In the Endemic Setting, Clostridium difficile Ribotype 027 Is Virulent But Not Hypervirulent.
BACKGROUND
Conflicting reports have been published on the association between Clostridium difficile ribotypes and severe disease outcomes in patients with C. difficile infection (CDI); several so-called hypervirulent ribotypes have been described. We performed a multicenter study to assess severe disease presentation and severe outcomes among CDI patients infected with different ribotypes.


METHODS
Stool samples that tested positive for C. difficile toxin were collected and cultured from patients who presented to any of 7 different hospitals in Houston, Texas (2011-2013). C. difficile was characterized using a fluorescent PCR ribotyping method. Medical records were reviewed to determine clinical characteristics and ribotype association with severe CDI presentation (ie, leukocytosis and/or hypoalbuminemia) and severe CDI outcomes (ie, ICU admission, ileus, toxic megacolon, colectomy, and/or in-hospital death).


RESULTS
Our study included 715 patients aged 61±18 years (female: 63%; median Charlson comorbidity index: 2.5±2.4; hospital-onset CDI: 45%; severe CDI: 36.7%; severe CDI outcomes: 12.3%). The most common ribotypes were 027, 014-020, FP311, 002, 078-126, and 001. Ribotype 027 was a significant independent predictor of severe disease (adjusted odds ratio [aOR], 2.24; 95% confidence interval [CI], 1.53-3.29; P<.001) and severe CDI outcomes (aOR, 1.71; 95% CI, 1.02-2.85; P=.041) compared with all other ribotypes in aggregate. However, in an analysis using all common ribotypes as individual variables, ribotype 027 was not associated with severe CDI outcomes more often than other ribotypes.


CONCLUSIONS
Ribotype 027 showed virulence equal to that of other ribotypes identified in this endemic setting. Clinical severity markers of CDI may be more predictive of severe CDI outcomes than a particular ribotype.
1Department of Pharmacy Practice and Translational Research,University of Houston College of Pharmacy,Houston,Texas.
Samuel L
SL
Aitken
1Department of Pharmacy Practice and Translational Research,University of Houston College of Pharmacy,Houston,Texas.
M Jahangir
MJ
Alam
Mohammed
M
Khaleduzzaman
1Department of Pharmacy Practice and Translational Research,University of Houston College of Pharmacy,Houston,Texas.
Mohammed
M
Khaleduzzuman
3Department of Microbiology and Immunology,Montana State University,Bozeman,Montana.
Seth T
ST
Walk
2Department of Pharmacy,Houston Methodist Hospital,Houston,Texas.
William L
WL
Musick
4Department of Pharmacy,Memorial Hermann Northwest Hospital,Houston,Texas.
Vy P
VP
Pham
5Department of Internal Medicine,Baylor College of Medicine Houston,Texas.
Jennifer L
JL
Christensen
6Department of Medicine,Section of Infectious Disease,Baylor College of Medicine Houston,Texas.
Robert L
RL
Atmar
7Merck & Co.,Whitehouse Station,New Jersey.
Yang
Y
Xie
1Department of Pharmacy Practice and Translational Research,University of Houston College of Pharmacy,Houston,Texas.
Kevin W
KW
Garey
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016360:Clostridioides difficile / Q000145:classification / Q000235:genetics*; D003015:Clostridium Infections / Q000453:epidemiology*; D003428:Cross Infection / Q000453:epidemiology*; D005260:Female; D006761:Hospitals; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies; D021521:Ribotyping / Q000379:methods*; D012720:Severity of Illness Index; D013781:Texas