Molecular Analysis of
            <i>Clostridium difficile</i>
            PCR Ribotype 027 Isolates from Eastern and Western Canada

MacCannell, Duncan; Louie, Thomas; Gregson, Dan; Laverdière, Michél; Labbé, Annie‐Claude; Laing, Felicia; Henwick, Scott

doi:10.1128/jcm.02563-05

Cited by 152 publications

(106 citation statements)

References 22 publications

Supporting

Mentioning

101

Contrasting

Unclassified

Order By: Relevance

“…Despite evidence that only 20% of all human CDAD cases are community-associated (25,26), 6 (46%) of 13 human toxinotype V cases in our study were identifi ed as CA-CDAD. The high prevalence of CA-CDAD among toxinotype V cases we found is consistent with other studies that have identifi ed variant toxinotypes more frequently in CA-CDAD than in HCFA-CDAD (27,28).…”

Section: Discussionsupporting

confidence: 92%

“…Current literature suggests that this considerable truncation of TcdC may impair its negative regulatory function and contribute to the increased toxin production observed in BI/NAP1/027 strains (27,36). Molecular analysis of toxinotype V C. diffi cile has demonstrated a similarly truncated TcdC (61 aa compared with 65 aa in BI/NAP1/027 strains and 232 aa in wild-type TcdC) (15), which may imply hypervirulence for this strain as well.…”

Section: Discussionmentioning

confidence: 97%

“…These changes have been largely attributed to the emergence of the BI/NAP1/027 C. diffi cile strain which, like the toxinotype V strains described here, is a toxin gene variant (i.e., toxinotype III) with an 18-bp deletion in tcdC (rather than the 39-bp deletion observed in toxinotype V strains) and with genes that encode binary toxin (4). In addition to this 18-bp deletion, and perhaps more importantly, BI/ NAP1/027 has an upstream single nucleotide deletion at nucleotide position 117 (∆117), leading to a reading frameshift and early termination of protein translation (27).…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Toxinotype VClostridium difficilein Humans and Food Animals

Jhung

Thompson

Killgore

et al. 2008

Emerg. Infect. Dis.

197

155

View full text Add to dashboard Cite

Clostridium diffi cile is a recognized pathogen in neonatal pigs and may contribute to enteritis in calves. Toxinotype V strains have been rare causes of human C. diffi cileassociated disease (CDAD). We examined toxinotype V in human disease, the genetic relationship of animal and human toxinotype V strains, and in vitro toxin production of these strains. From 2001 through 2006, 8 (1.3%) of 620 patient isolates were identifi ed as toxinotype V; before 2001, 7 (<0.02%) of ≈6,000 isolates were identifi ed as toxinotype V. Six (46.2%) of 13 case-patients for whom information was available had community-associated CDAD. Molecular characterization showed a high degree of similarity between human and animal toxinotype V isolates; all contained a 39-bp tcdC deletion and most produced binary toxin. Further study is needed to understand the epidemiology of CDAD caused by toxinotype V C. diffi cile, including the potential of foodborne transmission to humans. R ecent evidence suggests that the epidemiology of Clostridium diffi cile-associated disease (CDAD) is increasing in incidence and severity (1-3). These changes are due, at least in part, to the emergence of a more virulent C. diffi cile strain, designated NAP1 (based on its pulsed-fi eld gel electrophoresis [PFGE] pattern), BI (by restriction endonuclease analysis [REA]), toxinotype III (by PCR characterization of the pathogenicity locus), and 027 (by PCR ribotyping) (4). However, the emergence of BI/NAP1/027 may not be solely responsible for changes in CDAD epidemiology, and the origin of this and other virulent strains is still largely unknown. C. diffi cile has also recently emerged as a pathogen or commensal in food animals such as neonatal pigs and beef and dairy calves (5-7); most of these animal isolates are toxigenic. Although several ribotypes have been identifi ed in calves, the predominant ribotype in both calves and pigs is a toxinotype V strain (8,9). Moreover, recent reports suggest that C. diffi cile strains recognized as causes of human disease may contaminate retail meats (10).To better understand whether food sources could be a source of infection for humans, we investigated recent and past human CDAD caused by toxinotype V C. diffi cile and compared isolates from these cases with those recovered from neonatal pigs and calves. We documented apparent changes in the frequency with which these toxinotype V strains cause human CDAD and compared the molecular characterization and toxin production of these strains with those of recent epidemic (i.e., BI/NAP1/027) and nonepidemic isolates. Materials and Methods Human Case Finding and Defi nitionsCase fi nding was performed by reviewing recent and past human isolates of interest from 2 sources. Cases were defi ned as patients with clinical isolates identifi ed as toxinotype V by analysis of restriction fragment length polymorphisms (RFLPs) of toxin-encoding genes. First, we reviewed 620 C. diffi cile human isolates sent to the Centers for Disease Control and Prevention (CDC) from healthcare facilities and ...

show abstract

Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Toxinotype VClostridium difficilein Humans and Food Animals

Jhung

Thompson

Killgore

et al. 2008

Emerg. Infect. Dis.

197

155

View full text Add to dashboard Cite

show abstract

“…[1][2][3]5,9 The risk of re-infection increases with continued use of antimicrobials, advanced age, history of recurrence, and deficiency in the immune response to C. difficile toxins. [1][2][3]7,8 Recurrence may also be influenced by bacterial strain; for example, the toxin hyper-producing BI/NAP1/027 (NAP1) strain emerged during outbreaks a decade ago [10][11][12][13][14][15][16][17][18][19] and now accounts for 31% to 53% of infections. 20 The NAP1 strain is associated with significant patient morbidity and mortality 5 and high rates of severe, refractory recurrent C. difficile infection.…”

Section: R Ecurrentmentioning

confidence: 99%

Treatment Strategies for Recurrent Clostridium difficile Infection

Leong

Zelenitsky

2013

CJHP

View full text Add to dashboard Cite

show abstract

“…24 The ribotype 001 strain accounted for <15% of isolates between 2002 and 2004 and the ribotype 027 ⁄ NAP1 strain accounted for $5% of strains in nosocomial infections. 25 Overall, there were approximately 40 different ribotypes observed from hospitalized patient samples during the study period in an analysis of over 1200 strains. As observations during an epidemic may not be generalizable to endemic and lower case rate settings, we examined the relationship between PPI and CDI in two general hospitals in a region with low prevalence of the NAP1 strain.…”

Section: Introductionmentioning

confidence: 98%