Identification of Arcobacter species using phospholipid and total fatty acid profiles

Identification, characterization and description of Arcobacter faecis sp. nov., isolated from a human waste septic tank

A study on the taxonomic classification of Arcobacter species was performed on the cultures isolated from various fecal sources where an Arcobacter strain AF1078(T) from human waste septic tank near Ottawa, Ontario, Canada was characterized using a polyphasic approach. Genetic investigations including 16S rRNA, atpA, cpn60, gyrA, gyrB and rpoB gene sequences of strain AF1078(T) are unique in comparison with other arcobacters. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain is most closely related to Arcobacter lanthieri and Arcobacter cibarius. Analyses of atpA, cpn60, gyrA, gyrB and rpoB gene sequences suggested that strain AF1078(T) formed a phylogenetic lineage independent of other species in the genus. Whole-genome sequence, DNA-DNA hybridization, fatty acid profile and phenotypic analysis further supported the conclusion that strain AF1078(T) represents a novel Arcobacter species, for which the name Arcobacter faecis sp. nov. is proposed, with type strain AF1078(T) (=LMG 28519(T); CCUG 66484(T)).

Advances in mass spectrometry for the identification of pathogens

Mass spectrometry (MS) has become an important technique to identify microbial biomarkers. The rapid and accurate MS identification of microorganisms without any extensive pretreatment of samples is now possible. This review summarizes MS methods that are currently utilized in microbial analyses. Affinity methods are effective to clean, enrich, and investigate microorganisms from complex matrices. Functionalized magnetic nanoparticles might concentrate traces of target microorganisms from sample solutions. Therefore, nanoparticle-based techniques have a favorable detection limit. MS coupled with various chromatographic techniques, such as liquid chromatography and capillary electrophoresis, reduces the complexity of microbial biomarkers and yields reliable results. The direct analysis of whole pathogenic microbial cells with matrix-assisted laser desorption/ionization MS without sample separation reveals specific biomarkers for taxonomy, and has the advantages of simplicity, rapidity, and high-throughput measurements. The MS detection of polymerase chain reaction (PCR)-amplified microbial nucleic acids provides an alternative to biomarker analysis. This review will conclude with some current applications of MS in the identification of pathogens.

Inhibition of Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii by plant oil aromatics

The inhibitory effect of some plant oil aromatics against three strains of Arcobacter butzleri, two strains of Arcobacter cryaerophilus, and one strain of Arcobacter skirrowii was evaluated. When MICs were determined using the broth macrodilution method, cinnamaldehyde was most inhibitory followed by thymol, carvacrol, caffeic acid, tannic acid, and eugenol (P < 0.001). Sublethal concentrations of the three most potent plant oil aromatics also were examined. Overall, cinnamaldehyde was the most bacteriostatic against all arcobacters tested except A. butzleri when these strains were exposed to the MIC25 of this aromatic aldehyde. The bacteriostatic activities of thymol and carvacrol were concentration and species dependent.