Proteotyping as alternate typing method to differentiate Campylobacter coli clades

Abstract

Besides Campylobacter jejuni, Campylobacter coli is the most common bacterial cause of gastroenteritis worldwide. C. coli is subdivided into three clades, which are associated with sample source. Clade 1 isolates are associated with acute diarrhea in humans whereas clade 2 and 3 isolates are more commonly obtained from environmental waters. The phylogenetic classification of an isolate is commonly done using laborious multilocus sequence typing (MLST). The aim of this study was to establish a proteotyping scheme using MALDI-TOF MS to offer an alternative to sequence-based methods. A total of 97 clade-representative C. coli isolates were analyzed by MALDI-TOF-based intact cell mass spectrometry (ICMS) and evaluated to establish a C. coli proteotyping scheme. MLST was used as reference method. Different isoforms of the detectable biomarkers, resulting in biomarker mass shifts, were associated with their amino acid sequences and included into the C. coli proteotyping scheme. In total, we identified 16 biomarkers to differentiate C. coli into the three clades and three additional sub-clades of clade 1. In this study, proteotyping has been successfully adapted to C. coli. The established C. coli clades and sub-clades can be discriminated using this method. Especially the clinically relevant clade 1 isolates can be differentiated clearly.

Whole genome sequencing reveals extended natural transformation in Campylobacter impacting diagnostics and the pathogens adaptive potential

“…previously validated as indicative for correct species identification of Campylobacter spp. [16][17][18] . In order to clarify genetic relationship of "hybrid" and "half hybrid" strains within the Campylobacter population we performed an average nucleotide identity (ANI) analysis using the tool FastANI 19 .…”

“…Each identification obtains a score value. The identification at the species level with a score ≥ 2.000 was considered correct [16][17][18] .…”

Characterization of Clostridium tyrobutyricum Strains Using Three Different Typing Techniques

“…Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) typing has emerged as a fast and simple tool for intra-specific typing. It has been applied successfully for the subtyping and tracking of several bacterial pathogens [ 25 , 26 , 27 ]. A more recent development is the use of MALDI-TOF MS to characterize food spoilage organisms [ 28 ].…”

MALDI-TOF Mass Spectrometry and Specific Biomarkers: Potential New Key for Swift Identification of Antimicrobial Resistance in Foodborne Pathogens

“…Zautner and colleagues already reported the ability of MALDI-TOF MS to subtype Campylobacter spp. by shifts in biomarker masses, due to amino acid substitutions caused by single-point mutations in the respective biomarker gene [95], and they further described proteotyping as a promising tool for microbial typing at the species, subspecies, and even below subspecies levels [96][97][98]. These last studies show how generated spectra are exploitable and accurate enough to detect various AMR biomarkers in important pathogens such as Salmonella spp.…”