Campylobacter insulaenigrae: first isolation report from South American sea lion (Otaria flavescens, (Shaw, 1800)

Campylobacter insulaenigrae have been isolated from different pinnipeds but not from South American sea lion (Otaria flavescens). The aim of this work is to report the first isolation of C. insulaenigrae from South American sea lion (Otaria flavescens). The isolate, identified by its phenotypic and molecular characteristics, allow recognizing O. flavescens as a new host for C. insulaenigrae.

Campylobacter troglodytis sp. nov., isolated from feces of human-habituated wild chimpanzees (Pan troglodytes schweinfurthii) in Tanzania.

The transmission of simian immunodeficiency and Ebola viruses to humans in recent years has heightened awareness of the public health significance of zoonotic diseases of primate origin, particularly from chimpanzees. In this study, we analyzed 71 fecal samples collected from 2 different wild chimpanzee (Pan troglodytes) populations with different histories in relation to their proximity to humans. Campylobacter spp. were detected by culture in 19/56 (34%) group 1 (human habituated for research and tourism purposes at Mahale Mountains National Park) and 0/15 (0%) group 2 (not human habituated but propagated from an introduced population released from captivity over 30 years ago at Rubondo Island National Park) chimpanzees, respectively. Using 16S rRNA gene sequencing, all isolates were virtually identical (at most a single base difference), and the chimpanzee isolates were most closely related to Campylobacter helveticus and Campylobacter upsaliensis (94.7% and 95.9% similarity, respectively). Whole-cell protein profiling, amplified fragment length polymorphism analysis of genomic DNA, hsp60 sequence analysis, and determination of the mol% G+C content revealed two subgroups among the chimpanzee isolates. DNA-DNA hybridization experiments confirmed that both subgroups represented distinct genomic species. In the absence of differential biochemical characteristics and morphology and identical 16S rRNA gene sequences, we propose to classify all isolates into a single novel nomenspecies, Campylobacter troglodytis, with strain MIT 05-9149 as the type strain; strain MIT 05-9157 is suggested as the reference strain for the second C. troglodytis genomovar. Further studies are required to determine whether the organism is pathogenic to chimpanzees and whether this novel Campylobacter colonizes humans and causes enteric disease.

Arcobacter population dynamics in pigs on farrow-to-finish farms.

Healthy pigs are an important reservoir for the emerging human pathogen Arcobacter which can result in contamination of porcine carcasses and pork and the spread of arcobacters into the environment. Up to now, the excretion of arcobacters by pigs has been studied, but information about the transmission routes in fattening pigs is lacking. The present study aimed to elucidate the Arcobacter population dynamics in pigs during the fattening period on four farrow-to-finish farms. On each farm, 30 clinically healthy, 12-week-old piglets were selected. Fecal samples were collected on 10 sampling occasions until a slaughter age of 30 weeks was reached. Arcobacter spp. were isolated by a selective method and identified by multiplex PCR. The genetic diversity was examined by amplified fragment length polymorphism and enterobacterial repetitive intergenic consensus PCR. The Arcobacter presence in the fecal samples on the four farms ranged from 11.3 to 50.0%, with excretion levels of up to 10(4) CFU/g feces. The ratio in which Arcobacter species were isolated varied between the farms and over time. Characterization revealed a high degree of genotypic diversity among the isolates. Arcobacter strains persisted and spread within the finishing unit during the fattening period. The occurrence of both unique and shared genotypes in pigs in adjacent and nonadjacent pens demonstrates that transmission routes other than fecal-oral transmission occur.

Campylobacter Insulaenigrae: First Isolation Report from South American sea lion (Otaria Flavescens, (Shaw, 1800).

Campylobacter insulaenigrae have been isolated from different pinnipeds but not from South American sea lion (Otaria flavescens).The aim of this work is to report the first isolation of C. insulaenigrae from South American sea lion (Otaria flavescens).The isolate, identified by its phenotypic and molecular characteristics, allow recognizing O. flavescens as a new host for C. insulaenigrae.

Campylobacter subantarcticus sp. nov., isolated from birds in the sub-Antarctic region.

Six Gram-stain-negative, spiral-shaped, microaerobic isolates were obtained during a sampling from wild birds in the sub-Antarctic region. Based on initial observations, these isolates were classified as Campylobacter lari-like. The isolates were further characterized by whole-cell protein and amplified fragment length polymorphism (AFLP) analysis, which revealed that they were distinct from C. lari and all other known species of the genus Campylobacter. Here, we present comprehensive phylogenetic, genomic and phenotypic evidence that these isolates represent a novel species within the genus Campylobacter, for which the name Campylobacter subantarcticus sp. nov. is proposed. The type strain is R-3023(T) (=LMG 24377(T) =CCUG 38513(T)).

Reassessment of the taxonomy of Arcobacter cryaerophilus.

Arcobacter cryaerophilus is a heterogeneous species in which two distinct subgroups have been reported. In the present study, the taxonomic status of these subgroups was reassessed using amplified fragment length polymorphism and heat shock protein 60 gene sequence analysis. The results demonstrated that A. cryaerophilus has a complex taxonomic structure, which consists of multiple cores of strains that share intermediate levels of DNA-DNA hybridisation and exhibit low levels of DNA-DNA hybridisation towards other Arcobacter species. One of these cores consisted of the majority of strains and included most subgroup 2 strains from previous studies. A. cryaerophilus subgroup 1 strains represented three distinct cores, among which the type strain occupied a distinct position. These results therefore also demonstrate that the current subgroup nomenclature in A. cryaerophilus should be abandoned, and that the type strain is genetically aberrant and poorly represents strains belonging to this species.

Campylobacter volucris sp. nov., isolated from black-headed gulls (Larus ridibundus).

During a study of the prevalence of Campylobacter jejuni in black-headed gulls (Larus ridibundus) in Sweden, three isolates, strains LMG 24379, LMG 24380T and LMG 24381, were initially identified as Campylobacter lari. Further characterization by both AFLP and whole-cell protein SDS-PAGE analyses revealed that they formed a distinct group in the genus Campylobacter. This unique position was confirmed by phenotypic characterization, 16S rRNA and hsp60 gene sequence analysis and DNA-DNA hybridizations. The combined data confirm that these isolates represent a novel species within the genus Campylobacter, for which the name Campylobacter volucris sp. nov. is proposed. The type strain is LMG 24380T (=CCUG 57498T).

Arcobacter thereius sp. nov., isolated from pigs and ducks.

During a Danish study on the prevalence of campylobacteria in pig abortions and food of animal origin, eight Gram-negative, slightly curved, rod-shaped, non-spore-forming bacteria were clustered by using amplified fragment length polymorphism analysis in a distinct phenon within the genus Arcobacter. In the present study, numerical analysis of whole-cell protein profiles also showed that all isolates clustered in a single group distinct from other recognized Arcobacter species. DNA-DNA hybridization among two representative strains exhibited a mean DNA-DNA relatedness value of 79 %. DNA-DNA hybridization with the type strains of recognized Arcobacter species revealed levels of DNA-DNA relatedness of 41 % or less. The DNA G+C content of the type strain was 28.5 mol%. Pairwise comparison of the 16S rRNA gene sequences with those of the type strains of established species identified Arcobacter cryaerophilus (97.9 %), Arcobacter cibarius (97.5 %) and Arcobacter skirrowii (97.2 %) as the nearest phylogenetic neighbours. The isolates could be distinguished from other Arcobacter species by means of the following biochemical tests: activities of catalase and urease, reduction of nitrate and growth on minimal medium, lack of growth at 37 degrees C under standardized aerobic and microaerobic conditions, in 4 % NaCl and 1 % glycine media. Finally, DNA fingerprints obtained by using enterobacterial repetitive intergenic consenus-PCR showed that the eight isolates represent eight strains of a single novel Arcobacter species, for which the name Arcobacter thereius sp. nov. is proposed. The type strain is LMG 24486(T) (=CCUG 56902(T)).

Campylobacter avium sp. nov., a hippurate-positive species isolated from poultry.

Three strains of an unusual hippurate-positive Campylobacter species were isolated at 37 degrees C from caecal contents of broiler chickens and a turkey. All strains were initially identified as Campylobacter by means of genus-specific PCR, but none was further identified using specific PCRs for known thermophilic species. Phylogenetic analyses based on 16S rRNA, rpoB and groEL gene sequences revealed that these strains formed a robust clade distinct from other Campylobacter species. Amplified fragment length polymorphism analysis and whole-cell protein electrophoresis were subsequently carried out and confirmed the divergence between the avian strains and other taxa. These data indicate that the unidentified Campylobacter strains belong to a novel taxon which could be distinguished from other campylobacters through its phenotypic and genotypic characteristics. The name Campylobacter avium sp. nov., is proposed for the novel species, with the type strain 86/06T (=LMG 24591T=CCUG 56292T).

Campylobacter cuniculorum sp. nov., from rabbits.

Eight strains of an unknown thermotolerant Campylobacter species were isolated from the caecal contents of rabbits (Oryctolagus cuniculus). All strains were initially identified as belonging to the genus Campylobacter by means of genus-specific PCR, but none were identified using species-specific PCR for known thermophilic species. Cells were spiral shaped with bipolar unsheathed flagella, with no periplasmic fibres, and appeared coccoid after 10-12 days of incubation. Phylogenetic analyses based on 16S rRNA gene, rpoB and groEL sequences revealed that all strains formed a robust clade that was very distinct from recognized Campylobacter species. 16S rRNA gene sequence pairwise comparisons of strain 150B(T) with the type strains of other Campylobacter species revealed that the nearest phylogenetic neighbour was Campylobacter helveticus NCTC 12470(T), with 96.6 % similarity. The uniqueness of these rabbit isolates was confirmed by whole-cell protein electrophoresis. Taken together, these data indicate that the strains belong to a novel Campylobacter species for which the name Campylobacter cuniculorum sp. nov. is proposed, with 150B(T) (=LMG 24588(T) =CCUG 56289(T)) as the type strain.

Novel Campylobacter lari-like bacteria from humans and molluscs: description of Campylobacter peloridis sp. nov., Campylobacter lari subsp. concheus subsp. nov. and Campylobacter lari subsp. lari subsp. nov.

A polyphasic study was undertaken to clarify the taxonomic position of Campylobacter lari-like strains isolated from shellfish and humans. The diversity within the strain collection was initially screened by means of fluorescent amplified fragment length polymorphism analysis and whole-cell protein electrophoresis, revealing the existence of two clusters distinct from C. lari and other Campylobacter species. The divergence of these clusters was confirmed by phenotypic analysis and by 16S rRNA and hsp60 gene sequence analysis. Phylogenetic analysis identified C. lari, Campylobacter jejuni, Campylobacter coli and Campylobacter insulaenigrae as the closest phylogenetic neighbours of both taxa. DNA-DNA hybridizations revealed that one cluster, comprising 10 strains, represented a novel Campylobacter species, for which the name Campylobacter peloridis sp. nov. is proposed, with 2314BVA(T) (=LMG 23910(T) =CCUG 55787(T)) as the type strain. The second cluster, comprising six strains, represents a novel subspecies within the species C. lari, for which the name Campylobacter lari subsp. concheus subsp. nov. is proposed, with 2897R(T) (=LMG 21009(T) =CCUG 55786(T)) as the type strain. The description of C. lari subsp. concheus has the effect of automatically creating the subspecies Campylobacter lari subsp. lari subsp. nov. (type strain LMG 8846(T)=NCTC 11352(T)).

Comparative performance of different PCR assays for the identification of Campylobacter jejuni and Campylobacter coli.

The sensitivity and specificity of 7 PCR assays described for the identification of Campylobacter jejuni and Campylobacter coli were examined using alkaline cell lysates from a collection of 100 well characterized reference strains of C. jejuni, C. coli, Campylobacter lari and related Campylobacter, Helicobacter and Arcobacter species. Based on a preliminary evaluation, one multiplex test was excluded from further evaluation. The various assays differed considerably in sensitivity and specificity towards their target species. For C. coli, 4 of the 5 assays were 100% specific and sensitive, but for C. jejuni, none of the 5 assays were found to be 100% specific or sensitive. Subsequently, a statistically valid sample (n=263) was taken from a Belgian collection of 1906 human Campylobacter field isolates. This second collection was used to further evaluate two selected multiplex PCR assays. The present study indicates that PCR-based identification using each of the two selected multiplex PCR assays was highly reliable. The R-mPCR assay, followed by species-specific PCR assays or the ceu-oxr mPCR assay if necessary, is our current strategy of choice for the molecular identification of C. jejuni and C. coli. Results presented here should aid researchers in selecting a PCR assay suitable for their specific needs.