Investigation of Clostridium difficile interspecies relatedness using multilocus sequence typing, multilocus variable-number tandem-repeat analysis and antimicrobial susceptibility testing

Abstract

A B S T R A C TMultilocus sequence typing (MLST), multilocus variable-number tandem-repeat analysis (MLVA) and antimicrobial susceptibility were performed on 37 animal and human C. difficile isolates belonging to 15 different PCR-ribotypes in order to investigate the relatedness of human and animal isolates and to identify possible transmission routes.MLVA identified a total of 21 different types while MLST only distinguished 12 types. Identical C. difficile strains were detected in the same animal species for PCR-ribotypes 014, 078, UCL 16U and UCL 36, irrespective of their origin or the isolation date. Non clonal strains were found among different hosts; however, a high genetic association between pig and cattle isolates belonging to PCR-ribotype 078 was revealed. MLVA also showed genetic differences that clearly distinguished human from animal strains. For a given PCR-ribotype, human and animal strains presented a similar susceptibility to the antimicrobials tested. All strains were susceptible to vancomycin, metronidazole, chloramphenicol and rifampicin, while PCRribotypes 078, UCL 5a, UCL 36 and UCL 103 were associated with erythromycin resistance.The data suggest a wide dissemination of clones at hospitals and breeding-farms or a contamination at the slaughterhouse, but less probability of interspecies transmission. However, further highly discriminatory genotyping methods are necessary to elucidate interspecies and zoonotic transmission of C. difficile.

Quantification of Clostridioides (Clostridium) difficile in feces of calves of different age and determination of predominant Clostridioides difficile ribotype 033 relatedness and transmission between family dairy farms using multilocus variable-number tandem-repeat analysis

“…However, one report has associated C. difficile ribotype 033 with diarrhea and eventually death in an elderly hospitalized patient in Italy [ 26 ], which necessitates further epidemiological assessment of all C. difficile ribotypes. Detailed epidemiological investigation can be achieved employing multilocus variable-number tandem-repeat analysis (MLVA), which is the method of choice to identify routes of transmission between patients and the environment [ 27 – 29 ]. This method shows a high level of discrimination and was proven useful for geographical tracking of several outbreak strains of bacteria [ 30 – 32 ].…”

Clostridioides difficile in the environment, food, animals and humans in southern Italy: Occurrence and genetic relatedness

“…CA-CDI is a public health issue of emerging concern. Very few studies investigated the genetic relatedness of C. difficile isolates from humans, environmental, animal and food sources using MLVA [36,37]. Curry et al [38] found that MLVA has a sufficient discriminatory power to highlight the prevalence of C. difficile in food.…”

Clostridioides (Clostridium) Difficile in Food-Producing Animals, Horses and Household Pets: A Comprehensive Review

“…Madewell et al, suggested that the clinical environment can be a source for the contamination of cats with C. difficile [134]. Moreover, raw and processed food has been identified as vectors for the contamination of household pets with the bacterium [135]. Given the close contact between household pets and humans it is, therefore, desirable to screen the animals which may come into contact with people at risk, such as immunocompromised individuals and the elderly, in order to prevent the occurrence of CDI.…”