Application of multiple-locus variable-number tandem-repeat analysis to determine clonal spread of toxin A-negative Clostridium difficile in a general hospital in Buenos Aires, Argentina.
Isolates from patients with Clostridium difficile infection (CDI) usually produce both toxin A (TcdA) and toxin B (TcdB), but an increasing number of reports from Europe and Asia mention infections with TcdA-negative, TcdB-positive (A-/B+) strains, usually characterized as PCR ribotype 017 (type 017). Incidence rates of CDI per 10 000 admissions in a 200-bed Argentinean general hospital were 37, 84, 67, 43, 48 and 42 for the years 2000 to 2005, respectively. The annual percentages of type 017 CDI were 7.7%, 64.6%, 91.4%, 92.0%, 75.0% and 86.4%, respectively. Comparison of 112 017-CDI patients with 41 non-017-CDI patients revealed that 017-CDI patients were more often male (68.8% vs. 46.3%; odds ratio 2.55, 95% confidence interval 1.23-5.50). All type 017 strains tested belonged to toxinotype VIII and had a 1.8-kb deletion in tcdA. In addition, 90% of tested type 017 isolates had high-level resistance to clindamycin and erythromycin, determined by the presence of the ermB gene. Multiple-locus variable-number tandem-repeat analysis (MLVA) was applied to 56 Argentinean isolates and 15 isolates from seven other countries. Country-specific clonal complexes were found in each country. Among 56 Argentinean isolates, four clonal complexes were recognized, accounting for 61% of all isolates. These clonal complexes did not show correlation over time, but seemed to be restricted to specific wards, mainly internal medicine and pulmonology wards. A total of 56% of recurrent infections were caused by a different isolate, despite identification of an identical PCR-ribotype. We conclude that C. difficile type 017 gradually replaced other circulating PCR ribotypes and that MLVA provides detailed insight into nosocomial spread.
Goorhuis
A
A
Department of Medical Microbiology, Leiden University Medical Centre, Leiden, The Netherlands.
Legaria
M C
MC
van den Berg
R J
RJ
Harmanus
C
C
Klaassen
C H W
CH
Brazier
J S
JS
Lumelsky
G
G
Kuijper
E J
EJ
D001118:Argentina / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D016360:Clostridioides difficile / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D004761:Enterocolitis, Pseudomembranous / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D004768:Enterotoxins / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D006769:Hospitals, General / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D016133:Polymerase Chain Reaction; D021521:Ribotyping; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile