Identification of Campylobacter species and related organisms by matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry

First isolation of Campylobacter vicugnae sp. nov. in humans suffering from gastroenteritis

The present study describes the first isolation of a recently described Campylobacter species, Campylobacter vicugnae, in humans. The isolates were recovered by two independent French laboratories in 2020 and 2022 from a man and a woman suffering from gastroenteritis. Biochemical and growth characteristics, and electron microscopy for these two strains indicated that they belong to Campylobacter genus. 16S rDNA and GyrA-based phylogeny, as well as average nucleotide identity and in silico DNA-DNA Hybridization analyses revealed that both strains belong to the Campylobacter vicugnae species. Both isolates possess a complete cytolethal distending toxin (CDT) locus with cdtA, cdtB, and cdtC, and features of CDT activity were demonstrated in vitro with Caco-2 intestinal epithelial cells. Our data suggest that these two isolates of C. vicugnae were associated with gastroenteritis in humans and induced major cytopathogenic effects in vitro. C. vicugnae is likely to be a novel human pathogen, with a source of foodborne infection that needs to be determined.IMPORTANCECampylobacter species that display toxicity features are a worldwide public health issue. In clinical contexts, it is crucial to identify which isolate could be an urgent threat to a patient. Actual and widely used laboratory methods such as mass spectrometry or PCR may be flawed in the field of species identification. In contrast, the present study shows that next-generation sequencing allows to precisely identify isolates to species level that may have been omitted otherwise. Moreover, it helps to identify emerging species before they become a threat to human health. Recovery of a new Campylobacter species in human sample, such as the new species "Campylobacter vicugnae," is an important step for the identification of emerging pathogens posing threat to global health.

Quadruplex qPCR for detection and discrimination of C. Coli,C. fetus, and C. Jejuni from other Campylobacter species in chicken and sheep meat

Campylobacter is gram-negative bacteria considered the predominant genera isolated from poultry samples and associated with gastroenteritis. Due to the problems in conventional cultural methods of time-consuming and technically demanding requirements, a rapid and feasible method for their identification and discrimination of the closely related spp. Including Campylobacter coli, Campylobacter fetus, and Campylobacter jejuni is needed. This study analyzes the chicken and sheep meats samples (n = 125) using culture and pre-enrichment-based Quadraplex real-time PCR by targeting OrfA, CstA, HipO, and 16 S rRNA genes of C. coli, C. fetus, C. jejuni and Campylobacter spp. Respectively. The analysis of 125 chicken and sheep meat samples by culture and real-time PCR showed high concordance between the results of the two methods. The present study show high prevalence of Campylobacter species (35% and 32% from chicken and meat respectively) of which C. jejuni were the most abundant. Reaction efficiencies were between 90 and 110%, and detect as low as 8.9 fg in C. jejuni. The need for quick detection and discrimination methods in sheep and chicken meat can be met using the described Quadraplex real-time PCR methodology.

Comparative pangenomic analysis of Campylobacter fetus isolated from Spanish bulls and other mammalian species

Campylobacter fetus comprises two closely related mammal-associated subspecies: Campylobacter fetus subsp. fetus (Cff) and Campylobacter fetus subsp. venerealis (Cfv). The latter causes bovine genital campylobacteriosis, a sexually-transmitted disease endemic in Spain that results in significant economic losses in the cattle industry. Here, 33 C. fetus Spanish isolates were whole-genome sequenced and compared with 62 publicly available C. fetus genomes from other countries. Genome-based taxonomic identification revealed high concordance with in silico PCR, confirming Spanish isolates as Cff (n = 4), Cfv (n = 9) and Cfv biovar intermedius (Cfvi, n = 20). MLST analysis assigned the Spanish isolates to 6 STs, including three novel: ST-76 and ST-77 for Cfv and ST-78 for Cff. Core genome SNP phylogenetic analysis of the 95 genomes identified multiple clusters, revealing associations at subspecies and biovar level between genomes with the same ST and separating the Cfvi genomes from Spain and other countries. A genome-wide association study identified pqqL as a Cfv-specific gene and a potential candidate for more accurate identification methods. Functionality analysis revealed variations in the accessory genome of C. fetus subspecies and biovars that deserve further studies. These results provide valuable information about the regional variants of C. fetus present in Spain and the genetic diversity and predicted functionality of the different subspecies.

Combined genomic-proteomic approach in the identification of Campylobacter coli amoxicillin-clavulanic acid resistance mechanism in clinical isolates

Introduction

Aminopenicillins resistance among Campylobacter jejuni and Campylobacter coli strains is associated with a single mutation in the promoting region of a chromosomal beta-lactamase blaOXA61, allowing its expression. Clavulanic acid is used to restore aminopenicillins activity in case of blaOXA61 expression and has also an inherent antimicrobial activity over Campylobacter spp. Resistance to amoxicillin-clavulanic acid is therefore extremely rare among these species: only 0.1% of all Campylobacter spp. analyzed in the French National Reference Center these last years (2017-2022).

Material and methods

Whole genome sequencing with bioinformatic resistance identification combined with mass spectrometry (MS) was used to identify amoxicillin-acid clavulanic resistance mechanism in Campylobacters.

Results

A G57T mutation in blaOXA61 promoting region was identified in all C. jejuni and C. coli ampicillin resistant isolates and no mutation in ampicillin susceptible isolates. Interestingly, three C. coli resistant to both ampicillin and amoxicillin-clavulanic acid displayed a supplemental deletion in the promoting region of blaOXA61 beta-lactamase, at position A69. Using MS, a significant difference in the expression of BlaOXA61 was observed between these three isolates and amoxicillin-clavulanic acid susceptible C. coli.

Conclusion

A combined genomics/proteomics approach allowed here to identify a rare putative resistance mechanism associated with amoxicillin-clavulanic acid resistance for C. coli.

Isolation and Identification of Endophytic Bacterial Isolates from the Leaves, Roots, and Stems Parts of Artemisia annua, Moringa oleifera, and Ocimum lamiifolium Plants

Medicinal plants are known to harbor diverse species of endophytic bacteria which are known for secretion of beneficial secondary metabolites, like enzymes and antimicrobial compounds. The present study aimed to isolate, characterize, and identify the endophytic bacteria isolates from Artemisia annua, Moringa oleifera, and Ocimum lamiifolium plants. Certain endophytic bacterial isolates were screened. Phosphate and Zinc solubilization were performed for newly obtained isolates. The 16S rRNA gene sequencing was performed for RPAAI-8 isolate. Data were analyzed. Our study showed that endophytic bacterial isolates were recognized to be Bacillus cereus, B. subtilis, Citrobacter freundii, Enterobacter asburiae, E. cloacae, E. kobei, E. ludwigii, Enterococcus faecium, and Pseudomonas monteilli. From among these differentiated endophytic bacterial isolates, Enterobacter species are the most frequently obtained isolates. These bacterial isolates were shown 99.77% sequence similarity to Enterobacter ludwigii EN-119T (JTLO01000001) using 16S rRNA gene sequencing. This isolate was designated as Enterobacter sp. RPAAI-8. This isolate was able to employ selected cheap and cost-effective agro wastes as a carbon source. This cheap agro waste utilization by these Enterobacter species could be the first report. In conclusion, the present isolates are found to be employed for plant growth promotion and solubilizing insoluble phosphate and zinc. Before this time, most of the recent isolates were not identified from these medicinal plants. The ethyl acetate extract of the isolates also showed inhibitory activity against selected test pathogens.

Prosthetic valve endocarditis caused by Campylobacter fetus: a case report and literature review

Campylobacter fetus is a Gram-negative bacillus typically associated with bacteremia in immunocompromised patients. Prosthetic valve endocarditis (PVE) is a serious complication of prosthetic valve surgery, with a high mortality rate if not treated promptly. We present a rare case of PVE caused by C. fetus. A man in his mid-60s presented to the Emergency Department with a fever and showed elevated C-reactive protein concentrations. He had prosthetic mitral and aortic valve replacement surgery 15 years previously. Gram-negative rods were detected in a blood culture. These rods were identified as C. fetus using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and confirmed by 16S rRNA sequencing. The patient was treated with gentamicin and imipenem, and underwent valve replacement surgery. C. fetus was isolated in a left atrial appendage swab obtained during the surgery. Follow-up blood cultures were negative after treatment. However, after a cardiac arrest event, the patient's general condition deteriorated, and he died. To the best of our knowledge, this is the first case of PVE caused by C. fetus in Korea and the second fatality to date. This case highlights the importance of considering C. fetus as a potential cause of PVE, even in patients without known risk factors.

Campylobacter fetus Invasive Infections and Risks for Death, France, 2000-2021

Campylobacter fetus accounts for 1% of Campylobacter spp. infections, but prevalence of bacteremia and risk for death are high. To determine clinical features of C. fetus infections and risks for death, we conducted a retrospective observational study of all adult inpatients with a confirmed C. fetus infection in Nord Franche-Comté Hospital, Trevenans, France, during January 2000-December 2021. Among 991 patients with isolated Campylobacter spp. strains, we identified 39 (4%) with culture-positive C. fetus infections, of which 33 had complete records and underwent further analysis; 21 had documented bacteremia and 12 did not. Secondary localizations were reported for 7 (33%) patients with C. fetus bacteremia, of which 5 exhibited a predilection for vascular infections (including 3 with mycotic aneurysm). Another 7 (33%) patients with C. fetus bacteremia died within 30 days. Significant risk factors associated with death within 30 days were dyspnea, quick sequential organ failure assessment score >2 at admission, and septic shock.

Recurrent Campylobacter jejuni Infections with In Vivo Selection of Resistance to Macrolides and Carbapenems: Molecular Characterization of Resistance Determinants

We present two independent cases of recurrent multidrug-resistant Campylobacter jejuni infection in immunocompromised hosts and the clinical challenges encountered due to the development of high-level carbapenem resistance. The mechanisms associated with this unusual resistance for Campylobacters were characterized. Initial macrolide and carbapenem-susceptible strains acquired resistance to erythromycin (MIC > 256mg/L), ertapenem (MIC > 32mg/L), and meropenem (MIC > 32mg/L) during treatment. Carbapenem-resistant isolates developed an in-frame insertion resulting in an extra Asp residue in the major outer membrane protein PorA, within the extracellular loop L3 that connects β-strands 5 and 6 and forms a constriction zone involved in Ca2+ binding. The isolates presenting the highest MIC to ertapenem exhibited an extra nonsynonymous mutation (G167A|Gly56Asp) at PorA's extracellular loop L1. IMPORTANCE Carbapenem susceptibility patterns suggest drug impermeability, related to either insertion and/or single nucleotide polymorphism (SNP) within porA. Similar molecular events occurring in two independent cases support the association of these mechanisms with carbapenem resistance in Campylobacter spp.

A systematic assessment of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) application for rapid identification of pathogenic microbes that affect food crops: delivered and future deliverables

MALDI-TOF MS has decades of experience in the detection and identification of microbial pathogens. This has now become a valuable analytical tool when it comes to the identification and detection of clinical microbial pathogens. This review gives a brief synopsis of what has been achieved using MALDI-TOF MS in clinical microbiology. The major focus, however, is on summarizing and highlighting the effectiveness of MALDI-TOF MS as a novel tool for rapid identification of food crop microbial pathogens. The methods used and the sample preparation methodologies reported thus far have been highlighted and the challenges and gaps and recommendations for fine tuning the technique have been put forth. In an era where anything close to the health and welfare of humanity has been considered as the top priority, this review pitches on one such relevant research topics.

Overview of methodologies for the culturing, recovery and detection of Campylobacter

Campylobacter species are responsible for human gastroenteritis with diverse clinical spectra, ranging from acute watery or bloody diarrhea to life-threatening autoimmune disorders. Given the importance of Campylobacter in causing human illness, this article has reviewed the transmission and attribution sources as well as methodologies for the detection and virulence characterization of campylobacteria. The recovery and detection of Campylobacter from clinical, food and environmental samples has been achieved by the combinatorial use of selective enrichment and culturing methods. Biochemical, immunological, and nucleic acid-based methodologies have enabled the detection and differentiation of closely related Campylobacter isolates in foodborne outbreak investigations and have assessed the diversity and phylogenetic relationships of these bacterial pathogens. Analyses of motility, adherence, and invasiveness in host cells have assessed the pathogenic potential of campylobacteria. Further examination of determinants conferring antimicrobial resistance in Campylobacter have supported the growing need to closely monitor antimicrobials use in clinical and agricultural sectors.

Multicenter Retrospective Study of Vascular Infections and Endocarditis Caused by Campylobacter spp., France

The incidence of campylobacteriosis has substantially increased over the past decade, notably in France. Secondary localizations complicating invasive infections are poorly described. We aimed to describe vascular infection or endocarditis caused by Campylobacter spp. We included 57 patients from a nationwide 5-year retrospective study on Campylobacter spp. bacteremia conducted in France; 44 patients had vascular infections, 12 had endocarditis, and 1 had both conditions. Campylobacter fetus was the most frequently involved species (83%). Antibiotic treatment involved a β-lactam monotherapy (54%) or was combined with a fluoroquinolone or an aminoglycoside (44%). The mortality rate was 25%. Relapse occurred in 8% of cases and was associated with delayed initiation of an efficient antimicrobial therapy after the first symptoms, diabetes, and coexistence of an osteoarticular location. Cardiovascular Campylobacter spp. infections are associated with a high mortality rate. Systematically searching for those localizations in cases of C. fetus bacteremia may be warranted.

Occurrence of Campylobacter in Faeces, Livers and Carcasses of Wild Boars Hunted in Tuscany (Italy) and Evaluation of MALDI-TOF MS for the Identification of Campylobacter Species

A total of 193 wild boars hunted in Tuscany, an Italian region with a high presence of wild ungulates, were examined to assess the occurrence of Campylobacter species in faeces, bile, liver and carcasses, with the aim of clarifying their contribution to human infection through the food chain. Campylobacter spp. were found in 44.56% of the animals, 42.62% of the faecal samples, 18.18% of the carcass samples, 4.81% of the liver tissues and 1.97% of the bile samples. The Campylobacter species genotypically identified were C. coli, C. lanienae, C. jejuni and C. hyointestinalis. The prevalent species transpired to be C. coli and C. lanienae, which were isolated from all the matrices; C. jejuni was present in faeces and liver, while C. hyointestinalis only in faeces. Identification was carried out by matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS) on 66 out of 100 isolates identified genotypically, and the technique yielded unsatisfactory results in the case of C. lanienae, which is responsible for sporadic human disease cases. The level of Campylobacter spp. contamination of meat and liver underlines the need to provide appropriate food safety information to hunters and consumers.

Proteotyping of Campylobacter jejuni by MALDI-TOF MS and Strain Solution Version 2 Software

Identification of microorganisms by MALDI-TOF MS has become a popular method in the past 20 years. Strain Solution ver. 2 software appended with MALDI-TOF MS enables accurate discrimination of serotypes and strains beyond the genus and species level by creating a theoretical mass-based database. In this study, we constructed a theoretical mass database with the validated biomarkers to proteotype Campylobacter jejuni. Using 10 strains belonging to Campylobacter spp. available from culture collections and 41 Campylobacter jejuni strains isolated from humans and foods, the ribosomal protein subunits L36, L32, S14, L24, L23, L7/L12, and S11 could be selected as the effective biomarkers for the proteotyping of C. jejuni at MALDI-TOF MS. An accurate database of their theoretical mass-based values was constructed by matching these gene DNA sequences and the observed mass peaks. We attempted to automatically classify 41 strains isolated from nature using this database and Strain Solution ver. 2 software, and 38 strains (93%) were correctly classified into the intended group based on the theoretical mass-based values. Thus, the seven biomarkers found in this study and Strain Solution ver. 2 are promising for the proteotyping of C. jejuni by MALDI-TOF MS.

Metagenomic Strain-Typing Combined with Isolate Sequencing Provides Increased Resolution of the Genetic Diversity of Campylobacter jejuni Carriage in Wild Birds

As the world's leading cause of human gastro-enteritis, the food- and waterborne pathogen Campylobacter needs to be intensively monitored through a One Health approach. Particularly, wild birds have been hypothesized to contribute to the spread of human clinical recurring C. jejuni genotypes across several countries. A major concern in studying epidemiological dynamics is resolving the large genomic diversity of strains circulating in the environment and various reservoirs, challenging to achieve with isolation techniques. Here, we applied a passive-filtration method to obtain isolates and in parallel recovered genotypes from metagenomic sequencing data from associated filter sweeps. For genotyping mixed strains, a reference-based computational workflow to predict allelic profiles of nine extended-MLST loci was utilized. We validated the pipeline by sequencing artificial mixtures of C. jejuni strains and observed the highest prediction accuracy when including obtained isolates as references. By analyzing metagenomic samples, we were able to detect over 20% additional genetic diversity and observed an over 50% increase in the potential to connect genotypes across wild-bird samples. With an optimized filtration method and a computational approach for genotyping strain mixtures, we provide the foundation for future studies assessing C. jejuni diversity in environmental and clinical settings at improved throughput and resolution.

Genomic Diversity of Campylobacter lari Group Isolates from Europe and Australia in a One Health Context

Members of the Campylobacter lari group are causative agents of human gastroenteritis and are frequently found in shellfish, marine waters, shorebirds, and marine mammals. Within a One Health context, we used comparative genomics to characterize isolates from a diverse range of sources and geographical locations within Europe and Australia and assess possible transmission of food, animal, and environmental isolates to the human host. A total of 158 C. lari isolates from Australia, Denmark, France, and Germany, which included 82 isolates from human stool and blood, 12 from food, 14 from domestic animal, 19 from waterbirds, and 31 from the environment were analyzed. Genome-wide analysis of the genetic diversity, virulence, and antimicrobial resistance (AMR) traits was carried-out. Most of the isolates belonged to C. lari subsp. lari (Cll; 98, 62.0%), while C. lari subsp. concheus and C. lari urease-positive thermotolerant Campylobacter (UPTC) were represented by 12 (7.6%) and 15 (9.5%) isolates, respectively. Furthermore, 33 (20.9%) isolates were not assigned a subspecies and were thus attributed to distant Campylobacter spp. clades. Whole-genome sequence-derived multilocus sequence typing (MLST) and core-genome MLST (cgMLST) analyses revealed a high genetic diversity with 97 sequence types (STs), including 60 novel STs and 14 cgMLST clusters (≤10 allele differences), respectively. The most prevalent STs were ST-21, ST-70, ST-24, and ST-58 (accounting for 13.3%, 4.4%, 3.8%, and 3.2% of isolates, respectively). A high prevalence of the 125 examined virulence-related loci (from 76.8 to 98.4% per isolate) was observed, especially in Cll isolates, suggesting a probable human pathogenicity of these strains. IMPORTANCE Currently, relatedness between bacterial isolates impacting human health is easily monitored by molecular typing methods. These approaches rely on discrete loci or whole-genome sequence (WGS) analyses. Campylobacter lari is an emergent human pathogen isolated from diverse ecological niches, including fecal material from humans and animals, aquatic environments, and seafood. The presence of C. lari in such diverse sources underlines the importance of adopting an integrated One Health approach in studying C. lari population structure for conducting epidemiological risk assessment. This retrospective study presents a comparative genomics analysis of C. lari isolates retrieved from two different continents (Europe and Australia) and from different sources (human, domestic animals, waterbirds, food, and environment). It was designed to improve knowledge regarding C. lari ecology and pathogenicity, important for developing effective surveillance and disease prevention strategies.

Transmission pathways of campylobacter spp. at broiler farms and their environment in Brandenburg, Germany

Broiler meat is widely known as an important source of foodborne Campylobacter jejuni and Campylobacter coli infections in humans. In this study, we thoroughly investigated transmission pathways that may contribute to possible Campylobacter contamination inside and outside broiler houses. For this purpose we carried out a comprehensive longitudinal sampling approach, using a semi-quantitative cultivation method to identify and quantify transmissions and reservoirs of Campylobacter spp.. Three german broiler farms in Brandenburg and their surrounding areas were intensively sampled, from April 2018 until September 2020. Consecutive fattening cycles and intervening downtimes after cleaning and disinfection were systematically sampled in summer and winter. To display the potential phylogeny of barn and environmental isolates, whole genome sequencing (WGS) and bioinformatic analyses were performed. Results obtained in this study showed very high Campylobacter prevalence in 51/76 pooled feces (67.1%) and 49/76 boot swabs (64.5%). Average counts between 6.4 to 8.36 log10MPN/g were detected in pooled feces. In addition, levels of 4.7 and 4.1 log10MPN/g were detected in boot swabs and litter, respectively. Samples from the barn interior showed mean Campyloacter values in swabs from drinkers 2.6 log10MPN/g, walls 2.0 log10MPN/g, troughs 1.7 log10MPN/g, boards 1.6 log10MPN/g, ventilations 0.9 log10MPN/g and 0.7 log10MPN/g for air samples. However, Campylobacter was detected only in 7/456 (1.5%) of the environmental samples (water bodies, puddles or water-filled wheel tracks; average of 0.6 log10MPN/g). Furthermore, WGS showed recurring Campylobacter genotypes over several consecutive fattening periods, indicating that Campylobacter genotypes persist in the environment during downtime periods. However, after cleaning and disinfection of the barns, we were unable to identify potential sources in the broiler houses. Interestingly, alternating Campylobacter genotypes were observed after each fattening period, also indicating sources of contamination from the wider environment outside the farm. Therefore, the results of this study suggest that a potential risk of Campylobacter transmission may originate from present environmental sources (litter and water reservoirs). However, the sources of Campylobacter transmission may vary depending on the operation and farm environmental conditions.

Campylobacter in Wild Birds: Is It an Animal and Public Health Concern?

Campylobacteriosis continues to be one of the leading causes of foodborne bacterial zoonotic infections worldwide. Despite its public health importance, the status of this disease in wild birds and the possibility of transmission from wild birds to domestic animals and humans have not been clearly elucidated yet. This article reviews the available literature with the aim of making a comprehensive manuscript on this disease status in wild birds and the possibility of interspecies transmission. Campylobacter has been isolated from various species of wild birds worldwide, with C. jejuni being the most commonly isolated species. The prevalence of Campylobacter in wild birds may vary depending on several factors like geographical location, season, the bird’s health status, bird species, sample type, the method used, and ecological factors. Molecular studies over the past two to three decades have characterized Campylobacter strains isolated from wild birds and have come up with results that fall into two categories. The first are those that report overlapping strains among human, domestic animal, and wild bird isolates. The results of the studies under this category emphasize that wild birds carry strains of Campylobacter, which are indistinguishable from domestic animals and humans and are therefore an important public and animal health concern. In contrast, the studies under the second category highlight significant differences in Campylobacter population structure among these hosts. Despite the controversiality and the inadequacy of current research to draw a full conclusion, the role of wild birds in the epidemiology of Campylobacter should not be undermined as drug-resistant strains, especially resistance to tetracycline and fluoroquinolones, are increasingly documented. In addition, source attribution studies have linked human cases of Campylobacter infections to wild birds. Therefore, the role of wild birds in the epidemiology of Campylobacter infection should not be neglected. However, in order to determine disease status in wild birds and the precise role of wild birds in domestic animals and human health, detail-oriented epidemiological investigations characterizing the genetic relatedness of isolates from the respective species and environment through one health approach are warranted.

Retrospective multicentric study on Campylobacter spp. bacteremia in France: the Campylobacteremia study

BACKGROUND

Campylobacter spp. bacteremia is a severe infection. A nationwide 5-year retrospective study was conducted to characterize its clinical features and prognostic factors.

METHODS

Patients diagnosed with Campylobacter spp. bacteremia in 37 French hospitals participating in the surveillance network of the National Reference Center for Campylobacter and Helicobacter were included from January 1, 2015, to December 31, 2019. The goal was to analyze the effects of a delay of appropriate antibiotic therapy and other risk factors on 30-day mortality, antibiotic resistance, patient characteristics and prognosis according to the Campylobacter species.

FINDINGS

Among the 592 patients, Campylobacter jejuni and Campylobacter fetus were the most commonly identified species (42.9 and 42.6%, respectively). The patients were elderly (median age 68 years), and most had underlying conditions, mainly immunodepression (43.4%), hematologic malignancies (25.9%), solid neoplasms (23%) and diabetes (22.3%). C. jejuni and Campylobacter coli were associated with gastrointestinal signs, and C. fetus was associated with secondary localizations. Among the 80 patients (13.5%) with secondary localizations, 12 had endocarditis, 38 vascular, 24 osteo-articular and 9 ascitic fluid infections. The thirty-day mortality rate was 11.7%, and an appropriate antibiotic treatment was independently associated with 30-day survival (odds ratio [OR]=0.47, 95% CI [0.24-0.93], p=0.03). The median efficient therapy initiation delay was quite short (2 days, IQR [0-4]) but it had no significant impact on 30-day mortality (p=0.78).

INTERPRETATION

Campylobacter spp. bacteremia mainly occurred in elderly immunocompromised individuals with variable clinical presentations according to the species involved. Appropriate antimicrobial therapy was associated with improved 30-day survival.

Demographic, Husbandry, and Biosecurity Factors Associated with the Presence of Campylobacter spp. in Small Poultry Flocks in Ontario, Canada

This study is part of a 2 year disease surveillance project conducted to establish the prevalence of poultry and zoonotic pathogens, including Campylobacter spp., among small poultry flocks in Ontario, Canada. For each post-mortem submission to the Animal Health Laboratory, a pooled sample of cecal tissue was cultured for Campylobacter spp., and a husbandry and biosecurity questionnaire was completed by the flock owner (n = 153). Using both laboratory and questionnaire data, our objective was to investigate demographic, husbandry, and biosecurity factors associated with the presence of Campylobacter spp. in small flocks. Two multivariable logistic regression models were built. In the farm model, the odds of Campylobacter spp. were higher in turkeys, and when birds were housed in a mixed group with different species and/or types of birds. The odds were lower when antibiotics were used within the last 12 months, and when birds had at least some free-range access. The effect of pest control depended on the number of birds at risk. In the coop model, the odds of Campylobacter spp. were lower when owners wore dedicated clothing when entering the coop. These results can be used to limit the transmission of Campylobacter spp. from small poultry flocks to humans.

Campylobacter anatolicus sp. nov., a novel member of the genus Campylobacter isolated from feces of Anatolian Ground Squirrel (Spermophilus xanthoprymnus) in Turkey

Seventy-four Gram-negative, motile, slightly curved rod-shaped, microaerophilic, oxidase-positive and catalase-negative isolates, recovered from fecal samples of the Anatolian ground squirrel (Spermophilus xanthoprymnus) in Kayseri, Turkey, were subjected to a polyphasic taxonomic study. Results of a genus-specific PCR indicated that all isolates belonged to the genus Campylobacter. 16S rRNA gene sequence analyses revealed the closest match as Campylobacter curvus DSM 6644^T with identity levels of 96.41-96.70%. Based on the 16S rRNA gene phylogeny of the 74 isolates, six isolates (faydin-G24, faydin-G52, faydin-G105, faydin-G114, faydin-G129 and faydin-G140^T) were chosen as representatives for further characterization. The overall genome relatedness indices for the strain faydin-G140^T, compared to the most closely related type strain C. curvus ATCC 35224^T, were calculated as 15.2%, 72.5%, and 83.7% for digital DNA-DNA hybridization (dDDH), and average nucleotide identity (ANIb and ANIm), respectively. The G+C content and genome size of the strains ranged between 35.2-35.4 mol% and 1.7-1.8 Mb, respectively. Based on data obtained from the polyphasic taxonomy approach, including phenotypic characterization as well as genomic and chemotaxonomic analyses, these strains are concluded to represent a novel species, for which the name Campylobacter anatolicus sp. nov. is proposed with faydin-G140^T as the type strain (=DSM 112311^T = LMG 32238^T).

Current Scenario and Challenges in the Direct Identification of Microorganisms Using MALDI TOF MS

MALDI TOF MS-based microbial identification significantly lowers the operational costs because of minimal requirements of substrates and reagents for extraction. Therefore, it has been widely used in varied applications such as clinical, food, military, and ecological research. However, the MALDI TOF MS method is laced with many challenges including its limitation of the reference spectrum. This review briefly introduces the background of MALDI TOF MS technology, including sample preparation and workflow. We have primarily discussed the application of MALDI TOF MS in the identification of microorganisms. Furthermore, we have discussed the current trends for bioaerosol detection using MALDI TOF MS and the limitations and challenges involved, and finally the approaches to overcome these challenges.

Campylobacter fetus Meningitis: A diagnosis to suggest in immunocompromised patients

Campylobacter fetus causes in humans mostly gastroenteritis. Systemic infection occurs almost exclusively in immunocompromised patients with chronic debilitating diseases. We report the case of a Campylobacter fetus meningitis in a woman aged 48 years with a history of systemic lupus erythematosus treated with corticosteroids and immunosuppressive drugs. Cerebrospinal fluid culture was positive for Campylobacter fetus. The evolution was favorable using imipenem and ciprofloxacin.

MALDI-TOF Mass Spectrometry and 16S rRNA Gene Sequence Analysis for the Identification of Foodborne Clostridium Spp

BACKGROUND

Clostridium is a genus of Gram-positive, spore-forming, anaerobic bacteria comprising approximately 100 species. Some Clostridium spp. (C. botulinum, C. perfringens, C. tetani and C. difficile) were recognized to cause acute food poisoning, botulism, tetanus, and diarrheal illness in humans. Thus, rapid identification of Clostridium spp. is critical for source tracking of contaminated food and to understand the transmission dynamics of these foodborne pathogens.

OBJECTIVE

This study was carried out to rapidly identify Clostridium-like isolates by MALDI-TOF MS and rRNA sequencing methods.

METHODS

Thirty-three Clostridium-like isolates were recovered from various baby food and surveillance samples. Species identification of these isolates was accomplished using VITEK MS system. Sequence characterization of the 16S rRNA region was done on an ABI 3500XL Genetic Analyzer.

RESULTS

The VITEK MS system identified 28 of the 33 Clostridium-like isolates with a high confidence value (99.9%); no ID was observed for the rest of the five isolates. Nucleotide sequencing of 16S rRNA region identified all 33 Clostridium-like isolates. Furthermore, while characterizing the 16S rRNA gene, eleven distinct Clostridium spp. (Clostridium aciditolerans, Clostridium aerotolerans, Clostridium argentinense, Clostridium beijerinckii, Clostridium bifermentans, Clostridium butyricum, Clostridium cochlearium, Clostridium difficile, Clostridium perfringens, Clostridium sporogenes, and Clostridium subterminale) were recognized among the 33 Clostridium-like isolates. One of the Clostridium-like isolate was identified as the Citrobacter amalonaticus by both diagnostic methods. The generated 16S rRNA sequences matched completely (100%) with sequences available in GenBank for Clostridium and Citrobacter species. Species identification attained by the VITEK MS for the Clostridium-like isolates was comparable to the 16S rRNA sequencing based data.

HIGHLIGHTS

MALDI-TOF mass spectrometry and 16S rRNA sequencing can be used in the species identification of Clostridium species.

Evaluation of CAMPYLOBACTER QUIK CHEK™ rapid membrane enzyme immunoassay to detect Campylobacter spp. antigen in stool samples

Campylobacter spp. enteritis is the most frequent bacterial enteritis in both adults and children and is sometimes a source of severe complications. Its diagnosis by culture suffers from a lack of sensitivity and delays the result, preventing an early initiation of optimal antibiotic therapy in some cases. Our aim was to test a new rapid immuno-enzymatic method for Campylobacter spp. diagnosis in comparison to a composite reference standard (CRS). Stool samples from the French National Reference Center for Campylobacter and Helicobacter were tested with the CAMPYLOBACTER QUIK CHEK™ (Abbott). The CRS used to consider a case positive for Campylobacter spp. was a positive culture and, in case of a negative culture, a positive result obtained with both an ELISA and a molecular test. One hundred and eight stools were included: 53 were positive according to the CRS. If performed alone, culture would have missed 5 cases which the CAMPYLOBACTER QUIK CHEK™ detected. Finally, the CAMPYLOBACTER QUIK CHEK™ showed a sensitivity of 96.2% and a specificity of 94.5% and is relevant for clinical practice. Given the characteristics of the new method, it can be used as a screening method for Campylobacter spp. detection.

Occurrence and Antibiotic Resistance of Arcobacter Species Isolates from Poultry in Tunisia

ABSTRACT

Arcobacter is considered an emergent foodborne enteropathogen. Despite the high prevalence of this genus in poultry, the occurrence of Arcobacter spp. contamination in Tunisia remains unclear. The objectives of this study were (i) to isolate Arcobacter species (A. butzleri and A. cryaerophilus) by the culture method from different species of raw poultry meat, (ii) to verify the isolates by multiplex PCR (m-PCR) assay and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and (iii) to determine the antibiotic resistance profiles of the isolates. A total of 250 poultry product samples (149 chicken and 101 turkey) were collected from various supermarkets in Sfax. The samples consisted of breasts, wings, legs, and neck skins. The overall isolation frequency of Arcobacter spp. was 10.4%. Arcobacter spp. were found in 13.42% of the chicken samples and in 5.49% of the turkey samples. All the acquired isolates were subject to detailed confirmation with subsequent species classification using m-PCR and MALDI-TOF MS. A. butzleri was found in 22 samples (84.61%) and A. cryaerophilus in 4 samples (15.38%). Thus, m-PCR and MALDI-TOF MS were able to detect A. butzleri significantly better than the conventional method (χ2 = 49.1 and P < 0.001). Arcobacter was isolated from poultry in every season, at contamination levels of 30.76, 23.07, 19.23, and 26.92% in summer, spring, autumn, and winter, respectively. The disk diffusion method was used to determine the susceptibility of Arcobacter isolates to six antimicrobial drugs. All A. butzleri isolates (n = 24) were significantly resistant to erythromycin (P = 0.0015), ampicillin (P = 0.001), and ciprofloxacin (P = 0.05). All tested A. cryaerophilus strains (n = 4) were susceptible to ampicillin, gentamicin, and amoxicillin-clavulanic acid. Multidrug resistance was observed in 83% of the Arcobacter spp. isolates. Our study detected Arcobacter spp. in Tunisian poultry; because of their multidrug resistance, these species may constitute a public health problem.

HIGHLIGHTS

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

Campylobacter is the major bacterial agent of human gastroenteritis worldwide and represents a crucial global public health burden. Species differentiation of C. jejuni and C. coli and phylogenetic analysis is challenged by inter-species horizontal gene transfer. Routine real-time PCR on more than 4000 C. jejuni and C. coli field strains identified isolates with ambiguous PCR results for species differentiation, in particular, from the isolation source eggs. K-mer analysis of whole genome sequencing data indicated the presence of C. coli hybrid strains with huge amounts of C. jejuni introgression. Recombination events were distributed over the whole chromosome. MLST typing was impaired, since C. jejuni sequences were also found in six of the seven housekeeping genes. cgMLST suggested that the strains were phylogenetically unrelated. Intriguingly, the strains shared a stress response set of C. jejuni variant genes, with proposed roles in oxidative, osmotic and general stress defence, chromosome maintenance and repair, membrane transport, cell wall and capsular biosynthesis and chemotaxis. The results have practical impact on routine typing and on the understanding of the functional adaption to harsh environments, enabling successful spreading and persistence of Campylobacter.

Campylobacter armoricus sp. nov., a novel member of the Campylobacter lari group isolated from surface water and stools from humans with enteric infection

During a study on the prevalence and diversity of members of the genus Campylobacter in a shellfish-harvesting area and its catchment in Brittany, France, six urease-positive isolates of members of the genus Campylobacter were recovered from surface water samples, as well as three isolates from stools of humans displaying enteric infection in the same period. These strains were initially identified as members of the Campylobacter lari group by MALDI-TOF mass spectrometry and placed into a distinct group in the genus Campylobacter, following atpA gene sequence analysis based on whole-genome sequencing data. This taxonomic position was confirmed by phylogenetic analysis of the 16S rRNA, rpoB and hsp60 (groEL) loci, and an analysis of the core genome that provided an improved phylogenetic resolution. The average nucleotide identity between the representative strain CA656^T (CCUG 73571^T=CIP 111675^T) and the type strain of the most closely related species Campylobacter ornithocola WBE38^T was 88.5 %. The strains were found to be microaerobic and anaerobic, motile, non-spore-forming, Gram-stain-negative, spiral-shaped bacteria that exhibit catalase, oxidase and urease activities but not nitrate reduction. This study demonstrates clearly that the nine isolates represent a novel species within the C. lari group, for which the name Campylobacter armoricus is proposed. Here, we present phenotypic and morphological features of the nine strains and the description of their genome sequences. The proposed type strain CA656^T has a 1.589 Mbp chromosome with a DNA G+C content of 28.5 mol% and encodes 1588 predicted coding sequences, 38 tRNAs, and 3 rRNA operons.

Campylobacter spp. and bacteriophages from broiler chickens: Characterization of antibiotic susceptibility profiles and lytic bacteriophages

Bacteria of the genus Campylobacter are the most common pathogens causing zoonotic diseases in humans. Therefore, the aim of the study was to isolate Campylobacter bacteria from broiler chickens and evaluate their susceptibility to selected antibiotics by determining minimum inhibitory concentrations (MIC), followed by isolation and characterization of bacteriophages specific for Campylobacter spp. The material for the study consisted of field isolates of Campylobacter spp. obtained from the gut (cecum) of broiler chickens directly after slaughter in slaughterhouses, and bacteriophages specific for these strains. We isolated 48 strains from poultry (140 broiler chickens): 31 strains of Campylobacter jejuni and 17 of Campylobacter coli. Identification of the strains was confirmed by multiplex PCR and MALDI-TOF mass spectrometry. Over 83% of Campylobacter strains were resistant to ciprofloxacin, and over half the isolates were resistant to erythromycin, gentamicin, and tetracycline. Resistance to three or more antibiotics was observed in 91.6% of all strains. Four bacteriophages were obtained, and on the basis of their morphological structure, they were assigned to two families of the order Caudovirales: Myoviridae and Siphoviridae. A high percentage of the Campylobacter strains were resistant to at least three of the antibiotic groups tested. All of the phages exhibited lytic activity against the Campylobacter spp. isolates, but the antibacterial effect of the phages was not observed for all strains.

Clinical impact of the type VI secretion system on virulence of Campylobacter species during infection

BACKGROUND

The clinical course of Campylobacter infection varies in symptoms and severity depending on host factors, virulence of the pathogen and initiated therapy. The type VI secretion system (T6SS) has been identified as a novel virulence factor, which mediates contact-dependent injection of enzymes and toxins into competing bacteria or host cells and facilitates the colonisation of a host organism. We aimed to compare the clinical course of Campylobacter infection caused by strains with and without the T6SS and identify possible associations between this putative virulence factor and the clinical manifestations of disease.

METHODS

From April 2015 to January 2017, patients with detection of Campylobacter spp. were identified at the University Hospital of Basel and the University Children's Hospital of Basel and included in this case-control study. Presence of the T6SS gene cluster was assayed by PCR targeting the hcp gene, confirmed with whole genome sequencing. Pertinent clinical data was collected by medical record review. Differences in disease- and host-characteristics between T6SS-positive (case) and -negative (control) were compared in a uni- and multi-variable analysis. Hospital admission, antibiotic therapy, admission to intensive care unit, development of bacteraemia and in-hospital mortality were considered as clinical endpoints.

RESULTS

We identified 138 cases of Campylobacter jejuni infections and 18 cases of Campylobacter coli infections from a paediatric and adult population. Analyses were focused on adult patients with C. jejuni (n = 119) of which 16.8% were T6SS-positive. Comparisons between T6SS-positive and -negative C. jejuni isolates did not reveal significant differences regarding clinical manifestations or course of disease. All clinical endpoints showed a similar distribution in both groups. A higher score in the Charlson Comorbidity Index was associated with T6SS-positive C. jejuni isolates (p < 0.001) and patients were more likely to have a solid organ transplant and to be under immunosuppressive therapy.

CONCLUSIONS

Our study does not provide evidence that T6SS is associated with a more severe clinical course. Interestingly, T6SS-positive isolates are more commonly found in immunocompromised patients: an observation which merits further investigation.

Campylobacter fetus spondylodiscitis: A case report and review of the literature

Campylobacter are common zoonotic food borne pathogens but infrequent causes of disseminated human infection. Campylobacter fetus is an unusual cause of human infection and spondylodiscitis. We describe a case of C. fetus infection in a 72-year-old woman who presented with indolent onset lumbar spondylodiscitis. The literature is reviewed and the presentation of spondylodiscitis is contrasted with the usual aggressive nature of bacteremia with this pathogen.

Filling the gaps in clinical proteomics: a do-it-yourself guide for the identification of the emerging pathogen Arcobacter by matrix-assisted laser desorption ionization-time of flight mass spectrometry

Arcobacters are considered emerging gastrointestinal pathogens. Rapid, reliable and species-specific identification of these bacteria is important. Biochemical tests commonly yield negative or variable results. Molecular methods prove more reliable but are time consuming and lack specificity. Matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is a fast, cheap and robust technique that has revolutionized genus and species identification in clinical microbiology. The performance of an in vitro diagnostic (RUO) spectral database of MALDI-TOF MS for the identification of human clinically relevant Arcobacter isolates was validated and compared to an in house created Reference Spectral database (RS) containing a representative set of deposited Arcobacter strains of zoonotic interest. A challenge panel of clinical, human and veterinary, unique Campylobacteraceae strains was used to test accuracy. Using direct colony transfer, sensitivity with RS was significantly better than with RUO for A. butzleri and A. cryaerophilus identification (100% and 92% versus 74% and 16%). For A. skirrowii, sensitivity remained low (21% versus 0%). Reanalysis using formic acid overlay (on-target extraction) augmented sensitivity for the latter species to 64%. Specificity of RS database remained excellent without any misidentifications of human clinical strains including Campylobacter fetus and C. jejuni/coli. The use of an enriched database for MALDI-TOF MS identification of Arcobacter spp. of human interest produced high-confidence identifications to species level resulting in a significantly improved sensitivity with conservation of excellent specificity. Misidentifications, which can have therapeutic and public health consequences, were not encountered.

Development of a Custom MALDI-TOF MS Database for Species-Level Identification of Bacterial Isolates Collected From Spacecraft and Associated Surfaces

Since the 1970s, the Planetary Protection Group at the Jet Propulsion Laboratory (JPL) has maintained an archive of spacecraft-associated bacterial isolates. Identification of these isolates was routinely performed by sequencing the 16S rRNA gene. Although this technique is an industry standard, it is time consuming and has poor resolving power for some closely related taxa. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry is widely used in clinical diagnostics and is a promising method to substitute standard 16S rRNA sequencing. However, manufacturer-provided databases lack the bacterial diversity found in spacecraft-assembly cleanrooms. This study reports the development of the first custom database of MALDI-TOF MS profiles of bacterial isolates obtained from spacecraft and associated cleanroom environments. With the use of this in-house database, 454 bacterial isolates were successfully identified in concurrence with their 16S rRNA sequence-based classifications. Additionally, MALDI-TOF MS resolved strain-level variations, identified potential novel species and distinguished between members of taxonomic groups, which is not possible using conventional 16S rRNA sequencing. MALDI-TOF MS has proved to be an accurate, high-throughput approach for real-time identification of bacterial isolates during the spacecraft assembly process.

Epidemiologic cutoff values to separate wild-type from non-wild-type Campylobacter fetus to ciprofloxacin

The aim of the present study was to propose epidemiologic cutoffs that could be used in routine practice to separate wild-type from non-wild-type Campylobacter fetus to ciprofloxacin. A total of 123 C. fetus isolates obtained from human samples were used for this purpose. Based on the determination of inhibition zone diameter, minimum inhibitory concentration, and sequencing of the quinolone resistance determining region in the gyraseA gene, for all tested isolates, the following cutoffs were proposed: ciprofloxacin-wild type if the inhibition zone diameter was ≥22 mm or the minimum inhibitory concentration was ≤0.5 mg/L.

Comparative analysis of Campylobacter isolates from wild birds and chickens using MALDI-TOF MS, biochemical testing, and DNA sequencing

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was compared to conventional biochemical testing methods and nucleic acid analyses (16S rDNA sequencing, hippurate hydrolysis gene testing, whole genome sequencing [WGS]) for species identification of Campylobacter isolates obtained from chickens ( Gallus gallus domesticus, n = 8), American crows ( Corvus brachyrhynchos, n = 17), a mallard duck ( Anas platyrhynchos, n = 1), and a western scrub-jay ( Aphelocoma californica, n = 1). The test results for all 27 isolates were in 100% agreement between MALDI-TOF MS, the combined results of 16S rDNA sequencing, and the hippurate hydrolysis gene PCR ( p = 0.0027, kappa = 1). Likewise, the identifications derived from WGS from a subset of 14 isolates were in 100% agreement with the MALDI-TOF MS identification. In contrast, biochemical testing misclassified 5 isolates of C. jejuni as C. coli, and 16S rDNA sequencing alone was not able to differentiate between C. coli and C. jejuni for 11 sequences ( p = 0.1573, kappa = 0.0857) when compared to MALDI-TOF MS and WGS. No agreement was observed between MALDI-TOF MS dendrograms and the phylogenetic relationships revealed by rDNA sequencing or WGS. Our results confirm that MALDI-TOF MS is a fast and reliable method for identifying Campylobacter isolates to the species level from wild birds and chickens, but not for elucidating phylogenetic relationships among Campylobacter isolates.

High Prevalence of Resistance to Fluoroquinolones and Tetracycline Campylobacter Spp. Isolated from Poultry in Poland

Campylobacter spp. is a major cause of foodborne diseases in humans, particularly when transmitted by the handling or consumption of undercooked poultry meat. Most Campylobacter infections are self-limiting, but antimicrobial treatment (e.g., fluoroquinolones and macrolides) is necessary in severe or prolonged cases. The indiscriminate use of these drugs, both in clinical medicine and animal production, has a major impact on public health. The aim of the present study was to identify Campylobacter strains, isolated from turkey and broilers, using both PCR and the matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) methods to reveal the accuracy of identification, as well to evaluate the antimicrobial and genetic resistance of the investigated strains. MALDI-TOF and PCR methods were used to show differences, if any, in the specificity of that test. In this study, MALDI-TOF mass spectrometry gave the same results as multiplex PCR, in all cases. The highest rate of resistance (i.e., 100% of turkey and broiler strains) was detected against ciprofloxacin, whereas 58.1% of turkey and 78.6% of broiler strains were resistant to tetracycline. Multidrug-resistant isolates were not found in the study. All ciprofloxacin-resistant strains had a mutation in the gyrA gene, at the Thr-86 position. The presence of the tetO gene was found in 71% of turkey and in 100% of broiler strains. All resistant to tetracycline strains included tetO gene. Additionally, in five turkey and three broiler strains, susceptible to tetracycline, tetO gene was present. These results indicate the high prevalence of Campylobacter strains, which are phenotypically and genetically resistant to fluoroquinolones and tetracycline.

Evaluation of the Diagnostic Accuracy of Two Immunochromatographic Tests Detecting Campylobacter in Stools and Their Role in Campylobacter Infection Diagnosis

The detection of campylobacters in stools is performed essentially by culture, but this technique has a low sensitivity. New detection methods are now available. Among them, immunochromatography tests (ICTs) are very attractive in that they offer a result within 15 min. However, previous studies suggest that these tests have a relatively low specificity. The objective of this study was to evaluate the performance of these tests. During the study period, all patients who consulted the emergency units and had a stool culture were included. Their stool samples were tested with two ICTs, Ridaquick Campylobacter and ImmunoCard STAT! Campy. Stools were also tested by a home-made PCR and two commercially available enzyme-linked immunosorbent assays (ELISAs) when one of the ICTs was positive. The composite reference standard (CRS) was defined as positive if the culture was positive or, in case of a negative culture, if the PCR and one of the ELISAs were positive simultaneously. Three hundred and five patients were included. Among the 50 positive specimens with Ridaquick Campylobacter, 47 were considered true positives by the CRS, corresponding to a positive predictive value (PPV) of 94.0%. Among the 52 positive specimens with ImmunoCard STAT! Campy, 44 were considered true positives by the CRS, corresponding to a PPV of 84.6%. The negative predictive values were estimated at 94.9 and 92.4% for the Ridaquick Campylobacter and ImmunoCard STAT! Campy tests, respectively. ICTs appear to be very efficient and allow a very rapid detection of campylobacters, which is important for treating early campylobacter infections with an adapted antibiotherapy.

Prevalence of Thermophilic Campylobacter in Cattle Production at Slaughterhouse Level in France and Link Between C. jejuni Bovine Strains and Campylobacteriosis

Campylobacter is the leading cause of bacterial gastroenteritis in industrialized countries, with poultry reservoir as the main source of infection. Nevertheless, a recent study on source attribution showed that cattle could be a source of human contamination in France (Thépault et al., 2017). However, few data are available on thermophilic Campylobacter epidemiology in cattle in France. The aim of this study is to collect new data of thermophilic Campylobacter prevalence in these animals and to subtype C. jejuni isolates to assess the potential implication of cattle in campylobacteriosis. A 6-month survey was carried out in one of the largest European slaughterhouse of cattle. Based on a statistical representative sampling plan, 959 intestinal content samples (483 adult cattle and 476 calves) were collected. An adapted version of the ISO 10272 standard and Maldi-Tof were used for detection and speciation of thermophilic Campylobacter isolates. Within more than 2000 thermophilic Campylobacter isolates collected, a selection of 649 C. jejuni isolates was typed with Comparative Genomic Fingerprinting (CGF40) and a subset of 77 isolates was typed using Multilocus Sequence Typing (MLST). Simultaneously, clinical isolates occurred in France were genotyped. Prevalence of thermophilic Campylobacter in the global cattle population was 69.1% (CI_95% = 66.1, 72.1) at slaughterhouse level. In adult cattle, the prevalence was 39.3%, while 99.4% of calves were contaminated, and C. jejuni was the most prevalent species with prevalence of 37.3 and 98.5%, respectively and a higher genetic diversity in adult cattle. The prevalence of C. coli was lower with 3% in adult cattle and 12.5% in calves. MLST and CGF40 genotyping did not showed a high number of clusters within cattle isolates but the predominance of few clusters accounted for a large part of the population (CC-21, CC-61, CC-48, and CC-257). By comparison with clinical genotypes, genetic diversity was significantly lower in cattle. Moreover, significant overlap was observed between genotypes from both origins, with 3 of the 4 main cattle clusters present in human isolates. This study provides new insights on the epidemiology of thermophilic Campylobacter and C. jejuni in cattle production in France and their potential implication in human infection.

Wild, insectivorous bats might be carriers of Campylobacter spp

BACKGROUND

The transmission cycles of the foodborne pathogens Campylobacter and Salmonella are not fully elucidated. Knowledge of these cycles may help reduce the transmission of these pathogens to humans.

METHODOLOGY/PRINCIPAL FINDINGS

The presence of campylobacters and salmonellas was examined in 631 fresh fecal samples of wild insectivorous bats using a specially developed method for the simultaneous isolation of low numbers of these pathogens in small-sized fecal samples (≤ 0.1 g). Salmonella was not detected in the feces samples, but thermotolerant campylobacters were confirmed in 3% (n = 17) of the bats examined and these pathogens were found in six different bat species, at different sites, in different ecosystems during the whole flying season of bats. Molecular typing of the 17 isolated strains indicated C. jejuni (n = 9), C. coli (n = 7) and C. lari (n = 1), including genotypes also found in humans, wildlife, environmental samples and poultry. Six strains showed unique sequence types.

CONCLUSION/SIGNIFICANCE

This study shows that insectivorous bats are not only carriers of viral pathogens, but they can also be relevant for the transmission of bacterial pathogens. Bats should be considered as carriers and potential transmitters of Campylobacter and, where possible, contact between bats (bat feces) and food or feed should be avoided.

Minimal standards for describing new species belonging to the families Campylobacteraceae and Helicobacteraceae: Campylobacter, Arcobacter, Helicobacter and Wolinella spp

Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended.

Class 1 integrons and plasmid-mediated multiple resistance genes of the Campylobacter species from pediatric patient of a university hospital in Taiwan

Background

The Campylobacter species usually causes infection between humans and livestock interaction via livestock breeding. The studies of the Campylobacter species thus far in all clinical isolates were to show the many kinds of antibiotic phenomenon that were produced. Their integrons cause the induction of antibiotic resistance between bacterial species in the Campylobacter species.

Results

The bacterial strains from the diarrhea of pediatric patient which isolated by China Medical University Hospital storage bank. These isolates were identified by MALDI-TOF mass spectrometry. The anti-microbial susceptibility test showed that Campylobacter species resistant to cefepime, streptomycin, tobramycin and trimethoprim/sulfamethoxazole (all C. jejuni and C. coli isolates), ampicillin (89% of C. jejuni; 75% of C. coli), cefotaxime (78% of C. jejuni; 100% of C. coli), nalidixic acid (78% of C. jejuni; 100% of C. coli), tetracycline (89% of C. jejuni; 25% C. coli), ciprofloxacin (67% of C. jejuni; 50% C. coli), kanamycin (33% of C. jejuni; 75% C. coli) and the C. fetus isolate resisted to ampicillin, cefotaxime, nalidixic acid, tetracycline, ciprofloxacin, kanamycin by disc-diffusion method. The effect for ciprofloxacin and tetracycline of the Campylobacter species was tested using an E-test. The tet, erm, and integron genes were detected by PCR assay. According to the sequencing analysis (type I: dfr12-gcuF-aadA2 genes and type II: dfrA7 gene), the cassette type was identified. The most common gene cassette type (type I: 9 C. jejuni and 2 C. coli isolates; type II: 1 C. coli isolates) was found in 12 class I integrase-positive isolates.

Conclusions

Our results suggested an important information in the latency of Campylobacter species with resistance genes, and irrational antimicrobial use should be concerned.

Electronic supplementary material

The online version of this article (doi:10.1186/s13099-017-0199-4) contains supplementary material, which is available to authorized users.

MALDI-TOF MS contribution to the diagnosis of Campylobacter rectus multiple skull base and brain abscesses

Campylobacter rectus is rarely associated with invasive infection. Both the isolation and the identification requirements of C. rectus are fastidious, probably contributing to an underestimation of its burden. We report the case of a 66-year-old man who developed several skull base and intracerebral abscesses after dental intervention. Campylobacter rectus was isolated from the brain biopsy. Within 45 minutes of reading the bacterial plate, the strain was accurately identified by MALDI-TOF MS. This rapid identification avoided the extra costs and delays present with 16S rRNA gene sequencing and allowed for a rapid confirmation of the adequacy of the empirical antibiotic treatment.

Metabolomic Analysis of Campylobacter jejuni by Direct-Injection Electrospray Ionization Mass Spectrometry

Direct-injection mass spectrometry (DIMS) is a means of rapidly obtaining metabolomic phenotype data in both prokaryotes and eukaryotes. Given our generally poor understanding of Campylobacter metabolism, the high-throughput and relatively simple sample preparation of DIMS has made this an attractive technique for metabolism-related studies and hypothesis generation, especially when attempting to analyze metabolic mutants with no clear phenotype. Here we describe a metabolomic fingerprinting approach with sampling and extraction methodologies optimized for direct-injection electrospray ionization mass spectrometry (ESI-MS), which we have used as a means of comparing wild-type and isogenic mutant strains of C. jejuni with various metabolic blocks.

Contemporary approaches to the rapid molecular diagnosis of sepsis

INTRODUCTION

Although the administration of appropriate antimicrobials within the very first hour remains the mainstay of sepsis management, the correct selection of antimicrobials is hampered by the delay of conventional microbiology providing results after at least 48 hours. Methods of rapid detection of pathogens are an approach to overcome these difficulties. Areas covered: This review analyzes the advantages and the disadvantages of these approaches with major emphasis on technologies based on multiplex PCR for the rapid detection of pathogens using whole blood. The most broadly studied platform is SeptFast. Sensitivity ranges between 42% and 73% and specificity between 50% and 97%. The main disadvantages are high cost, the risk of contamination and the lack of information for the presence of resistance genes. A brief review of the use of PCR techniques for the diagnosis of endocarditis and of the recognition of the bacterial proteome for the rapid identification of grown colonies (MALDI-TOF) is also provided. Expert commentary: More randomized clinical trials are necessary to validate the use of molecular techniques for decision-making for patients' outcomes, taking into consideration the cost-benefit for the patient.

Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass-Spectrometry (MALDI-TOF MS) Based Microbial Identifications: Challenges and Scopes for Microbial Ecologists

Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) based biotyping is an emerging technique for high-throughput and rapid microbial identification. Due to its relatively higher accuracy, comprehensive database of clinically important microorganisms and low-cost compared to other microbial identification methods, MALDI-TOF MS has started replacing existing practices prevalent in clinical diagnosis. However, applicability of MALDI-TOF MS in the area of microbial ecology research is still limited mainly due to the lack of data on non-clinical microorganisms. Intense research activities on cultivation of microbial diversity by conventional as well as by innovative and high-throughput methods has substantially increased the number of microbial species known today. This important area of research is in urgent need of rapid and reliable method(s) for characterization and de-replication of microorganisms from various ecosystems. MALDI-TOF MS based characterization, in our opinion, appears to be the most suitable technique for such studies. Reliability of MALDI-TOF MS based identification method depends mainly on accuracy and width of reference databases, which need continuous expansion and improvement. In this review, we propose a common strategy to generate MALDI-TOF MS spectral database and advocated its sharing, and also discuss the role of MALDI-TOF MS based high-throughput microbial identification in microbial ecology studies.

Campylobacter

Campylobacter continues to be one of the most common bacterial causes of diarrheal illness in the United States and worldwide. Infection with Campylobacter causes a spectrum of diseases including acute enteritis, extraintestinal infections, and postinfectious complications. The most common species of Campylobacter associated with human illness is Campylobacter jejuni, but other Campylobacter species can also cause human infections. This comprehensive review includes discussion of the taxonomy, clinical manifestations of infection, epidemiology and the different methods of laboratory detection of Campylobacter.