Campylobacter jejuni virulence factors: update on emerging issues and trends.

Campylobacter jejuni is a very common cause of gastroenteritis, and is frequently transmitted to humans through contaminated food products or water. Importantly, C. jejuni infections have a range of short- and long-term sequelae such as irritable bowel syndrome and Guillain Barre syndrome. C. jejuni triggers disease by employing a range of molecular strategies which enable it to colonise the gut, invade the epithelium, persist intracellularly and avoid detection by the host immune response. The objective of this review is to explore and summarise recent advances in the understanding of the C. jejuni molecular factors involved in colonisation, invasion of cells, collective quorum sensing-mediated behaviours and persistence. Understanding the mechanisms that underpin the pathogenicity of C. jejuni will enable future development of effective preventative approaches and vaccines against this pathogen.

Antibiotic-induced microbiome depletion promotes intestinal colonization by Campylobacter jejuni in mice.

BACKGROUND: To establish a method to induce Campylobacter jejuni colonization in the intestines of C57BL/6 mice through antibiotic-induced microbiome depletion. RESULTS: Fifty-four female C57BL/6 mice were divided into the normal, control, and experimental groups. The experimental group was administered intragastric cefoperazone sodium and sulbactam sodium (50 mg/mL) for 2 days; then, the experimental and control mice were intragastrically administered 200 µL C. jejuni, which was repeated once more after 2 days. Animal feces were collected, and the HipO gene of C. jejuni was detected using TaqMan qPCR from day 1 to day 14 after modeling completion. Immunofluorescence was used to detect intestinal C. jejuni colonization on day 14, and pathological changes were observed using hematoxylin and eosin staining. Additionally, 16S rDNA analyses of the intestinal contents were conducted on day 14. In the experimental group, C. jejuni was detected in the feces from days 1 to 14 on TaqMan qPCR, and immunofluorescence-labeled C. jejuni were visibly discernable in the intestinal lumen. The intestinal mucosa was generally intact and showed no significant inflammatory-cell infiltration. Diversity analysis of the colonic microbiota showed significant inter-group differences. In the experimental group, the composition of the colonic microbiota differed from that in the other 2 groups at the phylum level, and was characterized by a higher proportion of Bacteroidetes and a lower proportion of Firmicutes. CONCLUSIONS: Microbiome depletion induced by cefoperazone sodium and sulbactam sodium could promote long-term colonization of C. jejuni in the intestines of mice.

Evaluation of the prevalence of Aeromonas spp., Campylobacter spp., and Clostridioides difficile in immunocompromised children with diarrhea.

AIM: Diarrhea is a common disease in immunocompromised patients and can be associated with greater morbidity and even mortality. Therefore, the present study was designed to determine the prevalence of Aeromonas spp., Campylobacter spp., and C. difficile among immunocompromised children. METHODS: This study was conducted on 130 stool samples from patients with diarrhea who had defects in the immune system and were referred to Hazrat Masoumeh Children's Hospital in Qom. Demographic information, clinical symptoms, immune status, and duration of chemotherapy were also recorded for each child. DNAs were extracted from the stool, and then direct PCR assays were done by specific primers for the detection of Aeromonas spp., Campylobacter spp., and toxigenic C. difficile, including tcdA/B and cdtA/B genes. Co-infection in patients was also evaluated. RESULTS: 60.8% and 39.2% were male and female, respectively, with a m ± SD age of 56.72 ± 40.49 months. Most cases of immunocompromised states were related to Acute Lymphocytic Leukemia (77.7%) and Non-Hodgkin Lymphoma (14.6%). 93.1% of patients were undergoing chemotherapy during the study. Among patients, most clinical symptoms were related to bloody diarrhea (98.5%) and fever (92.3%). Based on PCR, 14.6, 9.2, and 1.5% were positive for Aeromonas spp., C. difficile, and C. jejuni, respectively. Among the C. difficile-positive cases, the tcdA gene was only detected in one patient. In total, three co-infections were identified, which included Aeromonas spp./C. difficile (tcdA+), C. jejuni/C. difficile, and C. jejuni/Aeromonas spp. CONCLUSIONS: This is the first study in Iran to investigate the simultaneous prevalence of some pathogens in immunocompromised children with diarrhea. Because Aeromonas spp., Campylobacter spp., and C. difficile are not routinely detected in some laboratories, infections caused by them are underappreciated in the clinic. Our results showed that these pathogens are present in our region and can cause gastroenteritis in children, especially those with underlying diseases. Therefore, increasing the level of hygiene in some areas and controlling bacterial diarrheal diseases should be given more attention by health officials.

A population-based study of the appearances of enteric Campylobacter and non-typhoidal Salmonella infections on computed tomography.

BACKGROUND: Swift identification and diagnosis of gastrointestinal infections are crucial for prompt treatment, prevention of complications, and reduction of the risk of hospital transmission. The radiological appearance on computed tomography could potentially provide important clues to the etiology of gastrointestinal infections. We aimed to describe features based on computed tomography of patients diagnosed with Campylobacter, Salmonella or Shigella infections in South Sweden. METHODS: This was a retrospective observational population-based cohort study conducted between 2019 and 2022 in Skåne, southern Sweden, a region populated by 1.4 million people. Using data from the Department of Clinical Microbiology combined with data from the Department of Radiology, we identified all patients who underwent computed tomography of the abdomen CTA two days before and up to seven days after sampling due to the suspicion of Campylobacter, Salmonella or Shigella during the study period. RESULTS: A total of 215 CTAs scans performed on 213 patients during the study period were included in the study. The median age of included patients was 45 years (range 11-86 years), and 54% (114/213) of the patients were women. Of the 215 CTAs, 80% (n = 172) had been performed due to Campylobacter and 20% (n = 43) due to Salmonella enteritis. CTA was not performed for any individual diagnosed with Shigella during the study period. There were no statistically significant differences in the radiological presentation of Campylobacter and Salmonella infections. CONCLUSION: The most common location of Campylobacter and Salmonella infections was the cecum, followed by the ascending colon. Enteric wall edema, contrast loading of the affected mucosa, and enteric fat stranding are typical features of both infections. The CTA characteristics of Campylobacter and Salmonella are similar, and cannot be used to reliably differentiate between different infectious etiologies.

Biochemical and molecular characterization of Campylobacter fetus isolates from bulls subjected to bovine genital campylobacteriosis diagnosis in Spain.

BACKGROUND: Bovine genital campylobacteriosis (BGC) is caused by Campylobacter fetus subsp. venerealis (Cfv) including its biovar intermedius (Cfvi). This sexually transmitted disease induces early reproductive failure causing considerable economic losses in the cattle industry. Using a collection of well-characterized isolates (n = 13), C. fetus field isolates (n = 64) and saprophytic isolates resembling Campylobacter (n = 75) obtained from smegma samples of breeding bulls, this study evaluated the concordance of the most used phenotypic (H2S production in cysteine medium and 1% glycine tolerance) and molecular (PCR) methods for the diagnosis of BGC and assessed possible cross-reactions in the molecular diagnostic methods. RESULTS: Characterization at the subspecies level (fetus vs. venerealis) of C. fetus isolated from bull preputial samples using phenotypic and molecular (PCR targeting nahE and ISCfe1) methods showed moderate concordance (κ = 0.462; CI: 0.256-0.669). No cross-reactions were observed with other saprophytic microaerophilic species or with other Campylobacter species that can be present in preputial samples. Whole genome sequencing (WGS) of discrepant isolates showed 100% agreement with PCR identification. For the differentiation of Cfv biovars, comparison of the H2S test (at 72 h and 5 days of incubation) and a PCR targeting the L-cysteine transporter genes showed higher concordance when H2S production was assessed after 5 days (72 h; κ = 0.553, 0.329-0.778 CI vs. 5 days; κ = 0.881, 0.631-1 CI), evidencing the efficacy of a longer incubation time. CONCLUSIONS: This study confirmed the limitations of biochemical tests to correctly identify C. fetus subspecies and biovars. However, in the case of biovars, when extended incubation times for the H2S test (5 days) were used, phenotypic identification results were significantly improved, although PCR-based methods produced more accurate results. Perfect agreement of WGS with the PCR results and absence of cross-reactions with non-C. fetus saprophytic bacteria from the smegma demonstrated the usefulness of these methods. Nevertheless, the identification of new C. fetus subspecies-specific genes would help to improve BGC diagnosis.

Design of a multi-epitope-based vaccine candidate against Bovine Genital Campylobacteriosis using a reverse vaccinology approach.

BACKGROUND: Bovine Genital Campylobacteriosis (BGC), a worldwide distributed venereal disease caused by Campylobacter fetus subsp. venerealis (Cfv), has a relevant negative economic impact in cattle herds. The control of BGC is hampered by the inexistence of globally available effective vaccines. The present in silico study aimed to develop a multi-epitope vaccine candidate against Cfv through reverse vaccinology. RESULTS: The analysis of Cfv strain NCTC 10354 proteome allowed the identification of 9 proteins suitable for vaccine development. From these, an outer membrane protein, OmpA, and a flagellar protein, FliK, were selected for prediction of B-cell and T-cell epitopes. The top-ranked epitopes conservancy was assessed in 31 Cfv strains. The selected epitopes were integrated to form a multi-epitope fragment of 241 amino acids, which included 2 epitopes from OmpA and 13 epitopes from FliK linked by GPGPG linkers and connected to the cholera toxin subunit B by an EAAAK linker. The vaccine candidate was predicted to be antigenic, non-toxic, non-allergenic, and soluble upon overexpression. The protein structure was predicted and optimized, and the sequence was successfully cloned in silico into a plasmid vector. Additionally, immunological simulations demonstrated the vaccine candidate's ability to stimulate an immune response. CONCLUSIONS: This study developed a novel vaccine candidate suitable for further in vitro and in vivo experimental validation, which may become a useful tool for the control of BGC.

Antimicrobial resistance patterns and genes of Campylobacter jejuni isolated from chickens in Pasuruan, Indonesia.

Background: Poultry is one of the most prominent sources of Campylobacter jejuni, which is also a major means of transmission to people. Campylobacter jejuni contamination in chicken meat comes from chicken feces because it naturally exists in the intestines of chickens. Aim: The purpose of this study is to identify the antibiotic resistance patterns and genes of C. jejuni, which was found in chickens in Pasuruan, Indonesia. Methods: The samples used in this study were 200 contents of the small intestine of broiler chickens from 40 farms in Pasuruan Regency. The enriched sample was streaked on the selective media of modified charcoal cefoperazone deoxycholate agar containing the CCDA selective supplement. Antimicrobial susceptibility test utilizing the Kirby-Bauer diffusion test method in accordance with Clinical and Laboratory Standards Institute standards. The polymerase chain reaction (PCR) method was used to detect the (hipO), which encodes the C. jejuni strain, fluoroquinolone resistance (gyrA), beta-lactam resistance (blaOXA-61), and tetracycline resistance (tetO) genes. Results: The findings revealed a 14% (28/200) prevalence of C. jejuni in the small intestine of broiler chickens. These isolates showed high resistance to enrofloxacin (92.9%). All isolates (100%) were susceptible to amoxicillin-clavulanate. The PCR results showed all C. jejuni isolates (100%) detected the gyrA gene, 96.4% detected the blaOXA-61 gene, and 50% detected the tetO gene. Conclusion: The findings of antimicrobial resistance at a high level from the small intestine of broiler chickens illustrate the potential threat to human health. To lessen the effects now and in the future, coordinated and suitable action is needed, as well as steps to guarantee the poultry industry's economic survival and public health insurance.

Identification of a multidrug resistance genomic island harboring a nonfunctional optrA gene in Campylobacter coli of chicken origin.

Campylobacter spp., such as Campylobacter jejuni and Campylobacter coli, are important zoonotic Gram-negative pathogens that cause acute intestinal diseases in humans. In this study, a retrospective analysis was conducted on previously collected Campylobacter isolates from antimicrobial resistance surveillance. A total of 29 optrA-positive C. coli strains were identified and subjected to second-generation sequencing. Multilocus sequence typing and single nucleotide polymorphism analyses demonstrated that the 29 optrA-positive isolates were genetically homogeneous. Notably, among the 29 isolated strains, the ΔoptrA variants exhibit a nonsense mutation at position 979 where the base C is substituted by T, leading to the formation of a premature termination codon. The alignment of sequences and genetic environmental characteristics suggested that ΔoptrA located on a chromosomally carried multidrug-resistant genomic island. There are other resistant genes on the multidrug resistance genomic island, such as aph(2'')-If, aph(3')-III, aadE, tet(O), tet(L), cat, erm(A), optrA and blaOXA-61. As a result, the 29 ΔoptrA-positive strains displayed susceptibility to both florfenicol and linezolid. The ΔoptrA gene is linked to the erm(A) gene, resulting in the formation of translocatable unit (TU) that are encompassed by two copies of IS1216 mobile elements. Multiple occurrences of similar TUs have been documented in numerous C. coli and provided evidence for the significance of TUs in facilitating the transfer of drug resistance genes in C. coli.

Combined application of bacteriophages with a competitive exclusion culture and carvacrol with organic acids can reduce Campylobacter in primary broiler production.

For reducing Campylobacter (C.) in the food production chain and thus the risk to the consumer, the combined application of different measures as a multiple-hurdle approach is currently under discussion. This is the first study to investigate possible synergistic activities in vivo, aiming at reducing intestinal C. jejuni counts by administering (i) bacteriophages (phages) in combination with a competitive exclusion (CE) product and (ii) carvacrol combined with organic acids. The combined application of the two selected phages (Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1) and the CE product significantly reduced C. jejuni loads by 1.0 log10 in cecal and colonic contents as well as in cloacal swabs at the end of the trial (33 and 34 days post hatch). The proportion of bacterial isolates showing reduced phage susceptibility ranged from 10.9% (isolates from cecal content) to 47.8% (isolates from cloacal swabs 32 days post hatch) for the Fletchervirus phage, while all tested isolates remained susceptible to the Firehammervirus phage. The use of carvacrol combined with an organic acid blend (sorbic acid, benzoic acid, propionic acid, and acetic acid) significantly reduced Campylobacter counts by 1.0 log10 in cloacal swabs on day 30 only.

Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

In-vitro selection of lactic acid bacteria to combat Salmonella enterica and Campylobacter jejuni in broiler chickens.

Campylobacter and Salmonella are the two most prominent foodborne zoonotic pathogens reported in the European Union. As poultry is one of the major sources of these pathogens, it is imperative to mitigate the colonization of these pathogens in poultry. Many strains of lactic acid bacteria (LAB) have demonstrated anti-Salmonella and anti-Campylobacter characteristics to varying degrees and spectrums which are attributed to the production of various metabolites. However, the production of these compounds and consequent antimicrobial properties are highly strain dependent. Therefore, the current study was performed to select a potent LAB and determine its causal attribute in inhibiting Salmonella enterica and Campylobacter jejuni, in-vitro. Six LAB (Lactiplantibacillus plantarum (LP), Lacticaseibacillus casei (LC), Limosilactobacillus reuteri (LR), Lacticaseibacillus rhamnosus (LRh), Leuconostoc mesenteroides (LM) and Pediococcus pentosaceus (PP)) and three serovars of Salmonella enterica (Typhimurium, Enterica and Braenderup) and Campylobacter jejuni were used in the current study. Spot overlays, well diffusion, co-culture and co-aggregation assays against Salmonella and well diffusion assays against Campylobacter jejuni were performed. Organic acid profiling of culture supernatants was performed using HPLC. The results indicated that LRh, LM and PP had the most significant anti-Salmonella effects while LP, LC, LM and PP displayed the most significant anti-Campylobacter effects. Lactic acid and formic acid detected in the culture supernatants seem the most likely source of the anti-Salmonella and anti-Campylobacter effects exhibited by these LAB. In conclusion, Leuconostoc mesenteroides displayed the most significant overall anti-pathogenic effects when compared to the other LAB strains studied, indicating its potential application in-vivo.

Campylobacter presence on Dutch broiler farms and associated risk factors.

Campylobacter is the most reported zoonotic pathogen in humans in the European Union. Poultry is a major source of human infection with Campylobacter. Although many studies are done on the presence of Campylobacter in broilers and theoretically effective control measures are known, their relative importance at broiler farms remains poorly understood. Therefore, the aim of this study was to investigate the presence of Campylobacter on selected broiler farms in the Netherlands, to determine the moment of introduction, and associated risk factors. A longitudinal study on 25 broiler farms was carried out between June 2017 and December 2020. Fecal samples were collected weekly from 43 broiler houses. In total 497 flocks were sampled. Putative variables on flock and farm characteristics for a risk factor analysis were gathered through questionnaires. Risk factors associated with the presence of Campylobacter in a broiler flock were determined using regression models. In total 30% of the flocks included in the study were positive for Campylobacter. Factors associated with presence of Campylobacter at slaughter age included: season, mowing lawns and presence of agricultural side activities. While summer/autumn and mowing lawns were associated with an increase in Campylobacter presence in flocks, the farmer having agricultural side activities other than poultry production was associated with a decrease. Analysis of the age at which flocks first tested Campylobacter positive revealed that slower growing breeds became positive on average 1 wk later compared to regular growers. This study revealed a delayed introduction of Campylobacter in slower grower vs. regular grower broiler flocks reared indoors. In addition, it confirmed importance of season as major risk factor. The relevance of mowing and preceding positive flocks as risk factors needs further investigation.

Novel rpsK / rpsD primer-probe assay improves detection of Campylobacter jejuni and Campylobacter coli in human stool.

Campylobacter causes bacterial enteritis, dysentery, and growth faltering in children in low- and middle-income countries (LMICs). Campylobacter spp. are fastidious organisms, and their detection often relies on culture independent diagnostic technologies, especially in LMICs. Campylobacter jejuni and Campylobacter coli are most often the infectious agents and in high income settings together account for 95% of Campylobacter infections. Several other Campylobacter species have been detected in LMIC children at an increased prevalence relative to high income settings. After doing extensive whole genome sequencing of isolates of C. jejuni and C. coli in Peru, we observed heterogeneity in the binding sites for the main species-specific PCR assay (cadF) and designed an alternative rpsKD-based qPCR assay to detect both C. jejuni and C. coli. The rpsKD-based qPCR assay identified 23% more C.jejuni/ C.coli samples than the cadF assay among 47 Campylobacter genus positive cadF negative samples verified to have C. jejuni and or C. coli with shotgun metagenomics. This assay can be expected to be useful in diagnostic studies of enteric infectious diseases and be useful in revising the attribution estimates of Campylobacter in LMICs.

A broad host phage, CP6, for combating multidrug-resistant Campylobacter prevalent in poultry meat.

Campylobacter is a major cause of bacterial foodborne diarrhea worldwide. Consumption of raw or undercooked chicken meat contaminated with Campylobacter is the most common causative agent of human infections. Given the high prevalence of contamination in poultry meat and the recent rise of multi-drug-resistant (MDR) Campylobacter strains, an effective intervention method of reducing bird colonization is needed. In this study, the Campylobacter-specific lytic phage CP6 was isolated from chicken feces. Phage CP6 exhibited a broad host range against different MDR Campylobacter isolates (97.4% of strains were infected). Some biological characteristics were observed, such as a good pH (3-9) stability and moderate temperature tolerance (<50 ℃). The complete genome sequence revealed a linear double-stranded DNA (178,350 bp, group II Campylobacter phage) with 27.51% GC content, including 209 predicted open reading frames, among which only 54 were annotated with known functions. Phylogenetic analysis of the phage major capsid protein demonstrated that phage CP6 was closely related to Campylobacter phage CPt10, CP21, CP20, IBB35, and CP220. CP6 phage exerted good antimicrobial effects on MDR Campylobacter in vitro culture and reduced CFUs of the host cells by up to 1-log compared with the control in artificially contaminated chicken breast meat. Our findings suggested the potential of CP6 phage as a promising antimicrobial agent for combating MDR Campylobacter in food processing.

Menthol Pretreatment Alleviates Campylobacter jejuni-Induced Enterocolitis in Human Gut Microbiota-Associated IL-10-/- Mice.

Human Campylobacter jejuni infections are of worldwide importance and represent the most commonly reported bacterial enteritis cases in middle- and high-income countries. Since antibiotics are usually not indicated and the severity of campylobacteriosis is directly linked to the risk of developing post-infectious complications, non-toxic antibiotic-independent treatment approaches are highly desirable. Given its health-promoting properties, including anti-microbial and anti-inflammatory activities, we tested the disease-alleviating effects of oral menthol in murine campylobacteriosis. Therefore, human gut microbiota-associated IL-10-/- mice were orally subjected to synthetic menthol starting a week before C. jejuni infection and followed up until day 6 post-infection. Whereas menthol pretreatment did not improve campylobacteriosis symptoms, it resulted in reduced colonic C. jejuni numbers and alleviated both macroscopic and microscopic aspects of C. jejuni infection in pretreated mice vs. controls. Menthol pretreatment dampened the recruitment of macrophages, monocytes, and T lymphocytes to colonic sites of infection, which was accompanied by mitigated intestinal nitric oxide secretion. Furthermore, menthol pretreatment had only marginal effects on the human fecal gut microbiota composition during the C. jejuni infection. In conclusion, the results of this preclinical placebo-controlled intervention study provide evidence that menthol application constitutes a promising way to tackle acute campylobacteriosis, thereby reducing the risk for post-infectious complications.

Positive cases of bovine genital campylobacteriosis and bovine trichomonosis in the eradication program of La Pampa, Argentina: 2008-2021.

Bovine genital campylobacteriosis, caused by the gram-negative bacteria Campylobacter fetus venerealis, and bovine trichomonosis, caused by the parasite protozoan Tritrichomonas foetus, are venereal diseases that occur with long intercalving periods and abortion. The control of both diseases relies on microbiological testing and culling infected bulls. Vaccination and antibiotic treatment may help in controlling campylobacteriosis but are not recommended for trichomonosis control. Several regions of the world have active control programs for trichomonosis, not campylobacteriosis. In Argentina, the state of La Pampa aims to eradicate trichomonosis and campylobacteriosis by imposing annual diagnostic testing of every bull and slaughtering positive animals. Prior studies indicated a declining trend in the prevalence of campylobacteriosis and trichomonosis in La Pampa. It was also proposed that the prevalence of one disease could be estimated from the prevalence of the other. The purpose of this retrospective analysis of data gathered from 2008 to 2021 was to determine the La Pampa program's efficacy. Descriptive statistics were employed to determine the reason behind the correlation between tricomonosis and campylobacteriosis diagnostic results. The outcomes refute the notion that this program of venereal eradication was a success. Furthermore, an excess of false positives in both diagnoses may have contributed to the correlation between the prevalences of campylobactriosis and trichomonosis. The practice of killing animals without verifying positive results hinders the determination of disease prevalence and results in the death of numerous healthy animals.

Clinical isolate characteristics and demographics of patients with C.jejuni and C.coli infections in Northern Israel, 2015-2021.

C.coli is a significant cause of foodborne gastroenteritis worldwide, with the majority of cases attributed to C.jejuni. Although most clinical laboratories do not typically conduct antimicrobial susceptibility testing for C.coli, the rise in resistant strains has underscored the necessity for such testing and epidemiological surveillance. The current study presents clinical isolate characteristics and demographics of 221 patients with C.coli (coli and jejuni) infections in Northern Israel, between 2015 and 2021. Clinical and demographic data were collected from patient medical records. Susceptibility to erythromycin, tetracycline, ciprofloxacin, and gentamicin was assessed using the standard E-test. No significant correlations were found between bacterial species and patient ethnicity, patient gender, or duration of hospitalization. In contrast, significant differences were found between infecting species and patient age and age subgroup (P < 0.001). Furthermore, erythromycin resistance was observed in only 0.5% of the study population, while resistance to ciprofloxacin, tetracycline, and gentamicin was observed in 95%, 93%, and 2.3% of the population, respectively. The presented study underscores the need for routine surveillance of C.coli antibiotic resistance.

Effect of the polysaccharide capsule and its heptose on the resistance of Campylobacter jejuni to innate immune defenses.

Campylobacter jejuni is a commensal in many animals but causes diarrhea in humans. Its polysaccharide capsule contributes to host colonization and virulence in a strain- and model-specific manner. We investigated if the capsule and its heptose are important for interactions of strain NCTC 11168 with various hosts and their innate immune defenses. We determined that they support bacterial survival in Drosophila melanogaster and enhance virulence in Galleria mellonella. We showed that the capsule had limited antiphagocytic activity in human and chicken macrophages, decreased adherence to chicken macrophages, and decreased intracellular survival in both macrophages. In contrast, the heptose increased uptake by chicken macrophages and supported adherence to human macrophages and survival within them. While the capsule triggered nitric oxide production in chicken macrophages, the heptose mitigated this and protected against nitrosative assault. Finally, the C. jejuni strain NCTC 11168 elicited strong cytokine production in both macrophages but quenched ROS production independently from capsule and heptose, and while the capsule and heptose did not protect against oxidative assault, they favored growth in biofilms under oxidative stress. This study shows that the wild-type capsule with its heptose is optimized to resist innate defenses in strain NCTC 11168 often via antagonistic effects of the capsule and its heptose.

Prevalence and Antimicrobial Resistance of Campylobacter in Conventional and No Antibiotics Ever Broiler Farms.

Campylobacter is a leading cause of enteric disease worldwide. No antibiotics ever (NAE) poultry has become increasingly popular, yet little is known about the incidence and antimicrobial resistance (AMR) of Campylobacter in this production system. This study was conducted to determine the prevalence, concentration, and AMR of Campylobacter in conventional (CV) and NAE-raised broilers. Two CV and two NAE commercial broiler flocks were included in this study. Cecum (n = 420) and ileum (n = 420) of chickens were collected at different stages during the broiler grow-out phase and following transportation to the processing plant. Samples of litter (n = 24), feed (n = 24), and water (n = 24) were also collected. Screening for Campylobacter was conducted using real-time PCR assay, and enumeration was performed by direct plating on Campy Cefex agar. Campylobacter isolates were confirmed by real-time PCR, and antimicrobial susceptibility was evaluated following the National Antimicrobial Resistance Monitoring System (NARMS) methods. Whole Genome Sequencing (WGS) was used to identify AMR genes carried by the resistant isolates. Campylobacter prevalence reached 100% within the first 3 weeks of summer production under both NAE and CV rearing. A lower Campylobacter prevalence was detected in conventionally raised broilers during fall (P ≤ 0.05), yet no change in prevalence was observed in NAE birds (P > 0.05). Populations were high in the cecum, carrying an average of 6.6 Log10 CFU/g after transportation, and antimicrobial-resistant Campylobacter was isolated from CV broilers during the fall. Three isolates (1.2%), identified as C. coli, carrying the gyrA and tet(O) genes, exhibited simultaneous resistance to ciprofloxacin, tetracycline, and nalidixic acid. Results from this study can help identify important shifts in gut microbial community dynamics and Campylobacter prevalence associated with antibiotic administration within commercial poultry operations.

Detection and Distribution of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in Campylobacter jejuni Isolates from Chicken Livers.

Campylobacter jejuni is the leading foodborne bacterial pathogen that causes human gastroenteritis worldwide linked to the consumption of undercooked broiler livers. Application of bacteriophages during poultry production has been used as an alternative approach to reduce contamination of poultry meat by Campylobacter. To make this approach effective, understanding the presence of the bacteriophage sequences in the CRISPR spacers in C. jejuni is critical as they may confer bacterial resistance to bacteriophage treatment. Therefore, in this study, we explored the distribution of the CRISPR arrays from 178 C. jejuni isolated from chicken livers between January and July 2018. Genomic DNA of C. jejuni isolates was extracted, and CRISPR type 1 sequences were amplified by PCR. Amplicons were purified and sequenced by the Sanger dideoxy sequencing method. Direct repeats (DRs) and spacers of CRISPR sequences were identified using the CRISPRFinder program. Further, spacer sequences were submitted to the CRISPRTarget to identify potential homology to bacteriophage types. Even though CRISPR-Cas is reportedly not an active system in Campylobacter, a total of 155 (87%) C. jejuni isolates were found to harbor CRISPR sequences; one type of DR was identified in all 155 isolates. The CRISPR loci lengths ranged from 97 to 431 nucleotides. The numbers of spacers ranged from one to six. A total of 371 spacer sequences were identified in the 155 isolates that could be grouped into 51 distinctive individual sequences. Further comparison of these 51 spacer sequences with those in databases showed that most spacer sequences were homologous to Campylobacter bacteriophage DA10. The results of our study provide important information relative to the development of an effective bacteriophage treatment to mitigate Campylobacter during poultry production.