Laboratory diagnosis of Clostridioides (Clostridium) difficile infection in domestic animals: A short review

Comparison of Anaerobic Culture Methods for Detecting Clostridioides difficile in Bovine Faeces

BACKGROUND

The study of the epidemiology of Clostridioides difficile in populations is greatly facilitated by the ability to isolate and further characterize individual organisms, which requires effective culture protocols. In cattle, where little is known about the epidemiology of C. difficile, no studies have assessed or compared the performance of different assays for detecting C. difficile.

OBJECTIVES

This study compared two culture protocols for detecting C. difficile in bovine faeces from 121 gestating cows and 70 of their neonatal calves, while situating results obtained with each protocol relative to those obtained with shotgun metagenomic sequencing.

METHODS

Protocol 1 involved direct plating enrichment onto taurocholine-cycloserine-cefoxitin-fructose agar (TCCFA), while Protocol 2 included an ethanol shock step before plating on CCFA/ChromID agar. For both protocols, one aliquot underwent broth enrichment prior to plating, while the other aliquot did not.

RESULTS

Clostridioides difficile was detected following broth enrichment in two of the same calf samples using both protocols, and an additional cow sample was found to be positive with Protocol 2, though the difference in detection rates was not statistically significant (p = 1.0).

CONCLUSIONS

The detection of C. difficile in a much high number of these samples by shotgun metagenomics, albeit at low levels of relative abundance, suggests that neither of these culture protocols is sensitive when levels of abundance are low.

Emerging Diagnostics in Clostridioides difficile Infection

Clostridioides difficile detection in community settings is time-intensive, resulting in delays in diagnosing and quarantining infected individuals. However, with the advent of semi-automated devices and improved algorithms in recent decades, the ability to discern CDI infection from asymptomatic carriage has significantly improved. This, in turn, has led to efficiently regulated monitoring systems, further reducing endemic risk, with recent concerns regarding a possible surge in hospital-acquired Clostridioides difficile infections post-COVID failing to materialize. This review highlights established and emerging technologies used to detect community-acquired Clostridioides difficile in research and clinical settings.

Non-human Clostridioides difficile Reservoirs and Sources: Animals, Food, Environment

Clostridioides difficile is ubiquitous and is found in humans, animals and in variety of environments. The substantial overlap of ribotypes between all three main reservoirs suggests the extensive transmissions. Here we give the overview of European studies investigating farm, companion and wild animals, food and environments including water, soil, sediment, wastewater treatment plants, biogas plants, air, and households. Studies in Europe are more numerous especially in last couple of years, but are still fragmented in terms of countries, animal species, or type of environment covered. Soil seem to be the habitat of divergent unusual lineages of C. difficile. But the most important aspect of animals and environment is their role in C. difficile transmissions and their potential as a source for human infection is discussed.

Diagnostic Approach to Enteric Disorders in Pigs

The diagnosis of enteric disorders in pigs is extremely challenging, at any age. Outbreaks of enteric disease in pigs are frequently multifactorial and multiple microorganisms can co-exist and interact. Furthermore, several pathogens, such as Clostridium perfrigens type A, Rotavirus and Lawsonia intracellularis, may be present in the gut in the absence of clinical signs. Thus, diagnosis must be based on a differential approach in order to develop a tailored control strategy, considering that treatment and control programs for enteric diseases are pathogen-specific. Correct sampling for laboratory analyses is fundamental for the diagnostic work-up of enteric disease in pigs. For example, histology is the diagnostic gold standard for several enteric disorders, and sampling must ensure the collection of representative and optimal intestinal samples. The aim of this paper is to focus on the diagnostic approach, from sampling to the aetiological diagnosis, of enteric disorders in pigs due to different pathogens during the different phases of production.

Lethal acute diarrhea associated with Clostridioides difficile toxin A and B in a buffy-tufted-ear marmoset (Callithrix aurita)

This is a case of lethal acute diarrhea associated with a mild neutrophilic enteritis in a buffy-tufted-ear marmoset (Callithrix aurita) with detection of A/B toxins and isolation of a toxigenic clade 3 Clostridioides difficile strain (A⁺ B⁺ CDT⁺ , ST5), which should be considered as a potential cause of enteritis in this species.