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.
Department of Medical Microbiology, Leiden University Medical Centre, Leiden, The Netherlands.
A
A
Goorhuis
M C
MC
Legaria
R J
RJ
van den Berg
C
C
Harmanus
C H W
CH
Klaassen
J S
JS
Brazier
G
G
Lumelsky
E J
EJ
Kuijper
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