Bacterial Gastroenteritis Research Articles

The epidemiology and impact of persistent Campylobacter infections on childhood growth among children 0–24 months of age in resource-limited settings

Campylobacter is the leading cause of bacterial gastroenteritis worldwide. It is generally associated with an acute gastrointestinal infection causing a self-limiting diarrheal episode. However, there is evidence that persistent/recurrent carriage of Campylobacter also occurs. In hyperendemic settings the epidemiology and consequences of persistent Campylobacter enteric infections is poorly studied. Risk factors for and growth consequences of persistent Campylobacter infections detected by polymerase chain reaction (qPCR) were evaluated with data from the MAL-ED birth cohort study in children 0-24 months of age between November 2009 and February 2012. A persistent Campylobacter infection was defined as three or more consecutive Campylobacter positive monthly stools. Across all study sites, 45.5% (781/1715) of children experienced at least one persistent Campylobacter episode. The average cumulative duration of days in which children with persistent Campylobacter were positive for Campylobacter spp. was 150 days (inter-quartile range: 28-236 days). Children who experienced a persistent Campylobacter episode had an attained 24-month length-for-age (LAZ) score that was 0.23 (95% (CI):-0.31,-0.15) less than children without a persistent Campylobacter episode. Among children who had at least one episode of Campylobacter over a 3-month or 9-month window, persistent episodes were not significantly associated with poorer 3-month weight gain (-28.7g, 95% CI:-63.4g, 6.0g) but were associated with poorer 9-month linear growth (-0.134cm 95% CI:-0.246,-0.022) compared to children with an episode that resolved within 31 days. Persistent/recurrent Campylobacter infection is common among children and has a measurable negative impact on linear growth in early childhood. Funding for this study was provided by the Bill and Melinda Gates Foundation (OPP1066146 and OPP1152146), the National Institutes of Health United States (R01AI158576 and R21AI163801 to MNK and CTP; K43TW012298 to FS; K01AI168493 to JMC; GOL was supported by K01AI145080. This research was also supported in part by USDA-ARS CRIS project 2030-42000-055-00D. The funders had no role in study design, study implementation, data analysis, or interpretation of the results.

A Decade of Antimicrobial Resistance in Human and Animal Campylobacter spp. Isolates.

Objectives: Campylobacter spp. remain a leading cause of bacterial gastroenteritis worldwide, with resistance to antibiotics posing significant challenges to treatment and public health. This study examines profiles in antimicrobial resistance (AMR) for Campylobacter isolates from human and animal sources over the past decade. Methods: We conducted a comprehensive review of resistance data from studies spanning ten years, analyzing profiles in resistance to key antibiotics, ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), chloramphenicol (CHL), and gentamicin (GEN). Data were collated from various regions to assess global and regional patterns of resistance. Results: The analysis reveals a concerning trend of increasing resistance patterns, particularly to CIP and TET, across multiple regions. While resistance to CHL and GEN remains relatively low, the high prevalence of CIP resistance has significantly compromised treatment options for campylobacteriosis. Discrepancies in resistance patterns were observed between human and animal isolates, with variations across different continents and countries. Notably, resistance to ERY and CHL showed regional variability, reflecting potential differences in antimicrobial usage and management practices. Conclusions: The findings underscore the ongoing challenge of AMR in Campylobacter, highlighting the need for continued surveillance and research. The rising resistance prevalence, coupled with discrepancies in resistance patterns between human and animal isolates, emphasize the importance of a One Health approach to address AMR. Enhanced monitoring, novel treatment strategies, and global cooperation are crucial for mitigating the impact of resistance and ensuring the effective management of Campylobacter-related infections.

High Campylobacter diversity in retail chicken: epidemiologically important strains may be missed with current sampling methods.

Campylobacter spp. are leading bacterial gastroenteritis pathogens. Infections are largely underreported, and the burden of outbreaks may be underestimated. Current strategies of testing as few as one isolate per sample can affect attribution of cases to epidemiologically important sources with high Campylobacter diversity, such as chicken meat. Multiple culture method combinations were utilized to recover and sequence Campylobacter from 45 retail chicken samples purchased across Norwich, UK, selecting up to 48 isolates per sample. Simulations based on resampling were used to assess the impact of Campylobacter sequence type (ST) diversity on outbreak detection. Campylobacter was recovered from 39 samples (87%), although only one sample was positive through all broth, temperature, and plate combinations. Three species were identified (Campylobacter jejuni, Campylobacter coli, and Campylobacter lari), and 33% of samples contained two species. Positive samples contained 1-8 STs. Simulation revealed that up to 87 isolates per sample would be required to detect 95% of the observed ST diversity, and 26 isolates would be required for the average probability of detecting a random theoretical outbreak ST to reach 95%. An optimized culture approach and selecting multiple isolates per sample are essential for more complete Campylobacter recovery to support outbreak investigation and source attribution.

Genotypic characterization and antimicrobial susceptibility of human Campylobacter jejuni isolates in Southern Spain.

Campylobacter jejuni is the main cause of bacterial gastroenteritis and a public health problem worldwide. Little information is available on the genotypic characteristics of human C. jejuni in Spain. This study is based on an analysis of the resistome, virulome, and phylogenetic relationship, antibiogram prediction, and antimicrobial susceptibility of 114 human isolates of C. jejuni from a tertiary hospital in southern Spain from October 2020 to June 2023. The isolates were sequenced using Illumina technology, and a bioinformatic analysis was subsequently performed. The susceptibility of C. jejuni isolates to ciprofloxacin, tetracycline, and erythromycin was also tested. The resistance rates for each antibiotic were 90.3% for ciprofloxacin, 66.7% for tetracycline, and 0.88% for erythromycin. The fluoroquinolone resistance rate obtained is well above the European average (69.1%). CC-21 (n = 23), ST-572 (n = 13), and ST-6532 (n = 13) were the most prevalent clonal complexes (CCs) and sequence types (STs). In the virulome, the cadF, ciaB, and cdtABC genes were detected in all the isolates. A prevalence of 20.1% was obtained for the genes wlaN and cstIII, which are related to the pathogenesis of Guillain-Barré syndrome (GBS). The prevalence of the main antimicrobial resistance markers detected were CmeABC (92.1%), RE-cmeABC (7.9%), the T86I substitution in gyrA (88.9%), blaOXA-61 (72.6%), tet(O) (65.8%), and ant (6)-Ia (17.1%). High antibiogram prediction rates (>97%) were obtained, except for in the case of the erythromycin-resistant phenotype. This study contributes significantly to the knowledge of C. jejuni genomics for the prevention, treatment, and control of infections caused by this pathogen.IMPORTANCEDespite being the pathogen with the greatest number of gastroenteritis cases worldwide, Campylobacter jejuni remains a poorly studied microorganism. A sustained increase in fluoroquinolone resistance in human isolates is a problem when treating Campylobacter infections. The development of whole genome sequencing (WGS) techniques has allowed us to better understand the genotypic characteristics of this pathogen and relate them to antibiotic resistance phenotypes. These techniques complement the data obtained from the phenotypic analysis of C. jejuni isolates. The zoonotic transmission of C. jejuni through the consumption of contaminated poultry supports approaching the study of this pathogen through "One Health" approach. In addition, due to the limited information on the genomic characteristics of C. jejuni in Spain, this study provides important data and allows us to compare the results with those obtained in other countries.

Burden and epidemiology of Campylobacter species in acute enteritis cases in Burkina Faso

BackgroundCampylobacter spp. is a significant etiological agent of bacterial gastroenteritis globally. In Burkina Faso (BFA), the actual impact of this pathogen on gastroenteritis is considerably underestimated, primarily due to inadequate surveillance systems.ObjectivesThis study aimed to investigate the proportion of Campylobacter species responsible for acute gastroenteritis among patients of all ages in urban and rural areas of BFA, using molecular biology techniques.Study design & methodsBetween 2018 and 2021, faecal specimens were obtained from 1,295 individuals presenting with acute gastroenteritis. These samples underwent screening for the Campylobacter coli/jejuni/lari complex utilizing real-time polymerase chain reaction (PCR) assays. Subsequently, positive samples were subjected to species-level differentiation through the application of species-specific primers.ResultsCampylobacter spp. was detected in 25.0% (324/1,295) of the samples analysed. The majority of positive samples (95%, 308/324) were obtained from children under 5 years of age. Species identification was performed on a subset of 114 isolates, revealing 51 Campylobacter jejuni, 10 Campylobacter coli, and 53 Campylobacter isolates that remained unspeciated.ConclusionsThis study reveals a significant prevalence of Campylobacter species among patients with acute gastroenteritis, with a particularly high incidence observed in children under 5 years of age. Based on these findings, the implementation of routine Campylobacter surveillance in public health laboratories is strongly recommended to better monitor and address this health concern.

A Probiotic Bacterium with Activity against the Most Frequent Bacteria and Viruses Causing Pediatric Diarrhea: Bifidobacterium longum subsp. infantis CECT 7210 (B. infantis IM1®).

The second leading cause of death in children under five years old is diarrheal disease. Probiotics, specifically bifidobacteria, have been associated with a reduction in the number of diarrhea episodes and their severity in babies. In this paper, we summarize the preclinical and clinical evidence of the efficacy of B. longum subsp. infantis IM1® against various gastrointestinal pathogens using in vitro models, animal models, and clinical studies carried out in our laboratory. The preclinical data demonstrate that IM1® effectively inhibits rotavirus replication (by up to 36.05%) in MA-104 and HT-29 cells and from infection (up to 48.50%) through the production of an 11-amino-acid peptide. IM1® displays the capability to displace pathogens from enterocytes, particularly Cronobacter sakazakii and Salmonella enterica, and to reduce the adhesion to the HT29 cells of C. sakazakii and Shigella sonnei. In animal models, the IM1® strain exhibits in vivo protection against rotavirus and improves the clinical symptomatology of bacterial gastroenteritis. A clinical study involving infants under 3 months of age revealed that IM1® reduced episodes of diarrhea, proving to be safe, well tolerated, and associated with a lower prevalence of constipation. B. infantis IM1® emerges as an effective probiotic, diminishing episodes of diarrhea caused by gastrointestinal pathogens.

Virulence Genes, Antimicrobial Resistance, and Genotypes of Campylobacter jejuni Isolated from Chicken Slaughterhouses in South Korea.

Campylobacter jejuni represents one of the leading causes of bacterial gastroenteritis in humans and is primarily linked to chicken meat contamination. In the present study, we analyzed the virulence and survival genes, antimicrobial resistance, and the clonal distribution of 50 C. jejuni isolates obtained from various sources in 14 chicken slaughterhouses across 8 provinces in South Korea from 2019 to 2022. Furthermore, we determined their genetic relatedness to human-derived isolates registered in PubMLST using multilocus sequence typing (MLST). All isolates harbored various virulence and survival genes (flhA, cadF, cdtA, cdtC, cmeA, and sodB) out of 17 tested genes, as confirmed via polymerase chain reaction analysis. Adherence factor gene virB11 was not detected in any isolate. All isolates harbored 12 or more virulence and survival genes. Antimicrobial susceptibility testing indicated that ciprofloxacin resistance was the most prevalent (84.0%), followed by nalidixic acid (82.0%) and tetracycline (52.0%) resistance. MLST analysis of the isolates revealed 18 sequence types (STs), including four new ones. Overlapping STs between chicken slaughterhouse and human-derived isolates included ST42, ST45, ST50, ST137, ST354, and ST464. Our study identified 11 clonal complexes (CCs), with CC-21 being the most prevalent in both human and chicken slaughterhouse-derived isolates. This study provides comprehensive insights into recent C. jejuni isolates from chicken slaughterhouses, including data on quinolone resistance and virulence factors. The MLST-based genetic relatedness between isolates from humans and chicken slaughterhouses in this study suggests the potential of C. jejuni transmission from chickens to humans through the food chain. This study suggests the need for improved management practices in chicken slaughterhouses to reduce the transmission of chicken slaughterhouse-derived C. jejuni to humans.

Effect of WQ-3334 on Campylobacter jejuni carrying a DNA gyrase with dominant amino acid substitutions conferring quinolone resistance

IntroductionCampylobacteriosis stands as one of the most frequent bacterial gastroenteritis worldwide necessitating antibiotic treatment in severe cases and the rise of quinolones-resistant Campylobacter jejuni poses a significant challenge. The predominant mechanism of quinolones-resistance in this bacterium involves point mutations in the gyrA, resulting in amino acid substitution from threonine to isoleucine at 86th position, representing more than 90% of mutant DNA gyrase, and aspartic acid to asparagine at 90th position. WQ-3334, a novel quinolone, has demonstrated strong inhibitory activity against various bacteria. This study aims to investigate the effectiveness of WQ-3334, and its analogues, WQ-4064 and WQ-4065, with a unique modification in R1 against quinolones-resistant C. jejuni. MethodsThe structure-activity relationship of the examined drugs was investigated by measuring IC50 and their antimicrobial activities were accessed by MIC against C. jejuni strains. Additionally, in silico docking simulations were carried out using the crystal structure of the Escherichia coli DNA gyrase. ResultWQ-3334 exhibited the lowest IC50 against WT (0.188 ± 0.039 mg/L), T86I (11.0 ± 0.7 mg/L) and D90 N (1.60 ± 0.28 mg/L). Notably, DNA gyrases with T86I substitutions displayed the highest IC50 values among the examined WQ compounds. Moreover, WQ-3334 demonstrated the lowest MICs against wild-type and mutant strains. The docking simulations further confirmed the interactions between WQ-3334 and DNA gyrases. ConclusionWQ-3334 with 6-amino-3,5-difluoropyridine-2-yl at R1 severed as a remarkable candidate for the treatment of foodborne diseases caused by quinolones-resistant C. jejuni as shown by the high inhibitory activity against both wild-type and the predominant quinolones-resistant strains.

Detection and Characterization of Bacterial and Viral Acute Gastroenteritis among Outpatient Children under 5 Years Old in Guangzhou, China.

Acute gastroenteritis (AGE) in children can be attributed to a multitude of bacterial and viral pathogens. The objective of this study was to investigate the epidemiology of bacterial and viral AGE in children and to compare clinical characteristics between single and multiple enteric pathogen infections. A total of 456 stool samples were collected from outpatient children under 5 years old with AGE, which were subsequently analyzed for nine bacteria and three viruses using the Luminex xTAG® Gastrointestinal Pathogen Panel. The presence of at least one pathogen was detected in 260 cases (57.0%), with Salmonella being the predominant agent, followed by norovirus, Campylobacter, and rotavirus. A total of 69 cases (15.1%) exhibited positive results for two or more enteric pathogens. Although certain co-infections demonstrated significant differences in primary clinical features compared with mono-infections, no statistical variance was observed in terms of disease severity. In outpatient children from southern China, Salmonella emerged as the most prevalent causative agent of AGE, succeeded by norovirus and Campylobacter. This study underscores the burden posed by coinfections and highlights the clinical characteristics associated with AGE when accompanied by coinfections among children under 5 years old.

Isolation and Identification of Vibrio Species from Different Types of Water Sources Along with Their Drug Susceptible Pattern

Abstract Background: Human activities are almost usually the cause of contaminated water supplies and places with large population densities and intensive land usage are particularly prone to pollution of drinking water sources. It is challenging to detoxify polluted water sources. Cholera is an acute form of diarrheal disease that plagued human civilization over the centuries. Vibrio spp., commonly found in aquatic environments, are the most common cause of bacterial gastroenteritis in the world, those may spread to humans through the ingestion of contaminated drinking water or exposure to seawater. Methods: In the present study, a total of 12 samples were collected from four types of water sources for the isolation of Vibrio spp. along with their drug-resistant pattern through conventional, biochemical, and antibiotic disc diffusion methods. Results: The samples were enriched into alkaline peptone water and then inoculated into culture media such as nutrient agar, MacConkey, and TCBs agar medium. After incubation for 24 h at 37°C on TCBS agar, yellow and green colonies were screened out for biochemical identification. Nonsucrose-fermenting Vibrio parahaemolyticus, Vibrio mimicus, and Vibrio vulnificus showed green colonies, and sucrose-fermenting Vibrio cholera and Vibrio alginolyticus showed yellow colonies on TCBS. The antibiotics ERY (15 μg), PCN (10 μg), CEX (30 μg), and VAN (30 μg) were completely resistant while the more effective antibiotics against Vibrio spp. were SXT (25 μg), CHL (30 μg), and GEN (30 μg). However, ciprofloxacin and nitrofurantoin showed moderate efficacy. Conclusion: To expand current knowledge on the occurrence, ecological niche, and persistence of potential human pathogenic Vibrio spp. in aquatic environments, the extensive laboratory experiment is required. To sum up, this kind of information is crucial for bringing attention to the existence of Vibrio spp. and enabling prompt implementation of preventive measures.

Uncovering the boundaries of Campylobacter species through large-scale phylogenetic and nucleotide identity analyses.

Campylobacter species are typically helical shaped, Gram-negative, and non-spore-forming bacteria. Species in this genus include established foodborne and animal pathogens as well as emerging pathogens. The accumulation of genomic data from the Campylobacter genus has increased exponentially in recent years, accompanied by the discovery of putative new species. At present, the lack of a standardized species boundary complicates distinguishing established and novel species. We defined the Campylobacter genus core genome (500 loci) using publicly available Campylobacter complete genomes (n = 498) and constructed a core genome phylogeny using 2,193 publicly available Campylobacter genomes to examine inter-species diversity and species boundaries. Utilizing 8,440 Campylobacter genomes representing 33 species and 8 subspecies, we found species delineation based on an average nucleotide identity (ANI) cutoff of 94.2% is consistent with the core genome phylogeny. We identified 60 ANI genomic species that delineated Campylobacter species in concordance with previous comparative genetic studies. All pairwise ANI genomic species pairs had in silico DNA-DNA hybridization scores of less than 70%, supporting their delineation as separate species. We provide the tool Campylobacter Genomic Species typer (CampyGStyper) that assigns ANI genomic species to query genomes based on ANI similarities to medoid genomes from each ANI genomic species with an accuracy of 99.96%. The ANI genomic species definitions proposed here allow consistent species definition in the Campylobacter genus and will facilitate the detection of novel species in the future.IMPORTANCEIn recent years, Campylobacter has gained recognition as the leading cause of bacterial gastroenteritis worldwide, leading to a substantial rise in the collection of genomic data of the Campylobacter genus in public databases. Currently, a standardized Campylobacter species boundary at the genomic level is absent, leading to challenges in detecting emerging pathogens and defining putative novel species within this genus. We used a comprehensive representation of genomes of the Campylobacter genus to construct a core genome phylogenetic tree. Furthermore, we found an average nucleotide identity (ANI) of 94.2% as the optimal cutoff to define the Campylobacter species. Using this cutoff, we identified 60 ANI genomic species which provided a standardized species definition and nomenclature. Importantly, we have developed Campylobacter Genomic Species typer (CampyGStyper), which can robustly and accurately assign these ANI genomic species to Campylobacter genomes, thereby aiding pathogen surveillance and facilitating evolutionary and epidemiological studies of existing and emerging pathogens in the genus Campylobacter.

Whole genome sequence-based characterization of Campylobacter isolated from broiler carcasses over a three-year period in a big poultry slaughterhouse reveals high genetic diversity and a recurring genomic lineage of Campylobacter jejuni

Campylobacter is among the most frequent agents of bacterial gastroenteritis in Europe and is primarily linked to the consumption of contaminated food. The aim of this study was to assess genomic diversity and to identify antimicrobial resistance and virulence genes of 155 Campylobacter isolated from broiler carcasses (neck skin samples) in a large-scale Swiss poultry abattoir over a three-year period. Samples originated from broilers from three different types of farming systems (particularly animal-friendly stabling (PAFS), free-range farms, and organic farms).Campylobacter jejuni (n = 127) and Campylobacter coli (n = 28) were analysed using a whole genome sequencing (WGS) approach (MiniSeq; Illumina). Sequence types (STs) were determined in silico from the WGS data and isolates were assigned into complex types (CTs) using the cgMLST SeqSphere+ scheme. Antimicrobial resistance genes were identified using the Resistance Gene Identifier (RGI), and virulence genes were identified using the virulence factor database (VFDB).A high degree of genetic diversity was observed. Many sequence types (C. jejuni ST19, ST21, ST48, ST50, ST122, ST262 and C. coli ST827) occurred more than once and were distributed throughout the study period, irrespective of the year of isolation and of the broiler farming type. Antimicrobial resistance determinants included blaOXA and tet(O) genes, as well as the T86I substitution within GyrA. Virulence genes known to play a role in human Campylobacter infection were identified such as the wlaN, cstIII, neuA1, neuB1, and neuC1. Subtyping of the Campylobacter isolates identified the occurrence of a highly clonal population of C. jejuni ST21 that was isolated throughout the three-year study period from carcasses from farms with geographically different locations and different farming systems.The high rate of genetic diversity observed among broiler carcass isolates is consistent with previous studies. The identification of a persisting highly clonal C. jejuni ST21 subtype suggests that the slaughterhouse may represent an environment in which C. jejuni ST21 may survive, however, the ecological reservoir potentially maintaining this clone remains unknown.

Seek and you shall find: Yersinia enterocolitica in Ireland’s drinking water

IntroductionThree Yersinia species were identified from samples of drinking water from diverse geographic regions of Ireland. Conventional commercial biochemical identification systems classified them as Yersinia enterocolitica. Since this organism is the most common cause of bacterial gastroenteritis in some countries, further investigation was warranted. The aim of the study was to provide a microbial characterisation of three Yersinia species, to determine their pathogenicity, and to review the incidence rate of Yersinia enterocolitica detection in our region.MethodsOrganism identification was performed using conventional commercial diagnostic systems MALDI-TOF, API 20E, API 50CHE, TREK Sensititre GNID and Vitek 2 GN, and whole genome sequencing (WGS) was performed. Historical data for detections was extracted from the lab system for 2008 to 2023.ResultsAll three isolates gave “good” identifications of Yersinia enterocolitica on conventional systems. Further analysis by WGS matched two of the isolates with recently described Yersinia proxima, and the third was a member of the non-pathogenic Yersinia enterocolitica clade 1Aa.DiscussionOur analysis of these three isolates deemed them to be Yersinia species not known currently to be pathogenic, but determining this necessitated the use of next-generation sequencing and advanced bioinformatics. Our work highlights the importance of having this technology available to public laboratories, either locally or in a national reference laboratory. The introduction of molecular technologies for the detection of Yersinia species may increase the rate of detections. Accurate identification of significant pathogens in environmental, public health and clinical microbiology laboratories is critically important for the protection of society.

Veterinarians and zoonotic pathogens, infections and diseases – questionnaire study and case series, Finland

Background Veterinarians are at risk for numerous zoonotic infections. In this paper, we summarise descriptions of zoonotic infections from a questionnaire study and a series of work-related zoonotic cases, aiming to add to the knowledge on occupational zoonotic risks of veterinarians. Methods We collected data on zoonotic infections contracted by veterinarians in Finland in two studies:1) using a questionnaire in 2009, and 2) inviting veterinarians who had encountered an occupational zoonosis to report it in structured interviews in 2019. Results and conclusions In the questionnaire study in 2009, of 306 veterinarians several reported zoonotic bacterial skin infections (12%), dermatophytosis (ringworm; 4.2%), virus infections (3.9%), bacterial gastroenteritis (3.3%), other bacterial zoonoses (2.3%), and parasitic infections/infestations (2.3%). In the 2019 interviews, 16 occupational zoonosis cases were reported. Of them, seven were selected to the case series. The selected cases included Capnocytophaga canimorsus sepsis following a dog bite, cryptosporidiosis after a contact with calves, cutaneous listeriosis following calving assistance, Salmonella gastroenteritis contracted at laboratory, Trichophyton dermatophytosis after equine contact, Bacillus anthracis exposure at necropsy, and exposure to rabies through a horse bite. In four of the seven cases, the veterinarian disagreed or strongly disagreed with having had good knowledge of the zoonosis before the incident. The results from the questionnaire study and the case series illustrate the variety of zoonotic pathogens that veterinarians may encounter. There is a need to improve the occupational health of veterinarians and to increase awareness in the occupational health sector. We encourage addressing this need using a One Health approach.

Identification of knowledge gaps in whole-genome sequence analysis of multi-resistant thermotolerant Campylobacter spp.

BackgroundCampylobacter spp. is the most frequent cause of bacterial food-borne gastroenteritis and a high priority antibiotic resistant bacterium according to the World Health Organization (WHO). European monitoring of thermotolerant Campylobacter spp. does not reflect the global burden of resistances already circulating within the bacterial population worldwide.MethodsWe systematically compared whole genome sequencing with comprehensive phenotypic antimicrobial susceptibility, analyzing 494 thermotolerant Campylobacter poultry isolates from Vietnam and Germany. Any discrepancy was checked by repeating the wet lab and improving the dry lab part. Selected isolates were additionally analyzed via long-read Oxford Nanopore technology, leading to closed chromosomes and plasmids.ResultsOverall, 22 different resistance genes and gene variants (e. g. erm(B), aph(3’)-IIIa, aph(2’’)-If, catA, lnu(C), blaOXA, sat4) and point mutations in three distinct genes (gyrA, 23S rRNA, rpsL) associated with AMR were present in the Campylobacter isolates. Two AMR genes were missing in the database and one falsely associated with resistance. Bioinformatic analysis based on short-read data partly failed to identify tet(O) and aadE, when the genes were present as duplicate or homologous gene variants. Intriguingly, isolates also contained different determinants, redundantly conferring resistance to chloramphenicol, gentamicin, kanamycin, lincomycin and streptomycin. We found a novel tet(W) in tetracycline sensitive strains, harboring point mutations. Furthermore, analysis based on assemblies from short-read data was impaired to identify full length phase variable aad9, due to variations of the poly-C tract within the gene. The genetic determinant responsible for gentamicin resistance of one isolate from Germany could not be identified. GyrT86I, presenting the main determinant for (fluoro-)quinolone resistance led to a rare atypical phenotype of ciprofloxacin resistance but nalidixic acid sensitivity. Long-read sequencing predicted AMR genes were mainly located on the chromosome, and rarely on plasmids. Predictions from long- and short-read sequencing, respectively, often differed. AMR genes were often organized in multidrug resistance islands (MDRI) and partially located in proximity to transposase genes, suggesting main mobilization of resistance determinants is via natural transformation and transposition in Campylobacter.ConclusionsThe results of this study suggest that there is frequent resistance gene duplication, mosaicism, and mutation leading to gene variation and truncation in Campylobacter strains that have not been reported in previous studies and are missing from databases. Furthermore, there is a need for deciphering yet unknown resistance mechanisms and resistance spread in thermotolerant Campylobacter spp. that may pose a challenge to global food safety.

Disease-specific plasma protein profiles in patients with fever after traveling to tropical areas.

Fever is common among individuals seeking healthcare after traveling to tropical regions. Despite the association with potentially severe disease, the etiology is often not determined. Plasma protein patterns can be informative to understand the host response to infection and can potentially indicate the pathogen causing the disease. In this study, we measured 49 proteins in the plasma of 124 patients with fever after travel to tropical or subtropical regions. The patients had confirmed diagnoses of either malaria, dengue fever, influenza, bacterial respiratory tract infection, or bacterial gastroenteritis, representing the most common etiologies. We used multivariate and machine learning methods to identify combinations of proteins that contributed to distinguishing infected patients from healthy controls, and each other. Malaria displayed the most unique protein signature, indicating a strong immunoregulatory response with high levels of IL10, sTNFRI and II, and sCD25 but low levels of sCD40L. In contrast, bacterial gastroenteritis had high levels of sCD40L, APRIL, and IFN-γ, while dengue was the only infection with elevated IFN-α2. These results suggest that characterization of the inflammatory profile of individuals with fever can help to identify disease-specific host responses, which in turn can be used to guide future research on diagnostic strategies and therapeutic interventions.

Identification of Campylobacter jejuni and Campylobacter coli genes contributing to oxidative stress response using TraDIS analysis

BackgroundCampylobacter jejuni and Campylobacter coli are the major causative agents of bacterial gastroenteritis worldwide and are known obligate microaerophiles. Despite being sensitive to oxygen and its reduction products, both species are readily isolated from animal food products kept under atmospheric conditions where they face high oxygen tension levels.ResultsIn this study, Transposon Directed Insertion-site Sequencing (TraDIS) was used to investigate the ability of one C. jejuni strain and two C. coli strains to overcome oxidative stress, using H2O2 to mimic oxidative stress. Genes were identified that were required for oxidative stress resistance for each individual strain but also allowed a comparison across the three strains. Mutations in the perR and ahpC genes were found to increase Campylobacter tolerance to H2O2. The roles of these proteins in oxidative stress were previously known in C. jejuni, but this data indicates that they most likely play a similar role in C. coli. Mutation of czcD decreased Campylobacter tolerance to H2O2. The role of CzcD, which functions as a zinc exporter, has not previously been linked to oxidative stress. The TraDIS data was confirmed using defined deletions of perR and czcD in C. coli 15-537360.ConclusionsThis is the first study to investigate gene fitness in both C. jejuni and C. coli under oxidative stress conditions and highlights both similar roles for certain genes for both species and highlights other genes that have a role under oxidative stress.

Impact of the SARS-CoV-2 Pandemic on Prevalence and Incidence of Bacterial Gastroenteritis in Spain, 2019-2022.

The aim of this study was to describe the impact of non-pharmaceutical interventions (NPIs) against SARS-CoV-2 on bacterial gastroenteritis illnesses (BGIs), including Campylobacter spp., Aeromonas spp., Salmonella spp., Shigella spp./enteroinvasive Escherichia coli (EIEC), and Yersinia enterocolitica, in outpatients, inpatients, and emergency departments (ED). Data of patients from a health care area in Madrid (Spain) with diarrhea and positive-real-time polymerase chain reaction (RT-PCR) were collected. The periods analyzed were prepandemic (P0, April 1, 2019 to March 31, 2020), first (P1, April 1, 2020 to March 31, 2021), and second (P2, April 1, 2021 to March 31, 2022) pandemic years. We compared the prevalence, median age, patient profile, and absolute incidence (AI) per 100,000 population during the study periods using Fisher's test (p < 0.05). One thousand eighty-one (13.9%, [95% confidence interval, CI: 13.1-14.6]) of the 7793 patients tested during P0, 777 (13.3%, [95% CI: 12.4-14.2]) of the 5850 tested during P1, and 945 (12.4%, [95% CI: 11.7-13.2]) of the 7606 patients tested were positive for some BGIs. The global prevalence showed a decreasing trend that was statistically significant in P2. During P1, there was an increase in BGIs in the ED with a decrease of median age (p > 0.05). However, during P2, the prevalence for outpatients increased (p < 0.05). The individual prevalence analysis over the three periods remained homogeneous for most of the BGIs (p > 0.05). The AI of most BGIs showed a decreasing trend at P1 and P2 with respect to P0 (p > 0.05). However, Shigella spp./EIEC was the only BGI with a decrease in prevalence, and AI showed statistically significant variation in P1 and P2 (p < 0.05). The prevalence and AI for BGIs mostly showed a slight decrease during the first 2 pandemic years compared with the prepandemic may be explained by the greater impact of foodborne transmission on BGIs. The significant decrease in Shigella spp./EIEC illnesses could explain the mainly person-to-person transmission and the reduction of bacterial load in fomites for NPIs. This retrospective study was approved by the Ethics Committee with the code: HULP PI-5700.

P404 Monocyte distribution width differentiates bacterial gastroenteritis from Acute Severe Ulcerative Colitis in patients presenting with diarrhoea

Abstract Background Monocyte distribution width (MDW) is a haematological parameter that can be generated by newer generation blood analysers on routine full blood examination. It reflects the variation in the size of monocytes and is elevated in the setting of infection, however its utility in inflammatory disorders in unknown. We aimed to assess whether MDW can help differentiate bacterial gastroenteritis from Acute Severe Ulcerative Colitis (ASUC) among patients presenting to the Emergency Department (ED) with diarrhoea. We further aimed to assess whether MDW correlated with disease activity and clinical outcomes in ASUC. Methods We conducted a retrospective cohort study comprising three patient groups: (1) ASUC, (2) bacterial gastroenteritis and (3) a control group of patients without active inflammation. The control group consisted of outpatients with chronic hepatitis B in immune control phase with normal liver transaminases and suppressed viral load &amp;lt; 2000 IU/mL. Clinical outcomes, routine biomarkers and MDW were recorded. Results A total of 176 patients were identified (53 ASUC, 70 bacterial gastroenteritis and 53 controls). At time of ED presentation, patients with bacterial gastroenteritis had the highest MDW (median 23.6, IQR 20.7-25.8) compared to ASUC (19.0, IQR 17.9-21.2) and controls (16.8, IQR 15.9-18.0; P&amp;lt;0.001). On receiver operator characteristic curve analysis, MDW discriminated bacterial gastroenteritis from ASUC with an area under the curve (AUC) of 0.78 (95% CI 0.70-0.87, P&amp;lt;0.001). Using Youden’s index, a MDW threshold &amp;gt; 22.3 had 64.3% sensitivity, 84.6% specificity, 63.8% negative predictive value and 84.9% positive predictive value for bacterial gastroenteritis. Of the 53 patients with ASUC, 25 responded to intravenous hydrocortisone while 28 were steroid non-responders and required infliximab (IFX). 24 patients responded to IFX rescue, while the 4 IFX non-responders received tofacitinib sequential therapy. In ASUC, MDW correlated positively with established markers of disease activity including CRP (Spearman rank correlation, rho=0.54, P&amp;lt;0.001), platelet count (rho=0.36, P=0.009) and faecal calprotectin (rho=0.35, P=0.02). A lower MDW on the day of IFX administration appeared to predict IFX response (AUC 0.80, 95% CI 0.61-1.00, P=0.002). At follow-up (median 85 days), MDW was predictive of biochemical remission with a faecal calprotectin &amp;lt; 100 µg/g (AUC 0.80, 95% CI 0.64-0.95, P&amp;lt;0.001). Conclusion MDW is a novel biomarker that may help distinguish ASUC from bacterial gastroenteritis at time of ED presentation in patients with diarrhoea. In ASUC, MDW correlates with existing markers of activity and may help predict IFX response.

Genomic and clinical characteristics of campylobacteriosis in Australia.

Campylobacter spp. are a common cause of bacterial gastroenteritis in Australia, primarily acquired from contaminated meat. We investigated the relationship between genomic virulence characteristics and the severity of campylobacteriosis, hospitalisation, and other host factors.We recruited 571 campylobacteriosis cases from three Australian states and territories (2018-2019). We collected demographic, health status, risk factors, and self-reported disease data. We whole genome sequenced 422 C. jejuni and 84 C. coli case isolates along with 616 retail meat isolates. We classified case illness severity using a modified Vesikari scoring system, performed phylogenomic analysis, and explored risk factors for hospitalisation and illness severity.On average, cases experienced a 7.5 day diarrhoeal illness with additional symptoms including stomach cramps (87.1 %), fever (75.6 %), and nausea (72.0 %). Cases aged ≥75 years had milder symptoms, lower Vesikari scores, and higher odds of hospitalisation compared to younger cases. Chronic gastrointestinal illnesses also increased odds of hospitalisation. We observed significant diversity among isolates, with 65 C. jejuni and 21 C. coli sequence types. Antimicrobial resistance genes were detected in 20.4 % of isolates, but multidrug resistance was rare (0.04 %). Key virulence genes such as cdtABC (C. jejuni) and cadF were prevalent (>90 % presence) but did not correlate with disease severity or hospitalisation. However, certain genes (e.g. fliK, Cj1136, and Cj1138) appeared to distinguish human C. jejuni cases from food source isolates.Campylobacteriosis generally presents similarly across cases, though some are more severe. Genotypic virulence factors identified in the literature to-date do not predict disease severity but may differentiate human C. jejuni cases from food source isolates. Host factors like age and comorbidities have a greater influence on health outcomes than virulence factors.