on the sexual health practices of study respondents. Sexual health awareness was influenced by various factors including length of time in Canada and involvement in community-based services. Study respondents identified issues related to access to HIV testing and sexual health information, as well as language barriers, racism in healthcare, and HIV stigma. Gender and social norms played a significant role in discouraging communication about sex and safer sex practices. CONCLUSIONS: The study highlights the complex interplay of factors that influence the sexual health of migrants, and the need for targeted sexual health awareness campaigns and provision of sexual health information in languages spoken by migrants. Public health interventions focused on improving the sexual health outcomes for migrants should consider the socio-ecological elements identified in this study. These findings can inform public health campaigns to increase access to services and address sexual health inequities among migrant communities in Canada.

GABA receptor associated protein changes the electrostatic environment around the GABA type A receptor.

We have performed fully atomistic molecular dynamics simulations of the intracellular domain of a model of the GABAA receptor with and without the GABA receptor associated protein (GABARAP) bound. We have also calculated the electrostatic potential due to the receptor, in the absence and presence of GABARAP. We find that GABARAP binding changes the electrostatic properties around the GABAA receptor and could lead to increased conductivity of chloride ions through the receptor. We also find that ion motions that would result in conducting currents are observed nearly twice as often when GABARAP binds. These results are consistent with data from electrophysiological experiments.

Significant Reduction in Vaccine-Induced Antibody Levels and Neutralization Activity Among Healthcare Workers and Nursing Home Residents 6 Months Following Coronavirus Disease 2019 BNT162b2 mRNA Vaccination.

Antibody decline occurred from 2 weeks to 6 months post-BNT162b2 mRNA vaccination in nursing home (NH) residents and healthcare workers. Antispike, receptor-binding domain, and neutralization levels dropped >81% irrespective of prior infection. Notably, 69% of infection-naive NH residents had neutralizing antibodies at or below the assay's limit of detection.

Genomic Epidemiology of Vibrio cholerae O139, Zhejiang Province, China, 1994-2018.

Cholera caused by Vibrio cholerae O139 was first reported in Bangladesh and India in 1992. To determine the genomic epidemiology and origins of O139 in China, we sequenced 104 O139 isolates collected from Zhejiang Province, China, during 1994-2018 and compared them with 57 O139 genomes from other countries in Asia. Most Zhejiang isolates fell into 3 clusters (C1-C3), which probably originated in India (C1) and Thailand (C2 and C3) during the early 1990s. Different clusters harbored different antimicrobial resistance genes and IncA/C plasmids. The integrative and conjugative elements carried by Zhejiang isolates were of a new type, differing from ICEVchInd4 and SXTMO10 by single-nucleotide polymorphisms and presence of genes. Quinolone resistance-conferring mutations S85L in parC and S83I in gyrA occurred in 71.2% of the Zhejiang isolates. The ctxB copy number differed among the 3 clusters. Our findings provided new insights for prevention and control of O139 cholera .

Group-based telerehabilitation intervention using Wii Fit to improve walking in older adults with lower limb amputation (WiiNWalk): A randomized control trial.

OBJECTIVE: Determine efficacy of the novel WiiNWalk intervention on walking-related outcomes in older adults with lower limb amputation. DESIGN: Multi-site, parallel, evaluator-masked randomized controlled trial. SETTING: Home-setting in three Canadian cities. PARTICIPANTS: Community-dwelling lower limb prosthesis users over 50 years of age. INTERVENTIONS: The WiiNWalk group (n = 38) used modified Wii Fit activities for prosthetic rehabilitation. The attention control group (n = 33) used Big Brain Academy: Wii Degree, comprising of cognitive activities. Both groups completed a 4-week supervised phase with three 1-h sessions/week in groups of three overseen by a clinician via videoconferencing and a 4-week unstructured and unsupervised phase. MAIN MEASURES: Primary outcome was walking capacity (2 min walk test); secondary outcomes were balance confidence (activities-specific balance confidence scale), dynamic balance (four-step square test), and lower limb functioning (short physical performance battery). Outcomes were compared across time points with repeated measures analysis of covariance, adjusting for baseline and age. RESULTS: Mean age was 65.0 (8.4) years, with 179.5 (223.5) months post-amputation and 80% transtibial amputation. No group difference in a 2 min walk test with an effect size: 1.53 95% CI [-3.17, 6.23] m. Activities balance confidence was greater in the WiiNWalk group by 5.53 [2.53, 8.52]%. No group difference in the four-step square test -0.16 [-1.25, 0.92] s, nor short physical performance battery 0.48 [-0.65, 1.61]. A post-hoc analysis showed the greatest difference in balance confidence immediately after an unsupervised phase. CONCLUSIONS: The WiiNWalk intervention improved balance confidence, but not walking-related physical function in older adult lower limb prosthesis users. Future rehabilitation games should be specific to the amputation context.Clinical Trial Registration number, NCT01942798.

A qualitative analysis of pain meaning: results from the Oklahoma Study of Native American Pain Risk (OK-SNAP).

The most widely accepted definition of pain considers it a sensory and emotional experience associated with potential or actual physical harm. However, research tends to generalize findings from predominantly European American samples thereby assuming universality across cultures. Because of the high prevalence of pain within the AI group, it is important to consider whether their conceptualization of pain is similar to the universal definition. To accomplish this aim, a semi-structured interview was conducted with 152 AIs (primarily Southern Plains and eastern Oklahoma tribes) and 150 NHWs. Both groups were asked questions including what words describe hurtful experiences, the purpose of painful experiences, individual and culture-specific meanings of pain, and what constituted the opposite of pain. Many similarities were found between groups as well as differences. For example, NHWs used the word pain more often to describe physically hurtful experiences and were more likely to consider pain to be a signal or warning of an abnormality or pathology. By contrast, only AIs reported culture-specific meanings of pain, such as references to AI rituals or ceremonies. These observed differences are attenuated by small effect sizes. These findings are important to consider when hypothesizing the differences in pain among cultural groups.

Pyrogallate-Based Metal-Organic Framework with a Two-Dimensional Secondary Building Unit.

We report a metal-organic framework (MOF) with a rare two-dimensional (2D) secondary building unit (SBU). The SBU comprises mixed-valent Fe2+ and Fe3+ metal ions bridged by oxygen atoms pertaining to the polytopic ligand 3,3',4,4',5,5'-hexahydroxybiphenyl, which also define the iron-oxide 2D layers. Overall, the anionic framework exhibits rare topology and evidences strong electronic communication between the mixed-valence iron sites. These results highlight the importance of dimensionality control of MOF SBUs for discovering new topologies in reticular chemistry, and especially for improving electronic communication within the MOF skeleton.

Reduced BNT162b2 Messenger RNA Vaccine Response in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)-Naive Nursing Home Residents.

After BNT162b2 messenger RNA vaccination, antibody levels to spike, receptor-binding domain, and virus neutralization were examined in 149 nursing home residents and 110 healthcare worker controls. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-naive nursing home residents' median post-second vaccine dose antibody neutralization titers are one-quarter that of SARS-CoV-2-naive healthcare workers.

Association between distance from the radiation source and radiation exposure: A phantom-based study.

OBJECTIVES: The study evaluated the association between distance from radiation source and radiation exposure. BACKGROUND: Radiation exposure during medical procedures is associated with increased risk of cancer and other adverse effects. METHODS: An American National Standards Institute phantom was used to study the relationship between measured entrance surface exposure (MESE) and distance from the X-ray source in postero-anterior, left anterior oblique, and right anterior oblique projections. Three distance settings for table height were evaluated with "low" defined as 52 cm, "mid" 66 cm, and "high" 80 cm from the focal point of the X-ray source. Air-kerma and dose-area product measurements were recorded. Operator exposure with each of these conditions was measured, in a short operator (150 cm) as well as in a tall operator (190 cm). RESULTS: Aggregate results for the three projections were as follows. MESE (µGy/frame) significantly decreased as table-height increases (median, interquartile range, p-value) (low table-height 192.5 [122.4-201.2], mid table-height 105.8 [82.7-115.8], and high table-height 71.7 [58.4-75], p < .0005). The operator exposure (µGy/frame), significantly increased as the table-height increased (low table-height 0.0943 [0.0598-0.1157], medium table-height 0.1128 [0.0919-0.1397], and high table-height 0.158 [0.1339-0.2165], p < .0005). A shorter operator received higher radiation exposure compared to a taller operator (short operator 0.1405 [0.1155-0.1758] and tall operator 0.0995 [0.0798-0.1212], p < .0005). CONCLUSIONS: Increasing table-height is associated with a significant decrease in MESE. Operator radiation exposure increases with increasing table-height and shorter operators receive greater radiation exposure compared to taller operators.

Population Structure and Multidrug Resistance of Non-O1/Non-O139 Vibrio cholerae in Freshwater Rivers in Zhejiang, China.

To understand the environmental reservoirs of Vibrio cholerae and their public health significance, we surveyed freshwater samples from rivers in two cities (Jiaxing [JX] and Jiande [JD]) in Zhejiang, China. A total of 26 sampling locations were selected, and river water was sampled 456 times from 2015 to 2016 yielding 200 V. cholerae isolates, all of which were non-O1/non-O139. The average isolation rate was 47.3% and 39.1% in JX and JD, respectively. Antibiotic resistance profiles of the V. cholerae isolates were examined with nonsusceptibility to cefazolin (68.70%, 79/115) being most common, followed by ampicillin (47.83%, 55/115) and imipenem (27.83%, 32/115). Forty-two isolates (36.52%, 42/115) were defined as multidrug resistant (MDR). The presence of virulence genes was also determined, and the majority of the isolates were positive for toxR (198/200, 99%) and hlyA (196/200, 98%) with few other virulence genes observed. The population structure of the V. cholerae non-O1/non-O139 sampled was examined using multilocus sequence typing (MLST) with 200 isolates assigned to 128 STs and 6 subpopulations. The non-O1/non-O139 V. cholerae population in JX was more varied than in JD. By clonal complexes (CCs), 31 CCs that contained isolates from this study were shared with other parts of China and/or other countries, suggesting widespread presence of some non-O1/non-O139 clones. Drug resistance profiles differed between subpopulations. The findings suggest that non-O1/non-O139 V. cholerae in the freshwater environment is a potential source of human infections. Routine surveillance of non-O1/non-O139 V. cholerae in freshwater rivers will be of importance to public health.

Complexes of Platinum Group Metals with a Conformationally Locked Scorpionate in a Metal-Organic Framework: An Unusually Close Apical Interaction of Palladium(II).

We report synthetic strategies for installing platinum group metals (PGMs: Pd, Rh, Ir, and Pt) on a scorpionate-derived linker (TpmC*) within a metal-organic framework (MOF), both by room-temperature postsynthetic metalation and by direct solvothermal synthesis, with a wide range of metal loadings relevant for fundamental studies and catalysis. In-depth studies for the palladium adduct Pd(II)@Zr-TpmC* by density-functional-theory-assisted extended X-ray absorption fine structure spectroscopy reveals that the rigid MOF lattice enforces a close Pd(II)-Napical interaction between the bidentate palladium complex and the third uncoordinated pyrazole arm of the TpmC* ligand (Pd-Napical = 2.501 ± 0.067 Å), an interaction that is wholly avoided in molecular palladium scorpionates.

Does a lack of vaccine side effects correlate with reduced BNT162b2 mRNA vaccine response among healthcare workers and nursing home residents?

BACKGROUND: The BNT162b2 SARS-CoV-2 mRNA vaccination has mitigated the burden of COVID-19 among residents of long-term care facilities considerably, despite being excluded from the vaccine trials. Data on reactogenicity (vaccine side effects) in this population are limited. AIMS: To assess reactogenicity among nursing home (NH) residents. To provide a plausible proxy for predicting vaccine response among this population. METHODS: We enrolled and sampled NH residents and community-dwelling healthcare workers who received the BNT162b2 mRNA vaccine, to assess local or systemic reactogenicity and antibody levels (immunogenicity). RESULTS: NH residents reported reactions at a much lower frequency and lesser severity than the community-dwelling healthcare workers. These reactions were mild and transient with all subjects experiencing more local than systemic reactions. Based on our reactogenicity and immunogenicity data, we developed a linear regression model predicting log-transformed anti-spike, anti-receptor-binding domain (RBD), and neutralizing titers, with a dichotomous variable indicating the presence or absence of reported reactions which revealed a statistically significant effect, with estimated shifts in log-transformed titers ranging from 0.32 to 0.37 (all p < 0.01) indicating greater immunogenicity in subjects with one or more reported reactions of varying severity. DISCUSSION: With a significantly lower incidence of post-vaccination reactions among NH residents as reported in this study, the BNT162b2 mRNA vaccine appears to be well-tolerated among this vulnerable population. If validated in larger populations, absence of reactogenicity could help guide clinicians in prioritizing vaccine boosters. CONCLUSIONS: Reactogenicity is significantly mild among nursing home residents and overall, subjects who reported post-vaccination reactions developed higher antibody titers.

Phenotypic and Genotypic Correlates of Penicillin Susceptibility in Nontoxigenic Corynebacterium diphtheriae, British Columbia, Canada, 2015-2018.

In 2015, the Clinical and Laboratory Standards Institute (CLSI) updated its breakpoints for penicillin susceptibility in Corynebacterium species from <1 mg/L to <0.12 mg/L. We assessed the effect of this change on C. diphtheriae susceptibility reported at an inner city, tertiary care center in Vancouver, British Columbia, Canada, during 2015-2018 and performed whole-genome sequencing to investigate phenotypic and genotypic resistance to penicillin. We identified 44/45 isolates that were intermediately susceptible to penicillin by the 2015 breakpoint, despite meeting previous CLSI criteria for susceptibility. Sequencing did not reveal ß-lactam resistance genes. Multilocus sequence typing revealed a notable predominance of sequence type 76. Overall, we saw no evidence of penicillin nonsusceptibility at the phenotypic or genotypic level in C. diphtheriae isolates from our institution. The 2015 CLSI breakpoint change could cause misclassification of penicillin susceptibility in C. diphtheriae isolates, potentially leading to suboptimal antimicrobial treatment selection.