Molecular epidemiology and characteristics of Corynebacterium diphtheriae and Corynebacterium ulcerans strains isolated in Italy during the 1990s (original) (raw)
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Nontoxigenic corynebacterium diphtheriae: an emerging pathogen in England and Wales?
Emerging infectious diseases
Confirmed isolates of nontoxigenic Corynebacterium diphtheriae in England and Wales increased substantially from 1986 to 1994. Ribotyping of 121 isolates confirmed in 1995 showed that 90 were of a single strain isolated exclusively from the throat; none had previously been identified in toxigenic strains from U.K. or non-U.K. residents. The upward trend in nontoxigenic C. diphtheriae probably represented increased ascertainment, although dissemination of a particular strain or clone may have been a factor.
Communicable disease and public health / PHLS, 1999
These guidelines represent an application of the World Health Organization European Region's manual for the laboratory diagnosis of diphtheria for laboratories in the United Kingdom (UK), but they could be applied to laboratories overseas. The manual was rewritten in response to the re-emergence of diphtheria in eastern Europe and the emergence of other infections caused by Corynebacterium diphtheriae and C. ulcerans in the UK and overseas. The guidelines summarise our current recommendations and procedures for the microbiological diagnosis of infections caused by toxigenic and non-toxigenic isolates of corynebacteria, with particular reference to C. diphtheriae and C. ulcerans.
Corynebacterium ulcerans cutaneous diphtheria
The Lancet Infectious Diseases, 2015
We describe the case of a patient with cutaneous diphtheria caused by toxigenic Corynebacterium ulcerans who developed a right hand flexor sheath infection and symptoms of sepsis such as fever, tachycardia, and elevated C-reactive protein, after contact with domestic cats and dogs, and a fox. We summarise the epidemiology, clinical presentation, microbiology, diagnosis, therapy, and public health aspects of this disease, with emphasis on improving recognition. In many European countries, C ulcerans has become the organism commonly associated with cutaneous diphtheria, usually seen as an imported tropical disease or resulting from contact with domestic and agricultural animals. Diagnosis relies on bacterial culture and confirmation of toxin production, with management requiring appropriate antimicrobial therapy and prompt administration of antitoxin, if necessary. Early diagnosis is essential for implementation of control measures and clear guidelines are needed to assist clinicians in managing clinical diphtheria. This case was a catalyst to the redrafting of the 2014 national UK interim guidelines for the public health management of diphtheria, released as fi nal guidelines in March, 2015.
Investigations of 2 Cases of Diphtheria-Like Illness Due to Toxigenic Corynebacterium ulcerans
Clinical Infectious Diseases, 2008
We present 2 case reports in the United States and investigations of diphtheria-like illness caused by toxigenic Corynebacterium ulcerans. A fatal case occurred in a 75-year-old male Washington resident who was treated with clindamycin but did not receive equine diphtheria antitoxin. A second, nonfatal case occurred in a 66-year-old female Tennessee resident who received erythromycin and diphtheria antitoxin. Both case patients and close human and animal contacts were investigated by their respective state health departments. C. ulcerans isolated from the patient who died was resistant to erythromycin and clindamycin. For both isolates, conventional polymerase chain reaction results were positive for A and B subunits of diphtheria toxin gene tox, and modified Elek tests confirmed toxin production. The source of infection remained undetermined for both cases. Neither patient was up-to-date with diphtheria toxoid vaccination. These case reports highlight the importance of early treatment with diphtheria antitoxin, the selection of effective antimicrobial agents, and prevention through up-to-date vaccination.
Journal of clinical microbiology, 2015
Human infections caused by toxigenic corynebacteria occur sporadically across Europe. In this report, we undertook the epidemiological and molecular characterization of all toxigenic corynebacterium strains isolated in England between January 2007 and December 2013. Epidemiological aspects include case demographics, risk factors, clinical presentation, treatment, and outcome. Molecular characterization was performed using multilocus sequence typing (MLST) alongside traditional phenotypic methods. In total, there were 20 cases of toxigenic corynebacteria; 12 (60.0%) were caused by Corynebacterium ulcerans, where animal contact was the predominant risk factor. The remaining eight (40.0%) were caused by Corynebacterium diphtheriae strains; six were biovar mitis, which were associated with recent travel abroad. Adults 45 years and older were particularly affected (55.0%; 11/20), and typical symptoms included sore throat and fever. Respiratory diphtheria with the absence of a pharyngeal ...
Epidemiology and Infection, 2000
This study evaluated whether a correlation exists between carriage of corynebacteria and the lack of immunity to diphtheria toxoid. Samples of both nasal and pharyngeal secretions were taken from 500 apparently healthy subjects of both sexes and of all ages and inoculated onto Tinsdale's medium. A serum sample was also taken for ELISA test to determine the titre of diphtheria toxin antibodies. None of the subjects carried Corynebacterium diphtheriae. Ninetythree strains of Corynebacterium spp. were isolated from 93 subjects and 86 of these were classified to species or group level by biochemical tests. C. xerosis was the most common (25n8 %) followed by C. pseudodiphthericum (16n1%), C. jeikeium and C. striatum (both 10n8%), and C. urealyticum (9n7 %). Three other species accounted for approximately 20 % of strains and seven were unclassified as biochemically atypical corynebacteria. Non-protective antibodies to diphtheria toxin were found in 80 of the 93 subjects and a strong statistical association was demonstrated between carriage of corynebacteria and non-protective levels of anti-toxin antibodies. The remaining 13 subjects had protective levels of antitoxin antibodies. In contrast, only 45 of the 407 non-colonized subjects had non-protective antitoxin titres. The prevalence of carriage increased with age among males as did the percentage of non-protected subjects. The prevalence of female carriers of corynebacteria was significantly lower. Serum samples from 12 subjects with different antibody titres to diphtheria toxoid reacted to varying degrees with whole-cell lysates of a number of species of corynebacteria. The results suggest that a causal relationship may exist between nasopharyngeal carriage of corynebacteria and a low antidiphtheria toxin immune response. * Author for correspondence. 2000 indigenous respiratory diphtheria would be eliminated from Europe [2]. Nevertheless, in recent years, the World Health Organization (WHO) has reported epidemics of diphtheria in several countries of eastern Europe [3] and the major causal factors identified were the decline in immunization coverage in children and waning of immunity to diphtheria in adults [4].
Clinical Microbiology and Infection, 2011
Diphtheria is now rare in most European countries but, when cases do arise, the case fatality rate is high (5-10%). Because few countries continue to routinely screen for the causative organisms of diphtheria, the extent to which they are circulating amongst different European populations is largely unknown. During 2007-2008, ten European countries each screened between 968 and 8551 throat swabs from patients with upper respiratory tract infections. Six toxigenic strains of Corynebacterium diphtheriae were identified: two from symptomatic patients in Latvia (the country with the highest reported incidence of diphtheria in the European Union) and four from Lithuania (two cases, two carriers); the last reported case of diphtheria in Lithuania was in 2002. Carriage rates of non-toxigenic organisms ranged from 0 (Bulgaria, Finland, Greece, Ireland, Italy) to 4.0 per 1000 (95% CI 2.0-7.1) in Turkey. A total of 28 non-toxigenic strains were identified during the study (26 C. diphtheriae, one Corynebacterium ulcerans, one Corynebacterium pseudotuberculosis). The non-toxigenic C. ulcerans strain was isolated from the UK, the country with the highest reported incidence of cases due to C. ulcerans.
Journal of clinical microbiology, 1998
We have compared molecular, immunochemical, and cytotoxic assays for the detection of diphtheria toxin from 55 isolates of Corynebacterium diphtheriae and Corynebacterium ulcerans originally isolated in five different countries. The suitabilities and accuracies of these assays for the laboratory diagnosis of diphtheria were compared and evaluated against the "gold standard" in vivo methods. The in vivo and Vero cell cytotoxicity assays were accurate in their abilities to detect diphtheria toxin but were time-consuming; however, the cytotoxicity assay is a suitable in vitro alternative to the in vivo virulence test. There was complete concordance between all the phenotypic methods. Genotypic tests based upon PCR were rapid; however, PCR must be used with caution because some isolates of C. diphtheriae possessed toxin genes but failed to express a biologically active toxin. Therefore, phenotypic confirmation of toxigenicity for the microbiological diagnosis of diphtheria is ...