Cluster of Nontoxigenic Corynebacterium diphtheriae Infective Endocarditis and Rising Background C. diphtheriae Cases-Seattle, Washington, 2020-2023.

BACKGROUND: Nontoxigenic Corynebacterium diphtheriae, often associated with wounds, can rarely cause infective endocarditis (IE). Five patients with C. diphtheriae IE were identified within 12 months at a Seattle-based hospital system. We reviewed prior C. diphtheriae-positive cultures to determine if detections had increased over time and evaluated epidemiologic trends. METHODS: We conducted a formal electronic health record search to identify all patients aged ≥18 years with C. diphtheriae detected in a clinical specimen (ie, wound, blood, sputum) between 1 September 2020 and 1 April 2023. We collected patient demographics, housing status, comorbidities, substance-use history, and level of medical care required at detection. We extracted laboratory data on susceptibilities of C. diphtheriae isolates and on other pathogens detected at the time of C. diphtheriae identification. RESULTS: Between 1 September 2020 and 1 April 2023, 44 patients (median age, 44 years) had a C. diphtheriae-positive clinical culture, with most detections occurring after March 2022. Patients were predominantly male (75%), White (66%), unstably housed (77%), and had a lifetime history of injecting drugs (75%). Most C. diphtheriae-positive cultures were polymicrobial, including wound cultures from 36 (82%) patients and blood cultures from 6 (14%) patients, not mutually exclusive. Thirty-four patients (77%), including all 5 patients with C. diphtheriae IE, required hospital admission for C. diphtheriae or a related condition. Of the 5 patients with IE, 3 died of IE and 1 from COVID-19. CONCLUSIONS: Findings suggest a high-morbidity outbreak disproportionately affecting patients who use substances and are unstably housed.

Retrospective Study of Infections with Corynebacterium diphtheriae Species Complex, French Guiana, 2016-2021.

Human infections with Corynebacterium diphtheriae species complex (CdSC) bacteria were rare in French Guiana until 2016, when the number of cases diagnosed increased. We conducted an epidemiologic, multicenter, retrospective study of all human CdSC infections diagnosed in French Guiana during January 1, 2016-December 31, 2021. A total of 64 infectious episodes were observed in 60 patients; 61 infections were caused by C. diphtheriae and 3 by C. ulcerans. Estimated incidence increased from 0.7 cases/100,000 population in 2016 to 7.7 cases/100,000 population in 2021. The mean patient age was 30.4 (+23.7) years, and male-to-female ratio was 1.7:1 (38/22). Of the 61 C. diphtheriae isolates, 5 tested positive for the diphtheria toxin gene, and all results were negative by Elek test; 95% (61/64) of cases were cutaneous, including the C. ulcerans cases. The increase in reported human infections underscores the need to raise awareness among frontline healthcare practitioners to improve prevention.

Corynebacterium diphtheriae and Corynebacterium ulcerans: development of EUCAST methods and generation of data on which to determine breakpoints.

BACKGROUND: Evidence-based clinical susceptibility breakpoints have been lacking for antimicrobial agents used for diphtheria. OBJECTIVES: We aimed to evaluate broth microdilution and disc diffusion methods and create a dataset of MIC values and inhibition zone diameters (ZDs) from which breakpoints could be determined. METHODS: We included 400 recent clinical isolates equally distributed by species (Corynebacterium diphtheriae and Corynebacterium ulcerans) and by national surveillance programmes (France and Germany). Non-duplicate toxigenic and non-toxigenic isolates were chosen to enable the inclusion of a diversity of susceptibility levels for the 13 agents tested. Broth microdilution and disc diffusion, using EUCAST methodology for fastidious organisms, were used. RESULTS: The distributions of MIC and ZD values were largely in agreement among methods and countries. Breakpoints to allow categorization of WT isolates as susceptible, i.e. susceptible (S) or susceptible, increased exposure (I) were determined for 12 agents. The data supported a breakpoint for benzylpenicillin and amoxicillin of resistant (R) > 1 mg/L since WT isolates were inhibited by 1 mg/L or less. WT isolates were categorized as I (S ≤ 0.001 mg/L) for benzylpenicillin, emphasizing the need for increased exposure, and S (S ≤ 1 mg/L) for amoxicillin. Erythromycin breakpoints were set at S ≤ 0.06 mg/L and R > 0.06 mg/L. The corresponding ZD breakpoints were determined for all agents except amoxicillin, for which categorization was based on benzylpenicillin results. CONCLUSIONS: This work provided a large set of antimicrobial susceptibility data for C. diphtheriae and C. ulcerans, using a harmonized methodology. The dataset allowed EUCAST and experts in the diphtheria field to develop evidence-based breakpoints in January 2023.

Diphtheria case detection and carrier study of close contacts: A step towards diphtheria eradication.

INTRODUCTION: Diphtheria is an infectious disease caused by gram-positive bacilli C. diphtheriae involving nasal, pharyngeal, tonsillar, or laryngeal mucus membranes. The mortality rate is as high as 20%, with India contributing almost 78% of the world incidence. AIMS AND OBJECTIVES: We report a fatal case of nasopharyngeal diphtheria with carrier study in close contacts. MATERIALS AND METHODS: Seven years child presented with fever, throat pain, and earache for 3 days followed by neck swelling and noisy respiration. On examination, membrane was present in the throat, which was received for Albert and Gram staining and reported as positive for C. diphtheria like organisms followed by culture. The patient was treated with ADS and antibiotics, and intensively managed, but still succumbed to death. Follow-up was done for carriage of C. diphtheriae on the throat and nasopharyngeal swabs of siblings and close contacts. It was isolated in 3 of them. Samples were processed for Gram, Albert stain, and culture. Identification, antibiotic sensitivity, and toxigenicity were done. RESULTS AND DISCUSSION: Four samples, one from the patient and three from contacts showed the presence of gram-positive slender bacilli with cuneiform arrangement, less cellular infiltrate on the Gram stain, and the presence of few metachromatic granules in the Albert stain. C. diphtheriae was grown on Potassium Tellurite agar. Antibiogram of all isolates was similar with resistance to Erythromycin and sensitivity to Penicillin. Isolates were confirmed by PCR and ToxA gene was detected. Contacts were treated with Penicillin and repeat swabs were negative. CONCLUSION: Present health statistics and this study suggests, fight against diphtheria in India is far from being over. It still lurks in some remote areas. It is a need to remain vigilant, keep tracing, and treating contacts to curtail down the rate of infection. In view of the resurgence, Government has given directives to replace TT with Td in UIP. Still, a lot needs to be done.

Difteria pelo Corynebacterium ulcerans: uma zoonose emergente no Brasil e no mundo / Corynebacterium ulcerans diphtheria: an emerging zoonosis in Brazil and worldwide / Difteria por Corynebacterium ulcerans: una zoonosis emergente en Brasil y en el mundo

O artigo revisa a literatura sobre a emergência de infecções humanas causadas por Corynebacterium ulcerans em diversos países, incluindo o Brasil. Foi realizada análise de artigos publicados entre 1926 e 2011 nas bases Medline/PubMed e SciELO, bem como artigos e informes do Ministério da Saúde. Apresenta-se um esquema de triagem, rápido, econômico e de fácil execução, capaz de permitir a realização do diagnóstico presuntivo de C. ulcerans e C. diphtheriae na maioria dos laboratórios brasileiros públicos e privados. A circulação de C. ulcerans em vários países, aliada aos recentes casos de isolamento do patógeno no Rio de Janeiro, é um alerta a clínicos, veterinários e microbiologistas sobre a ocorrência de difteria zoonótica e a circulação do C. ulcerans em regiões urbanas e rurais do território nacional e/ou da América Latina.

The article is a literature review on the emergence of human infections caused by Corynebacterium ulcerans in many countries including Brazil. Articles in Medline/PubMed and SciELO databases published between 1926 and 2011 were reviewed, as well as articles and reports of the Brazilian Ministry of Health. It is presented a fast, cost-effective and easy to perform screening test for the presumptive diagnosis of C. ulcerans and C. diphtheriae infections in most Brazilian public and private laboratories. C. ulcerans spread in many countries and recent isolation of this pathogen in Rio de Janeiro, southeastern Brazil, is a warning to clinicians, veterinarians, and microbiologists on the occurrence of zoonotic diphtheria and C. ulcerans dissemination in urban and rural areas of Brazil and/or Latin America.

El articulo revisa la literatura sobre la emergencia de infecciones humanas causadas por Corynebacterium ulcerans en diversos países, incluyendo Brasil. Se realizó análisis de artículos publicados entre 1926 y 2011 en las bases Medline/Pubmed y SciELO, así como artículos e informes del Ministerio Brasileño de la Salud. Se presenta un esquema de selección, rápido, económico y de fácil ejecución, capaz de permitir la realización del diagnóstico presuntivo de C. ulcerans y C. diphtheriae en la mayoría de los laboratorios brasileños públicos y privados. La circulación de C. ulcerans en varios países, aliada a los recientes casos de aislamiento del patógeno en Rio de Janeiro (Sureste de Brasil), es un alerta a clínicos, veterinarios y microbiólogos sobre la ocurrencia de difteria zoológica y la circulación de C. ulcerans en regiones urbanas y rurales del territorio nacional y/o de América Latina.

Potential pathogenic role of aggregative-adhering Corynebacterium diphtheriae of different clonal groups in endocarditis

Invasive diseases caused by Corynebacterium diphtheriae have been described increasingly. Several reports indicate the destructive feature of endocarditis attributable to nontoxigenic strains. However, few reports have dealt with the pathogenicity of invasive strains. The present investigation demonstrates a phenotypic trait that may be used to identify potentially invasive strains. The study also draws attention to clinical and microbiological aspects observed in 5 cases of endocarditis due to C. diphtheriae that occurred outside Europe. Four cases occurred in female school-age children (7-14 years) treated at different hospitals in Rio de Janeiro, Brazil. All patients developed other complications including septicemia, renal failure and/or arthritis. Surgical treatment was performed on 2 patients for valve replacement. Lethality was observed in 40 percent of the cases. Microorganisms isolated from 5 blood samples and identified as C. diphtheriae subsp mitis (N = 4) and C. diphtheriae subsp gravis (N = 1) displayed an aggregative adherence pattern to HEp-2 cells and identical one-dimensional SDS-PAGE protein profiles. Aggregative-adhering invasive strains of C. diphtheriae showed 5 distinct RAPD profiles. Despite the clonal diversity, all 5 C. diphtheriae invasive isolates seemed to display special bacterial adhesive properties that may favor blood-barrier disruption and systemic dissemination of bacteria. In conclusion, blood isolates from patients with endocarditis exhibited a unique adhering pattern, suggesting a pathogenic role of aggregative-adhering C. diphtheriae of different clones in endocarditis. Accordingly, the aggregative-adherence pattern may be used as an indication of some invasive potential of C. diphtheriae strains.

Papel das hemaglutininas 67-72p de Corynebacterium diphtheriae na ligação a proteínas plasmáticas, superfícies celulares, invasão e indução de apoptose / Role of haemagglutinins 67-72p de Corynebacterium diphtheriae in binding to plasma proteins, cell surfaces, invasion and induction of apoptosis

Corynebacterium diphtheriae pode ser isolado tanto de quadros de difteria clássica, quanto de infecções sistêmicas, como endocardite. O fibrinogênio (Fbn) e a fibronectina (Fn) são glicoproteínas presentes na matriz extracelular de tecidos conjuntivos. A influência destas proteínas na patogênese das infecções locais e invasivas causadas por C. diphtheriae é objeto de estudo devido ao fato do bacilo diftérico poder ser encontrado em lesões nas quais o Fbn e a Fn são predominantes, incluindo a pseudomembrana diftérica e vegetações cardíacas presentes na endocardite infecciosa. São crescentes as evidências de que o C. diphtheriae pode, além de aderir, ser internalizado por células em cultura. No presente estudo, investigou-se a participação de C. diphtheriae e das proteínas de superfície 67-72p na aderência à Fn e ao Fbn de plasma humano e a eritrócitos. A aderência às células HEp-2 e internalização também foram analisadas. A participação de 67-72p nos mecanismos de morte celular foi avaliada através das colorações por Azul de Tripan e 4'6-diamidino-2-fenil indol (DAPI), pelo ensaio de redução utilizando dimetil-tiazol-difenil tetrazólio (MTT) e por citometria de fluxo. As 67-72p foram extraídas da superfície da amostra toxigênica C. diphtheriae subsp. mitis CDC-E8392 através de processos mecânicos e precipitação com sulfato de amônio saturado. Análises por SDS-PAGE e immunoblotting detectaram a presença das bandas protéicas de 67 e 72kDa nas amostras toxinogênicas e atoxinogênicas analisadas, as quais pertenciam aos biotipos fermentador e não fermentador de sacarose. C. diphtheriae foi capaz não só de formar agregados na presença de plasma de coelho, mas também de converter Fbn em fibrina independentemente da presença do gene tox. No entanto, a amostra atoxinogênica ATCC 27010 (tox-) foi menos aderente ao Fbn do que a homóloga ATCC 27012 (tox+). A interação bacteriana com eritrócitos foi inibida somente pela Fn. Ligações entre Fn e/ou Fbn com 67-72p foram ...

Corynbacterium diphtheriae have been isolated from classical diphtheria and systemic infections such as endocarditis. Fibrinogen (Fbn) and fibronectin (Fn) are high molecular-weight glycoproteins that may be found in extracellular matrix of connective tissues. Their influence in the pathogenesis of local and in invasive C. diphtheriae infection is object of interest due to the fact that diphtheria bacilli is recovered from lesions where such proteins are predominant, including pharyngeal pseudomembrane and valve heart vegetations in infectious endocarditis. There is growing evidence that C. diphtheriae may adhere to and be internalized by cells in culture. The present study investigated the participation of C. diphtheriae strains and 67-72p, a surface protein, in adherence to human plasma Fn, Fbn, erityrocytes, adherence to and internalization by HEp-2 cells. The participation of 67-72p in promoting cell death was evaluated by the Trypan blue, DAPI staining methods, methylthiazole tetrazolium (MTT) reduction assay and flow cytometry. The 67-72p was extracted from C. diphtheriae subsp. mitis CDC-E8392 toxigenic strain, by mechanical process and ammonium sulfate fractionation. SDS-PAGE and immunoblotting analysis detected the polypeptide bands of 67 and 72 kDa in all toxigenic and nontoxigenic strains from both sucrose-fermenting and non-fermanting biotypes. Diphtheria bacilli were capable to both form bacterial aggregates in rabbit plasma and to convert Fbn to fibrin independently to the presence of tox gene, albeit the ATCC 27010 (tox-) strain was less adherent to Fbn than the paental strain ATCC 27012 (tox+). Bacteria-erythrocytes interaction was inhibited only ...

Isolamento de Corynebacterium diphtheriae de líquido espermático / Isolation of Corynebacterium diphtheriae from sperm

Descrevemos o isolamento de Corynebacterium diphtheriae toxígeno de espermocultura. O microrganismo foi identificado pelo teste de fluorescência sob luz ultravioleta, pesquisa da enzima pirazina-carboxilamidase (Pyz), testes de virulência in vitro e in vivo (imunodifusäo radial simples, cultura de células e teste intradérmico em cobaio). A amostra foi inicialmente considerada atoxígena pelo teste de imunodifusäo radial simples, mas sua virulência foi observada posteriormente quando os testes acima foram aplicados. Sem adecuada especificaçäo, a amostra poderia ter sido considerada como um "difteróide"

Genetic relationship of Corynebacterium diphteriae strains isolated from diphteria case and carriers by restriction fragment length polymorphism of rRNA genes

No presente estudo, nos reportamos os resultados de uma analise, baseada na ribotipagem de cepas de C. diphtheriae intermedius isoladas de uma crianca de 9 anos com difteria e seus 5 contatos. Analise quantitativa por RFLP de rRNA foi usada para determinar a relacao destas 7 cepas de C.diphtheriae fornecendo dados de interesse epidemiologico...

Diagnóstico laboratorial da difteria / Laboratory diagnosis of diphtheria

A difteria representa ainda uma ameaça, apesar do estágio atual do desenvolvimento na área de saúde. O tratamento adequado depende, entre outros fatores, do reconhecimento laboratorial. Analisam-se fatores que podem interferir no diagnóstico laboratorial da difteria

Hemagglutination pattern of corynebacterium diphtheriae

O bacilo diftérico apresentou atividade hemaglutinante para hemácias de pinto, gato, macaco, ganso, humanos, cobaio e carneiro. Observou-se 8 padröes hemaglutinantes que foram relacionados com o comportamento bacteriano frente a sacarose. Os microrganismos de biotipo fermentador näo hemaglutinaram hemácias de pinto, gato e macaco. A aglutinaçäo de hemácias de carneiro, pelo bacilo diférico, näo sofreu inibiçäo após a variaçäo das condiçöes de cultivo, nem após o tratamento do microrganismo com diversos agentes como: calor, álcool, éter, tripsina, HC1, NaOH e açúcares

Diphtheria: current status and laboratory procedures for diagnosis / A difteria hoje e os procedimentos laboratoriais de diagnóstico

Os surtos de difteria que ocorreram no território brasileiro nos levaram a estudar recursos laboratoriais empregados no diagnóstico das amidalites. A pesquisa da produçäo de porfirina e a técnica de IF podem ser satisfatorialmente utilizadas na identificaçäo rápida do C. diphtheriae. A IF mostrou-se adequada, devendo, no entanto, estar sempre associada aos métodos convencionais

Isolamento de corynebacterium diphtheriae de úlceras cutâneo-mucosas por Leishmania / Isolation of Corynebacterium diphtheriae from mucocutaneous ulcers due to Leishmania

Descrevemos o isolamento do C. diphtheriae em uma regiäo endêmica da leishmaniose cutâneo-mucosa por Leishmania braziliensis braziliensis. Materiais das lesöes cutâneas foram obtidos de dezesseis pacientes. Nove deles foram portadores do bacilo (56%). Os microrganismos suspeitos foram identificados pelos testes de fluorescência sob luz ultravioleta, teste de virulência "in vitro" (por imunodifusäo radial simples), pesquisa da enzima pirazina-carboxilamidase (Pyz) e por imunofluorescência direta e indireta

Desenvolvimento e implementação de métodos laboratoriais aplicados ao diagnóstico fenotípico e genotípico do Corynebacterium diptheriae / Development and implementation of laboratory methods applied to phenotypic and genotypic diagnosis of Corynebacterium diphtheriae

A emergência de cepas de Corynebacterium diphtheriae atoxinogênicas como agentes de endocardite e outras infecções sistêmicas aliada ao aumento do número de adultos susceptíveis à difteria enfatizam a necessidade de métodos alternativos para o diagnóstico laboratorial desta doença, especialmente para laboratórios de rotina clínica. Neste estudo avaliou-se a atividade de DNase de 91 amostras de C. diphtheriae (37 toxinogênicas e 54 atoxinogênicas) e de 564 cepas clínicas de bacilo Gram positivo não diftérico. A atividade de DNase foi detectada em todas as amostras de C. diphtheriae examinadas, previamente identificadas por métodos bioquímicos e pelo sistema API Coryne System. Diferentemente, os resultados do teste de DNase foram negativos em 93.9 porcento das cepas clínicas de bacilo Gram positivo não diftérico. Também foi documentado o valor de uma PCR espécie-específica que tem como alvo o gene dtxR como um método para diferenciação entre C. diphtheriae e colônias similares ao gênero Corynebacterium. Os resultados da PCR-dtxR foram positivos para todas as amostras de C. diphtheriae estudadas e foram concordantes com os obtidos através de metodologia bioquímica padrão. Diferentemente, os resultados da PCR-dtxR foram negativos para 100 porcento das 111 amostras de bacilos Gram positivos não diftéricos estudadas. A partir destes resultados, uma PCR multiplex utilizando três pares de oligonucleotídeos iniciadores foi desenvolvida para a detecção do C. diphtheriae e diferenciação em amostras toxinogênicas ou atoxinogênicas. Dois pares de oligonucleotídeos iniciadores têm como alvo as regiões do gene tox relativas aos domínios A e B da toxina diftérica e um terceiro par direcionado para o gene dtxR. Todas as amostras de C. diphtheriae foram identificadas pela reação de PCR multiplex em concordância com os testes bioquímicos padrão e os ensaios de citotoxicidade celular...

The emergence of non-toxigenic Corynebaterium diphtheriae strains as the causative agent of endocarditis and other systemic infections and the significant rise in the percentage of adults susceptible to diphtheria emphasize the need for new laboratory diagnostic procedures. In this study, we examine techniques as alternative procedures for differentiating C. diphtheriae from Corynebacterium-like colonies for the presumptive identification of this pathogen, especially in the diagnosis laboratory. This study evaluated the DNase activity of 91 C. diphtheriae (37 toxigenic and 54 non-toxigenic) and 564 non-diphtherial Gram-positive rod clinical strains. The DNase activity was detected in all C. diphtheriae strains examined, previously identified by both conventional biochemical methods and API Coryne System. Conversely, DNase test results were negative in 93.9 percent of the 564 non-diphtherial Gram-positive rod clinical strains. We also documented the value of a species-specific PCR assay that targets the dtxR gene as a procedure for differentiating C. diphtheriae from Corynebacterium-like colonies. The results of the PCR-dtxR were all positive for 91 C. diphtheriae strains and completely correlated with the standard biochemical methods and commercial identification system for all strains tested. In other hand, the PCR-dtxR results were negative in 100 percent of the 111 non-diphtherial Gram-positive rod strains. Considering these results, a multiplex PCR using three primers pairs was developed for detection of C. diphtheriae infection and differentiation between toxigenic and non-toxigenic strains. Two primer pairs targeted to domains A and B of tox gene and a third primer pair targeted to a region of dtxR gene. All C. diphtheriae strains were diagnosed by the multiplex PCR in agreement with standard biochemical tests and citotoxicity assay in Vero cells. Thus, these tecniques emerged as viable, cost-effective screening methods for C. diphtheriae laboratory...